Suppression Test Research Articles

Antimalarial efficacy test of the aqueous crude leaf extract of Coriandrum sativum Linn.: an in vivo multiple model experimental study in mice infected with Plasmodium berghei

BackgroundMalaria continues to wreak havoc on the well-being of the community. Resistant parasites are jeopardizing the treatment. This is a wake-up call for better medications. Folk plants are the key starting point for antimalarial drug discovery. After crushing and mixing the leaves of Coriandrum sativum with water, one cup of tea is drunk daily for a duration of three to five days as a remedy for malaria by local folks in Ethiopia. Additionally, in vitro experiments conducted on the plant leaf extract elsewhere have also demonstrated the plant’s malaria parasite inhibitory effect. There has been no pharmacologic research to assert this endowment in animals, though. This experiment was aimed at evaluating the antimalarial efficacy of C. sativum in Plasmodium berghei infected mice.MethodsThe plant's leaf was extracted using maceration with distilled water. The extract was examined for potential acute toxicity. An evaluation of secondary phytoconstituents was done. Standard antimalarial screening models (prophylactic, chemosuppressive, curative tests) were utilized to assess the antiplasmodial effect. In each test, thirty mice were organized into groups of five. To the three categories, the test substance was given at doses of 100, 200 and 400 mg/kg/day before or after the commencement of P. berghei infection. Positive and negative control mice were provided Chloroquine and distilled water, respectively. Rectal temperature, parasitemia, body weight, survival time and packed cell volume were ultimately assessed. Analysis of the data was performed using Statistical Package for Social Sciences.ResultsNo toxicity was manifested in mice. The extract demonstrated a significant inhibition of parasitemia (p < 0.05) in all the models. The inhibition of parasite load was highest with the upper dose in the suppressive test (82.74%) followed by the curative procedure (78.49%). Likewise, inhibition of hypothermia, weight loss hampering, improved survival and protection against hemolysis were elicited by the extract.ConclusionsThe results of our experimental study revealed that the aqueous crude leaf extract of C. sativum exhibits significant antimalarial efficacy in multiple in vivo models involving mice infected with P. berghei. Given this promising therapeutic attribute, in depth investigation on the plant is recommended.

Assessing the predictive value of the suppressed 1 mg overnight dexamethasone suppression test in success of bariatric surgery.

Bariatric surgery has been proven to be a successful intervention for managing obesity. There are numerous studies in the literature aiming to predict the factors influencing the success of bariatric surgery. Our study aims to determine whether preoperative 1 mg overnight dexamethasone suppression test (1 mg-DST) serum cortisol levels can serve as predictors of the effectiveness of bariatric surgery in severe obese patients without Cushing syndrome. A total of 98 patients who underwent bariatric surgery were included in the study. The preoperative 1 mg-DST levels, insulin levels, thyroid function tests, and lipid profiles of the patients were recorded. The patients' preoperative, postoperative 3rd, and 6th month weights were recorded and the percent total weight loss (%TWL) is calculated. Patients were categorized into 2 groups based on their TWL at 6 months. The 1 mg-DST results were significantly lower in the high-TWL-6 group (0.93 ± 0.37 μg/dL) compared to the low-TWL-6 group (1.09 ± 0.36 μg/dL, P = .040). Similarly, Homeostatic Model Assessment for Insulin Resistance values were lower in the high-TWL-6 group (5.63 ± 2.21) compared to the low-TWL-6 group (6.63 ± 2.55, P = .047). The optimal cutoff value found for 1 mg-DST level was 0.97 µg/dL, providing 50% sensitivity and 70% specificity. This study is the first to examine the predictive role of suppressed 1 mg-DST levels on postoperative weight loss in nondiabetic patients. The most prominent result of this study was that we observed a negative correlation between 1 mg-DST levels and %TWL.

