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Biomedical subjects

H Ramirez

Publications and source records attributed to H Ramirez.

At least 19 recordsLinked to original sources
PubMed2002

[Value of MR angiography in follow-up after cruro-pedal bypass surgery].

Patients after crural or pedal revascularization need a consequent surveillance to prevent graft failure. We compared the results of the clinical examination including duplexscanning with contrast-enhanced magnetic resonance angiography (MRA). 26 bypass grafts were evaluated for potential stenosis in five locations. Using both techniques, 93 of 109 locations were classified identically. 10 of 16 locations which were categorized differently were reviewed angiographically (DSA). In contrast to duplexscanning, MRA detected 3 high grade stenosis, which had to be dilatated percutaneously. MRA should be used regularly in surveillance programs of distal bypass grafting.

Adult↗
PubMed2001

Anti-inflammatory and tissue-protectant drug effects: results from a randomized placebo-controlled trial of gastritis patients at high risk for gastric cancer.

BACKGROUND: The inflammatory process involving Helicobacter pylori-associated gastritis is thought to lead to epithelial damage and contribute to the development of gastric cancer. Evidence exists from animal and in vitro studies suggesting that tetracyclines have both anti-inflammatory and tissue-protectant effects unrelated to their antimicrobial activity. We attempted to modulate components of H. pylori's inflammatory process by: (i) eliminating the infection; (ii) using tetracycline to alter the host's reaction to the infection without reducing the bacterial load; and (iii) using calcium to counteract the effect of excessive dietary salt. METHODS: We conducted a 16-week placebo-controlled clinical trial with 374 H. pylori-associated gastritis patients randomly assigned to one of five groups: (1) triple therapy consisting of metronidazole, amoxicillin and bismuth subsalicylate for 2 weeks, followed by bismuth alone for 14 weeks; (2) calcium carbonate; (3) triple therapy and calcium carbonate; (4) tetracycline; or (5) placebo. RESULTS: Subjects in the tetracycline and triple therapy groups, but not the calcium carbonate only group, showed a reduction in inflammation and epithelial damage vs. those in the placebo group, independent of a change in H. pylori density and other factors. Our results also indicate that epithelial damage may be affected by mechanisms independent of H. pylori density or inflammation. CONCLUSION: The results are consistent with the hypothesis that tetracycline can decrease inflammation independent of a reduction in the bacterial load. More research is needed to investigate mechanisms leading to epithelial damage which are independent of H. pylori density and inflammation.

Adult↗
PubMed1996

Prevalence of precancerous lesions of the stomach in Venezuela.

Gastric biopsies from 1477 participants in a chemoprevention trial for precancerous lesions of the stomach in Venezuela were evaluated for the prevalence of precancerous lesions and Helicobacter pylori infection. These study subjects were selected from participants in an early detection program for gastric cancer using double-contrast X-ray. Overall, 94% had some type of chronic gastritis (CG) and were positive for H. pylori using Giemsa stain, 49% had atrophic gastritis, 34% had intestinal metaplasia (IM), and 6.5% had dysplasia. There were only three subjects (0.2%) with normal gastric mucosa, and 4% had only superficial gastritis. The prevalence of all of these precancerous lesions increased with age, but there was no clear difference by gender. The prevalence of the various lesions was higher in the antral mucosa than in the fundic mucosa. H. pylori infection was strikingly frequent in our study population, with prevalence rates ranging from 73% in subjects with superficial gastritis to 95% in those with atrophic gastritis and IM and 98% in those with CG. The prevalence of H. pylori was equally high in males and females, and it was significantly positively associated with the degree of infiltration of poly- and mononuclear cells and with that of active regeneration; it was inversely correlated with the degree of atrophy, IM, and dysplasia. Our findings support the precancerous nature of the various gastric lesions and the etiological role of H. pylori infection in CG.

Adult↗
PubMed1989

A survey of the human T-cell lymphotropic virus type I (HTLV-I) in south-western Colombia.

