The maturity of current 3D rendering software in combination with recent developments in computer vision techniques enable an exciting range of applications for the visualisation, measurement and interactive manipulation of volumetric data, relevant both for diagnostic imaging and for anatomy. This paper reviews recent work in this area from the Image Sciences Institute at Utrecht University. The processes that yield a useful visual presentation are sequential. After acquisition and before any visualisation, an essential step is to prepare the data properly: this field is known as ‘image processing’ or ‘computer vision’ in analogy with the processing in human vision. Examples will be discussed of modern image enhancement and denoising techniques, and the complex process of automatically finding the objects or regions of interest, i.e. segmentation. One of the newer and promising methodologies for image analysis is based on a mathematical analysis of the human (cortical) visual processing: multiscale image analysis. After preprocessing the 3D rendering can be acquired by simulating the ‘ray casting’ in the computer. New possibilities are presented, such as the integrated visualisation in one image of (accurately registered) datasets of the same patient acquired in different modality scanners. Other examples include colour coding of functional data such as SPECT brain perfusion or functional magnetic resonance (MR) data and even metric data such as skull thickness on the rendered 3D anatomy from MR or computed tomography (CT). Optimal use and perception of 3D visualisation in radiology requires fast display and truly interactive manipulation facilities. Modern and increasingly cheaper workstations (<$10000) allow this to be a reality. It is now possible to manipulate 3D images of 2563 at 15 frames per second interactively, placing virtual reality within reach. The possibilities of modern workstations become increasingly more sophisticated and versatile. Examples presented include the automatic detection of the optimal viewing angle of the neck of aneurysms and the simulation of the design and placement procedure of intra-abdominal aortic stents. Such developments, together with the availability of high-resolution datasets of modern scanners and data such as from the NIH Visible Human project, have a dramatic impact on interactive 3D anatomical atlases.

The results obtained using morphometric variables which describe fin ray regeneration patterns are reported for individual fin ray amputations in the goldfish (Carassius auratus) and zebrafish (Brachydanio rerio). Classical and updated experiments are compared to verify previous morphogenetic models of cell tractions (Oster et al. 1983) or epidermis-mesenchyme induction (Saunders et al. 1959) applied to the limb of other vertebrates. Position-dependent patterns within the fin of Carassius auratus are analysed under a comparative protocol using morphometric methods. Conditions in which the apical epidermis is separated from blastema may differentiate small fin rays, thus suggesting this epidermis is involved in blastemal formation. Blastemal cells differentiating as lepidotrichia forming cells (LFCs) may also be related to morphological changes in covering epidermis. Long-range interactions from neighbouring fin ray blastemas or short-range interactions within the blastema, may be postulated through the analysis of segmentation.

Complex arborisations occurs between the inferior ganglion of the vagus nerve and the superior cervical sympathetic ganglion (Braeucker, 1923; Fick, 1926; Siwe, 1931; Hoffman, 1957). The superior cervical sympathetic ganglion sends branches to the internal and the external carotid arteries, the inferior vagal ganglion, the superior laryngeal nerve and the cervical nerves, and provides superior cardiac and thyroid branches as well as the trunk that descends directly to the middle and inferior cervical sympathetic ganglia. There are communications between the vagus nerve (laryngeal branches) and the superior cervical sympathetic ganglion (SCSG). Cannizzaro et al. (1991) and Zerilli et al. (1994) reported abnormalities of sympathetic function among the effects of injury to the superior laryngeal nerve during thyroid surgery. The interconnections between these various nerves are therefore of clinical importance. We document here a rare example of complex communication between the vagus nerve and the SCSG in dissections of 113 adult (78 male, 35 female) Japanese cadavers. Both sides were examined in 88 cases, the right only in 18 and the left only in 7 (i.e. 201 sides in total).

Numerous theories of ageing have been proposed, and many have been tested experimentally, particularly using nematode models such as Caenorhabditis elegans. By combining those theories of ageing that remain plausible with recent findings from studies of C. elegans life span mutants, an integrated theory of ageing has been devised. This is formed from 3 interconnected elements: the evolutionary theory of ageing, the oxidative damage theory of ageing, and a nonadaptive programmed ageing theory. This tripartite theory of ageing gives rise to a number of predictions that may be tested experimentally.

