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Biomedical subjects

A M Berg

Publications and source records attributed to A M Berg.

15 recordsLinked to original sources
PubMed2001

Suicide in police--a critical review.

Police officers are commonly referred to as a high-risk group for suicide. So far no comprehensive review has been published about epidemiologic studies among police. This article systematically explores the worldwide literature on suicide in police. None of the recent nationwide studies show elevated suicide rates among police. Other studies show inconsistent results. Conclusively, it is not documented that there is an elevated suicide rate in police. A particular problem in previous research has been methodological shortcomings. There is need for further systematic research, and this review points out some strategies of research.

Bias↗
PubMed1999

Current results with pediatric heart transplantation.

BACKGROUND: Cardiac transplantation is an accepted treatment for children with end-stage heart failure or complex or inoperable congenital defects. METHODS: Since 1988, 95 transplants have been performed in 89 children aged 4 days to 18 years (median 6.9 years, 42 patients 0-5 years). Fifty-eight (61%) had congenital or acquired heart disease, 31 (33%) had idiopathic cardiomyopathy, and 6 (6%) were retransplants. Fifty-seven of the patients had prior cardiac surgery with a range of one to eight procedures (mean 3.4 procedures/patient). At the time of transplantation, 53 (56%) were United Network for Organ Sharing (UNOS) status I, including 23 children on mechanical ventilation and 4 with mechanical circulatory support. RESULTS: Thirty-day survival in this group was 96%. Posttransplant results showed a median time of ventilation of 1 day (mean 3.0+/-5.7 days), median duration of inotropic support of 2 days (mean 2.7+/-2.3 days), median intensive care unit (ICU) stay of 4 days (mean 6.9+/-9.6 days), and median hospitalization of 9 days (mean 14.3+/-13.9 days). Follow-up from 1 month to 10.3 years (mean 3.1 years) has demonstrated a 1-year actuarial survival of 79% and a 5-year actuarial survival of 69%. Rejection, both acute and chronic, accounted for the vast majority of deaths. CONCLUSIONS: Pediatric heart transplantation can be accomplished with excellent early survival despite multiple prior cardiac operations and relative severity of illness. Parameters such as postoperative ventilation, inotropic support, ICU stay, and hospitalization can be kept at reasonable levels with acceptable long-term results, although rejection remains a serious problem.

Actuarial Analysis↗
PubMed1996

Relapsing polychondritis and aseptic meningitis.

Aseptic meningitis is a rare complication of relapsing polychondritis. We describe a 60-year-old man who developed a prolonged episode of aseptic meningitis for which no cause could be determined and, that resolved spontaneously. He then developed classic relapsing polychondritis 14 months later. He subsequently had another episode of prolonged meningitis complicated by hydrocephalus. No infectious cause for the meningitis could be determined after extensive investigation including meningeal biopsy. The patient responded to corticosteroids and antituberculous therapy.

Biopsy↗
PubMed1993

Localized amyloidosis of the larynx: evidence for light chain composition.

We report the biochemical characterization of amyloid fibrils from a patient with localized amyloidosis of the epiglottis and larynx. Biopsy specimens showed amorphous material consistent with amyloid deposits with a plasmacytic infiltrate. Both plasma cells and amyloid deposits stained positively by immunohistochemistry for kappa light chains. Amyloid fibrils were isolated. The major constituent resolved as a 13 kd band was sequenced and found to be consistent with a kappa 1 light chain. A tryptic digest was carried out and 3 tryptic peptides were sequenced defining the first 45 residues of the protein and residues 110 through 119. Four amino acid substitutions were found, 3 of which have not been described previously. This study defines the immunoglobulin origin of amyloid deposits in localized amyloidosis. The benign nature of localized amyloidosis suggests that a localized clone of plasma cells producing an amyloidogenic light chain may represent the pathogenetic mechanism of this disease, which appears to be a form of plasma cell dyscrasia.

