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Biomedical subjects

S Guerra

Publications and source records attributed to S Guerra.

At least 37 records · Page 2Linked to original sources
PubMed1998

Age at symptom onset and distribution by sex and symptoms in patients sensitized to different allergens.

The aim of our study was to analyze the clinical features, particularly the age at symptom onset, of allergic subjects (asthma and/or rhinitis) on the basis of the etiologic elements (sensitization to various allergens). We identified a group of monosensitized patients and a group of polysensitized patients. Within these groups, we identified subgroups of subjects monosensitized to one of the five main allergenic mixes (mites, Gramineae, trees, Parietaria, and Artemisia) and five subgroups of patients sensitized nonexclusively, that is, polysensitized, to the same allergens. The comparison between the two groups and among the various subgroups enabled us to conclude that: 1) mono- and polysensitized patients present some clinical features so different as to constitute two clearly distinct clinical groups 2) analysis of the clinical features associated with the sensitization to a specific allergen brings us to significantly different conclusions when we consider subgroups of monosensitized or polysensitized patients 3) the parameter "age at symptom onset" shows great heterogeneity among both the mono- and the polysensitized subgroups--in particular, the great differences in mean age among the monosensitized subgroups (trees>Artemisia>Parietaria>Gramineae>mites) appear very interesting and are open to various interpretative hypotheses 4) unlike the polysensitized group, in the monosensitized group and subgroups, mean age is similar between men and women and, only for tree- and Parietaria-monosensitive patients, also between asthmatic and rhinitic subjects.

Adolescent↗
PubMed1992

Rapid detection of a protein C gene mutation present in the asymptomatic and not in the thrombosis-prone lineage.

The presence of mutations in the serine protease domain of protein C was investigated by temperature gradient gel electrophoresis of PCR products in five patients with protein C deficiency and thrombosis. Molecules with an altered melting behaviour were detected in one subject with a history of venous and arterial thrombosis. Direct sequencing showed that a G deletion, present in the heterozygous state, caused a reading frame shift at Trp 300 and subsequently a premature termination at the codon 335. The resulting suppression of the protein C catalytic function explains the reduction of protease activity to half. In addition the mutation caused a reduction of the antigen level in plasma. Temperature gradient gel electrophoresis enabled the rapid detection of the gene alteration in the family of the propositus. Several members of the paternal lineage had had severe thrombotic episodes. Unexpectedly the mutation was found to be inherited from the clinically asymptomatic maternal lineage, thus suggesting that an additional unknown defect from the paternal lineage is present in the thrombosis-prone propositus.

Adult↗
PubMed1992

Favorable clinical effects of iloprost infusion in 4 uremic patients with critical limb ischemia.

Four uremic patients with advanced peripheral arterial occlusive disease (PAOD) of lower limbs causing rest pain and ischemic-necrotic lesions were treated with a four-hour intravenous infusion of iloprost at doses of 0.75-2.5 ng/kg/min for twenty-eight days. After a week of the therapy all patients experienced disappearance of rest pain and prolonged walking distance. At the end of the trial a diabetic patient showed a complete regression of the necrotic areas of two toes while the other patients still showed ischemic-necrotic foot lesions that were well demarcated. Iloprost therapy can be effective in uremic patients with severe PAOD.

Acute Disease↗
PubMed1992

[Treatment of dysfunctional metrorrhagia with GnRH analogs].

Thirty patients diagnosed as affected by dysfunctional metrorrhagia were treated with goserelin in a registered formulation of 3.6 mg injected subcutaneously into the anterior abdominal wall. These patients suffered from hypochromic anemia secondary to metrorrhagia with asthenic symptoms. After six months' treatment there was a significant improvement in hemocrasia and symptoms resolved without collateral effects requiring the suspension of treatment. The 10 patients who subsequently underwent surgery were in excellent condition and did not require blood transfusions.

Abdominal Muscles↗
PubMed1991

Coagulation disorders and tumor markers in the diagnosis of pancreatic cancer.

