Silastic Tubing Research Articles

Validation of Tabletop Microscopes for Microsurgery Simulation and Training

Oral and maxillofacial surgery residency programs are increasingly adopting microsurgery as a core element of training; however, many barriers exist that limit trainees' proficiency. The purpose of this study was to perform a validation of 2 tabletop microscope simulations for their use as a training tool, which could serve as an affordable, alternative method to traditional microsurgery training methods. A prospective, single-institution, multidepartmental validation study was performed. Two microscopes (monocular digital [DM] and binocular stereo [SM]) were used to perform anastomoses on simulation vessels including a silastic tube and a chicken thigh femoral artery. A microsurgeon panel was selected from a population of microsurgery faculty and fellows at Michigan Medicine (Ann Arbor, MI) to perform the anastomoses. The surgeons each performed 4 anastomoses, using each microscope with each vessel, and subsequently completed a survey evaluating the simulation. Predictor variables were the microscope and the vessel. Primary outcome variable was readiness for use, which was defined as the simulation's ability to incorporate into a microsurgical training curriculum in its current state. Secondary outcome variables included realism, value, usefulness, relevance, difficulty, and cost. Paired t tests were used to compare responses. Alpha was set to 0.05. Seven microsurgeons performed the simulation from the departments of oral and maxillofacial surgery (n=5), plastic and reconstructive surgery (n=1), and otolaryngology (n=1). For readiness, the SM simulation required either no modification (n=4) prior to implementation into a microsurgery curriculum or minimal modification (n=3), compared to the DM simulation which required significant modification (n=4) or extensive modification and re-evaluation (n=3) (P=.002). The SM demonstrated a greater mean realism score than the DM for depth perception (5.00 vs 1.57, P<.001), field of view (4.57 vs 3.57, P=.038), lighting (5.00 vs 4.00, P=.038), and clarity (5.00 vs 3.86, P=.030). There was no statistically significant difference between SM and DM in value, usefulness, relevance, difficulty, or cost. Tabletop microscopes demonstrate considerable promise in the future of microsurgical education. The SM simulation was a realistic simulation that may be ready for use in a microsurgical curriculum. Future studies are required to demonstrate the efficacy of this simulation on microsurgical trainees.

Microvascular neural blood flow assessment for a chronic nerve compression neuropathy mouse model by fluorescein angiography

ABSTRACT Background and aims Intraoperative fluorescence angiography with indocyanine green or fluorescein is used in ophthalmology and neurosurgery. However, there are few reports on the use of fluorescence angiography for peripheral neuropathy. This study aimed to assess the validity of fluorescein angiography (FAG) for peripheral nerve entrapment neuropathy. Methods We used an established model of chronic nerve compression (CNC) neuropathy in C57BL/6 mice by entrapping their left sciatic nerve with a silastic tube. Mice were assigned to the uninjured group (control), two-week CNC neuropathy group, four-week CNC neuropathy group, or six-week CNC neuropathy group. We then performed FAG to assess neural blood flow and quantified the peak of the luminance at the compression site with luminance analysis software. Following FAG, histological examinations using an anti-fluorescein antibody and Masson’s trichrome staining were performed to evaluate the area of fluorescein distribution and epineural fibrosis. Results The luminance in the CNC neuropathy groups was significantly lower than that in the control group. Histological analysis revealed the fluorescein positive areas in the CNC neuropathy groups were significantly smaller than that in the control group, and the epineural fibrosis areas in the CNC neuropathy groups were significantly larger than that in the control group. Conclusion We observed a significant decline of luminance in the CNC neuropathy groups, and the histological assessment was consistent with this result. FAG was found to be a valid method for assessing CNC neuropathy in mice.

Post‐Pubertal Testosterone Implants Induce Hypertension in Female‐to‐Male Trans‐Sex Rat Model

