Archivio italiano di anatomia e di embriologia. Italian journal of anatomy and embryology最新文献

Some morphological data of the right and left human RLNs were evaluated with the aim of verifying possible differences in the fibre composition of the two nerves. The following parameters were evaluated in the right and left RLNs of five human cases: 1) the maximum diameter of the fibres; 2) the axon diameter and area; 3) the myelin sheath area obtained substracting the axon area from the total area of each fibre. The obtained data were plotted on histograms for each case: moreover, histograms of all fibres of both left and right nerves of all five cases were made. The results show that the values of the maximum diameter of the fibres and of the myelin sheath area are always greater in a statistically significant way in the left RLNs than in the right RLNs. On the other hand the axon diameter is nearly the same in the nerves of both sides. These data suggest that the greater calibre of the myelin sheath in the fibres of the left inferior laryngeal nerve can be responsible of the faster conduction speed in this nerve. This fact might explain the simultaneous arrival of the impulses to the laryngeal muscles of the two sides in spite to the different length of the two nerves.

The growth of the hepatic weight was correlated to fetal parameters of maturity (gestational age, crown-rump length and weight) in 70 human fetuses ranging from 14 to 39 weeks post-conception using the allometric method. The growth of the hepatic weight presents moderate positive allometry relative to age and C-R length, and isometry relative to fetal weight. The coefficiens of correlation are very high (p less than 0.001, Table 1). This study presents growth curves of the hepatic weight useful in medical branches such as anatomy, forensic medicine, fetopathology, medical imagery, onstetrics and pediatrics.

Lungless Salamanders of the family Plethodontidae have a reduced interatrial septum. The pulmonary vein is lacking. In these species, the septum as a membranous thin sheet attaches near the dorsal lip of the sino-atrial valve where a connective and muscular column, supporting the valve, extends its branches over the upper wall of the undivided atrial cavity where a sponge-like structure is formed. The meshes of this structure are the site of a erythropoietic activity as shown in the plates. Early stages in active reproduction are found in the external acid layer while in the basic inner layer the red cells undergo differentiation. This locus may be correlated to the particular anatomy of the heart concerning the lacking of the pulmonary vein, the position of the sino-arterial aperture shifted to the left side and the reduced interatrial septum. In the large upper cavity of the atrium a certain degree of blood stagnation could be possible which could allow the settlement of this locus. No ventricular erythropoiesis nor epicardial granulopoiesis have been found. This hemopoietic locus is lacking in the family Salamandridae and Anura.

Microphtalmic blanc mutation (mib/mib) displays a very mild form of osteopetrosis in rats. The autosomal recessive mib mutation shows pleiotropic expressions in homozygotes. Microphtalmia, absence of eye and skin pigmentation, retardation in the tooth eruption were observed in the mutants. Most bone abnormalities occurred in newborns. An increased radiological opacity of long bones, persistence of primitive bone in medullary cavities, reduced number of poorly differentiated osteoclasts in mandibulae, reduced number of mononuclear peritoneal cells as well as reduced number of mononuclear osteoclast precursors in peritoneal cell population were found. In 3 weeks old and in adult mutants, both bone structure and the number of mandible osteoclasts appear normal, but the number of blood monocytes, peritoneal cells and mononuclear osteoclast precursors in peritoneal cell population remain significantly lower than in the healthy littermates. These observations indicate that the early failure of osteoclast differentiation and maturation is transient in the mib/mib form of osteopetrosis.

Aim of our present work was to investigate a new method to study the three-dimensional arrangement, the length and the diameter of the different parts of the renal tubules. The ureter was cannulated after blocking the urinary flow with a binding of the ureter itself at its intermediate third, and injected in it against flow a synthetic resin (Mercox) normally used for vascular corrosion casts. It was demonstrated that the binding maintained only for 24 hours is adequate for morphological studies of the urinary tracts from papillar ducts until the Henle's loop. On the contrary the binding maintained for 7 days induced marked changes in the tubular architecture similar to the first anatomo-pathological changes of the nephrosclerosis following a chronic obstructive nephropathy.

