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Biomedical subjects

A Barceló

Publications and source records attributed to A Barceló.

At least 19 recordsLinked to original sources

A cohort analysis of type 1 diabetes mortality in Havana and Allegheny County, Pittsburgh, PA.

OBJECTIVE: To examine the mortality of type 1 diabetes (T1D) in two countries with very different health care systems using two population-based registries of childhood-onset T1D one in Havana (HA), Cuba, and the other in Allegheny County (AC), USA. RESEARCH DESIGN AND METHODS: Cases diagnosed with T1D between 1965 and 1980 in HA and between 1965 and 1979 in AC were included. Follow-up started with diagnosis in each individual and ended as of 1 January 1991, or with death. Life-table analyses were used to examine the mortality rates in both populations by duration of diabetes. RESULTS: Cumulative mortality by January 1991 in HA (14% in males and females, respectively) was higher than in AC (7% in males and 9% in females) for both genders (males, p=0.0005; females, p=0.0491). Mortality rates were considerably higher in HA for both men and women than in AC however, among females confidence intervals overlapped. Overall mortality rate for Caucasians (AC) was significantly lower than that for African-Americans (AC) or Hispanics (HR). An analysis of causes of death showed a greater proportion of deaths attributed to nephropathy (48.6%) in HA while acute complications (36%) and infections (27%) were more frequent in AC. CONCLUSIONS: This study shows a two-fold greater mortality among people with childhood-onset T1D in Havana, Cuba, than in Allegheny, USA. Different strategies may be needed to increase survival among those with type 1 diabetes in the USA and Cuba.

Age of Onset↗

Antioxidant status in patients with sleep apnoea and impact of continuous positive airway pressure treatment.

The episodes of hypoxia/re-oxygenation associated with the respiratory disturbances observed in patients with obstructive sleep apnoea syndrome (OSAS) may induce the generation of oxygen free radicals. Indeed, several studies suggest that OSAS is associated with oxidative stress. The present study tested the hypothesis that patients with OSAS have an alteration in antioxidant defences. The plasma levels of total antioxidant status (TAS), glutathione peroxidase (GPX), gamma-glutamyltransferase (GGT), vitamins A, E, B12 and folate, and homocysteine were determined in 47 patients with OSAS and 37 healthy subjects. Of these, 27 patients who used continuous positive airway pressure (CPAP) for >4 h.night-1 were re-examined 12 months later. Patients with OSAS had lower TAS (1.4+/-0.16 versus 1.50+/-0.10 mmol.L-1), vitamin A (64+/-19 versus 74+/-17 microg.dL-1) and vitamin E levels (1,525+/-499 versus 1,774+/-503 microg.dL-1), and increased values of GGT (42+/-22 versus 32+/-16 U.L-1) than controls. There was no difference between groups in GPX, homocysteine, vitamin B12 and folate plasma levels. CPAP treatment normalised the levels of TAS (1.50+/-0.13 mmol.L-1) and the activity of GGT (30+/-14 U.L-1) without any influence on vitamins levels. In conclusion, the results indicate that patients with obstructive sleep apnoea syndrome have a decreased antioxidant capacity that is partially reversed by continuous positive airway pressure treatment.

Adult↗

Plasminogen activator inhibitor-I (PAI-I) polymorphisms in patients with obstructive sleep apnoea.

Cardiovascular diseases are frequent among patients with the obstructive sleep apnoea syndrome (OSAS), The aetiopathogenesis of this association is unclear. Type 1 plasminogen activator inhibitor (PAI-1) is one of the primary regulators of the fibrinolytic system. A reported association between PAI-1 activity and an insertion/deletion polymorphism (4G/5G) in the promoter region of the PAI-1 gene suggests a critical role for this genomic region in the pathogenesis of several cardiovascular diseases. In this study, we determined the prevalence of this polymorphism in patients with OSAS and in healthy control subjects. The 4G/5G polymorphism in the promoter region of the PAI-1 gene was determined in 78 male patients with severe OSAS (56 +/- 2 apnoeas per hour) and in 70 healthy male, non-smoker volunteers of similar age, without personal or familial history of cardiovascular disease. The frequency ofthe 4G/4G, 4G/5G and 5G/5G genotypes in patients with OSAS (18%, 62%, 19%, respectively) was not significantly different from that seen in healthy subjects (16%, 60%, 24% P=NS). These results show that the distribution of the 4G/5G polymorphism in the promoter region ofthe PAI-1 gene in patients with OSAS is similar to that observed in healthy subjects. This observation suggests that the PAI-1 polymorphism has no relationship with the increased risk of cardiovascular diseases seen in patients with OSAS.

