Synergistic effect of copper and lead uptake by fish

Paracheirodon innesi was exposed (simultaneously or sequentially) to copper and lead in varying concentrations in a synthetic water solution. Metal accumulations in fish gills and the fish (without gills) were measured at the end of the exposure period. Results of the exposure experiment indicated that lead seems to facilitate the uptake of copper and vice versa when the exposure process is simultaneous. In the case of sequential exposure first to copper for 7 days then to lead for 20 days, lead accumulations in the fish and the gills were enhanced by copper, indicating a possible alteration of the physiological absorption process. The synergistic effects observed during either simultaneous or sequential exposure experiments can be described using logistic equations.

Uptake of particulate lead via the gills of fish (Carassius auratus)

Carassius auratus were exposed to mixtures of constant free lead (0. 1 mg/L) and particulate lead (adsorbed on gibbsite particles) at varied concentrations (0, 0.4, 0.8, 1.2, 2.0, and 3.0 mg/L). The concentrations of lead and aluminum in the gills and intestines of the fish were determined after exposure. The gills were examined (after the exposure) with a light microscope for any particles adhering to the surface. The examination results revealed that lead accumulations on the gills increased with increased particulate lead concentrations in the ambient water (under conditions of a constant level of free lead), indicating the bioavailability of lead via the gills. Gibbsite particles were also observed on the gill surface after exposure. The ratio of lead and aluminum in the gills was much higher than that in the particles. Our results suggest that there was a two-step process involved in the uptake of particulate lead by fish gills: (1) adherence of the particles on the gill surface where mucus was attached; and (2) desorption of lead from the particles under conditions of the gill microenvironment.

[New subtype of coltivirus isolated from mosquitoes in the northeast part of China]

OBJECTIVE

The purpose of this study was to isolate new arbovirus from mosquitoes collected from the northeast part of China during the summer of 1996.

METHODS

The cell used for isolation were C6/36 and BHK-21 cells.

RESULTS

Two strains (NE97-12 and NE97-31) of coltivirus were isolated among 68 mosquito specimens. The viruses caused cytopathogenic effects on C6/36 cell, but not on BHK-21 cells. They were resistant to both 5-IDU and ether, but sensitive to pH3.0 and temperature at 56 degrees C for 30 minutes. IFA of new isolates with mouse ascitic fluid anti-coltivirus TRT2 strain showed positive reaction. Polyacrylamide gel electrophoresis (PAGE) of two isolates showed 12 segments of double-stranded(ds) RNA and PAGE profiles were 6-5-1, which were different from that of coltivirus TRT2 strain(6-6). There was no cross neutralization between new isolates and TRT2 strain by tissue culture cross-neutralization test.

CONCLUSION

The results indicated while new isolates were serologically related to TRT2 strain of coltivirus by IFA, the neutralization test suggests that it represents a distinct serotype. These new isolates isolated firstly from the northeast part of China belong to a new subtype of coltivirus.

Prediction of fish bioconcentration factors of nonpolar organic pollutants based on molecular connectivity indices

The relationship between bioconcentration factors and molecular connectivity indices was investigated. A regression model was developed using 80 measured BCFs of nonpolar organic pollutants. The five topological parameters used were 1 chi, 2 chi, 3 chi c, 0 chi v and 2 chi v. Modified jackknife tests were applied to examine the robustness of the model by repeatedly removing a set of or a class of compounds from the database. The model was compared with one using Kow as an independent parameter. The mean absolute errors for the 80 compounds studied were 0.288 and 0.302 log-unit for the two models, respectively.

Quantitative study of the gray-scale fidelity of volume holographic images

The reconstruction fidelity of gray-scale holographic images is analyzed quantitatively and assessed by use of proposed quantities, especially the correlation coefficient between the original and the retrieved images. The physical factors affecting the fidelity of photorefractive holograms are investigated experimentally, leading to results that are useful for the determination of the recording-beam ratio and the exposure dosage for high-fidelity retrieval. Investigation of the effects of noise on the fidelity of multiplexed holograms suggests that, if multiple-gray-scale data pages are multiplexed in a given volume, the total bit capacity may be competitive with that realized by means of storing binary pages.

Evaluation of a structure-based statine cyclic diamino amide encoded combinatorial library against plasmepsin II and cathepsin D

A structure-based 18,900-member combinatorial library was synthesized containing a statine template and three cyclic diamino acids as potential P1, P2-P4 surrogates. Evaluation of this encoded library against two aspartyl proteases, plasmepsin II and cathepsin D, led to the identification of selective inhibitors for each enzyme.

[The further studies on the pharmacological actions of Bupleurum smithii var. parvifolium]

Bupleurum smithii var. parvifolium grown widely in Ningxia, had a long history as a common medicinal herb. Its crude saponin had significant protective effect in hepatic damage caused by CCl4 in mice, its ether extract had significant analgesic effect. The ether extract also had significant immunological facilitation effect in mice, it could increase the thymus gland weight and the serum IgG content. These results were similar to or better than that of B. chinense and indicated that B. smithii var. parvifolium could be used as B. chinense.

[Survey on recent progresses in glow discharge mass spectrometry]

Glow discharge mass spectrometry as a sensitive method for direct solid sample analysis has gained rapid development in recent years. In this paper, the progresses of glow discharge mass spectrometry in the designment of new types of discharge lamp and the achievement in the diagnostic study of the atomization and ionization in the discharge process have been reviewed. Also the analytical characteristics of this method in practical application have been described.

