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Biomedical subjects

A Montella

Publications and source records attributed to A Montella.

36 records · Page 2Linked to original sources
PubMed1990

Presence of antisperm antibodies in the serum of Sardinian adult people. I. Study on healthy adult men in north Sardinia.

Infertility is a problem estimated to occur in 15-20% of couples. Among many possible causes of this condition, an immunological factor must be considered, in particular the presence of antibodies to spermatozoa in the serum and also in the seminal plasma. Several researches agree in reporting that the incidence of such antibodies is considerably higher in men affected by impairment of spermatogenesis than in healthy subjects as showed also in our Institute. In order to widen our knowledge of the topic at issue, considering that there are no data concerning this problem in Sardinia, we thought it right to begin an epidemiological research about the incidence of antispermatozoal antibodies in the resident, adult and seemingly healthy male population. Therefore, we have tested the serum of 250 men, aged from 20 to 50, habitual blood donors registered in Transfusional Centres of North Sardinia, who have never manifested failures of the reproductive system; for the detection of the antispermatozoal antibodies, we have adopted the indirect immunofluorescence assay. The first results show that, in a few cases, corresponding to 2.4 per cent, also in a highly selected population antibodies to spermatozoa were present, and they were directed particularly against the acrosome and the equatorial segment. The ultimate aim of the research is to give epidemiological data, concerning both sexes, that may be utilized in a wider study of the local causes of infertility.

Adult↗
PubMed1990

[The gastric mucosa of the human fetus. I. The surface epithelium].

The ontogenesis of the surface epithelium in the gastric mucosa was studied by means of light and electron microscopy in 41 human foetuses ranging from 7th to 12th week of gestational age. The results obtained can be summarized as follows: 1) At the 7th week the gastric mucosa shows a simple pseudostratified epithelium; the epithelial cells are undifferentiated and filled, with glycogen clusters. 2) From the 8th week the epithelial surface shows small depressions that become deeper in the mesenchyme making the first bud of the gastric foveolae. 3) At the 9-10th week the gastric foveolae are more developed. The cells of the gastric epithelium can be therefore separated in two populations: a) the cells of the foveolae; b) the cell of the mucosal surfaces. 4) At the 12th week the cells of the mucosal surface become, on the basis of their histochemical and ultrastructural characteristics, surface mucous cells. The morphological differentiation is testified mainly by the transposition of the nuclei in the basal parts of the cells and by the gradual substitution of the cytoplasmic glycogen by mucous granules.

Epithelium↗
PubMed1983

Experimental varicocele in the rat--a new experimental model. I. Effect on testicular structure.

A new experimental model of a varicoele in the rat is proposed. The study has been carried out on the Wistar rat in which the gonadal vein enters into the iliac vein. A varicocoele was induced in different ways: by complete or incomplete ligature of the iliac vein medial to the entry of the gonadal bein (Group I and II); by creating a venous compression by positioning the iliac artery in front of the vein, thus reproducing the so called "nut cracker" phenomenon (Group III); by creation of a small arterio-venous fistula by means of a side-to-side anastomosis between the iliac artery and vein. The results were studied macroscopically and histologically. The damage was most evident in Group III and significant in Group IV, but the absence of damage to the contralateral testis remains unexplained.

Animals↗
PubMed1981

[Steroidogenic activity in the amniotic epithelium].

For evaluation of the steroid-producing structures during pregnancy, the human amnion has been studied from the early stages of pregnancy to the term by means of histo-enzymologic and submicroscopic techniques. The histo-enzymatic tests have shown the presence hydroxysteroid of 3 beta-hydroxysteroid-dehydrogenase in the cells of the amniotic epithelium throughout pregnancy. Also scattered mesenchymal cells of the subepithelial fibroblastic layer showed a positive reaction in their cytoplasm. Using FRIEND and BRASSIL's (1970) technique a steroidogenetic activity has been demonstrated at the level of the amniotic epithelium both in semithin and in ultrathin sections, the latter observed by electron microscopy. The above mentioned results suggest that the amniotic epithelium represents a site of steroidogenesis and conversion of steroids and plays, also under this point of view, an important role in the physiology of pregnancy.

3-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

An experimental study of the effect of ischemia on testicular structure in the rat. Efficacy of intravenous inosine.

