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Biomedical subjects

N Wagner

Publications and source records attributed to N Wagner.

11 recordsLinked to original sources
PubMed1992

Correlation of hepatitis B virus, hepatitis D virus and human immunodeficiency virus type I infection markers in hepatitis B surface antigen positive haemophiliacs and patients without haemophilia with clinical and histopathological outcome of hepatitis.

The hepatitis D virus (HDV) infection plays a major role in severe liver damage caused by hepatitis. To establish the prevalence of HDV infection in haemophilic patients and patients without haemophilia, 87 patients with chronic hepatitis B virus (HBV) infection were examined for serological evidence of delta hepatitis. In addition HBV, HDV and human immunodeficiency virus type 1 (HIV) infection markers were compared to clinical and histopathological outcome of hepatitis. Out of 46 haemophiliacs 30 (65%) were anti-HD-seropositive; 10 out of 30 anti-HD-positive patients (33%) had pathological liver function tests compared to 2 out of 16 anti-HD-negative haemophiliacs (13%). The rate of HIV infection did not differ between the HDV infected and the non-HDV infected individuals with haemophilia (17/27 anti-HD-positive patients versus 12/16 anti-HD-negative patients). Two haemophilic anti-HD-positive patients underwent liver biopsy, in both cases hepatitis D antigen (HDAg) was detected in the biopsies. Only 2 out of 41 patients without haemophilia were anti-HD-positive. Both had pathological liver function tests; chronic active hepatitis and cirrhosis, respectively, were diagnosed and HDAg was found in the liver biopsies. Out of 39 anti-HD-seronegative patients without haemophilia, 26 (67%) were hepatitis B e antigen positive; in the sera of 20 patients (51%) HBV-DNA was demonstrated, but only 6 patients (15%) had pathological liver function tests. In conclusion a high seroprevalence of HDV infection was found in haemophilic patients treated with non-pasteurized commercial clotting factor concentrates. An endemic spreading of HDV infection in patients without haemophilia with chronic HBV infection could not be detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1992

Visual field differences for clockwise and counterclockwise mental rotation.

Geometric line drawings were presented to normal subjects in the left visual field (LVF) or right visual field (RVF) at various degrees of rotation from a centrally presented vertical standard. The task of the subject was to indicate with a reaction time (RT) response whether the laterally presented stimulus could be rotated into the vertical standard or if it was a rotated mirror image of the standard. In Study 1, an overall right hemisphere superiority was found for RT and accuracy on match trials. Most interestingly, interactions between Visual Field and Rotation Angle for the match accuracy data and between Visual Field and Direction of Rotation (clockwise or counterclockwise) for the match RT slopes were found. These interactions suggested that clockwise rotations were more readily performed in the LVF and counterclockwise rotations in the RVF, consistent with other literature for mental rotation. The purpose of Study 2 was to replicate this finding of visual field differences for rotation direction using a design in which direction and degree of rotation were varied orthogonally. No main effect of Visual Field was found. However, significant interactions between Visual Field and Rotation Angle were found for both RT and accuracy, confirming the presence of visual field differences for rotation direction in a new sample of subjects. These differences were discussed in terms of the possibly greater relevance of medially directed stimuli and a possible hemispheric bias for rotation direction, and in terms of interhemispheric transmission factors.

Adolescent↗
PubMed1992

Intravenous immunoglobulin in HIV-I infected haemophilic patients.

In order to evaluate the efficacy of intravenous immunoglobulin (IVIG) in the early stages of HIV infection (patients without AIDS or AIDS related complex) a prospective controlled open trial was conducted in 36 patients (age 6-19 years) with haemophilia. Eighteen patients received 0.3 g/kg IVIG at two week intervals; 18 patients served as controls. Major criteria for the evaluation were progression of HIV disease assessed by the modified Brodt/Helm classification, number of infectious events and HIV associated thrombocytopenia, and the CD4+ T cell count. After 24 months of evaluation seven patients in the IVIG group and five patients in the control group deteriorated according to their staging, with one patient in each group developing AIDS. Thrombocytopenia and infectious events, but no severe bacterial infections, occurred in both groups in similar numbers. The absolute CD4+ T cell count decreased by 284/microliters in the IVIG group and by 143/microliters in the control group respectively (mean values). The statistical analysis of these criteria did not reveal any significant difference. In conclusion, IVIG was not effective in the early stages of HIV infection in patients with haemophilia. IVIG did not slow down the progression of HIV disease and did not prevent the development of an immunodeficiency as assessed by the CD4+ T cell count.

Adolescent↗
PubMed1991

Effects of diazepam on cerebral metabolism and mood in normal volunteers.

