In 1813 Gantzer described 2 accessory muscles in the human forearm which bear his name (Wood, 1868; Macalister, 1875) and these have subsequently been reported with variable attachments (Wood, 1868; Macalister, 1875; Turner, 1879; Schäfer & Thane, 1894; Le Double, 1897; Dykes & Anson, 1944; Mangini, 1960; Malhotra et al. 1982; Kida, 1988; Tountas & Bergman, 1993). The accessory heads of the deep flexors of the forearm (Gantzer's muscles) have been described as 2 different small bellies which insert either into FPL or FDP. There are no previous reports which have mentioned the existence of an accessory muscle which inserts into both of the 2 deep flexors of the forearm as in the case presented here.

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.

The past 20–30 years have seen major advances in our understanding of human reproduction and in our ability to manipulate it, as well as major social changes in human reproductive and sexual attitudes. Many of these advances and changes developed out of the first successful in vitro fertilisation (IVF) of the human oocyte. It is also the case that 30 years ago few foresaw what was to come, and many were at best doubtful and often were very critical of the scientific work which led to human IVF and to many of the subsequent developments. This lack of foresight provides us with a lesson about the dangers that we face in looking forward and attempting to predict the future. This review will try to convey, not comprehensively but through examples, the flavour of current activities in Assisted Reproduction clinics and research laboratories around the world and what is being talked about for the future in respect of emergent patient demands and anticipated clinical needs. This clinically driven approach will form the basis for consideration of some underlying scientific aspects of reproductive research, some of the ethicolegal issues that may arise, and the implications of this anticipated future for our current approaches to medical education. The future will be considered not simply in terms of the New Reproduction itself but also in its interaction with the opportunities and challenges presented by the New Genetics. It is perhaps in the interaction between these two fields of endeavour that some of the most difficult challenges ahead lie.

The angioarchitecture of the coeliac sympathetic ganglion complex (CGC) of the common tree shrew (Tupaia glis) was studied by the vascular corrosion cast technique in conjunction with scanning electron microscopy. The CGC of the tree shrew was found to be a highly vascularised organ. It normally received arterial blood supply from branches of the inferior phrenic, superior suprarenal and inferior suprarenal arteries and of the abdominal aorta. In some animals, its blood supply was also derived from branches of the middle suprarenal arteries, coeliac artery, superior mesenteric artery and lumbar arteries. These arteries penetrated the ganglion at variable points and in slightly different patterns. They gave off peripheral branches to form a subcapsular capillary plexus while their main trunks traversed deeply into the inner part before branching into the densely packed intraganglionic capillary networks. The capillaries merged to form venules before draining into collecting veins at the peripheral region of the ganglion complex. Finally, the veins coursed to the dorsal aspect of the ganglion to drain into the renal and inferior phrenic veins and the inferior vena cava. The capillaries on the coeliac ganglion complex do not possess fenestrations.

This study examined NADPH-d and nNOS expression in the SCG of hamsters. By light microscopy, numerous NADPH-d/NOS positive processes were widely distributed in the ganglion. Ultrastructurally, the NADPH-d reaction product was associated with the membranous organelles of neuronal soma, dendrites, myelinated fibres, small granular cells, and axon profiles bearing agranular vesicles. The NOS immunoreaction product, on the other hand, was localised in the cytoplasm of principal neurons and dendrites. Some of the NADPH-d/NOS labelled processes formed junctional contacts including synapses or zonulae adherentia. Compared with the neurons, the nonneuronal cells in the ganglion, namely, macrophages, satellite cells and endothelial cells were labelled by NADPH-d but devoid of nNOS immunoreaction product. The results suggest that the NADPH-d/NOS positive fibres in the SCG originate not only from the projecting fibres of the lateral horns of thoracic spinal cord, but also from the principal neurons and small granular cells; some may represent visceral afferent fibres. Electron microscopic morphometry has shown that about 67% of the principal neurons contain NADPH-d reaction product, and that the majority were small to medium sized neurons based on cross-sectional areas in image analysis. On the basis of the present morphological study, it is concluded NO is produced by some local neurons and possibly some nonneuronal cells in the SCG as well as some fibres of extrinsic origin. In this connection, NO may serve either as a neurotransmitter or neuromodulator.