Exogenous glucocorticoids to improve extinction learning for post-traumatic stress disorder patients with hypothalamic–pituitary–adrenal-axis dysregulation: a study protocol description

ABSTRACT Background: Trauma-focused treatments for post-traumatic stress disorder (PTSD) are effective for many patients. However, relapse may occur when acquired extinction memories fail to generalize beyond treatment contexts. A subgroup of PTSD patients – potentially with substantial exposure to early-life adversity (ELA) – show dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, which results in lower cortisol levels. Glucocorticoids, including cortisol, appear to facilitate strength and generalization of emotional memories. Objective: We describe the protocol of an integrated PTSD study. We investigate (A) associations between HPA-axis dysregulation, ELA, epigenetic markers, and PTSD treatment outcome (observational study); and (B) effects of exogenous glucocorticoids on strength and generalization of extinction memories and associated neural mechanisms [pharmacological intervention study with functional magnetic resonance imaging (fMRI)]. The objective is to provide proof of concept that PTSD patients with HPA-axis dysregulation often experienced ELA and may show improved strength and generalization of extinction learning after glucocorticoid administration. Method: The observational study (n = 160 PTSD group, n = 30 control group) assesses ELA, follow-up PTSD symptoms, epigenetic markers, and HPA-axis characteristics (salivary cortisol levels during low-dose dexamethasone suppression test and socially evaluated cold-pressor test). The pharmacological intervention study (n = 80 PTSD group, with and without HPA-axis dysregulation) is a placebo-controlled fMRI study with a crossover design. To investigate strength and generalization of extinction memories, we use a differential fear acquisition, extinction, and extinction recall task with spatial contexts within a virtual environment. Prior to extinction learning, 20 mg hydrocortisone or placebo is administered. During next-day recall, strength of the extinction memory is determined by recovery of skin conductance and pupil dilation differential responding, whereas generalization is assessed by comparing responses between different spatial contexts. Conclusion: The integrated study described in the current protocol paper could inform a personalized treatment approach in which these PTSD patients may receive glucocorticoids as a treatment enhancer in trauma-focused therapies. Trial registration: The research project is registered in the European Union Drug Regulating Authorities Clinical Trials (EudraCT) database, https://eudract.ema.europa.eu/, EudraCT number 2020-000712-30.

Inflammation-based scores in a large cohort of adrenocortical carcinoma and adrenocortical adenoma: role of the hormonal secretion pattern.

Serum inflammation-based scores can predict clinical outcome in several cancer types, including adrenocortical carcinoma (ACC). It is unclear whether the extent of inflammation-based scores alterations in ACC reflects malignancy, steroid excess, or both. We investigated a large retrospective cohort of adrenocortical adenomas (ACA, n = 429) and ACC (n = 61) with available baseline full blood count and hormonal evaluation. We examined the relationship between different inflammation-based scores [neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index (SII), and prognostic nutrition index (PNI)] and bothmalignancy and steroid secretion patterns. All inflammation-based scores differed between ACC and ACA: patients with ACC had higher NLR, PLR, SII and lower LMR and PNI levels compared to ACA (all p values < 0.001). NLR showed a positive correlation with cortisol levels after overnight 1mg-dexamethasone suppression test (1mg-DST), both in ACC and ACA (p < 0.01). The ROC curve analysis determined NLR > 2.6 as the best cut-off to discriminate ACC from ACA [AUC = 0.846, p < 0.01]. At multivariable analysis, NLR > 2.6 was independently associated with ACC, 1mg-DST cortisol levels and age, but not with tumour size. ConsideringtheACC, NLR and SII were higher and PNI was lower in patients with cortisol excess compared to those without cortisol excess (p = 0.002, p = 0.007, and p = 0.044 respectively). Finally, LMR and NLR differed between inactive-ACC (n = 10) and inactive-ACA (n = 215) (p = 0.040 and p = 0.031, respectively). Inflammation-based scores are related to steroid secretion both in ACC and ACA. ACCs present a higher grade of inflammation regardless of their hormonal secretion, likely as a feature of malignancy itself.

The Effect of Rheumatoid Arthritis on Middle and Inner Ear Functions.

