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Biomedical subjects

A Pinto

Publications and source records attributed to A Pinto.

At least 289 records · Page 16Linked to original sources
PubMed1990

Preliminary studies on antipyretic and analgesic properties of Taverniera abyssinica.

In an attempt to ascertain the pharmacological basis of the use of the marketed traditional drug Taverniera abyssinica A. Rich. (Amharic name Dingetegna), crude extracts as well as purified substances of this plant were tested for their antipyretic and analgesic properties. Antipyretic activity was determined on rats made hyperthermic by yeast injection and analgesic activity was determined by the hot plate, as well as the acetic acid induced writhing, methods. The study showed that the plant possesses significant antipyretic and analgesic activities.

Animals↗
PubMed1989

Immunohistochemical expression of neuron-specific enolase and Leu 7 in Ewing's sarcoma of bone.

Neural features have been documented in a series of small round cell tumors of bone, previously classified as Ewing's sarcoma of bone (ESB), using light microscopic, ultrastructural, immunohistochemical, and in vitro techniques. To date, correlation of the presence of these features in ESB with clinical outcome has not been performed. The authors investigated the clinical relevance of positivity to antibodies against neuron-specific enolase (NSE) and Leu 7 (HNK 1) using the avidin-biotin complex technique in 40 cases of ESB seen at St. Jude (Memphis, TN) during the period 1968 to 1986. Twenty-three cases (58%) were positive for NSE and/or Leu 7. The median disease-free survival of patients with localized tumors and NSE and/or Leu 7 positivity was 3.8 years compared to a median disease-free survival of 1.6 years for those without these markers and localized disease. Using the log-rank test, a statistically significant difference was shown in these two groups of patients (P = 0.049). The authors conclude that in this relatively small series ESB commonly expresses NSE and/or Leu 7 and that the presence of these markers is of no prognostic significance overall, but that in patients with localized ESB the presence of NSE and/or Leu 7 by immunostaining may be a favorable prognostic indicator.

Adolescent↗
PubMed1989

Differential role of distinct determinants of intercellular adhesion molecule-1 in immunologic phenomena.

This study analyzed 1) the relationship between the molecules recognized by anti-intercellular adhesion molecule-1 (ICAM-1) mAb RR 1/1 and by anti-96K melanoma-associated Ag mAb CL203.4 in lymphoid cells, 2) the induction of ICAM-1 on activated PBMC, and 3) the functional activity of distinct and spatially distant determinants recognized by mAb CL203.4 and RR1/1. Sequential immunoprecipitation experiments showed that the determinant recognized by mAb CL203.4 is expressed on a slightly broader population of ICAM-1 molecules than that defined by mAb RR1/1. Serologic and immunochemical assays have shown that ICAM-1 is induced on lymphocytes activated with Con A, PHA-M, IL-2, allogeneic HLA mismatched lymphocytes and autologous PHA-M-activated T cells. However, ICAM-1 was not detected on lymphocytes incubated with IFN-gamma. Incubation of monocytes with LPS induced ICAM-1 in the subpopulation which lacks it and increased its density on the cells which express it. Induction of ICAM-1 is an early event in the activation process and precedes the appearance of IL-2 and transferrin receptors. Comparison of the functional activity of the anti-ICAM-1 mAb CL203.4 and RR1/1 showed that both of them inhibit to a similar extent proliferation of lymphocytes stimulated with PHA-M and with allogeneic lymphocytes, but that only mAb RR1/1 inhibits PMA-induced aggregation of cultured B lymphoid cells JY, of promonocytic cells U-937 and of PHA-blasts as well as LAK cell-mediated cytotoxicity of target cells. mAb CL203.4 represents the first example of anti-ICAM-1 mAb without inhibitory effect on the aggregation of lymphoid cells. The differential functional activity of mAb CL203.4 and RR1/1 does not reflect differences in their affinity, because they display a similar affinity constant to lymphoid cells. These results suggest that distinct determinants of ICAM-1 play a different role in immunologic phenomena.

Antibodies, Monoclonal↗
PubMed1989

Monocytoid B-cell lymphoma with bone marrow and peripheral blood involvement at presentation.

