Perception of competence achievement and students' satisfaction using virtual laboratories in Medical Biochemistry course: Lessons from the COVID-19 pandemic.

After the COVID-19 pandemic, there was an increasing demand for remote learning and an expansion in the substitution of traditional practical sessions with lab-based virtual tools. This study aimed to assess the effectiveness of virtual labs in practicing biochemical experiments and to examine the student's feedback regarding this tool. Virtual and traditional labs training were compared in teaching qualitative analysis of proteins and carbohydrates experiments for first-year medical students. Students' achievements were assessed, and their satisfaction regarding virtual labs was estimated using a questionnaire. A total of 633 students were enrolled in the study. There was a significant increase in the average scores of students performing the virtual lab of protein analysis compared with those trained in a real lab and those who watched videos explaining the experiment (p < 0.001). The opposite was noticed in the qualitative analysis of carbohydrates with significantly high grades of students trained conventionally compared with those who practiced with virtual labs (p < 0.001). Students' feedback rates on the virtual labs were high (>70% satisfaction rate). Most students believed virtual labs were supported with a clear explanation, yet they thought it did not give a realistic experience. Students accepted virtual labs, but they still prefer using them as preparatory to classic labs. In conclusion, virtual labs can offer good laboratory practice in the Medical Biochemistry course. Their impact on students' learning might be increased if selected cautiously and implemented properly in the curriculum.

Omega-3 Polyunsaturated Fatty Acids Provoke Apoptosis in Hepatocellular Carcinoma through Knocking Down the STAT3 Activated Signaling Pathway: In Vivo and In Vitro Study.

Hepatocellular carcinoma (HCC) is a common type of liver cancer and is a leading cause of death worldwide. Signal transducer and activator of transcription 3 (STAT3) is involved in HCC progression, migration, and suppression of apoptosis. This study investigates the apoptotic effect of the dietary antioxidant (n-3 PUFAs) on HepG2 cells and analyzes the underlying molecular mechanisms of this effect both in vivo and in vitro. In vivo study: Seventy-five adult male albino rats were divided into three groups (n = 25): Group I (control): 0.9% normal saline, intraperitoneal. Group II: N-Nitrosodiethylamine (200 mg/kg b.wt) intraperitoneal, followed by phenobarbital 0.05% in drinking water. Group III: as group II followed by n-3 PUFAs intubation (400 mg/kg/day). In vivo study: liver specimens for biochemical, histopathological, and immunohistochemical examination. In vitro study: MTT assay, cell morphology, PCR, Western blot, and immunohistochemical analysis. n-3 PUFAs significantly improved the histopathologic features of HCC and decreased the expression of anti-apoptotic proteins. Further, HepG2 cells proliferation was suppressed through inhibition of the STAT3 signaling pathway, cyclin D1, and Bcl-2 activity. Here we report that n-3 PUFAs may be an ideal cancer chemo-preventive candidate by targeting STAT3 signaling, which is involved in cell proliferation and apoptosis.

Serum Follistatin Is Increased in Thyroid Cancer and Is Associated With Adverse Tumor Characteristics in Humans.

CONTEXT: Obesity and classical growth factors are associated with thyroid cancer (TC). However, less is known regarding novel hormones such as follistatins and activins. We hypothesized that serum follistatin but not activins would be increased in TC. OBJECTIVE: This work aimed to assess circulating levels of follistatins, activins, and growth factors in patients with a history of TC vs patients with nonmalignant thyroid diseases. METHODS: A hospital-based, unmatched case-control study was conducted with 170 thyroidectomized patients due to well-differentiated TC and 106 thyroidectomized patients without history of malignancy. Anthropometric, biochemical, and histological parameters were recorded. Serum samples were collected in the steady state 45 days after surgery. Multivariate models were used to adjust for baseline differences of the unmatched variables. Serum levels of follistatin (FST), follistatin like-3, activin A, activin B, bioactive insulin-like growth factor-1, and stanniocalcin-2 were assayed with novel, highly specific ELISA kits. RESULTS: In unmatched univariate models, TC patients had higher FST serum levels compared to cancer-free individuals, independently of histological subtype. In multivariate models adjusting for covariates, individuals in the highest tertile of FST levels were associated with an increased risk for the presence of any type of TC or specific histological subtypes, including papillary, follicular and Hürthle-cell carcinoma, and medullary TC. Higher postoperative FST concentrations were found in patients with vascular invasion and distant metastases and associated with TNM staging at diagnosis. CONCLUSION: FST serum levels are increased in TC patients and correlate with advanced tumor aggressiveness. Future longitudinal studies are needed to confirm and extend our observations.

