Histology and histopathology Vol.14, nº 2 (1999)

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Open Access
lmmunohistochemical analysis for cell proliferation-related protein expression in small cell carcinoma of the esophagus a comparative
(Murcia : F. Hernández, 1999) Okudela, K.; Ito, T.; Kameda, Y.; Nakamura, N.; Kitamura, H.
Small cell carcinoma is a rare neoplasm in the esophagus. To evaluate cell proliferation activity and its underlying mechanisms in this tumor, we examined immunohistochemically 5 cases of small cell carcinoma of the esophagus (SCCE) for expressions of tumor suppressor proteins, oncoproteins and cell proliferation markers including p53, p21WAF1/C1P1r,e tinoblastoma (Rb) protein, bcl-2, Ki-67 and PCNA, and compared the results with those of 5 cases of small cell carcinoma of the lung (SCCL) and 10 cases of squamous cell carcinoma of the esophagus (SQCE). The prevalence and labeling index of p53-immunoreactivity tended to be higher in SCCE (415; 56.6%) and SCCL (415; 79.9%) than in SQCE (6110; 48.8%). Expression of p21wAFl/C1P1w as observed in 2 of 10 cases of SQCE. In contrast, its expression could not be detected in any cases of SCCE and SCCL examined. Expression of Rb protein was observed in 9 out of 10 cases of SQCE, but not in any cases of SCCE and SCCL. SCCE and SCCL showed more frequent and intense immunoreactivity for bcl-2 than SQCE. In expression of cell proliferation markers (Ki-67 and PCNA), no remarkable difference was observed among SCCE, SCCL and SQCE. These results suggest that SCCE and SCCL could share some genetic alternations including mutation of p53, loss of Rb gene and overexpression of bcl-2, and these may be related to the similar biological potentials between the two. Futhermore, SCCE was different from SQCE in expression of Rb protein and bcl-2, and these two types of esophageal carcinoma could arise through different molecular mechanisms.
Open Access
Induction of NADPH diaphoraselnitric oxide synthase in the spinal cord motor neurons of rats following a single and multiple non-penetrative blasts
(Murcia : F. Hernández, 1999) Kaur, C.; Singh, J.; Moochhala, S.; Lim, M.K.; Lu, J.; Ling, E. A.
The present study has demonstrated the induction of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) reactivity and nitric oxide synthase-like immunoreactivity (NOS-LI) in the ventral horn motoneurons of the spinal cord in rats subjected to a single or multiple underground, or a single surface blast. Both enzyme activities were first detected in some motoneurons in laminae V111 and IX of Rexed, 3 hours after the blast. Some NADPH-d and NOS-L1 positive neurons were also distributed in laminae V1 and V11. The number and intensity of the labelled cells appeared to increase progressively, peaking at 2-3 days after the blast but were drastically reduced thereafter, so that at 7 days after the blast only a few positive neurons were observed. In rats killed at 2 weeks and in longer surviving intervals, i.e. up to 1 month, NADPH-d/NOS reactivity in the ventral horn motor neurons had diminished. The functional significance of the transient expression of neuronal NADPH-d/NOS after the blasts remains uncertain, although from a speculative point of view, the induction of these enzymes probably would reflect an increased production of nitric oxide (NO). In view of the lack of atrophic changes in most, if not all, of motor neurons, it is suggested that the increased levels of NO production after the blast injury may be involved in a neuroprotective function.
Open Access
T-2 toxin-induced acute skin lesions in 3 Wistar-derived hypotrichotic WBNIILA-Ht rats
(Murcia : F. Hernández, 1999) Albarenque, S.M.; Shinozuka, J.; Iwamoto, S.; Nakayama, Hiroyuki; Doi, K.
