ATP-dependent conformational dynamics in a photoactivated adenylate cyclase revealed by fluorescence spectroscopy and small-angle X-ray scattering

Structural insights into the photoactivated adenylate cyclases can be used to develop new ways of controlling cellular cyclic adenosine monophosphate (cAMP) levels for optogenetic and other applications. In this work, we use an integrative approach that combines biophysical and structural biology methods to provide insight on the interaction of adenosine triphosphate (ATP) with the dark-adapted state of the photoactivated adenylate cyclase from the cyanobacterium Oscillatoria acuminata (OaPAC). A moderate affinity of the nucleotide for the enzyme was calculated and the thermodynamic parameters of the interaction have been obtained. Stopped-flow fluorescence spectroscopy and small-angle solution scattering have revealed significant conformational changes in the enzyme, presumably in the adenylate cyclase (AC) domain during the allosteric mechanism of ATP binding to OaPAC with small and large-scale movements observed to the best of our knowledge for the first time in the enzyme in solution upon ATP binding. These results are in line with previously reported drastic conformational changes taking place in several class III AC domains upon nucleotide binding.

Maternal overnutrition elevates offspring's blood pressure-A systematic review and meta-analysis

BACKGROUND

Maternal overnutrition during pregnancy predisposes the offspring to cardiometabolic diseases.

OBJECTIVES

This systematic review and meta-analysis aimed to investigate the association between maternal overnutrition and offspring's blood pressure (BP) and the effect of offspring's obesity on this association.

DATA SOURCES

PubMed, EMBASE, Clinicaltrials.gov, CENTRAL.

STUDY SELECTION AND DATA EXTRACTION

Human studies published in English before October 2021 were identified that presented quantitative estimates of association between maternal overnutrition just before or during pregnancy and the offspring's BP.

SYNTHESIS

Random-effect model with the DerSimonian and Laird weighting method was used to analyse regression coefficients or mean differences.

RESULTS

After selection, 17 observational studies (140,517 mother-offspring pairs) were included. Prepregnancy body mass index (ppBMI) showed positive correlation with BP in offspring (regression coefficient for systolic: 0.38 mmHg per kg/m² , 95% confidence interval (CI) 0.17, 0.58; diastolic: 0.10 mmHg per kg/m² , 95% CI 0.05, 0.14). These indicate 1.9 mmHg increase in systolic and 0.5 mmHg increase in diastolic BP of offspring with every 5 kg/m² gain in maternal ppBMI. Results on coefficients adjusted for offspring's BMI also showed association (systolic: 0.08 mmHg per kg/m² , 95% CI 0.04, 0.11; diastolic: 0.03 mmHg per kg/m² , 95% CI 0.01, 0.04). Independent from ppBMI, gestational weight gain (GWG) showed positive correlation with systolic BP (systolic BP: 0.05 mmHg per kg, 95% CI 0.01, 0.09), but not after adjustment for offspring's BMI. Mean systolic BP was higher in children of mothers with excessive GWG than in those of mothers with optimal GWG (difference: 0.65 mmHg, 95% CI 0.25, 1.05).

CONCLUSIONS

Independent from offspring's BMI, higher prepregnancy BMI may increase the risk for hypertension in offspring. The positive association between GWG and offspring's systolic BP is indirect via offspring's obesity. Reduction in maternal obesity and treatment of obesity in children of obese mothers are needed to prevent hypertension.

Hyaluronic Acid Is an Effective Dermal Filler for Lip Augmentation: A Meta-Analysis

