Biomedical subjects
R Gross
Publications and source records attributed to R Gross.
Low environmental selenium availability as an additional determinant for goiter in East Java, Indonesia?
Iodine deficiency, which is most visibly indicated by goiter, is highly prevalent in Indonesia. Since 1994, Indonesia has a decree that all salt used for human, livestock, and industry must be iodized. However, despite the increased distribution of iodized salt, pockets with significantly higher prevalence of goiter still remain. This situation may be consequence of selenium (Se) deficiency. This study aimed to assess the Se level in the environment of goiter prevalent areas. Five hundred eleven school children participated in this study. Goiter was measured using both ultrasound and palpation. Ninety-nine eggs were collected from free-living chicken in 11 villages, and the Se contents of egg yolk and egg white were determined by neutron activation analysis. In the villages studied, Se concentration in egg yolk ranged from 0.15 to 1.52 microg/g and in egg white from 0.18 to 2.97 microg/g. The prevalence of goiter measured by palpation ranged from 18.4% to 70% and by ultrasound from 0% to 100%. Because of the inconsistency of goiter rate measured by palpation and ultrasonography, the question remains whether low availability of Se in the environment might be an additional contributing factor for goiter.
Correlates of a perceived need for mental health assistance and differences between those who do and do not seek help.
BACKGROUND: This study examined prevalence of perceived need for mental health assistance, characteristics of people with a perceived need, and how persons with a need who sought help were different from those who did not. METHODS: A national random phone survey (n = 1,394) was conducted in Israel, which included questions about (1) perceived need for mental health assistance and (2) help seeking. RESULTS: Prevalence of life-time and recent perceived need for males was 21% and 10.7%, and for females 31% and 15.1%. Of those with a perceived need, 31.4% of males and 41.6% of females had gone for help. Based on logistic regression models, the variables associated with need were being female, divorced, having a chronic physical disease, and low income (for males only), while predictors of help seeking were living in a big city and not being a recent immigrant. The major sources of help in descending order were: mental health professionals (46%), family physician (25%), family or friends (19%), and other (10%). CONCLUSIONS: A majority of people who feel that they need help for mental health problems do not get help.
The role of the twin-arginine motif in the signal peptide encoded by the hydA gene of the hydrogenase from wolinella succinogenes
The hydABC operon of Wolinella succinogenes encodes the three subunits of the membrane-integrated Ni-hydrogenase. The catalytic subunit, HydB, is on the periplasmic side of the membrane. Residues R41 and R42 of the twin-arginine motif within the signal peptide of the precursor of the iron-sulfur subunit, HydA, were replaced by two glutamine residues. The corresponding mutant did not grow with H(2) as the electron donor of anaerobic respiration. Mature HydB and the precursor protein of HydA were located exclusively in the cytoplasmic cell fraction of the mutant, which catalyzed the reduction of benzyl viologen by H(2), suggesting that HydB contained Ni. The HydC protein was located in the membrane fraction of the mutant in wild-type amounts. HydC was purified and was shown to contain heme. The results suggest that HydA and HydB are translocated across the membrane by the Tat (twin-arginine translocation) system. The translocation of HydA and HydB as well as the maturation of the precursor protein of HydA appear to depend on the presence of the twin-arginine motif. In contrast, maturation of HydB, the insertion of HydC into the membrane, and heme attachment to HydC are apparently independent of the twin-arginine motif and do not require translocation of the two other hydrogenase subunits.
Representational difference analysis identifies a strain-specific LPS biosynthesis locus in Bordetella spp.
Bordetella pertussis and B. bronchiseptica are genetically very closely related but differ significantly in their virulence properties. Using Representational Difference Analysis (RDA), 11 DNA fragments specific for B. pertussis Tohama I or B. bronchiseptica BB7865 were identified. All B. bronchiseptica BB7865-derived fragments also hybridized with chromosomal DNA from B. parapertussis but not from the B. pertussis strains Tohama I and W28, underlining the close phylogenetic relationship between B. bronchiseptica and B. parapertussis. The B. pertussis type strain BP18323 is a special case, as it contains DNA sequences characteristic for both B. pertussis and B. bronchiseptica. As demonstrated by pulsed-field gel electrophoresis, several of the BB7865-derived fragments are present on a single 30-kb XbaI fragment. Based on the sequences of putative coding regions, four of these fragments may code for proteins involved in carbohydrate metabolism or transport. In agreement with this notion, a mutant for one of these loci synthesizes a significantly altered lipopolysaccharide that lacks the O-specific side chains. The analysis of the corresponding genomic region in various Bordetella species showed that this locus is present in B. bronchiseptica and B. parapertussis but not in B. pertussis. This confirms that the RDA approach has identified a novel strain-specific LPS biosynthesis locus which accounts for the differences between the LPS structures elaborated by different Bordetella species.
