bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological and functional evidence, and clinical importance, of vascular anastomoses in the latissimus dorsi muscle of the sheep
Authors: SALMONS STANLEY , TANG AUGUSTINE T. M. , JARVIS JONATHAN C. , DEGENS HANS , HASTINGS MICHELLE , HOOPER TIMOTHY L.
Published: March 2003

Mobilisation of the latissimus dorsi muscle as a functional graft necessarily involves division of perforating arteries that enter the distal portion of the muscle, rendering it vulnerable to ischaemic damage when the muscle is stimulated electrically. Using a fluorescent microsphere technique we showed that the blood flow contributed by the thoracodorsal artery decreases in a proximal‐to‐distal direction, and that of the perforating arteries in a distal‐to‐proximal direction, but for neither does the flow decline to zero. This is consistent with earlier reports of anastomotic connections between the 2 arterial territories. We went on to use fluorescence microscopy to demonstrate the existence of these vascular anastomoses, the first such evidence obtained under physiological conditions of pressure and flow. In clinical applications, the existence of anastomotic connections offers the prospect of maintaining flow to the distal part of the grafted muscle without the delays inherent in neovascularisation procedures.
Regional differences in cell shape and gap junction expression in rat Achilles tendon: relation to fibrocartilage differentiation
Authors: RALPHS J. R. , BENJAMIN M. , WAGGETT A. D. , RUSSELL D. C. , MESSNER K. , GAO J.
Published: March 2003

Tendon cells have complex shapes, with many cell processes and an intimate association with collagen fibre bundles in their extracellular matrix. Where cells and their processes contact one another, they form gap junctions. In the present study, we have examined the distribution of gap junction components in phenotypically different regions of rat Achilles tendon. This tendon contains a prominent enthesial fibrocartilage at its calcaneal attachment and a sesamoid fibrocartilage where it is pressed against the calcaneus just proximal to the attachment. Studies using DiI staining demonstrated typical stellate cell shape in transverse sections of pure tendon, with cells withdrawing their cell processes and rounding up in the fibrocartilaginous zones. Coincident with change in shape, cells stopped expressing the gap junction proteins connexins 32 and 43, with connexin 43 disappearing earlier in the transition than connexin 32. Thus, there are major differences in the ability of cells to communicate with one another in the phenotypically distinct regions of tendon. Individual fibrocartilage cells must sense alterations in the extracellular matrix by cell/matrix interactions, but can only coordinate their behaviour via indirect cytokine and growth factor signalling. The tendon cells have additional possibilities — in addition to the above, they have the potential to communicate direct cytoplasmic signals via gap junctions. The formation of fibrocartilage in tendons occurs because of the presence of compressive as well as tensile forces. It may be that different systems are used to sense and respond to such forces in fibrous and cartilaginous tissues.
The incidence of the lateral bridge of the atlas vertebra
Authors: MITCHELL JEANETTE
Published: March 2003

The vertebral artery, in its course from the subclavian artery to the basilar artery, is vulnerable to damage or distortion from external factors such as bony, ligamentous or muscular structures (Mehalic & Farhat, 1974; Parkin et al. 1978; Schellhas et al. 1980; Braun et al. 1983; Dunne et al. 1987; Fast et al. 1987). In the atlas vertebra, the retroarticular canal and the lateral bridge are examples of bony outgrowth or exostosis which may cause external pressure on the vertebral artery as it passes from the foramen transversarium of the vertebra to the foramen magnum of the skull. If this pressure is severe enough, as may occur during the extreme rotatory movements carried out during therapeutic manipulation of the cervical spine, the vertebral artery may be compressed (Lamberty & Zivanovich, 1973), reducing its cross‐sectional area, and compromising its blood flow (Taitz & Nathan, 1986). Vertebrobasilar ischaemia from compression of the vertebral arteries by osteophytes is an uncommon occurrence under normal circumstances (Warlow, 1996).

There are few studies of the lateral bridge of the atlas reported in the literature (MacAlister, 1869, 1893; Lamberty & Zivanovic, 1973; Saunders & Popovich, 1978; Taitz & Nathan, 1986). The lateral bridge was first described by MacAlister (1869, 1893) as a variety of the ‘posterior glenoid process’ (the retroarticular canal), which he termed the ‘gleno‐transverse bony arch’. As its name implies, it is a lateral outgrowth of bone from the superior articular facet or lateral mass to the posterior root of the transverse process of the atlas (MacAlister, 1869, 1893; Lamberty & Zivanovic, 1973; Saunders & Popovich, 1978; Taitz & Nathan, 1986). The retroarticular canal is formed by an exostosis passing from the posterior surface of the lateral mass to the posterior margin of the vertebral artery groove of the atlas. Thus the lateral bridge forms another arch, secondary to the retroarticular canal, through which the vertebral artery must pass (MacAlister, 1869).
Thyroid transcription factor‐1, hepatocyte nuclear factor‐3β and surfactant protein A and B in the developing chick lung
Authors: ZENG XIN , YUTZEY KATHERINE E. , WHITSETT JEFFREY A.
Published: March 2003

