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Biomedical subjects

A Pinto

Publications and source records attributed to A Pinto.

At least 217 records · Page 12Linked to original sources
PubMed1995

Effect of methylguanidine on rat blood pressure: role of endothelial nitric oxide synthase.

1. The effect of acute i.v. administration of methylguanidine (MG) on mean arterial blood pressure (MABP) was investigated in anaesthetized male Wistar rats. 2. MG (1-30 mg kg-1 i.v.) produced an increase in MABP in a dose-dependent manner both in normal and in hexamethonium (5 mg kg-1, i.v)-treated rats. 3. L-Arginine (30 or 150 mg kg-1, i.v.), but not its enantiomer D-arginine (30 or 150 mg kg-1, i.v.), reversed the effect of MG on MABP in both normal and hexamethonium-treated rats. 4. L-Arginine (150 mg kg-1, i.v.) administered 2 min before MG (30 mg kg-1, i.v.) prevented the increase in MABP caused by MG in either normal or hexamethonium-treated rats. This effect was not observed with D-arginine (150 mg kg-1, i.v.). 5. Thus, the rise in MABP caused by MG in the anaesthetized rat is due to inhibition of endothelial NO-synthase activity. We speculate that the rise in the plasma concentration of endogenous MG associated with uraemia may contribute to the hypertension seen in patients with chronic renal failure.

Animals↗
PubMed1995

Conditioned enhancement of cough response in awake guinea pigs.

To determine whether psychological factors affect the cough response, we employed a classical conditioning procedure in which capsaicin challenge was paired with the presentation of an odor in awake guinea pigs. On days 1-4, animals received combined administrations of the unconditioning stimulus, capsaicin aerosols, and the conditioning stimulus, camphor aerosols (group 1), capsaicin and saline aerosols (group 2), and camphor and saline aerosols (group 3), and the number of coughs was counted. On day 5, all groups received camphor and saline aerosols. A significant number of coughs (p < 0.01) was observed only in group 1 when the animals were exposed to the odor alone on day 5. This suggests that associative learning enhances the cough response.

Aerosols↗
PubMed1995

CD40 ligand is constitutively expressed in a subset of T cell lymphomas and on the microenvironmental reactive T cells of follicular lymphomas and Hodgkin's disease.

Although CD40 has been extensively studied in B- and T-cell non-Hodgkin's lymphomas (NHLs)/leukemias, and more recently in Hodgkin's disease (HD), little is known about the expression of its ligand (CD40L) in lymphoproliferative disorders other than T-cell NHLs/leukemias. A series of 121 lymphoma/leukemia samples, including 35 cases of HD, 34 T-cell and 39 B-cells NHLs, 2 cases of adult T-cell leukemia/lymphoma, and 11 cases of T-cell acute lymphoblastic leukemia, were evaluated for CD40L expression by immunostaining of frozen tissue sections and flow cytometry with the anti-CD40L monoclonal antibody M90. CD40L was constitutively expressed by neoplastic cells in 15 of 36 (42%) T-cell NHLs/adult T-cell leukemia/lymphomas, almost invariably those displaying the CD4+/CD8- phenotype, whereas no CD40L-expressing tumor cells could be found in B-cell NHL and HD. Among T-cell acute lymphoblastic leukemias, CD40L was detected only on 2 cases displaying a stem-cell-like phenotype. In follicular B-cell lymphomas a large number of CD40L-expressing CD3+/CD4+ T lymphocytes were found admixed with tumor cells within the neoplastic follicles and in their surrounding areas. In the nonfollicular B-cell lymphomas, CD40L-positive CD3+/CD4+ T lymphocytes were few or absent. In all HD subtypes other than the nodular lymphocytic predominance, CD40L-expressing CD3+/CD4+ T lymphocytes were numerous in the HD-involved areas and were mainly located in close proximity to the Reed-Sternberg cells. Our data indicate that in human lymphomas CD40L is preferentially expressed by a restricted subset of T-cell lymphomas, mostly with CD4 immunophenotype. Finally, we have provided morphological evidence that CD40L may play an important role in the cell contact-dependent interaction of tumor B-cells (CD40+) within the neoplastic follicles or Reed-Sternberg cells (CD40+) in HD-involved areas and the microenvironmental CD3+/CD4+/CD40L+ T lymphocytes.

