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Biomedical subjects

I Rivera

Publications and source records attributed to I Rivera.

33 records · Page 2Linked to original sources
PubMed1990

Oral lesions in Mexican HIV-infected patients.

One hundred and twenty-five HIV-infected patients, of whom 49 (39%) were at early stages of the infection (CDC-II & III) and 76 (61%) in CDC IV, were prospectively examined. In 100 (80%) one or more oral mucosal lesions were observed; candidiasis (51%) and hairy leukoplakia (43%) were the commonest. Erythematous candidiasis was more often seen (35%) than the pseudomembranous type (16%), and appeared with the higher values at early than later stages. The prevalence of hairy leukoplakia, oral hyperpigmentation and xerostomia were incremented in groups CDC-IV. Pseudomembranous candidiasis and exfoliative cheilitis increased significantly with severity of disease. Our study demonstrates that oral alterations associated to HIV are a frequent finding, both at early (76%) and late (83%) stages of the infection in Mexican patients.

Adolescent↗
PubMed1989

[Pericardiocentesis: usefulness in the routine determination of intrapericardial pressure].

The usefulness of routine intrapericardial pressure determination and hemodynamic monitoring during therapeutic (n = 22) or diagnostic (n = 2) pericardiocentesis was analyzed. Hemodynamic data confirmed the presence of cardiac tamponade in all cases, including the 2 patients without clinical suspicion. Prior to fluid evacuation, abnormally elevated levels of intrapericardial (13 +/- 5 mmHg), right atrial (14 +/- 4 mmHg) and pulmonary capillary (16 +/- 3 mmHg) pressures were observed. A significant correlation was found between intrapericardial and right atrial pressures (r = 0.97, p less than 0.05) and also between intrapericardial and pulmonary capillary pressures (r = 0.69, p less than 0.05). The basal cardiac output was low (3 +/- 1 l/min) and increased after the pericardiocentesis in all but one patient. According to the results of pericardiocentesis, patients were classified into three groups. Group I: intrapericardial and right atrial pressures decreased to normal levels. The increment of cardiac output was high (72%) and the procedure was considered successful. Group II: right atrial and intrapericardial pressures remained elevated (7.7 +/- 4 and 7 +/- 2 mmHg, respectively) and the cardiac output increment was less marked (52%), thus indicating incomplete drainage. Group III: intrapericardial pressure decreased to normal levels but right atrial pressure remained elevated. All these patients were found to have associated cardiac disease, most frequently constriction. We conclude that routine determination of intrapericardial pressure: 1) reveals the presence of tamponade in cases without clinical suspicion; 2) indicates the efficacy of drainage; and 3) together with right atrial pressure recording, provides early diagnosis of associated cardiac disease, especially effusive-constrictive pericarditis.

Adult↗
PubMed1988

Interatrial conduction block and retrograde activation of the left atrium and paroxysmal supraventricular tachyarrhythmia.

We studied 16 patients with electrocardiographic evidence of advanced interatrial block and retrograde activation of the left atrium (P greater than or equal to 0.12 s, and diphasic (+/-) P waves in leads II, III, and VF). Eight patients had valvular heart disease, four had dilated cardiomyopathy and four had other forms of heart disease. Patients with valvular heart disease and cardiomyopathy were compared with a control group of 22 patients with similar clinical and echocardiographic characteristics, but without this type of interatrial block. Patients with advanced interatrial block and retrograde activation of the left atrium had a much higher incidence of paroxysmal supraventricular tachyarrhythmias (93.7%) during follow-up than did the control group, (27.7%) (P less than 0.001). Eleven of 16 patients (68.7%) with advanced interatrial block and retrograde activation of left atrium had atrial flutter (atypical in seven cases, typical in two cases, and with two or more morphologies in two cases). Six patients from the control group (27.7%) had sustained atrial tachyarrhythmias (five atrial fibrillation and one typical atrial flutter). The atrial tachyarrhythmias were due more to advanced interatrial block and retrograde activation of left atrium and frequent atrial extrasystoles than to left atrial enlargement, because the control group with a left atrium of the same size, but without advanced interatrial block and retrograde activation of left atrium and with less incidence of atrial extrasystoles, had a much lower incidence of paroxysmal tachycardia.

Aged↗
PubMed1988

Study of the evolution of masked bifascicular block.

Masked bifascicular block (MBB) (absent or minimal S in I and VL, high R in Vi and AQRS approximately -60 degrees) is a rare condition. We have found 16 such cases in the last 12 years, thirteen male and three female, mean age 70 +/- 9 years. The conventional electrocardiogram was tabulated and the clinical features and evolution of the patients were followed over 39.1 +/- 32 months. Ten patients required pacemakers, nine because of complete atrioventricular (AV) block or increase in the previous AV block. Seven patients died (follow-up 27.3 +/- 32 months), five from heart failure. This study shows: (1) MBB is a subgroup of patients with a high risk of advanced atrioventricular block; (2) a pacemaker implant does not significantly reduce the high mortality in this group because of the severity of the underlying disease; (3) these results should be evaluated in a larger series of patients in order to confirm our provisional results.

