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Biomedical subjects

G L Brown

Publications and source records attributed to G L Brown.

At least 91 records · Page 5Linked to original sources

Dopamine beta-hydroxylase in CSF. Relationship to personality measures.

Dopamine beta-hydroxylase (DBH), the enzyme that converts dopamine to norepinephrine, was measured in the CSF of 32 subjects. Those individuals with a low level of DBH in the CSF had significantly elevated profiles on the Minnesota Multiphasic Personality Inventory, suggesting a relationship between the central noradrenergic system and some aspects of personality in man.

Adolescent↗

A mechanism for the amelioration by hyperbaric oxygen of experimental staphylococcal osteomyelitis in rabbits.

Although hyperbaric oxygen (HBO) is as effective as cephalothin against osteomyelitis due to Staphylococcus aureus in the rabbit, the effect is not by directing killing. To investigate the mechanism, argon washouts (perfusion) and oxygen tensions were measured by intramedullary probes placed in the metaphyses of infected and uninfected tibias. In vitro phagocytic killing activity for S. aureus was determined at oxygen tensions found in these bones under ambient and HBO conditions. Mean tibial oxygen tensions (mm Hg) under ambient conditions were 21 (infected) and 45 (uninfected); under HBO conditions, 104 (infected) and 321 (uninfected). Perfusion was decreased in osteomyelitic bone and was not acutely increased by HBO in either normal or infected bone. Phagocytic killing of S. aureus was markedly decreased at 23 mm Hg of O2, significantly improved at 45 and 109 mm Hg, and most effective at 150 mm Hg. Thus, in osteomyelitic bone, HBO increased intramedullary oxygen to tensions consistent with normal phagocytic function.

Animals↗

Group B streptococcal neonatal infection: clinical review of plans for prevention and preliminary report of quantitative antepartum cultures.

The neonatal and obstetric approaches to preventing group B streptococcal neonatal infections are reviewed. Although recent reports recommend prophylactic antibiotic treatment of antepartum and intrapartum group B streptococcal carriers and low-birth-weight infants, acceptance of these schemes is not widespread. A preliminary study to evaluate the value of semiquantitative vaginal and cervical cultures of antepartum women for group B streptococcus in predicting maternal and neonatal infectious morbidity revealed: 1) 11% of the study population were carriers (group B streptococcus isolated from broth only) but only 2.8% had heavy colonization (growth in broth and on streaked plates), and 2) morbidity associated with 8 heavily colonized mothers during the current pregnancy included group B streptococcal endometritis (1 patient), neonatal sepsis (1), and readmission of a newborn for transient cyanosis (1). Two of the heavily colonized mothers were known carriers in their last pregnancy; 1 had group B streptococcal endometritis and the infant of the second developed clinical sepsis at 2 weeks of age. The clinical value of semiquantitative culture techniques requires additional investigation.

Ampicillin↗

The role of lymphadenectomy in the management of renal cell carcinoma.

Skinner and deKernion's datum, like ours, suffers from the fact it is retrospective and not randomized. Therefore, it provides suggestive but not conclusive evidence that lymphadenectomy enhances the chances for survival of a patient with a given stage and grade of renal cell carcinoma. In our study, lymphadenectomy was defined as removal of the regional lymph nodes from the diaphragm to the bifurcation of the common iliac artery on the homolateral side, which was the usual type of lymphadenectomy performed in this retrospective analysis. Because information may be obtained from lymphadenectomy alone which allows a more accurate estimate of the patient's prognosis in 8 per cent of the cases, and because our data suggest a statistical improvement in survival in patients with stage C and D disease if lymphadenectomy is performed, it is recommended that patients undergoing radical nephrectomy for renal cell carcinoma have a regional lymphadenectomy performed at the same time. It is also recommended that a prospective randomized study of th role of lymphadenectomy in patients with a given stage and grade of renal cell carcinoma be undertaken.

Adenocarcinoma↗

Plasma levels of d-amphetamine in hyperactive children. Serial behavior and motor responses.

