Insulin-stimulated Akt kinase activity is reduced in skeletal muscle from NIDDM subjects

The serum lipoprotein(a) [Lp(a)] level is a known risk factor for arteriosclerotic coronary artery disease. However, its association with restenosis after percutaneous transluminal coronary angioplasty (PTCA) is controversial. We hypothesized that the Lp(a) level is a significant risk factor for restenosis after angioplasty through a pathophysiological mechanism leading to excess thrombin generation or inhibition of fibrinolysis. We designed a prospective study of the relation of Lp(a) to outcome after PTCA, in which we measured selected laboratory variables at entry and collected clinical, procedural, lesion-related, and outcome data pertaining to restenosis. Restenosis was defined as >50% stenosis of the target lesion by angiography or as ischemia in the target vessel distribution by radionuclide-perfusion scan. Before the patients underwent PTCA, blood was obtained by venipuncture for measurement of Lp(a), total cholesterol, thrombin-antithrombin (TAT) complex, alpha2-antiplasmin-plasmin (APP) complex, and plasminogen activator inhibitor-1 (PAI-1). Evaluable outcome data were obtained on 162 subjects, who form the basis of this report. Restenosis occurred in 61 subjects (38%). The Lp(a) level was not correlated significantly with TAT, APP, PAI-1, or the TAT-APP ratio. Levels of TAT, APP, and PAI-1 were not statistically different in the patients with versus those without restenosis. The median ratio of TAT to APP was 2-fold higher in the restenosis group, and this difference approached statistical significance (P=0.07). Univariate analysis was performed for the association of clinical, lesion-related, and procedural risk factors with restenosis. Lp(a) levels did not differ significantly in the restenosis versus no-restenosis group, whether assessed categorically (>25 mg/dL versus <25 mg/dL) or as a continuous variable by Mann-Whitney U test. The number of lesions dilated and the lack of family history of premature heart disease were significantly associated with restenosis (P=0.002 and P=0.008, respectively). A history of diabetes mellitus was of borderline significance (P=0.055). By multiple logistic regression analysis, the number of lesions dilated was the only variable significantly associated with restenosis (P=0.03). We conclude that the number of lesions dilated during PTCA is a significant risk factor for restenosis, whereas the serum Lp(a) level was not a significant risk factor for restenosis in our patient population. The TAT to APP ratio merits further study as a possible risk factor for restenosis.     

Regulation of skeletal muscle hexokinase II by insulin in nondiabetic and NIDDM subjects

Impaired muscle glucose phosphorylation to glucose-6-phosphate by hexokinases (HKs)-I and -II may contribute to insulin resistance in NIDDM and obesity. HK-II expression is regulated by insulin. We tested the hypothesis that basal and insulin-stimulated expression of HK-II is decreased in NIDDM and obese subjects. Skeletal muscle HK-I and HK-II activities were measured in seven lean and six obese normal subjects and eight patients with NIDDM before and at 3 and 5 h of a hyperinsulinemic (80 mU x m(-2) x min(-1)) euglycemic clamp. To assess whether changes in HK-II expression seen during a glucose clamp are likely to be physiologically relevant, we also measured HK-I and HK-II activity in 10 lean normal subjects before and after a high-carbohydrate meal. After an overnight fast, total HK, HK-I, and HK-II activities were similar in lean and obese control subjects; but HK-II was lower in NIDDM patients than in lean subjects (1.42 +/- 0.16 [SE] vs. 2.33 +/- 0.24 nmol x min(-1) x mg(-1) molecular weight, P < 0.05) and accounted for a lower proportion of total HK (33 +/- 3 vs. 47 +/- 3%, P < 0.025). HK-II (but not HK-I) activity increased during the clamp in lean and obese subjects by 34 and 36% after 3 h and by 14 and 22% after 5 h of hyperinsulinemia; no increase was found in the NIDDM patients. In the lean subjects, muscle HK-II activity also increased by 15% 4 h after the meal, from 2.47 +/- 0.19 basally to 2.86 +/- 0.28 nmol x min(-1) x mg(-1) protein (P < 0.05). During the clamps, muscle HK-II activity correlated with muscle citrate synthase activity in the normal subjects (r = 0.58, P < 0.05) but not in the NIDDM patients. A weak relationship was noted between muscle HK-II activity and glucose disposal rate at the end of the clamp when all three groups were combined (r = 0.49, P < 0.05). In summary, NIDDM patients have lower muscle HK-II activity basally and do not increase the activity of this enzyme in response to a 5-h insulin stimulus. This defect may contribute to their insulin resistance. In nondiabetic obese subjects, muscle HK-II expression and its regulation by insulin are normal.     