[Isolation of coltivirus from mosquitoes in Beijing and it's biological characteristics]

Two strains (Beijing 95-70 and 95-75) of coltivirus were isolated from mosquitoes collected in Beijing during summer-autumn in 1994. The viruses caused cytopathogenic effect on C6/36 cells but not on BHK-21 and Vero cells, and were not lethal for new born mice and three week old mice. The isolates were resistant to 5'-IdU and ether, but sensitive to acid pH 3.0. There were 12 segments RNA shown by polyacrylamide gel electrophoresis (PAGE) and PAGE profile of the two isolates were similar (6-6). The PAGE profile was also similar to that of the TRT2 strain isolated in 1991, but there were at least 8 segments slightly different between the new isolates and TRT2 in band migration distance. Tissue culture cross-neutralization test showed that the new isolates were antigenically related to TRT2 strain identified as coltivirus. Growth curve of the two isolates on C6/36 cells showed that virus titer began to rise at the first day after infection and continued to increase up to 7.0 Log TCID50 per 0.1 ml and maintained a high level until the 21st day after infection. It seems that the virus may cause persistent infection on C6/36 cell.

Differential expression of thyrotropin receptor mRNA in the porcine heart

Thyrotropin receptor (TSHR) mRNA expression has previously been detected in human heart, suggesting a possible role for the receptor in cardiac function and pathophysiology. In the present study we examined the regional distribution of TSHR mRNA in pig heart to map potential cardiac sites of TSH action. Polyadenylated mRNA extracted from thyroid, atria, ventricles, aorta, coronary arteries, epicardial fat, and purified preparations of atrial and ventricular cardiomyocytes was subjected to reverse-transcriptase polymerase chain reaction (RT-PCR) using primers designed to amplify a 311 base pair (bp) DNA segment of the human TSHR. After reverse transcription of 100 ng mRNA, cDNA was amplified by PCR using TSHR primers and compared by electrophoresis on 2% agarose gels. Relative levels of TSHR cDNA (normalized to glyceraldehyde 3-phosphate dehydrogenase [GAPDH]) were as follows: Coronary arteries, epicardial fat > right atrium > left atrium > right ventricle, aorta > left ventricle, ventricular cardiocytes. In contrast to ventricular cardiocytes, purified atrial cardiocytes expressed levels of TSHR mRNA readily detectable with RT-PCR. These findings demonstrate that TSHR mRNA expression in porcine heart varies regionally, and furthermore suggest that areas of highest expression (coronary arteries, adipose tissue, right atrium) are potential sites for a functional or pathologic role of the TSHR.

[Giant-cell tumor of bone: a review of diagnosis and treatment of 105 cases]

OBJECTIVE

To summarize the experience in the diagnosis and treatment of giant-cell tumor of bone, the selection of various operation methods and their effects were evaluated and discussed.

METHODS

From 105 cases of giant-cell tumor of bone data were collected and reviewed. The clinical features were analyzed in association with radiological and histological characteristics. Prognosis was assessed by long-term follow-up.

RESULTS

Among 105 cases, one had multiple giant-cell tumors and two had distant metastases. In some cases, the radiological and histological appearances didn't accord with the clinical findings. The recurrence rate was 36% in patients treated with curettage. Although no recurrence was seen in patients treated by local excision, the joint function could not be fully retained.

CONCLUSION

Diagnosis should be made on the basis of integrated clinical, radiological and pathological manifestations. Early diagnosis and operation are important. The function of joint must be retained as much as possible. Pre-operative embolization of tumor of sacrum and pelvis is very helpful to ensure operative success and to minimize recurrence.

Descriptive analysis of eating behavior in school-age children with cystic fibrosis and healthy control children

STUDY OBJECTIVE

To investigate calorie intake, behavioral eating styles, and parent perception of eating behavior of school-age children with cystic fibrosis (CF) compared with healthy peers.

DESIGN

A two-group comparison study.

SETTING

A clinical sample of 28 school-age children with CF and a community sample of 28 healthy peers matched for age (6 to 12 years) and socioeconomic status.

MEASUREMENTS AND MAIN RESULTS

The children with CF consumed more calories per day (2175 cal/d) than the control children (1875 cal/d) and achieved a significantly higher recommended daily allowance (RDA) of energy (128% of the RDA) than the control children (91.61% of the RDA). Fifty-four percent of the CF sample were achieving the CF dietary recommendations of 120% of the RDA. Despite this energy intake, the CF sample was significantly below the control sample on weight (24.56 vs 31.23 kg), height (125.48 vs 133.06 cm), and z score for weight (-0.811 vs 0.528) and height (-0.797 vs 0.371). On measures of behavioral eating style, the CF sample had significantly longer meals (23.90 min) than the control sample (17.34 min) and had a significantly slower pace of eating (43.27% 10-second intervals with bites) than the control sample (51.29% 10-second intervals with bites) but did not differ significantly on the number of calories consumed during dinner. On a measure of parent report of mealtime behaviors, parents of the children with CF rated mealtime behavior problems of "dawdles" and "refuses food" as more intense (mean, 3. 46) than did the parents of control children (mean, 2.67). For the CF sample, a significant correlation was found between the parent intensity ratings of problem behavior in general and meal duration (r = .48), and a significant negative correlation was found between the parent intensity ratings of problem mealtime behaviors and the percentage of intervals with bites (pace of meal) (r = -.533).

CONCLUSIONS

Although the school-age children with CF were consuming more calories per day than their healthy peers, and more than 50% of the children in the CF sample were at or above the CF dietary recommendations, the children in the CF sample were significantly below the control children on measures of weight and height. The behavioral data suggest that increased caloric intake is not without cost, because the CF sample spent an additional 7 minutes per day at dinner and ate their meals at a slower pace than their healthy peers. These data were associated with higher intensity ratings of mealtime behaviors by parents of children with CF. These findings point to the need for individualized assessment of energy needs for school-age children with CF and comprehensive programs that teach parents behavioral strategies to motivate their children to meet these higher energy requirements in an adaptive manner.

