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Biomedical subjects

G Hartman

Publications and source records attributed to G Hartman.

At least 37 records · Page 2Linked to original sources

Neonatal effects of methyldopa therapy in pregnancy hypertension.

This study has been performed to assess the effect of methyldopa (MD) therapy in pregnancy hypertension on the neonatal adaptation. Infants born to mothers on MD for several weeks prior to delivery and presenting with excessive tremor and irritability were evaluated according to the dose of maternal MD. Pregnancy hypertension and high dose MD was associated with impaired placental perfusion, compromised function of fetoplacental unit and more frequent surgical delivery. Infants of mothers on high (1.25-2.0 g/day) or low (less than 1 g/day) MD had gestational age, head circumference, acid-base balance, Apgar score and blood pressure similar to those born to healthy control mothers. The birth weight of infants of the high MD group, however, were significantly lower than in the low-dose or control groups. MD therapy resulted in a dose-dependent increase in plasma levels of prolactin, thyrotropin and triiodthyronine indicating decreased dopaminergic inhibition of pituitary hormone release. Plasma thyroxine concentration, however, decreased significantly. Cerebrospinal fluid noradrenaline was found to be markedly depressed after maternal MD showing disturbed central nervous system monoamine metabolism. It is suggested that MD administration to mothers presenting with pregnancy hypertension interferes with cerebral monoamine metabolism of the neonate and induces alterations in some endocrine functions under dopaminergic control. The possible role of chronic fetal distress frequently associated with pregnancy hypertension should also be considered.

Adaptation, Physiological↗

Genitalia in human figure drawings: childrearing practices and child sexual abuse.

To replicate and explore the associations of drawing genitalia on a human figure, child-rearing practices, and a history of alleged sexual abuse, we designed a cross-sectional study of 109 alleged child sexual abuse victims, ages 3 through 8 years, and a group of 109 comparison children matched for age, sex, race, and socioeconomic status but with no history of abuse. A standardized format was used to collect drawings, administer the Peabody Picture Vocabulary Test, and gather background data on medical, developmental, and child-rearing issues. Seven alleged sexual abuse victims and one comparison child spontaneously drew genitalia (p = 0.02, one-tailed Fisher Exact Test, estimated relative risk 7.96). No differences in drawing maturity (Draw-A-Man score) were identified, although Peabody Picture Vocabulary Test scores were higher in comparison children (82.1 vs. 91.0, p less than 0.01). Neither drawing genitalia nor history of alleged sexual abuse were significantly associated with histories of medical problems, enuresis, encopresis, urinary tract infection, or child-rearing practices related to sleeping, nudity, bathing, sexual abuse education, or exposure to sexually explicit materials. The similar patterns of child-rearing practices in both samples should make professionals cautious in attributing allegations of abuse to specific child-rearing practices. This study confirms our previous report that the presence of genitalia spontaneously drawn on a child's drawing of a human figure is associated with alleged sexual abuse.

Art↗

Age-related red cell enzymes in children with transient erythroblastopenia of childhood and with hemolytic anemia.

Red cell enzymes of three children with transient erythroblastopenia of childhood were measured and compared with those of age-matched normal children and children with hemolytic anemia. While the activity of "age-dependent" enzyme such as hexokinase, aldolase, glucose-6-phosphate dehydrogenase, glutamic-oxaloacetic transaminase, and pyruvate kinase were greatly increased in the red cells of children with hemolytic anemia, they were not decreased in the red cells of children with erythroblastopenia of childhood. Only the activity of pyrimidine 5'-nucleotidase was consistently low red cells of these children. These findings are inconsistent with the usual concept that red cell enzyme activities decline throughout red cell life span. Rather, they suggest that there may be very rapid loss in the activity of some red cell enzymes during the first few days of red cell life with little further decline in enzyme activity.

5'-Nucleotidase↗

Phase I evaluation of beta-2'-deoxythioguanosine in pediatric patients with leukemia.

Thirty-one pediatric patients with acute leukemia who had relapsed on either 6-mercaptopurine or 6-thioguanine were treated with beta-2'-deoxythioguanosine, which was administered as an iv infusion every 12 hours for three or six doses every 2 weeks. Severe nausea and vomiting and urate nephropathy were the dose-limiting toxic effects. Therapeutic responses occurred in four of 24 children with acute lymphocytic leukemia and in two of seven with acute nonlymphoblastic leukemia.

