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Biomedical subjects

M Berlin

Publications and source records attributed to M Berlin.

At least 37 records · Page 2Linked to original sources
PubMed1997

HLA-DR predicts the prognosis in Scandinavian patients with pulmonary sarcoidosis.

Although most patients with sarcoidosis have a good prognosis, a significant proportion runs a more severe and prolonged disease course. There is no marker to distinguish these subpopulations of patients, however. To investigate the relationship between HLA haplotype and clinical course, 122 Scandinavian patients with sarcoidosis were genomically typed for HLA-DR, -DQA1 and -DQB1 alleles using PCR amplification with sequence-specific primers. Control subjects were 250 healthy Swedish volunteers. Patients were carefully clinically monitored for up to 10 yr. We found that HLA-DR17(3) was overrepresented among sarcoidosis patients (33%) compared with control subjects (17%, p < 0.001). Ninety-one patients were followed for more than 2 yr and classified into chronic or nonchronic patients, according to disease outcome. Among the 34 patients with a nonchronic form of sarcoidosis, 65% were DR17(3)-positive (p < 10(-5) versus control subjects). On the other hand, DR14(6) and DR15(2) were significantly associated with chronic disease. Even in patients with clinical manifestations that are normally associated with good prognosis, HLA typing enabled a subgrouping into two categories with significantly different clinical courses. Therefore, HLA class II typing is a valuable tool in predicting the outcome of the disease in Scandinavian sarcoidosis patients.

Adult↗
PubMed1997

Lung and blood T-cell receptor repertoire in extrinsic allergic alveolitis.

Patients with extrinsic allergic alveolitis (EAA) have accumulations of T-lymphocytes in their lungs. CD8+ lung T-cells, in particular, have been implicated in the pathogenesis of EAA. The objective of the present study was to analyse the T-cell receptor (TCR) V alpha and V beta gene usage of CD4+ and CD8+ lung and peripheral blood lymphocytes (PBLs) before and after treatment. Twelve patients with clinical signs of extrinsic allergic alveolitis were studied at disease onset, and nine of the 12 were also studied after treatment and clinical recovery. Lung cells, obtained by bronchoalveolar lavage (BAL), and paired PBL samples were analysed by flow cytometry using a panel of anti-TCR V monoclonal antibodies. The changes in TCR V gene usage were most pronounced in BAL CD8+ cells, as compared to the BAL CD4+, PBL CD8+ and PBL CD4+ subsets. At disease onset, 10 of the 12 patients had lung restricted expansions of CD8+ T-cells using a particular V alpha or V beta gene segment, and 8 of the 12 patients had CD8+ T-cell expansions in PBL. For the patients in whom a follow-up was possible, a majority of the expansions in the lungs were normalized, whereas most of the expansions in PBL remained. An over-representation of human leucocyte antigen (HLA)-DR2 (15) was detected, particularly among patients with farmer's lung. An increased selected T-cell receptor V gene usage may follow specific interactions between T-cells and antigens. In extrinsic allergic alveolitis, we determined that such expansions occur most frequently in the lung CD8+ T-cells. Since most expansions of lung CD8+ T-cells normalized with clinical improvement, these are further implicated in the pathogenesis of extrinsic allergic alveolitis.

Acute Disease↗
PubMed1996

Behavioral consequences of in utero exposure to mercury vapor: alterations in lever-press durations and learning in squirrel monkeys.