Divergent association of apolipoprotein E polymorphism with vascular disease in patients with NIDDM and control subjects

We analysed a well-characterized group of 83 patients (43 men, 40 women; mean age +/- SEM: 65.5 +/- 0.6 years at the 10-year examination) with non-insulin-dependent (Type 2) diabetes mellitus (NIDDM) and in 123 control subjects (56 men, 67 women; mean age +/- 0.9 years) retrospectively for the relationship of apolipoprotein E (apo E) genotypes (E2/3, E3/3 vs E3/4, E4/4) to the incidence of clinical macrovascular disease and its risk factors and the incidence of microvascular complications of diabetes during the first 10 years of NIDDM, as well as carotid intima-media thickness measured by B-mode ultrasound at the 10-year examination. In patients with NIDDM, apo E4 genotype showed no relationship to clinical events or carotid intima-media thickness. However, in the control subjects with apo E4, the incidence of non-fatal myocardial infarction during the follow-up was increased (apo E4 positivity: 17.1%; apo E4 negativity 5.1%; p = 0.035) and they had higher common carotid intima-media thickness than those with apo E2/3 or apo E3/3 (1.15 +/- 0.05 mm vs 1.01 +/- 0.03 mm, p = 0.008). Apo E genotype groups showed no relationship to microvascular complications of diabetes, although control subjects with apo E4 positivity showed a higher frequency of microalbuminuria than those lacking apo E4. We conclude that apo E4 was a marker of vascular disease and increased atherosclerosis in non-diabetic subjects, whereas in the diabetic patients these relationships were absent. It is likely that NIDDM per se influences the vascular risk so overwhelmingly that the effects of other risk factors are obscured.     

Unchanged gene expression of glycogen synthase in muscle from patients with NIDDM following sulphonylurea-induced improvement of glycaemic control

We have previously shown that the mRNA expression of muscle glycogen synthase is decreased in non-insulin-dependent diabetic (NIDDM) patients; the objective of the present protocol was to examine whether the gene expression of muscle glycogen synthase in NIDDM is affected by chronic sulphonylurea treatment. Ten obese patients with NIDDM were studied before and after 8 weeks of treatment with a weight-maintaining diet in combination with the sulphonylurea gliclazide. Gliclazide treatment was associated with significant reductions in HbA1C (p=0.001) and fasting plasma glucose (p=0.005) as well as enhanced beta-cell responses to an oral glucose load. During euglycaemic, hyperinsulinaemic clamp (2 mU x kg-1 x min-1) in combination with indirect calorimetry, a 35% (p=0.005) increase in whole-body insulin-stimulated glucose disposal rate, predominantly due to an increased non-oxidative glucose metabolism (p=0.02) was demonstrated in teh gliclazide-treated patients when compared to pre-treatment values. In biopsies obtained from vastus lateralis muscle during insulin infusion, the half-maximal activation of glycogen synthase was achieved at a significantly lower concentration of the allosteric activator glucose 6-phosphate (p=0.01). However, despite significant increases in both insulin-stimulated non-oxidative glucose metabolism and muscle glycogen synthase activation in gliclazide-treated patients no changes were found in levels of glycogen synthase mRNA or immunoreactive protein in muscle. In conclusion, improved blood glucose control in gliclazide-treated obese NIDDM patients has no impact on the gene expression of muscle glycogen synthase.     