Signalling pathways in two-component phosphorelay systems.
Two-component systems are characterized by phosphotransfer reactions involving histidine and aspartate residues in highly conserved signalling domains. Although the basic principles of signal transduction by these systems have been elucidated, several important aspects, such as their integration into more complex cellular regulatory networks and the molecular basis of the specificity of signal transduction, remain unknown.
Transient epileptic foci associated with intracranial hemorrhage in patients with subdural and epidural electrode placement.
We report two cases of transient epileptic foci in humans associated with placement of intracranial electrodes. The abnormalities consisted of restricted areas of active, almost continuous, rhythmic spiking, intermittently evolving into electrographic seizure activity, which resolved spontaneously within 3-4 days. The first occurred after placement of a subdural electrode grid and the second following insertion of epidural peg electrodes. Neuroimaging demonstrated a small subdural hematoma overlying the grid and a focal intraparenchymal hemorrhage underlying the affected epidural electrodes. The insertion of intracranial electrodes may be complicated by the induction of transient epileptic foci unrelated to a patient's typical epileptic generator.
Microsatellites reveal clonal structure of populations of the thelytokous ant platythyrea punctata (F. Smith) (Hymenoptera; formicidae)
Parthenogenesis is often thought to constitute an evolutionary dead end as compared with sexual reproduction because genetic recombination is limited or nonexistent in parthenogenetic populations. Yet there are many species to demonstrate that parthenogenesis can initially be extremely successful under certain environmental conditions. In this study we used microsatellite markers to investigate the genetic structure of four natural populations of the neotropical thelytokous parthenogenetic ant Platythyrea punctata. Ten dinucleotide microsatellites were isolated from a partial genomic library of P. punctata. Five of these were found to be polymorphic. In a subsequent analysis of 314 workers taken from 51 colonies, we detected low intraspecific levels of variation at all loci, expressed both in the number of alleles detected and heterozygosities observed. Surprisingly, we found almost no differentiation within populations. Populations rather had a clonal structure, with all individuals from all colonies usually sharing the same genotype. Only in one colony from Puerto Rico did some workers have an additional genotype. This low level of genotypic diversity probably reflects the predominance of thelytoky in P. punctata, together with genetic bottlenecks and founder effects. Cross-species amplification of all 10 loci in 29 ant species comprising four different subfamilies yielded positive amplification products in only a limited number of species.
Effect of daily and weekly micronutrient supplementation on micronutrient deficiencies and growth in young Vietnamese children.
BACKGROUND: Micronutrient deficiencies remain common in preschool children in developing countries. Interventions focus on single micronutrients and often lack effectiveness. Weekly instead of daily supplementation may improve effectiveness. OBJECTIVE: The efficacy of weekly and daily supplementation in reducing anemia prevalence and in improving the zinc, vitamin A, and growth status of 6-24-mo-old Vietnamese children was investigated. DESIGN: In this double-blind, placebo-controlled trial, the daily group (n = 55) received 8 mg elemental Fe (as iron sulfate), 5 mg elemental Zn (as zinc sulfate), 333 microg retinol, and 20 mg vitamin C 5 d/wk for 3 mo. The weekly group (n = 54) received 20 mg Fe, 17 mg Zn, 1700 microg retinol, and 20 mg vitamin C once a week. A third group (n = 54) received a placebo only. Venous blood samples were collected at the start and end of the supplementation period and anthropometric measurements were taken at the start and 3 mo after the end of supplementation. RESULTS: At baseline, 45.6% of subjects had hemoglobin concentrations < 110 g/L, 36.3% had zinc concentrations < 10.71 micromol/L, and 45.6% had retinol concentrations <0.70 micromol/L. Hemoglobin, retinol, and zinc concentrations of both the weekly and daily groups increased similarly compared with the placebo group (P < 0.001). There was no significant difference in growth between the supplemented groups and the placebo group. However, the height-for-age of subjects stunted at baseline increased with z scores of 0.48 (P < 0.001) and 0.37 (P < 0.001) for the daily and weekly groups, respectively. CONCLUSIONS: Weekly and daily supplementation improved hemoglobin, zinc, and retinol concentrations similarly. Neither intervention affected growth of the overall population, but growth of children stunted at baseline was improved through both types of supplementation.
