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Biomedical subjects

E Velasco

Publications and source records attributed to E Velasco.

At least 37 records · Page 2Linked to original sources
PubMed1999

HIV-associated pityriasis rubra pilaris responsive to triple antiretroviral therapy.

HIV-associated pityriasis rubra pilaris (PRP) or PRP type VI designates a new distinctive entity reported in HIV patients. It is characterized by cutaneous lesions of PRP and variable association with lesions of acne conglobata, hidradenitis suppurativa and lichen spinulosus. We report a patient with HIV-associated PRP which was treated by triple antiretroviral therapy (zidovudine, lamivudin and saquinavir) with complete response. The patient has remained free from symptoms for 20 months of follow-up. We review the clinical features, pathology, evolution, treatment and possible aetiology of this recently described entity.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Basal cell carcinoma of the scrotum.

An 80-year-old man with a 7 year history of a slowly enlarging, asymptomatic scrotal nodule is presented. He had a negative history for sexually transmitted disease, trauma to the area, radiotherapy and chemical or arsenic exposure. The lesion was excised with a margin of 0.8 cm of normal skin. Examination of the specimen revealed a basal cell carcinoma.

Aged↗
PubMed1999

Phase behavior of binary hard-sphere mixtures from perturbation theory.

Using a first-order perturbation theory, we have studied the phase diagram of a binary mixture of hard spheres for different values of the size ratio. Recent models for the two-body depletion potential between large spheres are used to take into account the role of the small spheres. The theory predicts a complex phase diagram including a fluid-solid transition at high packing fraction of small spheres, metastability of fluid-fluid demixing, an isostructural solid-solid transition at high packing fraction of the large spheres for sufficiently small values of the size ratio q of the spheres, and the tendency to sticky-sphere behavior in the limit q-->0. The agreement with recent simulation results is quite good. We also show that this phenomenology was already implicit in the pioneering work of Asakura and Oosawa.

Journal Article↗
PubMed1999

Comparison of the toxicity of amphotericin B in 5% dextrose with that of amphotericin B in fat emulsion in a randomized trial with cancer patients.

A multicentric randomized trial was undertaken to compare the toxicity of amphotericin B in 5% dextrose with that of amphotericin B in a fat emulsion (Intralipid) in cancer patients. Group 1 (n = 33) received amphotericin B diluted in 5% dextrose with premedication consisting of promethazine plus an antipyretic. Group 2 (n = 28) received amphotericin B diluted in 20% Intralipid without premedication. Amphotericin B was infused daily at a dose of 1 mg/kg of body weight over a 1-h period to members of both groups for empirical antifungal therapy (in neutropenic patients) or for the treatment of documented fungal infections. The majority of patients (80%) received empirical amphotericin B treatment. The two groups were comparable with regard to age, gender, underlying disease, and the following baseline characteristics: use of other nephrotoxic drugs and serum levels of potassium and creatinine. The median cumulative doses of amphotericin B were 240 mg in group 1 and 245 mg in group 2 (P = 0.73). Acute adverse events occurred in 88% of patients in group 1 and in 71% of those in group 2 (P = 0.11). Forty percent of the infusions in group 1 were associated with fever, compared to 23% in group 2 (P < 0.0001). In addition, patients in group 2 required less meperidine for the control of acute adverse events (P = 0.008), and fewer members of this group presented with hypokalemia (P = 0.004) or rigors (P < 0.0001). There was no difference in the proportions of patients with nephrotoxicity (P = 0.44). The success rates of empirical antifungal treatment were similar in the two groups (P = 0.9). Amphotericin B diluted in a lipid emulsion seems to be associated with a smaller number of acute adverse events and fewer cases of hypokalemia than amphotericin B diluted in 5% dextrose.

Adolescent↗
PubMed1998

Risk factors for bloodstream infections at a cancer center.

A hospital-based matched case-control study was conducted in order to identify risk factors for the development of bloodstream infections in adult hospitalized patients. Between January 1993 and December 1994, 264 episodes of bloodstream infection were evaluated. Significant variables identified by univariate analysis were included in a multivariate model that showed that central venous catheter [odds ratio (OR), 6.71], poor performance status (OR, 3.40), weight loss (OR, 2.47), hematologic diseases (OR, 2.24), and previous antimicrobial therapy (OR, 2.12) independently influenced the outcome. The knowledge of modifiable risk factors is useful in the development of strategies that may contribute to the prevention of bloodstream infections.

Adolescent↗
PubMed1998

Risk index for prediction of surgical site infection after oncology operations.

