European journal of morphology最新文献

A high-calorie (cafeteria) diet is known to cause changes in the intestinal morphology and functioning that seem to be related to calorie overfeeding. Among the cell lineages found in the small intestine epithelium, the Paneth cell (PC) population is known to be influenced by factors related mainly to the intestinal microbiota. The role of PCs in the intestinal cell concert remains unclear, because experimental evidence suggests PC involvement in local processes other than protection against pathogens. Participation of PC in digestive mechanisms has been proposed on this basis. We have analyzed the effect of high-carbohydrate (HC) and high-fat (HF) cafeteria diets on the PC population in the small intestine of the adult rat. For 8 weeks, both HC and HF diets caused a gain in body weight, but whereas the HC-fed rats showed reduced counts of intestinal crypts per 5-mum section, the HF-fed group showed the opposite. In control rats, the number of crypts per section showed a slight tendency to decrease along the duodenum - ileum axis, whereas the number of PCs per crypt was increased towards the ileum. As a result, the number of PCs per section (calculated from these data) remained constant along the three segments of the intestine. The hypercaloric diets did not modify the general tendencies seen in the crypt and PC counts, but reduced the number of PCs per section in the duodenum by 50%. HC-fed, but not HF-fed, rats showed a similar reduction in jejunum also. These changes do not correlate particularly with any of the predictable effects of diet composition, so that a multifactorial control of PC density is proposed.

The biphalangeal little toe is an anatomical anomaly that has been previously well described in the early anatomical literature. But, as is the case with many anomalies, there is a lack of awareness of it amongst current clinicians. We report the case of a fracture through the distal phalanx of the little toe, with a delay in the diagnosis due to confusion over the X-ray findings. X-rays revealed a biphalangeal toe with a fracture through the distal phalanx, which mimicked the usual triphalangeal toe. This is the first reported case of clinical confusion over this anatomical variation. A review of 102 human skeletal feet at the Department of Anatomy, University of Melbourne, was performed to evaluate the frequency of the biphalangeal little toe variant, revealing an incidence of 26%.

There are significant problems in obtaining normal human material for histology for teaching or research purposes. This study shows that tissue from cadavers embalmed for teaching can be used for routine histology. Twelve cadavers embalmed with four different formalin-containing embalming fluids were used (n = 3 per fluid): (1) formalin mix (10% formalin); (2) Dunedin mix (an alcohol-based fluid containing phenol); (3) Michigan mix (a water-based fluid); and (4) phenoxyethanol mix (an alcohol-based fluid containing phenoxyethanol). Tissue blocks of liver, heart, kidney, skin and skeletal muscle were taken from each cadaver, paraffin embedded, sectioned and stained with haematoxylin and eosin (H & E), Periodic Acid Schiff (PAS), or Mallory trichrome (Malt). Each section was assigned an overall score based on the histological quality of the cellular components of the tissue. Sections were scored from 1 to 3 (1 = poor, 2 = satisfactory, 3 = good). Satisfactory sections were obtained from all cadavers except those embalmed with the Dunedin mix. The Michigan and phenoxyethanol fluids resulted in consistently good quality sections. No significant differences in tissue morphology were observed between the different stains. The clearest morphology was observed in the skin and skeletal muscle sections, and in tissues embalmed with fluids which do not contain phenol.

The study of the contributions of different bones to the formation of the skeleton in birds is necessary: (1) to establish homologies in comparative anatomy; (2) to delimit each bone structure correctly, mainly in relation to the skull and mandible where the bones are fused to each other in adults; and (3) to standardize nomenclature in avian osteology. In this paper at least one young specimen belonging to each sub-family of Cuculidae was examined in order to identify each bone in terms of boundaries and contributions to skull and mandible formation. These cuckoos specimens were also compared with adults and young of turacos and hoatzin. The results show little variation of skull and jaw among the young cuckoos studied compared with the variations among adult specimens. However, it provides new suggestions for the boundaries and nomenclature of certain osseous structures in the skull and mandible of birds, specifically fissura zona flexoria craniofacialis, prominetia frontoparietalis, crista temporalis transversa, processus squamosalis, fossa laterosphenoidalis, tuberculum laterosphenoidale and processus retroangularis. This study also provides more reliable homologies for use in cladistic analysis and above all it contributes to the phylogenetic position of Cuculidae within Neognathae, specifically the skull formation suggest that turacos and hoatzin are more similar to each other than either is to the cuckoos.

Mechanical forces due to increased blood flow during the first pregnancy might induce a permanently higher conductance of the uterine arcade. Number of endothelial and smooth muscle cells, cross-sectional area and wall thickness of the uterine artery were measured in nulliparous mice (n = 11) and until the 93rd day after parturition in primiparous mice (n = 44). Inner diameter and wall area were calculated. Three months after the first pregnancy, uterine artery wall thickness was not altered compared to nulliparous mice. In contrast, inner diameter increased 1.6-fold, wall area 1.5-fold and the numbers of endothelial and smooth muscle cells increased 1.5 times. These changes were completely stable during the whole observation period. The increased blood flow during the first pregnancy might be a mandatory mechanical stimulus for uterine arcade maturation. This physiological maturation process could result in abortion explaining the higher prevalence of unexplained pregnancy losses in primiparous women.