The effects of diazepam on regional cerebral metabolism were examined in eight healthy volunteers using positron emission tomography with 18-fluorodeoxyglucose as the tracer. Each subject was tested three times, at 1-week intervals, with placebo, a low oral dose of diazepam (0.07 mg/kg), and a moderate dose of diazepam (0.14 mg/kg). Subjects completed mood questionnaires before and at regular intervals after taking the drug, and performed a vigilance task during the 60-minute period of tracer uptake. The effects of the drug on cerebral metabolism were examined alone and in relation to the subjective and behavioral effects of the drug. Both doses of diazepam decreased global (whole brain) metabolic rate but did not affect specific regions differentially. Subjects experienced sedative like effects during all three scans (placebo as well as drug). Compared to placebo, both doses of diazepam decreased anxiety, and neither dose produced significant impairment of task performance. Neither the subjective nor behavioral drug effects were correlated with the changes in metabolic rate. Thus, diazepam decreased whole brain metabolic rate at doses that produced only modest subjective or behavioral effects. The changes in metabolic rate were not clearly related to other observable drug effects.

Adult↗
PubMed1990

Graded cytopathogenicity of the human immunodeficiency virus (HIV) in the course of HIV infection.

To determine whether the biological variability of HIV-1 has any clinical significance, the highly variable cytopathogenicity of 153 HIV-1 strains, isolated from 119 hemophiliacs, was related to the number of CD4+ lymphocytes present in the patient's blood at the time of virus isolation. It was shown that the cytopathogenicity of the HIV-1 isolates was inversely correlated with the number of CD4+ lymphocytes. The highest CD4+ cell number were observed in 34 latently infected patients characterized by HIV seropositivity, failure of virus isolation, and detection of viral DNA by the polymerase chain reaction. Cytopathogenicity of the HIV-1 isolates was a reliable prognostic marker and correlated well with other less-sensitive prognostic parameters, including the detection of infectious virus and p24 antigen in the plasma, and the decline of p24 antibody in the serum. The results suggest that the viral isolates - if not subjected to extensive passage - represent in vivo variants selected from a heterogeneous viral population according to the particular immunological conditions of the host.

Base Sequence↗
PubMed1990

Behavioral and subjective effects of ethanol: relationship to cerebral metabolism using PET.

This study examined the effects of ethanol on regional cerebral metabolic rate using positron emission tomography (PET). The study explored the relationship between the mood-altering effects of ethanol and its effects on regional cerebral glucose utilization (CMRglu) in eight healthy male volunteers. In the first phase of the study, the subjects participated in a behavioral preference procedure conducted in a recreational environment to determine their responses to ethanol (0.5 g/kg) in a naturalistic setting. They then participated in three PET sessions, receiving at three to seven day intervals, in counterbalanced order, placebo, 0.5 g/kg or 0.8 g/kg ethanol. PET scans were conducted using a PETT-VI scanner with F-18-2-fluoro-2-deoxyglucose (FDG) as the tracer. The mood-altering effects of ethanol were measured in both the naturalistic and the PET phases of the study. Ethanol produced comparable effects on mood in the naturalistic and the PET settings (i.e., increases in positive mood). The lower dose of ethanol produced variable effects on whole brain and regional CMRglu across subjects. There was some suggestion that certain regional metabolic changes after ethanol were correlated with subjective responses to the drug. The higher dose of ethanol decreased whole brain CMRglu in most subjects. All regions were affected about equally. It was concluded that the mood-altering effects of ethanol are not related in a simple manner to regional changes in CMRglu.

Adult↗
PubMed1990

HIV-1 infection in a cohort of haemophilic patients.

The course of HIV infection in 53 haemophilic patients aged 5-20 years was evaluated by clinical examination and laboratory tests. During the evaluation time (median 30 months) two patients died of AIDS and 32 patients (60%) deteriorated when assessed by the Brodt-Helm classification. Nineteen patients (37%) had decreased absolute helper cell counts (less than 500 CD4 positive cells/microliters), and 45 patients (87%) had reduced helper cell to lymphocyte ratios (less than 0.35). HIV-1 was isolated from peripheral lymphocytes in 29 of 46 patients. As the disease progressed the number of positive viral cultures increased. Considerable progression of the HIV infection was seen in haemophilic children and adolescents during the median evaluation period of 30 months. The transition from symptomless HIV infection to immunodeficiency was easily recognised. A lowered ratio of helper cells to lymphocytes seems to be a useful marker of the beginning of the deterioration of the immune system.

Acquired Immunodeficiency Syndrome↗
PubMed1975

Functional changes in platelets during extracorporeal circulation.

An in vitro trauma test was conducted to determine the effects of extracorporeal circulation on platelet count and function. Fresh human blood was circulated in two identical in vitro circuits for six hours at a rate of 500 ml per minute (500 recirculations). One circuit included a G.E.--Peirce membrane lung and the other was a control. Platelet aggregation induced by adenosine diphosphate (ADP), epinephrine, or collagen was studied before and after six hours of perfusion. No important drop in platelet count occurred in the control circuit (Control-C) following bypass, but there was a 20% drop for the lung circuit (Lung-C). Platelet aggregation was reduced by about 30% for the control circuit and 65% for the lung circuit. The large decrease in platelet function accompanied by only a moderate decrease in platelet count is discussed in terms of loss of the youngest and most active platelets, platelet inhibition due to ADP released by red blood cell lysis, and platelet trauma.

Adenosine Diphosphate↗