PubMed Health⌕ Search

Biomedical subjects

P Muñoz

Publications and source records attributed to P Muñoz.

At least 109 records · Page 6Linked to original sources
PubMed1997

Haemophilus species bacteremia in adults. The importance of the human immunodeficiency virus epidemic.

BACKGROUND: Until the late 1970s, invasive infections caused by Haemophilus species were thought to occur mainly in children and only infrequently in adults. OBJECTIVE: To report the largest series to date of Haemophilus species bacteremia (HB) from a single center. DESIGN: Retrospective. SETTING: Large, tertiary care, general teaching hospital. METHODS: We reviewed the charts of adult patients with HB detected from January 1, 1986, to December 31, 1994. Haemophilus strains were serotyped, and the antimicrobial resistance pattern was analyzed. RESULTS: One hundred sixteen patients had HB (0.26 cases per 1000 admissions). Thirty-eight children and 16 adults were excluded. Human immunodeficiency virus (HIV) infection was the most common underlying condition (n = 18 [29%]), followed by malignant neoplasms (n = 12 [19%]) and chronic obstructive pulmonary disease (n = 12 [19%]). Prevalence in HIV-positive patients was 5 cases per 1000 admissions vs 0.2 cases per 1000 admissions in HIV-negative patients. Infection was nosocomial in 16 patients (26%). Focal diseases were pneumonia in 41 patients (66%), cholangitis in 5 patients (8%), endocarditis in 3 patients (5%), meningitis and septic arthritis each in 1 patient (2%), and primary bacteremia in 9 patients (14%). The HIV-positive patients were significantly younger and presented more frequently with pneumonia (P < .05). Overall, 14 patients died (22%). Bacteremia was polymicrobial in 11 patients (18%). Haemophilus influenzae was isolated in 53 patients (85%). Rates of antimicrobial resistance were 11% to chloramphenicol sodium succinate, 48% to ampicillin sodium, 78% to erythromycin stearate, 76% to combined sulfamethoxazole and trimethoprim, 15% to rifampin, and 57% to clarithromycin. CONCLUSIONS: Infection with HIV has become the most common underlying disease in adults with HB in our hospital. Therapeutic approaches must take into account the high rate of antimicrobial resistance.

AIDS-Related Opportunistic Infections↗
PubMed1997

Regulation of glucose transport, and glucose transporters expression and trafficking in the heart: studies in cardiac myocytes.

Cardiac muscle is characterized by a high rate of glucose consumption. In the absence of insulin, glucose transport into cardiomyocytes limits the rate of glucose utilization and therefore it is important to understand the regulation of glucose transporters. Cardiac muscle cells express 2 distinct glucose transporters, GLUT4 and GLUT1; although GLUT4 is quantitatively the more important glucose transporter expressed in heart, GLUT1 is also expressed at a substantial level. In isolated rat cardiomyocytes, insulin acutely stimulates glucose transport and translocates both GLUT4 and GLUT1 from an intracellular site to the cell surface. Recent evidence indicates the existence of at least 2 distinct intracellular membrane populations enriched in GLUT4 with a different protein composition. Elucidation of the intracellular location of these 2 GLUT4 vesicle pools in cardiac myocytes, their role in GLUT4 trafficking, and their relation to insulin-induced GLUT4 translocation needs to be addressed.

Animals↗
PubMed1997

Chronic high-fat feeding and middle-aging reduce in an additive fashion Glut4 expression in skeletal muscle and adipose tissue.

The interaction of middle-aging and chronic high-fat feeding on glucose transport in skeletal muscle and adipose tissue was examined. To this end, we studied the effects of 6 month treatment with a high-fat diet in 12-month old rats. Chronic high-fat feeding led to a substantial reduction in GLUT4 glucose transporter expression both in adipose tissue and in skeletal muscle, which was additive to the reduction in GLUT4 protein content detected in aged rats. In parallel, the high-fat diet led to a reduced insulin-stimulated glucose transport in the incubated soleus muscle and isolated adipocytes; insulin resistance induced by high-fat feeding was superimposed to the decreased insulin response detected in aged rats. Different mechanisms were responsible for GLUT4 repression in response to high-fat feeding or aging in skeletal muscles and adipose tissue.

Adipose Tissue↗
PubMed1997

[The prediction of the degree of metabolic control by minimal technical norms in a diabetes program].

