The identification and expression analysis of candidate chemosensory genes in the bird cherry-oat aphid Rhopalosiphum padi (L.).

The bird cherry-oat aphid Rhopalosiphum padi (L.) is one of the most important wheat pests with polyphagia and autumn migrants. And, chemosensory genes were thought to play a key role in insect searching their hosts, food and mate. However, a systematic identification of the chemosensory genes in this pest has not been reported. Thus, in this study, we identified 14 odorant-binding proteins, nine chemosensory proteins, one sensory neuron membrane protein, 15 odorant receptors, 19 gustatory receptors and 16 ionotropic receptors from R. padi transcriptomes with a significantly similarity (E-value < 10-5) to known chemosensory genes in Acyrthosiphon pisum and Aphis gossypii. In addition, real-time quantitative polymerase chain reaction (RT-qPCR) was employed to determine the expression profiles of obtained genes. Among these obtained genes, we selected 23 chemosensory genes to analyze their expression patterns in different tissues, wing morphs and host plants. We found that except RpOBP1, RpOBP3, RpOBP4 and RpOBP5, the rest of the selected genes were highly expressed in the head with antennae compared with body without head and antennae. Besides that, the stimulation and depression of chemosensory genes by plant switch indicated that chemosensory genes might be involved in the plant suitability assessment. These results not only provide insights for the potential roles of chemosensory genes in plant search and perception of R. padi but also provide initial background information for the further research on the molecular mechanism of the polyphagia and autumn migrants of it. Furthermore, these chemosensory genes are also the candidate targets for pest management control in future.

Dietary sodium and potassium, socioeconomic status and blood pressure in a Chinese population.

The average total intake of sodium was 6.11 g in a Chinese urban diet and 6.49 g in the rural sample in China. Discretionary use of salt provided 53% of the total sodium intake in the urban and 63% in the rural diet. Sodium intakes derived from processed foods, soy sauce and monosodium glutamate were 17%, 16% and 6% respectively in the urban diet, and 4%, 16%, 2% respectively in the rural diet. The mean intake of potassium was 1.95 g in the urban and 1.83 g in the rural diet. Cereals and vegetables were the major sources of dietary potassium. The intakes of total sodium, salt and soy sauce decreased as educational level increased. Similar results were found in white-collar workers and blue-collar workers or farmers. Nevertheless, an inverse association between blood pressure and education was found. The results suggest that reduction in sodium intake, especially cooking salt, and increased potassium intake are needed for nutritional control of hypertension in population-based interventions aimed at all social classes.

A dietary survey of the Chinese population in urban and rural areas of Tianjin.

OBJECTIVES: A survey was carried out to assess the food pattern and of nutrient intakes of 15-64 year old Chinese in Tianjin. DESIGN: The survey was randomised and the diet assessed by weighing household food items and by individual food records over 3 consecutive days. SETTING: The survey was carried out in Tianjin; the third largest city in China (population about 8 million). SUBJECTS: A random stratified multi-level cluster sampling technique was used. Of the 5233 eligible subjects, 207 dropped out, and the response rate was 96%. RESULTS: Distinct differences in dietary patterns and nutrient intakes were found between subjects living in urban and rural areas. The diet of urban people was richer in fat and high quality protein compared with that of rural people. Energy intake from fat was about 31% in the urban diet and about 21% in the rural diet. Low intakes of vitamin A, riboflavin, calcium and zinc were found in both areas, with the situation being worse in the rural areas. Sodium intake was found to be high in both areas. Cholesterol intake was much higher among urban people. CONCLUSION: The present survey revealed that the intake of some nutrients was lower than recommended and that total sodium intake was very high in Tianjin. An integrated nutrition intervention program would appear necessary for such a population.

Changes in sodium intake and blood pressure in a community-based intervention project in China.

A sodium intervention project was carried out in Tianjin, China, as part of the Tianjin Project, which is a national pilot, community-based intervention programme to reduce non-communicable diseases. The aim of this 3 year sodium project was to evaluate the feasibility and effects of sodium reduction in the population. The evaluation of the programme was based on examinations of independent cross-sectional population samples in 1989 (1719 persons) and in 1992 (2304 persons) in the intervention and matched reference areas. Food weighing and consecutive 3 day food records were used to measure dietary intake. The mean sodium intake fell 22 mmol/day in men and 11 mmol/day in women in the intervention area from 1989 to 1992. The reduction was significant in men (P = 0.001) and near significance in women (P = 0.05). The sodium intake increased significantly in men in the reference area. There was a significant net reduction in sodium intake in men in the intervention area. This reduction was similar in different educational and occupational groups suggesting that the intervention had reached the whole community. The mean systolic blood pressure (SBP) decreased 3 mm Hg for the total population and 2 mm Hg for normotensives in the intervention area. There was a significant net reduction in SBP both in all or in normotensive subjects. These results support the conclusion that community-based sodium intervention is feasible for hypertension prevention. However, the sodium intake is still very high in this population, which warrants further effective intervention.

Relationship between serum lipids and dietary and non-dietary factors in a Chinese population.