Introduction: The lips and the mouth play an indispensable role in vocalization, mastication and face aesthetics. Various noxious factors may alter and destruct the original structure, and appearance of the lips and the anatomical area surrounding the mouth. The application of hyaluronic acid (HA) may serve as a safe method for lip regeneration. Although a number of studies exist for HA effectiveness and safety, its beneficial effect is not well-established. Aim: The present meta-analysis and systematic review was performed to investigate the effectiveness of HA on lip augmentation. We also investigated the types and nature of adverse effects (AEs) of HA application. Methods: We reported our meta-analysis in accordance with the PRISMA Statement. PROSPERO protocol registration: CRD42018102899. We performed the systematic literature search in CENTRAL, Embase, and MEDLINE. Randomized controlled trials, cohort studies, case series and case reports were included. The untransformed proportion (random-effects, DerSimonian-Laird method) of responder rate to HA injection was calculated. For treatment related AEs descriptive statistics were used. Results: The systematic literature search yielded 32 eligible records for descriptive statistics and 10 records for quantitative synthesis. The results indicated that the overall estimate of responders (percentage of subjects with increased lip fullness by one point or higher) was 91% (ES = 0.91, 95% CI:0.85-0.96) 2 months after injection. The rate of responders was 74% (ES = 0.74, 95% CI:0.66-0.82) and 46% (ES = 0.46, 95% CI:0.28-0.65) after 6 and 12 months, respectively. We included 1,496 participants for estimating the event rates of AEs. The most frequent treatment-related AEs were tenderness (88.8%), injection site swelling (74.3%) and bruising (39.5%). Rare AEs included foreign body granulomas (0.6%), herpes labialis (0.6%) and angioedema (0.3%). Conclusion: Our meta-analysis revealed that lip augmentation with injectable HA is an efficient method for increasing lip fullness for at least up to 6 months after augmentation. Moreover, we found that most AEs of HA treatment were mild or moderate, but a small number of serious adverse effects were also found. In conclusion, further well-designed RCTs are still needed to make the presently available evidence stronger.

Patterns of alcohol consumption in university students: a European study

Background

In Europe, alcohol consumption (AC), especially binge drinking (BD) and behavioural risk factors among students in higher education remain to be investigated. The aim of the study was to assess the evolution of AC, and BD and the behavioural factors associated in university students in four European universities: Chisinau (Ch) in Republic of Moldova, Cluj-Napoca (Cl) in Romania, Miskolc (Ms) in Hungary and Rouen (Ro) in France.

Methods

In the four countries in 2018, students in higher education completed an anonymous standardized self-questionnaire. The questionnaire collected age, gender (M, W), housing, curricula, smoking, cannabis consumption. Alcohol abuse problems were assessed by ADOSPA test and by AUDIT test.. Frequent BD was determined as a consumption of five or most alcoholic drinks on one occasion at least twice a month. A risk profile of consumers was conducted according to the consumption of alcohol and frequency of BD.

Results

A total of 3076 students were included, 705 in Ch, 582 in Cl, 534 in Ms and 1255 in Ro. Globally, the sex-ratio was quite similar (M:F=0.45), the mean age was 21.2 (SD = 4.1). In Ro, 83.6% of students consumed alcohol at least 1 per week, 86.4% in Ch, 27.6% in Cl, 43.6% in Ms. The prevalence of frequent BD was 15.9% in Ms and 13.8% in Ro, 11.5% in Ch and 12.6% in Cl. Alcohol hazardous drinking and risk of addiction levels were found in 19.3% of students in Ro, 27.6%, in Ms, 7.4% in Cl and 13,6% in Ch. Regarding patterns of consumption significant difference by gender were found. After multivariate analysis, different risk behaviours were found.

Conclusions

BD patterns in students were quite similar in the four countries, especially in male students. BD appears as a frequent, whose consequences remain to be investigated. It might be necessary in the future to screen students for potential ED upon entry to the university and also to inform student about the risk of ED and advise them to consult a healthcare professional.

Key messages

The study showed that alcohol is a central part of students’ lives in France, Hungary, Republic of Moldova and Romania. Specific target populations for public health interventions were identified.

The quadrivalent HPV vaccine is protective against genital warts: a meta-analysis

BACKGROUND

The quadrivalent human papillomavirus (HPV) vaccine has been assumed to give protection against genital warts (GW) as well as cervical cancer. Our main question was whether HPV vaccine has any effects on the prevention of GW reported in randomised controlled clinical trials (RCTs) and time-trend analyses.

METHODS

This meta-analysis was performed according to the PRISMA guidelines using the PICO format. We searched in three electronic databases (PubMed, Embase, Cochrane Trials), and assessed heterogeneity using the Q-test and I-squared statistics, meta-regression was also performed. Odds ratios (OR) and their confidence intervals (CI) were calculated. The sensitivity was tested by leave-one-out method. We evaluated the presence of publication bias using the funnel plot graph and the Copas selection model. The strength of evidence was assessed using the GRADE approach.

RESULTS

Eight RCTs (per-protocol populations) and eight time-trend ecological studies were included in this meta-analysis. A significant reduction (pooled OR = 0.03, 95% CI: 0.01-0.09; I-squared = 53.6%) of GW in young women was recorded in RCTs, and in time-trend analyses both in young women (pooled OR = 0.36, CI 95% = 0.26-0.51; I-squared = 98.2%), and in young men (pooled OR = 0.69, 95% CI = 0.61-0.78; I-squared = 92.7%). In subgroup analysis, a significant reduction of the number of GW events was observed especially in women under 21 years (pooled OR = 0.33, 95% CI = 0.17-0.63). Leave-one-out analysis showed that similar results could be obtained after excluding one study, meta-regression did not show significant difference.