Expression of surfactant proteins SP‐A, SP‐B and the transcription factors TTF‐1 and HNF‐3β was identified by immunohistochemistry in the developing chicken. SP‐B, a small hydrophobic peptide critical for lung function and surfactant homeostasis in mammals, was detected in the epithelial cells of parabronchi in embryonic chicken lung from the 15th day of incubation, prior to the onset of the breathing movements and was expressed at high levels in the posthatching chicken lung. SP‐A, an abundant surfactant protein involved in innate defence of the mammalian lung, was detected in the chick embryo in subsets of epithelial cells in the mesobronchus, starting from d 15 and was detected in the posthatching chicken lung. The transcription factors hepatocyte nuclear factor 3β (HNF‐3β) and thyroid transcription factor‐1 (TTF‐1), both regulators epithelial cell differentiation and gene expression in mammalian species, were detected at the onset of lung bud formation (d 4 of incubation) and throughout lung development. Abundant nuclear expression was detected in nuclei of respiratory epithelial cells of developing bronchial tubules for both transcription factors. In contrast to the surfactant proteins, expression of both TTF‐1 and HNF‐3β decreased markedly in posthatching chicken lung. The expression of SP‐A and SP‐B in chick lung demonstrates the conservation of surfactant proteins in vertebrates. The temporospatial pattern of TTF‐1 and HNF‐3β overlaps with that of SP‐A and SP‐B, supporting their potential roles in chick lung development and demonstrating the conservation of regulatory mechanisms contributing to gene expression in respiratory epithelial cells in vertebrates.
Histological and cytological studies on the developing thymus of sharpsnout seabream, Diplodus puntazzo
Authors: ROMANO NICLA , FANELLI MONICA , DEL PAPA GIOVANNI MARIA , SCAPIGLIATI GIUSEPPE , MASTROLIA LUCIA
Published: March 2003

The structure of the developing thymus of the marine teleost, Diplodus puntazzo, was studied by light and transmission electron microscopy. The first anlage of the thymus developed by d 20 postfertilisation (p.f.) as a group of undifferentiated cells dorsal to the epithelium of the branchial chamber. The organ increased significantly in size around d 51–66 p.f. and differentiation of cortex and medulla occurred concomitantly. On the basis of their localisation, 4 main types of epithelial cell were distinguished: (1) limiting, adjacent to the connective capsule; (2) medullary and cortical reticular cells; (3) nurse cells, located in the corticomedullary boundary; (4) Hassall‐like corpuscles. The majority of medium to large blast‐like lymphoid cells were localised in the medulla, while small lymphocytes were housed in the cortical region. These morphological features were maintained at later stages. However, in juveniles in the medulla we observed reticular epithelial cells with cysts and rare Hassall‐like corpuscles. The study was designed to obtain more information concerning the histology of the developing thymus of sharpsnout seabream and give a concise description of the differentiation of epithelial cells and lymphoid cells in the thymic parenchyma.
Morphological and histochemical variations of mucous and oxynticopeptic cells in the stomach of the seps, Chalcides chalcides
Authors: FERRI DOMENICO , LIQUORI GIUSEPPA ESTERINA , SCILLITANI GIOVANNI
Published: March 2003

Mucous and oxynticopeptic cells in the gastric mucosa of the seps, Chalcides chalcides (Linnaeus, 1758) were examined by standard histochemical staining methods and by lectin histochemistry. The epithelial mucous cells lining the surface of the stomach and the mucous cells of the fundic glands elaborated mainly neutral glycoproteins with β(1,4)GlcNAc oligomers, GalNAc glycosidic residues and Galβ1,3GalNAc terminal sequences. The mucous cells of the fundic glands were stained specifically with the Paradoxical Con A method. The mucosecreting cells of the pyloric glands produced neutral glycoproteins, with β(1,4)GlcNAc oligomers, GalNAc residues and Galβ1,3GalNAc terminal sequences. Terminal L‐fucose bound to the penultimate GlcNAc residues, and/or difucosylated oligosaccharides were also present. The pyloric glands did not stain with the Paradoxical Con A procedure. The morphology of the oxynticopeptic cells changes from the oral to the aboral region of the fundic mucosa. In the oral fundic tract the oxynticopeptic cells showed cytoplasm filled with zymogen granules, while in the aboral fundic region these cells contained few zymogen granules and showed cytoplasm full of empty vesicles, typical of the acid secreting cells. A secretion gradient of proteolytic enzymes and hydrochloric acid along the fundic mucosa of the seps can be hypothesised.
Granulated metrial gland cells and interstitial trophoblast in the uterine wall of the bank vole, Clethrionomys glareolus, in early pregnancy
Authors: STEWART I. J. , CLARKE J. R.
Published: March 2003

The morphology and distribution of granulated metrial gland cells and of interstitial trophoblast cells in the uterine wall was studied in the first half of pregnancy in the bank vole, Clethrionomys glareolus. The morphology and distribution of granulated metrial gland cells was generally similar to that found in other members of the Rodentia, although they were absent from the walls of the arterial vessels passing through the decidua basalis. Interstitial trophoblast invaded the decidualising endometrium mesometrial to, and antimesometrial to, the implanted embryos. There was no apparent spatiotemporal relationship between the distribution of granulated metrial gland cells and interstitial trophoblast cells.
Morphology of the lymphoid organs of the bottlenose dolphin, Tursiops truncatus
Authors: COWAN DANIEL F. , SMITH TOBY L.
Published: March 2003