The insulin receptor substrate 1 associates with phosphotyrosine phosphatase SHPTP2 in liver and muscle of rats

OBJECTIVE: To determine efficacy of a vaccine containing modified-live bovine viral diarrhea virus (BVDV) type 1 for protecting pregnant cows and their fetuses against virulent heterologous BVDV type 1. DESIGN: Randomized controlled cohort study. ANIMALS: 18 yearling beef heifers seronegative for BVDV and negative when tested for BVDV by virus isolation. PROCEDURE: Cattle were randomly assigned to control (unvaccinated; n = 6) or vaccinated (12) groups. Vaccinated heifers were given a combination vaccine containing modified-live BVDV type 1 comprising a cytopathic (NADL) strain. All 18 heifers were then bred and challenge-exposed between 70 and 75 days of gestation with BVDV type 1, administered intranasally. Cattle were monitored, and infection status of offspring was determined after parturition. Antibody concentrations of vaccinated and control heifers were also monitored. RESULTS: All 6 calves from control heifers had positive results on multiple virus isolation tests and were considered persistently infected. In comparison, only 2 calves from vaccinated cows had positive results on virus isolation tests and were considered persistently infected. One vaccinated heifer aborted, but the fetus was not persistently infected, and the abortion was not attributed to BVDV infection. CLINICAL IMPLICATIONS: Analysis of these data indicated that a single dose of a modified-live NADL-derived BVDV type 1 vaccine will confer protection to dams and their fetuses against challenge-exposure to heterologous BVDV type 1 organisms.     

Different change in lipoprotein(a) levels from lipid levels of other lipoproteins with improved glycemic control in patients with NIDDM

OBJECTIVE: To evaluate change both in lipoprotein(a) [Lp(a)] and lipid levels in other lipoproteins in non-insulin-dependent diabetes mellitus (NIDDM) after short-term improvement of glycemic control. RESEARCH DESIGN AND METHODS: We compared Lp(a) levels in 210 NIDDM patients with those in 46 control subjects and evaluated the relationship between glycemic control and Lp(a) levels in diabetic patients. In addition, changes in Lp(a) levels and lipid levels were assessed after the improvement of glycemic control in 54 poorly controlled NIDDM patients. RESULTS: In NIDDM, Lp(a) levels in all patients, 62 patients with HbA1c < 6.0%, and 75 patients with HbA1c between 6.0 and 8.0%, were significantly higher than those in control subjects (19.1 [1.7-106.6], 19.2 [6.0-106.6], and 20.3 [2.7-75.3] vs. 15.4 [2.0-61.7] mg/dl, median [range], P < 0.05). Lp(a) levels in 73 patients with HbA1c of > or = 8.0% (18.7 [1.7-58.8] mg/dl) were not significantly different from those in control subjects. After glycemic control, lipid levels in plasma and in other lipoproteins fell significantly, but Lp(a) did not change (from 18.3 [1.7-58.8] to 18.4 [6.6-95.3] mg/dl). Changes in lipid levels, including Lp(a), did not correlate with those in fasting plasma glucose or HbA1c. CONCLUSIONS: These results suggest that elevated Lp(a) levels do not reflect poor glycemic control and that Lp(a) levels are independent of lipid levels in other lipoproteins after improved glycemic control in NIDDM.     

Acid phosphatase activity in lymphocytes from patients with Spielmeyer-Vogt-Batten's syndrome

The purpose of the investigation presented was to study whether the lymphocytes from patients with Spielmeyer-Vogt-Batten's syndrome deviate from normal with respect to acid phosphatase activity. The distribution of the activity seems to show that the patients with Spielmeyer-Vogt-Batten's syndrome can be divided into two groups, viz. one in which the values are concentrated around the normal level, and another with increased values.     