Serum uric acid and its correlates in Chinese adult populations, urban and rural, of Beijing. The PRC-USA Collaborative Study in Cardiovascular and Cardiopulmonary Epidemiology

BACKGROUND

Reports on serum uric acid (SUA) levels in Chinese populations are sparse, but there is evidence that hyperuricaemia and gout are not uncommon. This paper characterizes SUA levels, their correlates, and their relationship to blood pressure (BP) and prevalent high blood pressure (HBP) for urban and rural adult population samples in north China.

METHODS

In 1987-1988, a cross-sectional study was carried out, using standardized methods, on men and women aged 40.58 in a Beijing area urban steel mill (N = 2013) and on rural farms (1507). Main outcome measures were SUA, systolic and diastolic blood pressure (SBP, DBP), and prevalent HBP (SBP > or = 140 or DBP > or = 90 mmHg or receiving an antihypertensive drug).

RESULTS

Mean SUA levels for men were 5.75 mg/dl in urban and 5.58 mg/dl in rural settings; for women, 4.67 and 4.48 mg/dl. Mean values were higher with age in women, but not in men. Age-standardized prevalence rates of HBP were significantly higher in upper SUA strata (men > or = 7.00, women > or = 6.00 mg/dl) than lower SUA strata both with and without inclusion of those on antihypertensive drugs. Mean SUA levels were correspondingly higher in hypertensive than non-hypertensive people. In multiple regression analyses, body mass index and serum triglycerides were strongly associated with SUA. Also SBP, DBP, and HBP were generally associated with SUA for the whole population sample, with smaller coefficients after excluding those on antihypertensive drugs. However, in these multivariate analyses the strength of the association was low order.

CONCLUSION

In addition to its strong association with body mass index, SUA is independently related to serum lipids, particularly triglycerides, and to serum glucose. While some of the univariate relation of SUA to BP is apparently due to the strong relation of body mass to both SUA and BP, a low order significant relation between SUA and BP remains with control for BMI.

[Pharmacological effects of zisu and baisu]

The extract and volatile oil of zisu (Perilla frutescens) has shown significant antipyretic effect in rabbits and antiemetic effect in pigeons. The fatty oil extracted from its seeds has significant antitussive effect in mice and anti-asthmatic effect in guinea pigs. The extract, volatile oil and fatty oil of Baisu, which is of the same genus as Zisu have the same effects as those of Zisu. The acute toxicities of the extract and fatty oil of Zisu and Baisu, whether by peroral or by intraperitoneal, are similar to each other. These results indicate that Baisu has the same pharmacological effects as Zisu, and thus can be used as a substitute for Zisu.

Changes in average blood pressure and incidence of high blood pressure 1983-1984 to 1987-1988 in four population cohorts in the People's Republic of China. The PRC-USA Cardiovascular and Cardiopulmonary Epidemiology Research Group

OBJECTIVE

To assess comparative changes in systolic and diastolic blood pressure and incidence of high blood pressure over 4 years, and factors related to these changes, in northern and southern, urban and rural adults in the People's Republic of China.

SETTING

This is a prospective study of populations surveyed by standardized methods in 1983-1984 and 1987-1988 in north China, Beijing area steel mill workers and farmers, and south China, Guangzhou area shipyard workers and farmers.

SUBJECTS

The subjects were 8805 men and women aged 35-54 years at baseline (1983-1984), of whom 7338 were non-hypertensive (systolic blood pressure < 140, diastolic blood pressure < 90 mmHg, not being administered antihypertensive drugs).

MAIN OUTCOME MEASURES

The main outcome measures were 4-year changes in systolic and diastolic blood pressures and the 4-year incidence of high blood pressure in persons not hypertensive at baseline.

RESULTS

At baseline, the average systolic and diastolic blood pressures were higher for Beijing than for Guangzhou cohorts. At resurvey the average systolic blood pressure had increased for seven of eight sex-city-setting cohorts (all but Guangzhou urban men). The Beijing urban cohorts had the greatest increases (men 6.2 mmHg, women 4.9 mmHg, slopes of 1.6 and 1.2 mmHg/year). The incidence of high blood pressure was higher for Beijing than for Guangzhou cohorts in all four comparisons (men and women, urban and rural). Beijing men, urban and rural, had the highest incidence rates (about 21%). In multiple logistic analyses by sex, variables significantly related to 4-year high blood pressure incidence were city, baseline systolic blood pressure and body mass index, change in weight, and, for men, baseline alcohol use and heart rate.

CONCLUSION

Modifiable lifestyle traits, previously shown to be related to blood pressure and high blood pressure in cross-sectional studies, also relate to the incidence of hypertension.