With the exception of the 7th vertebra, both past and recent literature describe the lower cervical vertebrae as possessing similar morphological characteristics (Soemmering, 1794; Cruveilhier, 1862; Luschka, 1862; Henle, 1871; Braus-Elze, 1954; Romanes, 1981; Williams et al. 1989; Benninghof, 1994). Gross anatomical differences from the 3rd to the 7th cervical vertebrae comprise the shapes of the vertebral body and uncinate and spinous processes (Putz, 1976; Penning, 1988; Lang, 1990) and the more developed anterior tubercle and anterior root of the transverse process of the 6th cervical vertebra (C6) (Paturet, 1951). During routine examination of a series of dried skeletons, the articular processes (AP) of C6 were found to be distinct from the rest of the cervical vertebrae. The aim of this study was to confirm this unusual appearance of the C6 process by inspecting a sample of dried skeletons. We report the morphology of the AP of C6 in 76 well preserved complete adult skeletons (58 males, 18 females; age 31–77 y) and 5 young specimens from the Anatomical Institutes of Alicante, Valencia and Murcia (Spain) and Munich (Germany). Another 12 skeletons were excluded from the study due to arthritic changes in their cervical APs.

Sympathetic nerve-mediated vasoconstriction in iris arterioles of mature rats occurs via the activation of α1B-adrenoceptors alone, while in immature rat iris arterioles, vasoconstriction occurs via activation of both α1- and α2-adrenoceptors. In mature rats the vast majority of sympathetic varicosities form close neuroeffector junctions. Serial section electron microscopy of 14 d iris arterioles has been used to determine whether restriction in physiological receptor types with age may result from the establishment of these close neuroeffector junctions. Ninety varicosities which lay within 4 μm of arteriolar smooth muscle were followed for their entire length. Varicosities rarely contained dense cored vesicles even after treatment with 5-hydroxydopamine. 47% of varicosities formed close associations with muscle cells and 88% formed close associations with muscle cells or melanocytes. Varicosities in bundles were as likely as single varicosities to form close associations with vascular smooth muscle cells, although the distribution of synaptic vesicles in single varicosities did not show the asymmetric accumulation towards the smooth muscle cells seen in the varicosities in bundles which were frequently clustered together. We conclude that restriction of physiological receptor types during development does not appear to correlate with the establishment of close neuroeffector junctions, although changes in presynaptic structures may contribute to the refinement of postsynaptic responses.

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.

Granulated metrial gland (GMG) cells differentiate in the uterine wall in pregnancy in mice but the mechanisms which control their differentiation and maintenance are unknown. In vivo, GMG cells share an intimate association with fibroblast-like stromal cells. The importance of this association has been assessed by examining the effects of withdrawal of stromal cell contact on GMG cell maintenance in vitro. When single cell suspensions of cells were prepared from mouse metrial glands there was a steady decline in numbers with days of culture but usually some remained at 7 d of culture. The ability of metrial gland cells to kill Wehi 164 target cells in 51Cr-release cytotoxicity assays was retained by cells cultured for at least 3 d. When explants of metrial gland were maintained in culture to allow GMG cell migration onto the culture flask, the attached GMG cells were lost by 1 d later. Overall, these results suggest that a juxtacrine regulatory mechanism maintains GMG cells. The rapid loss of unsupported GMG cells in culture has major implications in the design of assays to examine GMG cell function.

A class of primitive progenitor cells with high proliferative potential in vitro (HPP-CFC), has been identified in fetal liver and adult bone marrow both in murine and human systems. The kinetic properties of HPP-CFC2 and the more mature granulocyte-macrophage colony forming units (CFU-GM) derived from murine fetal liver on d13, d15 and d19 of gestation, newborn liver and neonatal liver on d3 and d8 postpartum have been evaluated and compared with the kinetic properties of these progenitor cell populations derived from adult bone marrow. The frequency of HPP-CFC2 in fetal liver was found to be greatest on d15 of gestation then subsequently declined in newborn and neonatal liver. Similarly, the highest proportion of HPP-CFC2 engaged in DNA synthesis (53±3%) was detected in d15 fetal liver. This proportion decreased to 13±2% in the liver 1 wk after birth, which is comparable to the number of HPP-CFC2 derived from adult BM which were in S-phase (10±1%). Production of CFU-GM was found to be greater in adult bone marrow than in either fetal or newborn liver. While the proportion of CFU-GM in S-phase was high in all 3 tissue samples, the greatest proportion of cycling CFU-GM (50±2%) was detected in d15 fetal liver. These results suggest that HPP-CFC2 derived from fetal liver are actively cycling while HPP-CFC2 derived from adult bone marrow are relatively quiescent. In contrast, a high proportion of CFU-GM derived from fetal, newborn liver and adult bone marrow are engaged in DNA synthesis.

