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Biomedical subjects

L Fisher

Publications and source records attributed to L Fisher.

At least 91 records · Page 5Linked to original sources

No evidence for a schizophrenia susceptibility gene in the vicinity of IL2RB on chromosome 22.

Pulver et al. [1994a] reported modest linkage evidence for a dominantly (D) inherited "schizophrenia gene" in the vicinity of IL2RB on chromosome 22q12, and Coon et al. [1994] adduced moderate evidence under a recessive (R) model. We report here a replication study to test the hypothesis that one of these two models (or a third, intermediate (I) model) adequately describes the co-segregation of schizophrenia and chromosome 22q12 markers in an independent sample of 23 multiplex families. Altogether nine transmission models were evaluated. The models differed depending on whether the 15 family members with a diagnosis of schizophrenia spectrum disorders were considered unaffected (a "narrow" (N) definition), affected (a "wide" (W) definition), or declared "unknown" (U). The entire region between D22S268 and D22S307 is excluded (i.e., lod <-2) for models RN, RW, RU, and IW. Lod scores for the remaining models are uniformly negative; albeit, equivocal with respect to the dominant hypothesis over a small region between D22S268 and IL2RB. Nonparametric analysis under both diagnostic criteria also failed to yield any evidence for a susceptibility locus in this region of chromosome 22.

Chromosomes, Human, Pair 22↗

No association between polymorphisms in the human dopamine D3 and D4 receptors genes and alcoholism.

The human dopamine D2 receptor gene (DRD2) has received considerable attention for the past several years as a potential candidate that may affect susceptibility to alcoholism. The association studies that compared the frequencies of alleles of DRD2 gene between alcoholics and control groups have produced equivocal results. Dopamine D3 and D4 receptor genes (DRD3 and DRD4) are in the same class as DRD2 but with different pharmacological properties. We have used relative risk and haplotype relative risk approaches to test associations between alleles of DRD3 and DRD4 genes and alcoholism. For relative risk studies 162 probands from multiple incidence alcoholic families have been compared to 89 psychiatrically normal controls. Haplotype relative risk approaches have used 29 alcoholic probands in which both parents were available for genotyping. The Bal I restriction enzyme site in DRD3 and tandem repeat (VNTR) in DRD4 genes polymorphisms were used to genotype the above samples. The results of relative risk approaches for both DRD3 and DRD4 genes were negative for comparisons of alcoholics and subtypes of alcoholics with normal controls. Haplotype relative risk approaches also were negative for both genes. These results suggest that any role played by these receptors may account for only part of the variation in susceptibility to alcoholism.

Alcoholism↗

Apnea after immunization of preterm infants.

OBJECTIVE: To determine the frequency of adverse reactions, particularly the occurrence of apnea, among preterm infants after immunization with diphtheria and tetanus toxoids and whole cell pertussis vaccine adsorbed (DTP) and Haemophilus influenzae type b conjugate (HibC) vaccine in the neonatal intensive care unit. STUDY DESIGN: After the occurrence of apnea in two preterm infants following immunization with DTP and HibC, a prospective surveillance of 97 preterm infants younger than 37 weeks of gestation who were immunized with DTP (94 also received HibC at the same time) in the neonatal intensive care unit was performed to assess the frequency of adverse reactions and in particular, the occurrence of apnea. For each infant, data were recorded for a 3-day period before and after receipt of the immunization. RESULTS: The majority of preterm infants tolerated immunizations with DTP and HibC without ill effects. However, 12 (12%) infants experienced a recurrence of apnea, and 11 (11%) had at least a 50% increase in the number of apneic and bradycardic episodes in the 72 hours after immunization. This occurred primarily among smaller preterm infants who were immunized at a lower weight (p = 0.01), had experienced more severe apnea of prematurity (p = 0.01), and had chronic lung disease (p = 0.03). CONCLUSION: The temporal association observed between immunization of preterm infants and a transient increase or recurrence of apnea after vaccination merits further study. Cardiorespiratory monitoring of these infants after immunization may be advisable.

Apnea↗

Bismuth subsalicylate instead of metronidazole with lansoprazole and clarithromycin for Helicobacter pylori infection: a randomized trial.