Acute lesions in the dorsal skin topically applied with T-2 toxin (10 p1 of 0.5 mg/ml-solution to lcm2) were examined in Wistar-derived hypotrichotic WBNIILA-Ht rats up to 24 hours after treatment (24HAT). In the epidermis, depression of basal cell proliferating activity was detected at 3HAT by immunostaining for proliferating cell nuclear antigen (PCNA), and the percentage of PCNA-positive basal cells decreased thereafter. At 12HAT, in addition to intracytoplasmic edema of spinous cells, acidophilic degeneration of basal cells characterized by shrinkage of cell body with acidophilic cytoplasm and pyknotic or karyorrhectic nuclei became prominent. Most of these nuclei were positive for TUNEL which is a widely used immunostaining for the in situ detection of fragmented DNA, i.e. apoptosis, and the percentage of TUNELpositive basal cells increased thereafter. The nuclei of these basal cells also showed ultrastructural changes characteristic for apoptosis. On the other hand, in the dermis, infiltration of inflammatory cells including mast cells started at 3HAT and increased thereafter. In addition, capillary and small vessel endothelial degeneration developed at 6HAT and progressed thereafter. These results suggest that T-2 toxin directly affects the epidermis and produces apoptosis in basal cells.
Open Access
Cytokeratin expression patterns in normal and malignant urothelium, a review of the biological and diagnostic implications
(Murcia : F. Hernández, 1999) Southgate, J.; Harnden, P.; Trejdosiewicz, L.K.
The cytokeratins are the intermediate filament proteins characteristic of epithelial cells. In human cells, some 20 different cytokeratin isotypes have been identified. Epithelia1 cells express between two and ten cytokeratin isotypes and the consequent profile which reflects both epithelial type and differentiation status may be useful in tumour diagnosis. The transitional epithelium or urothelium of the urinary tract shows alterations in the expression and configuration of cytokeratin isotypes related to stratification and differentiation. In transitional cell carcinoma, changes in cytokeratin profile may provide information of potential diagnostic and prognostic significance. The intensification of immunolabelling with some CK8 and CK18 antibodies may underly an active role in tumour invasion and foci of CK17-positive cells may represent proliferating populations. Loss of CK13 is a marker of grade and stage and de novo expression of CK14 is indicative of squamous differentiation and an unfavourable prognosis. However, perhaps the most important recent finding is the demonstration that a normal CK20 expression pattern is predictive of tumour non-recurrence and can be used to make an objective differential diagnosis between transitional cell papilloma and carcinoma. This review will consider cytokeratin expression in urothelium and discuss the application of cytokeratin typing to the diagnosis and prognosis of patients with TCC.
Open Access
Detection and significance of minimal residual disease in colorectal cancer
(Murcia : F. Hernández, 1999) Merrie, A.E.H.; Yun, K.; van Rij, A.M.; McCall, J.L.
Colorectal cancer (CRC) is one of the most common causes of cancer death in the developed world. Although the primary treatment for CRC is surgical, disease relapse due to minimal residual disease (MRD) following apparently curative surgery occurs in up to fifty percent of patients. Most patients who develop overt metastases beyond the regional lymph nodes eventually die of the disease. At present adjuvant chemotherapy is used to improve survival in patients with metastases to regional lymph nodes demonstrated by routine histopathology with no other evidence of spread. The ability to identify metastatic disease at an earlier stage could be of considerable benefit in directing adjuvant therapy to patients at high risk of relapse who are not identified by current methods. Several techniques have been developed for the detection of MRD, including immunohistochemical and molecular methods, however their role in clinical practise is not yet established. The purpose of this paper is to review these techniques and their potential clinical use in the management of CRC.
Open Access
Cholecystokinin, acting through the A receptor subtype, stimulates the proliferative activity of adrenocortical cells and thymocytes in the ra
(Murcia : F. Hernández, 1999) Malendowicz, L.K.; Tretjer, M.; De Caro, Raffaelle; Jedrzejczak, N.; Brelinska, R.; Markowska, A.; Nussdorfer, G.G.; Nowak, M.
Cholecystokinin (CCK) is a multifunctional regulatory peptide, which acts through two main subtypes of receptors, named CCK-A and CCK-B. Evidence indicates that CCK modulates cell proliferation in various tissues in a paracrine manner, and proofs are available of the presence of CCK in both adrenal glands and thymus. Hence, we have investigated the possible mitogenic action of this peptide on these two tissues, by evaluating the %o of metaphase-arrested cells after vincristin injection (mitotic index). The systemic administration of CCK (three subcutaneous injections of 20 nmollkg, 28, 16 and 4 h before the sacrifice) increased the mitotic index in both the outer adrenal and thymus cortexes of immature (20-day-old) rats and the enucleated adrenal gland of adult (2-month-old) animals at day 5 and 8 of regeneration. The simultaneous administration of equimolar doses of a selective CCK-A receptor antagonist blocked the effect of CCK, while a CCK-B antagonist was ineffective. These findings indicate that CCK exerts a marked CCK-A-mediated proliferogenic effect on both adrenal cortex and thymus in the rat, the physiological relevance of which, however, remains to be demonstrated. In fact, the administration of the CCK-A antagonist alone was ineffective, thereby casting doubts on the role played by endogenous CCK in the maintenance and stimulation of adrenal and thymus growth.
