The glycan composition of the N- and O-linked oligosaccharides of the follicle (Sertoli) cells of the urodele amphibian Pleurodeles waltl testis were identified by lectin histochemistry, performed alone or in combination with enzymatic and chemical deglycosylation methods. The follicle cells were shown to contain: (1) Fuc, Galβ(1,4)GlcNAc, GalNAc and Neu5Acα(2,3)Galβ(1,4)GlcNAc in both N- and O-linked oligosaccharides; (2) Man in N-linked glycans; and (3) Galβ(1,3)GalNAc in O-linked sugar chains. The follicle cells at the pre- and postmeiotic stages showed some differences in the UEA-I-positive Fuc characterisation, suggesting differences in the glycan composition. In addition, the sequence Neu5Acα(2,6)Gal/GalNAc was shown in the follicle cells only after spermiation, in the sperm-empty lobules of the developing glandular tissue. These results suggest that the follicle cells modify their glycoprotein content, probably for the performance of new roles, as the spermatogenetic cells develop. Thus the follicle cells surrounding male germ cells at different spermatogenetic stages would contain different glycoproteins involved in specific roles during male germ cell proliferation and maturation.

Anatomical Society of Great Britain

15–18 April, 1998. Joint meeting with the Nederlandse Anatomen Vereniging in Rolduc, Netherlands, in cooperation with the South African Anatomical Society.

24–26 July, 2000. University of Cambridge.

International Society for the Study of the Lumbar Spine

MacNab/Larocca Research Fellowship Award. Deadline: March 1, 1998

1998 Smith & Nephew Travelling Fellowship Award. Deadline April 1, 1998.

A superficial artery may be present in the forearm, arising from the axillary, brachial or superficial brachial arteries and crossing over the origin of the flexor muscles of the forearm to reach the palm (Adachi, 1928; Bergman et al. 1988). When this superficial artery continues as the normal ulnar artery accompanying the ulnar nerve at the wrist, it is referred to as the superficial ulnar artery, with an incidence of ∼4%. When the artery passes below or superficial to the flexor retinaculum in the middle of the forearm, sometimes continuing to join the superficial palmar arch, it is called the superficial median artery, with an incidence of ∼1%. We have observed a relatively rare variation involving the presence of a superficial median artery in both upper limbs. We discuss the clinical importance and the developmental aspects of this arterial variation.

Cortical cerebellar basket cells are stable postmitotic cells; hence, they are liable to endure age-related changes. Since the cerebellum is a vital organ for the postural control, equilibrium and motor coordination, we aimed to determine the quantitative morphological changes in those interneurons with the ageing process, using unbiased techniques. Material from the cerebellar cortex (Crus I and Crus II) was collected from female rats aged 2, 6, 9, 12, 15, 18, 21 and 24 mo (5 animals per each age group), fixed by intracardiac perfusion, and processed for transmission electron microscopy, using conventional techniques. Serial semithin sections were obtained (5 blocks from each rat), enabling the determination of the number-weighted mean nuclear volume (by the nucleator method). On ultrathin sections, 25 cell profiles from each animal were photographed. The volume density of the nucleus, ground substance, mitochondria, Golgi apparatus (Golgi) and dense bodies (DB), and the mean surface density of the rough endoplasmic reticulum (RER) were determined, by point counting, using a morphometric grid. The mean total volumes of the soma and organelles and the mean total surface area of the RER [SN (RER)] were then calculated. The results were analysed with 1-way ANOVA; posthoc pairwise comparisons of group means were performed using the Newman-Keuls test. The relation between age and each of the parameters was studied by regression analysis. Significant age-related changes were observed for the mean volumes of the soma, ground substance, Golgi, DB, and SN (RER). Positive linear trends were found for the mean volumes of the ground substance, Golgi, and DB; a negative linear trend was found for the SN (RER). These results indicate that rat cerebellar basket cells endure important age-related changes. The significant decrease in the SN (RER) may be responsible for a reduction in the rate of protein synthesis. Additionally, it may be implicated in a cascade of events leading to cell damage due to the excitotoxic activity of glutamate, which could interfere in the functioning of the complex cerebellar neuronal network.

