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D Bustos

Publications and source records attributed to D Bustos.

At least 19 recordsLinked to original sources
PubMed2000

Conversion from azathioprine [correction of azathioprina] to mycophenolate mofetil in pediatric renal transplant recipients with chronic rejection.

BACKGROUND: Chronic rejection is the leading cause of graft failure. Both nonimmunological and immunological mechanisms contribute to this pathology. METHODS: We studied changes in kidney function, mixed lymphocyte culture, cell-mediated lympholysis, serum HLA class I antigens, cytotoxic antibodies, and lymphocyte population before and after 6 months of follow-up in 22 pediatric renal transplanted patients. The immunosuppressive protocol used was: cyclosporine, azathioprine, and corticosteroids. Eight patients demonstrated chronic graft rejection (by biopsy), group I; and eight patients had no clinical evidence of chronic and/or acute rejection, group II. Substitution of mycophenolate mofetil (MMF) (600 mg/m2 bid for azathioprine was done in patients of groups I and II. Another six patients with chronic rejection, did not receive MMF, group III. RESULTS: Creatinine clearance increased in group I (44+/-5 vs. 51.1+/- ml/min/1.73 m2, P<0.03) but it decreased in group III (30+/-3 vs. 25+/-2, P<0.01). Urinary protein excretion decreased only in group I (0.3+/-0.03 to 0.06+/-0.03 g/24 hr, P<0.03). During MMF therapy antidonor mixed lymphocyte culture decreased 62 and 70% (P<0.05) in group I and II. Cell-mediated lympholysis against lymphocyte of the donor decreased 65% (P<0.05) in group I. Cell-mediated lympholysis toward control cells decreased 54% (P<0.01) in group II. Serum HLA class I antigens, only decreased from 0.7+/-0.1 to 0.5+/-0.1 microl/ml, P<0.05, in group I. CD19+ decreased from 7.9+/-1.1 to 5.6+/-0.8%, P<0.05, and 7.8+/-1.2 to 5.5+/-0.9%, P<0.05, in groups I and II, respectively. CD16+ increased from 5.7+/-1.1 to 8.6+/-1.3 (P<0.05) only in group I. CONCLUSIONS: Our data suggest that substituting MMF for azathioprine therapy leads to an improvement in the immunosuppression and renal function in children with on-going chronic rejection.

Adolescent↗
PubMed2000

Biologically active alkaloids and a free radical scavenger from Prosopis species.

The biological activity of extracts from the aerial parts of five Argentinian Prosopis species and the exudate of P. flexuosa were assessed for DNA binding, beta-glucosidase inhibition and free radical scavenging effect using the DPPH decoloration assay. DNA binding effect was found mainly in the basic fraction. The alkaloids tryptamine as well as piperidine and phenethylamine derivatives were isolated from the basic extracts. At 0.50 mg/ml, DNA binding activities ranged from 28% for tryptamine to 0-27% for the phenethylamine and 47-54% for the piperidine derivatives. Tryptamine and 2-beta-methyl-3-beta-hydroxy-6-beta-piperidinedodecanol showed a moderate inhibition (27-32%) of the enzyme beta-glucosidase at 100 microg/ml. The exudate of P. flexuosa displayed a strong free radical scavenger effect in the DPPH decoloration assay. The main active constituent was identified as catechin.

Alkaloids↗
PubMed2000

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Journal Article↗
PubMed2000

Quantification of fecal neutrophils by MPO determination (myeloperoxidase) in patients with invasive diarrhea. Cuantificación de neutrofilos fecales mediante la determinación de MPO (Mieloperoxidasa) en pacientes con diarrea invasiva.

Myeloperoxidase (MPO), a specific polymorphonuclear leukocyte enzyme, has been used previously to quantify the number of neutrophils in tissue. MPO activity was found to be linearly related to the number of neutrophil cells. In an attempt to use this method in leukocytes measuring in stool, fecal MPO was solubilized with hexadecyltrimethylammonium bromide and the MPO activity was measured by a dianisidine-H2O2 assay. Stools from 10 normal subjects and 39 patients with diarrhea produced by enteropathogenic bacteria were examined for leukocytes by MPO activity as well as microscopically using methylene blue stain, MPO activity was positive in 36 patients (92%) and leukocytes were present by microscopic observation in 30 (77%). Fecal leukocytes were not found in healthy controls and the MPO activity was undectable. Stool MPO activity had a range of from 1.6 to 2,830.0 x 10(3) UMPO per gram of feces (median 460.0). The number of neutrophils obtained through MPO activity had a range of 6.0 to 13,216.0/ mm3 (median 1,261.0). Fecal MPO activity is a simple biochemical assay for the detection and quantification of fecal leukocytes.