OBJECTIVE: To assess whether scores on the minimum technical norms (MTN) of the diabetes mellitus programme are of use in determining the level of metabolic control achieved. DESIGN: A retrospective study. SETTING: Two teaching health centres in the city of Santander. PATIENTS AND OTHER PARTICIPANTS: 204 patients, the total chosen by the Santander area management for the 1994 annual evaluation of the Diabetes programme. MEASUREMENTS AND RESULTS: The values reached by the variables of the MTN were measured. For a control criterion we took the value of glycosylated haemoglobin HbA1C or over. 52% of patients fulfilled the criteria of good control, 20% acceptable and 28% bad. CONCLUSIONS: Scoring on the MTN has little value in predicting lower values of HbA1C and is no use in assessing the level of metabolic control achieved by the Diabetes programme. The evaluation of the programme should include results indicators.

Community Health Centers↗
PubMed1997

Insulin-induced recruitment of glucose transporter 4 (GLUT4) and GLUT1 in isolated rat cardiac myocytes. Evidence of the existence of different intracellular GLUT4 vesicle populations.

UNLABELLED: Using isolated rat cardiomyocytes we have examined: 1) the effect of insulin on the cellular distribution of glucose transporter 4 (GLUT4) and GLUT1, 2) the total amount of these transporters, and 3) the co-localization of GLUT4, GLUT1, and secretory carrier membrane proteins (SCAMPs) in intracellular membranes. Insulin induced 5.7- and 2.7-fold increases in GLUT4 and GLUT1 at the cell surface, respectively, as determined by the nonpermeant photoaffinity label [3H]2-N-[4(1-azi-2,2,2-trifluoroethyl)benzoyl]-1, 3-bis-(D-mannos-4-yloxy)propyl-2-amine. The total amount of GLUT1, as determined by quantitative Western blot analysis of cell homogenates, was found to represent a substantial fraction ( approximately 30%) of the total glucose transporter content. Intracellular GLUT4-containing vesicles were immunoisolated from low density microsomes by using monoclonal anti-GLUT4 (1F8) or anti-SCAMP antibodies (3F8) coupled to either agarose or acrylamide. With these different immunoisolation conditions two GLUT4 membrane pools were found in nonstimulated cells: one pool with a high proportion of GLUT4 and a low content in GLUT1 and SCAMP 39 (pool 1) and a second GLUT4 pool with a high content of GLUT1 and SCAMP 39 (pool 2). The existence of pool 1 was confirmed by immunotitration of intracellular GLUT4 membranes with 1F8-acrylamide. Acute insulin treatment caused the depletion of GLUT4 in both pools and of GLUT1 and SCAMP 39 in pool 2. IN CONCLUSION: 1) GLUT4 is the major glucose transporter to be recruited to the surface of cardiomyocytes in response to insulin; 2) these cells express a high level of GLUT1; and 3) intracellular GLUT4-containing vesicles consist of at least two populations, which is compatible with recently proposed models of GLUT4 trafficking in adipocytes.

Animals↗
PubMed1997

Group B streptococcus bacteremia in nonpregnant adults.

BACKGROUND: We report the largest series of group B streptococcal (GBS) bacteremia cases reported at a single institution. METHODS: During a 10-year period (1985-1994), 90 GBS bacteremia cases (0.95% of significant bacteremic episodes) were detected. We describe the 51 episodes that occurred in nonpregnant adults for which enough clinical and microbiological information is available. RESULTS: Incidence of GBS has significantly increased during the study period (from 0.08 per 1000 admissions in 1985 to 0.3 per 1000 in 1994). Mean age of patients was 63.3 years (range, 21-88 years) and 53% were men. The most common underlying conditions were liver diseases (35.3%), malignancies (33.3%), and diabetes mellitus (27.5%). Only 2 patients did not have any underlying condition and no patient with the human immunodeficiency virus had GBS bacteremia in our series. The origins of the episodes of bacteremia were as follows: primary bacteremia (39.2%), skin and soft tissue infections (15.7%), urinary tract infections (11.8%), pneumonia (9.8%), peritonitis (9.8%), catheter infection (5.9%), postendoscopic bacteremia (5.9%), and endocarditis (2%). All isolates were susceptible to penicillin G potassium, ampicillin sodium, cephalothin sodium, cefotaxime sodium, and vancomycin hydrochloride. One ciprofloxacin hydrochloride-resistant strain was discovered and resistance to erythromycin stearate increased from 8% in 1992 to 18% in 1994. The overall mortality rate was 33.3% and deaths were considered related to the GBS bacteremia in 25.5% of the cases. Factors for poor prognosis were central nervous system diseases, alcoholism, shock, renal failure, and consciousness impairment. CONCLUSIONS: Group B streptococcus is a rising cause of bacteremia in elderly patients with severe underlying conditions. It conveys high morbidity and mortality rates. Macrolides should not be used empirically for treatment of patients with penicillin allergies.