IntroductionAndrogens induce increases in blood pressure (BP) and risk of cardiovascular diseases (CVDs) in females, as seen in polycystic ovary syndrome females. However, it is not clear whether treatment with gender‐affirming hormone therapy in trans‐men have an impact on their BP or risk of CVD. Therefore, the present study was undertaken to test the hypothesis that chronic androgen supplements (starting post pubertal) in a rodent model of transgender men, will increase BP and promote metabolic dysfunction.MethodsFemale SD rats were implanted with testosterone propionate (TP, 7.5 mg in 5 mm silastic tubes, replaced every 3 wks, n = 10) starting at 7 wks of age (post‐puberty) and compared to controls (empty silastic implants, n = 10). Rats were weighed weekly. Radiotelemetry transmitters were implanted at 13 wks of age (n = 5‐6/group) and mean arterial pressure (MAP) was measured at 15, 21 and 25 wks of age. Body composition was determined at 15, 21 and 23 wks of age and proteinuria was determined at 15 and 21 wks of age (n = 4/group). Serum testosterone was measured by LC/MS at 15 wks of age (n = 4/group). Oral glucose tolerance test was performed at 11 and 22 wks of age (n = 4/group).ResultsTP supplements increased serum testosterone at 15 wks of age by 30‐fold compared to female controls (6.4 ± 1.5 vs 0.2 ± 0.05 ng/ml, respectively; p&lt;0.005). Body weight (BW) increased significantly in TP group compared to controls by 10 wks of age (241 ± 4 g vs 220 ± 2 g, respectively; p&lt;0.05) and was sustained through 26 wks of age (311 ± 7 g vs 276 ± 5 g, respectively; p&lt;0.05). Fat mass and fat mass/BW were similar between TP and controls. Lean mass was significantly higher in TP group compared to controls at 15, 21 and 23 wks of age (254 ± 7, 268 ± 12 and 273 ± 12 g vs 218 ± 6, 227 ± 5 and 229 ± 5 g, respectively; p&lt;0.01); however, when factored for BW, there were no differences between TP and controls. Proteinuria was significantly higher in TP group compared to controls at 15 wks of age (4.9 ± 1.2 vs 2.1 ± 0.3 mg/24 h, respectively, p&lt;0.05) and 21 wks of age (7.6 ± 1.1 vs 2.4 ± 0.5 mg/24 h, respectively, p&lt;0.005). Importantly, MAP was increased significantly in TP group at 15 wks of age (112 ± 3 vs 106 ± 4 mmHg, p&lt;0.05), 21 wks of age (114 ± 3 vs 105 ± 2 mmHg; p&lt;0.05) and 24 wks of age (115 ± 3 vs 104 ± 2 mmHg, p&lt;0.05), compared to controls, respectively. Oral glucose tolerance test at 11 and 22 wks of age was similar between groups.ConclusionTestosterone used in a form of sex‐affirming therapy in female rats induced increases in BP that are independent of adiposity or Insulin resistance and maybe associated to renal injury. Future studies should determine whether these changes are sustained with aging, and the mechanisms responsible for the increase in BP in the female‐to‐male trans‐sex model.

Role of the JAK/STAT3 Pathway in Obesity‐Induced Renal Injury in Polycystic Ovary Syndrome

BackgroundPolycystic ovary syndrome (PCOS), the most common endocrine disorder in reproductive‐age women, is characterized by oligo‐ or anovulation, hyperandrogenism, and polycystic ovaries. Both animal models and women with PCOS exhibit inflammation, obesity, and renal damage. The molecular mechanisms that mediate renal injury and dysfunction in PCOS, as well as its modulation by the diet are poorly understood. The JAK/STAT3 pathway, which is activated by interleukin‐6 (IL‐6) and leptin receptors, is involved in the pathophysiology of different models of renal injury. Despite its chronic activation in extra‐renal tissues in PCOS and obesity models, the role of the JAK/STAT3 pathway in PCOS‐mediated renal damage remains unknown. We aim to test the hypothesis that an obesogenic diet, via increased leptin and IL‐6, activates the JAK/STAT3 signaling pathway to exacerbate androgen‐induced renal injury.MethodsThree‐week‐old peripubertal female mice were implanted with Silastic tubes filled with the non‐aromatizable androgen dihydrotestosterone (DHT, 8 mg) or vehicle (empty tubes). Animals were fed either a high‐fat diet (HFD; 60% kcal fat) or a low‐fat diet (LFD; 10% kcal fat, sucrose‐matched) for 90 days. Fat mass (EchoMRI), serum leptin (ELISA), kidney weight (gravimetry), and urinary albumin to creatinine ratio (UACR, clinical chemistry analyzer) were measured. Markers of renal inflammation [IL‐6, tumor necrosis factor‐α (TNF‐α)], oxidative stress [NADPH oxidase2 (Nox2)], and fibrosis [collagen I, collagen III, transforming growth factor‐β (TGF‐β), and fibronectin] were quantified by RT‐qPCR. Western blot analysis of active STAT3 [phosphorylated‐STAT3 (Tyr705)] and total STAT3 proteins expression in the kidneys was also performed.ResultsIn LFD‐fed mice, DHT increased fat mass (20.28 ± 1.10 vs. 6.78 ± 0.43 g, p&lt;0.05), serum leptin (1114.13 ± 133.68 vs. 299.27± 25.32 pg/mL, p&lt;0.05), kidney weight (33.79 ± 1.35 vs. 26.52 ± 1.08 g, p&lt;0.05) and UACR (1,227 ± 420 vs. 404 ± 169 μg albumin/g creatinine, p&lt;0.05). DHT also increased the expression of renal inflammatory markers (TNF‐α and IL‐6). Notably, while DHT upregulated the expression of the fibrotic marker TGF‐β in LFD‐fed mice, it only induced the expression of Collagen I and Nox2 in the HFD‐fed mice. Furthermore, HFD exacerbated DHT‐mediated increases in adiposity and circulating leptin and IL‐6, as well as renal inflammation, hypertrophy, and UACR. The disturbance in the aforementioned parameters was associated with increased renal STAT3 phosphorylation in HFD‐fed DHT‐treated mice compared to LFD‐ or HFD‐fed controls (2.00‐ and 2.86‐fold, respectively, p&lt;0.05).Conclusion and significanceOur findings suggest that diet‐induced obesity plays a significant role in the renal outcomes in PCOS, and that increased STAT3 activation may explain the exacerbated renal injury in HFD‐fed DHT‐treated female mice. JAK/STAT3 pathway modulation could be novel therapeutic approach for diet‐induced renal injury in PCOS. The implications of inhibiting specific STAT3 pathway components on the exacerbated renal impairment caused by obesity in our model of PCOS are currently being investigated.

