Enhanced decolorization of dyes by an iron modified clay and thermodynamic parameters.

The sorption processes of red 5 (R5) and yellow 5 (Y5) dyes by iron modified and sodium bentonite in aqueous solutions was evaluated. The modified clay was prepared, conditioned and characterized. The sodium clay did not remove any of either dye. The sorption kinetics and isotherms of R5 and Y5 dyes by iron modified clay were determined. The maximum removal percentages achieved were 97% and 98% for R5 and Y5, respectively, and a contact time of 72 h; the experimental data were best adjusted to Ho model. The isotherms of both dyes were best adjusted to the Langmuir model and the maximum adsorption capacities of the modified clay were 11.26 mg/g and 5.28 mg/g for R5 and Y5, respectively. These results indicate that adsorption processes have a high probability to be described as chemisorption on a homogeneous material. Temperature range between 283 and 213 K does not affect the adsorption of Y5 by the iron modified clay, but the adsorption process of R5 was affected, and the thermodynamic parameters could be calculated, which indicate a chemisorption mechanism.

A PCR-Based Diagnostic System for Differentiating Two Weevil Species (Coleoptera: Curculionidae) of Economic Importance to the Chilean Citrus Industry.

A PCR-based method was developed to identify Naupactus cervinus (Boheman) and Naupactus xanthographus (Germar), two curculionids affecting the citrus industry in Chile. The quarantine status of these two species depends on the country to which fruits are exported. This identification method was developed because it is not possible to discriminate between these two species at the egg stage. The method is based on the species-specific amplification of sequences of internal transcribed spacers, for which we cloned and sequenced these genome fragments from each species. We designed an identification system based on two duplex-PCR reactions. Each one contains the species-specific primer set and a second generic primer set that amplify a short 18S region common to coleopterans, to avoid false negatives. The marker system is able to differentiate each Naupactus species at any life stage, and with a diagnostic sensitivity to 0.045 ng of genomic DNA. This PCR kit was validated by samples collected from different citrus production areas throughout Chile and showed 100% accuracy in differentiating the two Naupactus species.

Vitamin D deficiency in systemic lupus erythematosus: prevalence, predictors and clinical consequences.

OBJECTIVES: We aimed to establish the prevalence, predictors and clinical consequences of vitamin D deficiency in patients with SLE. METHODS: Cross-sectional study including patients fulfilling ACR criteria for the classification of SLE. Serum 25(OH)D levels at 30 and 10 ng/ml were the cut-off values for vitamin D insufficiency and vitamin D deficiency, respectively. SLE activity was measured by SLEDAI and irreversible organ damage by the SLICC-ACR index. Fatigue was quantified using a 0-10 visual analogue scale (VAS). RESULTS: Ninety-two patients (90% women, 98% white) were included in the study. Sixty-nine (75%) and 14 (15%) patients presented with vitamin D insufficiency and deficiency, respectively. Female sex (P = 0.001), treatment with HCQ (P = 0.014) and treatment with calcium and vitamin D (P = 0.049) predicted higher levels of 25(OH)D. Photosensitivity [odds ratio (OR) 3.5] and photoprotection (OR 5.7) predicted vitamin D insufficiency and deficiency, respectively. Higher age (OR 0.95) and HCQ use (OR 0.29) protected against vitamin D deficiency. Patients with vitamin D deficiency had a higher degree of fatigue as quantified by a 0-10 VAS (mean 5.32 vs 4.03, P = 0.08). No relation was seen between vitamin D insufficiency or deficiency and disease duration, SLEDAI or SLICC-ACR indexes. CONCLUSIONS: Vitamin D insufficiency and deficiency are common in patients with SLE and are associated with sun avoidance. HCQ prevented vitamin D deficiency. Vitamin D deficiency was related to a higher degree of fatigue. Vitamin D levels had no relation with SLE severity.

Alumina cream-induced focal motor epilepsy in cats. IV. Thickness and cellularity of layers in the perilesional motor cortex.

Thickness and cellularity of motor cortical layers adjacent to epileptogenic lesions produced by administration of alumina cream (AC) were measured in the brains of 18 cats that were at latent, convulsive, and remissive stages of an experimental model of epilepsy. Sham-operated animals were used as controls. Brains were fixed by perfusion and embedded in paraffin. Sections of motor cortex adjacent to the AC deposit were obtained at constant thickness to measure thickness and cellularity in each cortical layer. A statistically significant reduction in thickness and cellularity was detected in layers 2, 4, and 6, whereas reduction in these aspects was not significant in layers 3 and 5 in the initial stages of the model (latent and convulsive). It is suggested that AC may exert a cytotoxic effect on inhibitory neurons located at layers 2 and 4, to determine an imbalance of intracortical excitability.