To investigate the middle and inner ear functions, and efferent auditory systems in patients with rheumatoid arthritis (RA). Thirty-five RA patients and 40 control subjects participated in the study. Pure-tone audiometry, high-frequency audiometry, multifrequency tympanometry, transient evoked otoacoustic emissions, and contralateral suppression tests were administered to all participants. Pure-tone hearing thresholds of RA patients were significantly higher at all frequencies except for 2000 Hz, 14,000 Hz, and 16,000 Hz in the right ear and 16,000 Hz in the left ear (p<0.05). Resonance frequency values of RA patients were statistically significantly lower than those of the control group (p<0.001). Emission amplitudes obtained with contralateral acoustic stimulation were significantly lower at 1400 Hz frequency in both groups than without contralateral acoustic stimulation (p<0.05). While contralateral suppression was observed at all frequencies in the control group, no suppression occurred at 2800 Hz and 4000 Hz in RA patients. The results obtained in this study demonstrated the presence of hearing dysfunction in patients with RA. When a patient is diagnosed with RA, an audiological evaluation should be made, and the patient should be informed about the possibility of audiological involvement.

Feasibility of a new ‘balanced binocular viewing’ treatment for unilateral amblyopia in children aged 3–8 years (BALANCE): results of a phase 2a randomised controlled feasibility trial

ObjectivesThis study aimed to evaluate the safety of dichoptic balanced binocular viewing (BBV) for amblyopia in children, plus feasibility, adherence, acceptability, trial methodology and clinical measures of visual function.DesignWe carried...

Aldosterone-Cortisol co-secretion in different adrenal tumors: A case series

Primary aldosteronism is the most common cause of endocrine hypertension. It commonly presents as refractory hypertension, carrying an elevated risk of cardiac and renal complications. Concurrent hypercortisolemia exacerbates the susceptibility to metabolic disorders, including obesity, dyslipidemia, abnormal blood glucose levels, and cardiovascular and renal diseases. Among the reported patients with co-secretion of aldosterone, the majority are aldosterone producing adenoma. Cases of bilateral adrenal hyperplasia secreting both aldosterone and cortisol are rarely reported. In this study, we conducted a comparative analysis of the clinical manifestations, laboratory tests, and imaging findings in two cases involving unilateral aldosterone-producing adenomas and bilateral macronodular adrenal hyperplasia respectively. Notably, our patients exhibited a cortisol circadian rhythm during the initial screening, complicating the diagnosis of Cushing's syndrome. The incorporation of early or routine low-dose dexamethasone suppression tests may prove beneficial in identifying co-secretory lesions promptly, assessing the risk of perioperative adrenal insufficiency, and guiding subsequent treatment and prognosis evaluation.

Atypical presentation of Cushing's disease with weight loss and hypokalemia.

ACTH-secreting pituitary adenomas causing Cushing's disease (CD) typically present with weight gain, whereas weight loss and hypokalemia in endogenous Cushing's patients are suggestive of ectopic ACTH production. We report a case of CD presenting with atypical features of marked weight loss and hypokalemia. A 75-year-old female was admitted to the hospital with a history of profound weight loss, associated with uncontrolled hypertension, hyperglycemia, severe proximal muscle weakness, and hypokalemia. Subsequent investigations, including 24-h urinary free cortisol, 48-h low-dose dexamethasone suppression test, MRI of the sella, and bilateral inferior petrosal sinus sampling, confirmed CD without any evidence of ectopic ACTH production. She became eucortisolemic with medical therapy of ketoconazole and cabergoline, subsequently regained her weight, and became normokalemic. This case illustrates that patients with CD may present with symptoms and biochemical findings that would otherwise suggest ectopic ACTH production. Patients with CD do not always present with classical clinical features and may present with symptoms and biochemical findings that would otherwise suggest ectopic ACTH production. While most patients with CD typically lose weight after biochemical remission, some patients gain weight after the normalization of cortisol levels. This case highlights the need to entertain a broad differential in patients presenting with hypokalemia and weight loss and the need to exclude hypercortisolemia.

Study protocol for a prospective, multicentre study of hypercortisolism in patients with difficult-to-control type 2 diabetes (CATALYST): prevalence and treatment with mifepristone

IntroductionEven with recent treatment advances, type 2 diabetes (T2D) remains poorly controlled for many patients, despite the best efforts to adhere to therapies and lifestyle modifications. Although estimates vary, studies...

Amenorrhea as a presentation of Cushing's syndrome.

