Drug-induced diabetes

Intra-gastrically administration of Stevia and particularly Nano-Stevia reversed the hyperglycemia, anxiety, and memory impairment in streptozotocin-induced diabetic rats

Type II diabetes mellitus is a group of metabolic disorders considered chronic hyperglycemia resulting from deficits in insulin secretion or insulin function. This disease usually links with various psychological problems such as anxiety and cognitive dysfunctions. Stevia (Stevia rebaudiana Bertoni) is a natural and healthy substitute sweetener for sugar and artificial sweeteners. It has become essential for human diets and food manufacturers. The aim of this research was to investigate the effects of Stevia and Nano-stevia on the regulation of anxiety and memory processes in male diabetic rats. The elevated plus-maze (EPM) test-retest procedure was used to assess anxiety and memory in male diabetic rats. The findings exhibited that induction of diabetes caused a distorted cellular arrangement in the liver tissue of male rats. On the other hand, intra-gastrically administration of Stevia (1 ml/kg) and nano-Stevia (1 ml/kg) indicated a normal appearance in the liver tissue of male diabetic rats. Moreover, induction of diabetes caused the augmentation of blood glucose, reduction in time spent in%open-arm time (%OAT) on the test day, and enhancement of%OAT on the retest day. Therefore, induction of diabetes in rats produced hyperglycemia, anxiogenic effect, and memory impairment and these responses were reversed by drug treatment. Furthermore, intra-gastrically application of Stevia (1 ml/kg) and nano-Stevia (1 ml/kg) reversed the hyperglycemia, anxiogenic effect, and memory impairment in male diabetic rats. Interestingly, Nano-Stevia exhibited the highest significant response rather than Stevia. In conclusion, the results of this research suggested the beneficial properties of Stevia and particularly Nano-Stevia on inducing anti-diabetic effects, anxiolytic behavior, as well as memory improvement in male diabetic rats.

Induction of anxiolytic, antidepressant and analgesic effects by Shiff base of (E)-3-(1H-imidazol-4-yl)-2-((2-oxoindolin-3-ylidene)amino)propanoic acid derivatives in diabetic rats

Diabetes mellitus is a metabolic disorder with several psychological problems such as anxiety, depression, and pain sense. This study aimed to evaluate the effect of Schiff base on the modulation of anxiety, depression, and pain behaviors in diabetic rats. Anxiety, depression, and pain behaviors were evaluated by elevated plus maze (EPM), forced swim test (FST), and hot-plate test, respectively. The results indicated that induction of diabetes decreased time spent in open arms (OAT) in the EPM whereas injection of insulin (1 ml/kg), glibenclamide (5 mg/kg), and Schiff base II (100 mg/kg) increased OAT in the EPM. So, induction of diabetes in rats caused an anxiogenic effect that this effect reversed by drug treatment. Interestingly, co-treatment of insulin and glibenclamide along with an ineffective dose of Schiff base II potentiated anxiolytic behavior in diabetic rats. Furthermore, induction of diabetes increased immobility time in the FST but administration of insulin (1 ml/kg), glibenclamide (5 mg/kg), and Schiff base II (25, 50, and 100 mg/kg) decreased immobility time in the FST which indicated depressant effect in diabetic rats without drug-treatment and antidepressant effect in diabetic rats with drug-treatment. Additionally, induction of diabetes decreased latency in the hot-plate test while injection of insulin (1 ml/kg), glibenclamide (5 mg/kg), Schiff base I (50 mg/kg), and Schiff base II (25, 50, and 100 mg/kg) enhanced latency in the hot-plate test which revealed hyperalgesic effect in diabetic rats without drug-treatment and analgesic effect in diabetic rats with drug-treatment. Consequently, induction of diabetes-induced anxiogenic, depressant, and hyperalgesia effects that administration of insulin, glibenclamide, Schiff bases I, and II reversed these effects.

