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Biomedical subjects

R García

Publications and source records attributed to R García.

At least 253 records · Page 14Linked to original sources
PubMedDate not supplied

Study of the DNA content by flow cytometry and proliferation in 281 brain tumors.

In this paper we investigate the distribution of DNA ploidy as well as proliferation rate (S phase of the cell cycle Ki-67 staining) in 281 tumors of the central and peripheral nervous system (87 meningiomas, 75 astrocytomas, 44 nerve sheath tumors, 25 brain metastases, 18 pituitary adenomas, 17 ependymomas, 12 oligodendrogliomas and 3 medulloblastomas) and their correlation with the histopathological grade. Considering all 281 tumors, aneuploidy is the most frequent finding present: 52%. This percentage increases with malignancy: 69% of malignant tumors are aneuploidy. Levels of aneuploidy decrease from brain metastases to pituitary adenoma (92% in brain metastases, 83% in oligodendrogliomas, 59% in nerve sheath tumors, 47% in ependymomas, 40% in astrocytomas, 35% in meningiomas and 33% in pituitary adenomas), but aneuploidy is also found in many benign tumors. With respect to proliferation rate of tumors, S phase above 20% were recorded in the more malignant tumors: brain metastases, oligodendrogliomas, high-grade ependymomas, high grade astrocytomas, and in atypical and malignant meningiomas, but this parameter is not able to distinguish between low and high grade tumors. However, Ki-67 reactivity was equivalent in all histologies with significant differences between low and high grade tumors.

Adenoma↗
PubMedDate not supplied

Relationship between low bone mineral density and highly active antiretroviral therapy including protease inhibitors in HIV-infected patients.

PURPOSE: The objectives of this study were to determine the prevalence of osteopenia and the factors associated with its presence in HIV-infected patients under highly active antiretroviral therapy (HAART) and to assess the changes of bone mineral density (BMD) in a population followed prospectively. METHOD: BMD was assessed by dual-energy X-ray absorptiometry (DEXA) scans at the lumbar spine and at the femoral neck in 78 HIV-infected patients who had previously received HAART as the first antiretroviral regimen and in 11 antiretroviral-naive HIV-infected patients. BMD measurements were repeated in 70 treated patients who had completed 1 year of follow-up. RESULTS: Thirty-seven (42%) patients showed osteopenia at any localization. The prevalence of osteopenia in PI-naive patients was 23% versus 49% in individuals who had received PI at any moment [p =.001; adjusted odds ratio (95% CI) = 0.11 (0.02-0.48)]. The frequency of osteopenia was significantly higher among men than among women [50% vs. 17%; p =.016; adjusted OR (95% CI) = 12.1 (2.22-66.20)]. The level of plasma albumin was independently associated with osteopenia [adjusted OR (95% CI) per each g/dL of plasma albumin decrease 2.55 (1.18-10)]. In patients in whom a second DEXA was done, no significant changes in BMD were found. CONCLUSION: The prevalence of osteopenia in HIV-infected patients on HAART is high. Loss of BMD is associated with PI therapy, low plasma albumin level, and male sex. Osteopenia does not progress after 1 year of continued HAART.

Absorptiometry, Photon↗
PubMedDate not supplied

Patterns of immunoglobulin E sensitization to chironomids in exposed and unexposed subjects.

We present our study of four patients with occupational type I allergy to red midge larvae (group 1) who we compared with seven individuals also sensitized to red midge larvae but who had not apparently been exposed to them (group 2). All patients showed elevated specific IgE against Chironomus thummi, and positive skin prick tests (SPT) and provocation tests with red midge larvae. We carried out SPT with Dermatophagoides pteronyssinus, Acarus siro, shrimp, cockroach and common mosquito (Culex pipiens) and specific serum IgE was also determined. The red midge larvae wheal size was significantly larger in group 1 (x = 149.2 mm2) than in group 2 (x = 18 mm2). Significant differences between levels of IgE anti-C. thummi were also found in group 1 (x = 52.12 kU/l) and in group 2 (x = 1.5 kU/l). The patients in group 2 had high levels of specific IgE against other allergens (D. pteronyssinus, shrimp and/or common mosquito) and had positive SPTs with these allergens, while the patients in group 1 were only sensitized to chironomids. The IgE-immunoblotting profile was quite different in both groups. The patients in group 1 seemed to have IgE against Chi t 1, the main Chironomus allergen, while the patients in group 2 had IgE against several protein bands in Chironomus, mosquito, shrimp and D. pteronyssinus extracts, some of them with equivalent molecular weights. We believe that the patients in group 2 were sensitized to Chironomus as a result of cross-reactivity with other insect or crustacean species.

Adolescent↗
PubMedDate not supplied

Nonpigmented fixed drug eruption caused by paracetamol.

Fixed drug eruption from paracetamol is not rare but no cases of nonpigmented fixed drug eruption caused by paracetamol have been previously described. We present the case of a woman who developed a nonpigmented fixed drug eruption following administration of paracetamol. Patch tests performed on affected and unaffected skin with paracetamol were negative. The diagnosis was made by a double-blind oral challenge with paracetamol. The patient tolerated aspirin.

