bluuebunny/crossref_metadata_2025 huggingface dataset:
A superficial ulnar artery anastomosing with a larger anterior interosseous artery to supply the wrist and hand
Authors: SAÑUDO J. R. , MIRAPEIX R. M. , GARCIA R. , RODRIGUEZ‐NIDENFÜNR M.
Published: March 2003

The term superficial ulnar artery (SUA) is applied to an artery which arises from the axillary, brachial or superficial brachial arteries and courses over the origins of the superficial forearm muscles to join at the midlevel of the forearm with the ulnar artery, sometimes replacing it (Wankoff, 1962; Lippert & Pabst, 1985; Nakatani et al. 1996, 1997). Its incidence ranges from 0.7% (Adachi, 1928) to 3.3% (Müller, 1903). The SUA has been reported with different terminologies; arteria antebrachialis superficialis ulnaris (Gruber, 1867; Müller, 1903; Adachi, 1928), high origin of the ulnar artery (Rodriguez‐Baeza et al. 1995; Aharinejad et al. 1997) and SUA with a high origin (Fuss, 1988).

The present observation adds several aspects to the anatomical variations of the superficial ulnar arteries already described, most notably its anastomosis with the anterior interosseous artery. This anastomosis has previously been reported twice (Quain, 1844; Gruber, 1867) but without explanation as to the course taken by the anastomotic branch. The SUA was found in the right arm of a 66‐y‐old male during routine dissections in the Unit of Anatomy and Embryology at the Autonomous University of Barcelona.
Fluorescence‐aided detection of microdamage in compact bone
Authors: LEE T. C. , MYERS E. R. , HAYES W. C.
Published: March 2003

En bloc staining with basic fuchsin is an established method for demonstrating microdamage in bone. Using transmitted light microscopy, variations in light intensity, depth of focus and magnification are necessary to distinguish fully‐stained microcracks generated in vivo, from partially‐stained or unstained artefactual cracks due to cutting and machining. This process is both difficult and time‐consuming. In this study, 2 methods were used to examine fuchsin‐stained microcracks in human rib sections, transmitted light and epifluorescence microscopy. No differences were found in crack number, density or length between the 2 methods indicating comparable accuracy. Using green epifluorescence, only microcracks containing fuchsin fluoresced orange against the darkfield background, enabling unstained, artefactual cracks to be screened out. Under UV epifluorescence, microcracks stained through the full 100 μm depth of the section fluoresced purple. Partially‐stained artefactual cracks failed to fluoresce and were screened out. Epifluorescence is a simple, rapid and accurate screening method for differentiating fully‐stained from artefactual microcracks in bone.
Symposium on Computer Modelling for Anatomists and Clinicians
Authors: KAUFMAN M. H.
Published: March 2003

The following review articles are based on presentations given at a Symposium on Computer Modelling for Anatomists and Clinicians held in July 1997 at the Department of Anatomy, University of Edinburgh. The Symposium formed part of the Summer Meeting of the Anatomical Society of Great Britain and Ireland. There were 6 invited speakers, and 4 of these have produced review articles which are published in this issue of the Journal. In 3 of the presentations, recent advances in the use of 3D methodology to analyse mouse and human developmental anatomy were described. The reviews by Kaufman et al. and Baldock et al. (the latter to be published in a forthcoming issue of the Journal) complement each other in that they describe different aspects of a collaborative project (the Mouse Atlas Project, or MAP) involving the preparation of a text database of mouse developmental anatomy and a digital Atlas of normal mouse development. In the first of these presentations the principles underlying the methodology employed to reconstruct a range of early post‐implantation mouse embryos spanning the stages between the primitive streak and the early limb‐bud that had previously been serially sectioned was briefly described. Because of the efficiency of the computer technology involved (termed the warping program), the grey level images of the embryo histology could be arbitrarily resectioned to view the embryo as if sectioned in any orientation. Furthermore, all anatomically‐defined tissues could be individually delineated (or painted) and viewed either in isolation or in combination with other appropriately labelled tissues and organs.
The degenerative fate of germ cells not conforming to stage in the pubertal golden hamster testis
Authors: MIETHING ANDREAS
Published: March 2003

In the golden hamster (Mesocricetus auratus), pubertal establishment of spermatogenesis includes a defined period (d 26–30 of life) during which elongation of spermatids is selectively arrested. The resulting appearance of germ cell associations not conforming to stage and the phenomenon of desynchronisation‐related germ cell degeneration are analysed both quantitatively and qualitatively by means of light and ‘retrospective’ electron microscopy. From d 26 onwards, the portion of tubules containing non‐stage conforming germ cell associations gradually increases up to 37.5% of sectioned tubules on d 32. Concomitantly, the degree of desynchronisation rises to a maturational gap between spermatids and associated younger germ cells of 7 stages of the seminiferous epithelium cycle, i.e. of fully half a cycle. Beyond d 32, the frequency of desynchronised tubule segments decreases again. Some of the arrested round spermatids and, eventually, all belatedly elongating spermatids degenerate and are lost from the epithelium. Thus a regular maturation of advanced spermatids does not succeed under non‐stage conforming conditions. Possibly it is not the desynchronisation between the associated germ cell generations and the spermatids by itself that impedes normal further development of the latter cells. Instead this may be due to the maturational delay of the stage‐aberrant cells by several stages compared to the seminiferous epithelium as a whole and, especially, in relation to the stage‐conditioned functional state of the neighbouring Sertoli cells.
Maternal adrenocortical hormones maintain the early development of pancreatic B cells in the fetal rat
Authors: KOMATSU SUGURU , YAMAMOTO MASAKO , ARISHIMA KAZUYOSHI , EGUCHI YASUNOBU
Published: March 2003

