Automobile exhaust particle-induced apoptosis and necrosis in MRC-5 cells

To study the effect of particulate extracts (PE) collected from a heavy traffic road in Lanzhou City, on MRC-5 cell apoptosis, and to explore the toxicity action of PE and its mechanism. Cultured MRC-5 cells were incubated in the extracts of different concentrations. Inhibition of proliferation was measured with a colorimetric 3-[4,5-dimethyl thiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological assessment of apoptosis was performed with fluorescence microscopy and electronic microscopy. Extracted DNA from the cells was electrophoresed on agarose gel in order to observe DNA fragmentation. The amount of apoptotic cells was measured by flow cytometry. The results indicated that exposure of exponentially growing MRC-5 cells exposed to PE 5-160 microg l(-1) for 24-96 h resulted in dose- and time-dependent reduction of survival of MRC-5 cells. After treatment with PE, markedly morphological changes of MRC-5 cells including "apoptotic bodies", were observed with a fluorescence microscope. Agarose gel electrophoresis of DNA from the cells treated with PE for 48 and 72 h revealed a "ladder" pattern. PE induced apoptosis in low doses but necrosis in high doses. Apoptotic rates were 12.95, 17.40 and 29.80% after treatment with PE 5, 10, and 20 microg l(-1), respectively. A typical sub-diploid apoptosis peak was demonstrated in MRC-5 cells treated with PE. A significant dose-effect response and time-effect correlation could be found between apoptosis rates and PE. All results confirmed that the PE could induce and accelerate apoptosis in low doses but necrosis in high doses.

Downregulation of adenosine and P2X receptor-mediated cardiovascular responses in heart failure rats

Neurohormonal changes in congestive heart failure (CHF) include an enhanced peripheral sympathetic nerve activity which results in increased release of noradrenaline, neuropeptide Y and ATP. To examine if such changes in CHF would modulate peripheral pre- and postsynaptic receptors of ATP and its degradation product adenosine, experiments were performed in a rat model of ischaemic CHF. In this model, ischaemia was induced in rats by ligation of the left coronary artery. Our results demonstrate that there is a selective downregulation of P2X receptor-mediated pressor effects, while the hypotensive effects mediated by the endothelial P2Y receptors are unaffected in CHF. Moreover, the adenosine-mediated inhibitory effects on heart rate and blood pressure were also attenuated in the CHF rats. The most important changes in adenosine and P2-receptor function induced by ischaemic CHF were the reduced pressor effect mediated by the P2X receptor and the increased heart rate due to an attenuated inhibitory effect of adenosine.

Characterization of recombinant phosphatidylinositol 4-kinase beta reveals auto- and heterophosphorylation of the enzyme

Phosphatidylinositol (PI) 4-kinases catalyze the synthesis of PI 4-phosphate, an important intermediate for the synthesis of membrane polyphosphoinositides, regulators of multiple cellular functions. Two mammalian PI 4-kinases have been cloned, a 230-kDa enzyme (alpha-form) and a 110-kDa (beta-form), both of which are inhibited by >0.1 microm concentrations of the PI 3-kinase inhibitor, wortmannin (WT). In the present study, we created a glutathione S-transferase-PI4Kbeta fusion protein for expression in Escherichia coli. The purified protein was biologically active and phosphorylated PI in its 4-position with WT sensitivity and kinetic parameters that were identical to those of purified bovine brain PI4Kbeta. In addition to its lipid kinase activity, the enzyme exhibited autophosphorylation that was enhanced by Mn(2+) ions and inhibited by WT and another PI 3-kinase inhibitor, LY 294002. The recombinant protein was unable to transphosphorylate, but its isolated C-terminal catalytic domain still displayed autophosphorylation, suggesting that the autophosphorylation site resides within the C-terminal catalytic domain of the protein and is held in position by intramolecular interactions. Autophosphorylation inhibited subsequent lipid kinase activity, which was reversed upon dephosphorylation, by protein phosphatases, PP1 and PP2A(1), suggesting that it may represent a regulatory mechanism for the enzyme. Phosphorylation of endogenous or overexpressed PI4Kbeta was also observed in COS-7 cells; however, the in vivo phosphorylation of the expressed protein was only partially inhibited by WT and also occurred in a catalytically inactive form of the enzyme, indicating the presence of additional phosphorylation site(s). Successful bacterial expression of PI4Kbeta should aid research on the structure-function relationships of this protein as well as of other, structurally related enzymes.

