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Biomedical subjects

J Fuchs

Publications and source records attributed to J Fuchs.

At least 271 records · Page 15Linked to original sources

Isolation of an Escherichia coli mutant deficient in thioredoxin reductase.

A mutant of Escherichia coli defective in thioredoxin reductase has been isolated and partially characterized. This mutant has no detectable thioredoxin reductase activity in vitro and yet it exhibits no in vivo defect in reduction of ribonucleotides. Evidence is presented that indicates that, in cells permeabilized via ether treatment, ribonucleoside diphosphate reduction can utilize glutathione as an alternate reducing system.

Escherichia coli↗

[On the clinical picture and therapy of arachnitis optico-chiasmatica (author's transl)].

From 20 cases of arachnitis optico-chiasmatica (a. o.) the symptoms of this relatively rare but pathologico-anatomically proved disuse of the brain base involving the optic nerves are described. In this description newer methods of investigation are mentioned which allow a differentiation of the clinical picture of o.a. from that of tumors of the middle cranial fossa. A single case is described in especial detail because a remarkable corneal cloudiness occured in it. The anatomical connection between this corneal cloudiness and vegetative nerve fibers in the region of the Gasserian ganglion is mentioned in honour of the theory of Speransky on nerve-directed tissue changes.

Aged↗

[Cytotoxic and antitumor effect of antibiotic PSX-1 in vitro and in vivo].

The inhibitory effect of antibiotic PSX-1 on tumour cells was studied in vitro and in vivo. The antibiotic inhibited above all the utilization of the added 14C-labelled uridine and adenine in EAC cells. After a short exposure to PSX-1 (180 min) the synthesis of nucleic acids and proteins in EAC proliferating in vitro was suppressed. Antibiotic PSX-1 in concentrations of about 2.5 mg/ml showed relatively low toxicity on normal human fibroblasts but caused a marked cytotoxic and cytopathic effect on tumour cells. A potential antitumor effect of PSX-1 was evaluated in vivo by using gradually EAC and L 1210 tumours. All the animals treated with the antibiotic in doses of 2.5--5.0 mg/kg/day with the use of EAC and 5.0 mg/kg/day with the use of L 1210 survived for 90 and 40 days respectively and no tumours developed in the treated mice during this period.

Animals↗

[The two-way syringe. A comparison to modified aspiration methods in cataract surgery, and more recent indications for its use (author's transl)].

After description of construction, indication, and application of the two-way syringe in cataract surgery, this instrument is compared to some of its numerous modfications. The original device has the advantage of simplicity, and enables the surgeon to perform simultaneous irrigation and aspiration under zero pressure conditions without an assistant. More recent indications for the use of the two-way syringe are vitreous prolapse, and retinal detachment. These operations are described in detail.

Cataract Extraction↗

Uncoupler- and hypoxia-induced damage in the working rat heart and its treatment. II. Hypoxic reduction of aortic flow and its reversal.

In the working rat heart we investigated heart function (aortic and coronary flow) during a normoxic, a hypoxic, and a reoxygenation phase after hypoxia. A depressed heart function was obtained by limiting oxygen supply and reducing left ventricular filling pressure (preload). After hypoxic perfusion for about 90 min, reoxygenation resulted in a 50% decrease of aortic flow. Lactate production and release increased immediately after oxygen deprivation and reached a maximum after about 35 min of hypoxia. Following reoxygenation, lactate release decreased. Lactate dehydrogenase became significant after reoxygenation. After stabilization of aortic flow at 50% in the reoxygenation phase different reagents were examined for their influence on heart performance. 1.5 mM of 2-Mercaptopropionylglycine (MPG) significantly increased aortic flow by 40%. The oxidized form of MPG (ox-MPG) at a concentration of 0.6 mM increased aortic flow by 125%. A molecular mechanism is proposed involving reorientation of the ATPase molecules at their membrane sites.

Animals↗

Uncoupler- and hypoxia-induced damage in the working rat heart and its treatment. I. Observations with uncouplers of oxidative phosphorylation.