To investigate the effect of maternal adrenocortical hormones on the development of fetal pancreatic islet cells, pregnant rats were adrenalectomised on d 6 of gestation. On d 12–16 the growth patterns of fetal insulin‐producing B cells, glucagon‐producing A cells, and somatostatin‐producing D cells were observed histometrically. Maternal adrenalectomy resulted in growth retardation of fetal B cells on d 12–15. Maternal corticosterone therapy prevented this retardation. Maternal adrenalectomy, however, did not affect the developmental patterns of A and D cells. By Western blotting and immunohistochemistry, glucocorticoid receptors were demonstrated to be present in the islet cells from d 12 to d 15. These results suggest that maternal adrenocortical hormones, glucocorticoids in particular, maintain the early development of fetal pancreatic B cells through their specific intracellular glucocorticoid receptor.
Morphology of intraepithelial corpuscular nerve endings in the nasal respiratory mucosa of the dog
Authors: YAMAMOTO Y. , KONDO A. , ATOJI Y. , TSUBONE H. , SUZUKI Y.
Published: March 2003

Corpuscular nerve endings in the nasal respiratory mucosa of the dog were investigated by immunohistochemical staining specific for protein gene product 9.5 by light and electron microscopy. In the nasal respiratory mucosa, complex corpuscular endings, which displayed bulbous, laminar and varicose expansions, were distributed on the dorsal elevated part of the nasal septum and on the dorsal nasal concha. The endings were 300–500 μm long and 100–250 μm wide. Some axons gave rise to a single ending while others branched into 2 endings. Cryostat sections revealed that the corpuscular endings were located within the nasal respiratory epithelium. On electron microscopy, immunoreactive nerve terminals that contained organelles, including mitochondria and neurofilaments, were observed within the epithelial layer near the lumen of the nasal cavity. Some terminals contacted the goblet cell. Such terminal regions were covered by the cytoplasmic process of ciliated cells and were never exposed to the lumen of the nasal cavity. These nerve endings are probably activated by pressure changes.
Adrenergic innervation in reactive human lymph nodes
Authors: PANUNCIO A. L. , DE LA PEÑA S. , GUALCO G. , REISSENWEBER N.
Published: March 2003

Several experimental models have demonstrated that the central nervous system is functionally linked to the immune system by means of the autonomic nervous system. Samples of 36 lymph nodes of patients whose ages ranged from 16 to 69 y were studied. In order to demonstrate the existence and distribution of sympathetic nerve fibres, a polyclonal antibody antityrosine hydroxylase (TH), with the streptavidin‐biotin system of detection, was used. TH‐positive nerve fibres appeared in all reactive patterns of the lymph nodes studied. Thin nerve fascicles ramified at the hilar region and also in the connective tissue septae. Adventitial adrenergic nerve fibres were found following afferent, and to a lesser extent, efferent blood vessels. Another source of incoming nerve fibres was found at capsular level, accompanying blood vessels. On the arterial side, the innervation ceased before reaching the follicular arterioles. Our demonstration of innervation in postcapillary venules could support a regulatory role of adrenergic neurotransmitters in lymphocyte traffic. Occasional nerve fibres were also seen in T areas among parenchymatous cells. These findings confirm the existence of sympathetic innervation in human lymph nodes, and provide indirect evidence that the psychoneuroimmune axis could also exist in humans.
Differences in the width of the intercellular spaces in the epithelial basal infolding and the renal glomerular filtration site between freeze‐substitution and conventional fixation
Authors: IWASA HIROO , KONDO HISATAKE
Published: March 2003

After aldehyde prefixation, pretreatment with cryoprotectant and subsequent freeze‐substitution with OsO4 in acetone (AC‐FS), extensive gap junction‐like close membrane appositions are frequently found in the basal infolding of the salivary gland epithelium, although the desmosomal intercellular space had the same width as with conventional electron microscopy. The intercellular space between podocyte pedicles and endothelial cells at the renal glomerular filtration site was narrower by the total width of 2 laminae lucidae following AC‐FS than with conventional electron microscopy and was occupied by a homogeneous lamina densa without a lamina lucida, although no marked difference was discernable in the thickness of the lamina densa itself between the 2 preparative procedures. In addition, a decrease in the thickness of the glycocalyx was evident in the intestinal epithelial microvilli following AC‐FS. It is thus likely that osmication in acetone at freezing temperatures remove the glycocalyx and related structures to a variable extent, and that this loss is responsible for reducing the intercellular spaces at some of the simple appositions narrower to the dimensions of the gap junction. It is also responsible for disappearance of the lamina lucida of the basement membrane.
Quantitative analysis of the sympathetic innervation of the rat knee joint
Authors: CATRE MEL G. , SALO PAUL T.
Published: March 2003