Renal and cardiovascular role of the neuropeptide Y Y1 receptor in ischaemic heart failure rats

The cardiovascular role of the neuropeptide Y Y1 receptors in-vivo and in-vitro in ischaemic heart failure was evaluated by using the novel neuropeptide Y Y1 selective antagonist BIBP 3226 (R-N2-(diphenylacetyl)-N-[(4-hydroxyphenyl)methyl]-D-arginine-amid e). In pithed rats, incremental doses of BIBP 3226 inhibited the exogenous neuropeptide Y induced pressor response in a dose-related fashion and a bolus injection of BIBP 3226 (0.5 mg kg(-1)) significantly shifted the pressor response curve of exogenous neuropeptide Y to the right. The potentiation effect to exogenous neuropeptide Y on the pressor response to preganglionic sympathetic nerve stimulation in ischaemic heart failure rats as well as on the contractile response to noradrenaline in renal arteries in sham-operated animals were also inhibited by the neuropeptide Y Y1 antagonist. In conscious ischaemic heart failure rats, incremental doses of BIBP 3226 (0.125-1 mg kg(-1)) significantly reduced basal blood pressure and heart rate. Compared with sham-operated rats, neuropeptide Y by itself induced no contraction and no potentiation on noradrenaline elicited contraction in renal artery of the ischaemic heart failure rat. Furthermore, under in-vivo conditions, BIBP 3226 did not influence basal renal function or the response to exogenous neuropeptide Y on urinary volume, urinary sodium and urinary potassium. Our results demonstrate that although there is a downregulation of the Y1 receptors by ischaemic heart failure, Y1 receptors are still mainly involved in cardiovascular actions of exogenous neuropeptide Y and play a role in maintaining basal blood pressure and heart rate in ischaemic heart failure. However, our data do not imply any significant role of Y1 receptors on basal renal function in the ischaemic heart failure rat model.

[High performance thin layer chromatographic (HPTLC) determination of PAF in cerebrospinal fluid of patients with subarachnoid hemorrhage(SAH)]

The Platelet Activating Factor (PAF) is believed to be the major function in human after cerebral vascular spasm and cerebral ischemia. PAF has been found to participate in cerebral vascular spasm and cerebral ischemia by the basic and clinical study. The symptom of cerebral vascular spasm and cerebral ischemia has appeared with SAH. It has not been reported that the rule and change of PAF with SAH. In the present work, the concentration of PAF in human cerebral spinal fluid (CSF) with SAH were determined by high performance layer thin chromatography. The TLC plate was coated with high performance silica gel G using V(chloroform):V(methanol):V(water) = 65:35:6 as developing solvent. The PAF was determined by TLC scanning method and detected at 630 nm. The method was applied to determine the concentration of PAF in 16 CSF samples with SAH. The samples were collected in 1-3 d, 7-10 d and 14-21 d. CSF samples were deproteinized with methanol and chloroform. After centrifugation, the chloroform layer separated was dried at room temperature with nitrogen and stored under 20 degrees C in the refrigerator. The linear range of the method was 0.5-2.5 micrograms/L with regression coefficient of 0.9990. The lower limit of detection were 50 ng/L. The recovery of the method was 98.6%. The method enables a simple, rapid and reproducible quantification of PAF with SAH.

Increase in cardiac P2X1-and P2Y2-receptor mRNA levels in congestive heart failure

