Biomedical subjects

K Thoma

Publications and source records attributed to K Thoma.

At least 37 records · Page 2Linked to original sources

PubMed1991

[The solubility kinetics of enteric-resistant tablets using riboflavin test tablets. 6. Pharmaceutic-technologic and analytic studies on gastric juice-resistant dosage forms].

To examine the dissolution kinetics of enteric coatings in vivo a test system with riboflavine was developed. This system allows to realize the beginning of disintegration in the small gut because riboflavine is excreted in urine already within 1 h after ingestion, and to locate the area of dissolution of the tablet in vivo, because riboflavine absorption is reduced in the great gut and colon. Thus the test system allows to examine and improve coating compositions in vivo and to demonstrate changes of drug dissolution in vivo conditioned by storage of enteric coated pharmaceuticals.

Chemistry, Pharmaceutical↗

PubMed1990

[The effect of changing the association properties of psychopharmaceuticals in colloidal solutions on their liberation. 4. The effect of chemical structure as well as environmental conditions on the elevation of critical micelle formation concentration and reduction of micelle weight with hydrotropic material].

As shown by 8 different tri- and tetracyclic psychiatric drugs the authors demonstrated that the rate of desaggregation is markedly influenced by the chemical structure of drugs. In presence of 0.1 mol/l nicotinamide the cmc increased between 1.3 times for Maprotiline-HCl and 3.5 times for Chlorprothixene-HCl in acetate buffer pH 5.0; I = 0.154. Investigations about influences on the micellar weights showed for Flupenthixol-di HCl, Clomipramine-HCl and Melitracen-HCl decreases of 21.5, 16.1 and 14.0 per cent conferred by addition of 0.3 mol/l nicotinamide. There was a good correlation to the increase of the cmc. Different hydrotropic substances may show great differences of influence on the micellar weights and the cmc respectively. The micellar weight of Flupenthixoldi HCl for example reduces for about 17 per cent by concentrations of 0.2 mol/l nicotinamide or 1 mol/l propandiol-1.2, but the cmc increases to the 3.6- and 1.4fold value.

Chemistry, Pharmaceutical↗

PubMed1989

Control of HBV and HDV infection in an isolated Pacific Island: 1. Pattern of infection.

Hepatitis B virus (HBV) and hepatitis delta virus (HDV) infections are known to be hyperendemic in Nauru. Because of the consequences of chronic HBV infection, the Nauruan Government has commenced a program that aims to reduce and eventually eliminate hepatitis B infection by immunizing susceptible adults and children on the island and every newborn baby. At the outset of this program, a national seroepidemiological survey was undertaken. Eighty-eight percent of the population were tested, of whom 69.1% had markers of HBV infection. Evidence of superinfection with HDV was found in 22.7% of HBV carriers, with the highest prevalence in adolescents and young adults. All seronegative individuals were offered three doses of plasma derived hepatitis B vaccine. A post-vaccination survey of 64% of those vaccinated showed that 98% had developed circulating antibodies.

Adolescent↗

PubMed1988

Changing mortality patterns in Nauruans: an example of epidemiological transition.

An analysis of mortality data for the years 1982-5 was carried out for the Micronesian population (aged 15 years and over) of the central Pacific Island, Nauru. Among males, the most common causes of death were circulatory system disorders (33.3%), accidents (25.2%), and diabetes mellitus (12.1%). The majority of accidents occurred in the 15-34 year age group and involved motor vehicles. Among females, neoplasms (almost all lung and cervix) (22.4%), circulatory system disorders (20.7%), and diabetes mellitus (17.2%) were the most common causes of death. When accidents are excluded, 59.4% of deaths were in persons with diabetes. Compared with Australia, mortality rates in almost all age groups were at least five times higher for males and females for a comparable period. Nauruan life expectancy (39.5 years for men and 48.5 years for women) is one of the lowest in the world. These data confirm the high mortality associated with diabetes mellitus in Nauruans as evidenced in earlier studies. Modernization of this society through the affluence acquired by the mining of phosphate has led to serious public health problems relating to non-communicable diseases so that the mortality trends now mirror those of developed societies.

Adolescent↗

PubMed1988

Mortality from diabetes in Nauru. Results of 4-yr follow-up.

A population survey in 1982 confirmed that Nauruan adults suffer from an extremely high prevalence (24%) of non-insulin-dependent diabetes mellitus. A follow-up study of the survey subjects was conducted in 1986. The aim was to assess the burden of diabetes to Nauruans in terms of premature mortality. Age-adjusted mortality rates for diabetic subjects were significantly increased when compared with normal subjects (relative risks for 4-yr mortality were 4.53 in men, P less than .01, and 3.96 in women, P less than .05). Although there was an excess number of deaths among diabetic subjects compared with normal subjects and subjects with impaired glucose tolerance, there was no significant association between cause of death and diabetes.

Adult↗

PubMed1988