The anatomy of the lymphoid organs was studied during the course of detailed dissections of 50 beach‐stranded bottlenose dolphins, Tursiops truncatus. Constant lymph nodes occur in 4 groups, based on their location and structure. These groups are somatic, including nodes of the cervical region and pelvic recess; lung‐associated, included marginal, diaphragmatic and hilar nodes; visceral, including the mesenteric, pancreatic, pericolic and porta hepatis nodes; and aortic arch nodes. Lymphatic drainage of the lung is primarily to the marginal and diaphragmatic nodes. The mesenteric node mass is well‐endowed with capsular and trabecular smooth muscle, and a network of muscle fascicles within the organ implies an important contractile function in the circulation of lymph. In addition to constant nodes, occasionally nodes are found in relation to the thoracic aorta, the kidney, and under the scapula. Gut‐associated structures include dorsal and ventral oropharyngeal tonsils, mucosal aggregates in the straight segment of the intestine (colon) and anal tonsils; this gut‐associated lymphoid tissue tends to involute with age, being greatly reduced by puberty. Formed lymphoid organs include the thymus and the spleen, the latter being relatively small in relation to body size. None of these structures is unique among cetaceans, but the anal tonsils are particularly well developed in T. truncatus. The lymphoid aggregates in the colon resemble the arrangement in the vermiform appendix, which is lacking in most cetaceans, and may have functions analogous to that organ.
The topography, architecture and structure of the enteric nervous system in the jejunum and ileum of cattle
Authors: BALEMBA O. B. , MBASSA G. K. , SEMUGURUKA W. D. , ASSEY R. J. , KAHWA C. K. B. , HAY‐SCHMIDT A. , DANTZER V.
Published: March 2003

To date, there appear to have been no detailed and clear descriptions of the nerve plexuses and their subdivisions in the intestine of cattle. In this study, the enteric nervous system in the jejunum and ileum of 12 1‐y‐old calves was examined using neurofilament protein and vasoactive intestinal peptide immunohistochemistry in wholemounts and paraffin sections combined with staining of paraffin and historesin sections with haematoxylin and eosin. The main organisation of the plexuses was similar to that of the pig, horse and man with external and internal submucous plexuses being morphologically distinct, with further subdivisions of the internal submucous plexus into the external and internal subplexuses. However, in contrast to pig, horse and man, the submucous layer was firmly attached to the inner circular muscle layer. The myenteric plexus was well developed with large ganglia, and primary and secondary nerve strands. Its main axis was oriented parallel to the outer longitudinal smooth muscle; large ganglia and primary nerve strands fused to form complex ganglia, and 2 types of tertiary nerve strands were observed. Antibodies to neurofilament proteins and vasoactive intestinal peptide revealed adendritic, pseudouniaxonal or multiaxonal type II neurons only in the myenteric and submucous plexuses. This appears to be the first report of the identification of isolated uniaxonal, multidendritic type IV neurons in the mucous pericryptal plexus. The new information presented here provides further evidence for the existence of anatomical and functional differences between the external and internal submucous plexuses and for supporting the nomenclature proposed earlier.
Ultrastructural study of the relationship between the morphogenesis of filiform papillae and the keratinisation of the lingual epithelium in the rat
Authors: IWASAKI S. , YOSHIZAWA H. , KAWAHARA I.
Published: March 2003

Tongues were removed from rat fetuses on d 16 of gestation (E16) and from newborn (P0) and juvenile rats on d 7 (P7) and d 21 (P21) postnatally for examination by light and transmission electron microscopy. In the fetuses at E16, no rudiments of filiform papillae were visible on the dorsal surface of the tongue. No evidence of keratinisation could be recognised over the entire dorsal lingual epithelium. At P0, rudiments of filiform papillae showed a similar distribution to that seen in the adult, but had a more rounded appearance. The columnar structure of cells in the epithelium, with the different degrees of keratinisation as observed in the mature adult, was indistinct, but a keratinised layer was clearly located at the tip of each filiform papilla. In juveniles at P7, the filiform papillae on the anterior part of the tongue were long and slender, and the anterior and posterior cell columns of the filiform papillae and the interpapillary cell columns were clearly distinguishable. In juveniles at P21, the structure of filiform papillae was identical to that in the adult. These results indicate that, in rats, the morphogenesis of filiform papillae advances in parallel with keratinisation of the lingual epithelium from just before birth to a few weeks after birth.
Temporal expression of the matrix metalloproteinase MMP‐2 correlates with fibronectin immunoreactivity during the development of the vascular system in the chick embryo chorioallantoic membrane
Authors: RIBATTI DOMENICO , NICO BEATRICE , VACCA ANGELO , IURLARO MONICA , RONCALI LUISA
Published: March 2003

In this study we have examined in the chick embryo chorioallantoic membrane (ChAM) the expression of the matrix metalloproteinase 2 (MMP‐2) and have correlated this parameter with the expansion of the ChAM vasculature and with the expression of 3 extracellular matrix components (fibronectin, laminin and type IV collagen), which differentially modulate angiogenesis. In the early phases of ChAM development, between d 6 and d 8 of incubation, when the increase of the ChAM vasculature is maximal, higher values of MMP‐2 and, respectively, of fibronectin immunoreactive area, are detectable. These results indicate that MMP‐2 activity and fibronectin expression are 2 strictly related components of angiogenesis occurring in vivo.
The porcine bronchial artery. Anastomoses with oesophageal, coronary and intercostal arteries
Authors: GADE JOHN , NØRGAARD MARTIN A. , ANDERSEN CLAUS B. , JAKOBSEN HEIDI , BREITOWICZ BETTINA , SVENDSEN ULRIK G. , OLSEN PETER S.
Published: March 2003