Case-Control Studies↗

Functional analysis of the Neurospora crassa PZL-1 protein phosphatase by expression in budding and fission yeast.

The gene pzl-1 from the filamentous fungus Neurospora crassa encodes a putative Ser/Thr protein phosphatase that is reminiscent of the Ppz1/Ppz2 and Pzh1 phosphatases from Saccharomyces cerevisiae and Schizosaccharomyces pombe, respectively. The entire PZL-1 protein, as well as its carboxyl-terminal domain, have been expressed in Escherichia coli as active protein phosphatases. To characterize its cellular role, PZL-1 was also expressed in Sz. pombe and in S. cerevisiae. Expression of PZL-1 in S. cerevisiae from the PPZ1 promoter was able to rescue the altered sensitivity to caffeine and lithium ions of a ppz1 strain. Furthermore, high copy number expression of PZL-1 alleviated the lytic phenotype of a S. cerevisiae slt2/mpk1 mitogen-activated protein (MAP) kinase mutant, similarly to that described for PPZ1, and mimicked the effects of high levels of Ppz1 on cell growth. Expression of PZL-1 in fission yeast from a weak version of the nmt1 promoter fully rescued the growth defect of a pzh1Delta strain in high potassium, but only partially complemented the sodium-hypertolerant phenotype. Strong overexpression of the N. crassa phosphatase in Sz. pombe affected cell growth and morphology. Therefore, PZL-1 appears to fulfil every known function carried out by its S. cerevisiae counterpart, despite the marked divergence in sequence within their NH(2)-terminal moieties.

Catalytic Domain↗

Angiotensin converting enzyme in patients with sleep apnoea syndrome: plasma activity and gene polymorphisms.

The prevalence of several cardiovascular diseases is increased with obstructive sleep apnoea syndrome (OSAS), due to, as yet, unclear reasons. Angiotensin converting enzyme (ACE) abnormalities have been implicated in the pathogenesis of various cardiovascular diseases. In this study, plasma ACE activity and the distribution of an insertion (I)/deletion (D) polymorphism of the ACE gene were determined in OSAS patients and in healthy controls. A total of 63 patients with OSAS (mean+/-SEM 54.5+/-2.5 apnoea/hypopnoeas.h(-1)) and 32 healthy subjects were studied. To avoid potential confounding factors, patients treated with ACE inhibitors or continuous positive airway pressure were excluded, as well as controls in whom a blood sample was not obtained early in the morning. ACE activity was determined spectrophotometrically in 46 OSAS patients and 25 controls. The I/D ACE polymorphism was determined by polymerase chain reaction in 44 patients and 32 controls. ACE activity was higher in OSAS patients (53.9+/-2.5 IU.L(-1)) than in healthy controls (42.4+/-3.1 IU.L(-1), p<0.01). This was independent of the presence of arterial hypertension. The frequency distribution of the DD, II and ID genotypes in OSAS patients (30%, 16%, 54%, respectively) was not significantly different from that seen in healthy subjects (31%, 28%, 41%, respectively, p=0.356). These results indicate that ACE plasma activity is increased in untreated OSAS patients. This increased activity may contribute to the pathogenesis of the cardiovascular disease in these patients.

Cardiovascular Diseases↗

Incidence and prevalence of diabetes mellitus in the Americas.

OBJECTIVE: To present the incidence and prevalence of diabetes mellitus in the Americas as found through a thorough review of published information on the subject. METHODS: Data were obtained through a comprehensive review using the MEDLINE and BIREME bibliographical databases. In addition, government publications, conference reports, and meeting documents were identified by contacting government and nongovernmental organizations and other institutions. Incidence and prevalence rates were adjusted by age and sex, when possible, by the direct method using the world Segi population as the standard. The 95% confidence intervals were calculated using the Poisson distribution or the normal distribution. RESULTS: Diabetes mellitus represents a major public health problem in the Americas, and there is evidence that its prevalence is increasing in some countries. CONCLUSIONS: Given that most Latin American and Caribbean nations are experiencing a demographic transition, it is expected that the prevalence of diabetes will continue to increase rapidly in the near future. Despite the economic constraints faced by the countries of the Americas, there is a clear need for more efforts in the area of diabetes prevention and control.

Adolescent↗

Diabetes in Bolivia.