Open Access
Cytological and functional aspects of telornere maintenance
(Murcia : F. Hernández, 1999) Dandjinou, A.T.; Dionne, I.; Gravel, S.; LeBel, C.; Parenteau, J.; Wellinger, R.J.
The fact that eukaryotic chromosomes are linear poses a special problem for their maintenance: the natural ends of chromosomes must be distinguished from ends generated by chromosomal breakage and somehow, the chromosome ends must also be fully replicated to maintain their integrity. Telomeres, the complex structures at the ends of chromosomes are thought to be instrumental for both of these functions. However, recent insights in telomere biology suggest that these terminal structures do much more than just fulfil1 these two basic functions. Cytological data demonstrate that telomeres may play leading roles in chromatin organization and nuclear architecture during mitosis and meiosis. Moreover, non-functional telomeres may lead to genetic instability, a common prelude to cancer. Here, we review the basic functions of telomeres during chromosome replication and discuss the cytological aspects of telomere function during mitosis and meiosis.
Open Access
Ri bonuclease-gold labels proteoglycancontaining cytoplasmic granules and ribonucleic acid-containing organelles - A survey
(Murcia : F. Hernández, 1999) Dvorak, A. M.; Morgan, E.S.
An enzyme-affinity-gold method to detect RNA in routinely prepared ultrastructural samples is based on the affinity of the gold-coupled enzyme, ribonuclease, for its substrate, RNA. High concentrations of a known inhibitor of RNase, heparin, are uniquely located in human mast cell granules. Specific labeling for the presence of heparin in these structures was determined using the RNase-gold (R-G) reagent based on the RNase inhibitor property of heparin. This property was used to probe for the presence of proteoglycans (PG) known to be present in a wide variety of ultrastructural samples, none of which contain heparin. In addition to known subcellular sites of RNA, the R-G reagent was shown to bind to PG-rich cytoplasmic granules in a wide variety of leukocytes and secretory cells of epithelial, endocrine, and neuroendocrine origin. This newly recognized property was used to image the changing distribution of labeled PGs during cellular maturation, secretion, and recovery from secretion of secretory cells in vivo, ex vivo, in vitro and in isolated, biochemically defined guinea pig basophil granule preparations.
Open Access
Cellular and molecular alterations of osteoblasts in human disorders of bone formation
(Murcia : F. Hernández, 1999) Marie, P.J.
Osteogenesis is a complex process characterized sequentially by the committment of precursor cells, the proliferation of osteoprogenitor cells, the differentiation of pre-osteoblasts into mature osteoblasts and the apposition of a calcified bone matrix. Recent advances in cell and molecular biology have improved our knowledge of the cellular and molecular mechanisms controlling the different steps of bone formation in humans. Using ex vivolin vitro studies of disorders of bone formation, we showed that the recruitment of osteoprogenitor cells is the most important step controlling the rate of bone formation in both rodents and humans. Accordingly, treatments stimulating osteoblast recruitment were found to increase bone formation in experimental models of osteopenic disorders. Using models of human osteoblastic cells, we identified the profile of phenotypic markers expressed during osteoblast differentiation, and found that hormones and growth factors control osteoblastic cell proliferation and differentiation in a sequential and coordinate manner during osteogenesis in vitro. Our recent evaluation of the phenotypic osteoblast abnormalities induced by genetic mutations in the G,a and FGFR-2 genes led to the characterization of the role of these genes in the alterations of osteoblast proliferation and differentiation in humans. These studies at the histological, cellular and molecular levels provided new insight into the mechanisms that are involved in pathological bone formation in humans. It is expected that further determination of the pathogenic pathways in metabolic and genetic abnormalities in human osteoblasts will help to identify novel target genes and to conceive new therapeutic tools to stimulate bone formation in osteopenic disorders.
