bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunocytochemical Analysis of Vimentin Expression Patterns in Porcine Embryos Suggests Mesodermal Differentiation from Day 9 after Conception
Authors: Prelle K. , Holtz W. , Osborn M.
Published: March 2003

The expression of the intermediate filament proteins vimentin and keratin in porcine embryos was studied by whole‐mount immunocytochemistry between day 7 and day 11 after conception. Expression of vimentin was first detected in the inner cell mass of about 50% of the 9‐day‐old embryos. In elongated 11‐day‐old embryos, cells expressing vimentin were observed in the epiblast (after disappearance of Rauber’s membrane) and in cells migrating from the epiblast between the trophoblast and the underlying hypoblast layer. A keratin‐positive response was observed in trophectoderm cells at all stages. These findings suggest that inner cell mass cells in the pig start differentiating into mesodermal cells not later than day 9 after conception. While the delamination of the mesodermal germ layer is known to correlate with the loss of pluripotency of the inner cell mass cells, the early onset of mesodermal differentiation in the porcine embryo, characterized by vimentin expression and in contrast to the mouse, could in part be responsible for the lack of success in establishing pluripotent embryonic stem cell lines in this species. Our results suggest that further attempts to isolate inner cell mass‐derived pluripotent cells should be attempted well before day 9 after conception.
Immunohistochemical Demonstration of Leu‐7 (HNK‐1), Neurone‐Specific Enolase (NSE) and Protein‐Gene Peptide (PGP) 9.5 in the Developing Camel (Camelus dromedarius) Heart
Authors: El Sharaby A. A. , Egerbacher M. , Hammoda A. K. , Böck P.
Published: March 2003

The development of the heart‐conducting system has been controversially discussed. The common opinion that these specialized myocytes originate from mesodermal precursors has been challenged when nerve‐specific antigens (Leu‐7, NF, G1N2) were demonstrated in embryonic hearts of various species, suggesting a neural crest contribution to the embryonic conducting tissue. Anti‐Leu‐7 (HNK‐1) antibodies were reported to reliably mark the conducting system in developing rat, chicken and human hearts. The present investigation was carried out on the hearts of 15 camel fetuses at 35, 45, 60, 75 and 100 cm crown‐rump length (three specimens for each stage), in addition to three adult hearts. We investigated the antigenicity of cardiac structures for Leu‐7, NSE (Neurone specific Enolase) and PGP (Protein Gene Peptide) 9.5. In all specimens investigated, both NSE and PGP 9.5 were expressed by cardiac nerves and conducting system components. The sinuatrial and atrioventricular nodes, the atrioventricular bundle as well as subendocardial and intramyocardial Purkinje fibers were stained. In contrast, the developing conducting system did not react with anti‐Leu‐7 antibody, although Leu‐7 antigenicity was strongly expressed by the developing cardiac nerves. In adult camel hearts, the same pattern of immunoreactivity for the markers studied was still retained. Our results show that the expression of marker proteins for the developing conducting system is species‐specific. Therefore, these markers are of little significance in discussions on the possible neurogenic nature of the heart conducting tissue.
Double Aortic Arch in a Dog (Canis Familiaris): a Case Report
Authors: Ricardo C. , Augusto A. , Canavese S. , Marcos A. , Ticona E. , Fernandes M. , Rita M. , Singareti F.
Published: March 2003

We herein report a case of a double aortic arch in a 10‐week‐old male dog of no defined race, which presented episodes of regurgitation at the time of weaning. This vascular malformation was characterized by the persistence of two aortic arches, right and left, of varying dimensions. The right aortic arch was observed to be larger. During post mortem examination the vessels of the animal were injected with coloured latex bi‐centrifuged CIS I‐4 polisopreno which revealed the patency of the two aortic arches. Concomitantly, dilation of the cranial oesophagus causing constriction was observed, indicating megaesophagus. Apart from the constriction, the oesophagus presented normal morphometric parameters in relation to its dimensions.
An Explanation of a Groove found on the Nasal Process of the Equine Incisive Bone
Authors: Pérez W. , Martin E.
Published: March 2003

Thirteen fresh equine heads were dissected in an attempt to determine the cause of a groove frequently found on the dorsal border and medial side of the nasal process of the incisive bone. This groove appeared on both sides in 40 out of 44 equine skulls. The sulcus seems to be caused by the combined action of the lateralis nasi muscle and the medial accessory cartilage of the nose (cartilago nasalis accessoria medialis). Other sulci found on the nasal process of the bone may be explained as impressions caused by nerves.
Lingual Ultrastructure of the Long‐Finned Pilot Whale (Globicephala melas)
Authors: Pfeiffer D. C. , Wang A. , Nicolas J. , Pfeiffer C. J.
Published: March 2003

