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Biomedical subjects

A F Holstein

Publications and source records attributed to A F Holstein.

140 records · Page 8Linked to original sources
PubMedDate not supplied

Scanning electron microscopic observations on the epithelium of the human spongy urethra.

The human spongy urethras of individuals submitted to emasculation because of glans carcinoma have been studied by means of scanning electron microscopy. The luminal surface of the organ shows longitudinal folds and small glandular openings, surrounded by epithelial elements arranged in form of rosettes. Spermatozoa, partially degenerated, adhere to the epithelium. The slightly prominent apices of the superficial epithelial cells are more or less polygonal in shape and covered with short microvilli among which small granules as possible morphological expression of a secretory activity are detectable. Only seldom microplicae, intermingled with microvilli, can be observed. Additionally, some apices appear swollen and protrude into the lumen. Such a pattern may be escalated so that a cell seems to transform itself into a globular mass and then is expulsed from the epithelial surface. Sometimes an epithelial cell appears empty of its contents: only the crumpled plasmalemma remains. This may represent the morphological expression of an apocrine or holocrine secretory activity of the superficial epithelium. In few cases, the proximal portion of the spongy urethra shows small groups of ciliated elements.

Aged↗
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Neuron-specific enolase-like immunoreactivity in human Leydig cells.

Using the peroxidase anti-peroxidase immunocytochemical technique, neuron-specific enolase (NSE)-like immunoreactivity (NSE-LI) was revealed in Leydig cells of adult human testes at the light microscopic level. Differences in the NSE staining intensity were observed between the individual Leydig cells, separate cell groups within a testis and between the testes of individual patients. Together with the already established substance P-like immunoreactivity (SP-LI), the results obtained provided further evidence for the possible neuroectodermal origin of human Leydig cells and their presumable relation to the APUD- or the Diffuse Neuroendocrine System (DNES).

Adult↗
PubMedDate not supplied

Combination of alkaline phosphatase anti-alkaline phosphatase (APAAP)- and avidin-biotin-alkaline phosphatase complex (ABAP)-techniques for amplification of immunocytochemical staining of human testicular tissue.

An amplification procedure was developed for the visualization of antigens in human testis using monoclonal antibodies against desmin and vimentin. The technique combines the high sensitive and specific APAAP- and ABAP-methods. Depending on the quality of the antibodies used and the processing of the material prior to the immunocytochemical staining the amplification technique may be applied either as a single APAAP and ABAP- or as a double APAAP and ABAP-combination. Especially after the double amplification reaction a distinct increase of the staining intensity of the vimentin- (in Sertoli cells, myofibroblasts of the lamina propria, and fibroblasts of the interstitium) and desmin- (in myofibroblasts of the lamina propria and smooth muscle cells of the blood vessels) like immunoreactivity was observed. If different diazonium salts were used for the visualization of the alkaline phosphatase activity (e.g. Fast Red TR Salt, Fast Blue BB Salt) desmin- and vimentin-like immunoreactivity can be demonstrated in the same tissue section in a double sequential staining approach. For double staining, the alkaline phosphatase technique may be combined successfully with a technique or a combination that uses peroxidase as a marker.

Alkaline Phosphatase↗
PubMedDate not supplied

Neuroendocrine marker substances in human Leydig cells--changes by disturbances of testicular function.

A number of neuroendocrine and neuronal markers were demonstrated in Leydig cells of the testes of 18 men aged between 20 and 81 years. Tissue sections were divided into five groups, i.e. carcinoma of the prostate (control cases; n = 4), seminoma (n = 8), anti-androgen therapy (n = 3), oestradiol therapy (n = 2) and cryptorchidism (n = 1). The following substances were immunocytochemically tested: the monoamine synthesizing enzymes tyrosine hydroxylase, aromatic L-amino acid decarboxylase, dopamine-beta-hydroxylase and phenylethanolamine-N-methyltransferase, the indolamine serotonin, the calcium-binding proteins parvalbumin, calbindin and S-100 protein, the microtubule associated protein-2, as well as neurofilament protein 200, synaptophysin, neuron specific enolase, substance P and chromogranin A + B. All these substances were found in Leydig cells of all sections independently of the pathological changes of the testes. Compared with the control cases, all the other groups showed a significantly weaker immunoreactivity for all markers. The uniformity of staining among the different antibodies allows the deduction that these neuroactive peptides may belong to a basic equipment of Leydig cells probably stabilizing their function in an autocrine manner. On the other hand, Leydig cells themselves seem to be a stable structural component of the testis, which are not essentially involved in the pathogenesis of the disturbances mentioned above.