Adult↗
PubMed1997

Sequence of eruption of deciduous dentition in a Chilean sample with Down's syndrome.

The eruption of the deciduous teeth in Down's individuals is reportedly delayed, but the extent of delay in comparison to normal children has been little studied. The eruption characteristics of the deciduous teeth in a sample of Chilean individuals with Down's syndrome were compared with those of the normal Chilean population. The sample consisted of 255 Down's individuals (all with trisomy 21), 127 males and 128 females. Boys with Down's syndrome showed significantly delayed eruption in six teeth: in the maxilla the right central incisor and right and left lateral incisors, and in the mandible the right central incisor and right and left canines. Girls with Down's syndrome showed significant delays in the eruption of 11 teeth: in the maxilla the right and left lateral incisors, right and left canines and first left molar, and in the mandible the left central incisor, right and left lateral incisors and canines and second right molar. The chronological sequence of eruption in Down's children was not completely different from that of normal individuals. With a few exceptions no significant departures from Gaussian distribution were found in the age of eruption among both normal and Down's individuals. The variance was significantly larger in cases of Down's syndrome.

Age Factors↗
PubMed1997

Postsurgical mediastinitis: a case-control study.

We report the results of a case-control study of postsurgical mediastinitis (PSM) that we conducted from 1985 to 1993. The incidence of PSM was 2.2% (81 of 3,711 cases who underwent sternotomy); we analyzed the findings for 73 cases and 73 controls. Univariate analysis revealed that the risk factors for PSM were emergency surgery (27% of cases vs. 13% of controls), New York Heart Association functional class IV (46.5% vs. 21.9%), heart transplantation (12% vs. 0), and coronary artery bypass graft (CABG) surgery (60% vs. 41%). The incidences of fever, reoperation for bleeding, pacemaker placement, use of vasoactive drugs, prolonged mechanical ventilation, use of central lines, and treatment in the intensive care unit were also higher for cases. Multivariate analysis identified the following independent risk factors for PSM: reoperation (risk ratio [RR], 9.2), need for vasoactive drugs (RR, 3.5), CABG surgery (RR, 3.2), and fever that persisted after the third postsurgical day (RR, 406). The related mortality was 13.7%, and death was significantly more frequent among cases (17.7%) than among controls (2.7%). Multivariate analysis identified the following independent risk factors for mortality: bacteremia (RR, 21.5), the use of an intraaortic balloon (RR, 14.9), advanced age (RR, 1.14 per year), and prolonged mechanical ventilation (RR, 1.1 per day).

Adult↗
PubMed1997

Outbreak among HIV-infected patients of Staphylococcus aureus resistant to cotrimoxazole and methicillin.

OBJECTIVE: To describe an outbreak of trimethoprim-sulfamethoxazole (cotrimoxazole)-resistant and methicillin-resistant Staphylococcus aureus (CMRSA) in a unit housing patients infected with the human immunodeficiency virus (HIV). DESIGN: Prospective study involving patients colonized or infected with CMRSA. PATIENTS: 15 hospitalized patients with cultures positive for CMRSA. METHODS: Isolates of CMRSA were collected and characterized. Molecular typing of the epidemic strains was carried out after total DNA extraction by restriction endonuclease analysis and random amplification of polymorphic DNA. RESULTS: The epidemic was brought under control with the reinforcement of nosocomial transmission measures and with systematic nasal decontamination with mupirocin of all patients admitted to the HIV unit. Molecular typing techniques showed the existence of two epidemic strains: strain A was present in the 12 patients admitted to the HIV unit and strain B in the remaining 3 patients hospitalized elsewhere. CONCLUSIONS: Cotrimoxazole may no longer be a reliable and effective alternative for glycopeptides in patients with infection caused by MRSA strains, and HIV units should be particularly alert for CMRSA strains.

Adult↗
PubMed1997

Ocular tuberculosis. A prospective study in a general hospital.