Amino Acid Sequence↗
PubMed1993

Established fibromyalgia syndrome and parvovirus B19 infection.

OBJECTIVE: To determine the seroprevalence of prior and persistent parvovirus B19 (B19) infection in a group of patients with fibromyalgia (FS) compared with controls. METHODS: Fifteen female patients with FS who recalled a viral prodrome (+VP) preceding the onset of FS symptoms and eleven patients with FS who did not recall any such illness (-VP) were selected from a referral practice. We excluded patients with FS who described a history of trauma prior to the onset of FS symptoms. Twenty-six female medical workers served as controls. Serum IgM and IgG anti-B19 antibodies were measured by ELISA: Polymerase chain reaction (PCR) products from serum were analyzed by dot blot hybridization for B19 DNA. Fisher's 2-tailed exact test was used to compare the proportion of positive serologies in each group. RESULTS: No patient or control had positive IgM levels. For all patients with FS, the prevalence of prior B19 infection was comparable to that of healthy controls (11/26 vs 12/26, p = 1.00) and that of the general population. No significant difference was found in the prevalence of prior B19 infection in FS + VP and FS-VP patients (8/15 vs 3/11, p = 0.25). None of the patients or controls showed evidence for persistent B19 viremia, as determined by PCR analysis. CONCLUSION: Our data do not suggest that B19 plays a pathogenic role in this population of patients with FS. Testing for IgM against B19 within 2-3 months of symptom onset may prove more helpful in further defining the role of B19 in FS.

Adult↗
PubMed1990

Gamma-aminobutyric acid concentration in lumbar cerebrospinal fluid from patients with febrile convulsions and controls.

The cerebrospinal fluid (CSF) concentration of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) was analysed in 41 children with febrile convulsions (FC), 41 febrile controls of similar age (control group 1), and 59 controls, who had no fever and/or were outside the age range for FC (control group 2). A significant correlation between CSF-GABA and age was demonstrated for controls (1 + 2) (r = 0.63, p less than 0.00001), as well as for patients with FC (r = 0.42, p = 0.003). Patients with FC did not differ significantly from control group 1 in respect to CSF-GABA. Duration of FC was related to both CSF-GABA and age (GABA: r = -0.29, p less than 0.05; age: r = -0.32, p less than 0.05). For 56 controls (1 + 2) greater than 1 year of age, a significant negative correlation between CFC-GABA and body temperature was found (r = -0.34, p = 0.01). The low CSF-GABA in the FC-labile age group, the negative correlation of CSF-GABA to body temperature, and the negative correlation of the duration of FC to both CSF-GABA and age, all indicate that GABA could be of importance in the pathophysiology of FC.

Adolescent↗
PubMedDate not supplied

A mechanistic study of evolvability using the mitogen-activated protein kinase cascade.

Evolvability is a function of the way genetic variation interacts with the mechanisms that produce the phenotype. We explore an explicitly mechanistic way of studying the evolvability of phenotypes that are produced by a relatively simple genetic mechanism, the mitogen-activated protein kinase (MAPK) cascade. We developed a quantitative model of MAPK activation that can be used to study the effects of genetic variation on the various components of this signaling cascade. We show how some standard tools of applied mathematics, such as steady-state formulations and nondimensionalization, can be used to elucidate the relative importance of variation in each gene of this mechanism. We also give insights into non-intuitive patterns of dependence and trade-off among the genes. The mechanism produces several different phenotypes (ultrasensitivity to stimulation, switch-like behavior, amount of MAPK-PP delivered, persistence of MAPK-PP activity), each of which is sensitive to different (but partially overlapping) combinations of genes. We show that the mechanism imposes clear limitations on the evolvability of each of the different phenotypes of the pathway, even in the presence of genetic variation in the components of the mechanism. This approach to the study of evolvability is generally applicable and complements the traditional approach through statistical genetics by providing a mechanistic understanding of the genetic interactions that produce the phenotype.

Biological Evolution↗