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Biomedical subjects

G Kaiser

Publications and source records attributed to G Kaiser.

At least 55 records · Page 3Linked to original sources

Congenital intracranial cysts: clinical findings, diagnosis, treatment and follow-up. A multicenter, retrospective long-term evaluation of 72 children.

A multicenter, retrospective evaluation of 72 children born between 1973 and 1987 with intracranial cysts was performed: 37 had an arachnoid cyst, 25 a Dandy-Walker malformation and 10 a porencephalic cyst. The following criteria were evaluated: history, clinical findings, diagnostic work-up (neuroradiology, CSF and intracystic pressures), surgical therapy and follow-up (outcome and cyst volumes).

Adolescent↗

Monoclonal antibodies to human chorionic gonadotropin (HCG) and their use in two-site binding enzyme immunoassays.

A panel of mouse monoclonal antibodies (MABs) was produced against human chorionic gonadotropin (HCG) and its isolated beta-subunit (beta-HCG). According to their binding specificities the antibodies could be divided into HCG-specific and cross-reactive MABs. The HCG-specific antibodies reacted with antigenic sites on holo-HCG or holo-HCG and beta-HCG, or exclusively with the non-associated beta-HCG chain. The cross-reactive antibodies reacted with either HCG and luteinizing hormone (LH) or with HCG, LH, follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH). According to the binding specificities of the MABs and their reciprocal inhibition detected in two-site binding enzyme immunoassays (EIA), altogether 13 epitopes (including the 3 hidden epitopes detectable only on free non-associated beta-HCG) were distinguished by the antibodies described here. Antibody combinations resulting in most effective and specific HCG- or beta-HCG-determination were used as clinical assays and proved their reliability and correctness for monitoring patients with HCG- and/or beta-HCG-producing tumors before and after therapy.

Animals↗

Increased levels of serum intercellular adhesion molecule 1 in HIV infection are related to immune activation.

Cytopathic mechanisms in human immunodeficiency virus type 1 (HIV-1) infection involve syncytia formation, and it appears likely that increased expression of intracellular adhesion molecule 1 (ICAM-1) is involved in these cell adhesion phenomena. In this study, we determined serum concentrations of soluble ICAM-1 (sICAM-1) in 27 patients with HIV-1 infection and a control group. In addition, we compared sICAM-1 values to CD4+ T-cell counts, serum beta 2-microglobulin (beta 2M) and serum neopterin levels. HIV-1-infected patients had significantly higher sICAM-1, beta 2M and neopterin levels than controls. The subgroup of patients with Walter-Reed stages 3-6 had only slightly higher sICAM-1 concentrations in serum than Walter-Reed stages 1-2. The sICAM-1 concentrations in HIV-1-seropositive patients correlated with beta 2M levels but neither with neopterin nor with CD4+ T-cell counts. Increased sICAM-1 may result from immune activation, which enhances the expression of ICAM-1 in patients with HIV-1 infection.

Adult↗

[The value of conservative therapy in kidney trauma in childhood].

Between 1975 and 1991 74 children with a renal injury after blunt abdominal trauma were treated at the Department of Pediatric Surgery of the University Hospital of Berne. There were 22 girls and 52 boys with a mean age of 9.4 years. 55 patients were treated conservatively and 19 operatively. The mean follow-up was for the operated patients 2.6 years and for the not operated 2.5 years. The conservatively treated patients had a shorter hospitalization time, were fewer days on the ICU, needed less blood transfusions and had a minor complication rate compared with the operated ones.

Adolescent↗

Bispecific IgA/IgM antibodies and their use in enzyme immunoassay.

Two hybrid hybridomas secreting polymeric bispecific antibodies to human chorionic gonadotropin and calf intestinal alkaline phosphatase were produced by fusion of IgA- and IgM-secreting mouse hybridomas. Both hybrid antibodies were purified from ascitic fluid by size exclusion chromatography. An IgM-like fraction was shown to exhibit bispecific activity. Bispecificity was completely lost following mild reduction and alkylation. Both bispecific antibodies were used to develop a sensitive enzyme immunoassay for hCG.

Alkaline Phosphatase↗

Pharmacokinetics of the antidepressant levoprotiline after intravenous and peroral administration in healthy volunteers.

To investigate the pharmacokinetics and the disposition of levoprotiline after i.v. and p.o. administration and to assess the absolute bioavailability, 12 healthy volunteers (11 women, 1 man) were given a 10 min i.v. infusion of 15 mg and a p.o. dose of 75 mg in a two-way crossover study. Blood and urine samples were collected after each dose. Unchanged levoprotiline and the sum of unchanged and glucuronidated levoprotiline (= total levoprotiline) were determined by a specific gas chromatographic-mass spectro-metric method. Intravenous levoprotiline was rapidly and extensively distributed into extravascular sites of the body; the steady-state volume of distribution was 18.81 kg-1. The elimination of levoprotiline from blood was independent of the dosing route, the half-life being 18.8 h. Only 1.8 and 0.6 per cent of the i.v. and p.o. dose, respectively, were excreted unchanged in the urine, whereas 57 per cent of each dose were renally excreted as total levoprotiline. The absolute bioavailability of p.o. levoprotiline was 40 per cent. About 60 per cent of the dose was subject to a first-pass effect in the liver. The systemic blood clearance of levoprotiline, determined after i.v. dosing, was 885 ml min-1, the renal blood clearance after i.v. and p.o. dosing was only 16.0 and 14.2 ml min-1, respectively. Presystemic and systemic clearance of levoprotiline occurred predominantly by direct glucuronidation.