Worldwide genetic diversity at the HLA-DQA1 locus.

Genotype, gene, or phenotype frequency data, obtained by PCR analysis with sequence specific oligonucleotide probes at the HLA-DQA1 locus, in 176 population samples, each consisting of 30 or more individuals, from all around the world were analyzed. The sampled populations were assigned to the following nine groups: African, Afro-American, American Native, American Mestizo, Asian, American Caucasian, European Caucasian, Caucasian from other regions, and Pacific Islanders. Observed genotype proportions agreed with Hardy-Weinberg expectations (HWE) in 90 of the 102 populations for which genotype data are available. The 12 discordant population samples were of substantial mixed origin. For these discordant populations, 41 of the 252 (population by genotype) data points showed significant departures of the observed frequencies in comparison to their HWE predictions. The deviations, by and large (38 of the 41), were in the direction of HWE over-estimating the actual genotype frequencies. Total heterozygosity (HT ) at a worldwide level was 79%, and varied from 56% in American Natives to >80% in Caucasians. Of the total diversity, 94.4% was due to intra-population and 5.6% to inter-population variation (FST ), partitioned into 3.0% inter-population within groups and 2.6% inter-group variation. FST for the locus was high among Africans and American Natives (>9%) and low in Afro-Americans and American Caucasians (<0.5%). The range for allele specific FST was 0.2% to 5.9%, and the lowest value did not correspond to the same allele in all nine groups. A variance component analysis of allele frequencies showed no relationship of the ratio of between/within group variation with the world average frequency of the respective alleles. The first three principal components explained 36.2%, 27.5%, and 22.9% of the total allelic diversity, respectively. For Caucasian and Afro-American samples, the first two PCs formed clusters by groups. In contrast, the American Native, Asian, and Pacific Islander groups showed a greater inter-population diversity, while the corresponding principal component scores of the American Mestizo samples were between American Natives and Caucasians. In aggregate, the analyses indicate that genetic drift in contrast to natural selection, more readily explains the pattern of worldwide diversity at the HLA-DQA1 locus. Am. J. Hum. Biol. 9:735-749, 1997. © 1997 Wiley-Liss, Inc.

[Dilated cardiomyopathy in infants and children]. / Miocardiopatía dilatada en lactantes y niños.

Three cases of dilated cardiomyopathy manifested at 2, 5, and 13 months of age are reported. The clinical, radiographic, electrocardiographic, echocardiographic and angiocardiographic findings are analyzed. The follow up during 11, 14 and 16 years is described. After several years of the onset, 2 patients recovered a normal cardiac function. The third patient required a cardiac transplant when he was 9 years old, and now, after 2 and a half years, he is healthy, without congestive heart failure. Current references about indications of cardiac transplant in this disease are reviewed. We got the following conclusion: In patients with dilated cardiomyopathy, at least in those who begin before 2 years, the indication and the time of the cardiac transplant have to be established by individual valuation of each case, considering the follow up of the risk's criteria, mainly the congestive heart failure.

On the screening for inborn errors of galactose metabolism.

The utility of a simplified diagram of procedures for screening specimens for genetic disorders in galactose metabolism is stressed. Both, early detection and institution of the dietetic treatment are imperative since these inherited disorders have clinical and pathological consequences which can be very severe in galactose-1-phosphate uridyltransferase and uridine diphosphate galactose-4-epimerase deficiencies.

A simple assay for uridine diphosphate galactose 4-epimerase activity.

A simple fluorescent test for the activity of blood uridine diphosphate galactose 4-epimerase which converts uridine diphosphate galactose to uridine diphosphate glucose is described. The enzyme activity is visually estimated by to reduction of NAD+ (non fluorescent) to NADH (fluorescent) in a coupled reaction with uridine diphosphate glucose dehydrogenase. The appearance of fluorescence indicates that epimerase activity is present in the sample. The usefulness of this test in newborn screening programs for inborn errors of galactose metabolism is stressed.

A simple screening procedure for adenylate kinase, hexokinase and glucose-6-phosphate dehydrogenase deficiencies.