Open Access
Effects of long-term treatment with ethanol on the ultrastructure of the golden hamster parathyroid gland
(Murcia : F. Hernández, 1999) chen, H.; Hayakawa, D.; Emura, S.; Tamada, A.; Jamali, M.; Ozawa, Y.; Taguchi, H.; Yano, R.; Ohtake, N.; Shoumura, S.
The ultrastructure of the parathyroid gland in golden hamsters after long-term treatment with ethanol was studied. Male hamsters of experimental groups were given ethanol at the concentration of 7% for 3 and 5 months with food and water freely available. In the ethanol-treated hamsters, the Golgi complexes associated with many prosecretory granules were well developed and many secretory granules were located near the plasma membrane as compared with those of the control animals. Exocytotic events were observed in 5-month-treated animals. These findings suggest that the secretory activity of the parathyroid gland is stimulated after long-term treatment with ethanol.
Open Access
Ultrastructural and biochemical analysis of epidermal xanthophores and dermal chromatophores of the teleost Sparus aurata
(Murcia : F. Hernández, 1999) Ferrer, C.; Solano, F.; Zuasti, A.
We have studied the pigmentary system of the teleost Sparus aurata skin by electron microscopy and chromatographic analysis. Under electron microscopy, we found the dermis to contain the three major types of recognized chromatophores: melanophores, xanthophores and iridophores. Melanophores were more abundant in the dorsal region, whereas the iridophores were more abundant in the ventral region. The most important discovery was that of epidermal xanthophores. Epidermal xanthophores were the only chromatophores in the epidermis, something only found in S. azirara and in a teleost species living in the Antartic sea. In contrast, the biochemical analysis did not establish any special characteristics: we found pteridine and flavin pigments located mostly in the pigmented dorsal region. Riboflavin and pterin were two of the most abundant coloured pigment types, but other colourless pigments such as xanthopterin and isoxanthopterin were also detected.
Open Access
Epidermal growth factor receptor EGFR biology and human oral cancer
(Murcia : F. Hernández, 1999) Todd, R.; Wong, D.T.W.
Dysregulation of the epidermal growth factor receptor (EGFR) is one of the most frequently studied molecular events leading to oral carcinogenesis. Overexpression of EGFR is a common event in many human solid tumors. Elevated levels of EGFR mRNA in human cancer occur with and without gene rearrangement. Structural alterations in the receptor can also result in the dysregulation of the EGFR pathway. EGFR overexpression without gene re-arrangement is frequently observed in human oral cancers. However, little is known whether structural alterations in the receptor or perturbations in the EGFR pathway contribute to oral carcinogenesis. Several preliminary studies suggest that EGFR-targeted therapeutic approaches might be successful in controlling oral cancer.
Open Access
Neutrophils as a source of cytokines in inflammation
(Murcia : F. Hernández, 1999) Matsukawa, A.; Yoshinaga, M.
The recruitment of neutrophils into inflammatory foci is a fundamental process observed in inflammation. The function of neutrophils has long been regarded only as an effector cell that kills the invading pathogens. Recent evidence has demonstrated that neutrophils are capable of producing inflammatory cytokines. The findings are, however, mainly based on the findings obtained in vitro. It has not been fully elucidated if neutrophils could synthesize and secrete cytokines in vivo. Animal models of inflammation are essential to address the issue and provide insight into the involvement of neutrophils in producing cytokines.
Open Access
Ultrastructural localization of acetylcholinesterase AChE activity in the chicken Harderian gland
(Murcia : F. Hernández, 1999) Hiramatsu, K.; Ohshima, K.
Localization of acetylcholinesterase (AChE) was investigated in the chicken Harderian gland at the electron microscopic level. Nerve cells in the pterygopalatine ganglion showed AChE activity. They had a pale and large nucleus which was round or oval in shape. Reaction product of AChE was detected between the nuclear envelopes, in the cisterna of rough endoplasmic reticulum and the lumen of the Golgi lamellae, and on the plasma membrane of the nerve cell. In the interstitium of the gland, nerve fibers showing AChE activity were easily found. They were often seen in the perivascular space and between plasma cells. These neve fibers had varicosities in contact with plasma cells and the endothelium or the smooth muscle fiber of the blood vessels. AChE-positive varicosities or terminals contained many small clear vesicles (about 50nm in diameter) and a few large dense-cored vesicles (about 100 nm in diameter). No contacts of nerve fibers with acinar cells or the ductal epithelium were observed in the present study. Our data indicate that cholinergic nerves play distinct roles in the regulation of the immune function of the chicken Harderian gland.