We wanted to study the expression of P2-receptors at the mRNA-level in the heart and if it is affected by congestive heart failure (CHF). To quantify the P2 receptor mRNA-expression we used a competitive RT-PCR protocol which is based on an internal RNA standard. The P2 receptor mRNA-expression was quantified in hearts from CHF rats and compared to sham-operated rats. Furthermore, the presence of receptor mRNA was studied in the myocardium from patients with heart failure. In the sham operated rats the G-protein coupled P2Y-receptors were expressed at a higher level than the ligand gated ion-channel receptor (P2X1). Among the P2Y-receptors the P2Y6-receptor was most abundantly expressed (P2Y6 > P2Y1 > P2Y2 = P2Y4 > P2X1). A prominent change was seen for the P2X1- and P2Y2-receptor mRNA levels which were increased 2.7-fold and 4.7-fold respectively in the myocardium from the left ventricle of CHF-rats. In contrast, the P2Y1-, P2Y4- and P2Y6-receptor mRNA levels were not significantly altered in CHF rats. In human myocard the P2X1-, P2Y1-, P2Y2-, P2Y6- and P2Y11-receptors were detected by RT-PCR in both right and left atria and ventricles, while the P2Y4-receptor band was weak or absent. In conclusion, most of the studied P2-receptors were expressed in both rat and human hearts. Furthermore, the P2X1- and P2Y2-receptor mRNA were upregulated in CHF, suggesting a pathophysiological role for these receptors in the development of heart failure.

p200 ARF-GEP1: a Golgi-localized guanine nucleotide exchange protein whose Sec7 domain is targeted by the drug brefeldin A

The drug brefeldin A (BFA) disrupts protein traffic and Golgi morphology by blocking activation of ADP ribosylation factors (ARFs) through an unknown mechanism. Here, we investigated the cellular localization and BFA sensitivity of human p200 ARF-GEP1 (p200), a ubiquitously expressed guanine nucleotide exchange factor of the Sec7 domain family. Multiple tagged forms of the full-length polypeptide localized to tight ribbon-like perinuclear structures that overlapped with the Golgi marker mannosidase II and were distinct from the pattern observed with ERGIC53/58. Analysis of several truncated forms mapped the Golgi-localization signal to the N-terminal third of p200. BFA treatment of transiently or stably transfected cells resulted in the redistribution of Golgi markers and in loss of cell viability, thereby indicating that overproduction of p200 may not be sufficient to overcome the toxic effect. A 39-kDa fragment spanning the Sec7 domain catalyzed loading of guanosine 5'-[gamma-thio]triphosphate onto class I ARFs and displayed clear sensitivity to BFA. Kinetic analysis established that BFA did not compete with ARF for interaction with p200 but, rather, acted as an uncompetitive inhibitor that only targeted the p200-ARF complex with an inhibition constant of 7 microM. On the basis of these results, we propose that accumulation of an abortive p200-ARF complex in the presence of BFA likely leads to disruption of Golgi morphology. p200 mapped to chromosome 8q13, 3.56 centirays from WI-6151, and database searches revealed the presence of putative isoforms whose inhibition may account for the effects of BFA on various organelles.

Congestive heart failure induces downregulation of P2X1-receptors in resistance arteries

OBJECTIVE

Congestive heart failure (CHF) is accompanied by enhanced peripheral sympathetic nerve activity, increased vascular resistance and impaired peripheral blood flow. Besides noradrenaline and neuropeptide Y, the sympathetic nervous system also releases ATP, which has contractile effects mediated by different subtypes of P2-receptors on the vascular smooth muscle cells. The present study was designed to examine postsynaptic changes of the contractile responses to ATP and other extracellular nucleotides in CHF.

METHODS

CHF was induced by left coronary artery ligation resulting in a reproducible myocardial infarction in Sprague-Dawley rats. Contractile responses were examined in cylindrical segments of aorta and the mesenteric artery after endothelium removal. To determine if an altered response was regulated on the transcriptional level, competitive reverse transcription polymerase chain reaction (RT-PCR) was used to estimate the amount of P2X1-receptor mRNA.

RESULTS

ATP, which is both a P2X1- and a P2Y-receptor agonist, induced a weaker contraction in the mesenteric artery from CHF as compared to sham operated rats. A decrease in both potency and maximum contraction was shown for the selective P2X1-receptor agonist, alpha beta-MeATP, in the mesenteric artery (pEC50 = 6.04 vs. 5.76, Cmax = 57% vs. 33%, sham vs. CHF operated rats), but not in the aorta. Competitive RT-PCR also revealed decreased P2X1-receptor mRNA levels in CHF operated rats in the mesenteric artery (9106 x 10(3) vs. 714 x 10(3) molecules/microgram, sham vs. CHF operated rats), while it remained unaltered in the aorta. To study the P2Y-receptor induced contractile effects, the P2X1-receptors were first desensitised with alpha beta-MeATP (10(-5) M for 8 min). After P2X1-receptors desensitisation, UTP and UDP induced strong contractions in both the mesenteric artery and in the aorta, while ATP and ADP were much less effective. These contractions were not altered by CHF, indicating that vascular contraction mediated by P2Y-receptors are unaffected by CHF.