Drug-Induced Hyperglycaemia and Diabetes

Drug-induced hyperglycaemia and diabetes is a global issue. It may be a serious problem, as it increases the risk of microvascular and macrovascular complications, infections, metabolic coma and even death. Drugs may induce hyperglycaemia through a variety of mechanisms, including alterations in insulin secretion and sensitivity, direct cytotoxic effects on pancreatic cells and increases in glucose production. Antihypertensive drugs are not equally implicated in increasing serum glucose levels. Glycaemic adverse events occur more frequently with thiazide diuretics and with certain beta-blocking agents than with calcium-channel blockers and inhibitors of the renin-angiotensin system. Lipid-modifying agents may also induce hyperglycaemia, and the diabetogenic effect seems to differ between the different types and daily doses of statins. Nicotinic acid may also alter glycaemic control. Among the anti-infectives, severe life-threatening events have been reported with fluoroquinolones, especially when high doses are used. Protease inhibitors and, to a lesser extent, nucleoside reverse transcriptase inhibitors have been reported to induce alterations in glucose metabolism. Pentamidine-induced hyperglycaemia seems to be related to direct dysfunction in pancreatic cells. Phenytoin and valproic acid may also induce hyperglycaemia. The mechanisms of second-generation antipsychotic-associated hyperglycaemia, diabetes mellitus and ketoacidosis are complex and are mainly due to insulin resistance. Antidepressant agents with high daily doses seem to be more frequently associated with an increased risk of diabetes. Ketoacidosis may occur in patients receiving beta-adrenergic stimulants, and theophylline may also induce hyperglycaemia. Steroid diabetes is more frequently associated with high doses of glucocorticoids. Some chemotherapeutic agents carry a higher risk of hyperglycaemia, and calcineurin inhibitor-induced hyperglycaemia is mainly due to a decrease in insulin secretion. Hyperglycaemia has been associated with oral contraceptives containing high doses of oestrogen. Growth hormone therapy and somatostatin analogues may also induce hyperglycaemia. Clinicians should be aware of medications that may alter glycaemia. Efforts should be made to identify and closely monitor patients receiving drugs that are known to induce hyperglycaemia.

Quantifying the effects of diuretics and β-adrenoceptor blockers on glycaemic control in diabetes mellitus - a systematic review and meta-analysis

AIMS

Although there are reports that β-adrenoceptor antagonists (beta-blockers) and diuretics can affect glycaemic control in people with diabetes mellitus, there is no clear information on how blood glucose concentrations may change and by how much. We report results from a systematic review to quantify the effects of these antihypertensive drugs on glycaemic control in adults with established diabetes.

METHODS

We systematically reviewed the literature to identify randomized controlled trials in which glycaemic control was studied in adults with diabetes taking either beta-blockers or diuretics. We combined data on HbA1c and fasting blood glucose using fixed effects meta-analysis.

RESULTS

From 3864 papers retrieved, we found 10 studies of beta-blockers and 12 studies of diuretics to include in the meta-analysis. One study included both comparisons, totalling 21 included reports. Beta-blockers increased fasting blood glucose concentrations by 0.64 mmol l(-1) (95% CI 0.24, 1.03) and diuretics by 0.77 mmol l(-1) (95% CI 0.14, 1.39) compared with placebo. Effect sizes were largest in trials of non-selective beta-blockers (1.33, 95% CI 0.72, 1.95) and thiazide diuretics (1.69, 95% CI 0.60, 2.69). Beta-blockers increased HbA1c concentrations by 0.75% (95% CI 0.30, 1.20) and diuretics by 0.24% (95% CI -0.17, 0.65) compared with placebo. There was no significant difference in the number of hypoglycaemic events between beta-blockers and placebo in three trials.

CONCLUSIONS

Randomized trials suggest that thiazide diuretics and non-selective beta-blockers increase fasting blood glucose and HbA1c concentrations in patients with diabetes by moderate amounts. These data will inform prescribing and monitoring of beta-blockers and diuretics in patients with diabetes.

Mechanistic Evidence of Viscum schimperi (Viscaceae) Antihyperglycemic Activity: From a Bioactivity-guided Approach to Comprehensive Metabolite Profiling