Differential alteration of neuronal and cardiovascular responses to adenosine microinjected into the nucleus tractus solitarius of spontaneously hypertensive rats

We previously reported that adenosine elicited site-dependent neuronal and cardiovascular responses in two subareas of the nucleus tractus solitarius (NTS) of normotensive rats. Pressor and tachycardic responses were obtained from the rostral NTS (adenosine pressor system), and depressor and bradycardic responses were obtained from the caudal NTS (adenosine depressor system). In both areas, adenosine inhibited the firing rate of barosensitive neurons. The present study investigated whether spontaneously hypertensive rats (SHR) exhibit abnormal neuronal and cardiovascular responses mediated by the adenosine pressor and depressor systems within the NTS. Male SHR and Wistar-Kyoto rats (WKY) were anesthesized with urethane and prepared for blood pressure and heart rate recording, stereotaxic microinjection of adenosine into the NTS, and extracellular recording of single-unit neuronal activity of NTS neurons. Chemical identification of the targeted neuronal pool was made by L-glutamate (5 nmol) and confirmed by histology. SHR exhibited significantly higher mean arterial pressure and firing rate of caudal NTS neurons (45.0 +/- 4.5 versus 27.3 +/- 4.7 spikes per 2.5 seconds, P <.05) but similar heart rate and neuronal firing rate of rostral NTS neurons compared with WKY. Adenosine (0.1, 1, and 10 nmol) elicited dose-related neuronal and cardiovascular responses in both strains. However, SHR exhibited differential alterations in both adenosine systems. Compared with WKY, SHR exhibited attenuated pressor, tachycardic, and neuronal responses mediated by the adenosine pressor system and exaggerated depressor, bradycardic, and neuronal responses mediated by the adenosine depressor system. In both strains, the responses elicited by adenosine were virtually abolished by theophylline (10 mg/kg IV), suggesting that these responses were mediated by adenosine receptors in the NTS. Furthermore, the theophylline-evoked increase in blood pressure was twofold higher in SHR (15.0 +/- 1.7 versus 6.9 +/- 1.5 mm Hg, P <.05); larger but nonsignificant increases in heart rate and neuronal firing rate also were evident in SHR compared with WKY. These findings suggest differential alterations in adenosine pressor and depressor systems in the NTS of SHR, which may be implicated in the pathophysiology of this model of hypertension.

Re-evaluation of the mechanism and treatment of angina decubitus

30 patients with angina decubitus (AD) were studied during hospitalization. These patients were found to have severe coronary artery obstructive lesions and an increase of myocardial oxygen consumption (MOC) before the onset to AD, indicating that AD belongs to the category of effort angina. 18 patients were investigated by continuous hemodynamic monitoring. Three patients had significant increase in pulmonary artery diastolic pressure (PADP) before the onset. In the other 15 patients, PADP increased slightly in 12 and remained unchanged in 3 cases before the onset. Left ventriculography showed ejection fraction (EF) > 45% in 25 of the 27 patients. These results indicate that left ventricular (LV) systolic dysfunction is not a major factor in the pathogenesis of AD. The patients with LVEDP > 12 mmHg constituted 60% of 25 patients with EF > 45%, suggesting that these patients had obvious LV diastolic dysfunction, which may be the major factor in the pathogenesis of AD. According to the results of our treatment, beta blockers may be used as the major form of treatment in the patients with AD.

[Repairing bone defect with autogenous periosteal pieces in coagulum: experimental study and clinical application]

A 1.5 cm-long bony defect was established in rabbits one each on both sides. The defected area was filled with coagulum of peripheral blood or bone marrow blood, then autogenous pieces of the periosteum was put in the coagulum on one side, while the other side was served as the control without periosteal autograft. The osteogenetic capacity of the periosteum and the influence of different blood coagulum were evaluated by means of X-ray film, histology, the contents of calcium and phosphate in new osteocytes in the defected area, bone tissue morphometry, and computer-assisted image analysis. The autograft of the periosteum had osteogenetic effect. Autologous bone marrow blood had potential osteogenetic capacity, which however, was weaker than that of the periosteum. Peripheral blood coagulum did not have any osteogenetic effect. We have successfully used the periosteum-bone marrow blood complex (bone marrow blood as a carrier) in 12 patients.

PKC mediates LPS- and phorbol-induced cardiac cell nitric oxide synthase activity and hypocontractility

Lipopolysaccharide (LPS) treatment impairs cardiac myocyte contractility in a nitric oxide synthase (NOS)-dependent manner. The objective of this study was to assess whether protein kinase C (PKC) transduces the LPS signal into an enhanced NOS activity in rat cardiac myocytes. LPS (100 ng/ml) stimulated myocyte PKC activity, inducible NOS (iNOS) expression, and NOS activity in a time- and protein synthesis-dependent fashion. Directly activating PKC with beta-phorbol 12,13-dibutyrate (beta-PDB) also induced myocyte iNOS synthesis and NOS activity and reduced electrically stimulated contractility, while the inactive alpha-PDB was ineffectual. Contractility could be restored to beta-PDB-incubated cells by superfusion with the NOS inhibitor N omega-nitro-L-arginine methyl ester. PKC blockade with sphingosine, chelerythrine, or calphostin-C precluded LPS- and beta-PDB-induced increases in NOS activity and protected contractility. Depletion of PKC by 18 h of incubation with beta-PDB in the presence of chelerythrine also blocked acquisition of enhanced NOS activity and contractile dysfunction when the myocytes were subsequently exposed to LPS. These findings suggest that PKC is a significant intracellular mediator for the effects of LPS on cardiac cell NOS activity and contractile function.

Prevalence of hypertension and its trends in Chinese populations

The third nation-wide survey of blood pressure level and hypertension was carried out in China in 1991. In total, 950,356 residents aged > or = 15 years were examined. Sampling population were composed of half urban and half rural from 27 provinces or autonomous regions and three municipalities. The results showed that: (1) the age-adjusted prevalence rate of hypertension (systolic blood pressure > or = 140 mmHg or diastolic blood pressure > or = 90 mmHg) was 11.26% (male 12.15%, female 10.32%) and the definite hypertension rate (systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg, or on medication) was 5.29% (male 5.38%, female 5.21%); rate of borderline hypertension was evaluated from 2.82% to 6.15% during the 10-year period from 1979/1980 to 1991; (2) the prevalence rate was progressively increased with age, especially after age 35; prevalence rates were generally higher in men than women before about age 44, however by age 60, women had a higher prevalence of hypertension; (3) a general trend of decrease in prevalence from north-eastern to south-western China was confirmed; (4) there were significantly lower rates in rural than in urban areas. Results of preliminary analysis for prevalence of hypertension among different occupations, nationalities, and educational levels were presented.