Acute Disease↗

Effects of halothane anesthesia on equine liver function.

Effects of halothane anesthesia were investigated in ponies prepared surgically with chronic external biliary fistulas (T tubes) to determine the effects on liver function and biliary excretion during 2 hours of anesthesia. Four studies were performed on 2 ponies, 2 to 6 months after surgery with the enterohepatic circulation held intact between studies. Intravenous bile acid infusion was used to maintain steady-state bile flow, bilirubin, and bile acid excretion during each study. Compared with the immediate 2-hour preanesthesia values (base line), halothane caused a 138% increase in bilirubin excretion, a 60% increase in biliary bilirubin concentration, and a 43% increase in PCV. Halothane anesthesia also caused a 16% reduction in plasma bilirubin, a 46% reduction in biliary bile acid concentration, and a 27% reduction in bile acid excretion. The bile acid independent fraction of bile flow appeared to increase. Plasma aspartate transaminase concentration did not change during anesthesia. The ratio of conjugated bilirubin fractions in bile [82% to 83% disconjugates of glucuronide and glucoside (2 forms) and 17% to 18% monoconjugates of glucoside, glucuronide, and xyloside] did not change during anesthesia and less than 1% was excreted unconjugated. Halothane anesthesia did not appear to affect adversely the activity of the transferase-conjugating enzymes in the presence of an increased bilirubin load. Seemingly, greatly increased conjugated bilirubin excretion observed during halothane anesthesia was most likely the result of a combination of increased hepatic clearance from plasma and increased hepatic bilirubin production from turnover of free hepatic heme or heme from the induced cytochrome P-450 system.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗

Effects of isoflurane anesthesia on equine liver function.

The acute 2-hour effects of isoflurane anesthesia on liver function and biliary excretion were examined in 2 ponies prepared surgically with chronic external biliary fistulas (T-tubes). Studies were conducted 2 to 8 months postoperatively with the enterohepatic circulation held intact between studies. Bile acid infusion IV (8.1 to 8.8 mumol/min) helped maintain bile flow and bile acid and bilirubin excretion during complete biliary diversion throughout each study. Following 3-hour control periods, anesthesia was induced and maintained at 1.3 to 1.5 minimal alveolar concentration plus O2 (spontaneous breathing) for 2 hours. Compared with the immediate 2-hour preanesthesia values, isoflurane caused significant increases in PCV (27%) and biliary bilirubin excretion (24%). However, no significant differences were detected in plasma or biliary bilirubin concentrations, biliary bile acid concentration or excretion, bile flow, or plasma aspartate aminotransferase concentrations between preanesthesia control and anesthesia periods. The results indicate that although isoflurane anesthesia enhanced hepatic bilirubin excretion, its effects on hepatic bilirubin formation and/or clearance are modest, compared with effects of halothane anesthesia which have previously been shown to enhance equine bilirubin excretion by 138% and reduce bile acid excretion by 27%. Isoflurane anesthesia in ponies does not appear to affect hepatic bile acid transport or bile formation significantly.

Anesthesia, Inhalation↗

The influence of radiation therapy quality control on survival, response and sites of relapse in oat cell carcinoma of the lung: preliminary report of a Southwest Oncology Group study.

Two hundred and ninety-eight patients with limited (confined to chest and supraclavicular area, encompassable by a single radiation portal) small cell carcinoma of the lung were entered on Southwest Oncology Group Protocol 7628. Patients were treated with multi-agent chemotherapy and radiation therapy with or without BCG. Radiation therapy quality control analysis, including dosimetric reconstruction and port film review was introduced after the protocol was activated and was retrospectively applied. Patients who were considered major protocol variations had statistically worse survival (40 weeks versus 60 weeks; P = .002), a lesser improvement in response rate after induction chemotherapy (27 versus 48%; P = .05) and a higher chest failure rate (77 versus 55%; P = .047) than evaluable patients. Five patients relapsed in the brain, all associated with chest failure. Quality control is essential in cooperative group studies.

Antineoplastic Agents↗

Immunologic and clinical effects of repeated blood exchange in familial erythrophagocytic lymphohistiocytosis.

