PubMed Health⌕ Search

Biomedical subjects

G Valente

Publications and source records attributed to G Valente.

At least 109 records · Page 6Linked to original sources
PubMed1983

Immunohistochemical and enzyme histochemical contributions to the problem concerning the role of the thymus in the pathogenesis of myasthenia gravis.

Normal fetal and postnatal thymuses, as well as thymuses from patients with myasthenia gravis (MG), were investigated by immunohistochemical and enzyme histochemical techniques and their morphology reviewed. Intrathymic B-cells, detected by ATPase activity, were found to be markedly increased in number in MG thymuses. They were scattered in the medulla and accumulated around the junctional and medullary vessels and Hassall's corpuscles (HCs). Large epithelial cells, singly or within HCs, were found to be unevenly distributed in the medulla of all the thymuses examined. The striated muscle-like nature of some of these cells was revealed by the presence of myoglobin in their cytoplasm. In myasthenics these cells and small developing HCs characteristically surrounded lymph follicles and were in direct contact with the expanded cap of the follicle mantle, without interposition of reticulin fibres. The close association of immune reactive foci (lymphoid follicles, junctional and medullary vessels, and HCs) with structures involved in autoimmune responses in the thymus (muscle-like and true myoid cells, HCs) strongly suggests that the autoimmune reactions against AChR (acetylcholine receptor) and other muscular components, which constitute the basic defects in myasthenia gravis, may begin in the thymus.

Adenosine Triphosphatases↗
PubMed1982

Histochemical study on human germinal centre, mantle-zone and extra-follicular area lymphoid cell subpopulations. Immunological and cytochemical correlations with lymphomatous cells, peripheral normal and leukemic lymphocytes.

Tissue sections of lymph nodes, appendices and tonsils, together with smears of immunologically separated peripheral lymphoid cells from a B-CLL and lymphomatous cells from an immunocytoma were submitted to combined enzyme cytochemical investigations with acid alpha-naphthyl acetate esterase (ANAE), beta-glucuronidase (B-G), acid phosphatase (AcPh), adenosine triphosphatase (ATPase), a,d 5'nucleotidase (5'N). T-cells were Acph+, ATPase- and 5'N-. The vast majority of T- and B-cells displayed ANAE and B-G activities with two distinct staining patterns (T-like and B-like pattern). A high proportion of lymphoid cells in the germinal centre (G.C.) and the vast majority of lymphoid cells in the mantle-zone (M.Z.) were shown to belong to B-cell system because of the expression of ATPase and 5'N in their membranes. Some lymphoid cells positive for ANAE and B-G with a B-like pattern and for AcPh were recognizable in the G.C. In the M.Z. only a few lymphoid cells being ANAE+, with a T-like pattern, and AcPh+ were shown to belong to the T-cell system. In contrast, in this zone a high proportion of small lymphoid cells (64% +/- 10%) showed ANAE activity, mostly with B-like pattern. Therefore, these findings indicate that in the M.Z. a high proportion of B-cells ATPase+ and 5'N+ also display ANAE activity. By comparison of the results obtained from lymphoid tissue sections, B-CLL and immunocytoma cell suspensions and normal circulating lymphocytes we can conclude that B-ANAE-positive cells of the M.Z. do not usually appear in the peripheral blood. They circulate in large numbers only in some pathological conditions (like our reported B-CLL). Therefore, B-ANAE-positive lymphoid cells of the mantle, with a B-like staining pattern, include a wide range of subsets which exclude large lymphoid cells and plasma cells.

5'-Nucleotidase↗
PubMed1980

Detection and distribution of alfa-naphthyl acetate esterase activity in thymocytes of normal, myasthenic thymus and thymoma. Histochemical and cytochemical study in relation to E-rosetting.

