Biomedical subjects
Publications and source records attributed to M Guerra.
The authors describe the maxillo-facial and dental anomalies present in a rare polymalformative syndrome: Sotos' syndrome. After having examined the syndrome and reported a case, they propose a therapeutic approach for the treatment of young handicapped cooperating patients.
The authors studied the symptoms, signs and diagnostic procedures in 9 cases of abdominal tuberculosis, six in women, three in men, 17 to 84 and average of 43 years old, who were treated in the Social Security Arnulfo Arias Madrid Hospital Complex in Panama City. In 8 cases the diagnosis was confirmed by biopsy with laparotomy, in 5 with laparoscopy in 1 case because by concomitant lung tuberculosis and improvement with antituberculosis drugs. They present the clinical histories of 2 patients in order to discuss the presenting complaints in abdominal tuberculosis, review the pathology and arouse interest in the study of this entity precisely now that since the initiation of the AIDS epidemic in Panama in 1984 until July 1992 there have been a total of 369 confirmed cases of which 18% had tuberculosis as the first or second opportunistic infection.
In normal subjects increasing atmospheres of absolute pressure (ATA) on the cardiopulmonary system, in a hyperbaric chamber, results in a marked diuresis and an increase of circulating concentration of atrial natriuretic peptide (ANP). The present investigation was designed to determine the effect of ATA in a group of 5 sodium-retaining cirrhotic patients on hydro-saline balance, renin-angiotensin-aldosterone system and ANP. After seven days on a 10 mEq sodium intake, each patient was studied on both a control and experimental (4-hour stay at 2-ATA in hyperbaric chamber) day. On each day, measurement of the following were obtained: plasma ANP, plasma renin activity (PRA) and aldosterone, electrolytes, creatinine clearance, volume and sodium and potassium urinary excretion. The increasing ATA lacked to induce both diuresis, natriuresis and increase in ANP plasma concentration. In these patients baseline, pre-hyperbaric, mean levels of PRA, aldosterone and ANP were 15.5 +/- 11.5 ng/ml/h, 808.4 +/- 360 pg/ml, 86 +/- 10.1 pg/ml, respectively, and were significantly elevated compared with normal range for control subjects without sodium restriction. In conclusion, increasing pressure at 2-ATA, in a hyperbaric chamber is unable to elicit both diuresis and natriuresis as well as modification on ANP and renin-angiotensin-aldo-sterone system in sodium-retaining cirrhotic patients.
BACKGROUND: The aim of the study was to evaluate the variability between four observers in the reading of the tuberculin test (TT). METHODS: The study was carried out in the Centro de Salud Mendiguchía Carriche (Madrid) 72 subjects. By direct inspection, four observers read tuberculin determination (skin induration) independently in each subject. To assess variability, the kappa index (K) was calculated. RESULTS: On considering the variable as a dichotomous one, with a cut-off point of 5 mm was 0.88; and of 10 mm, 0.78. Upon considering the index as qualitative in four categories the kappa index in 0 mm was 0.89; in 1-4 mm, 0.24; in 5-9 mm, 0.40 and greater than 9 mm, 0.79. In eight of the subjects studied, the variability observed in reading the test had conditioned further different clinico-epidemiologic attitudes. CONCLUSIONS: The degree of concordance when reading TT is significantly lower at the 1-4 mm and 5-9 mm intervals.
The potassium bromate (PB) is the flour improving additive for bread making, most widely used in Venezuela. This additive has been reported to have hazardous effects. For this reason it has been forbidden in various countries. In order to find a substitute for PB, the feasibility of using ascorbic acid (AA) in bread making flours was considered. Flours with 80, 40 and 20 ppm of AA were tested and contrasted with an experimental and industrial flour with 80 ppm of PB, maximum quantity allowed by the Venezuelan Legislation. The effect of these additives was evaluated on French bread, of high consumption in our country. It was found that the bread prepared using the flour containing 20 ppm of AA did not present significant differences from those made out of the pattern flour, concerning their organoleptic and physico-chemical properties. It was demonstrated that it is technically feasible to replaced 80 ppm of PB for 20 ppm of AA in the flours, without affecting the bread acceptability.
The mechanisms by which endothelin-1 (ET-1) acts on polymorphonuclear leukocytes (PMN) are insufficiently known. In this study, we assessed the hypotheses that ET-1 is a PMN-aggregating agent, and that platelet-activating factor (PAF) is the principal mediator of ET-1-induced PMN aggregation. ET-1 induced dose-related PMN aggregation, which started 1 min after ET-1 exposure. Two different specific PAF receptor antagonists blocked the effect of ET-1 on PMN aggregation. In addition, ET-1 induced a significant increase in the production of PAF by PMN after 2 to 5 min of ET-1 incubation. ET-1 induced PAF release from PMN rather than accumulation. This PAF production was dependent on intra- and extracellular Ca2+. In this regard, the PAF receptor antagonists significantly blunted the ET-1-induced peak in cytosolic free Ca2+ ([Ca2+]i). Our results, therefore, indicate that ET-1 is effective in causing aggregation of human PMN and that its action appears to be mediated by PAF production via a Ca(2+)-dependent mechanism.