OBJECTIVES: To describe the distribution of serum lipids and examine the relationship between serum lipids and dietary and non-dietary factors. DESIGN: A randomised survey. SETTING: The survey was carried out in Tianjin, China. SUBJECTS: Altogether 680 subjects were screened. Forty-nine of those were excluded but 314 men and 317 women remained. INTERVENTION: The serum lipids were measured by enzymatic methods. The diet was assessed by food weighing plus consecutive individual 3-day food records. RESULTS: The mean cholesterol concentrations were 4.08 and 3.94 mmol/l in men and women respectively. The mean high-density lipoprotein cholesterol (HDL-C) levels were 1.24 and 1.35 mmol/l, and the mean triglyceride levels were 1.48 and 1.20 mmol/l. The energy intake derived from fat was approximately 29% (6.9% from saturated fat) and the polyunsaturates:saturates ratio of the diet was 1.3 in both sexes. Multiple regression analyses showed that no association was discovered between serum lipids and dietary variables. Age and body mass index (BMI) were strong and independent predictors of serum lipids in both sexes. BMI was positively related to serum total cholesterol, triglyceride and low-density lipoprotein cholesterol (LDL-C), and inversely related to HDL-C. Education was a predictor only in men. Men with a higher education had more coronary heart disease risk factors than men with lower education attainment. CONCLUSION: The Chinese have favourable serum lipid profiles and dietary fat pattern. No relationship was found between lipids and dietary variables, which warrants further studies because these relationships have not been investigated previously in any Chinese population.

Assessment of sodium and potassium in processed foods in an urban area in China.

OBJECTIVE: To identify commonly consumed processed foods with high sodium (Na) content and sodium to potassium (Na:K) ratio for the purpose of using this information in a community-based nutrition education programme. DESIGN: Calculations of Na and K intake were based on the data of a dietary survey carried out in Tianjin in 1992. All processed foods were randomly sampled based on manufacturers and market survey. SETTING: The survey was conducted in the urban area in Tianjin, China. PARTICIPANTS: 2317 subjects aged 15-64 years old were included in the dietary survey. The response rate was 95%. MAIN RESULTS: The mean sodium intake was 6517 mg in men and 5708 mg in women. 38% of the total Na intake came from processed foods and condiments in both of the urban men and women in Tianjin. 122 processed foods with sales volumes were identified. Most of the processed foods had high Na content and high Na:K ratio, especially Na-rich condiments, salted vegetables, fried dough cake and sausages. The Na content of most processed foods in Tianjin was higher than the mean value reported in the Chinese Food Composition Table. CONCLUSION: Processed foods contribute an important part of dietary Na in the urban diet in Tianjin. It is necessary to initiate nutrition intervention activities aiming at regulations on the Na content of processed foods and to advise the people to reduce consumption of salty foods.

Dietary survey in a Chinese population.

OBJECTIVES: To assess food pattern and nutrition profile aiming at planning population-based nutrition intervention for chronic diseases control. DESIGN: A randomized survey. SETTING: The survey was carried out in Tianjin, one of the three largest cities in China. SUBJECTS: 3683 subjects aged 15-64 years old were selected by a random stratified multilevel cluster sampling. INTERVENTION: The diet was assessed by food weighing plus consecutive individual 3 day food records. RESULTS: Distinct differences in dietary pattern and nutrient intakes were found between subjects living in urban and rural areas. The diet of urban people was richer in fat and high quality protein compared with the diet of rural people. Low intakes of vitamin A, calcium, riboflavin, and zinc were found in both areas, the situation being worse in the rural areas. The sodium intake and sodium:potassium ratio was very high in both areas. Cholesterol intake was much higher among the urban people. CONCLUSION: The study suggests that integrated nutrition intervention is needed to prevent insufficient intake of some nutrients and control dietary risk factors related to chronic diseases.

Associations between blood pressure and dietary intake and urinary excretion of electrolytes in a Chinese population.

OBJECTIVE: To examine the associations between blood pressure and sodium, potassium, calcium and magnesium in a cross-sectional study by 24-h urine collections and food weighing with 3-day food records in 328 males and 335 females in Tianjin, People's Republic of China. RESULTS: A very high sodium intake and sodium:potassium ratio was confirmed in the study population. After adjusting for confounding variables, both dietary and urinary sodium and sodium:potassium ratio were significantly and positively correlated with blood pressure. Although a negative correlation was found between potassium and blood pressure, the association was significant only between urinary potassium and systolic blood pressure in females and in both sexes combined. No significant associations were found between blood pressure and either intake of or urinary excretion of calcium and magnesium. The dietary intake correlated highly with urinary excretion of electrolytes. In both sexes a strong positive association was found between blood pressure and age, and between blood pressure and body mass index. Higher blood pressure was shown in subjects with higher sodium and alcohol intake, higher body mass index and lower potassium intake. CONCLUSION: The present results indicate that factors contributing to high blood pressure in Tianjin, People's Republic of China, are related to age, body mass index, high sodium intake and sodium:potassium ratio.