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Biomedical subjects

A F Holstein

Publications and source records attributed to A F Holstein.

At least 73 records · Page 4Linked to original sources
PubMed1984

Dislocated type-A spermatogonia in human seminiferous tubules.

Type-A spermatogonia can be found in different locations throughout the germinal epithelium of human seminiferous tubules. Generally they represent the population of germ cells adjacent to the basal lamina, but under special conditions they may be located in the adluminal compartment. This aberrant location is found not only in the terminal segments but also in the seminiferous tubules of men older than 65 years of age, and in cases of intratubular seminoma. Furthermore, in both cases, type-A spermatogonia may occupy an intermediate position between basal and intraluminal locations, without showing any signs of cytological damage.

Aged↗
PubMed1983

Intraepithelial lymphocytes and macrophages in the human epididymis.

The epididymides from 7 young adults and 5 older patients with prostatic cancer were investigated by means of light and electron microscopy. The existence of lymphocytes and macrophages between epithelial cells of various segments of the ductuli efferentes and the ductus epididymidis is proven, and the distribution and morphology of these cells are described. A possible relationship between these two intraepithelial cell types, as well as their presumptive role with regard to an immunological barrier-function are discussed.

Adult↗
PubMed1983

Studies on the arrangement of the collagenous fibers in infant epiphyseal plates using polarized light and the scanning electron microscope.

The architecture of the collagenous fibers in epiphyseal plates of infantile long bones was investigated using polarized light and scanning electron microscope. In the zone of columnar cartilage the collagenous fiber bundles are arranged longitudinally in the intercolumnar cartilaginous septa. In addition to this main longitudinal orientation, some of the fibers branch off at an acute angle and flow through the cartilage columns surrounding rhombus-shaped groups of chondrocytes. In the area adjaced to the inert cartilage the collagen fibers become curved and form a network of arcades. In the zone of inert cartilage the collagenous fibers are arranged in a honeycomb-like fashion. The importance of the arrangement of the collagen fibers to the loading strength of the epiphyseal plate is discussed.

Age Factors↗
PubMed1982

[Morphology of spermatids in elderly subjects].

This study has been performed with the aim of clarifying whether spermatid differentiation still proceeds regularly in advanced age. Specimens have been observed of testicular tissue from 108 patients orchidectomized because of prostatic carcinoma and before initiation of hormone therapy. In 30 subjects, 65 to 85 years old, mature spermatids have been found in the semithin sectioned germinal epithelium. The testicular tissue of these 30 patients has been investigated by means of transmission electron microscope. In the studied material most of the spermatids appear malformed. In patients less than 75 years old, about 70% of all spermatids are abnormal, in older patients nearly 90%. The malformations concern all cellular components, but can be seen most frequently in the acrosome and in the nucleus. There are isolated malformations, e.g. of the acrosome; however also combined malformations, e.g. the acrosome, the nucleus and the tail can be observed. In addition to these disturbances of spermatid differentiation, even disturbances of spermiation can be found, presumably caused by a misled function of the Sertoli cells. In these cases, a spermatid loses its contact with the Sertoli cell before final maturation.

Acrosome↗
PubMed1982

Steroidogenic capacity of isolated adult mouse Leydig cells does not decrease with age.

Leydig cells were isolated from the testes of adult young (5--7 months), old (21 months), and senile (27 months) mice using a highly preservative Percoll procedure. The yield in Leydig cells per testis from young animals was slightly lower than from the old age groups. hCG-induced testosterone synthesis proceeded in a linear fashion for at least 5 h in all three groups. The maximal steroidogenic capacity of cells from old animals was identical to that from young adults. There was no significant difference between Leydig cells from young and old mice with respect to hCG-induced cAMP accumulation and protein kinase activation. Determination of hCG concentrations required for half-maximal stimulation of testosterone synthesis and cAMP accumulation showed identical, or even lower, values in the old age groups. The phenomenon may be connected with the significant augmentation with age of the DNA content per cell (polyploidization), possibly acting as a compensatory mechanism of age-induced deficiencies. Detailed kinetic studies of cAMP accumulation, protein kinase activation, protein kinase activation, and steroidogenesis as well as ultrastructural analyses support the findings of unimpaired or increased capacities of the testosterone-forming cells in old animals. Thus, the aging of Leydig cells appears to differ from that of other tissues of the mouse (e.g. skeletal muscle), which exhibit decreasing abilities to respond to stimuli.

