PubMed Health⌕ Search

Biomedical subjects

B Valentino

Publications and source records attributed to B Valentino.

At least 19 recordsLinked to original sources
PubMed2006

Kinking, coiling, and tortuosity of extracranial internal carotid artery: is it the effect of a metaplasia?

INTRODUCTION: Morphological anomalies of the extracranial internal carotid artery (ICA) cause symptomatic cerebrovascular insufficiency in 4-16% of the cases. The aim of the present study is to evaluate macroscopic and microscopic features of a group of extracranial ICA anomalies, specifically kinking, coiling, and tortuosity, eventually affecting the surgical approach. MATERIALS AND METHODS: From January 2003 to December 2005, 10 out of 169 (6%) revascularized patients (pts) were operated upon because of an ICA anomaly. They were all but two symptomatics. Seven pts were treated by ICA transection and end-to-side reimplantation of the ICA at the level of the carotid bulb; three pts were treated by ICA resection and end-to-end anastomosis. In all the cases a segment of ICA was resected; in three cases one more segment was also obtained from a common carotid artery (CCA) and these specimens were histologically examined. Patients were followed-up through a 3-year period. RESULTS: No pts died and none suffered of neurologic events. Duplex scan and arteriographic postoperative control showed the correct surgical reconstruction. Matching preoperative clinical findings with presence or absence of significant atherosclerotic stenotic lesion, we found out a positive cerebral CT in one pt (20%) in both groups; fluent neurological deficit was preeminent in pts with pure ICA anomalies (40% vs. 0%) (P = 0.2); pts with pure ICA anomalies were significantly younger than 65 years old (80% vs. 0%) (P = 0.03) and males were more involved by pure ICA anomalies (60% vs. 40%) (P = 0.1). The histological examination of ICA specimens showed a reduction of elastic fibers and muscular cells with a compensative increase of connective fibers. CONCLUSIONS: At our knowledge this is the first study focused on ICA anomalies like kinking, coiling, and tortuosity, comparing histologic features of CCA and ICA specimens coming from the same affected carotid axis. Our results, although preliminary, show elastic and muscular tissue substituted by loose connective tissue, configuring a metaplasia of tunica media limited to the ICA. Our hypothesis is that extracranial ICA, being a segment of transition between an elastic vessel (CCA) and a muscular vessel (intracranial ICA), is particularly subject to metaplastic transformation, analogously to other transition zones in human body. Our purpose is now to confirm by ultrastructural and molecular biology techniques, in a wider series, the presence of this metaplasia, since this could condition also the revascularization techniques.

Age Factors↗
PubMed2003

Presence of atrial natriuretic factor in normal and hyperplastic human prostate and its relationship with oxytocin localisation.

In this work, we showed the presence of atrial natriuretic factor (ANF) in human prostate and compared its localisation in normal and hyperplastic conditions. ANF was localised in epithelial and stromal cells, being increased in hyperplasia, mainly in the stromal component. Moreover, we compared ANF and oxytocin positivity in the same glands, focusing on the possible relationship between the paracrine effects of these two hormones.

Atrial Natriuretic Factor↗
PubMed2003

Localization of the atrial natriuretic factor in the human inferior turbinates. An immunohistochemical study.

In man, the architecture of the turbinates is able to modify some of the physiochemical characteristics of the air inhaled. These modifications depend on the nervous system and on the action of neurotransmitters such as vasoactive intestinal peptide. Substance P, calcitonin gene-related peptide and other neuropeptides. As atrial natriuretic factor has been detected in the trachea and lung, the present immunohistochemical study was carried out to establish the presence and localisation of the atrial natriuretic factor on the inferior turbinates of the human being. The findings show atrial natriuretic factor to be present in the serous epithelial cells and in some cells of the tonaca propria near the sinusoids and the arteriovenous shunts and the acinar cells of the glands. Atrial natriuretic factor, therefore, could play a part in the stratification of mucus on the luminal surface and also regulate the blood flow of the capillaries, modifying, in this way, the physiochemical features of the air inhaled.

Atrial Natriuretic Factor↗
PubMed2001

The hypothalamic magnocellular neurosecretory system in developing rats.

