Predicted maximal oxygen uptake in normal Hong Kong Chinese schoolchildren and those with respiratory diseases

To assess the maximum oxygen uptake (V'O2 max) of Hong Kong Chinese children and to explore its association with respiratory illnesses, we conducted the Multistage Fitness Test (MFT), a 20-m shuttle run test, in 1,427 schoolchildren aged between 8-12 years. Information on respiratory symptoms in the previous year, cumulative respiratory illnesses, and habitual physical activities were collected. Spirometry was carried out to derive forced expiratory volume in 1 sec (FEV1). The V'O2max was 30.3 mL x kg( - 1) x min( - 1) for boys, and 28.6-mL x kg( - 1) x min( - 1) for girls; these values were low by Western standards. V'O2max was significantly reduced in children with asthma ( - 1.3 mL x kg( - 1) x min( - 1)) and bronchitis ( - 0.7.mL x kg( - 1) x min( - 1)) when adjusted for other covariates. A significant decrease in FEV1 was also observed in these children. The correlation between V'O2max and FEV1 was significant but weak. Habitual physical activity was an independent predictor of V'O2max, but not of FEV1. The low V'O2 max in Hong Kong children may be explained in part by ethnic differences and possibly a low level of physical activity.

Effect of long-term fertilization on soil nitrate distribution

A thirteen years long-term field fertilizer experiment was conducted to monitor the effect of different fertilization on soil nitrate distribution. The results showed: (1) Applying relative excessive N fertilizer could result large quantities of NO3- residue and NO3- movement downward in soil profiles; amending phosphate fertilizer or organic manure with nitrogen fertilizer together could significantly improve the status of NO3- leaching downward due to the balanced uptake of nutrients by crops. (2) Appropriate amounts of nitrogen fertilizer which was equal or smaller than the optimal fertilization rate could not result in more NO3- leaching in Northern China. (3) Precipitation influenced the amounts and depth of soil NO3- leaching: NO3- could move to 80 cm depth or below at autumn or at the next spring when rainfall was higher during the rainy season through July to September in North China.

A study on occupational exposure to petrochemicals and smoking on seminal quality

A cross-sectional study of 68 petrochemical workers (23 had never smoked [E/NS], 45 were current smokers [E/S]) and 130 subjects with no known history of exposure to petrochemicals (49 had never smoked [NE/NS], 81 were current smokers [NE/S]) was conducted to assess the effect of occupational exposure to petrochemicals and smoking on semen quality. In-person interviews revealed occupational history, smoking habit, and lifestyle. Semen parameters such as volume, viability, sperm forward progression rate, sperm density, and total sperm count were determined for all subjects. The results show that the E/NS workers had a lower sperm forward progression rate (P < .05) compared with controls (NE/NS). Individuals in the NE/S group showed a significant inverse relationship between years smoked and sperm density (r = -.24, P < .05). The data also revealed that cigarette smokers who had worked in a petrochemical plant had significantly poorer quality semen, including sperm density, total sperm count, and forward progression rate, compared with the control (NE/NS) group (P < .01). Furthermore, there was a significant inverse correlation between combined exposure and smoking years, and sperm density (r = -.28, P < .05). These findings suggest that occupational exposure to petrochemical compounds may aggravate the adverse effect that smoking has on semen quality.

Respiratory symptoms and functional status in workers exposed to silica, asbestos, and coal mine dusts

This study aims to provide further understanding of physiologic and symptomatic changes and radiographic abnormalities due to exposure to silica, asbestos, and coal dusts. Questionnaires and pulmonary function tests were given to 220 silica, 277 asbestos, and 511 coal workers from three different industries in China. Posteroanterior chest radiographs were classified as stages 0, I, II, and III according to degree of parenchymal fibrosis. Significantly poorer pulmonary function and a higher prevalence of dyspnea and chronic cough were observed in workers with pneumoconiosis than those without, irrespective of dust type. Workers with stages II and III silicosis had worse pulmonary function and more common symptoms relative to workers with equivalent coal workers' pneumoconiosis or asbestosis. After adjusting for relevant confounders, reductions in the spirometric parameters and single breath diffusing capacity for carbon monoxide (DLCO) and the occurrence of respiratory symptoms were associated with increasing stage of silicosis, whereas lower DLCO and the occurrence of symptoms were associated with increasing stage of asbestosis and coal workers' pneumoconiosis. The study suggests that despite the differences in degree and pattern due to exposure to different fibrogenic dusts, respiratory impairments of all of the workers are associated with the presence and progression of parenchymal fibrosis and smoking.