The pattern of expression of a variety of placental nitric oxide synthase isoforms has contributed to elucidating the regulatory mechanisms of nitric oxide (NO) synthesis during gestation. The maintenance of vascular tone, attenuation of vasoconstriction, prevention of platelet and leukocyte adhesion to the trophoblast surface, and possible participation in uterine blood flow seem to be the main functions of NO generated at the fetal-maternal interface in humans and mice. Extending this knowledge to other rodent species commonly used as laboratory animals, in this study we focus on NADPH-diaphorase activity and the distribution of nitric oxide synthase isoforms (NOS) in the trophoblast cells of Calomys callosus during different phases of pregnancy. NADPH-diaphorase activity was evaluated cytochemically and the presence of NOS isoforms detected by immunohistochemistry. These techniques were performed on pre- and postimplantation embryos in situ and in vitro, as well as in placentae on d 14 and 18 of pregnancy. Neither NADPH-diaphorase activity nor inducible or endothelial NOS isoforms were found in pre-implanting embryos except after culturing for at least 48 h, when some of the embryonic cells were positive for the diaphorase reaction. On d 6·5 of pregnancy, trophoblast cells showed intense diaphorase activity both in situ and under in vitro conditions. A positive reaction was also found in the different placental trophoblast cells on d 14 and 18 of pregnancy. The inducible NOS (iNOS) isoform, but not the endothelial isoform, was immunodetected in trophoblast cells from the placenta and from postimplantation embryos in situ and under in vitro conditions. These results strongly suggest the production of NO by the iNOS isoform in the trophoblast of Calomys callosus after embryo implantation. The data also emphasise a possible role for the trophoblast in producing and releasing cytotoxic molecules at the fetal-maternal interface.

A 14 d ovarian primordium was transplanted with a fetal testis (13–18 d and 21 d of gestation) or a neonatal testis (15, 20, 30 and 45 d after birth) into the renal subcapsular position of an adult male rat. Two weeks after transplantation, transplants were examined as to the degree of ovarian and testicular differentiation. In the combination of a 14 d ovary and a 13 d testis, there were 3 types of result: either the ovary or the testis alone developed or both gonads developed well. Ovaries transplanted in union with 15–18 d testes did not develop, although the testes developed normally. Some ovaries in union with 21 d testes developed normally. In combination with infantile testes, the incidence of developed ovaries increased as the age of testes advanced. These results suggest that the 13 d fetal testes begin to suppress the development of cotransplanted 14 d ovaries, that 14–18 d fetal testes maintain such suppressive effects and that this effect gradually diminishes in infantile testes as they progress toward 45 d after birth.

The expression of carbonic anhydrase (CA) in the quail metanephros was investigated during embryonic development. The immunohistochemical localisation of the isoenzymes CAII and CAIII was compared with the distribution of enzyme activity visualised by a histochemical cobalt-precipitation procedure. The developmental profile of CA activity was also evaluated by means of a biochemical method. The occurrence of a moderate and diffuse CAII immunostaining from the first developmental appearance of the metanephros anlage testified to an early expression of carbonic anhydrase. This finding is discussed in relation to the involvement of the enzyme in the morphogenetic mechanisms leading to the establishment both of cell polarity and epithelial phenotype. CA expression in the renal sites that are positive in adults proved to be developmentally regulated. In the collecting duct system, enzyme activity could not be identified until the time of hatching. No CA was detected at any stage examined at the sites where, in adults, enzyme occurrence has previously been interpreted as a membrane-associated CA isoform. The differentiating renal tubules displayed no CAIII immunoreactivity. It can be argued that the bulk of the enzyme activity in the embryonic metanephros is due to the cytosolic isoenzyme CAII.