Sodium arsenite does not affect prostate carcinogenesis in a chemically-hormonally-induced rat model

There is epidemiologic evidence to suggest that arsenic exposure is associated with risk of prostate cancer incidence and mortality. There are no studies indicating that arsenic can induce prostate cancer in animals. We evaluated whether drinking water exposure to sodium arsenite would affect prostate carcinogenesis in a rat model that depends on long-term low dose treatment with testosterone. WU rats received a sequential treatment with the antiandrogen flutamide followed by a single androgen administration to stimulate prostatic cell proliferation during which a single injection of N-methyl-N-nitrosourea was given. Two weeks later the animals received subcutaneous slow release testosterone-containing silastic tubing implants and provided with drinking water containing 5 mg/L sodium arsenite or with control drinking water for the duration of the 64 week-long experiment. Arsenite provided in drinking water did not modify the induction of prostate cancer in this rat model compared to control rats or survival. It also did not affect the growth of the animals or their drinking water intake. This animal study with drinking water exposure to 5 mg/L sodium arsenite does not support the notion that arsenic enhances prostate carcinogenesis.

High‐Fat Diet Exacerbates Androgen‐Mediated Obesity and White Adipose Tissue Hypertrophy in a Mouse Model of Polycystic Ovary Syndrome

BackgroundPolycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in reproductive age women. PCOS is characterized by hyperandrogenemia, oligo‐ or anovulation and polycystic ovaries and is associated with obesity and white adipose tissue (WAT) dysregulation. The deleterious metabolic profile of women with PCOS is exacerbated by obesity. However, the molecular mechanisms that mediate WAT dysfunction in PCOS, as well as its modulation by the diet, are poorly understood. We aim to investigate the effect of an obesogenic diet on androgen‐mediated WAT hypertrophy by assessing the adipocyte size of the different WAT depots [mesenteric fat (MF), subcutaneous fat (SCF) and retroperitoneal fat (RPF)] using a well‐established model of PCOS in mice.MethodsThree‐week old female mice (C57BL/6J) were implanted with Silastic tubes filled with the androgen dihydrotestosterone (DHT, 8.0 mg, S.C.) or vehicle (empty tubes). Animals were fed high‐fat diet (HFD; 60% kcal fat) or low‐fat diet (LFD; 10% kcal fat, sucrose‐matched) for 90 days. Weekly body weights and body composition (EchoMRI) were assessed. Animals were sacrificed and multiple WAT depots (MF, SCF and RPF) were harvested for histological analysis. Formalin‐fixed paraffin‐embedded tissues from the three WAT depots were sectioned (5 µm thick) and stained with hematoxylin and eosin. The stained sections were imaged at 40X magnification. Adipocyte size (cross‐sectional area) was determined using ImageJ software with the Adiposoft plugin [~2,000 adipocytes/section, 3 sections/animal, n = 6/group]. GraphPad Prism 8.4.2 was used for statistical analysis, and P‐values of 0.05 were considered statistically significant.ResultsLFD‐fed DHT‐treated mice showed significant increases in body weight (28.00 ± 0.60 vs. 23.59 ± 0.41 g, p&lt;0.05), lean mass (21.70 ± 0.30 vs. 20.04 ± 0.23 g, p&lt;0.05), and fat mass (6.20 ± 0.50 vs. 3.42 ± 0.33 g, p&lt;0.05) compared to their vehicle‐treated controls. Adipocyte size analysis showed that LFD‐fed DHT‐ treated mice have significantly larger adipocytes when assessed in MF (1512.0 ± 15.55 vs. 833.3 ± 6.50 µm2, p&lt;0.05), SCF (1907.0 ± 22.04 vs. 1395.0 ± 12.43 µm2, p&lt;0.05) and RPF (2284.0 ± 26.20 vs. 1396.0 ± 11.61 µm2, p&lt;0.05), compared to their vehicle‐treated controls. Notably, HFD‐fed DHT‐treated mice showed greater MF and RPF adipocyte size compared to HFD‐fed vehicle‐treated mice, which was not observed in SCF. Interestingly, HFD exacerbated DHT‐mediated increases in body weight (1.54‐fold), lean mass (1.17‐fold), and fat mass (3.03‐fold) compared to LFD‐fed DHT‐treated mice. Additionally, the increase in adipocyte size in all fat depots in response to DHT was greater in mice fed HFD by 1.50‐fold compared to those fed LFD.Conclusion and significanceThe hypertrophic effect of androgens on the WAT is modulated by the diet. Increased adipocyte size is associated with insulin resistance in women with PCOS. Our results may help explain why obesity is associated with a worsened metabolic profile in women with PCOS at the cellular level. Weight loss with a low‐fat diet may be an effective approach to ameliorate WAT dysfunction and the subsequent metabolic dysregulation in PCOS.