INTRODUCTION: Several studies have shown that surgical site infections represent most hospital-acquired infections, with the major impact being on average hospital stay and cost of hospitalization. METHODS: To develop a risk model for prediction of surgical site infections in cancer patients undergoing operative procedures and identify those with high probability of infection we performed a prospective cohort study in a tertiary cancer care hospital in Rio de Janeiro, Brazil. Risk factors were studied in single and multivariate analyses. RESULTS: Over a 24-month period, 1205 patients underwent operations for malignant disease. The overall surgical site infection rate was 17.3%. A multivariate stepwise logistic regression model identified six independent predictive risk factors: contaminated and infected operations, surgical duration greater than 280 minutes, male sex, prior radiotherapy, American Society of Anesthesiology class III to V, and antimicrobial prophylaxis not according to protocol. On the basis of individual risk scores, two groups of patients were identified: a low-risk (score < or = 8; surgical site infection rate 10%) and a high-risk group (score > or = 9; surgical site infection rate 33.6%; relative risk 3.4; 95% confidence interval 2.6 to 4.4). CONCLUSION: The oncology risk model allowed for the identification of a high-risk score group of patients and implementation of a more efficient and selective intervention program.

Brazil↗
PubMed1998

Fungemia in cancer patients in Brazil: predominance of non-albicans species.

The objective of this study was to characterize the epidemiology of candidemia in cancer patients in the city of Rio de Janeiro, Brazil. An 18-month survey of fungemia in patients with cancer was undertaken in three Hospitals in Rio de Janeiro. Forty-three episodes of candidemia were identified in 43 patients, 43 of which were episodes of candidemia; in ten case the strains were not available for further identification of species and were excluded from this analysis. The overall distribution of fungi causing fungemia was: Candida albicans (5), Candida tropicalis (16), Candida parapsilosis (6), Candida guilliermondii (4), Candida lusitaniae (1) and Candida stellatoidea (1). Antifungal prophylaxis had been administered before the episode of fungemia in only six patients (18.2%): oral itraconazole in three patients and oral nistatin, low dose intravenous amphotericin B and oral fluconazole in one patient each. There was no difference in the presence of risk factors, clinical characteristics or in the outcome between albicans and non-albicans species, nor between Candida tropicalis and other non-albicans species. There was a clear predominance of non-albicans species, regardless of the underlying disease, antifungal prophylaxis or the presence of neutropenia.

Brazil↗
PubMed1998

Risk factors for death among cancer patients with fungemia.

In order to identify prognostic factors for death among cancer patients with fungemia, an 18-month survey of fungemia in patients with cancer was undertaken in three hospitals in Rio de Janeiro. For the assessment of risk factors for death, the following variables were analyzed: age; gender; underlying cancer; last treatment for the underlying disease; previous surgery; use of antibiotics, antifungal agents, steroids, or total parenteral nutrition; use of a central venous catheter; chemotherapy; radiotherapy; presence and duration of neutropenia; etiologic agent of the fungemia; treatment of the fungemia; clinical manifestations; and performance status (Karnofsky score) on the day of the positive blood culture. In multivariate analysis, the variables associated with an increased risk for death were older age, persistent neutropenia, and low performance status. Identifying risk factors for death may help to define a group-risk patients for whom new therapeutic options should be tried.

Adult↗
PubMed1998

An outbreak of Bacillus species in a cancer hospital.

Bacillus species were recovered from the blood cultures of 39 oncology patients over 14 weeks. A matched case-control study showed a strong association of Bacillus species bacteremia with use of calcium gluconate solution (odds ratio=25.0) and of central venous lines (odds ratio=8.8). Stopping use of the implicated calcium gluconate vials controlled the outbreak.

Adolescent↗
PubMed1998

Analysis of the monomeric alphoid sequences in the pericentromeric region of human chromosome 7.

To further define the structure of the pericentromeric region of human chromosome 7, we have identified and characterized a YAC clone (YAC 311.H5) containing the D7S1480 locus, which maps to the short arm near the centromere of this chromosome, by linkage in CEPH families and radiation hybrid analysis. This YAC contains two new blocks of alphoid DNA (named Z5 and Z6). Both Z5 and Z6 show monomeric structures and a lack of higher-order repeats, and, therefore, belong to suprachromosomal family type 4 (M1). The orientation of the two blocks and the physical distances over the region were defined by pulsed-field gel electrophoresis (PFGE) and fluorescence in situ hybridization on chromatin fibers (FiberFISH). A YAC contig spanning the centromeric region has been developed by STS content.

Cells, Cultured↗
PubMed1998

Distinct location and prevalence of alpha-, beta-catenins and gamma-catenin/plakoglobin in developing and denervated skeletal muscle.

