PubMed Health⌕ Search

Biomedical subjects

M Bustamante

Publications and source records attributed to M Bustamante.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Significance of the determination of antineutrophil cytoplasmic antibodies (ANCA) in ulcerative colitis and Crohn's disease].

We have studied prospectively 126 consecutive patients recruited with a known diagnosis of ulcerative colitis (UC; n = 78) and Crohn's disease (CD; n = 48) for anti-neutrophil cytoplasmatic antibodies (ANCA) by indirect immunofluorescence (IFI). Forty-six percent of UC and 18% of CD patients were found positive. The sensitivity and specificity for UC diagnosis were 0.46 and 0.81, respectively. We evaluated the pattern of IFI exhibited (perinuclear: pANCA and cytoplasmatic: cANCA). cANCA was found in 77% of CD and in only 30% of UC patients (p = 0.01). Sera from all CD patients were positive at a 1:20 dilution (and not at higher dilution) and it occurred in only in 14 UC patients (30%). Positive sera were also tested to characterize the antigen specificity by enzyme-linked immunosorbent assay (ELISA) but the antigenic nature of ANCA could not be identified in most cases. No differences were found between ANCA positive and ANCA negative patients regarding colonic extension (UC) or colonic involvement (CD), activity and colectomy. We conclude that ANCA may be a helpful diagnostic test in UC patients but it not seems to be important as a marker of activity. ANCA positivity can reflect disease heterogeneity in UC patients, perhaps discriminating those with immunologic disturbances.

Adolescent↗
PubMed1998

Relationship between smoking and colonic involvement in inflammatory bowel disease.

UNLABELLED: The effects of smoking on the onset and clinical course of inflammatory bowel disease (IBD) have been widely debated. Although smoking appears to have a clearly unfavorable effect on the course in Crohn's Disease (CD), the relationship between smoking and localization of the disease is less clear. AIM: To evaluate, in our group of patients, the relationship between smoking and the development of ulcerative colitis (UC) or CD, and between smoking and the localization of CD in the large bowel or in other sites. PATIENTS AND METHODS: The smoking habits of 171 patients at the time of diagnosis were assessed with a questionnaire. Subjects were classified into three subgroups as smokers, nonsmokers and ex-smokers. Current smokers were grouped according to their level of consumption as those who smoked fewer than or more than 10 cigarettes per day. A total of 161 patients were studied (UC n = 69, CD n = 92). Patients with CD were divided into those with colonic disease and those with no colonic involvement. We evaluated the relationship between smoking and the form of IBD, localization (colonic or noncolonic) and the presence of perianal disease (PAD) in CD. The results were analyzed with the chi-squared test. RESULTS: Smoking was more frequent in patients with CD than in those with UC (72.8% vs 31.9%). Among patients with CD, more patients without colonic involvement were smokers (84.6% vs 64.2%). However, among patients with CD involving the colon, smoking was significantly more common (64.2%) than among patients who had UC (31.9%). CONCLUSIONS: Our findings confirm a relationship between smoking and CD. Smoking seems to be associated with some degree of protection of the colonic mucosa, especially in heavy smokers.

Adolescent↗
PubMed1996

Effects of individual vs group penning on the performance of weanling pigs.

Two experiments (five trials) were conducted to determine the effects of individual vs group penning on the performance of 4-wk-old crossbred barrows and gilts. In each experiment, half the pigs were tested in a group pen (four pigs) for two 7-d periods and individually for one 7-d period and the other pigs were fed individually for two periods and as a group for one period. In Exp. 1 (two trials, each with five replicates of eight pigs), individually penned pigs had physical and visual contact with pigs in the adjoining pens; in Exp. 2 (three trials, each with five replicates of eight pigs), such contact was denied. Growth rate, feed intake, and feed efficiency were determined at the end of each period. In addition, during Trial 3 of Exp. 2 blood samples were collected at the end of each period and plasma was assayed for cortisol and triiodothyronine (T3) concentrations. Penning sequences produced inconsistent weight gains and feed intake. Differences in gain favored (P < .04) the individually penned pigs during Trial 3 of Exp. 2 and differences in feed intake favored the individually penned pigs during Trial 2 of Exp. 1 (P < .009) and during Trials 2 and 3 of Exp. 2 (P < .02 and P < .009, respectively). Penning treatment had no effect on feed efficiency, plasma cortisol, or T3 concentrations. These data suggest that pigs perform equally well whether fed and housed individually or in groups, with no indications of stress associated with individual pens and isolation.