Beta-adrenoceptor-linked protein kinase A (PKA) activity in human fibroblasts from normal subjects and from patients with major depression

Human fibroblasts from normal subjects and from patients with major depression are cultured and their beta-adrenoreceptor-cyclic AMP-protein kinase A (PKA) system characterized. The results indicate that the beta-adrenoreceptor-mediated activation of PKA in the 900 g supernatant fraction of human fibroblasts is mediated via beta-adrenoreceptors. The activation of PKA by isoproterenol is very rapid with maximal stimulation occurring at 5 seconds. The time course of PKA activation by isoproterenol in fibroblasts from patients with major depression is identical to that in fibroblasts from normal subjects but the magnitude of activation is significantly reduced in fibroblasts from patients with major depression. Dose-response curves on cyclic AMP mediated activation of PKA confirmed the previously reported reduction in activation of PKA in patients with major depression but demonstrated that this reduction occurs without a change in the EC50 values of cyclic AMP (approximately 20 nmol/L). The blunted beta-adrenoceptor-linked PKA responses in patients with major depression occur without a change in the expression of the PKA catalytic subunit C alpha. The studies suggest that the beta-adrenoceptor-coupled adenylate cyclase PKA system in human fibroblasts may represent a valid model to explore possible abnormalities in the fine tuning of the beta-adrenergic transduction cascade in patients with affective disorders.     

Platelet cNOS activity is reduced in patients with IDDM and NIDDM

Several studies in vitro and in vivo suggest that the nitric oxide (NO) production is impaired in diabetes mellitus. Reduced levels of NO could contribute to vascular alteration facilitating platelet-vascular wall interaction, adhesion of monocytes to endothelium, vascular smooth muscle proliferation and by decreasing endothelium-dependent vasodilation. In this study we evaluated the activity of the constitutive nitric oxide synthase (cNOS) in platelets of patients with insulin-dependent diabetes mellitus (IDDM) and with non-insulin-dependent diabetes mellitus (NIDDM). When compared to that of normal subjects, cNOS activity is significantly lower in patients with IDDM and with NIDDM (1.57 +/- 0.25 vs. 0.66 +/- 0.10 fmol/min/10(9) PLTs and 1.57 +/- 0.25 vs. 0.67 +/- 0.08, respectively; p<0.005). These data demonstrate that the platelet cNOS activity is decreased in diabetes mellitus.     

Decreased basal, noninsulin-stimulated glucose uptake and metabolism by skeletal soleus muscle isolated from obese-hyperglycemic (ob/ob) mice

Insulin resistance of diaphragms of ob/ob mice has been repeatedly demonstrated previously both in vitro and in vivo. In the present study, transport and metabolism of glucose with and without insulin stimulation were compared in a skeletal muscle more likely than diaphragm or heart to be representative of the overall striated muscle mass, i.e. isolated soleus muscle. Compared with soleus muscle from lean controls, unstimulated lactate release in the presence of exogenous glucose was depressed from 16.2 to 12.3 nmol/60 min per mg wet wt in soleus from ob/ob mutants; glycolysis was decreased from 6.6 to 3.7 and [14C]glucose oxidation to 14CO2 from 0.90 to 0.33 nmol glucose/60 min per mg wet wt. Uptake of 2-deoxyglucose (2-DOG), both with and without insulin, was very much less for soleus from ob/ob than from lean mice, at 2-DOG concentrations ranging from 0.1 to 10 mM, and in mice of 6-15 wk. When 2-DOG concentration was 1 mM, its basal uptake was 0.53 nmol/30 min per mg wet wt for soleus of ob/ob as against 0.96 for soleus of lean mice. The absolute increment due to 1 mU/ml insulin was 0.49 in muscle of ob/ob as against 1.21 in that of lean mice. When the resistance to insulin action was decreased by pretreatment in vivo by either streptozotocin injection or fasting, the decreased basal 2-DOG uptake of subsequently isolated soleus muscle was not improved. Inhibition of endogenous oxidation of fatty acids by 2-bromostearate, while greatly increasing 14CO2 production from [14C]glucose, did not affect basal [5-3H]glucose metabolism or 2-DOG uptake. It is suggested that transport and/or phosphorylation of glucose under basal, unstimulated conditions are depressed in soleus muscle of ob/ob mice, whether or not resistance to insulin and hyperinsulinemia are also present. Although the origin of the decreased basal glucose uptake remains unknown it might be related to a similar decrease in basal glucose uptake by ventromedial hypothalamic cells, an event presumably resulting in a tendency to hyperphagia. Decreased basal glucose uptake by soleus muscle of ob/ob mice might explain the hyperglycemia, and hence partly the hyperinsulinemia and excessive fat deposition of those animals.     