Salvage Surgery after a Grade C Pancreatico-Jejunostomy Leak; Sparing the Remnant Pancreas

Introduction: Grade C pancreatic fistula is a feared complication after a pancreaticoduodenectomy, and carries a distinct risk of mortality in patients. Traditionally, this problem has been managed with completion pancreatectomy, or pancreas-preserving techniques that involve an external drainage procedure of the remnant pancreas followed by re-approximation of the pancreatico-jejunostomy (PJ) after an interval period, requiring two separate procedures. Our pancreas-preserving approach involves re-approximation of the PJ anastomosis over an externalized PJ stent through the biliary-pancreatic limb at re-exploration. Method:1.A silastic tube is brought into the abdomen via a stab incision in the abdominal wall approximately 2 fingerbreadths below the costal margin.2.The tube is introduced into the pancreatico-biliary limb through the jejunum and brought out through the disrupted PJ anastomosis. A glide wire may be needed to accomplish this step.3.The tube is threaded into the pancreatic duct and secured with PDS.4.The pancreatic parenchyma can then be re-approximated with the jejunum with the drain in place. Additional drains are placed around the anastomosis.5.The silastic tube is then secured with a purse string suture at the jejunal exit site and to the inner abdominal wall. The drain is placed on gravity drainage. Results: Two patients were treated using this technique. Both these patients required only one re-operative intervention. Median length of hospital stay was 22.5 days without readmission. Both patients have had complete resolution of the leak. Conclusion: Our technique has been effective in pancreas preservation and limits the number of operative interventions.

A Technique for Witzel Tunnel Catheter Drainage of the Biliary and Pancreatic Anastomosis of a Whipple Procedure

Introduction: Stenting the pancreatic and biliary anastomoses in a Whipple procedure has been shown to lower the rate of anastomotic leak. Method: We have identified a combined biliary and pancreatic ductal external drainage catheter/stent to decompress the small bowel limb and both anastomoses. The single catheter is a combination of a red Robinson catheter and a silastic pediatric feeding tube each of appropriate size for the duct they are draining. The silastic feeding tube is inserted into the lumen of the red rubber catheter though a small tight fenestration in the elastic external segment of the red catheter and exits the red rubber catheter through a similar fenestration at the level of the hepatico-jejunostomy. The silastic feeding tube is then advanced into the pancreatic duct where it is secured to the small bowel mucosa with a fine absorbable suture to prevent dislodgement. The combined tubes then exits the small bowel “Whipple limb” though a Witzel tunnel. The small bowel is secured to the right upper quadrant abdominal wall with several interrupted 3-0 Vicryl sutures. Results: Our technique offers several advantages. It’s a more durable way of stenting the two anastomoses and prevents stent migration. It provides an opportunity to study the two anastomosis via contrast administration. The witzel tunnel and the anchoring of the jejunal limb to the lateral abdominal wall opens the door for several IR/endoscopic interventions. Conclusion: The use of a combined biliary and pancreatic ductal external drainage catheter/stent system has many theoretical advantages.

Extended Ulaanbaatar Procedure with Preputial Skin Graft for Proximal Hypospadias.

Two stage urethroplasty for proximal penile hypospadias is time consuming, expensive and; traumatic both for parents and phallus. On the other hand, single stage procedure technically demanding. We would like to describe Extended Ulaanbaatar Procedure (EUP) which is not a two stage procedure. Rather, might be called as 'extended single stage' procedure. In EUP we have done orthoplasty along with urethroplasty with preputial skin graft at same sitting as primary procedure keeping urination diverted through proximal hypospadiac meatus as "controlled fistula" which was closed after six months as secondary procedure. We operated on 35 patients of proximal penile hypospadias with moderate to severe chordee. Chordee was excised till correction of curvature. Two distracted cut ends of native plate was bridged with preputial skin graft (PSG) in between. Following that, silastic tube was placed over glandular plate as scaffold, on both cut ends of native plate and PSG. All the urethral plates and PSG were buried with tunica vaginalis flap before glanuloplasty. After six months, proximal "controlled fistula" was closed with scrotal dartos fascia and skin to join distal to proximal urethra. Vertical meatus in glans was found in 32 patients. One patient had glans dehiscence, two patients had medium sized fistula, another two patients had stenosis in neourethra and six had suture track fistula. Twenty-nine patients had satisfactory curve with good flow in uroflowmetry as per nomogram at sixth month of follow up. In classic Ulaanbaatar procedure authors do distal urethroplasty and glanuloplsaty in 1st stage following orthoplasty to avoid repeat trauma in glans in repeat procedures. Left over urethroplasty in classic Ulaanbaatar was done in 2nd stage. However, in EUP; we did urethroplasty for full length following orthoplasty as primary procedure. This procedure is less invasive than two staged as we avoided repeat degloving and repeat dissection on operated tissues. Urethroplasty done as primary procedure shunned the need of repeat degloving, decreased the period of morbidity, stay, and cost of surgery. We also avoided problems of urination through not matured, long, neo-urethra. Similarly complications i.e disruption, stenosis in neo-urethra can be managed utilizing the advantages of urinary diversion.