Aging↗
PubMed1995

Ser-127-to-Leu substitution in the DNA gyrase B subunit of Streptococcus pneumoniae is implicated in novobiocin resistance.

We report the cloning of the gyrB gene from Streptococcus pneumoniae 533 that carries the nov-1 allele. The gyrB gene codes for a protein homologous to the gyrase B subunit of archaebacteria and eubacteria. The same amino acid substitution (Ser-127 to Leu) confers novobiocin resistance on four isolates of S. pneumoniae. This amino acid position is equivalent to Val-120 of Escherichia coli GyrB, a residue that lies inside the ATP-binding domain as revealed by the crystal structure of the protein.

Amino Acid Sequence↗
PubMed1994

The prevalence of childhood asthma in Costa Rica.

The prevalence of asthma in children between the ages of 5 and 17 years in Costa Rica was determined using a large sample (n = 2682). The definition of asthma was based on a combination of a physician's diagnosis and a symptom score, using information from a questionnaire given to the parents. An overall asthma prevalence as high as 23.4% was found. Sex, age, urban/rural location, or rain precipitation did not show any association with the diagnosis of asthma. The presence of smokers in the home was found to be an important risk factor (odds ratio = 1.6). Another identified risk factor was a high yearly average outside temperature, i.e. above 25 degrees C (odds ratio = 1.8). Furthermore, the proportion of children with more than four upper respiratory infections during the preceding year was found to be significantly increased in children with asthma (odds ratio = 4.3). The non-asthma group seemed to use equal amounts of drugs for the treatment of asthma as the asthma group. For a country like Costa Rica with limited economic resources the current work indicates two important issues for consideration in the future; firstly, to try to define the cause(s) of asthma and secondly, to continuously inform the physicians about the best way of diagnosing and treating asthmatic patients to ensure optimal handling of this large patient group.

Adolescent↗
PubMed1990

[Frequency with which semiquantitative expressions are used in Mexican medical literature].

OBJECTIVE: To describe the frequency with which semiquantitative expressions are used in Mexican medical journals. STUDY DESIGN: [corrected] Comparative survey. Frame of reference. Four Mexican medical journals considered representative of the medical literature in Mexico were studied (Revista de Investigación Clínica, Archivos de Investigación Médica, Revista Médica del IMSS and the Boletín Médico del Hospital Infantil de México). STUDY UNITS: Ten articles randomly selected and considered as original research material published in 1987 from each journal were used. MEASUREMENTS: Eight terms were identified in each text of the selected articles: almost always, very probably, probable, probably, frequent, possible, improbable and almost never. MAIN RESULTS: One hundred and fifty three expressions were identified, for a global average of 3.8 expressions per article. No statistical significant differences were found between the journals in relation to the frequency with which the expressions were used (P = 0.76). When comparing the chapters of each article, significant statistical differences were found which disappeared when the comparison was rated. In 89% of the cases, the expressions did not have a referral which therefore did not allow for their quantification. Finally, those articles defined as "clinical" had a greater frequency of semiquantitative expressions than those considered as "biomedical" (4.2 vs 1.3 on the average, respectively). CONCLUSIONS: On the average, semiquantitative expressions are used four times per article, 75% of the times without a referral which would allow to quantify them, which could condition for a wide variety of interpretations on behalf of the readers.

Mexico↗
PubMed1989

[Secondary and residual choledocholithiasis. Our experience].

A retrospective study was made of 780 patients who underwent surgery of the biliary tract for lithiasis between 1973 and 1984; of them, 110 (14.1%) presented secondary choledocholithiasis and 14, residual choledocholithiasis. The decade of highest incidence of choledocholithiasis was 60 to 70 years; the proportion of women-men was 2:1. The predominant symptom was biliary colic, which occurred in 99% of patients; jaundice appeared in 65% of cases. In 5.6% of patients choledocholithiasis was complicated with suppurative cholangitis. The operation most frequently practiced was choledochotomy with extraction of calculi and closure on a Kehr tube, performed in 50% of patients, followed by transduodenal sphincteropapillotomy in 31% of patients. In 32 patients complications occurred during the immediate postoperative period, representing a morbidity of 22.5% and a mortality of 3.2%. The most frequent complications were of infectious nature.