Exposure to mercury vapor in utero results in the accumulation of mercury in the cerebellum, hippocampus, and other regions of the nervous system associated with motor function and learning, but little is known about the functional consequences of prenatal exposure. The offspring of pregnant squirrel monkeys exposed to 0.5 or 1.0 mg/m3 of mercury vapor during the last 2/3 or more of gestation were studied. Median maternal blood levels ranged from 0.025 to 0.18 microgram/g and exposures were estimated to range from 20 to 62 micrograms/day, with cumulative doses of 1304 to 4305 micrograms. Unexposed monkeys born at about the same time served as controls. The monkeys' lever pressing was maintained under various Concurrent Random-Interval Random-Interval schedules of reinforcement. Time allocation on each lever was examined during behavioral transitions and in steady state. No difference in sensitivity to reinforcer ratios was identified in steady state, but there was much more variability in the steady-state performance of exposed monkeys, as indicated by the standard deviation of the regression, than in controls. Logistic regression was used to examine the transition to new schedule parameters. Exposed monkeys were found to produce smaller or slower transitions than controls. The magnitude and stability of lever-press durations for controls and exposed monkeys were indistinguishable early in the experiment, but at the end the exposed monkeys had longer lever-press durations and the session-to-session variability was much greater. One monkey's exposure began during the third week of gestation (earlier than any of the others) and the behavior of this monkey was so erratic that some of the analyses could not be accomplished. Long-term effects of prenatal mercury vapor exposure included instability in lever-press durations and steady-state performance under concurrent schedules of reinforcement as well as aberrant transitions. The levels used were close to those reported in occupational settings under conditions of poor hygiene, but were at least 10- to 50-fold greater than those more commonly reported.

Administration, Inhalation↗
PubMed1996

Racial differences in survival from gynecologic cancer.

OBJECTIVE: To determine whether survival from gynecologic cancer is different between African-American and white patients at an inner-city hospital with both a large clinic and a private service. METHODS: We studied 538 patients (89 African American, 449 white) diagnosed with cervical, uterine, or ovarian cancer at a single institution from January 1, 1989 through December 31, 1993. Information was obtained on age, stage, site of disease, histology, and type of health insurance (public or commercial). Insurance coverage was used as a proxy for socioeconomic status. Overall survival was estimated by the method of Kaplan and Meier and compared by the log-rank test. Cox proportional hazard modeling was used to evaluate the effects of multiple factors on survival. RESULTS: African-American patients were significantly older and were more likely to have cervical cancer and public insurance than white patients. Overall survival was worse for African-American patients than for white patients (P < .05). However, stage for stage, there was no significant difference in survival between the groups. There was also no difference when patients were grouped by insurance status. African Americans had a significantly worse survival for cervical cancer than whites, and African-American patients older than 65 years had a worse survival than whites of similar age. On multivariate analysis, only stage and insurance coverage were significant predictors of survival. CONCLUSIONS: African-American patients with gynecologic cancer at our institution have worse overall survival than white patients. The survival difference seems to be due predominantly to differences in socioeconomic status and stage at diagnosis.

Black People↗
PubMed1996

Sarcoidosis and regional enteritis in two patients.

Both sarcoidosis and Crohn's disease (regional enteritis) are characterized by granuloma formation and they also have an unknown etiology. Only a few subjects with co-existing sarcoidosis and Crohn's disease have been reported in the literature. We report two cases who suffered from both disorders. In the two subjects Crohn's disease began first and the symptoms of sarcoidosis came later; four and sixteen years, respectively.

Adolescent↗
PubMed1995

Pathological changes in the Brown Norway rat cerebellum after mercury vapour exposure.

Our previous studies have demonstrated that mercury vapour exposure of Brown Norway rats induced an autoimmune response with development of glomerulonephritis and resulted in mercury deposition in the central nervous system, particularly in the neurons. The aim of this study was to investigate the effect on the central nervous system. A loss of Purkinje cells accompanied by Bergmann glial cell proliferation was found at a brain mercury level of 0.71 micrograms/g and became even more pronounced as the exposure dose increased. At a brain mercury level of 5.0 micrograms/g, a heavy gliosis was present in the brain stem, particularly around the pontine nuclei. In comparison with our previous study, the pathological changes in the brain appeared at the same mercury exposure dose as the glomerulonephritis. However, the location of pathological changes at the mercury level of 0.71 micrograms/g was not completely in accordance with the mercury distribution in the brain, which might be due to the sequence of mercury deposition, its amount or the vulnerability of the various cells classes.