Adult dorsal root ganglion neurons express oligosaccharides conjugated to lipids that may be involved in cell–cell recognition, and consequently in the laminar organisation of their central terminations. This paper describes an immunohistochemical study of the developmental expression of 2 lactoseries (LA4 and LD2) and 1 globoseries (SSEA4) oligosaccharide conjugates in rats from embryonic d 19 to postnatal d 60. The expression of calcitonin gene related peptide and the growth associated protein GAP43 was also examined for comparative purposes. We found that these oligosaccharide conjugates begin to be expressed after birth, suggesting that they may be involved in maturation of the central or peripheral terminations, rather than axonal guidance.

During development of the central nervous system (CNS) both deafferentation and axotomy induce increased neuronal death and result in a smaller brain with diminished function at maturity. Unilateral cerebellar pedunculotomy has been used as a model to study the relative importance of these 2 types of lesion on the survival of developing CNS neurons. Within the cerebellum, unilateral pedunculotomy causes deafferentation of the hemicerebellum and axotomy in the efferent pathway from the ipsilateral deep cerebellar nuclei. This results in a smaller hemicerebellum with normal cortical laminae but no extracerebellar outflow. In order to identify the sequence of events which leads to this altered structure and therefore to understand the relative importance of afferent versus target-derived trophic support, unilateral cerebellar pedunculotomy was performed on neonatal rat pups, aged between 1 and 3 days. The cerebella were analysed for histological and vascular changes after survival times of 0, 3, 6, 9, 12, 18, 21, 24 and 48 h. The results show that the effects of axotomy on the deep cerebellar nuclear neurons begin within 3 h of the lesion and apoptotic neuronal degeneration occurs within 48 h. However, the cerebellar cortical neurons continue to undergo normal histological development for at least 48 h after deafferentation. In addition, since ischaemia induces similar effects, a study of the vascular tree was made. The results indicate that the pedunculotomy does not alter the blood supply to the cerebellum, nor induce ischaemia of the cerebellar neurons. From this it may be hypothesised that target-derived trophic support is more crucial for the survival of immature neurons than is the trophic effect of afferent input.

In muscle spindles of the cat, independent control of dynamic and static components of the response of the primary sensory ending to stretch is provided by separate motor inputs to the various kinds of intrafusal muscle fibre: dynamic axons (γ or β) to the bag1 fibres and static axons to the bag2 (typically γ only) and chain (γ or β) fibres. Nonlinear summation of separately evoked effects during combined stimulation of dynamic and static motor axons appears to be due to mutual resetting by antidromic invasion of separate encoding sites, leading to partial occlusion of the momentarily lesser response by the greater. The encoding sites are thought to be located within the primary ending's preterminal branches which from first-order level are normally segregated to the bag1 fibre and to the bag2 and chain fibres. Here we describe the analysis of a special case that arose in a histophysiological study which had shown that the degree of occlusion was related to the minimum number of nodes between the putative encoding sites. Three-dimensional reconstruction of the primary ending revealed that the terminals of one chain fibre were derived entirely from the first-order branch that supplied the bag1 fibre, including one terminal that was shared directly with the bag1 (sensory cross-terminal). The other first-order branch supplied the bag2 and remaining chain fibres as normal. The degree of occlusion seen during simultaneous stimulation of a dynamic β axon and a static γ axon indicated that the encoding sites were separated by both first-order branches. Schematic reconstruction of the motor innervation revealed that the static γ axon was most unlikely to have supplied the chain fibre which shared sensory terminals with the bag1, but that these fibres also shared a motor input with histological characteristics of β type. Ramp-frequency stimulation of the dynamic β axon at constant length evoked a driving effect which persisted after fatiguing the extrafusal component and was therefore explicable on the basis of the observed pattern of motor innervation, though the identity of the axon could not be conclusively proved. Individually, instances of shared sensory terminals and motor input of bag1 and chain fibres are rare in the cat; their combination in a single spindle with correlated physiology is described here for the first time. The observation is considered in relation to the importance of dynamic and static segregation in motor control, since it may imply that there is a lower limit to the degree of segregation that the developmental programme can provide.

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.