Histology and histopathology Vol. 9, nº 3 (1994)

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Open Access
The selective anticancer activity of the endogenous inhibitor of calcium-activated neutral proteinase. A histological,...
(Murcia : F. Hernández, 1994) Logothetou-Rella, H.
The cytotoxicity of an endogenous inhibitor of calcium-activated neutral proteinase (CANP-I) was evaluated using various mammalian tumor-derived cell lines and human cell cultures. The inhibitor was selectively cytotoxic to human tumor cells from lung, bladder, melanoma and chronic myeloid leukemia tissues, in a dose-dependent manner, and was also cytotoxic to Walker rat tumor cells. The inhibitor was not cytotoxic to normal human, urothelial, fallopian tube, liver and resting white blood cells. Cytological examination of the treated malignant cells revealed cells with vacuolated cytoplasm, pyknotic, hyperchromatic nuclei and membranous, granular haematoxylinophilic extracellular matrix. The use of the inhibitor on urothelial tumor tissues caused great exfoliation of necrotic cells while not affecting normal urothelial tissues. When the inhibitor was tested on mixed cell cultures, consisting of normal and malignant cell clones, a selective cytotoxicity to the malignant cells occurred allowing the normal cells to grow unaffected. Cytogenetic and cytological examination of the remaining cells, after the inhibitor treatment, showed normal diploid karyotype and morphology. The inhibitor was also tested in vivo on Wistar rats bearing Walker tumors. Treatment with 50 Units1100 g i.p. daily for 5 days caused 90% tumor regression and necrosis of metastatic foci in the liver and abdomen, without toxic side effects. The protease inhibitors trypsin-chymotrypsin, aprotinin, leupeptin and E64 were also tested in vitro and showed no anticancer activity. In conclusion, the endogenous inhibitor of CANP selectively killed malignant cells of different chromosomal abnormalities, tissue and species origin; also nuclear vlimata and chemoresistant cells. These results are discussed in the context of a model for the action of the endogenous inhibitor of CANP, extracellular matrix and nuclear Offprint requests to: Dr. Helen Logothetou-Rella, Department of Experimental Physiology, Medical School, University of Athens. P.O. Box 601 14, GR-153 10 Agia Paraskevi, Athens, Greece vlimata.
Open Access
Neuroblastoma. A study of the clinicopathological features influencing prognosis based on the analysis of 54 cases
(Murcia : F. Hernández, 1994) Valera-Durán, J.; Böhm, N.; Díaz-Flores, Lucio; Ramon y Cajal-Junquera, S.; Toro Rojas, M.; Valera-Nuñez, R.
The retrospective analysis of 54 cases of neuroblastoma taken from the files of the Department of Pathology, University of Santiago Hospital, Spain, and the Ludwig-Aschoff Institute of Pathology, University of Freiburg, Germany confirmed the validity and significance of various clinical and histopathological features when trying to establish the prognosis and the proper therapeutic approach in a given case of neuroblastoma. When the age of the patients was compared to survival it was shown that all but three of the patients older than 2 years of age had died from tumor within ten months. In contrast, there was a 37.5% five-year survival rate among patients who were 24 months of age or younger at the time of diagnosis and treatment. The primary tulnor was located in the adrenal gland in 27 cases (50%), in 9 cases (17%) the tumor was retroperitoneal but extra-adrenal, and in the remaining 18 patients (33%) the tumor arose from the paravertebral sympathetic ganglia. Adrenal primaries behaved in an extremely aggresive manner as all but three patients with tilmors at this location were dead within 18 months. Retroperitoneal extra-adrenal neuroblastomas followed an almost equally poor outcome with only one five-year survivor ( 1 1 %). In contrast, 49% of the patients with paravertebral neuroblastoma had survived five years and a further 33% were alive with shorter follow-up. According to histological criteria, there were 6 grade I turnors, 15 grade I1 and 33 grade 111 tumors in our series. All grade I tumors were clinical stage 1 at diagnosis and all are alive 2 to 3 112 years later. Grade I1 tumors were clinical stage 2, 3 or 4 and showed a 46% five-year survival. With the exception of three patients with paravertebral tumors, all patients with grade 111 neuroblastoma were clinical stage 3 or 4 when initially Offprint requests to: Dr. Juan Varela-Duran, Departamento de Anatomia Patologica, Hospital General de Galicia, C/ Galeras s/n, 15702 Santiago de Cornpostela, Spain seen and all were dead from tumor within ten months, with a five-year survival of 9%. It is concluded that the age at diagnosis, location of the primary tumor and histological differentiation, all of which are interrelated, are the most reliable clinicopathological features affecting prognosis and therapy in neuroblastoma.
