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Biomedical subjects

M Gonzalez

Publications and source records attributed to M Gonzalez.

At least 199 records · Page 11Linked to original sources
PubMed1991

Comparison between the positive inotropic effects of enoximone, a cardiac phosphodiesterase III inhibitor, and dobutamine in patients with moderate to severe congestive heart failure. A study using the end-systolic pressure-volume relationship method.

This study was designed to compare the positive inotropic properties of enoximone, a cardiac phosphodiesterase III inhibitor, with those of dobutamine in a population of moderate to severe congestive heart failure patients. The end-systolic pressure-volume relationship method was used. In addition, the haemodynamic effects of both drugs were compared. In seven of the 11 patients studied, enoximone induced a significant shift upwards and to the left of the end-ejection pressure/end-systolic volume (EEP/ESV) relation, giving evidence of a true positive inotropic effect. In the remaining patients, improvement in cardiac pump function was observed together with a shift of the EEP/ESV relation along the line of iso-inotropism and appeared to be the result of the vasodilatory effect of the drug alone. Data from nine patients were available for comparison with dobutamine which induced a shift upward and to the left of the EEP/ESV relation in seven patients. At the therapeutic doses chosen, the difference between the inotropic effects of the two drugs was not significant (P = 0.07). Of the three patients available for comparison who did not manifest inotropic response with enoximone, two were also dobutamine 'non-responders': they differed from the 'responder' patients in two respects: they had undergone surgery for correction of valvular disease and had significantly higher pulmonary artery pressures. The haemodynamic measurements confirmed the vasodilatory properties of enoximone; in particular, the fall in ventricular filling pressures was much greater with enoximone than with dobutamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗
PubMed1991

[The difficulty of diagnosing Caffey's disease in utero. Apropos of a case simulating lethal osteogenesis imperfecta].

A very early case of infantile cortical hyperplasia (Caffey disease) is reported. The ultrasound examination performed at 22 weeks gestational age evidenced angulations of the long bones, leading to the diagnosis of lethal osteogenesis imperfecta. Hydrops fetalis developed and the pregnancy was terminated. The roentgenographic study of the fetus and results of pathological studies led to the correct diagnosis of Caffey disease. The difficulty of the diagnosis of these early forms of infantile cortical hyperostosis should be pointed out.

Adult↗
PubMed1990

Prospective study of diarrheal diseases in Venezuelan children to evaluate the efficacy of rhesus rotavirus vaccine.

The efficacy of a rhesus rotavirus vaccine (MMU 18006, serotype 3) against infantile diarrhea was evaluated by active home surveillance of a group of 320 children 1-10 months of age in Caracas, Venezuela. During a 1 year period following oral administration of vaccine or placebo under a double-masked code, over 600 diarrheal episodes were detected. Etiologic studies revealed that heat-stable toxin (ST) producing enterotoxigenic E. coli (ETEC) was the most common diarrheal agent detected (34%) followed by enteropathogenic E. coli (EPEC, 10.9%), heat-labile toxin (LT) producing ETEC (7.6%), rotavirus (6.9%), Cryptosporidium (4.8%) and Campylobacter (1.3%). ST-producing ETEC were also recovered from over 20% of control stool specimens obtained during diarrhea-free periods, whereas EPEC, rotavirus, Cryptosporidium, and Campylobacter were rarely detected in such control specimens. Rotavirus was responsible for about one-half of the more severe cases of diarrhea. Twenty-two of 151 infants who received placebo (14.6%) and eight of 151 receiving a 10(4) PFU dose of vaccine (5.3%) had rotavirus diarrhea during the follow-up period for an efficacy level of 64% against any rotavirus diarrhea. However, vaccine efficacy reached 90% against the more severe cases of rotavirus diarrhea and was noticeably high in the 1-4 month age group. Serotypic analysis of the rotaviruses detected suggests that the resistance induced by the vaccine was type specific since significant protection was only evident against serotype 3 rotaviruses. A 10(3) PFU dose tested initially in 18 children did not appear to protect against rotavirus diarrhea.

Complement Fixation Tests↗
PubMed1990

Comparison of vaccine strains and the virus causing the 1986 foot-and-mouth disease outbreak in Spain: epizootiological analysis.