Menstrual cycle abnormalities are common in premenopausal females with Cushing's syndrome, although the underlying mechanism is poorly understood. Signs and symptoms found in Cushing's syndrome overlap with polycystic ovarian syndrome (PCOS). The patient is a 33-year-old female previously diagnosed by a gynecologist with PCOS and treated with oral contraceptive pills (OCPs) for 2 years. She then discontinued her OCPs without consulting a clinician, resulting in amenorrhea for 6 months, for which she presented. She also had symptoms of depression and anxiety but had no other signs and symptoms of Cushing's syndrome, except a plethoric face. Initial lab work showed evidence of central hypogonadism (low luteinizing hormone, follicle-stimulating hormone, and estrogen), so a complete anterior pituitary hormone workup was done. Her thyroid-stimulating hormone was also low with a low free T4 level. Prolactin level was normal, but surprisingly, her AM cortisol level was high. The Cushing's syndrome workup revealed non-suppressed cortisol after a 1 mg dexamethasone suppression test and positive 24-h urine cortisol with suppressed adrenocorticotrophic hormone. A CT scan of her adrenal glands revealed a left adrenal adenoma. She underwent a left adrenalectomy, after which her menstrual cycles became regular again, and pituitary function has recovered. In Cushing's syndrome, female patients can have menstrual abnormalities due to the high cortisol levels, which can affect gonadotrophin levels. We encourage clinicians to include Cushing's syndrome in the differential diagnosis of patients with central hypogonadism.

The value of midnight 1 mg dexamethasone suppression test combined with ACTH stimulation test in the diagnosis of primary aldosteronism subtypes

Objective: To explore the value of the midnight 1 mg dexamethasone suppression test combined with adrenocorticotropic hormone (ACTH) stimulation test in the diagnosis of primary aldosteronism (PA) subtypes. Methods: A cross-sectional study. Clinical data of patients diagnosed with PA at the First Medical Center of Chinese PLA General Hospital from January 2020 to September 2022, who completed the midnight 1 mg dexamethasone suppression test combined with ACTH stimulation test, were analysed retrospectively. The clinical characteristics and trial results of patients with aldosterone-producing adenoma (APA) and idiopathic hyper aldosteronism (IHA)were compared. The efficacy of the midnight 1 mg dexamethasone suppression test combined with ACTH stimulation test in distinguishing APA and IHA was evaluated by drawing receiver operating characteristic (ROC) curves, and the cut-off value of the diagnostic indicator was determined with the maximum Youden index. Results: A total of 82 patients with PA were included, including 43 males and 39 females, aged (50.8±11.4) years old. They were divided into APA group (n=49) and IHA group (n=33) based on PA subtype. There was no statistically significant difference in body mass index, systolic and diastolic blood pressure between the two groups (all P>0.05). The blood potassium and orthostatic renin levels in the APA group were lower than those in the IHA group, and the differences were statistically significant (all P<0.001). The orthostatic plasma aldosterone concentration (PAC), orthostatic aldosterone to renin ratio (ARR), PAC before and after captopril challenge test(CCT), ARR after CCT, PAC before and after saline infusion test (SIT), and the proportion of unilateral lesions in the APA group were all higher than those in the IHA group, and the differences were statistically significant (all P<0.001). After the midnight 1 mg dexamethasone suppression test combined with ACTH stimulation test (30, 60, 90, 120 min), the PAC and PAC/cortisol levels in the APA group were significantly higher than those in the IHA group (all P<0.05). The PAC at 90 min showed the highest diagnostic capability according to the area under the ROC(AUC) (0.930,95%CI:0.874-0.986), and the Youden index was the highest at a PAC cut-off value of 39.05 ng/dl(0.766). The sensitivity and specificity for distinguishing APA from IHA were 91.8% and 84.8%, respectively. Conclusions: The midnight 1 mg dexamethasone suppression test with ACTH stimulation test could be useful for differentiating the subtypes of PA. Among them, the PAC and PAC/cortisol at 90 min showed best diagnostic efficacy.

