Blood pressure and risk of cardiovascular disease in Chinese men and women

BACKGROUND

We examined the relationship between systolic and diastolic blood pressure (BP) and the incidence of cardiovascular disease (CVD) in a nationally representative cohort of 169,871 men and women > or = 40 years of age in China.

METHODS

Data on BP and other variables were obtained at a baseline examination in 1991 using standard protocols. Follow-up evaluation was conducted in 1999-2000, with a response rate of 93.4%.

RESULTS

After adjustment for age, sex, cigarette smoking, alcohol consumption, physical activity, body mass index, education, geographic region, urbanization, and time-dependent history of diabetes, a strong and linear association between both systolic and diastolic BP and incidence of CVD, coronary heart disease and stroke were observed (all P < 0.0001). For example, the relative risks (95% confidence interval (CI)) of CVD incidence were 1.09 (1.00-1.18), 1.25 (1.16-1.35), 1.49 (1.38-1.62), 2.15 (1.99-2.31), 3.01 (2.78-3.27), and 4.16 (3.84-4.51) for those with systolic/diastolic BP of 110-119/75-79, 120-129/80-84, 130-139/85-89, 140-159/90-99, 160-179/100-109, and > or = 180/110 mm Hg compared to those with BP <110/75 mm Hg. Increases in systolic BP were associated with a greater risk of CVD compared to corresponding increases in diastolic BP. The linear trend for increased CVD risk being related to higher BP levels was observed in all subgroups of gender, age, body weight, and cigarette smoking.

CONCLUSIONS

Our results indicate that there is a strong, linear, and independent relationship between BP levels and the risk of CVD in Chinese adults. Systolic BP is a stronger predictor of CVD risk compared to diastolic BP.

Hypertension and cardiovascular diseases intervention in the capital steel and iron company and Beijing Fangshan community

Two intervention studies are described involving >110,000 subjects in each. The first was in a steel factory where one intervention site had health promotion, aimed at altering diet, and particularly reducing salt and fat intake, modest alcohol drinking and smoking cessation, together with a high-risk strategy of hypertension control. The second study involved similar population and high-risk strategies in three of five rural communities. Significant reductions occurred in both intervention and control factory sites in blood pressure, with greater falls in the intervention site, together with a marked additional reduction in salt intake and better control of hypertension. In the rural communities, blood pressure fell in all communities to a more modest degree than in the factory, but with greater blood pressure falls, together with greater smoking cessation and more modest alcohol drinking in the intervention compared with the control communities. Stroke mortality fell by 74.3% and all strokes morbidity by 54.7% in the steel factory as a whole. In the rural communities, the intervention sites showed significantly greater falls in stroke rates than in the control communities. These data show the value and effectiveness of combining a population and high-risk strategy for controlling blood pressure and cardiovascular diseases in both a rural setting and in the work place in China.

Alcohol consumption and the risk of end-stage renal disease among Chinese men

We examined the relationship between alcohol consumption and incidence of end-stage renal disease (ESRD) in a prospective cohort of 65 601 Chinese men aged 40 years and older. Information on the amount and type of alcohol consumed was collected at a baseline examination with follow-up evaluations conducted 8-9 years later. During the 500 876 person-years of follow-up, 176 participants initiated renal replacement therapy or died from renal failure. Compared to non-drinkers, the relative risk of ESRD was 0.67 among men consuming less than 21 drinks per week and 0.52 among men consuming this amount or more after adjustment for age, geographic region, urbanization, education, body mass index, physical activity, and cigarette smoking. The inverse association between alcohol consumption and ESRD existed even after adjustment for systolic blood pressure, and history of diabetes and cardiovascular disease. Our results suggest an inverse relationship between alcohol consumption and risk of ESRD in Chinese men. Heavy alcohol consumption, however, may lead to increased risk of morbidity and mortality from other causes; therefore, the implications from these findings should be interpreted cautiously.

Cardiovascular risk prediction tools for populations in Asia

BACKGROUND

Cardiovascular risk equations are traditionally derived from the Framingham Study. The accuracy of this approach in Asian populations, where resources for risk factor measurement may be limited, is unclear.

OBJECTIVE

To compare "low-information" equations (derived using only age, systolic blood pressure, total cholesterol and smoking status) derived from the Framingham Study with those derived from the Asian cohorts, on the accuracy of cardiovascular risk prediction.

DESIGN

Separate equations to predict the 8-year risk of a cardiovascular event were derived from Asian and Framingham cohorts. The performance of these equations, and a subsequently "recalibrated" Framingham equation, were evaluated among participants from independent Chinese cohorts.

SETTING

Six cohort studies from Japan, Korea and Singapore (Asian cohorts); six cohort studies from China; the Framingham Study from the US.

PARTICIPANTS

172,077 participants from the Asian cohorts; 25,682 participants from Chinese cohorts and 6053 participants from the Framingham Study.

MAIN RESULTS

In the Chinese cohorts, 542 cardiovascular events occurred during 8 years of follow-up. Both the Asian cohorts and the Framingham equations discriminated cardiovascular risk well in the Chinese cohorts; the area under the receiver-operator characteristic curve was at least 0.75 for men and women. However, the Framingham risk equation systematically overestimated risk in the Chinese cohorts by an average of 276% among men and 102% among women. The corresponding average overestimation using the Asian cohorts equation was 11% and 10%, respectively. Recalibrating the Framingham risk equation using cardiovascular disease incidence from the non-Chinese Asian cohorts led to an overestimation of risk by an average of 4% in women and underestimation of risk by an average of 2% in men.

INTERPRETATION

A low-information Framingham cardiovascular risk prediction tool, which, when recalibrated with contemporary data, is likely to estimate future cardiovascular risk with similar accuracy in Asian populations as tools developed from data on local cohorts.

Association analysis of the variant in the regulatory subunit of phosphoinositide 3-kinase (p85alpha) with Type 2 diabetes mellitus and hypertension in the Chinese Han population

AIMS

To determine whether variants in the gene for the regulatory subunit of phosphoinositide 3-kinase (p85alpha) are associated with Type 2 diabetes mellitus (Type 2 DM) and hypertension in a Chinese population.

METHODS

We performed a case-control study genotyping the Met326Ile and IVS4+82A>G polymorphisms in 494 patients with Type 2 DM and hypertension and 557 normal controls from the north of China. Individual genotypes were identified by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The IVS4+82A>G polymorphism was further confirmed by direct sequencing in 20 randomly selected cases.