Microscopic studies on the cetacean tongue are limited and, to date, only a few ultrastructural reports on dolphins have been published. This report presents the initial description of the lingual ultrastructure of the long‐finned pilot whale. The lingual integumental surface was smooth, lacking papillae, although flaking of outer stratum corneum cells could be observed at high resolution. The keratinocytes of the stratum spinosum of the epidermis resembled those of cetacean skin on other regions of the body. The similarities included the presence of cytoplasmic lipid droplets around the nuclei of stratum spinosum cells, a lingual feature not seen in terrestrial mammals. Keratin intermediate filaments were numerous and occasionally formed aggregates of circular whorls. At cell surfaces, bundles of keratin intermediate filaments were frequently observed inserting into desmosomal plaques. Pigment granules were not evident and organelles were sparse. Stratum corneal cells contained nuclear remnants (parakeratosis) and small multivesicular bodies, and the corneal layer was approximately 18 cells thick. The nuclei of the stratum basale keratinocytes possessed exceptionally numerous and deep clefts. The dermis was non‐distinctive. The skeletal muscle of the tongue was arranged in widely separated fasiculi containing small numbers of muscle fibres. Typical fine structure of skeletal muscle bands and tubular elements was observed by transmission electron microscopy.
Epithelial Cell Proliferation and Apoptosis in the Developing Murine Palatal Rugae
Authors: TAKANOSU M. , AMASAKI H. , IWAMA Y. , OGAWA M. , HIBI S. , SUZUKI K.
Published: March 2003

Epithelial cell proliferation and apoptosis during morphogenesis of the murine palatal rugae (PR) were examined histochemically by using anti‐bromodeoxyuridine (BrdU) and the terminal deoxynucleotidyl transferase‐mediated UTP nick‐end‐labelling (TUNEL) technique. Formation of the PR rudiment was observed as an epithelial placode in fetuses at 12.5 days post‐coitus (dpc). During the PR formation, BrdU‐positive cells were detected mainly in the epithelium of the interplacode and interprotruding areas in fetuses administered BrdU maternally at 2 h before killing. TUNEL‐positive cells were detected only at the epithelial placode area in 12.5–14.5 dpc. At 16.5–18.5 dpc, the BrdU‐positive cells were decreased in number in the epithelial cells at the interprotruding area of the PR. Only a few TUNEL‐positive cells were observed in the protruding area of the PR at 16.5 dpc. These results suggest that cell proliferation and apoptosis in the palatal epithelium are involved spatiotemporally in the murine PR morphogenesis.
Involution of Bursa Cloacalis (Fabricii) and Thymus in Cyclosporin A‐Treated Chickens
Authors: MILIĆEVIĆ Ž. , ŽIVANOVIĆ V. , MILIĆEVIĆ N. M.
Published: March 2003

Fifty‐day‐old Arbor Acres chickens received a daily oral dose of 30 mg/kg Cyclosporin A for 21 consecutive days. This treatment induced the striking morphological changes in the bursa cloacalis (Fabricii). The number of bursal follicles did not change, but they were markedly decreased in size. The pars lymphoreticularis was collapsed and contained smaller accumulations of lymphocytes. The pars lymphoepithelialis was almost totally devoid of lymphocytes and it was composed of an empty network of epithelial cells. Interfollicular epithelium, follicle‐associated epithelium, basement‐membrane‐associated epithelium and bursal epithelial cytoreticulum were not changed. The thymus also displayed substantial structural changes, whereby the thymic medulla was strongly reduced in size.
Periods and Stages of the Prenatal Development of the Domestic Cat
Authors: KNOSPE C.
Published: March 2003

Twenty‐two stages of the prenatal development of the domestic cat are described for intraspecies comparison in embryological studies. These are assigned to the 15 embryonal periods based on the Nomina Embryologica Veterinaria to make the interspecies comparison possible.
The Regional Distribution and Relative Frequency of Gastrointestinal Endocrine Cells in SHK‐1 Hairless Mice: An Immunohistochemical Study
Authors: KU S.‐K. , LEE J.‐H. , LEE H.‐S. , PARK K.‐D.
Published: March 2003

The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the eight portions (fundus, pylorus, duodenum, jejunum, ileum, caecum, colon and rectum) of the gastrointestinal tract of SKH‐1 hairless mice were investigated using immunohistochemical methods and seven types of specific antisera against somatostatin, serotonin, glucagon, cholecystokinin (CCK)‐8, secretin, pancreatic polypeptide (PP) and gastrin. In this study, somatostatin‐, serotonin‐, glucagon‐, CCK‐8‐, secretin‐ and gastrin‐immunoreactive (IR) cells were identified. Most of these IR cells in the intestinal portion were generally spherical or spindle‐shaped (open‐type cell) while cells that were round in shape (close‐type cell) were occasionally found in the stomach regions. Their relative frequencies were varied according to each portion of gastrointestinal tract. Somatostatin‐IR cells were found throughout the gastrointestinal tract except for the large intestine. Serotonin‐IR cells were detected throughout the whole gastrointestinal tract and were the most predominant endocrine cell types in this species of mouse. Glucagon‐IR cells were restricted to the fundus, occurring rarely. CCK‐8‐IR cells were observed in the pylorus, duodenum and jejunum with freuqencies that were numerous, moderate and few, respectively. Peculiarly, secretin‐IR cells were demonstrated in the whole intestinal tract with either few or rare frequencies. Gastrin‐IR cells were restricted to the pylorus and were numerous. However, no PP‐IR cells were found in this study. In conclusion, some peculiar distributional patterns of gastrointestinal endocrine cells were found in SKH‐1 hairless mouse.
Musculus Extensor Digiti Medii Proprius and Musculus Extensor Digitorum Brevis Manus – A Case Report of a Rare Variation
Authors: CIGALI B. S. , KUTOGLU T. , CIKMAZ S.
Published: March 2003