Diabetes mellitus is possibly the world's largest growing metabolic disorder. Effective treatment of diabetes is increasingly dependent on active constituents of medicinal plants capable of controlling hyperglycemia as well as its secondary complications. Viscum schimperi Engl. is a plant growing in Saudi Arabia and known for its antidiabetic activity. The potential antidiabetic activity of its methanol extract as well as its chloroform, n-butanol, and the remaining water fractions was evaluated in streptozotocin-induced diabetic rats at two dose levels. The antidiabetic activity was assessed through the determination of fasting blood glucose level, insulin levels, area under the curve (AUC) in oral glucose tolerance test, glucose absorption in isolated rat gut assay, and glucose uptake by psoas muscle. Moreover, large-scale untargeted metabolite profiling of methanol extract was performed via UPLC-PDA and qTOF-MS (ultra-performance liquid chromatography photodiode array detection and quadrupole time-of-flight mass spectrometry) respectively, to explore its chemical composition and standardization of its extract. Multivariate statistical analysis including principal component analysis and orthogonal projection to latent structures discriminant analysis was used to determine bioactives in its fractions. In conclusion, oleanane triterpenes and O-caffeoyl quinic acid conjugates were the major compounds that might account for antihyperglycemic effect of the plant.

Pregabalin attenuates excitotoxicity in diabetes

Diabetes can exacerbate seizures and worsen seizure-related brain damage. In the present study, we aimed to determine whether the standard antiepileptic drug pregabalin (PGB) protects against pilocarpine-induced seizures and excitotoxicity in diabetes. Adult male Sprague-Dawley rats were divided into either a streptozotocin (STZ)-induced diabetes group or a normal saline (NS) group. Both groups were further divided into subgroups that were treated intravenously with either PGB (15 mg/kg) or a vehicle; all groups were treated with subcutaneous pilocarpine (60 mg/kg) to induce seizures. To evaluate spontaneous recurrent seizures (SRS), PGB-pretreated rats were fed rat chow containing oral PGB (450 mg) for 28 consecutive days; vehicle-pretreated rats were fed regular chow. SRS frequency was monitored for 2 weeks from post-status epilepticus day 15. We evaluated both acute neuronal loss and chronic mossy fiber sprouting in the CA3 area. In addition, we performed patch clamp recordings to study evoked excitatory postsynaptic currents (eEPSCs) in hippocampal CA1 neurons for both vehicle-treated rats with SRS. Finally, we used an RNA interference knockdown method for Kir6.2 in a hippocampal cell line to evaluate PGB's effects in the presence of high-dose ATP. We found that compared to vehicle-treated rats, PGB-treated rats showed less severe acute seizure activity, reduced acute neuronal loss, and chronic mossy fiber sprouting. In the vehicle-treated STZ rats, eEPSC amplitude was significantly lower after PGB administration, but glibenclamide reversed this effect. The RNA interference study confirmed that PGB could counteract the ATP-sensitive potassium channel (KATP)-closing effect of high-dose ATP. By opening KATP, PGB protects against neuronal excitotoxicity, and is therefore a potential antiepileptogenic in diabetes. These findings might help develop a clinical algorithm for treating patients with epilepsy and comorbid metabolic disorders.

Increased nerve growth factor signaling in sensory neurons of early diabetic rats is corrected by electroacupuncture

Diabetic polyneuropathy (DPN), characterized by early hyperalgesia and increased nerve growth factor (NGF), evolves in late irreversible neuropathic symptoms with reduced NGF support to sensory neurons. Electroacupuncture (EA) modulates NGF in the peripheral nervous system, being effective for the treatment of DPN symptoms. We hypothesize that NGF plays an important pathogenic role in DPN development, while EA could be useful in the therapy of DPN by modulating NGF expression/activity. Diabetes was induced in rats by streptozotocin (STZ) injection. One week after STZ, EA was started and continued for three weeks. NGF system and hyperalgesia-related mediators were analyzed in the dorsal root ganglia (DRG) and in their spinal cord and skin innervation territories. Our results show that four weeks long diabetes increased NGF and NGF receptors and deregulated intracellular signaling mediators of DRG neurons hypersensitization; EA in diabetic rats decreased NGF and NGF receptors, normalized c-Jun N-terminal and p38 kinases activation, decreased transient receptor potential vanilloid-1 ion channel, and possibly activated the nuclear factor kappa-light-chain-enhancer of activated B cells (Nf-κB). In conclusion, NGF signaling deregulation might play an important role in the development of DPN. EA represents a supportive tool to control DPN development by modulating NGF signaling in diabetes-targeted neurons.