In the isolated working rat heart, the damaging effect of 0.05-0.06 microM Carbonylcyanide-p-trifluoro-methoxyphenylhydrazone (FCCP) was reversible within 20 sec by perfusion with fresh buffer. Cysteine 3 mM restored the aortic flow to the initial value within an additional 15-20 sec. Thereafter, the FCCP effect became irreversible due to a progressive structural membrane change. The structural change by FCCP is probably brought about by 'internalization' of polar groups (R-SH; R-NH3+) of the mitochondrial (and other) membrane.

Animals↗

Analysis of treatment efficiency of carboplatin and etoposide in combination with radical surgery in advanced and recurrent childhood hepatoblastoma: a report of the German Cooperative Pediatric Liver Tumor Study HB 89 and HB 94.

BACKGROUND: Hepatoblastoma (HB) is the most common liver tumor of childhood, and comprises approximately 1% of all pediatric malignancies. Although recent data from multicenter trials of GPOH, SIOP, CCG and POG indicate a remarkable improvement of therapy results, the prognosis of advanced or recurrent HB is still not satisfying. PATIENTS AND METHODS: During 1989 and 1997, the German Cooperative Pediatric Liver Tumor Studies HB 89 and HB 94 registered 141 patients with HB, who were treated according to the study protocols. These patients received standard chemotherapy with ifosfamide, cisplatin and doxorubicin (IPA) pre-operatively and/or post-operatively. Fourteen children with recurrent or advanced HB were additionally treated with carboplatin and etoposide (CARBO/VP 16), the reason being observations of drug resistance in children with HB after four or more courses of IPA-therapy in the HB 89 study. The clinical data and course of these patients were evaluated to investigate the efficiency of CARBO/VP 16 chemotherapy and for analyzing the role of surgery. RESULTS: Mean follow-up for survivors was 4.3 years (range 13 months-8 years). Tumor resection was attempted in 13 children but, in only 3 cases, was a complete tumor resection achieved in one operation. There was no perioperative death, and 7 of the patients (50%) are in remission. Two patients underwent adjuvant chemotherapy with CARBO/VP 16 for advanced HB at first operation: all are alive and well. Five patients with local relapse and/or distant metastases responded partially to CARBO/VP 16 therapy, and a complete remission was achieved in one patient. In five patients, progressive disease was observed during therapy with CARBO/VP 16. One patient, stable while on chemotherapy, had a successful resection. Acute toxicity of chemotherapy was observed in 7 patients (50%). CONCLUSION: An aggressive approach using IPA and CARBO/VP 16 chemotherapy and highly developed surgical techniques may improve the prognosis of advanced or recurrent HBs.

Antineoplastic Combined Chemotherapy Protocols↗

[Central venous indwelling catheter systems in pediatric oncology from the surgical viewpoint].

A total of 307 central venous access devices were implanted by open surgery in 268 pediatric oncology patients. Their data were retrospectively evaluated from a surgical point of view. The cumulative duration of implantation of 116 subcutaneous tunneled Catheter (STC) was 12,206 days and 45,524 days for 191 portsystems. According to the duration in each group, ports were superior to STC when infection, complication and occlusion were taken into consideration. Infection of the ports was more frequent in children under 3 years than in older patients. Conversely, in the STC-group, children over 10 years presented with the highest rate of infection episodes. The number of complications was high in young children for both types of catheter, decreasing with age. Occlusion rates were similar for both systems and were not age related. However, thrombolysis was more successful in portsystems and few catheters had to be removed for this reason. The age-related data of the presented study are discussed with regard to the surgical procedure. Recommendations are made concerning the adequate choice of catheter system, the surgical technique and postoperative management. Additionally, the medicotechnical aspect of different catheter types is discussed and some suggestions and/or requests are directed to the industrial developing laboratories.

Bacteremia↗

Idiopathic edema in a male.

A 15-year-old boy who suffered from leg edema of unknown origin is described. The exclusion of any other cause for the edema, the clinical features, and the results of the dynamic tests performed suggested the diagnosis of "idiopathic edema," a syndrome described previously in women only. Spironolactone therapy brought about the disappearance of the edema and enabled the patient to return to his normal activities. This case report suggests that "idiopathic edema" is a syndrome common to both sexes, and is therefore not related to estrogen disturbances.

Adolescent↗