PubMed Health⌕ Search

Biomedical subjects

M Bustamante

Publications and source records attributed to M Bustamante.

At least 37 records · Page 2Linked to original sources
PubMed2000

Coagulating and lipolytic activities of artisanal lamb rennet pastes.

Lamb rennet pastes were prepared by the procedure most commonly used by Idiazabal cheese manufacturers. We studied the effects on their coagulating and lipolytic activities of the state of the stomach at the time of death (full of milk or empty), the amount of NaCl added, the origin of the lambs and paste storage time. Coagulating activities were generally between 155 and 363 units/g tissue. Pastes prepared from stomachs of lambs from slaughterhouse flocks had significantly higher coagulating activities than those of lambs from separate flocks. No significant decrease in coagulating activity was observed after 1 year storage at 4 degrees C. Chymosin represented 75-80% of the total coagulating activity with the remainder being pepsin. Rennet paste extracts with pH < 4.7 did not have increased coagulating activities when their pH was lowered to 2.0, while those with pH > 5.2 had activities 1.5-fold those before treatment. Lipase activity was higher in extracts of rennet pastes prepared using the stomachs of lambs that arrived at the slaughterhouse in the morning just prior to slaughter than in those prepared with the stomachs of lambs that had arrived on the previous evening. However, the reverse was the case for esterase activity. Activating the coagulating activity by pH cycling completely destroyed both lipolytic activities. Storage at 4 degrees C for > 1 year did not affect esterase activity but lipase activity decreased substantially after 4-5 months. Lipase, but not esterase, activity was responsible for the liberation of short-chain free fatty acids from ovine milk fat.

Animals↗
PubMed2000

The efficacy of proton-pump inhibitors in acute ulcer bleeding: a qualitative review.

Despite remarkable progress in the treatment of chronic peptic ulcer disease, acute gastroduodenal ulcer hemorrhage remains a therapeutic challenge. Numerous trials of H-2 receptor antagonists have not consistently shown a significant benefit in such patients. Proton-pump inhibitors, which more profoundly suppress gastric acid, are being increasingly evaluated. We have performed a qualitative systematic review to analyze the results of these trials to determine if a reasonable consensus can be reached. We searched for all published, randomized, controlled studies that evaluated proton-pump inhibitors in patients with acute peptic ulcer hemorrhage. The primary outcomes evaluated were: (A) persistent or recurrent bleeding; (B) need for surgery; and (C) mortality. Sixteen trials were evaluated, enrolling 3154 patients. Four of the sixteen studies showed a statistically significant decrease in overall rebleeding rate, and two described specific benefit in patients with Type IIa and IIb endoscopic stigmata. Four studies also showed a significantly decreased surgery rate, but none demonstrated a significant mortality reduction. Proton-pump inhibitors may improve outcome in acute peptic ulcer bleeding, but the available clinical data remain inconsistent. Further study is necessary to define the optimal dosage, route of administration, duration of therapy, and subsets of patients most likely to benefit.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Transjugular approach to treat portal vein stenosis after liver transplantation--a case report.

The authors present a case of portal vein stenosis that developed shortly after liver transplantation in a 48-year-old woman treated successfully with portal stent implantation by use of a transjugular approach to achieve portal vein access. To their knowledge, there are no other reports in the literature on the use of a transjugular approach with vein stent placement in the treatment of portal stenosis complicating orthotopic liver transplantation.

Constriction, Pathologic↗
PubMed2000

Usefulness of gadolinium-enhanced MR imaging in the evaluation of the vascularity of scaphoid nonunions.

OBJECTIVE: The objective of this article is to identify the role of gadolinium-enhanced MR imaging in the preoperative evaluation of the vascular status of the proximal fragment in scaphoid nonunions. SUBJECTS AND METHODS: Thirty consecutive patients (27 men and three women; age range, 19-52 years; mean age, 28 years) with nonunion of the scaphoid were prospectively examined with unenhanced and gadolinium-enhanced MR imaging. MR images and surgical findings were classified in four groups according to the vascular status of the proximal fragment (normal bone, moderate ischemic bone, severe ischemic bone, and avascular necrosis). Sensitivity, specificity, and accuracy of unenhanced and gadolinium-enhanced MR studies were calculated. Surgical findings were used as the gold standard. The postoperative rate of union at 12 months was evaluated for each group. RESULTS: Unenhanced MR imaging showed a global sensitivity of 36%, specificity of 78%, and accuracy of 68% in the preoperative evaluation of the vascular status of the proximal fragment. Correlation with the surgical findings was not statistically significant (p < 0.149). Global sensitivity, specificity, and accuracy of gadolinium-enhanced MR imaging were 66%, 88%, and 83%, respectively. Correlation with the surgical findings was good (p < 0.0001). Gadolinium-enhanced sequences allowed accurate diagnosis and enabled the creation of prognostic groups having better correlation with surgical findings and postoperative results. CONCLUSION: Gadolinium-enhanced MR imaging is the most reliable imaging method for investigating the vascularity of the proximal pole in scaphoid nonunions.