Open Access
The contribution of cavernous body biopsy in the diagnosis and treatment of male impotence
(Murcia : F. Hernández, 1994) Malovrouvas, D.; Petraki, C.; Constantinidis, E.; Petraki, K.; Antoniadis, G.; Constantinidis, C.; Kranidis, A.
This study concerns the results of penile biopsies in 50 patients aged 27 to 80, with secondary impotence removed with a biopty gun or during penile surgery. The biopty gun specimens were equally representative as the open biopsy ones. The cause and the degree of erectile dysfunction were determined by clinical and laboratorial investigation. The histological study of the cavernous bodies in the patients with psychogenic impotence revealed normal erectile tissue. In patients with organic impotence, histological lesions were graded as mild, moderate or severe. The most severe lesions were observed in the erectile tissue and in particular in the smooth muscle of the trabeculae and the helicine arteries, which had been reduced and replaced by connective tissue. Histological lesions were found not only in the arterial but also in the venous leak cases. There was a correlation between their severity and the degree of impotence, although of no statistical significance. The penile biopsy determines the condition (state) of the functional cavernous smooth muscle tissue, the integrity of which is essential for the erectile mechanism as well as for the action of the vasoactive drugs and the results of vascular surgery. Its important role is evident as it contributes not only to the diagnosis of the cause, but also to the choice of treatment of male impotence.
Open Access
High endothelial venules and cell adhesion molecules in B-cell chronic lymphocytic leukaemia and related low grade B-cell lymphoma leu kaemia II...
(Murcia : F. Hernández, 1994) Csanaky, G.
The expression of cell adhesion molecules (LECAM-1, LFA-1, VLA-4, ICAM-1 and CD44) of lymph nodes from B-cell chronic lymphocytic leukaemia (B-CLL; mature: 16 cases, immature: 8), lymphocytic lymphoma (LL; M:5, IM:2) and reactive lymph nodes (10) were investigated in frozen tissue sections. In order to assess the B- and T-cell compartments of the lymph nodes some additional markers CD3, CD20, CD45 RO were used, and for follicular dendritic reticulum cells (FDCs) CD35. The expression of the LECAM-1 molecule was correlated to the expression of activation (CD23, CD25) and proliferation (Ki67) markers. Findings, in accordance with the relevant data of the literature, indicate that B-CLL and LL show and identical adhesion profile to the mantle zone of the germitial centres of reactive lymph nodes; narnely, they were CD44+/LECAM- I+/VLA-4+. The T-zones of the reactive lymph nodes were characterized by an LFA-lf and the follicles by an ICAM-I+ pattern. while in B-CLL and LL cases the LFA-I+ and ICAM- I + were detected without coexpression of these molecules in only a small ii~imber of cases. The ratio and location of CD3+ and LFA-I+ cells was very similar in lyinph nodes from B-CLL and LL, and from this fact may arise the suspicion that LFA-I+ reported in LL cases derive from the sometimes significant T-cell compartment of the diseased lyrnph nodes. The LECAM-I molecule did not show any correlation with the investigated activation/proliferation markers.
Open Access
Pancreatic duct infiltration in the low-dose streptozocin-treated mouse
(Murcia : F. Hernández, 1994) Papaccio, G.; Strate, C.; Linn, T.