Cardiac fibrosis is a characteristic feature of left ventricular hypertrophy. The aim of this study was to develop a simple and accurate method to analyse collagen accumulation, taking into account the variation in cardiac muscle fibre orientation and nonuniform collagen distribution. This technique was used to determine the amount and types of collagen that accumulate during pressure overload cardiac hypertrophy. These data were correlated with myocyte size, and with the diastolic stress–strain relationship of the intact myocardium. Myocyte size was significantly increased in the hypertrophied hearts, compared with age and sex matched controls (control 363±25 μm2 vs experimental 244μm2; mean±S.E., P < 0.05). No overall collagen accumulation was observed in the hypertrophied hearts, but a significant increase in collagen I was found with a reduction in the amount of collagen III in experimental animals. Since no increase in diastolic stiffness of the hearts was observed, these results indicate that an increase in the overall collagen content of the heart, rather than the upregulation of a specific type, may be necessary to cause diastolic dysfunction.

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.

Thirty-two human vertebral columns were selected from the Kanazawa Collection at the University of Kanazawa, Japan. The superior articular joint surface was categorised into the thoracic type and the lumbar type, and the pattern of the change from one type to the other in the lower thoracic and upper lumbar region was examined. In 21 of 32 cases (66%), the change from the thoracic to the lumbar type occurred over 2 vertebral segments, either between the 12th thoracic and 1st lumbar vertebrae (44%) or between the 11th and 12th thoracic vertebrae (22%). In the remaining 11 cases (34%), the change occurred over 3 vertebral segments, with a transitional type of articular surface. The change from the thoracic to lumbar type of articular surface has been believed to occur over 2 vertebral segments, but occurs over 3 segments in as many as 34% of the articular surfaces.

The presence of 2 phalanges in the 5th toe was first described by Leonardo da Vinci in 1492 (O’Malley & Saunders, 1952) and is recognised as a normal variant. It is probably a true anatomical variant resulting from incomplete segmentation rather than the result of phalangeal fusion (Venning, 1960; Le Minor, 1995) and has been noted to be present in fetuses from as early as 12 wk (Venning, 1960). This variant (and the much rarer 2 biphalangeal 2nd–4th toes) is an exclusively human phenomenon suggesting it is a response to bipedalism (Le Minor, 1995). Various investigators have reported the incidence of the 2 phalanged 5th toe of populations as between 35.5% and 80.4% with the lower values being seen in Europeans and the higher in Japanese (Venning, 1960; Thompson & Chang, 1995). Our study compared foot radiographs in the old and young to see if there was any difference in incidence.

Olfactory neuroepithelium of adult vertebrates retains a population of basal stem cells capable, throughout life, of dividing and differentiating into mature olfactory receptor neurons (see Farbman, 1994). The rate of turnover of olfactory receptor neurons is influenced, in part, by environmental conditions (Hinds et al. 1984). The olfactory system is known, however, to undergo a general decline in function with age. Age-related changes have been described in the rat olfactory bulb, with a decline in size in later life (Hinds & McNelly, 1981). However, this was thought to be secondary to changes within the olfactory epithelium as changes in the number of olfactory receptor neurons directly influence the size of the olfactory bulb. Thus the primary deficit in declining olfactory function may reside in the olfactory epithelium. Studies in humans demonstrated that olfactory function diminishes with increasing age (Ship et al. 1996), suggesting a possible decrease in the number of olfactory sensory neurons. Although the structure of both developing and mature olfactory epithelium (Farbman, 1994) have been well characterised, less information exists on changes relating specifically to ageing. A reduction in thickness of the olfactory epithelium was evident in ageing humans, with a concomitant loss of the normal zonal distribution of supporting and sensory cell nuclei, a less well defined boundary between respiratory and sensory epithelia, and an increase in pigment granules within the supporting cells (Naessen, 1971). Similar lysosome-like inclusion bodies were also noted in olfactory epithelium of adult rabbits (Mulvaney, 1971) and dogs over the age of 17 y (Hirai et al. 1996). Decreases both in the total area of olfactory epithelium and in dendritic knob density have been described in rats aged 29 mo and above (Hinds & McNelly, 1981). This is unlikely to be due to a loss of regenerative capacity since, in hamsters, regeneration of olfactory receptor neurons is observed in aged animals (Morrison & Costanzo, 1995). A scanning electron microscopic comparison of young and old rat olfactory epithelium revealed changes in membrane-limited dense bodies in olfactory receptor neuronal cell bodies (Naguro & Iwashita, 1992). In old rats (21 and 36 mo), large irregular bodies were found in the supranuclear area of olfactory receptor neurons and were also abundant throughout the sustentacular cells, resulting in cell enlargement and the loss of about 2 layers of olfactory receptor neuron perikarya. They contained lipid droplets and numerous irregular osmiophilic lamellae resembling lipofuscin granules (Naguro & Iwashita, 1992). No attempt was made to quantify these age related changes. The present study aimed to detail fully the morphological changes in the aged mouse olfactory epithelium and is a continuation of a previous pilot study (Appleton et al. 1996).