Metabolic regulation of activins in healthy individuals and in obese patients undergoing bariatric surgery.

OBJECTIVE: Follistatin binds and inactivates activins, which are potent inhibitors of muscle growth and metabolism and are currently being developed for the treatment of obesity and type 2 diabetes (T2D). We have recently reported that follistatin is regulated by glucose (and not lipids) and can prospectively predict the metabolic improvements observed after bariatric surgery. We utilized novel assays herein to investigate whether activins are regulated by glucose or lipids, whether their circulating levels change after bariatric surgery and whether these changes are predictors of metabolic outcomes up to 12 months later. DESIGN AND METHODS: Activin A, B, AB and their ratios to follistatin were measured in (a) healthy humans (n = 32) undergoing oral or intravenous lipid or glucose intake over 6 h, (b) morbidly obese individuals with or without type 2 diabetes undergoing three different types of bariatric surgery (gastric banding, Roux-en-Y bypass or sleeve gastrectomy) in two clinical studies (n = 14 for the first and n = 27 for the second study). RESULTS: Glucose intake downregulates circulating activin A, B and AB, indicating the presence of a feedback loop. Activin A decreases (~30%), activin AB increases (~25%) and activin B does not change after bariatric surgery. The changes in activin AB and its ratio to follistatin 3 months after bariatric surgery can predict the BMI reduction and the improvement in insulin and HOMA-IR observed 6 months postoperatively. CONCLUSION: Activins are implicated in glucose regulation in humans as part of a feedback loop with glucose or insulin and predict metabolic outcomes prospectively after bariatric surgery.

Targeted Analysis of Three Hormonal Systems Identifies Molecules Associated with the Presence and Severity of NAFLD.

AIMS: To investigate circulating levels and liver gene expression of 3 hormonal pathways associated with obesity, insulin resistance, and inflammation to identify leads towards potential diagnostic markers and therapeutic targets in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: We compared circulating levels of (1) proglucagon-derived hormones (glucagon-like peptide [GLP]-1, GLP-2, glicentin, oxyntomodulin, glucagon, major proglucagon fragment [MPGF]), (2) follistatins-activins (follistatin-like [FSTL]3, activin B), (3) IGF axis (insulin-like growth factor [IGF]-1, total and intact IGF binding protein [IGFBP]-3 and IGFBP-4, and pregnancy-associated plasma protein [PAPP]-A) in 2 studies: (1) 18 individuals with early stage NAFLD versus 14 controls (study 1; early NAFLD study) and in (2) 31 individuals with biopsy proven NAFLD (15 with simple steatosis [SS] and 16 with nonalcoholic steatohepatitis [NASH]), vs 50 controls (24 lean and 26 obese) (study 2). Liver gene expression was assessed in 22 subjects (12 controls, 5 NASH, 5 NASH-related cirrhosis). RESULTS: Patients in early stages of NAFLD demonstrate higher fasting MPGF and lower incremental increase of glicentin during oral glucose tolerance test than controls. In more advanced stages, FSTL3 levels are higher in NASH than simple steatosis and, within NAFLD patients, in those with more severe lobular and portal inflammation. The IGF-1/intact IGFBP-3 ratio is lower in patients with liver fibrosis. Genes encoding follistatin, activin A, activin B, and the IGF-1 receptor are higher in NASH. CONCLUSION: MPGF and glicentin may be involved in early stages of NAFLD, whereas FSTL3 and IGF-1/intact IGFBP3 in the progression to NASH and liver fibrosis respectively, suggesting potential as diagnostic markers or therapeutic targets.

Circulating levels of gastrointestinal hormones in response to the most common types of bariatric surgery and predictive value for weight loss over one year: Evidence from two independent trials.

