Endocrinology Research Center Research Articles

EGFR inhibition with erlotinib induces membrane accumulation of aquaporin-2 via PDK1 and RSK activation

In the canonical aquaporin-2 (AQP2) signaling pathway, vasopressin (VP) binds to its V2 receptor, which in turn activates adenylate cyclase and protein kinase A (PKA), resulting in AQP2 S256 phosphorylation and accumulation of AQP2 in the membrane. The epidermal growth factor receptor (EGFR) inhibitor erlotinib also increases AQP2 S256 phosphorylation and membrane accumulation, yet it does not increase cAMP or PKA activity. We hypothesize that the ribosomal s6 kinase (RSK), a downstream effector in the EGFR-MAPK/ERK pathway, is the terminal kinase phosphorylating AQP2 in this novel PKA-independent pathway activated by erlotinib, and that the phosphoinositide dependent kinase-1 (PDK1), a well-established activator of RSK, is indispensable for erlotinib-induced AQP2 activation. Using our LLC-AQP2 cell model, we show that erlotinib-induced AQP2 membrane accumulation and S256 phosphorylation are abolished by the specific RSK inhibitor BI-D1870. RSK knockdown with siRNA also blocked AQP2 S256 phosphorylation and membrane accumulation, as did RSK knockout with CRISPR/cas9 editing. Next, rat kidney slices were incubated in Hank’s buffer with or without BI-D1870 and treated with erlotinib. BI-D1870 inhibited AQP2 membrane accumulation in collecting duct principal cells, supporting the relevance of this pathway in kidney cells in situ. An in-vitro kinase assay using purified proteins demonstrated that RSK directly phosphorylates AQP2 at the S256 residue. Additionally, erlotinib consistently increased phosphorylation of RSK T359, a residue associated with RSK’s active state. In canonical RSK activation, a phosphorylation cascade results in PDK1 binding to and activating RSK. We found that PDK1 inhibition with an experimental compound PS-222 also blocked erlotinib-induced AQP2 membrane accumulation and S256 phosphorylation. This implicates PDK1 along with RSK in the novel erlotinib-induced pathway of AQP2 traffcking. Our data show that RSK and PDK1 are terminal effectors in the novel, PKA-independent pathway of AQP2 activation induced by erlotinib. Further elaboration of this new non-canonical pathway promises to uncover potential pharmacological targets for the treatment of water balance disorders. This work was supported by the National Institutes of Health (NIH) grant DK096586 (D. Brown). P. W. Cheung was supported was supported by NIH K-award DK115901. Richard Babicz is the recipient of the Ben J Lipps Research Fellowship (American Society of Nephrology). Additional support for the Program in Membrane Biology Microscopy Core came from the Boston Area Diabetes and Endocrinology Research Center (DK057521) and the Massachusetts General Hospital (MGH) Center for the Study of Inflammatory Bowel Disease (DK043351). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Oxidative stress induced by menadione (vitamin K3) results in non-canonical AQP2 membrane traffcking in LLC-AQP2 cells

Oxidative stress affects a wide variety of cellular processes including morphology, protein traffcking, and cell death. Several studies show that reactive oxygen species (ROS) are able to pass through some water channels, and that ROS may modulate aquaporin expression and traffcking. However, a relationship between ROS status and the traffcking of aquaporin-2 (AQP2) has yet to be well-defined. To address this question, we first treated LLC-PK1 cells expressing cmyc-tagged AQP2 (LLC-AQP2 cells) for 30 min with menadione (MK3, 20 μM), an agent widely used to generate ROS in cell culture. Similar to vasopressin (VP), MK3 induced significant AQP2 accumulation in the plasma membrane of these cells. Using LLC-AQP2 cells expressing secreted soluble green fluorescent protein (ss-GFP), we revealed significantly increased vesicle exocytosis upon treatment with MK3. Surprisingly, MK3 did not affect rhodamine-labeled dextran endocytosis, suggesting that the MK3 effect is mainly due an increase in AQP2 exocytosis into the plasma membrane. Next, we studied the role of AQP2 c-terminal serine 256 phosphorylation in this process. MK3 treatment resulted in significant plasma membrane accumulation of the non-phosphorylatable AQP2 S256A mutant, whereas VP had no effect, as previously reported. To understand the contribution of protein kinase A (PKA) to MK3-mediated AQP2 traffcking, we used CRISPR-generated LLC-AQP2,koPKA cells that lack PKA isoforms. Interestingly, an increase in AQP2 membrane accumulation was still observed, suggesting that the MK3 effect is PKA-independent. By western blotting with anti-phospho-AQP2 antibodies, we found that MK3 did not affect phosphorylation of the critical S256 residue, but in contrast to VP, MK3 actually increased the phosphorylation level of S261 instead of reducing it. Finally, we showed that AQP2 accumulation in both LLC-AQP2 and LLC-AQP2 S256A cells was inhibited in the presence of glutathione (5 mM), an anti-oxidant or reducing agent. Interestingly, western blot analysis showed that glutathione abolished the MK3-induced increase of S261 AQP2 phosphorylation. In summary, our study shows that menadione (MK3) induces AQP2 membrane accumulation in LLC-AQP2 cells, suggesting a role of ROS in this process. This effect is largely due a change in AQP2 vesicle exocytosis. It does not require phosphorylation of the c-terminal S256 residue of AQP2, but MK3 does cause increased S261 phosphorylation. While incompletely understood at present, these data reveal that alternative, probably ROS-related, regulatory mechanisms can be involved in AQP2 traffcking and recycling. This work was supported by the National Institutes of Health (NIH) grant DK096586 (D. Brown). P. W. Cheung was supported was supported by NIH K-award DK115901. Richard Babicz is the recipient of the Ben J Lipps Research Fellowship (American Society of Nephrology). Additional support for the Program in Membrane Biology Microscopy Core came from the Boston Area Diabetes and Endocrinology Research Center (DK057521) and the Massachusetts General Hospital (MGH) Center for the Study of Inflammatory Bowel Disease (DK043351). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Novel anthropometric indices for predicting type 2 diabetes mellitus