Aging↗
PubMed1980

[Scanning electron microscopy of the human spermatic tract].

The human excurrent duct system of the testis (rete testis, ductuli efferentes, ductus epididymis and vas deferens) have been studied by the S.E.M. The specimens have been taken from subjects who underwent surgery for prostatic carcinoma. For the S.E.M. the specimens have been prepared according to usual techniques: fixed with 2.5% glutaraldehyde and 1% OsO4 in Millonig's buffer, dehydrated in ethanol, dried by the critical point technique in CO2 and coated with gold-palladium 10%. The cavities of the rete testis show a flat epithelium with short microvilli and single cilia. The ductuli efferentes are lined by long-ciliated columnar elements and by stubby elements provided with microvilli. Globular extrusions, probably representing the swollen apices of epithelial cells, have been interpretated like the expression of a secretory activity. The ductus epididymis is lined by high columnar epithelium provided with thick microvilli. In the lumen it is possible to observe little globular masses with variable diameters, isolated or more often grape-shaped. These have been interpretated as the expression of secretory activity microapocrine in nature. The vas deferens is bounded with columnar epithelial cells with variable morphology. Some of them, infact, have crowded microvilli, while some others have swollen apices bulging into the lumen. These globular extrusions are probably the expression of the secretory activity.

Epididymis↗
PubMed1980

New development in surgical andrology. Alloplastic spermatocele.

We developed a cup-shaped silicone-dacron prosthesis that may be used as a sperm reservoir. Spermatozoa aspirated from this reservoir and stored as pellets in liquid nitrogen for 6 weeks induced pregnancies and normal births in 50 per cent of inseminated cows. Because of aplasia or long stenosis of the vas deferens 26 prostheses were implanted upon the epididymis in 14 patients. Percutaneous aspirations up to 7 months postsurgery showed 0.3 to 105 million spermatozoa the quality and quantity of which decreased with time. Insemination of patients' wives has not resulted in pregnancy.

Animals↗
PubMed1980

[Scanning electron microscopy of the human male genital tract].

The three-dimensional features of the human male genital tract (rete testis, ductuli efferentes, ductus epididymis and vas deferens) and seminal vesicles epithelium have been studied by scanning electron microscopy. The luminal surface of the epithelial cells shows a particular pattern in the different organs, especially for the development of the microvilli and for the nature of the secretion. Particularly, while the columnar cells of the ductus epididymis and vas deferens present a secretory activity, microapocrine in nature, the seminal vesicles epithelium is characterized by a merocrine secretion. The present results are discussed in relation to the previous observations obtained by light microscopy and transmission electron microscopy.

Epididymis↗
PubMed1979

Distribution and fine structure of the lymphatic system in the human testis.

The distribution of lymph vessels in the human testis was investigated using ink injection methods, and light and electron microscopy. Lymph capillaries occur in the septula testis but are absent in the intertubular tissue. They consist of endothelial cells provided with an incomplete basal lamina and anchoring filaments of the adjacent connective tissue. Frequently, the endothelial cells are separated by gaps measuring up to 2 micron. The lymph capillaries of the septula testis are connected to lymph vessels in the rete testis and tunica albuginea. These vessels have occasional smooth muscle cells and valves. At the posterior margin of the testis, the network of lymph vessels merges into collecting ducts, which together with vessels derived from the rete testis are drained by the lymphatic system in the spermatic cord.

Endothelium↗
PubMed1979

[Lymphatic system of the human testis].