The damages caused by experimental testicular ischemia lasting 60 minutes have been examined in the rat. The histologic alterations of the germinal epithelium and of the tunica propria are studied, using semi-thin sections stained with 1% toluidine blue. The results show that a testicular ischemia of 60 minutes causes damages to the testicular structures. These damages cannot be prevented or avoided by either surface cooling or cold perfusion; however, intravenous inosine prior to ischemia has a protective effect.

Animals↗
PubMedDate not supplied

Inner ear pressure changes modify ADH secretion in freely moving guinea pig.

The present study was designed to elucidate the relationship between endolymphatic pressure and plasma ADH levels in conscious guinea pigs. Plasma ADH (pADH) was measured in basal conditions and after having applied positive or negative pressure of 20 cmH2O to the inner ear. The experimental protocol was designed to avoid any interference on ADH release caused by anesthesia and surgical stress. There was no change in blood pressure, heart rate, plasma Na (pNa) and osmolality (pOsm) after inner ear pressure (IEP) modifications. However, pADH was inversely related with IEP: pADH averaged 31.4 +/- 7.0 pg/ml (mean +/- S.D.) in basal conditions, rising to 48.8 +/- 19.3 when IEP was lowered and falling to 16.6 +/- 10.3 when IEP was raised. These results confirm that structures in the inner ear help control of ADH release.

Animals↗
PubMedDate not supplied

Dating of palaeoanthropological nuragic skeletal tissues using electron paramagnetic resonance (EPR) spectrometry.

Dating of skeletons of Nuragic population living in Sardinia island centuries BP, based on the quantitative evaluation of the concentration of stable paramagnetic species produced by ionising radiation in tooth enamel was performed by using EPR spectrometry. Applying the additive dose method (60Co gamma rays) and comparative calculations based on analogous measurements done with Roman skeleton of the known age as discovered close to Nuragic tomb (Tombs of Giants, La Testa S. Teresa di Gallura, Sardinia) the age of Nuragic skeleton was evaluated as equal to about 3,200 years (1,200 years BC). The total error of EPR measurements and dose extrapolation was estimated for 10-12%. Crystallinity of bone mineral in Nuragic skeleton evaluated by the EPR technique, adapted earlier by some of the authors of the present paper for biomedical studies on mineralised tissues, is only little changed after the centuries of its deposition in the tomb when compared with contemporary bone tissue. Comparison of chemical composition of Nuragic skeleton contaminated through slow percolation by rain of floods with that of contemporary bone sample shows the increase of the concentration of Fe, PO4, SiO2, Al and Mg, Fe, SiO2, AP are not present in contemporary bones. As expected, the contamination was minimal in tooth enamel.

Bone Density↗
PubMedDate not supplied

Localization of collagen type IV, fibronectin and elastin in the flexor digitorum tendons and in the perichondrium during prenatal development of the human hand.

The distribution of collagen type IV, fibronectin and elastin in the flexor digitorum tendons and in the perichondrium of staged human embryos and fetal hand (from 6 to 12 weeks of gestation) has been studied to analyse the immunohistochemical features of the human hand during the first trimester of pregnancy. At 6 weeks in the transverse sections of the fingers there is no evidence of the presence of collagen type IV and elastin which remain absent even in the controls of 9, 11 and 12 weeks. On the contrary from 6 weeks of intrauterine life the fibronectin is widely distributed with thickening above all in the perichondrium and in the subjacent portion of the cartilaginous model of the bone. At 9 weeks a high positivity is detected not only along the perichondrium but even into the extra-cellular matrix of every mesenchymal cell. At 11 and 12 weeks the perichondrium is always positive but a high positivity is now present along the flexor tendons and their related sheaths that show a high grade of differentiation. To sum up, the absence of the collagen type IV into the flexor and extensor tendons is understandable because it isn't a fibrillar collagen. More difficult is to understand the absence of the elastin (component of the mature tendons) until the 12th week. On the contrary the presence of the fibronectin, a structural glycoprotein, proof of active morphogenesis of mesenchvmal cells, earlier in the perichondrium and cartilaginous sketch and later in the flexor tendons and their sheaths indicates that probably among the cells of mesenchymal origin the perichondrium with the cartilaginous model of the bone come before and perhaps orient the differentiation of the other components of the human hand.

Bone and Bones↗
PubMedDate not supplied

Human articular cartilage in osteoarthrosis. I. The matrix. Transmission electron microscopic study.