Adult↗
PubMed1995

Rapid surveys in support of district health information systems: an experience from Uganda.

The role of rapid health assessment in generating data other than routine reporting for a multi-element primary health care information system is presented. Rapid surveys, based on the adaptation of the WHO/EPI cluster survey methodology, may generate reliable and valid results useful for the support of a managerial PHC information system. However, because of the limitations inherent to the method, so far, only few studies have investigated more than few PHC related issues. The experience of a household rapid survey conducted in Arua District, Uganda, using a modified EPI cluster survey methodology, is reported. Rapid appraisal methods were used to prioritize the information requirement and to identify the survey items. Fully supervised teams of primary school teachers were used as interviewers. Data processing, check and analysis were speeded up by a lap-top computer, in spite of problems of erratic power. Within a 10-day time span between the start of the survey and the publishing of results, data on health services' utilization, health seeking behaviour, coverage of PHC services, including immunization, and anthropometric data on the nutritional status of under-five children were obtained. Standard errors and 95% confidence intervals were calculated taking into account the variability of the parameters under investigation and true design effects were computed. The findings were utilized for the identification of health priorities and the monitoring of effectiveness of programmes, as well as to validate routine reporting. The methodological package was built up looking at the local context, so that it could become an operational tool for the district health management team.

Adolescent↗
PubMed1995

[Incomplete Boerhaave syndrome of the cervical esophagus].

It is known that an acute postemetic injury may evoke a spontaneous rupture of the oesophagus. This spontaneous rupture may produce an intramural hematoma or a laceration of the oesophagus wall. The intramural hematoma is restricted to the esophageal wall and may produce a fistula into the lumen of the oesophagus (with creation of a double lumen) or into the mediastinum (haematoma of the mediastinum). On the other hand the rupture may extend from the mucosa (lesion of Mallory-Weiss) into the complete wall of the oesophagus (Boerhaave's Syndrome). There are reports on a lesion of the exterior muscular layer of the third distal half of the oesophagus, which had evoked an acute haemorrhage into the mediastinum and has been defined as a variant of Boerhaave's syndrome. We now describe a similar case which is confined to the cervical oesophagus and has been treated without surgical intervention.

Airway Obstruction↗
PubMed1995

Clinical-anamnestic and instrumental data in outpatients suffering from venous disease.

The authors studied 200 consecutive outpatients with symptoms due to venous disease of the lower limbs. All the patients underwent anamnestic, clinical and instrumental evaluation (c.w. Doppler velocimetry and strain-gauge plethysmography). The results of this study showed that some anamnestic and clinical data are significantly related to venous disease detected by instrumental techniques. The superficial and deep vein hypertension were, instead, correlated to oral contraceptive use.

Adolescent↗
PubMed1994

Total body irradiation and prednimustine in chronic lymphocytic leukemia and low grade non-Hodgkin's lymphomas. A 9-year experience at a single institution.

BACKGROUND: The efficacy and toxicity of total body irradiation (TBI) in patients with chronic lymphocytic leukemia (CLL) and low grade non-Hodgkin's lymphomas (NHL) were evaluated. METHODS: Between January 1984 and September 1992, 81 consecutive patients, 40 affected with CLL and 41 with low grade NHL, with symptomatic Stage III and IV disease, were treated with TBI followed by prednimustine. TBI was given with a 6 MV linear accelerator, applying two opposite alternating fields, including total body, with two fractions of 15 cGy given per week (3-day interval). A total dose of 150 cGy was given over 5 weeks. Six to nine courses of prednimustine (100 mg/m2 orally for 5 consecutive days every 4 weeks) was administered 2 months after TBI treatment as consolidation therapy. RESULTS: Of 40 patients with CLL, 18 (Group I; median age 58.5 years) were younger than 65 years and 22 (Group II; median age 73 years) were older. The overall response rates were 78% in Group I and 91% in Group II, with a median response time of 16.5 and 16 months, respectively. Hematologic toxicity was 72% in Group I and 73% in Group II. It was reversible in all but one heavily pretreated patient who died of progressive anemia and thrombocytopenia after TBI alone. In the 40 patients with CLL, the response rate was 85%; there were 5 complete responses (CRs) (12.5%) and 29 partial responses (PRs) (72.5%). Of the 41 patients with NHL, 29 (Group I; median age 55 years) were younger than 65 years and 12 (Group II; median age 71.5) were older. The overall response rate in both groups was 83%, with median response times of 18.5+ and 14.5+ months for Groups I and II, respectively. Hematologic toxicity was 59% in Group I, whereas it was 50% in Group II. It was reversible in all patients. Overall, in the 41 patients with symptomatic Stage III and IV low grade NHL, the response rate was 82.8%; there were 10 CRs (24.3%) and 24 PRs (58.5%). The prednimustine regimen was generally well tolerated. CONCLUSIONS: In our experience, TBI given in a dose of 150 cGy in 10 fractions twice a week, followed by prednimustine, is an effective treatment for patients with CLL and patients with low grade NHL. This treatment also is effective in patients older than 65 years. The toxicity is acceptable, particularly when TBI and prednimustine are given as initial treatment. Pretreated patients should be monitored strictly.