BackgroundThis study aimed to compare anthropometric indices to predict type 2 diabetes mellitus (T2DM) among first-degree relatives of diabetic patients in the Iranian community.MethodsIn this study, information on 3483 first-degree relatives (FDRs) of diabetic patients was extracted from the database of the Endocrinology and Metabolism Research Center of Isfahan University of Medical Sciences. Overall, 2082 FDRs were included in the analyses. A logistic regression model was used to evaluate the association between anthropometric indices and the odds of having diabetes. Furthermore, a receiver operating characteristic (ROC) curve was applied to estimate the optimal cutoff point based on the sensitivity and specificity of each index. In addition, the indices were compared based on the area under the curve (AUC).ResultsThe overall prevalence of diabetes was 15.3%. The optimal cutoff points for anthropometric measures among men were 25.09 for body mass index (BMI) (AUC = 0.573), 0.52 for waist-to-height ratio (WHtR) (AUC = 0.648), 0.91 for waist-to-hip ratio (WHR) (AUC = 0.654), 0.08 for a body shape index (ABSI) (AUC = 0.599), 3.92 for body roundness index (BRI) (AUC = 0.648), 27.27 for body adiposity index (BAI) (AUC = 0.590), and 8 for visceral adiposity index (VAI) (AUC = 0.596). The optimal cutoff points for anthropometric indices were 28.75 for BMI (AUC = 0.610), 0.55 for the WHtR (AUC = 0.685), 0.80 for the WHR (AUC = 0.687), 0.07 for the ABSI (AUC = 0.669), 4.34 for the BRI (AUC = 0.685), 39.95 for the BAI (AUC = 0.583), and 6.15 for the VAI (AUC = 0.658). The WHR, WHTR, and BRI were revealed to have fair AUC values and were relatively greater than the other indices for both men and women. Furthermore, in women, the ABSI and VAI also had fair AUCs. However, BMI and the BAI had the lowest AUC values among the indices in both sexes.ConclusionThe WHtR, BRI, VAI, and WHR outperformed other anthropometric indices in predicting T2DM in first-degree relatives (FDRs) of diabetic patients. However, further investigations in different populations may need to be implemented to justify their widespread adoption in clinical practice.

History of establishment and formation of Endocrine gynecology Department of the Endocrinology Research Centre

This article presents the historical review of establishment and formation of Endocrine Gynecology Department (Endocrinology Research Centre, Moscow, Russian Federation) since 1960 until 2024s. The basic aim of establishment of the Endocrine Gynecology Department are organization and providing of conservative and surgery medical aid for female patients with reproductive pathologies and endocrinopathies. The members of the Department also provide scientifical and educational work in the area of personalized diagnostic and treatment approaches of reproductive pathologies. The review is supplied with evolutionary, historical and biographical datas about all leaders of Department throughout its history. Authors group dedicates the present article to scientific supervisors and mentors.

The 3% hypertonic saline infusion test for the differential diagnosis of diabetes insipidus and primary polydipsia: assessment of diagnostic accuracy

