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Biomedical subjects

K Thoma

Publications and source records attributed to K Thoma.

At least 55 records · Page 3Linked to original sources
PubMed1987

[Effect of film formers and plasticizers on the stability of resistance and disintegration behavior. 4. Pharmaceutical-technological and analytical studies of gastric juice-resistant commercial preparations].

Chemical an physical properties of film coating materials determine stability of enteric coated pharmaceutical dosage forms. About 80% of commercial enteric coated drugs with coatings of celluloseacetate phthalate or polymethacrylic acid ester did not change acid resistance or disintegration time after 2 years, storage at 20 degrees C or 40 degrees C. Disintegration time of 4 drugs which are enteric coated with hydroxypropylmethylcellulose phthalate, decreased more often. Some of these did not fulfill acid resistance requirements of the Ph. Eur., tests which show influence of softeners to stability of enteric coatings have to be extended.

Cellulose↗
PubMed1986

[Thin layer chromatographic detection of emollients in gastric juice-resistant coatings. 2. The pharmaceutic technology and analysis of gastric juice-resistant dosage forms].

Softeners in enteric coatings as phthalic acid esters, citric acid esters, tartaric acid esters, glycerine esters, alcohols or surfactants can be identified by thin layer chromatography. Normally they are extracted by ether out of a phosphate buffer solution of the coating. In exceptional cases, it is necessary to extract dry isolated enteric coatings with acetone/ethanol. As developing solvents butanol and methylene-chloride are recommended. To separate similar substances as glycerine-diacetate from glycerine-triacetate it can be necessary to evaluate the results in both developing solvents. Softeners had been isolated and identified from 9 examples of commercial drugs.

Chromatography, Thin Layer↗
PubMed1985

Non-insulin-dependent diabetes in Nauruans: a comparison of newly and previously diagnosed cases.

A comparison of 148 newly diagnosed ('incident') and 202 previously diagnosed ('prevalent') Nauruan diabetics, examined during a population survey in 1982, has permitted cautious inference regarding the natural history of non-insulin-dependent diabetes (NIDDM) in this Micronesian population. As might be expected the results of the comparison do suggest that Nauruan diabetics undergo further deterioration in glucose tolerance, subsequent to diagnosis of the disease. Plasma glucose concentration is higher in prevalent than incident cases (males: fasting--12.2 versus 10.4 mmol/l; 2 h--18.9 versus 16.3 mmol/l; and females: fasting--13.1 versus 9.3 mmol/l; 2 h--20.3 versus 15.8 mmol/l) suggesting that present treatment measures may not be effective in this population. There was also some evidence that the metabolic consequences of NIDDM may be greater in female than in male Nauruans. Apart from plasma glucose concentration, of 8 other biological variables examined by univariate and multiple logistic regression analysis, three showed consistent differences between incident and prevalent cases in females, but none were consistently different in males. A relatively small difference in estimates of obesity was observed between incident and prevalent cases, and this was particularly notable in males. A number of potential sources of bias in this study are highlighted, and definitive, longitudinal studies will be required to corroborate these findings.

Adult↗
PubMed1985

Mortality patterns in the modernized Pacific Island nation of Nauru.

Nauru is a small phosphate-rich independent island country situated in the Central Pacific. The population is Micronesian and was estimated to be 4,680 in mid-1981. An analysis of mortality data for the years 1976-81 indicates a high adult male mortality due to accidents, injuries, cardiovascular disease, and diabetes. The life expectancy estimate at birth for men was 49 years, and for women 62 years. The male life expectancy is among the lowest in the region. The considerable adult male mortality appears to be related to the rapidly acquired affluence and the ready availability of motorcycles, cars, imported foods, tobacco, and alcohol. The data suggest that modernization of the economy in Pacific Island nations can lead to new and serious public health problems.

Accidents↗
PubMed1984

The high prevalence of diabetes mellitus, impaired glucose tolerance and diabetic retinopathy in Nauru--the 1982 survey.

A population survey in 1982 has confirmed that Nauruan adults suffer from an extremely high prevalence of Type 2 (noninsulin-dependent) diabetes mellitus. The crude population prevalence of Type 2 diabetes was 24%. Abnormal glucose tolerance (impaired glucose tolerance and diabetes) was present in over 40% of the adult population and exceeded 80% in both sexes after the age of 55 yr. Diabetic retinopathy was present in 24% of diabetic patients, confirming that this Micronesian population is susceptible to the microvascular consequences of hyperglycaemia. Subjects with impaired glucose tolerance had a prevalence of retinopathy three times that of normal subjects, though the difference did not reach statistical significance. Prevalence of retinopathy was substantially higher in diabetic patients than either normal subjects or those with impaired glucose tolerance.

Adult↗
PubMed1983

Genetics of diabetes in Nauru: effects of foreign admixture, HLA antigens and the insulin-gene-linked polymorphism.

Genetic factors play a major role in predisposition to diabetes in the Micronesian population of Nauru. In people aged 60 years and older, 83% of full-blooded Nauruans were diabetic compared with 17% of those with ancestral foreign admixture, as detected by HLA typing. HLA distributions also showed a small increased risk for early onset of diabetes (less than 46 years) associated with HLA-Bw22 (Bw56). Variation in the restriction fragment length of DNA near the insulin gene was found, but was not associated with diabetes. The distribution in fragment lengths, previously reported in Caucasoids, was observed in healthy Polynesians, Melanesians and Micronesians.

Adult↗
PubMed1983

[Amphiphilic drugs. 2. Relation between colloidal properties and pharmaceutic-technological, pharmacokinetic and pharmacodynamic behavior].

The physicochemical properties of amphiphilic drugs may affect the technological, pharmacokinetic and pharmacodynamic behaviours. Micelle formation of a drug is of considerable importance for its solubility, stability, adsorption pattern, mixed micelle formation and influences thus its pharmaceutical availability. The biological availability is in many cases decreased by interactions of a surface active drug with other substances before absorption, by altered diffusion behaviour and distribution properties. Colloidal association may also result in an alteration of pharmacodynamic effects. These relations depend on the fact, that discrete hydrophobic an hydrophilic parts in a molecule are also prerequisites for micelle formation and receptor interactions. Furthermore the high membrane affinity of these drugs is responsible for some therapeutic and toxic effects.

Animals↗