Gluten sensitivity: problems of an emerging condition separate from celiac disease

Gluten sensitivity appears to be emerging as a separate condition from celiac disease, yet no clear definition or diagnosis exists. As a result, patients with gluten sensitivity experience delayed diagnosis and continuing symptoms if they consume gluten. This emerging medical problem may involve human genetics, plant genetic modifications, gluten as a food additive, environmental toxins, hormonal influences, intestinal infections and autoimmune diseases. The treatment is similar to that for celiac disease - a gluten-free diet. The use of a gluten-free diet or an elimination diet is encouraged in assisting people to determine whether or not they are gluten sensitive. It is time to not only recognize, but to treat and further research gluten sensitivity, as unconfirmed environmental factors continue to spread this problem further into the general population.

Electroacupuncture counteracts the development of thermal hyperalgesia and the alteration of nerve growth factor and sensory neuromodulators induced by streptozotocin in adult rats

AIMS/HYPOTHESIS

Diabetes is considered the leading cause of neuropathies in developed countries. Dysfunction of nerve growth factor (NGF) production and/or utilisation may lead to the establishment of diabetic neuropathies. Electroacupuncture has been proved effective in the treatment of human neuropathic pain as well as in modulating NGF production/activity. We aimed at using electroacupuncture to correct the development of thermal hyperalgesia and the tissue alteration of NGF and sensory neuromodulators in a rat model of type 1 diabetes.

METHODS

Adult rats were injected with streptozotocin to induce diabetes and subsequently treated with low-frequency electroacupuncture for 3 weeks. Variation in thermal sensitivity was studied during the experimental course. Hindpaw skin and spinal cord protein content of NGF, NGF receptor tyrosine kinase A (TrkA), substance P (SP), transient receptor potential vanilloid 1 (TRPV1) receptor and glutamic acid decarboxylase-67 (GAD-67) were measured after electroacupuncture treatments. The skin and spinal cord cellular distribution of TrkA was analysed to explore NGF signalling.

RESULTS

Early after streptozotocin treatment, thermal hyperalgesia developed that was corrected by electroacupuncture. The parallel increases in NGF and TrkA in the spinal cord were counteracted by electroacupuncture. Streptozotocin also induced variation in skin/spinal TrkA phosphorylation, increases in skin SP and spinal TRPV1 and a decrease in spinal GAD-67. These changes were counteracted by electroacupuncture.

CONCLUSIONS/INTERPRETATION

Our results point to the potential of electroacupuncture as a supportive therapy for the treatment of diabetic neuropathies. The efficacy of electroacupuncture might depend on its actions on spinal/peripheral NGF synthesis/utilisation and normalisation of the levels of several sensory neuromodulators.

Short-term glucocorticoid intake improves exercise endurance in healthy recreationally trained women

The present study investigated whether short-term oral administration of glucocorticoid would modify performance and selected hormonal and metabolic parameters during submaximal exercise in healthy women. Nine recreational female athletes completed cycling trials at 70-75% VO(2) max until exhaustion after either placebo (Pla, gelatin) or oral prednisone (Cor, Cortancyl, 50 mg per day for 1 week) treatment, according to a double-blind and randomized protocol. Blood samples were collected at rest; after 10, 20, and 30 min of exercise; at exhaustion; and after 10 and 20 min of passive recovery for adrenocorticotrophic hormone (ACTH), dehydroepiandrosterone (DHEA), prolactin (PRL), growth hormone (GH), insulin (Ins), blood glucose (Glu), and lactate (Lac) determination. Cycling time was significantly increased with short-term Cor intake (Cor: 66.4 +/- 8.4 vs. Pla: 47.9 +/- 6.7 min, P < 0.01). ACTH and DHEA remained completely blunted throughout the experiment with Cor versus Pla (P < 0.01), whereas GH and PRL were significantly decreased with Cor after, respectively, 20 and 30 min of exercise (P < 0.05). No significant difference in Ins or Glu values was found between the two treatments but Lac concentrations were significantly increased with Cor versus Pla between 10 and 30 min of exercise (P < 0.05). These data indicate that short-term glucocorticoid intake improved endurance performance in women, but further investigation is needed to determine whether these results are applicable to elite female athletes and, if so, current WADA legislation needs to be changed.

Antihyperglycemic effects of total flavonoids from Polygonatum odoratum in STZ and alloxan-induced diabetic rats

AIM OF THE STUDY

Total flavonids of Polygonatum(P) odoratum (TFP) were tested for anti-diabetic activity in streptozotocin (STZ)-induced diabetic mice and alloxan-induced diabetic rats.

