Biomedical subjects

M Borner

Publications and source records attributed to M Borner.

27 records · Page 2Linked to original sources

PubMed1993

Aspects of rabies infection and control in the conservation of the African wild dog (Lycaon pictus) in the Serengeti region, Tanzania.

Lycaon pictus is amongst the most endangered wildlife species in Africa. In 1990 rabies virus was isolated from the brain of an adult Lycaon found dead in the Serengeti region of Tanzania. One adult and six pups of the same pack feeding on the carcass showed clinical signs and rabies was suspected; within two days they had disappeared and are presumed to have died. Subsequently, two Lycaon packs in the Serengeti National Park were given inactivated rabies vaccine either by dart or by parenteral inoculation following anaesthesia. Lycaon sera which had been collected over the previous two years and sera collected pre- and post-vaccination were examined for the presence of rabies virus neutralizing antibody. Three of 12 unvaccinated Lycaon had antibody levels > 0.5 IU/ml; post-vaccination samples from two Lycaon showed increased antibody levels. Between four and ten months post-vaccination, at least four of the vaccinated animals had died from unknown causes. Issues relating to wildlife vaccination and veterinary intervention in conservation are discussed.

Animals↗

PubMed1992

Considerable side effects of chemoembolization for colorectal carcinoma metastatic to the liver.

The feasibility of one whole liver chemoembolization (CE) procedure with Angiostat, a vasoocclusive collagen, mitomycin, doxorubicin, and cisplatin was evaluated in eight patients with unresectable colorectal carcinoma metastatic to the liver and good performance status. One heavily pretreated patient showed a partial response in the liver lasting 188 days. Five patients had stabilization of the disease for 85-150 days. The side effects of the treatment were considerable with a fatigue syndrome lasting up to eight weeks, chemical and ischemic hepatitis, severe thrombopenia (WHO grade 4 in 2 pts) and icterus being the most disturbing toxicities. We recommend to restrict CE to patients with a life expectancy of more than 4-6 months confined to protocols, which evaluate efficacy, toxicity and influence on quality of life of CE with various cytotoxic drugs. We further suggest to perform staged unilobar CE at 4- to 6-week intervals rather than whole liver CE.

Adult↗

PubMed1991

[The biochemical modulation of 5-fluorouracil by leucovorin].

5-fluorouracil (5-FU) is the most effective drug in the treatment of advanced colorectal carcinoma and has definite activity in a variety of other solid tumors. However, remissions occur in only about 20% of the patients and usually are of short duration. Biochemical modulation is a way of enhancing the efficacy of 5-FU by manipulation of intracellular metabolic pathways. Leucovorin (LV) prolongs the inhibition of the key enzyme, thymidylate synthetase, by stabilizing the ternary complex with activated 5-FU, thus leading to "thymidine-less" death. Phase II trials showed promising response rates in colorectal, gastric, and breast cancer. This translated into prolonged survival and into an increased therapeutic index in some phase III studies comparing the combination 5-FU/LV with 5-FU monotherapy in colorectal cancer. The present article focuses on the pharmacological background of the therapy with 5-FU/LV, summarizes the clinical data and gives a short overview on other ways of increasing the therapeutic index of 5-FU.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1991

Cardiac myxomas: immunohistochemical study of benign and malignant variants.

Immunohistochemical investigation of 11 cardiac myxomas (CMs) including one malignant metastasizing CM showed a co-expression of epithelial (lu-5 and CAM 5.2), mesenchymal (vimentin) and neuroendocrine antigens (neuron-specific enolase) in all tumour cells. Factor VIII was found in the endothelial cells of capillaries only. In the subendocardium of fetal heart tissue close to the foramen ovale myofibroblasts reacting with the panepithelial antibody lu-5 were detected. We conclude that CMs are neoplasms that may develop from embryonic cell remnants.

Adult↗

PubMed1991

Population pharmacokinetics of quinidine.