To evaluate altitude of birthplace and residence as factors associated with geographic clustering of HTLV-I infection in Colombia, we sampled a total of 670 current residents of the South Pacific coastal lowland and of upland regions (Cali and environs) of the Valle and Cauca Provinces, located at an altitude of 3,100 ft. Among the 255 lowland study subjects, 4.3% had antibody against HTLV-I, compared to 0.9% of the 415 upland study subjects. A hypothesis emerging from this study is that the lower socio-economic status of lowland residents and associated diseases, particularly untreated syphilis and other sexually transmitted diseases, may explain the increased HTLV-I seropositivity rates in this population.

Adult↗
PubMed1989

[Diagnosis of facial pain: a clinical experience].

A sample of 228 patients with facial pain is reported in the present paper. Among them, 112 cases are typical idiopathic trigeminal neuralgias, 111 are cases of secondary facial pain (including 7 cases symptomatic trigeminal neuralgias) and 5 patients were classified as vascular facial pain. Among the 119 cases of clinically diagnosed trigeminal neuralgias there were 112 (94, 11%) with no evidence of organic cause. Only 7 cases (5.89%) were identified as organic, including 3 cases of bulbar and pontic vascular lesions, 2 cases of iatrogenic injuries following neurosurgery, 1 case of meningioma of the ponto-cerebellar angle and 1 case of neurosyphillis. The most frequent conditions that produce secondary facial pain were: miofacial pain syndrome, sinusitis, cervical vertebral lesions, post herpetic neuralgias, malignant head and neck tumours and encephalic vascular lesions of the pain pathway.

Adult↗
PubMed1989

[Pharmacotherapy of trigeminal neuralgia].

The efficacy of drug treatment on 119 patients with trigeminal neuralgia is reported in the present paper. Among them, 112 were idiopathic trigeminal neuralgias while only 7 cases were secondary trigeminal neuralgias. All patients were treated with drugs at different stages of the evolution of the neuralgia. Carbamazepine was used on all patients. 12.6% was treated with imipramine (tricyclic antidepressive drug), 4 patients received amphetamines due to psychiatric emergencies, 4 patients were treated with phenytoin before this study and three patients received baclofen during short periods of follow-up. Drug therapy was the only treatment method in 51 patients. In 43 patients it was combined with peripheral surgical treatments including injections of alcohol and neurectomies. 16.8% of the patients were treated with drugs and acupuncture; the results of this experience will be reported in a future paper. Only 4.2% (5 patients) underwent neurosurgical treatment: one ponto cerebellar angle tumour, one electrocoagulation of the gasserian ganglion through the stereotaxic method and three cases of microvascular decompression of the trigeminal root. Clinical, pharmacological and neurophysiological aspects of trigeminal neuralgia pharmacotherapy are discussed.

Amphetamines↗
PubMed1986

Meningeal neurosarcoidosis mimicking convexity en-plaque meningioma.

A 34-year old man presented with headaches. Computed tomography scanning revealed an enhancing subdural mass extending from the skull base to the convexity, thought to represent an en-plaque meningioma. Pathologic study revealed extraaxial subdural granulomatous inflammation consistent with neurosarcoidosis.

Adult↗
PubMed1985

Development of lipidic composition of neonatal chick liver and intestine microsomes: changes induced by cholesterol feeding.

Changes in cholesterol and phospholipid content of chick liver and intestine microsomes were studied throughout the two first weeks of life. Differences observed throughout postnatal development were mainly due to the free cholesterol. Cholesterol feeding resulted in a clear increase of the amounts of both free and esterified cholesterol. Phospholipid content of chick liver and intestine microsomes did not change significantly after hatching. Phosphatidylcholine and phosphatidylethanolamine were found to be the major phospholipids. Although the amount of each phospholipid could be affected by cholesterol feeding, its relative percentage did not change by this treatment.

Aging↗
PubMed1985

Computed tomography detection of cervical spinal cord hemangioblastoma: a case report.

Hemangioblastomas of the spinal cord are uncommon, accounting for 1.6% and 2.1% of all spinal cord tumors (1). Until recently these vascular lesions were best evaluated angiographically. Several cervical hemangioblastomas have been studied by computed tomography with intravenous contrast medium enhancement (2-4). This report illustrates the use of computed tomography with combined intravenous and intrathecal contrast medium enhancement, which permitted preoperative diagnosis and treatment planning of an intramedullary hemangioblastoma.