The musculus extensor digiti medii proprius and musculus extensor digitorum brevis manus are anomalous extensor muscles of the hand. During the routine dissection of a white male cadaver a musculus extensor digiti medii proprius was seen on both hands and a musculus extensor digitorum brevis manus was seen on the left hand. The extensor medii proprius has a belly originating from the distal third of the ulna near the extensor indicis proprius and its tendon is inserted into the dorsal aponeurosis of the middle finger on both hands. On the left hand there was another anomalous muscle (musculus extensor digitorum brevis manus) which originated from the distal end of the radius, carpal ligaments and carpal joint capsule and inserted on the tendon of the extensor digiti medii proprius. This case is a multivariation of the hand extensor muscles and a musculus extensor digitorum brevis manus inserting on the musculus extensor digiti medii proprius has not been reported previously.
Embryo Transfer and Embryonic Capsules in the Bobcat (Lynx rufus)
Authors: MILLER D. L. , WALDHALM S. J. , LEOPOLD B. D. , ESTILL C.
Published: March 2003

Bobcats (Lynx rufus) (n=22) were used to test a surgical embryo transfer protocol for wild felines. Five blastocysts were collected 8–14 days post‐initial copulation (PIC). Translucent capsule‐like structures were recovered at 12 days PIC and are the first report of such a structure in a felid. Endometrial fibrosis was observed in one cat but, in general, post‐surgical fibrosis of the uterus did not seem to impede ova or embryo transport. One embryo underwent cryopreservation and this embryo plus two other transferrable embryos were placed in recipient cats during the course of the study. No pregnancies were maintained; but one non‐cryopreserved embryo was detected by ultrasound examination at 2 weeks post‐transfer. This study provides valuable groundwork for future studies and warrants optimism for continued research in this area.
Cyclical Reproductive Changes in the Non‐ciliated Epithelia of the Epididymis of Birds
Authors: AIRE T. A.
Published: March 2003

The epididymis of two species of domestic birds, the domestic fowl (Gallus domesticus), duck (Anas platyrhynchos), and of domestic and feral guinea‐fowl (Numida meleagris) was studied during the three main phases of the reproductive cycle (prepuberal, sexually mature and active, and sexually mature but inactive or resting) with a view to identifying major histological and ultrastructural changes associated with and distinctive for each phase. Rete testis cells accumulated numerous variably sized lipid droplets in all birds, as well as large heterogeneous and lipofuscin‐containing dense bodies in the guinea‐fowl, during the resting but not in the other phases. The principal or Type III cells of the connecting and epididymal ducts exhibited profound structural changes, including, but not limited to, rarefied cytoplasm, inconspicuous and general loss of sparsely granular endoplasmic reticulum, loss of secretory vesicles in the drake, and an enhanced and conspicuous presence of lipid droplets in the guinea‐fowl. The rete cells appeared to be less sensitive than the Type III cells to a reduced level or absence of lumenal androgens. These phase‐dependent changes may help to prevent or minimize discrepancies in the interpretation of the normal structure of the epididymis in birds during the sexually active phase, as distinct from the other two phases and their intermediate phases.
Morphological Changes in the Sciatic Nerve of Diabetic Rats Treated with Low Molecular Weight Heparin OP 2123/Parnaparin
Authors: Artico M. , Massa R. , Cavallotti D. , Franchitto S. , Cavallotti C.
Published: March 2003

This study points out the early alterations that affect the sciatic nerve of rats with experimentally induced diabetes. It emphasizes the advantages deriving from treatment with low molecular weight heparin (LMWH) OP 2123/parnaparin and correlates these findings with observations emerging from a review of the relevant literature. In fact, the number and diameter of the capillaries within the sciatic nerve of diabetic rats appear to be increased consistent with a microangiopathy (the main characteristic of which is the fragility of new vessels), that is related to the evolution of diabetes in humans and animals. Our results suggest a possible therapeutic role for OP 2123/parnaparin in both diabetic neuropathy and microangiopathy, frequent complications of diabetes.
A Quantitative Study of the Neural Changes Underlying Pyloric Stenosis in Dogs
Authors: Abel R. M. , Doré C. J. , Bishop A. E. , Facer P. , Polak J. M. , Spitz L.
Published: March 2003

This study aimed to quantify the neural changes in congenital pyloric stenosis in dogs and to study the comparative anatomy between this condition in dogs and that in infantile hypertrophic pyloric stenosis. Eight specimens from the pylorus of dogs with pyloric stenosis and six control specimens were examined using conventional histology and immunohistochemistry for a range of neural antigens. The changes in the proportion of nerves immunoreactive for each antigen were quantified and analysed statistically. The morphology of the nerves in the diseased dogs was similar to that in controls. Only vasoactive intestinal peptide was reduced in expression in dogs (median proportion in control dogs 0.57, in diseased dogs 0.17;P = 0.065). This study demonstrates both morphological similarities and significant differences between closely related conditions in dogs, humans and other species.
Study of the Nervous Tissue Development in Rainbow Trout (Oncorhynchus mykiss) Embryos Treated with Oxytetracycline
Authors: Arias P. , Pinochet L. F. , Disi A.
Published: March 2003

The purpose of this study was to discover whether the use of different doses of oxytetracycline causes any alteration in the development of nervous tissue in rainbow trout embryos. Five thousands eggs of females rainbow trout were divided into five groups. One group acted as control and the other four were administered with one of four doses of oxytetracycline, 0.025, 0.050, 0.100, or 0.201 μm, at the moment of fertilization. The eggs were incubated under pisciculture conditions to just before being ready to spring off. From the 10th day, 10‐egg samples were taken regularly and fixed. Five were processed for histological techniques and stained with haematoxylin and eosin, cresyl fast violet and silver, the other five were homogenized for antibiotic detection. Histological alterations appeared in 37‐day‐old embryos, with an abnormal migration of the neuroblasts to the marginal layer of the neural cord, and alterations in the development of the lens and eye layers. Some embryos showed abnormal curvature of the spinal cord but these changes were not statistically significant.
Ultrastructural Observations on the Platelets of the Arabian Tahr (Hemitragus jayakari)
Authors: Johnson E. H. , Muirhead D. E. , Wood R. J. , King G. J. , Al‐Busaidy R.
Published: March 2003

