Polymorphisms and haplotypes of TOLLIP and MUC5B are associated with susceptibility and survival in patients with fibrotic hypersensitivity pneumonitis

INTRODUCTION AND OBJECTIVES

Hypersensitivity pneumonitis (HP) is an interstitial lung disease with diverse clinical features that can present a fibrotic phenotype similar to idiopathic pulmonary fibrosis (IPF) in genetically predisposed individuals. While several single nucleotide polymorphisms (SNPs) have been associated with IPF, the genetic factors contributing to fibrotic HP (fHP) remain poorly understood. This study investigated the association of MUC5B and TOLLIP variants with susceptibility, clinical presentation and survival in Portuguese patients with fHP.

MATERIAL AND METHODS

A case-control study was undertaken with 97 fHP patients and 112 controls. Six SNPs residing in the MUC5B and TOLLIP genes and their haplotypes were analyzed. Associations with risk, survival, and clinical, radiographic, and pathological features of fHP were probed through comparisons among patients and controls.

RESULTS

MUC5B rs35705950 and three neighboring TOLLIP variants (rs3750920, rs111521887, and rs5743894) were associated with increased susceptibility to fHP. Minor allele frequencies were greater among fHP patients than in controls (40.7% vs 12.1%, P<0.0001; 52.6% vs 40.2%, P = 0.011; 22.7% vs 13.4%, P = 0.013; and 23.2% vs 12.9%, P = 0.006, respectively). Haplotypes formed by these variants were also linked to fHP susceptibility. Moreover, carriers of a specific haplotype (G-T-G-C) had a significant decrease in survival (adjusted hazard ratio 6.92, 95% CI 1.73-27.64, P = 0.006). Additional associations were found between TOLLIP rs111521887 and rs5743894 variants and decreased lung function at baseline, and the MUC5B SNP and radiographic features, further highlighting the influence of genetic factors in fHP.

CONCLUSION

These findings suggest that TOLLIP and MUC5B variants and haplotypes may serve as valuable tools for risk assessment and prognosis in fibrotic hypersensitivity pneumonitis, potentially contributing to its patient stratification, and offer insights into the genetic factors influencing the clinical course of the condition.

Chronic Aerobic Training at Different Volumes in the Modulation of Macrophage Function and in vivo Infection of BALB/c Mice by Leishmania major

Physical inactivity is one of the main causes of chronic diseases; however, strenuous exercise can induce immunosuppression. Several studies suggest that moderate amounts of exercise lead to a Th1 response, favoring the resolution of infections caused by intracellular microorganisms, while high volumes of exercise tend to direct the response to Th2, favoring infection by them. Leishmaniasis is a parasitic disease promoted by parasites of the Leishmania genus, with clinical manifestations that vary according to the species of the parasite and the immune response of the host. The experimental Leishmania major–BALB/C mouse model provides a good model for the resistance (Th1 response) or susceptibility (Th2 response) that determines the progression of this infection. The aim of this study was to evaluate the effect of aerobic training at different volumes on modulation of in vitro macrophage infection by L. major, as well as to assess the effect of high volume (HV) aerobic training on the development of L. major in vivo in BALB/c mice. Uninfected animals were submitted to various exercise volumes: none (SED), light (LV), moderate (MV), high (HV), very high (VHV), and tapering (TAP). The macrophages of these animals were infected by L. major and the LV and MV groups showed a decrease in the infection factor, while the VHV showed an increase in the infection factor, when treated with LPS. The cytokine concentration pattern measured in the supernatants of these macrophages suggested a predominant Th1 response profile in the LV and MV groups, while the Th2 profile predominated in the VHV and TAP groups. Groups of BALB/C mice infected with L. major were subjected to high volume (iHV) or non-periodized high volume (iNPHV) exercise or kept sedentary (iSED). The exercised animals suffered a significant increase in injuries caused by the parasites. The animals in the group submitted to high volume exercise (iHV) showed visceralization of the infection. These data strongly suggest that a very high volume of aerobic training increased the susceptibility of BALB/C mice to L. major infection, while moderate distribution of training loads promoted immunological balance, better controlling the infection by this parasite.

Revisiting the Phlebotominae subfamily records in Bahia, Brazil

Brazil is one of the countries that concentrates 90% of all tegumentary and visceral leishmaniases cases and Bahia is one of the highly affected states. In the present report, we consolidated secondary data from several complementary databases that allowed us to record the sand fly species identified including areas of Leishmania spp. transmission in the state of Bahia. We then overlayed the geographical distribution data onto maps of vegetational aspects found across the state. Overall, 21 602 records of phlebotomine sand flies occurrence between 1949 and 2016 were analysed, encompassing 85% of Bahia's municipalities. Seventy-six sand fly species under 17 genera were enlisted. Among described species, 27 were proven or putative Leishmania spp. vectors and three were considered exclusively endemic in the state. Lutzomyia longipalpis, Nyssomyia intermedia and Nyssomyia whitmani were found in 74, 29 and 27% of municipalities, respectively. Salvador, the state capital and major city presented records for 21 different sand fly species, including known vectors for leishmaniasis. In particular, a wide distribution of Evandromyia sallesi was detected for this city. This consolidated account on phebotomine fauna and distribution may be explored for improving the planning and deployment of vector-focused leishmaniasis control measures in affected areas of Bahia.