[Determination of six ginsenosides in Panax species by high performance liquid chromatography]

A method for the determination of six major ginsenosides in panax species by high performance liquid chromatography (HPLC) with UV detection at 203 nm is described. The six major ginsenosides, which were reported to account for more than 90% of the total ginsenosides content of the panax species' root, were successfully separated using gradient HPLC. The column to be used was a Cosmosil-C18 reversed-phase, 4.6 mm i.d. x 250 mm, 5 microns (Japan), connected with a C18 guard column and the mobile phase was acetonitrile and water. The calibration curves of the six ginsenosides were all linear over the range of 25 mg/L-300 mg/L with good correlation coefficients (> 0.99). The recoveries for the ginsenosides were all above 80%. For real samples and recovery study, the major ginsenosides were ultrasonically extracted by methanol. The extracts were evaporated to 1 mL, under vacuum, at about 50 degrees C and then diluted by methanol. Just prior to HPLC analysis, the sample solutions were filtered using a C18 cartridge. This method has been successfully applied to the analysis of four commercial panax samples.

[Protective effect of xinxin capsule on learning and memory impairment in mice]

OBJECTIVE

To investigate the effect of Xinxin Capsule on the scopolamine or ethanol induced impairment of learning and memory retention in mice.

METHOD

Step-through and Morris Water-maze methods, wer used to the protective effect of Xinxin Capsule(0.4, 0.8, 1.6 g.kg-1, ig, 16 d) on the scopolamine or ethanol induced impairment of learning and memory retention in mice.

RESULT

The Capsule(0.8, 1.6 g.kg-1, ig,) can turn over the Scope so as to induce the impairment of learning, and the Capsule((0.4, 0.8, 1.6 g.kg-1, ig) can improve the ethanol induced impairment of memory retention in mice.

CONCLUSION

Xinxin Capsule helps regain as well as impair the learning and memory retention in mice.

[Comparison of several rib rings with intercostal muscles for tracheal replacement in dogs]

OBJECTIVE

To compare the effect of several types of rib rings with intercostal muscles for the replacement of trachea in thorax.

METHODS

The surface layer of the third rib of dogs were ripped off and curved into triangular, quadrilateral and polygonal form. These three types of rib rings with intercostal muscles were used to replace a segment of trachea in thorax.

RESULTS

The stability of triangular rib ring was very well, but stricture of ring were often happened because of its smaller internal diameter. These stability of quadrilateral rib ring was the worst. The polygonal rib ring presented the biggest diameter and good stability compared to the other two kinds of rings. If silicone tube was supplemented in the polygonal rib ring, the quality of artificial trachea was excellent.

CONCLUSION

The rib rings with intercostal muscles are successfully used for replacing the defect of trachea in canine thorax. The polygonal rib rings have the best quality in the three types of rib ring for tracheal replacement.

Effect of TCDD on maternal toxicity and chorionic gonadotropin--bioactivity in the immediate post-implantation period of macaque

The purpose of this experiment was to observe the alterations in bioactivity of chorionic gonadotropin (CG) associated with early fetal loss (EFL), induced by the environmental toxin TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) in the cynomolgus macaque. Ten of twelve females administered single doses of 1, 2 or 4 microg/kg TCDD on gestational day (GD) 12 had EFL from ten to twenty days later. Seven control animals treated only with the vehicle had normal pregnancies. Blood samples were repeatedly collected for hormone evaluation, from two days before treatment to thirty-one days following treatment. Immunoreactive monkey chorionic gonadotropin (mCG) was measured in serum using ELISA, and bioactive mCG was measured using a luminescence LH/CG bioassay. No change in immunoreactive mCG levels was detected as a result of TCDD, treatment, but bioactive mCG levels were significantly lower in TCDD-treated animals compared to controls. This change in bioactivity of mCG was also reflected in the ratio of mCG bioactivity to mCG immunoreactivity (B/I ratio) which began to rise in normal pregnancies by GD 20, but did not rise in TCDD treated animals. These results demonstrate that normal pregnancy in the monkey, as in humans, is characterized by a post-implantation change in the B/I ratio of CG. These findings therefore suggest that changes in the production of bioactive CG may be used as a biomarker of environmental toxicant exposures which lead to EFL.

Changes in tissue metals after cadmium intoxication and intervention with chlorpromazine in male rats

