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A response by C.C. Lin and colleagues to a letter to the editor about their article on Hardy-Weinberg equilibrium is presented.

Three platelet glycoprotein (GP) IIb/IIIa receptor antagonists have been evaluated in patients undergoing percutaneous coronary intervention (PCI). One of these agents, abciximab, is structurally and pharmacologically quite different from the other 2, eptifibatide and tirofiban. We conducted a meta-analysis to determine whether different antagonist types achieved different clinical outcomes, possibly related to their structural differences. Odds ratios (OR) were calculated and a random effects model was used to combine the outcomes of 14,644 patients enrolled in 8 prospective, randomized, placebo-controlled clinical trials assessing treatment with a GP IIb/IIIa inhibitor to prevent ischemic complications of PCI. Neither abciximab (OR 0.69; 95% confidence interval [CI] 0.4 to 1.9) nor eptifibatide or tirofiban treatment (OR 0.74; 95% CI 0.4 to 1.28) resulted in reductions in mortality. Only the abciximab-treated patients had reductions in myocardial infarction (4.3% vs 8.5%, OR 0.49; 95% CI 0.40 to 0.59). There was no effect of eptifibatide or tirofiban on myocardial infarction (OR 0.85; 95% CI 0.69 to 1.04). Urgent revascularization was reduced in both abciximab-treated (2.7% vs 6.2%, OR 0.42; 95% CI 0.34 to 0.53) and eptifibatide- and tirofiban-treated (4.2% vs 5.5%, OR 0.76; 95% CI 0.60 to 0.96) groups. Only abciximab-treated patients had increased major bleeding (5.8% vs 3.8%; OR 1.53; 95% CI 1.24 to 1.90). There was no effect of eptifibatide or tirofiban on major bleeding (5.0% vs 4.3%; OR 1.19; 95% CI 0.94 to 1.52). Thus, significant differences exist between clinical outcomes achieved by abciximab and those achieved by eptifibatide or tirofiban following PCl procedures. [ABSTRACT FROM AUTHOR]

Microarray-based pooled DNA methods overcome the cost bottleneck of simultaneously genotyping more than 100 000 markers for numerous study individuals. The success of such methods relies on the proper adjustment of preferential amplification/hybridization to ensure accurate and reliable allele frequency estimation. We performed a hybridization-based genome-wide single nucleotide polymorphisms (SNPs) genotyping analysis to dissect preferential amplification/hybridization. The majority of SNPs had less than 2-fold signal amplification or suppression, and the lognormal distributions adequately modeled preferential amplification/hybridization across the human genome. Comparative analyses suggested that the distributions of preferential amplification/hybridization differed among genotypes and the GC content. Patterns among different ethnic populations were similar; nevertheless, there were striking differences for a small proportion of SNPs, and a slight ethnic heterogeneity was observed. To fulfill appropriate and gratuitous adjustments, databases of preferential amplification/hybridization for African Americans, Caucasians and Asians were constructed based on the Affymetrix GeneChip Human Mapping 100 K Set. The robustness of allele frequency estimation using this database was validated by a pooled DNA experiment. This study provides a genome-wide investigation of preferential amplification/hybridization and suggests guidance for the reliable use of the database. Our results constitute an objective foundation for theoretical development of preferential amplification/hybridization and provide important information for future pooled DNA analyses.

In order to evaluate the linkage of schizophrenia to loci at chromosome 15q, we genotyped six microsatellite markers at chromosome 15q11-14 in 52 Taiwanese schizophrenic families. Two phenotype models (narrow: DSM-IV schizophrenia only; and broad: including schizophrenia, schizoaffective, and other nonaffective psychotic disorders) were used to define the disease phenotype. Maximum nonparametric linkage scores (NPL scores) of 3.33 (P = 0.0003) and 2.96 (P = 0.0008) were obtained at the marker D15S976 under broad and narrow models, respectively. Positive linkage results were also observed at the marker D15S1360, previously reported to have significant linkage to a neurophysiological deficit of schizophrenia, with NPL scores of 2.71 (P = 0.003) and 2.78 (P = 0.002) under broad and narrow models, respectively. The results provide suggestive linkage evidence of schizophrenia to loci at chromosome 15q13-14 in an ethnically distinct Taiwanese sample., (Copyright 2001 Wiley-Liss, Inc.)

Objective: To evaluate the efficacy of a comprehensive asthma program on emergency department (ED) visits and hospital admission rates in an inner-city pediatric population., Design: A12-month prospective randomized trial., Methods: Three hundred asthma patients, ages 2 to 17 years, were recruited and randomized in an inner-city pediatric ED, to obtain asthma care in a specialty clinic or to continue receiving care by other health resources. The specialty clinic provided intensive medical and environmental control, education, close monitoring, and 24-hour availability. For the prospective study, monthly questionnaires were sent to the caregivers of these children to evaluate use of hospital facilities for asthma care. For the retrospective study, use of hospital resources by the study participants was analyzed using a hospital database., Results: One hundred twenty-nine patients (60 in the treatment group and 69 in the control group) were included in the final analysis. Asthma severity index was significantly higher for the patients in the treatment versus the control group (35% versus 16.2%, P = .05). Fewer patients in the treatment group visited the ED at least once during the first study year, 32 versus 46, (P = .11), and they made fewer visits, 73 versus 269. The mean number of ED visits of the patients who used the ED was 0.1 versus 0.326 for the control group (P = .01). There were also fewer admissions in the treatment group, 22 versus 29 (P < .59). The 53 patients remaining in the treatment group in the second study year made fewer visits to the ED versus the control group (P < .03). In comparison to the first year, fewer patients in the treatment group visited the ED or were hospitalized in the second year (P = .007 and P = .04, respectively)., Conclusions: A comprehensive asthma care program is efficacious in reducing hospital utilization.

During a survey of carnivores and omnivores for bovine tuberculosis conducted in Michigan (USA) since 1996, Mycobacterium bovis was cultured from lymph nodes pooled from six coyotes (Canis latrans) (four adult female, two adult male), two adult male raccoons (Procyon lotor), one adult male red fox (Vulpes vulpes), and one 1.5-yr-old male black bear (Ursus americanus). One adult, male bobcat (Felis rufus) with histologic lesions suggestive of tuberculosis was negative on culture but positive for organisms belonging to the Mycobacterium tuberculosis complex when tested by polymerase chain reaction. All the tuberculous animals were taken from three adjoining counties where M. bovis is known to be endemic in the free-ranging white-tailed deer (Odocoileus virginianus) population. There were two coyotes, one raccoon, one red fox, and one bobcat infected in Alpena county. Montmorency County had two coyotes and one raccoon with M. bovis. Two coyotes and a bear were infected from Alcona County. These free-ranging carnivores/omnivores probably became infected with M. bovis through consumption of tuberculous deer. Other species included in the survey were opossum (Didelphis virginiana), gray fox (Urocyon cinereoargenteus), and badger (Taxidea taxus); these were negative for M. bovis.

When analyzing complex traits such as asthma, heterogeneity needs to be assumed. With this in mind, to identify a more homogeneous group of asthmatic patients, we analyzed the Southampton data using the data mining technique known as the regression tree method and the two most inheritable quantitative phenotypes (LnIgE and RAST) as the target variables. Two-point and multipoint nonparametric linkage analyses were carried out using one of the subgroups as affected. In addition, we performed quantitative trait loci nonparametric linkage analysis using each phenotype as the outcome. The results from the affected-sibpairs method and quantitative linkage analysis were compared.