AIM: assessment of the diagnostic accuracy of a 3% hypertonic saline infusion test in relation to a set of clinical and laboratory data (including a water deprivation test and MRI data) for differential diagnoses of diabetes insipidus (DI) and primary polydipsia (PP).METHODS: An interventional cross-sectional study was carried out at Endocrinology Research Centre From September 2021 to September 2023 ninety patients with polyuria-polydipsia syndrome were included. In order to assess the diagnostic characteristics, all the subjects underwent two tests with osmotic stimulation: a 3% hypertonic saline infusion test and a water deprivation test. Adverse events were assessed.RESULTS: Based on the results of clinical, anamnestic, laboratory and instrumental data, and the results of a water deprivation test, a final diagnosis of DI was made in 48 (53%) patients and PP in 42 (47%) patients. The agreement between the two samples is significant — Kappa = 0.823, 95% CI (0.707, 0.939). The operational parameters of the 3% hypertonic saline infusion test are: sensitivity 98% (95% CI: 89%; 100%); specificity 98% (95% CI: 87%; 100%), positive and negative predictive values 98% (95% CI: 89%–100%) and 98% (95% CI: 87%–100%). Respectively. Chills occurred significantly more often (31% vs. 12%), and dizziness and headache were more pronounced during the 3% hypertonic saline infusion test. The median duration of the water deprivation test in patients was 11 hours, and median duration of 3% hypertonic saline infusion test was 1.5 hour (P<0.001).CONCLUSION: The 3% hypertonic saline infusion test has a high overall diagnostic accuracy 98%; 95% CI 92% to 100%)) in relation to the classical set of clinical, laboratory and instrumental data of patients (including a water deprivation test), However, it is important the advantage of the latter is its short duration and, as a consequence, better tolerability and probably better compliance, while no significant differences in adverse events frequencies during the tests were identified.

Association between preoperative cholecalciferol therapy and hypocalcemia after parathyroidectomy in patients with primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a endocrine disorder characterized by excessive secretion of parathyroid hormone (PTH) from parathyroid gland tumors. Parathyroidectomy (PTE) is the main treatment for PHPT, but it can lead to hypocalcemia in up to 46% of cases. Hypocalcemia is associated with seizures and life-threatening cardiac arrhythmias, and vitamin D deficiency can exacerbate PHPT severity and contribute to «hungry bones syndrome,» resulting in severe and persistent postoperative hypocalcemia. To evaluate the association and determine the strength of the relationship between preoperative cholecalciferol therapy and the occurrence of hypocalcemia within 1-3 days after PTE in patients with PHPT. The study was conducted at the Endocrinology Research Centre, during the periods of 1993-2010 and 2017-2020. The inclusion criteria consisted of patients diagnosed with PHPT who required PTE, had a serum 25-hydroxyvitamin D (25(OH)D) level below 20 ng/mL, and a serum total calcium level below 3 mmol/L. The exclusion criterion was the use of medications that affect calcium-phosphorus metabolism, including cinacalcet, denosumab, or bisphosphonates, either as monotherapy or as part of combination therapy. There were 117 patients, including 110 (94%) females and 7 (6%) males. The median age and interquartile range were 58 [49; 65] years. Among the participants, 21 (18%) received cholecalciferol supplementation for a duration of 2 weeks to 2 months prior to PTE, aiming to address vitamin D deficiency. The remaining 96 (82%) participants did not receive -cholecalciferol supplementation. Both groups, i.e., participants receiving cholecalciferol and those who did not, were similar in terms of anthropometric factors (sex and age at the time of surgery), preoperative clinical characteristics (BMD decrease), and laboratory parameters (PTH, total calcium, phosphorus, ALP, OC, CTX-1, and 25(OH)D levels). The occurrence of postoperative hypocalcemia was significantly lower in participants who received cholecalciferol supplementation (10% vs. 63%, p<0,001, FET2). Cholecalciferol intake showed a negative association with hypocalcemia development (RR=0,15, 95% CI (0,03; 0,51)). Preoperative cholecalciferol supplementation for 2 weeks to 2 months before PTE reduces the risk of postoperative hypocalcemia in patients with PHPT by 2-33 times.

The impact of premature ovarian insufficiency on sexual function; which domain is mostly disrupted?

This study aimed to compare the sexual function (SF) and its domains between women with idiopathic premature ovarian insufficiency (POI) and healthy control. A cross-sectional study was conducted on 63 married women with idiopathic POI, referred to the reproductive endocrinology research center (Tehran, Iran), and 784 married women with regular menstrual cycles who visited for routine annual gynecological exams in 2021-2022. The Female Sexual Function Index (FSFI) questionnaire was used to assess the SF of participants. Linear regression and factor analysis were used to analyze the data. Characteristics were similar in both study groups except for body mass index, hip circumference, job status, and number of deliveries. The mean score (standard deviation) of FSFI in women with POI and control were 21.70 (9.0) and 24.30 (5.0), respectively (P < 0.001). All domains' scores of FSFI were significantly lower in POI women than in the control group (P < 0.05). After adjusting for potential confounders, these findings remained unchanged. Factor analysis demonstrated the arousal and lubrication domains as the most influential factors SF among POI women, while the desire domain played the lowest role. In addition to various health conditions threatening POI women's future lives, sexual disturbances must be addressed in their routine care.