Open Access
Regulation of tumor cell invasion by extracellular matrix
(Murcia : F. Hernández, 1999) Crowe, D.L.; Shuler, C.F.
The ability of malignant tumor cells to invade normal surrounding tissue contributes in large part to the significant morbidity and mortality of these cancers. The process of invasion involves adherence of the tumor cells to the extracellular matrix (ECM), degradation of matrix components, and movement of the cell body. Attachment to ECM molecules is mediated by the integrin family of extracellular matrix receptors. Integrins are a large family of heterodimeric proteins which transduce a variety of signals from the ECM. Ligand occupancy is critical for activation of integrin signaling. This signaling may occur via several different pathways. One of the best characterized of these pathways is the mitogen activated protein kinase (MAPK) cascade. This serial phosphorylation of substrate proteins terminates in activation of transcription factors which regulate expression of target genes. Many of these genes are critical for extracellular matrix degradation or cell migration. Among these are the matrix metalloproteinases (MMPs), a large family of ECM-degrading enzymes. Regulatory elements in the promoters of MMPs have been characterized, providing insight into how MMP expression is controlled. This review focuses on mechanisms by which the ECM regulates tumor cell invasion through integrin signaling via the MAPK pathway using MMP expression as the model.
Open Access
Hepatotoxicity induced by the anti-oxidant food additive, butylated hydroxytoluene BHT, in rats. An electron microscopical study
(Murcia : F. Hernández, 1999) Safer, A.M.; Al-Nughamish, A.J.
The anti-oxidant food additive, butylated hydroxytoluene (BHT), was fed to Sprague-Dawley rats at three concentrations: 0.2%, 0.4% and 0.8% for periods of 6, 12, 18 and 24 weeks, and the results were compared with corresponging groups treated with a potent carcinogen, 7,12-dimethylbenz[a]anthracene (DMBA) groups, with olive oil, and with untreated control groups. BHT resulted in a significant increase in liver weight. The liver cells presented gradual vacuolization, cytoplasmic disintegration, "moth-eaten" appearance, ballooning degeneration, hepatocellular necrosis, aggregation of chromatin material around the periphery of the nuclear envelope, SER proliferation, RER clumping with broken cisternae, withered and autolyzed mitochondria, augmentation of lipid droplets and glycogen depletion. On the other hand, there was no sign of tumorigenicity. Whether or not BHT acts as a carcinogen in long-term administration may depend not only upon the organ system examined, but also on the strain of the animal used.
Open Access
The molecular pathology of Barrett's esophagus
(Murcia : F. Hernández, 1999) Werner, M.; Mueller, J.; Walch, A.; Hofler, H.
The incidence of adenocarcinoma of the distal esophagus is rapidly increasing in the Western world. The histopathological sequence of (Barrett's) metaplasia, which develops as a consequence of chronic reflux, to dysplasia and then to carcinoma is well established for these tumors. In Barrett's esophagus a variety of molecular changes have been characterized and correlated with tumor initiation and progression. Among the early changes in premalignant stages of metaplasia are alterations of the transcripts of FHIT, a presumptive tumor suppressor gene which spans the common fragile site FRA3B. Mutations of p53 seem to accumulate mainly in the transition from low to high grade dysplasia. Inactivation of other tumor suppressor genes by mutation (APC, p16) or hypermethylation (p16) as well as amplification of oncogenes such as cerbB2 are relatively late events in the development of adenocarcinoma. Among the phenotypic changes in Barrett's esophagus are an expansion of the Ki67 proliferation compartment which correlates with the degree of dysplasia. Moreover, accumulation of rabll molecules which are involved in membrane trafficking has been reported to be specific for the loss of polarity seen in low grade dysplasia. Reduced expression of the cadherinlcatenin complex as well as increased expression of various proteases develop chiefly in invasive carcinomas. Despite the progress that has been made in the identification of molecular markers in Barrett's carcinoma, to date the histopathogical diagnosis of high grade dysplasia in endoscopic biopsies remains the best predictor of invasive cancer. Immunohistochemistry applying a panel of antibodies including p53, Mib-l or rabll can be helpful to diagnose regenerative metaplastic epithelium or low and high grade dysplasia.