Amphetamine has been clearly documented to be an efficacious treatment for hyperactive children. The pharmacokinetics of amphetamine have been studied in adults, but not in children. Sixteen male children who scored greater than 2SD from norms on Factors I and IV of Conner's Teacher Rating Scale and who were not excluded for reasons to do with medical or psychiatric conditions, intelligence, or age, had a plasma d-amphetamine apparent elimination half-life of 6.8 +/- 0.5h. Peak plasma level occurred between 3 and 4h (62.7 +/- 3.8 and 65.9 +/- 3.6 ng/ml, respectively). Six of these children had a repeat study and there were no significant differences within subject in apparent elimination half-lives and attained peak blood levels. The variation in plasma levels was greater during absorption than during elimination. Both behavioral and motor activity responses as analyzed by differences between amphetamine and placebo days (by paired t-tests) indicate significant responses between hours 1--4; however, these responses do not correlate with plasma amphetamine levels; they occur during the absorption phase. The decreased response to later similar plasma levels of d-amphetamine may be related to depletion of catecholamine stores, to replacement by a 'false neurotransmitter' metabolite of amphetamine, or to alteration in receptor sensitivity.

Child↗

Alcohol and central serotonin metabolism in man.

Animal studies and some of thephenomena associated with alcoholism in humans suggest that some central effects of alcohol may involve serotonergic systems. The CSF metabolites of serotonin and dopamine, 5-hydroxyindoleacetic acid (5HIAA), and homovanillic acid (HVA) were studied in hospitalized alcoholics. There were no significant differences in HVA levels between groups. The level of 5HIAA of alcoholics in the abstinence phase, 28 to 63 days after their last drink, was significantly lower (21.8 +/- 1.9 ng/mL) than both a nonalcoholic comparison group (31.7 +/- 2.0 ng/mL) and alcoholics in the immediate postintoxication phase, within one to two days after their last drink (32.3 +/- 2.9 ng/mL).

Adult↗

Aggression in humans correlates with cerebrospinal fluid amine metabolites.

Cerebrospinal fluid of the major central metabolites of serotonin (5HT), norepinephrine (NE), and dopamine (DA)--5-hydroxyindoleacetic acid (5HIAA), 3-methoxy-4-hydroxy=phenylglycol (MHPG), and homovanillic acid (HVA), respectively--were studied in a group of 26 age-similar military men with no history of major psychiatric illness, but with various personality disorders and difficulties adjusting to military life. Independently scored history of aggressive behavior showed a significant negative correlation with 5HIAA (r = -0.78) and a significant positive correlation with MHPG (r = 0.64).

Adult↗

The role of plasma amine oxidase, platelet monoamine oxidase, and red cell catechol-O-methyl transferase in severe behavioral reactions to disulfiram.

The authors assayed platelet monoamine oxidase (MAO), plasma amine oxidase (AO), and red cell catechol-O-methyl transferase (COMT) in 32 male alcoholics before they began disulfiram treatment. Seven subjects developed psychotic reactions to disulfiram; these 7 had significantly lower pretreatment MAO and AO levels and significantly higher COMT than the patients who had no adverse reactions to disulfiram, which suggests that severe behavioral reactions to disulfiram are associated with differences in enzyme activities.

Adolescent↗

Effects of hyperbaric oxygen upon S. aureus, Ps. aeruginosa and C. albicans.

Numerous in vitro investigations have reported that prolonged, continuous hyperbaric oxygen (OHP) exposure to certain bacteria and yeast is bacteriostatic. While it is tempting to attribute the lower infection rates reported in OHP-treated patients to this bacteriostatic effect, the duration and intensity of OHP exposure in these experimental studies exceeds that of normal therapeutic use. This study was designed to investigate the effects of human OHP treatment protocols upon the in vitro growth and survival of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Additional studies using antibiotic-containing culture media were conducted to investigate the possible OHP enhancement of antibiotic sensitivity. No differences were observed between the bacterial and yeast growth curves of the control and experimental group. OHP also failed to produce any measurable difference in the bactericidal effectiveness of the selected antibiotics.

Candida albicans↗

The quantitative measurement of depression and anxiety in male alcoholics.