We sought to study the effect of synovectomy on the surface morphology of articular cartilages of the rabbit knee using scanning electron microscopy (SEM). Fifteen rabbits were surgically synovectomised and allowed to regenerate their synovia during time intervals ranging from 3 to 44 wk. Cartilage specimens were shaved from 5 distinct articular sectors of synovectomised, contralateral and sham-operated knees and prepared for SEM using tannic acid. Applying structural reinforcement by tannic acid was found to secure the in vivo surface morphology of the cartilages and thus production of surface irregularities during preparation was excluded. The surface morphology of cartilages both from the synovectomised and contralateral joints was found to differ from that of intact healthy rabbits. A ‘chaotic’ nature of the altered cartilaginous morphology persisted as late as 44 wk postsynovectomy. Cartilages from sham-operated joints did not differ detectably from normal cartilages.

A separate supernumerary muscle in the lateral cubital fossa originating from the humerus or brachioradialis and inserting into the radius, pronator teres or supinator muscle has been considered as a variation of the brachioradialis muscle (Dawson, 1822; Meckel, 1823; Lauth, 1830; Halbertsma, 1864; Gruber, 1868b; Testut, 1884; LeDouble, 1897; Spinner & Spinner, 1996). However, a similar description was used to report additional heads of the brachialis or biceps brachii muscles (Gruber, 1848; Wood, 1864, 1868; Macalister, 1864–66, 1966–69, 1875; Gruber, 1868a; Wolff-Heidegger, 1937).

The innervation of these variant muscles would be a good tool to assign each variation to its associated muscle. Consequently, innervation by the radial nerve would indicate that it is a derivative of the humero–radialis group of muscles, while innervation by the musculocutaneous nerve would support it as a derivative of the anterior musculature of the arm (Rolleston, 1887; Lewis, 1989). However, no references to the innervation were found in the available literature.

Therefore this study set out to establish the phylogenetic origin of the brachioradialis accessorius muscle and, with the help of its innervation, to determine its incidence and unreported detailed morphology.

Grafts of living or freeze-killed freshly dissected colonic smooth muscle from young inbred Fischer rats were implanted into the corpus striatum of adult Fischer rats. Sections of brain were examined electron microscopically 3 and 6 wk after implantation. At both times, living grafts were vascularised and contained healthy differentiated smooth muscle cells, fibroblasts, interstitial cells of Cajal and some macrophages. Large bundles of small nonmyelinated axons, identified as CNS axonal sprouts, could be observed in the brain at and near the interface between the living smooth muscle and the CNS tissue. Bundles of regenerating CNS axons, often associated with astrocyte processes, had grown into the grafts. Some axons within the grafts had matured, enlarged and become myelinated by oligodendrocyte processes or Schwann cells. In some cases, smooth muscle cells were observed in close and intricate association with axons. In contrast to the living grafts, grafts of freeze-killed smooth muscle, examined 3 and 6 wk after implantation, contained macrophages, fibroblasts, collagen and large amounts of cellular debris, but no living muscle cells, astrocytes or Schwann cells. The striatal neuropil around freeze-killed grafts did not contain large bundles of CNS axonal sprouts and bundles of axons were not observed within the freeze-killed graft. This study demonstrates that cells from the smooth muscle layers of the colon, in the absence of myenteric ganglia, can stimulate a vigorous regenerative response from CNS axons when implanted into the corpus striatum of adult rats.

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.

Mean glomerular volume has previously been estimated, using stereological techniques, specifically the point-sampled intercept (PSI), either from isotropic or from vertical sections. As glomeruli are approximately spherical structures, the same stereological technique was carried out on vertical and arbitrary sections to determine whether section orientation had any effect on mean glomerular volume estimation. Equine kidneys from 10 individuals were analysed using the PSI method of estimating volume-weighted mean glomerular volume (MGV); for each kidney, arbitrary and vertical sections were analysed. MGVs were not significantly different between arbitrary and vertical sections (P = 0.691) when analysing the data with the paired t test; when plotting MGV estimates from arbitrary sections against those from vertical sections the intercept was found not to be significantly different from zero (P > 0.8) and the slope of the regression line not to be significantly different from 1.0 (P > 0.4). For the estimation of MGV in equine kidneys using PSI, arbitrary sections may be used if it is not possible to use isotropic or vertical sections, but some caution must be exercised in the interpretation of results so gained.