Cloning, purification, and properties of a phosphotyrosine protein phosphatase from Streptomyces coelicolor A3(2)

We have investigated by restriction fragment analysis genomic abnormalities involving the c-myc gene in DNA isolated from adenomas and hepatocellular carcinomas (HCCs). Adenomas and HCCs were induced by the "resistant hepatocyte" protocol in diethylnitrosamine-initiated male F344 rats. Southern-blot analysis of EcoRI-restricted DNA from normal liver, early and late adenomas, 12 weeks (EAs) and 30 weeks (LAs) after initiation, and HCCs, showed 2 bands of 18 and 3.2 kb hybridizing with c-myc, in all tissues. c-myc amplification occurred in almost all HCCs, and in the majority of EAs and LAs. These results were confirmed by dilution analysis. c-myc amplification was also seen in adenomas and HCCs by Southern analysis with HindIII-restricted DNA, and in HCCs by differential PCR. c-myc mRNA increase occurred in all adenomas and HCCs, but it was higher in the lesions showing gene amplification. Moreover, a 13-kb DNA extraband, hybridizing with c-myc, was found in the HindIII-restricted DNA from HCCs, but not in normal liver and adenomas, and a 7.1-kb extra band was present in EcoRI-digested DNA from one LA. EcoRI-restricted DNA from some adenomas exhibited a decrease in intensity of the 18-kb fragment, and an increase in intensity of the 3.2-kb fragment. No alteration in banding pattern occurred in the beta-actin gene in adenomas. These results provide evidence of amplification and some other rearrangements involving the c-myc gene, in pre-malignant and malignant liver lesions, induced by the RH protocol, and suggest a role of c-myc rearrangement in the progression of adenomas to malignancy.     

Apolipoprotein (a) levels and phenotypes in NIDDM patients with microalbuminuria and albuminuria

This study was conducted to determine whether circulating levels of lipoprotein (a), an independent risk factor of macrovascular disease, are increased in non-insulin-dependent diabetes mellitus (NIDDM) patients with microalbuminuria who have an increased risk of cardiovascular mortality. Apolipoprotein (a) [apo(a)] levels and phenotypes, and other circulating lipid levels were determined in 227 Chinese NIDDM patients with varying stages of diabetic nephropathy. None was on lipid-lowering therapy. Apo(a) levels in normoalbuminuric (geometric mean 166 U/L; 95% confidence intervals 137, 200; n = 105) and microalbuminuric patients (162; 132, 209; n = 77) were similar to values in controls (166; 143, 193, n = 168). Albuminuric patients, however, had higher apo(a) levels than both normoalbuminuric patients and controls (242; 184, 317; n = 45; P < 0.05). The overall size range of the apo(a) phenotypes and the frequency of having at least one small isoform, i.e. < 700 kDa, were similar among the four groups of subjects. A positive correlation was found between log apo(a) and log plasma creatinine levels (P < 0.01). Compared to normoalbuminuric patients, both microalbuminuric and albuminuric patients were older (P < 0.01) and had higher HbA1c (P < 0.01), greater BMI (P < 0.05) and longer disease duration (P < 0.05) compared to normoalbuminuric patients. Nevertheless, using multiple linear regression analysis, it was found that the presence of nephropathy conferred an independent influence on increasing total cholesterol (P < 0.001), triglyceride (P < 0.001) and apoB (P < 0.01), and decreasing HDL cholesterol (P < 0.05) levels even when only the normoalbuminuric and microalbuminuric groups were analysed. The prevalence of macrovascular disease was significantly increased in microalbuminuric and albuminuric patients (45.1 and 48.7% respectively vs 20.2% in normoalbuminuric patients, P < 0.01). It is concluded that circulating apo(a) levels were not increased in Chinese NIDDM patients with microalbuminuria. However, atherogenic changes in other lipid and lipoprotein levels may contribute to an increased risk of macrovascular disease in these patients.     