CONCLUSIONS

Prophylactic, quadrivalent HPV vaccination can prevent GW in healthy women and men, therefore, it should be included in routine immunization programme.

Abdominal obesity increases metabolic risk factors in non-obese adults: a Hungarian cross-sectional study

Background

The prevalence of abdominal obesity is increasing worldwide. Adults with abdominal obesity have been reported to have increased risk of cardiometabolic disorders.

The aim of this study was to examine whether non-obese subjects (body mass index (BMI) < 25 kg/m²) with abdominal obesity examined in the framework of the Swiss–Hungarian Cooperation Programme had increased metabolic risk compared to participants without abdominal obesity.

Methods

A cross-sectional study was carried out in 5228 non-obese individuals. Data were collected between July 2012 and February 2016. Descriptive statistics, Pearson’s correlation analysis and multiple logistic regression models were applied, odds ratios (OR) with 95% confidence interval (CI) being the outcomes.

Results

607 (11.6%) out of the 5228 non-obese individuals had abdominal obesity. The correlation analysis indicated that the correlation coefficients between BMI and waist circumference (WC) were 0.610 in males and 0.526 in females. In this subgroup, the prevalence of high systolic blood pressure, high fasting blood glucose, and high total cholesterol and triglyceride levels were significantly higher. The logistic regression model based on these data showed significantly higher risk for developing high systolic blood pressure (OR = 1.53; 95% CI = 1.20–1.94), low HDL cholesterol (OR = 2.06; 95% CI = 1.09–3.89), and high trygliceride level (OR = 1.65; 95% CI = 1.27–2.16).

Conclusions

There was a very high, significant, positive correlation between WC and BMI. Abdominal obesity was found to be strongly related to certain metabolic risk factors among non-obese subjects. Hence, measuring waist circumference could be recommended as a simple and efficient tool for screening abdominal obesity and related metabolic risk even in non-obese individuals.

Eating disorders among university students: a public health challenge. An European study

Background

Eating disorders (ED) and behavioural risk factors among students in higher education remain to be investigated. The aim of the study was to identify the prevalence of ED and the behavioural factors associated with ED in university students in four European universities: Chisinau (Ch) in Republic of Moldava, Cluj-Napoca (CN) in Romania, Miskolc (Ms) in Hungary and Rouen (R) in France.

Methods

In the four countries, students in higher education completed an anonymous standardized self-questionnaire, from 2016 to 2018. The questionnaire collected age, gender (M, W), housing, curricula, smoking, cannabis consumption, alcohol abuse problems (ADOSPA test), and perceived stress (Cohen score). The Sick, Control, One stone, Fat, Food (SCOFF scale) screening test was used to identify student with ED.

Results

A total of 3076 students were included, 705 in Ch, 582 in CL, 534 in Ms and 1255 in R. The sex-ratio was M:F=0.31 Ch, 0.30 in CN, 0.44 in Ms and 0.66 in R. The mean age was 21.2 (SD = 3.98) in Ch, 21.2 (SD = 3.2) in CL, 23.8 (SD = 5.1) in Ms and 20.0 (SD = 3.4) in R. The global prevalence of ED was 23.8%. According to the gender, the prevalence of ED in the four universities was 14.7% in M and 38.3% in W in Ch, 21.8% in M and 24.7% in W in CN, 19.7% in M and 21.4% in W in Ms and 16.1% in M and 34.0% in W in R (p &lt; 10-4). After logistic regression, significant positive relation between the positive SCOFF was observed with female gender, alcohol abuse problems and stress level.

Conclusions

ED prevalence patterns were quite similar in the four countries, with high prevalence of ED, even in men. Associated behavioural risk-factors were quite similar. It might be necessary in the future to screen students for potential ED upon entry to the university and also to inform student about the risk of ED and advise them to consult a healthcare professional.

Key messages

Our study highlights the high prevalence of eating disorders, with similar behaviours in university students in four countries. Because of the detrimental effects of ED on physical and emotional health, it seems mandatory to set up public health programs (health promotion, prevention).