The ultrastructure of platelets was studied in specimens of peripheral blood from 18 healthy adult Arabian tahrs (Hemitragus jayakari). The platelets were characterized by their extreme polymorphism. The number of alpha granules, typically one to six per cell, was considerably less than that reported for most animal platelets. Similar to humans, the platelets of the Arabian tahr had nucleoids within the alpha granules. However, nucleoids were not a consistent finding. One or more electron‐dense granules, most commonly contained within clear vesicles, was commonly observed. A unique feature was the lack of an open canalicular system, which is considered a hallmark feature of this cell type in most mammalian and reptilian platelets.
The Renal Structure in an Asian Elephant (Elephas maximus)
Authors: Endo H. , Akihisa N. , Sasaki M. , Yamamoto M. , Arishima K.
Published: March 2003

The renal structure of a female Asian elephant (Elephas maximus) was observed in both macroscopic and light microscopic levels. The left kidney was elongated‐ellipse in shape, whereas the right appeared round. The left kidney was 31 cm in cranio‐caudal length, 21 cm in medio‐lateral length, and 2950 g in weight. The right kidney was 34 cm in cranio‐caudal length, 22 cm in medio‐lateral length, and 3250 g in weight. The external appearance showed the six separated renal lobes in both sides of the kidney. The four pairs of the lobes were fused in the deepest region in both sides of kidney, so we considered it as an incompletely lobated kidney in this species. We observed the proximal and distal urinary tubules in histological sections. Many renal corpuscles consisted of the glomerulus and Bowman's capsule. Many mesangial cells and some podocytes were confirmed in each glomerulus; however, Bowman's capsules were larger than those in other mammalian species.
Gross and Microscopic Observations on the Lingual Structure of the Florida Manatee Trichechus manatus latirostris
Authors: Levin M. J. , Pfeiffer C. J.
Published: March 2003

The tongue of the Florida manatee (Trichechus manatus latirostris) was studied macroscopically, light and electron microscopically. The tongue was slender, muscular and firmly fixed in the oral cavity; only the cranial tip was free and mobile. Numerous filiform papillae were distributed over the dorsal surface of the rostral tongue. Multiple raised, round fungiform‐like papillae were distributed over most of the dorsum. Typical fungiform papillae were restricted to the lateral margins of the tongue. Foliate papillae, presenting as multi‐fossulate openings, were noted on the caudolateral margins. Open pits were located on the dorsocaudal surface and lateral walls. Microscopic examination showed that most of the lingual dorsum was covered with a thick stratified squamous epithelium. Open pits led to well‐developed mucous salivary glands. Glands within the foliate papillae were mostly mucous, although some seromucous glands were present. Taste buds were restricted to the epithelium of the foliate papillae. Throughout the tongue, striated muscle was abundant below the epithelium. Blood vessels, lymph channels and nerve fibres were freely distributed throughout the intermuscular stroma. Nerve fibres reacted positively with neurone specific enolase (NSE) antibody throughout the tongue, including nerve bundles, glands and taste buds. Clear to translucent vacuoles were found juxtaposed to nuclei in the stratum spinosum in the foliate papillae epithelium.
Distribution of Nociceptin‐like Immunoreactivity in the Central Nervous System of the Mongolian Gerbil: an Immunohistochemical Study
Authors: KIM H. W. , Kwon Y. B. , Ham T. W. , Roh D. H. , Yoon S. Y. , Han H. J. , Kim K. W. , Lee W. S. , Kim J. K. , Yoon O. B. , Lee J. H.
Published: March 2003

This study is designed to demonstrate the distribution of nociceptin, endogenous ORL1 receptor ligand, in the central nervous system of the Mongolian gerbil. To intensify the nociceptin‐like immunoreactivity (NOC‐LI), colchicine was administered into the lateral ventricle, at 48 h prior to the trans‐cardiac perfusion. In the group without colchicine treatment, NOC‐LI was observed in the fibres of the spinal dorsal horn, specifically in the superficial layers. However, the NOC‐LI in the superficial layers disappeared after the administration of colchicine. In the brain, NOC‐LI was prominent in the hypothalamus, hippocampus, cerebral peduncle, substantia nigra, dorsal raphe, periaqueductal grey, locus coeruleus and trapezoid nucleus. Colchicine treatment markedly intensified the NOC‐LI in the somata of the central nervous system, whereas the untreated sections were too weak to observe and analyse. The distribution of NOC‐LI provides informative data for studies of the neuronal circuit that nociceptin may be involved in.
Lymphocyte Proliferation in Lymphoid Organs of the Dromedary Camel using the Monoclonal Antibody MIB‐5 Against the Proliferation‐Associated Nuclear Epitope Ki‐67
Authors: Zidan M. , Pabst R.
Published: March 2003