Effect of Larval Food Availability on Adult Aedes Aegypti (Diptera: Culicidae) Fitness and Susceptibility to Zika Infection

Aedes (Stegomyia) aegypti (Linnaeus, 1762) is a mosquito species of significant medical importance. The use of this vector in research studies usually requires a large number of mosquitoes as well as rearing and maintenance in a laboratory-controlled environment. However, laboratory conditions may be different from field environments, presenting stressful challenges such as low food concentration, especially during larval stages, which may, in turn, impair vector biology. Therefore, we tested herein if larval food availability (0.004, 0.009, 0.020, and 0.070% diets) would affect overall adult insect fitness. We observed slower development in mosquitoes fed a 0.004% diet 15 d post-eclosion (DPE) and shorter mean time in mosquitoes fed a 0.020% diet (7 DPE). Larval diet and adult mosquito weight were positively correlated, and heavier females fed higher larval diets exhibited greater blood feeding capacity and oviposition. In addition, larval diet concentrations led to median adult lifespan variations (male/female in days-0.004%: 30 ± 1.41, 45 ± 1.3; 0.009%: 31.5 ± 1.33, 41 ± 1.43; 0.020%: 26 ± 1.18, 41 ± 1.45; 0.070%: 29 ± 1.07, 44 ± 1.34), reduced tolerance to deltamethrin (1 mg/m2) and changes in detoxification enzyme activities. Moreover, in the larval 0.070% diet, females presented higher Zika susceptibility (plaque-forming unit [PFU]: 1.218 × 106) compared with other diets (0.004%: 1.31 × 105; 0.009%: 2.0 × 105; 0.020%: 1.25 × 105 PFU). Altogether, our study demonstrates that larval diet restriction results not only in larval developmental arrest but also in adult fitness impairment, which must be considered in future assessments.

Impact of copper sulfate application at an urban Brazilian reservoir: A geostatistical and ecotoxicological approach

A landscape ecotoxicology approach was used to assess the spatial distribution of copper in the recent bottom sediment (surficial sediment) of a Brazilian subtropical reservoir (the Guarapiranga reservoir) and its potential ecotoxicological impacts on the reservoir ecosystem and the local society. We discuss the policies and procedures that have been employed for the management of this reservoir over the past four decades. Spatial heterogeneity in the reservoir was evaluated by means of sampling design and statistical analysis based on kriging spatial interpolation. The sediment copper concentrations have been converted into qualitative categories in order to interpret the reservoir quality and the impacts of management policies. This conversion followed the Canadian Water Framework Directive (WFD) ecotoxicological concentration levels approach, employing sediment quality guidelines (SQGs). The SQG values were applied as the copper concentration thresholds for quantitative-qualitative conversion of data for the surficial sediment of the Guarapiranga. The SQGs used were as follows: a) interim sediment quality guideline (ISQG), b) probable effect level (PEL), and c) regional reference value (RRV). The quantitative results showed that the spatial distribution of copper in the recent bottom sediment reflected the reservoir's management policy and the copper application protocol, and that the copper concentrations varied considerably, ranging from virtually-zero to in excess of 3g_copper/kg_ds. The qualitative results demonstrated that the recent bottom sediment was predominantly in a bad or very bad condition, and could therefore have impacts on the local society and the ecosystem. It could be concluded that the management policy for this reservoir was mainly determined by the desire to minimize short-term costs, disregarding long-term socioeconomic and environmental consequences.

Selection of prey to improve biological parameters of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) in laboratory conditions

Mass production of predatory stinkbugs in the laboratory is prioritized to release them into the field as part of IPM programs. Therefore, the aim of this study was to identify the best prey for rearing the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) among five different species of insect (three of Lepidoptera, one of Coleoptera, and one of Diptera). Second-instar P. nigrispinus nymphs were conditioned in transparent 1000-mL plastic pots, adults were placed in Petri dishes for mating, and both stages were maintained under controlled conditions (25 ± 1°C, 12 hours of photophase, 70 ± 10% RH). Nymphs and adults of P. nigrispinus consumed more Musca domestica (Linnaeus, 1758) (Diptera: Muscidae) larvae than the other tested prey. The consumption of fly larvae was 1.5 larvae/day/nymph and adults 1.7 larvae/day/adult. However, the number of eggs per female was less when the predator consumed M. domestica larvae (407.8 eggs/female) and most when consumed the Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) larvae (797.7 eggs/female). Furthermore, the percentage of hatched eggs was greater when the predator females consumed D. saccharalis larvae (90.0%). D. saccharalis larvae is the best prey to rearing P. nigrispinus.

