Brazilin isolated from Caesalpinia sappan L. acts as a novel collagen receptor agonist in human platelets.

BACKGROUND: Brazilin, isolated from the heartwood of Caesalpinia sappan L., has been shown to possess multiple pharmacological properties. METHODS: In this study, platelet aggregation, flow cytometry, immunoblotting analysis, and electron spin resonance (ESR) spectrometry were used to investigate the effects of brazilin on platelet activation ex vivo. Moreover, fluorescein sodium-induced platelet thrombi of mesenteric microvessels was also used in in vivo study. RESULTS: We demonstrated that relatively low concentrations of brazilin (1 to 10 µM) potentiated platelet aggregation induced by collagen (0.1 µg/ml) in washed human platelets. Higher concentrations of brazilin (20 to 50 µM) directly triggered platelet aggregation. Brazilin-mediated platelet aggregation was slightly inhibited by ATP (an antagonist of ADP). It was not inhibited by yohimbine (an antagonist of epinephrine), by SCH79797 (an antagonist of thrombin protease-activated receptor [PAR] 1), or by tcY-NH2 (an antagonist of PAR 4). Brazilin did not significantly affect FITC-triflavin binding to the integrin αIIbß(3) in platelet suspensions. Pretreatment of the platelets with caffeic acid phenethyl ester (an antagonist of collagen receptors) or JAQ1 and Sam.G4 monoclonal antibodies raised against collagen receptor glycoprotein VI and integrin α2ß(1), respectively, abolished platelet aggregation stimulated by collagen or brazilin. The immunoblotting analysis showed that brazilin stimulated the phosphorylation of phospholipase C (PLC)γ2 and Lyn, which were significantly attenuated in the presence of JAQ1 and Sam.G4. In addition, brazilin did not significantly trigger hydroxyl radical formation in ESR analysis. An in vivo mouse study showed that brazilin treatment (2 and 4 mg/kg) significantly shortened the occlusion time for platelet plug formation in mesenteric venules. CONCLUSION: To the best of our knowledge, this study provides the first evidence that brazilin acts a novel collagen receptor agonist. Brazilin is a plant-based natural product, may offer therapeutic potential as intended anti-thrombotic agents for targeting of collagen receptors or to be used a useful tool for the study of detailed mechanisms in collagen receptors-mediated platelet activation.

[Age variations of head-face morphological traits of Hakka in Guangdong province].

OBJECTIVE: To investigate the age variations of head-face morphological traits of Hakka in Guangdong Province. METHODS: Thirty-eight physical indices of head and face of 671 Hakka adults (151 urban males, 181 urban females, 162 rural males and 177 rural females) from Meizhou city of Guangdong were investigated. Twelve physical indices of head and face were calculated and counted its indices distributions. The age changes of morphological traits of head and face were analyzed. RESULTS: With the age growing, the rate of eyefold of the upper eyelid was increased, and the Mongoloid fold decreased, the direction of eyeslits tended to level, nasal root height dropped, the zygomatic projection was more projected, the eye color turned to lighter, the upper red lips became thinner; medium-sized facial height, nasal height, upper lip skin height, physiognomic ear length, physiognomic ear breadth and breadth of alae nasi were decreased. The index of mouth breadth, morphological facial skin fold were positively correlated with the age. The index of minimum frontal breadth, face breadth, bigonial diameter, interocular breadth, external biocular breadth, lip height, thickness of lips and horizontal head circumference were negatively correlated with the age. With the age growing, morphological facial index and vertical cephalo-facial index was ascending. Moreover, length-height index of head, transverse frontoparietal index, zygomatico-frontal index and lip index were declining. CONCLUSION: With the age growing, the head and face measurements, physical indices and the proportion of observed indices have changed in Hakka in Guangdong province.

[Genetic study on somatotype of child and adolescent twins in Han nationality].