The ultrastructure and size distributions of collagen fibrils in Glisson's sheath were investigated in the rat liver to analyse the mechanical environment around the fibrils and their possible cells of origin. Glisson's sheath was found to contain 2 populations of collagen fibrils with different diameters and distinct localisations, namely fibroblast-associated and bile epithelium-associated. Fibroblast-associated collagen was composed of fibrils arranged in bundles and constituted the majority of the collagen in Glisson's sheath. Bile epithelium-associated collagen was represented by small dispersed groups of fibrils just beneath the basement membrane of the bile duct. The basement membrane of the bile duct was frequently reduplicated into a few or as many as 10 layers of laminae densae, with scattered collagen fibrils between these laminae. The diameters of the fibrils of both groups of collagen increased in relation to the calibre of the bile duct, whereas at any given place in Glisson's sheath bile epithelium-associated collagen fibrils had a smaller diameter compared with those of the fibroblast-associated fibrils. The increment in fibril diameter along the bile duct is considered to be correlated with the increase in mechanical stress acting on Glisson's sheath. The difference in diameter between the 2 populations as well as the incorporation of fibrils between the laminae densae of the basement membrane of the bile duct supports the view that the bile epithelium-associated collagen is produced by the epithelial cells of the bile duct, thus having a different origin from that of fibroblast-associated collagen. These findings provide the first evidence that the epithelial cells of the interlobular bile duct produce fibril-forming collagen. Furthermore, it is suggested that cholestasis stimulates the epithelial cells of interlobular bile duct to increased synthesis of fibril-forming collagen that is also produced by these cells under physiological conditions.

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.

The sciatic artery is the major arterial supply to the lower limb bud at an early embryological stage. It primarily originates from the dorsal root of the umbilical artery. After the 22 mm embryological stage, the sciatic artery involutes and the femoral artery system develops as the major inflow source to the lower limb. In the adult, remnants of the sciatic artery persist as the proximal portion of the inferior gluteal artery, the popliteal and peroneal arteries (Williams et al. 1989). It is suggested that either failure in development of the femoral system or failure in regression of the sciatic artery results in persistence of this artery (Arey, 1965). We report a rare example of persistent sciatic artery (PSA) accompanied by arterio-arterial and arteriovenous anastomoses.

Human ovarian granulosa cells were cultured on a basement membrane preparation (Matrigel) to investigate the role of extracellular matrix components in granulosa cell cluster formation. Time-lapse videomicroscopy of these cultures revealed a rapid aggregation of cells which was initiated during the first 2–4 h of culture so that by 8 h most of the granulosa cells were incorporated into clusters. Further amalgamation then occurred with the transfer of cells along ‘bridges’ between combining clusters. The clustering process, which was complete by about 24 h, was accompanied by reorganisation of matrix which was visualised by immunolabelling of laminin. Clustering cells appeared to gather matrix which became distributed around the clusters. Confocal microscopy showed matrix to be present over the surface of each cluster as well as around the base apparently anchoring the aggregate to the culture surface. Results suggest the potential for active rearrangement of matrix by granulosa-derived cells during corpus luteum development.