Administration, Inhalation↗
PubMed1995

Efficacy of oral beta-agonist maintenance therapy in preterm labor: a meta-analysis.

OBJECTIVE: To analyze the available data on the efficacy of oral beta-agonist maintenance therapy in delaying delivery and in decreasing the incidence of preterm birth and its complications. DATA SOURCES: A computer search of English-language abstracts using MEDLINE (medical subject heading terms: labor, premature and beta-adrenergic receptor agonist, therapeutic use) was supplemented with a review of the bibliographies of obstetric texts to identify randomized trials of oral beta-agonist maintenance therapy. METHODS OF STUDY SELECTION: Six trials were identified, of which four met our inclusion criteria for the meta-analysis. DATA EXTRACTION AND SYNTHESIS: Trials to be included in this meta-analysis underwent trial quality evaluation and data abstraction independently by two blinded investigators. An estimate of the odds ratio (OR) and risk difference was calculated for the dichotomous outcomes using both a random effects model and a fixed effects model. Continuous outcomes were pooled using a simple weighted average of the within-study difference in means. The pooled OR for preventing preterm delivery was 1.09 (95% confidence interval [CI] 0.60-1.99) and the OR for preventing recurrent preterm labor was 1.05 (95% CI 0.53-2.05). The pooled difference in the mean interval to delivery was -0.22 days (95% CI -2.5 to +1.99). CONCLUSIONS: The available data do not support a role for beta-agonist maintenance therapy after resolution of an acute episode of preterm labor in reducing the incidence of preterm delivery, increasing the interval to delivery, or reducing the incidence of recurrent preterm labor.

Administration, Oral↗
PubMed1995

Neurodevelopmental test selection, administration, and performance in the main Seychelles child development study.

The Seychelles Child Development Study was designed to provide data on normal neurodevelopment of Seychellois children and to examine the relationship of their neurodevelopmental outcomes to in utero fetal exposure to low concentrations of methylmercury from a maternal diet high in fish. This paper outlines the strategies used to select, modify, and field test evaluation tools used in the main longitudinal prospective study of 740 children (95% of the cohort of 779 initially enrolled in 1989). It also gives population statistics and quality assurance data for the tests administered and the evaluation of the home environments.

Child↗
PubMed1995

Longitudinal neurodevelopmental study of Seychellois children following in utero exposure to methylmercury from maternal fish ingestion: outcomes at 19 and 29 months.

UNLABELLED: Despite the importance of defining developmental consequences for humans of in utero exposure to low levels of methylmercury, it is not yet clear if there are postnatal effects in fish-eating populations. The Seychelles Child Development Study (SCDS), now underway in the Republic of Seychelles, is following children to test the hypothesis that prenatal exposure to low concentrations of MeHg through maternal ingestion of fish is related to child development outcomes. In this study, children were evaluated with the Bayley Scales of Infant Development (BSID) at 19 mos. of age (N = 738). The cohort was evaluated again at 29 mos. (N = 736) with the BSID and the Bayley Infant Behavior Record. Mercury exposure determined by cold vapor atomic absorption analysis of maternal hair segments corresponding to pregnancy revealed a median exposure of 5.9 ppm (Range 0.5 - 26.7 ppm). The association between maternal hair mercury concentrations and neurodevelopmental outcomes at 19 and 29 mo. of age was examined by multiple regression analysis with adjustment for confounding variables. RESULTS: BSID Intertester reliability was ascertained by the Kappa statistic and was high. The mean BSID Mental Scale Indexes at both 19 and 29 mo. were comparable to the mean performance of US children. The mean BSID Psychomotor Scale Indexes at 19 and 29 mo. were 2 SD units above US norms, but consistent with previous findings of motoric precocity in children reared in African countries. No effect of mercury was detected on BSID scores at either age. On the Bayley Infant Behavior Record, activity level in boys, but not girls, decreased with increasing mercury exposure. Only one subjective endpoint was correlated with prenatal exposure to mercury. This study may have implications for environmental health policies concerning mercury in fish or fish consumption during pregnancy. Follow-up data are needed to determine if adverse effects occur at older ages and if such effects are determined to be related to mercury.