Acetaminophen↗
PubMedDate not supplied

[Neurophysiological clinical study of 70 patients with type 2 spinocerebellar ataxia].

INTRODUCTION: The prevalence of hereditary ataxia in Holguín, Cuba, is 43 per 100,000 inhabitants, but in some regions reaches 503 per 100,000 inhabitants, a figure never previously recorded in the international literature. OBJECTIVES: To evaluate the part played by non-cerebellar structures and vias in causing some of the clinical signs of the disorder by means of clinico-electro physiological correlation. PATIENTS AND METHODS: A neurological examination, peripheral nerve conduction studies and somato-sensorial evoked potentials of the median and posterior tibial nerves were done in 70 patients with type 2 spinocerebellar ataxia. RESULTS: The commonest clinical signs were ataxia on walking, dysarthria, dysmetria and adiadochokinesia. Correlation analysis showed that the variable most significantly correlated with the degree of ataxia and Romberg's sign was latency of the P40 component, whilst tendon reflexes were best correlated with H reflex latency. However, the duration of the disease was not found to have statistical correlation. CONCLUSIONS: These results suggest that degeneration of long peripheral nerves and sensory paths contributes to the degree of ataxia and other clinical signs. At present no correlation has been found between the duration of the illness and increasing electrophysiological changes, and therefore seems not to have a major effect on neurodegenerative mechanisms.

Adolescent↗
PubMedDate not supplied

[Early prognosis in chronic subdural hematomas. Multivariate analysis of 137 cases].

INTRODUCTION: In the literature there is evidence relating different factors such as age and preoperative clinical condition with prognosis in patients treated surgically for chronic subdural haematoma. OBJECTIVE: To clarify and quantify the magnitude of the factors which determine early prognosis (during hospital admission) of these patients. PATIENTS AND METHODS: We made a prospective study of 137 patients who had been operated on in our centre and found the relationship between different clinical and therapeutic variables with the clinical course and morbidity-mortality by means of multivariate and survival analysis. RESULTS: A high Markwalder functional score (3-4) is an independent factor of poor prognosis (OR = 13.15; CI 95% 6.1-28.4; p = 0.01), as is the presence of a coexisting coagulopathy (OR = 27.2; CI 95% 9.3-79.5; p = 0.01). Advanced age tended to increase the risk (OR = 1.104) but did not reach statistical significance (p = 0.0654). A multivariate logistic model, which included the functional score and presence of coagulopathy, correctly classified 94.7% of the cases studied. Analysis of survival showed two groups with different early mortality as a function of the Markwalder score (high: 3-4 and low: 0-1-2), which could be differentiated statistically (Log-Rank chi squared test: 3.95; p = 0.0468). CONCLUSIONS: The preoperative clinical state classified by functional scores and the presence of underlying coagulopathy are the main prognostic factors in chronic subdural haematoma during hospital admission. Advanced age is probably not in itself an independent factor for bad prognosis.

Aged↗
PubMedDate not supplied

[Is the correlation between adequate dialysis in peritoneal dialysis and nutritional parameters mathematical or biological? Influence of residual renal function and comorbidity].

The relationship between urea Kt/V and nPCR (nPNA) is partly due to a mathematical coupling and greatly depends on the residual renal function (RRF). On the other hand, albumin could be just a comorbidity marker. Our objective in this study was to verify whether dialysis dose in peritoneal dialysis (PD) is biologically related to the nutritional state measured by the mean values of several parameters not mathematically related while analyzing the influence of RRF and comorbidity (C). 101 stable PD patients, 60M and 41F with a mean age of 59.3 +/- 14.3 years, were studied and followed up every six months for a mean time of 35.8 +/- 22.3 months (8-112). The variables studied were initial comorbidity, plasma albumin, normalized protein nitrogen appearance (nPNA), lean body weight % (LBW%) and fat-free mass index (FFMI) derived from creatinine, and RRF. In every study (n = 471) the 24 hours dialysate and urine volumes were collected and the total (T), dialytic (P) and renal (R) urea KT/V and normalized creatinine clearance (CCR) were determined and compared with the nutritional parameters. When starting PD 48 patients (47.5%) had some C and 34 (33.7%) were already anuric. The correlations of nPNA with T-KT/V and T-CCR (n = 101) were r = 0.67 and 0.50 (p < 0.0005) while the correlations of LBW% with T-KT/V and T-CCR were r = 0.36 and 0.40 (p < 0.0005) respectively. The correlations of albumin with T, P and R KT/V and CCR did not reach significance. The nutritional state was better in patients with a higher RRF and albumin showed significant differences when related to morbidity. KT/V and CCR correlations with nutritional variables not mathematically related verify the hypothesis that dialysis dose is biologically associated with the nutritional state.

Adult↗
PubMedDate not supplied

[Hereditary ataxias in Cuba. Historical, epidemiological, clinical, electrophysiological and quantitative neurological features].