Ocular tuberculosis has traditionally been considered uncommon or anecdotal. Imprecise and variable diagnostic criteria have contributed to the confusion surrounding this topic. The increase in extrapulmonary manifestations of tuberculosis during the AIDS era established the need for a prospective study of ocular involvement in patients with all types of tuberculosis using well-defined criteria. During a 15-month period, 300 cases had culture-proven tuberculosis at our institution. We randomly selected 100 for systematic ophthalmologic evaluation. Our criteria for ocular tuberculosis were divided as follows: certainty (isolation of Mycobacterium tuberculosis from ocular specimens), probability (patients with isolation of M. tuberculosis from extraocular samples, with ocular lesions not attributable to other causes that respond to anti-tuberculous treatment), and possibility (same as probability but follow-up impossible). Ocular tuberculosis was present in 18 patients (18%) of which 10 patients fulfilled probability and 8 patients fulfilled possibility criteria. Eleven of 18 patients had HIV infection. In 11 patients, ocular involvement was asymptomatic. Almost all patients (17/18) had choroiditis, and other ocular lesions included papillitis, retinitis, vitritis, vasculitis, dacryoadenitis, and scleritis. Multivariate analysis showed as risk factors independently predicting ocular involvement in patients with ocular tuberculosis the presence of miliary disease (odd ratio 43.92, p = 0.002), ocular symptoms (odds ratio 6.35, p = 0.0143), and decreased visual acuity (odds ratio 0.04, p = 0.012). We observed an unexpectedly high (18%) incidence of ocular involvement, frequently asymptomatic, in patients with tuberculosis. Miliary disease is a clear predisposing factor in both HIV-infected and noninfected populations. Ocular examination should be routinely considered in patients with proven or suspected tuberculosis.

AIDS-Related Opportunistic Infections↗
PubMed1997

Pneumocystis carinii infection in heart transplant recipients. Efficacy of a weekend prophylaxis schedule.

Most series of heart transplant patients report incidences of Pneumocystis carinii pneumonia (PCP) below 5% but do not individually describe the cases. From August 1988 to March 1994, 138 patients received 1 or more heart transplants at our institution. No anti-PCP chemoprophylaxis was provided, and 5 (3.6%) patients developed PCP. Incidence for listeriosis was 0.7% and for nocardiosis, 3.6%. We found descriptions of 14 more heart transplant patients with PCP in the medical literature. Data from the 19 patients follow. Mean age was 52 years, and PCP was diagnosed a median of 75 days after heart transplant (range, 37-781 d). Clinical presentation was acute (less than 48 h) with fever (89%), shortness of breath (84%), dry cough (74%), and hypoxia (63%). Cytomegalovirus was isolated from lung or blood in 74% of patients. Chest X-ray usually showed interstitial pneumonia (84%). Three patients required ventilatory support. All patients were treated with trimethoprim-sulfamethoxazole (TMP/SMX) (4 also with corticosteroids and 5 with ganciclovir). Mortality was 26%. Older age was the only significant poor prognostic factor (61 versus 49 years; p < 0.03). From March 1994, 50 heart transplant patients were given TMP/SMX prophylaxis at our institution (1 double-strength tablet, 160/800 mg, every 12 hours on Saturdays and Sundays), and no new cases of PCP, Listeria or Nocardia have been detected since then. Tolerance has been excellent. Heart transplant recipients are at a substantial risk of PCP pneumonia, which presents with an abrupt onset and a high mortality. Weekend TMP/SMX chemoprophylaxis was very effective at our institution.

Adult↗
PubMed1997

Characterization of two distinct intracellular GLUT4 membrane populations in muscle fiber. Differential protein composition and sensitivity to insulin.

A major objective for the understanding of muscle glucose disposal is the elucidation of the intracellular trafficking pathway of GLUT4 glucose carriers in the muscle fiber. In this report, we provide functional and biochemical characterization of two distinct intracellular GLUT4 vesicle pools obtained from rat skeletal muscle. The two pools showed a differential response to insulin; thus, one showed a marked decrease in GLUT4 levels but the other did not. They also showed a markedly different protein composition as detected by quantitative vesicle immunoisolation analysis. The GLUT4 pool showing no response to insulin contained SCAMP proteins and the vSNARE proteins VAMP2 and cellubrevin, whereas only VAMP2 was found in the insulin-recruitable GLUT4 pool. SDS-PAGE and further silver staining of the immunoprecipitates revealed discrete polypeptide bands associated to the insulin-sensitive pool, and all these polypeptide bands were found in the insulin-insensitive population. Furthermore, some polypeptide bands were exclusive to the insulin-insensitive population. The presence of cellubrevin and SCAMP proteins, endosomal markers, suggest that the insulin-insensitive GLUT4 membrane population belongs to an endosomal compartment. In addition, we favor the view that the insulin-sensitive GLUT4 membrane pool is segregated from the endosomal GLUT4 population and is undergoes exocytosis to the cell surface in response to insulin. Intracellular GLUT4 membranes obtained from skeletal muscle contain cellubrevin, and VAMP2 and GLUT4-vesicles from cardiomyocytes also contain cellubrevin. This suggests that vSNARE proteins are key constituents of GLUT4 vesicles. The presence of the tSNARE protein SNAP25 in skeletal muscle membranes and SNAP25 and syntaxin 1A and syntaxin 1B in cardiomyocyte plasma membranes further suggest a role of the SNAREs in GLUT4 trafficking in muscle.