Safety and Validity of Silastic Tympanum-Eustachian Tube Drainage Strips: A Preliminary Study in Beagles

Safety and Validity of Silastic Tympanum-Eustachian Tube Drainage Strips: A Preliminary Study in Beagles

Cervical Spine Reconstruction with Chest Tube Technique After Metastasis Resection: A Single-Center Experience

The silastic tube technique, in which a chest tube is placed into the vertebral body defect and impregnated with polymethyl methacrylate, showed good results in patients with lumbar and thoracic neoplastic diseases. There has been only 1 study about the effectiveness and safety of this technique in patients with cervical metastases. We aimed to report our experience in using this technique to reconstruct the spine after corpectomy for cervical metastasis. All patients with cervical spinal metastasis who underwent surgical treatment using a chest tube impregnated with polymethyl methacrylate in conjunction with anterior cervical plate stabilization were retrospectively recruited. Demographics, tumor histology, revised Tokuhashi score, preoperative and postoperative American Spinal Injury Association score, preoperative and postoperative ambulatory status, perioperative complications, and survival time were collected. This study included 16 patients. The most common primary tumor site was the lung (6 patients; 37.5%). The mean (SD) survival time was 408 (795) days (range, 1-2797 days), and the median survival time was 72 days (95% confidence interval 28-116 days). Four patients (25%) died within 30 postoperative days. There was no surgical site infection or instrument failure after the surgery. Five patients (31.2%) lived >180 days, and 3 patients (18.8%) lived >360 days. One patient (6.2%) was still alive at the end of the study. The silastic tube technique in conjunction with anterior cervical plate stabilization might be safe, effective, and cost-effective for patients with cervical spine metastasis.

Post-operative outcomes of endoscopic dacrocystorhinostomy without intubation at holy family hospital, Pakistan.

Objective: This study aims to present the outcomes of the patients who underwent endoscopic dacryocystorhinostomy (DCR) without intubation at a tertiary care hospital. Study Design: Observational Study. Setting: Holy Family Hospital, Rawalpindi, Pakistan. Period: October 2018 to November 2019. Material &amp; Methods: Endoscopic dacryocystorhinostomy operation was performed in a total of 52 patients presenting with chronic epiphora. Silastic tubes were not used to maintain the patency. Patients were prescribed antibiotic eye drops, oral painkillers, decongestant eye drops, and regular nasal douches. Results: Fifty patients (96.2%) presented with successful post-operative outcomes on the 12th week for follow-up. Post-operative canal patency was evaluated by endoscopic examination and syringing. Patients were also evaluated for the presence of epiphora. Conclusion: Our results of 52 patients who underwent endoscopic DCR without stenting are as promising as those with stenting. Hence, the procedure without intubation is recommended.

Hepatic Dysregulation of Bile Acid Homeostasis in Hyperandrogenemic Female Mouse Model of Polycystic Ovary Syndrome

Introduction and Purpose: Polycystic Ovary Syndrome (PCOS) is recognized as the most common endocrine disorder in women of reproductive age. Notably, PCOS women with hyperandrogenism have a pronounced increased risk for cardio-metabolic comorbidities compared with healthy individuals. Bile acids are endocrine signaling molecules that modulate hepatic lipid, glucose, and energy metabolism by aiding in absorption of lipids. Alteration of bile acid homeostasis affects overall metabolic homeostasis and contributes to pathogenesis of an array of metabolic diseases, although the molecular mechanisms of this have not been studied in PCOS. Methods: Four-week old C57BL/6N female mice were implanted subcutaneously with dihydrotestosterone (DHT, 8.0 mg) or vehicle silastic tubes (n=8/grp). Weekly body weight, food intake, and body composition was assessed. Fasting serum was obtained and the oral glucose tolerance test (OGTT) was performed in the last week of treatment. Animals were euthanized on treatment day 90 and livers were harvested. Expression levels of mRNA were assessed using RT-qPCR. Results: DHT treated females had significantly higher liver mass (1,387 ± 51 vs 1,197 ± 29 g, p<0.05), increased lean mass (21.25 ± 0.27 vs 19.58 ± 0.23 g, p<0.05) and increased fat mass (4.83 ± 0.47 vs 3.59 ± 0.36 g, p<0.05) compared to the vehicle counterparts. These hyperandrogenemic females additionally showed altered glucose homeostasis, having increased fasting glucose (201.10 ± 11.11 vs 152.80 ± 9.23 mg/dL, p<0.05) and an increased area under the curve (209.2± 11.0 vs 160.8± 3.5 mg.min/dL, p<0.05) following OGTT. Hepatic expression of both classic (Cyp8b1, 1.4 ± 0.1-fold, p<0.05) and alternative (Cyp7b1, 2.0 ± 0.3-fold, p<0.05) bile acid synthesis cytochrome P450 enzyme genes were significantly upregulated in DHT treated animals. Additionally, expression of sulfotransferase Sult2a2 was completely abolished in DHT treated animals compared with vehicle animals, indicating the possibility of androgen regulation of the sulfonation of bile acids marked for elimination. Liver expression of both the bile acid receptor G-protein coupled bile acid receptor 1 and the androgen receptor were both significantly downregulated (Gpbar1: 0.68 ± 0.08-fold, AR: 0.46 ± 0.04-fold, p<0.05) in DHT treated animals. Conclusions: Bile acid synthesis, transport, and elimination are tightly controlled processes in the liver to maintain a constant bile acid pool and limit reabsorption. Together, our results highlight the potential role of androgens in DHT-treated female mice in the dysregulation of bile acid homeostasis and its potential contribution to influence metabolic dysfunction. (Supported by NIH grants NIGMS P20GM-121334 to LLYC and DGR, and NIH NIDDK R21DK-113500 to DGR and the Mississippi Center of Excellence in Perinatal Research.)