CONCLUSION

CHF induces downregulation of P2X1-receptor stimulated contraction in the mesenteric artery depending on decreased mRNA synthesis for the receptor, while the P2Y-receptor activity remains unchanged. Downregulation of P2X1-receptors appears to be specific for peripheral resistance arteries. This may represent a compensatory response to enhanced peripheral sympathetic nerve activity and increased vascular resistance in CHF.

Enhanced acetylcholine and P2Y-receptor stimulated vascular EDHF-dilatation in congestive heart failure

OBJECTIVE

Congestive heart failure (CHF) is accompanied by impaired peripheral blood flow and endothelial dysfunction with decreased release of nitric oxide (NO). Strong evidence supports the existence of another vasodilatory substance, endothelium derived hyperpolarising factor (EDHF), which has not previously been studied in CHF.

METHOD

CHF was induced by left coronary artery ligation resulting in a reproducible myocardial infarction in Sprague Dawley rats. Vasodilatory responses to acetylcholine and extracellular nucleotides (ATP, ADP beta S, ADP and UTP) were examined in cylindrical segments of the mesenteric artery, precontracted with noradrenaline. The combined NO- and EDHF-dilatation (after inhibition of cyclo-oxygenase pathways) was called "total dilatation", as indomethacin had only minor effects in this system. NO-dilatation was studied in segments pretreated with indomethacin and the potassium channel inhibitors charybdotoxin (10(-7.5) M) and apamin (10(-6) M), while EDHF-dilatations were studied in the presence of indomethacin (10(-5) M) and L-NOARG (10(-3.5) M).

RESULTS

EDHF-dilatations in CHF were strongly up-regulated for ACh (36% vs. 73%; sham vs. CHF operated rats), ADP beta S (10% vs. 42%), ADP (0% vs. 21%) and UTP (3% vs. 35%). These dilatations were abolished by a combination of charybdotoxin and apamin, confirming that they were mediated by EDHF. The NO-dilatations on the other hand were down-regulated in CHF as compared to sham operated rats for ACh (93% vs. 76%; sham vs. CHF operated rats), ADP beta S (61% vs. 37%). ADP (60% vs. 30%), ATP (49% vs. 34%) and UTP (65% vs. 47%), while a minor decrease was seen in the total dilatation for ACh (87% vs. 75%; sham vs. CHF operated rats), ADP beta S (47% vs. 42%), ADP (59% vs. 39%), ATP (52% vs. 39%) and UTP (59% vs. 44%).

CONCLUSION

In this model of non-atherosclerotic CHF there was a minor decrease in the total dilatation and a marked down-regulation of the NO-mediated dilatation, while the EDHF-dilatation was up-regulated. Increased EDHF-activity in CHF may represent a compensatory response to decreased NO-activity to preserve endothelial function and tissue perfusion.

A "defeated" rice resistance gene acts as a QTL against a virulent strain of Xanthomonas oryzae pv. oryzae

The genetic components responsible for qualitative and quantitative resistance of rice plants to three strains (CR4, CXO8, and CR6) of Xanthomonas oryzae pv. oryzae (Xoo) were investigated using a set of 315 recombinant inbred lines (RILs) from the cross Lemont (japonica) x Teqing (indica) and a complete linkage map with 182 well distributed RFLP markers. We mapped a major gene (Xa4) and ten quantitative trait loci (QTLs) which were largely responsible for segregation of the resistance phenotype in the RILs. The Teqing allele at the Xa4 locus, Xa4T, acted as a dominant resistance gene against CR4 and CXO8. The breakdown of Xa4T-associated resistance mediated by the mutant allele at the avrXa4 locus in the virulent strain CR6 results from significant changes in both gene action (lose of dominance) and the magnitude of gene effect (approximately 50% reduction). Nevertheless, Xa4T still acted as a recessive QTL with a significant residual effect against CR6. The mutant alleles at the avrXa4 locus in CXO8 and CR6 that lead to a reduction in effect, or "breakdown", of Xa4T were apparently accompanied by corresponding penalties for their fitness. The quantitative component of resistance to Xoo in the RILs was largely due to a number of resistance QTLs. Most resistance QTLs mapped to genomic locations where major resistance genes and/or QTLs for resistance to Xoo, blast and sheath blight were identified in the same cross. Most QTLs showed consistent levels of resistance against all three Xoo strains. Our results suggest that a high level of durable resistance to Xoo may be achieved by the cumulative effects of multiple QTLs, including the residual effects of "defeated" major resistance genes.