Female↗
PubMed1985

Effect of dietary cholesterol and cholestyramine on developmental pattern of 3-hydroxy-3-methylglutaryl-CoA reductase.

Supplementation of the diet with 2% cholesterol suppressed the increase observed in the hepatic and intestinal 3-hydroxy-3-methylglutaryl-CoA reductase activity from normally fed chicks during the first days after hatching. Cholestyramine feeding clearly increased both hepatic and intestinal reductase activities. In contrast, brain reductase did not show significant changes by cholesterol or cholestyramine feeding. Dietary cholesterol produced a clear increase in the cholesterol/lipidic phosphorus molar ratio of hepatic and intestinal microsomal membranes. However, this molar ratio did not change by cholestyramine feeding during postnatal development. Both dietary cholesterol and cholestyramine had practically no effect on the cholesterol/lipidic phosphorus molar ratio of brain microsomes. The relationship between the inhibition of reductase activity by dietary cholesterol and the increase of cholesterol/lipidic phosphorus molar ratio is in agreement with a mechanism of regulation of both hepatic and intestinal reductase by alterations of membrane fluidity, mechanism that would be already operative during the neonatal period.

Animals↗
PubMed1984

Relationship between inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase by cholesterol feeding and short-term changes in membrane fluidity during neonatal development.

Both 5% cholesterol feeding and fasting produced a decrease in the hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity, although certain diurnal variations remained during the second day of treatment. Supplementation of 5% cholesterol to the diet produced a significant increase in cholesterol content of hepatic microsomes, whereas no significant variations were observed after fasting. The phospholipid content of hepatic microsomes did not change by fasting. However, cholesterol feeding produced a clear decrease in microsomal phospholipids. After 7 hr of cholesterol feeding, an increase of nearly 3-fold in the cholesterol/lipidic phosphorus molar ratio was found. Fasting had no effect on this molar ratio. The changes observed by cholesterol feeding agree with a mechanism of regulation of hepatic reductase by alteration in membrane fluidity, a mechanism that would be already operative during the neonatal period.

Animals↗
PubMed1984

Lipid composition of brain myelin from normal and hyperphenylalaninemic chick embryos.

The influence of hyperphenylalaninemia on the lipid composition of brain myelin has been investigated in 19-day-old chick embryos. CNP-ase activity was used as myelin marker enzyme for myelin isolation. CNP-ase activity was significantly lower in hyperphenylalaninemic myelin when compared with control. No significant differences were observed after experimental treatment in the total lipid content of myelin as well as in the proportion of cholesterol:phospholipid:galactolipid. Nevertheless, a clear increase in the percentage of esterified cholesterol was found. No appreciable alterations were observed in the phospholipid composition of brain myelin from both control and hyperphenylalaninemic chick embryos. However, the ratio of unsaturated to saturated fatty acids in serine plasmalogen and sphingomyelin was considerably increased by this treatment. This ratio in choline and ethanolamine phosphatides from treated embryos did not differ from that of controls.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗
PubMed1984

"Cupid's bow" contour of the lumbar vertebral endplates detected by computed tomography.

A characteristic pattern of altered lumbar spine endplate morphology has been frequently noted in patients being evaluated for unrelated indications. The "owl's eyes" configuration of intravertebral disc material on axial transverse computed tomographic sections easily distinguishes this normal variant from pathologic processes. Two representative cases are provided for illustration, one of which on coronal reformations demonstrated the normal "Cupid's bow" contour previously described on frontal plain radiographs.

Adult↗
PubMed1984

Intraosseous pneumatocysts of the ilium. Findings on radiographs and CT scans.

CT scans demonstrated a localized collection of gas adjacent to a normal sacroiliac joint in 5 patients. In each case the lesion was sharply demarcated by a thin sclerotic rim. A benign bone cyst was confirmed histologically in 2 cases. The radiologist should be aware of this appearance so as to avoid invasive procedures based on a misdiagnosis of infection or neoplasm.

Adult↗