A racial difference in apolipoprotein E allele frequencies between the Japanese and Caucasian populations

We have examined the apo E phenotype frequencies in the Japanese population (n = 576, 16-78 years of age). Apo E phenotypes were determined by the rapid flat gel isoelectric focusing method that we previously reported. The apo E phenotype frequencies in the Japanese were 0.3% for E2/2, 6.1% for E3/2, 71.9% for E3/3, 0.7% for E4/2, 19.3% for E4/3 and 1.7% for E4/4. The apo E allele frequencies were 0.037, 0.846 and 0.117 for the epsilon 2, epsilon 3 and epsilon 4 alleles, respectively. These frequencies were compared with those in the Caucasian populations (n = 3033) reported by Sing & Davignon (1985). There was a significant difference in the apo E phenotype frequencies between the Japanese and Caucasian populations. In addition, a significantly lower frequency of the epsilon 2 and epsilon 4 alleles and a significantly higher frequency of the epsilon 3 allele were found in the Japanese than those reported for the Caucasian populations. It is concluded that there is a racial difference in the apo E allele frequencies between the Japanese and Caucasian populations.     

Molecular defects in the beta-globin gene identified in different ethnic groups/populations during prenatal diagnosis for beta-thalassemia: a Malaysian experience

Abstract   β-thalassemia is the most-common genetic disorder of hemoglobin synthesis in Malaysia, and about 4.5% of the population are heterozygous carriers of the disorder. Prenatal diagnosis was performed for 96 couples using the Amplification Refractory Mutation System and Gap-Polymerase Chain Reaction. We identified 17 β-globin defects-initiation codon for translation (T-G), -29 (A-G), -28 (A-G), CAP +1 (A-C), CD 8/9 (+G), CD 15 (G-A), CD 17 (A-T), CD 19 (A-G), Hb E (G-A), IVS1-1 (G-T), IVS1-5 (G-C), CD 41/42 (-CTTT), CD 71–72 (+A), IVS2-654 (CT), poly A(A-G), 100-kb ^Gγ(^Aγδβ)° and 45-kb Filipino deletions. The 192 β-alleles studied comprised Chinese (151 patients), Malay (21), Orang Asli from East Malaysia (15), Filipino (1), Indian (1), Indonesian Chinese (2), and Thai (1). In the Chinese, 2 β-globin defects at CD 41/42 and IVS2-654 were responsible for 74% of β-thalassemia. β-mutations at CD 19, IVS1-1 (G-T), IVS1-5, poly A, and hemoglobin E caused 76% of the hemoglobin disorders in the Malays. The Filipino 45-kb deletion caused 73.3% of bthalassemia in the Orang Asli. Using genomic sequencing, the rare Chinese β-mutation at CD 43 (G-T) was confirmed in 2 Chinese, and the Mediterranean mutation IVS1-1 (G-A) was observed in a Malay β-thalassemia carrier. The β-globin mutations confirmed in this prenatal diagnosis study were heterogenous and 65 (68%) couples showed a different globin defect from each other. The use of specific molecular protocols has allowed rapid and successful prenatal diagnosis of β-thalassemia in Malaysia.     

The effect of cathartic agents on transmucosal electrical potential difference in the human rectum

Summary Active ion transport in the colon is generating a transmucosal electrical potential difference (PD) of about 40 mV. Cathartic agents inhibit electrolyte and water net-absorption or cause net-secretion which should be reflected in a change of PD.In 83 normal subjects the effect of an isotonic eletrolyte solution (control) and different cathartic agents on rectal PD was tested: Laxatives (bisacodyl, rhein), bile acids (cholic and deoxycholic acid), fatty acids (oleic and ricinoleic acid) and cardiac glycosides (meproscillarin, digitoxin, digoxin). Bisacodyl, deoxycholic acid in high concentration, meproscillarin and digitoxin significantly decreased PD, while the other substances did not.Cathartics act on different transport mechanisms which together with different absorption characteristics of the proximal and distal colon may explain the difference in effecting the PD. Rectal PD measurement provides an easy and convenient tool to document effects of cathartic agents on electrolyte transport, otherwise difficult to obtain, and is applicable for clinical use.To Prof. Dr. H.P. Wolff on the occasion of his 65th birthday     

Sexual dimorphism in digit‐length ratios of laboratory mice

The lengths of the index finger (2D) and ring finger (4D) are sexually dimorphic in humans, and men have a smaller 2D:4D ratio compared to women. Prenatal androgens appear to be important in the development of the 2D:4D sex difference, since it has been reported in children as young as 2 years old, and since humans exposed to supernormal prenatal androgen levels display a smaller 2D:4D ratio. We tested whether another mammalian species in which the process of peripheral sexual differentiation is androgen‐dependent might also show a sex difference in digit ratios. The 2D:4D ratio of adult outbred mice was calculated for both the left and right rear paws. A sex difference was observed in the right rear paw: female mice had a larger 2D:4D ratio than did males. We also found this difference in prepubescent weanling mice. This sex difference is in the same direction as that observed in humans, and suggests that sexual dimorphism in digit length ratios is a feature common to many, if not all, mammals. The mouse may therefore be a useful animal model for studying the factors that influence finger length patterns, which have recently been correlated with several specific behaviors and disease predispositions in humans. Anat Rec 267:231–234, 2002. © 2002 Wiley‐Liss, Inc.     

