Plasma carnitine reference values.
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Adolescent↗
Biomedical subjects
S Schwartz
Publications and source records attributed to S Schwartz.
The fallacy of the ecological fallacy: the potential misuse of a concept and the consequences.
Ecological studies have been evaluated in epidemiological contexts in terms of the "ecological fallacy." Although the empirical evidence for a lack of comparability between correlations derived from ecological- and individual-level analyses is compelling, the conceptual meaning of the ecological fallacy remains problematic. This paper argues that issues in cross-level inference can be usefully conceptualized as validity problems, problems not peculiar to ecological-level analyses. Such an approach increases the recognition of both potential inference problems in individual-level studies and the unique contributions of ecological variables. This, in turn, expands the terrain for the location of causes for disease and interventions to improve the public's health.
Ecology↗
Shopping around: supply prices trend downward.
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Data Collection↗
Effect of vitamin C and vitamin E analog on aged fibroblasts.
Human dermal fibroblasts were cultured and aged in vitro. Survival of young and aged fibroblasts was determined in the presence and absence of different concentrations of two vitamins. Vit C at doses of 5, 12.5, 25 and 50 mumol/L and water-soluble Vit E (Trolox) at 1, 5, 10 and 50 mg/L, were added 30 minutes before oxidative stress, consisting of exposure to 5 mM hydrogen peroxide for 30 minutes. A non-radioactive cell proliferation cytotoxicity assay (MTT) was used to determine the protective effect of the vitamins studied. Vit C produced a clear cytoprotective effect on aged cells over the entire range of doses applied. The protection provided by Vit E, was less pronounced.
Aging↗
p53 mutations in bladder carcinoma cell lines.
Point mutations and deletions in the p53 tumor suppressor gene occur frequently in advanced stage bladder tumors. To extend these observations to an in vitro model of bladder tumorigenicity, we have evaluated the presence of p53 mutations in a panel of bladder carcinoma cell lines. p53 alleles were cloned using the reverse transcriptase-polymerase chain reaction method, and exons 2-11 were sequenced. Of 11 cell lines examined, 5 cell lines had missense point mutations, and each overexpressed p53 protein on western blot analysis. Except for the HT-1197 cell line, these point mutations occurred in evolutionarily conserved domains, which are characteristic hot spots for mutations. HT-1197 encodes an unusual C-terminal point mutation in codon 365, within the basic motif tetramerization domain, suggesting a linkage between induction of a mutant p53 conformation and alterations in protein oligomerization. Six of 11 cell lines had wild-type levels of p53 expression, with 4 producing p53 proteins having either internal deletions or truncations, and 2 producing wild-type p53. Presence of wild-type p53 was found only in cell lines derived from either a low-grade, papillary tumor (RT4) or fetal bladder (FHs 738Bl). The T24 cell line was found to contain a novel p53 mutant having an in-frame deletion of tyrosine 126. This p53 mutant does not bind SV40 large T antigen, yet is expressed at low levels, comparable to cell lines containing wild-type p53 alleles. Our findings characterize p53 mutations in a panel of bladder carcinoma cell lines, and provide a model for testing the role of wild-type or mutant p53 cDNA to suppress or induce tumorigenic properties.
Animals↗
Nongenetic familial transmission of psychiatric disorders? Evidence from children of Holocaust survivors.
There is considerable evidence that psychiatric disorders aggregate in families, a phenomenon for which both genetic and nongenetic explanations have been proposed. However, since genetic and social inheritance usually co-occur, it is difficult to separate out their effects. In this paper, we argue that examining the rates of disorder among children of Holocaust survivors provides a special situation where genetic and nongenetic factors in familial transmission can be separated, and where specific nongenetic mechanisms can be tested. We specify competing hypotheses, and test their viability using data from an epidemiological study of psychiatric disorders conducted in Israel. We find no evidence of higher symptom scale scores or higher rates of current psychiatric disorders for the children of Holocaust survivors. However, they did have higher rates of past disorders.
Family Health↗
Effect of bezafibrate on lipids, lipoproteins, apolipoproteins and platelet aggregation in hypertriglyceridemic patients.