Androgens and Diet Regulation of SARS‐CoV‐2 Viral Entry Proteins: Implications for COVID‐19 Cardiorenal Outcomes Severity in Polycystic Ovary Syndrome

BackgroundThe susceptibility and the severity of coronavirus disease 2019 (COVID‐19) caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) are associated with hyperandrogenism, obesity, and pre‐existing pulmonary, metabolic, renal or cardiac conditions. Hyperandrogenemia and ovarian dysfunction characterize polycystic ovary syndrome (PCOS), the most common endocrine disorder in premenopausal women. Women with PCOS have higher prevalence of obesity and higher incidence of cardiovascular diseases and renal injury, making them a population at risk for severe COVID‐19 outcomes.MethodsThree‐week‐old female mice were implanted with Silastic tubes filled with the nonaromatizable androgen dihydrotestosterone (DHT, 8 mg) or vehicle (empty tubes). Animals were maintained on high‐fat diet (HFD; 60% kcal fat) or low‐fat diet (LFD; 10% kcal fat, sucrose‐matched) for 90 days. Fat mass (EchoMRI), kidney and left ventricle (LV) weights as well as the cardiac and renal expression of the inflammatory markers interleukin‐6 (IL‐6), tumor necrosis factor‐α (TNF‐α), and interleukin‐1β (IL‐1β) were assessed. Moreover, circulatory, urinary, renal and cardiac levels of SARS‐CoV‐2 host cell receptor angiotensin converting enzyme 2 (ACE2) were quantified. Additionally, renal and cardiac mRNA and protein expression of the multiple cellular proteases required for viral entry (TMPRSS2, TMPRSS4, furin, cathepsin L, and ADAM17) were assessed.ResultsHFD exacerbated DHT‐mediated increases in fat mass (20.28 ± 1.10 vs. 6.78 ± 0.43 g, p<0.05), kidney weight (33.79 ± 1.35 vs. 26.52 ± 1.08 g, p<0.05), LV hypertrophy (7.48 ± 0.21 vs. 6.41 ± 0.28 g, p<0.05) and renal and cardiac expression of the inflammatory marker IL‐6 (1.5 and 2.5‐fold, respectively). PCOS mice on both diets showed higher urinary ACE2 (LFD: 18‐fold, HFD: 10‐fold) and altered renal mRNA and/or protein expression of all the measured targets. DHT upregulated renal TMPRSS2 (1.19 ± 0.04 vs. 0.98 ± 0.03 AU, p<0.05) and cathepsin L (2.64 ± 0.25 vs. 0.62 ± 0.25 AU, p<0.05) proteins in HFD‐fed DHT‐treated mice compared to LFD‐fed DHT‐treated mice. In the heart, LFD‐fed DHT‐treated mice showed no change in ACE2 and the cellular proteases on either the mRNA or protein levels except for ADAM17 protein that was significantly upregulated (1.63‐fold) compared to the vehicle‐treated group. On the other hand, while HFD‐fed DHT‐treated mice showed similar increase in cardiac ADAM17 protein (1.64‐fold vs. LFD‐fed vehicle‐treated), they showed higher mRNA expression of ACE2 (1.83‐fold) and furin (1.32‐fold) compared to the HFD‐fed vehicle‐treated mice.Conclusion and significanceOur findings highlight women with PCOS as a population with a high risk of COVID‐19 associated cardiac and renal complications. Further, our study suggests dietary control recommendations for optimal management of women with PCOS that can ultimately attenuate COVID‐19 cardiorenal outcomes.

UCP1 and TRPM8 Expression in the Brown Fat Did Not Affect the Restriction of Menthol-Induced Hyperthermia by Estradiol in Ovariectomized Rats.

