Chromogranin A expression in human colonic adenocarcinoma.

The presence of CgA positive cells occuring in scattered elements or in clusters within human colonic adenocarcinomas has been documented in recent data. The number of these cases has ranged from 10% to 40% depending on the method of demonstration. The aim of this study is to assess the presence of CgA positive cells on a set of 60 tumours that, by standard histological procedures, were classified as well differentiated (n.5), moderately differentiated (n.48) and poorly differentiated (n.7) adenocarcinoma. 4-5 microm thick sections were processed by means of immunoperoxidase method using the primary CgA monoclonal antibody. Our results showed CgA positive cells in two cases of poorly differentiated and three cases of moderately differentiated adenocarcinoma. These specimens (8% of cases) showed diffuse, irregular areas of CgA immunoreactive cells as components of the neoplasm. These cases could be considerer as "mixed exocrine and neuroendocrine carcinoma" that develops from the same stem cell which differentiates into two atypical cell lines. Therefore, we suggest that to carry out a proper adenocarcinoma histological examination, and to establish a consequent therapy, not only common staining techniques but also immunohistochemical methods should be used.

Expression of metabotropic glutamate receptors in the rat and human testis.

The G protein-coupled receptor kinase type 4 mediates the homologous desensitisation of type-1 metabotropic glutamate (mGlu1) receptors and is predominantly expressed in the testis. Hence, we searched for the expression of mGlu1 or other mGlu receptor subtypes in rat and human testes. RT-PCR analysis showed the presence of mGlu1, -4 and -5 (but not -2 or -3) receptor mRNA in the rat testis. The presence of mGlu1 and -5 (but not mGlu2/3) receptor proteins was also demonstrated by Western blot analysis. In the rat testis, both mGlu1a and -5 receptors were highly expressed in cells of the germinal line. It is likely that these receptors are functional, because the agonist, (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid, was able to stimulate inositol phospholipid hydrolysis in slices prepared from rat testes. Immunocytochemical analysis of bioptic samples from human testes showed a high expression of mGlu5 receptors inside the seminiferous tubuli, whereas mGlu1a immunoreactivity was restricted to intertubular spaces. mGlu5 receptors were also present in mature spermatozoa, where they were localised in the mid-piece and tail. This localisation coincided with that of beta-arrestin, a protein that is critically involved in the homologous desensitisation and internalisation of G protein-coupled receptors. Taken collectively, these results offer the first evidence for the expression of any glutamate receptor in testes, and suggest that at least mGlu5 receptors are present and functionally active in mature human sperm.

Some considerations on the human Leydig cell (immunohistochemical observations).

The presence and functional activity of human Leydig cells were assessed at diverse stages of human gonad development in biopsies obtained from healthy controls and subjects with cryptorchidism or varicocele. In our investigation primary antibodies directed against vimentin and testosterone by immunoperoxidase technique of biotin-streptoavidin amplified system were used to analyse immunoreactive sites. The antivimentin antibody is, in general, a specific marker of cells of mesenchymal origin and also detects the presence of Leydig cells, while the antitestosterone antibody shows the functional status of these cells. The immunohistochemical examination revealed the presence of two main populations in the testes of healthy subjects: a foetal and an adult population. The former appeared during the embryonal period, remained throughout foetal life and disappeared after birth. The latter was detected just before puberty and was present for the whole fertile period. Leydig cells in testes affected by cryptorchidism or varicocele showed normal morphology when the disease did not involve intertubular connective tissue. Leydig cells disappeared or were very altered when intertubular tissue was seriously damaged. The intertubular damage was observed in some children with cryptorchidism after prolonged hormonal therapy and in some adults with long term cryptorchidism or varicocele. These observations confirm that if hormonal therapy fails to bring the testis down into the scrotum surgery is required at first years of the life and that in selected cases the varicocele vascular alteration must be surgically corrected.

Immunohistochemical study of intrinsic innervation in the human pancreas.

Immunohistochemical identification of nerve structures in the human pancreas was achieved using immunohistochemical techniques. The antibodies used are specific for the myelin present in the periphery of ganglia and pregangliar nerve fibers, and for adrenergic neurotransmitters as well. In this study we observed the presence of numerous ganglia and nerve fibers in the periacinar tissue and near vascular structures. Adrenergic neurotransmitters were detected within pancreatic islets. These results would reveal that the exocrine pancreatic component is mainly innervated by parasympathetic ganglia and pregangliar fibers, as observed in the alimentary canal. Diversely, the endocrine component seems to be regulated by nonmyelinic orthosympathetic postgangliar fibers and parasympathetic fibers forming the perivascular plexus. The morphology and distribution of nerve structures in the pancreas recall those of the alimentary canal because these organs share the same embryogenetic derivation.

Intermediate filaments of human Sertoli cells in germinal alterations.

