A family case report of parathyroid carcinoma associated with CDC73 mutation in hyperparathyroidism-jaw tumor syndrome.

Background: Hereditary primary hyperparathyroidism (PHPT) accounts for 5-10% of all PHPT cases, necessitating genetic testing for diagnosis and management. Among these, hyperparathyroidism-jaw tumor syndrome (HPT-JT) is an autosomal dominant disorder caused by CDC73 mutations with variable clinical presentations and incomplete symptoms. Case summary: The proband, diagnosed with PHPT, underwent parathyroidectomy at the age of 41 with pathological examination of parathyroid carcinoma (PC). Hereditary PHPT was initially suspected due to the early-onset PHPT and family history. Genetic testing identified a heterozygous CDC73 mutation, NM_024529.4: c. 687_688delAG (p. Arg229Serfs*37). Even in the absence of jaw tumors, the diagnosis of HPT-JT was confirmed based on the discovery of renal cysts. A secondary thyroidectomy was performed to reduce the risk of recurrence. Conclusion: Genetic testing is strongly recommended in cases of early-onset PHPT, family history, jaw tumors, renal and uterine involvement, atypical parathyroid tumors, and PC. This testing provides valuable information for personalized management, and counseling is available for affected families.

ROS­mediated autophagy through the AMPK signaling pathway protects INS­1 cells from human islet amyloid polypeptide­induced cytotoxicity.

Oligomerization of human islet amyloid polypeptide (hIAPP) is toxic and contributes to progressive reduction of ß cell mass in patients with type 2 diabetes mellitus. Autophagy is a highly conserved homeostatic mechanism in eukaryotes. Previous studies have confirmed that hIAPP can promote autophagy in ß cells, but the underlying molecular mechanism and cellular regulatory pathway of hIAPP­induced autophagy remains not fully elucidated. Accumulation of reactive oxygen species (ROS) causes hIAPP induced­ß cell death. At present, little is known about the association between hIAPP­induced oxidative stress and autophagy in ß cells. Therefore, the present study investigated the underlying molecular mechanism and regulatory pathway of hIAPP­induced autophagy. Transmission electron microscopy was used to observe the number of autophagosome in cells. Cell viability was determined by an MTT test. A 2',7'­dichlorofluorescin diacetate assay was used to measure the relative levels of reactive ROS. Western blotting was used to detect expression of adenosine monophosphate­activated protein kinase (AMPK) and autophagic markers p62 and microtubule associated protein 1 light chain 3. The results demonstrated that hIAPP induces autophagy through ROS­mediated AMPK signaling pathway in INS­1 cells. Upregulation of autophagy by AMPK activator 5­aminoimidazole­4­carboxamide1­ß­D­ribofuranoside decreased ROS and malondialdehyde generation, whereas inhibition of autophagy by 3­methyladenine and AMPK inhibitor compound C aggravated hIAPP­induced oxidative stress and toxicity in INS­1 cells. Taken together, the present study suggested that hIAPP induces autophagy via a ROS­mediated AMPK signaling pathway. Furthermore, autophagy serves as a cell­protective mechanism against hIAPP­induced toxicity and chemical promotion of autophagy through AMPK signaling pathway attenuates hIAPP induced cytotoxicity and oxidative stress in INS­1 cells.

Effect of hypercortisolism on bone mineral density and bone metabolism: A potential protective effect of adrenocorticotropic hormone in patients with Cushing's disease.

Objective To investigate the effects of Cushing's disease (CD) and adrenal-dependent Cushing's syndrome (ACS) on bone mineral density (BMD) and bone metabolism. Methods Data were retrospectively collected for 55 patients with hypercortisolism (CD, n = 34; ACS n = 21) from January 1997 to June 2014. BMD was examined in all patients, and bone turnover markers were tested in some patients. Healthy controls (n = 18) were also recruited. Results The lumbar spine and femoral neck BMD were significantly lower in the ACS and CD groups than in the control group. Lumbar BMD was significantly lower in the ACS than CD group. The collagen breakdown product (CTX) concentrations were significantly higher while the osteocalcin and procollagen type I N-terminal propeptide (PINP) concentrations were significantly lower in the ACS and CD groups than in the control group. The PINP concentration was significantly lower while the CTX concentration was significantly higher in the ACS than CD group. In the CD group only, lumbar BMD and serum adrenocorticotropic hormone had a significant positive correlation. Conclusions Bone turnover markers indicated suppressed osteoblast and enhanced osteoclast activities. PINP and CTX changes might indicate bone mass deterioration. Adrenocorticotropic hormone might be protective for lumbar BMD in patients with CD.