A case of malignant lymphoma showing in a lymph node the characteristic morphologic features of the so-called monocytoid B-cell lymphoma (MBCL) is described. This case differs from the reported cases in the literature because atypical cells were observed in the bone marrow biopsy and marrow and peripheral blood smears that were obtained from the patient, a 61-year-old man, during the staging procedures. Lymphocyte surface marker studies on peripheral blood by flow cytometry and DNA analysis revealed a monoclonal population of lambda-positive lymphocytes. The immunophenotype of MBCL cells was studied both in paraffin-embedded lymph node sections by immunoperoxidase method and in peripheral blood by flow cytometric analysis; the cells expressed the SIg with lambda light chain restriction and the HLA-DR antigen; they also had positive results for B-cell-associated antigens, including LN1, LN2, CD 20, CD 22, CD 19, CD 9 but not CD 21, CD 24, and CD 10, T-cell-associated antigens and monocytic markers. In addition, they had negative results for CD 25, CD 38, PCA-1. This report emphasizes that in MBCL, peripheral and marrow involvement may occur at presentation analogous to other low-grade B-cell lymphomas. The immunophenotypic characteristics of MBCL cells, though not pathognomonic, are considered to be helpful in differentiating them from circulating cells of other B-cell lymphomas.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1989

Castor oil increases intestinal formation of platelet-activating factor and acid phosphatase release in the rat.

1. When castor oil was administered by gavage to rats, the duodenum and jejunum but not ileum and colon produced large amounts (5-6 fold greater than control) of platelet activating factor (Paf). 2. Intraluminal release of acid phosphatase (AP) was also markedly increased (5-6 fold greater than control) in the duodenum and jejunum of castor oil-treated rats and there was a correlation between the elevated release of AP and intestinal hyperaemia. 3. These findings support a role for Paf as a mediator of intestinal damage induced by castor oil.

Acid Phosphatase↗
PubMed1989

[A case of recurrent sciatica following a free adipose tissue graft].

The authors present a case of recurrence of sciatic pain in a patient operated upon for lumbar disc herniation two days before. It was related to the migration to the vertebral canal of the fat tissue graft used ward for preventing fibrotic tissue invasion from outside. After removal of the graft, healing was uneventful.

Adipose Tissue↗
PubMed1989

[Role of intraoperative echo-Doppler color echocardiography in cardiac surgery. Preliminary study].

Intraoperative echocardiography with Doppler color flow imaging technique can provide the surgeon with an immediate and direct assessment of cardiac anatomy and function. To determine the utility of this recent technique, we have examined 15 patients pre, per, and postoperatively with Doppler color flow imaging. The intraoperative study was performed before and after cardiopulmonary bypass. A sterile transducer was placed directly on the epicardial surface of the heart, and multiple views were recorded. Intraoperative echocardiography with Doppler color flow imaging technique demonstrated excellent correlation with preoperative and postoperative findings, allowing an immediate evaluation of the surgical results. These preliminary results suggest that intraoperative Doppler color flow imaging technique is a valuable adjunct in heart surgery. It is particularly useful in valve repair, and in surgical repair of congenital heart disease.

Cardiac Surgical Procedures↗
PubMed1988

Recent trends in human leptospirosis in Italy.

The recent epidemiological trends of human leptospirosis in Italy were investigated using data collected for the years 1981-1985. A total of 626 hospitalized patients with clinical diagnoses of suspected leptospirosis were reported by hospital centers from several Italian regions. Epidemiological, clinical and seroimmunological data were collected in 517 of these cases and examined by the National Center for Leptospirosis. Serological findings in 33.5% of these subjects met the criteria for confirmation of the disease. In 21.8% of the subjects, low titer antibodies were detected, which possibly reflected previous leptospiral infections. An early antibiotic treatment of the current infection may also have lowered the seroimmunological response in some of these patients. In 59.3% of the confirmed cases, modes of transmission were allotted equally between accidental events and recreational or occupational activities. Drinking water from an open air fountain emerged as an uncommon mode of transmission; it was responsible for an outbreak of 33 cases of leptospirosis. In another 37.07% of the subjects, it was impossible to establish the mode of transmission. Respiratory or influenza-like symptoms were the only clinical signs of illness in 21.2% of the patients with confirmed leptospirosis. In comparison to the sixties and seventies, the prevalence of infecting serovars showed increasing incidence of infections due to serovars of the Javanica (11.0%) and Australis (11.0%) serogroups and an important decrease in the Bataviae serogroup infections (from 58.8% in rice-field workers in the forties to 0.6% in the years 1981-1985). Sejroe serogroup infections accounted for 4.5 per cent of confirmed cases of leptospirosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Expression of markers shared between human natural killer cells and neuroblastoma lines.