Первичная надпочечниковая недостаточность с Х-сцепленным наследованием у детей

Primary adrenal insufficiency (PAI) is a rare pathology with a prevalence of 100 to 140 cases per one million. X-linked adrenoleukodystrophy (X-ALD) and X-linked congenital adrenal hypoplasia (X-CAH) are the leading pathologies among boys (after congenital cortical dysfunction adrenal glands) and account for 3.1% and 2.0% of all PAI, respectively. Establishing the PAI etiology is necessary to predict the course of the disease and adhere to special protocols for examining patients. The purpose of this research was to compare the PAI course in diseases with an X-linked type of inheritance. Materials and methods used: a single-center, one-stage observational comparative retrospective study was conducted in 25 male patients with genetically confirmed diagnoses of X-ALD, X-CAH and who had PAI as a component of the disease. The study was conducted at the Pediatric Endocrinology Institute with the Endocrinology Research Centre of the Ministry of Healthcare of Russia (Moscow, Russia) in 2019-2022 as well as based on the patients’ medical records that have been forwarded for a genetic search for the causes of adrenal insufficiency under the “Alfa-Endo” Charity Program for children with endocrine diseases in the same period of time. Results: X-ALD was detected in 11/25 (44%) patients, median age of manifestation was 6.2 [4.5; 7.2] y/o and 2 y/o was the earliest. A single patient with X-ALD was found to have TARTs (testicular adrenal rest tumors). X-CAH was diagnosed in the remaining 14/25 (56%) patients, median age of manifestation was 1.9 [0.04; 3.9] y/o, p=0.015. The oldest age of manifestation was 14 y/o. A single patient was found to have hypogonadotropic hypogonadism (HH) and another one had bilateral cryptorchidism. There were no statistically significant differences in symptoms, adrenocorticotropic hormone (ACTH), cortisol levels during the manifestation of PAI and doses of replacement therapy (p=0.756 for ACTH, p=0.591 for cortisol, p=0.825 for hydrocortisone and p=0.148 for fludrocortisone). Conclusion: it is necessary to exclude X-ALD and X-CAH when diagnosing PAI in boys regardless of the age of the disease manifestation. It is highly recommended to conduct a genetic study of a panel of genes responsible for the development of PAI in order to establish the PAI etiology, and regardless of the established PAI etiology it is necessary to perform an ultrasonic study of the testicles with the purpose of excluding the space-occupying formations. It is necessary to evaluate ACTH levels in patients with testicular masses for timely diagnosis of PAI and optimal treatment.

History of establishment and formation of Institute for Reproductive Medicine in the Endocrinology Research Centre

This article presents the historical review of establishment and formation of reproductive medicine department included since 2016 into the Institute for Reproductive Medicine (Endocrinology Research Centre, Moscow, Russian Federation). The basic aim of establishment of the Institute for Reproductive Medicine are coordination between its subdivisions effective treatment and scientific researches among patients with reproductive pathologies and endocrinopathies. The review is supplied with biographical and graphic datas about all leaders of reproductive medical departments from the 1960s until 2020s such as endocrinological gynecology, assisted reproductive technologies, andrology &amp; urology. Authors; group dedicates the present article to scientific supervisors and mentors.

Parathyroid carcinoma case-report in a patient with multinodular goiter and chronic kidney disease: difficulties in diagnosis and treatment (observation from practice)

We would like to present a clinical case of severe primary hyperparathyroidism due to a parathyroid carcinoma of atypical location in a patient with chronic kidney disease of complex etiology and multinodular goiter. Patient S., 59 years old, was followed-up for a long time in tertiary referral hospitals for “chronic tubulointerstitial nephritis with nephrosclerosis”, secondary hyperparathyroidism due to chronic kidney disease (CKD) G3–4, osteoporosis, and a multinodular euthyroid colloid goiter. In July 2021 she was referred to the Endocrinology Research Centre in order to clarify the diagnosis because of the persistence of an extremely high level of parathyroid hormone (PTH) despite cinacalcet treatment. During examination, primary hyperparathyroidism, a left parathyroid gland lesion, multinodular goiter with subclinical thyrotoxicosis, and vitamin D deficiency were diagnosed. After the removal of the left parathyroid gland lesion (histologically confirmed parathyroid carcinoma) and a left-sided hemithyroidectomy, hypocalcemia («hungry bone syndrome») developed, but the level of parathyroid hormone remained elevated. After 3–18 months after surgery, no data for relapse of primary hyperparathyroidism was obtained. The persistent moderate increase in PTH was regarded as secondary hyperparathyroidism in CKD and hypocalcemia. Complex therapy of osteoporosis with the antiresorptive drug denosumab, vitamin D and its active metabolite, calcium preparations, and parathyroidectomy led to a significant increase in bone mineral density (BMD) and no repeated fractures 18 months after surgery.Conclusion. In patients with pre-dialysis CKD and high PTH levels, it is necessary to make a differential diagnosis between primary (PHPT) and secondary hyperparathyroidism (SHPT). Severe manifestations of primary hyperparathyroidism can be suspicious for parathyroid carcinoma.

