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Biomedical subjects

R Steffen

Publications and source records attributed to R Steffen.

At least 217 records · Page 12Linked to original sources
PubMed1989

[Medical aspects of the artificial liver].

Artificial liver support may be indicated in cases of fulminant toxic or drug-induced liver failure, in fulminant viral hepatitis, after surgical procedures such as extended liver resections or liver transplantation with primary graft failure, and in some cases of chronic endstage liver disease. Neither artificial nor biological liver support systems have shown any convincing results, whereas plasma exchange combined with intensive medication is suitable for temporary liver failure or for providing support until a donor organ for liver transplantation becomes available.

Animals↗
PubMed1988

Travelers' diarrhea in West Africa and Mexico: fecal transport systems and liquid bismuth subsalicylate for self-therapy.

The goals of this study were threefold: to compare the etiology of travelers' diarrhea in West Africa and Mexico, to evaluate two fecal transport systems for the recovery of enteropathogens, and to verify the efficacy of liquid bismuth subsalicylate (BSS) in different locations and under different entrance criteria for disease severity. The study populations consisted of 133 European tourists in West Africa and 112 American students in Mexico who had suffered from travelers' diarrhea. In 60% and 38% of the stool samples at the two study sites, similar proportions of enteropathogens were detected. A two-vial system consisting of Enteric Plus medium and polyvinyl alcohol fixative was slightly superior for identifying enteric pathogens than was a three-vial system with buffered glycerol saline, Cary-Blair medium with campylobacter antibodies, and polyvinyl alcohol fixative. In a parallel, double-blind, randomized trial, BSS significantly shortened disease duration at both study sites.

Aeromonas↗
PubMed1988

Age-dependent stimulation of assembly and of membrane-association of polysomes in rat brain after treatment with xanthine derivatives in vivo.

A new pharmacological approach is described to change the structural state of polyribosomes in old rats. It is shown that the ratio of free to membrane-bound polysomes in rat brain increases significantly depending on age (immature animals, 1.40; mature and old rats, 1.48 and 1.67, respectively). Moreover, the portion of heavy polysomes (number of ribosomes: five and greater) decreases age-dependently with respect to light polysomes (number of ribosomes: four and smaller). The values for the fraction of free polysomes are as follows: immature animals; 4.0; mature and old animals; 4.3 and 2.9, respectively; and for membrane-bound polysomes: immature, 4.9; mature, 4.7; and old 3.3. It is shown that after in vivo application (80 mumol/kg p.o. daily for 14 days) the xanthine derivative propentofylline reverted the structural state of the polyribosomal translation system in old brain to those values which are characteristic for polysomes in immature and mature brains. The xanthine derivatives theophylline, theobromine and caffeine were without effect under otherwise identical conditions. It is suggested that propentofylline has an activating influence on polysomal function in old rat brain.

Aging↗
PubMed1987

[Focal nodular hyperplasia of the liver].

The differential diagnosis of focal nodular hyperplasia of the liver (FNH) encompasses a variety of hepatic mass lesions with differing prognosis and therapy. Ten patients with FNH confirmed by histology form the basis of this review of the pathogenesis, the clinical features and of diagnostic and therapeutic aspects. - FNH is usually diagnosed fortuitously in women of childbearing age. It is considered to be a reactive process rather than a true neoplasia, and its biological behaviour seems to be modified by female sex steroids. In contrast to liver cell adenoma, rupture and bleeding are exceptional. For the diagnosis of FNH a combination of dynamic computed tomography and 99mTc sulphur colloid liver scintigraphy is most reliable, whereas ultrasonography lacks specificity. Once the diagnosis of FNH is established, surgery usually is unnecessary.

Adult↗
PubMed1987

Importation of poliomyelitis to industrialised nations between 1975 and 1984: evaluation and conclusions for vaccination recommendations.

World Health Organisation and public health authority records show that 175 cases of paralytic poliomyelitis were imported to industrialised countries between 1975 and 1984. Detailed case reports were therefore analysed to identify characteristic features associated with acquisition of the infection. Of the 175 cases, 96 (55%) were diagnosed in foreign workers or their families, 47 (27%) in nationals travelling on holiday or business, 11 (6%) in immigrants, and 21 (12%) either in contacts who had not travelled or in unclassified groups. Poliomyelitis principally affected children under 5, but travellers aged 41-65 had the highest case fatality rate. The main serotype isolated was poliovirus type 1. The findings suggest that though fewer than one in every 100,000 travellers may be infected by poliomyelitis, all travellers and all immigrants, refugees, and foreign workers should be given full protection against all three polioviruses by routine vaccination.

Adolescent↗
PubMed1987

Extracorporeal isolated pig liver perfusion: influence of various blood primes on liver function.