The mechanical breaking stress and strain of cobra leather, along with their mechanical anisotropies, were studied in relation to body movement. The mechanical breaking strain in the transverse direction (TD), which was perpendicular to the direction (CCD) from the caudal to the cranial end, was much larger around the dorsum, and slightly larger around the abdomen, than that in the CCD. The mechanical strain is closely related to the expansion of skin. The mechanical anisotropy of cobra leather was relatively large in the dorsum, but smaller in the abdomen. These findings indicate that it was comparatively easy for the cobra body to expand preferentially in the TD around the dorsum and also to expand roughly equally in all directions around the abdomen, whereas expansion of the dorsum in the CCD was restricted by the spinal column. These findings also suggest that the strong mechanical anisotropy in cobra leather is closely related to the motion of the skin around the waist, which accompanies movement of the body.

The middle meningeal vascular network leaves its traces on the endocranial surface because of the tight relationship between neurocranial development and brain growth. Analysing the endocast of fossil specimens, it is therefore possible to describe the morphology of these structures, leading inferences on the cerebral physiology and metabolism in extinct human groups. In this paper, general features of the meningeal vascular traces are described for specimens included in the Homo erectus, Homo neanderthalensis, and Homo sapiens hypodigms. The complexity of the arterial network is quantified by its fractal dimension, calculated through the box-counting method. Modern humans show significant differences from the other two taxa because of the anterior vascular dominance and the larger fractal dimension. Neither the fractal dimension nor the anterior development are merely associated with cranial size increase. Considering the differences between Neanderthals and modern humans, these results may be interpreted in terms of phylogeny, cerebral functions, or cranial structural network.

Bone formation and growth are controlled by genetic, hormonal and biomechanical factors. In this study, an established rat disuse osteoporosis model, hindlimb-suspension (HLS), was used to relate morphological change and gene expression to altered mechanical load in the underloaded femora and the ostensibly normally loaded humeri of the suspended rats (39 days old at onset; 1, 3, 7 and 14 days suspension). Morphological change was measured by labelling new bone formation with fluorescent agents during the experimental period and subsequent histological analysis of bone sections post-sacrifice. Hindlimb suspension reduced both the total amount of bone present, assessed as cross-sectional area, and the bone formation rate at the mid-diaphysis of the unloaded femora while no significant effect was found in the loaded humeri. In addition, the femora of the suspended animals were found to have a markedly increased circularity as a result of unloading. A sensitive semi-quantitative method of gene expression analysis, involving the creation of SMART cDNA arrays, was successfully implemented. This technique amplified all populations of mRNA to levels where they could be assessed using standard molecular biology protocols. Gene expression patterns of two candidate genes, c-fos and osteocalcin were assessed in periosteal tissue. Altered gene expression patterns were identified and tracked over the suspension period. The altered levels of both candidate genes were found to be consistent with the changes observed in the histological analysis.

This study aimed to describe the impressive diversity of vascular plexiform structures of the hypodermal layer of human skin. We chose the human body site with the highest concentration of dermal corpuscles, the human digit, and processed it with the corrosion casting technique and scanning electron microscopy analysis (SEM). This approach proved to be the best tool to study these microvascular architectures, free from any interference by surrounding tissues. We took high-definition pictures of the vascular network of sweat glands, thermoreceptorial and tactile corpuscles, the vessels constituting the glomic bodies and those feeding the hair follicles. We observed that the three-dimensional disposition of these vessels strictly depends on the shape of the corpuscles supplied. We could see the tubular vascularization of the excretory duct of sweat glands and the ovoid one feeding their bodies, sometimes made up of two lobes. In some cases, knowledge of these morphological data regarding the normal disposition in space and intrinsic vascularization structure of the dermal corpuscles can help to explain many of the physiopathological changes occurring during chronic microangiopathic diseases.

The ontogenetic allometry of the lumbar region of 1913 humans (1228 females and 685 males), ranging from newborn to 21-year-old individuals, was studied by means of length, width, projected surface area and bone mineral density of the segment L2 - L4, obtained by dual X-ray absorptiometry (DXA). All these parameters were regressed to body mass and height of the individuals, considered alternatively as the independent variable. Firstly, we addressed the comparison between the results obtained on both sexes in order to elucidate whether ontogenetic differences existed. Length of the segments increased significantly faster in females than in males, independently whether the regression was made against body mass or height, while in both types of regression width scaled in males faster than in females. Regarding bone mineral density, although males increased bone mineral density faster than females, slope differences were not significant. However, y-interception was significantly higher in females than in males when bone mineral density was regressed to body mass. Results on length and width are compared with others from previous research on allometry. Finally, global results are discussed as regards the slope predictions for interspecific scaling.