Information abut the existence and anatomy of arterial anastomoses with the porcine bronchial artery is lacking in the literature. Prior to basic physiological investigations in a porcine model related to lung transplantation with bronchial artery revascularisation, this study was designed to examine the anatomy of systemic arterial anastomoses with the bronchial artery system. Twenty pigs were studied in 3 groups. In 2 groups the heart–lung block was removed with all mediastinal structures. One group served for investigation of coronary–bronchial artery anastomoses and one for investigation of oesophageal–bronchial artery anastomoses. The systemic arteries to be examined were cannulated. The inflated heart–lung block was examined macroscopically with Evans blue, and radiographically after contrast injection. In the 3rd group intercostobronchial artery anastomoses were studied radiographically with the heart–lung block in situ. Coronary–bronchial artery anastomoses were demonstrated in 3 of the 5 pigs with an aortic ‘pouch’ technique, but contrast was very limited in 2 of these 3. Oesophageal arterial anastomoses with bronchial arterial branches and/or the pulmonary veins were demonstrated in 6 of the 7 pigs and more markedly than the coronary–bronchial anastomoses. Intercostobronchial artery anastomoses could not be demonstrated angiographically. It was concluded that the existence of coronary–bronchial and oesophageal–bronchial artery anastomoses in the pig appear to establish an arterial net between the base of the heart and the distal oesophagus. The resemblance to human oesophageal–bronchial artery anastomoses supports use of a porcine model for experimental studies.
Kinetics of neovascularisation of splenic autotransplants in mice
Authors: ALVES HUMBERTO J. , VIANA GISELE , MAGALHÃES MÔNICA M. , ARANTES ROSA M. E. , COELHO PAULO M. Z. , CUNHA‐MELO JOSÉ R.
Published: March 2003

The aim of this study was to examine the kinetics of neovascularisation of splenic autoimplants into the abdominal cavity after splenectomy in mice. Sixty‐eight female Swiss mice were submitted to splenectomy. The spleen from each animal was sliced and the slices were implanted into the abdominal cavity. Groups of animals were killed after 1, 2, 3, 5, 7, 15, 21, 28, 42, 56, 70 and 84 d. Fluorescent polystyrene microspheres were injected via the orbital venous plexus before killing and the splenules were removed 5 min later for light and electron microscopy. Mesenteric blood vessels were injected with coloured latex to study the origin of the nutrient vessels. Three days after the implant the microspheres were observed at the periphery and then migrating to the internal parts of the implant in the subsequent days. The blood supply to the implants originated from branches of the splenic, short gastric, mesenteric and gastroepiploic arteries. It is concluded that revascularisation of splenic autografts proceeds centripetally, starting as early as 3 d after implantation.
Ultrastructural characterisation of the olfactory mucosa of the armadillo Dasypus hybridus (Dasypodidae, Xenarthra)
Authors: FERRARI C. C. , CARMANCHAHI P. D. , ALDANA MARCOS H. J. , AFFANNI J. M.
Published: March 2003

The ultrastructure of the olfactory mucosa of the armadillo Dasypus hybridus was studied. A comparison with the olfactory mucosa of another armadillo (Chaetophractus villosus) was made. The olfactory mucosa of D. hybridus shows many features which are similar to those of other mammals. Interestingly, it differs from the olfactory mucosa of the armadillo C. villosus. A suggestion is made that these differences may be due to differences in the digging habits of these species. In Dasypus, the supporting cells (SCs) showed dense vacuoles, multivesicular bodies and lysosome‐like bodies probably related with the endocytotic system. The SCs show a dense network of SER presumably associated with xenobiotic mechanisms. The olfactory receptor neurons exhibit lysosome‐like bodies and multivesicular bodies in their perikarya. These organelles suggest the presence of an endocytotic system. Duct cells of Bowman's glands exhibit secretory activities. Bowman's glands are compound‐branched tubulo‐acinar mixed glands with merocrine secretory mechanisms.
Investigating human evolutionary history
Authors: WOOD BERNARD
Published: March 2003

We rely on fossils for the interpretation of more than 95% of our evolutionary history. Fieldwork resulting in the recovery of fresh fossil evidence is an important component of reconstructing human evolutionary history, but advances can also be made by extracting additional evidence for the existing fossil record, and by improving the methods used to interpret the fossil evidence. This review shows how information from imaging and dental microstructure has contributed to improving our understanding of the hominin fossil record. It also surveys recent advances in the use of the fossil record for phylogenetic inference.
Editorial Announcement
Authors: THOMAS P. K. , COWEN T.
Published: March 2003