Cortical maturation in fetuses referred for 'isolated' mild ventriculomegaly: a longitudinal ultrasound assessment

OBJECTIVES

To compare cortical maturation between fetuses with isolated mild ventriculomegaly (IMV) and healthy fetuses, and to explore its potential prognostic value in IMV.

METHODS

This prospective study quantified cortical maturation by ultrasound in 24 fetuses with IMV and 46 healthy fetuses. Depth and grading the developmental pattern of the parieto-occipital fissure (POF), calcarine fissure (CF) and sylvian fissure, and grading the Sylvian fissure operculization at 23-25, 27-28 and 31-32 weeks gestation were determined.

RESULTS

At 23-25 and 27-28 gestational weeks, POF and CF mean depths were statistically lower in the IMV group. The POF and CF depth distribution had a normal distribution in the control group but displayed a bimodal distribution in the IMV group. IMV with progression of ventricular dilatation showed mean depth of CF lower than IMV in which ventriculomegaly regressed or remained stable. The sensitivity, specificity, positive predictive value and negative predictive value of a CF depth below the fifth percentile to predict progression of ventricular dilatation were, at 28 weeks, 100%, 88%, 67% and 100%, respectively.

CONCLUSIONS

Cortical fissure assessment by ultrasound allowed the differentiation of a subgroup of IMV fetuses with a higher risk of progression of ventricular dilatation.

Autoantibodies and high-risk HLA susceptibility markers in first-degree relatives of Brazilian patients with type 1 diabetes mellitus: a progression to disease based study

PURPOSE

The objective of this study was to determine the frequencies of autoantibodies to heterogeneous islet-cell cytoplasmic antigens (ICA), glutamic acid decarboxylase(65) (GAD(65)A), insulinoma-associated antigen-2 (IA-2A) and insulin (IAA)-and human leukocyte antigen (HLA) class II markers (HLA-DR and -DQ) in first degree relatives of heterogeneous Brazilian patients with type I diabetes (T1DM). A major focus of this study was to determine the influence of age, gender, proband characteristics and ancestry on the prevalence of autoantibodies and HLA-DR and -DQ alleles on disease progression and genetic predisposition to T1DM among the first-degree relatives.

METHODS

IAA, ICA, GAD(65)A, IA-2A and HLA- class II alleles were determined in 546 first-degree-relatives, 244 siblings, 55 offspring and 233 parents of 178 Brazilian patients with T1DM.

RESULTS

Overall, 8.9% of the relatives were positive for one or more autoantibodies. IAA was the only antibody detected in parents. GAD(65) was the most prevalent antibody in offspring and siblings as compared to parents and it was the sole antibody detected in offspring. Five siblings were positive for the IA-2 antibody. A significant number (62.1%) of siblings had 1 or 2 high risk HLA haplotypes. During a 4-year follow-up study, 5 siblings (expressing HLA-DR3 or -DR4 alleles) and 1 offspring positive for GAD(65)A progressed to diabetes.

CONCLUSIONS

The data indicated that the GAD(65) and IA-2 antibodies were the strongest predictors of T1DM in our study population. The high risk HLA haplotypes alone were not predictive of progression to overt diabetes.

Cardiovascular, metabolic and hormonal responses to the progressive exercise performed to exhaustion in patients with type 2 diabetes treated with metformin or glyburide

OBJECTIVES

To evaluate the effects of Metformin and Glyburide on cardiovascular, metabolic and hormonal parameters during progressive exercise performed to exhaustion in the post-prandial state in women with type 2 diabetes (T2DM).

DESIGN AND METHODS

Ten T2DM patients treated with Metformin (M group), 10 with Glyburide (G group) and 10 age-paired healthy subjects exercised on a bicycle ergometer up to exercise peak. Cardiovascular and blood metabolic and hormonal parameters were measured at times -60 min, 0 min, exercise end, and at 10 and 20 minutes of recovery phase. Thirty minutes before the exercise, a standard breakfast was provided to all participants. The diabetic patients took Metformin or Glyburide before or with meal.

RESULTS

Peak oxygen uptake (VO(2)) was lower in patients with diabetes. Plasma glucose levels remained unchanged, but were higher in both diabetic groups. Patients with diabetes also presented lower insulin levels after meals and higher glucagon levels at exercise peak than C group. Serum cortisol levels were higher in G than M group at exercise end and recovery phase. Lactate levels were higher in M than G group at fasting and in C group at exercise peak. Nor epinephrine, GH and FFA responses were similar in all 3 groups.

CONCLUSION

Progressive exercise performed to exhaustion, in the post-prandial state did not worsen glucose control during and after exercise. The administration of the usual dose of Glyburide or Metformin to T2DM patients did not influence the cardiovascular, metabolic and hormonal response to exercise.