Cadmium (Cd), one of the most dangerous heavy metals, has a very similar ionic radius to calcium (Ca). The interference of cadmium in calcium homeostasis may play an important role in cadmium toxicity. Recent reports indicate that calmodulin (CaM) inhibitors such as trifluoperazine and chlorpromazine (CPZ) could protect rodents against cadmium toxicity. It was also reported that pretreatment of mice with zinc (Zn) could reduce the adverse effects induced by cadmium. The aim of this study is to determine whether Cd changes the balance of other essential metals such as Zn and copper (Cu) in rat tissues, and whether CPZ can reverse these changes which are induced by cadmium intoxication. Adult male Sprague-Dawley (SD) rats were injected intraperitoneally (i.p.) with cadmium chloride (CdCl2) (0.2, 0.4, 0.8 mg Cd/kg body weight) alone and 0.4 mg Cd/kg in association with CPZ (5 mg/kg) daily for a week. The control animals were injected with normal saline only. The results showed that the cadmium content in the liver, kidney and testis increased significantly with a dose-response relationship. Cadmium treatment markedly increased the Zn and Ca content in some of the tissues. Hepatic and renal metallothionein (MT) increased significantly after cadmium intoxication. CPZ treatment, however, reduced cadmium content in liver, but not blood and kidney. CPZ seemed to decrease the content of MT in liver and significantly increase the amounts of MT in kidney. These data suggest that the intervention of cadmium with tissue essential metals may play a role in cadmium toxicity in rats, and calmodulin inhibitors to some extent can reduce the adverse effect of cadmium by decreasing the cadmium load in tissues and reversing the unbalance of essential metals.

Phylogenetic relationships of Eurasian pines (Pinus, Pinaceae) based on chloroplast rbcL, MATK, RPL20-RPS18 spacer, and TRNV intron sequences

The sequence divergence of chloroplast rbcL, matK, trnV intron, and rpl20-rps18 spacer regions was analyzed among 32 Pinus species and representatives of six other genera in Pinaceae. The total aligned sequence length is 3570 bp. Of the four sequences examined, matK evolved much faster than rbcL in Pinus and in other Pinaceae genera. The two noncoding regions did not show more divergence than the two coding regions, especially within each Pinus subgenus. Phylogenetic analyses based on these four sequences gave consistent results and strongly supported the monophyly hypothesis for the genus Pinus and its two recognized subgenera. Pinus krempfii, the two-flat-needle pine endemic to Vietnam, was placed in subgen. Strobus and showed closer affinity to subsect. Gerardianae. The ancient character of sect. Parrya is further confirmed. However, monophyly of the sect. Parrya is not supported by our data. Among the Eurasian pines of subgen. Pinus, Mediterranean pines formed one clade and the Asian members of subsect. Sylvestres formed another. The Himalayan P. roxburghii showed considerable divergence from all the other hard pines from both regions. Pinus merkusii was distinctly separated from all the Asian members of subsect. Sylvestres. The implications of our results for Pinus classification are discussed.

The impact of alanyl-glutamine on clinical safety, nitrogen balance, intestinal permeability, and clinical outcome in postoperative patients: a randomized, double-blind, controlled study of 120 patients

PURPOSE

To evaluate the impact of alanyl-glutamine (Ala-Gln)-supplemented parenteral nutrition (PN) on clinical safety, nitrogen balance, intestinal permeability, and clinical outcome in postoperative patients.

METHODS

One hundred twenty patients undergoing major abdominal surgery were enrolled. Protocol was approved and informed consent obtained. A double-blind protocol was designed as used in Europe. The clinical safety and outcome were observed for 60 patients in 2 centers (30 each). Sixty patients from 2 additional centers (30 each) were observed for clinical safety, nitrogen balance, intestinal permeability, and clinical outcome. All patients received isonitrogenous (0.20 g/kg body wt per day) and isocaloric (30 kcal/kg body wt per day) parenteral nutrition. The study group received Ala-Gln (Dipeptiven, Fresenius Kabi, Bad Homberg, Germany) 0.50 g/kg per day. Clinical chemistry variables, plasma amino acids profile, nitrogen balance, intestinal permeability (lactulose/mannitol ratio [L/M ratio]) were measured; hospital stay and infection rate were monitored. Statview was used for analysis of variance (ANOVA) or chi2 tests. Data were expressed as means +/- SD, and the significance level was p < .05.

RESULTS

The patients in both groups were comparable prior to the operation. Vital signs and clinical chemical parameters were similar between groups. L/M ratio was 0.047+/-0.029 in control and 0.058+/-0.049 in study group before the operation (AOD-3). The L/M ratio was 0.132+/-0.081 in the control group, and 0.097+/-0.063 in study group on the seventh postoperative day. The difference of L/M ratio between groups was significant (p = .02). The cumulative nitrogen balance values were -5+/-162 mg/kg for 6 days in control and 144+/-145 mg/kg for 6 days in study group (p = .0004). All the patients recovered without incision infection. However, there were 3 cases that had infection-related complications in the control group; the difference was not significant between groups. The hospital stay in the study group was 12.5 days, which was 4 days less than that of the control group (p = .02).

CONCLUSIONS

Ala-Gln-supplemented PN was clinically safe, had better nitrogen balance, and maintained intestinal permeability in postoperative patients. The clinical outcome of the patients in study group was better; it was significantly different from the control group.

Urinary follicle stimulating hormone can be used as a biomarker to assess male reproductive function

AIM

To develop an algorithm for use in population-based studies to assess testicular function by measurements of total urinary follicle stimulating hormone (FSH).