Diarrhea↗
PubMed1998

Primary mycotic aneurysm of the ascending aorta diagnosed by transesophageal echocardiography.

Primary mycotic aneurysms are rare, and they can be difficult to diagnose before rupture. Early diagnosis is the cornerstone to effective management. Preoperative diagnosis has traditionally involved angiography and computed tomography. We report a case of Staphylococcus aureus aortitis with an aortic wall abscess and posterior pseudoaneurysm formation involving the ascending aorta in which transesophageal echocardiography was fundamental in diagnosis and patient management.

Abscess↗
PubMed1998

Colonic proteinases: increased activity in patients with ulcerative colitis.

In order to study the colonic intraluminal proteinase-antiproteinase imbalance under inflammatory conditions, we determined proteolytic activity (PA), alpha-1-antitrypsin and the activities of trypsin, chymotrypsin and neutrophil elastase in feces from patients with ulcerative colitis (UC) comparing the results with a control group. A fecal sample was obtained from each 25 patients with ulcerative colitis and 10 control subjects were studied. The severity of the disease was assessed by the Truelove index. Proteolytic activity was measured using azocasein as proteolytic substrate. The fecal concentration of alpha-1-antitrypsin was measured by radial immunodiffusion and the activities of the enzymes were measured using specific substrates. We found an increase in fecal PA, alpha-1-antitrypsin and neutrophil elastase in patients with UC and the correlation between the severity of the disease and the PA was statistically significant (r = 0.62, P < 0.05). We conclude that elevated colonic proteinase activity could contribute to the pathophysiology of ulcerative colitis.

Chymotrypsin↗
PubMed1997

In vitro response of Plasmodium falciparum to atovaquone and correlation with other antimalarials: comparison between African and Asian strains.

Atovaquone (dihydroxynaphthoquinone 566C80) is a broad-spectrum antiprotozoal compound demonstrating potent antimalarial activity against multidrug-resistant malaria. We present the results of in vitro drug sensitivity tests of 142 Plasmodium falciparum isolates, 108 from 14 countries of West and Central Africa, 32 from the Philippines, and one each from Laos and Myanmar. These were tested in vitro against nine drugs: the classic antimalarials chloroquine, quinine, mefloquine and halofantrine, the four qinghaosu derivatives, artemisinin, artemether, artesunate, and arteether, and the new compound atovaquone. Results showed the Asian strains have a higher median 50% inhibitory concentration (IC50) to almost all drugs compared with those from Africa. This was significantly different for chloroquine, halofantrine, and artemisinin. We used three different approaches to estimate the threshold for resistance of atovaquone to be approximately 5-7 nmol/L. The global median of 96 pooled strains is 1.4 nmol/L and the 90th percentile is 5.5 nmol/L for atovaquone. There were no correlations of atovaquone with the eight other antimalarials among African strains, but significant correlations, except for halofantrine, were observed among Asian strains. The absence of a correlation between atovaquone and the other available drugs indicates the potential of atovaquone as an alternative antimalarial in Africa. The correlation observed among Asian strains, however, suggests that atovaquone has to be used cautiously in Asia. Nevertheless, the association with proguanil in recently concluded clinical trials in Europe, South America, Asia, and Africa has demonstrated its antimalarial efficacy.

Africa↗
PubMed1996

Abnormal fecal flora in a patient with short bowel syndrome. An in vitro study on effect of pH on D-lactic acid production.

D-Lactic acidosis associated with encephalopathy is a clinical condition that occurs in patients with short bowel syndrome. We studied the fecal flora and the composition of fecal water of a child who developed this unusual disorder. Bacteriological studies showed that the patient's stool contained a marked predominance of gram-positive anaerobes. Two strains were identified, Lactobacillus plantarum and Lactobacillus salivarius, as the main bacteria isolated. Fecal water showed pH 4.8 and total lactic acid (sum of L- and D-lactic acids) was the principal organic anion found in the feces. We also incubated the patient's stool in a continuous culture with a view to determining the effect of the pH on the production of volatile fatty acids (VFA) and L- and D-lactic acids. The culture was maintained at pH 5.0, 5.5, 6.0, and 6.5 for four consecutive periods of four days each. We then studied the culture for a further four days at pH 5.0 once again. This study showed that with the progressive rise of the pH from 5.0 to 6.5 L- and D-lactic acids decreased and VFA production increased. D-Lactic acid formation was inhibited at pH 6.5, but when the culture was returned to pH 5.0, it increased to a high level again. These results suggest that the pH plays an important role in the ecological changes in the colonic bacteria that result in D-lactic acid production.