Gender- and age-related variations in blood viscosity in normal volunteers: a study of the effects of extract of Allium sativum and Ginkgo biloba

This study sought to compare the effects of age and gender on blood viscosity and to appraise the effectiveness of Ginkgo biloba and Allium sativum extracts in reducing blood viscosity. Stage 1: Our sample consisted of 80 male volunteers (40 aged 18-60 and 40 aged 61 and over) and 80 females with the same age profile. Stage 2: We studied 60 male volunteers allocated in groups: placebo, G. biloba, and A. sativum. Stage 3: We studied 25 male volunteers and in the initial, intermediate, and final evaluations, the measures of blood viscosity were repeated. Volunteers were given a clinical evaluation and submitted to laboratory tests. G. biloba led to the highest reduction in blood viscosity compared with placebo and A. sativum. In relation to the use of the two substances, G. biloba and A. sativum, dry extract of G. biloba proved to be more effective in reducing blood viscosity.

The effects of metformin and glibenclamide on glucose metabolism, counter-regulatory hormones and cardiovascular responses in women with Type 2 diabetes during exercise of moderate intensity

AIMS

To compare the effects of metformin and glibenclamide on cardiovascular, metabolic and hormonal parameters during exercise of moderate intensity performed in the postprandial state, in women with Type 2 diabetes.

METHODS

Ten patients treated with metformin, 10 with glibenclamide and 10 control subjects (C) exercised on a bicycle ergometer at 50% of oxygen uptake (VO(2)) peak for 45 min. Cardiovascular, blood metabolic and hormonal parameters were determined at times -60 min (fasting), 0, +15, +30, +45 min (exercise) and at +60, +90 min (recovery). Thirty minutes prior to exercise, participants consumed a standard breakfast. Patients with diabetes took metformin or glibenclamide before the meal.

RESULTS

Systolic and diastolic blood pressure and plasma glucose were higher in both diabetic groups, for the whole experiment. Blood glucose did not change during exercise in the three groups and increased at recovery only in the control group. Plasma glucagon concentrations at the end of exercise and recovery, and plasma lactate concentrations at recovery were higher in the metformin group. Insulin, noradrenaline, growth hormone, cortisol and free fatty acid responses were similar in all three groups.

CONCLUSIONS

Our results suggest that the usual dose of glibenclamide and metformin can be taken safely before postprandial exercise of moderate intensity without affecting cardiovascular, metabolic and hormonal responses. However, after exercise, glibenclamide and metformin prevent the normal rise in blood glucose and metformin delays the fall in plasma lactate concentrations.

Effects of type of physical exercise and leisure activities on the depression scores of obese Brazilian adolescent girls

Several studies have indicated that depressive states may lead to hypokinesia with diminished metabolic rate and energy use. Hypokinesia associated with certain eating behaviors may lead to an unfavorable energy balance that can contribute to the emergence and prevalence of obesity among children and adults. The purpose of the present study was to examine the possibility of reducing depression inventory scores in female adolescents with third-degree obesity while testing the effectiveness of different exercise programs in reducing anxiety and depression scores. The sample consisted of 40 female subjects (mean age 16 +/- 1.56 years) divided into 4 groups (aerobic training, anaerobic training, leisure activities, and control). Subjects had a body mass index of 95% or more in relation to the 50th percentile. The aerobic program consisted of three ergometric bicycle sessions per week over a 3-month period (12 weeks) and the activities were prescribed after determining the anaerobic ventilatory threshold (VO2 threshold). Anaerobic training was based on the Wingate anaerobic power test. The leisure program consisted of a varied range of activities (games, exercises, etc.). A nutritionist interviewed the members of these two groups and the control group every week in order to adapt them to the nutritional guidelines proposed for the study. The study showed that all three programs (aerobic exercise, anaerobic exercise and leisure activities) were effective in reducing body mass. However, we found a significant reduction when analyzing the depression scores only for aerobic exercise (18.9 +/- 9.33 to 10.6 +/- 9.56 or 43.9%) but no significant alterations for anaerobic exercise (11.36 +/- 5.23 to 9.63 +/- 4.78 or 15.22%) and leisure (17.28 +/- 7.55 to 15.07 +/- 7.54 or 12.78%), thus indicating that in principle this type of activity could be included to improve emotional well-being of obese adolescent girls.

Effects of paradoxical sleep deprivation on blood parameters associated with cardiovascular risk in aged rats

The effects of 96 h of paradoxical sleep deprivation (PSD) on blood parameters associated with cardiovascular risk were studied in young (3-month old) and aged (22-month old) rats. In general, aging was associated with an overall increase in most measures, irrespective of sleep deprivation condition. The latter manipulation also had significant effects on blood variables, but not in a consistent pattern. Thus, PSD significantly reduced triglyceride levels in both young and aged rats; it reduced blood viscosity in aged but not in young rats, and had no effect on the increased cholesterol levels observed in aged controls. Examinations of cholesterol fractions revealed significant increases in low density lipoprotein and high density lipoprotein in aged PSD rats compared to respective controls, whereas very low density lipoprotein was significant decreased after PSD in both young and aged animals. PSD increased vitamin B(12) levels in aged rats, and significantly decreased homocysteine levels in young but not in aged rats which in turn were already reduced. Folate levels were the only variable that was unaffected by aging and/or PSD. These results indicate that PSD has significant but heterogeneous physiological effects in aged rats and may intensify certain aging-related effects which contribute to cardiovascular disease risk while attenuating others.