Modulation of phosphoenzyme forms of the Na/K pump by Na+ and K+ was studied by measuring the rate of Pi-promoted ouabain binding to resealed ghosts made from human red cells. This system permits distinguishing the effects of the ions at intracellular and external binding sites. Internal K+, Ki, inhibited the rate of Pi-promoted ouabain binding, contrary to a prediction based on a current model of the pump. External K+, Ko, failed to inhibit ouabain binding in the absence of Ki. However, Ko enhanced the inhibition by Ki. Nai also inhibited ouabain binding; this inhibition was much less affected by Ko than was inhibition by Ki, suggesting that Ki and Nai affect ouabain binding at different internal sites. Nao inhibited ouabain binding in the absence of Ki or Ko, so Nao and Ko also act at different sites. With Nao present, Ki stimulated ouabain binding. Thus a condition was found in which the predicted stimulation of binding by Ki was observed. The results of this study are interpreted in terms of three phosphoenzyme forms of the pump: E1P, E*P, and E2P. E*P is the form binding ouabain with highest affinity. Ki promotes E*P----E2P, thereby inhibiting ouabain binding. Ko binds only to E2P, therefore Ki is required for inhibition by Ko, and there is little E2P present with no Ki. Nao inhibits binding by stabilizing E1P whereas Nai inhibits by stabilizing E1. The stimulation by Ki with Nao present means that Ki and Nao together favor formation of E*P. Furthermore, Ki and Nao may bind to the pump simultaneously. Ki may play a role in the normal pump cycle, binding at allosteric sites to promote E*P----E2P.
A previously described human DNA fragment which is replicated early in S-phase of HL-60 cell DNA (C. Tribioli, G. Biamonti, M. Giacca, M. Colonna, S. Riva, and A. Falaschi, Nucleic Acids Res. 15:10211-10232, 1987) was used to screen a genomic library in lambda Ch28. A clone which contained a 13.7-kb insert (L30E) found to code for several transcripts was isolated. The transcription of L30E DNA exhibited a complex pattern and a tissue-specific and proliferation-dependent type of regulation. The data were consistent with two tandemly arranged transcription units, the 3' end of one separated from the 5' end of the other by a sequence of about 600 bp containing an active promoter. The isolation and sequencing of L30E-specific cDNAs permitted identification of two genes, one of which encoded a B-type human lamin (analogous to mouse lamin B2). L30E DNA was mapped by in situ hybridization at the G-negative subtelomeric band p13.3 of chromosome 19. Interestingly, in synchronized HL-60 cells, L30E DNA is replicated in the first minute of S-phase. Replication of the lamin gene early in S-phase may reflect a coupling between early replication and transcription of genes for S-phase-specific proteins such as lamins.
A randomized, prospective study was performed on 73 male children between 3 and 14 months of age with mild to moderate dehydration caused by acute diarrhea, and who were rehydrated with WHO-ORS, and then at 4 h after admission were fed either cow's milk or an experimental diet based on chicken, plantain, and coconut oil. There were no statistically significant differences in the admission characteristics. The group of children fed cow's milk had a higher total volume of diarrheic evacuations (p less than 0.05). The average duration of diarrhea was 20 h shorter in the group of infants on the milk-free formula. A significant correlation was observed between the volume of diarrhea and the WHO-ORS consumed during the first 48 h, but not to the volume of diet intake.
With a purified Na+/K(+)-ATPase preparation reconstituted into phospholipid vesicles, Na+/K+, Na+/Na+, and uncoupled Na+ transport were studied using three nucleotides and five substrates of the K(+)-phosphatase reaction that this enzyme also catalyzes. For Na+/K+ exchange, CTP was half as effective as ATP and GTP one-twentieth; of the phosphatase substrates only carbamyl phosphate and 3-O-methylfluorescein phosphate produced significant transport and at merely 1% of the rate with ATP. For Na+/Na+ exchange, comparable rates of transport were produced by ATP, CTP, carbamyl phosphate and acetyl phosphate, although the actual rate of transport with ATP was only 2.4% of that for Na+/K+ exchange; slower rates occurred with GTP (69%), 3-O-methylfluorescein phosphate (51%), and nitrophenyl phosphate (33%). Only umbelliferone phosphate was ineffective. For uncoupled Na+ transport results similar to those for Na+/Na+ exchange were obtained, but the actual rate of transport was still slower, 1.4% of that for Na+/K+ exchange. Thus, not only nucleotides but a variety of phosphatase substrates (which are phosphoric acid mixed anhydrides) can phosphorylate the enzyme at the high-affinity substrate site to form the E1P intermediate of the reaction sequence. Oligomycin inhibited Na+/K+ exchange with ATP by half, but with carbamyl phosphate not at all; with CTP the inhibition was intermediate, one-fourth. By contrast, oligomycin inhibited Na+/Na+ exchange by one-fifth with all three substrates. A quantitative, steady-state kinetic model accounts for the relative magnitudes of Na+/K+ and Na+/Na+ exchanges with ATP, CTP, and carbamyl phosphate as substrates, as well as the extents of inhibition by oligomycin. The model requires that even when Na+ substitutes for K+ a slow step in the reaction sequence is the E2 to E1 conformational transition.
