Heart transplantation in Catalonia, 1984-1997.
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Biomedical subjects
Publications and source records attributed to T Salas.
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The aim of this study was to describe children's hospitalization and to analyse gender differences by selected diagnostic and procedure groups. Using the Clinical Classification for Health Policy Research Version 2 (CCHPR), 81 888 hospitalizations from the Minimum Basic Data Set of Hospital Discharge (CMBDAH) of 1995 related to children under 15 y of age in Catalonia, Spain, were studied. Hospitalization rates, number of days in hospital, average length of stay (d) in hospital and the standardized hospitalization ratio (SHR) (hospitalization rate in boys/hospitalization rate in girls) were computed. Two independent approaches were taken: (i) gender-specific categories were excluded in order to compare hospitalizations by sex; (ii) a selected group of 17 diagnostic and procedure categories were chosen in order to carry out the specific gender comparison. In both approaches, the selected indicators were compared by age groups, and totals were standardized by age using the direct method. An excess of hospitalization in boys was observed (SHR = 1.18; 95% CI: 1.17-1.19). The number of days spent in hospital and hospitalization rates were higher in infants and were also higher for boys than for girls. The average length of stay in hospital was higher in infants and in girls at all ages. These differences were systematic when stratified by health region, admission and discharge circumstances and hospital category. Except for urinary infection, which was higher in girls (SHR: 0.65; CI 95%: 0.54-0.76), the SHR was higher in boys in all diagnostic and procedure categories analysed (all SHR >1). Specific sex categories, injuries and poisonings cannot on their own explain a higher level of hospitalization among boys. More specific studies are needed to explain the role of the family and the healthcare system in gender inequalities in children's hospitalization.
Recent studies have shown that the treatment of nonmetastatic K-1735 murine melanoma cells with cytokines induces the production of nitric oxide (NO) and hence cell death. The purpose of this study was to determine the mechanism of this cytokine-induced NO-mediated apoptosis. Incubation of nonmetastatic K-1735 cells with interleukin-1 alpha (IL-1alpha) and interferon-gamma (IFN-gamma) induced high NO production, Bcl-2 downregulation, and apoptotic cell death. In contrast, incubation of metastatic K-1735 cells with IL-1alpha and IFN-gamma did not induce significant production of NO, downregulation of Bcl-2, or cell death. The exposure to exogenous NO derived from the NO donors, sodium nitroprusside (SNP), or GEA5024 produced a dose-dependent apoptotic cell death in both the metastatic and nonmetastatic K-1735 cells, which was associated with downregulation of Bcl-2 at the mRNA level and, to a lesser extent, at the protein level. Nonmetastatic and metastatic K-1735 cells transfected with the Bcl-2 gene were more resistant to apoptosis mediated by both endogenous and exogenous NO. Subsequent to intravenous injection, the tumor cells transfected with the Bcl-2 gene had an increased survival rate in the lungs of nude mice and produced a higher number of experimental lung metastases. These data suggest that NO-induced apoptosis in K-1735 melanoma cells is associated with downregulation of Bcl-2.
The purpose of this study was to determine whether sustained local production of murine IFN-beta (mIFN-beta) could inhibit the tumorigenicity and metastasis of human and murine tumor cells implanted into nude mice. Human melanoma cells (A375SM), renal carcinoma cells (SN12PM6), and colon carcinoma cells (KM12SM) were transfected with mIFN-beta or a control neomycin resistance vector. All cell lines grew well in culture. Tumor cells were injected into the subcutis, kidney, spleen, or lateral tail vein of nude mice. Parental or control transfected cells produced local tumors and experimental or spontaneous lung metastases, whereas mIFN-beta-transfected cells did not. In vivo survival experiments using [125I]IdUdR-labeled cells showed that by day 7 after s.c. implantation, all IFN-beta-transfected cells died. IFN-beta transfection prevented the outgrowth of parental or control-transfected cells only when they were injected together with transfected cells into one site, suggesting that IFN-beta promoted a local lysis of the bystander cells. Similar indirect antitumor activity was demonstrated in various human (KM12SM and SN12PM6) and murine (CT-26 colon carcinoma, RENCA renal cell carcinoma, and 3LL Lewis lung carcinoma) tumors. The IFN-beta-transfected tumor cells stimulated a high level of nitric oxide production by murine macrophages under in vitro and in vivo conditions, which correlated with the vigorous nonspecific antitumor activity. Collectively, these results demonstrate that local production of IFN-beta can eradicate tumor cells of different histology by inducing inducible nitric oxide synthase expression in infiltrating cells.