Detection of proliferating lymphocytes is useful for studying immune reactions and for the prognosis of tumours of lymphocyte origin. Markers detecting proliferating cells are lacking in the dromedary camel. This study deals with the immunohistochemical detection of the Ki‐67 proliferation‐associated nuclear epitope using MIB‐5 in frozen sections from spleens, different lymph nodes and haemal nodes of eight camels (0.5–12 years old). Frozen sections from rat spleens were labelled in parallel with camel tissue as a positive control. Large numbers of cells expressing the Ki‐67 epitope were localized in germinal centres of all lymphoid organs tested. A few cells were found in the periarterial lymphoid sheath and the red pulp of the spleen, also in the lymphatic cords of the lymph nodes and the haemal nodes. There were no obvious differences in respect to the age of the animals. The Ki‐67 epitope is well expressed by proliferating cells in camel lymphoid organs. MIB‐5 can be applied to identify this epitope and will be a useful marker for cell production in immune reactions.
Is the Male Dog Comparable to Human? A Histological Study of the Muscle Systems of the Lower Urinary Tract
Authors: Stolzenburg Jens‐Uwe , Schwalenberg Thilo , Do Minh , Dorschner Wolfgang , Salomon Franz‐Viktor , Jurina Konrad , Neuhaus Jochen
Published: March 2003

Because of their superficial anatomical resemblance, the male dog seems to be suitable for studying the physiologic and pathological alterations of the bladder neck of human males. The present study was carried out to compare and contrast the muscular anatomy of the male dog lower urinary tract with that of humans. The complete lower urinary tract, including the surrounding organs (bulb of penis, prostate, rectum and musculature of the pelvic floor) were removed from adult and newborn male dogs and histologically processed using serial section technique. Based on our own histological investigations, three‐dimensional (3D)‐models of the anatomy of the lower urinary tract were constructed to depict the corresponding structures and the differences between the species. The results of this study confirm that the lower urinary tract of the male dog bears some anatomical resemblance (musculus detrusor vesicae, prostate, prostatic and membranous urethra) to man. As with human males, the two parts of the musculus sphincter urethrae (glaber and transversostriatus) are evident in the canine bladder neck. Nevertheless, considerable differences in formation of individual muscles should be noted. In male dogs, no separate anatomic entity can be identified as vesical or internal sphincter. The individual course of the ventral and lateral longitudinal musculature and of the circularly arranged smooth musculature of the urethra is different to that of humans. Differences in the anatomy of individual muscles of the bladder neck in the male dog and man suggest that physiological interpretations of urethral functions obtained in one species cannot be attributed without qualification to the other.
Comparative Functional Morphology of the Masticatory Apparatus in the Long‐snouted Crocodiles
Authors: Endo H. , Aoki R. , Taru H. , Kimura J. , Sasaki M. , Yamamoto M. , Arishima K. , Hayashi Y.
Published: March 2003

The masticatory muscles and their related structures of the skull were observed in the Indian gavial (Gavialis gangeticus), the false gavial (Tomistoma schlegelii), and the African slender‐snouted crocodile (Mecistops cataphractus) to detail some morphological differences in comparison with the other crocodile species, and to compare and elucidate the functional strategy of themasticatory apparatus in these long‐snouted species. The Musculus pterygoideus posterior was relatively smaller in the three species compared with many short‐snouted crocodiles. It suggests that the masticatory power in fish‐eating long‐snouted species is not so high as in the short‐snouted crocodiles, while the masticatory muscles were morphologically different among the three long‐snouted species as follows. The M. pterygoideus posterior of the false gavial was extended in the lateral side of the lower jaw unlike the Indian gavial. The M. pseudotemporalis and the Fenestra supratemporalis were largely developed in the Indian gavial, however we suggest that the other two species possess the weak bundles in this muscle. The false gavial and the African slender‐snouted crocodile have the pterygoid bone well‐developed extending dorso‐ventrally and it is suggested that the M. adductor mandibulae posterior attached to the pterygoid bone may be much larger than the Indian gavial. These data morphologically clarify the masticatory mechanism in the long‐snouted crocodiles different from the short‐snouted species, and demonstrate that the evolutional strategy to share the functional role in the masticatory muscles have been differently established between the Indian gavial and the other two species. We also obtained the morphological data in the fossil skull of the Machikane crocodile (Toyotamaphymeia machikanense) and concluded from the fossil characters that the considerable developments of the M.pterygoideus posterior and the M.pseudotemporalis in this species had not morphologically been consistent with both the Indian and false gavials.
Long‐Term Degeneration and Regeneration of the Rabbit Facial Nerve Blocked with Conventional Lidocaine and Bupivacaine Solutions
Authors: Gözi̇l R. , Kurt İ. , Erdoğan D. , Çalgüner E. , Keski̇l S. , Kurt M. N. , Elmas Ç.
Published: March 2003

The alterations due to the long‐term degeneration and regeneration of the rabbit facial nerve were investigated. The facial nerve was blocked with conventional lidocaine and bupivacaine solutions. The rabbits were sacrificed and facial nerves were removed 2, 4, 6 and 8 weeks after the administration of normal saline, lidocaine and bupivacaine. The samples were then processed for electron microscopic observation.

Degenerations were seen 2–4 weeks after the injection of normal saline, lidocaine and bupivacaine. In the normal saline group the regeneration process was observed after 6 weeks, whereas in the lidocaine and bupivacaine groups this process was first noticed after 8 weeks.