Adult↗
PubMed2000

[The prediction of the endoscopic diagnosis in the dyspepsia patient: the value of the predominating presenting symptom and the initial clinical presumption].

AIM: To assess, in our patient population, whether upper gastrointestinal symptoms can be used to predict the presence of relevant pathology on endoscopy. PATIENTS AND METHODS: In the first retrospective phase, 311 gastroscopies, indicated for dyspeptic symptoms were selected. The gastroscopies were performed by the same endoscopist from April 1998 to March 1999. Patients were divided into four groups according to the main presenting symptom (epigastralgia, epigastralgia with pyrosis, pyrosis with nonspecific symptoms). The positive and negative predictive value, as well as the overall sensitivity and specificity of each group of symptoms for the presentation of a relevant pathology were calculated. In the second, prospective, phase an attempt was made, based on the clinical history taken in the initial consultation, to predict the results of the gastroscopies of 77 dyspeptic patients. There were four possibilities: normal or not relevant, esophagitis, ulcer and neoplasia. The positive predictive value, negative predictive value, sensitivity and specificity of the diagnostic hypothesis were calculated. RESULTS: a) Retrospective phase: the overall positive predictive value of dyspeptic symptoms to predict relevant pathology was 0.38. The highest positive predictive value corresponded to symptoms of pyrosis (0.48). Dividing the patients into groups according to age (older or younger than 45 years) did not improve the predictive value of symptoms. b) Prospective phase: the highest positive predictive value corresponded to "pathology without relevance" (0.7). The prediction of ulcer only gave a positive predictive value of 0.55. CONCLUSION: The main presenting symptom is not a good predictor of whether relevant pathology will be found on gastroscopy. The initial diagnostic hypothesis is not a sufficiently effective tool to accurately detect which patients will most benefit from gastroscopy.

Adolescent↗
PubMed2000

[A new instrument for the evaluation of the medical profession. Use of the OSCE method].

BACKGROUND: Objective structured clinical examination has advantages over traditional oral examination of medical student. However, it is not routinely used in Chile. AIM: To describe the objective structured clinical examination system and report the results of its first use with Chilean medical students. MATERIAL AND METHODS: Thirteen interns ware evaluated at the end of their surgical rotation, using the objective structured clinical examination. Thirteen stations were structured for this examination: one for history taking, two for physical examination, four for problem solving and knowledge, one for radiological interpretation, one for instrumental recognition, one for skills and one for text comprehension. There were a total of 88 questions. RESULTS: All students exceeded 60% of requirements. Mean approval score was 73%. The higher score was 80% and the lower 61%. Ten students had a score over 70%. The method was well accepted by teachers and students. CONCLUSIONS: This first local experience with the objective structured clinical examination was successful.

Chile↗
PubMed1999

Normal esophageal function after myotomy in a patient with idiopathic diffuse esophageal spasm.

A 52-year-old man with idiopathic diffuse esophageal spasm and hypertensive lower esophageal sphincter presented with dysphagia for several years. After unsuccessful therapy with forceful pneumatic dilation of the cardia, a myotomy of the cardia and distal esophagus was performed. The patient became asymptomatic, lower esophageal sphincter pressure diminished to less than 10 mm Hg, and esophageal body motor activity was normalized. This situation remains unchanged 6 years after the operation.

Cardia↗
PubMed1999

Response to treatment with interferon-alfa in patients with chronic hepatitis C and high titers of -M2, -M4 and -M8 antimitochondrial antibodies.