Effect of green tea on the gastrointestinal absorption of amoxicillin in rats

BACKGROUND

The investigation of food-drug and plant-drug interactions has become increasingly important. In case of antibiotics, it is essential to achieve and maintain a plasma concentration sufficient for the antimicrobial action. Although, on theoretical basis, the interaction of polyphenols and antibiotics may be hypothesized, experimental data are lacking to assess its clinical relevance. The aim of our study was to assess the interaction between one of the most widely used antibiotics, amoxicillin, and green tea, the most frequently consumed drink with high polyphenol content.

METHODS

The effects of green tea on the plasma level of amoxicillin was studied in an in vivo experiment in rats. The plasma level of amoxicillin was monitored by LC-MS/MS for 240 min after oral administration. The polyphenol content of green tea was determined by the Folin-Ciocalteu method.

RESULTS

The peak plasma concentration of amoxicillin significantly decreased upon its co-administration with green tea, although the AUC0-240 of the antibiotic did not decrease significantly in the group treated with amoxicillin suspended in green tea.

CONCLUSIONS

Our results suggest a potentially relevant interaction between green tea and amoxicillin, worth being further studied in humans.

Repeated-dose toxicity of common ragweed on rats

Ambrosia artemisiifolia L. is an invasive species with highly allergenic pollens. Ragweed originates from North America, but it also occurs and is spreading in Europe, causing seasonal allergic rhinitis for millions of people. Recently, the herb of A. artemisiifolia has gained popularity as medicinal plant and food. The effects of its long-term intake are unknown; there are no toxicological data to support the safe use of this plant. The aim of our study was to assess the repeated dose toxicity of A. artemisiifolia on animals. Ragweed puree was administered in low dose (500 mg/kg b. w.) and high dose (1000 mg/kg b. w.) to male Wistar rats according to 407 OECD Guidelines for the Testing of Chemicals. Clinical symptoms, various blood chemical parameters, body weight and organ weights of the rats were measured. Reduced liver function enzymes (AST, ALT), reduced triglyceride level in the low dose and increased carbamide level in the high dose group were observed. The weight of the liver relative to body weight was significantly reduced in both groups, while the brain weight relative to body weight was significantly elevated in both groups. According to our results, the repeated use of ragweed resulted in toxic effects in rats and these results question the safety of long-term human consumption of common ragweed.

Better cardiorespiratory fitness associated with favourable metabolic control and health-related quality of life in youths with type 1 diabetes mellitus

OBJECTIVE

to explore the relationship among health-related quality of life (HRQoL), clinical variables, anthropometric measures, physical activity and cardiorespiratory fitness in children and adolescents with type 1 diabetes.Furthermore, we aimed to find predictors of HRQoL and metabolic control.

METHODS

A total of 106 patients (sex ratio: 1:1) with mean HbA1c of 8.55 (± 1.44) % and diabetes duration of 5.15 (± 3.24) years were assessed. The average age was 13.22 (± 3.08) years.

RESULTS

We observed statistically significant negative medium correlation between HbA1c and VO2max (r = – 0.343; p = 0.000). There was statistically significant small positive correlation between the HRQoL and the maximal oxygen consumption (r = 0.208; p = 0.032). We found no significant correlation between the HbA1c and the patients' HRQoL. In the multiple linear regression analysis both the better metabolic control and the HRQoL was predicted by the VO2max, other variables had no effect. Physical activity level did not explain the HRQoL. Boys had significantly better HRQoL and less skinfold thickness than girls.

CONCLUSION

Better cardiorespiratory fitness associated with both favourable metabolic control and better HRQoL of diabetic youths.Regular aerobic exercise improves the young patients' physical fitness and overall health status, and perception of health-related quality of life, respectively.

Altered open field behavior in rats induced by acute administration of 3-nitropropionic acid: possible glutamatergic and dopaminergic involvement

3-nitropropionic acid (3-NP), a substance used for modelling Huntington's disease, was given to male Wistar rats in a single 20 mg/kg b.w. dose, and the resulting behavioral alterations in spontaneous locomotor activity were measured after 30 minutes. To detect the involvement of neurotransmitter systems in this immediate effect, the NMDA antagonist MK-801 (0.8 mg/kg); as well as an agonist, quinpirole (QP, 5 mg/kg) and an antagonist, sulpiride (SP, 80 mg/kg) of the dopamine D2 receptors, were given before 3-NP to separate groups of rats. Controls were given saline. All substances were injected ip. 3-NP decreased the rats' locomotor, especially vertical, activity, whereas local activity was increased. Based on the further changes of 3-NP effects in the combination groups it could be concluded that dopaminergic rather than glutamatergic mechanisms were possibly involved in the acute behavioral effect of 3-NP.