RESULTS

The IVS4+82A>G polymorphism that is common in Caucasians was not detected in our population. Frequencies of genotypes and alleles of Met326Ile polymorphism were not significantly different between cases and controls in whole samples by univariate analysis. Logistic regression analysis demonstrated that Ile326Ile genotype was associated with a 2.085-fold (95% CI, 1.043-4.168, P = 0.0377) relative risk of diabetes and hypertension. After stratification by obesity, the frequency of Ile326Ile genotype in cases was higher than that in controls (18/304 vs. 13/510, P = 0.015) among non-obese individuals (BMI < 28 kg/m2). We did not find that this missense mutation was associated with blood pressure, glucose and blood lipids in the control group.

CONCLUSION

Our data indicate that the Met326Ile variation in the gene encoding the p85alpha protein might contribute to the increased risk of Type 2 DM and hypertension in Chinese.

beta2-Adrenergic receptor gene variations associated with stage-2 hypertension in northern Han Chinese

The aim of this study was to investigate the association between polymorphisms in the beta(2)-adrenergic receptor gene (ADRB2) (-47C/T, Arg16/Gly, Gln27/Glu) and stage-2 hypertension in northern Han Chinese. We recruited 503 individuals with stage-2 hypertension and 504 age-, gender-, and area-matched controls from the International Collaborative Study of Cardiovascular Disease in Asia. Genotyping was performed using PCR-RFLP. Logistic regression analyses revealed that carriers of the Gly16 allele had a significantly higher odds ratio (OR) for hypertension, while carriers of the Glu27 allele had a significantly lower OR. In multivariate linear regression analyses, the Arg16/Gly and Gln27/Glu genotypes were significantly associated with systolic blood pressure level (p = 0.004 and p < 0.001, respectively). In haplotype analyses, we found the frequency of haplotypes composed of the Gly16 and Gln27 alleles was significantly higher, whereas the frequency of haplotypes composed of the Arg16 and Glu27 alleles was significantly lower, in hypertensives compared to their controls (both p = 0.001). These results indicate that the Gly16 and Gln27 alleles of the ADRB2 gene confer an increased risk for stage-2 hypertension in this northern Han Chinese population.

Linkage analysis of chromosome 1 with essential hypertension and blood pressure quantitative traits in Chinese families

Summary Several recent studies have linked human chromosome 1p to essential hypertension (EH) or blood pressure (BP) levels. In an independent population of 148 hypertensive families from China we tested these findings. Thirty highly informative microsatellite markers spanning about 284 cM were genotyped. Qualitative linkage analysis was conducted using non-parametric linkage analysis implemented within the GENEHUNTER 2.0 software, whereas quantitative analysis was performed with the variance-component method integrated in the S.O.L.A.R. 1.7.4. software with an additional Haseman-Elston method using the SAGE/SIBPAL2 program. We observed suggestive linkage between D1S2890 (1p31, 80.9 cM) and hypertension using the multipoint non-parametric linkage analysis (NPL = 2.19, P = 0.01). In the quantitative analysis we didn't observe a significant excess of identity-by-descent allele sharing between the systolic blood pressure levels and the markers. However, the D1S207 microsatellite marker (1p21) which is located about 107 cM from the telomere of 1p showed weak linkage evidence with the diastolic blood pressure levels (LOD = 1.42). These findings suggest linkage of 1p31 with essential hypertension in the ethnic Chinese, and provide a potential clue for future studies involving candidate genes for hypertension.

Smoking, quitting, and the risk of cardiovascular disease among women and men in the Asia-Pacific region

BACKGROUND

Although smoking is a major risk factor for cardiovascular disease, it has been suggested that Asians may be less susceptible to the adverse effects of smoking than Caucasians. This may have contributed to the high prevalence of smoking, and the low quitting rates, in Asian men. Worldwide, smoking rates are increasing for women, amongst whom cardiovascular awareness is relatively poor.

METHODS

An individual participant data analysis of 40 cohort studies was carried out, involving 463 674 Asians (33% female) and 98 664 Australasians (45% female). Cox proportional hazard models, stratified by study and sex where appropriate, were employed.

RESULTS

The HR [95% confidence interval (CI)], comparing current smokers with non-smokers, for coronary heart disease (CHD) was 1.60 (1.49-1.72); haemorrhagic stroke 1.19 (1.06-1.33); ischaemic stroke 1.38 (1.24-1.54). There was a clear dose-response relationship between the number of cigarettes smoked per day and both CHD and stroke, with no significant difference (P >/= 0.20) between populations from Asia and Australia/New Zealand. Although there was no sex difference for stroke in the effect of amount smoked (P = 0.16), for CHD, women tended to have higher hazard ratios than men (P = 0.011). Quitting gave a clear benefit, which was not significantly different between the sexes or regions (P > 0.63). The HR (CI) for ex-smokers compared with current smokers was 0.71 (0.64-0.78) for CHD and 0.84 (0.76-0.92) for stroke.

CONCLUSIONS

Unless urgent public health measures are put into place, the impact of the smoking epidemic in Asia, and among women, will be enormous. Tobacco control policies that specifically target these populations are essential.

A Comparison of Lipid Variables as Predictors of Cardiovascular Disease in the Asia Pacific Region

PURPOSE

Many guidelines advocate measurement of total or low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL), and triglycerides (TG) to determine treatment recommendations for preventing coronary heart disease (CHD) and cardiovascular disease (CVD). This analysis is a comparison of lipid variables as predictors of cardiovascular disease.

METHODS

Hazard ratios for coronary and cardiovascular deaths by fourths of total cholesterol (TC), LDL, HDL, TG, non-HDL, TC/HDL, and TG/HDL values, and for a one standard deviation change in these variables, were derived in an individual participant data meta-analysis of 32 cohort studies conducted in the Asia-Pacific region. The predictive value of each lipid variable was assessed using the likelihood ratio statistic.

RESULTS

Adjusting for confounders and regression dilution, each lipid variable had a positive (negative for HDL) log-linear association with fatal CHD and CVD. Individuals in the highest fourth of each lipid variable had approximately twice the risk of CHD compared with those with lowest levels. TG and HDL were each better predictors of CHD and CVD risk compared with TC alone, with test statistics similar to TC/HDL and TG/HDL ratios. Calculated LDL was a relatively poor predictor.

CONCLUSIONS

While LDL reduction remains the main target of intervention for lipid-lowering, these data support the potential use of TG or lipid ratios for CHD risk prediction.

