Search PubMed⌕ Search

Biomedical subjects

G Morales

Publications and source records attributed to G Morales.

At least 55 records · Page 3Linked to original sources
PubMed1993

Induction of axonal growth by heterophilic interactions between the cell surface recognition proteins F11 and Nr-CAM/Bravo.

F11 and Nr-CAM/Bravo are two axon-associated glycoproteins belonging to different subgroups of the immunoglobulin superfamily. In this report we have investigated the interaction of both proteins using neurite outgrowth and binding assays. Antibody blocking experiments demonstrate that neurite extension of tectal cells on immobilized F11 is mediated by Nr-CAM/Bravo. Binding studies further reveal a direct heterophilic interaction between F11 and Nr-CAM/Bravo. This activity can be mapped to the amino-terminal second or third immunoglobulin-like domain within F11 with domain-specific monoclonal antibodies and deletion mutant proteins expressed on COS cells. Furthermore, perturbation experiments with domain-specific monoclonal antibodies demonstrate that this region is required for adhesion and neurite extension.

Animals↗
PubMed1993

Correlation between esophageal motility and 24-hour pH recording in patients with gastroesophageal reflux.

The relationship between manometric and pH-metric data was studied in a group of 50 patients with symptoms of gastroesophageal reflux. Using a multiple regression analysis, we found that the total percentage of reflux was significantly correlated to the infradiaphragmatic length and resting pressure of the lower esophageal sphincter and also to the mean amplitude of the contractile waves of the distal esophagus, thus revealing the important role of these factors in the antireflux mechanism. When the patients were divided into groups according to their manometric characteristics and the values of the various pH-metric parameters between these groups compared using a one-way analysis of variance, we found that the amplitude of the contractile waves and the percentage of deglutitions without response were related not only to the total percentage of reflux but also to the number of reflux episodes of greater than 5 min duration and to the duration of the longest episode. This shows that prolonged exposure of the esophageal mucosa to the refluxed material may be due, in part, to an alteration in the capacity for esophageal clearing.

Adolescent↗
PubMed1992

Reversible achalasia-like motor pattern of esophageal body secondary to postoperative stricture of gastroesophageal junction.

Two cases are presented of benign stenosis of the cardia secondary to fibrosis following antireflux surgery in which the patients developed a motor alteration in the esophageal body similar to that of achalasia of the cardia. There was a complete absence of contractions in one patient, which had developed over a long period of time, and a vigorous pattern in the other patient, which had evolved over a short period. In both cases, after surgical treatment of the stenosis, normal motility in the esophageal body returned.

Adult↗
PubMed1992

Long-term results of Nissen fundoplication in reflux esophagitis without strictures. Clinical, endoscopic, and pH-metric evaluation.

The present paper evaluates the efficiency of Nissen fundoplication as an antireflux technique in a series of 51 patients with different grades of esophagitis. Follow-up time averaged 6.6 years. The evaluation includes a clinical assessment, endoscopic study, and 24-hr pH monitoring. The results reveal an acceptable rate of recurrences, with clinical (9.8%) being less frequent than endoscopic (13.7%) or pH-metric (19.6%) recurrences. Side effects appeared in 37.3% of the patients (mainly inability to belch or vomit, and postprandial fullness), which were mild and transitory in most cases. Nissen fundoplication proved effective in controlling long-term gastroesophageal reflux, as over 80% of the patients presented an excellent-to-good clinical situation, without or with minimal digestive consequences.

Adult↗
PubMed1992

Outreach to injecting drug users and female sexual partners of drug users on the lower east side of New York City.

In 1984, outreach to injecting drug users and their female sexual partners was initiated as part of HIV behavioral research projects. HIV, health, drug treatment and family planning information and services were provided in addition to recruiting subjects to the research program. Such outreach also poses certain problems--especially potential disruption of neighborhood day-to-day life and clashes with police. This paper discusses an outreach program to injecting drug users and their female sexual partners that was initiated in New York City to provide HIV-related information and services. We examine the successes of the program and problems that were involved in conducting outreach to persons who are typically not accessible through formal institutional channels.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Impaired atrial natriuretic factor systemic clearance contributes to its higher levels in uremia.