RNAs of the most recent foot-and-mouth disease virus isolated in Spain (A5Sp86) during the 1986 outbreak, and of the three vaccine strains in use at that time in that country, have been compared. Although these viruses are serologically indistinguishable, differences have been found among them by T1 fingerprinting. This genetic heterogeneity affects the immunogenic VP1 gene, with amino acid changes located at the carboxyterminal end of the molecule. VP1-coding sequences obtained have been compared with those previously reported for European A5 FMDVs and it has been possible to trace their phylogenetic origin. The most parsimonious evolutionary tree obtained shows that the viruses analyzed are closely related to those previously isolated in 1983 in Spain, Portugal and Morocco. In spite of the VP1 sequence homology shown by this group of viruses, the genetic distances among field isolates and vaccine strains are significantly shorter than the distances found among field isolates. Thus, a significant relationship among virus recovered from recent outbreaks and the vaccine strains in use at that time in Spain, has been obtained.

Amino Acid Sequence↗
PubMed1990

Improvement in motor function after brachial plexus surgery.

Motor functional recovery of 52 patients with brachial plexus surgery followed up for more than 2 years was evaluated. Fifty-eight surgical procedures were done, including autologous nerve grafting (38 cases), neurolysis (14 cases), and neurotization (6 cases). Overall results, evaluated according to the 0 to 5 formula of the Medical Research Council, were as follows: good, 58%; fair, 15%; and poor, 27%. Good results were evident in 58% of patients with nerve grafts and in 64% of those with neurolysis. In patients with neurotization, no good recovery and only one fair recovery were seen. Patients with open injuries showed good recovery, whereas the group with closed injury showed good recovery in only 48%. Patients with closed injuries caused by traffic accidents showed a worse recovery than those caused by other means. Patients with closed injuries and nerve grafting done within 3 months of injury or neurolysis within 6 months showed better recovery.

Adolescent↗
PubMed1990

Mitochondrial DNA variation and genetic structure in Old-World populations of Drosophila subobscura.

To discover the relation between mitochondrial DNA (mtDNA) polymorphism and the geographic population structure of Drosophila subobscura previously established for other genetic traits, a wide Paleartic survey was carried out. A total of 24 nucleomorphs was observed among 261 isofemale lines assayed by 11 restriction endonucleases with 38 different sites in the mtDNA cleavage map. The differentiation of the Canary Islands populations (delta = 0.0119) compared with the mean among all the other continental and insular populations (delta = 0.0002) is striking. Both the great divergence among Canary Islands nucleomorphs (delta = 0.021) compared with the maximum nucleomorph distance in all other populations (delta = 0.017) and the abundance of endemic nucleomorphs (11) on the Canary Islands (50% of the total number of different nucleomorphs found in the entire distribution area) suggest that this molecular differentiation most probably results from the very old age of the Canary Islands populations rather than from drift and founder effects.

Animals↗
PubMed1990

Intermediate filaments in DMBA-induced mammary adenocarcinomas in rats.

Experimental DMBA (7,12-dimethylbenzanthracene)-induced mammary tumours in rats were studied. Microscopic examination revealed a high rate of adenocarcinomas (95.3% in 148 mammary tumours studied). An immunohistochemical study of cytoskeleton intermediate filaments (I.F.) showed cytokeratins in neoplastic epithelial cells; myoepithelial cells expressed cytokeratins, vimentin and desmin. Finally we propose the immunocytochemical localization of desmin as a useful method to recognize myoepithelial proliferation areas in mammary tumours.

Adenocarcinoma↗
PubMed1990

Surface phenotype and immunoglobulin levels in B-cell chronic lymphocytic leukaemia.

The aim of the present study is to analyze the relationship between serum immunoglobulin (Ig) levels and the immunological phenotype and the clinicohaematological features of B-cell chronic lymphocytic leukaemia (B-CLL) in a series of 126 patients. Eighty-eight of the cases (70%) had a decreased concentration of at least one Ig. IgM and IgA were the most frequently decreased (60% and 49% respectively). A serum monoclonal gammapathy was found in 4 patients, Ig M/k in two cases and IgM/l and IgG/k in one case. Patients with hypogammaglobulinaemia had a similar surface phenotype as patients with normal Ig levels (MRFC+, sIg+, CD20+, HLA/DR+, FMC7-, CD5+, CD9+). On the other hand the cases with hypogammaglobulinaemia displayed the features of a more advanced disease, a higher incidence of organomegalies (p less than 0.05), anaemia and/or thrombopenia (p less than 0.05), a diffuse bone marrow pattern (p less than 0.05), advanced clinical stages (p less than 0.05) as well as higher levels of both peripherial blood (p less than 0.02) and bone marrow lymphocytosis (p less than 0.02). These findings suggest that the presence of hypogammaglobulinaemia in B-cell patients is probably more related to a higher tumor burden than to either certain stages of B-cell differentiation or a particular cellular phenotype.