Effect of thalidomide and rosiglitazone on the prevention of diabetic retinopathy in streptozotocin-induced diabetic rats

AIMS/HYPOTHESIS

Our aim was to compare the therapeutic effect of thalidomide and rosiglitazone on the prevention of diabetic retinopathy in streptozotocin-induced diabetic rats.

METHODS

Male Holtzman rats of 6 to 8 weeks of age and weighing 170+/-30 g were randomly divided into four groups: control ( n=13), untreated diabetic ( n=17) and diabetic rats treated with thalidomide (200 mg kg(-1) day(-1)) ( n=8) or rosiglitazone (1 mg kg(-1) day(-1)) ( n=22) for 3 months. Diabetes was induced by streptozotocin with the rats having a body weight of 70 mg/kg. After treatment, vascular endothelial growth factor (VEGF) concentrations in ocular fluid were compared between the different groups, and retinal capillary basement membrane thickness was measured by electron microscopy.

RESULTS

Higher VEGF concentrations in ocular fluid and thicker basement membranes were observed in untreated diabetic rats compared to the control rats. Similar VEGF concentrations and basement membrane thickness were observed for the thalidomide-treated group compared with the control group, whereas no difference in these parameters was observed between the rosiglitazone-treated rats and the control or untreated diabetic rats.

CONCLUSIONS/INTERPRETATION

Our findings confirm the association between VEGF concentrations and diabetic retinopathy as suggested by other investigators. Thalidomide, but not rosiglitazone, was associated with the inhibition of basement membrane thickening and the blockade of the increase of VEGF in ocular fluid, thus representing a potential therapeutic drug for the prevention of diabetic retinopathy.

Cognitive performance, SPECT, and blood viscosity in elderly non-demented people using Ginkgo biloba

The aging process is associated with several cognitive alterations. This study looks at the effects of taking dried extract of Ginkgo biloba, which has been used in several countries in an attempt to minimize these effects. The subjects were 48 men aged 60 - 70 matched between control and experimental groups for educational level. Evaluation was based on a number of neuropsychological tests in an attempt to cover the largest possible number of functions including Single Photon Emission Computer Tomography (SPECT) and measures of blood viscosity. The study was run on a double-blind basis with placebo and Ginkgo biloba groups evaluated over a period of 8 months. After treatment, the experimental group showed a reduction in blood viscosity, improved cerebral perfusion in specific areas and improved global cognitive functioning. The control group showed the opposite - higher blood viscosity, a reduction in cerebral perfusion (in specific areas), and cognitive deterioration in different functions. Although the mechanisms by which Ginkgo biloba may contribute to overall enhancement of the parameters evaluated have not been specified, this plant extract certainly appears to be effective in the treatment of cognitive deficits in older people. Further research into its use is called for on the basis of the results obtained here.

Depot-specific hormonal characteristics of subcutaneous and visceral adipose tissue and their relation to the metabolic syndrome

Visceral adipose tissue (VAT) imaged by computed tomography (CT) or magnetic resonance imaging (MRI) is associated with the metabolic syndrome features, being morphologically and functionally different from subcutaneous adipose tissue (SAT). Insulin effect is lower and catecholamine effect higher in visceral adipose tissue, with its metabolites and its secretions draining through portal system, partially at least, to the liver. Thus, visceral cells transfer and release fatty acids more extensively, have increased glucocorticoid and reduced thiazolidinedione responses, produce more angiotensinogen, interleukin-6 and plasminogen activator inhibitor-1, and secrete less leptin and adiponectin than SAT. Furthermore, there are regional differences in the intrinsic characteristics of the preadipocytes, with those of SAT presenting greater differentiation and fat cell gene expression but less apoptosis than that of VAT. All features contribute to the morbidity associated with increased VAT. To evaluate the relationship between VAT and components of the metabolic syndrome, 55 non-diabetic women, 11 lean (VAT < 68 cm 2) and 44 obese were studied. The obese with VAT within the normal range (VAT < or = 68 cm 2) had higher BMI, WHR, BP and resistance to FFA suppression during oGTT in comparison to the lean controls. The obese with VAT > 68 cm 2 compared to those with VAT < or = 68 cm 2 had similar body mass index (BMI) but significantly higher in vivo homeostasis model assessment for insulin resistance (HOMA IR ) results and triglycerides. By pooling all data, correlation analysis indicated that VAT contributes more to insulin resistance (HOMA IR ) than SAT does, but not when insulin-suppressed plasma free fatty acids during oral glucose tolerance test as an index of insulin resistance are taken into consideration.

Erythrocyte insulin receptor tyrosine kinase activity is increased in glyburide-treated patients with type 2 diabetes in good glycaemic control

AIM

The goal of this study was to test the hypothesis that insulin receptor tyrosine kinase activity of isolated erythrocytes would be greater in glyburide-treated patients with type 2 diabetes in good glycaemic control (n = 13) than in untreated patients (n = 12) with significant fasting hyperglycaemia.