Adult↗
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Segmental angioarchitecture of the testicular lobule in man.

There is a close correlation between the angioarchitecture of the human testis and its inner subdivision into testicular lobules. Serial sections from paraffin and epon-embedded testicular tissue were used to examine the angioarchitecture of the human testis, and computer-aided 3-D-reconstruction was used to demonstrate the correlation between blood vessels and tissue organization. The recurrent arteries arise from the centripetal arteries, and run in the central axis of the testicular lobule. At regular intervals of on average, 300 microns the segmental arteries arise from the recurrent artery, which supplies segments of the testicular parenchyma perpendicular to the long axis of the testicular lobules. Within such a segment, the segmental artery supplies the microvasculature, which is partly surrounded by Leydig cells and partly stands in close contact with the wall of the seminiferous tubules. The venous drainage occurs through the intralobular veins, which run to the periphery of the lobule (towards the septum). These veins lead into the septum and there they join the collecting veins. A lobule can have several segments depending on its size. The base of such a tissue segment is directed towards the septum whereas the top is directed towards the centre of the lobule. Sections of several seminiferous tubules can be found in such a segment. The flow of blood from the arterial to the venous side of the testicular circulation occurs radially from the centre of the lobule to the septum.

Arteries↗
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Microvasculature of the human testis in correlation to Leydig cells and seminiferous tubules.

The microvasculature of the human testis is closely related to the Leydig cells and the seminiferous tubules. Semi-thin sections of testicular tissue serve as a basis for the computer-aided 3-D reconstruction of the microvasculature, the seminiferous tubules and the Leydig cells. After vascular perfusion with glutaraldehyde (5.5%) and paraformaldehyde (4%), it is possible by means of light and electron microscopy, to analyse the organization of the capillaries between the Leydig cells (inter-Leydig cell capillaries) as well as of those within the lamina propria (intramural capillaries). These arise from arterioles, deriving from branches of the segmental arteries. The capillaries ramify between the Leydig cells and run either semi-circumferentially around the seminiferous tubules (peritubular capillaries) or penetrate the lamina propria of the neighbouring tubules. This is the beginning of the intramural capillary which after leaving the tubular wall continues to a further capillary path. Consequently, the microvasculature of the human testis with regard to the seminiferous tubules is subdivided into afferent, intramural and efferent capillaries. Leydig cell clusters are present on both the arterial and the venous sides of the microvasculature.

Capillaries↗
PubMedDate not supplied

Neuroendocrine characteristics of human Leydig cell tumours.

The neuroendocrine nature of a subset of Leydig cells has already been established. The present investigation deals with neuroendocrine characteristics of Leydig tumour cells. A number of neuroendocrine and neuronal markers were demonstrated in Leydig cell tumours of 7 men aged 25-41 years. The following substances were immunocytochemically tested in Leydig tumour cells: the monoamine-synthesizing enzymes tyrosine hydroxylase and aromatic L-amino acid decarboxylase, the indoleamine serotonin, the calcium-binding protein parvalbumin, the microtubule associated protein-2, neurofilament protein 200, synaptophysin, neuron specific enolase, substance P and neuronal nitric oxide synthase (NOS). Compared to the normal interstitial cells beyond the tumours, all neoplastic cells showed a significantly weaker immunoreactivity for nerve cell markers as well as for testosterone and cyclic guanosine monophosphate (cGMP), which is usually accumulated by nitric oxide (NO). This provides evidence for a certain dedifferentiation of Leydig tumour cells. However, these results suggest that tumourous development of Leydig cells does not include loss of neuronal phenotype. Moreover, on the assumption that 'neuronal' Leydig cells exist beside 'non-neuronal' ones in normal testicular tissue, we propose the hypothesis that 'neuronal' Leydig cells can transform to tumour cells.

Adult↗
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Induction of high titer mouse--antihuman spermatozoal antibodies by liposome incorporation of spermatozoal membrane antigens.

This is the first report of induction of high titer mouse-antihuman spermatozoal antibodies using a spermatozoal antigen incorporated in liposomes. The peptide antigens that were incorporated into pure phosphatidylcholine liposomes are known to react with the naturally occurring antibodies in sera of sterile patients. Electron microscopy and the complement-dependent glucose release tests indicated that the peptides were entrapped in the aqueous phase between the lipid bilayers in the liposome vehicles. This is in contrast to most other liposomal antigens that are expressed on the outer lipid surface. In view of the nontoxic nature of the liposomes these results could be of some interest in immunological fertility regulation trials with appropriate antigens in an allogeneic system.