Analysis of Risk Factors for Hypoglycemic Coma in 194 Patients with Type 2 Diabetes.

BACKGROUND The present study was conducted to analyze possible risk factors in patients with type 2 diabetes who are in hypoglycemic coma. MATERIAL AND METHODS A total of 194 patients with type 2 diabetic hypoglycemic coma who were admitted to our hospital between January 2010 and January 2016 were included. The patients were all in coma on admission, and their blood glucose levels were lower than 2.8 mmol/L. None of the patients had type I diabetes, specific types of diabetes, or gestational diabetes. Multiple linear regression analysis was used to determine possible factors associated with hypoglycemic coma. RESULTS Among the patients, 82 were male and 112 were female (mean age, 66.88±10.62 years). In addition, 72 patients lived in urban areas and 122 lived in rural areas. Occurrence of hypoglycemic coma was correlated with difference between urban and rural residence, glycosylated hemoglobin (HbA1c) level, combined hypertension, and combined neural complications. Self-purchased drugs resulted in significantly lower blood glucose level at the onset of hypoglycemic coma than insulin, secretagogue, or non-secretagogue drugs. Blood glucose level at onset was correlated with season. Patients living in rural areas or with combined macrovascular or microvascular complications had prolonged hospital stay and poor prognosis. CONCLUSIONS Our results demonstrate that rural residence, higher HbA1c level, combined hypertension, and combined neural complications increase the incidence of hypoglycemic coma. Use of self-purchased drugs and colder seasons may result in lower blood glucose levels in patients with hypoglycemic coma.

Risk Score for Detecting Dysglycemia: A Cross-Sectional Study of a Working-Age Population in an Oil Field in China.

BACKGROUND Dysglycemia (pre-diabetes or diabetes) in young adults has increased rapidly. However, the risk scores for detecting dysglycemia in oil field staff and workers in China are limited. This study developed a risk score for the early identification of dysglycemia based on epidemiological and health examination data in an oil field working-age population with increased risk of diabetes. MATERIAL AND METHODS Multivariable logistic regression was used to develop the risk score model in a population-based, cross-sectional study. All subjects completed the questionnaires and underwent physical examination and oral glucose tolerance tests. The performance of the risk score models was evaluated using the area under the receiver operating characteristic curve (AUC). RESULTS The study population consisted of 1995 participants, 20-64 years old (49.4% males), with undiagnosed diabetes or pre-diabetes who underwent periodic health examinations from March 2014 to June 2015 in Dagang oil field, Tianjin, China. Age, sex, body mass index, history of high blood glucose, smoking, triglyceride, and fasting plasma glucose (FPG) constituted the Dagang dysglycemia risk score (Dagang DRS) model. The performance of Dagang DRS was superior to m-FINDRISC (AUC: 0.791; 95% confidence interval (CI), 0.773-0.809 vs. 0.633; 95% CI, 0.611-0.654). At the cut-off value of 5.6 mmol/L, the Dagang DRS (AUC: 0.616; 95% CI, 0.592-0.641) was better than the FPG value alone (AUC: 0.571; 95% CI, 0.546-0.596) in participants with FPG <6.1 mmol/L (n=1545, P=0.028). CONCLUSIONS Dagang DRS is a valuable tool for detecting dysglycemia, especially when FPG <6.1 mmol/L, in oil field workers in China.

Adding Prandial Insulin to Basal Insulin Plus Oral Antidiabetic Drugs in Chinese Patients with Poorly Controlled Type 2 Diabetes Mellitus: An Open-Label, Single-Arm Study.