Immunohistochemical techniques were used to examine testis biopsy specimens in subjects of different ages, in whom histological examination of the seminiferous tubules revealed a reduction in number, immaturity or absence of germinal elements. Our aim was to detect changes in the expression of the vimentin and cytokeratin (8-18-19) intermediate filaments in Sertoli cells. The use of anti-vimentin antibodies demonstrated intense Sertoli cell positivity in all the cases studied, confirming that germinal alterations do not interfere with the expression of these filaments. The Sertoli cells of the subjects affected by pathological conditions also reacted positively to anti-cytokeratin antibodies. This finding was constant in all the testes, showing evident signs of germinal immaturity. In contrast, anti-cytokeratin positivity was not observed in the control specimens after the pre-pubertal stage. Our findings show that persisting co-expression of vimentin and cytokeratin filaments in the Sertoli cells of productive subjects may be a marker of germinal cell degeneration.

Morphological aspects of the epithelium of the trigone of the human urinary bladder: immunohistochemical findings and histogenetic features.

An immunohistochemical method was used to study the structural characteristics of the epithelium of the bladder trigone in 20 premenopausal women. Fragments of mucosa were obtained by cystoscopy from the trigones of the 20 subjects. Monoclonal antibodies (34 beta E12 and 34 beta B4) were used to demonstrate the presence of stratified squamous epithelium-specific cytokeratins in these samples. Based on our results, we believe that the frequent finding of stratified squamous epithelium in the trigone of the female bladder is a consequence of the stimulation of estrogen, which is believed to act on the trigone, but not on the rest of the bladder. This may be due to the complex histogenesis of the bladder. Embryologically, the trigone derives from the mesoderm, while the rest of the bladder derives from the endoderm.

[Morpho-functional considerations on the annulate lamellae of the human oocyte]. / Considerazioni morfo-funzionali sulle lamelle anulate dell'ovocita umano.

Ovarian biopsy specimens from four girls in complete remission state of acute lymphoblastic leukemia, previously treated with antiblastic chemotherapy for about three years, were examined by means of electron microscopy. The normal morphology of residual follicles and, in particular, the observation that annulate lamellae were always present in oocytes of primordial and primary follicles, gave the chance to consider a possible functional role and to suggest a prognosis for future fertility. The similarities in structure to the nuclear envelope and the relation between annulate lamellae and other cellular organelles (especially endoplasmic reticulum and ribosomes) suggest that lamellae may be involved in the release, assembly or activation of stored development information. The annulate lamellae could prove to be an important organelle that participates in the regulation of gene expression. Therefore, the presence of annulate lamellae in oocytes of primordial and primary follicles may present the possibility of a normal development for these cells in which long-lived gene products are synthesized and transported to the cytoplasm for storage and use later in development. The above hypothesis, while leads to consider these patients at risk for low fertility and early menopause, does not consider them as definitely infertile.

Structural and ultrastructural study of the ovary in childhood leukemia after successful treatment.

Ovarian biopsy specimens from ten girls (three postmenarcheal) who had undergone antiblastic treatment for acute lymphoblastic leukemia (ALL) and were in complete remission were examined by light microscope. The biopsy specimens from four of these patients (three postmenarcheal) were also observed by electron microscope. The structural and ultrastructural analysis showed a reduction in the number of follicles which were otherwise normal. No follicles were found in the thin sections from two of the three postmenarcheal girls, whereas normal follicles were observed in the third. The cortical stroma showed moderate to severe signs of fibrosis and changes of capillaries. All of these alterations were more evident in patients where ALL was diagnosed at an older age and this finding suggests that they are at a higher risk for low fertility or early menopause.

Ultrastructural changes of the pulmonary parenchyma after experimentally induced endotoxic shock in dogs with and without drug protection.

The authors describe the ultrastructural alterations of the pulmonary parenchyma produced in dogs by endotoxic shock, and they examine the effects that a 'secretolytic' drug (bromexine) has in modifying those changes. In the animals under shock there is a complete breakdown of the normal structure of the pulmonary parenchyma. According to the authors, these lesions are caused by the damage of the lining layer and of the cells which produce the constituents of the surfactant system. In dogs under shock and treated with bromexine the authors have seen a better organization of the pulmonary parenchyma: the cellular limits of the pneumocytes of types I and II were more clearly defined and the osmiophilic bodies were increased both in number and volume. The authors conclude that the damage of the lining layer and of the pneumocytes of type II plays an important role in the development of the ARDS and they say that bromexine can improve clinical and morphological aspects of that syndrome.

Fine structure of the epithelium of the human ejaculatory duct.

Normal human ejaculatory ducts were examined by scanning and transmission electron microscopy. The lumen, which shows an irregular shape due to complex mucosal folds, is lined by a simple secretory epithelium. A strong cell polymorphism has been observed concerning cell height, nuclear shape, and amount of secretory organelles. Apart from small differences, the epithelium appears to be identical to that of the seminal vesicle and deferential ampulla. These observations demonstrate that the human ejaculatory duct is not only a passage for semen, but also contributes to its formation.