The effect of dietary sulfur-containing amino acids on calcium excretion

The relationships between dietary protein and sulfur amino acid (methionine and cystine or taurine) intakes and urinary calcium excretion were examined both in animals and in young men. Thirty-two adult Wistar rats were divided into 4 groups, i.e., basal diet (group I), supplemented with albumin (II), methionine and cystine (III), or taurine (IV). During the 5-week feeding period, food consumption was recorded and 48 h urine samples were collected 4 times for each rat. Urinary calcium, creatinine and sulfate were measured. The results showed that the calcium and sulfate excretion in rats in group II and III were significantly higher than rats in the basal diet group. In contrast, supplementing a basal diet with taurine did not increase sulfate excretion and failed to induce hypercalciuria. The same result was also observed in the study carried out in Chinese young men. An increase in protein intake from 67 g to 107 g caused an increase in urinary calcium and sulfate. Supplementation with methionine and cystine in an amount to simulate those in the high protein diet had a similar effect. Adding taurine to the diet had no effect on urinary calcium and sulfate excretion. About 60 percent of the supplemented taurine in the diet was detected in the urine.

Does the neuropeptide Y Y1 receptor contribute to blood pressure control in the spontaneously hypertensive rat?

OBJECTIVE

To study the effects of the selective neuropeptide Y (NPY) Y1 receptor antagonist BIBP 3226 in spontaneously hypertensive rats (SHR) in order to elucidate whether NPY function may be altered in the SHR and whether the NPY Y1 receptor plays a specific role in the maintenance of high blood pressure in this genetic form of hypertension.

METHODS

Pithed and conscious SHR were studied after intravenous administration of 0.125-1 mg/kg BIBP 3226. The cardiovascular effects were evaluated under baseline conditions, under acute stress and after exogenous administration of 20 microg/kg NPY. The potentiating effects of NPY on pressor responses to phenylephrine and tyramine were studied in the SHR.

RESULTS

Intravenous administration of 0.125-1 mg/kg BIBP 3226 dose-dependently inhibited the pressor response to exogenous NPY in pithed SHR. At higher doses BIBP 3226 had an effect duration of 20-40 min. In the pithed SHR, a 0.5 mg/kg bolus injection of BIBP 3226 shifted the pressor response curve for exogenous NPY significantly to the right It also inhibited significantly the potentiating effects of NPY on pressor responses to phenylephrine and tyramine. In conscious SHR, 0.125-1 mg/kg BIBP 3226 did not reduce the basal blood pressure. In combination with a hypotensive dose of prazosin, administration of 0.5 mg/kg BIBP 3226 had no added effects lowering the basal blood pressure. A stressful stimulus, namely an air jet, caused a brief increase in blood pressure and heart rate in the conscious SHR. In this model, 0.5 mg/kg BIBP inhibited the heart rate response slightly but had no effect on the blood pressure response.

CONCLUSIONS

Our results demonstrate that, although the selective NPY Y1 receptor antagonist BIBP 3226 may shift the pressor response to exogenous NPY potently, it does not influence basal blood pressure significantly in the SHR.

Effects of phosphorothioated neuropeptide Y Y1-receptor antisense oligodeoxynucleotide in conscious rats and in human vessels