HLA-DR1, DR4, and DRB1 disease related subtypes in rheumatoid arthritis. Association with susceptibility but not severity in a city wide community based study

OBJECTIVE

To determine the relationship of DR1, DR4, and DR4 subtypes with disease severity in patients with rheumatoid arthritis (RA).

METHODS

We studied a cohort of 103 Caucasian patients with an onset of disease in 1985, and 6 to 7 years of disease at the time of the study. All rheumatologists in Edmonton participated in the city wide study which included hospital and community based patients with mild and severe disease. HLA status was determined using polymerase chain reaction amplification and amplified fragment length polymorphism typing. Outcome measures included joint counts, radiological scores, and physical functional status.

RESULTS

Fifty-six patients (54%) were DR4 positive, (OR = 2.3, 95% CI 1.4-3.6, compared to controls). This association was only statistically significant for seropositive patients (OR = 2.8 in seropositive patients and OR = 1.5 in seronegative patients). A higher risk was observed for DR1/DR4 heterozygotes (OR = 6.8 in seropositive patients and OR = 1.7 in seronegative patients). No significant differences were observed in disease activity, joint counts, radiological scores, or functional status among patients carrying 1, 2 or no disease related alleles, although the prevalence of rheumatoid factor (RF) showed a linear association with allele dose (0, 1, or 2).

CONCLUSION

DR4 and in particular DR1/DR4 heterozygosity were related to susceptibility to RA only in seropositive patients. RF was a better predictor of severity than disease related HLA subtypes. These findings suggest that the effect of these alleles on severity may be related to seropositivity, or that perhaps, seropositive and seronegative RA are genetically distinct entities. The results of our study suggest that in community based settings, which include patients with milder disease, DR1 and DR4 disease related alleles increase susceptibility for RA, but are not clinically useful as predictors of longer term outcome.

Spatioangular-multiplexing scheme for dense holographic storage

A novel multiplexing scheme for dense holographic storage in photorefractive crystals, spatioangular multiplexing, is described in detail. Compared with spatial multiplexing, spatioangular multiplexing increases the storage capacity by fully utilizing the volume of the storage medium. On the other hand, spatioangular multiplexing reduces the number of holograms overlapping any one hologram in a given volume and so increases the diffraction efficiency achievable as compared with angular multiplexing. Using this scheme, we succeeded in storing 756 high-resolution patterns in an Fe:LiNbO(3) crystal of volume 1 cm(3), with an average diffraction efficiency of 0.5%. This large database is designed for practical use in a novel associative-memory system, called a high-order feedback neural network.

Hypertension prevalence and status of awareness, treatment and control in China

A nation-wide survey of blood pressure (BP) and high BP was made in China in 1991, using standardized methods and covering 950,356 men and women aged 15 years and above, from 30 provinces, autonomous regions, and municipalities. The purpose of the study was to estimate the prevalence and the status of awareness, treatment, and control of hypertension. The overall prevalence rate of hypertension defined as systolic BP > or = 140 or diastolic BP > or = 90 mmHg or currently on antihypertensive medication was 13.6%, and was higher in urban (16.3%) than in rural (11.1%) setting. The rate was 6.6% if a BP cut-point of 160/95 mmHg was used. Rates were low in younger age-groups but rose sharply after age 45. The total number of hypertensives in 1990 was estimated to be close to 90 millions. Of all hypertensives, about 1/4 were aware of their high BP, half of these were on medication, and only 3% had their BP controlled. All the rates were higher if the BP cut-point was 160/95 mmHg. Higher rates were found in urban than rural setting and, to a lesser degree, for women than men. In conclusion, hypertension was found to be common in China, and the rates of awareness, drug treatment, and controlled BP were low, indicating an urgent need for developing a national program of treatment and prevention of high BP.

Allelic variation at the TAP 1 locus influences disease phenotype in HLA-B27 positive individuals with ankylosing spondylitis

The objective was to determine the role of the TAP 1 gene in influencing the phenotype of disease in adult patients with ankylosing spondylitis (AS). The distribution of TAP 1 gene alleles was determined using the PCR RFLP method and restriction enzymes Bcl I and Acc I. The study population included 115 HLA-B27 positive patients with well-documented AS and 41 HLA-B27 positive normal controls. No significant difference in distribution of TAP 1 alleles was noted in comparisons of all AS patients with normal controls. However, AS patients with extraspinal disease were noted to have a significantly increased prevalence of the TAP 1B allele (17.0%) as compared to AS patients without extraspinal disease (2.9%) (P = 0.005) or normal controls (1.9%) (P = 0.005). Polymorphism at the TAP 1 locus may influence disease outcome in patients with AS.

Activation of the intracellular glutathione system by oxydative stress during cardiopulmonary bypass and myocardial perfusion

The glutathione (GSH) system is the main defence of tissues against free radicals and red blood cells (RBC) are the most efficient sites for GSH redox cycle activation. Total GSH was assayed during cardiopulmonary bypass (CPB) in RBC and serum from the coronary sinus, peripheral arteries and veins in 18 children corrected of their cardiac defect. Our conclusions are: (1) RBC-GSH redox cycle is activated during heart ischaemia and reperfusion; (2) the activation of intracellular GSH system is preponderant compared with the extracellular one; (3) variations in intraerythrocytic total GSH during heart ischaemia and perfusion are detectable in peripheral veins and arteries, which can be the convenient sites for monitoring changes in the GSH cycle; and (4) increased total GSH levels are present in RBC before aortic crossclamping: at the beginning of mechanical ventilation in veins and, when CPB is started, also in arteries.