Ethnic variation in the HER-2 codon 655 genetic polymorphism previously associated with breast cancer

HER-2, a protooncogene located on chromosome 17q21, encodes a transmembrane glycoprotein (p185) with tyrosine kinase activity. Alterations of the HER-2 gene have been implicated in the carcinogenesis and prognosis of breast cancer and other solid tumors. It is also a cancer-therapeutic target for antibody-based therapy against the HER-2 protein. A single-nucleotide polymorphism (SNP) at codon 655, resulting in a G-to-A transition (Ile655Val) in the transmembrane domain-coding region of this gene has been associated with an increased risk of breast cancer, particularly among younger women. To understand the importance of this finding throughout the world, we evaluated this polymorphism in Ghanaian, Kenyan, Sudanese, Caucasian, African–American, Saudi, and Filipino subjects using a polymerase chain reaction-restriction fragment length polymorphism assay. The frequency of the Val allele, which is associated with increased breast cancer risk, was highly variable between populations (0%–24%). Continental African populations had a lower frequency of the Val allele than did Saudi, Chinese, Filipino, Caucasian, and African–American subjects. The data suggest that this SNP has variable frequency in different ethnic groups. The findings in this study correspond with the lower incidence and lower risk of breast cancer in African women compared with Caucasian and African–American women. Received: December 13, 2001 / Accepted: January 16, 2002     

Temporal aspects of the dependency of a dimorphic rate of extinction on testosterone.

Previous work has shown that rate of extinction of a conditioned taste aversion is affected by concurrent levels of testosterone in adult rats. In the present study, castrated male and female adult rates were given either oil or testosterone during acquisition of the conditioned taste aversion and then either oil or testosterone during extinction. The males and females that received testosterone during the extinction of the aversion showed the slower, masculine rate of extinction regardless of the type of injections they received during acquisition. Conversely, the animals that received oil during extinction showed the faster, feminine rate of extinction regardless of the type of injection during acquisition. In light of these findings, a number of alternative behavioral changes that could account for the effect of testosterone on the rate of extinction were evaluated.     

Gender difference in the relationship of performance in the handgrip and standing long jump tests to lean limb volume in young adults

Summary Groups of young, adult males and females performed the handgrip and standing long jump tests. Their total forearm and leg volumes were calculated from a series of circumference and length measurements, and the lean volumes (bone + muscle) calculated by taking the skinfold thickness into consideration. In the handgrip, the mean female performance was 298 N compared with 496 N for the males. In the standing long jump, mean performance expressed as distance x body mass was 87.3 kg · m for females compared with 137.7 kg · m for males. These superior performances of males could simply reflect their greater muscle mass, as the mean lean volumes of female and male limbs respectively were 0.54 l and 0.89 l for forearms, and 11.82 l and 14.82 l for the two legs. However, when the performances of males and females were grouped by lean limb volume, it was found that while in both tests there were linear relationships, males and females did not share a common line. In both tests the male relationship was at a higher level than the female; therefore, for a given lean volume, the male performance was significantly superior to that of the female. The gender difference found in this study has not been seen in other studies in which the performance of skeletal muscle has been related to the cross-sectional area of the active muscles and the possible reasons for the differences are considered.     

Neighbourhood migrant composition and tobacco-related cancer mortality: A census-linked study among five origin groups in urban Belgium

We studied the role of ‘ethnic density’ in the neighbourhood for tobacco-related cancer mortality among five migrant origin groups in urban Belgium. Using full population linked census data, multilevel Poisson models were applied to model effects of three linear and categorical indicators of same-origin presence for each origin group, and to test effect mediation by migrant generation and educational level. We first of all found that increased same migrant-origin presence in the neighbourhood had protective effects on tobacco-related cancer mortality for men in most groups. Second, only Turkish men had a mortality disadvantage when Turkish concentration was higher. Third, effects were not detected across all indicators of same-origin presence, nor among most groups of women. Finally, for several groups, neighbourhood effects were mediated by generational status and educational level.     

一种基于色差的彩色图像的边缘检测方法

传统的边缘检测方法大都是基于灰度图像的,这就不能充分利用彩色图像的全部信息。文章提出了一种基于色差的彩色图像的边缘检测方法,它能快速准确地检测到图像的边缘,具有低的错判率和较高的效率,优于传统基于灰度的边缘检测方法。     

Stabilization of positive coupled differential‐difference equations with unbounded time‐varying delays

This paper researches the static output‐feedback stabilization of single‐input single‐output (SISO) positive coupled differential‐difference equations (CDDEs) with unbounded time‐varying delays. First, a necessary and sufficient condition is provided for the positivity and asymptotical stability of CDDEs with unbounded time‐varying delays. For this type of system, based on the constructed estimates of its solution, a necessary and sufficient condition on asymptotical stability is provided. Then, based on this criterion, for CDDEs with unbounded time‐varying delays, a kind of static output‐feedback controller is designed to ensure the positivity and asymptotical stability of the corresponding closed‐loop systems. It is also worth pointing out that the controller is designed by the linear programming method without parameterization technique. This design approach can also be applied to the static state feedback stabilization problem of CDDEs with unbounded time‐varying delays. Finally, two illustrative examples are given to show the effectiveness of our results.