Subchronic heavy metal and alcohol treatment in rats: changes in the somatosensory evoked cortical activity

Young adult male Wistar rats were treated, by gavage, with 80 or 320 mg/kg Pb2+ (lead acetate), 0.4 or 1.6 mg/kg Hg2+ (mercuric chloride) or both by combining the lower doses. For combination with alcohol, ethanol was added to the rats' drinking water in 5 v/v %. After 12 weeks of treatment, electrophysiological recording was made from the somatosensory cortex in urethane anaesthesia. Evoked potentials obtained by stimulation of the whiskers were recorded. Both metals, and alcohol alone, increased significantly the latency of the evoked response. Alcohol seemed to abolish the effect of Pb, but not of Hg. Fatigue, calculated form the response amplitude, was increased by Pb and Hg treatment and this effect of Hg was reduced by ethanol. Evoked activity and its dynamic characteristics were sensitive to the complex neurotoxic effect induced in the rats and can provide a basis for developing functional markers.

Neurotoxic and general effects of combined subchronic exposure of rats to insecticides and heavy metals

Three different insecticides: dimethoate, cypermethrin and amitraz were given, alone or combined with the heavy metals Pb, Hg and Cd, to male Wistar rats per os for 12 weeks from their 4th week of life. After the treatment period, the left hemisphere of the rats was exposed in urethane anaesthesia, and spontaneous and evoked cortical activity was recorded from the primary sensory areas. The effects of dimethoate on the spontaneous activity, and of dimethoate and amitraz on the evoked responses, were increased by the metal combination treatment, whereby the metals alone had no effect on the spontaneous and mild effect on the evoked activity. Finally, the animals were dissected, organ weights measured, and relative organ weights calculated. The weight gain of all treated groups was significantly retarded compared to the control. Several organ weights were also significantly reduced, mainly in groups receiving insecticide plus metal treatment. The toxic interactions observed in this work indicate that combined human exposure to environmental pesticide residues and heavy metals may have unexpectedly severe effects.

Immunotoxicological investigation of subacute combined exposure with low doses of Pb, Hg and Cd in rats

Detectable interactions between NOEL (No Observed Effect Level) doses of Pb, Hg and Cd in general toxicological, hematological, and immune function parameters were investigated. The metals (Pb-acetate, 20 mg/kg; HgCl2, 0.40 mg/kg; CdCl2, 1.61 mg/kg) were combined. First, the rats received the combination Pb + Hg + Cd for 4 weeks per os. Significant difference vs. control was found only in the weight of lung and popliteal lymph node (PLN). The Pb + Hg and Pb + Cd combinations significantly decreased the PLN to 100 g body weight and PLN to brain weight ratio, and Pb+Hg also decreased the relative adrenal weight. After 12 weeks treatment with the same doses, effects on the thymus, kidney, and adrenal weights in the Pb + Hg, and thymus weight in the Pb + Cd, combination were seen. Pb + Cd also affected the white and red blood cell count and hematocrit. Combined with Hg or Cd, NOEL dose Pb showed toxicity, indicating that exposure limits may be inefficient in combined exposure situations.

Dynamics of information access on the web

While current studies on complex networks focus on systems that change relatively slowly in time, the structure of the most visited regions of the web is altered at the time scale from hours to days. Here we investigate the dynamics of visitation of a major news portal, representing the prototype for such a rapidly evolving network. The nodes of the network can be classified into stable nodes, which form the time-independent skeleton of the portal, and news documents. The visitations of the two node classes are markedly different, the skeleton acquiring visits at a constant rate, while a news document's visitation peaks after a few hours. We find that the visitation pattern of a news document decays as a power law, in contrast with the exponential prediction provided by simple models of site visitation. This is rooted in the inhomogeneous nature of the browsing pattern characterizing individual users: the time interval between consecutive visits by the same user to the site follows a power-law distribution, in contrast to the exponential expected for Poisson processes. We show that the exponent characterizing the individual user's browsing patterns determines the power-law decay in a document's visitation. Finally, our results document the fleeting quality of news and events: while fifteen minutes of fame is still an exaggeration in the online media, we find that access to most news items significantly decays after 36 hours of posting.