Sepsis stimulates an increase in the number and activity of mononuclear phagocytes in systemic host-defence organs. The present study was conducted to define the ultrastructural and cytochemical characteristics of the mononuclear phagocytes that sequester in the lung microvasculature of septic rats. Fourteen rats were challenged with a single intraperitoneal injection of saline (0.5 ml/100 g), E. coli (2×107/100 g) or glucan (4 mg/100 g), and euthanased 2, 4, or 7 d later. The lungs were inflation fixed and processed for transmission electron microscopy. Cellular morphology was used to identify the intravascular mononuclear phagocytes and acid phosphatase (AcPase) expression was monitored as an index of cellular differentiation and activation. Control rats contained a limited number of monocytes in the pulmonary vasculature. In contrast, large numbers of activated mononuclear phagocytes were seen in the microvasculature within 48 h of treatment with either microbial product. The recruited pulmonary intravascular mononuclear phagocytes (PIMP) exhibited AcPase-reactive Golgi complexes, accumulation of secretory vesicles and other features of cell activation consistent with enhanced biosynthetic activity. Subsequent electron microscopy, conducted 4 and 7 d posttreatment, suggested that a progressive decline in the number and activity of PIMPs then occurred. In order to quantify the sepsis-induced accumulation of AcPase-positive PIMP, the experimental challenges were repeated in 11 rats and, 48 h later, tissue samples were evaluated by light microscopy for tartrate-insensitive acid phosphatase. Control rats exhibited 0.148±0.107 AcPase-positive PIMP/alveoli. E. coli and glucan challenged animals exhibited significant (P<0.01) increases in AcPase-positive mononuclear phagocytes, with 0.782±0.073 and 0.636±0.170 PIMP/alveoli respectively. The results demonstrate that focal sepsis stimulates a significant, but transient, recruitment of activated mononuclear phagocytes into the rat pulmonary microvasculature.

In order to delineate the effects of death on the immunofluorescence of autonomic nerves supplying the human ventricular myocardium, we studied percutaneous myocardial samples obtained postmortem from 5 individuals within 3 h of death. Subsequent samples were obtained daily from the same individuals up to a total of 5–11 d. The antibodies employed included those against protein gene product 9.5 to demonstrate nervous tissue, dopamine β-hydroxylase and tyrosine hydroxylase to reveal catecholaminergic neural tissue and neuropeptide Y. An indirect immunofluorescence technique using the avidin-biotin method was employed. The density of myocardial protein gene product 9.5 immunoreactive nerves declined on the 7th day, and became markedly diminished by the 11th day. Immunoreactive dopamine β-hydroxylase nerves decreased on the 5th day, and were difficult to idenitify by the 9th day. The density of tyrosine hydroxylase and neuropeptide Y containing nerves rapidly diminished on the 3rd and 4th days, and became undetectable by the 7th and 8th days, respectively. The present results indicate that, depending on the type of antibodies used, immunohistochemical techniques can be used on human hearts obtained up to within 6 d of death to study cardiac innervation.

The pig is often used in experimental studies on the significance of bronchial artery circulation, but the anatomy of this artery is only poorly described. The purpose of this study was to improve the anatomical basis for experimental studies on the porcine bronchial artery circulation. The origin of the artery from the aorta is described in 32 pigs. Heart–lung blocks were perfused with saline and removed in 16 pigs, and the broncho-oesophageal orifice was identified and cannulated. In these 16 specimens the intrapulmonary ramification was studied by angiography, and the extrapulmonary distribution and supply area by injection of Evans Blue. The broncho-oesophageal artery originated from the aorta as a single trunk in 91%. Angiography showed that each principal bronchus was accompanied by 2 bronchial artery branches far into the lung parenchyma. The central branching pattern of the artery between the aorta and the principal bronchi was divided into 3 subtypes. Evans Blue showed communication with the whole mediastinum. The anatomical relations are described. It is concluded that the broncho-oesophageal artery divides to follow each bronchus with 2 bronchial branches. A nomenclature for these branches is suggested. The pig anatomy is suited for experimental investigations on the bronchial circulation.