In the lidocaine and bupivacaine groups, regeneration was not completed at the end of 8 weeks; however, it was faster in the bupivacaine group. Bupivacaine is therefore suggested as the drug of choice for neural blockade as it caused less damage and a faster regeneration.
Histological Thin‐Sections: a Method for the Microscopic Study of Teeth in Spanish Red Deer (Cervus elaphus hispanicus)
Authors: Azorit C. , Hervas J. , Analla M. , Carrasco R. , Mun˜oz‐Cobo J.
Published: March 2003

A method to obtain thin histological sections (4–5 μm thick) from teeth, using a conventional microtome, is described for incisors, molars and canines from Spanish red deer (Cervus elaphus hispanicus). Decalcifying solutions of formic acid and nitric acid at different concentrations were ineffective. This was not the case for a solution of 14% hypochloric acid and polyvinylpyrrolidone (TBD‐1® of Shandon). However, the time needed to complete decalcification was longer than the time estimated by other authors. Incisors required between 4 and 6 days, molars between 7 and 15 days, and canines between 8 and 12 days. The preparation of histological thin‐sections from teeth with a conventional microtome, required some training or prior specialization, because most of defective or lost material occurred during the preliminary stage of the study. However this technique is inexpensive enough to be implemented in any histological laboratory. The preparations obtained are suitable for growth mark observation in dentine and in cementum for dating studies. Nevertheless, they are not suitable for enamel change studies, because the enamel is completely destroyed during the decalcifying process.
Brain Selenium Accumulation in Rat Pups of Selenium Supplemented Mothers
Authors: Bou‐Resli M. N. , Mathew T. C. , Dashti H. M. , Al‐Zaid N. S.
Published: March 2003

Selenium is essential for normal mammalian development. Being a component of antioxidant enzyme, glutathione peroxidase, it plays a major role in protecting the cells from free radical damage. The level of glutathione peroxidase was directly related to the amount of selenium present in various tissues and organs. A decrease in selenium leads to various pathological changes in humans as well as in various laboratory animals. The aim of the present study was to understand whether there is an increase in the level of selenium in different brain regions of rat pups whose mothers were supplemented with selenium, either 2 or 4 mg/l of their drinking water throughout the period of their pregnancy. There was a significant increase in the level of selenium in the cerebellum, cortex and hypothalamic and hippocampal tissues of selenium supplemented mothers as compared with those of non‐supplemented mothers. The brain stem of these animals did not show any significant difference in the level of selenium. Furthermore, the differences in the level of selenium between the rat pups of 2 mg/l selenium supplemented mothers and 4 mg/l selenium supplemented mothers were not statistically significant. These studies suggest that supplementation of selenium to mothers during the period of their pregnancy can selectively increase the level of this trace element in different brain regions. Further studies are necessary to understand the significance of selective accumulation of selenium in specific brain regions on brain development and function.
Prenatal Thyroid Gland in Sheep with Regard to the Presence of Isthmus
Authors: Hájovská K.
Published: March 2003

We studied the embryonal thyroid gland in 18 foetuses of sheep of Slovac merino breed by light microscopy in the period from 32nd to 36th day of evolution.

We found that in the majority of sheep foetuses, the thyroid gland consists of two separate lobes and their structure was the same during the afore‐mentioned period.

Parenchyma, composed of solid cell networks or cell groups in the form of nests, was irregularly divided by septa, containing embryonal blood vessels.

Almost all cases of this experiment showed slight asymmetry of lobes. In one case the asymmetry reached a considerable proportion ‐ nearly the length of one lobe.

Glandular isthmus was presented in only eight cases from 18 foetuses. We did not find fibrous isthmus in any case.
A Study of the Immunohistochemical Localization of the Progesterone and Oestrogen Receptors in the Magnum of the Immature Ostrich, Struthio camelus
Authors: Madekurozwa M.‐C.
Published: March 2003

The immunolocalization of the progesterone (PR) and oestrogen receptors (OR), in the magnum of the immature ostrich, was investigated during periods of ovarian activity and inactivity. In the immature ostrich, with an active ovary, numerous well‐developed tubular glands were present in the lamina propria. Significantly, PR immunostaining was strong in the surface epithelium and tubular glands of these birds. In contrast, weak staining for the PR was observed in the surface epithelium of birds with inactive ovaries. Tubular gland formation, in these birds, was indicated by bud‐like invaginations of the surface epithelium. Oestrogen receptor immunoreactivity was negligible in both birds with active and inactive ovaries. These findings suggest that steroid hormones, produced by the active ovary of the immature ostrich, influence the differentiation of the magnum. Furthermore, the action of these steroid hormones appears to be mediated through the PR.
Structure and Ultrastructure of the Celiac–Mesenteric Ganglion Complex in the Domestic Dog (Canis familiaris)
Authors: Ribeiro A. A. C. M. , Elias C. F. , Liberti E. A. , de Lima Guidi W. , de Souza R. R.
Published: March 2003