Open Access
A putative role for calpain in demyelination associated with optic neuritis
(Murcia : F. Hernández, 1999) Banik, N.L.; Shields, D.C.
Calcium activated neutral proteinase (calpain) is an endopeptidase present in the central nervous system which degrades myelin proteins. To examine the role of calpain in demyelination associated with optic neuritis, immunocytochemical expression of calpain was evaluated in Lewis rats with experimental optic neuritis. Calpain expression was increased in activated microglia, infiltrating macrophages, activated T cells, and reactive astrocytes in experimental optic neuritis compared to controls. Calpain activity and translational expression were also examined by Western blotting studies measuring the extent of myelin protein degradation, calpain-specific fodrin proteolysis, axonal neurofilament degradation, and calpain proenzyme content. Results showed myelin associated glycoprotein and 68 kD neurofilament protein levels were significantly decreased while calpain translational expression and calpain-autolyzed fodrin levels were significantly increased in experimental optic neuritis compared to controls. Thus, increased activity and translational expression of calpain in optic neuritis may be integral to the pathogenesis of this disorder.
Open Access
Antinuclear antibody-keratinocyte interactions in photosensitive cutaneous lupus erythematosus
(Murcia : F. Hernández, 1999) Furukawa, F.
Autoimmune diseases are characterized by various circulating autoantibodies, especially antinuclear antibodies (ANA). It has been a long-standing issue as to whether andlor how ANA interact with epidermal cells to produce skin lesions. Of these ANA, the anti-SS-AIR0 antibody is the most closely associated with photosensitivity in patients with systemic lupus erythematosus (SLE) and its subgroups, including subacute cutaneous lupus erythematosus (SCLE) and neonatal lupus erythematosus (NLE). SS-A/Ro antigens are present in the nucleus and cytoplasm, and interestingly, ultraviolet B (UVB) light translocates these antigens to the surface of the cultured keratinocytes. Thus, anti-SS-AIR0 antibodies in the sera can bind to the relevant antigens expressed on the UVB-irradiated keratinocyte surface, and have been speculated to be an important inducer of antibody-dependent keratinocyte damage. This interaction between the anti-SS-A/Ro antibodies and UVBirradiated keratinocytes may induce the skin lesions through a cytotoxic mechanism. This review will focus on the involvement of antibody-dependent cellular cytotoxicity in the pathogenesis of the skin lesions observed in photosensitive cutaneous lupus erythernatosus.
Open Access
Human osteoclast ontogeny and pathological bone resorption
(Murcia : F. Hernández, 1999) Athanasou, N.A.; Sabokbar, A.
Monocytes and macrophages are capable of degrading both the mineral and organic components of bone and are known to secrete local factors which stimulate host osteoclastic bone resorption. Recent studies have shown that monocytes and macrophages, including those isolated from neoplastic and inflammatory lesions, can also be induced to differentiate into cells that show all the cytochemical and functional characteristics of mature osteoclasts, including lacunar bone resorption. Monocyte/macrophage- osteoclast differentiation occurs in the presence of osteoblasts/bone stromal cells (which express osteoclast differentiation factor) and macrophage-colony stimulating factor and is inhibited by osteoprotegerin. Various systemic hormones and local factors (eg cytokines, growth factors, prostaglandins) modulate osteoclast formation by controlling these cellular and humoral elements. Various pathological lesions of bone and joint (eg carcinomatous metastases, arthritis, aseptic loosening) are associated with osteolysis. These lesions generally contain a chronic inflammatory infiltrate in which macrophages form a significant fraction. One cellular mechanism whereby pathological bone resorption may be effected is through generation of increased numbers of bone-resorbing osteoclasts from macrophages. Production of humoral factors which stimulate mononuclear phagocyte-osteoclast differentiation and osteoclast activity is also likely to influence the extent of pathological bone resorption.