Studies concerning the development of the magnocellular system are scarce and discordant in literature. We carried out an immunohistochemical study on supraotic and paraventricular hypothalamic nuclei using antivasopressin and antioxytocin antibodies in developing rats between the 15th day of intrauterine life and the 6th day of postnatal life. In addition, we performed RT-PCR experiments to establish the stage at which these hormones appear and neurosecretory activity commences. The results showed that supraoptic and paraventricular nuclei appear, respectively, on the 16th and the 18th day of intrauterine life and both immediately synthetize vasopressin neurohormone. By contrast, synthesis of oxytocin takes place from the 2nd day after birth. Probably, these nuclei synthetize oxytocin in conjunction with the decline of placental maternal oxytocin.

Animals↗
PubMed1999

Immunohistochemical localization of atrial natriuretic factor (ANF) in the excretory system of the rabbit parotid gland.

The immunohistochemical localization of atrial natriuretic factor (ANF) in the rabbit parotid gland was performed using an antibody against rabbit ANF and avidin-biotin or streptoavidin as detector. Results showed positivity in cuboidal and columnar cells of intralobular ducts and in basal cells of extralobular and main excretory duct. These data support the hypothesis that ANF produced by intralobular ducts could act through a paracrine mechanism; ANF produced by extralobular and main ducts may play a role in the regulation of salivary composition.

Animals↗
PubMed1993

Interaction between the muscles of the neck and the extraocular muscles of the myopic eye. An electromyographic study.

The functional relationships between the extraocular muscles of the myopic eye and the muscles of the neck were studied by means of electromyography, with the aim of demonstrating a possible alteration of the posture of the head due to abnormal tonus of the trapezius and sternocleidomastoid mm. in subjects with defective vision. The study was conducted in a group of 10 subjects with normal vision and a group of 10 myopic subjects, between the ages of 20 and 40 years. Electromyographic recordings of the relevant muscles were made during varied eye movements. Analysis of the results demonstrated a marked difference in tonic activity of the named muscles between the myopic and the normal groups. The findings suggest that, in the correction of visual defects, attention should be paid to postural adjustment of the neck by means of a series of programmed exercises directed towards the trapezius and sternocleidomastoid mm.

Adult↗
PubMed1993

Evidence for soluble and nuclear site I binding of estrogens in human aorta.

The purpose of this study was to establish the estrogen receptor (ER) expression and content in human aorta fragments removed at the time of by-pass surgery. To this end, we adopted a radioligand binding assay to evaluate either soluble (S) or nuclear (N) ER using dextran-coated charcoal (DCC) and filtration methods, respectively. To better define the intratissular distribution and content of ER, we also measured the presence of a 27 kDa heat shock protein (HSP27), a well established ER-associated protein, using D5 monoclonal antibody. Finally, we analysed the different molecular isoforms of both S and N ER using size exclusion-high performance liquid chromatography (SE-HPLC). High affinity (type I) sites of estrogen binding were detected in 17 out of 19 samples in either S or N fraction, although only 9 out of 19 cases displayed site 1 ER in both cell compartments. ER levels in aortic tissues, detected by radioligand method, compare well with those we have found in other hormone-sensitive human cancer tissues and cells. SE-HPLC analysis revealed two main receptor isoforms in the soluble fraction, having 65 kDa and 18 kDa molecular mass, while a minor component of 29 kDa was also found; the nuclear fraction displayed again two major components of 38 and 23 kDa. Using the HSP27 immunohistochemistry we observed a major staining occurring in smooth muscle cells (SMC), with an increasing intensity towards the lumen. All samples, including the ER negative ones, exhibited some degree of histochemical staining. Using an arbitrary cut-off value, 7 out of 12 samples displayed a highly positive staining, 6 of which showed nuclear ER. Furthermore, SE-HPLC separation indicated the presence of a 64.9 kDa component in the soluble fraction, according to the well known relative molecular mass of ER. Following HSP27 immunohistochemistry, the overall staining intensity in aortic SMC approaches that seen in endometrial and breast epithelia, whilst the muscle ER content is generally lower. Although our data are compatible with a direct role of estrogens in arterial function, the extent of the link with arterial disease remains to be established.

Adult↗
PubMed1992

[Transmission electron microscopy observations of a homologous bone graft preserved at -196 degrees C].