Agammaglobulinemia↗
PubMed1989

Identification by flow cytometry of two distinct rhodamine-123-stained mitochondrial populations in rat liver.

Isolated rat liver mitochondria were split into three fractions of increasing density when applied to a Percoll gradient. NADH-ubiquinone oxidoreductase, succinate dehydrogenase and cytochrome-c oxidase but not F1-ATPase activities increased with density as well as respiratory rate in state 3 and the respiratory control index. Flow cytometry of mitochondrial density fractions stained with rhodamine-123 revealed the occurrence in each density fraction of two distinct mitochondrial populations with different fluorescence intensity. The high fluorescence population was minor and its proportion decreased with density. The extent of high fluorescence population staining depended on the deenergized state of the mitochondria suggesting that this population represents an immature form of the mitochondria which may develop into a fully functional organelle by the incorporation of structural and/or functional proteins.

Animals↗
PubMed1989

B-cell chronic lymphocytic leukaemia: prognostic value of the immunophenotype and the clinico-haematological features.

Sixty-two previously untreated patients with B-cell chronic lymphocytic leukaemia were analysed to study the prognostic value of both the immunologic phenotype and the clinicobiologic characteristics. Univariate studies showed that none of the immunological markers analysed, sheep-rosette, mouse-rosette, slg, and HLA/DR, CD20, FMC7, CD5, and CD9 antigens, had a significant influence on survival. On the other hand, several clinical and haematological characteristics were identified as being associated with survival: 1) clinical features--presence of lymphadenopathies (P less than .05) and hepatomegaly and/or splenomegaly (P less than .04); 2) haematologic parameters--presence of anaemia and/or thrombopenia (P less than .05), the absolute peripheral blood lymphocyte count (P less than .03), and the presence of hypogammaglobulinemia (P less than .08); 3) biochemical parameters--serum uric acid (P less than .03); and 4) bone marrow histopathological features--biopsy pattern (P less than .04) and the percentage of lymphocytes in bone marrow aspirate (P less than .03). Both the Rai staging and the International Workshop on CLL staging systems were effective in identifying groups of patients with significantly different prognoses (P less than .05). Multivariate regression analysis demonstrated that the combination of three clinicopathologic characteristics (bone marrow histopathologic pattern, absolute peripheral blood lymphocyte count, and the presence or not of hypogammaglobulinaemia) had the strongest predictive relationship with survival time. In summary, our findings show that the clinicobiological and anatomopathologic parameters have much more prognostic relevance than the immunological markers analysed in the present study.

Antigens, Differentiation↗
PubMed1989

Meconium contamination of the neonatal middle ear.

The neonatal middle ear and mastoid cavity are frequently contaminated by cells and hair of the amniotic fluid. This amniotic fluid cellular content provokes a foreign body inflammatory reaction that can persist for months. To evaluate whether clinical and postmortem findings might correlate with the amount of amniotic fluid cellular content in the middle ear, we compared temporal bones of nine patients born through meconium-contaminated amniotic fluid with those of 10 patients born through clear amniotic fluid. All patients were examined at less than 17 days postpartum and provided 37 temporal bones for histologic analysis. The volume of contaminant was quantified for each patient. The cases were arranged according to volume of contaminant in the middle ear and compared with clinical information and autopsy findings. Patients with larger volumes of contaminant in the middle ear were born through thick, meconium-stained amniotic fluid (1.9-38 mm3; average 9.3 mm3). Conversely, patients with lesser volumes of contaminant in the middle ear were born through unstained amniotic fluid (none to 3.2 mm3; average 0.9 mm3). We speculate that patients born through thick, meconium-stained amniotic fluid may be at greater risk of sequelae such as otitis media from this foreign body inflammatory reaction in the middle ear and mastoid cavity.