Haplotypic analyses of the aldosterone synthase gene CYP11B2 associated with stage-2 hypertension in northern Han Chinese

The objective of this study was to investigate the association of polymorphisms in the aldosterone synthase gene CYP11B2 (-344T/C, Lys173/Arg, and an intronic conversion [IC]) with stage-2 hypertension in northern Han Chinese. A total of 503 hypertensives and their age-, gender-, and area-matched controls were included in this study. The female hypertensives had significantly higher frequencies of the -344T, 173Lys, and IC-conversion alleles (p = 0.002, 0.002, and 0.014, respectively). The estimated frequency of haplotype composed of the -344T, 173Lys, and IC-conversion alleles (haplotype 4) was significantly higher in the female hypertensives compared with their controls (p = 0.007). Using a multivariate score test, we found that haplotype 4 remained associated with female hypertension after the adjustment for covariates (p = 0.003), while the haplotype 3 of T-Arg-WT showed a protective effect both in the males and in the females (p = 0.03 and 0.006, respectively). The odds ratio for haplotype phase of 4-4 was 2.60 (95% CI, 1.21-5.58) and for 3-3, 0.20 (95% CI, 0.03-0.77). These results indicate that the Lys173 and the IC-conversion allele of the CYP11B2 gene confer an increased risk for stage-2 hypertension in northern Han Chinese women.

Prevalence of diabetes and impaired fasting glucose in the Chinese adult population: International Collaborative Study of Cardiovascular Disease in Asia (InterASIA)

AIMS/HYPOTHESIS

To estimate the prevalence of diagnosed and undiagnosed diabetes and impaired fasting glucose in the general adult population of China.

METHODS

The International Collaborative Study of Cardiovascular Disease in ASIA, conducted from 2000 to 2001, included a nationally representative sample of 15 540 adults, aged 35 to 74 years. An overnight fasting blood specimen was collected to measure serum glucose and information on history of diabetes and use of hypoglycaemic medications was obtained by a standard questionnaire. Undiagnosed diabetes (fasting glucose > or =7.0 mmol/l) and impaired fasting glucose (6.1-6.9 mmol/l) were defined using the American Diabetes Association criteria.

RESULTS

Prevalence of self-reported diagnosed diabetes, undiagnosed diabetes, and impaired fasting glucose in Chinese adults were 1.3%, 4.2%, and 7.3%, respectively. Overall, 5.2% or 12.7 million men and 5.8% or 13.3 million women in China aged 35 to 74 years had diabetes (self-reported diagnosis plus undiagnosed diabetes). The age-standardized prevalence of diabetes was higher in residents of northern compared to southern China (7.4% vs 5.4%, p<0.001) and in those living in urban compared to rural areas (7.8% vs 5.1%, p<0.001).

CONCLUSIONS/INTERPRETATION

Our results show that the prevalence of diabetes in the adult population in China is much higher than previously reported. Three out of every four diabetes patients are undiagnosed, indicative of a lack of population-based screening programmmes and a relatively rapid and recent increase in incidence of diabetes. These results indicate that diabetes has become a major public health problem in China and underscore the need for national strategies aimed at prevention and treatment of diabetes.

[The development and application of computer-aided bone histomorphometry system]

The aim of this study is to develop a Computer-aided Bone Histomorphometry System. The method is based on the Micro-graphical Digital System composed of microscope, digital camera, computer and related programs. The methodology was developed to measure the basic data on each image of visual field of hard bone tissue with computer-assistance. Following this, the parameters of bone volume, bone structure and bone metabolism were calculated based on the standardization of bone histomorphometry. Such method has been used in the experimental and clinical studies of osteoporosis to predict the fracture risk and evaluate the drug effect.

[Evaluation on the effect of cardiovascular prevention program in Fangshan, Beijing]

OBJECTIVE

To evaluate the effect of cardiovascular prevention program in Fangshan, Beijing (BFCP) from 1991-1999.

METHODS

BFCP was a comprehensive community trial covering 120,000 residents in five communities, including three as intervention communities (IC), and two as control communities (CC), in Fangshan, suburb of Beijing. The program was implemented under both population and high risk individual strategies, focusing on health education and hypertension control. The main intervention measures were as follows: (1) network setup; (2) health education and promotion; (3) health professional training; (4) detection and management of hypertensive patients.

RESULTS

Baseline, midterm and final cross-sectional surveys were conducted in the year 1991, 1995 and 1999, respectively. After 9-year intervention, improvement was found in population of IC versus CC (P < 0.01 or P < 0.05) for knowledge, attitude and behavior of CVD prevention, awareness on hypertension, treatment and control rates, as well as the quantity of dietary intake of protein, potassium and calcium. Risk factors such as systolic blood pressure, diastolic blood pressure, rates of smoking and alcohol drinking declined in the population in IC versus CC (P < 0.01). The average morbidity and mortality of stroke were 18.7% (u = 2.81, P < 0.01) and 17.7% (u = 2.91, P < 0.01), significantly lower in the IC versus CC. No significant difference was identified on the morbidity and mortality of coronary heart diseases between IC and CC.

CONCLUSION

The comprehensive community prevention approach was feasible and effective in the prevention and control of cardiovascular diseases in rural populations in China.

[Job strain and hypertension risk in Capital Steel and Iron Company in Beijing]

OBJECTIVE

To assess the relation between the scales of Job Demand control Model (or "Job strain") and the prevalence of hypertension.

METHODS

A standardized questionnaire base-line survey was conducted among 1,556 male and female employees aged 18-65 in two factories of the Capital Steel and Iron Company, Beijing, in 1997 to investigate the socio-demographic factors and job strain so as to identify the major risks of hypertension.

RESULTS

The prevalence of hypertension increased from 6.5% to 21.2% with an age-adjusted relative prevalence ratio (95% CI) of 3.26 (2.30, 4.41) when the job strain pattern changed from high control and low demand to moderate control and moderate demand and further to low control and high demand among the male employees. After adjustment for confounding effects from age, education, body mass index, smoking, alcohol consumption, and physical activity, the odds ratio (95% CI) was attenuated to 2.31 (1.45, 3.81). Such a phenomenon was not typical among females.

CONCLUSION

The risk of hypertension was elevated with the increase of job strain in men.

Determination of active component in silymarin by RP-LC and LC/MS

Silybin, isosilybin, silydianin and silycristin in silymarin were separated and quantitatively determined by RP-HPLC. Two diastereoisomers of silybin and isosilybin were respectively separated by RP-HPLC and confirmed by LC/MS. Chromatographic condition consisted of column: Shim-pack VP-ODS (150 x 4.6mm i.d. 5 microm) and Pre-column (10 x 4.6 mm i.d. 5 microm); mobile phase: methanol and solvent mixture (water: dioxane=9:1) by gradient; flow rate: 1.5ml/min; column temp.: 40 degrees C; detector wavelength: 288 nm; The recovery of 99.66% for silycristin, 99.48% for silydianin, 100.0% for silybin and 98.72% for isosilybin was respectively obtained.