The acute effects of 3-nitropropionic acid on the behavior and spontaneous cortical electrical activity of rats

In this study, the acute effect of 3-nitropropionic acid was investigated on open field and startle behavior of rats, and on their cortical electrical activity. Spontaneous locomotor activity, acoustic startle response, and pre-pulse inhibition of acoustic startle were measured in male Wistar rats (10 weeks old, 180-200 g body weight) after a single dose of 10 or 20 mg/kg i.p. 3-nitropropionic acid. After the behavioral tests, the rats were anaesthetized, and spontaneous cortical electrical activity was recorded. The vertical, horizontal and local open field performance showed dose-dependent deterioration in the rats treated with 3-nitropropionic acid. The number of "noise-positive" startle responses showed non-significant changes, but the inhibition by pre-pulse was significantly reduced in the high dose animals. High dose also increased the proportion of low-frequencies in the cortical activity. 3-nitropropionic acid, known primarily to act in repeated doses (e.g., in animal models of Huntington's disease) had also some clear-cut acute effects on behavioral and electrophysiological parameters of the treated rats.

Measurement of the optical parameters of purple membrane and plant light-harvesting complex films with optical waveguide lightmode spectroscopy

Purple membrane (bacteriorhodopsin) and plant light-harvesting complexes (LHCII) were dried on the optical waveguide sensor with varying thicknesses in a wide range (from 20 to several hundreds of nanometers) and the optical parameters were studied with optical waveguide lightmode spectroscopy. It was found that applying the approximate 4-layer mode equations for the measured effective refractive indices resulted in unacceptable results for the optical parameters: with increasing thickness the refractive index decreased monotonously from 1.5 to 1.1. Therefore an inverse waveguide numerical method was developed and used to obtain reliable results from the experiments. The inverse method yielded an approximately constant (1.53) refractive index independently of the thickness for the purple membrane and LHCII films. Light-induced changes in the optical parameters of the purple membrane and LHCII films were also studied. For purple membrane films the most significant effect is the change in refractive index and absorption. For LHCII films prolonged illumination induced irreversible structural changes, most probably of thermo-optic origin.

Bacteriorhodopsin photocycle kinetics analyzed by the maximum entropy method

A maximum entropy method (MEM) was developed for the study of the bacteriorhodopsin photocycle kinetics. The method can be applied directly to experimental kinetic absorption data without any assumption for the number of the intermediate states taking part in the photocycle. Though this method does not give a specific kinetics, its result is very useful for selection between possible photocycle kinetics. Using simulated data, it is shown that MEM gives correct results for the number of the intermediate states and the amplitude distributions around the characteristic lifetimes. Analyzing experimental absorption data at five different wavelengths, MEM gives seven or eight characteristic lifetimes, which means that at least so many distinct intermediate states exist during the photocycle. Many possible photocycle kinetic models were studied and compared with the MEM result. The best agreement was found with a branching photocycle model of eight intermediate states (K, L, M(1), M(2), M(3), M(4), N, O). The branching occurs at the L intermediate state (M(1) and M(2) being in one branch and M(3) and M(4) in the other branch), but at high pH it occurs already at the K state.

Application of the maximum entropy method to absorption kinetic rate processes

The maximum entropy method, originally developed for astronomical image restoration, has already been successfully applied to a variety of biophysical problems. Through numerical inverse Laplace transformation, the method determines the lifetime distribution function with the largest informational entropy. Starting from a flat distribution, it results in the consistent selection of a single distribution from the numerous possible ones that correctly fit the data. In this paper, we discuss the application of the method to kinetic processes that have both rise and decay components, and test the algorithm with different signal to noise ratio generated data. It is proved that the mass conservation constraint can be taken into account by reducing the search to a lower dimensional subspace. The effect of noise on the width of lifetime distribution is studied and it is shown that an inherent entropy connected to the underlying kinetics can be separated from the noise generated entropy. The possibility of the application of the method to the photocycle kinetics of bacteriorhodopsin is also shown.

Increased frequency of intracellular interleukin (IL)-13 and IL-10, but not IL-4, expressing CD4+ and CD8+ peripheral T cells of patients with atopic dermatitis

BACKGROUND

A number of studies exist demonstrating the increased expression of type 2 cytokines and decreased capacity to produce interferon-gamma (IFN-gamma) in peripheral blood mononuclear cells (PBMCs) of patients with atopic dermatitis (AD).