METHODS

Total concentrations of urinary FSH were measured in a group of 44 men at the University of California, Davis (UCD) and were compared to FSH measurements in serum. On the basis of these and other published data, a urinary FSH value of >2 ng/mg creatinine (Cr) was selected as the cutoff point to identify men with elevated serum FSH ( > 12 IU/L) or low sperm counts ( < 20 million/mL).

RESULTS

The sensitivity and specificity of this algorithm for detecting elevated serum FSH in a group of 58 agricultural workers in the People' s Republic of China were 100% and 50%, respectively. The sensitivity and specificity of this algorithm for detecting low sperm counts in a population of 105 infertility patients at UCD were 58 % and 76 %, respectively.

CONCLUSION

This test may have particular value in identifying populations with no evidence of testicular toxicity, and in which labor-intensive semen studies may not be feasible.

Selection effects on an estimation of long-term changes in pulmonary function

To reveal the association of initial pulmonary function level with subsequent mortality and participation in a follow-up reexamination, a prospective cohort study was performed. Female residents in a volcanic area of southern Kyushu, Japan, were followed up for their vital status and the pulmonary function 15 years after they received the first pulmonary function test. A cohort of 512 Japanese female residents who were examined for pulmonary function as indicated by forced expiratory volume and forced expiratory volume in one second was measured in a baseline examination in 1980. After 15 years, 35 females were lost to follow-up. Of the remaining 477 females, 340 and 137 females provided good and poor levels of pulmonary function tests (PFT) at baseline, respectively. Mortality by 1995 in the poor PFT group was significantly higher than that in the good PFT group (33.6% vs 9.4%). The mortality differences were still highly significant when the 35 lost cases were included as all alive. Among the 399 survivors, the nonparticipation rate in the reexamination in 1995 was significantly higher in the poor PFT group than that in the good PFT group (80.2% vs 69.5%). The results of the present study, a longitudinal study of pulmonary function, provide evidence of selection effects due to death or failure to participate in a subsequent reexamination.

A silicosis patient presenting with an enlarged supraclavicular lymph node

A stone splitter was discovered to have an enlarged supraclavicular lymph node which showed nodules with bi-refringent crystals on histological examination. He had worked in a dusty environment for more than 10 years with ineffective respiratory protection. He gave a history of occasional cough with blood-stained sputum for 10 years for which no definite diagnosis was made. Silicosis (classified as type s/s with profusion 1/1) was confirmed after his chest radiographs were reviewed. The presentation was unusual and illustrated the importance of an occupational history in clinical practice.

Pulmonary function of nonsmoking female asbestos workers without radiographic signs of asbestosis

Researchers disagree about whether exposure to asbestos causes significant respiratory impairments and airway obstruction in the absence of radiographic asbestosis and smoking. To obtain confirmatory information, the authors examined pulmonary function of 208 nonsmoking female asbestos workers who did not have asbestosis and 136 controls. The authors observed an overall lower single-breath carbon monoxide diffusing capacity in the asbestos workers than in controls. In addition, significant decreases in percentage vital capacity, percentage forced vital capacity, and percentage mean forced expiratory flow during the middle half of the forced vital capacity were evident in the older workers. Logistic regression analysis revealed that asbestos exposure was associated with abnormal single-breath carbon monoxide diffusing capacity, vital capacity, and mean forced expiratory flow during the middle half of the forced vital capacity among the older workers. The age-related decline in vital capacity, forced vital capacity, and mean forced expiratory flow during the middle half of the forced vital capacity was significantly greater in the asbestos workers than the controls. The findings imply that asbestos-exposure per se contributes predominantly to restricted lung volume and reduced single-breath carbon monoxide diffusing capacity. Asbestos may also cause slight airway obstruction, especially in workers who are heavily exposed.

RNA editing in gymnosperms and its impact on the evolution of the mitochondrial coxI gene

Sequence analysis of the mitochondrial coxI gene in eight gymnosperm species revealed a high rate of nonsynonymous nucleotide substitutions with a strong (98%) predominance of C-T substitutions. Further analysis of the corresponding coxI cDNA sequences showed that all the non-synonymous C-T changes in the coxI genomic DNA sequences were eliminated by RNA editing resulting in nearly identical mRNA (amino acid) sequences among the species. Pronounced variation in the number and location of edited sites was found among species. Most species had a relatively large number of edited sites (from 25 to 34). However, no RNA editing of the coxI sequence was found in Gingko biloba or Larix sibirica. The sequence composition of the investigated coxI fragment suggests that the coxI gene in G. biloba and L. sibirica originated from edited mitochondrial coxI transcripts by reverse transcription followed by insertion into the nuclear genome or back into the mitochondrial genome. Our results also demonstrate that where there are a large number of edited sites, RNA editing can accelerate the divergence of nucleotide sequences among species.