Epidermal growth factor (EGF) has been implicated in the control of embryonic development, but although the receptor is expressed from an early stage, there is little evidence of embryonic expression of EGF. In order to investigate the role of maternally derived EGF during organogenesis, rat embryos were explanted at d 9.5 and cultured in serum depleted of low molecular weight molecules (retenate) which was then supplemented with EGF. Serum depleted of low molecular weight molecules by prolonged filtration loses its capacity to support normal embryonic development, possibly due to the loss of growth promoting factors. The addition of EGF to retenate significantly improved embryonic development with a maximal effect at 8 ng/ml. The addition of an analogue of EGF, long EGF, to retenate also caused a significant increase in development, although at higher concentrations a decrease in its effect was observed, possibly due to down regulation of the EGF receptor. Therefore, embryos may be able to utilise maternally derived EGF during organogenesis. To test the effects of inhibiting the EGF receptor during organogenesis, d 9.5 embryos were cultured in the presence of tyrphostin 47, a specific EGF receptor inhibitor. Tyrphostin 47 caused a significant dose-dependent decrease in the development of embryos which was also observed when tyrphostin 47 was injected into the vitelline circulation at d 11.5 to bypass the effects of the yolk sac. These findings suggest that the EGF receptor is essential for normal organogenesis and may play a role in the control of proliferation and differentiation. Although EGF is not expressed in the rat embryo at this stage, maternally derived EGF may be the ligand for the embryonic EGF receptor.

During the course of a systematic study on the human vertebrobasilar arterial system (De Caro et al. 1995), our attention was drawn in one case to a strange morphology of the ventrolateral aspect of one side of the medulla. While initially our impression was that we were facing an actual malformation, review of the structure of the brainstem as described in most standard anatomical texts showed that it could correspond to the circumolivary fasciculus (Williams et al. 1995).

The subject was a 63-y-old man who had died from rupture of an atherosclerotic aneurysm of the abdominal aorta. The medical history was negative for neuropsychiatric pathology. Brain examination showed severe atherosclerosis of the cerebral arteries and hypoplasia of the initial segment of the right posterior cerebral artery. A recent infarct was found in the white matter of the right occipital lobe. After removal of the vertebrobasilar arterial system, the right pyramid showed a superficial groove extending from about 2 mm lateral to the foramen caecum obliquely downwards to the right anterolateral sulcus of the medulla, at the level of the superior margin of the inferior root of the hypoglossal nerve (Fig. 1a). Due to this groove, the lateral part of the pyramid formed a ridge that crossed the anterolateral sulcus of the medulla passing between the 2 main roots of the hypoglossal nerve and then continued, below the inferior pole of the olive, over the lateral region of the medulla ending at the level of the posterolateral sulcus (Fig. 1b). The general appearance was that of a small cord forming a loop around the anterior margin and the inferior pole of the olive, with a descending part (8 mm long), a horizontal part (6 mm long) and with a transverse diameter of 3 mm. After formalin fixation, the brainstem was cut in 8 transverse sections. At the level of the medulla the right pyramid appeared larger than the contralateral and the small lateral cord was separated from the main part of the pyramid by a thin whitish transverse stria (Fig. 1c). Macroscopic examination of the cerebellum showed nothing of relevance.

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.

Using electron immunocytochemistry, blood vessels in the normal rat liver and in 2 different animal models of liver metastases: (1) Hooded Lister rat with MC28 tumour, a sarcoma, and (2) nude rat with HT29 tumour, a carcinoma, were investigated for the presence of endothelin-1. In the normal livers, small subpopulations of vascular endothelial cells displayed discrete immunoreactivity for endothelin-1. In the livers with malignant tumours, there was a substantial increase in endothelin-1-immunoreactive endothelial cells in vessels located at the tumour periphery. In the controls, antibody to endothelin-1 also labelled sporadically some fibroblast/fibroblast-like cells associated with the blood vessels. In contrast, intense immunoreactivity for endothelin-1 was frequently associated with the tumour cells and/or fibroblast cells in both types of tumour examined.