OBJECTIVE: To assess the genetic and environmental influences on the somatotype of children and adolescents, and the effects of sex and age. METHODS: The components of somatotype were calculated by using Heather-Cater method in a total of 376 twin pairs of Han nationality, including 245 monozygotic (MZ) and 131 like-sex dizygotic (DZ) twin pairs aged 6 to 18 years. Model-fitting method by Mx package was performed to evaluate the proportion of variance components and to analyze the effects of sex and age on each component of somatotype using the adjusted data for other two somatotype components. The heritability of each component in different development periods divided by growth spurt was also evaluated. RESULTS: The estimated heritabilities of endomorphic, mesomorphic and ectomorphic components were 0.45, 0.80, 0.44 in boys, 0.82, 0.79 and 0.81 in girls respectively after adjusting age. In boys, the heritability of endomorphic component during late puberty was significantly higher than that during pre-puberty (t = 4.99, P < 0.01) and puberty (t = 6.16, P < 0.01), while the heritability of ectomorphic component during late puberty was significantly lower than that during pre-puberty (t = 3.35, P < 0.01) and puberty (t = 4.12, P < 0.01). In girls, the heritability of endomorphic (t = 2.77, P < 0.01) or mesomorphic (t = 2.08, P < 0.05) component during pre-puberty was significantly higher than that in early puberty. CONCLUSION: The genetic influence on somatotype of girls should be much more than that of boys, especially on the endomorphic and ectomorphic components. For boys, the mesomorphic component is mainly determined by genetic factors, but the other components are mainly affected by environmental ones. The effects of the development periods on the heritability of somatotype should be paid much attention to.

[Genetic effects on physical growth items of child twins in Han nationality].

OBJECTIVE: To analyse the heritabilities of physical growth items of body and its related factors. METHODS: An 116 twin pairs of Han nationality, 67 monozygotic (MZ) and 49 like-sex dizygotic (DZ) aged 6 to 12 years, were investigated from June to October in 2004. The measurements included height, weight, sitting height, chest circumference, biacromial breadth and biiliac breadth, and BMI index calculated by the former two measurements. The heritabilities were estimated by using intraclass correlation coefficient method from the adjusted data for age. RESULTS: The intraclass correlation coefficient was greater in the MZ twins than in the DZ twins. The estimated heritabilities of height, weight, BMI, sitting height, chest circumference, biacromial breadth and biiliac breadth were 0.89, 0.88, 0.73, 0.87, 0.78, 0.78, 0.73 in boys and 0.87, 0.74, 0.72, 0.86, 0.62, 0.56, 0.59 in girls adjusted for age. Therefore, there were no sex difference for the heritabilities of height, sitting height and BMI, but the male heritabilities of weight, chest circumference, biacromial breadth and biiliac breadth were higher than the female's respectively. CONCLUSION: Physical growth items should be mainly determined by the genetic factors. There are sex differences for the heritabilities of weight, chest circumference, biacromial breadth and biiliac breadth, i.e., the girls might be affected more easily by environmental factors than the boys in these items.

[Study on 4 human population genetic characters of Mongol and Han in Western inner Mongolia].

From 1998 to 2001, a sample of 2760 Mongol and Han individuals was investigated in 3 areas (Eerduosi city, Xilinguole and Bayannaoer leagues) from Inner Mongolia. Each individual was studied on 4 genetic characters (thumb type, palmar digital formular, fingernail type and plantar digital formular). The result is as follows: (1) The frequencies of the straight thumb were over 60%, and there were no significant sexual differences in all of 6 groups. (2) The frequencies of the ring-finger-longer were much higher in 6 groups, and there were significant sexual differences in 4 groups. (3) The frequencies of the long-shaped fingernail were the highest in all groups, the squat-shaped were the lowest. (4) The big toes were longer than the second toes in most people of 6 groups,but without significant sexual differences in each groups. (5) There were no significant correlations between 4 characters.

[Studies of hereditary mode on three tongue moving types].

The data of 72 families were analyzed by the method of proband's sib and the method of segregation analysis. The results showed that the hereditary mode of rolling tongue or pointed tongue is the dominant heredity of single gene of autosome, and the positive type of them is the dominant character. Twisting tongue is the recessive heredity of single gene of autosome,while the positive type is the recessive character. Present study suggested, although environmental might affect these characters,hereditary factors seemed to be dominant.

[Gene frequency of 12 characters in 5 nationalities in inner mongolia].

The gene frequency of 12 characters was reported in Ewenki, Oroqen, Daur, Mongol and Han nationalities in Inner Mongolia, and compared among these nationalities. The result indicated that the difference of Mongoloid fold among nationalities was significant, followed by the Folding tongue, while the difference of Handedness and Nasal profile was relatively insignificant.

[Study of hereditary mode on handedness, preferential foot and hand-clasping].

The data of 21 families were analyzed by the method of Slater's calculating model to differentiate between single-gene and multi-gene heredity and by the method of non-deviation analysis. The results showed that the hereditary mode of handedness or preferential foot or hand-clasping is the dominant heredity of single gene of autosome, and the right type of all of them is the dominant character. In a way, although environmental factors affected the phenotypes of these characters,hereditary factors were also the decisive ones.