Adolescent↗
PubMed1982

Increased activity of the renin-angiotensin-aldosterone system during the perinatal period.

Plasma renin activity (PRA), plasma renin substrate (PRS), plasma renin concentration (PRC), and plasma aldosterone concentration (PAC) were measured in normal full-term newborn infants and infants up to 22 days after birth (36 in all). As compared to the control, PRA and PAC levels were significantly higher (p less than 0.001) in cord blood, and in 2 to 6 and 12 to 22 day old infants. The high values of PRA in 2 to 6 day old infants were due to the high PRS values. In cord blood and in 12 to 22 day old infants, however, the high levels of PRA reflect elevation of PRC. No correlation was found between PRA, PAC and serum potassium in cord blood and in 2 to 6 day old infants, but there was a significant correlation between the parameters (r = 0.72 and p less than 0.02) in 12 to 22 day old infants, indicating that at this age, as in healthy adults, the renin-angiotensin system and serum potassium seem to be the major stimuli for aldosterone secretion.

Adult↗
PubMedDate not supplied

[Study of the sentinel node in breast cancer using lymphoscintigraphy and a fast method for cytokeratin].

INTRODUCTION: Histopathological examination of the axillary sentinel node (SN) is becoming a routine procedure in the surgical phase of infiltrating ductal carcinoma of the breast (IDC). The SN exam may yield false negative cases mainly due to identification failure of the SN but some of the false negative cases may be the result of the pathological examination procedure applied. MATERIAL AND METHODS: Sixty two (62) cases of clinically staged N0 IDC of the breast by TNM nomenclature were assigned to breast surgery along with conventional axillary node dissection. The identification technique included lymphoscintigraphy and intraoperative gamma-detecting probe after peritumoral injection of 99mTc-labeled colloids.The histological study of SN was performed with paired 4 microm slices and staining with hematoxylin-eosin and with a fast method of cytokeratins for freezing. RESULTS: In only two of the 62 patients, it was not possible to identify the SN. Eighteen of the remaining 60 had SN involvement by metastasis, having no metastases in the other nodes of the axillary dissection in 6 of them. Ten of those were micrometastasis (size of metastasis= or <0.2 cm). In two out of these last 10 cases, diagnosis of the micrometastasis was only possible using slices stained with CK. There were no false negative results. CONCLUSIONS: The lymphoscintigraphy, after peritumoral injection of small volumes and low dose of the tracer, makes it possible to obtain excellent results in the intraoperative detection of the SN in breast cancer. The study of this SN with a fast method for CK decreases the number of false negative results of the technique.

Breast Neoplasms↗
PubMedDate not supplied

Intensive care during prolonged anhepatic state after total hepatectomy and porto-caval shunt (two-stage procedure) in surgical complications of liver transplantation.

BACKGROUND/AIMS: Recently, total hepatectomy and temporary porto-caval shunt has been indicated in surgical complications of liver transplantation. Four cases of liver transplantation which presented liver hemorrhage at the time of implant, and a 5th case with surgical trauma of hepatic hilum are presented. METHODOLOGY: The graft was removed and a porto-caval shunt was performed in all patients. Retransplantation was possible in all recipients, after an anhepatic period of 16-24 hours. RESULTS: Early persistent ionic hypocalcemia and late olyguric renal failure were the most constant and prominent complications during the anhepatic period. Two patients died of renal failure and respiratory distress syndrome at 6 and 28 days, respectively, after liver transplantation. The other 3 patients are alive and without complications at 48, 33 and 11 months of follow-up. CONCLUSIONS: Total hepatectomy with a temporary porto-caval shunt and later retransplantation must be considered as a useful procedure for surgical complications of liver transplantation which may not be treated using other techniques. Special attention should be paid to preserve renal function in the anhepatic state in order to improve survival in similar cases of two-stage liver transplantation.

Adolescent↗