Effect of potassium supplementation on blood pressure in Chinese: a randomized, placebo-controlled trial

OBJECTIVE

To examine the effect of potassium supplementation on blood pressure (BP) in a Chinese population who consume a habitual high sodium and low potassium diet.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Community sample from Beijing, China.

PARTICIPANTS

A total of 150 men and women aged 35-64 years with an initial systolic BP 130-159 mmHg and/or diastolic BP 80-94 mmHg.

INTERVENTIONS

Participants were randomly assigned to take 60 mmol potassium chloride supplement or placebo for 12 weeks.

MAIN OUTCOME MEASURE(S)

BP measurements were obtained at baseline, and at 6 weeks and 12 weeks during the trial, using random-zero sphygmomanometers.

RESULTS

The average baseline urinary excretion of sodium and potassium was 182 mmol/24 h and 36 mmol/24 h. Baseline BP and other measured variables were similar between the potassium supplementation and placebo groups. In the active compared to the placebo treatment group, the urinary excretion of potassium was significantly increased by 20.6 mmol/24 h (P< 0.001) during 12 weeks of intervention. Compared to placebo, active treatment was associated with a significant reduction in systolic BP (-5.00 mmHg, 95% CI: -2.13 to -7.88 mmHg, P < 0.001) but not diastolic BP (-0.63 mmHg, 95% CI: -2.49 to1.23 mmHg, P = 0.51) during 12-week intervention.

CONCLUSION

These data indicate that moderate potassium supplementation resulted in a substantial reduction in systolic BP. Our findings suggest that increased potassium intake may play an important role in the prevention and treatment of hypertension in China.

[Application of computer image process to the research on the contact characteristics of subtalar joint]

With the use of computer image processing technology, a new method was proposed for studying the contact characteristics of the subtalar joint. The results showed the total subtalar articulation area was 9.52 +/- 0.40 cm2. On neutral position and under 600 N load, the contact area of the subtalar joint was 2.00 +/- 0.11 cm2. The contact area of the posterior articulation was significantly larger than that of the anterior and medial articulation (p < 0.01). The average contact pressure was 19.3 +/- 1.38 N, the force transmitted by the subtalar was 389.16 +/- 28.75 N, which accounted for about 64.86% of the applied shank load (600 N), and 69.39% of the force was transmitted by the posterior articulation. The posterior articulation plays an important role in the load. The fracture line of the calcaneus often appears in this area.

[Study on the relationship between methylenetetrahydrofolate reductase gene C677T mutation and coronary heart disease]

OBJECTIVE

To investigate whether methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism is linked with coronary heart disease (CHD).

METHODS

Transmission/disequilibrium test(TDT), sib transmission/disequilibrium test(STDT), and sibship disequilibrium test(SDT) were used. Forty-five CHD pedigrees with at least one CHD patient in the first degree relatives of probands were recruited from Oct. 1998 to Feb. 1999. Among those recruited were 21, 2 and 22 pedigrees with the genotypes of both parents known, one parental genotype unknown and both unknown, respectively. MTHFR genotype was measured by PCR-RFLP technique.

RESULTS

Neither the TDT for 23 nuclear families with at least one parental genotype known or the STDT and SDT for 40 sibships found significant difference between the transmitted and untransmitted MTHFR gene 677T allele distributions.

CONCLUSION

The above results suggest that MTHFR gene 677T allele is probably not linked with CHD in Chinese population.

Matrix immobilization enhances the tissue repair activity of growth factor gene therapy vectors

Although growth factor proteins display potent tissue repair activities, difficulty in sustaining localized therapeutic concentrations limits their therapeutic activity. We reasoned that enhanced histogenesis might be achieved by combining growth factor genes with biocompatible matrices capable of immobilizing vectors at delivery sites. When delivered to subcutaneously implanted sponges, a platelet-derived growth factor B-encoding adenovirus (AdPDGF-B) formulated in a collagen matrix enhanced granulation tissue deposition 3- to 4-fold (p < or = 0.0002), whereas vectors encoding fibroblast growth factor 2 or vascular endothelial growth factor promoted primarily angiogenic responses. By day 8 posttreatment of ischemic excisional wounds, collagen-formulated AdPDGF-B enhanced granulation tissue and epithelial areas up to 13- and 6-fold (p < 0.009), respectively, and wound closure up to 2-fold (p < 0.05). At longer times, complete healing without excessive scar formation was achieved. Collagen matrices were shown to retain both vector and transgene products within delivery sites, enabling the transduction and stimulation of infiltrating repair cells. Quantitative PCR and RT-PCR demonstrated both vector DNA and transgene mRNA within wound beds as late as 28 days posttreatment. By contrast, aqueous formulations allowed vector seepage from application sites, leading to PDGF-induced hyperplasia in surrounding tissues but not wound beds. Finally, repeated applications of PDGF-BB protein were required for neotissue induction approaching equivalence to a single application of collagen-immobilized AdPDGF-B, confirming the utility of this gene transfer approach. Overall, these studies demonstrate that immobilizing matrices enable the controlled delivery and activity of tissue promoting genes for the effective regeneration of injured tissues.

Cholecystokinin expression in the developing and regenerating pancreas and intestine

In developmental terms, the endocrine system of neither the gut nor the pancreatic islets has been characterized fully. Little is known about the involvement of cholecystokinin (CCK), a gut hormone, involved in regulating the secretion of pancreatic hormones, and pancreatic growth. Here, we tracked CCK-expressing cells in the intestines and pancreata of normal mice (BALB/c), Non Obese Diabetic (NOD) mice and interferon (IFN)-gamma transgenic mice, which exhibit pancreatic regeneration, during embryonic development, the postnatal period and adulthood. We also questioned whether IFN-gamma influences the expression of CCK. The results from embryonic day 16 showed that all three strains had CCK in the acinar region of pancreata, and specifically in alpha cells that also expressed glucagon. However, in adulthood only BALB/c and NOD mice continued this pattern. By contrast, in IFN-gamma transgenic mice, CCK expression was suppressed from birth to 3 months of age in the pancreata but not intestines. However, by 5 months of age, CCK expression appeared in the regenerating pancreatic ductal region of IFN-gamma transgenic mice. In the intestine, CCK expression persisted from fetus to adulthood and was not influenced by IFN-gamma. Intestinal cells expressing CCK did not co-express glucagon, suggesting that these cells are phenotypically distinct from CCK-expressing cells in the pancreatic islets, and the effect of IFN-gamma on CCK varies depending upon the cytokine's specific microenvironment.