AIMS: Bariatric surgery leads to profound and sustainable weight loss. Gastrointestinal hormones are involved in energy and glucose homeostasis, thus postoperative changes of their circulating levels may be mediating future weight loss. To investigate how the circulating concentrations of gastrointestinal hormones change in response to the most common types of bariatric operation and whether these changes can predict future weight loss. MATERIALS AND METHODS: We measured circulating GLP-1, GLP-2, oxyntomodulin, glicentin, glucagon, major proglucagon fragment (MPGF), ghrelin, GIP, PYY after overnight fasting and/or after a mixed meal test (MMT) in: a) 14 subjects that have undergone either an adjustable gastric banding [AGB] (n = 9) or a Roux-en-Y bypass (RYGB) (n = 5) (Pilot study 1), b) 28 subjects that have undergone either a vertical sleeve gastrectomy (n = 17) or a RYGB (n = 11) before and three, six and twelve months after surgery. RESULTS: In addition to the expected associations with GLP-1, the most robust increases were observed in postprandial levels of oxyntomodulin and glicentin three months after VSG or RYGB (but not after AGB) and are associated with degree of weight loss. Oxyntomodulin and glicentin levels at the third and sixth month postoperative visit are positively associated with feeling of satiety which may be underlying the observed associations with future weight loss. CONCLUSION: Beyond GLP-1, early postprandial changes in circulating oxyntomodulin and glicentin are predictors of weight loss after bariatric surgery, possibly through regulation of satiety. Further studies should focus on underlying mechanisms, and their potential as attractive therapeutic tools against obesity and related comorbidities.

Follistatins in glucose regulation in healthy and obese individuals.

AIMS: It has been suggested recently that follistatin (FST) and its homologous protein, follistatin-like 3 (FSTL3), may be a therapeutic target in the treatment of type 2 diabetes because of their glucose-regulatory effects in rodents. MATERIALS AND METHODS: We investigated this hypothesis in humans by studying the physiology of a possible glycaemia-follistatin feedback loop, that is, whether glucose, but not lipid intake (oral or intravenous), can regulate circulating FST and FSTL3 in healthy humans (n = 32), whether the levels of follistatins change in response to various types of bariatric operation in morbidly obese individuals, with or without type 2 diabetes (n = 41), and whether such changes are associated prospectively with improvement of glucose homeostasis/insulin sensitivity. RESULTS: In healthy individuals, circulating FST decreases after intravenous or oral glucose intake compared to controls, indicating the presence of a negative feedback mechanism. In morbid obesity, insulin resistance, glycaemia, circulating FST and FSTL3 are all reduced (by 22%-33%) after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy. Importantly, the changes in circulating FST 3 months after bariatric surgery are associated prospectively with the changes in glucose, insulin, HOMA-IR and HbA1c observed 6 months postoperatively in individuals with and without type 2 diabetes. CONCLUSIONS: Our findings provide evidence of an important role of FST in glucose homeostasis in healthy individuals as well as in severely obese individuals with insulin resistance and type 2 diabetes. Our data extend recent results from animal studies to humans and support the need for further evaluation of FST inactivation strategies for targeting hyperglycaemia and insulin resistance.

Physiology of Activins/Follistatins: Associations With Metabolic and Anthropometric Variables and Response to Exercise.

Context: Clinical trials are evaluating the efficacy of inhibitors of the myostatin pathway in neuromuscular and metabolic diseases. Activins and follistatins are major regulators of the myostatin pathway, but their physiology in relation to metabolic and anthropometric variables and in response to exercise remains to be fully elucidated in humans. Objective: We investigated whether concentrations of circulating activin A, activin B, follistatin, and follistatin-like 3 (FSTL3) are associated with anthropometric and metabolic variables and whether they are affected by exercise. Design: Activin A, activin B, follistatin, and FSTL3 were measured in (1) 80 subjects divided according to age (young vs old) and fitness status (active vs sedentary) before and after exercise at 70% maximal oxygen consumption (VO2max), followed by 90% of VO2max until exhaustion; and (2) 23 subjects [9 healthy and 14 with metabolic syndrome (MetS)] who completed four sessions: no exercise, high-intensity interval exercise, continuous moderate-intensity exercise, and resistance exercise for up to 45 minutes. Results: At baseline, follistatin and FSTL3 concentrations were positively associated with age, fat percentage, and body mass index (P < 0.001). Follistatin was positively associated with serum cholesterol (P = 0.005), low-density lipoprotein cholesterol (P = 0.01), triglycerides (P = 0.033), and blood pressure (P = 0.019), whereas activin A and activin B were higher in physically active participants (P = 0.056 and 0.029, respectively). All exercise types increased the levels of all hormones ∼10% to 21% (P = 0.034 for activin B, P < 0.001 for the others) independent of the presence of MetS. Conclusion: Concentrations of circulating activins and follistatins are associated with metabolic parameters and increase after 45 minutes of exercise.