The distribution of glycine-immunoreactive (glycine-IR) neurons and their associated axon terminals in the rat cuneate nucleus was studied using antiglycine postembedding immunoperoxidase labelling and immunogold staining, respectively. The immunoperoxidase-labelled glycine-IR neurons were widely distributed in the entire rostrocaudal extent of the nucleus. They made up 30.8% (9671/31368) of the neurons surveyed. Quantitative evaluation showed that the percentage of glycine-IR neurons in the caudal level was significantly higher than that in the middle and rostral levels. The glycine-IR neurons were small cells (mean area=198±1.9 μm2, n=2862) with ovoid or spindle-shaped somata. Statistical analysis showed that the size of the glycine-IR neurons in the rostral level was significantly smaller than that in the middle and caudal levels. Immunogold labelled glycine-IR terminals which contained predominantly pleomorphic synaptic vesicles were mostly small (mean area=1.24±0.03 μm2, n=286) and they constituted 24.7% (286/1158) of the total terminals surveyed. They formed axodendritic, axosomatic and axoaxonic synapses with unlabelled elements. It is suggested from this study that glycine is one of the major neurotransmitters involved in the depression of synaptic transmission in the cuneate nucleus.

Retinal microglia were selectively and sequentially labelled in different layers of the retina of postnatal rats following a single intravenous injection of the fluorescent dye, rhodamine isothiocyanate (RhIc). The fluorescent cells were doubly immunostained with OX-42 and ED-1 antibodies that recognise complement type 3 (CR3) receptors and macrophage antigen, respectively. RhIc was first detected in the retinal blood vessels 5 min after injection. At 1 h, a variable number of microglia in the inner layers of the retina, namely, the nerve fibre and ganglion cell layers appeared to emit weak fluorescence. Labelled microglial cells in the inner nuclear and outer plexiform layers were not detected until 1 and 2 d had elapsed following RhIc injection. The number of labelled retinal microglia was progressively increased with time, peaking at 4 d after RhIc injection. The frequency of RhIc labelled cells also increased with age, with the largest number of cells occurring in 7-d-old rats but declined thereafter. In 11 d or older rats, RhIc was confined to the retinal blood vessels. It is concluded that when injected into the circulation, RhIc could readily gain access into the retina tissues due to an inefficient blood-retina barrier in early postnatal stages. It became impeded with maturation of the blood-retina barrier, which was established between 11 and 13 d of age. RhIc that inundated the retinal tissues was thoroughly sequestered by the resident microglial cells. It is therefore suggested that the latter could play a protective role against serum-derived substances that may be deleterious to the developing retina.

Opposition, one of the most important functions of the hand, is lost or impaired after median nerve injury. Complete recovery does not always occur after treatment, and various techniques of opponensplasty are used for restoring opposition. This study was performed in order to develop an alternative method for selective restoration of thenar muscle function. Ten arms from 5 cadavers were used. The median nerve with its thenar motor branch (Tb) and the anterior interosseous nerve with its motor branch to pronator quadratus (PQb) were prepared in the distal forearm. The mean widths and the number of myelinated fibres of these nerves were: PQb 1.3±0.10 mm, Tb 1.4±0.12 mm and PQb 912±88 mm, Tb 1020±93 mm. The minimum necessary distance from the distal flexor crease of the wrist for neurotisation of the Tb by the PQb was 60±5.41 mm. It was concluded that PQb-Tb neurotisation would be possible anatomically. The advantages are that motor function is reestablished with a motor nerve, the diameters and the number of myelinated fibres of both nerves are similar, the loss of function after denervation of the pronator quadratus is slight and opponensplasty still remains as a final option.

We report the morphogenesis of a new mouse mutant, Doublefoot (Dbf). The major phenotypic features involve the limb and craniofacial regions. There is polydactyly of all 4 limbs, with typically 6–8 digits per limb. All of the digits are triphalangeal; some show bifurcations and some are not attached to the carpus/tarsus. The carpus and tarsus are broader than normal, and their elements are partially fused. There are also tibial defects. Mutant embryos show a diencephalic bulge on d 10.0, with older animals exhibiting broadened and bulbous skulls sometimes with an additional midline skeletal element, shortened snouts and bulging eyes. Homozygotes, which do not survive beyond d 15, show midline facial clefting. In this study of the embryonic and fetal development of Dbf animals, we focus on the morphogenesis of the limbs and head, and discuss the possible molecular developmental mechanisms.