OBJECTIVE: We evaluated the efficacy of lansoprazole, clarithromycin, and metronidazole (LCM) administered twice daily for 7 days. Because there is growing concern about the development of metronidazole-resistant H. pylori (HP) strains, we also tested a novel regimen consisting of lansoprazole, clarithromycin, and bismuth subsalicylate (LCB). METHODS: Patients with active HP infection and peptic ulcer, a history of peptic ulcer, or nonulcer dyspepsia were randomized to either lansoprazole 30 mg b.i.d., clarithromycin 500 mg b.i.d., and metronidazole 500 mg b.i.d. or lansoprazole 30 mg b.i.d., clarithromycin 500 mg b.i.d., and bismuth subsalicylate 524 mg b.i.d. (LCB) for 7 days. Compliance and side effects were recorded by using a diary. RESULTS: "Per protocol" eradication with LCM was achieved in 41 of 47 (87%). By using "intention to treat" analysis, LCM eradicated HP infection in 43 of 53 patients (81%). By using "per protocol" analysis, LCB eradicated HP infection in 40 of 47 patients (85%). On an "intention to treat" basis, LCB led to HP eradication in 42 of 52 (81%). The most common significant side effects observed with LCM were altered taste (39%) and abdominal pain (19%). With LCB, the most common significant side effects were altered taste (23%) and dark stools (23%). CONCLUSIONS: LCB for 7 days was as effective in eradicating HP infection as a 7-day course of LCM. Further studies evaluating the role of bismuth compounds in proton-pump inhibitor based triple therapy are warranted. Such therapy may have particular importance in areas where high metronidazole resistance is a concern.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Transgenic model for the discovery of novel human secretory non-pancreatic phospholipase A2 inhibitors.

Transgenic mice were created which overexpress human secretory non-pancreatic phospholipase A2 (sPLA2) pansomatically as a potential disease and drug-testing model. The mice were produced using a DNA construct in which the inducible mouse metallothionein gene promoter drives expression of a human sPLA2 minigene. High levels of sPLA2 were detected in several tissues by immunofluorescence localization. Expression in the testes caused hypospermia and male infertility. Circulating catalytically active sPLA2 could be induced to levels observed in patients undergoing a systemic inflammatory response but had no detectable effect on the mice. Therefore, these results suggest that sPLA2 hyperphospholipasemia alone may have only limited pathophysiological consequences. We further show that 3-[3-acetamide-1-benzyl-2-ethylindolyl-5-oxy]propane phosphonic acid LY311727), a potent new inhibitor of phospholipase A2 catalysis developed by our group, dramatically suppresses the circulating enzyme activity in these animals whereas 3-[3-acetamide-1-benzyl-2-propylindolyl-5-oxy]propane phosphonic acid (LY314024), a substantially less potent LY311727 analog, is without effect. These later results thus motivate the further development of this compound as a potential new therapeutic agent and valuable research tool.

Animals↗

Long-term sun exposure alters the collagen of the papillary dermis. Comparison of sun-protected and photoaged skin by northern analysis, immunohistochemical staining, and confocal laser scanning microscopy.

BACKGROUND: Long-term solar irradiation produces both morphologic and functional changes in affected skin. Because collagen is the major structural component of skin, any alteration in its production or degradation could have profound effects on cutaneous functional integrity. OBJECTIVE: Our purpose was to investigate alterations in the production and morphology of collagen fibers brought about by long-term sun exposure. METHODS: We compared collagen and collagenase gene expression and collagen immunohistochemical staining and used confocal laser scanning microscopy for morphologic examination of dermal collagen fibers in photodamaged compared with sun-protected skin from the same persons. RESULTS: Despite a large increase in elastin messenger RNA in sun-damaged skin, collagen and collagenase gene expression remained essentially unchanged. However, striking alterations in the papillary dermis of photoaged skin were found, which revealed large, abnormally clumped elastic fibers and deformed collagen fibers of various diameters, replacing the normal architecture of the papillary dermis. CONCLUSION: Our data provide evidence for normal collagen gene expression in sun-damaged skin and suggest that degradation and remodeling of collagen take place in the papillary dermis accompanied by deposition of other matrix components, predominantly abnormal elastic fibers.