[Spatial structure and pattern of Nilaparvata lugens population in large-scale]

Brown planthopper(BPH), Nilaparvata lugens, is a major pest of rice. Its spatial distribution of different generations in Guangdong Province was studied by using variograms. The results showed that this population distributed in a clump pattern in rice fields during the 1st rice season. 3 generations of this population had different spatial structures, with the clump range of 400 km, 200 km and 205 km respectively in the 1st rice season. The simulation distribution maps of BPH, which was interpolated by Ordinary Kriging, showed that the density of BPH populations in west Guangdong province were higher than that in the east. The effect of sampling size on the spatial structure of BPH was not significant.

[Application of molecular markers-assisted selection of wx genes in breeding the waxy wheat]

Chinese Spring and its null-tetrasomic lines were used to identify the specific bands of STS-marker and microsatellites (SSR) marker of wx genes. Twelve varieties and five waxy wheat lines were screened with these two markers, and the results are in agreement with those from Wx subunits SDS-PAGE. A F2 segregating population from cross Jiangsu Baihuomai x Kanto 107 was also detected by molecular markers, not only eight wx genotypes were developed while three genotypes did not exist in the nature, but also the first batch of waxy wheat lines were bred. The Jiangsu Bainuomai improvement population was screened, and six 7D momosomic plants with wx-D1b were obtained, which could provide materials for waxy wheat breeding. Application molecular markers of wx genes will improve the selection procedure for the waxy wheat and good noodle-quality wheat.

[Hostility behavior as risk factor of coronary heart disease]

OBJECTIVE

To explore the relationships between hostility, and the risks of coronary-prone behavior and the clusters of unhealthy behaviors in individuals with different levels of hostility.

METHODS

A cross-sectional study was carried out among 1 010 male employees from two factories in Beijing Capital Steel and Iron Company in 1997. Data on major risks of cardiovascular, other social-demographic factors and levels of hostility by Cook-Medley Scales were collected.

RESULTS

Body mass index, amounts of cigarette smoking and alcohol drinking were significantly increased (P < 0.01) with a characteristic of reduced social support from one's colleagues, when individual's level of hostility increased. In addition, less years of education, higher prevalence of other chronic diseases (P < 0.05) and clustering of various unhealthy behaviors were found related to the increase of individual's hostility. The odds ratio in the group with highest hostility was 2.37 times higher than in the lowest one, after confounding effects from age, blood pressure, education level, status of chronic disease and social support being adjusted. No significant differences on both systolic and diastolic blood pressures among groups with different levels of hostility were discovered.

CONCLUSION

The association between hostility, coronary-prone risk behavior and cluster of unhealthy behaviors suggested that hostility might increase the risk of coronary heart diseases through affecting individual's behavior.

Sterols and inhibitors of sterol transport modulate the degradation and secretion of macrophage ApoE: requirement for the C-terminal domain

Macrophage-derived apoE, produced in the vessel wall, may have important effects during atherogenesis. The production of apoE by macrophages can be regulated at a transcriptional level by cellular differentiation state, cytokines and sterol loading. In addition, there are post-transcriptional and post-translational loci for regulation. We have recently identified an intermediate density cell membrane fraction in which the degradation of apoE can be modulated by sterols. Suppressing degradation of apoE in this fraction by pre-incubating cells in sterols led to enhanced apoE secretion. In this report we demonstrate that the suppressive effect of sterols on the degradation of newly synthesized apoE in this fraction depends on the presence on its C-terminal domain, by studying a macrophage cell line transfected to express a mutant form of apoE in which amino acids beyond amino acid 202 were deleted. In addition, two modulators of cellular sterol transport, progesterone and U1866A, inhibited the degradation of full-length apoE. In contrast, incubation of cells in the acyl-CoA:cholesterol acyltransferase inhibitor S58035 did not influence apoE degradation. As would be predicted based on the results of degradation assays, U1866A, but not S58035, increased the secretion of apoE from a cell line transfected to constitutively express full-length apoE cDNA. The effect of U1866A on apoE degradation, like the effect of sterol, required the presence of the apoE C-terminal domain. Our results indicate that alteration of intracellular sterol homeostasis by pre-incubation in sterols or by drugs that modify the subcellular transport of sterol, modulates the susceptibility of apoE to degradation and that this modulation requires the presence of C-terminal lipid binding domains.

Outcome of an institutional sexual offender treatment program: a comparison between treated and matched untreated offenders

Data from a sexual offender treatment program operated by the Correctional Service of Canada at the Regional Psychiatric Center (Saskatoon) supported the conclusion that cognitive behavioral treatment can reduce sexual offense recidivism. The study compared 296 treated and 283 untreated offenders followed for a mean of 6 years after their release. An untreated comparison subject was located for each treated offender on three dimensions: (a) age at index offense, (b) date of index offense, and (c) prior criminal history. Data were analyzed using tests of proportion, survival analysis, and analysis of offender Criminal Career Profiles. Over a mean follow-up period of almost 6 years, convictions for new sexual offenses among treated offenders were 14.5% versus 33.2% for untreated offenders. During the follow-up period, 48% of treated offenders remained out of prison compared to 28.3% of untreated offenders. Time series comparisons of treated and comparison samples also showed that treated men reoffended at significantly lower rates after 10 years. A Criminal Career Profile (CCP) was constructed by taking the Age at First Conviction and plotting the offender's successive lengths of time free against time incarcerated. Pre- and posttreatment slopes of the CCP were lower for both groups posttreatment; however, the degree of change was significantly greater for the treated group, indicating a greater reduction in criminal activity among these offenders. Taken together, the results of all three analytic techniques supported the efficacy of appropriate correctional treatment for effective reduction of recidivism.

Expression of ErbB receptors during pancreatic islet development and regrowth

We have characterized expression of the ErbB receptor family and one of its ligands, heregulin, in an effort to identify molecules associated with pancreatic development and regeneration. In addition to studying expression during fetal pancreatic development, we have also studied expression during pancreatic regeneration in the interferon-gamma (IFNgamma)-transgenic mouse, which exhibits significant duct cell proliferation and new islet formation. These studies demonstrate significant expression of the ErbB2, ErbB3, and ErbB4 receptors, in addition to heregulin isoforms, in the developing murine fetal pancreas. We also report significant ductal expression of these proteins during IFNgamma-mediated pancreatic regeneration. This striking expression was absent in 1-week-old neonates, but was clearly visible in pups by 5 weeks of age. These data therefore indicate that ErbB receptor and ligand expression decline by birth in both the IFNbeta-transgenic and non-transgenic mice, and that expression resumes early in postnatal life in the IFNbeta-transgenic mice. The expression of ErbB receptor family members at sites of islet development and regrowth suggests that these molecules might be relevant to these processes.