Total protein and acid phosphatase concentrations in prostatic fluid from patients with BPH compared to carcinoma

Efficacy of reperfusion therapy in acute myocardial infarction is strictly time dependent. As is evidenced by several studies, most benefit in terms of myocardial salvage and short- and long-term mortality is achieved with initiation of therapy within the first 60-90 minutes after onset of symptoms. Nearly exclusively, prehospital initiation of thrombolysis makes it possible to take advantage of this early time window. Moreover a time gain of more than 30 minutes, up to 130 minutes, is possible by prehospital initiation of thrombolysis, depending on local circumstances. Randomized studies yielded a better outcome when a time gain of > or = 90 minutes was achieved. Since it has been shown that prehospital diagnosis of an acute myocardial infarction is reliable and out-of-hospital initiation of therapy has no additional specific risk, patients seen within the first 60-90 minutes after onset of symptoms or for whom a relevant time gain of > or = 90 minutes can be expected are ideal candidates for, and therefore should receive, prehospital thrombolysis.     

Neck and total body fat deposition in nonobese and obese patients with sleep apnea compared with that in control subjects

Recent animal and human studies have suggested that leptin secretion is closely linked to the functions of the hypothalamic-pituitary-adrenal (HPA) axis and the immune system, both of which are crucial in influencing the course and outcome of critical illness. Therefore, we measured basal plasma leptin levels and examined the circadian secretion of leptin, in parallel with the hormones of the HPA axis and a key cytokine, interleukin-6, in critically ill patients with acute sepsis. Sixteen critically ill patients from the University of Leipzig Intensive Care Unit were recruited for this study. All of these patients fulfilled the standard diagnostic criteria for sepsis. Plasma leptin levels were measured in all patients and controls at 09:00. In addition, in a subgroup of eight critically ill patients and all of the nine controls plasma leptin, cortisol, ACTH and interleukin-6 concentrations were measured every 4 hours for 24 hours. Mean plasma leptin levels were three-fold higher (18.9 +/- 4.5 ng/ml) in critically ill patients than controls (3.8 +/- 1.0 ng/ml, p < 0.05). Similarly, ACTH levels were lower (7.8 +/- 3.4 pmol/l) in patients than in controls (17.1 +/- 1.5 pmol/l, p < .001), while plasma cortisol levels were increased (947.6 +/- 144 nmol/l) in patients compared to controls (361.1 +/- 29, p < 0.001). Morning plasma interleukin-6 levels were markedly elevated in all patients with sepsis (1238.0 +/- 543.1 pg/ml) versus controls (6.4 +/- 1.7, p < 0.001). The controls exhibited a nyctohemeral fluctuation in plasma leptin levels with peak levels at 23:00; in contrast, septic patients, had no nocturnal rise of leptin. In healthy controls, plasma leptin and cortisol had reciprocal circadian rhythms with high nocturnal leptin levels and low nocturnal cortisol concentrations; in critically ill patients, this relation was abolished. Mean leptin levels were three-fold higher in patients who survived the septic episode (25.5 +/- 6.2, n = 10) than in non-survivors (8.0 +/- 3.7, n = 6, p < 0.01). We conclude that in addition to its function as an anti-obesity factor, leptin may play a role in a severe stress state such as acute sepsis.     

