Study of the usefulness of optic fundi examination of patients with hypertension in a clinical setting.

The purpose of this study was to evaluate the usefulness of direct opthalmoscopy by non-opthalmologists in patients with hypertension. In a cross-sectional survey, we analysed the association between optic fundi abnormalities, individually and according to the criteria of Keith and Wagener (KW), with blood pressure and duration of known hypertension in 400 non-diabetic hypertensive patients. The optic fundi abnormalities were more frequent in patients with diastolic blood pressure (DBP) > 105 mm Hg (P = 0.002), SBP > 180 mm Hg (P < 0.0001) and with a duration of known hypertension > 3 years (P = 0.002). The severity of hypertension did not vary in parallel with the KW classes I and II: 34.5% of patients classified as KW I had a diastolic pressure of > 105 mm Hg compared with only 25.3% of those classified as KW II. Class III abnormalities were infrequent (2.5% of the whole cohort). In a logistic regression model, diffuse arteriolar narrowing was associated with DBP (P = 0.002) and age (P < 0.001). Abnormalities of the arteriovenous crossings were associated with SBP (P = 0.001) and duration of disease (P = 0.008). The positive predictive value of any fundoscopic abnormality to estimate the severity of hypertension was 59% and the negative value was 60%. The results of this study demonstrate that optic fundi examination by internists and cardiologists does not give an accurate assessment of the severity of hypertension in most patients, and that the Keith-Wagener classification of retinopathy has a limited applicability.(ABSTRACT TRUNCATED AT 250 WORDS)

Atherosclerosis and acute arterial thrombosis in rabbits: a model using balloon desendothelization without dietary intervention.

Acute thrombosis can be induced in rabbits by a triggering protocol using Russell's viper venom and histamine given after 8 months of a 1% cholesterol diet and balloon desendothelization. In the present study, we tested the hypothesis that aortic desendothelization performed 4 months before the triggering protocol without a high cholesterol diet is a highly effective and less expensive way of producing arterial atherosclerosis and thrombosis. Nineteen male New Zealand white rabbits on a normal diet were studied. The control group (N = 9) received no intervention during the 4-month observation period, while the other group (N = 10) was submitted to aortic balloon desendothelization using a 4F Fogarty catheter. At the end of this period, all animals were killed 48 h after receiving the first dose of the triggering treatment. Eight of 10 rabbits (80%) in the balloon-trauma group presented platelet-rich arterial thrombosis while none of the animals in the control group had thrombus formation (P < 0.01). Thus, this model, using balloon desendothelization without dietary manipulation, induces arterial atherosclerosis and thrombosis and may provide possibilities to test new therapeutic approaches.

[The neuropathological findings in the acquired immunodeficiency syndrome (AIDS): a review of 138 cases]. / Achados neuropatológicos na síndrome da imunodeficiência adquirida (SIDA): revisão de 138 casos.

This is an autopsy study performed in a retrospective fashion to determine the incidence of diseases that could affect the central nervous system in AIDS. For this purpose, 138 autopsies of patients with AIDS performed at the "Hospital de Clínicas de Porto Alegre", Brazil, between January/85 and December/90 were studied. All the brains were evaluated macroscopically and microscopically mainly through hematoxylin-eosin staining and if necessary special techniques like PAS, Grocott, Giemsa and Ziehl-Nielsen were done. Results have revealed 29 (21%) cases with cerebral toxoplasmosis; cryptococcosis in 17 (12%); tuberculosis in two (1%) and one case (0.7%) of candidiasis. Besides these inflammatory lesions, 15 (10%) presented vascular lesion; 8 (6%) had gliosis and 7 (5%) cases had suggestive findings of HIV encephalopathy. We can conclude that the CNS is a important target affected by AIDS and that cerebral toxoplasmosis is the principal disease in the CNS in AIDS patients.

[The sensitivity and specificity of the clinical, serological and tomographic diagnosis of Toxoplasma gondii encephalitis in the acquired immunodeficiency syndrome (AIDS)]. / Sensibilidade e especificidade do diagnóstico clínico, sorológico e tomográfico da encefalite por Toxoplasma gondii na síndrome da imunodeficiência adquirida (SIDA).