We have previously noted an association between proviral load and the severity of immune disease in individuals with a wide range of CD4 cell counts. Using the quantitative DNA polymerase chain reaction technology developed in our laboratory, we sought to extend these observations, with a view to establishing guidelines for the use of proviral load in a clinical context. We studied 199 patients with a range of CD4 cell counts attending an urban tertiary care center. Proviral load/10(6) peripheral blood mononuclear cells (PBMCs) was measured using a microtiter plate assay designed specifically for this purpose. Human immunodeficiency virus proviral DNA was detected in 193 of 199 clinical samples. Levels of proviral load were tabulated for patients and evaluated in seven categories defined by CD4 cell counts. Although a wide range of proviral loads was observed in each category of patients, there was a trend toward increasing proviral load with decreasing CD4 cell count. Statistically significant relationships were observed between proviral load and the CD4 cell count and the CD4 cell percentage (Spearman's correlation coefficient -0.19, p = 0.01 for both absolute CD4 and CD4 percentage). These relationships were quite weak and could not be taken to explain disease progression in isolation. If we defined a cutoff between low and high proviral loads at 100 copies/10(6) PBMCs, we noted that 52% (24 of 46) of patients with CD4 cell counts > 400/microliters had lower loads, as compared with 16% (24 of 143) of those with more advanced disease (p < 0.01). There is a weak, but statistically significant association between proviral load and CD4 cell depletion.(ABSTRACT TRUNCATED AT 250 WORDS)
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Data from 1569 AIDS cases reported to the population-based AIDS Registry of Catalonia have been analysed to describe the epidemiology and temporal evolution of both Kaposi's sarcoma (KS) and non-Hodgkin lymphoma (NHL). Of the 1569 cases reported, 53 (3.4%) presented with NHL and 135 (8.6%) with KS. KS cases were more frequent among homosexual/bisexual men and the age of KS cases was significantly higher than all others presenting diseases (38.22 years). NHL cases were more frequently among men but no significant age difference was found. The percentage of KS over time decreased significantly only among intravenous drug users. Cases presenting with a NHL had by far the worst prognosis (median survival time = 169 days). Biases affecting the measurement of AIDS associated malignancies (AAM) using surveillance data are analysed. The prevalence of AAM will increase during the next few years, and NHL may be one of the leading causes of death among AIDS patients in the near future.
OLIGSCAN (oligonucleotide scanner) is a computer program for IBM-PC-compatible computers that allows the user to scan up to 200 DNA sequences for homology to oligonucleotide sequences of interest. Once a core sequence of longer than the user-defined minimum length is found, the remainder of the oligonucleotide is compared to the corresponding positions of the larger sequence to identify matches or mismatches flanking the core region. This algorithm results in identification of the longest possible homologous regions first. The program was originally designed to assist in the identification of potential annealing sites for polymerase chain reaction (PCR) primers in the genomic DNA of related strains of viruses. However, it may also be used for more general pattern-identification purposes, including scanning for various sequence motifs of functional importance. We present the analysis of homology to an oligonucleotide primer in 16 complete genomic sequences of the human and simian immunodeficiency viruses.
Variable-number-tandem-repeats (VNTRs) are highly polymorphic and provide informative genetic markers for distinguishing between individuals. We have used PCR amplification of VNTR locus pMCT118 to identify mislabelled specimens submitted for HIV PCR testing. The method is rapid, can be applied to large numbers of samples and eliminates the need for radioactive probes. DNA samples (10 ng) are amplified for 25 cycles using fluorescence-labelled oligonucleotide primers (blue dye). An aliquot of the PCR product is then combined with an internal lane size standard (labelled with a red dye), electrophoresed through a 2% agarose gel on an automated fluorescence DNA fragment analyser and the size and quantity of the fragments determined automatically relative to the internal standard. Fifteen alleles, ranging in size from 398 tp 709 bp were readily identified in a random sampling of DNA from 63 unrelated HIV-infected patients. Fragment size was reproducible and corresponded to alleles containing from 16 to 35 repeats of a 16 bp unit. VNTR genotyping will prove useful for resolving discordant results due to specimen mix-up and ensuring that the correct samples have been analyzed.
Blood sampling on filter paper has many advantages for the detection of perinatal human immunodeficiency virus (HIV) infection by the polymerase chain reaction (PCR). However, if the method is to be widely used, an assessment of its performance under field conditions is required. To simulate conditions in the field, 50-microliters aliquots of whole blood containing low levels of HIV proviral DNA (4 to 1,024 copies per 100,000 nucleated cells) were spotted onto filter paper; dried; and subjected to heat, humidity, and prolonged storage at room temperature. After exposure, the DNA was recovered and amplified with primers to human leukocyte antigen DQ alpha- and HIV-specific sequences. Treatment at 37 degrees C and 60% humidity for 7 days, storage for 12 weeks at 22 degrees C, and freeze-thawing twice had no adverse effect on PCR reactivity when compared with the results obtained with reference spots stored at -20 degrees C. The lower limits of HIV detection in all tests ranged from 4 to 16 HIV copies per 100,000 cells. Fixation in 70% ethanol improved the amplification of low levels of HIV DNA and reduced biohazard risks. These findings suggest that dried blood spots will provide a powerful new resource for testing for HIV by PCR, especially in remote areas where refrigeration and immediate sample processing are unavailable.