Ca2+ release from the sarcoplasmic reticulum compared in amphibian and mammalian skeletal muscle

This paper describes and evaluates a method for quantifying the amounts of specific plasma proteins adsorbed to biomaterial surfaces. In particular, it demonstrates that macroscopic images ('stains'), that assess the spatial distribution of albumin, IgG, fibrinogen, and HMK (high molecular weight kininogen), can be obtained over areas of at least 12 cm2 using immunospecific adhesion of dyed polystyrene beads. Stain intensities, measured with a scanner and an image analysis system, were found to quantify the amount of specific protein in the solution used to coat the surfaces. Results obtained with the proposed method produced single protein isotherms for albumin, immunoglobulin G (IgG) and fibrinogen that followed Langmuir-like adsorption behavior and were similar to previously published isotherms. The HMK isotherm also exhibited Langmuir-like adsorption behavior. The proposed method also detected the presence of an expected maximum in the adsorption of fibrinogen onto glass as a function of plasma dilution. Adsorption of fibrinogen out of 6.4% plasma onto glass from a separated flow produced results indicating the quantity as well as the location of fibrinogen at the boundary of the separated region. This result confirmed the utility of the proposed method for detecting spatial distributions of specific proteins adsorbed from plasma in practical devices.     

Dihydropyridine receptor gene expression in skeletal muscle from mdx and control mice

The expression of isoform-specific dihydropyrine receptor-calcium channel (DHPR) alpha 1-subunit genes was investigated in mdx and control mouse diaphragm (DIA) and tibialis anterior (TA). RNase protection assays were carried out with a rat DHPR cDNA probe specific for skeletal muscle and a mouse DHPR cDNA probe specific for cardiac muscle. The level of expression of the gene encoding the cardiac DHPR was very weak in TA muscle from both control and mdx mice. Compared to TA, DIA expressed mRNA for the cardiac isoform at significantly higher levels, but mdx and control mouse DIA levels were similar to one another. In contrast, mRNA expression levels for the DHPR skeletal muscle isoform were lower in control DIA than TA. However, there was a dramatic increase in the expression for the DHPR skeletal muscle isoform in mdx DIA compared with control DIA, reaching the TA expression level, whereas dystrophy did not affect TA expression. [3H]-PN200-110 binding was used to further assess DIA DHPR expression at the protein level. The density of binding sites for the probe was not significantly affected in DIA muscles of mdx vs. control mice, but it was reduced in older mdx and control mice. The increase in DHPR mRNA levels without a consequent increase in DHPR protein expression could be secondary to possible enhanced protein degradation which occurs in mdx DIA. The altered DHPR expression levels found here do not appear to be responsible for the severe deficits in contractile function of the mdx DIA.     

Role of tyrosine kinase and phosphotyrosine phosphatase in growth of the intestinal crypt cell (IEC-6) line

Antibodies to hepatitis C virus (HCV) were measured in 1,580 Ethiopian subjects representing urban and rural populations. Sera found positive by a repeated second generation enzyme immunoassay (EIA) were subjected to three additional confirmatory tests. The overall confirmed seroprevalence was 2.0%. Less than 1% were confirmed to be seropositive in rural communities, with 1.4% positive among blood donors, 1.6% positive among patients with dermatologic disorders, 3.6% among leprosy patients, and 6.0% among patients attending a University Hospital clinic for neurologic disorders. The patients in the groups with leprosy and neurologic disorders have most likely been in ill health for many years and have sought relief by traditional healers or treatment at poorly equipped clinics. This group of patients demonstrated a high prevalence of antibodies to HCV. In Ethiopia, especially in small clinics, there is a shortage of syringes and needles and they have to be reused many times often with inadequate sterilization. Therefore, these syringes and needles may be contaminated, thus being a risk factor for HCV and HIV infection.     