Age Factors↗
PubMed1994

Expression of the c-kit receptor in human lymphomas is restricted to Hodgkin's disease and CD30+ anaplastic large cell lymphomas.

The product of the proto-oncogene c-kit is a transmembrane receptor protein that plays an important role in the regulation of normal and neoplastic hematopoiesis via the interaction with its specific ligand termed stem cell factor. To examine whether c-kit product is possibly involved in the pathogenesis of human lymphomas, we analyzed the expression of the c-kit protein in neoplastic cells from a variety of lymphoid tumors by immunostaining of lymph node frozen sections with the 17F11 antibody, detecting an extracellular epitope of the c-kit receptor, and of c-kit RNA by Northern blot hybridization. Of 24 nonHodgkin's lymphomas (NHL) of B- and T-cell phenotype, none expressed immunodetectable c-kit protein that was also not evidenced in lymphoid cells of reactive lymph nodes and normal tonsils. In contrast, c-kit protein was expressed by Reed-Sternberg cells and their mononuclear variants from 11 of 21 Hodgkin's disease (HD) cases, and in tumor cells from 11 of 16 cases of CD30+ anaplastic large cell lymphoma (ALCL). c-kit specific mRNA was also detected in lymph node tissues from HD and ALCL cases but not in neoplastic tissues from NHL other than ALCL. In addition, c-kit/CD30+ tumor cells were evidenced by flow cytometry in a patient displaying massive bone marrow involvement by ALCL. With the exclusion of lymphocyte predominance cases of HD that resulted c-kit expression and the other histologic subtypes of HD or the immunologic phenotype of tumor cells (B, T, nonB-nonT) in both HD and ALCL. The highly restricted expression of the c-kit product among human lymphomas to HD and ALCL provides a further biologic link between these two closely related lymphoma entities.

Hodgkin Disease↗
PubMed1994

Survey on the prevalence of leptospira infections in the Italian population.

This investigation is the first nationwide survey on the circulation of leptospira infections in human beings in Italy. In nine out of twenty Italian regions, representative samples of the population were investigated for the presence of leptospira infections. Unexpectedly, leptospira infections were found to be widespread, the number of cases being much higher than the diagnosed clinical cases. There were found to be high, medium, and low risk areas. On the whole, the risk for the rural population was no higher than the risk for urban dwellers; leisure activities, contact with animals and residence on the plain versus residence in the hills were important risk factors. There was an unidentified risk factor in urbanites which was absent in the rural population. A changing pattern in infecting serovars was observed, with infections from serogroups Sejroe, Javanica and Australis prevailing over infections from the Icterohaemorrhagiae and Bataviae serogroups, which were the main agents of human leptospirosis during the 1950s. The mechanisms of these changes, the need for epidemiological surveys and improved diagnostic methods of screening are discussed.

Adult↗
PubMed1994

CD26/dipeptidyl peptidase IV expression in human lymphomas is restricted to CD30-positive anaplastic large cell and a subset of T-cell non-Hodgkin's lymphomas.