Regulation of the activins-follistatins-inhibins axis by energy status: Impact on reproductive function.

BACKGROUND: We have previously demonstrated that the adipose tissue derived hormone leptin controls reproductive function by regulating the hypothalamic-pituitary-gonadal axis in response to energy deficiency. Here, we evaluate the activins-follistatins-inhibins (AFI) axis during acute (short-term fasting in healthy people) and chronic energy deficiency (women with hypothalamic amenorrhea due to strenuous exercise [HA]) and investigate their relation to leptin and reproductive function in healthy subjects and subjects with HA. METHODS: The AFI axis was investigated in: a) A double-blinded study in healthy subjects having three randomly assigned admissions, each time for four days: in the isocaloric fed state, complete fasting with placebo treatment, complete fasting with leptin replacement, b) A case-control study comparing women with HA vs healthy controls, c) An open-label interventional study investigating leptin treatment in women with HA over a period of up to three months, d) A randomized interventional trial investigating leptin treatment vs placebo in women with HA for nine months. RESULTS: The circulating levels of activin A, activin B, follistatin and follistatin-like 3 change robustly in response to acute and chronic energy deficiency. Leptin replacement in acute energy deprivation does not affect the levels of these hormones suggesting an independent regulation by these two hormonal pathways. In chronic energy deficiency, leptin replacement restores only activin B levels, which are in turn associated with an increase in the number of dominant follicles. CONCLUSIONS: We demonstrate for the first time that the AFI axis is affected both by acute and chronic energy deficiency. Partial restoration of a component of the axis, i.e. activin B only, through leptin replacement is associated with improved reproductive function in women with HA.

Obesity as a Disease.

Obesity is a complex disease with many causal factors, associated with multiple comorbidities that contribute to significant morbidity and mortality. It is a highly prevalent disease that poses an enormous health and economic burden to society. This article reviews the mechanisms of obesity and its related comorbidities.

Erythropoietin protects against doxorubicin-induced heart failure.

The hormone erythropoietin (EPO) has been demonstrated to have cardioprotective properties. The present study investigates the role of EPO to prevent heart failure following cancer treatment with doxorubicin [adriamycin (AD)]. Male Wistar rats (150 ± 10 g) were treated with saline (vehicle control group); with EPO, subcutaneously at 1,000 IU/kg body wt, three times per week for 4 wk (EPO group); with adriamycin, intraperitoneally at 2.5 mg/kg body wt, three times per week for 2 wk (AD group); and with adriamycin and EPO (EPO-AD group). Echocardiographic measurements showed that EPO-AD treatment prevented the AD-induced decline in cardiac function. Each of the hearts was then exposed to ischemia and reperfusion during Langendorff perfusion. The percentage of recovery after ischemia-reperfusion was significantly greater in EPO-AD than the AD-treated group for left ventricular developed pressure, maximal increase in pressure, and rate pressure product. The level of oxidative stress was significantly higher in AD (5 µM for 24 h)-exposed isolated cardiomyocytes; EPO (5 U/ml for 48 h) treatment prevented this. EPO treatment also decreased AD-induced cardiomyocyte apoptosis, which was associated with the decrease in the Bax-to-Bcl2 ratio and caspase-3 activation. Immunostaining of myocardial tissue for CD31 showed a significant decrease in the number of capillaries in AD-treated animals. EPO-AD treatment restored the number of capillaries. In conclusion, EPO treatment effectively prevented AD-induced heart failure. The protective effect of EPO was associated with a decreased level of oxidative stress and apoptosis in cardiomyocytes as well as improved myocardial angiogenesis.