Neuroblastoma is a tumor of neuroectodermal origin arising most commonly from the adrenal medulla. We have examined the ability of several monoclonal antibodies which recognize markers predominantly expressed on human natural killer (NK) cells to react with neuroblastoma cell lines in vivo derived sections of tumor. HNK-1 (Leu 7) is a monoclonal IgM antibody which recognizes a carbohydrate epitope on NK cells and a wide range of tumor cell types. We have shown that HNK-1 recognizes the human neuroblastoma lines SMS-KCNR, SMS-KAN, NMB/N7, and IMR/5. Expression of this antigen on cell lines can be slightly increased by retinoic acid-induced differentiation of the cells. N901 (NKH1), a monoclonal antibody raised against interleukin 2-dependent human NK cell lines also recognizes all human neuroblastoma cell lines examined. This expression is independent of differentiation induction and levels remain unaltered following retinoic acid treatment of the cell lines. Lastly, with monoclonal antibody 49H.8, it has been found that reactivity of the lines is weak until induction of differentiation, after which highly significant increases of reactivity are seen. 49H.8 recognizes several cryptic carbohydrate antigens with varying affinities, shown to identify mouse and rat NK cells. In contrast to other NK markers, human neuroblastoma cell lines did not express significant reactivity with B73.1, Leu 11b, or Leu 18. Immunohistochemical staining of sections of human neuroblastoma tumors correlated with the in vitro findings; however, staining with N901 and 49H.8 was only seen on frozen sections, not paraffin-embedded. The significance of shared NK cell-neuroblastoma/neuron antigens is currently under investigation.

Animals↗
PubMed1988

Differentiation of human leukaemic cell lines and fresh leukaemia cells by low dose Ara-C: monitoring by expression of c-myc and c-fos oncogenes.

The effects of low dose Ara-C on cellular oncogene expression were measured in HL-60 and U-937 cell lines and in primary cultures from leukaemic patients. Expression of c-myc was completely abolished in U-937 and greatly reduced in HL-60 after a 3 day exposure to the drug, whereas specific c-fos transcripts were increased. In fresh myeloid leukaemia samples, growth and DNA synthesis were reduced as in the two cell lines. Conversely, changes compatible with the induction of differentiation along the myelomonocytic pathway were much less pronounced than in cell lines treated with the same dose of Ara-C. Cells from one patient did not show any appreciable morphological change. The same sample displayed a greatly reduced expression of c-myc accompanied by a concurrent 10-fold increased expression of c-fos. The data suggest that the action of low dose Ara-C on oncogene expression is comparable to that of other differentiation-inducing agents that display both cytostatic and maturation promoting effects. Evaluation of cellular oncogene expression may therefore represent a useful tool for monitoring effects of low dose Ara-C on leukaemia cells.

Cell Differentiation↗
PubMed1988

Characteristics of Yorkshire swine natural killer cells.

The present study examined the properties of NK activity in Yorkshire swine. The results support other porcine studies which indicate the swine NK system has both similarities and differences to this system in other species. Profiles of NK activity indicated swine NK cells are highly reactive against the YAC-1 lymphoma, the K-562 myeloid leukemia, the P-815 mastocytoma, and the TU-5 virally transformed fibroblast. In contrast, the MOLT-4 and SB leukemias are NK resistant. Kinetic studies indicated that in Yorkshire swine, NK lysis begins 6 h after mixing effectors and targets. The kinetics of the lytic reaction differ both from other breeds of swine and from other species, where cytotoxicity is readily measured in 4-h assays. The delayed lysis was not due to delayed target cell recognition, because Yorkshire swine NK cells are rapidly bound to tumor targets. The delayed lysis seems to be due to a refractoriness in the NK lytic mechanism. This delay may relate to the morphologic finding that the target-binding cell in Yorkshire swine appeared quite different from the large granular lymphocyte (LGL) reported as the NK effector in humans and rodents. Indeed, in light microscopic studies the typical tumor-binding cell in Yorkshire swine is a small, apparently nongranular, lymphocyte. Analysis of NK activity at the single cell level was performed with single effector-tumor conjugates immobilized in agarose. Generally, lysis by target binders paralleled sensitivity to lysis in 51Cr release tests, indicating lysis in agarose may be used as an NK index in swine. Like other species, swine NK cells were found to be nonadherent lymphocytes with a characteristic tissue distribution. Peripheral blood and spleen had the highest levels of NK activity. Lymph node cells displayed a small amount of NK activity which was limited to the YAC-1 target, while thymocytes showed no appreciable NK activity against any of the cell lines tested.