Depression and anxiety have been reported to be commonly associated with alcoholism. Most attempts to clarify this relationship have suffered from a patient selection bias in that only those alcoholics who sought treatment were studied. The authors performed quantitative measurements of depression and anxiety in a group of 48 men referred for treatment solely on the basis of excessive drinking. The prevalence of depression and anxiety as measured by both the Zung and Hamilton scales was lower than that shown in previous studies. The results of this study indicate that problems in young, healthy male alcoholics.

Adult↗

Dopamine-beta-hydroxylase in the cerebrospinal fluid: relationship to disulfiram-induced psychosis.

Cerebrospinal fluid (CSF) dopamine-beta-hydroxylase (DBH) activity in 32 male alcoholics was measured using a modification of the radioenzymatic method of Molinoff et al. In most, the CSF was obtained before treatment with disulfiram, while in others it was obtained while they were on the drug (250 or 500 mg). As expected, treatment with this reversible DBH inhibitor had no effect on the activity of the enzyme measured in our in vitro assay. However, low pretreatment DBH activity was found to correlate with adverse reactions to disulfiram. Mean DBH activity of four individuals who went on to become psychotic on disulfiram was 0.13 +/- 0.02 nmole/ml per hr (mean +/- SEM). An additional four individuals who developed dysphoric but nonpsychotic reactions had a mean DBH of 0.23 +/- 0.03. Both these values were significantly lower than the mean DBH activity of the remaining 24 individuals treated with disulfiram who had no adverse side effects, 0.53 +/- 0.06 p less than 0.02 and p less than 0.05, respectively, 2-tailed t-test.

Adolescent↗

Immunologic dysfunction in the myeloproliferative disorders.

Forty patients with various types of myeloproliferative disorders were evaluated immunologically. Serum immunoglobulin levels were within the normal range in most patients and no monoclonal gammopathies were detected. Serum C'3 levels were decreased in 19 of 40 (48%) patients. The response of peripheral blood lymphocytes to phytohemagglutinin was decreased in 26 of 40 (65%) and to pokeweed mitogen in 18 of 28 (64%) patients studied. Lymphocytes from patients with polycythemia vera were least affected. Unstimulated lymphocytes from some patients demonstrated markedly increased thymidine uptake activity. Despite the diminished mitogenic response, only 2 of 33 patients (6%) were anergic by intradermal skin testing. There was no association between depressed lymphocyte response and recent chemotherapy except in chronic myelogenous leukemia where 6 of 8 patients were receiving cytotoxic therapy when studied. These observations suggest that most of our patients with myeloproliferative disorders have abnormal cellular responses in vitro, but that delayed hypersensitivity and humoral responses are minimally affected.

Adult↗

Nucleoprotein localization by bismuth staining.

Experiments on isolated mouse liver muclei involving enzyme digestion, the crosslinking of amino groups and alkaline hydrolysis demonstrate that bismuth binds to nucleoproteins through amino and phosphate groups. Analysis of the nucleoproteins extracted with salt and acid solutions in conjunction with bismuth staining after these treatments suggests that: (1) a bismuth amino group interaction occurs on ribonucleo-protein particles, histones and perhaps some non-histone chromosomal proteins, and (2) bismuth phosphate binding is specific for one, or all, of three distinct species of non-histone proteins. These results suggest that histones not tightly bound to DNA through their amino groups are present on interchromatin granules, the presumed transcriptionally active regions of chromatin. Phosphorylated non-histone proteins are also localized at these sites. Staining with heavy metals such as bismuth may be the best method for high resolution localization of nucleoproteins involved with regulating gene activity and maintaining chromatin structure.

Animals↗

A laboratory evaluation of immune complexes in patients on inhalant immunotherapy.

Patients with allergic rhinitis receiving maintenance inhalant immunotherapy and two control groups were studied for evidence of circulating immune complexes. The first control group contained patients with allergic rhinitis who had never received immunotherapy. The second control group contained normal volunteers. Patients in the treatment group had no proteinuria. When compared with the control group, the treatment group had no statistically significant differences in incidence of Clq binding immune complexes, cryoglobulinemia, rheumatoid factor, or complement depletion. This initial study suggests that maintenance immunotherapy does not result in an increase of circulating immune complexes.

Antigen-Antibody Complex↗