Aged↗
PubMedDate not supplied

Bladder-sparing treatment of invasive bladder cancer.

BACKGROUND: Radical cystectomy with pelvic lymph node dissection is the standard treatment for patients with invasive bladder cancer. However, many alternative techniques to spare the bladder have been investigated. METHODS: We review the experience reported in the literature on bladder-sparing techniques, including transurethral resection, chemotherapy, and radiation for muscle-invasive disease. RESULTS: Most comparative studies indicate that local recurrence and survival outcomes for bladder-sparing approaches are inferior to those from radical cystectomy to control muscle-invasive bladder cancer. CONCLUSIONS: Although molecular biologic techniques may have the capacity to identify a subgroup who may benefit from a bladder-sparing approach, cystectomy is normally required for optimal results.

Antineoplastic Agents↗
PubMedDate not supplied

Threshold and retreatment parameters of NPe6 photodynamic therapy in retinal and choroidal vessels.

BACKGROUND AND OBJECTIVE: To determine the threshold fluence for producing choroidal and retinal vascular occlusion with mono-L-aspartyl chlorin e6 (NPe6) photodynamic therapy (PDT) during primary treatment and the effect of retreatment. METHODS: Primary treatment: Rats, rabbits, and monkeys underwent NPe6 PDT to determine the threshold fluences for choroidal and retinal vessel occlusion. The threshold was determined by analyzing fluorescein angiograms for areas of nonperfusion. Retreatment: Dutch-belted rabbits underwent NPe6 PDT followed by fluorescein angiography. Rabbits were retreated one week later at the same parameters. RESULTS: Fluence levels and vascular damage thresholds were always higher for retinal than for choroidal vascular occlusion. Retreatment caused choroidal vessel closure at all tested fluences but retinal capillaries closed only at a fluence > 17.7 J/cm2. CONCLUSION: NPe6 PDT has a lower threshold to occlude choroidal vessels than retinal vessels. The cumulative effect of retreatment does not damage retinal vessels unless the threshold is exceeded during a single retreatment session.

Animals↗
PubMedDate not supplied

[Oral pathology in 161 asymptomatic and symptomatic HIV-positive patients].

The aim of this study was to establish the prevalence of oral manifestations in HIV-infected patients and to correlate their frequency with the clinical stage. One hundred and sixty one HIV-positive individuals were examined, of whom 64 (40%) were in stages CDC-II and III and 97 (60%) in stage CDC-IV. The patients were examined at the AIDS out-patient clinic of the Instituto Nacional de la Nutrición Salvador Zubirán. The oral exams were performed by three examiners who were intra and inter calibrated, so that standard clinical criteria were followed. One hundred and twenty five patients (78%) showed one or more oral lesions. The proportion of patients with oral lesions increased significantly (p less than 0.05) according to the severity of the infection. Hairy leukoplakia (40%) and erythematous candidiasis (31%) were the most frequent lesions. When the prevalence of the different oral lesions was compared between the patients at early stages with the patients at the late stage no significant differences were found; only the pseudomembranous candidiasis and the exfoliative cheilitis were found with significantly higher values at stage CDC-IV than at earlier stages (p less than 0.001 and p less than 0.05 respectively). No association was found between oral candidiasis and tobacco use or xerostomia. Our study demonstrates that the prevalence and clinical features of the oral manifestations found showed similarities with those reported in other countries, but ulcero-necrotizing gingivitis was not found in our patients.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Successful fibrinolytic treatment in a patient with acute mitral prosthetic thrombosis].

A case is described of a 50 year-old man with an acute prosthetic dysfunction due to valve thrombosis and cardiogenic shock, on a prosthesis in the mitral position (Bjork-Shiley). The patient was promptly treated with a streptokinase in two infusions 1.5 x 10(6) UI over 180 and 90 minutes, respectively. Early clinical, fluoroscopy and echocardiography improvement was observed. The authors comment the present role of the thrombolytic therapy in front of surgery of prosthetic valve thrombosis.

Acute Disease↗
PubMedDate not supplied

[The risk factors in primary bacteremias: a case-control study].

Nosocomial bacteremias are a important cause of mobility and mortality for hospitalized patients which, in addition, generate additional and elevated costs to the institutions. Its frequency has increased in the last year in relation to a greater number of patients, many of them immunosuppressed, which are submitted to invasive procedures. In this study, we analyzed the primary nosocomial bacteremias which occurred in our institution, carrying out a comparative case and control study in order to find the main risk factors which condition their occurrence. In a period of 42 months, 83 episodes of nosocomial primary bacteremias were detected. These represented an incidence of 8 per 1000 of patients which left the hospital and with a clear rising incidence in the last six months. In the Intensive Care Unit (ICU) a greater rate was found per sector (21.3 x 1000). The predominating agents were S. epidermidis, enterobacteremia, S. aureus and enteroccocci. Of the 15 possible risk factors analyzed by multiple regression, those significant were over two weeks of hospital stay and the use of parenteral feeding. These results make it imperative to reinforce control measures in the preparation of parental feeding solutions as in patients with prolonged hospital stay, especially in the ICU.

Adolescent↗