A number of neurons of the autonomic nervous system are situated in the ganglia and can be systematically divided into pre‐vertebrals, paravertebrals, intramural and para‐viscerals. The celiac–mesenteric ganglion, an important pre‐vertebral ganglion, is located together with the abdominal aorta and links the central nervous system to the peripheral system, participating in the coordination of peripheral reflexes and principally innervating the stomach, intestines, accessory glands (liver and pancreas). In addition, the celiac–mesenteric ganglion also contributes to the innervation of the spleen and has a role in gastrointestinal motility control. This study examined the structural and ultrastructural aspects of 40 celiac–mesenteric ganglia from domestic dogs. For light microscopy ganglia were included in paraplast and stained with haematoxylin–eosin, picrosirius, toluidine blue, Calleja's and Masson's trichrome. For examination by electron microscopy, the ganglia were submitted to cryofracture, enzyme digestion, hydrolysis and fixed in 5% glutaraldehyde in 0.1 M phosphate buffer (pH 7.4). The celiac–mesenteric ganglion was observed as a ganglionic complex composed of various ganglionic units separated by types I and III collagen fibres, predominantly unmyelinated nerve fibres and continuous capillaries. This complex is surrounded by a double‐layer capsule (internal and external). The principal ganglion cells had eccentric nuclei with two nucleoli, the nucleolemma was double and presented nuclear pores. In the cytoplasm there were vesicles of the Golgi apparatus, electron‐dense vacuoles, mitochondrias, smooth and granulated endoplasmic reticulum and free ribosomes. In conclusion, this ganglionic complex, in contrast to similar structures in the enteric nervous system, presents separate ganglionic units in a systematic arrangement related to the extrinsic and specific innervation of the target organs.
Gross Anatomy and Ultrasonographic Images of the Reproductive System of the Sumatran Rhinoceros (Dicerorhinus sumatrensis)
Authors: Zainal Zahari Z. , Rosnina Y. , Wahid H. , Jainudeen M. R.
Published: March 2003

The Sumatran rhinoceros (Dicerorhinus sumatrensis) is the smallest of all the rhino species. It is one of the rarest mammals in the world and is in imminent danger of extinction. A study was carried out on seven wild‐caught females, three wild‐caught males and one captive born female Sumatran rhinoceros at the Sumatran Rhinoceros Breeding Centre in Sungai Dusun, Selangor, Malaysia, beginning 1990. As a result of the paucity of scientific information on the reproductive biology of the Sumatran rhinoceros, this study was conducted to obtain information, which could assist in the captive breeding of this endangered and near extinct species. The anatomy of the reproductive system was based on two post‐mortem specimens and transrectal real‐time ultrasonography in six adult females. Genitalia of the Sumatran rhinoceros were similar to those of other species of rhinoceroses. The cervix consisted of several folds, the uterus was bicornuate with a short body and prominent horns and the ovaries were completely covered by the fimbriated end of the fallopian tube. The internal genitalia could be imaged by ultrasonography. The testes were located within a pendulous scrotum. Two lateral projections were located at the base of the penis. A well‐defined process glandis was present at the tip of the penis. The accessory sex glands and the testes could be imaged by ultrasonography.
A Method of Biomechanical Testing the Suspensory Apparatus of the Third Phalanx in Cattle: a Technical Note
Authors: Maierl J. , Böhmisch R. , Dickomeit M. , Liebich H.‐G.
Published: March 2003

There are a number of differences between the claws of the front and hind limbs in cattle concerning macroscopic shape, chemical and physical properties of claw horn and epidemiological data. Front claws have superior data in almost every respect. Virtually no information is available on the mechanical stability of the suspensory apparatus of the third phalanx.

It was the objective of this study to develop a method to measure the maximum strength (N/mm2) of the suspensory apparatus of the bovine distal phalanx. This apparatus includes all layers of tissue such as bone, corium, corioepidermal junction and wall horn. The feet of 13 clinically healthy beef bulls were collected from the local abattoir. Testing was performed in three locations of the wall segment (dorsal, abaxial, axial) in a material testing machine. The corium and the corioepidermal junction were set under increasing tension until failure occurred. Maximum stress was recorded.

The values ranged between 2.47–3.13 N/mm2 (dorsal), 4.08–4.87 N/mm2 (abaxial) and 2.27–2.66 N/mm2 (axial). No differences could be validated statistically between front and hind claws and between lateral and medial claws respectively. Abaxial ultimate stress values were significantly higher than dorsal and axial ones. Between the two a statistical difference could not be validated. Most of the specimens (57.1%) were torn apart at the corioepidermal junction, almost a quarter of the samples (27.6%) were to a degree disrupted at the corioepidermal junction and to a certain extent in the deeper layers of the corium. A few samples showed disruption within the horn (11.5%) or at the attachment of the third phalanx (3.8%).

Biomechanical features of the experimental set‐up are discussed. The biological significance of these findings is that the body weight and the additional dynamic loading is predominantly taken over by the abaxial part of the claw, while the dorsal and axial aspects are less loaded.
Rat Neonatal Intestinal Wall‐Free Graft
Authors: Losada J. , Juarros B. , Lopez Ariztegui M. A. , Fernandez Val J. F. , Sarria R.
Published: March 2003

An experimental study was carried out in order to evaluate the regeneration capacity of the neonatal intestinal wall in ischaemia and its repercussion over organs of the immune system such as the spleen. We isolated a reservoir of small intestine in adult Sprague–Dawley rats that, after having been everted and placed at a subcutaneous level, was grafted with a free small intestine segment of neonatal Sprague–Dawley rats and analysed 3, 15 and 30 days after grafting. Samples obtained were stained with Martin's trichromic stain and studied at the light microscopic level. A total regeneration of the crypt architecture, formed by absorptive enterocytes, was observed in the interior of the reservoirs. A quantitative immunohistochemical study with monoclonal antibodies against CD4, CD8, MHC I and MHC II was carried out in the spleen of these animals. An additional immunohistochemical study was also performed in the small intestine reservoirs and spleen of transplanted animals using nitric oxide synthase (NOS) antibodies. Three days after transplantation NOS immunoreactive cells were observed in the reservoirs with transplanted neonatal small intestine. Antigenic stimulation produced, in the spleen red pulp of transplanted animals, a significant increase (P<0.001) in the percentage of NOS, CD8 and MHC I immunoreactive cells in relation with values observed in control animals. These morphometric changes could be related with the stimulation that nitric oxide produces in the proliferation of the cytotoxic T cells.
The Comparative Analysis of the Myenteric Plexus in Pigeon and Hen
Authors: Kuder T. , Nowak E. , Szczurkowski A. , Kuchinka J.
Published: March 2003