In order to determine the most sensitive method for the early detection of HIV infection, polymerase chain reaction (PCR) and serology were compared using matched peripheral blood mononuclear cells (PBMC) and serum samples taken sequentially at 3-month intervals on 17 HIV seroconverters. All samples from the time of enrollment in the study to the time of seroconversion were studied. [There were only two of the 17 cases where PCR and antigen positivity preceded EIA detectable seroconversion.] Initially, one of these cases was found to be PCR positive 11 months prior to seroconversion, however DNA fingerprinting techniques indicated that the early positive specimen did not belong to the subject in question. In a single subject, PCR was negative at the time of serologic evidence of infection but was positive at the next sampling 3 months later. In the remaining 14 cases, PCR was positive at the same sample time as full or partial seroconversion as determined by three EIA screening tests and Western blot. EIA antibody screen tests showed variability in detection of early HIV antibodies. We found no evidence for prolonged HIV infection prior to seroconversion. PCR offers little if any advantage over serology in the early detection of HIV infection in adults.
We have used the polymerase chain reaction (PCR) to detect HIV proviral sequences in minute amounts of peripheral blood collected onto newborn screening blotters. Forty-three newborns, infants, and children of HIV-infected mothers were serially studied: dried blood spot (DBS) specimens were processed for PCR; serum was assayed for HIV antibodies, p24 antigen, and immunoglobulins; mononuclear cells were cultured and CD4 cells were quantitated by immunofluorescence. There was excellent agreement between the results of blood spot PCR, viral culture, and clinical and immunological indicators of HIV infection. Eighteen of 19 infected children tested positive by both PCR and culture, including six asymptomatic infants who were less than 10 weeks of age. As expected, p24 antigen capture assays were insensitive, detecting only 13 of the 19 infected children. One infected infant tested positive by PCR, but negative by culture and antigen. This infant was seropositive at 27 months and had pronounced hypergammaglobulinemia in association with non-specific symptoms. Twenty-four of the 43 infants were asymptomatic with normal immune profiles, declining antibody levels and no evidence of infection. These children tested repeatedly negative by PCR, culture, and p24 antigen assays. Our results indicate that DBS PCR is a sensitive, specific, and cost-effective alternative to viral culture for the early diagnosis (or exclusion) of perinatal HIV infection. DBS sampling opens the way for large-scale prospective studies to determine the exact rates of vertical HIV transmission in industrialized, as well as, nonindustrialized countries.
We describe inosine-substituted 'consensus' primers for the detection of HIV-1 envelope sequences by the polymerase chain reaction. The primers, modifications of SK68 and SK69, are highly specific (100%) and sensitive (greater than 94%) and they prevent false-negative results due to variation in the HIV-1 genome. Consensus primers are needed to ensure the detection of most, if not all, variants of HIV-1 including American, African and newly emerging strains.
Dried blood spots (DBSs) constitute a potentially valuable source of material for human immunodeficiency virus (HIV) serologic and molecular testing. To facilitate molecular testing, we have adapted the polymerase chain reaction (PCR) to the detection of HIV proviral DNA in DBS samples. The method is highly reproducible, with 75 microliters of whole dried blood providing sufficient DNA for duplicate testing with three primer sets. By using DBS PCR, 66 of 69 (95.6%) seropositive at-risk individuals tested positive by at least two primer sets and 85 of 85 (100%) low-risk seronegative blood donors tested negative by all three sets of primers. The frequency of HIV DNA detection in seronegative at-risk individuals was low, with only 1 of 58 (1.7%) individuals testing positive. These results show that in a clinical environment, HIV PCR analysis of DBS specimens is specific and sensitive. The method is cost effective and presents a useful alternative to the isolation of HIV from seropositive babies with an undefined infection status.
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In this article, we evaluate the effect of the 1987 revised CDC AIDS definition on the AIDS epidemiological surveillance in Catalonia. From data collected in our population-based registry, we observed a 1.3- and a 1.6-fold increase in AIDS prevalence and incidence rates, respectively. In our setting, the new criteria appear to affect case ascertainment in male intravenous drug abusers, with extrapulmonary tuberculosis being the disease that accounts for the major increase in the identified cases. An additional effect of this case revision has been on the median survival time of AIDS patients, which will probably increase due to the use of the new definition criteria.
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Since the beginning of the acquired immunodeficiency syndrome (AIDS) epidemic, the systems for epidemiological surveillance have monitored the dynamics of spread of the disease, thus permitting to identify the possible risk factors and the evaluation of the preventive measures that have been carried out. In the present article the data collected in the AIDS registry for Catalonia are reported. In contrast with the overall figures for the rest of Spain, in Catalonia the most numerous group of patients was represented by homosexual or bisexual males until the second half of 1986; since then, parenteral drug abusers became the major group of risk as in other countries from Southern Europe. In addition, a consistent increase in the number of involved females and children and a small increase in those cases where the only possible known route of transmission was heterosexual contact was observed.