Use of daily compared with weekly iron supplementation: apples and pears.
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4-Hydroxyisoleucine: experimental evidence of its insulinotropic and antidiabetic properties.
We have recently shown in vitro that 4-hydroxyisoleucine (4-OH-Ile), an amino acid extracted from fenugreek seeds, potentiates insulin secretion in a glucose-dependent manner. The present study was designed to investigate whether 4-OH-Ile could exert in vivo insulinotropic and antidiabetic properties. For this purpose, intravenous or oral glucose tolerance tests (IVGTTs and OGTTs, respectively) were performed not only in normal animals but also in a type II diabetes rat model. During IVGTT in normal rats or OGTT in normal dogs, 4-OH-Ile (18 mg/kg) improved glucose tolerance. The lactonic form of 4-OH-Ile was ineffective in normal rats. In non-insulin-dependent diabetic (NIDD) rats, a single intravenous administration of 4-OH-Ile (50 mg/kg) partially restored glucose-induced insulin response without affecting glucose tolerance; a 6-day subchronic administration of 4-OH-Ile (50 mg/kg, daily) reduced basal hyperglycemia, decreased basal insulinemia, and slightly, but significantly, improved glucose tolerance. In vitro, 4-OH-Ile (200 microM) potentiated glucose (16.7 mM)-induced insulin release from NIDD rat-isolated islets. So, the antidiabetic effects of 4-OH-Ile on NIDD rats result, at least in part, from a direct pancreatic B cell stimulation.
Response to missile attacks on civilian targets in patients with panic disorder.
BACKGROUND: The complex interaction that exists between biological and cognitive factors determines the reaction of panic-disorder patients to stressors. The current study was conducted to systematically assess the behavioral effects of a real, life-threatening event on panic-disorder patients. METHOD: Sixty-five panic-disorder patients completed structured telephone interviews during the first 4 weeks of the Persian Gulf War. Evaluation included frequency of panic attacks, anxiety levels, and function levels both during and between air raid alarms. RESULTS: The findings indicate that panic-disorder patients, despite high levels of anxiety, did not demonstrate an increased frequency of panic attacks during the Persian Gulf War. In addition, the majority of patients reported good-to-high levels of functioning during the crisis in both everyday and alarm-related functioning. Grouping of subjects according to proximity to risk or current antipanic treatment did not produce significant differences in the frequency of panic attacks or levels of anxiety. CONCLUSION: The findings suggest that vulnerability of patients with panic disorder to a "panic-stricken" response does not increase during real-life stressors. The lack of increased frequency of panic attacks observed under these circumstances provides additional support for the opinion that panic and fear are two distinct entities.
Food safety training for nutritionists.
A course on food safety for nutritionists has been developed in Indonesia through collaboration between government, industry, academia and international agencies. By teaching the basic principles of the subject it equips the participants to recommend foods that are safe as well as nutritious.
The dorzolamide/timolol combination versus timolol plus pilocarpine: patient preference and impact on daily life. United States Patient Preference Study Group. International Patient Preference Study Group.
PURPOSE: To compare the 2.0% dorzolamide/0.5% timolol fixed combination (COSOPT; Merck & Co., Whitehouse Station, NJ) to 0.5% timolol plus 2.0% pilocarpine given concomitantly, and to determine patient preference, tolerability, and impact on daily life in patients with elevated intraocular pressure (IOP). METHODS: Two multi-center, randomized, cross-over, observer masked studies were conducted, one in the United States (97 patients) and one in Europe (93 patients). The Comparison of Ophthalmic Medications for Tolerability questionnaire was used to assess patient preference and perception of side effects and activity limitations resulting from study medications. Intraocular pressure was measured before and 2 hours after the morning dose of study medication (hour 0 and hour 2). RESULTS: In both studies, among patients with a preference, the combination was preterred to timolol plus pilocarpine by a ratio of 4 to 1. The most commonly cited reason for this preference was side effects. Patients in both studies also reported that the combination interfered significantly less with daily life in terms of side effects and activity limitations. They also reported missing significantly fewer doses of study medication while taking the combination and being significantly more satisfied with it. The efficacy of these two treatments was not significantly different, based on IOP measurements at hour 0 and 2 hours after administration. Patients reported significantly more adverse events while receiving timolol plus pilocarpine in both studies, and in the U.S. study, significantly more patients discontinued therapy while receiving timolol plus pilocarpine than while receiving the combination. CONCLUSION: Compared with timolol plus pilocarpine, patients preferred the combination of 2% dorzolamide/0.5% timolol, and reported less interference in daily activities, better tolerability, and better compliance with therapy.