Retrograde tracing with Fluoro‐Gold (FG) was used to identify the complete population of knee joint sympathetic postganglionic efferents in the lumbar sympathetic chain of adult female Wistar rats. In 6 rats, the total number and distribution of FG‐labelled neurons in the lumbar sympathetic chain was determined. The rat knee joint is supplied by an average of 187±57 sympathetic afferents with the majority at the L3 and L4 levels. Immunohistochemistry using antibodies specific for tyrosine hydroxylase (TH), somatostatin (SS) or vasoactive intestinal polypeptide (VIP) revealed that 33% of knee joint sympathetic afferents contained TH, 42% contained VIP, and none contained somatostatin. Retrograde tracing with FG provided accurate and reproducible labelling of the joint‐innervating subpopulation of sympathetic efferent neurons. This model lends itself to the further study of the molecular responses of this neuronal population in the various disorders and conditions affecting joints.
Case report: bilateral occurrence of a chondroepitrochlearis muscle
Authors: FLAHERTY G. , O'NEILL M. N. , FOLAN‐CURRAN J.
Published: March 2003

The chondroepitrochlearis is an extremely rare muscular anomaly. Bergman et al. (1988) in their book on anatomical variations refer to ‘costoepitrochlearis, chondroepitrochlearis, or chondrohumeralis’ and describe the anomaly as a muscular slip which arises from one or more ribs, crosses the axilla, and inserts into the median intermuscular septum or medial humeral epicondyle. The phylogenetic significance of the muscle has received attention (Landry, 1958; Chiba et al. 1983; Bergman, 1991), and case reports with ulnar nerve entrapment and restriction of arm movements (FitzGerald, 1935–1936; Voto & Weiner 1987; Lin, 1988; Spinner et al. 1991) have emphasised its clinical relevance.
Neuronal nitric oxide synthase in the neural pathways of the urinary bladder
Authors: ZHOU YUAN , LING ENG‐ANG
Published: March 2003

Nitric oxide (NO) is a unique biological messenger molecule. It serves, in part, as a neurotransmitter in the central and peripheral nervous systems. Neurons containing NO have been identified histochemically by the presence of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH‐d) reactivity or immunohistochemically by the antibody for neuronal NO synthase (n‐NOS). Previous histochemical or pharmacological studies have raised the possibility that NO may play an important role in the neural pathways of the lower urinary tract. There is also considerable evidence to suggest that n‐NOS is plastic and could be upregulated following certain lesions in the lower urinary tract. The present review summarises the distribution of n‐NOS containing neurons innervating the urinary bladder and the changes of the enzyme expression in some experimentally induced pathological conditions.
PROFESSOR ROBERT WALMSLEY (1906–1998)
Authors: FRAME JOHN , SINCLAIR DAVID
Published: March 2003

Robert Walmsley, Emeritus Professor of Anatomy at the University of St Andrews, died on 24 August 1998 aged 92. He was appointed Bute Professor of Anatomy in St Andrews University in 1946, after a distinguished career in the University of Edinburgh, where he was appointed demonstrator in Anatomy with J. C. Brash as professor and E. B. Jamieson as senior lecturer. He carried out studies on the vertebral column and the knee joint with John Bruce (later Sir John Bruce), Professor of Surgery in Edinburgh, with whom he was associated in the production of 3 editions of a textbook of surgical anatomy. His work on the vascular system of the whale, conducted at the Carnegie Institute of Embryology in Baltimore, USA, was the subject of his thesis for the MD (Edinburgh University) which was awarded with honours and gold medal in 1937.
Histological and immunohistological investigation of lymphoid tissue in the platypus (Ornithorhynchus anatinus)
Authors: CONNOLLY J. H. , CANFIELD P. J. , McCLURE S. J. , WHITTINGTON R. J.
Published: March 2003

The gross and histological appearance and the distribution of T and B lymphocytes and plasma cells are described for lymphoid tissues obtained from 15 platypuses. The spleen was bilobed and surrounded by a thick capsule of collagen, elastic fibres and little smooth muscle. White pulp was prominent and included germinal centres and periarterial lymphoid sheaths. Red pulp contained haematopoietic tissue. A thin lobulated thymus was located within the mediastinum overlying the heart. The cortex of lobules consisted of dense aggregates of small and medium lymphocytes, scattered macrophages and few reticular epithelial cells. In the medulla, Hassall's corpuscles were numerous, lymphocytes were small and less abundant, and reticular cells were more abundant than in the cortex. Lymphoid nodules scattered throughout loose connective tissue in cervical, pharyngeal, thoracic, mesenteric and pelvic sites measured 790±370 μm (mean±S.D., n = 39) in diameter, the larger of which could be observed macroscopically. These consisted of single primary or secondary follicles supported by a framework of reticular fibres. Macrophages were common in the germinal centres. The platypus had a full range of gut‐associated lymphoid tissue. No tonsils were observed macroscopically but histologically they consisted of submucosal follicles and intraepithelial lymphocytes. Peyer's patches were not observed macroscopically but histologically they consisted of several prominent submucosal secondary follicles in the antimesenteric wall of the intestine. Caecal lymphoid tissue consisted of numerous secondary follicles in the submucosa and densely packed lymphocytes in the lamina propria. Bronchus‐associated lymphoid tissue was not observed macroscopically but was identified in 7 of 11 platypus lungs assessed histologically. Lymphoid cells were present as primary follicles associated with bronchi, as aggregates adjacent to blood vessels and as intraepithelial lymphocytes. The distribution of T lymphocytes, identified with antihuman CD3 and CD5, and B lymphocytes and plasma cells, identified with antihuman CD79a and CD79b and antiplatypus immunoglobulin, within lymphoid tissues in the platypus was similar to that described in therian mammals except for an apparent relative paucity of B lymphocytes. This study establishes that the platypus has a well‐developed lymphoid system which is comparable in histological structure to that in therian mammals. It also confirms the distinctiveness of its peripheral lymphoid tissue, namely lymphoid nodules. Platypus lymphoid tissue has all the essential cell types, namely T and B lymphocytes and plasma cells, to mount an effective immune response against foreign antigens.
Freeze‐dried specimens for gross anatomy teaching
Authors: O'SULLIVAN E. , STEWART I. J.
Published: March 2003