MATERIALS AND METHODS

Rhizoma Polygonati Odorati, well-known Chinese traditional medicine, is widely used for treatment of diverse diseases for example diabetes. In our study, TFP was extracted by 70% ethanol and purified by macroreticular resin. The experiments were designed to detect the anti-diabetic activity of TFP by determination of blood glucose (BG) using one touch gluco-meter and insulin levels by using a radioimmunoassay kit in streptozotocin (STZ)-induced diabetic mice and alloxan-induced diabetic rats and alpha-amylase inhibitory activity by alpha-amylase inhibition assay in vitro.

RESULTS

TFP had beneficial effects on regulation of blood glucose. Daily administration with 50-200 mg/kg body weight of TFP for 9 days can reduce significantly hyperglycemia in STZ-induced diabetic mice. Thirtieth day administration with TFP (50-200 mg/kg body weight) also decreased significantly fasting blood glucose in alloxan-induced diabetic rats. The hypoglycemic effect of TFP at 50 and 100 mg/kg is less than that of acarbose 20 mg/kg and gliclazide 15 mg/kg. The hypoglycemic effects of TFP at 200 mg/kg is similar to that of acarbose 20 mg/kg and gliclazide 15 mg/kg. TFP also could increase significantly the insulin level in alloxan-induced type 2 diabetic rats (P<0.05) compared with control. Alpha-amylase inhibition assay in vitro showed that TFP inhibited significantly alpha-amylase activity in a dose-dependent manner.

CONCLUSIONS

TFP possess significant dose-dependent anti-diabetic activity. TFP is one of the primary hypoglycemic active compounds of Polygonatum odoratum which would worth further study and development.

Effects of short-term prednisolone intake during submaximal exercise

PURPOSE

To examine the prednisolone's ergogenic and metabolic effects during submaximal exercise.

METHODS

Ten recreational male athletes completed two cycling trials at 70-75% peak O2 consumption until exhaustion after either placebo (Pla, lactose) or oral prednisolone (Pred, 60 mg.d(-1) for 1 wk) treatment, according to a double-blind and randomized protocol. Blood samples were collected at rest and during exercise and recovery to determine ACTH, growth hormone (GH), prolactin (PRL), DHEA, insulin, blood glucose, and blood lactate values.

RESULTS

Time of cycling was significantly increased after chronic Pred treatment (Pred: 74.5+/-9.5 min; Pla: 46.1+/-3.3 min, P<0.01). Pred intake significantly lowered basal, exercise, and recovery ACTH, DHEA, and PRL concentrations, whereas GH concentrations were significantly lowered by Pred after 30 min of exercise. Blood glucose and insulin were significantly (P<0.05) increased by Pred during the whole experiment and until 30 min of exercise. Blood lactate concentrations were higher after Pred versus Pla at 10 min of exercise until 10 min of recovery (P<0.05).

CONCLUSION

From these data, short-term Pred intake did seem to significantly improve performance during submaximal exercise, with concomitant alterations in hormonal and metabolic responses. Further studies will be necessary to elucidate the mechanisms of these hormonal and metabolic changes, and to determine whether the changes may be associated with the marked performance improvement obtained.

Endocrine sequelae of cancer and cancer treatments

INTRODUCTION

Exposure to cancer and its treatments, including chemotherapy and radiotherapy, may result in late adverse effects including endocrine dysfunction. Endocrine disorders are the most commonly reported long-term complications of cancer treatment, especially by adult survivors of childhood cancers. This review will explore the endocrinologic adverse effects from non-endocrine cancer therapies.

METHODS

Searches including various Internet-based medical search engines such as PubMed, Medline Plus, and Google Scholar were conducted for published articles.

RESULTS

One hundred sixty-nine journal articles met the inclusion criteria. They included case reports, systematic analyses, and cohort reports. Endocrine disorders including hypothalamus dysfunction, hypopituitarism, syndrome of inappropriate anti-diuretic hormone secretion, diabetes insipidus, growth hormone disorders, hyperprolactinemia, gonadotropin deficiency, serum thyroid hormone-binding protein abnormalities, hypothyroidism, hyperthyroidism, hypomagnesium, hypocalcemia, hyperparathyroidism, hyperparathyroidism, adrenal dysfunction, gonadal dysfunction, hypertriglyceridemia, hypercholesterolemia, diabetes mellitus, and glycosuria were identified and their association with cancer therapies were outlined.

