Predicting Risks of Cadmium Toxicity in Salinity-Fluctuating Estuarine Waters Using the Toxicokinetic-Toxicodynamic Model.

In estuaries, salinity fluctuates rapidly and continuously, greatly affecting the bioavailability and thus toxicity of contaminants, especially metals, causing difficulties in deriving site-specific water quality criteria. We developed a method for predicting the toxicity of the metal cadmium (Cd) in estuarine waters of any salinity fluctuation scenario. Cd bioaccumulation and toxicity were measured in an estuarine clam Potamocorbula laevis under stable salinities (salinity = 5, 15, 25) and fluctuating salinities (5-25), using the toxicokinetic-toxicodynamic (TK-TD) framework. Cd bioaccumulation decreases with increasing salinity; whereas intrinsic Cd sensitivity of organisms reaches the minimum at an intermediate salinity around 20. At each specific Cd level, interpolating TK-TD parameters measured at the stable salinities well predicts the Cd bioaccumulation and toxicity under fluctuating salinities. To extend the model for various Cd levels, the biotic ligand model (BLM) was integrated into the TK-TD framework. The BLM-based TK-TD model was successfully applied to scenarios of simulated and monitored salinity fluctuations in estuarine waters, for which the median lethal concentrations and no-effect concentrations (2.0-3.1 µg L-1) of Cd were derived. Overall, we integrated the BLM and TK-TD models and provided a useful tool for predicting metal risks and deriving criteria values for salinity-fluctuating estuarine waters.

Making Acute Tests More Ecologically Relevant: Cadmium Bioaccumulation and Toxicity in an Estuarine Clam under Various Salinities Modeled in a Toxicokinetic-Toxicodynamic Framework.

Salinity has considerable effects on the toxicity of metals in estuarine waters. The effects of salinity are manifold, making it difficult to summarize for risk assessments. In this study, we separated and quantified the multiple effects of salinity on cadmium (Cd) in a toxicokinetic-toxicodynamic framework. The estuarine clam, Potamocorbula laevis, was used as a model organism. Cd bioaccumulation was measured using a stable-isotope-tracer technique; in parallel, toxicity tests were conducted. With the increase of salinity from 5 to 30, Cd uptake decreased monotonically. In contrast, the intrinsic sensitivity of organisms, measured by the toxicodynamic parameters, reached its minimum at intermediate salinities (i.e., 10 to 20). The overall salinity effects were dominated by the effects on Cd bioaccumulation; therefore, Cd toxicity decreased monotonically with the increases of salinity. The model developed in this study could provide predictions of no-effect concentration (1.7 to 34.9 µg L-1, end point mortality) and the median lethal concentration (LC50) of Cd at different salinities. In conclusion, we developed a framework for quantifying the multiple effects of salinity and a method for estimating no-effect concentration from acute toxicity tests, which can be used for better assessments of metal risks in estuarine waters.

Estimation of stature by using the dimensions of the right hand and right foot in Han Chinese adults.

The Han Chinese people are the main ethnic group in China and the largest ethnic group in the world. The dimensions of the hands and feet have been successfully used for the estimation of stature. A total of 26,927 healthy adult subjects, comprising 13,221 men and 13,706 women, were recruited. The survey samples were chosen through random cluster sampling. The mean values were significantly higher in men than those in women for all measurements (P<0.001). All the measurements showed a statistically significant correlation with stature (P<0.01). The combination of the right hand length and the right foot length was the best predictor of stature because it had the lowest standard error of estimate. The use of multiple regression equations yielded better results than did the use of linear regression equations. The accuracy of stature prediction ranged from ±4.81 to ±6.39 cm. The present study was of great importance with regards to improving the physical anthropology database of ethnic groups in China.

Physical characteristics of Chinese Hakka.

Using standard and internationally validated methods, 86 anthropologic characteristics were determined in 650 male (305 from urban areas and 345 from rural areas) and 704 female (331 from urban areas, 373 from rural areas) Chinese Hakka adults living in Guangdong and Jiangxi. The data were used to calculate 24 anthropologic indices, which were analyzed statistically. The physical characteristics of Hakka subjects were analyzed and compared with reference ethnic data. There were four main findings of this study. First, a small proportion of Hakka adults had an eye fold on the upper eyelid, but a large proportion had a mongoloid fold. The eye slits were narrow in most adults, had a medium nasal root height and straight bridges, and most of the external angles were prominent. The nasal base was upturned in most men. The distributions of the three types of nasal base in women were similar. The proportions of subjects with middle and high alae nasi heights were high and similar. Males with a maximum nostril diameter were mostly classified as transverse and oblique, while many women were classified as transverse and had relatively wide alae nasi. The round lobe type was the most common. Upper lip skin height was mostly classified as medium. Lips were classified as thin. The hair was black, eyes were brown, and the skin was yellowish. Second, the head length was long in male Hakka. The minimum frontal breadth, face breadth, lip height, and interocular breadth were similar to those of North-Asian populations. Meanwhile, head breadth, morphological facial height, nose breadth, mouth breadth, and nose height were similar to those of South-Asian populations. Head length was long in female Hakka. The minimum frontal breadth, face breadth, lip height, and interocular breadth were similar to those of North-Asian populations. Head breadth, nose breadth, and mouth breadth were similar to those of South-Asian populations. Third, the stature of male and female Hakka in urban and rural areas was classified as medium. The proportions of male and female Hakka classified as mesocephaly (length-breadth index of the head), hypsicephalic type, metriocephalic type (breadth-height index of the head) mesorrhiny, long trunk, subbrachyskelic type, broad shoulder breadth, and narrow distance between iliac crests were higher than those of other types. Finally, principal component analyses showed that the physical characteristics of Hakka were between those of South-Asian and North-Asian ethnic populations, but were generally closer to those of North-Asian populations in China.

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.

Morphological traits in peoples of Mongolian nationality of the Hulunbuir league, Inner Mongolia, China.

A sample of 947 Mongolians of Bargud, Elute and Buriat was investigated on 9 indexes (hair form, forehead hair-ledge point, eyefold of the upper eyelid, Mongoloid fold, ear lobe type, nasal profile, nostril type, front teeth type, and chin projection) in the Hulunbuir league, Inner Mongolia in September 1997. The results are as follows: 1. Most of the Mongolians in Hulunbuir league are characterised by straight hair, forehead hair-ledge point absence, eyefold eyelid, Mongoloid fold appearance, shovel-shaped front teeth, straight nose, wide nostril, free ear lobe, non-projecting chin. 2. The frequencies of the forehead hair-ledge point appearance, shovel-shaped front teeth appearance and projecting chin showed significant differences between the three groups. 3. The incidence of ear lobe type, nasal profile and front teeth type showed obvious sexual differences. 4. Correlations did not occur between most of the nine traits.

[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.