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Biomedical subjects

G Bartsch

Publications and source records attributed to G Bartsch.

At least 19 recordsLinked to original sources

Pregnancies associated with sperm concentrations below 10 million/ml in clinical studies of a potential male contraceptive method, monthly depot medroxyprogesterone acetate and testosterone esters.

A potential male contraceptive approach was evaluated in clinical trials involving monthly injections of depot medroxyprogesterone acetate and either subdermal implants of testosterone propionate or monthly injections of testosterone enanthate. Pregnancies occurred in partners of 9 men with recent sperm counts of 10 million/ml or below. In 5 of the 9 instances, the sperm counts were less than 1 million/ml. It appears that male contraceptive methods involving spermatogenic suppression may require attainment and maintenance of azoospermia. The pregnancy rate cannot be calculated, because the extent of other contraceptive use is uncertain. There were no spontaneous abortions. 6 pregnancies were carried to term, and all progeny were normal, based on physical examination at birth or 3 months after birth.

Contraceptive Agents, Male

Electron microscopic stereological analysis of the normal human prostate and of benign prostatic hyperplasia.

Normal and benign hyperplastic prostatic tissue was studied by quantitative electron microscopic measurements. Quantitative morphological procedures provide values for volume, surface, number of tissue and cellular components within human prostatic tissue. When a comparison is made of the stereological data of the glandular cell of benign prostatic hyperplasia to that of the normal human prostate no statistically significant difference in the relative volumetric amount of the cell organelles is indicated. An attempt was made to characterize the fine structure of the smooth muscle cells of the stromal area (fibromuscular) in normal and benign hyperplastic prostatic tissue. In benign prostatic hyperplasia a significant increase in the relative amount of organelles in the smooth muscle cell was found, indicating an activation of these cells. Light microscopic analysis has revealed that benign prostatic hyperplasia is primarily a stromal disease.

Cytological Techniques

Light microscopic stereological analysis of the normal human prostate and of benign prostatic hyperplasia.

Normal prostate glands from 6 men less than 30 years old and enucleated tissue of benign prostatic hyperplasia were analyzed by stereological methods. Studies on the relative volumetric amount of fibromuscular (stromal) and glandular areas of the gland reveal no statistically significant difference between the inner and outer parts of the normal prostate and between the inner part of the normal prostate and benign prostatic hyperplasia. However, in benign prostatic hyperplasia there is a significant increase in the volumetric amount of the fibromuscular tissue and a decrease in the glandular area compared to the outer part of the normal prostate and the whole normal prostate (sum of the inner and the outer parts). These stereological data are discussed with respect to the pathogenesis of benign prostatic hyperplasia.

Adult

[Adrenal scintigraphy-value and indications in adrenal disease].

Adrenal scintillation scanning is a very useful method in the diagnosis of steroid producing diseases of the adrenal glands. The diagnosis of bilateral hyperplasia and primary adenoma of the adrenal cortex in Cushing's syndrome and Conn's syndrome is possible by this non-invasive procedure. Morphological questions (e.g. the localization of a phaeochromocytoma) cannot be answered. It is not a screening examination.

Adenoma

Quantification of human sperm morphology and motility by means of semi-automatic image analysis systems.

Sperm morphology and motility are determined using a semi-automatic image analysis system under opto-manual control. The system consists of a microscope equipped with a drawing-tube, a digitizer-tablet, and a cursor interfaced to a small microcomputer. A light-emitting diode is mounted on the cursor, visible as a bright red pilot-light in the microscopic field. Sperm head and midpiece as well as the pathway of motile spermatozoa are traced with the cursor's red pilot light. The microcomputer calculates area, circumference, and length simultaneously. Motility and sperm density are determined altogether using microchamber technique. In a selected group of male subjects with normal, doubtful, and pathological semen analyses biometrical analyses of sperm morphology and motility were performed. Sperm morphology is best described by the variation of the head size and by the average midpiece width. Motility is best described by % motile spermatozoa and mean velocity determined 1 hour after semen collection. Biometrical semen analyses are superior to subjective evaluations regarding degree of information, objectivity, and reproducibility.

Cell Survival

Hormonal influences on the dog prostate--a correlation study with light microscopy, transmission and scanning electron microscopy.

Dog prostates under defined hormonal influences were investigated by light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The normal acinar cell apices exhibited well-developed, densely packed microvilli. TEM demonstrated numerous secretory granules, indicating a high secretory activity. Following castration, the acinar cells of the dog prostate showed rounded apices. Most of the microvilli disappeared and only knob-like protrusions were seen. Castrated dogs following administration of 3 alpha-androstandiol showed fewer microvilli than the controls; however, a well-developed undulating surface could be observed. Castrated dogs given 3 alpha-androstandiol and cyproterone acetate showed almost completely atrophic glandular cells. Prostates of dogs with spontaneous benign prostatic hyperplasia (BPH) were characterized by pleomorphism of cell shapes and surfaces. The different hormonal influences induced changes of the prostatic surface structures and secretory activity.

Androstanols

Comparative scanning and transmission electron microscopy of the prostatic gland in different species (mouse, rat, dog, man).