Blotting, Northern↗

Mapping the lipid-exposed surfaces of membrane proteins.

Phospholamban forms a stable complex of five long transmembrane helices. We show that the relative rotational orientation of the helices in the pentameric complex can be distinguished by S-H to S-D exchange of cysteine sulphydryl groups located in the transmembrane segment of the protein and exposed to the lipid environment. Of the three cysteine residues in phospholamban, two residues (Cys 36 and Cys 46) are oriented towards the helix interface and protected from exchange, while the third cysteine (Cys 41) is oriented towards the lipid interface and undergoes exchange with water diffused into the bilayer. Distinguishing the external and internal faces of a membrane protein by sulphydryl exchange provides a general approach for determining the three-dimensional fold of membrane proteins and enhances model building efforts to generate high-resolution structures.

Adenosine Triphosphatases↗

A nurse-managed smoking cessation program for hospitalized smokers.

OBJECTIVES: This study evaluated a nurse-managed smoking cessation program for smokers hospitalized for a variety of conditions. METHODS: Hospitalized patients who smoked prior to hospitalization and who were motivated to quit (n = 660) were randomized to intervention or usual-care groups and followed for the next year. The intervention included a meeting with the nurse-case manager; the use of a videotape, workbook, relaxation audiotape, and nicotine replacement therapy; and nurse-initiated phone contacts after discharge. RESULTS: The 12-month confirmed cessation rates were 21% and 31% for, respectively, the usual-care and intervention groups (odds ratio = 1.7; 95% confidence interval = 1.1, 2.3). CONCLUSIONS: A nurse-managed smoking cessation intervention can significantly increase cessation rates for hospitalized patients.

Adult↗

A starch-hemoglobin resuscitative compound.

A resuscitative compound in freeze-dried form has been synthesized between a modified starch and a tetremerically stabilized hemoglobin. In order to complex the hemoglobin, the starch has been prepared in mono-, di-, tri-, and tetra-aldehyde moieties. The hemoglobin was stabilized with low molecular weight diacids. Electrophoretic densitometric patterns indicate compound formation. The resulting polymers were characterized with respect to oxygen transport (biotonometry), Hill constant and P50. The in vivo evaluation indicates that these compounds are effective in exchange-transfusion experiments with rats to a level of about 85% replacement of whole blood. The final product is a cost-effective acellular resuscitative compound which can be stored in freeze-dried form at room temperature for extended periods of time. This artificial blood substitute can be reconstituted upon the addition of water.

Animals↗

A comparison of filtered leukocyte-reduced and cytomegalovirus (CMV) seronegative blood products for the prevention of transfusion-associated CMV infection after marrow transplant.

We performed a prospective, randomized trial in CMV seronegative marrow recipients to determine if filtered blood products were as effective as CMV-seronegative blood products for the prevention of transfusion-transmitted CMV infection after marrow transplant. Before transplant, 502 patients were randomized to receive either filtered or seronegative blood products. Patients were monitored for the development of CMV infection and tissue-documented CMV disease between days 21 and 100 after transplant. Infections occurring after day 21 from transplant were considered related to the transfusion of study blood products and, thus, were considered evaluable infections for the purpose of this trial. In the primary analysis of evaluable infections, there were no significant differences between the probability of CMV infection (1.3% v 2.4%, P = 1.00) or disease (0% v 2.4%, P = 1.00) between the seronegative and filtered arms, respectively, or probability of survival (P = .6). In a secondary analysis of all infections occurring from day 0 to 100 post-transplant, although the infection rates were similar, the probability of CMV disease in the filtered arm was greater (2.4% v 0% in the seronegative arm, P = .03). However, the disease rate was still within the prestudy clinically defined acceptable rate of < or = 5%. We conclude that filtration is an effective alternative to the use of seronegative blood products for prevention of transfusion-associated CMV infection in marrow transplant patients.

Adolescent↗

Monoamine oxidases and alcoholism. I. Studies in unrelated alcoholics and normal controls.