DISCUSSION/CONCLUSIONS

The journal articles have highlighted the association of cancer therapies, including chemotherapy and radiotherapy, with endocrine dysfunction. Some of the dysfunctions were more often experienced than others. Especially in patients treated with radiotherapy, some endocrinologic disorders were progressive in nature.

IMPLICATIONS FOR CANCER SURVIVORS

Recognition and awareness of endocrine sequelae of cancer treatments may permit for early detection and appropriate follow-up care for cancer survivors, thus improving their overall health and quality of life.

Effects of acute prednisolone administration on exercise endurance and metabolism

OBJECTIVE

To examine whether acute glucocorticoid (GC) intake alters performance and selected hormonal and metabolic variables during submaximal exercise.

METHODS

In total, 14 recreational male athletes completed two cycling trials at 70-75% maximum O(2) uptake starting 3 h after an ingestion of either a lactose placebo or oral GC (20 mg of prednisolone) and continuing until exhaustion, according to a double-blind randomised protocol. Blood samples were collected at rest, after 10, 20, 30 minutes, and at exhaustion and recovery for measurement of growth hormone (GH), adrenocorticotropic hormone (ACTH), dehydroepiandrosterone (DHEA), prolactin, insulin, blood glucose, lactate and interleukin (IL)-6 determination.

RESULTS

Cycling duration was not significantly changed after GC or placebo administration (55.9 (5.2) v 48.8 (2.9) minutes, respectively). A decrease in ACTH and DHEA (p<0.01) was observed with GC during all of the experiments and in IL-6 after exhaustion (p<0.05). No change in basal, exercise or recovery GH, prolactin, insulin or lactate was found between the two treatments but blood glucose was significantly higher with GC (p<0.05) at any time point.

CONCLUSION

From these data, acute systemic GC administration does seem to alter some metabolic markers but did not influence performance during submaximal exercise.

State of stem cell pools in experimental diabetes mellitus

We studied the state of pools of mesenchymal precursor cells of different maturity in the bone marrow and peripheral blood and the dynamics of the content of regional parenchymal stem cells and stromal precursors in the pancreas during experimental diabetes mellitus. Reduced content of organ-specific stem cells and increased content of stromal precursors in the pancreas in the absence of compensatory reaction of deep reserve mechanisms, mesenchymal bone marrow cells, were revealed.

Effect of dichlorvos on hepatic and pancreatic glucokinase activity and gene expression, and on insulin mRNA levels

Several studies have shown that organophosphate pesticides affect carbohydrate metabolism and produce hyperglycemia. It has been reported that exposure to the organophosphate pesticide dichlorvos affects glucose homeostasis and decreases liver glycogen content. Glucokinase (EC 2.7.1.1) is a tissue-specific enzyme expressed in liver and in pancreatic beta cells that plays a crucial role in glycogen synthesis and glucose homeostasis. In the present study we analyzed the effect of one or three days of dichlorvos administration [20 mg/kg body weight] on the activity and mRNA levels of hepatic and pancreatic glucokinase as well as on insulin mRNA abundance in the rat. We found that the pesticide affects pancreatic and hepatic glucokinase activity and expression differently. In the liver the pesticide decreased the enzyme activity; on the contrary glucokinase mRNA levels were increased. In contrast, pancreatic glucokinase activity as well as mRNA levels were not affected by the treatment. Insulin mRNA levels were not modified by dichlorvos administration. Our results suggest that the decreased activity of hepatic glucokinase may account for the adverse effects of dichlorvos on glucose metabolism.