CD26 is identical to the cell surface ectoenzyme dipeptidyl peptidase IV (DPPIV). CD26/DPPIV is associated with T-cell activation and proliferation and also may function as an auxiliary adhesion factor. Although CD26/DPPIV has been previously studied on lymphoid populations and on leukemias/lymphomas of B- and T-cell phenotype, little is known about its expression and functional role in some specific types of lymphomas, such as CD30-positive anaplastic large cell (ALC) lymphomas and Hodgkin's disease (HD). A series of 81 lymphoma samples, including 23 cases of HD, 17 cases of CD30-positive ALC lymphomas, 41 cases of other non-Hodgkin's lymphomas (NHL), and a panel of HD- or ALC lymphoma-derived human cell lines were evaluated for CD26/DPPIV expression by enzyme histochemistry and immunohistochemistry on frozen sections and cell smears. CD26/DPPIV protein was expressed on neoplastic cells in 12 of 17 (71%) ALC lymphomas irrespective of their antigenic phenotype and in seven of 15 (47%) T-cell NHLs. In contrast, we did not detect CD26/DPPIV expression in tumor cells from 26 cases of B-cell NHL other than ALC lymphomas or in Reed Sternberg (RS) cells and variants of 21 of 23 HD cases. Accordingly, CD26/DPPIV expression was maintained on the CD30-positive ALC lymphoma cell line Karpas 299, but the molecule was not detected on HD-derived cell lines of B, T, or non-B non-T phenotype. These results may support a new potential tool for the phenotypic separation of ALC lymphomas from HD based on the differential expression of the CD26/DPPIV molecule. Moreover, given the demonstration that CD26/DPPIV is identical to the human adenosine deaminase (ADA) binding protein, it could be speculated that CD26/DPPIV also may function by interacting with ADA to regulate the growth of CD26/DPPIV expressing neoplastic cells in ALC lymphomas.

Dipeptidyl Peptidase 4↗
PubMed1994

5-Aza-2'-deoxycytidine induces growth inhibition and upregulation of epidermal growth factor receptor on human epithelial cancer cells.

BACKGROUND: The epidermal growth factor (EGF-R) receptor is an important growth regulator of epithelial cancer cells, and is presently considered a tumor-associated antigen (TAA) which is overexpressed by several human cancers and barely detectable in most normal tissues. Since TAA density at the tumor cell surface is a critical factor regulating the efficiency of immunotargeting procedures, a therapeutic advantage may derive from the pharmacologic enhancement of membrane expression of such antigens on tumor cells. MATERIALS AND METHODS: Utilizing a panel of different human cancer cell lines of epithelial derivation, we have investigated in the in vitro effects of 5-aza-2'-deoxycytidine (5azaCdR), an antineoplastic agent able to induce gene activation and phenotypic modulation, on the surface expression of EGF-R by tumor cells. RESULTS: 5azaCdR (10-1000 nM) induced growth inhibition, in the absence of acute cell kill, on KB (human oropharyngeal carcinoma), LoVo and the drug-resistant clone LoVo-DX (colon carcinoma) and A549 (lung adenocarcinoma) cell lines, along with a significant enhancement of EGF-R expression at the tumor cell surface. A single 24 h pulse of 5azaCdR, followed by 96 h of culture in drug-free medium, induced 50% growth inhibition on KB cells at a concentration (IC50) of 500 nM, on A549 (IC50 = 490 nM), LoVo (IC50 = 400 nM) and LoVo-DX (IC50 = 100 nM) cell lines. Under these conditions the specific binding of 125I-EGF was significantly upregulated at the surface of growth-inhibited cancer cells. Scatchard analysis of EGF-binding data revealed no changes in the Kd of EGF-R for its ligand in 5azaCdR-treated tumor cells and demonstrated a significant increase in the number of both the high- and low-affinity EGF-binding sites on KB cells, while only one class of EGF-binding site was detectable on A549, LoVo and LoVo-DX tumor cell lines before and after exposure to 5azaCdR. The EGF-R upregulation induced by 5azaCdR was paralleled by the increased binding of the anti-EGF-R monoclonal antibody (MAb) 108.1 on the surface of cancer cells. Finally, the rate of endocytosis of the anti-EGF-R MAb by KB cells was not modified by drug treatment, indicating that exposure to 5azaCdR does not hamper MAb internalization by the tumor cells. This latter represents an essential process for the cytotoxic effects of immunoconjugate drugs or toxins. CONCLUSIONS: We suggest a role for 5azaCdR in enhancing the efficacy of therapeutic approaches involving the use of anti-EGF-R immunoconjugated for the imaging and the treatment of human epithelial neoplasias.