As more and more emphasis is placed on the use of prosected specimens to support teaching and learning of gross anatomy, consideration must be given to developing new methods to preserve human cadaveric material, and in ways which will resist the wear and tear to which they are necessarily subjected. Taxidermists have developed techniques for freeze‐drying whole small animals as a method of long term preservation (Metcalf, 1981). We have explored the use of this methodology to preserve small prosected specimens for use in the teaching of gross anatomy. The technique we report here was tested initially on larynges (Fig. 1) but has since been applied with equal success to other structures, including pieces of small intestine dissected to show the arterial arcades (Fig. 2). We have used material from cadavers which were preserved using our standard embalming procedure (O'Sullivan & Mitchell, 1993).
Evolution of the basal ganglia: new perspectives through a comparative approach
Authors: SMEETS WILHELMUS J. A. J. , MARÍN OSCAR , GONZÁLEZ AGUSTÍN
Published: March 2003

The basal ganglia (BG) have received much attention during the last 3 decades mainly because of their clinical relevance. Our understanding of their structure, organisation and function in terms of chemoarchitecture, compartmentalisation, connections and receptor localisation has increased equally. Most of the research has been focused on the mammalian BG, but a considerable number of studies have been carried out in nonmammalian vertebrates, in particular reptiles and birds. The BG of the latter 2 classes of vertebrates, which together with mammals constitute the amniotic vertebrates, have been thoroughly studied by means of tract‐tracing and immunohistochemical techniques. The terminology used for amniotic BG structures has frequently been adopted to indicate putative corresponding structures in the brain of anamniotes, i.e. amphibians and fishes, but data for such a comparison were, until recently, almost totally lacking. It has been proposed several times that the occurrence of well developed BG structures probably constitutes a landmark in the anamniote‐amniote transition. However, our recent studies of connections, chemoarchitecture and development of the basal forebrain of amphibians have revealed that tetrapod vertebrates share a common pattern of BG organisation. This pattern includes the existence of dorsal and ventral striatopallidal systems, reciprocal connections between the striatopallidal complex and the diencephalic and mesencephalic basal plate (striatonigral and nigrostriatal projections), and descending pathways from the striatopallidal system to the midbrain tectum and reticular formation. The connectional similarities are paralleled by similarities in the distribution of chemical markers of striatal and pallidal structures such as dopamine, substance P and enkephalin, as well as by similarities in development and expression of homeobox genes. On the other hand, a major evolutionary trend is the progressive involvement of the cortex in the processing of the thalamic sensory information relayed to the BG of tetrapods. By using the comparative approach, new insights have been gained with respect to certain features of the BG of vertebrates in general, such as the segmental organisation of the midbrain dopaminergic cell groups, the occurrence of large numbers of dopaminergic cell bodies within the telencephalon itself and the variability in, among others, connectivity and chemoarchitecture. However, the intriguing question whether the basal forebrain organisation of nontetrapods differs essentially from that observed in tetrapods still needs to be answered.
Characterisation of human soft palate muscles with respect to fibre types, myosins and capillary supply
Authors: STÅL PER S. , LINDMAN ROLF
Published: March 2003

Four human soft palate muscles, and palatopharyngeus, the uvula, the levator and tensor veli palatini were examined using enzyme‐histochemical, immunohistochemical and biochemical methods and compared with human limb and facial muscles. Our results showed that each palate muscle had a distinct morphological identity and that they generally shared more similarities with facial than limb muscles. The palatopharyngeus and uvula muscles contained 2 of the highest proportions of type II fibres ever reported for human muscles. In contrast, the levator and tensor veli palatini muscles contained predominantly type I fibres. A fetal myosin heavy chain isoform (MyHC), not usually found in normal adult limb muscles, was present in a small number of fibres in all palate muscles. The mean muscle fibre diameter was smaller than in limb muscles and the individual and intramuscular variability in diameter and shape was considerable. All palate muscles had a high capillary density and an unusually high mitochondrial enzyme activity in the type II fibres, in comparison with limb muscles. No ordinary muscle spindles were observed. The fibre type and MyHC composition indicate that the palatopharyngeus and uvula muscles are functionally involved in quick movements whereas the levator and tensor veli palatini muscles perform slower and more continuous contractions. The high aerobic capacity and the rich capillarisation suggest that the palate muscles are relatively fatigue resistant. Absence of ordinary muscle spindles indicates a special proprioceptive control system. The special morphology of the palate muscles may be partly related to the unique anatomy with only one skeletal insertion, a feature consistent with muscle work at low load and tension and which may influence the cytoarchitecture of these muscles. Other important factors determining the special morphological characteristics might be specific functional requirements, distinct embryological origin and phylogenetic factors.
Cytokine/neurotrophin interaction in the aged central nervous system
Authors: MACDONALD NANCY J. , DECORTI FRANCESCO , PAPPAS TODD C. , TAGLIALATELA GIULIO
Published: March 2003

