Search PubMed⌕ Search

Biomedical subjects

R Steffen

Publications and source records attributed to R Steffen.

At least 253 records · Page 14Linked to original sources
PubMed1984

[Epidemiology of travel diarrhea].

Travelers' diarrhea is the most frequent health problem during a stay in developing countries. A recent study basing on interviews with 16,568 charter flight passengers returning to Europe from 13 destinations in various climatic regions provides epidemiological data on a worldwide scale. Significant differences in diarrheal incidence varied not only between individual destinations, but also between hotels in the same area. The highest incidence for a two weeks' stay exceeded 50% in some regions of North and West Africa. Persons under 30 were more often affected than older travelers. Within international groups meeting in developing countries, the risk varied according to the patient's country of origin, with the residents of industrialized nations being most often affected. Even in the tropics, diarrhea usually takes a short and mild course. The various regions show unessential differences in chronology and symptomatology. E. coli is the most frequent causative agent of this ailment.

Adult↗
PubMed1984

[Preventive measures against travel diarrhea].

The rules of exposition prophylaxis for traveler's diarrhea are strictly adhered to by only 2% of tourists in developing countries even though the benefits have been well documented. Vacationers generally prefer to take various types of drug prophylaxis despite the fact that a protective effect has only been proven for chemotherapeutic agents and for subsalicylate bismuth. Since their use is strictly limited, therapeutic self-medication becomes even more important. Glucose-electrolyte-solutions may initially increase the number of bowel movements and antidiarrheal agents tend to prolong illness in dysenteric patients. Chemotherapeutic agents are indicated only in select cases.

Anti-Bacterial Agents↗
PubMed1983

Epidemiology of diarrhea in travelers.

To investigate diarrhea in tourists on a worldwide scale, 16,568 passengers were interviewed during their flights home from 13 destinations in various climatic regions. Significant differences in diarrheal incidence were observed between individual destinations and also between hotels in the same area. The highest rates exceeded 50%. Younger persons were more often affected. Sex, travel characteristics, and a record of former tropical journeys influenced the incidence to a minor degree. Even in the tropics, diarrhea usually takes a short (average, 3.6 days) and mild (average of 4.6 stools per day) course. Prophylactic or therapeutic medication only slightly influenced these values. The various regions showed minor differences in chronology and symptomatology. This is consistent with quantitative rather than qualitative geographic variations in causative agents. The traditional nutritional recommendations for prophylaxis seemed to be unrealistic and usually unsuccessful.

Adolescent↗
PubMed1983

Epidemiology of cholera in travellers, and conclusions for vaccination recommendations.

All cases of cholera imported to Europe and North America between 1975 and 1981 were reviewed to assess the danger of cholera for visitors to endemic areas. Data were obtained from the health authorities of the respective countries. From a total of 129 cases notified to the World Health Organisation detailed reports were obtained on 117 patients. Of these, 66 (56%) were immigrants, refugees, from endemic areas, or foreign workers returning from leave in their native countries. Only 51 (44%) were citizens of countries in Europe or North America. The incidence per journey for foreign travellers visiting Africa or Asia was about 1 in 500 000. Stay in hospital was always short, and fewer than 2% of patients died. In view of the minimal risk and lack of reliability of cholera vaccination, such protection is not indicated for ordinary tourists visiting developing countries.

Africa↗
PubMed1983

Hepatitis B vaccination of high-risk individuals in the canton of Zurich.

In an effort to vaccinate as many high-risk individuals as possible against hepatitis B, 10,484 persons received a total of 27,818 injections of H-B-Vax (Merck Sharp & Dohme) or HEVAC B (Sanofi/Pasteur) between January 1982 and January 1983. They represented 1.1% of the total population of the canton of Zurich including approximately 70% of all medical and dental personnel, a great proportion of eligible high-risk patients and contacts of HBs Ag carriers, but not more than 10% of drug addicts and promiscuous homosexuals. Twelve to 17% of the vaccine injections were accompanied by side effects which were benign in nature and transitory. Six vaccinated individuals developed hepatitis B, all within 60 days after the first vaccine dose. One hundred and seventy-seven cases of hepatitis B were recorded in 1982, 109 in the first half of the year and 68 in the second half. It was concluded that the vaccination campaign provided protection for medical and dental personnel. There was still no conclusive evidence of a vaccine-related drop in the incidence of hepatitis B in other high-risk groups vaccinated or - as a secondary effect - in other non-vaccinated populations.