In vitro endotoxin exposure induces contractile dysfunction in adult rat cardiac myocytes

In vivo endotoxin treatment causes a nitric oxide-mediated hypocontractility in cardiac myocytes. The objective of this study was to assess whether in vitro endotoxin exposure confers similar contractile defects in adult rat cardiac cells. We found that incubation of cardiac myocytes for 6 h with 10-100 ng/ml endotoxin resulted in progressive time- and protein synthesis-dependent decreases in electrically stimulated twitch magnitudes and increased contraction and relaxation times. Serum was not required for the endotoxin-induced hypocontractility. The endotoxin-induced defect in contractility was reversed over time, since myocytes continuously incubated with endotoxin for 24 h exhibited normal contractility; in contrast, control cells incubated for 18 h were suppressed by a subsequent 6-h exposure to endotoxin. Nitric oxide synthase activity was increased after a 6-h endotoxin treatment as evidenced by a dose-dependent enhanced conversion of [3H]arginine to [3H]citrulline and by elevated guanosine 3',5'-cyclic monophosphate levels. Superfusion of endotoxin-incubated cells with N omega-nitro-L-arginine methyl ester restored contractile function, whereas superfusion with L-arginine reimposed abnormal contractility. Naive myocytes superfused with 8-bromoguanosine 3',5'-cyclic monophosphate expressed contractile defects similar to those induced by endotoxin. These findings demonstrate that endotoxin has direct negative effects on cardiac cell contractile function and that induction of NO synthase activity is a primary intracellular mediator of the diminished contractility.

A north-south comparison of blood pressure and factors related to blood pressure in the People's Republic of China: a report from the PRC-USA Collaborative Study of Cardiovascular Epidemiology

OBJECTIVES

To compare blood pressures in northern (Beijing) and southern (Guangzhou) Chinese population samples aged 35-54 years, males and females, urban and rural, and to assess the role of blood pressure-related traits in explaining north-south differences.

DESIGN

Cross-sectional surveys were conducted in 1983-1984 of northern and southern populations employed in industry (urban) or farming (rural).

METHODS

In the north samples were selected from the Capital Iron and Steel Complex (urban) and Shijingshan district (rural); in the south samples from the Guangzhou Shipyard (urban) and Panyu County (rural) were used.

RESULTS

The number of subjects surveyed in north and south were 4706 and 4179, respectively: 1500 and 1052 urban males, and 717 and 914 rural males; and 1300 and 1061 urban females, and 1189 and 1152 rural females, respectively. Average systolic (SBP) and diastolic (DBP) blood pressures, were consistently higher in the north than in the south. SBP and DBP were significantly and independently related to age, body mass index, heart rate, use of antihypertensive drugs, serum triglycerides level, alcohol use (males only) and inversely to cigarette smoking. Northerners were older, taller, heavier and had higher body mass index and triglycerides level than southerners. With adjustment of SBP and DBP for blood pressure-related traits, north-south blood pressure differences decreased, but remained significant for urban males, rural males and rural females, with sizeable differences for rural samples in particular.

CONCLUSIONS

North-south differences in blood pressure in these samples are accounted for only partly by north-south differences in the cited blood pressure-related traits. The role of other traits requires assessment.

Exposure limits for ultra-short wave radiation in work environments

Exposure limit values for ultra-short wave radiation of humans were derived on the basis of epidemiological survey and experimental exposure of rabbits. Eighteen male rabbits were divided into 4 groups randomly. Three groups were irradiated with ultra-short waves (100 MHz) at 35, 1.5-3.5, and 0.07 mW/cm2 power density in an E-polarized TEM Cell at 24 +/- 4 degrees C ambient temperature. The last group in a sham chamber served as controls. Irradiation was performed 3 hours per day, 5 days per week for 24 weeks. Thermal effects occurred in the group irradiated at 35 mW/cm2. The thermal threshold limit value was set at 1.5 mW/cm2. An epidemiological survey was carried out on 136 factory workers and TV operators exposed over one year to ultra-short wave radiation at 0.2 mW/cm2. They were compared with 108 controls. The only complaint of the exposed group was neurosis. The exposure limit value (ELV) to short wave radiation was set at 0.2 mW/cm2 by using a 15- and 20-fold safety factor.

Ethanol-clonidine hemodynamic interaction in normotensive rats is modified by anesthesia

Our previous findings have shown that ethanol attenuates the decreases in plasma norepinephrine (NE) levels, and blood pressure elicited by centrally acting antihypertensive drugs in spontaneously hypertensive rats (SHRs). The present study investigated whether this interaction can be influenced by baseline blood pressure (BP) and sought direct evidence to support the involvement of the SNS by recording the sympathetic neural activity (SNA) of the splanchnic nerve. The conscious aortic barodenvervated (ABD) rat model was utilized because it exhibits greater hypotensive responses to clonidine compared with sham-operated (SO) rats. Although ABD and SO rats (332 + 33 vs. 227 + 18 pg/ml). Clonidine (30 micrograms/kg, i.v.) elicited significantly greater decreases in mean arterial pressure (MAP; -20.0 + 2.1 vs. -10.4 + 0.8 mm Hg) and plasma NE (-194 + 26 vs. -50 + 11 pg/ml) in conscious ABD vs. SO rats. Ethanol (1 g/kg, i.v.) reversed clonidine-evoked decreases in BP and plasma NE levels, but the interaction was more prominent in ABD rats. To support the hypothesis that the interaction occurs within the CNS, the effect of ethanol was studied on clonidine-evoked decreases in preganglionic SNA and BP in anesthetized rats. In contrast to its effects in conscious rats, ethanol augmented both the hypotensive and sympathoinhibitory responses to clonidine in anesthetized rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoendocrine cell carcinoma of the gallbladder: a histochemical and immunohistochemical study