[Cost-effectiveness analysis of Beijing Fangshan cardiovascular prevention program in 1992 - 1997]

OBJECTIVE

To determine whether a community-based cardiovascular disease (CVD) intervention program, undertaken over six years, was cost-effective.

METHODS

Based on Beijing Fangshan Cardiovascular Disease Comprehensive Prevention Program, the cost for intervention and expenditure saved from caring for CVD in the communities with intervention from 1992 to 1997 were calculated, and cost-effectiveness analysis was performed using disability-adjusted life years (DALYs) gained as an indicator of effectiveness.

RESULTS

The cost for one DALY gained reduced gradually from 1992 to 1997, with an average ratio of cost to effectiveness of four to one (4:1). It cost annually 1,586.00, 1,380.20, -2,350.80, -905.30, -1,495.60 and -1,766.70 RMB yuan for one life-year saved, from 1992 to 1997 respectively, in a gradually decreasing trend with the increase in length of intervention. After intervention for two years, ratio of cost to effectiveness has become negative since 1994, which meant a positive benefit from intervention. Sensitivity analysis showed that ratio of cost to effectiveness was little sensitive to the changes in discount rate, weight of age and increase in cost of hospitalization for stroke and coronary heart disease, which reflected its reliability.

CONCLUSION

Community-based comprehensive intervention for CVD in rural population is cost-effective.

Immunization levels among premature and low-birth-weight infants and risk factors for delayed up-to-date immunization status. Centers for Disease Control and Prevention Vaccine Safety Datalink Group

CONTEXT

Studies have noted that health care professionals may not conform to proper immunization schedules for premature and low-birth-weight infants in the United States. Little is known about the success of current efforts to immunize these high-risk infants.

OBJECTIVE

To describe current immunization practices for premature and low-birth-weight infants and ascertain risk factors for poor immunization status, using large population-based data sources.

DESIGN AND SETTING

Cohort and case-control analyses of immunization data tracked from March 1991 through March 1997 for 3 large health maintenance organizations (HMOs) participating in the Centers for Disease Control and Prevention's Vaccine Safety Datalink project.

PARTICIPANTS

A total of 11580 low-birth-weight and premature infants were enrolled from birth to age 2 months; 6832 of these were continuously enrolled from birth to age 24 months. At age 2 months, there were 173373 full-term, normal-birth-weight infants enrolled as controls; at age 24 months, there were 103 324.

MAIN OUTCOME MEASURES

Age-specific immunization status by prematurity and birth weight (<1500 g, 1500-2500 g, born at <38 weeks' gestation with birth weight of >2500 g, or full-term with normal birth weight) and patient characteristics associated with up-to-date status.

RESULTS

At each age, infants weighing less than 1500 g at birth had lower up-to-date immunization levels than other infants. At age 6 months, 52% to 65% of infants weighing less than 1500 g were up-to-date at each of the 3 HMOs compared with 69% to 73% of those weighing 1500 to 2500 g, 66% to 80% of premature infants weighing more than 2500 g, and 65% to 76% of full-term, normal-birth-weight infants. By age 24 months, 78% to 86% of infants weighing less than 1500 g were up-to-date, significantly less than heavier infants, who had levels of 84% to 89%. Well-child preventive care strongly predicted immunization status, while concomitant pulmonary disease did not.

CONCLUSIONS

Our data suggest that infants born prematurely are vaccinated at levels approaching that of the general population, but levels of vaccination for very low-birth-weight infants lag slightly behind.

Transgenic expression of epidermal growth factor and keratinocyte growth factor in beta-cells results in substantial morphological changes

The upregulation of a limited number of growth factors in our interferon-gamma transgenic model for regeneration within the pancreas lead us to propose that these factors are important during pancreatic regeneration. In this study, we have assessed the influence of two growth factors within the pancreas, epidermal growth factor (EGF) and keratinocyte growth factor (KGF), by ectopically expressing these proteins under the control of the human insulin promoter in transgenic mice. This beta-cell-targeted expression of either EGF or KGF resulted in significant morphological changes, including cellular proliferation and disorganized islet growth. Intercrossing the individual Ins-EGF and Ins-KGF transgenic mice resulted in more profound changes in pancreatic morphology including proliferation of pancreatic cells and extensive intra-islet fibrosis. Insulin-producing beta-cells were found in some of the ducts of older Ins-EGF and Ins-EGFxKGF transgenic mice, and amylase-producing cells were observed within the islet structures of the double transgenic mice. These data suggest that both EGF and KGF are capable of affecting pancreatic differentiation and growth, and that co-expression of these molecules in islets has a more substantial impact on the pancreas than does expression of either growth factor alone.

Unmodified supported thiol/lipid bilayers: studies of structural disorder and conducting mechanism by cyclic voltammetry and AC impedance

Supported thiol/lipid bilayer assembly, one of the most spectacular bilayer systems in recent years, has provided a good model to study biomembranes because of its high mechanical stability. In this work, the structural and conducting property of unmodified Au supported octadecanethiol/phosphatidylcholine bilayers were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The forming process of bilayer was monitored by capacitance plane plot. The normalized membrane capacitance of supported bilayer is 0.52 microF cm(-2). Kinetically controlled voltammograms determined by Butler-Volmer equation were obtained for both thiol monolayer and thiol/lipid bilayer in linear sweep voltammetry. Results of EIS experiment indicate that collapsed sites and pinhole defects exist in thiol monolayer and lipid monolayer, respectively. The difference between the values of experimental and theoretical standard electron transfer rate constant indicates that the conducting mechanism of Au supported thiol monolayer is electron tunneling at collapsed sites. The conducting mechanism of Au supported thiol/lipid bilayer is attributed as the following: the electroactive species could diffuse through pinholes in the lipid monolayer and reach collapsed sites in thiol monolayer, where electron transfer occurs via a tunneling process. The fractional coverage of the lipid monolayer measure by EIS experiments is about 0.98 or higher.

Pancreatic expression of keratinocyte growth factor leads to differentiation of islet hepatocytes and proliferation of duct cells

Keratinocyte growth factor, (KGF), a member of the fibroblast growth factor (FGF) family, is involved in wound healing. It also promotes the differentiation of many epithelial tissues and proliferation of epithelial cells as well as pancreatic duct cells. Additionally, many members of the highly homologous FGF family (including KGF), influence both growth and cellular morphology in the developing embryo. We have previously observed elevated levels of KGF in our interferon-gamma transgenic mouse model of pancreatic regeneration. To understand the role of KGF in pancreatic differentiation, we generated insulin promoter-regulated KGF transgenic mice. Remarkably, we have found that ectopic KGF expression resulted in the emergence of hepatocytes within the islets of Langerhans in the pancreas. Additionally, significant intra-islet duct cell proliferation in the pancreata of transgenic KGF mice was observed. The unexpected appearance of hepatocytes and proliferation of intra-islet duct cells in the pancreata of these mice evidently stemmed directly from local exposure to KGF.