The extent and distribution of alfa-naphthyl acetate esterase (ANAE) activity in both normal thymuses and thymuses or thymomas from patients with myasthenia gravis were investigated by enzyme histochemistry. In all a closely similar distribution of ANAE activity was recognizable. ANAE positive thymic lymphocytes were distributed preferentially at the cortico-medullary junction and in the medulla. Their numbers at these sites were higher in myasthenic patients than in normal adults (P less than 0.001) and lowest in fetuses. The relative numbers of cells showing both ANAE activity and EN-rosette-forming capacity was lower in thymocytes than peripheral lymphocytes but was increasing higher in thymuses from fetal, adult and myasthenic patients and in thymomas. These findings are discussed in relation to the stage of maturity of thymocytes and the importance of intrathymic immunological challenge in the attainment of these cells of functional properties usually acquired in the periphery.

Adolescent↗
PubMed1980

[Infective endocarditis with particular references to incorrect diagnosis in elderly subjects: a study of autopsied cases (author's transl)].

20091 autopsies performed in the period 1946-77 yielded 110 cases of infective endocarditis. The anatomical findings were compared with those of published studies on groups of patients of similar age groups. The diagnosis of infective endocarditis was suspected during the life in 40.6% of patients below 50 years of age, in 10.8% over 50 and in none of the patients over 70. Moreover the diagnostic accuracy was down from 36.8% in the 1946-61 period to 23.3% in the 1962-77 period. These negative data are discussed, emphasizing usefulness of autopsy as a systematic check on clinical diagnosis in practical medicine, and especially in geriatric medicine.

Adolescent↗
PubMed1977

[S-adenosylmethionine as a regulator of protein synthesis. Influence on plasmatic fibrinogen].

S-adenosyl-L-methionine (SAMe) is a physiological compound which plays an important role in numerous biological processes, such as transmethylations, transulphurations and aminopropylations. Starting from a study about the usefulness of the SAMe to normalize protein synthesis in old age, the drug was found to have an interesting action with respect to fibrinogen. Later research regarding a large number of patients, led us to discover after treatment for 40 days with 60 mg/die of SAMe, highly significant variations in fibrinogen values with constant normalization of this parameter, in both hypo- and hyper-fibrinogenemia. So far we don't know anything about the action of the drug on various metabolic stages of the fibrinogen; interestingly however our data exclude a rise in fibrinolysis.

Adult↗
PubMedDate not supplied

Gabapentin treatment for muscle cramps: an open-label trial.

To evaluate the efficacy and safety of gabapentin in the treatment of muscle cramps, we engaged an open-label trial with a group of 30 patients with frequent (> 5 cramps/week), stable, long-lasting cramps, associated with different diseases. Gabapentin was effective in reducing the frequency and severity of muscle cramps and associated sleep disturbances (clinical outcome measures) within the first 2 weeks of medication at 600 mg/d. At the 1 month control (mean dosage, 825 +/- 35 mg), almost every patient had responded to treatment and two thirds experienced a total remission of symptoms. After 3 months of therapy (mean dosage, 892 +/- 180 mg), cramps disappeared in 100% of patients and this benefit persisted as long as 6 months. Additionally, we evaluated in 10 patients the Cramps Threshold Frequency (CTF) (neurophysiological outcome measure) before and during gabapentin treatment. Gabapentin significantly increased the CTF, returning it to normal values. With the limitation of an open-label methodology, our clinical and neurophysiologic experience suggests that a gabapentin dose of 600-1200 mg/d would be helpful in the treatment of muscular cramps.

Acetates↗
PubMedDate not supplied

Small cell carcinoma of the esophagus: a case report and review of the literature.

We present a case of small cell esophageal carcinoma (SCEC) treated with alternated chemotherapy (including cisplatin, etoposide, vincristine, cyclophosphamide and doxorubicin) and irradiation (36 Gy) followed by surgery. Despite a pathological complete response, the patient died of regional disease recurrence 29 months after the diagnosis. We reviewed the available literature on SCEC with regard to the incidence, clinical symptoms, radiological signs, diagnostic workup, therapeutic modalities and prognosis of this malignancy.

Carcinoma, Small Cell↗