A case of adenoendocrine cell carcinoma of the gallbladder with adenomucous cells and neuroendocrine cells is reported. A histochemical and immunohistochemical study revealed that the primary tumor in the gallbladder was composed of mucus-secreting and/or argyrophil cells. Furthermore, the tumor showed a positive reaction to carcinoembryonic antigen (CEA) in all tumor cells, to chromogranin A and cytokeratin in many tumor cells, to endocrine granule constituent (EGC) in some tumor cells, and to serotonin and somatostatin in a few tumor cells. In addition, a few mucous cells showed argyrophilia and EGC-positivity in their cytoplasms. This case suggests that the adenoendocrine cell tumor is derived from endodermal stem cells as a result of bidirectional (exocrine and endocrine) differentiation.

Spectral measurements of NH(3) absorption lines by a 1.5-microm grating-external-cavity semiconductor laser

Forty-four NH(3) absorption spectral lines of the combination tones of the vibration-rotation transitions were observed at 1.4988-1.5520 microm with a 1.5-microm grating-external-cavity semiconductor laser. The linewidth and absorption rate of NH(3) absorption spectral lines were measured. Also, the changes of center frequency and linewidth of the NH(3) absorption spectral line with the our knowledge the first time.

Fatty acid composition of lecithin is a key factor in bile metastability in supersaturated model bile systems

We studied the effect of fatty acid saturation of biliary lecithin on bile metastability, determined by nucleation time, using model bile solutions with identical lipid compositions except for the lecithin species (total lipid concentration, 9 g/dl; cholesterol, 12 mM; lecithin, 31 mM, bile salts, 116 mM). Gel permeation chromatographic studies revealed that nonmicellar cholesterol distribution was inversely related to the degree of unsaturation of the lecithin species. Differential interference contrast microscopy and cholesterol crystal growth assay showed that a lower degree of saturation of the lecithin species was associated with a faster nucleation time and crystal growth rate. These results suggest that vesicular lecithin containing more unsaturated fatty acyl chains binds less tightly to cholesterol as compared with lecithin containing predominantly saturated fatty acids and that the biliary lecithin species modulates cholesterol crystal nucleation in bile. Also, the high ratio of cholesterol to lecithin (more than 1.0) was found in the crystal forming model biles, although the vesicle aggregation was not always observed prior to the cholesterol crystal formation. These findings indicated that there are different processes in cholesterol crystal nucleation, with or without vesicle aggregation, and that such processes depend, in part, on lecithin species in vesicles.

Apolipoprotein A-I stabilizes phospholipid lamellae and thus prolongs nucleation time in model bile systems: an ultrastructural study

To explore the mechanisms whereby apolipoprotein A-I inhibits the nucleation of cholesterol crystals, we performed an ultrastructural study using supersaturated model bile systems. Vesicles, micelles and phospholipid lamellae were consistently separated by gel permeation chromatography either in the absence or presence of apolipoprotein A-I. Furthermore, apolipoprotein A-I coeluted with phospholipid lamellae. A sequential study using transmission electron microscopy revealed that phospholipid lamellae without apolipoprotein A-I showed a rapid transformation, with formation of multilamellae and fusion followed by microcrystal nucleation. In contrast, lamellae with apolipoprotein A-I showed little transformation. In conclusion, apolipoprotein A-I stabilizes the phospholipid lamellae, thereby inhibiting the nucleation of cholesterol crystals in supersaturated model bile systems.

Neuronal and cardiovascular responses to adenosine microinjection into the nucleus tractus solitarius

This study investigated neuronal, blood pressure, and heart rate responses to adenosine microinjection into caudal and rostral NTS of anesthetized rats. The site of recording and microinjection was verified chemically by observing the responses to a test dose of l-glutamate (5 nmol) and histologically at the conclusion of the experiment. Neuronal firing rate increased (+29.4 +/- 5.3%) and decreased (-48 +/- 9.4%) in response to l-glutamate microinjection into the rostral and caudal NTS, respectively. These opposite neuronal responses were followed by depressor (-32.4 +/- 8.3 vs. -36 +/- 5.5 mmHg) and bradycardic (-25.2 +/- 7.7 vs. -25.8 +/- 3.4 beats/min) responses to l-glutamate microinjection into the two subareas of the NTS. Microinjection of a submaximal dose (1 nmol) of adenosine into the NTS produced site-dependent cardiovascular responses which were preceded by similar inhibition of neuronal firing (-60 +/- 4 vs. -55.9 +/- 1.7%). Whereas adenosine microinjection into the rostral NTS elicited modest pressor (+10.1 +/- 2.1 mmHg) and tachycardic (+9 +/- 3.9 beats/min) responses, its microinjection into the caudal NTS produced depressor (-29.2 +/- 5.3 mmHg) and bradycardic (-14.6 +/- 1.7 beats/min) responses. These findings suggest that compared to l-glutamate, adenosine produces opposite (rostral) and similar (caudal) neuronal and cardiovascular effects in the two subareas of the NTS. In the caudal NTS, adenosine (0.1, 1, and 10 nmol) elicited dose-related inhibitory neuronal and cardiovascular responses that were attenuated by systemic theophylline but not 8-(p-sulfophenyl) theophylline (8-SPT) administration. The neuronal and cardiovascular responses to adenosine microinjection into the caudal NTS were also attenuated by microinjection of 8-SPT into the same area. Finally, single-unit activity inhibited by adenosine or l-glutamate microinjection into the caudal NTS was also inhibited by baroreceptor loading and excited by baroreceptor unloading. These findings suggest a) l-glutamate elicits opposite neuronal responses in the rostral and caudal NTS; b) the distinct hemodynamic responses elicited by adenosine in the two subareas may be related, at least in part, to their differing responses to l-glutamate; and c) the similarity between the neuronal responses to adenosine and l-glutamate microinjection into the caudal NTS and the response of the same neurons to baroreceptor activation support the hypothesis that adenosine plays a neuromodulatory role in the processing of baroreceptor information.