Patients' views of direct access to specialists: an Israeli experience.
CONTEXT: Surveys carried out among users of medical services can be a useful tool for health care organizations in designing proper services. Specifically, patients' views of direct access to specialists can be useful to health organizations considering the gatekeeper model. OBJECTIVE: To assess patients' opinions about direct access to specialists and referral to specialists through their primary care physician. DESIGN: An intercept survey, in which patients were interviewed at the randomly selected service provision sites, was carried out in 3 districts in Israel during 1995. A total of 1445 and 1289 patients were interviewed in primary care and specialty clinics, respectively. SETTING: Primary care and specialty clinics in 3 regions in Israel serving 750000 members of Kupat Holim Clalit, Israel's largest sick fund. PARTICIPANTS: Hebrew-speaking members of Kupat Holim Clalit who visited the primary care or specialty clinics in the 3 regions during the study period. MAIN OUTCOME MEASURES: Rate of preferences for direct access to specialists and preferences for referral through primary care physician. RESULTS: Fifty-two percent of the respondents preferred direct access to specialists, while 48% preferred a referral from their primary care physician. Multivariate logistic regression analysis indicated that the preference for direct access was significantly lower among patients older than 45 years (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.62-0.91); patients whose primary care physician was a specialist in family medicine (OR, 0.80; 95% CI, 0.67-0.97); and patients who were satisfied with their primary care physician (OR, 0.34; 95% CI, 0.27-0.44). Preference for direct access was significantly higher among more highly educated patients (OR, 1.38; 95% CI, 1.16-1.65) and patients residing in Jerusalem (OR, 2.46; 95% CI, 2.05-2.95) and those younger than 45 years who were dissatisfied with their family physician or a primary care physician who was not board certified. If direct access was not available, 33% of respondents would leave the sick fund and 48% would remain; 19% did not know. CONCLUSIONS: Informing sick fund members, particularly the younger and more educated among them, about the advantages of consulting with the primary care physician, as well as providing specialty training in family medicine to primary care physicians, may reduce patients' preference for direct access to specialists.
[Primary care physicians in Israel--compared with European countries].
This study compares Israeli primary care physicians with those of European countries. In Israel a larger proportion of those in primary care are women. The Israeli physicians see many patients a day, but almost never make home visits. They also report for work the fewest hours a day, but spend 21 hours a month in continuous medical education. (more than Europeans?) The Israeli primary care physician scores high in screening for breast cancer and blood cholesterol level, but very low in the fields of minor surgery and alcohol and smoking prevention, contraception, nutrition counseling and normal pregnancy follow-up. Residency training and education may be inadequate, and more emphasis has to be put on the health system and recognizing environmental influences.
[Screening tests for early detecting breast cancer in women in Israel--performance rates and patient characteristics].
Screening tests including mammograms for early detection of breast cancer are in the basket of services provided under the National Health Insurance Law. The law also defines the population groups entitled to mammograms, and sets the frequency of the test as once every 2 years. The aim of this study was to examine the screening rates for early detection of breast cancer at the inception of the law, in order to monitor future changes in performance rates, and identify the characteristics of those unlikely to undergo these tests, in order to promote the use of screening tests by them. This study is part of a comprehensive survey examining the effect of the National Health Insurance Law on the Israeli population. The survey, carried out in the summer of 1995, included a sample of 1,400 Israeli residents aged 22 and over. To determine performance rates for clinical breast examinations a subgroup of 515 women aged 30 and over was sampled. To determine performance rates for mammograms, 173 women were aged 50-74 (the entitlement ages under the law), were sampled. 54% of women aged 30+ reported having had at least 1 clinical breast examination during their lifetime, and 56% of women aged 50-74 reported having had a mammogram during the past 2 years. Variables with an independent effect on the likelihood of having had a clinical breast examination by a physician during the past 2 years were: being over the age of 50, having at least 9 years of education, being a veteran resident of Israel (as opposed to a new immigrant), and being Jewish. Variables with an independent effect on the likelihood of having a mammogram during the past 2 years were: being a veteran resident of Israel, and having a high income--which was found to have a borderline effect. The findings of the survey emphasize the importance of changing the behavior patterns of both women and physicians, informing women about their entitlement to the tests, and raising consciousness of the importance of having repeated clinical examinations by a physician, as well as mammograms.
Efficacy of different types of iodised oil.
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