OBJECTIVES

To clarify the results of recent studies concerning the role of interleukin (IL)-4 and IL-13 in PBMCs of AD patients, we analysed the activation status of lymphocyte subpopulations.

METHODS

We measured the intracellular expression and serum levels of certain type 1 and type 2 cytokines, using cell surface and intracellular cytokine staining, flow cytometry and enzyme-linked immunosorbent assay techniques.

RESULTS

The frequency of IL-10 and IL-13 producing CD4+ and CD8+ T cells was significantly higher in patients with AD, while the frequency of IFN-gamma secreting helper and cytotoxic T cells was significantly lower in patients with AD than in control subjects. The serum levels of IL-10 and IL-13 were also significantly increased. There were no significant differences observed between the experimental groups in the frequency of IL-4 producing CD4+ and CD8+ cells.

CONCLUSIONS

This study demonstrates a type 2 cytokine production in the CD4+ and CD8+ T cells of AD patients, which is characterized by an elevated IL-13, but not by IL-4 secretion, and by an increased level of the immunoregulatory IL-10, which can contribute to a decrease in IFN-gamma expression.

Prevalence, genotype distribution and outcome of hepatitis C infections among the employees of the Hungarian Central Hospital for infectious diseases

Blood samples from 477 hospital workers (HWs) at the Central Hospital for Infectious Diseases, Budapest, Hungary were tested for hepatitis C virus (HCV) antibodies by enzyme immunoassay (EIA), and 13 (2.7%) of these were found to be HCV antibody positive. Ten (2.7%) were from nursing/housekeeping staff and three (2.9%) from medical staff. HCV antibody positive HWs were detected in 10 of 17 work places, and the prevalence rates in these departments or units varied between 1.2% and 6.5%. The prevalence increased gradually with increasing age, being 0% in these under 21 years of age and 9.5% in those above 50 years of age. Eleven (85%) of 13 HCV antibody positive HWs had HCV RNA in their sera, four of them intermittently during the follow-up period. HCV genotype 1 was present in two HWs, 1b in six HWs, 3a in one HW and 4 in two HWs. Chronic hepatitis C has developed in six (46%) HCV antibody positive HWs. Although the source of infection through needlestick could only be traced directly in one case, circumstantial evidence indicated that the majority of infections were occupationally acquired, originating from percutaneous or mucocutaneous exposure.

[Late detection of vascular injuries]

Generally recognizing of traumatical vascular injuries isn't difficult since clinical signs and symptoms show them unambiguously. For some time-mainly in case of blunt and shot wounds-lacking unanimous signs the vascular injuries can't be diagnosed. Later on appearing symptoms as complications raise the chance of existence of an earlier vascular injury. In case of three patients the elapsing time between the vascular injury and its diagnosis was 4 weeks, 3 years and more than 50 years.

Flexibility of myosin-subfragment-1 in its complex with actin as revealed by fluorescence resonance energy transfer

The flexibility of the acto-myosin complex in rigor conditions was characterized by measuring the temperature profile of normalized fluorescence resonance energy transfer efficiency, f' [Somogyi, B., Matkó, J., Papp, S., Hevessy, J., Welch, G.R. & Damjanovich, S. (1984) Biochemistry 23, 3403-3411]. Fluorescence acceptors were introduced to the Cys374 residues of actin and the donors were covalently attached either to Cys707 in the catalytic domain or to Cys177 in the essential light-chain of myosin S1. Fluorescence resonance energy transfer measurements revealed that the protein matrix between Cys374 of actin and Cys707 of S1 is rigid. In contrast, the link between the catalytic and light-chain-binding domains in myosin S1 is flexible. We have recently shown that the positional distribution of Cys707 was narrow relative to the actin filament, while that of the Cys177 was broad. Accordingly, the broad positional distribution of Cys177 is likely to be due to the large flexibility of the link between the catalytic and light-chain-binding domains. This flexibility is probably essential for the interdomain reorganization of the myosin head during the force generation process and for accommodating the symmetry difference between actin and myosin filaments to allow the formation of cross-bridges.