Twenty patients (42-80 years old of whom 9 women) affected by instrumentally ascertained pancreatic cancer (7 cases were operated on) were studied. In all of them the following coagulation indices (fibrinopeptide A, FpA; beta-thromboglobulin, BTG; platelet factor IV, PF4; fibrinogen degradation products, XDP) and tumor markers (gastrointestinal cancer associated antigen, GICA; tissue polypeptide antigen, TPA; carcinoembryonic antigen, CEA; alpha-fetoprotein, or AFP) were assessed at the time of diagnosis, and 10 and 30 days after diagnosis, to test whether and which of the above parameters are more sensitive for entertaining the underlying affection. In both operated and nonoperated patients FpA was shown to be the most sensitive index. Lesser sensitivity was shown by XDP, GICA, and BTG. AFP proved to be quite useless as its serum levels constantly fell within the normal range.

Adult↗
PubMed1990

A de novo and heterozygous gene deletion causing a variant of von Willebrand disease.

An abnormal von Willebrand factor (vWF) gene restriction pattern has been found in a patient with von Willebrand disease. Because this gene alteration is not present in his parents or in 50 normal and 25 affected subjects, and the restriction fragment length polymorphism haplotypes are inherited normally in the patient's family, we suggest that a de novo mutation is present. Bands with reduced intensity and additional fragments, observed in several restriction digests, hybridize with noncontiguous copy DNA (cDNA) portions, thus indicating the presence of a heterozygous gene deletion. The deletion removes a genomic region containing at least codons 1147 through 1854 and corresponding to the D3-A3 homologous protein domains. The extent of the vWF pseudogene on chromosome 22 is roughly similar to that of the deleted area. However, the pseudogenic nature of the deletion is excluded by the mapping of bands with reduced intensity in the patient to the true vWF gene. The vWF antigen levels are one fourth of normal and ristocetin cofactor activity is severely impaired. The reduction of high molecular weight multimers in plasma and platelets and the altered triplet morphology are compatible with the presence of a dominant variant of type II von Willebrand disease.

Bleeding Time↗
PubMed1990

Ethnobotanical inventory of medicinal plants used by the Guaymi Indians in western Panama. Part II.

A list of newly identified plants is presented to supplement Part I (Joly et al. (1987) Journal of Ethnopharmacology 20, 145-171). A comparative analysis is made between our work and two other recent inventories of plants used by the Guaymi Indians of Panama and Costa Rica. As in Part I, the results of a literature survey are also provided, including medicinal uses, known constituents and pharmacological effects.

Medicine, Traditional↗
PubMed1990

Pre- and postsurgery activation of blood coagulation in gastric and large bowel cancers: diagnostic, therapeutic and prognostic hints.

In 12 patients with gastric cancer and in 14 with large bowel neoplasia, classified according to the TNM system, some major blood indices of hemostasis, platelet activation and fibrinolysis were assessed before and for 1 month after surgery, to show whether possible variations of such indices may provide useful clues to follow-up, treatment effectiveness and prognosis. The following conclusions may be drawn: (1) the assay of platelets, fibrinogen, AT III, fibrin(ogen) degradation products, fragment X, platelet factor 4 has provided useful clues in neither group of patients; (2) preoperative high beta-thromboglobulin (beta-TG) is a reliable index of tumor presence in both gastric and large bowel cancer; (3) postoperative high beta-TG and fibrinopeptide A (FpA) are reliable indices of (a) tumor persistence in both gastric and large bowel cancer; (b) lymph node involvement in gastric much more than in large bowel cancer; (c) metastatic spreading from gastric cancer; (4) the FpA levels are proportional to the tumor mass in gastric cancer. The finding of lower plasma heparin levels in neoplastic patients, when compared with controls (20 patients having undergone abdominal surgery for extraneoplastic affections) suggests higher than conventional doses (5,000 units every 8 h s.c.) of the drug should be given to neoplastic patients in order to prevent thromboembolic bouts and possibly reduce metastatic spreading.

Adult↗
PubMed1989

Evidence for a factor promoting the conversion of VWF from low and intermediate to high molecular mass polymers on the platelet membrane.