Using the thiocholine method and histological techniques the myenteric plexuses of pigeon and hen were studied. Investigations revealed the presence of a nervous network in the wall of the small intestine of both animals. It consists of many nerve fibres crossing each other and creating meshes in a variety of shapes. The density of the network was different according to the species and to the parts of intestine. The myenteric plexus from the pigeon's duodenum is thicker (3.7‐fold) than in the remaining part of the small intestine; in the hen this is approximately 2.2‐fold thicker. The meshes of the duodenum in both species are smaller than in the jejunum and ileum. The results of histological investigations showed different localization of myenteric plexuses; in pigeon in the space between the circular and longitudinal muscle layers, and in hen within the circular muscle.
Arterial Supply of the Penis in the New Zealand Rabbit (Oryctolagus cuniculus L.)
Authors: Ozgel O. , Dursun N. , Cengelci A. , Ates S.
Published: March 2003

In the present study, the distributional pattern of the penile artery and the vessels joining the blood supply of the penis were investigated in the New Zealand rabbit. Eight adult rabbits were used in the study. In order to exhibit the vascular network by dissection, latex was injected via the abdominal aorta.

The main vessel which supplies blood to the penis, the penile artery, is a branch of the internal pudendal artery. It divides into two branches which form the deep and dorsal penile arteries at the level of the ischiadic arch. The deep penile artery penetrates the tunica albuginea, and forms the arterial network of corpus cavernosum penis. On the other hand, the dorsal penile artery gives off three small branches for the subischiocavernosus muscle and at the level of the attachment of this muscle sends two small branches for the preputium. The course of both arteries follows the dorsolateral surface of the penis to the glans and ends in an anastomosis. Hence, a caudal branch of the prostatic artery which originates from the umbilical artery joins the blood supply of the penis in the rabbit. After vascularizing the prostate complex, it ends by entering the corpus spongiosus penis at the dorsolateral surface at the level of the ischiadic arch.
Morphology of the Small Intestine of Weaned Piglets and a Novel Method for Morphometric Evaluation†
Authors: Wiese F. , Simon O. , Weyrauch K. D.
Published: March 2003

The intestinal morphology of 7‐week‐old pigs was investigated by light (LM) and scanning electron microscopy (SEM). The piglets were fed either a semisynthetic or a cereal‐based diet. The shapes of the intestinal villi and crypts of the duodenum, jejunum and ileum were examined. The villi were predominantly tongue‐shaped. In the duodenum they were also ridged, branched and folded, and in the jejunum they were also leaf‐like and ridged. At places with lymph follicles, the surface of the ileum was rugged with meandering fold‐like villi. The crypts of the three segments of the small intestine were mainly coiled and sometimes branched. A novel morphometric evaluation method was introduced using the enlargement factors of each villus and crypt surface. The enlargement factor for the villus surface of the duodenum, jejunum and ileum was 3.13, 3.72 and 2.71, respectively. The factor for the crypt surface of the duodenum, jejunum and ileum was 9.07, 8.94 and 6.53, respectively. Furthermore, the relative proliferation rate and the epithelial renewal index were calculated for the first time. The relative proliferation rate of the duodenum, jejunum and ileum was 32.88, 34.78 and 50.77 proliferations per mm crypt perimeter, respectively. The diets consumed had an influence on the epithelial renewal index being higher for piglets fed the cereal‐based diets.
An Immunohistochemical Study of the Gastrointestinal Endocrine Cells in the C57BL/6 Mice
Authors: Ku S. K. , Lee H. S. , Lee J. H.
Published: March 2003

The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the eight portions (fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum) of the gastrointestinal tract of C57BL/6 mouse was studied with immunohistochemical method using seven types of specific anti‐sera against chromogranin A (CGA), serotonin, somatostatin, human pancreatic polypeptide (HPP), glucagon, gastrin and cholecystokinin (CCK)‐8. In this study, all the seven types of immunoreactive (IR) cells were identified. Most of these IR cells in the intestinal portion were generally spherical or spindle in shape (open‐type cell) while cells showing round in shape (closed‐type cell) were found in the intestinal gland and stomach regions occasionally. Their relative frequencies were varied according to each portion of gastrointestinal tract. CGA‐IR cells were demonstrated throughout the whole gastrointestinal tract and they showed most predominant in the pylorus and duodenum. Serotonin‐IR cells were detected throughout whole gastrointestinal tract and they showed highest frequency in the stomach and colon. Somatostatin‐IR cells were demonstrated throughout whole gastrointestinal tract except for large intestine and showed highest frequency in the fundus. HPP‐IR cells were found in the fundus with rare frequency. Peculiarly, glucagon‐IR cells were restricted to the fundus, ileum and colon with a few frequencies. Gastrin‐IR cells were restricted to the pylorus with numerous frequency and CCK‐8‐IR cells were observed in the pylorus, duodenum and jejunum with numerous and/or a few frequencies, respectively. In conclusion, some peculiar distributional patterns of gastrointestinal endocrine cells were found in C57BL/6 mouse.