Twenty-seven hypertriglyceridemic patients were recruited for an open placebo-controlled, 7-month study of the effect of bezafibrate (CAS 41859-67-0, Bezalip, Cedur) on lipids, lipoproteins, apolipoproteins, and platelet aggregation. Patients received 3 placebo tablets a day for a stabilization period of 2 months, followed by a treatment period of 5 months during which one group received bezafibrate 200 mg 3 times a day, and a control group continued to receive placebo. Values measured at the end of the stabilization period were considered as the baseline values. Bezafibrate therapy significantly reduced triglycerides by 43%, and increased HDL-cholesterol by 22%. Apolipoprotein A-1 increased by 14%, and apolipoprotein A-2 by 42%. There was a small reduction of cholesterol (6%), and of apolipoprotein B (11%). A small increase occurred in LDL-cholesterol (2%), suggesting increased catabolism of high VLDL levels which were converted to LDL-cholesterol. Platelet aggregation was measured by the degree of light transmission through a platelet suspension. The improvement of the lipoprotein profile was associated with significant reduction of platelet aggregation in vitro, stimulated by adenosine diphosphate (ADP) at concentrations of 1.15 mumol/ml and 0.75 mumol/ml, and by collagen 2.0 micrograms/ml. Average decrease of platelet reactivity was 45%, 30% and 42%, respectively. The decrease of light transmission with ADP concentration of 2.3 mumol/ml was not significant, suggesting that the aggregatonic effect of the higher ADP concentration overcame the attenuating effect of bezafibrate. The control groups, displayed no significant changes in the blood constituents and platelet functions.(ABSTRACT TRUNCATED AT 250 WORDS)
Adenosine Diphosphate↗
Quality-adjusted life years: a reply.
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Australia↗
A one-year statistical analysis of dental emergencies in a pediatric hospital.
Data on 1,373 emergency dental visits to a pediatric hospital during a calendar year period were reviewed. Chief complaints were categorized and the associated pathological conditions were identified and analyzed. A classification of pediatric dental emergencies is presented.
Adolescent↗
[Immunophenotyping of acute lymphatic leukemia: diagnostic aspects and clinical relevance].
During the past two decades immunophenotyping has yielded significant new information regarding the biological heterogeneity of ALL and has provided a solid basis for a biologically oriented and reliable classification of this disease. At present, lineage commitment of acute leukaemias can be achieved in more than 98% of cases by applying a standardized panel of mAbs to pan-B-cell (CD19, cyCD22), pan-T-cell (cyCD3, CD7) and pan-myeloid antigens (CD13, CD33, MPO) that are expressed either on the surface or in the cytoplasm of the earliest progenitors of the respective cell lineage. Further subclassification of ALL based on the analysis of antigens more closely associated with different maturational stages of B- and T-cell lineage has proven useful for the identification of biologically and clinically distinct entities in both B-cell precursor and T-lineage ALL. Immunophenotyping in about 2800 patients recruited for the German multicentre trials has shown that children and adults differ markedly in frequency distribution of immunological subgroups, with a higher adult incidence of immature B-cell precursor (i.e., pre-pre-B ALL) and T-lineage ALL immunophenotypes (i.e., pre-T ALL). Detailed immunological analyses using a broad panel of mAbs have recently documented typical ALL cases inappropriately expressing myeloid antigens (My+ ALL) as well as morphologically/cytochemically defined acute myeloid leukaemia (AML) with lymphoid-associated markers (Ly+ AML). Based on our own results and a critical review of published data, leukaemic blasts in 5-20% of ALL patients disclose My+ ALL, whereas a coexpression, mostly of T-cell-associated antigens, can be identified in 10-25% of AML cases.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Small marker X chromosomes lack the X inactivation center: implications for karyotype/phenotype correlations.
The abnormal phenotype and/or mental retardation seen in persons with small marker X (mar(X)) chromosomes has been hypothesized to be due to the loss of the X inactivation center (XIC) at Xq13.2, resulting in two active copies of genes in the pericentromeric region. In order to define precisely the DNA content of mar(X) chromosomes and to correlate phenotype with karyotype, we studied small mar(X) chromosomes, using FISH with probes in the juxtacentromeric region. One of the probes was a 40-kb genomic cosmid for the XIST gene, which maps to the smallest interval known to contain the XIC and is thought to be involved in X inactivation. Our findings reveal that small mar(X) chromosomes do not include the XIC and therefore cannot be subject to X inactivation, supporting the premise that abnormal dosage of expressed genes in the pericentromeric region of the X generates the aberrant phenotype seen in patients with small mar(X) chromosomes.