We studied the distribution of alpha-catenin, beta-catenin and gamma-catenin/plakoglobin in developing, adult and denervated mouse skeletal muscle. During primary myogenesis, all three catenins present a subsarcolemmal distribution within primary myotubes. During secondary myogenesis they accumulate at myotube-myotube contacts. In contrast to the other catenins, gamma-catenin is strongly expressed in the sarcoplasm. In adult muscle, all three catenins are localized on the presynaptic elements of the neuromuscular junction. In denervated muscles, alpha- and beta-catenins are upregulated like N- and M-cadherin, while the levels of gamma-catenin/plakoglobin remain unchanged. The developmental changes in localization and regulation of alpha- and beta-catenins in muscle compared to gamma-catenin/plakoglobin are suggestive of a privileged association of alpha- and beta-catenins with N- and M-cadherins, while gamma-catenin/plakoglobin appears to be expressed quite independently and must assume a different role during myogenesis.

Animals↗
PubMed1998

The peripheral nerve and the neuromuscular junction are affected in the tenascin-C-deficient mouse.

A thorough examination of the structure and plasticity of the neuromuscular system was performed in tenascin-C mutant mice deficient in tenascin-C. The study of the peripheral nerve revealed a number of abnormal features. In the motor nerve, numerous unmyelinated and myelinated fibers with degraded myelin were present. Schwann cell processes often enclosed degenerative terminals. Transgene (beta-galactosidase) expression analyzed at the ultrastructural level was found to be unequally distributed in the mutant's neuromuscular tissues. At the NMJ, preterminal disorganization was prevalent. Some axon terminals exhibited abnormal overgrowth. A surprising lack of beta-galactosidase expression at some cellular sites known to possess tenascin-C in wild type mice correlated best with marked changes in the cytoarchitecture of the peripheral nerve and NMJ. In some other -but not all- cellular sites which normally express the molecule, immunofluorescence analysis suggested the presence of significant but low levels of tenascin-C-like immunoreactivity together with beta-galactosidase expression. Messenger RNA detection by RT-PCR confirmed the presence of low amounts of tenascin-C mRNA in skeletal muscle suggesting that the mice deficient in tenascin-C are not complete knock-outs of this gene, but low-expression mutants. Following in vivo injections of botulinum type-A toxin, we observed a greatly reduced sprouting response of the motor nerves in tenascin-C mutant mice. We also observed that N-CAM and beta-catenin were overexpressed in the mutant. Our results suggest that tenascin-C is involved both in stabilization and in plasticity of the NMJ.

Animals↗
PubMed1997

Identification of de novo deletions at the NF1 gene: no preferential paternal origin and phenotypic analysis of patients.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder. To date, a relatively small number of NF1 mutations have been characterized, thus precluding genotype-phenotype correlations. By genotyping 75 NF1 families, we have detected six hemizygous patients (two of whom are members of the same family). The five presumed deletions were confirmed by two quantitative methods of analysis of NF1 copy number: Southern hybridization with cDNA probes and a single-strand conformation polymorphism analysis that discriminates between the NF1 gene and the pseudogene sequences. The five deletions remove most of the NF1 gene, at least 225 kb, from exon 9 to the 3' end of the coding sequence. The origin of de novo mutations in the NF1 gene has been reported to be mainly paternal but we have determined that four of the de novo deletions involved the maternal chromosome and one the paternal chromosome. The six patients with deletions exhibited precocious, multiple clinical features of the disease. The incidence of tumor complications, particularly plexiform neurofibromas and intracranial tumors, among this group of patients is higher than the observed incidence in our NF1 population, suggesting that NF1 haploinsufficiency may cause a more severe phenotype with regard to tumor development. In contrast to other reports that associated large deletions with mildly dysmorphic facies, mental retardation and a large number of cutaneous neurofibromas, only one out of our six patients presented this phenotype.

Adolescent↗
PubMed1997

Nosocomial infections in an oncology intensive care unit.

INTRODUCTION: Treatment of cancer has contributed to a growing number of immunocompromised patients with life-threatening nosocomial infections (NI). High mortality with considerable cost is observed when they are admitted to the intensive care unit (ICU). Few studies on infection control and surveillance have been undertaken in this population group. METHODS: All patients treated at a six-bed medical-surgical oncology ICU for > 48 hours were prospectively observed for the development of an NI and the influence of device utilization on infection rates. The analysis used the standard definitions of the National Nosocomial Infection Surveillance System Intensive Care Unit surveillance component. RESULTS: From September 1993 through November 1995, 370 infections occurred in 623 patients during 4034 patient-days, for an overall rate of 50.0 per 100 patients or 91.7 per 1000 patient-days. Pneumonia (28.9%), urinary tract infections (25.6%), and bloodstream infections (24.1%) were the main types of infection. The most common microorganisms isolated were Enterobacteriaceae (29.7%), fungi (22.2%), and Pseudomonas aeruginosa (13.2%). The median device utilization ratios were 0.63, 0.83, and 0.86 for ventilator, indwelling urinary catheter, and central venous catheter, respectively. The highest median device-specific associated infection rate was 41.7 for ventilator. The median for the average length of stay was 8.8 days, and the average severity of illness score was 4.0. There was a strong positive correlation between the overall NI patient rate and device utilization (r = 0.56, p < 0.01), average severity of illness score (r = 0.54, p < 0.01), and average length of stay (r = 0.67, p < 0.01). No correlations were statistically significant when patient-days were used in the denominator. Among the devices only the number of central venous catheter days was significantly correlated with infections (r = 0.51, p = 0.01). The NI patient-day rates were progressively higher the longer the patients stayed in the ICU. CONCLUSIONS: The high rates reported in this study may reflect a combination of several factors related to the underlying illness, neutrophil count, and exposure to invasive procedures. The adjusted infection rates described here provide specific surveillance data for further interhospital comparisons and also to assess the influence of invasive medical interventions, allowing the implementation of preventable measures to control infections.