The pancreatic-duct system was observed during the initial stage of type 1 diabetes in C57BLI6J mice rendered diabetic with low doses of streptozocin. Light microscopy revealed that the ducts located in close proximity to islets (islet ducts) were involved in the infiltrating process: inflammatory cells extended from the islets to these ducts. However, ducts that were located far from islets (non-islet ducts) were generally free from infiltration. Immunocytochemistry revealed that both islet ducts and non-islet ducts express MHC class I1 and ICAM-l molecules: this positivity seems to be mainly expressed by elements infiltrating the connective layer or by endothelia of vessels surrounding ducts. Strong ICAM-l positivity demonstrates that adhesiveness is widely represented in early diabetes in this animal model. At the ultrastructural level only a few endocrine elements were observed scattered within the epithelia1 layer and single infiltrating elements were rarely encountered within the connective layer of ducts. The existence of other sites of ccactivation>>o ther than the islets of Langerhans, in this as well as in other animal models of types 1 diabetes, is consistent with the hypothesis of an initially more widespread and less specific process that later undergoes restriction.
Open Access
Hypothalamocerebellar and cerebellohypothalamic projections - circuits for regulating nonsomatic cerebellar activity.
(Murcia : F. Hernández, 1994) Dietrichs, E.; Haines, D.E.; Roste, G. K.; Roste, L. S.
Cerebellar involvement in visceral and affective responses is known from physiological and behavioral studies, but the pathways involved in these responses have remained enigmatic. Over the last ten years neuroanatomical studies have shown that the cerebellum and hypothalamus are interconnected by direct hypothalamocerebellar and cerebellohypothalamic projections and by a multitude of indirect pathways. The hypothalamocerebellar projection terminates in the cerebellar nuclei and in all layers of the cerebellar cortex as multilayered fibres. This projection is, at least in part, histaminergic. New immunocytochemical experiments indicate that small numbers of hypothalamocerebellar neurones may contain GABA- or glycine-like immunoreactivity. GABA may function as a transmitter in hypothalamocerebellar fibres, probably in conjunction with histamine, but it is not clear whether glycine may also function as a transmitter or only serve metabolic functions. The bidirectional pathways between the cerebellum and hypothalamus may be part of the circuits through which the cerebellum participates in the modulation of a variety of nonsomatic events. In addition, new observations on patients with well localized cerebellar lesions reveal simultaneous somatic and visceral dysfunction. Recent research on direct hypothalamocerebellar pathways and on other connections between hypothalamus and cerebellum is reviewed. It is hypothesized that the cerebellum may act as a general modulator and coordinator of a wide range of central nervous activities, somatic as well as nonsomatic.
Open Access
The pathology of the atrophylhypertrophy complex (AHC) of the liver. A light microscopic and immunohistochemical study
(Murcia : F. Hernández, 1994) Lory, J.; Schweizer, W.; Blumgart, L.H.; Zimmermann, Astrid
The term, atrophylhypertrophy complex (AHC) of the liver, denotes a distinct combination of hepatic atrophy and hypertrophy occurring in situations of significant impairment of bile flow andlor portal or hepatic venous blood flow. In the lobes or segments concerned atrophy ensues, whereas areas not or less involved develop compensatory hypertrophy, resulting in a characteristic gross deformity of the organ and, in some instances, in rotation of the liver around a virtual hilar axis. As recognition and early detection of AHC have a strong implication on the treatment of several hepatobiliary diseases, adequate combined clinical, radiological and histopathological strategies have to be used in order to arrive at a correct diagnosis. The present investigation was designed to analyze the morphology of AHC in detail and to define lesion patterns having the highest predictive value. For atrophy, the following features were highly characteristic: 1) Advanced septal fibrosis with or without nodular change of parenchyma; 2) Biliary piecemeal necrosis with formation of vascular structures; 3) Ductular proliferations, frequently extending into septa and involving the parenchyma; 4) Capillarization of sinusoids with type IV collagen deposition in Disse's space; 5) Factor VIII-associated antigen expression by sinusoidal endothelia; 6) a seemingly paradoxical increase of proliferative activity of hepatocytes as based on PCNA staining. The severity of lesions in atrophy was related to the type of underlying disease, in that the changes were clearly more expressed in situations of longstanding obstruction due to benign disease. Using a set of well-defined morphological parameters, atrophy can be reproducibly distinguished from hypertrophy in biopsy material from AHC.