A battery of seven different horseradish-peroxidase labelled lectins (DBA, PNA, SBA, UEA I, WGA, ConA, LTA) was used to study the distribution of sugar residues in the glycoconjugates along the nephron and the collecting duct of the kidney of Gallus domesticus. As far as the glomerular components are concerned, we have demonstrated that the podocytes and, with a lesser extent, the mesangial cells are characterised by the presence of D-mannose, D-galactose-(beta 1- greater than 3)-N-acetyl-D-galactosamine and sialic acid. The glomerular capillary wall shows the presence of the disaccharide D-galactose-(beta 1- greater than 3)-N-acetyl-D-galactosamine and sialic acid. With regards to the tubules, the proximal tubule, the descending limb of the loop of Henle, the connecting tubule and the collecting one, are characterised by N-acetyl-D-galactosamine, (1- greater than 6)-alpha-L-fucose, D-mannose, N-acetyl-D-galactosamine and D-galactose-(beta 1- greater than 3)-N-acetyl-D-glucosamine. The cells of the connecting and collecting ducts show the presence of intracellular sialic acid, found also as component of the mucous secretion. The ascending limb of the loop of Henle and the distal tubule contain only three saccharidic residues, i.e. (1- greater than 6)-alpha-L-fucose, D-mannose and N-acetyl-D-glucosamine. Lectin histochemistry was also useful to define the saccharidic components of the mucus, which is normally present within the connecting and collecting ducts of the kidney of the birds. The cellular variability of the connecting and the collecting ducts is similar to that found in the kidney of some mammals. Such a variability seems to suggest a possible cell specialization along a single kidney tubule.

The regeneration of the sciatic nerve fibres was studied in both normal and vitamin E-deficient rats at 30 and 60 days after crush. The vitamin E is involved in one of the most important mechanisms of protection against peroxidation of plasma membrane lipids; the plasma membrane plays certainly a role in nerve regeneration. Both the diameter and the total number of myelinated nerve fibres was calculated at different times. The number of myelinated fibres in the undenervated deficient animals was lower than that found in the undenervated normals animals. Following the nerve crush, in normal animals after two months the number of myelinated fibres exceeded the number found in undenervated normal animals, whereas in the deficient rat nerves it was significantly lower than in the corresponding controls and moreover it did not even reach the number found in the nerves of undenervated deficient rats. Finally, the caliber distribution of myelinated fibres in undenervated and denervated deficient rats shows a relative percent increase in the number of greatest axons and a decrease in smaller axons. This result confirm the vitamin E to be an important factor of the normal process of nerve regeneration.

The follicular epithelium of dormouse thyroid consists of two distinct cellular types, follicular and parafollicular cells. Parafollicular cells can be easily identified by their high cytoplasmic dye-affinity for phloxine, round to ovoid shape, basal arrangement and lack of contact with follicular colloid. The wide cytoplasmic matrix is clear and contains many secretory granules of variable electron density whose contents histochemically appears to be proteic with a lean glucidic component. Furthermore immunocytochemical reactions with antibodies against calcitonin and somatostatin showed that both hormones are co-stored in the secretory granules of all parafollicular cells. Both follicular and parafollicular cells show seasonal morphological variations in their secretory activity. Follicular cell activity is high in summer, reaches a peak in late fall or prehibernation and progressively slows down throughout hibernation. Parafollicular cells exhibit a fair synthetic activity in summer, in fall, and in the animals captured during winter hibernating sleep and killed after 12 days stay in laboratory. In winter sleep, granules with interrupted membrane and cottony contents are prevalent and the ultrastructural aspects suggest an intense discharge of secretion. The results are compared with those from other hibernating mammalians and discussed in the light of blood calcium values and seasonal balances of other metabolisms.

The purpose of the present researches was to confirm the hypothesis that in the human placenta the microcirculation is subjected to humoral control, because of the absence of innervation in the chorionic villi and the ability of the capillaries to contract themselves. Chorionic villi were incubated in presence of vasoactive substances, Histamine, Serotonin, Bradykinin, Dopamine, Enkephalin Prostaglandins. After incubation, the specimens were fixed and embedded in resin. Semithin sections were submitted to a computerized analysis for the evaluation of the ratio between surface of capillaries and surface of the villus. The results confirmed that in the control of capillaries in the human placenta most of the tested substances show a specific action, dose- or time-dependent.

The mean wall thickness (MWT), measured by the Kragstrup technique, and the trabecular bone volume (TBV), have been measured in 50 transiliac undecalcified bone biopsies performed in 50 subjects who died suddenly (traffic accident, carbon monoxide, poisoning). Diseases affecting the skeleton were excluded in the autopsies. Our values for MWT were similar to those found in previously published studies except those of Kragstrup's group, in which values are higher. As our measuring technique was that of Kragstrup, these results could be explained either by a difference in staining methods (Solocromo cyanine R and Goldner method respectively) or by the differences in populations considered (French and Danish respectively). Our study confirmed a significant decrease in MWT and TBV with age and a positive correlation between MWT, TBV and age.