To evaluate the interaction between plasma levels and the systemic uptake of atrial natriuretic factor (ANF) with thyroid hormone levels during acute renal failure (ARF), seven groups of rats were analyzed: Group 1, Controls (C); Group 2, ARF; Group 3, filtering kidney with uremia; Group 4, ARF with thyroxine (T4) supplement (ARF + T4); Group 5, thyroidectomy (Tx); Group 6, ARF on Tx rats (Tx + ARF); Group 7, Tx + ARF supplemented with T4 (Tx + ARF + T4). Plasma creatinine (Cr), urea, T4, blood volume, and ANF were measured; ANF half-life (ANF t1/2; expressed in seconds) was calculated. Rats with ARF developed uremia (Cr, 377 +/- 58 versus 41 +/- 5 mumol/L), significant reduction in T4 (40 +/- 4 versus 89.2 +/- 6 nmol/L). elevation of ANF (287.7 +/- 35 versus 60.9 +/- 8 fmol/mL), and lengthening of ANF t1/2 (69.7 +/- 8 versus 37.2 +/- 6 s) compared with C (P less than 0.01). T4 supplements to ARF rats resulted in a lesser degree of uremia (Cr, 283 +/- 27; P less than 0.05) and normalization of ANF t1/2 (31.4 +/- 5); however, ANF levels remained higher than C (100.4 +/- 11.4 versus 60.9 +/- 8; P less than 0.01). Tx by itself did not change either parameter. The filtering kidney with uremia group developed mild uremia (Cr, 199 +/- 8), T4 fell (58 +/- 8), ANF levels rose (83.4 +/- 5.4), and ANF t1/2 was prolonged (54.5 +/- 12). Tx before ARF doubled the ANF level and lengthened ANF t1/2 similarly than in ARF. T4 addition (Tx + ARF + T4) normalized ANF t1/2 (29.8 +/- 3) in spite of a persistently high ANF (145.7 +/- 21). Blood volume did not change in any group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Can pH recordings suggest defective esophageal peristalsis in patients with gastroesophageal reflux?

The data provided by 24-h pH monitoring in 40 patients with gastroesophageal reflux, divided in three groups in accordance with esophageal motor pattern, were compared. Patients with hypomotility had significantly greater reflux rates than those with normal motility or hypermotility, if we consider both total time with pH < 4 and time with pH < 4 corresponding to episodes of > 5 min duration. We conclude that when 24-h pH monitoring shows very high reflux rates, basically corresponding to episodes lasting > 5 min, we should suspect the presence of defective esophageal peristalsis, which must be confirmed with a manometric study.

Adolescent↗
PubMed1992

Clinical and epidemiologic studies of Chagas' disease in rural communities of Oaxaca, Mexico, and an eight-year followup: II. Chila.

A seroepidemiologic survey conducted in 1971 in the rural Pacific coastal community of Chila in the Mexican state of Oaxaca showed an unusually high prevalence of antibody against the Chagas' disease agent Trypanosoma cruzi. Further studies were undertaken in 1973 and 1981 to (1) determine the pathologic impact of T. cruzi infection in humans, (2) investigate the natural history of the disease, (3) confirm that serologically positive persons were parasitologically positive, and (4) evaluate whether T. cruzi transmission continued into the next decade. This article reports results derived from those studies.

Adolescent↗
PubMed1991

Colonic motility: electric and manometric description of mass movement.

"Mass movement" was described at the beginning of the century by radiologists who occasionally observed how, during their explorations, barium was transported suddenly from one section of the colon to another. In the present study we wanted to center our attention on electromechanical activities accompanying large evacuations via the colostomy, as we believe that they are an expression in myoelectric and pressure terms of the "mass phenomenon" described by radiologists. To do this, we designed an electromyographic recording probe to which we attached a conventional microtransducer probe, joining them by suction. With this method we made 24-hour recordings in eight patients with sigmoid colostomy. We witnessed five large evacuations. When the electric and pressure activities that occurred a few minutes before the evacuation were analyzed, we observed that there were two clearly different phases. The first, which we call "Preliminary Phenomenon," consists of a series of contractions and spiking potentials averaging 5.6 minutes (SD 2.22); after this the "Big Contraction" appears, with mean pressure values of 127 mm Hg (SD 38.77) and mean electric values of 10.6 mV. The duration of this phenomenon averaged 24.93 seconds (SD 6.19), recorded almost simultaneously at the three recording sites studied. There is no doubt that these electro-pressure phenomena resulted in a mass transport, as we observed an intense evacuation via the colostomy in the five patients.