Adult↗
Parent and teacher ratings of attention-deficit hyperactivity disorder symptoms: implications for case identification.
This study was designed to evaluate the relationship between the DSM-III criteria for attention-deficit deficit disorder with hyperactivity (ADDH) and the DSM-III-R criteria for attention-deficit hyperactivity disorder (ADHD). Seventy-two children from an inner-city elementary school were evaluated using parent and teacher ratings on a scale consisting of the symptoms of DSM-III-R ADHD and oppositional-defiant disorder and DSM-III ADDH. Each child was also assessed using a psychometric test battery designed to examine cognitive function, attention, and activity level. Teacher ratings identified more children as DSM-III-R ADHD than DSM-III ADDH. Among these ADHD children, those who also met the ADDH criteria missed more targets on a continuous performance test (CPT) and were rated more overactive than controls. They also had a greater likelihood of being rated ADHD by parents. Children rated as meeting criteria for DSM-III-R ADHD, but not DSM-III ADDH, were not substantially different from controls on teacher ratings of overactivity, CPT performance, or parent ratings of ADHD, which raises questions regarding the nature and severity of the pathology in this group.
Attention↗
Liquid ventilation provides uniform distribution of perfluorocarbon in the setting of respiratory failure.
BACKGROUND: We evaluated the effect of perfluorocarbon liquid ventilation (LV) on gas exchange and pulmonary function in the setting of respiratory failure and the distribution of the ventilating medium during LV when compared to gas ventilation (GV). METHODS: Ten sheep, 17.3 +/- 4.2 kg in weight, underwent oleic acid induction of lung injury followed by either GV (n = 5) or perfluorocarbon LV (n = 5). After 1 hour animals were killed, and chest computed tomographic (CT) imaging was performed. Average CT attenuation number was assessed as an indicator of the distribution of gas or perfluorocarbon in the dependent (posterior) and nondependent (anterior) zones of the lung (air = -1000; soft tissue = 0; perfluorocarbon = +2300 Hounsfield units [H]). RESULTS: Significant increases in PaO2 (LV = 298 +/- 76 mm Hg, GV = 43 +/- 18 mm Hg, p < 0.001), SvO2 (LV = 74% +/- 6%, GV = 32% +/- 18%, p < 0.01), and lung compliance (LV = 1.65 +/- 0.50 ml/cm H2O/kg, GV = 0.58 +/- 0.06 ml/cm H2O/kg, p < 0.01) were observed. Significant decreases in physiologic shunt (LV = 24% +/- 6%, GV = 62% +/- 14%, p < 0.01) were noted. CT attenuation data showed the presence of minimal gas ventilation in the dependent regions during GV although the nondependent regions remained well aerated (CT attention number during GV: ND = -654 +/- 160 H; D = -92 +/- 160 H, p < 0.0001). During LV, there was a fairly homogenous distribution of perfluorocarbon in the lungs (CT attenuation number during LV: D = 1071 +/- 330 Hounsfield units; ND = 1112 +/- 287 Hounsfield units; p = 0.240). Lung biopsy analysis in the LV animals was consistent with a reduction in intraalveolar hemorrhage, intraalveolar edema, and the inflammatory infiltrate. CONCLUSIONS: On the basis of the data, we conclude that in this lung injury model, (1) the distribution of the ventilating medium is uniform during LV when compared to GV, (2) LV improves gas exchange and pulmonary function, and (3) histologic evidence of lung injury is reduced after LV when compared to GV.
Animals↗
Molecular cytogenetic analysis of inv dup(15) chromosomes, using probes specific for the Prader-Willi/Angelman syndrome region: clinical implications.