Administration, Oral↗

Surgical significance of the duplex kidney with bifid ureter.

Between 1974 and 1990 in 16 children (5 boys and 11 girls) with a duplex kidney and bifid ureter surgery was indicated. The mean age of the 15 already operated patients was 7 years (0.3-12 years). 14 had uretero-ureteric reflux, 1 had a stenosis of the ureteric bifurcation, and 1 had a lower pole pelvi-ureteric junction obstruction. An interpyelic anastomosis was performed in 14 and a ureteroneocystostomy "en bloc" in 1. The follow-up was 3-10 years with a mean of 5 years. All 15 patients had normal uroradiological findings, and out of the 9 patients with longer follow-up (more than 3 years) 7 had a significantly diminished infection rate.

Child↗

Preliminary experiences with the Orbis-Sigma-System as a ventriculo-peritoneal shunt.

In the last 3 years an Orbis-Sigma system has been implanted in 40 hydrocephalic children (as a primary shunt in 28 and following another shunt system in 12). Its usefulness was tested by regular clinical examinations, head circumference measurement, ultrasonography or CT and the causes and frequency of shunt revisions. The preliminary results of a mean follow-up time of 1.4 years are discussed.

Cerebrospinal Fluid Shunts↗

Intracranial lipomas.

Intracranial lipomas are very rare tumors, mostly being localized in the midline and often asymptomatic. We report on three children with intracranial lipomas (one with extension to the cervical spinal cord) diagnosed by CT and/or MR. All three had different symptoms and neurological signs. We summarize the case reports in the literature since the CT-era.

Brain Neoplasms↗

Low-dose oral natural human interferon-alpha in 29 patients with HIV-1 infection: a double-blind, randomized, placebo-controlled trial.

OBJECTIVE: To evaluate clinical efficacy and toxicity of low-dose oral natural human interferon-alpha (nHuIFN alpha) on CD4+ lymphocyte counts and clinical symptoms in patients with HIV-1 infection. DESIGN: Double-blind, randomized, placebo-controlled trial with crossover. SETTING: Private practice specializing in the treatment of patients with AIDS. PATIENTS, PARTICIPANTS: Only patients with HIV-1 infection and CD4+ lymphocyte counts between 200 and 500 x 10(6)/l were included for study. Thirty out of thirty-one patients at study entry completed treatment with placebo, and 29 completed nHuIFN alpha treatment. Mean patient age was 36 years (range, 25-58 years). The 30 patients included 26 men, of whom 22 were homosexual, and four women; five were drug users and none were currently on zidovudine therapy, although three had been previously. INTERVENTIONS: Patients were randomly assigned to cohorts of 10 to receive either 200 IU nHuIFN alpha once daily orally absorbed or placebo with crossover after 6 weeks. MAIN OUTCOME MEASURES: Every 2 weeks, a detailed history, physical examination, and laboratory tests, including CD4+ and CD8+ lymphocyte counts, were conducted. RESULTS: There was only a slight, transient increase in mean CD4+ lymphocyte counts after 4 weeks of treatment with nHuIFN alpha, compared with a slight decline when placebo was administered. This effect reached statistical significance in a subgroup of patients only and was not sustained after 6 weeks. There were no significant changes in weight and clinical symptoms. All patients remained HIV-1-antibody-positive. Treatment-related adverse reactions were not observed. CONCLUSIONS: Our double-blind, randomized, placebo-controlled clinical trial did not confirm a previous report of efficiency of oral nHuIFN alpha. Although non-toxic, our data do not justify the widespread use of low-dose oral nHuIFN alpha in HIV-infected patients outside controlled clinical trials.

Administration, Oral↗

Determination of the antidepressant levoprotiline and its N-desmethyl metabolite in biological fluids by gas chromatography/mass spectrometry.

A specific and sensitive gas chromatographic/mass spectrometric method was developed and validated for the determination of the antidepressant levoprotiline in blood, plasma and urine and the simultaneous determination of levoprotiline and its desmethyl metabolite in urine. Deuterium-labelled analogues were used as internal standards. The compounds were isolated from the biological fluids by liquid-liquid extraction under basic conditions. Following derivatization with perfluoropropionic anhydride, the samples were analysed by capillary column gas chromatography/electron impact mass spectrometry with selected ion monitoring. The analysis of spiked samples demonstrated the high accuracy and precision of the method. Blood concentrations of levoprotiline down to 0.7 nmol l-1 (1 ml used for analysis) could be quantified with a coefficient of variation of 10% or less. The method is suitable for use in pharmacokinetic and bioavailability studies of levoprotiline in humans.