Open Access
Retinal photoreceptor fine structure in the short-tailed stingray. Dasyatis brevicaudata
(Murcia : F. Hernández, 1994) Braekevelt, Charlie R.
The fine structure of the retinal photoreceptors has been studied by light and electron microscopy in the short-tailed stingray (Dasyatis brevicaudata). The duplex retina of this elasmobranch contains rods and cones in a ratio of about 10:l. No multiple receptors were noted nor was a repeating or mosaic arrangenient of the cones obvious. Only lightadapted specimens were studied but retinomotor movements of the photoreceptors were felt to be minimal or absent. The rods are large cylindrical cells with inner and outer segments of much the same diameter. Cones are short stout cells with a conical outer segment and a wider inner segment. Rod outer segment discs show peripheral incisures while cones do not. The inner segment of rods and cones are rich in organelles indicating much synthetic activity. The nuclei of rods and cones appear quite similar but cone nuclei are invariably at least partially protruded through the external limiting membrane which is formed by a series of zonulae adherentes between photoreceptor cells and Miiller cells. The synaptic region of both rods and cones display both invaginated (ribbon) synapses and superficial (conventional) synapses.
Open Access
Páginas de High endothelial venules and cell adhesion molecules in B cell chronic lymphocytic leukaemia and related low grade B-cell ...
(Murcia : F. Hernández, 1994) Csanaky, G.
The high endothelial venule (HEV)-content and the lymphocyte migration index (LMI) of reactive lymph nodes and lymph nodes from patients with B-cell chronic lymphocytic leukaemia (B-CLL), as well as some related B-cell malignancies (lymphocytic lymphoma -LL-, prolymphocytic leukaemia -PLL-) were determined and statistically analyzed. The HEV-content and the LMI were significantly higher in reactive lymph nodes than in the low grade B-cell lymphomas and leukaemias (p< 0.001). The number of HEVs among lymphoma/leukaemia cases was the highest in LL independently of the maturation. However, the maturation of the process seems to determine the intensity of lymphocyte migration; i.e. a significantly higher LMI was found in mature (B-CLL, PF, mature; M and LL, M) than in immature subtypes (B-CLL, PF, immature -1M-, diffuse -D- and LL, IM) subtypes (levels of significance varied from p< 0.05 to p< 0.001). Rased on these findings, a more intense migration of lymphocytes from blood to peripheral lymph nodes may be supposed in LL than in B-CLL, thus explaining the nodal sites of involvement in LL and the peripheral blood in B-CLL. Within the same histological categories the morphometric features in mature subtypes may implicate an enhanced HEV-lymphocyte interaction when compared to the immature subtypes.
Open Access
Retinal pigment epithelial fine structure in the short-tailed stingray. Dasyatis brevicaudata
(Murcia : F. Hernández, 1994) Braekevelt, Charlie R.
The retinal pigment epithelium (RPE), choriocapillaris and Bruch's membrane (complexus basalis) have been studied by light and electron microscopy in the short-tailed stingray (Dasyatis brevicaudata). The RPE consists of a single layer of cuboidal cells which display numerous basal (choroidal) infoldings as well as many apical (vitreal) processes which interdigitate with photoreceptor outer segments. The lateral cell borders are relatively smooth and joined by a series of tight junctions. Within these epithelial cells, smooth endoplasmic reticulum is the dominant organelle with only scattered profiles of rough endoplasmic reticulum. Polysosomes, mitochondria and phagosomes are abundant. Melanosomes are totally absent over the tapetum and are scarce in non-tapetal locations. The RPE nucleus is large, vesicular and centrally located. Rruch's membrane is a pentalaminate structure. The choriocapillaris is a single layer of large capillaries. The endothelium of these capillaries is typically thin but only minimally fenestrated.
Open Access
The use of fluorescent dextrans as a marker of sarcolemmal injury
(Murcia : F. Hernández, 1994) Carter, G.T.; Kikuchi, N.; Horasek, S.J.; Walsh, S.A.