Conformational distributions and proximity relationships in the rigor complex of actin and myosin subfragment-1

Cyclic conformational changes in the myosin head are considered essential for muscle contraction. We hereby show that the extension of the fluorescence resonance energy transfer method described originally by Taylor et al. (Taylor, D. L., Reidler, J., Spudich, J. A., and Stryer, L. (1981) J. Cell Biol. 89, 362-367) allows determination of the position of a labeled point outside the actin filament in supramolecular complexes and also characterization of the conformational heterogeneity of an actin-binding protein while considering donor-acceptor distance distributions. Using this method we analyzed proximity relationships between two labeled points of S1 and the actin filament in the acto-S1 rigor complex. The donor (N-[[(iodoacetyl)amino]ethyl]-5-naphthylamine-1-sulfonate) was attached to either the catalytic domain (Cys-707) or the essential light chain (Cys-177) of S1, whereas the acceptor (5-(iodoacetamido)fluorescein) was attached to the actin filament (Cys-374). In contrast to the narrow positional distribution (assumed as being Gaussian) of Cys-707 (5 +/- 3 A), the positional distribution of Cys-177 was found to be broad (102 +/- 4 A). Such a broad positional distribution of the label on the essential light chain of S1 may be important in accommodating the helically arranged acto-myosin binding relative to the filament axis.

[Screening for hepatitis C of hospital personnel at the Szent László Hospital of Budapest]

The health-care workers are known to be at risk of occupational transmission of blood-borne viruses. The goal of the investigation was to determine the prevalence of hepatitis C virus (HCV) antibody and the occupational risk of HCV transmission among personnel at the Central. Hospital for Infectious Diseases, Budapest, Hungary. Serum samples of 409 health-care workers were tested for antibody to HCV with second and third generation ELISA-s and anti-HCV positive samples were confirmed with Western Blot Line EIA. A total of 10 (2.4%) of the health-care workers were confirmed to be anti-HCV positive. The prevalence of anti-HCV increased with advancing age: zero under 20 yr age group (N = 0/15), 0.9% in 21-30 yr age group (N = 1/112), 1.8% in 31-40 yr age group (N = 2/111), 3.1% in 41-50 yr age group (N = 3/96) and 4.0% in above 50 yr age group (N = 3/75). We found anti-HCV positive hospital worker in 9 out of 17 departments. The prevalence of hepatitis C antibody was 7.1-1.9% among the personnel of internal departments, pathology, intensive care unit and pediatric departments. No anti-HCV positive health-care worker was found in the surgery and laboratories. None of the physicians tested was seropositive for HCV. Eight of the nurses, one of the sanitary personnel and one pathological technician were seropositive for HCV. Two nurses developed a chronic C hepatitis after a needlestick accident.

CONCLUSIONS

1. The hospital personnel is at risk for HCV infection. 2. The occupational risk of HCV infection increases with age but the risk is considerable lower than that of hepatitis B infection. 3. The occupational risk is highest among the workers of the chronic internal department, pathology and intensive care unit. 4. The nurses are at higher risk of HCV infection than the physicians. 5. The needlestick injury is associated with an increased risk for acquiring HCV infection.

[Effect of vaccination on the risk of hepatitis B infection in hospital personnel]

The effect of vaccination on acute B hepatitis, on HBsAg carrier state and on the seropositivity of hepatitis B virus was examined in the personnel of the St. László Hospital in two periods. Human plasma origin vaccine was introduced gradually from 1985 to 1989. From 1989 till the end of 1994 recombinant vaccines were provided for all workers. A total of 10577 tests were done from 3524 sera of 2019 hospital workers. A total of 2.4% of the workers developed acute hepatitis. Hepatitis B was confirmed most frequently (29%) of hepatitis cases. In the first and second period HBsAg positivity was 4.1% and 2.1% (P = 0.1), respectively. Although the annual frequency of acute hepatitis has not changed, that of HBsAg positivity showed a decreasing tendency during the nine years of the study. The prevalence of hepatitis B markers could be characterized by a significant rise in close correlation with age. The protective effect of vaccination is markedly reflected by the altered prevalence of hepatitis B virus markers in the different age groups. At the age of fifty and above hepatitis B seropositivity was 47.2% and 36.4% in the first and second period (P = 0.1), respectively. The frequency of seropositivity was the highest among the workers of surgical, pathological, hepatological departments and ICU. Our results show that vaccination is an effective tool in hepatitis B prevention. Every effort has to be made to promote hepatitis B immunity to all health care workers and strictly follow hygienic preventive measures.

[Dupuytren disease of the sole]

The authors discuss the essence of Dupuytren disease occurring in the plantar aponeurosis with literary surveys. They briefly outline the essence of the well-known different theories which endeavour to explain the causes of the development of this disease of unknown etiology. In their article, they deal with its clinical manifestation, histological changes and therapeutical possibilities in connection with the 5 cases treated by them.