Alterations in glucose metabolism associated with liver cirrhosis persist in the clinically stable long-term course after liver transplantation

With increasing long-term survival rates after orthotopic liver transplantation (OLT), metabolic alterations complicating the clinical course, such as diabetes mellitus (DM), become increasingly important. Liver cirrhosis is associated with severe alterations in glucose metabolism. However, it is currently unclear whether these changes are reversed by successful OLT. We therefore characterized glucose metabolism in patients with liver cirrhosis and normal fasting glucose levels before OLT (cir), in the clinically stable long-term course after OLT (OLT), and control subjects (con) using oral glucose tolerance tests (cir = 100, OLT = 62, con = 32), euglycemic-hyperinsulinemic clamps (cir = 10, OLT = 27, con = 14), and positron emission tomography (PET) scan analysis with 18F-fluorodeoxyglucose (FDG) as a tracer (cir = 7, OLT = 7, con = 5). Fasting insulin and C-peptide levels were significantly elevated in patients with liver cirrhosis compared with both control subjects (P <.001) and patients after OLT (P <.001). After OLT, insulin was normalized, whereas C-peptide remained elevated (P < 0.01). In the patients with liver cirrhosis, 27% had a normal glucose tolerance, 38% had an impaired glucose tolerance (IGT), and 35% were diabetic. After OLT, 34% had a normal glucose tolerance, 29% an IGT, and 37% were diabetic. Comparison of the same patients before and after OLT demonstrated that IGT or diabetes before OLT was the major risk factor for these conditions after OLT, which was independent of either immunosuppression (cyclosporine vs FK506) or low-dose prednisolone. Total glucose uptake was reduced in patients with liver cirrhosis to less than half the values in control subjects (21.2 +/- 2.8 vs 43.7 +/- 2.4 micromol/kg/minute, respectively, P <.001), whereas patients after OLT showed intermediate values (35.7 +/- 1.4 micromol/kg/minute, P < 0.05 vs con, P < 0.01 vs cir). This difference was caused by a reduction in nonoxidative glucose metabolism in patients with liver cirrhosis compared with control subjects (7.4 +/- 1.9 vs 28.7 +/- 1.8 micromol/kg/minute, respectively, P <.01) and patients after OLT (20.1 +/- 1.4 micromol/kg/minute, P < 0.05 vs con and OLT). In the PET study, skeletal muscle glucose uptake was significantly reduced in patients with liver cirrhosis compared with control subjects (3.5 +/- 0.4 vs 11.8 +/- 2.5 micromol/100g/minute, respectively, P <.05). After OLT, muscle glucose uptake improved compared with patients with liver cirrhosis (5.9 +/- 1.0 micromol/100g/minute, P <.05) but remained significantly lower than in control subjects (P <.05). In conclusion, these results demonstrate that preexisting IGT or diabetes are the major risk factors for IGT and diabetes after OLT. This finding was independent of the immunosuppressive medication. The peripheral insulin resistance in cirrhosis is characterized by a decrease in nonoxidative glucose disposal that is improved, but not normalized, after OLT.

Transformation of barbituric acid into alloxan by hydroxyl radicals: interaction with melatonin and with other hydroxyl radical scavengers

Barbituric acid (2,4,6-pyrimidinetrione) can be transformed by a non-enzymatic hydroxylation into alloxan (2,4,5,6-pyrimidinetetrone). This transformation can be used as a reaction indicating the formation of hydroxyl radicals (.OH). This conversion was detected using HPLC. Formation of .OH was demonstrated by electron spin resonance (ESR) spectroscopy combined with spin-trapping techniques. It was shown that .OH generated via the Fenton reaction abstracts first a hydrogen atom from barbituric acid (BA) and forms intermediately a paramagnetic derivative of BA. After a second attack by another .OH, the BA radical is transformed into dialuric acid (DA), which autoxidizes via the alloxan radical (.ALX) to ALX. Superoxide radicals (.O2-) are formed during autoxidation of DA and.ALX. They are able to regenerate ferrous ions. As a result, traces of iron salts are capable of catalyzing the conversion of large amounts of BA into ALX. Several scavengers of .OH were tested with regard to their efficiency in preventing the transformation of BA into ALX. Of all the scavengers analyzed, melatonin was shown to be one of the most potent compounds.

Trichloroethylene--a review of the literature from a health effects perspective

This report reviews the literature on the impact of exposure to trichloroethylene (TCE) on human health. Special emphasis is given to the health effects reported in excess of national norms by participants in the TCE Subregistry of the Volatile Organic Compounds Registry of the National Exposure Registries--persons with documented exposure to TCE through drinking and use of contaminated water. The health effects reported in excess by some or all of the sex and age groups studied were speech and hearing impairments, effects of stroke, liver problems, anemia and other blood disorders, diabetes, kidney disease, urinary tract disorders, and skin rashes.