INTRODUCTION: There is relatively little data from China on the efficacy and safety of adding prandial insulin to basal insulin plus oral antidiabetic drugs (OADs) in people with poorly controlled type 2 diabetes mellitus (T2DM). This study assessed the efficacy and safety of basal insulin dose optimization followed by the addition of prandial insulin in Chinese people with T2DM achieving suboptimal glycemic control with basal insulin and OADs. METHODS: In this open-label, single-arm study, adults with T2DM receiving basal insulin plus OADs underwent insulin dose optimization for 12 weeks. At week 12, subjects who achieved fasting blood glucose (FBG) ≤6.5 mmol/L but not HbA1c ≤7% added one injection of prandial insulin at the main meal for an additional 24 weeks. Endpoints included mean HbA1c, the achievement rate of HbA1c ≤7%, hypoglycemia, and other adverse events (AEs). RESULTS: A total of 120 subjects underwent basal insulin optimization; At week 12, 110 study subjects achieved FBG ≤6.5 mmol/L, of whom 66 did not achieve HbA1c ≤7% and therefore initiated prandial insulin. Three patients discontinued prandial insulin due to dissatisfaction with treatment outcome (n = 1), accidental injury (n = 1), or personal reasons (n = 1). After 24 weeks of basal-plus treatment, mean HbA1c significantly decreased (8.06% to 7.17%; p < 0.001), 65.1% of subjects achieved HbA1c ≤7%, there was no change in FBG (6.23-6.20 mmol/L; p = 0.118), and mean post-prandial blood glucose decreased (13.17-10.14 mmol/L; p < 0.001). During basal-plus treatment, three individuals experienced hypoglycemia, and no significant change in the mean subject weight was observed (73.2 vs. 73.3 kg; p = 0.379). CONCLUSIONS: In people with T2DM who are achieving suboptimal glycemic control with basal insulin plus OADs, basal insulin dose optimization followed by the addition of prandial insulin improves glycemic control, is well tolerated, and is associated with a low incidence of hypoglycemia.

Silymarin improved diet-induced liver damage and insulin resistance by decreasing inflammation in mice.

CONTEXT: Silymarin is the main flavonoid extracted from milk thistle, which has been used to treat liver diseases. OBJECTIVE: The in vivo effect of silymarin on HFD-induced insulin resistance and fatty liver in mice was studied. MATERIALS AND METHODS: Male C57BL/6 mice were fed with high-fat diet (HFD) to induce obesity and insulin resistance and treated with 30, 60 mg/kg silymarin for 18 days. Food intake, body weight and the content/histology of epididymal fat and liver tissue were examined; the content of lipids, AST, ALT and inflammatory cytokines in serum were estimated. RESULTS: Administration of silymarin caused bodyweight loss in diet induced obesity (DIO) mice (HFD group: 47.7 g, 60 mg/kg group: 43.0 g) while the food intake remain unchanged. Silymarin (60 mg/kg) significantly reduced the epididymal fat mass (from 1.75 g to 1.12 g). Elevated plasma lipids (TC 6.1 mM, TG 1.3 mM, LDL 1.2 mM) in DIO mice were all suppressed by silymarin (TC 4.5 mM, TG 0.89 mM, LDL 0.9 mM), as well as insulin (5.1 ng/ml in HFD group to 2.0 ng/ml (60 mg/kg silymarin). Examination of cytokine levels (TNF-α, IL-1ß and IL-6) in each group proved that silymarin treatment significantly decreased inflammation in DIO mice. Finally, silymarin effectively protected liver from HFD-induced injury as evidenced by decreasing histological damage and reducing ALT and AST levels, as follows: ALT; 47.4 U/L in HFD group to 28.4 U/L (60 mg/kg silymarin); AST; 150.1 U/L in HFD group to 88.1 U/L (60 mg/kg silymarin) in serum. DISCUSSION AND CONCLUSION: Our results suggested that silymarin-induced alleviation of inflammatory response could be a mechanism responsible for its benefits against liver damage and insulin resistance.

[The effects and mechanism of islet amyloid polypeptide on insulin secretion in INS-1 cells stimulated by glibenclamide].

OBJECTIVE: To observe the effects, and study the mechanism of islet amyloid polypeptide (IAPP) on insulin secretion in INS-1 cells stimulated by glibenclamide. METHODS: Whole cell patch clamp technique was employed to study the influences of short exposure to IAPP on electrophysiological characteristics of ATP-sensitive K+ channel (K(ATP) channel) upon sulfonylurea stimulation. Intracellular free calcium changes in this process was observed by laser scanning confocal microscope. Insulin was measured by enzyme-linked immunoassay. RESULTS: (1) Insulin secretion stimulated by 1 micomol/L glibenclamide was significantly decreased from (11.43 +/- 1.22) microg/L to (9.40 +/- 0.87) microg/L and to (7.11 +/- 1.85) microg/L after 1 micromol/L and 10 micromol/L IAPP incubation, respectively. (2) Glibenclamide-stimulated calcium influx was dose dependently inhibited by IAPP from 1 micromol/L to 10 micromol/L, with the AUC of fluorescence intensity-time reduced from 427.78 +/- 2.32 to 380.59 +/- 1.49, and to 246.53 +/- 8.41, respectively. (3) Compared with that in control cells (14.59 +/- 0.69) mV, the half activation voltage of KA, channel in response to glibenclamide was significantly increased to (28.75 +/- 0.77) mV and to (46.95 +/- 1.81) mV in cells pretreated with 1 micromol/L and 10 micromol/L IAPP, implicating an inhibitory effect of IAPP on activation of K(ATP) channel. CONCLUSION: Short-term exposure to high concentration of IAPP inhibited glibenclamide-induced closure of K(ATP) channels and decreased calcium influx, which may ultimately lead to the reduction of insulin secretion in INS-1 cells

[The mechanism of inhibition of the increase in intracellular calcium concentration by the islet amyloid polypeptide in high glucose-stimulated INS-1 cells].