Screening of hypercortisolism among patients with hypertension: an Italian nationwide survey

PurposeScreening of Cushing Syndrome (CS) and Mild Autonomous Cortisol Secretion (MACS) in hypertensive patients is crucial for proper treatment. The aim of the study was to investigate screening and management of hypercortisolism among patients with hypertension in Italy.MethodsA 10 item-questionnaire was delivered to referral centres of European and Italian Society of Hypertension (ESH and SIIA) in a nationwide survey. Data were analyzed according to type of centre (excellence vs non-excellence), geographical area, and medical specialty.ResultsWithin 14 Italian regions, 82 centres (30% excellence, 78.790 patients during the last year, average 600 patients/year) participated to the survey. Internal medicine (44%) and cardiology (31%) were the most prevalent medical specialty. CS and MACS were diagnosed in 313 and 490 patients during the previous 5 years. The highest number of diagnoses was reported by internal medicine and excellence centres. Screening for hypercortisolism was reported by 77% in the presence of specific features of CS, 61% in resistant hypertension, and 38% in patients with adrenal mass. Among screening tests, the 24 h urinary free cortisol was the most used (66%), followed by morning cortisol and ACTH (54%), 1 mg-dexamethasone suppression test (49%), adrenal CT or MRI scans (12%), and late night salivary cortisol (11%). Awareness of referral centres with expertise in management of CS was reported by 67% of the participants, which reduced to 44% among non-excellence centres.ConclusionsCurrent screening of hypercortisolism among hypertensive patients is unsatisfactory. Strategies tailored to different medical specialties and type of centres should be conceived.

Modified space suspension bentonite-based powder for suppression dust explosion in moist conditions: Experimental testing and validations

Bentonite, a non-metallic mineral mainly composed of montmorillonite, has been found to be effective in preventing explosion propagations. However, it is prone to absorbing water, leading to the issue of solidifying into lumps (caking problems) and reducing its ability to entrain in the pressure front of an explosion for stopping propagation. In this paper, three different dispersion modification technologies for bentonite are proposed. The corresponding modified bentonite samples are prepared and treated in various moist environments to assess their moisture absorption properties. Subsequently, space suspension testing is performed using a designed dispersion test device. Additionally, pipeline explosion suppression tests are conducted for different samples. The flame length, flame development time and flame peak velocity of various modified bentonite-based powders are measured. Through comparisons, the optimal modified explosion suppression bentonite used in mines is selected. It is determined that the use of calcium-based bentonite with a cation exchange capacity 0.75 times modified by bisdodecyldimethylammonium chloride for insertion exhibits better dispersion effects. Such modified bentonite-based powder can also demonstrate effective explosion suppressions and holds potential for widespread application in practices of explosion controls in the future.

DIFFERENCES IN ANTIMALARIAL ACTIVITY OF CITRUS MAXIMA,ANREDERA CORDIFOLIA, COMBINATION SOLANUM LYCOPERSICUM-MALUS DOMESTICA-DAUCUS CAROTA IN MICE INFECTED WITH PLASMODIUM BERGHEI

Malaria drug resistance, both new and old drugs, causes severe symptoms and treatment failure. In order to develop new drug, we screen several plants that potentially used as antimalaria. This study aimed to screen and compare antimalaria activity of Citrus maxima, Anredera cordifolia, Solanum lycopersicum, combination Solanum lycopersicum-Malus domestica-Daucus carota in a mouse model. Balb/ c mice male were divided into six groups (n=5). The dried plants were extracted by maceration using 80% methanol. A 4-day suppressive test was done to ascertain the anti-plasmodial effect of those various plants. After inoculation with Plasmodium berghei, the treatment groups were given 1000 mg/kg of the extract, while 5% RPMI and DHP (Dihydroartemisinine Piperaquine) served as controls. The results of this study revealed that all extracts showed significantly lower parasitemia compared to the negative control. This study showed a percentage parasite suppression of 58.7, 84.3, 77.4, 61.4 and 83.9 % for Anredera cordifolia, Citrus maxima, Solanum lycopersicum, combination Solanum lycopersicum-Malus domestica-Daucus carota and Dihydroartemisinine Piperaquine, respectively. The highest parasite suppression (84.3%) was found in the group given Citrus maxima extract. This study concluded that the fruit extract of Citrus Maxima, Anredera Cordifolia, Solanum Lycopersicum-Malus Domestica-Daucus Carota have different antimalaria activity, Citrus maxima has the best potential as an antimalarial.