Predicting the presence of MEN1 gene mutation based on the clinical phenotype of patients with primary hyperparathyroidism

Timely referral of patients for genetic testing to rule out MEN1-associated primary PHPT is important factor in determining treatment strategy and prognosis. In the context of the limited availability of genetic testing, the search for clinical markers indicative of MEN1 gene mutations remains an extremely relevant task. To determine the diagnostic value of clinical features of primary PHPT in young patients for predicting the presence of MEN1 gene mutations. A single-center, prospective study was conducted at the Endocrinology Research Centre, involving 273 patients with PHPT in the period 2015-2022. Based on the results of genetic and laboratory tests, patients were divided into three groups: those with MEN1 gene mutations (MEN+ group, n=71), those without MEN1 gene mutations - isolated sporadic PHPT (MEN- group, n=158), and patients with PHPT and associated endocrine gland disorders - MEN-1 syndrome phenocopies (PHEN group, n=32). Subgroups of patients younger than 40 years of age were also identified. Comparative analysis was performed among the independent groups and subgroups, and logistic regression analysis was used to develop a mathematical model for predicting the probability of the presence of MEN1 gene mutation. Patients in the MEN+ and MEN- groups were comparable by gender and age at manifestation, as well as calcium-phosphorus metabolism parameters and PHPT complications. In the PHEN group, PHPT manifested at older age compared to the other groups (p&lt;0.001 for all), with lower total calcium levels and a trend toward lower iPTH concentrations. The MEN+ group had a significantly higher frequency of multiglandular parathyroid (PG) involvement, PHPT recurrence, and positive family history compared to the MEN- and PHEN groups. Histologically, adenomas predominated in the PHEN and MEN- groups (92% and 94%, respectively), whereas hyperplasia of PGs were more common in the MEN+ group (49%). None of the PHEN patients had all three «classic» components of the MEN-1 syndrome, and the clinical course of PHPT was similar to that of the MEN- group. These differences were also observed in the subgroups of patients younger than 40 years, which formed the basis for the development of a mathematical model. The logistic regression equation for predicting the probability of the presence of the MEN1 gene mutation included eight predictors, with a diagnostic sensitivity of 96% and specificity of 98%. Based on the analysis performed, eight hereditary predictors of PHPT within the MEN-1 syndrome were identified. A mathematical model was developed to predict the presence of the MEN1 gene mutation in patients, which demonstrated high classification performance on the training dataset. Further refinement of the model will help improve the quality of medical care for patients with PHPT.

Prediction of the development of hypocalcemia in primary hyperparathyroidism patients 1–3 days after radical parathyroidectomy

BACKGROUND: It was impossible to predict the development of hypocalcemia following parathyroidectomy (PTE) in patients with primary hyperparathyroidism (PHPT) until now. Hypocalcemia may be accompanied by myalgia, generalized seizures up to tetany, and arrhythmias. Hypocalcemia following PTE can be prevented by preoperative cholecalciferol supplementation. However, patients with severe hypercalcemia above 3 mmol/L do not receive vitamin D due to the risk of hypercalcemia progression. Despite the existing data showing the safety of cholecalciferol therapy in case of mild elevation of serum calcium, not all patients are prescribed vitamin D supplementation, probably due to the lack of a suitable tool to assess the postoperative hypocalcemia risks.AIM: To design a mathematical model and a software tool for predicting hypocalcemia 1–3 days post-PTE in PHPT patients using the patient’s demographic and clinical data, laboratory test results and preoperative therapy status.MATERIALS AND METHODS: This retrospective study included 478 PHPT patients diagnosed with adenomas and carcinomas of the parathyroid gland (PTG) who underwent radical PTE between 1993–2010 or 2018–2020 at the Endocrinology Research Centre. The following parameters were analyzed: sex; age; laboratory markers prior to calcimimetic and antiresorptive therapy: PTH, total calcium, phosphorus; osteocalcin (OC), alkaline phosphatase (ALP), C-terminal telopeptide of type 1 collagen. Also we analyzed 25-hydroxyvitamin D (25(OH)D); bone mineral density (BMD) measured by X-ray densitometry; medical history of low-energy fractures; preoperative therapy with denosumab, bisphosphonates, cinacalcet, cholecalciferol. Categorical gradient boosting (CatBoost) was built to predict the risk of postoperative hypocalcemia.RESULTS: The prevalence of severe osteoporosis is higher in the postoperative hypocalcemia group compared to the nonhypocalcemia group (27% vs. 15%), wherein the frequency of preoperative administration of cholecalciferol in this group is lower (8% vs. 25%). A CatBoost model was built to predict postoperative hypocalcemia using 13 predictors (sex, age, PTH, serum total calcium, phosphorus, OC, BMD reduction, 25(OH)D, administration of cholecalciferol, bisphosphonates, denosumab, and cinacalcet. The proposed model http://194.87.111.169/hypocalcemia for post-PTE hypocalcemia in PHPT patients achieved the following metrics: positive predictive value 73.3%-86.7%; negative predictive value 74.9%-89.3%.CONCLUSION: The model can be used to choose the appropriate preand postoperative approaches for patients who undergo rPTE.