We investigated the use of intravenously injected fluorescent dextran molecules (FDx) as a histological marker of sarcolemmal injury. Using fluorescent microscopy, uptake of FDx (average MW 10 kD) was assessed in sections of quadriceps muscles from three models: l ) normal (C57BLlIOSnJ) mice. 2) normal mice run downhill (0, 3, and 7 days post exercise), and 3) non-exercised mdx (dystrophin-deficient) mice. These were compared to serial sections stained with hematoxylin and eosin (H&E). In control muscles. strong fluorescence was seen between fibers (intercellular). Intracellular FDx was observed within cells of the quadriceps from normal mice run downhill at days 0 and 3 post exercise, but not at day 7. On H&E staining. muscle pathology was not observed until day 3, with regeneration by day 7. Intracellular FDx was also observed within mdx muscles, particularly in fibers that appeared pre-necrotic on H&E stained sections. FDx appears to be useful as a histological marker of changes in sarcolemmal integrity associated with muscle injury from eccentric exercise or muscle disease.
Open Access
A comparative study on the effects of bfluorouracll on glycosaminoglycan synthesis during palate development in quail and hamster
(Murcia : F. Hernández, 1994) Young, A.V.; Hehn, B.M.; Cheng, K. M.; Shah, R.M.
A comparative study was undertaken to investigate the effects of 5-fluorouracil (FU) on glycosaminoglycans (GAG) synthesis during morphogenesis of the secondary palate in birds (where, unlike mammals, palate morphogenesis begins in a horizontal direction ad initpm and lacks mammalian-type shelf reorientation) and mammal. Previous studies have shown that FU induces cleft palate in both birds and mammals. Air sacs of quail eggs were injected with 100 pg FU in 0.1 m1 saline or 0.1 m1 saline only. Hamsters were given intramuscular injection of 81 mg/kg FU in 1 m1 saline or 1 ml saline only. Total GAG synthesis was measured by incorporation of 3~-glucosamineS. ulfated and non-sulfated GAGs were identified by Alcian Blue histochemistry combined with the use of GAGdegrading enzymes. The results indicated that a continuous synthesis of GAG at a steady rate was associated with normal palate morphogenesis in both quail and hamster. The amount of GAG synthesized in hamster palate was four-fold higher than in quail palate. In contrast to the developing hamster palate where the predominant GAG was hyaluronate, the major GAGs present during quail palate development were sulfated and were concentrated on the nasal side. FU treatment did not affect the rate of GAG synthesis in the developing palate of quail. In contrast, FU administration altered the rates of GAG synthesis. and affected hyaluronate accumulation, during palate morphogenesis in hamster. Following an analysis of data of the present study and those from literature, it was suggested that, in contrast to the proposed role of hyaluronate in mammalian shelf reorientation, the sulfated GAGs may contribute to shelf volume and may be associated with tissue differentiation in both hamster and quail. Also, critical differences in timings, rates, and types of macromolecular synthesis between quail and hamster may be related to the evolutionarily diverse morphogenesis of palate seen in birds and mammals.
Open Access
Different effects of neurotensin and neuromedin-N on the proliferative activity of rat adrenal cortex
(Murcia : F. Hernández, 1994) Markowska, A.; Nussdorfer, G.G.; Malendowicz, L.K.
Evidence indicates that neurotensin (NT) and neuromedin-N (NMN) exerts an adrenocorticotropic effect in the rat. The present study aimed to investigate whether these neuropeptides are able to stimulate the proliferation of rat adrenocortical cells in vivo and to compare their mode of action. Adrenocortical proliferative activity was assessed by the metaphasearrest technique and metaphases were counted per medulla-containing adrenal section. A bolus administration of NT (3 pglrat) resulted in a significant increase in the number of metaphases in both zona fasciculata and the entire cortex, an effect observed 48 h after the in.jection. The administration of NMN (3 yglrat) induced a notable rise in the number of metaphases in the zona fasciculata and the entire cortex within 12 h, followed by a subsequent drop after 24 h and a return to normal values at 48 h. These findings indicate that NT and NMN enhance rat adrenal growth in vivo acting via different mediators.