Dystrophin, utrophin and beta-dystroglycan expression in skeletal muscle from patients with Becker muscular dystrophy

The precise localization and semiquantitative correlation of dystrophin, utrophin and beta-dystroglycan expression on the sarcolemma of skeletal muscle cells obtained from patients with Becker muscular dystrophy (BMD) was studied using three types of double immunofluorescence. Staining intensity was measured using a confocal laser microscope. Each of these proteins was identified at the same locus on the sarcolemma. The staining intensities of dystrophin and utrophin were approximately reciprocal at sarcolemmal sites where dystrophin expression was obviously observed. The staining intensity of beta-dystroglycan was strong in areas where dystrophin staining was also strong and utrophin expression was weak. Quantitative analysis revealed that the staining intensity of beta-dystroglycan minus that of dystrophin approximated the staining intensity of utrophin, indicating that the sum of dystrophin and utrophin expression corresponds to that of beta-dystroglycan. These results suggest that utrophin may compensate for dystrophin deficiency found in BMD by binding to beta-dystroglycan.     

Normal levels of DM RNA and myotonin protein kinase in skeletal muscle from adult myotonic dystrophy (DM) patients

A major question about the pathogenesis of myotonic dystrophy (DM) is how the (CTG)n repeat mutation alters expression of the DM gene and how that is related to disease causation. Most previous studies have found a decrease in DM RNA and protein in patient tissue. In contrast to these reports we find, unexpectedly, that independent of the size of the CTG repeat: (1) there are equal levels of RNA products of mutant and normal alleles, and (2) levels of Mt-PK in skeletal muscle from DM patients is unaltered from normal. These findings are consistent with the recent hypothesis that mutant DM DNA or RNA may cause disease by disrupting the function of other, yet unidentified, genes.     

The efficacy and safety of miglitol therapy compared with glibenclamide in patients with NIDDM inadequately controlled by diet alone

OBJECTIVE: To compare the therapeutic effects of the alpha-glucosidase inhibitor miglitol (BAY m 1099), the sulfonylurea glibenclamide, and placebo on parameters of metabolic control and safety in patients with NIDDM that is inadequately controlled by diet alone. RESEARCH DESIGN AND METHODS: After a 4-week placebo run-in period, 201 patients in 18 centers in 4 countries were randomized in a double-blind manner to miglitol (50 mg t.i.d., followed by 100 mg t.i.d.), glibenclamide (3.5 mg q.d/b.i.d.), or placebo for 24 weeks. Efficacy criteria were changes from baseline of HbA1c, fasting and postprandial blood glucose and insulin levels, body weight, and serum triglycerides. RESULTS: Efficacy was assessed in 119 patients who completed the full protocol, and the results were similar to those obtained in 186 patients who fulfilled the validity criteria for analysis. Compared with placebo, mean baseline-adjusted HbA1c decreased by 0.75% (P = 0.0021) and 1.01% (P = 0.0001) in the miglitol and glibenclamide treatment groups, respectively. Blood glucose decreased slightly in the fasting state and considerably in the postprandial state in both treatment groups but not in the placebo group. Fasting insulin levels increased slightly (NS) in all treatment groups; however, postprandial insulin levels decreased with miglitol, while increasing markedly with glibenclamide (P = 0.0001 between all treatment groups). Gastrointestinal side effects (flatulence and diarrhea) occurred mostly in the miglitol-treated patients, while some glibenclamide-treated patients had symptoms suggestive of hypoglycemia. CONCLUSIONS: Miglitol monotherapy is effective and safe in NIDDM patients. Compared with glibenclamide, it reduced HbA1c less effectively and caused more gastrointestinal side effects. On the other hand, glibenclamide, unlike miglitol, tended to cause hypoglycemia, hyperinsulinemia, and weight gain, which are not desirable in patients with NIDDM.