Long-term results of corrective surgical interventions in patients with diabetic midfoot neuroosteoarthropathy

BACKGROUND: Diabetic neuroosteoarthropathy is a disabling complication of diabetes mellitus that develops as a result of impaired peripheral innervation and characterized by damage to bones and joints of non-infectious origin. As a result of pathological bone fractures, gross deformities of the foot are formed, which entails development of chronic ulcerative defects in areas of excessive load pressure. Currently, a number of surgical interventions are used to correct deformities, such as resection of bone structures, correction with metal structures and external fixation devices, but there is practically no data on their long-term results in the domestic literature.AIM: To study the results of orthopedic corrective interventions in patients with diabetes mellitus and midfoot neuroosteoarthropathy.MATERIALS AND METHODS: An analysis was made the data collected by questionnaire method of 55 patients operated in the diabetic foot department in the Endocrinology research centre from 2009-2019. All patients underwent a reconstructive operation aimed correcting a gross deformity of the midfoot. In postoperative period, the affected limb was off-loaded by total contact cast for a period of 3-6 months, and in the future, complex orthopedic shoes for permanent use and regular podiatric care were recommended to patients.RESULTS: After the first surgical intervention, 16 patients developed a recurrence of deformity, which required a second surgical intervention. The median period between interventions was 3 years. Chronic wounds of various localization of the operated foot were found in 25 patients.The median period between surgery and ulcer formation was 5 years. 9 patients with chronic wounds underwent minor amputations at the same foot. Amputations on the contralateral limb were performed in 7 patients. None of the patients underwent major amputations.CONCLUSION: Charcot foot is a severe complication of diabetes mellitus that can lead to loss of a lower limb. Due to results of the research orthopedic corrections of the midfoot deformities in patients with DNOAP can reduce the risk of ulcer developement and possible major amputations. Active monitoring and adequate orthopedic care in the postoperative period significantly reduce the risk of deformity recurrence and the need for repeated surgical interventions.

Investigation of neural network models application in EU-TIRADS thyroid nodules classification for personalization of thyroid gland ultrasound diagnostic

SUBSTANTIATION. It is known that about 69% of all thyroid nodules undergoing surgical treatment are benign formations, and up to 75% of patients with an intermediate cytological conclusion undergo unnecessary surgical intervention. This suggests that improving the quality of differential diagnosis of nodular formations will avoid excessive economic costs for the healthcare system. In this regard, AI technologies in diagnostic algorithms for the classification of thyroid nodules were involved.AIM. Improving the efficiency of automatic classification of thyroid nodules on ultrasound images by using a set of neural network models.MATERIALS AND METHODS. We used ultrasound images of thyroid nodules available in open sources and obtained with the help of 3 ultrasound devices of Endocrinology Research Centre as part of Project № 22-15-00135 of the grant of the Russian Science Foundation. This article check the hypothesis that the size of the training set cannot be increased by repeating similar images from the ultrasound cine loop of one patient, but only by expanding the dataset with new unique specimens of other patients and/or data from the augmentation process.RESULTS. As a result, a neural network model EfficientNet-B6 was proposed to solve the problem of EU-TIRADS classification of thyroid nodules based on ultrasound images of the thyroid gland.CONCLUSION. The results obtained allow us to advance in the use of artificial intelligence methods for personalized medicine in thyroid diseases.

Effect of components of the renin-angiotensin system, rs2106809 polymorphism of the ACE2 gene, and therapy with RAS blockers on the severity of COVID-19

Angiotensin-converting enzyme 2 (ACE2) is a key component of the renin-angiotensin system (RAS), providing counter-regulation of its effects and, simultaneously, a receptor for the SARS-CoV-2 entering. It is suggested that factors regulating the balance of the major components of RAS, including ACE2 gene polymorphism, therapy with RAS blockers (ACE inhibitors and angiotensin receptor blockers) - may affect the severity of COVID-19. The aim of the study was to investigate the effect of RAS components, the relationship of ACE2 gene polymorphism rs2106809 and ACEi/ARBs therapy with the COVID-19 severity. The study included patients with COVID-19 hospitalized in Endocrinology research centre (n = 173), who were divided into groups of moderate and severe course. Determination of RAS components was performed by ELISA, identification of polymorphism by PCR. Statistical analysis was performed using nonparametric statistical methods; differences in the distribution of genotype frequencies were assessed using Fisher's exact test χ2. The groups differed significantly in age, blood glucose levels, and inflammatory markers: leukocytes, neutrophils, IL-6, D-dimer, C-reactive protein, ferritin and liver enzymes, which correlated with the severity of the disease. When comparing patients in terms of ACE, ACE2, angiotensin II, ADAM17 there were no statistically significant differences between the groups (p=0.544, p=0.054, p=0.836, p=1.0, respectively), including the distribution by gender (in men: p=0.695, p=0.726, p=0.824, p=0.512; in women: p=0.873, p=0.196, p=0.150, p=0.937). Analysis of the distribution of AA, AG, and GG genotypes of the rs2106809 polymorphism of the ACE2 gene also revealed no differences between patients: χ2 1.35, p=0.071 in men, χ2 5.28, p=0.244 in women. There were no significant differences in the use of RAS blockers between groups with different course severity: χ2 0.208, p=0.648 for ACEi, χ2 1.15, p=0.283 for ARBs. In our study, the influence of activation of RAS components (ACE, ACE2, AT II, ADAM17) and ACE2 gene polymorphism on the severity of COVID-19 course was not confirmed. The severity of COVID-19 course correlated with the level of standard inflammatory markers, indicating the general principles of the infection as a systemic inflammation, regardless of the genetic and functional status of the RAS.