Estradiol (E2) modulates the central and peripheral thermoregulatory responses to cold. Menthol is an agonist of transient receptor potential melastatin type 8 (TRPM8), which is a peripheral cold receptor. E2 suppresses menthol-induced elevation of body temperature (Tb) in ovariectomized rats, but the mechanism is unknown. The aim of the present study is to investigate the effect of E2 on uncoupling protein 1 (UCP1), a thermogenic gene, and TRPM8 mRNA levels in ovariectomized rats applied menthol. A silastic tube was implanted in ovariectomized rats with and without E2 underneath the dorsal skin (E2(+) and E2(-) groups), and data loggers for Tb measurement into peritoneal cavity. After application of 10% L-menthol or vehicle to the skin of the whole trunk of rats, Tb was measured for 2 h. The interscapular brown adipose tissue (BAT) and spinal ganglia of cervical, thoracic, and lumbar parts were obtained for RT-qPCR assay. In the menthol application, Tb in the E2(+) group was lower than that in the E2(-) group. The UCP1 mRNA in the BAT, TRPM8 mRNA in the BAT and spinal ganglia in all areas did not differ between the E2(+) and E2(-) groups. In conclusion, the UCP1 and TRPM8 expression in the brown fat did not affect the restriction of the menthol-induced hyperthermia by estradiol in ovariectomized rats.

Effects of L-dopa on expression of prolactin and synaptotagmin IV in 17-estradiol-induced prolactinomas of ovariectomized hemiparkinsonian rats

ABSTRACTParkinson’s disease (PD) is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. Dopamine precursor levodopa (L-dopa) is used as the first-line treatment for PD. Evidence suggests neuroprotective effects of estrogens in PD. Since both 17b-estradiol (E2) and L-dopa act as regulators of prolactin (PRL) secretion from the pituitary gland, we investigated their effect on the expression of PRL in prolactinomas that developed in ovariectomized hemiparkinsonian rats treated with E2. We also investigated the effect of E2 and L-dopa on the expression of synaptotagmin IV (Syt IV), an immediate early gene whose product is abundant in the pituitary gland and was found to be highly co-expressed with PRL in lactotrophs (>90%). The hemiparkinsonian rat model was obtained by unilateral lesioning of dopaminergic nigrostriatal neurons. Rats received silastic tubing implants with E2 and were treated with L-dopa. Enzyme-linked immunosorbent assay and immunohistochemistry were used to assess the serum concentrations of PRL and E2 and expression of PRL and Syt IV in the tissue of adenohypophysis, respectively. We found that high levels of serum E2 were associated with the upregulation of Syt IV and PRL in PRL-ir cells, while treatment with L-dopa decreased the size of prolactinomas and downregulated Syt IV but had no effect on PRL expression or serum concentrations.

Neuroprotective Effects of Testosterone in Male Wobbler Mouse, a Model of Amyotrophic Lateral Sclerosis.

Patients suffering of amyotrophic lateral sclerosis (ALS) present motoneuron degeneration leading to muscle atrophy, dysphagia, and dysarthria. The Wobbler mouse, an animal model of ALS, shows a selective loss of motoneurons, astrocytosis, and microgliosis in the spinal cord. The incidence of ALS is greater in men; however, it increases in women after menopause, suggesting a role of sex steroids in ALS. Testosterone is a complex steroid that exerts its effects directly via androgen (AR) or Sigma-1 receptors and indirectly via estrogen receptors (ER) after aromatization into estradiol. Its reduced-metabolite 5α-dihydrotestosterone acts via AR. This study analyzed the effects of testosterone in male symptomatic Wobblers. Controls or Wobblers received empty or testosterone-filled silastic tubes for 2 months. The cervical spinal cord from testosterone-treated Wobblers showed (1) similar androgen levels to untreated control and (2) increased levels of testosterone, and its 5α-reduced metabolites, 5α- dihydrotestosterone, and 3β-androstanediol, but (3) undetectable levels of estradiol compared to untreated Wobblers. Testosterone-treated controls showed comparable steroid concentrations to its untreated counterpart. In testosterone- treated Wobblers a reduction of AR, ERα, and aromatase and high levels of Sigma-1 receptor mRNAs was demonstrated. Testosterone treatment increased ChAT immunoreactivity and the antiinflammatory mediator TGFβ, while it lessened vacuolated motoneurons, GFAP+ astrogliosis, the density of IBA1+ microgliosis, proinflammatory mediators, and oxidative/nitrosative stress. Clinically, testosterone treatment in Wobblers slowed the progression of paw atrophy and improved rotarod performance. Collectively, our findings indicate an antiinflammatory and protective effect of testosterone in the degenerating spinal cord. These results coincided with a high concentration of androgen-reduced derivatives after testosterone treatment suggesting that the steroid profile may have a beneficial role on disease progression.

A technique for witzel tunnel catheter drainage of the biliary and pancreatic anastomosis of a Whipple procedure