Adult↗
PubMed1995

Monitoring methylmercury during pregnancy: maternal hair predicts fetal brain exposure.

Autopsy brains were obtained from infants dying from a variety of causes within a few days of birth in a population exposed to methylmercury in fish. Infant and maternal blood and hair samples were also obtained. The concentration of total mercury in 6 major brain regions were highly correlated with maternal hair levels. This correlation was confirmed by a sequence of comparisons of maternal hair to maternal blood to infant blood and finally to infant brain. The results lend support to the use of maternal hair in assessing fetal exposure to methylmercury in fish-eating populations.

Brain↗
PubMed1995

Summary of the Seychelles child development study on the relationship of fetal methylmercury exposure to neurodevelopment.

The Seychelles Child Development Study is examining the association between fetal methylmercury exposure from a maternal diet high in fish and subsequent child development. The study is double blind and uses maternal hair mercury as the index of fetal exposure. An initial cross-sectional pilot study of 804 infants aged 1 to 25 months suggested that mercury may affect development. A follow up of 217 pilot children at 66 months of age also suggested that neurodevelopmental effects might be present, but the result was dependent on outcomes in a small number of children. On the basis of initial results in the pilot study a prospective, longitudinal main study with more covariates and expanded endpoints was begun on a new cohort of 779 children. No association with neurodevelopment was seen at 6 1/2, 19, or 29 months of age, but there was an inverse relationship at 29 months in boys only between mercury level and activity as judged by the examiner. Adverse neurodevelopmental effects from fetal mercury exposure in the pilot study are highly dependent on how the data are analyzed and no definite effects have been detected through 29 months of age in the main study. In a related study, 32 brains were obtained at autopsy from Seychellois infants. These were examined histologically and analyzed for mercury. No clear histological abnormalities were found. Mercury levels ranged from a background of about 50 ppb up to 300 ppb, and correlated well between brain regions. For 27 brains maternal hair from delivery was available and hair mercury correlated well with brain mercury.

Child Development↗
PubMed1994

Prolonged behavioral effects of in utero exposure to lead or methyl mercury: reduced sensitivity to changes in reinforcement contingencies during behavioral transitions and in steady state.

Postnatal exposure to lead or methyl mercury results in mental retardation, learning deficits, and other neurobehavioral effects in humans, and adverse consequences of prenatal exposure have been clearly documented with methyl mercury. To examine the developmental neurotoxicity of these metals, especially lead, concurrent schedules of food reinforcement were used to identify learning deficits in squirrel monkeys exposed during gestation to either methyl mercury or lead. Pregnant squirrel monkeys were administered methyl mercury (0.7 to 0.9 ppm in maternal blood) or lead (21 to 79 micrograms/dl in maternal blood) during the last half to two-thirds of gestation. At about 5-6 years of age, offspring were trained to lever press under concurrent schedules of reinforcement in which separate random interval reinforcement schedules operated independently on two levers. Reinforcement densities were varied such that 20 to 90% of the reinforcers were programmed to derive from the left lever (i.e., one lever was "richer" than the other). At steady state, the behavior of the controls was sensitive to reinforcement density and showed little lever bias, but the behavior of monkeys exposed to more than 40 micrograms/dl of lead and to methyl mercury was less sensitive to reinforcement rates and heavily biased. When relative reinforcement density on a lever changed, the unexposed animals' response rates gradually shifted to the newly rich lever. The behavior of monkeys exposed to methyl mercury or more than 40 micrograms/dl of lead changed slowly, not at all, or in the wrong direction. Steady-state behavior of monkeys exposed to less than 40 micrograms/dl resembled controls, but acquisition progressed more slowly and required 2-4 times as many reinforcers to complete. These effects suggest a behavioral mechanism--insensitivity to changing reinforcement contingencies--by which learning deficits and behavioral changes associated with these metals might be related to toxicant exposure. Since maternal blood levels corresponded to those that could be experienced in occupational settings, the present data raise the possibility of fetal hazards associated with maternal lead exposures at levels tolerated in humans in occupational settings.