Animals↗
PubMed1988

Inhibitory effects of fungi on aggregation of rabbit platelets and rat polymorphonuclear leucocytes in vitro.

Fungi of six families, encompassing 28 species, have been screened for their inhibitory effects on adenosine-5'-diphosphate (ADP), acetyl-glyceryl-phosphorylcholine (PAF) or collagen-induced rabbit platelet aggregation. Some fungi have also been studied for their ability to inhibit neutrophil aggregation induced by calcium ionophore A 23187. The results suggest that fungi may be a potential source of inhibitors of platelet and neutrophil aggregation.

Adenosine Diphosphate↗
PubMed1988

Rickettsiae of the spotted fever group associated with the host-parasite system Oryctolagus cuniculi/Rhipicephalus pusillus.

Wild rabbits--Oryctolagus cuniculi--living in large numbers in a protected zone of Tuscany, the park of Migliarino--San Rossore--Massaciuccoli, showed to be carriers of the hard tick Rhipicephalus pusillus, previously observed in North Africa and Sicily. Antibodies to Rickettsia conorii and R. slovaca were detected in 78.9 per cent of the wild rabbits captured in that area. Seroconversion towards R. conorii was also observed in guinea pigs inoculated with homogenates of R. pusillus parasitizing the wild rabbits. These results identify an ecological niche of rickettsiae of the Spotted fever group in the host-parasite system O. cuniculi/R. pusillus. Attempts to isolate rickettsiae from the ticks and the wild rabbits were unsuccessful both in the egg yolk sac and in the guinea pig. This failure probably shows the low pathogenicity of the rickettsiae parasitizing the biosystem O. cuniculi/R. pusillus.

Animals↗
PubMed1988

Flavonoids, leucocyte migration and eicosanoids.

Quercetin reduced the concentration of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) in the pleural exudate induced in rats by 1% carrageenan given intrapleurally. Leucocyte migration in the exudate was also reduced by the flavonoid. Inhibition of eicosanoids and leucocytes in the exudate was dose-related. Quercetin also reduced LTB4 synthesis in cells stimulated with ionophore A23187, either ex-vivo or in-vitro. A similar, though less active, mode of action was found with quercitrin, while apigenin and luteolin reduced leucocyte accumulation and PGE2 formation, but not LTB4-formation.

Animals↗
PubMed1988

A retrovirus carrying the polyomavirus middle T gene induces acute thrombocythemic myeloproliferative disease in mice.

Mice inoculated with an artificially constructed retrovirus carrying the middle T gene of polyomavirus develop acute myeloproliferative disease with severe thrombotic and hemorrhagic disorder and impaired platelet function. The megakaryocytic lineage appears to be a target for polyoma-murine leukemia virus infection and middle T gene expression. This newly described disease represents a unique model system for studying disorders of the megakaryocytic lineage.

Adenosine Triphosphate↗
PubMed1988

Effects of felodipine on natriuresis, atrial natriuretic factor, the renin-angiotensin-aldosterone system, and blood pressure in essential hypertension.

The aim of this study was to evaluate the short-term and long-term effects of felodipine, a new dihydropiridine calcium antagonist, on arterial blood pressure (BP), the renin-angiotensin-aldosterone system, diuresis, natriuresis, and the atrial natriuretic factor (ANF). In 15 essential hypertensives (WHO class II) BP, venous BP at the posterior tibial vein (VBPTV), diuresis, natriuresis, plasma renin activity (PRA), and both plasma aldosterone and ANF levels were evaluated at the end of a washout period and after two and 24 hours and 30, 90, and 180 days of follow-up with felodipine, 5 mg twice daily. The first dose of felodipine induced a significant decrease in BP, which was associated with increases in both heart rate and VBPTV. An acute diuretic and natriuretic effect, increases in ANF and PRA, and a transient decrease in plasma aldosterone levels were also observed. Throughout the follow-up period, the antihypertensive efficacy remained unchanged, whereas variations in electrolyte balance and hormonal parameters quickly disappeared, except for the increase in PRA, which lasted until the 30th day of therapy. In our study, felodipine showed a great antihypertensive activity during both short-term and long-term treatment. Moreover, the effect of the first dose was characterized by transient increases in circulating ANF and decreases in plasma aldosterone concentrations, which were associated with marked diuresis and natriuresis.

Adult↗