UNLABELLED: The prevalence of antimitochondrial antibodies (AMA) in chronic hepatitis C is 2%; titers of AMA are usually low (< 1:40). The prevalence decreases to 0.5% when the results are verified by determination of the M2 subtype (anti-M2, ELISA). In patients in whom both hepatitis C virus (HCV) and AMA are present, the therapeutic decision to give interferon-alfa is complicated, because AMA may be 'real', and if it reflects primary biliary cirrhosis, cholestasis can be triggered or exacerbated. This does not occur when AMA positivity results from induction by hepatotropic C virus; however, this is rarely the case when AMA titers are high (> 1:160). OBJECTIVE: to undertake a preliminary analysis of the submitochondrial profile of AMA in three patients with chronic hepatitis C and positive AMA titers (> 1:160). METHODS: we determined antibodies to submitochondrial particles (subtypes) -M2, -M4 and -M8 by ELISA, complement binding (CB) and western immunoblotting with Immunoblot-M2 or WIB-M2 (immunoreactive bands). RESULTS: two patients were positive for mitochondrial subtypes by ELISA (IgG/IgM subclass) and CB (ELISA M2 470/365 in patient 1 and 600/1370 in patient 2; M4 490/1200 in patient 2. CB M2 1:128, M4 1:64, M8 1:64 in patient 1, M2 1:128 in patient 2). Immunoreactive epitopes (bands) were detected with WIB-M2 for 70, 56, 51, 45 and 36-kDa molecules. Interferon-alfa treatment was unsuccessful, with biochemical exacerbation of cholestasis. In contrast, the patient with no submitochondrial particles according to ELISA, CB and WIB-M2 results responded favorable to this drug. CONCLUSION: these preliminary results suggest that analyses to detect antibodies to submitochondrial particles (-M2, -M4 and -M8 subtypes) and -M2-immunoreactive epitopes in patients with chronic hepatitis C and AMA titers > 1:160 facilitates the diagnosis of primary biliary cirrhosis, and establishes a contraindication for treatment with interferon-alfa despite the presence of HCV infection.

Adult↗
PubMed1999

[Acute intermittent porphyria: a possible cause of abdominal pain].

Acute intermittent porphyria (AIP) is an inherited disorder of heme metabolism. It can produce a variety of symptoms including abdominal pain. In Spain it is an uncommon disease and consequently may not be included in the differential diagnosis of acute abdominal pain. Two cases of AIP are reported, both of which started with recurrent abdominal pain. A brief commentary of the main topics of the disease is made with special emphasis on the importance of an early diagnosis.

Abdominal Pain↗
PubMed1999

[In vitro immunosuppressive effect of low density lipoproteins].

BACKGROUND: Immune cells participate in the formation of atheromatous plate, however little is known about the effects of native or oxidatively modified lipoproteins on these cells. AIM: To study the effects of lipoproteins on in vitro mononuclear cell proliferation. MATERIAL AND METHODS: Peripheral blood mononuclear cells were obtained from 10 patients with type 2 diabetes mellitus (aged 52 +/- 9 years old with a disease duration of 8.2 +/- 5.7 years and a mean glycosilated hemoglobin of 9.3 +/- 2.2%) and 10 non diabetic healthy controls (aged 50.3 +/- 7.1 years old). These were stimulated with phytohemagglutinin (PHA) alone or in the presence of native LDLS, malondialdehyde modified LDLs or glycated LDLs. Proliferation was measured as 3H-thymidine incorporation and expressed as Stimulation Index (SI). RESULTS: SI of patients and healthy subjects, after PHA stimulation were similar: (57.5 +/- 29.8 and 61.1 +/- 23.5) respectively LDLs did not induce proliferation in neither group. Native LDLs produced a 98% inhibition of PHA induced proliferation. Malondialdehyde modified and glycated LDLs caused a 50% inhibition. The suppressive effect was maintained when lipoproteins were incorporated to culture media 60 min prior or after PHA stimulation. CONCLUSIONS: Lipoproteins inhibit in vitro PHA induced peripheral blood mononuclear cell proliferation both in diabetic and in non diabetic subjects.

Adult↗
PubMed1998

[Incidence of de novo neoplasms after liver transplantation].

BACKGROUND: De novo malignancy developing after transplantation constitutes a well-known complication or organ transplantation, mainly described among renal recipients. AIM: To determine the incidence of de novo internal malignancies (excluding therefore skin cancers and recurrent hepatocellular carcinoma) in a cohort of 183 patients undergoing liver transplantation (OLT) between 6/1/1991 and 12/1/1996 with a minimum follow-up of 12 months and under cyclosporine-azathioprine-prednisone. PATIENTS AND METHODS: The study comprised 183 patients (mean age: 53 [8] years, with 70% males) whose charts were reviewed retrospectively. Rejection, steroids treatment, methyl-prednisolone bolus and OKT3 use were compared in the cases and in the matched control group. RESULTS: Seven malignancies were detected: 3 lung carcinomas, 1 larynx, 1 prostate, 1 colon and 1 ovarian. The mean age was 53 (8) years. The diagnosis of cancer was made at an average time of 24 (17) months (range, 10-54) post-OLT. Three patients died with a mean survival of 31 (16) months. OLT indication was mainly for viral liver disease (5/7). Although not statistically significant, immunosuppression data were higher among patients with cancer than in the matched group. Two additional patients developed post-transplantation lymphoproliferative diseases at 2 and 9 months, respectively. CONCLUSION: We observed a wide variety of malignancies after OLT, but no associated factor was found, even though there was a trend to higher doses of immunosuppression in patients with cancers. The institution of preventive measures and surveillance programs may allow for early institution of therapy, improving therefore the survival.