OBJECTIVE: To explore the potential mechanism of the inhibition of increased intracellular free calcium concentration ([Ca²âº]i) by short-term exposure to the islet amyloid polypeptide (IAPP) in high glucose-stimulated pancreatic ß cells. METHODS: The pancreatic ß cells were loaded with calcium sensitive fluorescent indicator Fluo-4/AM. The fluorescence intensity, which represented [Ca²âº]i, was measured in time by laser scanning confocal microscope before and after stimulated by glucose, KCl, caffeine and carbachol. RESULT: The fluorescence intensity F/F0 in INS-1 cells, increased to about 2 folds after glucose stimulation. After the exposure to the IAPP with different concentration, the fluorescence intensity F/F0 was decreased slightly in the pretreated cells by 16.7 mmol/L glucose with 0.5 µmol/L IAPP. However, after the pretreatment of IAPP with the concentration of 1.0, 5.0, 10.0 µmol/L, the fluorescence intensity F/F0 showed a dose-dependent decrease with statistical difference. The fluorescence intensity F/F0 in the cells increased rapidly in a peak pattern after the stimulation of 30 mmol/L KCl. But with the pretreatment of 10.0 µmol/L IAPP, the fluorescence intensity F/F0 decreased with statistical difference. With 20 mmol/L caffeine and 100 µmol/L carbachol which stimulated Ca²âº release respectively from internal ryanodine receptor (RYR) and inositol triphosphate (IP3) Ca²âº storage, the fluorescence intensity F/F0 curve presented a peak pattern. After 10 µmol/L IAPP pretreatment, the fluorescence intensity F/F0 showed no statistical difference from the control group. CONCLUSIONS: The short-term effect of IAPP on pancreatic ß cells has no influence on the caffeine and carbachol stimulated Ca²âº release from endoplasmic reticulum RYR and IP3 Ca²âº storage. The inhibition of calcium increase in INS-1 cells by short-term exposure to IAPP may mainly via inhibiting the voltage-gated L-calcium channels with intact release capacity of Ca²âº storage.

[Construction of human phage antibody library and screening for human monoclonal antibodies of amylin].

AIM: To screen monoclonal antibodies to amylin from a constructed human phage antibody library and identify their antigenic specificity and combining activities. METHODS: The heavy chain Fd fragment and light chain of human immunoglobulin genes were amplified from peripheral blood lymphocytes of healthy donors using RT-PCR, and then inserted into phagemid pComb3XSS to generate a human phage antibody library. The insertion of light chain or heavy chain Fd genes were identified by PCR after the digestion of Sac I, Xba I, Xho Iand Spe I. One of positive clones was analyzed by DNA sequencing. The specific anti-amylin clones were screened from antibody library against human amylin antigens and then the positive clones were determined by Phage-ELISA analysis. RESULTS: A Fab phage antibody library with 0.8×10(8); members was constructed with the efficacy of about 70%. DNA sequence analysis indicated V(H); gene belonged to V(H);3 gene family and V(λ); gene belonged to the V(λ); gene family. Using human amylin as panning antigen, specific anti-amylin Fab antibodies were enriched by screening the library for three times. Phage-ELISA assay showed the positive clones had very good specificity to amylin antigen. CONCLUSION: The successful construction of a phage antibody library and the identification of anti-amylin Fab antibodies provide a basis for further study and preparation of human anti-amylin antibodies.

Islet amyloid polypeptide acts on glucose- stimulated beta cells to reduce voltage-gated calcium channel activation, intracellular Ca(2+) concentration, and insulin secretion.