Antidepressive Agents↗

Enzyme sensor-FIA-system for on-line monitoring of glucose, lactate and glutamine in animal cell cultures.

Enzyme sensors for glucose, lactate and glutamine were connected via flow-injection analysis (FIA) devices to two different bioprocesses. They were used for on-line process control of perfused bioreactor systems containing mammalian cell lines producing a monoclonal antibody and recombinant interleukin-2. The biosensor system gives direct access to important process data which can be used as control parameters for long term cell cultivation systems.

Animals↗

Results of extended craniectomy including supraorbital advancement in premature coronal and frontal craniosynostosis.

Between 1982-1989 an extended craniectomy including supraorbital advancement was performed in 27 infants. Age ranged from 2.5 to 10 months (median 4.5 months). Six had a premature synostosis of the frontal suture, 11 a monolateral synostosis of the coronal suture and 10 a bilateral coronal synostosis. Eighty per cent had an excellent or good result. The amount of remodelling, as measured by the orbital roof angle, showed a tendency to normalisation of the anterior fossa in the lateral projection 3-4.5 months following surgery. In some of the infants the neurological signs and psychomotor development were ameliorated by the operation. But, in monolateral cases of coronal synostoses a squint of various types was observed more frequently.

Craniofacial Dysostosis↗

Cerebrospinal fluid pressure in 10-day-old rats with congenital hydrocephalus.

Rats from the H-Tx strain develop hydrocephalus through a developmental obstruction of the cerebral aqueduct. The progressive ventriculomegally is accompanied by thinning of the cerebral cortex which is already present 10 days after birth. However, a previous study found that the CSF pressure was not significantly raised until 21 days after birth. New experiments have now been performed over a 90 min. period using control and hydrocephalic 10-day-old rats under light pentobarbitone anaesthesia, in order to study the level, time-course and morphology of the resting intraventricular pressure. The mean pressure and its fluctuations were calculated for each minute. Control rats had a mean pressure of 19.3 +/- 1.23 (SEM) mm H2O (n = 9, range: 13.6-24.7) and in hydrocephalic rats, pressure was significantly higher at 23.5 +/- 1.13 mm H2O (n = 9, range: 18.1-28.3). There was no consistent trend with time and no significant difference between groups in pressure fluctuations, but at least two of the hydrocephalic rats showed episodic waves similar to "B"-waves in humans.

Animals↗

The disposition of [14C]-labelled benazepril HCl in normal adult volunteers after single and repeated oral dose.

1. The disposition of [14C]-labelled benazepril HCl, an ACE-inhibitor, was studied in four normal adult volunteers after a single oral dose of 20 mg and after repeated doses of 20 mg once daily for 5 days. Radioactivity was measured in plasma, urine and faeces. The prodrug ester benazepril and the pharmacologically active metabolite benazeprilat were determined quantitatively in plasma and urine by a g.c.-m.s. method. The pattern of metabolites in urine was analysed semiquantitatively by h.p.l.c.-radiometry. 2. After a single oral dose at least 37% was absorbed, as indicated by urinary recovery. The peak plasma concentration of benazepril (0.58 +/- 0.13 nmol/g (SD] was observed at 0.5h after dose, indicating rapid absorption. Peak concentrations of radioactivity (1.88 +/- 0.48 nmol/g) and of active benazeprilat (0.84 +/- 0.25 nmol/g) were observed at 1 h after dose, demonstrating rapid bioactivation. 3. The area under the plasma curve (AUC0-96 h) of total radioactivity amounted to 9.7 +/- 1.1 (nmol/g)h, 5% of which was accounted for by benazepril and about 50% by benazeprilat. 4. Over 9 days 96.8 +/- 0.5% of the dose was excreted in urine and faeces. Urinary excretion accounted for 37.0 +/- 6.0% of the dose, 80% of which was recovered in the first 8 h after dosing. 5. In urine, only 0.4% of the dose (1% of the radioactivity) was excreted as unchanged benazepril, indicating that the compound was extensively metabolized. Benazeprilat accounted for 17% of the dose (about half of the radioactivity; 0-96 h). Glucuronide conjugates of benazepril and benazeprilat constituting approximately 11% and 22% of the radioactivity (about 4% and 8% of the dose; 0-48 h) were tentatively identified. 6. Repeated oral treatment with benazepril HCl did not influence the pharmacologically relevant kinetics and disposition parameters.

Administration, Oral↗

Immunoaffinity purification of human alpha-fetoprotein (AFP) using monoclonal antibodies.

A two-step immunoaffinity isolation procedure for human alpha-fetoprotein (AFP) was developed resulting in highly purified AFP at high yield. A monoclonal antibody immunoadsorbent was used in the first step. Elution of AFP was carried out at alkaline pH by a solution of 0.5 mol/l ammonia containing 0.5 mol/l sodium chloride. To remove impurities caused by the first step, an anti-mouse immunoglobulin antibody immunoadsorbent was applied in the second step.

Antibodies, Monoclonal↗