Amniotic Fluid↗
PubMed1989

Prognostic factors and classification in multiple myeloma.

Analyses of prognostic factors have allowed the design of staging systems in different haematological disorders. In a series of 220 patients with multiple myeloma, univariate analysis showed that nine parameters had a significant adverse effect on survival; poor performance status (Karnowsky scaling system less than 70%), infections before diagnosis, renal impairment (assessed either by creatinine clearance greater than 2 mg dl-1 or urea greater than 40 mg dl-1), serum calcium (greater than 10 mg dl-1), severe anaemia (less than 8.5 g dl-1), the presence of Bence-Jones proteinuria, failure to achieve complete remission, more than 40% plasma cells in bone marrow and a low paraprotein index (monoclonal component/% plasma cells: P less than 0.09). In addition, this index correlated significantly with all the other prognostic factors except performance status. The best combination of disease characteristics selected by means of the Cox regression proportional hazards method were performance status and creatinine levels. Additionally, by factor analysis of principal components we obtained a regression equation that included creatinine levels, haemoglobin, performance status and paraprotein index. Using this it was possible to separate the series of patients into three risk categories: A (65 patients), B (69 patients) and C (65 patients) with a median survival of 41, 24 and 12 months, respectively. The model provided similar results to those of the British Medical Research Council, whereas the staging systems proposed by Durie and Salmon, Merlin et al. and Carbone et al. had a lower discriminant value in our series.

Humans↗
PubMed1989

Assessment of two venous drainage techniques in coronary artery bypass graft surgery.

We compared the influence on immediate postoperative cardiac performance, incidence of supraventricular tachyarrhythmia, fluid balance, and respiratory function of two methods of venous drainage during cardiopulmonary bypass (CPB). Two groups of 50 patients were studied. All 100 patients were operated electively for coronary artery bypass grafting. In group 1, cardiac drainage was achieved by using a two-stage cavo-atrial cannula, group 2 patients had drainage cannulae in the superior and inferior vena cava with caval tapes. There were no significant differences between both groups regarding postoperative hemodynamics. Right ventricular stroke work index in groups 1 and 2 differed insignificantly. The incidence of episodes of supraventricular tachyarrhythmia were 19 in group 1 and 23 in group 2 (p NS). Peroperative fluid balance was higher in group 1, but hematocrit during CPB was in the same range. Blood gas analysis values did not differ among the groups during the first 32 hours. The average duration of assisted ventilation was 30.3 +/- 5.4 hours in group 1 and 27.8 +/- 3.1 hours in group 2 (p NS). Thus, in patients undergoing coronary artery bypass grafting with standard techniques of intermittent cardioplegia, double caval cannulation is not superior to single atrio-caval drainage as far as postoperative left and right heart performance, and prevention of supraventricular tachyarrhythmia is concerned. Single cannulation did not increase the risk of undue hemodilution or respiratory dysfunction.

Body Fluids↗
PubMed1989

The sympatho-adrenal tone and reactivity in human hypertension.

In the last two decades, remarkable advances have permitted a better understanding of the modulation of sympathetic tone and reactivity at the sympathetic nerve and at the effector cell levels. In man, several indirect approaches have permitted to suggest the possibility of increased sympathetic nerve activity and reactivity in an important subgroup of essential hypertensive patients. The demonstration of significant correlations between circulating levels of sympathetic transmitters and various parameters of cardiovascular functions supports the hypothesis of a participation of the sympathetic system in the maintenance of an elevated blood pressure in those patients. Moreover, several experimental evidences have indicated that the sensitivity of cardiovascular effector cells may be altered in hypertensive patients. The blunted beta receptor responsiveness and the normal or enhanced alpha receptor responsiveness which were observed suggest the possibility of an imbalance between adrenergic receptor functions in hypertension, which may explain the preferential alpha 1 modulation of blood pressure through changes in peripheral resistance in hypertensive patients. Such an abnormality could contribute to the development of cardiac and vascular wall hypertrophy during the evolution of hypertension. These studies therefore suggest that a variety of sympathetic dysfunctions could play a role in the development, maintenance and evolution of human essential hypertension.

Adrenal Glands↗