Animals↗
PubMed1997

[Mycobacterium avium complex infection: a growing problem in our country].

Since the emergence of AIDS, disseminated Mycobacterium avium complex (MAC) infection has become a growing cause of morbidity and mortality in this group of patients. Our objective was to study the incidence and the clinical and microbiological features of MAC infection in HIV-positive patients as well as the response to a therapy regimen combining clarithromycin and ethambutol. At our hospital, the first patient with disseminated MAC infection was diagnosed in 1988. Since then, 54 HIV-positive patients with MAC infection have been diagnosed (30/1,000 HIV-positive patients). MAC represented 12% of recovered mycobacteria in HIV-positive patients and this percentage has increased from 3.9% in 1988 to 16.4% in 1994. All episodes of MAC infection occurred in patients with advanced HIV diseases (mean CD4: 73/microliter). MAC infection was the disease diagnosing AIDS in 23.4% of cases. The most common clinical manifestations included fever (85.7%), weight loss (55%), and pulmonary involvement (50%). A total of 55 specimens were processed for mycobacterial culture from 54 patients (mean of 10.2 specimens per patient). A total of 122 were positive (21.9%: 2.25 positive specimens per patient). The specimens with the greater percentage of positive results were bone marrow aspirates (65.3%) and blood cultures (47.7%), followed by respiratory (16.5%) and urine specimens (5.3%). Regarding therapy, sixteen of the 54 investigated patients did not receive specific drugs for MAC infection, 7 were treated with different combinations of active drugs against MAC (rifampin, clofazimine, amikacin, ethambutol, and isoniazid) and 31 received a combination of clarythromicin (1 g/12 hourly) and ethambutol (400 mg/12 hourly). Seventy-four percent of patients treated with clarythromicin and ethambutol improved clinically, and the mean survival time in these patients (253 days) was significantly longer than that in not treated patients (p < 0.05). No significant differences were noted in survival time between the group of patients treated with clarythromicin and ethambutol and that with other drug combinations. The incidence of disseminated MAC infection in our environment is increasing in patients with advanced HIV disease. The combination of clarythromicin plus ethambutol was well tolerated and efficient for the treatment of disseminated MAC infection.

AIDS-Related Opportunistic Infections↗
PubMed1996

Evidence for posttranscriptional regulation of GLUT4 expression in muscle and adipose tissue from streptozotocin-induced diabetic and benfluorex-treated rats.

In this study we explored the expression of GLUT4 glucose carriers in muscle and adipose tissues from streptozotocin-induced diabetic and benfluorex-treated rats. In nondiabetic rats, benfluorex treatment decreased GLUT4 protein content in muscle and brown adipose tissue, with no change in GLUT4 mRNA. This effect occurred in the presence of normal circulating levels of insulin and glucose. Seventeen days after streptozotocin injection, diabetic rats showed a decreased GLUT4 protein content in adipose tissues and in both red and white skeletal muscle. Diabetic rats showed decreased GLUT4 mRNA levels in white and brown adipose tissue, whereas messenger concentrations remained unaltered in red and white fibers of skeletal muscle. The interaction of benfluorex and diabetes on GLUT4 protein expression showed a tissue-specific pattern. Benfluorex treatment to some extent prevented the decrease in GLUT4 protein in white and brown adipose tissue and in white muscle associated with diabetes. In contrast, diabetes and benfluorex caused an additive decrease in GLUT4 expression in red skeletal muscle. The effects of benfluorex on GLUT4 content in tissues from diabetic rats occurred in the absence of alterations in GLUT4 mRNA levels, suggesting a modification of translational or posttranslational steps. Benfluorex did not ameliorate the hyperglycemia of diabetic rats. Our results indicate that red and white skeletal muscle respond to diabetes and benfluorex in a heterogeneous manner, which suggests the existence of differences in the mechanisms that regulate GLUT4 expression. Furthermore, our data indicate that GLUT4 expression in muscle and adipose tissue can be regulated by modification of translational or posttranslational steps.

Adipose Tissue↗