OBJECTIVE: This review has been designed to describe the main clinical, epidemiological, electrophysiological, molecular and quantitative neurological characteristics in SCA2. DEVELOPMENT: The prevalence rate of patients with ataxia in Holguin province is 43 per 100,000 inhabitants. The prevalence of family members at risk of having this disorder is 159.33 per 100 thousand in this province. The main neurophysiological abnormality observed was reduction in the amplitudes of sensory potentials. These alterations are the expression of a predominantly axonal peripheral lesion with signs of myelin damage. Techniques of quantitative neurology were developed for evaluation of the main disorders of coordination such as asymmetry and adiadochokinesis. In Cuba 125 families have hereditary ataxia, 772 patients and 8 to 10,000 family members are at risk of developing this condition. Seventy percent of the patients with ataxia are concentrated in Holguin province. The most severely affected towns are Báguanos (a rate of 129.20 per 100,000 inhabitants), Holguin (71.85 per 100,000) and Cacocúm (69.83 per 100,000). These are the highest rates in the world. CONCLUSIONS: The commonest molecular form in Cuba is the SCA2, observed in 120 families. Clinically it is characterized by a cerebellar syndrome associated with disorders of eye movements and osteotendinous reflexes.

Adolescent↗
PubMedDate not supplied

[Epidemiology of Cuban hereditary ataxia].

INTRODUCTION: The hereditary ataxias in Cuba make up the highest concentration of these patients in the world. The spinocerebellar ataxia type 2 (SCA2) molecular form is predominant. OBJECTIVES: To determine the prevalence and incidence of hereditary ataxias. PATIENTS AND METHODS: We made a descriptive study of 440 patients and 1,633 members of families at risk from this disorder in the province of Holguín. We calculated the prevalence rate and incidence. RESULTS: The rate of prevalence of patients in the province is 43 cases per 100,000 inhabitants; the highest rate was 503 cases per 100,000 inhabitants in part of the municipality of Baguanos. The age group that was most affected was that of 30-39 years, with a prevalence of 63.97 cases per 100,000 inhabitants. The rural population showed the highest incidence (62.04 cases per 100,000 inhabitants). The risk of members of affected families showing the disorder was 159.33 cases per 100,000 inhabitants in this province. The highest incidence was 18.08 cases per 100,000 inhabitants in Cacocum, where the incidence in the province was 4.39. CONCLUSIONS: On average the disorder passes from one state to the next every year, which suggests that the extent of the disorder worsens with time. The prevalence and incidence are the highest in the world. This together with the dominant pattern of inheritance, the effect of anticipation and inexorably progressive course of the disorder shows the serious health problem that affects the Eastern region of Cuba.

Adult↗
PubMedDate not supplied

Mean hospital stay and treatment with electroconvulsive therapy.

INTRODUCTION: The objective is to analyze if the mean hospital stay is less than the episodes or not in which electroconvulsive therapy (ECT) is applied. METHODS: With a retrospective design, we studied a sample of 30 patients in whom ECT was applied between 1996 and 2001. These patients were suffering a disorder for which ECT has been shown to be effective (schizophrenia, bipolar disorder and major depression). Each one of the episodes (n = 185) of these patients was studied, comparing the length of stay in the hospital in these patients in which ECT was applied (n = 135) with those where it was not (n = 50). Statistical analysis was carried out by non-parametric Mann-Whitney-U tests. The descriptive level of statistical significance was established at p < 0.05. RESULTS: This work shows statistically significant differences between the treatment groups (p = 0.000), the length of stay being longer when ECT is applied.

Adult↗
PubMedDate not supplied

[Prevalence of Trypanosoma cruzi infection in Nicaraguan students. Isle of Youth Special Municipality. February, 1987].

A seroepidemiologic study on American trypanosomiasis was performed to a group of Nicaraguan students in Isle of the Youth Special Municipality, during February 1987, using indirect hemagglutination and indirect immunoflorescence techniques. The prevalence obtained with both tests and the percentage of the most frequent titer of indirect immunofluorescence are pointed out. The youth living in rural zones presented higher risk of acquiring the infection than those living in urban zones. The students coming from the Atlantic Coast, Rio San Juan and Masaya, presented the highest positive rates. Of those who were interviewed, 59% identified the Triatoma, and 13% of them manifested to have seen it inside homes. The background of being bitten by the Tritoma was present in 16.2% of those with positive results.

Adolescent↗
PubMedDate not supplied

[Evaluation of a molecular hybridization trial for the detection of circulating DNA of hepatitis B virus. Immunoclinical correlation].

Immunoclinical correlation of the HBV circulating DNA was performed. The DNA was detected by means of a hybridization technique set-up in fluid phase using a complementary DNA probe labelled with 125I (Abbott-Genostics). The correlation was carried-out in 12 serum including 8 from known HBV carriers with or without liver disease. Only the positive HBeAg serum shown circulating viral DNA in ranges between 60 to 2800 pcg/ml. The assay shows to be easy to perform, however the expensive cost plus the use of a short-life isotope makes difficult in routine use, which still is under research. The immunopathogenic significance of the findings is discussed.

DNA, Viral↗