Necrotizing myopathy induced by overexpression of interferon-gamma in transgenic mice

A transgenic mouse model has been established in which the cytokine interferon-gamma (IFN-gamma) is overexpressed through the action of the acetylcholine receptor epsilon promoter acting at the neuromuscular junction. While originally developed as a model for the study of the pathogenesis of myasthenia gravis, there are important differences from both human myasthenia gravis and its animal model, experimental autoimmune myasthenia gravis. By 4 months of age there was a well-established inflammatory, predominantly necrotizing myopathy, with marked dystrophic calcification. Dystrophic and degenerative changes in terminal axons and adjacent Schwann cells were also apparent. The acetylcholine receptor was not the primary target of the inflammatory response, since at 10 weeks of age the receptor content was not decreased and antibodies were not detected bound to the receptor. The IFNgamma transgenic mouse model may provide a clinically relevant model of necrotizing myopathy for investigation of the pathological changes associated with, and presumably precipitated by, overexpression of the pro-inflammatory cytokine interferon-gamma on the neuromuscular junction, intramuscular nerves and myofibers.

[Iridoid glycosides from Pedicula dicora Franch]

OBJECTIVE

To study the components in the root of Pedicula dicora.

METHODS

Column chromatography with silica gel and polyamide was employed for the isolation and purification of ingredients. The structures were elucidated by spectral method.

RESULT

Three iridoid glycosides were obtained and elucidated as mussaenoside, shanzhiside methyl ester and lamalbid.

CONCLUSION

All the three compounds were separated from P. dicora for the first time.

[Protective effects of Ginkgo biloba extract on focal cerebral ischemia and thrombogenesis of carotid artery in rats]

Rat focal cerebral ischemia induced by occlusion and thrombogenesis of middle cerebral artery(MCAO) was used as experimental model to study the effects of extract of Ginkgo biloba (EGb) and the positive control drugs were urokinase and nimodipine on cerebral infarct size and neurological deficits. The results showed that cerebral ischemia and neurological deficits appeared in rat focal cerebral ischemic models, and the degree was of cerebral ischemia larger in occlusion model than in thrombogenesis model. The cerebral infarct size was significantly smaller and neurological deficits greatly improved at large dose of EGb(200 mg.kg-1, i.v.), the preventive effect appeared to be better than the treatment effect. The positive control drugs urokinase and nimodipine were also shown to distinctly decrease the cerebral infarct size and improve the neurological deficits in the models. Small dose of EGb(100 mg.kg-1, i.v.) was found to decrease the cerebral infarct size of thrombogenesis model, and improve neurological deficits of both thrombogenesis and occlusion model. EGb was also shown to inhibit the thrombogensis of rat common carotid artery stimulated by electrical current in dose-dependent manner. This experiment indicates that EGb might have beneficial effects on prevention and treatment of ischemic stroke and thrombogenesis.

[An approach to operative treatment for acute abdomen complicated by malignant hemopathy]

The experience of operative treatment in 14 cases of acute abdomen complicated by malignant hemopathy was reported. Primary diseases consisted of AL, NHL, MM, MH and MDS-RA, 13 cases of them were at progressing stage. The acute abdominal conditions included acute appendicitis, acute pancreatitis, acute cholecystitis, peritonitis secondary to intestinal perforation, intestinal obstruction, primary peritonitis and ileocecal syndrome. The type of acute abdomen was related with primary desease and chemotherapy. 8 cases were operated and 2 of them died of complications after operation. Biopsy of excised tissue showed tumor cells in 2 cases. The rate of correllation between preoper active and postoperative diagnosis was 62.5%. These findings suggest that malignant infiltration in the viscera, duration of abdominal pain before operation and the change of blood picture are the major factors for determining operative indication and the postoperative prognosis.

[Chyle fistula after radical neck dissection: 3 cases reports]

3 cases of chyle fistulae were found after complete laryngectomy and radical neck dissection. One case was hydrothorax. Two cases were lately cervical chyle fistula. In this article the cause, diagnosis and treatment of chyle fistula were discussed.

[Vitrectomy for the treatment of retinal detachment uncomplicated by advanced proliferative vistreoretinopathy]

PURPOSE

To determine the role of vitrectomy be used in retinal detachment uncomplicated by proliferative vitreoretinopathy (PVR).

METHODS

We studied 54 cases who had undergone vitrectomy for retinal detachment uncomplicated by severe proliferative vitreoretinopathy. The indications for vitrectomy fell into three main groups: 1) retineal detachment of PVR-B (n = 15), 2) Retinal breaks at the posterior of PVR-C1 or C2 (n = 11), 3) retinal view was poor (n = 28).

RESULTS

The success rate with one procedure was 74% and with further surgery retinal reattachment was achieved in 96%. After surgery, the visual acuity was improved in 43 eyes (79.6%) unchanged in 9 eyes (16.7%), and worse in 2 eyes (3.7%).

CONCLUSION

Vitrectomy is an effective method for treatment of selected cases of retinal detachment uncomplicated by proliferative vitreoretinopathy.

[Incorporation of cortical allograft: a biomechanical study]

OBJECTIVE

To explore the changes of biomechanical properties of cortical allograft in different mechanical environments.

METHOD

Cortical allograft was transplanted to each side of the midshaft diaphyseal ulnar of 40 rabbits. The left transplanted allograft underwent normal physiological load, while the right underwent lower load. Animals were killed and specimens taken for examination of bone mineral density, bone porosity and maximal three-point-bend breaking load.

RESULT

The union strength of allograft-host bone junction increased constantly, while the internal creeping substitution led to an initial greater weakening of the cortical allograft itself and the later recovery of its strength. In comparison, the union strength of the normally loaded graft-host surface was significantly higher than that of the lower loaded side at eight and sixteen weeks after transplantation. At the sixteenth week, there was greater bone strength in normally loaded graft than that in less loaded graft.

CONCLUSION

The internal repair would lead to initial greater weakening of cortical allograft and the later gradual recovery of its strength. The effect of physiological load can accelerate the improvement of the biomechanical properties of allograft.