OBJECTIVE: To measure the prevalence of diabetes mellitus (DM), hypertension, obesity, and related risk factors in major cities in Bolivia. METHODS: A population-based survey was conducted in four Bolivian cities: La Paz, El Alto, Santa Cruz, and Cochabamba. The total sample size was chosen to be 2,948 persons. The overall response rate was 86%, with the rate varying somewhat among the four cities. DM was diagnosed through an oral glucose tolerance test (OGTT) 2 hours after an overload of 75 grams of glucose, using World Health Organization criteria. RESULTS: The overall prevalence of DM in the four urban areas combined was 7.2% (95% confidence interval (CI): 6.2%-8.3%) and of impaired glucose tolerance (IGT) was 7.8%. A total of 73.1% (95% CI: 65.0%-81.0%) of those previously diagnosed with DM and 73.7% (95% CI: 61.0%-86.4%) of newly diagnosed cases were overweight, according to measurements of body mass index. Hypertension was found in 36.5% (95% CI: 27.6%-45.5%) of known diabetics and in 36.6% (95% CI: 23.0%-50.1%) of newly diagnosed cases, compared to only 15.9% (95% CI: 14.3%-17.5%) among people without DM. The disease was most common among older persons and those with little education. CONCLUSIONS: Diabetes is a genuine public health problem in Bolivia. Further, the high prevalence of IGT that was found suggests that diabetes prevalence will increase in the near future in the country unless prevention strategies are implemented.

Adult↗

[National campaign to detect suspected diabetes cases in Brazil: a preliminary report].

The Ministry of Health of Brazil is implementing a National Plan for the Reorganization of Health Care for Hypertension and Diabetes Mellitus, with the aim of reducing the morbidity and mortality associated with diabetes. This plan is divided into four stages, one of which was a national campaign to detect suspected diabetes cases that was carried out in March and April 2001. This was the first survey of its kind carried out by public health services in Brazil, and the preliminary results are described in this article. Out of a total of 5,507 participating municipalities, 4,446 of them (81%) submitted data to the Ministry of Health. Twenty million people were tested (71% of the target population), and 3.3 million of them were identified as possibly having diabetes. The campaign will contribute towards restructuring the systematic and resolution-oriented care that the national, public Unified Health System provides to diabetics. The preliminary results confirm that diabetes is one of the main health problems in Brazil. Priority should be given to preventing type 2 diabetes.

Brazil↗

[An intervention to improve diabetes control in Chile].

OBJECTIVE: Previous research has shown that controlling blood glucose improves short-term and long-term outcomes among patients who have either type 1 or type 2 diabetes. The objective of this study was to investigate, in a developing country, the effectiveness of an intervention that included patient education, self-monitoring of blood glucose, and determination of the level of glycosylated hemoglobin (HbA1c). METHODS: The patients were grouped into three categories, taking into account such clinical manifestations as the duration of their diabetes, its treatment, and their hospitalization history. After the inclusion and exclusion criteria were applied, the persons were randomly assigned to two groups. One group (210 patients) received the educational intervention, and the control group (206 patients) received customary care. The intervention group received educational information needed for self-monitoring of blood glucose and for the self-evaluation of positive and negative behaviors related to metabolic control of the disease. RESULTS: The two groups were similar with respect to age (mean of 52.3 and 50.5 years) and to the proportion of patients with type 1 diabetes (13.8% and 16.0%). There were no initial differences in the average concentration of HbA1c in the two groups (8.9% +/- 0.1% and 8.9% +/- 1.4%). A total of 50 persons dropped out of the study, 14.8% of those in the intervention group and 9.2% of those in the control group. In the intervention group, compliance with dietary recommendations increased by 43.5%, from 57.5% at the beginning of the study to 82.5% at the end (P < 0.001); in the control group there was also a change but it was not significant. Although patients with a high initial HbA1c concentration were underrepresented in this study, the average HbA1c concentration declined significantly in the intervention group (-0.4% +/- 1.1%, P = 0.001) but not in the control group (-0.1% +/- 0.1%). CONCLUSIONS: In one developing country, educating patients about diabetes helped improve metabolic control, a fact that can be attributed mainly to the intervention's positive impact on those persons' diet.

Adolescent↗

Rare variants in the promoter of the fragile X syndrome gene (FMR1).