OBJECTIVE: the mechanism by which islet amyloid polypeptide (IAPP) inhibits insulin release is unclear. We hypothesized that reduced voltage-gated calcium channel activity and intracellular Ca(2+) concentration might contribute to IAPP-mediated inhibition of glucose-stimulated insulin release. RESEARCH DESIGN AND METHODS: rat islet beta cells were cultured and treated with various extracellular concentrations of IAPP, and insulin release was stimulated via addition of glucose. Activation voltage, high voltage-gated calcium channel currents, intracellular Ca(2+) concentration, and insulin secretion were detected by patch clamp electrophysiology, fluorescent digital imaging microscopy using calcium-sensitive fluorescent dye, and radioimmunoassay, respectively. RESULTS: high voltage-gated calcium channel currents, intracellular Ca(2+) concentration, and insulin secretion increased in a dose-dependent manner when rat beta cells were exposed to glucose. After short-term IAPP treatment (5 or 10 µM), these parameters decreased significantly in glucose-stimulated beta cells. However, no significant changes were observed with lower doses of IAPP. CONCLUSIONS: glucose-stimulated islet beta-cell high voltage-gated calcium channels were activated in conjunction with insulin secretion, while high extracellular concentrations of IAPP inhibited beta-cell high voltage-gated calcium channel activation and insulin secretion in a dose-dependent manner.

[The effects of amylin on the islet beta-cells voltage-gated L-calcium channels in rats].

OBJECTIVE: To observe the effect of amylin on the islet beta-cells voltage-gated L-calcium channels in rats. METHOD: Patch clamp technique was employed in the observation of the features and changes of electric current of islet beta-cells voltage-gated L-calcium channels before and after using amylin. RESULTS: In the glucose environment of 5.5 mmol/L, the electric current of rat islet beta-cells voltage-gated L-calcium channels was activated at -40 mV and reached the peak at about +20 mV, with a peak value of about -120 pA and the insulin secretion level was (0.76 +/- 0.12) microg/L. Under the stimulation of glucose of 16.7 mmol/L, the peak current voltage moved to the left and increased up to - 140 pA and the level of insulin secretion measured (1.78 +/- 0.13) microg/L. Hatch islet beta-cells in amylin at the concentrations of 0.5, 1.0, 5.0 and 10.0 micromol/L, respectively. It was observed that in the 0.5 micromol/L and 1.0 micromol/L groups, there was no remarkable change in the peak potential activation voltage, current, and insulin secretion volume in comparison with the control group. However, in the environment of 5.5 mmol/L glucose, the increase of activation voltage of the 5.0 and 10.0 micromol/L groups was - 30 mV, with the peak current reduced to approximately -80 pA and -60 pA and the insulin secretion decreased to (0.49 +/- 0.11) microg/L and (0.36 +/- 0.12) microg/L respectively. Under the concentration of 16.7 mmol/L glucose, the activation voltage increased from -40 mV up to -30 mV and the peak current reduced to -80 pA and -40 pA. In the meantime, the insulin secretion decreased respectively to (1.20 +/- 0.13) microg/L and (0.89 +/- 0.14) microg/L, which is of significance. CONCLUSION: The secretion of insulin is synchronized with the opening of the islet beta-cells voltage-gated L-calcium channels at the stimulation of glucose. The amylin inhibition of the insulin secretion is also synchronized with the opening of islet beta-cells voltage-gated L-calcium channels and it's in a positive concentration-dependent manner.

[The effect of Ca2+ channel blocker on insulin secretion in rat pancreatic islet cells].

OBJECTIVE: To study the effect and mechanism of Ca2+ channel blocker on the insulin secretion in islet beta cells of rats. METHODS: The cells were divided into two groups: the low sugar concentration and high sugar concentration groups. These cells were examined with radioimmunoassay and fluorescence method and the effects of nifedipine (NIF), verapamil (VER), and diltiazem (DIL) on the contents of Ca2+ in the islet cells and the secretion volume of insulin at different concentrations were observed. RESULTS: In the low sugar concentration group, NIF, VER and DIL at concentration of 25, 50 and 100 microg/L respectively showed no effect on the contents of Ca2+ in islet cells and the insulin secretion (no statistical significance, P > 0.05). In the high sugar concentration group, these drugs had no inhibitory effect on insulin secretion at concentration of 25 microg/L. However, there was remarkable reduction in Ca2+ contents and insulin secretion when NIF was at the concentration of 50 and 100 microg/L, showing a relationship with dosage (P > 0.05, P > 0.01). VER, when given at 50 microg/L, showed a tendency of reduction in insulin secretion and there was a remarkable reduction at a dosage of 100 microg/L as compared with the control group (P > 0.05). When DIL was given at 100 microg/L, there was a noticeable difference in reduction of insulin secretion as compared with the control group (P > 0.05). CONCLUSION: High dosage of NIF, VER and DIL has an inhibitory effect on the entrance of extracellular Ca2+ into islet cells and thus reduces insulin secretion.