Twenty-seven cases of inverted duplications of chromosome 15 (inv dup [15]) were investigated by FISH with two DNA probes specific for the Prader-Willi syndrome/Angelman syndrome (PWS/AS) region on proximal 15q. Sixteen of the marker chromosomes displayed two copies of each probe, while in the remaining 11 markers no hybridization was observed. A significant association was found between the presence of this region and an abnormal phenotype (P < .01). This is the largest study to date of inv dup(15) chromosomes, that uses molecular cytogenetic methods and is the first to report a significant association between the presence of a specific chromosomal region in such markers and an abnormal phenotype.
Adolescent↗
Cytogenetic studies of primary cultures of esophageal squamous cell carcinoma.
Cytogenetic analysis was performed on primary cultures of 21 squamous cell carcinomas of the esophagus (SCCE). Seven cases exhibited mosaic clonal chromosome abnormalities distributed as follows: two contained tetraploid cell populations, one with t(3;7)(p21;q11); two showed loss of the Y chromosome, one with double minutes; single cases demonstrated der(11)t(4;11)(q?27;q23); add(1)(p35) and del(4)(p12); and del(7)(p13), del(7)(q22q34), and der(11)t(7;11)(p?15;p?13). The remaining 14 cases had apparently normal karyotypes, possibly derived from stromal elements. These results demonstrate numerical abnormalities and the multiple occurrence of rearrangements involving chromosomes 7 and 11 in SCCE.
Aged↗
Clarification of subtle reciprocal rearrangements using fluorescence in situ hybridization.
Fluorescence in situ hybridization (FISH) using chromosome-specific DNA libraries as painting probes was applied in the analysis of six subtle, balanced chromosome rearrangements. Both fresh and older slides, some of which had been previously G-banded, were used to determine if FISH could identify unambiguously very small amounts of translocated material. Our results indicate that this procedure can clearly and precisely distinguish the specific components of extremely subtle translocations, in different cell types, such as leukocytes, aminocytes, and chorionic villus, and irregardless of preparation age. This ability makes FISH a valuable tool in clinical cytogenetics for the confirmation of preliminary G-banded karyotypes.
Chromosomes, Human, Pair 1↗
Precise mapping of a de novo duplication 18(q21-->q22) utilizing cytogenetic, biochemical, and molecular techniques.
We describe the first de novo inverted duplication of 18q. Due to the difficulty of identifying de novo chromosome abnormalities based solely on cytologic studies, precise definition of the 18q duplication was attempted by integrating cytogenetic and clinical findings with biochemical and molecular dosage studies. The combined results demonstrated that the proposita had a duplication of 18q21-->q22 with a karyotype of 46,XX,-18, + inv dup(18) (pter-->q12.1::q22-->q21::q12.1-->qter). The duplication of this specific chromosome region does not result in the typical 18 phenotype, supporting the hypothesis that various loci on chromosome 18 may interact to produce the manifestations of this syndrome.
Abnormalities, Multiple↗
[Anthropometric reference parameters for the aged population].
BACKGROUND: Anthropometry is an effective method used in the evaluation of the state of nutrition. Anthropometric reference values obtained from the general population have frequently been used. The aim of this study was to determine the anthropometric parameters of the elderly in Manresa and demonstrate the different evolution of these values in both sexes between the ages of 65 and 85 or more. METHODS: Following randomization a representative sample of 1,034 healthy elderly subjects living in Manresa was obtained with the following being determined: weight, height, tricipital, subscapular and abdominal fat folds, arm circumference, arm muscle perimeter, weight/height indexes, muscle and fat areas of the arm and percentage of fat. All the measurements were obtained by the same person with the use of a tallimeter scale with a flexible metric tape and a Holtain lipocalibrater. RESULTS: The values are presented in percentiles by subgroups of age and sex. The weight, height and indexes of lean mass were greater in males while those determining fatty mass were greater in females. In females all the values decreased between 65 and 85 or more years of age (p < 0.001), while in males all decreased (p < 0.001) except; tricipital and abdominal skin folds. Upon comparison of these parameters with those obtained in other geographic areas, differences were observed between both. CONCLUSIONS: By the characteristics of the population studied it was considered that the anthropometric parameters obtained are extensible to all the elderly population of Catalonia and may be used as reference values of the same.
Aged↗