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Biomedical subjects

K Stahl

Publications and source records attributed to K Stahl.

6 recordsLinked to original sources
PubMed1979

Ultrastructural morphometric investigations on human platelets after long-term ingestion of oral contraceptives.

Platelets from healthy females, who were taking oral contraceptives over a long period of time, were investigated by ultrastructural morphometry. The size, shape, relative volumes, numerical and surface densities of the platelets and their organelles were measured. In 'long-term pill users' the platelets showed a significant increase in the area of section profile. Further changes as, for example, increased volume of platelet granules, reduced number of mitochondria, decreased volume and surface of the open canalicular system, and increased surface of the dense tubular system are to be noted.

Adolescent↗
PubMed1978

Ultrastructural morphometric investigations on normal human platelets.

Platelets from normal human volunteers were investigated by ultrastructural morphometry. Preparation of blood samples was done in two different ways in order to evaluate the possible influence of the preparative method on the size and shape of platelets and their organelles. No significant differences could be dmonstrated for any of the measured parameters. Relative volumes of specific granules, mitochondria and the open canalicular system were calculated according to the method of Weibel. Surface and numerical densities of some compartments were determined. Direct measurements of the long and short axes of the platelets were conducted to ascertain further information about their size and shape. Absolute data are in good agreement with the few reports in the literature.

Blood Platelets↗
PubMed1978

Ultrastructural morphometric investigations on normal human liver biopsies.

Normal liver biopsies of 14 volunteers were investigated ultrastructural morphometrically. Besides the determination of morphometric baseline data for comparative purposes particular emphasis was placed on the question, if morphometric evaluations of human livers yield reliable results in spite of the higher range of distribution than in experimental liver material. The results showed that the surface of the smooth endoplasmic reticulum of human liver is significantly greater than the surface of rough endoplasmic reticulum. Otherwise the morphometric data of the human liver tissue did not differ essentially to the values of the laboratory rat. The variance analytical consideration of the mean evaluated from the data of the 14 liver biopsies indicated that the standard error of nearly all proved parameters was less than 10% of the mean. The results suggest that ultrastructural morphometric evaluation of human liver biopsy samples yield reliable results provided the samples investigated are sufficiently extensive.

Animals↗
PubMed1977

[Ultrastructural-morphometric investigations on liver biopsies--the influence of oral contraceptives on the human liver (author's transl)].

Liver biopsies from 12 healthy women were investigated morphometrically--according to the methods of Weibel (1969). All women had taken an oral contraceptive agent during 2 til 76 months. The evaluated stereological datas were compared with base-line dates for normal human liver biopsies, which were elaborated in a previous investigation (Roessner et al., 1977). Statistical analysis was performed on an IBM 360/50 computer system, including F- and student's t-test. In the liver biopsy-specimen from the women, which were on oral contraceptives, the volume-density of lysosomes per ml hepatocytes shows a pronounced, significant (p less than 0.001) increase. A moderate increase of cytoplasm is combined with decrease of nuclei-volume. The surface-densities of the rough and smooth endoplasmatic reticulum do not differ significantly from the datas calculated from normal human liver biopsies. All other datas too demonstrate that there are no striking changes in the ultrastructure of human liver, caused by oral contraceptives. Functional alterations however can not be excluded.

Biopsy, Needle↗
PubMed1977

One pediatric burn unit's experience with sleepwear-related injuries.

Review of the records of 678 children with acute injuries referred during an eight-year period to this burn unit indicated that flame burns from a single ignition source (50%) outranked scalds (27%) or house fires (12%) as causes of injury. There was no temporal trend in the rank pattern. The majority of these single-source flame injuries were severe and involved ignition of the child's clothing. From 1969 through 1973, sleepwear was the clothing involved in 32% of the instances. Since that time and coincident with promulgation of strict federal and state standards for flammability of children's night clothing, a dramatic decline in the number of children, referred with injuries of this type has taken place. It is probable that the single factor most important to the decline, in our experience with these injuries, is lower fabric flammability but, because our data may not be representative, corroboration is needed before one can exclude factors such as altered garment design, fire safety-related practices at home, or changing patterns of hospital referral.

Age Factors↗