Open Access
Neuromedins and their involvement in the regulation of growth, structure and function of the adrenal cortex
(Murcia : F. Hernández, 1994) Malendowicz, L.K.; Markowska, A.
Current data on the synthesis and the mechanism of action of neuromedins on adrenal cortex are presented. The localization of these biologicallyactive peptides in all components of the hypothalamopituitary- adrenal axis as well as their action on the adrenal cortex both in vivo and in vitro suggest their involvement in the regulation of growth, structure and function of the adrenal cortex. Neuromedins may exert both direct and indirect effect on the adrenal cortex. Direct effect is proven by the stimulation of glucocorticoid synthesis by adrenocortical cells in culture (NMK, NML) while indirect effects may be mediated by ACTH, vasopressin (aldosterone secretagogue effect) and angiotensin (prompt proliferative response) or by substances of medullary origin. The last mechanism of action is well documented for NMU.
Open Access
Ultrastructural localization of calcium in neuromuscular junctions of smooth and skeletal muscles after aminoglycoside antibiotics treatment
(Murcia : F. Hernández, 1994) Nouhnejad, P.; Dehpour, A.R.; Samadian, T.; Amini, Sh.
Aminoglycoside antibiotics are all capable of producing clinically significant neuromuscular paralysis. Since part of the mechanism of action of these antibiotics at neuromuscular junction is a calciumdependent inhibition of acetylcholine release, so this experiment was carried out in vitro on both somatic (isolated rat phrenic-nerve hemidiaphragm) and autonomic neuro-effector transmission (guinea-pig ileum) using gentamicin and amikacin, to determine the calcium contents at this level. Electron microscopic observations on gentamycinandlor amikacin-treated materials, using potassium pyroantimonate method suggest a reduction of internal calcium in nerve terminals of both preparations.
Open Access
Polarization microscopy of picrosirius red stained sections. A useful method for qualitative evaluation of intestinal wall collagen
(Murcia : F. Hernández, 1994) Rabau, M. Y.; Dayan, D.
Collagen pattern in healing anastomosis of intestinal wall was compared with its normal pattern in the submucosal layer. Polarization colours were recorded for thin (0.8 pm or less) and thick (1.6-2.4 pm) collagen fibres. The polarization colours of thick collagen fibres in the anastomotic site were more greenish-yellow and yellow than those in normal intestine which were more yellowish-orange and orange. These findings indicate that the collagen in the anastomotic site 4 days after operation is less packed than the collagen of normal rat intestine. Examination of the polarization colours of Picrosirius red-stained sections is a useful procedure to follow healing of anastomotic sites or diagnosis of collagen pathology in different pathologic conditions in the intestinal wall.
Open Access
Possible role of brown adipose tissue as a mediator during cyclosporine-A treatment
(Murcia : F. Hernández, 1994) Buján, J.; Jurado, F.; Gianonatti, M.C.; Contreras, L.A.
Cyclosporine-A (CsA) is a potent immunosuppressor used successfully to control rejection in organ transplantation. According to the most recent evidence, this drug modifies the lipid metabolism of the patient, provoking a rise in the blood lipids, constituting an important risk factor for acceleration of the atherogenic process. Taking into account that brown adipose tissue (BAT) constitutes the major storage site for cholesterol and triglycerides in the rat, and given the apparent lack of references about the implications of CsA on this tissue in the literature, we proposed to study the possible morphological changes occurring in BAT following the administration of this drug. Two groups of female Sprague-Dawley rats were set up, the control group and a treated group in which each animal received subcutaneous injection of 5 mglkg body weightlday of CsA. After 4, l l , 25 and 34 days of treatment, subgroups of animals were sacrificed and the brown adipose tissue removed was apportioned for subsequent microscopic assessment. The greatest degree of atypia and activity in the BAT was observed after administration of 11 doses of the drug, at which point there was a marked reduction in the cell size with loss of lipidic coalescence. With subsequent doses, the tissue slowly initiated a process of recovery. CsA also induced morphological changes in the BAT that. in the early stages of the study, appeared to be correlated with a lipolytic response of the tissue to the drug; thus, the BAT may be acting as a system to eliminate the excess of lipids in the blood provoked by CsA administration, while toward the end of treatment, there was a certain stability between the drug and the activity of the brown adipose tissue, and a tendency to reach a balance between lipolysis and lipogenesis.