Depressed cellular immune function and increased susceptibility to infection characterize familial erythrophagocytic lymphohistiocytosis (FEL), a usually fatal autosomal recessive disease. One component of the immunodeficiency is plasma-mediated inhibition of lymphocyte proliferation. We have tested whether repeated plasma or blood exchange would decrease plasma inhibitory activity and improve cellular immune function in FEL. Following this treatment, reduction in plasma inhibitory activity, reversal of depressed antigen-specific lymphocyte proliferative responses and monocyte antibody-dependent cytotoxic function in vitro, and clinical improvement were complete in two and partial in one of three patients studied. Relapse, which was ultimately fatal, was associated with recurrence of the immune defects. These findings suggest that cellular immunodeficiency in FEL is acquired and possibly related to circulating immunosuppressive activity, the removal of which is associated with transient immunologic and clinical recovery.

Antibody-Dependent Cell Cytotoxicity↗

The involvement of parenchymal, Kupffer and endothelial liver cells in the hepatic uptake of intravenously injected liposomes. Effects of lanthanum and gadolinium salts.

125I-labeled albumin or poly(vinyl pyrrolidone) encapsulated in intermediate size multilamellar or unilamellar liposomes with 30-40% of cholesterol were injected intravenously into rats. In other experiments liposomes containing phosphatidyl[Me-14C]choline was injected. 1 h after injection parenchymal or non-parenchymal cells were isolated. Non-parenchymal cells were separated by elutriation centrifugation into a Kupffer cell fraction and an endothelial cell fraction. From the measurements of radioactivities in the various cell fractions it was concluded that the liposomes are almost exclusively taken up by the Kupffer cells. Endothelial cells did not contribute at all and hepatocytes only to a very low extent to total hepatic uptake of the 125I-labels. Of the 14C-label, which orginates from the phosphatidylcholine moiety of the liposomes, much larger proportions were recovered in the hepatocytes. A time-dependence study suggested that besides the involvement of phosphatidylcholine exchange between liposomes and high density lipoprotein, a process of intercellular transfer of lipid label from Kupffer cells to the hepatocytes may be involved in this phenomenon. Lanthanum or gadolinium salts, which effectively block Kupffer cell activity, failed to accomplish an increase in the fraction of liposomal material recovered in the parenchymal cells. This is compatible with the notion that liposomes of the type used in these experiments have no, or at most very limited, access to the liver parenchyma following their intravenous administration to rats.

Animals↗

Human B-lymphocyte antigens expressed by lymphocytic and myelocytic leukemia cells. I. Detection by rabbit antisera.

A previously uncharacterized human B-lymphocyte antigen has been detected by rabbit antisera raised to papain digests of spleen cell membranes. The unabsorbed sera reacted in both cytotoxicity and immunofluorescent tests with normal B lymphocytes and cultured B-cell lines but not with normal T lymphocytes or cultured T-cell lines. The cytotoxicity titers against B cells were as high as 1:32,000, whereas the same sera undiluted were negative against T cells. By immunofluorescent staining 6-14% of unfractionated normal lymphocytes and 48-85% of B-rich lymphocyte preparations were positive. Normal peripheral blood granulocytes, platelets, erythrocytes, and phytohemagglutinin blasts were negative. The antisera reacted with the same high titers against leukemia cells from approximately 70% of the patients with acute lymphocytic leukemia, acute myelocytic leukemia, chronic myelocytic leukemia, and seven of eight cases of chronic lymphocytic leukemia. From absorption studies it appeared that the same antigen was being expressed by leukemia cells and normal B lymphocytes. Using immunofluorescent staining the anti-B-cell antisera were able to detect positive leukemia cells in the bone marrow of patients with advanced leukemia and to monitor the elimination of these cells after chemotherapy. Soluble B-cell antigen was found in the serum of some leukemia and lymphoma patients do but not in normal serum.

Antigens↗

Evaluation of the BAX system for detection of Listeria monocytogenes in foods: collaborative study.

A multilaboratory study was conducted to compare the automated BAX system and the standard cultural methods for detection of Listeria monocytogenes in foods. Six food types (frankfurters, soft cheese, smoked salmon, raw, ground beef, fresh radishes, and frozen peas) were analyzed by each method. For each food type, 3 inoculation levels were tested: high (average of 2 CFU/g), low (average of 0.2 CFU/g) and uninoculated controls. A total of 25 laboratories representing government and industry participated. Of the 2335 samples analyzed, 1109 were positive by the BAX system and 1115 were positive by the standard method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, except radishes, the BAX system performed as well as or better than the standard reference methods based on the Chi square results.

Chi-Square Distribution↗