1. Metabolically stabilized (phosphorothioate) human and rat NPY Y1 receptor oligodeoxynucleotides (ODNs) complimentary to the rat or human Y1 mRNA were synthesized; [sense (rY1-SODN, 5'-AATTCAACTCTGTTCTCC-3'), antisense (hY1-ASODN, 5'-CCTGGGAAAATAATGTTG-3' and rY1-ASODN, 5'-GGAGAACAGAGTTGAATT-3') and mismatches (hY1-MMODN, 5'-CCTGAGATAA-TAAGGTTG-3' and rY1-MM 5'-GTAGATCAGAGATGAAGT-3')] and used to modulate cardiovascular function in vitro in human vessels as well as in vivo in the rat. 2. The objectives of the experiments were to assess the influence of the NPY Y1 receptor on vasomotor function human resistance arteries in vitro and to investigate the contribution of the NPY receptor system to cardiovascular haemodynamics in vivo. 3. Human subcutaneous resistance arteries removed from patients who underwent surgery for nonvascular diseases were incubated in vitro with the stabilized phosphorothioated hY1-receptor ASODN or MMODN (10(-7) TO 10(-5) M). 4. In human resistance vessels preincubated with hY1-AS (10(-7) to 10(-5) M), the contractile response to NPY was significantly reduced in a dose-dependent fashion. No effects were observed in the hY1-MMODN-incubated vessels at lower concentrations (10(-7) M to 10(-6) M). 5. The haemodynamic effects of the phosphorothioated rY1-ASODN, SODN or MMODN were investigated in conscious rats during 48 h of continuous infusions. The continuous infusion with rY1-ASODN did not change MAP while the rY1-SODN unexpectedly induced an early (10-20) increase in ambulatory MAP and the rY1-MMODN a late (24-44 h) increase. 6. Contractile responses to NPY (2, 4, 8, 16 and 32 micrograms kg-1) were significantly reduced in the rats treated with long-term infusion of rY1-ASODN (2.1 mg kg-1 h-1, i.v. infusion for 48 h) compared with animals treated with rY1-SODN and MMODN, as well as animals treated with saline and glucose. Notably, the group infused with the rY1-SODN showed an exaggerated response to tested doses of NPY. 7. We conclude that the incubation of human subcutaneous arteries with a metabolically stabilized 18 base pair hY1-ASODN and long-term infusion with a corresponding rY1-ASODN attenuate NPY-induced vasoconstriction.

[Rates of hip fractures in Beijing China]

One-third of the world's hip fractures are said to occur in Asia, but there have been no validated studies of hip fracture rates in China. In 1988-1992 all 76 hospitals in Beijing reported 820 hip fracture admissions coded as ICD-9. Checking against original discharge logs, medical records, X-ray reports, operation notes and operating room logs of a random sample of Beijing hospitals to discover underestimated and misclassified cases. In order to estimate hip fracture treated outside hospitals, we also interviewed a random sample of 2113 women aged 50 and over with a 97% response rate in Beijing. Finally, we also surveyed 27 hospitals in the suburbs of Beijing, but have found that no Beijing residents had been treated for hip fracture outside the city. Based on the 1990 China census, age-standardized rates (per 100,000) of hip fractures in Beijing were 88 for women, 97 for men. From 1988 to 1992, the rates in Beijing increased 35% in women and 33% in men. This is the first validated population-based study on the rates of hip fractures in China that has confirmed the completeness and accuracy of reports of hip fracture cases and has estimated the degree of under-reporting of hospital discharge. Hip fracture rates in Beijing are among the lowest in the world but may rise rapidly.

Bone density and lifestyle characteristics in premenopausal and postmenopausal Chinese women

The relationships between bone health and various lifestyle factors were examined in a cross-sectional study in 775 Chinese women aged 35-75 years. Bone mass was significantly positively associated with body weight, height, body mass index (BMI) and duration of breastfeeding, but was not significantly associated with other lifestyle variables, including alcohol consumption, parity, age at menarche and age at menopause after adjusting for age and body weight. A positive association was observed in premenopausal women (but not in postmenopausal women) for bone density with current cigarette smoking and plasma and urinary cotinine (the major metabolite of smoking). However, the confounding effects of other unknown factors present in this cross-sectional study may not be excluded. Daily physical activity, as indicated by time spent working in the fields, was found consistently to be positively associated with bone mass (p < 0.0001). When these women were grouped into three physical activity levels on the basis of occupation and daily work intensity, those undertaking heavy labor also had significantly higher radial bone mass than women undertaking light or medium labor. These results suggest a protective effect of daily physical activity on bone health in both pre- and postmenopausal women.

[Analytical study on processing of Rheum palmatum L. by HPLC]

This paper deals with the effect of processing on Rheum palmatum. A HPLC method for the determination of rhein in the drug processed five different ways has been established. The method is simple, specific and accurate. The recovery is 98.52% and relative standard deviation.