Hipercortisolismo de origen adrenal

Hypercortisolism of adrenal origin is a hormonal disorder caused by chronic exposure to excess glucocorticoids due to adrenal overproduction of cortisol. There is a wide spectrum of clinical presentations of hypercortisolism, from apparently subclinical to full-blown cases depending on the duration and intensity of the hypercortisolism. Consequently, the diagnosis can be complex, given that most of the signs and symptoms are nonspecific. The clinical manifestations are related to an unfavorable cardiometabolic profile, which leads to increased morbidity and mortality in these patients. The biochemical diagnosis is based on confirming autonomous glucocorticoid production by demonstrating the absence of physiological cortisol suppression via a dexamethasone suppression test. The adrenocorticotropic hormone (ACTH) concentration is requested in order to establish the etiological diagnosis. Once the biochemical diagnosis is confirmed, the next step is a radiological study, with the first imaging technique being a computed tomography (CT) scan of the adrenal gland without contrast. The most common cause of endogenous ACTH-independent hypercortisolism is a unilateral cortisol-producing adrenal adenoma. Treatment will be individualized according to the cause and degree of hypercortisolism as well as associated comorbidities.

Indicaciones e interpretación de los estudios analíticos hormonales de la corteza suprarrenal

In the adrenal cortex, entities ranging from benign diseases such as adrenocortical adenomas to malignant diseases such as adrenocortical carcinoma or adrenal metastases can be found. Regarding functionality, the spectrum of diseases varies widely: from non-functioning adenomas, patients with autonomous cortisol secretion (ACS), primary hyperaldosteronism (PHA), ACTH-independent Cushing's syndrome, excess secretion of sex hormones, congenital adrenal hyperplasia (CAH), and adrenal insufficiency (AI). A hormonal study is essential for the proper characterization of these disorders. Baseline hormonal tests and functional studies are both necessary in some cases to reach the definitive diagnosis. The test of choice for Cushing's syndrome screening is urinary free cortisol, late-night salivary cortisol, or a 1mg dexamethasone suppression test (DST). For ACS, it is a DST. For PAH, it is calculation of the plasma aldosterone concentration and renin activity or concentration ratio. For AI, it is the determination of plasma cortisol between 8:00 and 9:00 a.m. and after cosyntropin stimulation. Lastly, for CAH, it is the measurement of plasma 17-hydroxyprogesterone.

Cortisol secretion autonomy associated with weight loss outcome after laparoscopic sleeve gastrectomy: a prospective cohort study in Asian patients.

Laparoscopic sleeve gastrectomy (LSG) is a widely recognized effective bariatric surgery. However, variable weight loss outcomes post-surgery remained a clinical challenge. Currently, there is no established consensus on the factors influencing weight loss failure following LSG. This study aimed to explore the association between preoperative cortisol secretion autonomy and postoperative weight loss in obese patients undergoing LSG. A cohort of 181 patients with simple obesity (BMI ≥ 28 kg/m2) who underwent LSG and were followed up for one year was analyzed. Weight loss was measured by the percentage of excess weight loss (%EWL), and cortisol secretion autonomy was evaluated using a 1 mg dexamethasone suppression test (DST). Regression models were used to analyze the correlation between preoperative 1 mg DST results and %EWL one year after laparoscopic sleeve gastrectomy (LSG). Cortisol secretion autonomy was significantly lower in the %EWL ≥ 75% group and higher in the %EWL < 75% group, showing a negative correlation with %EWL (R = -0.336, p = 0.001). Logistic regression analysis indicated that high cortisol secretion autonomy was significantly correlated with %EWL < 75% after LSG. The likelihood of %EWL being < 75% was 10.47 times greater in patients with high cortisol secretion autonomy compared to those with low cortisol secretion autonomy (odds ratio 10.472, confidence interval: 1.660-66.048, p = 0.012). Cortisol secretion autonomy emerges as an independent predictor of weight loss outcomes in Asian patients undergoing LSG. This finding suggests the potential for cortisol secretion autonomy to inform preoperative assessments and personalized treatment strategies in bariatric surgery.