Animals↗
PubMed1993

Autoimmune glomerulonephritis induced by mercury vapour exposure in the Brown Norway rat.

Subcutaneous injections of mercuric chloride induce an autoimmune glomerulonephritis with both granular and linear IgG deposits along the glomerular capillary wall and proteinuria. This disease is due to a T cell dependent polyclonal B cell activation responsible for production of antibodies against self (glomerular basement membrane, immunoglobulins, DNA, myeloperoxydase) and non self (sheep red blood cells, trinitrophenol (TNP)) components. Increase in serum IgE concentration is the hallmark of this disease. To determine if mercury vapours have pathogenic effects is an important problem of public health. The aim of this study was, first to compare the effects of mercury vapour exposure to those of mercury injections and, second, to compare the effects of high doses to those of low doses of mercury. Two exposure levels were studied corresponding to a mercury absorption of 13.1 mumol/week per kg body wt. and 1.7 mumol/week per kg body wt. during a 5-week period. It will be shown that, whereas the mercury concentration in the kidneys was similar in injected--and vapour exposed--rats, the mercury concentration in blood at the end of the exposure was about twice as high in the injected animals. Blood concentration of mercury was related to dose level but kidney content of mercury was similar in all groups, in spite of a dose difference by a factor of seven between low and high exposure. Mercury vapour and HgCl2 injections both trigger autoimmunity to the same extent and, in both cases the extent of autoimmune manifestations was dose-dependent.

Administration, Inhalation↗
PubMed1993

HIV-infected health care professionals. Public opinion about testing, disclosing, and switching.

BACKGROUND: We wanted to know what the public believes about the risks of human immunodeficiency virus (HIV) transmission in health care settings, and what opinions the public holds regarding HIV-infected health care professionals. We also wanted to uncover the correlates and predictors of those opinions. METHODS: A telephone survey of a nationwide random probability sample of adults was conducted in summer 1991. Thirteen hundred fifty adults completed the survey. The response rate was approximately 63%. We assessed (1) public opinion about whether HIV-infected physicians, surgeons, and dentists should quit working, and (2) the public's self-reported intention to remain in the care of an HIV-infected professional or to switch to another provider. RESULTS: Public concern about HIV transmission in health care settings has increased from 19% in 1988 to 38% in 1991. More of the public now believes that transmission from HIV-infected physicians is likely (up from 33% in 1988 to 46% in 1991). Yet, fewer respondents believe that HIV-infected physicians should not be allowed to work (45% vs 39%). Only 5% would deprive HIV-infected physicians of their livelihood as physicians. Fewer would switch from HIV-infected physicians now than in 1988 (56% vs 37%). Knowing someone with HIV infection was related to less concern and to less belief in likelihood of transmission as well as to increased support of HIV-infected health professionals' right to work. CONCLUSIONS: Although the public is more concerned about HIV transmission in health care settings since 1988, fewer would not allow HIV-infected health care professionals to work now than in 1988. Personalizing the epidemic, by using personal physicians and people with acquired immunodeficiency syndrome as educators, might help continue the trend toward improved attitudes toward HIV-infected health care professionals.

Adolescent↗
PubMed1993

Histopathologic correlation of the three-layered intravascular ultrasound appearance of normal adult human muscular arteries.