Bacteria, Anaerobic↗
PubMed1995

Prevention of asthma with ketotifen in preasthmatic children: a three-year follow-up study.

Growing morbidity and mortality rates call for research towards more effective methods of preventing asthma. During the last decade several groups have reported the results of natural history and asthma prevention studies. However, the attempt to prevent development of asthma in genetically predisposed children, has not resulted in a generally accepted management scheme. The aim of this study was to evaluate the effectiveness of ketotifen in preventing the onset of asthma in infants considered to be at high risk of developing the disease, but who had no history of respiratory obstruction. These children have been described as preasthmatic. In this double-blind, placebo-controlled, parallel study, 100 infants with a family history of major allergy and elevated serum IgE levels, but with no history of bronchial obstruction, were treated with either ketotifen (n = 50) or placebo (n = 50) over a 3-year period. There were no statistically significant differences between the two groups with regard to age, sex, degree of hereditary allergy, levels of serum IgE upon joining the study, and family smoking habits. At the end of 3 years, only four of the 45 infants who had received ketotifen had developed asthma (9%). Of the 40 children given placebo, 14 had developed asthma (35%) (P = 0.003). These results suggest that ketotifen is effective in preventing the onset of asthma in preasthmatic children.

Asthma↗
PubMed1994

Fecal lactate and short bowel syndrome.

In patients with short bowel syndrome (SBS), the carbohydrate overload to the colon may disturb the normal pattern of colonic fermentation with production of D-lactic acid and subsequent development of a metabolic D-lactic acidosis. We measured D-lactic acid in blood, urine, and feces, as well as the composition of fecal water and fecal reducing substances from 11 patients with SBS, comparing the results with those from normal subjects. The fecal water from patients with SBS was characterized by low pH, potassium, and volatile fatty acids, high osmotic gap, and high concentration of L- and D-lactic acid. Five of 11 had abnormal amounts of fecal reducing substances. Fecal D-lactic acid was increased in nine of 11 patients. However, none of these patients showed D-lactic acid in urine, and only one had a very low concentration in plasma. These results show that D-lactic acid was overproduced in the colon of most of the patients with SBS. However, other factors such as absorption or impaired D-lactic acid metabolism may be necessary for a plasmatic increase of D-lactic acid.

Adult↗
PubMed1994

Colonic proteolysis following pancreatic duct ligation in the rat.

Luminal proteolytic activity (PA) of different colonic segments was ascertained in animals subjected to pancreatic duct ligation (PDL) and in control rats. The PDL rats revealed a significant PA reduction in the cecum, proximal colon (P < 0.01), and distal colon (P < 0.005). Proteolytic activity, trypsin, and chymotrypsin activity in control rats diminished progressively from the cecum to the distal colon. Conversely in PDL rats, we found maximal PA in distal colon. The conclusion is drawn that a significant proportion of colonic proteolytic activity can be attributed to pancreatic proteases with a maximal contribution at cecum level.

Animals↗
PubMed1993

Polymorphism in Plasmodium vivax MSA1 gene--the result of intragenic recombinations?

The diversity in a 925 bp portion of the Plasmodium vivax MSA1 gene in isolates from the Philippines, China, the Solomon Islands and Papua New Guinea was investigated. A total of 74 base pair changes was found in the amplified fragment from 18 isolates. Most of these changes were single or double base pair substitutions. In several regions, these point changes were tightly linked with one set always present or always absent in the different isolates. Seven such blocks were identified. These blocks were present in different combinations in the different isolates indicating that extensive intragenic recombination has occurred.

Amino Acid Sequence↗
PubMed1993

Effects of right hemicolectomy on fecal nitrogen excretion in rats.