As from 1997, the Journal of Anatomy will be published in 8 issues per year instead of the current 6. The purpose is to reduce the time between acceptance and publication. Otherwise there will be no change in editorial policy. The Journal will continue to publish high quality papers on human and comparative anatomy and cell biology, both experimental and descriptive. Articles on experimental pathology are also acceptable if they contribute to the understanding of normal structure and function. Review articles, if topical and authoritative, are welcome. Short reports are published: these should not exceed 5 pages of printed text. Reports on isolated anatomical variations, if of sufficient interest and relevance, are now included in the Correspondence section, to which letters on matters arising out of previously published papers or on questions of general anatomical interest can be submitted.
Innervation of NADPH diaphorase‐containing neurons correlated with acetylcholinesterase, tyrosine hydroxylase, and neuropeptides in the pigeon cloaca
Authors: ATOJI YASURO , YAMAMOTO YOSHIO , SUZUKI YOSHITAKA
Published: March 2003

The motility of the avian cloaca is under neural control, but little is known about the neural network that accomplishes this function. This present study was designed to determine the distribution of nitric oxide‐synthesising neurons in the pigeon cloaca by enzyme histochemistry for reduced nicotinamide adenine dinucleotide phosphate‐diaphorase (NADPH‐d). NADPH‐d‐positive staining was seen in the neurons and fibres in the cloaca. The highest density of nerve fibres was noted in the coprodeum and the lowest in the proctodeum. In the coprodeum, NADPH‐d neurons were found singly, formed small groups of 2–10 neurons, or were seen in plexuses in the muscle layer, lamina propria, or around the arterioles. Several NADPH‐d‐positive neurons were also observed in the ganglia of the cloaca. NADPH‐d fibres ran in the muscle layer, lamina muscularis mucosae and lamina propria, or surrounded blood vessels. The distribution pattern of acetylcholinesterase (AChE)‐stained neurons and fibres in the cloaca was similar to that of NADPH‐d. Double staining for NADPH‐d and AChE showed colocalisation of the 2 enzymes in many neurons of the cloaca. Tyrosine hydroxylase (TH)‐immunoreactive nerve fibres originating outside the cloaca were also noted. In the urodeum and proctodeum, neurons or fibres positive for NADPH‐d, AChE or TH were scattered in the lamina propria. Nerve fibres immunoreactive for calcitonin‐gene related peptide, galanin, methionine‐enkephalin, substance P, and vasoactive intestinal peptide were found sparsely in the cloaca. Our results demonstrate that nitrergic neurons constitute a subpopulation which is closely associated with the cholinergic system in the pigeon cloaca.
Ultrastructural response of pulmonary intravascular macrophages to exogenous oestrogen in the bovine lung: translocation of the surface‐coat and enhanced cell membrane plasticity and angiogenesis
Authors: ATWAL ONKAR S. , MINHAS KANWAL J. , WILLIAMS CAROL S.
Published: March 2003

The pulmonary intravascular macrophages (PIMs) of domestic ungulates are recognised by their specific surface coat, consisting of linearly arranged globules along the external leaf of the plasma membrane. The coat is sensitive to in vitro digestion with lipolytic lipase (LPL), intravenous heparin and clinical exposure to halothane anaesthesia. The sensitivity to these experimental manipulations suggests that the globules of the coat are predominantly composed of lipoproteins (LDL). The present administration of oestradiol proprionate in castrated male calves potentiated the translocation of the surface coat into the endocytotic pathway of the PIMs. Concurrently with mobilisation of the coat, the plasma membrane was thrown into prominent arrays of lamellipodial extensions. The sprawling macrophages made extensive adhesive contacts with the lining endothelium of the capillaries. Consequently, the endothelial cells were highly attenuated and precariously maintained the integrity of the vascular wall. At some focal points, the vascular wall was penetrated by the filopodial processes of PIMs, which protruded into the perivascular space. Furthermore, there were signs of neovascularisation in the form of overt mitotic changes, sprouting and precursor capillary formation. It is conceivable that the evolving profile of angiogenesis is due to the vascular endothelial growth factor (VEGF) paracrine function of PIMs. Endothelial cell specificity has been considered an important advantage of VEGF for neovascularisation. It allows pleotrophic response of endothelial cells to proliferate and to assemble into endothelial tubes.
Insect oenocytes: a model system for studying cell‐fate specification by Hox genes
Authors: GOULD ALEX P. , ELSTOB PHILIP R. , BRODU VÉRONIQUE
Published: March 2003

abstract

During insect development, morphological differences between segments are controlled by the Hox gene family of transcription factors. Recent evidence also suggests that variation in the regulatory elements of these genes and their downstream targets underlies the evolution of several segment‐specific morphological traits. This review introduces a new model system, the larval oenocyte, for studying the evolution of fate specification by Hox genes at single‐cell resolution. Oenocytes are found in a wide range of insects, including species using both the short and the long germ modes of development. Recent progress in our understanding of the genetics and cell biology of oenocyte development in the fruitfly Drosophila melanogaster is discussed. In the D. melanogaster embryo, the formation of this cell type is restricted to the first 7 abdominal segments and is under Hox gene control. Oenocytes delaminate from the dorsal ectoderm of A1‐A7 in response to an induction that involves the epidermal growth factor receptor (EGFR) signalling pathway. Although the receptor itself is required in the presumptive oenocytes, its ligand Spitz (Spi) is secreted by a neighbouring chordotonal organ precursor (COP). Thus, in dorsal regions, local signalling from this component of the developing peripheral nervous sytem induces the formation of oenocytes. In contrast, in lateral regions of the ectoderm, Spi signal from a different COP induces the formation of secondary COPs in a homeogenetic manner. This dorsoventral difference in the fate induced by Spi ligand is controlled by a prepattern in the responding ectoderm that requires the Spalt (Sal) transcription factor. Sal protein is expressed in the dorsal but not lateral ectoderm and acts as a competence modifier to bias the response to Spi ligand in favour of the oenocyte fate. We discuss a recently proposed model that integrates the roles of Sal and the EGFR pathway in oenocyte/chordotonal organ induction. This model should provide a useful starting point for future comparative studies of these ectodermal derivatives in other insects.
Frequency variations of discrete cranial traits in major human populations. IV. Vessel and nerve related variations
Authors: HANIHARA TSUNEHIKO , ISHIDA HAJIME
Published: March 2003