Man, dog, rat and mouse prostatic glandular cells were compared by light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). In rodents and dogs, a merocrine secretion exists, and in these species the undulating surface represented a confluence of secretory granules. The prominent secretory blebs observed in dog and human benign prostatic hyperplasia (BPH) corresponded to apocrine secretions. Also variations in the amount of secretory activity were seen. Androgenic hormones were responsible for the differentiation of the prostatic epithelial cells during development. Therefore, an absence of microvilli as well as the appearance of ruffles, microplicae, and bare cells were seen in the prepuberal and castrated rat. In the elderly rat and in human BPH, a pleomorphism of the apical cell surface was evident.

Age Factors

Improved method for the rapid determination of isosorbide dinitrate in human plasma and its application in pharmacokinetic studies.

A rapid, accurate and highly sensitive method was developed for the determination of isosorbide dinitrate in human plasma. Concentrations in the lower nanogram and subnanogram range are determined by a one-step extraction of 2 ml plasma, containing 4 ng/ml nitroglycerine as internal standard, with 5.5 ml n-pentane. The extract is subjected to gas--liquid chromatography--electron capture detection analysis. The lower limit of quantitation is 200 pg/ml, but concentrations as low as 50 pg/ml are still detectable. The method allows the quantitative determination of isosorbide dinitrate plasma levels in man following a 5 mg sublingual administration up to four hours after application.

Chromatography, Gas

A stereological study of adrenocortical cells in spontaneously hypertensive rats (shr).

The ultrastructure of SHR (Spontaneously Hypertensive Rats) fasciculata cells was compared descriptively and quantitatively with that of nonstimulated fasciculata cells of Wistar rats using sterological methods. The volume and surface densities are expressed per cm3 of cytoplasm. The smooth endoplasmic reticulum in the SHR was significantly increased compared to the control animals (surface density : 28%, volume density: 35%). Mitochondria volume remained unchanged although the inner mitochondrial membranes were significantly reduced (37%). An attempt was made to draw up a relation between sterological and biochemical data of steroid synthesis within the fasciculata cell. A genetically determined enzymatic defect in the early steps of the transformation of cholesterol to pregnenolone may exist at the level of the inner mitochondrial membrane. Whether this altered steroid metabolism is important to the etiology of hypertension in the SHR requires further investigation.

Adrenal Cortex

Stereological study of the zona fasciculata of the adrenal cortex in stress situations (hypothermia, catabolism).

The ultrastructure of the rat fasciculata cells in stress situations, such as catabolism and hypothermia was compared descriptively and quantitatively by stereological methods with that of the nonstimulated rat fasciculata cell. The volume and surface densities are expressed per cm3 of cytoplasm, mitochondria and smooth endoplasmic reticulum. Furthermore, absolute values are given. In both stress situations the volume density of the mitochondria compared to the controls is enlarged significantly (H: 37% CA: 50%). The significant increase of the average single mitochondrium of the fasciculata cell (H: 58% CA: 58%) shows a real growth of the mitochondria in these stress situations. Also the surface density of the mitochondrial inner membranes--the mitochondrial enzymes for steroid genesis are partly located in these membranes--shows a significant increase (H: 31%, CA: 84%). Whereas the volume density of the smooth endoplasmic reticulum remains unchanged, the surface density is significantly raised (H: 44%, CA: 60%). An attempt was made to draw up a relationship between stereological and known biochemical data of steroid genesis within the fasciculata cell. An activation in both stress situations could be observed. The stereological data reflect a subcellular reaction pattern, which is similar to exogenous ACTH administration, thus indicating an endogenous ACTH liberation due to these stress conditions.

Adrenal Cortex

[Characterization of Ca-uptake by a microsomal fraction from vascular smooth muscle].

A microsomal fraction was isolated from the media-intima of the bovine carotid artery; the preparation is a mixed fraction of membranal and mitochondrial debris, which is able to bind Ca-ions and to take them up in the presence of ATP. The Ca-uptake is activated within a pCa range from 7--5. The involvement of two different systems in the Ca-uptake is discussed. A Ca-stimulatable ATPase was demonstrated, whose relationship with a Ca-transport system could not be established, however. The substrate for Ca-uptake is MgATP; in addition, free Mg has a stimulating effect. The Na/Kratio has no influence on the Ca-uptake. The influence of the pH-value on the Ca-binding and Ca-uptake was studied. Phosphate increased the Ca-uptake, while oxalate did not. The investigated system is discussed as a model for the action of vaso-active drugs.

Adenosine Triphosphatases

Radioimmunoassays of ethinyl-norgestrienone (R-2323) and medroxyprogesterone acetate (MPA) and their clinical applicability.

Radioimmunoassays for 2 synthetic progestins (Ethinyl-norgestrienone, R 2323 and medroxyprogesterone acetate, MPA) are demonstrated. 10 patients aged 31 to 72 years were treated with ethinyl-norgestrienone with different schedules and 3 men suffering from benign prostatic hypertrophy were treated with medroxygesterone acetate. Plasma levels of testosterone, LH, FSH were monitored before, during and after treatment.

Adult