Presenter: Mridul Pansari MD | Florida Atlantic University Background: Stenting of the pancreatic and biliary anastomoses of a Whipple procedure has been shown to lower the rate of anastomotic leak in several retrospective and prospective studies. We describe here a combined biliary and pancreatic ductal external drainage catheter we have used successfully in our pancreatico-duodenectomy operations. Methods: We have identified a combined biliary and pancreatic ductal external drainage catheter / stent which we construct on the operating table to decompress the small bowel limb and both anastomoses. The single catheter is a combination of a red Robinson catheter and a silastic pediatric feeding tube each of appropriate size for the duct they are draining. The silastic feeding tube is inserted into the lumen of the red rubber catheter though a small tight fenestration in the elastic external segment of the red catheter and exits the red rubber catheter through a similar fenestration at the level of the choledocho or hepatico- jejunostomy. The silastic feeding tube is then advanced well into the lumen of the pancreatic duct where it is secured to the small bowel mucosa with a fine absorbable suture to prevent dislodgement. Multiple small extra openings are cut into both tubes at their distal segments to facilitate ductal drainage. The combined tubes then exeunt the small bowel “Whipple limb” though a Witzel tunnel. The small bowel is secured to the right upper quadrant abdominal wall with several interrupted 3-0 Vicryl sutures. The tube is secured to the skin externally with a heavy nylon suture. The pediatric feeding tube is then secured to the outer part of the red rubber catheter with benzoin and three ¼ inch steri-strips. Both catheters are connected to separate external drainage bags. We perform our pancraetico- jejunostomy with a single layer of interrupted 3-0 silk suture and our bile duct anastomosis with a single layer of 4-0 or 5-0 PDS or Maxon suture. Two 10 mm Jackson Pratt drains are then placed in the right upper quadrant. Results: There are several theoretical advantages that our procedure offers. First, it diverts the pancreatic fluid and bile, decreasing it's flow through the respective anastomosis which helps in the healing of the anastomosis. Secondly, our technique is a more durable way of stenting the two anastomoses and prevent the migration of the stents. The pediatric feeding tube has three areas of resistance that prevents its migration. The fenestration in the external portion, the fenestration in the internal portion and the mucosal stitch that is placed to hold it in place. The red rubber catheter is kept in place by the Witzel tunnel itself. Third advantage is that it provides an opportunity to study the two anastomosis via contrast administration. Fourth, the witzel tunnel and the anchoring of the jejunal limb to the lateral abdominal wall opens the door for several wire based treatments in a Seldinger fashion, should a leak be identified in the post operative period. Conclusion: The use of a combined biliary and pancreatic ductal external drainage catheter / stent system has many theoretical advantages.

Common Challenges and Solutions Associated with the Preparation of Silicone-Injected Human Head and Neck Vessels for Anatomical Study.

Neuroanatomy laboratory training is crucial for the education of neurosurgery residents and medical students. Since the brain is a complex and three-dimensional structure, it is challenging to understand the anatomical relationship of the cortex, internal structures, arteries, and veins without appropriate adjuncts. Several injection agents—including the inks/dyes, latex, polyester, acrylic resins, phenol, polyethylene glycol, and phenoxyethanol—have been explored. Colored silicon injection protocols for the head and neck vessels’ perfusion have greatly aided the study of neuroanatomy and surgical planning. This report presents a colored silicone injection method in detail, and also highlights the technical shortcomings of the standard techniques and workarounds for common challenges during 35 human cadaveric head injections. The human cadaveric head preparation and the coloring of the head vessels are divided into decapitation, tissue fixation with 10% formalin, the placement of the Silastic tubing into the parent vessels, the cleaning of the vessels from clots, and the injection of the colored silicone into the vessels. We describe the technical details of the preparation, injection, and preservation of cadaveric heads, and outline common challenges during colored silicone injection, which include the dislocation of the Silastic tubing during the injection, the injection of the wrong or inappropriate colored silicone into the vessel, intracranial vessel perforation, the incomplete silicone casting of the vessel, and silicone leakage from small vessels in the neck. Solutions to these common challenges are provided. Ethyl alcohol fixed, colored human heads provided the long-term preservation of tissue, and improve the sample consistency and preservation for the teaching of neuroanatomy and surgical technique.

Оценка эффективности эндоскопической биканаликулярной интубации слезоотводящих путей силиконовым дренажем при врожденном дакриоцистите

Purpose. To evaluate effectiveness of nasolacrimal duct intubation with silicone tube in congenital dacryocystitis (CD) and substantiate optimal timing of its removal. Material and Methods. 25 patients with CD were operated in the Khabarovsk branch of the S. Fyodorov Eye Microsurgery Federal State Institution in order to restoring conductivity of nasolacrimal duct of using the intubation set FCI (France). In addition to ophthalmic examination methods, all children underwent scleral examination which includes determination of acid base state (pH) of the wound exudate (secretion) from the nasal cavity. Inflammatory index was also scored which characterized the severity of standard signs of inflammation in the nasal mucosa after surgery. Results. There were no complications during the surgery. Normalization of nasal exudate pH values in children with uncomplicated СD was registered by the 4th week after the surgery. Normalization of nasal exudate pH values in children with recurrent СD was registered by the 6th week, coinciding with full disappearance clinical signs of inflammation. At the indicated periods, the silastic tubes were removed. One child had relapse of disease after suffering acute rhinitis 6 months after the surgery. This patient underwent dacryocystorhinostomy with positive effect. Conclusion. Bicanalicular temporary intubation of nasolacrimal duct using silicone tube in children with CD is considered as an effective treatment. In accordance with obtained results, in children with uncomplicated CD the removal of silicone implant is advisable 4 weeks after its installation, in children with recurrent CD the removal of silicone implant is advisable no earlier than 6 weeks. Key words: congenital dacryostenosis, intubation set, endoscopic rhinoscopy.