Low platelet MAO activity has been associated with alcoholism. In order to evaluate the role of MAO genes in susceptibility to alcoholism, we have taken a biochemical and molecular genetic approach. The sample consisted of 133 alcoholic probands who were classified by subtypes of alcoholism and 92 normal controls. For those subjects typed for platelet MAO activity, alcoholics (N = 74) were found not to differ from the non-alcoholics controls (N = 34). Neither was there a significant difference between type I and type II alcoholics or between either subtype and normal controls. However, we do find significant differences between male and female alcoholics, but not between male and female controls. The allele frequency distribution for the MAO-A and MAO-B dinucleotide repeats is different between the alcoholic sample (N = 133) and the normal control sample (N = 92). In a two-way analysis of variance of MAO-B activity as a function of the allelic variation of each marker locus and diagnosis, there is no evidence for mean differences in activity levels for the different alleles. Our findings do not rule out a role for the MAO-B gene in controlling the enzyme activity because the dinucleotide repeats are located in introns.

Adult↗

Cataracts after bone marrow transplantation: long-term follow-up of adults treated with fractionated total body irradiation.

PURPOSE: To determine the risk of, and risk factors for, developing cataracts after bone marrow transplantation. METHODS AND MATERIALS: Four hundred and ninety-two adults who underwent bone marrow transplantation in Seattle were followed for 2 to 18 (median, 6) years. Before transplantation, patients received a preparative regimen of chemotherapy plus total body irradiation (TBI) (n = 407) or chemotherapy alone, without TBI (n = 85). TBI was administered in a single dose of 10 Gy (n = 74) or in fractionated doses totaling 12-15.75 Gy (n = 333). The risk of cataracts was determined for groups of patients with respect to the type of preparative regimen received and other pretransplant and posttransplant variables. RESULTS: One hundred and fifty-nine patients (32%) developed cataracts between 0.5 to 11 (median, 2.3) years after transplantation. The probability of cataracts at 11 years after transplantation was 85%, 50%, 34%, and 19% for patients receiving 10 Gy of single-dose TBI, > 12 Gy fractionated TBI, 12 Gy fractionated TBI, and no TBI, respectively (p < 0.0001). Among those developing cataracts, the severity was greater in patients after single-dose TBI (59% probability of surgical extraction) than after > 12 Gy fractionated TBI, 12 Gy fractionated TBI, or no TBI (33%, 22% and 23%, respectively). Patients given corticosteroids after transplant had a higher probability of cataracts (45%) than those without steroids (38%) (p < 0.0001). In a proportional hazards regression model, the variables that were correlated with an increased probability of cataracts were single-dose TBI (relative risk (RR) = 2.46) and steroid therapy (RR = 2.34), while a decreased probability of cataracts was correlated with a nonTBI preparative regimen (RR = 0.41). The yearly hazard of developing cataracts in recipients of single-dose TBI was highest during the third year after transplantation, while in recipients of fractionated TBI, the hazard was distributed among years one through seven. The probability of cataracts in all groups reached a plateau at 7 years after transplantation, after which the development of cataracts was extremely unlikely. CONCLUSION: TBI is the major risk factor for developing cataracts after BMT. Single-dose TBI results in the highest risk of cataracts. However, the risk of cataracts in recipients of fractionated-TBI is significantly higher than in patients who receive no TBI. In addition to TBI, steroid therapy is an independent risk factor for cataracts after BMT.

Adolescent↗

Fungal liver infection in marrow transplant recipients: prevalence at autopsy, predisposing factors, and clinical features.

To determine the prevalence of fungal liver infection at autopsy in marrow transplant recipients, we reviewed autopsy results for the period 1980-1989. Cases were compared to randomly chosen autopsied controls without fungal infection. Fungal liver infection was found in 67 (9%) of 731 patients. Fungal cultures of liver lesions were positive for 34 of 67 patients, most of whom had been culture-positive for the same fungal species (largely Candida) during life. Multivariate analysis revealed that independent predictors of fungal liver infection were deep fungal infection after transplantation (RR, 35), colonization or superficial infection after transplantation (RR, 13), and severe liver dysfunction caused by veno-occlusive disease of the liver and/or graft-versus-host disease (RR, 7). Clinical and laboratory findings during the last month of life revealed no differences between cases and controls. Liver imaging studies performed during the last 15 days of life had a sensitivity of only 18% for detecting fungal liver lesions.

Adult↗