Serum lipids and their correlates in Chinese urban and rural populations of Beijing and Guangzhou. PRC-USA Cardiovascular and Cardiopulmonary Epidemiology Research Group

In 1983 and 1984, surveys were conducted in four Chinese population samples, urban and rural for both Beijing and Guangzhou, as part of PRC-USA collaborative research in cardiovascular and cardiopulmonary epidemiology. Serum total cholesterol (TC), HDL-cholesterol (HDL-C), and triglycerides (TG) were measured in 4280 men and 4695 women aged 35-54 years, in laboratories standardized by the US Centers for Disease Control. Age-adjusted mean serum TC was higher in urban than rural samples and generally higher in Beijing than Guangzhou, ranging from 155 mg/dL for Guangzhou rural women to 187 mg/dl for Guangzhou urban women. Group mean values of HDL-C varied from 48 to 59 mg/dl, higher in Beijing than Guangzhou, and higher in women than men. TC/HDL-C ratio ranged from 3.05 to 3.82. Serum TG values were higher for Beijing than Guangzhou; the lowest group mean values of 78 mg/dl and 75 mg/dl were in rural Guangzhou men and women. Mean body mass index (BMI) was uniformly low, ranging from 20 kg/m2 for rural Guangzhou to 24 kg/m2 for urban Beijing. Multiple regression analyses showed that BMI was positively and independently related to serum TC, LDL-C, TG, and TC/HDL-C, and inversely related to HDL-C. Smoking was positively related in both sexes to TG and TC/HDL-C, and inversely related to HDL-C. Smoking was also positively related to TC and LDL-C in men. In men, alcohol was positively related to TC and HDL-C, and was inversely related to TG and TC/HDL-C. Heavy manual work was inversely related to TC, LDL-C, and TC/HDL-C in men, but not related to lipids in women. Thus, for these Chinese population samples, despite their lower serum TC and BMI, the correlates of serum lipids are similar to those in western populations. These variables accounted for only part of the observed urban-rural and north-south differences in serum lipids among these Chinese population samples. The significance of the relatively low serum TC and TG and high HDL-C in relation to low cardiovascular disease in Chinese populations is the object of further investigation in follow-up studies.

Hemodynamic observation and treatment approach for patients with angina decubitus

In order to investigate the mechanism and treatment of angina decubitus, 20 patients (18 men and 2 women aged 36-70 years) were studied during hospitalization. All patients were found to have an increased heart rate x systolic blood pressure product before the onset of angina decubitus, indicating that this type of angina pectoris belongs to the category of effort angina. Of the 11 patients investigated by continuous hemodynamic monitoring, 3 had significant progressive increases in pulmonary artery systolic pressure (PASP) and pulmonary artery diastolic pressure (PADP) before onset: their episodes of angina could not be completely controlled by digoxin and diuretics, but quickly subsided after beta blockers were added. Among the other 8 patients, PADP increased slightly in 5 and remained unchanged in 3 cases before onset: these patients had no manifestations of LV dysfunction, and beta blockers combined with coronary vasodilators produced satisfactory effects. These results indicate that LV failure is not a major factor in the pathogenesis of angina decubitus. The LV diastolic dysfunction seen in 8/11 cases may have been related to LV hypertrophy caused by long-term hypertension or chronic persistent ischemia.

High-isolation optical isolator using a BiCalnVIG single crystal

To the best of our knowledge this is the first time a new optical isolator has been developed that uses BiCaInVIG, a non-rare-earth iron garnet. The device has high isolation > 40 dB with an insertion loss of 1.0 dB at 1.3-microm wavelength and > 43 dB with 1.1 dB at 1.52-microm wavelength, including Fresnel reflection losses of ~0.8 dB for two polarizers. In addition, the device is inexpensive. In order to adjust maximum isolation when the isolator is assembled, a theoretical basis is presented, and the calculated values are in good agreement with the experimental results.

Interspecies structural diversity among chlamydial genes encoding histone H1

Recently, a eukaryotic histone H1-like protein has been detected in Chlamydia trachomatis serovar L2 [Hackstadt et al., Proc. Natl. Acad. Sci. USA 88 (1991) 3937-3941; Tao et al., J. Bacteriol. 173 (1991) 2818-2822]. We have cloned the corresponding gene from C. trachomatis serovar J and the Chlamydia psittaci strain mn. Sequencing demonstrated absolute gene identity between the two C. trachomatis serovars L2 and J, but divergence in the C. psittaci strain mn. These differences resulted in altered aa residues (in particular no cysteines) and a smaller molecular mass for H1 from C. psittaci strain mn. The amino acid (aa) sequence comparisons with other histone proteins show best alignment to sea urchin H1, notably in the C terminus, for both C. trachomatis and C. psittaci histones. Chlamydial interspecies aa homology, however, is most conserved at the N terminus, suggestive of a bi-functional role for these unique histone proteins.