METHODS

The two groups were similar in age, sex distribution, and body mass index. By selection, glyburide-treated patients had significantly (p < 0.001) lower (mean +/- s.e.m.) fasting glucose (6.9+/-0.4 vs. 13.9+/-0.8 mmol/l) and HbA(IC) (7.4+/-0.2 vs. 11.8+/-0.9%) concentrations. In addition, insulin-stimulated tyrosine kinase activity was increased in erythrocytes from glyburide -treated patients (p < 0.01).

RESULTS

Although insulin receptor number was similar in solubilized erythrocytes from the two groups, tyrosine kinase activity per insulin receptor was significantly (p < 0.02) greater in erythrocytes from glyburide-treated patients with type 2 diabetes.

CONCLUSIONS

These findings are quite similar to previously published data in metformin-treated patients. As such, it is suggested that decreases in insulin receptor tyrosine kinase activity may contribute to the loss of insulin sensitivity in hyperglycaemic subjects (glucotoxicity), and that an improvement in glycaemic control, irrespective of how it is achieved, will help rectify this abnormality.

Overnight lowering of free fatty acids with Acipimox improves insulin resistance and glucose tolerance in obese diabetic and nondiabetic subjects

Obesity is commonly associated with elevated plasma free fatty acid (FFA) levels, as well as with insulin resistance and hyperinsulinemia, two important cardiovascular risk factors. What causes insulin resistance and hyperinsulinemia in obesity remains uncertain. Here, we have tested the hypothesis that FFAs are the link between obesity and insulin resistance/hyperinsulinemia and that, therefore, lowering of chronically elevated plasma FFA levels would improve insulin resistance/hyperinsulinemia and glucose tolerance in obese nondiabetic and diabetic subjects. Acipimox (250 mg), a long-acting antilipolytic drug, or placebo was given overnight (at 7:00 P.M., 1:00 A.M., 7:00 A.M.) to 9 lean control subjects, 13 obese nondiabetic subjects, 10 obese subjects with impaired glucose tolerance, and 11 patients with type 2 diabetes. Euglycemic-hyperinsulinemic clamps and oral glucose tolerance tests (75 g) were performed on separate mornings after overnight Acipimox or placebo treatment. In the three obese study groups, Acipimox lowered fasting levels of plasma FFAs (by 60-70%) and plasma insulin (by approximately 50%). Insulin-stimulated glucose uptake during euglycemic-hyperinsulinemic clamping was more than twofold higher after Acipimox than after placebo. Areas under the glucose and insulin curves during oral glucose tolerance testing were both approximately 30% lower after Acipimox administration than after placebo. We conclude that lowering of elevated plasma FFA levels can reduce insulin resistance/hyperinsulinemia and improve oral glucose tolerance in lean and obese nondiabetic subjects and in obese patients with type 2 diabetes.

Effect of metformin on insulin-stimulated tyrosine kinase activity of erythrocytes from obese women with normal glucose tolerance

The purpose of this study was to document the possible effect of solubilised erythrocytes on insulin-receptor binding and tyrosine kinase activity after 12 weeks of metformin administration to 13 healthy obese women with no history of diabetes and normal glucose as evaluated by conventional criteria. Subjects were given metformin 850 mg twice a day for 12 weeks. The results showed that plasma glucose response to an oral glucose challenge did not change following metformin, but that insulin response was significantly lower (p < 0.0001). In addition, both the number of insulin receptors and the tyrosine kinase activity per receptor of solubilised erythrocytes were significantly greater following metformin administration. Since both body weight and plasma glucose concentrations were similar before and after treatment, the effect of metformin on insulin-receptor binding and tyrosine kinase activity appeared to be independent of either of these variables. In summary, oral administration of metformin led to an increase in tyrosine kinase activity or erythrocyte insulin receptors, suggesting that such action occurs in the absence of any significant change in plasma glucose concentration.

Changes in insulin receptor tyrosine kinase activity associated with metformin treatment of type 2 diabetes

This study was performed to define the effect of metformin on glycaemic control and erythrocyte insulin receptor tyrosine kinase activity in patients with non-insulin-dependent (Type 2) diabetes mellitus. A case-control study of the effect of metformin treatment in hyperglycaemic patients with Type 2 diabetes was conducted in outpatients of the Diabetes Clinical Center. The study population consisted of 14 patients with Type 2 diabetes (5 males, 9 females) whose hyperglycaemia was uncontrolled by diet. Patients were treated with metformin 850 mg twice daily for 2 1/2 months. Fasting plasma glucose concentrations decreased from 8.9 to 6.4 mmol/L after 10 weeks of metformin treatment (p < 0.001), in association with significantly lower (p < 0.001) plasma glucose and insulin concentrations in response to an oral glucose load. In addition, both fasting plasma triglyceride and cholesterol concentrations were significantly (p < 0.001) lower after metformin treatment. There was no change in erythrocyte insulin receptor binding associated with metformin treatment, but both basal and insulin-stimulated insulin receptor tyrosine kinase activities of solubilized erythrocyte insulin receptors were significantly higher after 10 weeks of metformin treatment. It is concluded that the increase in insulin-stimulated tyrosine kinase activity contributed to the improvement in glucose insulin and lipoprotein metabolism associated with metformin treatment of Type 2 diabetes.