A simple screening procedure for the detection of adenilate kinase (AK), hexokinase (Hx) or glucose-6-phosphate dehydrogenase (G6PD) deficiencies in blood, is described. It consists of two assays : in the first, the ATP formed by blood AK is coupled to Hx and G6PD, and in the second, the glucose-6-phosphate formed by blood Hx is coupled to G6PD. The enzyme activities are visually estimated by the reduction of NADP+ (non-fluorescent) to NADH (fluorescent). The appearance of fluorescence in the first assay indicates that the three enzyme activities are present. The absence of fluorescence could be due to the deficiency of any one of the three enzymes; in this case the second assay used in combination with the Beutler's screening test for G6PD permits the detection of the specific enzymatic deficiency.

A simple rapid fluorescent assay for adenosine deaminase activity.

A simple, rapid (2 hours), fluorescent test for the activity of blood adenosine deaminase (ADA) is described. The test which can be performed on both heparinized and dried blood, is based on the conversion of adenosine to inosine and ammonium in the presence of ADA. The enzyme activity is visually estimated by the oxidation of NADH (fluorescent) to NAD+ (non-fluorescent) in a coupled reaction with glutamate dehydrogenase. The disappearance of fluorescence indicates ADA activity in the sample. The advantages are discussed of the use of this test for the study of the autosomal recessive severe combined immunodeficiency.

G-6-PD Guadalajara. A new mutant associated with chronic nonspherocytic hemolytic anemia.

This paper describes a new G-6-PD variant designated Guadalajara, which was found in a Mexican boy suffering from chronic hemolytic anemia. The red cell enzyme activity of the subject is about 14%. The mutant enzyme showed rapid electrophoretic mobility, slightly increased affinity for glucose-6-phosphate, slightly decreased affinity for NADP+, moderately elevated utilization of substrate analogues, and normal heat stability, pH curve, and inhibition by NADPH. G-6-PD Guadalajara differs from all previously reported variants and is the first variant associated with chronic hemolysis found in Mexico.

alpha, 1-4 Glucosidase activity in human seminal plasma from normal, vasectomized, and subfertile men.

Neutral alpha, 1-4 glucosidase activity was assayed by a spectrophotometric method using p-nitro-phenyl-alpha-D-glucopyranoside as the substrate in the seminal plasma of normal, vasectomized, and oligospermic men. The latter groups showed lower values than the controls. These results suggest that the main source of the alpha, 1-4 glucosidase activity is between the vasectomy site and the tubule, and that the enzyme is related to sperm density or to a spermatogenesis factor.

Effect of exogenous melatonin on hepatic energetic status during ischemia/reperfusion: possible role of tumor necrosis factor-alpha and nitric oxide.

BACKGROUND: This study was designed to determine if the very potent antioxidant melatonin is able to reduce organ damage and improve energetic status in an in situ liver ischemia/reperfusion model. MATERIALS AND METHODS: Total hepatic ischemia was induced in rats by occlusion of the hepatic artery, portal vein, and bile duct. A portojugular shunt was inserted. After 60 min of ischemia, reperfusion was established for a period of 120 min. Rats were assigned to one group receiving systemic melatonin administration or to another receiving only normal saline. Variables were observed at preischemia, after 60 min of ischemia, and at 30, 60, and 120 min of reperfusion. RESULTS: Energy charge, measured as the arterial ketone body ratio, showed higher values in the melatonin group during the first 60 min of reperfusion. Rises in plasma nitrite, tumor necrosis factor (TNF)-alpha, aspartate aminotransferase, alanine aminotransferase, lipid peroxidation products, and inducible nitric oxide synthase (iNOS) expression were less severe with melatonin. Linear regression analysis demonstrated a significant correlation between nitrites and arterial ketone body ratio (R(2) = 0.2454). Bile production was higher with melatonin. Seven-day survival rates were 52% for control, 80% for melatonin, and 100% for sham groups. CONCLUSIONS: Exogenous melatonin is capable of preserving the functional and energetic status during ischemia/reperfusion which is associated with reduced concentrations of TNF-alpha and inhibited expression of iNOS and NO production. This improvement may be due to an adequate preservation of the hepatic mitochondrial redox status.

Reproductive history in mothers of children with neural tube defects.