Efficacy of Albizia malacophylla (A.Rich.) Walp. (Leguminosae) methanol (80%) leaf extract and solvent fractions against Plasmodium berghei-induced malaria in mice model

Ethnopharmacological relevanceNovel drugs are needed to address the issue of malarial infection resistance; natural items can be a different source of these medications. Albizia malacophylla (A. Rich.) Walp. (Leguminosae) is listed as one of the antimalarial medicinal plants in Ethiopian folk medicine. However, there are no reports regarding the biological activity or phytochemistry of the plant. Aim of the studyThus, this study aimed to evaluate the A. malacophylla crude extract and solvent fractions' in vivo antimalarial activity utilizing 4-day suppressive, preventative, and curative tests in mice infected with P. berghei. Materials and methodsThe parasite Plasmodium berghei, which causes rodent malaria, was used to infect healthy male Swiss Albino mice, weighing 23–28 g and aged 6–8 weeks. Solvent fractions such as methanol, water, and chloroform were given in addition to an 80% methanolic extract at 100, 200, and 400 mg/kg doses. A Conventional test such as parasitemia, survival time, body weight, temperature, and packed cell capacity were employed to ascertain factors such as the suppressive, curative, and preventive tests. ResultsEvery test substance dramatically reduced the number of parasites in every experiment. Crude extract (with the highest percentage suppression of 67.78%) performs better antimalarial effect than the methanol fraction, which is the most efficient solvent fraction with a percentage suppression of 55.74%. With a suppression value of 64.83% parasitemia level, the therapeutic effects of 80% methanolic crude extract were greater than its curative and preventative effects in a four-day suppressive test. The survival period (17 days) was longer with the hydroalcoholic crude extract dose of 400 mg/kg than with other doses of the materials under investigation. ConclusionsThe results of this investigation validate the antimalarial characteristics of A. malacophylla leaf extract. The crude extract prevented weight loss, a decline in temperature, and a reduction in PCV. The results demonstrate that the plant has a promising antimalarial effect against P. berghei, hence supporting the traditional use of the plant. Therefore, it could serve as a foundation for the development of new antimalarial drugs.

Low-frequency Acoustic Collimation Modulation Based on Monopole Mie Resonance Acoustic Metamaterials

Acoustic metamaterials show great flexibility in manipulating acoustic waves and exhibit important applications. However, an increasing number of applications are suitable for the low-frequency range, which makes it challenging to design acoustic metamaterials for low-frequency modulation. Here, we propose a subwavelength monopole Mie resonance acoustic metamaterial that can flexibly control the propagation route of acoustic waves. Compared to the background medium, the designed Mie unit has a higher refractive index and can achieve directional manipulation of low-frequency acoustic waves based on monopole Mie resonance. Furthermore, an array formed by multiple Mie units in a specific arrangement can achieve the acoustic collimation phenomenon. The designed monopole Mie resonance acoustic metamaterial has potential application prospects in fields such as low-frequency filtering, noise suppression, and nondestructive testing.

Frequency of low-dose dexamethasone suppression test (LDDST) response patterns and their correlation with clinicopathologic signs in dogs suspected of having Cushing's syndrome: A retrospective study

A retrospective cross-sectional study was conducted to assess the frequency of low-dose dexamethasone suppression test (LDDST) patterns in canine patients that had clinicopathologic signs consistent with Cushing's syndrome (CS). Medical records for patients of interest (N = 128) were reviewed between January 2014 and December 2020 to analyse and classify LDDST results based upon the following patterns: lack of suppression, partial suppression, complete suppression, escape, or inverse. Complete suppression, lack of suppression, partial suppression, escape, and inverse patterns were identified in 39.1%, 31.2%, 14.1%, 10.1% and 5.5% of cases respectively. LDDST results were also evaluated with respect to clinical signs, serum alkaline phosphatase (ALP) activity, urine specific gravity (USG) and adrenal ultrasonographic findings. There was no association between LDDST patterns and clinical signs (p = 0.11), increased ALP (p = 0.32), USG (p = 0.33) or adrenal ultrasonographic findings (p = 0.19). In all dogs that demonstrated complete suppression or an inverse pattern, CS was excluded by the attending clinician. The diagnosis of CS was also excluded without further exploration in 23.1%, 7.5% and 5.6% of dogs that demonstrated an escape pattern, lack of suppression and partial suppression pattern, respectively. These results suggest that the clinical significance of LDDST patterns, particularly escape and inverse patterns, are misunderstood by some clinicians, leading them to prematurely exclude the diagnosis of CS.