Endocrine/exocrine intermediate cells in streptozotocin-treated Ins-IFN-gamma transgenic mice

To trace the ontogeny of beta cell regrowth in adult transgenic mice that produce interferon-gamma in the islets (ins-IFN-gamma), their existing beta cells were depleted by treatment with high doses of streptozotocin (STZ). Initially, beta cell necrosis and degranulation were apparent in STZ-treated mice of both the BALB/c and the ins-IFN-gamma transgenic strains. The newly emerging transitional cells were then characterized by ultrastructural analysis. Interestingly, transitional cells harboring both exocrine and endocrine granules appeared frequently in ins-IFN-gamma transgenics after high-dose STZ treatment. New beta cells were produced primarily by the formation of new islets from the small pancreatic ducts. Beta cell regeneration in the ins-IFN-gamma transgenic mouse model is thus explained primarily by the budding of new islets from the ducts with acinar cells as possible precursors of islet cells.

alpha-Cell neogenesis in an animal model of IDDM

Currently there is debate regarding the capacity of pancreatic islets to regenerate in adult animals. Because pancreatic endocrine cells are thought to arise from duct cells, we examined the pancreatic ductal epithelium of the diabetic NOD mouse for evidence of islet neogenesis. We have evidence of duct proliferation as well as ductal cell differentiation, as suggested by bromodeoxyuridine-labeling and the presence of glucagon-containing cells within these ducts. In addition, the ductal epithelia in diabetic NOD mice expressed the neuroendocrine markers neuropeptide Y and tyrosine hydroxylase. These ducts also expressed the homeobox gene product, insulin promoter factor 1. Ductal cell proliferation and expression of these markers was not observed in transgenic NOD mice (NOD-E), which do not develop clinical or histopathological symptoms of IDDM. This suggests that the observed ductal cell proliferation and differentiation was a direct result of beta-cell destruction and insulin insufficiency in these adult diabetic mice, which further suggests that these events are recapitulating islet ontogeny observed during embryogenesis. It is possible that comparable processes occur in the human diabetic pancreas.

Long-term prognosis of percutaneous transluminal coronary angioplasty in 229 cases

OBJECTIVE

To evaluate long-term efficacy of percutaneous transluminal coronary angioplasty (PTCA) and the factors affecting its efficacy in Chinese patients.

METHODS

Two hundred and twenty-nine patients who underwent successful PTCA in this institution were followed-up by direct interview or letters. The rate of follow-up was 95%. The period of follow-up were 0.5-8.4 (with mean of 2.3 +/- 1.8 years).

RESULTS

Angina Pectoris recurred in 76 (33.2%) of the patients. Cox regression analysis revealed that the relative risk of recurrence of angina pectoris was increased among the patients with triple vessel disease and with history of hypertension. During the period of follow-up, 2 (0.9%) patients died, 6 (2.6%) had non-fatal acute myocardial infarction, 4 (1.7%) had coronary artery bypass graft surgery and 29 (12.7%) had repeat PTCA. The cardiac event-free survival rate calculated by Kaplan-Meier method was 84.8% at the first year and 70.5% at the eighth year. Cox regression analysis revealed that there were positive correlation between the relative risks of cardiac events and stenosis of lesions before PTCA and residual stenosis of LAD after PTCA.

CONCLUSION

The long-term efficacy of PTCA in Chinese patients was good. The results of this study suggest that to decrease the residual stenosis of LAD during procedures could probably decrease the relative risk of cardiac events during follow-up.

Interdecadal Climate Fluctuations That Depend on Exchanges Between the Tropics and Extratropics

The unexpected and prolonged persistence of warm conditions over the tropical Pacific during the early 1990s can be attributed to an interdecadal climate fluctuation that involves changes in the properties of the equatorial thermocline arising as a result of an influx of water with anomalous temperatures from higher latitudes. The influx affects equatorial sea-surface temperatures and hence the tropical and extratropical winds that in turn affect the influx. A simple model demonstrates that these processes can give rise to continual interdecadal oscillations.

Structural alterations of resistance vessels of spontaneously hypertensive rats and protective effects of captopril

OBJECTIVE

To observe the structural alterations of resistance vessels in spontaneously hypertensive rats (SHRs) and to evaluate the effects of captopril on them.

METHODS

15-week-old male SHRs were treated with oral captopril (100 mg/kg/day) for 12 weeks. Age- and sex-matched SHRs and Wistar-Kyoto rats (WKY) were fed under the same conditions without captopril administration for the same duration. All rats were killed at the age of 27 weeks. The structural parameters included media width, lumen diameter, media-lumen ratio, vascular collagen area (VCA) and vascular collagen density (VCD). The media width, lumen diameter and media-lumen ratio were measured in hhematoxylin and eosin staining sections under a direct light microscope and VCA and VCD in picrosirius red staining sections under a polarizing light microscope. All the values were processed with a computer image analyzer.

RESULTS

There were thicker media width, smaller lumen diameter, higher media-lumen ratio and larger VCA in untreated SHRs than in WKY. Captopril inhibited media thickening, with lumen diameter decreasing, media-lumen ratio increasing and VCA enlarging. There was no significant difference in VCD among the three groups.

CONCLUSIONS

Adverse structural alterations occur in resistance vessels of SHRs and captopril may prevent their progression.

Determination of nerve conduction velocity distribution from sampled compound action potential signals

The sampled compound action potential (CAP) data sequence was expressed as the circular convolution of the delay sequence and the sampled single fiber action potential (SFAP) data sequence. An algorithm, based on Hirose's method [1], was then developed to separate the delay sequence from the sampled CAP data sequence, and the nerve conduction velocity distribution (NCVD) was consequently calculated from the delay sequence. The NCVD was found to be the product of the amplitude of the SFAP and the number of fibers. Simulations show that the estimated results were in good agreement with the calculated results. Experiments were performed on ten sciatic nerves from five bullfrogs (Rana pipens) using two independent variables: interelectrode distance and stimulus current strength. The results estimated from CAP's recorded under each condition reflect the corresponding feature of NCVD of the condition. The advantage of the technique is to provide detailed information about both slow and fast conducting fibers. This technique also offers the possibility to directly calculate the nerve fiber diameter distribution from the sampled CAP data sequences.

Growth factors in the regenerating pancreas of gamma-interferon transgenic mice

We examined the distribution of several relevant growth factors in gamma-interferon transgenic mice, which undergo continual growth and differentiation in the pancreas. As a result, epidermal growth factor (EGF), TGF-alpha, and the EGF receptor were identified as potentially important in mediating some of these regenerative changes. Transient up-regulation of EGF, TGF-alpha, and the EGF receptor were observed in acini undergoing differentiation into duct-like structures. These ducts have been shown to proliferate and potentiate regeneration of the pancreatic islet mass.