Age‐associated neurodegenerative diseases such as Alzheimer's disease are characterised by neuronal impairment that leads to cognitive deficits. As certain affected neurons depend on trophic factors such as neurotrophins (NTs), impairment in NT function has been suggested to be a component of neuronal damage associated with such disorders. Age‐related neurodegenerative diseases are also characterised by high levels of proinflammatory cytokines such as tumour necrosis factor alpha (TNFα) in the CNS. Because TNFα receptors and certain NT receptors share a high degree of homology and are capable of activating similar signalling pathways, one possibility is that altered cytokine levels may affect NT function in the aged or diseased CNS. Here we wish briefly to review the evidence suggesting a role for cytokine and NT in the onset of age‐associated neurodegenerative diseases. We propose that cytokine/NT interactions may alter neuronal homeostasis, thus possibly contributing to some of the neuronal degeneration occurring during such age‐associated CNS diseases.
Immunolocalisation of sodium channel NaG in the intact and injured human peripheral nervous system
Authors: COWARD K. , MOSAHEBI A. , PLUMPTON C. , FACER P. , BIRCH R. , TATE S. , BOUNTRA C. , TERENGHI G. , ANAND P.
Published: March 2003

The voltage‐gated ‘glial’ sodium channel NaG belongs to a distinct molecular class within the multi‐gene family of mammalian sodium channels. Originally found in central and peripheral glia, NaG has since been detected in neurons in rat dorsal root ganglia (DRG) and may play a role in Schwann cell‐axon interactions. We have studied the presence of NaG‐like immunoreactivity in the intact and injured human peripheral nervous system using a specific affinity‐purified antibody. Nerve fibres in normal and injured peripheral nerves and normal skin exhibited intense NaG‐immunoreactivity. Numerous NaG‐immunoreactive nerve fibres surrounded neuronal cell bodies within postmortem control DRG, and in DRG avulsed from the spinal cord (i.e. after traumatic central axotomy). There were no significant differences in the pattern of NaG immunostaining between control and avulsed DRG, or with delay after injury. Generally, the neuronal cell bodies were only very weakly immunoreactive to NaG, indicating that the NaG immunoreactivity was predominantly in Schwann cells/myelin. In accord, we demonstrated NaG immunostaining in cultured human and rat Schwann cells, and in distal nerve after wallerian degeneration. NaG thus appears to be a useful new marker for Schwann cells in the human PNS, and a role in neuropathy deserves investigation.
Fourier analysis methodology of trabecular orientation measurement in the human tibial epiphysis
Authors: HERRERA M. , PONS A. M. , ILLUECA C. , ERADES D.
Published: March 2003

Methods to quantify trabecular orientation are crucial in order to assess the exact trajectory of trabeculae in anatomical and histological sections. Specific methods for evaluating trabecular orientation include the ‘point counting’ technique (Whitehouse, 1974), manual tracing of trabecular outlines on a digitising board (Whitehouse, 1980), textural analysis (Veenland et al. 1998), graphic representation of vectors (Shimizu et al. 1993; Kamibayashi et al. 1995) and both mathematical (Geraets, 1998) and fractal analysis (Millard et al. 1998). Optical and computer‐assisted methods to detect trabecular orientation of bone using the Fourier transform were introduced by Oxnard (1982) later refined by Kuo & Carter (1991) (see also Oxnard, 1993, for a review), in the analysis of planar sections of vertebral bodies as well as in planar radiographs of cancellous bone in the distal radius (Wigderowitz et al. 1997). At present no studies have applied this technique to 2‐D images or to the study of dried bones. We report a universal computer‐automated technique for assessing the preferential orientation of the tibial subarticular trabeculae based on Fourier analysis, emphasis being placed on the search for improvements in accuracy over previous methods and applied to large stereoscopic (2‐D) fields of anatomical sections of dried human tibiae. Previous studies on the trajectorial architecture of the tibial epiphysis (Takechi, 1977; Maquet, 1984) and research data about trabecular orientation (Kamibayashi et al. 1995) have not employed Fourier analysis.
NADPH‐diaphorase distribution in the rabbit superior colliculus and co‐localization with calcium‐binding proteins
Authors: González‐Soriano Juncal , Contreras‐Rodríguez Julio , Martínez‐Sainz Pilar , Martín‐Palacios Susana , Marín‐García Pilar , Rodríguez‐Veiga Elisia
Published: March 2003