Toxoplasmic encephalitis (TE) is among the most common neurologic affections and it is the most prevalent cause of intracerebral mass lesions in AIDS patients. All patients with AIDS hospitalized at the Hospital de Clínicas de Porto Alegre between May/85 and December/91 (516 cases) had their files revised to determinate TE prevalence, serology, sensitivity and specificity of the computed tomography (CT) brain scan, clinical findings and serology to make its diagnosis. The prevalence on CT was 13% (presumptive diagnosis). Blood serology and cerebrospinal (CSF) serology to toxoplasma were positive respectively in 65% and 49%. Autopsies of 125 patients were also revised with a prevalence of 22% (definite diagnosis). CT scan had 65% of sensitivity and 82% of specificity. Sensitivity and specificity of serology on blood was respectively 95% and 30%, while the cerebrospinal fluid (CSF) serology had 77% of sensitivity and 56% of specificity. The following clinical findings were considered: fever (sensitivity = 92%; specificity = 56%), neurological focal signs (sensitivity = 59%; specificity = 82%) and headache (sensitivity = 41%; specificity = 69%). We conclude that, based on the high serology sensitivity and high CT scan specificity, they constitute an useful approach to make TE diagnosis.

Oxidized-LDL and paraoxonase-1 as biomarkers of coronary artery disease in patients with sleep-disordered breathing.

UNLABELLED: Coronary Artery Disease (CAD) and OBJECTIVES: Sleep Disordered Breathing (SDB) are both oxidative stress disorders. SDB intermittent hypoxia induces oxidative stress, and reduces NO(·) availability, causing endothelial dysfunction. Low-density lipoprotein (LDL) peroxidation is involved in atherosclerosis, and is reported in SDB. Oxidized LDL (ox-LDL) and malondialdehyde (MDA) are lipid peroxidation markers. High-density lipoprotein (HDL) presents antiatherosclerotic properties related to paraxonase-1 (PON-1) activity. PON-1 hydrolyseyses lipid peroxides as ox-LDL. This study compares the relationship of HDL and PON-1, the lipid peroxidation markers ox-LDL and MDA, and 8-OHdG DNA damage marker in the association of SDB and CAD. DESIGN AND METHODS: 29 controls and 27 cases with CAD (defined as > 30% coronary narrowing) patients were included. The apnea-hypopnea index (AHI), and several lipid and oxidative stress parameters were measured in these patients. RESULTS: AHI is increased in CAD patients, and PON-1 activity and HDL levels are decreased. Regression analyseyses showed that lower PON-1 activity and higher ox-LDL levels are important CAD predictors, compared to HDL or MDA levels and present an age-dependent increase. Nitrites and nitrates, indirect NO(·) markers, are positive vs correlated with PON-1 and are negatively correlated to ox-LDL. SDB is not correlated to PON-1 activity decrease or ox-LDL increase. AHI is inversely correlated to HDL levels. CONCLUSIONS: These results indicate that PON-1 and ox-LDL are important predictors of CAD, however they may not be directly related to SDB.

Atherosclerosis and acute arterial thrombosis in rabbits: a model using ballon desendothelization without dietary intervention

Acute thrombosis can be induced in rabbits by a triggering protocol using Russell's viper venom and histamine given after 8 months of a 1 per cent cholesterol diet and balloon desendothelization. In the present study, we tested the hypothesis that aortic desendothelization performed 4 months before the triggering protocol without a high cholesterol diet is a highly effective and less expensive way of producing arterial atherosclerosis and thrombosis. Nineteen male New Zealand white rabbits on a normal diet were studied. The control group (N = 9) received no intervention during the 4-month observation period, while the other group (N = 10) was submitted to aortic balloon desendothelization using a 4F Fogarty catheter. At the end of this period, all animals were killed 48 h after receiving the first dose of the triggering treatment. Eight of 10 rabbits (80 per cent) in the balloon-trauma group presented platelet-rich arterial thrombosis while none of the animals in the control group had thrombus formation (P<0.01). Thus, this model, using balloon desendothelization without dietary manipulation, induces arterial atherosclerosis and thrombosis and may provide possibilities to test new therapeutic approaches.