Colon↗
PubMed1990

Sequence and expression of the Drosophila phenylalanine hydroxylase mRNA.

We report the cloning, nucleotide (nt) sequence and expression of the cDNA (pah) encoding phenylalanine hydroxylase (PAH) of Drosophila melanogaster. The strong hybridization signals observed in genomic blots when D. melanogaster DNA was probed with 32P-labeled human pah cDNA, indicated the existence of a high degree of sequence similarity between the pah genes of both species. The length of the pah genomic fragment is about 30 to 40 kb. The cDNA contains 84 bp of the 5'-untranslated region, 1359 bp of the protein-coding region and 87 bp of the 3' region, with only one polyadenylation signal. The isolated cDNA is probably full-length, since the size of the D. melanogaster PAH mRNA is 1.5 kb. At the nt level, the similarity of the D. melanogaster cDNA with human and rat pah cDNAs is 57.9% and 58.1%, respectively. The highest similarities are restricted to the nt sequence coding for the presumed hydroxylation domain. There is no nt sequence similarity between the first three exons of the human pah gene and an equivalent fraction of the D. melanogaster pah gene. At the amino acid (aa) level, the similarity in the presumed hydroxylation domain is 88.5%, in which two motifs of the structure AGLLSSXXXL are found, where X represents any aa. It was interesting to notice the conservation of aa 408, 311 and 280, where mutations are associated with phenylketonuria in humans. We observed, moreover, that, as it occurs in humans and rats, the expression of the D. melanogaster pah gene is tissue-specific and temporally regulated.

Amino Acid Sequence↗
PubMed1989

Molecular cloning of a Drosophila potential Z-DNA forming sequence hybridizing in situ to a developmentally regulated subdivision of the polytene chromosomes.

We describe the selection of a group of plasmids with potential to form Z-DNA, from libraries of Drosophila hydei nuclear DNA using anti Z-DNA monoclonal (22) or polyclonal (10c) antibodies. The supercoiled closed circular forms of most of the selected recombinant plasmids from the 10c Z-DNA library show affinity to the polyclonal 10c antibody as indicated by DNA binding assays. One of these plasmids, pF17, was selected for further study. The insert in this plasmid adopts the Z conformation at bacterial supercoiled density. Analysis of deletion plasmids indicates that a Z-epitope is located within a short fragment of the insert in which 3 GC repetitions are found. The Drosophila DNA insert in pF17 hybridizes in situ with locus 4-75C1-2 of the polytene chromosomes, a locus whose transcriptional activity is developmentally regulated during the third instar.

Animals↗
PubMed1986

Drinking patterns of inner-city black Americans and Puerto Ricans.

Alcoholic patients--183 Black Americans (62 women) and 132 Puerto Ricans (18 women)--at an inner-city alcoholism treatment program were surveyed using the Drinking History Questionnaire. Significantly more Puerto Rican men than Black men reported drinking distilled spirits, daily drinking, drinking in the morning to relieve a hangover, shakes when sobering up, blackouts when drinking, convulsions after a bout, psychoperceptual withdrawal symptoms and alcohol-related marital difficulties. Puerto Rican women were significantly older at the first time of drunkenness than the other groups. These women tended to drink at home daily and they reported a surprisingly high mean alcohol consumption. Significantly more Black women reported drinking to make friends. The tendency for Blacks to drink with their spouse, and to encourage their spouse to drink, was a major finding. This finding may have clinical implications for treatment and suggests that in lower class Black alcoholics a careful history of the drinking patterns of the spouse or living companion should be taken to determine the proper treatment approach.

Adaptation, Psychological↗