The present research has been carried out with the aim of contributing to the understanding of morphological changes in human articular cartilage during osteoarthrosis and to evaluate the usefulness of TEM in this application. Only the matrix was examined in this first phase of study. Fragments from the femoral head of 20 patients subjected total hip arthroplasis, were studied by TEM after treatment with current procedures. The images obtained were considered observing the division of cartilage into superficial, intermediate and deep layers. Patients were divided according to the gravity of their clinical conditions. The least severe forms of pathology seem to involve only the superficial layer, which quickly loses the lamina splendens and may be affected by rarefactions of the matrix, which becomes fissured, while the deep layers are only slightly involved. During the later stages, the pathology progresses with irregularity of disposition and size of the collagen fibres and an increase in the number and size of fissures. The intermediate layer shows architectural disorder in the collagen fibres, even reaching the deep layer. The interfibrillar distance appears greater. As pathology progresses, the superficial layer tends to disappear, while the successive layers undergo progressive alteration in disposition and size of the collagen fibres. Globular aggregations of various dimensions and electron density similar to collagen are present in the deep layer.

Aged↗
PubMedDate not supplied

The sertolian epithelium in the testis of men affected by 'Sertoli-cell-only syndrome'.

Because of the architectural complexity of the seminiferous epithelium, the Sertoli cell is extremely difficult to study. The individual cellular constituents of the tubular wall are intimately associated with one another; especially Sertoli cells and germinal cells are tightly connected. As implied by the name, Sertoli-cell-only syndrome (SCOS) is characterized by the presence of only Sertoli cells in the seminiferous tubule. The absence of germinal cells makes this condition ideal for the morphological study of Sertoli cell. Testicular biopsy specimens of subjects affected by SCOS were studied under light and electron microscopy. The Sertoli cells appeared to be morphologically normal, except for their shape, that appears to be columnar as result of the complete absence of the germinal cells. The cellular outlines were irregular, particularly at the base, but the cytoplasm contained normal organelles and inclusions. The presence of both pale and dark elements was evident. These differences in staining reflect the variability in concentration of glycogen particles and intermediate microfilaments in the cytoplasm. In spite of these differences between Sertoli cells in SCOS and those in normal subjects, SCOS represents a satisfactory model for the morphological and functional analysis of the Sertoli cells.

Actin Cytoskeleton↗
PubMedDate not supplied

Nuragic bone collagen retains its molecular structure.

The molecular structure of bone collagen was found to be preserved in Nuragic bone samples several centuries after burial. Enhanced birefringence of bone and dentin collagen fibres observed in polarized light after Sirus red staining was used to demonstrate this fact.

Anthropology, Physical↗
PubMedDate not supplied

The early development of muscle spindle in human foetus.

The normal development of muscle spindles has been carefully described in a variety of species but only a few attempts were made to study the embryological development of the muscle spindle in humans. Most of the studies aimed to define the early development of muscle spindle in human foetuses, stated the begin of this process at the 11th week of intrauterine life, when the formation of a network of very fine nerve fibres with enlargements and ringle around developing muscle cells occur. In the present study we tried to document the probably earliest time of appearance of muscle spindles in the skeletal muscle of human foetuses. To this aim we examined fragments of deltoid and gastrocnemius muscles removed from human foetuses at the 9th and 10th week of gestation by using the light microscope technique. Data collected in muscle specimens at the 9th and 10th week of gestation showed the presence, at this time, of a structure with features clearly different from that of the adjacent muscular areas. This structure consists in a number of flat mesenchymal cells surrounding and forming several layers around a bundle of myoblasts smaller and lesser differentiated than the muscle cells located around and it is in close relationship with nervous fibres. These morphological findings might allow to identify the earliest stage of muscle spindle formation in human species.

Gestational Age↗
PubMedDate not supplied

Morphometric analysis of the lateral ventricles in living human.

The evaluation of the volume of the encephalic ventricles in the living human has a great importance in diagnosis and monitoring of several pathologies. As well as a good measuring accuracy, a great usefulness has the facility of execution. The present study would be a contribution to the search of systems of analysis that assure both fast execution and greatest precision of the quantitative values. Brain MRI scans from 10 female individuals, aged from 25 to 60, with no apparent neurologic or psychiatric pathology have been studied. The brains were evaluated with 5 mm slices thickness (gap 1 mm) scans performed in axial and coronal planes and obtained by means of long and short spin echo sequences. Images have been acquired on a Personal Computer and submitted to a semiautomatic morphometric analysis. The values obtained are in accordance with the range of normal values reported from the literature, showing also a lower standard deviation; besides this clear accuracy of measurement, it's important to emphasize the facility and swiftness in the execution of the imagine evaluation.

Adult↗