The authors have studied the ultrastructural modifications after one year of a homologous bone grafting stored for 8 days in nitrogen liquid at -196 degrees C. It was observed that the osteocytes showed nuclear and cytoplasmic degenerations; the empty lacunae showed precipitates of mineralized matrix. In comparison with a bone autografting a homologous bone grafting lost the ability of bone synthesis.

Animals↗
PubMed1991

Functional relationships between the muscles of mastication and the muscles of the leg. An electromyographic study.

The authors have shown, with the help of electromyography, the functional relationship which exists between the muscles of mastication and certain muscles of the leg after artificially creating interdental occlusal dysfonction. While the activity of the tibialis anterior was not affected by the alteration in occlusion, that of the peroneus longus and gastrocnemius was markedly changed. This is due to the activation of long muscle chains as a consequence of the activation of complex nervous reflexes.

Adult↗
PubMed1991

The functional relationship between the occlusal plane and the plantar arches. An EMG study.

We studied many postural tests with an electromyographical methodology on a group of young men who had a right molar precontact. We compared the results of these tests before and after changing the right plantar arch by placing some plastic on the medial right margin of the homolateral plantar arch (talipes valgus) or on the whole plantar arch (flat foot). We demonstrated the dependence of the occlusal plane on the morphological variations of the plantar arch.

Adult↗
PubMed1990

Electromyographic activity of a muscular group in movements specific to boxing.

The dentate, triceps, deltoid and the middle bundle of the trapezius have been studied in two movements specific to boxing in a group of professionals. Analysis of results has shown a higher commitment of the trapezius; in the jab considerable deltoid activity was evident. In the upper-cut we noticed little commitment of the deltoid and triceps, in the jab, little commitment of dentate and triceps.

Biomechanical Phenomena↗
PubMed1985

Electromyography for the investigation and early diagnosis of scoliosis.

A clinically normal 5 year old child with a family history of scoliosis was studied. Electromyography of the thoracic and lumbar erector spinae muscles and roentgenography of the spine were both done on two separate occasions, six months apart. On the first electromyographic investigation, moderate predominance of activity was found over the left thoracic erector spinae muscles. At that time, spinal roentgenography showed normal results, whereas six months later left thoracolumbar scoliosis was evident. It was concluded that electromyographic investigation is useful for the early diagnosis of scoliosis in school-age children.

Child, Preschool↗
PubMed1984

[Ultrastructural observations on the presence of stereocilia in myoblasts of Scyllium stellare].

Many Authors described primary 9+0 cilia in different tissue of different animal species. In relation to the study on the ultrastructural architecture of the embryonic heart of a elasmobranch "Scyllium stellare", we saw some primary 9+0 cilia in very undifferentiated heart tissue. The hearts dissected from the Scyllium stellare embryo at 6 months of gestation, were processed for the observations at the transmission electron microscope. The cilia are found in deep invagination of the plasma membrane, near the Golgi complex and in the perinuclear region. Various functions have been postulated for the primary 9+0 cilia.

Animals↗
PubMed1983

[Ultrastructural observations on B cells in the human synovial membrane].

Two cellular type, A and B cells, are evident in the intimal layer of the human synovial membrane. The Authors studied the B-cells that show in their cytoplasm some secretory granules that are still unknown. In the normal synovial membrane of human knee, with transmission electron microscopic techniques, the relationship between the B-cells and the blood capillary vessels and some morphological features of the secretory granules, are studied. The blood capillary vessels have a continuous cellular wall, surrounded by a basal membrane. Typical features of the B-cells are the marked development of the rough endoplasmic reticulum, the Golgi apparatus and dense secretory vesicles. The B-cells appear to constitute some specific secretory cells, but its function has yet to be determined.

Cytoplasmic Granules↗
PubMed1981

[Ultrastructural study of chorionic villi in maternal-fetal isoimmunity].

The Authors studied the Human normal full term placenta and in the feto-maternal Rh and ABO incompatibilities. In the Human normal full term placenta the sincitium trophoblastum coat shows the usual microvillosity and the normal cytoplasmatic organules; in the placenta of ABO isoimmunized subjects the sincitium trophoblastum coat is intensely vacuolyzated; in the placenta of Rh isoimmunized subjects the lamina sincitiale vacuolyzation is more evident in the basal side. Discussion on the morphology related to the placenta barrier function.

ABO Blood-Group System↗