This concludes a series of descriptive statistical reports on discrete cranial traits in 81 human populations from around the world. Four variants classified as vessel and nerve related characters were investigated: patent condylar canal; supraorbital foramen; accessory infraorbital foramen; and accessory mental foramen. A significant asymmetric occurrence without any side preference was detected for the accessory mental foramen. Significant intertrait associations were found between the accessory infraorbital and supraorbital foramina in the panPacific region and Subsaharan African samples. The intertrait associations between the accessory infraorbital foramen and some traits classified as hypostotic were found mainly in the samples from the western part of the Old World, and those as hyperostotic traits in the samples from eastern Asian and the related population samples. With a few exceptions, the occurrence of a patent condylar canal and a supraorbital foramen was predominant in females, but the accessory infraorbital and accessory mental foramina were predominant in males. The frequency distributions of the traits showed interregional clinality and intraregional discontinuity. A temporal trend was found in the Northeast Asian region in the frequencies of the accessory infraorbital and accessory mental foramina. The diversity of modern human discrete cranial traits may at least in part be attributable to differential retention or intensification from an ancestral pattern.
Persistent sciatic vessels associated with an arteriovenous malformation
Authors: KURTOĞLU ZELIHA , ULUUTKU HALUK
Published: March 2003

The sciatic artery is the major arterial supply to the lower limb bud at an early embryological stage. It primarily originates from the dorsal root of the umbilical artery. After the 22 mm embryological stage, the sciatic artery involutes and the femoral artery system develops as the major inflow source to the lower limb. In the adult, remnants of the sciatic artery persist as the proximal portion of the inferior gluteal artery, the popliteal and peroneal arteries (Williams et al. 1989). It is suggested that either failure in development of the femoral system or failure in regression of the sciatic artery results in persistence of this artery (Arey, 1965). We report a rare example of persistent sciatic artery (PSA) accompanied by arterio‐arterial and arteriovenous anastomoses.
The sacroiliac part of the iliolumbar ligament
Authors: POOL‐GOUDZWAARD A. L. , KLEINRENSINK G. J. , SNIJDERS C. J. , ENTIUS C. , STOECKART R.
Published: March 2003

The iliolumbar ligament has been described as the most important ligament for restraining movement at the lumbosacral junction. In addition, it may play an important role in restraining movement in the sacroiliac joints. To help understand its presumed restraining effect, the anatomy of the ligament and its orientation with respect to the sacroiliac joints were studied in 17 cadavers. Specific dissection showed the existence of several distinct parts of the iliolumbar ligament, among which is a sacroiliac part. This sacroiliac part originates on the sacrum and blends with the interosseous sacroiliac ligaments. Together with the ventral part of the iliolumbar ligament it inserts on the medial part of the iliac crest, separate from the interosseous sacroiliac ligaments. Its existence is verified by magnetic resonance imaging and by cryosectioning of the pelvis in the coronal and transverse plane. Fibre direction, length, width, thickness and orientation of the sacroiliac part of the iliolumbar ligament are described. It is mainly oriented in the coronal plane, perpendicular to the sacroiliac joint. The existence of this sacroiliac part of the iliolumbar ligament supports the assumption that the iliolumbar ligament has a direct restraining effect on movement in the sacroiliac joints.
Thoracic splanchnic nerves: implications for splanchnic denervation
Authors: NAIDOO N. , PARTAB P. , PATHER N. , MOODLEY J. , SINGH B. , SATYAPAL K. S.
Published: March 2003

Splanchnic neurectomy is of value in the management of chronic abdominal pain. It is postulated that the inconsistent results of splanchnicectomies may be due to anatomical variations in the pattern of splanchnic nerves. The advent of minimally invasive and video‐assisted surgery has rekindled interest in the frequency of variations of the splanchnic nerves. The aims of this study were to investigate the incidence, origin and pattern of the splanchnic nerves in order to establish a predictable pattern of splanchnic neural anatomy that may be of surgical relevance. Six adult and 14 fetal cadavers were dissected (n = 38). The origin of the splanchnic nerve was bilaterally asymmetrical in all cases. The greater splanchnic nerve (GSN) was always present, whereas the lesser splanchnic nerve (LSN) and least splanchnic nerve (lSN) were inconsistent (LSN, 35 of 38 sides (92%); LSN, 21 of 38 sides (55%). The splanchnic nerves were observed most frequently over the following ranges: GSN, T6–9: 28 of 38 sides (73%); LSN, when present, T10–11: (10 of 35 sides (29%); and lSN, T11–12: 3 of 21 sides (14%). The number of ganglionic roots of the GSN varied between 3 and 10 (widest T4–11; narrowest, T5–7). Intermediate splanchnic ganglia, when present, were observed only on the GSN main trunk with an incidence of 6 of 10 sides (60%) in the adult and 11 of 28 sides (39%) in the fetus. The higher incidence of the origin of GSN above T5 has clinical implications, given the widely discussed technique of undertaking splanchnicectomy from the T5 ganglion distally. This approach overlooks important nerve contributions and thereby may compromise clinical outcome. In the light of these variations, a reappraisal of current surgical techniques used in thoracoscopic splanchnicectomy is warranted.
Histology and immunohistochemistry of the gut‐associated lymphoid tissue of the eastern grey kangaroo, Macropus giganteus
Authors: OLD JULIE M. , DEANE ELIZABETH M.
Published: March 2003