The reproductive history of 100 women with at least 1 child with a neural tube defect (NTD) has been studied. The data analyzed correspond to the period previous to their first visit to a genetic counseling service. A total of 204 pregnancies resulted in 205 outcomes. Of the 100 sibships, 14 (14%) had more than 1 affected member. The pregnancy was shorter than 28 weeks in 56/205 (27%) of the total outcomes. Of 104 evaluable previous outcomes, 34 corresponded to short pregnancies, positioned before an affected (23/60, 38%), a healthy (2/18, 11%), or an undiagnosed product (9/26, 35%). Short pregnancies subsequent to affected outcomes were also increased. The inter-gestational interval varied according to diagnosis: it was longer in the affected group than in the healthy one (0.1 > p > 0.05) and the subsequent intervals were shorter for the affected group (p < 0.05). An increased number of abortions adjacent to affected offspring and a changing fertility pattern, depending on the product diagnosis, point to an environmental etiological component in this high-risk NTD group of mothers.

On the deletion 4p16 Wolf-Hirschhorn syndrome.

Two girls (aged 46 and 5 months) and one boy aged 5 months) were studied and found to have the Wolf-Hirschhorn syndrome. Chromosomal complement in all three cases implicated the deletion of the 4p16 band ; in two of them an extra segment of autosomal material was found to be translocated to 4p. Parents' karyotypes were normal. It is concluded that the expression of the 4p16 monosomy is stronger than that of some simultaneous partial trisomies.

Detection of inborn errors of metabolism in 1,117 patients studied because of suspected inherited disease.

Results of screening tests for the detection of inborn errors of metabolism in 1,117 consecutive patients are reported in this work; patients came for a second consultation to the Departamento de Genética, Centro Médico de Occidente, IMSS. Simple qualitative test were made that revealed the presence of abnormal metabolites (amino-acids, sugars, organic acids and mucopolysaccharides) in urine and blood as well as identification tests for variant proteins. Results were positive in 138 patients and test for confirmation and/or specificity were made in all patients; in 35 the following diagnosis and incidence were established: classic galactosemia, 2; glucose-6-phosphate dehydrogenase deficiency, 20; essential pentosuria, 1; hyperphenylalaninemia, 5; blue diaper syndrome, 1; cistinuria 1, and type 1 mucopolysaccharidosis, 5.

[Indoor air pollution in a zone of extreme poverty of La Pintana, Santiago-Chile]. / Contaminación intradomiciliaria en un sector de extrema pobreza de la comuna de la pintana.

BACKGROUND: Indoor pollution can be an important risk factor for human health, considering that people spend more than 60% of their time in their houses. AIM: To investigate indoor pollution in a zone of extreme poverty in Metropolitan Santiago. MATERIAL AND METHODS: During 24 h, carbon monoxide (CO), sulfur dioxide (SO2), respirable particulate matter (PM10), polycyclic aromatic hydrocarbons absorbed in PM5, temperature and humidity, were measured in the interior of 24 houses in a La Pintana, Santiago. RESULTS: The higher pollutant concentrations were observed during hours when heating was used, in houses that used coal (mean PM10 250 micrograms/m3, CO 42 ppm, SO2 192 pph) or firewood (mean PM10 489 micrograms/m3, CO 57 ppm, SO2 295 pph). In all houses, polycyclic aromatic hydrocarbons were detected and they came from the interior of the house and not from external filtered air. Coal, firewood and cigarette smoke were important sources of carcinogenic and kerosene and gas were sources of non carcinogenic polycyclic aromatic hydrocarbons. CONCLUSIONS: In the houses studied, the population was exposed to an accumulation of highly toxic pollutants, caused by a lack of ventilation. A high relative humidity also contributed to the growth of biological pollutants.

The C677T polymorphism of the methylenetetrahydrofolate reductase gene in Mexican mestizo neural-tube defect parents, control mestizo and native populations.

The C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene, associated with the thermolabile form of the enzyme, has reportedly been found to be increased in neural-tube defects (NTD), though this association is still unclear. A group of 107 mestizo parents of NTD children and five control populations: 101 mestizo (M), 50 Huichol (H), 38 Tarahumara (T), 21 Purepecha (P) and 20 Caucasian (C) individuals were typed for the MTHFR C677T variant by the PCR/RFLP (HinfI) method. Genotype frequencies were in agreement with the Hardy-Weinberg expectations in all six populations. Allele frequency (%) of the C677T variant was 45 in NTD, 44 in M, 56 in H, 36 in T, 57 in P, 35 in C. Pairwise inter-population comparisons of allele frequency disclosed a very similar distribution between NTD and M groups (exact test, P=0.92). Among controls, differences between M and individual native groups were NS (0.06