Dynamics the parameters of mineral metabolism in hospitalized patients with COVID-19, the impact of etiotropic and pathogenetic therapy

To study the dynamics of mineral metabolism parameters in patients with a confirmed COVID-19 at the time of hospitalization and after discharge, including the impact of etiotropic and pathogenetic therapy on them. A single-center study of 106 patients (aged ≥18 years) with clinically or laboratory confirmed diagnosis of COVID-19 was carried out at the Endocrinology Research Centre, Moscow. Baseline biochemical parameters, including serum calcium, phosphorus, albumin, 25(OH)D, parathyroid hormone (PTH), inflammatory markers, and instrumental assessment of COVID-19 severity were performed before specific immunotherapy, as well as on 3rd and 7th days of hospitalization and before discharge. Statistical analysis was performed with Statistica 13 software (StatSoft, USA). On the first day, hypocalcemia (low albumin-adjusted calcium level) was detected in 40.6% of cases, the prevalence of vitamin D deficiency/insufficiency amounted to 95.3% of cases. At the same time, secondary hyperparathyroidism was identified only in 14.2% of patients. A comparative analysis of mineral metabolism during hospitalization (between 1, 3, 7 days of hospitalization and before discharge) during baricitinib treatment revealed a statistically significant increase in albumin-adjusted calcium by the end of hospitalization (p&lt;0.001, Friedman criterion, Bonferroni correction p0=0.01). A pairwise comparison of subgroups, depending on the therapy, revealed a statistically significantly lower level of albumin-adjusted calcium on 3rd day among patients on baricitinib monotherapy or combined with tocilizumab compared with a subgroup of patients undergoing etiotropic treatment (2.16 [2.13; 2.18] mmol/l vs 2.23 [2.19; 2.28] mmol/l, p=0.002, U-test, Bonferroni correction p0=0.012). Patients with severe coronavirus infection are characterized by a high prevalence of vitamin D deficiency and hypocalcemia. Associations between calcium and saturation as well as the severity of lung lesion characterizes hypocalcemia as an important predictor of severe course and poor outcome in COVID-19. Pathogenetic therapy with baricitinib, including in combination with tocilizumab, contributes to achieve normocalcemia, but further studies are required.

Metastatic lesions of the adrenal glands. The experience of Endocrinology Research Center.

Differentiation between benign, primary and secondary malignant tumors is a critical problem in the clinical treatment of adrenal tumors, especially in patients with isolated adrenal lesions. In most cases, the correct diagnosis can be established microscopically with standard staining with hematoxylin and eosin. However, there are cases when it is almost impossible to distinguish metastasis from primary adrenal cancer, so an accurate diagnosis requires an immunohistochemical examination.This article presents five unique observations of secondary adrenal tumors that were diagnosed by us in the current surgical material: metastasis of clear cell renal cell carcinoma, follicular variant of papillary thyroid cancer, metastasis of keratinizing squamous cell carcinoma of the cervix, lymphoepithelioma-like carcinoma of the bladder, as well as malignant mesothelioma. Taking into account the extreme rarity of the presented observations, we present an analysis of the literature data.