We report 20 cases of post-traumatic boutonnière deformity treated by a modification of the direct anatomical repair technique, particularly indicated in late cases which have complete passive motion. A swallow-tailed flap is excised from the fibrous tissue between the two ends of the central slip. The proximal one is then advanced up to the coaptation with the distal edge of the scarred capsular tissue at the insertion on the middle phalanx to which it is sutured in correct tension. Excellent results have been obtained in 72% of cases and good in 5.5%. The 16% of fair results are probably due to the fact that patients didn't use the splint post-operatively and didn't cooperative with physiotherapy.
The rationale for orthodontic/surgical management of dentofacial deformities was reviewed for single and double jaw problems. Coordinated interdisciplinary work-ups and treatment modalities can produce predictable results. In well-selected cases, esthetics and functional stability are greatly enhanced by the combined technique.
The mouth breathing is a multidisciplinary problem; in fact, when the orthodontist finds a patient with altered dento-skeletal growth due to this abnormal mode of breathing, to establish a correct treatment planning, he needs to be supported [correction of comforted] by ear, nose and throat examinations. Among these, the tympanogram, because of its simple execution and of the interesting data obtained, has a very important role in the orthodontic approach of the oral breather.
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To help characterize the Na,K-ATPase active site with enzyme incorporated into phospholipid vesicles, the activities with alternative substrates were compared, 22Na/Na-transport was equivalent with ATP, CTP, carbamylphosphate and acetylphosphate, but slower with CTP, 3-O-methylfluoresceinphosphate (3-O-MFP), nitrophenylphosphate and umbelliferonephosphate. It indicates a slower rate of formation of phosphorylating enzyme complex in conformation position of E1 (E1P) when the second group of substrates is bound with enzyme active center. 22Na/K-transport was half as effective with CTP as with ATP and was far slower with the other substrates. It indicates a more stringent selectivity at the low-affinity site of enzyme in conformation E2 that accelerates the slow step of this transport mode. Although enzyme modification with fluoresceinisothiocyanate blocks the high-affinity site to ATP, the K-phosphatase reaction catalyzed by E2 is retained, even with a substrate, 3-O-MFP, that binds to the adenine pocket. Dimethylsulfoxide inhibits hydrolysis of the nucleotides and of the carboxylic phosphate substrates of the K-phosphatase reaction, but stimulates hydrolysis of the phenolic phosphate substrates (nitrophenylphosphate and umbelliferone phosphate) which normally are hydrolyzed more slowly than the other substrates. On the basis of these data the authors propose the model of Na,K-ATPase active center.
We have previously shown that Na,K-ATPase activity (the enzymatic machinery for the sodium pump) in brain areas such as the medial basal hypothalamus (MBH) and the preoptic-suprachiasmatic region (POSC) can be changed by experimental manipulations of gonadal function. We now report enzyme levels in brain regions as related to hormonal changes occurring during sexual behavior. Male rats were exposed to receptive females and decapitated immediately after displaying one of the following behavioral events: the start of copulatory activity, first ejaculation, and the beginning of a second copulatory series. A group of noncopulating animals were used as control. The variables measured included serum levels of LH, PRL and testosterone and Na,K-ATPase activity in MBH, POSC and parietal cerebral cortex (CC). A steady increase in enzyme activity in the POSC, but not the MBH or CC, was found in copulating animals. Serum LH levels changed in a similar fashion. A sharp increase in serum PRL levels, seemingly related to ejaculation, was also observed. These data are consistent with our previous findings on monoaminergic neurotransmission in brain regions related to male sexual behavior.
We performed real time echotomographic studies in 203 patients with a clinical diagnosis of obstructive jaundice. All patients were operated on and a diagnosis of choledocholithiasis was established in 125. The same diagnosis had been made by echo in 69 of them for a 63% sensitivity rate. The specificity was 92% and the positive predictive value 93%. An improvement in sensitivity from 52 to 80% and in specificity from 91 to 94% along the 3 year study period was detected. This high yield of the echographic study, not widespread in the literature, may be attributed to a careful study of the intrapancreatic section of the common duct were 92% of the stones were found. Also, the experience and training of the radiologist performing the examination is essential.
An empiric correlation between the inflamed gingiva and hormonal variations during physiological conditions such as pregnancy and menstrual cycle is already known. The demonstration of specific steroid receptors in human gingiva has suggested a relationship between the ovarian hormones and the dimensional changes of the gingiva. In this work, estrogen and progesterone receptors in healthy and inflamed gingiva have been studied.