The purpose of this study was to correlate intravascular ultrasound images from normal peripheral muscular arteries with the microscopic arterial components by using surgical microdissection techniques. There has been uncertainty about the precise anatomic constituents that are represented by the intravascular ultrasound three-layer image in human peripheral arteries. Forty of 66 grossly normal human femoropopliteal arterial segments obtained at autopsy were found to have a three-layered appearance and were subjected to selective surgical microdissection of intima, media, or adventitia. After microdissection, arteries were imaged with a 30 MHz intravascular ultrasound system; two observers blindly reviewed video tapes to assess for the presence or absence of a one-, two-, or three-layered arterial appearance. Removal of internal elastic lamina and/or intima results in a weak but evident inner ultrasound acoustic interface as a result of the media, which is normally echo-lucent. Removal of the adventitia and/or external elastic lamina results in a weak outer ultrasound acoustic interface. Isolated removal of the media does not alter the three-layered ultrasound image. In normal adult human femoropopliteal arteries the inner bright acoustic reflection (layer) is derived from the interface of blood with the intima and internal elastic lamina and the second bright interface (third layer) is from the external elastic lamina and adventitia. The mid-echo-lucent zone is the result of the media. However, any portion of the arterial wall, including muscular media, can act as an acoustic interface.

Adult↗
PubMed1993

A two-year experience with excimer laser photorefractive keratectomy for myopia.

PURPOSE: This report summarizes the authors' 2-year experience with excimer laser photorefractive keratectomy (PRK) on 160 eyes of 128 patients. METHODS: All eyes were treated with an excimer laser: fluence, 160 mJ/cm2; frequency, 5 Hz; ablation zone diameter, 5.0 to 5.5 mm; and depth per pulse, 0.21 to 0.27 microns. A suction fixation ring was used in all eyes either with nitrogen flow (79 eyes) or without nitrogen flow (81 eyes) across the cornea. Follow-up ranged from 1 month (152 eyes) to 24 months (12 eyes). RESULTS: At 3 months, 82% (139) of eyes achieved an uncorrected visual acuity of 20/40 or better; 83% were corrected to within +/- 1 diopter (D) of intended correction and 30% lost one line of best-corrected visual acuity. At 6 months, 88% (124) of eyes achieved an uncorrected visual acuity of 20/40 or better; 84% were corrected to within +/- 1 D of intended correction and 15% lost one line of best-corrected visual acuity. At 12 months, 91% (71) of eyes achieved an uncorrected visual acuity of 20/40 or better; 84% were corrected to within +/- 1 D of intended correction and 17% lost one line of best-corrected visual acuity. At 24 months, 100% (12) of eyes achieved an uncorrected visual acuity of 20/40 or better; 91.6% were within +/- 1 D of intended correction and 0% lost one line of best-corrected visual acuity. CONCLUSIONS: In eyes with a follow-up of 6 to 24 months, 77% to 100% achieved an uncorrected visual acuity of 20/40 or better and 84% to 92% were corrected to within +/- 1 D of the intended correction. The authors conclude that excimer laser PRK appears to be a safe procedure capable of correcting the eyes of patients with low to moderate myopia with approximately the same degree of accuracy as radial keratotomy.

Adult↗
PubMed1992

Mercury distribution in the rat brain after mercury vapor exposure.

Brown Norwegian rats were exposed to mercury vapor at a concentration of approximately 1 mg/m3 for 5 weeks 24 hr/day 7 days a week and 6 hr/day 3 days a week, respectively. The total mercury absorption was calculated to 264 and 35 micrograms per week and 100 g body weight. The mean blood mercury concentration was 0.25 +/- 0.03 and 0.09 +/- 0.01 microgram/g, and the total concentration in the brain was 5.03 +/- 0.73 and 0.71 +/- 0.10 microgram/g tissue, respectively. The mercury distribution in the brains was examined using a method based on chemographic principles. Mercury was found primarily in the neocortex, in the basal nuclei, and in the cerebellar Purkinje cells. This distribution pattern corresponded to the pattern of inorganic mercury described after exposure to methyl mercury. Distribution of mercury after administration of different mercury compounds is discussed.

Administration, Inhalation↗