Mesenteric lymph nodes and gut‐associated lymphoid tissue (GALT) from juvenile eastern grey kangaroos were investigated. The mesenteric nodes had a similar structure to that described for eutherian mammals. They contained distinct regions of medulla and cortex, with prominent follicles and germinal centres. Gut associated lymphoid tissue consisted of areas of submucosal follicles. These varied from areas of densely packed lymphocytes with darkly staining, prominent coronas to areas with no defined follicles. The distribution of T cells in these tissues was documented by use of species‐crossreactive antibodies to the surface markers CD3 and CD5; B cells were identified by antibodies to CD79b. Within the lymph nodes T cells were located mainly in the paracortex and cortex, with limited numbers observed in the follicles; B cells were located on the marginal zone of the follicles. In GALT, T cells were located in the peripheral regions of the germinal centres of secondary follicles, while B cells were abundant in primary follicles. These observations are consistent with those made in a range of other marsupials (metatherian) and eutherian mammals and are indicative of the capacity to respond to antigens entering via the mouth.
Vimentin, cytokeratin 8 and cytokeratin 18 are not specific markers for M‐cells in human palatine tonsils
Authors: KOSHI RACHEL , MUSTAFA YARDULAK , PERRY MARTA E.
Published: March 2003

Standard immunohistochemical methods were used to detect the presence of vimentin, cytokeratin 8, cytokeratin 18, macrophages and Langerhans cells in the human tonsillar epithelium in formalin‐fixed and frozen tissue specimens. Vimentin detection was restricted to infiltrating cells of the lymphoid series, dendritic and vascular endothelial cells. All epithelial cells were negative. Cytokeratin 8 and 18 were readily detected in a large proportion of epithelial cells lining the crypt, but these cells bore no resemblance to the intestinal M‐cells. Langerhans cells and macrophages were seen in both the oropharyngeal and crypt epithelium and were more common in the latter. This study confirms the presence of antigen‐presenting cells, macrophages and Langerhans cells in the tonsillar epithelium and shows that intermediate filament proteins, vimentin, cytokeratin 8 and 18 are unreliable markers for human tonsillar M‐cells, if indeed such cells exist in human tonsils.
Myoarchitecture and vasculature of the heart ventricle in some freshwater teleosts
Authors: Simões K. , Vicentini C. A. , Orsi A. M. , Cruz C.
Published: March 2003

The morphological characteristics of the ventricular myocardium and of coronary vascularization were studied in three freshwater teleost species, Piaractus mesopotamicus, Colossoma macropomum and Clarias gariepinus (African catfish), by correlating their ventricular shapes and swimming habits. In Piaractus mesopotamicus and Colossoma macropomum, species with highly active swimming habits, the cardiac ventricle showed a pyramidal shape and a richly vascularized myocardium consisting of an outer compact layer and inner spongy layer. In Clarias gariepinus, a less active species, we observed a saccular ventricle with a mixed myocardium and coronary arteries, in contrast to the ventricular structure of other species described in the literature.
Human ES cells – haematopoiesis and transplantation strategies*
Authors: Kaufman D. S. , Thomson J. A.
Published: March 2003

Human embryonic stem (ES) cells provide a novel opportunity to study early developmental events in a human system. We have used human ES cell lines, including clonally derived lines, to evaluate haematopoiesis. Co‐culture of the human ES cells with irradiated bone marrow stromal cell lines in the presence of fetal bovine serum (FBS), but without other exogenous cytokines, leads to differentiation of the human ES cells within a matter of days. A portion of these differentiated cells express CD34, the best‐defined marker for early haematopoietic cells. Haematopoietic colony‐forming cells (CFCs) are demonstrated by methylcellulose assay. Myeloid, erythroid, megakaryocyte and multipotential CFCs can all be derived under these conditions. Enrichment of CD34+ cells derived from the human ES cells markedly increases the yield of CFCs, as would be expected for cells derived from adult bone marrow or umbilical cord blood. Transcription factors are also expressed in a manner consistent with haematopoietic differentiation. This system now presents the potential to evaluate specific conditions needed to induce or support events in early human blood development. Human ES cells are also a novel source of cells for transplantation therapies. The immunogenicity of ES cell‐derived cells is unknown. The unique properties of ES cells afford the opportunity to explore novel mechanisms to prevent immune‐mediated rejection. Potential strategies to overcome rejection will be presented, including creation of haematopoietic chimerism as a means to successfully transplant cells and tissues derived from human ES cells.
De‐ and remyelination in spinal roots during normal perinatal development in the cat: a brief summary of structural observations and a conceptual hypothesis
Authors: Berthold C.‐H. , Remahl I. Nilsson
Published: March 2003