Adenocarcinoma↗
PubMed1994

Pharmacological modulation of peptide growth factor receptor expression on tumor cells as a basis for cancer therapy.

Membrane receptors for peptide growth factor receptors (PGF-R) play a crucial role in the regulation of cancer cell proliferation and may behave as tumor associated antigens (TAA), which are currently regarded as specific targets for immunodetection and immunotherapy of human cancer. PGF-R are often more expressed by tumor cells than by normal counterparts and, by analogy to TAA, their surface expression may be regulated by cytokines. Moreover, the biological functions and specific ligands of most PGF-R are presently well elucidated as opposed to the great majority of TAA. PGF-R may, therefore, represent ideal cellular targets for at least two different therapeutic approaches: (i) naked or conjugated monoclonal antibodies and (ii) genetically engineered fusion proteins composed of PGF-R physiological ligands linked to genetically modified bacterial toxins. To date, clinical studies based on targeting of receptors for epidermal growth factor and interleukin-2 on tumor cells have been performed. Information from such studies suggests that PGF-R as well as TAA targeting strategies are clinically feasible, but that they still have to be optimized. A variety of host and tumor factors which affect targeting of neoplastic cells have been recently identified. For instance, it has been demonstrated that the antigenic density of the targeted molecule at the tumor cell surface is an important factor. In this view upregulation of PGF-R on cancer cells could be of major clinical advantage in immunotargeting. It has been reported that several cytokines and chemical compounds can induce PGF-R modulation on tumor cells. This paper reviews therapeutic opportunities related to the pharmacologic modulation of PGF-R expression. In addition a mechanistic hypothesis regarding PGF-R upregulation induced by cytostatic drugs and cytokines is proposed.

Antibodies, Monoclonal↗
PubMed1994

Immunological abnormalities in patients with chronic fatigue syndrome.

Between January 1991 and January 1993, 265 patients who fulfilled the CDC criteria of the working case definition of Chronic Fatigue Syndrome (CFS) have been observed at our Institution and submitted for clinical and laboratory evaluation. One hundred and sixty-three patients were females and 102 males, the median age was 35 years (range 4-55 years); all patients reported profound and prolonged fatigue, lasting for a median of 3 years (range 6 months-10 years), preceded or accompanied at appearance by fever in 185 cases, and neuropsychologic problems including inability to concentrate, difficulty in thinking, confusion, irritability, forgetfulness, and depression. The fatigue was so severe that it required 102 patients to stop their working activities for a period of time ranging from 3 months to 2 years (range 7 months). In 40 consecutive patients a comprehensive immunologic testing by single and two-colour flow cytometry was performed and results compared with a group of 35 healthy, age- and sex-matched controls. Whilst no significant differences were found in the absolute numbers of circulating total T cells (CD3+) and of total helper/inducer (CD4+) or suppressor/cytotoxic (CD8+) T cells, an evident reduction in CD3-/CD16+ and CD57+/CD56+ NK lymphocytes along with an expansion of the CD8+/CD56+ and CD16-/CD56+ NK subsets, were found in the CFS group. In addition, CD56+ NK cells from CFS subjects were found to express an increased amount of cell adhesion molecules (CD11b, CD11c, CD54) and activation antigens (CD38). Both the percentage and absolute numbers of CD4+ T cells bearing the CD45RA antigen appeared significantly reduced in CFS patients, and CD4+ T lymphocytes from CFS subjects displayed an increased expression of the intercellular adhesion molecule-1 (ICAM-1/CD54). Finally, the total numbers of circulating (CD19+) B lymphocytes, were significantly higher in CFS cases than in controls, and in 11 out of 30 CFS patients the increase in circulating B cells was sustained by the expansion of the CD5+/CD19+ subset of B lymphocytes. We conclude that CFS is a syndrome not previously described in Italy, with already known clinical characteristics and appears to be associated with several immunologic abnormalities, including those reported previously in cohort of patients from different countries. We also show for the first time that CD56- NK cell subsets from CFS patients display an abnormally increased expression of cell adhesion molecules and activation markers.

Adolescent↗