Brazil↗
PubMed1997

Fungaemia caused by Hansenula anomala--an outbreak in a cancer hospital.

Yeasts belonging to the genus Hansenula are rarely encountered as the cause of infection in clinical practice. A wide spectrum of infections caused by these fungi can be seen, ranging from asymptomatic fungaemia to severe disease. We describe an outbreak of 24 cases of infection due to H. anomala in an oncological hospital in Rio de Janeiro, Brazil. The median age of the patients was 11 years, of whom 54.2% were female; 91.7% of the Hansenula fungaemia occurred in the haematology unit. The most frequent primary disease diagnosis was leukaemia (62.5%), and all of those infected had had a central venous catheter or peripheral venous catheter and had been treated previously with broad-spectrum antibiotics. Numerous other risk factors were observed in our cases: previous use of steroids, chemotherapy, radiation therapy and neutropenia (data not shown). No deaths could be attributed to Hansenula.

Brazil↗
PubMed1996

Risk factors for infectious complications after abdominal surgery for malignant disease.

BACKGROUND: The emergence of nosocomial infection as a serious complication after intraabdominal operations for cancer prompted us to identify major independent risk factors associated with postoperative infection. METHODS: Risk factors were studied in single and multivariate analyses. Variables considered were remote infection, antimicrobial prophylaxis, preoperative stay, chemotherapy, radiotherapy, weight loss, elective versus emergency operation, wound class, duration of operation, drains, sex, age, and physical status. RESULTS: During 24 months, 236 patients were entered in the study. The overall postoperative infection rate was 45.7%; the surgical site infection rate was 22.4%. Multivariate analysis identified three independent variables: duration of operation longer than 5 hours (odds ratio 6.41, 95% confidence interval 3.28 to 12.54), presence of remote infection at operation (odds ratio 3.76, 95% confidence interval 1.76 to 8.03), and preoperative stay longer than 22 days (odds ratio 2.03, 95% confidence interval 1.04 to 3.95). The relative risk of infection increased from 3.0 when one risk factor was present to 7.3 when all three risk factors were present. CONCLUSIONS: The predictive power of our final multivariate risk index clearly groups these patients according to differing risk for postoperative infection. This classification contributes substantially to the effectiveness of infection control strategies to prevent the occurrence of postoperative infection in the high-risk population of patients with cancer.

Abdominal Neoplasms↗
PubMed1996

Molecular analysis of the SMN and NAIP genes in Spanish spinal muscular atrophy (SMA) families and correlation between number of copies of cBCD541 and SMA phenotype.

Spinal muscular atrophy is an autosomal recessive disorder which affects about 1 in 10,000 individuals. The three clinical forms of SMA were mapped to the 5q13 region. Three candidate genes have been isolated and shown to be deleted in SMA patients: the Survival Motor Neuron gene (SMN), the Neuronal Apoptosis Inhibitory Protein gene (NAIP) and the XS2G3 cDNA. In this report we present the molecular analysis of the SMN exons 7 and 8 and NAIP exon 5 in 65 Spanish SMA families. NAIP was mostly deleted in type I patients (67.9%) and SMN was deleted in 92.3% of patients with severe and milder forms. Most patients who lacked the NAIP gene also lacked the SMN gene, but we identified one type II patient deleted for NAIP exon 5 but not for SMN exons 7 and 8. Two other patients carried deletions of NAIP exon 5 and SMN exon 7 but retained the SMN exon 8. Three polymorphic variants from the SMN gene, showing changes on the sequence of the centromeric (cBCD541) and telomeric copies of the SMN gene, were found. In addition, we show several genetic rearrangements of the telomeric SMN gene, which include duplication of this gene in one normal chromosome, and putative gene conversion events in affected and normal chromosomes. Altogether these results corroborate the high genetic variability of the SMA region. Finally, we have determined the ratio between the number of centromeric and telomeric copies of the SMN gene in parents of SMA patients, showing that the majority of parents of types II and III patients carried three or more copies of the cBCD541 gene; we suggest a relationship between the number of copies of cBCD541 and the disease phenotype.

Base Sequence↗