Open Access
Hirschsprung's disease - immunohistochemical findings
(Murcia : F. Hernández, 1994) Larsson, L.T.
Hirschsprung's disease (HSCR) is characterized by a non-propulsive distal intestinal segment (usually colon) leading to a functional obstruction. An absence of ganglia in the affected - - segment explains the synonymous term ccaganglionosis coli,,. The lack of peristalsis is partly due to a deficient intestinal smooth muscle relaxation based on an absence of non-adrenergic, non-cholinergic (NANC) inhibitory innervation. Morphological studies using conventional microscopy, imrnunohistochemistry and immunochemistry against general neuronal markers and neuropeptides have been used to characterize the disturbed NANC innervation in HSCR. An increased cholinergic and adrenergic innervation is registered in the aganglionic segment in spite of the lack of neuronal cell bodies: Neuropeptides like vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating polypeptide (PACAP), gastrin-releasing peptide (GRP), calcitonin generelated peptide (CGRP), substance P (SP), enkephalins and galanin imrnunoreactive nerve fibres are all reduced in number i n the aganglionic segment. In contrast, neuropeptide Y (NPY)-containing nerve fibres are increased in number in the diseased segment, probably reflecting the adrenergic hyperinnervation. General neuronal markers including chromogranins have been used to map the ne~lron~l network in the HSCR intestine and also to investigate the endocrine cell system in the intestinal mucosa. Nitric oxide is a potent component of the NANC inhibitory innervation and its synthesizing enzyme, nitric oxide synthase (NOS). is shown to be almost absent in the neuronal system in aganglionic intestine.
Open Access
Effect of dietary fat on toad liver tumor induced by DMBA. Ultrastructural studies
(Murcia : F. Hernández, 1994) Sadek, I.A.; Abdul-Salarn, F.
Toads injected with 2 mg 7,12-dimethylbenza( a)anthracene (DMBA)/toad, 3 timeslweek for 12 weeks induced liver tumors in 12 out of 50 cases. The electron micrograph of toad liver tumor showed disorganization of the rough endoplasmic reticulum which encircles or partially surrounds the mitochondria. Cristae mitochondrialis are rare in comparison with control. Enhancement of liver tumor incidences (29 out of 50 cases) by DMBA at the same dose level plus 2cc corn oilltoad, 3 timeslweek for 12 weeks was detected. Electronmicrograph of this group showed the same criteria of malignancy as in the first group. No tumor incidences were detected in toads fed corn oil only. The electronmicrograph of liver cells showed a high increase in glycogen and lipid droplets.
Open Access
Differentiation of human lymphocytes into nuclear vlimata by meiosis. The cytotoxic effect of calcium-activated neutral proteinase inhibitor
(Murcia : F. Hernández, 1994) Logothetou-Rella, H.
Phytohaemagglutinin (PHA)-activated lymphocytes differentiated into nuclear vlimata (NVs) in vitro. Lymphocyte attachment was followed by formation and extrusion of cytoplasmic vesicles. nuclear elongation and fragmentation into NVs. NVs and cytoplasmic vesicles were detached and organized into large cell nodules in suspension. Immunocytochemistry showed that T-lymphocytes differentiated mainly to NVs while B-lymphocytes to buds. During differentiation there was a loss or gain of T-antigenicity by either mother or daughter cell. Cytogenetic analysis by chromosomal spreading and in situ techniques showed that NVs do carry chromosomes of hypodiploid or hypohaploid sets. NVs were the result of meiosis stimulated by PHA. A ly~nphocyticp opulation exhibited diploidies attributed to mitosis or symmetrical meiosis and hypodiploidies, hypohaploidies attributed to meiosis. A comparison between NVs and spermatozoa was provided. The inhibitor of calcium-activated neutral proteinase (CANP-I) was cytotoxic to NVs without interfering with NV production. A model was proposed for the action of CANP-I which is a promising agent against autoimmune diseases.