The distribution of lymph vessels in the human testis was investigated using ink injection methods, light and electron microscopy. Lymph capillaries occur in the septula testis but are absent in the intertubular tissue. They consist of endothelial cells provided with an incomplete basal lamina and bound by anchoring filaments to the adjacent connective tissue. Frequently, the endothelial cells are separated by gaps (measuring up to 2 microns). The lymph capillaries of the septula testis are connected to lymph vessels in the rete testis and tunica albuginea. These vessels have occasional smooth muscle cells and valves. At the posterior margin of the testis, the network of lymphatics merges into collecting ducts that together with vessels derived from the rete testis are drained by lymphatics in the spermatic cord.

Adolescent↗
PubMed1978

A further type of transient cytoplasmic organelle in human spermatids.

Osmiophilic granules with surrounding vesicles resembling flower-like structures occur transiently during the differentiation of human spermatids. These organelles are incorporated into the residual bodies when mature spermatids are released from the germinal epithelium.

Cytoplasmic Granules↗
PubMed1978

[Contribution to the formal pathogenesis of the classical seminoma. Early diagnosis from testicular biopsies?].

13 cases of seminoma of the testes were investigated in detail by means of light microscopy using paraffin and semithin sections. Paraffin sections were the basis for diagnosis, therapy, and prognosis. In semithin sectins, even individual seminoma cells within the seminiferous tubules were recognized by characteristic cytological features. In semithin sections also the development of the solid tumor from intratubular seminoma cells was elucidated. On the basis of our findings, the following concept of seminoma spread may be advanced: intratubular seminoma cells invade the lamina propria and gain access to to the interstitial tissue. Subsequent to the migration of seminoma cells, the tubules are smaller in diameter and contain only Sertoli cells. The seminoma cells in the interstitial tissue increase in number and build up the solid tumor.

Adult↗
PubMed1977

On the histology of human seminoma: development of the solid tumor from intratubular seminoma cells.

Intratubular seminomas of the testis associated with solid tumors were studied by light and electron microscopy in order to obtain information about the earliest stage of emigration from the tubules and invasion of the interstitial space. Careful examination of numerous sections reveals that at this stage neoplastic cells protrude into evaginations of the tubule covered by basement membrance or directly invade that membrane. At the site of tumor cell emigration, the basement membrane is thickened and multilayered. Tumor cells devoid of basement membrane were found in the interstitium. Their transmigration through the basement membrane was never observed. Subsequent to the migration of seminoma cells the tubules are smaller in diameter and contain only Sertoli cells. From the observations described it is inferred that tumor cells in the interstitial tissue increase in number, form strands and lobules, and finally build up the solid tumor.

Adult↗
PubMed1976

The rete testis in man: ultrastructural aspects.

The ultrastructure of the normal human rete testis was analyzed. The rete testis cavities are irregularly shaped and contain virtually no spermatozoa. Smooth muscle cells often surround the cavities. In the epithelial lining, two cell types are distinguishable. Flat, dark cells exhibit numerous slender microvilli, and numerous apical and basal micro-vesicles. Prismatic, lighter cells have more cell organelles, mostly polarized towards a supranuclear position. Both cell types contain variable amounts of glycogen and fat, and an occasional cilium. All cells display intricate lateral cell surfaces that possess different cell-to-cell attachment devices. Intermediate cell types are frequently found. On a morphological basis, the epithelial cells seem to be involved in the release of substances into the lumen and probably also in transport towards the base. Connective tissue elements are found subjacent to the epithelium. Scattered among the fibrocytes are typical smooth muscle cells. Expansions of some smooth muscle cells are connected to the epithelial basement membrane by a network of microfibrillar materia. The smooth muscle cells may be involved in changing the shape of the rete testis channels, thus promoting the flux of the rete testis fluid. Different types of nerve fibre bundles are distinguished in the connective tissue of the rete testis which may correspond to autonomic and sensory nerves or sensory receptors.

Adult↗