Nitric oxide (NO) and calcium‐binding proteins (CaBP) are important neuromodulators implicated in brain plasticity and brain disease. In addition, the mammalian superior colliculus (SC) has one of the highest concentrations of NO within the brain. The present study was designed to determine the distribution of nitric oxide‐synthesizing neurons in the SC of the rabbit by enzyme histochemistry for reduced nicotinamide adenine dinucleotide phosphate‐diaphorase (NADPH‐d), and its degree of co‐localization with CaBP, parvalbumin (PV) and calbindin (CB). NADPH‐d‐labelled fibres formed dense patches of terminal buttons within the intermediate grey layer and streams of fibres within the deepest layers of SC. Cells expressing NOS constitute a subpopulation of neurons in which practically all cell types are represented. Combined PV/NADPH‐d experiments showed a complete lack of co‐localization within individual neurons and fibres. On the contrary, double‐labelled neurons appeared in CB/NADPH‐d‐stained sections, only in the superficial layers, and mostly in the SGS and SO. These cells, which were intermingled with other neurons containing either NADPH‐d or CB, appear to be a subtype of narrow‐field and wide‐field vertical cells, and display an anterior–posterior gradient of density. Owing to the involvement of the superficial layers of the SC in the organization and integration of the visual information, it is suggested that these neurons may play a concrete role within the visual circuits. Our data indicate a clear selectivity in the expression of NADPH‐d, PV and CB in the SC, and that NO and CB probably serve as co‐modulators and/or co‐transmitters in the connectivity of the superficial layers of this midbrain structure.
Stem cells: potency, plasticity and public perception*
Authors: Gardner R. L.
Published: March 2003

Production of chimaeras with embryonal carcinoma and embryonic stem cells enabled a very thorough investigation of the potency of these cells in the mouse. Human embryonal carcinoma and embryonic stem cell differ from their murine counterparts in a number of respects and, for obvious reasons, their potency is more difficult to assess. Recently, findings attesting to a surprising degree of plasticity of cells from adults have begun to emerge, which, aside from offering a possible further route to stem cell therapy, raise intriguing questions about the importance of lineage in the process of cellular diversification. Biomedical research is widely perceived to be advancing too fast to allow proper consideration of the implications of its clinical applications. Whilst this was clearly not true in the case of human in vitro fertilization, it has some validity regarding stem cell therapy, even though many of the issues are common to both. Casual use of the term ‘embryo’ proved unhelpful in the past debate on whether research on early stages of human development should be permitted. Likewise, introduction of the term ‘therapeutic cloning’ has complicated the present one regarding extension of such research to stem cell therapy.
Extracellular matrix, junctional integrity and matrix metalloproteinase interactions in endothelial permeability regulation*
Authors: Alexander J. S. , Elrod John W.
Published: March 2003

Vascular endothelial permeability is maintained by the regulated apposition of adherens and tight junctional proteins whose organization is controlled by several pharmacological and physiological mediators. Endothelial permeability changes are associated with: (1) the spatial redistribution of surface cadherins and occludin, (2) stabilization of focal adhesive bonds and (3) the progressive activation of matrix metalloproteinases (MMPs). In response to peroxide, histamine and EDTA, endothelial cells sequester VE‐cadherin and alter its cytoskeletal binding. Simultaneously, these mediators enhance focal adhesion to the substratum. Oxidants, cytokines and pharmacological mediators also trigger the activation of matrix metalloproteinases (MMPs) in a cytoskeleton and tyrosine phosphorylation dependent manner to degrade occludin, a well‐characterized tight junction element. These related in vitro phenomena appear to co‐operate during inflammation, to increase endothelial permeability, structurally stabilize cells while also remodelling cell junctions and substratum.
Parathyroid hormone‐related protein (PTHrP) production sites in elasmobranchs
Authors: Trivett M. K. , Walker T. I. , Macmillan D. L. , Clement J. G. , Martin T. J. , Danks J. A.
Published: March 2003

This study describes the distribution of parathyroid hormone‐related protein (PTHrP) antigen and its mRNA in seven species of cartilaginous fish from six elasmobranch families. Antigen was detected using antibodies to synthetic human PTHrP and the mRNA with a riboprobe to human PTHrP gene sequence. The distribution pattern of PTHrP in the cartilaginous fish studied, reflected that observed in mammals but PTHrP further occurs in some sites unique to cartilaginous fish. Of particular note was the demonstration of PTHrP in the shark skeleton, which although considered not to contain bone, may form by a process similar to that forming the early stages of mammalian endochondral bone. The distribution of PTHrP in the elasmobranch skeleton resembled the distribution of PTHrP in the developing mammalian skeleton. Differences in the staining pattern between antisera to N‐terminal PTHrP and mid‐molecule PTHrP in the brain and pituitary suggested that the PTHrP molecule might be post‐translationally processed in these tissues. The successful use of antibodies and a probe to human PTHrP in tissues from the early vertebrates examined in this study suggests that the PTHrP molecule is conserved from elasmobranchs to humans.
Seed mass, habitat conditions and taxonomic relatedness: a re‐analysis of Salisbury (1974)
Authors: KELLY C. K.
Published: March 2003

Re‐analysis of data from Salisbury (1974) shows no significant relationship between seed size and habitat conditions, a relationship for which this paper is frequently cited as support. The discrepancy between the results reported here and those found in the original paper is due to Salisbury's ‘evidence’ being a table of congeneric pairs collected specifically because they possessed the target relationship. This paper emphasizes particularly the need for an unbiased sampling of species pairs in comparisons attempting to define ecological relationships. The analysis presented here represents the fourth such instance in which previously assumed robust examples of the relationship between seed size and habitat type are shown not to be so when the appropriate methods are used to account for relatedness among species.
A stay‐green mutation of Lolium perenne affects NO3− uptake and translocation of N during prolonged N starvation
Authors: BARKEN ANNE KJERSTI , MACDUFF JAMES , HUMPHREYS MERVYN , RAISTRICK NEIL
Published: March 2003