We have studied the perinatal development of large myelinated axons (adult D > 10 µm) in cat ventral and dorsal lumbo‐sacral spinal roots using autoradiography and electron microscopy (serial section analysis). These axons acquire their first myelin sheaths 2–3 weeks before birth and show nearly mature functional properties first at a diameter of 4–5 µm, i.e. 3–4 weeks after birth. The most conspicuous event during this development takes place around birth, when a transient primary myelin sheath degeneration strikes already well myelinated although short ‘aberrant’ Schwann cells. The aberrant Schwann cells become completely demyelinated, then measuring about 10 µm in length, and are subsequently eliminated from their parent axons. Morphometry indicates that on average 50% of the Schwann cells originally present along a prospective large spinal root axon suffer elimination. Here it should be noted that in cat lumbo‐sacral spinal roots, the longitudinal growth of myelinated Schwann cells that belong to the group containing what will be the largest fibers is on average twice that of their parent axons. The elimination phenomenon is particularly striking in the dorsal roots close to the spinal cord where CNS tissue invades the root for several hundred micrometres. Our observations suggest that, once demyelinated and then eliminated, Schwann cells (i.e. aberrant Schwann cells) colonize neighbouring axons, future myelinated as well as future unmyelinated ones. In the former case the immigrant Schwann cells appear to start myelin production, possibly risking a second demyelination and elimination. We take our observations to indicate that Schwann cells in the cat, during normal development, may switch iteratively between a ‘myelin‐producing’ and a ‘non‐myelin‐producing’ phenotype. From a functional point of view the transient presence along a myelinated axon of intercalated unmyelinated segments ∼10 µm long, due to aberrant Schwann cells, would mean a slowing down of the action potential. The rapid disappearance of aberrant Schwann cells during the two first postnatal weeks could then explain the progressing normalization of the leg‐length conduction time.
Dejerine–Sottas syndrome grown to maturity: overview of genetic and morphological heterogeneity and follow‐up of 25 patients*
Authors: Gabreëls‐Festen Anneke
Published: March 2003

Dejerine–Sottas syndrome (DSS) is an early onset demyelinating motor and sensory neuropathy with motor nerve conduction velocities below 12 m s−1. The phenotype is genetically heterogeneous, and autosomal dominant (AD) as well as autosomal recessive (AR) inheritance is described. Nerve pathology is highly variable. It is generally presumed that clinical course is severe, leading to wheelchair dependency at an early age. In this study we documented the clinical and pathological features in 25 patients with a DSS and we evaluated the clinical course. In our series 14 patients had an AD mutation and six were probably affected by an AR disorder. In three patients inheritance mode was unknown and two patients obviously suffered from an acquired disorder. The clinical course in all patients was documented. Nine of the 25 patients showed a moderate handicap in adult life; walking distance was still at least 1 km. Age at last investigation of the ambulant patients ranged from 22 to 62 years (mean 38.6 years), and ambulant patients were found in all genetic subgroups. We conclude that DSS, although in general denoting a more serious neuropathy than CMT1, does not imply a severe disability or wheelchair dependency in adult life.
The effects of high glucose on connexin 43 in human endothelial cells
Authors: Willmott T. , Leach L.
Published: March 2003

Connexins (cx) are a family of gap junctional proteins found in most mammalian cells with cx43 being one of the residents in endothelial cells. Gap junctional communications are thought to play a major role in maintaining tissue homeostasis and in angiogenesis. The latter functions are impaired in diabetes mellitus but the specific role of connexins in this pathology is currently not known. The aim of this study was to identify any changes in surface expression of cx43 in primary endothelial cells isolated from the human umbilical cord (HUVEC) and exposed to different duration of glycaemic insult. Cells were grown in euglycaemic (5 mm D glucose) and hyperglycaemic (25 mm d‐glucose) conditions with l‐glucose as the osmotic control for 2, 7 and 14 d. Confocal microscopy using identical laser settings was employed to look at both pattern of localisation and fluorescence intensity. At d 2, under euglycaemic conditions cx43 was localised throughout the cytosol (punctate labelling) but predominantly at perinuclear regions. Cx43 was also seen at cell‐cell margins as a diffuse ‘zigzag’ pattern. By 7 d this latter staining at cell‐cell borders resembled a ‘beads on a string’ formation, indicative of discrete gap junctions. By 14 d the cells were forming tubes with punctate labelling throughout the cytosol and beads on a string localisation in the paracellular clefts. Cells cultured in 25 mm d‐glucose showed a different pattern of expression of cx43; at 2 d cx43 was present as discrete puncta at cell‐cell borders and throughout the cytosol and perinuclear region. Both fluorescent intensity and frequency of puncta appear diminished. By 7 d cell‐cell borders are immuno‐negative to cx43. By 14 d HUVEC cells had formed tubes. There was intense immunoreactivity to cx43 in the cytosol but not at paracellular clefts. This change in expression pattern is not an osmotic effect as the cells cultured in 25 mm l‐glucose reflected a similar pattern of expression as cells grown in euglycaemic conditions. In conclusion this study is a first indication that hyperglycaemia alters targetting of cx43 to cell‐cell borders and formation of connexons.

Funded by Smith & Nephew & The University of Nottingham