Animals↗
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Preservation of testicular tissue before fixation.

An optimum evaluation of testicular tissue for diagnostic purposes is only possible by means of the semithin-section-technique, which implies fixation in glutaraldehyde/OsO4 followed by embedding in Epon. Since in clinical departments adequate fixatives are not always available, various storage conditions until further processing were tested. Testicular tissues from 5 men, who underwent orchidectomy, were stored for different periods in solutions of Ringer, 0.9% NaCl, Macrodex, Dextran, 1640 Medium or in a humid chamber either at room temperature or at 4 degrees C, subsequently fixed and then studied by means of light and electron microscopy. Under most conditions, primary spermatocytes and Leydig cells disintegrated rather quickly, while spermatogonia, spermatids and Sertoli cells without fixation were relatively well preserved up to 5 hrs. For optimum preservation the storage of testicular tissue in a humid chamber at 4 degrees C is recommended.

Aged↗
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Macrophages lysing seminoma cells in patients with carcinoma-in-situ (CIS) of the testis.

Testicles of 15 subfertile men who underwent orchidectomy because of intratubular seminoma cells resp. carcinoma-in-situ (CSI) pattern in testicular biopsy were examined by semithin sections as well as by ultrathin sections. With one exception the volume of the testicles was reduced (means = 16 ml). 6 cases (= 40%) had exclusively intratubular seminoma cells, 4 cases (= 26.6%) intratubular and interstitial seminoma cells and 5 cases (= 33.3%) a solid seminoma near the rete testis. In all patients an interstitial inflammatory infiltration as well as tubular shadows of various degree could be observed. Some tubular shadows contained macrophages in the center heavily loaded with lipid droplets. Furthermore, in two cases many seminiferous tubules could be detected which contained activated macrophages in the lumen lysing tumor cells. One of the patients had only intratubular tumor cells, whereas the other patient had a solid seminoma near the rete testis. Our data suggest that activated macrophages killing intratubular tumor cells in patients with CIS pattern of the testis resp. with an early stage of a seminoma represent a physiological immunological reaction of the host in preventing further invasive tumor growth. Tubular shadows represent the final process of macrophage activity and may explain the reduced testicular volume in patients with CIS. However, the density of the inflammatory reaction and the extent of intratubular macrophages lysing tumor cells does not correlate with a low or high risk of tumor growth.

Adult↗
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Transformed spermatocytes constituting the ejaculate of an infertile man.

In the ejaculate of an infertile man exclusively free immature germ cells were found. Electron microscopic examination of their cytology revealed some characteristics of primary spermatocytes. After having been released from the germinal epithelium, these cells, however, have developed into totally new cell forms, which finally degenerate and disintegrate.

Adult↗
PubMedDate not supplied

[Megalospermatocytes: degeneration of spermatocytes in aged human testis].

Megalospermatocytes are very large primary spermatocytes, which show a meiotic disorder in form of an asynapsis of the chromosomes. They appear as localized cell populations within the normal seminiferous epithelium and represent one or several clones of synchronously degenerating germ cells. The spatial extension of these megalospermatocyte populations is spherical to elliptical, some of them look like a section of a spiral around the longitudinal axis of the seminiferous tubule. Neighbouring megalospermatocyte populations in a segment of a seminiferous tubule show characteristic relative positions to each other: Their centers of gravity succeed one another in the longitudinal course of the tubule by distances of 40 to 85 micron. They are displaced against each other by angles between 120 degrees and 240 degrees around the longitudinal axis of the tubule. The centers of gravity of several megalospermatocyte populations, which follow each other in a segment of a tubule, show different distances from the basement membrane to the lumen of the tubule. The topographic arrangement of the megalospermatocytes in the human seminiferous epithelium obviously corresponds to an organization pattern, which is based upon the geometry of spirals, as it has been postulated for the normally proliferating seminiferous epithelium.

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[How many testicular lobules does a human testicle contain? Reexamination of an old problem].

In 20 autoptically obtained testes from men of various ages, 250-290 testicular lobules per testicle could be recognized by preparation with a stereomicroscope. The most appropriate technique was the fixation of the testes in 10% formol for at least 14 days and a following dehydration in a series of increasing concentrations of alcohol. Using other methods of fixation higher numbers of lobules were counted due to splitting of lobules into subunits. The number of the testicular lobules cannot be correlated to the volume of the testicle. When simulating a testicular biopsy in the autoptic testicle 3-5 testicular lobules are concerned.

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