Adult↗
PubMed1998

[Bronchial embolization in the treatment of hemoptysis].

The aim of this retrospective study was to evaluate the efficacy of bronchial artery embolization to treat hemoptysis. Eight hundred sixty-five patients were admitted to our hospital with hemoptysis during the study period. Bronchial arteriographs were obtained for 48, who suffered life-threatening hemoptysis refractory to medical treatment. The likely origin of bleeding was identified in 37: embolization was performed with particles measuring 250 to 1000 micra in size (Contour Emboli, Interventional Therapeutic Corporation, South San Francisco, California, USA) in 35 and with hemostatic collagen sponges in 2. The most common causes of hemoptysis were bronchiectasis (40%), pulmonary tuberculosis (33%), pulmonary aspergilloma (8%) and malignant neoplasm (8%), chronic bronchitis (6%); 4% of the cases were idiopathic. Immediate technical success was achieved in 34 patients (92%) as defined by the absence of hemorrhage for at least 24 hours. All embolized patients were followed until the first recurrence of bleeding or until discharge. Recurrence of hemoptysis (in the first month) was early in 5 patients (13.5%) and late (2 to 96 months) in 9 (24%). The severity of the initial and later episodes of hemoptysis was similar in all early recurrences and most late recurrences. A second embolization was performed six times, and medical and/or surgical treatment was given in all other cases. No significant complications attributable to the technique were observed. The results show that bronchial embolization is valid for the immediate control of life-threatening hemoptysis and has a low rate of severe complication; recurrence is relatively common.

Adult↗
PubMed1998

CT in spontaneous adrenal gland rupture. A case report.

PURPOSE: To report on an exceptional case of spontaneous, idiopathic, unilateral adrenal gland rupture that caused massive retroperitoneal hemorrhage. METHODS AND RESULTS: US and CT were performed in a patient who presented with acute abdominal pain. Urgent adrenalectomy was required to prevent the blood loss from continuing. The CT findings were correlated with the histological findings. CONCLUSION: CT proved to be an accurate imaging modality by which to diagnose adrenal hemorrhage. The absence of irregular tissue enhancement showed that neoplasia was not the underlying cause of the hematoma.

Adrenal Gland Diseases↗
PubMed1998

Transjugular biopsy of the liver with an automated device.

PURPOSE: To evaluate the results of transjugular liver biopsies conducted with an automated device. MATERIAL AND METHODS: Transjugular liver biopsies were conducted on 37 patients. The principal indication was coagulation disorders. The biopsies were performed with a 1.3-mm automated device. Each patient underwent three biopsies: anterior, lateral and posterior. A fourth biopsy was conducted if the first three did not produce at least one core sample that was sufficient for the histologic diagnosis. RESULTS: Transjugular liver biopsy was successful in all 37 patients. We performed a mean of 3.06 punctures per patient (average 2.86 samples). The length of the samples varied from 5 to 23 mm (mean 13.6 mm). Biopsy specimens were useful for histologic diagnosis in 97% of the cases. No serious complications were caused by the procedure. CONCLUSION: The transjugular liver biopsy technique is an efficient way of obtaining tissue samples. The procedure shows a high success ratio and a low complication rate.

Adolescent↗
PubMed1998

[Recent alcohol and drug consumption in victims of work related accidents].

BACKGROUND: Twenty to twenty two percent of work related accidents have a direct or indirect relationship with recent alcohol use. AIM: To detect recent alcohol or drug use in patients who required hospitalization for severe work related accidents. PATIENTS AND METHODS: Blood and urine samples were obtained from patients admitted to a hospital within 6 hours of an accident severe enough to require hospitalization. Blood alcohol and urinary metabolites of cocaine, marijuana, amphetamines and benzodiazepines were measured. Patient identity was kept confidential throughout the study. Once patients were stabilized, they were interviewed by a psychologist that was blind to laboratory results. RESULTS: Two hundred thirty men and 18 women were studied and 29% (30% of men and 17% of women) had recent use of alcohol or drugs. The most common substances were alcohol in 15% and benzodiazepines in 13%. Use of alcohol or drugs was found in 21% of professionals, in 33% of other occupational levels, half of agricultural workers and 25% of commerce workers. Only two of 60 positive cases, admitted substance use during the interview. Most of negative cases admitted the use of alcohol or other drugs during the month prior to the accident. CONCLUSIONS: Recent use of alcohol and drugs is frequent among severe work related accident victims. Probably, a high proportion of these subjects are problem drinkers. The combination of alcohol and benzodiazepines is an additional risk factor.

Accidents, Occupational↗