Adolescent↗
PubMed1983

Immunochemical identification of the cell surface bound leucine aminopeptidase, the target enzyme for the immunostimulant bestatin.

The microbial product bestatin is known to inhibit soluble microsomal- and cytosolic leucine aminopeptidase (Leu-APm and Leu-APc) as well as aminopeptidase B (AP-B). To clarify which of these enzymes is the target for bestatin on the cell surface, indirect immunofluorescence studies with antisera raised against purified Leu-APm and AP-B were performed. These antibodies (anti-Leu-APm and anti-AP-B) were found to react with intracellularly localized Leu-APm and AP-B of ethanol-treated L5178y cells. Using non-treated L5178y cells fluorescence was detected only on the cell surface after incubation with anti-Leu-APm. To confirm the supposition that only Leu-APm is present on the cell surface, the AP from the cell membrane was solubilized and analyzed electrophoretically. Based on relative migration data it could be shown, that the cell surface is charged with Leu-APm and not with detectable amounts of Leu-APc or AP-B. Moreover, it could be demonstrated that the solubilized Leu-APm binds to [3H]bestatin.

Adjuvants, Immunologic↗
PubMed1983

Epidemiology of travellers' diarrhoea.

Travellers' diarrhoea is the most frequent health problem encountered during a stay in developing countries. A recent study based on interviews with 16,568 charter-flight passengers returning to Europe from 13 destinations in various climatic regions provides epidemiological data on a worldwide scale. Significant differences in diarrhoeal incidence varied not only between individual destinations, but also between hotels in the same area. Travel characteristics, and a record of former tropical journeys influenced the incidence to a minor degree. Persons under 30 were more often affected than older travellers. Within international groups meeting in developing countries, the risk varied according to the patient's country of origin, with the residents of industrialised nations being most often affected. The various regions show non-essential differences in chronology and symptomatology. This is consistent with quantitative rather than qualitative geographical variations in causative agents. Potentially life-threatening gastrointestinal infections, such as typhoid and cholera, are very rarely acquired by tourists.

Adolescent↗
PubMed1982

Electron microscopical characterization of sponge aggregation factors.

Aggregation factors, purified from 14 sponges which belong to the classes Tetraxonida and Cornacuspongia, Were visualized electron microscopically. Two types of basic structural forms were detected; first, circular structures from the species Ancorina cerebrum, Mycale massa, Hemimycale columella, Crella rosea, Clathria coralloides, Axinella cannabina, Pellina semitubulosa, Ircinia muscarum, Hippospongia communis, Verongia aerophoba and second, rod-like structures from Tethya lyncurium, Tedania anhelans, Hymeniacidon sanguinea, Dysidea tupha. In most of the cases the structures carry side chains.

Animals↗
PubMed1981

Salmonella and Shigella infections in Switzerland, with special reference to typhoid vaccination for travellers.

This prospective study reveals that 48% of 368 salmonelloses and 81% of 43 shigelloses diagnosed within one year in the Zurich area were imported from abroad. Travellers in close contact with the local population have a higher risk of being affected by typhoid fever or shigellosis than the average tourist. The clinical course was generally mild, and there was no lethal case. As the incidence of Salmonella typhi is very low, typhoid vaccination is recommended only for high-risk travellers.

Adolescent↗
PubMed1981

Intercontinental travel and its effect on pre-existing illnesses.

Over 12,000 European air passengers were interviewed as to whether the status of any pre-existing illness changed as a result of their vacation in the tropics or in North America (United States or Canada). Of the travelers to tropical destinations, 1.6% reported their disease had improved, which significantly exceeded the rate of 0.5% in visitors to North America, mainly due to a more favourable influence in chronic respiratory tract infections and chronic rheumatologic impairment. Aggravation of pre-existing disease occurred in 0.9 and 0.7%, respectively, of the travelers in the two groups and was only rarely severe. In the tropics, patients below the age of 30 and those who suffered from digestive problems were most frequently adversely affected.

Adolescent↗