Apparent Km and Vmax for net NOS″ uptake and short‐term translocation patterns of recently absorbed N were compared in a stay‐green mutant and wild‐type selection line of Lolium perenne L. by means of a series of depletion studies using 18NO3, performed over 12 d under conditions of progressively increasing N deprivation. In view of the greater retention of N in senescent leaves of the stay‐green phenotype, it was predicted that NOS″ uptake would be up‐regulated relative to the normal line, and that a proportionally higher fraction of recently absorbed N would be allocated to young leaves. It was shown that the stay‐green trait had significant phenotypic consequences for plant N relations, with higher ‘sink strength‘ of shoots for recently absorbed N, and higher Vmaxfor NO3 uptake compared with those of normal plants. The stay‐green mutation had no effect on the Km of the nitrate uptake system. Although the N‐use efficiency might he expected to be lower in stay‐green than in normal plants, there were no differences in rates of dry matter production.
The effect of NaCl on growth, dry matter allocation and ion uptake in salt marsh and inland populations of Armeria maritima
Authors: KÖHL KARIN I.
Published: March 2003

Salt resistance was compared in populations of Armeria maritima (Mill.) Willd. from salt marshes and from inland sites to investigate which salt‐resistance‐related traits are present in all populations and which are derived traits of the salt‐marsh ecotype. Plants were raised from seeds from six different populations and grown on a mixture of sand and ion‐exchange resin at different salinity levels. Inland populations grew better at 40 mM NaCl than with salt‐free treatment and survived several months at 200 mM NaCl, and were thus as salt‐resistant as many species from brackish habitats. Salt‐marsh populations were as salt‐resistant as euhalophytes. Growth enhancement by NaCl was related to an increase in shoot:root d. wt ratio, which was shown not to be the result of damage to the roots. Carbon allocation to roots seemed to be reduced as a consequence of a better nutrient supply at elevated NaCl concentrations. In plants from all populations, tissue tolerance of sodium and chloride (500–1000 mmol kg−1 d. wt) was higher than that in glycophytes. Na substituted for K and to some extent Ca and Mg without growth reduction. Betaines were accumulated as cytoplasmic compatible solutes by all populations, whereas proline accumulation was not involved in adjustment to long‐term salt stress. The halophytic capacity to load the xylem with Na was found in all populations of A. maritima. However, the allocation of Na to the shoot started at higher salinities in inland populations than in salt‐marsh populations. This was presumably due to the Na storage capacity of roots of inland populations being higher than that of coastal populations. Nevertheless, the inland populations of A. maritima were significantly salt‐tolerant as a consequence of their capacity to accumulate betaines and allocate Na to the shoot; this might have facilitated the colonization of salt marshes by the species.
A fructan: fructan fructosyltransferase activity from Lolium rigidum
Authors: ST. JOHN J. A. , BONNETT G. D. , SIMPSON R. J. , TANNER G. J.
Published: March 2003

Fructan: fructan fructosyltransferase (FFT) activity was purified about 300‐fold from leaves of Lolium rigidum Gaudin by a combination of affinity chromatography, gel filtration, anion exchange and isoelectric focusing. The FFT activity was free of sucrose: sucrose fructosyltransferase and invertase activities. It had an apparent pI of 4.7 as determined by isoelectric focusing, and a molecular mass of about 50000 (gel filtration). The FFT activity utilized the trisaccharides 1‐kestose and 6G‐kestose as sole substrates, but was not able to use 6‐kestose as sole substrate. The FFT activity was not saturated when assayed at concentrations of 1‐kestose, 6G‐kestose or (1,1)‐kestotetraose of up to 400 mM The rate of reaction of the FFT activity was most rapid when assayed with 1 ‐kestose and was less rapid when assayed with 6G kestose, (1,1)‐kestotetraose or (1,1,1)‐kestopentaose. The FFT activity when assayed at a relatively high concentration of enzyme activity (approximately equivalent to about half the activity in crude extracts per gram fresh mass) did not synthesize fructan of degree of polymerization > 6, even during extended assays of up to 10 h. When assayed with a combination of 1‐kestose and uniformly labelled [14C]sucrose as substrates, was the transfer of a fructosyl residure from 1‐kestose to sucrose resulting in the re‐synthesis of 1‐kestose. Tetrasaccharide and 6G‐kestose were also synthesized. When assayed with 6G‐kestose and [14C]sucrose as substrates, the major reaction of the FFT activity was the synthesis of tetrasaccharide. However, some synthesis of 1‐kestose and re‐synthesis of 6G‐kestose also occurred. When 6G‐kestose was the sole substrate for the FFT activity, synthesis of tetrasaccharide was 2.7 to 3.4‐fold slower than when 1‐kestose was used as the sole substrate. Owing to differences in the fructan: sucrose fructosyltransferase activity of the FFT with each of the trisaccharides, net synthesis of tetrasaccharide by the FFT was altered significantly in the presence of sucrose. The magnitude of this effect depended on the concentration of the trisaccharides. In the presence of sucrose, 6G‐kestose could be a substrate of equivalent importance to 1‐kestose for synthesis of tetrasaccharide.
Polyphosphates in the red macroalga Chondrus crispus (Rhodophyceae)
Authors: CHOPIN T. , LEHMAL H. , HALCROW K.
Published: March 2003

Plants of Chondrus crispus Stackhouse, collected from mid‐littoral tidepools, were treated as follows. Some plants were kept for a few weeks under controlled starvation conditions in order to decrease their initial content of total tissue phosphorus, then incubated for up to 48 h in phosphorus (15 μm) and nitrogen (25 μM)enriched sea water. Other plants were directly incubated in enriched sea water. Chemical analyses showed that the total phosphorus content of fresh and starved plants remained stable, reflecting the nutritional status of the plants. The predominant acid‐soluble phosphate fraction was larger in fresh than in starved plants. The content of acid–soluble polyphosphates, similar in both types of plants at the beginning of the experiment, doubled in starved plants, and increased by a factor of 2′7 in fresh plants, over 48 h. The content of acid‐insoluble polyphosphates was lower than that of acid‐soluble polyphosphates.