Insulinoma: analysis of prevalence and incidence in the world

BACKGROUND: Currently, there are no data on the prevalence and incidence of insulinoma in Russia. The published world data on the epidemiology of the tumor are largely variable. Thus, it is important to systematize information on the prevalence and incidence of insulinoma in the world, including in Russia. AIM: To assess the prevalence and incidence of insulinoma in the world.TASKS Analysis of literature data.Analysis of the database of the Endocrinology Research Centre.MATERIALS AND METHODS: To implement Task 1, an analysis of foreign and Russian articles published in the PubMed and eLIBRARY.RU databases from 1927 was carried out until June 1, 2023, including the following keywords: «Insulinoma», «Epidemiology», «Frequency», «Incidence», «Nationwide», «Database». Based on the obtained results, an analysis of the prevalence and incidence of insulinoma in the world and in Russia was made. To implement Task 2, the analysis of patient records and the electronic database of the Endocrinology Research Centre was carried out.RESULTS: Based on data in individual countries the prevalence and incidence of insulinoma for the world population amounted to: an average of 16.4 per 1 million population and 0.9 per 1 million population per year, respectively. If extrapolating the world data, the number of patients with insulinoma in Russia can be 1066–2362 and 72–173 new cases are diagnosed annually (11.9 per 1 million population and 0.9 per 1 million population per year, respectively). The largest number of patients with insulinoma in Russia was recorded in the Endocrinology Research Centre and amounted to 275 cases for the period 2006–2022.CONCLUSION: In the Russian Federation, it is important to create a register of patients with insulinoma on the basis of the existing electronic database of the Endocrinology Research Centre in order to obtain accurate information about the current needs of patients with insulinoma in medical care and drug provision, as well as to conduct full-fledged scientific research.

Diabetes mellitus associated with type A insulin resistance

Insulin resistance type A is a monogenic disorder with insulin action defect, observed in females with acanthosis nigricans (AN), hyperandrogenism, hyperinsulinemia, insulin resistance (IR) without obesity. We present a family case of diabetes mellitus (DM) with IR in two sisters with obesity and positive family history of DM in three generations. Hyperglycemia was identified at the age of 13 in the older sister and at 11 in the younger sister after COVID-19. Type 2 diabetes (DM2) was diagnosed in mother in the same time with children. Maternal grandmother was diagnosed with DM2 in 58 years old. Patients were examined in 6 months after diagnosis hyperglycemia in Endocrinology Research Centre. The older sister had obesity, AN, and striae distensae. Glycosylated hemoglobin (HbA1c) 6.2%. Impaired glucose tolerance (IGT), hyperinsulinemia and IR, hyperandrogenism, non-alcoholic fatty liver disease (NAFLD), arterial hypertension were diagnosed. The younger sister had obesity, striae distensae. HbA1c — 6.0%. Impaired fasting glucose (IFG), IGT, hyperinsulinemia, IR, NAFLD were diagnosed. Antibodies (AAb) to ZnT8A, IA2, GAD absented in both sisters. A genetic test was provided, a heterozygous mutation in the INSR gene p.V167M was identified in both sisters, mother and grandmother. IR type A was identified in a family with the phenotype of DM2 in this case. This case demonstrated that children with carbohydrate metabolism disorders and obesity without Islet cell autoantibodies have to reffered for a genetic testing. Disordered carbohydrate metabolism was diagnosed in the same time after a COVID-19 in three family members who did not previously have disordered carbohydrate metabolism. We suppose that SARS-CoV-2 can be a trigger for the development of carbohydrate metabolism disorders in IR type A.

The Russian registry of primary hyperparathyroidism, latest update.

Until recently no major epidemiological research of primary hyperparathyroidism (PHPT) has been conducted in the Russian Federation, this led to the creation of the Russian online registry. The objective of this study is to estimate the clinical and biochemical profile, classical and non-classical complications, surgical intervention and medical therapy of the patients with different forms of PHPT in the Russian Federation. The cross-sectional, observational, continuous study was conducted at the Endocrinology Research Centre (Moscow). The present study explored retrospective data from 6003 patients submitted to the Registry between 12.12.2016 and 25.10.2022 from 81 regions of the Russian Federation (http://pgpt.clin-reg.ru/). The median age was 59 [60; 66] years with a female:male ratio of 11.7:1. Symptomatic PHPT was observed in 74.3% while asymptomatic form - only in 25.7% of cases. Bone pathology was the predominant clinical manifestation in 62.5% of cases (n=2293), mostly in combination with visceral complications 45.7% (n=1676). The majority of patients (63.3%) had combined visceral disorders including kidney damage in 51.8% and gastroduodenal erosions/ulcers in 32.3% of patients. Symptomatic patients were older (60 [53; 67] vs. 54 [45; 62] years, p<0.001) and had more severe biochemical alterations of calcium-phosphorus metabolism. Cardiovascular disease (СVD) was recorded in 48% of patients, among them the most frequent was arterial hypertension (up to 93.9%). A genetic test was conducted in 183 cases (suspicious for hereditary PHPT) revealing the mutations in MEN1, CDC73, RET genes in 107, 6 and 2 cases, respectively. Surgery was performed in 53.4% of patients with remission achievement in 87%, the relapse/persistence were recorded in 13% of cases. Histological examination revealed carcinoma in 4%, atypical adenoma in 2%, adenoma in 84% and hyperplasia in 11% of cases. Drug therapy was prescribed in 54.0% of cases, most often cholecalciferol. The detection rate of PHPT has increased in the Russian Federation in recent years. This increase is associated with the start of online registration. However, the majority of patients remain symptomatic with significant alterations of phosphorus-calcium metabolism that indicates delayed diagnosis and requires further modifications of medical care.