Fragile X syndrome, the most common form of familial mental retardation, is mainly caused by the expansion of an unstable region of CGG repeats in the 5' untranslated region of the FMR1 (Fragile X Mental Retardation-1) gene. Molecular tools to detect an abnormal CGG expansion in FMR1 include Southern blot hybridization and PCR amplification. Southern blotting with the StB12.3 probe and Eco RI/Eag I double digestion is widely used as a routine test for fragile X syndrome diagnosis in laboratories around the world. A patient with mental retardation of unknown origin showed absence of digestion for Eag I due to a -149C-->G substitution in the CpG island of the FMR1 gene, which destroys that restriction enzyme site. Screening for other changes around that region also detected a -154insGGC in a patient with a phenotype highly suggestive of fragile X syndrome but without CGG expansion. Expression studies did not show any abnormal changes in FMR1 function. In summary, we have identified two different changes (a C to G substitution at -149 and a GGC insertion at -154) in the promoter of the FMR1 gene. These are the first variants described in the promoter of the FMR1 gene.

Adolescent↗

Abnormal lipid peroxidation in patients with sleep apnoea.

The prevalence of cardiovascular diseases is increased in patients with the obstructive sleep apnoea syndrome (OSAS). The fall and rise of arterial oxygenation that follows each apnoea may increase lipid peroxidation and contributes to explaining this association. In the present study, the authors determined lipid peroxidation in patients with OSAS and the effect of treatment with continuous positive airway pressure (CPAP). Fourteen male patients with severe OSAS (59+/-5 apnoea x h(-1)) (+/-SEM) and 13 healthy nonsmoking, male volunteers of similar age were studied. Patients were studied at diagnosis and after treatment with CPAP for more than 1 yr (>4 h x night(-1)). A venous blood sample was obtained early in the morning after fasting all night. In patients with OSAS, a sample before and during sleep was also obtained. Low density lipoprotein (LDL) particles were isolated by sequential ultracentrifugation. Their level of oxidation was determined by the thiobarbituric acid assay (TBARs), and their susceptibility to oxidation by the lag phase measurement. Patients with OSAS showed higher TBARs (28.1+/-2.8 versus 20.0+/-1.8 nmol x malondialdehyde x mgLDL protein(-1), p=0.02) and shorter lag phase values (83.8+/-3.4 versus 99.7+/-3.4 min, p=0.005) than controls. These differences were not due to the smoking status of the patient. Likewise, these values did not change significantly throughout the night yet, the lag phase value was significantly improved by treatment with CPAP (124.9+/-8.5 min; p<0.001). These results indicate that obstructive sleep apnoea syndrome is associated with abnormal lipid peroxidation and that this is improved by chronic use of Continuous positive airway pressure. These results can contribute towards explaining the high prevalence of cardiovascular diseases seen in Obstructive sleep apnoea syndrome.

Adult↗

A tomato peroxidase involved in the synthesis of lignin and suberin.

The last step in the synthesis of lignin and suberin has been proposed to be catalyzed by peroxidases, although other proteins may also be involved. To determine which peroxidases are involved in the synthesis of lignin and suberin, five peroxidases from tomato (Lycopersicon esculentum) roots, representing the majority of the peroxidase activity in this organ, have been partially purified and characterized kinetically. The purified peroxidases with isoelectric point (pI) values of 3.6 and 9.6 showed the highest catalytic efficiency when the substrate used was syringaldazine, an analog of lignin monomer. Using a combination of transgenic expression and antibody recognition, we now show that the peroxidase pI 9.6 is probably encoded by TPX1, a tomato peroxidase gene we have previously isolated. In situ RNA hybridization revealed that TPX1 expression is restricted to cells undergoing synthesis of lignin and suberin. Salt stress has been reported to induce the synthesis of lignin and/or suberin. This stress applied to tomato caused changes in the expression pattern of TPX1 and induced the TPX1 protein. We propose that the TPX1 product is involved in the synthesis of lignin and suberin.

Kinetics↗

Single-strand conformation polymorphism analysis in the FMR1 gene.

The fragile X syndrome is due to an expansion of the CGG trinucleotide repeat in the FMR1 gene and hypermethylation of its 5' upstream CpG island in about 95% of the cases. The remaining 5% of cases correspond to other molecular alterations in FMR1 gene such as partial or complete deletions, or point mutations within the coding sequence. We selected 31 patients with clinical manifestations of fragile X syndrome, scoring 16 or more in Hagerman's checklist, but without the CGG expansion. We performed single-strand conformation polymorphism analysis using a nonradioactive technique (silver staining) and we detected six anomalous migrations that, by sequence analysis, corresponded to six nucleotide changes. We screened two different populations (control and fragile X) for these changes, and concluded that they correspond to five new polymorphisms within the FMR1 gene and to one possible synonymous mutation.

Fragile X Messenger Ribonucleoprotein 1↗