Transmission electron microscopy and energy dispersive X–ray microanalysis confirmed the presence, mostly in medullary cells, of acid‐insoluble polyphosphates in the form of cytoplasmic granules and precipitates along the plasmalemma, particularly near pit plugs. This is the first report of such phosphorus storage structures in a red macroalgal species.
Effects of short‐term phosphorus deficiency on carbohydrate storage in sink and source leaves of barley (Hordeum vulgare)
Authors: WANG C. , TILLBERG J.‐E.
Published: March 2003

Barley (Hordeum vulgare L. cv. Agneta) was cultivated hydroponically under continuous light, constant temperature and relative humidity. The relative growth rate (RGR) was kept at 25% by an exponential supply of complete medium for 2 wk. The cultures were then transferred to phosphorus‐free media and the amounts of total P, fructans, starch, sucrose, glucose and fructose in sink and source leaves were measured at 0, 12, 24, 48, 72, 120 and 156 h. The capacity of net fructan synthesis (i.e. total activity of sucrose∶sucrose 1‐fructosyltransferase (1‐SST) and sucrose∶fructan 6‐fructosyltransferase (6‐SFT)), the activity of fructan exohydrolase (FEH), as well as the activity of acid invertase were also measured in the two types of leaves. Omission of P from the growth medium caused a decrease in the P content in both sink and source leaves, whereas the RGR was not affected during the 156 h of the experiment. The fructan concentration increased in low‐P plants whilst there was little or no effect on the concentrations of starch, sucrose, glucose and fructose. There was a slight increase in the capacity of net fructan synthesis in both sink and source leaves at 156 h after the onset of P‐starvation. There was no change in the activity of FEH or acid invertase. The results indicate that in barley leaves the mechanism for carbon partitioning into fructans is more sensitive towards low P conditions than the mechanism for carbon partitioning into starch.
Genetic analysis of some flowering time and adaptive traits in wheat
Authors: LAW C. N. , WORLAND A. J.
Published: March 2003

summary

The present understanding of the genetic control of flowering in wheat is reviewed. Although this information will continue to be of value in breeding and in recognizing the role such genes have had in adapting the wheat crop to global agriculture, its use in denning the processes responsible for flowering will be limited. Progress here will depend on developments in model plant systems such as Arabidopsis, where methods for isolating genes are much more advanced than in wheat. These developments, which have already started, will probably be used to establish homologies between the genes for flowering within the cereals, as well as more widely. An understanding of the flowering process in wheat is likely to emerge from this approach. In the meantime, there are some unknowns in the genetics of flowering in wheat which need to be resolved. These include the identification of a gene(s) on the group 4 chromosomes of wheat which is homoeoallelic with the gene Sh in barley. Also, the proposed gene(s) delaying flowering and located on the group 6 chromosomes needs to be recognized and mapped. Similar needs occur for the group 1 chromosomes as well as the resolution of whether or not Vrn5 is correctly positioned on chromosome 7BS.
Relationships between relative water content and growth parameters under water stress in barley: a QTL study
Authors: TEULAT B. , MONNEVEUX P. , WERY J. , BORRIES C. , SOUYRIS I. , CHARRIER A. , THIS D.
Published: March 2003

summary

Drought strongly affects cereal yield in several regions of the world. Plant growth and plant water status in response to soil water deficit play an important role in tolerance to drought and in yield stability. In order to investigate the relationship between plant growth and water relations, 187 barley (Hordeum vulgare L.) recombinant inbred lines from a cross between two Mediterranean varieties, Tadmor and Er/Apm, were studied in a growth chamber for RWC, number of leaves on the main tiller (NL), number of tillers (NT) and total shoot fresh and dry biomass (TSFM and TSDM). Measurements were made at the beginning of tillering on well watered plants and at a soil moisture content of 14% of field capacity. A negative phenotypic correlation between RWC and growth parameters was obtained in both treatments. Under water stress, a negative genetic correlation was also found between the same characters. QTLs involved in RWC, NL and TSFM variation were positioned on a RFLP‐RAPD genetic map. Different DNA regions involved in constitutive and water stress responses were detected. In the stress treatment, one region on chromosome 1 was involved in RWC and NL variation giving a genetic basis to the phenotypic correlations found. Separated map positions were also found for RWC and NL. Epistatic interactions between several QTLs and between QTLs and other markers were detected only in the water stress treatment, suggesting that some chromosomal regions might be involved in the regulation of the expression of the traits under water stress. This work suggested that even if some parameters are strongly correlated, finding QTLs for only one trait is not sufficient to detect all the candidate regions which might be involved in the control of the correlated traits. The results of localization and co‐localization of QTLs are physiologically interpreted.