The influence of right hemicolectomy (RH) on fecal nitrogen excretion was determined with selected protein levels up to 25%. The endogenous fecal N was determined by extrapolating protein intake to zero. Fecal N was higher in RH than in control rats at all protein levels used. However, the slope of regression curves describing fecal nitrogen excretion was greater for RH compared with the control group. The endogenous fecal nitrogen was not significantly different between the two groups of rats. The feces from rats fed with 25% of protein were partitioned into individual fractions by physical separation and a study was made of the distribution of nitrogen in the bacterial, soluble and fiber fractions of the stool. RH decreased the N excreted in the bacterial fraction by 33% (from 1.71 +/- 0.32 to 1.15 +/- 0.18 mmol/day) and increased the N excreted in the soluble fraction by 280% (from 1.60 +/- 0.30 to 6.08 +/- 1.16 mmol/day). These results show that the RH increased the fecal N excretion and that this N is mainly in the soluble fraction.

Animals↗
PubMed1993

[Postmortem diagnosis of cardiac amyloidosis in the aged. Anatomoclinical correlation].

The absence of specific clinical signs makes the diagnosis of cardiac amyloidosis difficult. Moreover, it is established that this condition, the prevalence of which increases with age, aggravates the prognosis of cardiac failure. The present study was undertaken to identify the clinical or paraclinical signs enabling more accurate diagnosis of this disease. Analysis of 2589 autopsy reports from the University Institutes of Geriatrics of Geneva between January 1972 and January 1990 recensed 58 cases of microscopic cardiac amyloidosis, but this diagnosis was not made in any of these patients before death. Of the potential indicators, the good specificity but poor sensitivity of atrial fibrillation and low voltage electrocardiogram was confirmed. On the other hand, the author's research found the association of radiological cardiomegaly and a raised erythrocyte sedimentation rate in nearly 70% of cases of cardiac amyloidosis with a false positive rate of only 10% in a control group.

Aged↗
PubMed1993

[Influence of sodium butyrate intake on murine colonic carcinogenesis].

The role of short chain fatty acids (SCFA) in murine colonic carcinogenesis (MCC) has not yet been clarified. In rats, Freeman et al have reported an increased number of colonic tumors induced with dimethylhydrazine (DMH) and sodium butyrate in drinking water. On the other hand, Deschner et al showed that tributyrin intake did not increase MCC induced with azoxymethane. Both of them have reported high levels of fecal butyric acid with sodium butyrate and tributyrin intake. Although salt intake has been positively associated with colorectal cancer some authors do not support this association. We have evaluated the influence of right hemicolectomy (RH) (right colon as main source of SCFA) and the intake of 2%-pH 7 sodium butyrate (S.BUT) and 4 g/l sodium chloride (S.CHL) in drinking water, in MCC. Forty eight male Wistar rats weighing 150 g were divided into 4 groups: RH, S.BUT, S.CHL, control (C). Half of the animals received weekly DMH 20 mg/kg subcutaneously for 12 weeks. Necropsy was performed after 6 months. We have determined fecal SCFA content by gas chromatography. Neoplasm was present in 70% of rats treated with DMH. The number of animals with tumors was: RH 4/6, S.BUT 4/6, S.CHL 3/5, C 6/6. Tumor frequency was: RH 1.17 +/- 0.48, S.BUT 1.50 +/- 0.76, S.CHL 1.20 +/- 0.49, C 1.50 +/- 0.22. S.BUT group, treated with DMH, presented a lower butyric acid concentration (p < 0.05) in comparison with other groups. We have no explanation for this finding; gastric absorption of sodium butyrate may be an important factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effects of right hemicolectomy on nitrogen balance in the rat.

Rats with right hemicolectomy were divided into two groups. One group was free-fed (RHFF), the other group pair-fed (RHPF) and both were compared with a group of control animals. The nitrogen balance (NB) was studied for 5 days at 2 and 14 weeks after surgery. The two groups of rats with right hemicolectomy excreted significantly more fecal nitrogen than the control group (p less than 0.01) during the two periods of study. At 2 weeks the RHFF group increased N intake so that their NB was similar to that of the control group. In the same period the nitrogen lost in urine and the NB were reduced in the RHPF rats (p less than 0.01). At 14 weeks the results were similar to those for 2 weeks although the increase in food intake for RHFF and the decrease in NB for RHPF were not statistically significant. The rats with right hemicolectomy showed a decreased gain in body weight. This decrease was more pronounced in the RHPF group. The nitrogen content of the carcass and liver was significantly reduced in the RHPF group 4 months after surgery. It is concluded that the rats with right hemicolectomy were characterized by an increment in the nitrogen lost in feces, and when they were only allowed the same intake of food as the control group, the animals showed marked abnormalities in growth and in the nitrogen content of the organism.

Animal Nutritional Physiological Phenomena↗