1. Population pharmacokinetic parameters of quinidine were determined based on 260 serum drug concentration measurements in 60 patients treated for arrhythmias with quinidine sulphate or quinidine bisulphate (Kinidin duriles) orally. 2. Quinidine kinetics were best described by a two compartment model with zero order absorption from the gastrointestinal tract. The pharmacokinetics are influenced by severe heart or liver failure and renal function impairment. No effect was found for mild or moderate heart failure, for age, for body weight or for coadministration of nifedipine. 3. Population pharmacokinetic parameters of quinidine (assuming 100% bioavailability of oral quinidine sulphate) were: nonrenal clearance for patients without severe heart and liver failure 12.6 l h-1, reduction in patients with severe heart or liver failure to 6.8 l h-1, renal clearance (l h-1) related to creatinine clearance (ml min-1), proportionality constant 0.0566, volume of distribution of the central compartment 161 l, maximum serum drug concentration 1.4 h after administration of quinidine sulphate and 6.0 h after administration of quinidine bisulphate. 4. The results were validated by predicting the serum drug concentration in a separate group of 30 patients. The model reliably predicted both the population average and the variability of the serum concentration of quinidine. 5. Using Monte Carlo computer simulations, an a priori dosing regimen was derived that should maximize the proportion of patients having quinidine serum concentrations within the recommended range (2-5 mg l-1): initial dose of 600 mg quinidine sulphate in all patients, 3 h later first maintenance dose of quinidine bisulphate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Effectiveness and low toxicity of hepatic artery infusion with fluorouracil and mitomycin for metastatic colorectal cancer confined to the liver. The Swiss Group for Clinical and Epidemiological Cancer Research (SAKK).

The usefulness of hepatic artery infusion (HAI) with floxuridine is limited by the severe biliary and hepatic toxicity of floxuridine. This prompted the SAKK to evaluate the effectiveness, toxicity and feasibility of HAI with fluorouracil (FU) and mitomycin (MMC) administered by an external portable pump. Of 28 patients treated, partial responses were obtained in 14 (50%, 95% confidence interval: 30% to 70%) and stabilization in 11 (39%, 21% to 60%), for a median duration of 12.6+ months. Median survival was 19.5+ months. Grade I-II toxicity (WHO) consisted of nausea (46%), leucopenia (32%) thrombocytopenia (21%) and abdominal discomfort (25%). Two patients developed gastro-duodenal ulcers and two others grade III leucopenia. No life-threatening side effects, especially no sclerosing cholangitis or chemical hepatitis, were observed. In conclusion, HAI with FU and MMC is a valid alternative to floxuridine HAI in metastatic colorectal cancer confined to the liver.

Adult↗

PubMed1989

[Antibiotic therapy and long-term course in spondylodiscitis].

Long-term outcome and therapy are reported in 29 patients with vertebral osteomyelitis. Antibiotics were administered for a mean period of 21 (6-102) weeks. In 13 patients surgery was additionally necessary. After a mean follow-up of 53 (10-136) months only one relapse had occurred. Radiographs and erythrocyte sedimentation rate were the best indicators of successful treatment.

Adult↗

PubMed1983

Action of gamma-hydroxybutyrate and GABA on neurones of cultured rat central nervous system.

gamma-Hydroxybutyrate (GHB) and GABA caused a hyperpolarization of cultured spinal, brainstem and cerebellar neurones. When KCl electrodes were used, the hyperpolarizations were reversed to depolarizations, suggesting that the actions of GHB and GABA are associated with an increase in conductance for chloride ions. Both the hyperpolarizations and depolarizations by these compounds were accompanied by an increase in membrane conductance and were reversibly blocked by the GABA antagonist bicuculline. It is suggested that GHB might either exert its effects by mimicking the action of GABA, or act as neurotransmitter or neuromodulator in the mammalian CNS.

Animals↗

PubMedDate not supplied

Molecular genetic and morphological analyses of the African wild dog (Lycaon pictus).

African wild dog populations have declined precipitously during the last 100 years in eastern Africa. The possible causes of this decline include a reduction in prey abundance and habitat; disease; and loss of genetic variability accompanied by inbreeding depression. We examined the levels of genetic variability and distinctiveness among populations of African wild dogs using mitochondrial DNA (mtDNA) restriction site and sequence analyses and multivariate analysis of cranial and dental measurements. Our results indicate that the genetic variability of eastern African wild dog populations is comparable to that of southern Africa and similar to levels of variability found in other large canids. Southern and eastern populations of wild dogs show about 1% divergence in mtDNA sequence and form two monophyletic assemblages containing three mtDNA genotypes each. No genotypes are shared between the two regions. With one exception, all wild dogs examined from zoos had southern African genotypes. Morphological analysis supports the distinction of eastern and southern African wild dog populations, and we suggest they should be considered separate subspecies. An eastern African wild dog breeding program should be initiated to ensure preservation of the eastern African form and to slow the loss of genetic variability that, while not yet apparent, will inevitably occur if wild populations continue to decline. Finally, we examined the phylogenetic relationships of wild dogs to other wolf-like canids through analysis of 736 base pairs (bp) of cytochrome b sequence and showed wild dogs to belong to a phylogenetically distinct lineage of the wolf-like canids.

Africa, Eastern↗