Extracorporeal isolated pig liver perfusion was performed in three groups of five piglets each to assess the influence of different blood primes on liver function. All prime volumes were hemodiluted to a hematocrit of 0.3-0.35 and adjusted to a pH of 7.35-7.45 with sodium bicarbonate at a temperature of 38 degrees C. Fresh slaughterhouse blood was collected, mechanically filtered and used in Group A, whereas analogously collected blood was biologically filtered by passage through the organism of the piglet in Group B. In Group C, the priming blood consisted of autologous blood gained during hepatectomy by a special technique. A high potassium concentration (10.4 +/- 0.94 mmol/l) in Group A and impurities of the slaughterhouse blood in both Groups A and B led to rapid edema formation and an increase in vascular resistance of the perfused liver, and a prolonged perfusion was not achieved. In the third group, however, liver perfusion over a period of 5 h without any deterioration of liver function was possible. Beside liver function tests, oxygen consumption, the macroscopic aspect and bile flow of the liver seemed to be the most reliable parameters in assessing the function of the isolated perfused pig liver. Our technique to gain autologous blood can be recommended not only for extracorporeal liver perfusion but also for any other extracorporeal isolated organ perfusion.

Animals↗
PubMed1987

Travellers' diarrhoea.

Travellers' diarrhoea each year affects six million persons. At highest risk are those originating in an industrialized country for a visit in the Third World; their incidence of diarrhoea is 20-56% for the first 14 days of the stay abroad. Younger travellers, those who care less, and those with a lack of nonspecific gastrointestinal immune factors are more susceptible. The ailment mostly takes a mild and short course. Travellers' diarrhoea is usually due to faecally contaminated food and beverages, the predominant agent being enterotoxigenic E. coli. Therefore, the traditional rules of nutritional prophylaxis play the main role in prevention; drug prophylaxis can hardly ever be recommended.

Diarrhea↗
PubMed1987

Efficacy of malaria prophylaxis in American and Swiss travelers to Kenya.

The protective effect of malaria chemoprophylaxis with either Fansidar (pyrimethamine-sulfadoxine) or chloroquine was estimated by determining the attack rates of Plasmodium falciparum infections acquired in Kenya and imported by U.S. and Swiss travelers who had used no chemoprophylaxis, who had used only chloroquine for prophylaxis, and who had used Fansidar weekly, either alone or in combination with chloroquine. The estimated attack rates were almost identical in U.S. and Swiss travelers. The attack rate per 100,000 travelers averaged 280 in those who did not use chemoprophylaxis, 162 in those who took 4-aminoquinolines (P greater than .05), and 27 in those who used Fansidar for prophylaxis (P less than .001). Non-immune travelers to Kenya have an appreciable risk of acquiring a P. falciparum infection and need to be informed of current guidelines for chemoprophylaxis. The changing drug susceptibility patterns in Africa require continuous evaluation of the efficacy of recommended drug regimens for malaria prophylaxis.

Aminoquinolines↗
PubMed1987

Health problems after travel to developing countries.

Travelers to developing countries participated in a follow-up study of the health risks associated with short (less than three months) visits to these nations. Travelers to the Greek or Canary Islands served as a control cohort. Participants completed a questionnaire to elicit information regarding pretravel vaccinations, malaria prophylaxis, and health problems during and after their journey. Relevant infections were confirmed by the respondent's personal physician. The questionnaire was completed by 10,524 travelers; the answer rate was 73.8%. After a visit to developing countries, 15% of the travelers reported health problems, 8% consulted a doctor, and 3% were unable to work for an average of 15 days. The incidence of infection per month abroad was as follows: giardiasis, 7/1,000; amebiasis, 4/1,000; hepatitis, 4/1,000; gonorrhea, 3/1,000; and malaria, helminthiases, or syphilis, less than 1/1,000. There were no cases of typhoid fever or cholera.

Adult↗
PubMed1987

Prospective comparative study of intradiscal high-dose and low-dose collagenase versus chymopapain.

The mixed results of two studies on intradiscal therapy with collagenase versus chymopapain are presented. The first study was performed from January 1983 to March 1984 and consisted of 71 patients treated with collagenase injection (600 ABC units) and 93 patients treated with chymopapain injection (4,000 units) into lower lumbar discs. The second study was started in May 1985 and ended December 1985. The results of 41 patients injected with chymopapain and 45 patients injected with collagenase (400 ABC units) are reported. The overall success rate after 3 months was 69%/63% for chymopapain/high-dose collagenase and 73%/71% for chymopapain/low-dose collagenase and 75%/72% after 6 months for chymopapain/high-dose collagenase. Eighteen percent of the chymopapain-treated patients and 21% of the collagenase-treated patients of the first study had to be operated on within 6 months and 12% of chymopapain patients and 29% of collagenase patients within 3 months in the second study. Six of the 134 patients who had chymopapain treatment had slight allergic reactions. Patients who had collagenase treatment had no allergic reactions under the same regimen of systemic prophylactic measures. Patients who had high-dose collagenase injections suffered significantly more from postinjectional pseudoradicular and low-back pain in the first 3 months. In the first study, no permanent neurologic complications occurred. Two patients in the low-dose collagenase group developed cauda equina syndromes in the 2 weeks after injection because of large extruded disc fragments.

Adult↗