On the membrane surface of resting platelets exists a factor capable of promoting the conversion of plasma von Willebrand factor from low and intermediate molecular mass to high molecular mass polymers. The process is accompanied by a parallel increase in the von Willebrand factor activity. This could be a regulatory system for the molecular mass distribution of von Willebrand factor during its lifetime in plasma. Glycoprotein Ib of the platelet membrane appears not to be involved in the process.

Blood Platelets↗
PubMed1988

von Willebrand disease investigated by two novel RFLPs.

Two partial cDNAs for von Willebrand factor (vWF) were used to investigate gene lesions and restriction fragment length polymorphisms (RFLPs) in vW disease (vWd) and normal controls. No gene alteration was detected but two TaqI RFLPs, likely to be intronic and originating from point mutations, were found in the 3' part of vWF gene. The two TaqI RFLPs, identified by the same probe, are informative in approximately 50% of the subjects. Used in combination with two other known RFLPs, they define several haplotypes similarly distributed in vWd and normals. Linkage disequilibrium between loci identified by the RFLPs is present. In a family study the RFLP patterns demonstrate homozygosity for the affected vWF gene in a severe (type III) patient and identify several heterozygous subjects. The RFLPs analysis has been related to the haemostatic values and multimer distribution. In two of the four unrelated patients with severe vWd examined the RFLPs study indicates double heterozygosity for the affected vWF genes.

Genetic Linkage↗
PubMed1987

Advantage of desogestrel containing pill in oral contraception: influence on blood lipids and LCAT activity.

In the present study the effects of a combined oral contraceptive preparation containing 0.150 mg desogestrel and 0.030 mg ethinylestradiol on lipid metabolism were investigated. In particular, we observed significant increase in HDL-cholesterol and apolipoprotein-A-I (apo A-I) and B (apo B). Triglycerides were not significantly modified. The cholesterol esterifying enzyme LCAT, assayed under "maximal" conditions against an exogenous substrate, was significantly decreased despite an increase in the physiological stimulator apo A-I. No changes were observed in the anti-atherogenic indexes apo A-I/apo B and HDL-cholesterol/LDL-cholesterol. Thus, it appears that this combined oral contraceptive has the promising ability to increase the anti-atherogenic HDL-cholesterol particle without altering the atherogenic LDL-cholesterol.

Adult↗
PubMed1985

A contribution to the pathology of acquired plasma factor XIII deficiency.

The biologic activity of Factor XIII was measured in four groups of patients: 20 with liver cirrhosis, ten with acute DIC, 30 with acute leukemia with DIC, and 20 with acute leukemia without DIC. In all groups, the plasma Factor XIII transamidating activity was reduced, but this deficiency was more evident in patients with DIC alone or with leukemia and DIC. The immunologic determination of the a and b subunits of Factor XIII was also performed. Both subunits were below the normal range in the groups of patients studied, except for subunit b, which was normal in patients with leukemia without coagulopathy. Acute DIC patients showed an equally reduced level of both subunits, whereas in patients with leukemia, even in the presence of a complicating coagulopathy, a lesser decrease of subunit b than subunit a was found. Both subunits were equally reduced in patients with cirrhosis, suggesting an impaired synthesis of these proteins. In conclusion, our findings do not support the use of Factor XIII subunit measurements in distinguishing between thrombin- or protease-mediated consumption coagulopathy, and they seem to suggest that the deficiency pattern of the subunits is not accounted for by a simple pathogenetic mechanism.

Acute Disease↗
PubMed1985

Public opinion on and potential demand for vasectomy in semi-rural Guatemala.

In this study of 1,600 men aged 25-50 from semi-rural Guatemala, three-fourths had heard of vasectomy. Among these, 54 per cent approved of it. However, the survey reveals a widespread lack of knowledge regarding the procedure, as well as negative perceptions or doubts about its effect on sexual performance, ability to do hard work, health, and manhood. One-fourth of the respondents who knew of vasectomy and who desired no more children expressed interest in having the operation, a finding which raises questions as to the potential (unrecognized) demand for vasectomy in other developing countries.

Adult↗