The arterial supply of the digits of the forelimb of the Bactrian camel is described. The arteries supplying the digits were the palmar metacarpal and common palmar digital arteries III. The palmar metacarpal artery III was the continuation of the deep medial proximal metacarpal branch which was derived from the medial branch of the radial artery. It gave rise to a nutrient branch, medial branch, lateral branch and distal perforating palmar branch at the proximal end of the distal sixth of the cannon bone (fused third and fourth metacarpal bones). The common palmar digital artery III was the continuation of the median artery, which divided into medial and lateral branches. The medial branch of common palmar digital artery III which occasionally arose from the axial palmar proper digital artery III, after giving rise to the axial proximal proximal phalangeal branch, divided into the axial and abaxial palmar proper digital arteries III. The axial palmar proper digital artery III gave off the dorsoaxial distal proximal phalangeal, dorsoaxial proximal middle phalangeal, dorsoaxial distal middle phalangeal, palmoaxial middle phalangeal, palmoaxial distal phalangeal, dorsoaxial distal phalangeal branches, coronal artery and some digital tori branches. The abaxial palmar proper digital artery III gave rise to the abaxial proximal proximal phalangeal, dorsoabaxial distal proximal phalangeal, dorsoabaxial middle phalangeal, palmoabaxial middle phalangeal, palmoabaxial distal phalangeal, dorsoabaxial distal phalangeal branches, coronal artery and some digital tori branches. The lateral branch of the common palmar digital artery III in its origin, course, branching pattern and supply in the fourth digit was similar to the medial branch of common palmar digital artery III in the third digit.

In the theoretical analysis of arterial networks the existence of geometric optimisation has long been suggested, although observational studies have not yet fully corroborated these theories. Since this could be due to experimental flaws, the aim of this study was to establish the validity of arterial geometric optimisation using a new experimental design and to assess the influence of ageing. Solid vascular casts of arterial mesenteric branching systems of 8-wk-old and adult dogs (beagles) were used to examine vascular diameters and branching angles, the latter in a manner that allowed optimisation of the line of view, thus minimising distortion errors due to a line of view not normal to the branching plane. Internal and external vessel diameters were found to be in accordance with the theoretical principle of minimum work (8-wk-old internal: r = 0.994; adult internal: r = 0.971; adult external: r = 0.985). Although branching angles were found to be in agreement with basic qualitative principles of arterial branching geometry, the measurements still showed a large amount of scatter and were generally smaller than expected on theoretical grounds, despite the newly designed measuring technique. These branching angles demonstrated small age-related differences. However, when biological cost was considered per bifurcation, surprisingly, guidance towards minimum lumen volume and pumping power with increase in age could clearly be demonstrated (P<0.001). It is concluded that our findings support the existence of a degree of arterial geometric optimisation in favour of minimum lumen volume and pumping power, increasing with age. Future investigations should focus on the biofeedback mechanisms involved.

The mucosubstances in the epithelium lining the segment from gizzard to duodenum during development of the chick embryo was studied histochemically using monoclonal antibodies against gizzard mucus and lectins, with attention to the regional differentiation of the epithelium in this segment. The anterior limit of epithelial CdxA mRNA expression detected by in situ hybridisation, which served as the position of the gizzard-duodenal boundary, was clearly found from d 3. Granules positive for some antibodies or lectins were found in the region ranging from the posterior part of the gizzard to the duodenum at d 3, which was followed by an increase in the number of granules and a gradual enlargement of the granule-positive area to the anterior part of the gizzard over 4–6 d. From d 4, the epithelia of the gizzard body and of the pyloric or duodenal region came to be differently stained with some antibodies or lectins. From d 10, each region showed a specific pattern of staining. The epithelia of the gizzard body and pyloric region contained abundant mucus granules with a different staining pattern. In the duodenum the number of stained granules was low except in occasional goblet cells. Thus the epithelia of the gizzard body, pyloric region and duodenum may produce different mucosubstances and the regional differentiation in these epithelia may start at rather early stages soon after the formation of digestive tube.

MyoD1 alleles distinguish between the Mm musculus and Mm domesticus subspecies of Mus musculus. SJL/J mice, which belong to the Mm musculus subspecies, are able to regenerate skeletal muscle more efficiently than BALB/c mice which possess the Mm domesticus MyoD1 allele. Hence the possibility that regeneration responses are due to species-specific genetic differences including MyoD1 was investigated in this study. Quantitative morphometric analysis following muscle crush injury of 2 Mm musculus strains, MBK and MGL, has indicated that regeneration phenotype is not species-specific and may not be directly related to MyoD1 alleles. These results contrast with prior investigations conducted in SJL/J and BALB/c mice, and indicate that other genes may have a direct influence on skeletal muscle regeneration.