Insulin-receptor tyrosine kinase activity is decreased in erythrocytes from non-obese patients with NIDDM

We have examined insulin binding, and insulin receptor associated tyrosine kinase activity in detergent solubilized and Ricin II-agarose purified receptor preparations from erythrocytes of obese and non-obese subjects with normal glucose tolerance and non-obese patients with NIDDM. Insulin receptor activity, as assessed by [125I Tyr A14] insulin binding, was significantly lower in erythrocyte preparations from the obese group when compared with similar preparations from non-obese subjects, with either normal glucose tolerance or NIDDM. The affinity of the receptor for insulin, however, was reduced in both obese subjects and patients with NIDDM as compared to non-obese subjects with normal glucose tolerance. Insulin receptor tyrosine kinase activity, measured in the absence (basal) and presence of insulin (0.3-3000 nM), was decreased in obese and NIDDM subjects with normal glucose tolerance and in patients with NIDDM. Insulin sensitivity, measured as the dose of insulin required for half-maximal activation of kinase activity, however, was comparable among three groups. In contrast, insulin-stimulated tyrosine kinase activity, when normalized to insulin binding activity, was unchanged in both non-obese and obese subjects with normal glucose tolerance, but was reduced approximately 60% in the NIDDM group. These findings indicate that the functional behavior of insulin receptor-kinase signaling system is markedly impaired in non-obese patients with NIDDM. Furthermore, the insulin receptor-tyrosine kinase defect (i.e. decrease in activity) observed in patients with NIDDM is probably related to a reduction in coupling efficiency between insulin binding and the activation of the receptor tyrosine kinase activity.

Effect of anatomical site on insulin action and insulin receptor phosphorylation in isolated rat adipocytes

The effects of insulin were evaluated on adipocytes isolated from three different anatomical sites in male, Sprague-Dawley rats: epididymal (EPI), retroperitoneal (RP), and dorsal subcutaneous (SC). The results indicated that maximal insulin-stimulated glucose transport was significantly lower (P less than 0.001) in cells from the SC region as compared to EPI and RP cells. In addition, the ED50 value for SC cells (259 +/- 34 pmol/l) was significantly higher than for EPI (66 +/- 5 pM) or RP adipocytes (111 +/- 32 pmol/l). Insulin inhibition of catecholamine-induced lipolysis was also significantly greater (P less than 0.001) in EPI cells as compared to RP or SC adipocytes, and that was true when expressed in absolute or relative terms. The decrease in the ability of insulin to either stimulate glucose transport or inhibit catecholamine induced lipolysis in SC cells was associated with a decrease in insulin receptor autophosphorylation and receptor tyrosine kinase activity. These data show that insulin action on isolated adipocytes varies as a function of anatomical site, and that these changes are associated with variations in insulin receptor autophosphorylation and insulin receptor tyrosine kinase activity.

Characterization of insulin receptor kinase activity and autophosphorylation in different skeletal muscle types

We have examined insulin binding, autophosphorylation, and tyrosine kinase activity in detergent-solubilized and wheat germ agglutinin-purified insulin receptor preparations from four rat muscles of different fiber composition (i.e., tensor fascia latae, soleus, vastus intermedius, and plantaris). Insulin binding activity was similar in three of the four muscles but lower in tensor fascia latae. No significant differences were noted in the affinity of insulin for its receptor from various muscle types. Insulin receptor tyrosine kinase activity measured in the absence (basal) and presence of insulin (0.3-300 nM) was comparable in all muscle types (normalized to the amount of insulin bound). Insulin sensitivity, measured as the dose of insulin required for half-maximal activation of kinase activity, was also similar in all muscle types. Likewise, incubation of receptor preparations with [gamma-32P]ATP, Mn2+, and insulin (0.25-100 nM) resulted in a dose-dependent autophosphorylation of the beta-subunit (relative molecular weight approximately 95 kDa) with similar kinetics in all muscle types. In conclusion, these results show that the functional behavior of the insulin receptor autophosphorylation-kinase system (in vitro) is not changed by alterations in muscle fiber composition, indicating that differences in insulin sensitivity between different skeletal muscle types is probably not due to modulation of the insulin receptor phosphorylation system.

Effects of exercise training on the relationship between insulin binding and insulin-stimulated tyrosine kinase activity in rat skeletal muscle

The effect of exercise training on insulin binding and insulin receptor tyrosine kinase activity was studied using detergent solubilized wheat germ agglutinin (WGA)-agarose purified receptor preparations from rat biceps femoris (BF) and tensor fascia lata (TFL) muscles. Insulin receptor activity, as assessed by A14 [125I] insulin binding, was significantly elevated in BF of exercise-trained rats when compared with similar preparations from a sedentary control group. This increase in binding activity was due to change in Bmax not KD. In contrast, neither the Bmax nor the KD of insulin binding to TFL changed with exercise training. The structure of insulin receptors isolated from BF or TFL was unaltered by exercise training as determined by affinity labeling (alpha-subunit, molecular weight (mol wt) approximately 131 kilodaltons [kDa]) and electrophoretic mobility of the alpha- and beta-subunit. Furthermore, basal tyrosine kinase activity was not affected by exercise training in extracts from either BF or TFL. However, the insulin dependent increase in maximal tyrosine kinase activity (Vmax) of the BF, but not TFL, was enhanced by exercise training. Specifically, insulin stimulated phosphorylation of both the beta-subunit of the insulin receptor (auto phosphorylation) and of a synthetic peptide (exogenous phosphorylation) were increased over control values in BF from exercise-trained rats, whereas both measurements of tyrosine kinase activity of TFL from the two experimental groups were similar. In contrast, both insulin-stimulated autophosphorylation and tyrosine kinase activity were significantly decreased in BF of exercise-trained rats when normalized to insulin binding activity. This disassociation was only seen in BF from exercise-trained rats, and was not true of TFL. These data indicate that exercise training can lead to increases in insulin receptor number and tyrosine kinase activity, as well as modifying the relationship between these two variables. The changes noted are not observed in all exercising muscles, and their development seems to depend upon the fiber composition. These results emphasize the complex relationship that exists in the regulation of insulin action at the level of its receptor.

Prevention of insulin resistance by environmental manipulation as young rats mature

This study was initiated in an attempt to see if the insulin resistance associated with maturation in young rats could be prevented by environmental manipulation. Consequently, seven week-old rats were either housed in standard laboratory cages and fed a calorie-restricted diet or placed individually in exercise wheel cages and allowed to eat chow ad lib. A control group of rats was housed in standard laboratory cages from seven weeks to five months of age, and also allowed to eat chow ad lib. When studied at five months of age, the chow-fed rats weighed more (624 +/- 8 g) than either the calorie restricted (479 +/- 9 g) or exercise trained (485 +/- 13 g) rats. Insulin action was compared in the three groups by assessing the steady-state serum glucose (SSSG) and insulin (SSSI) concentrations achieved during a continuous intravenous infusion of glucose and exogenous insulin. The results of these studies indicated that SSSG concentration was significantly higher (P less than 0.001) in chow-fed rats than in the two experimental groups. Since SSSI concentrations were the same in all three groups, lower SSSG concentrations in calorie-restricted and exercise trained rats indicates that insulin-stimulated glucose uptake was preserved in these two groups as compared to the chow-fed population. In an attempt to understand why exercise training and calorie restriction prevented the development of insulin resistance, muscle glycogen synthase activity and muscle capillary density were compared in the three groups of five month-old rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Simple suture with or without proximal gastric vagotomy for perforated duodenal ulcer

To assess the results of proximal gastric vagotomy (PGV) in the definitive treatment of perforated duodenal ulcers, a prospective study was carried out comparing PGV in association with omental patch suture (PGV + S) with the simple omental patch suture procedure (S). The PGV + S series consisted of 38 consecutive patients with perforated duodenal ulcer and the S series consisted of 38 survivors of a similar series of 41 consecutive patients. Surgical mortality was zero in the PGV + S series. The patients were followed up for 1 to 7 years. No cases of dumping or diarrhoea were observed. Thirty-three patients in the PGV + S series (87 per cent) were classified as Visick grade I and only two (5 per cent) as Visick grade IV. In contrast, 11 patients (29 per cent) were Visick grade I and 22 (58 per cent) were Visick grade IV in the S series. Recurrent ulcer was detected endoscopically in 58 per cent of the patients who had been treated with simple suture and in only 5 per cent after suture plus PGV. PGV is a safe operation with a negligible morbidity rate and with a significant rate of effective control of ulcer disease. Depending on the general condition of the patient and on the surgeon's skill, it appears preferable to treat not only the acute perforation but also the ulcer disease by PGV.

Morphological patterns in Petunia hybrida plants regenerated from tissue cultures and differing by their ploidy

Quantitative variation in seven morphological characteristics (leaf length and width, leaf length/ width ratio, flower, petal and stomata length, and number of chloroplasts in guard cells) were studied in Petunia hybrida plants regenerated from anther tissue culture and belonging to four different classes of ploidy (2n, 2n-3n, 3n-2n, 4n-8n). Results showed that leaf size is not a good characteristic for discriminating between plants of different ploidy - flower and stomata characteristics being more adequate for this purpose. After applying stepwise discriminant analysis the association "chloroplast number - leaf length/width ratio - petal length" was verified to be more appropriate for the discrimination of ploidy classes.