Assessment of a modified household food weighing method in a study of bone health in China

OBJECTIVE

A 'modified' household dietary method to estimate individual intakes from total household intakes was evaluated in comparison to the individual food weighing method, i.e. direct weighing of foods consumed by individuals.

DESIGN

Foods consumed by the household were weighed and recorded over a 3 day period and were proportionally allocated to a specific person in the household by using energy conversion factors based on age, gender and physical activity. The individual dietary intakes were standardized by body weight (ratio of individual body weight to reference body weight from Chinese Recommended Daily Allowances (Acta Nutr. Sin. 12, 1-9), and were compared with the estimates from the individual food weighing method for both accuracy and associations with bone density.

SETTING

The subjects were randomly selected from five rural countries in China, characterized by different dietary patterns.

SUBJECTS

A total of 712 women aged 35-75 years participated in the dietary and bone measurements.

RESULTS

Nutrient intakes estimated by the modified household method (adjusting for body weight were very similar to those obtained by the individual method (r = 0.53-0.78, P < 0.001), except for sodium which had the largest deviation from the individual methods (r = 0.23, P < 0.001). Calcium intakes were 405 +/- 271 and 409 +/- 323 mg/day, respectively, as estimated by the individual and modified household methods. A very similar degree of correlation with radial bone density also was obtained for both calcium estimates.

CONCLUSION

The results indicate that the modified household method is appropriate for assessing food intakes of individuals in large nutritional studies.

Dietary intakes and urinary excretion of calcium and acids: a cross-sectional study of women in China

The relationship between dietary intakes and urinary calcium was examined in a cross-sectional survey of 764 middle-aged and elderly women with markedly different dietary patterns and lifestyles. Urinary calcium was correlated positively with urinary acids, including titratable acid (r = 0.46, P < 0.0001), ammonia (r = 0.42, P < 0.0001), and sulfate (r = 0.52, P < 0.0001). Urinary excretions of calcium and acids were correlated positively with intakes of animal and nondairy animal protein but were correlated negatively with plant-protein intake, possibly because of the alkaline nature of plant foods. Further analyses showed that urinary calcium and acids were associated positively with acid-forming foods and were associated negatively with plant foods. These results indicate that under free-living conditions urinary calcium excretion is likely determined by the acid-base status of the total diet, including among other factors the contribution of sulfur amino acids to urinary acid production.

Dietary calcium and bone density among middle-aged and elderly women in China

Associations between dietary calcium and bone status were investigated in 843 Chinese women aged 35-75 y who were selected from five rural counties where dietary calcium varied considerably. Bone mineral content (BMC) and bone mineral density (BMD) at the radius were significantly higher in one of the pastoral counties with higher calcium intake than in the nonpastoral counties. Analysis by individual for all counties combined showed that BMC and BMD were correlated positively with total calcium (r = 0.27-0.38, P < 0.0001), dairy calcium (r = 0.34-0.40, P < 0.0001), and to a lesser extent with nondairy calcium (r = 0.06-0.12, P = 0.001-0.100), even after age and/or body weight were adjusted for. The results strongly indicated that dietary calcium, especially from dairy sources, increased bone mass in middle-aged and elderly women by facilitating optimal peak bone mass earlier in life.

Specificity and treatment of thermal and inhalation injury following an explosion in a cement manufacturing kiln

Six patients sustained a unique type of burn injury while working during the manufacture of cement in China. These patients suffered a combination of chemical and thermal injuries with extensive deep burns and inhalation injury, when they were involved in an accidental explosive leakage of cement from a manufacturing kiln. This report discusses the aetiology of the burn injury and the principles of treatment. All of these burns were preventable.

Age-related changes in transmitter glutamate and NMDA receptor/channels in the brain of senescence-accelerated mouse

The senescence-accelerated mouse (SAM-P/8) is known as a murine model of aging and memory dysfunction. In the hippocampus and cerebral cortex of P/8, the contents of glutamic acid and glutamine were significantly higher than those of normal strain R/1 during 2 and 14 months. High K(+)-evoked endogenous glutamic acid release from the slices of P/8 was increased in comparison with R/1 at 9 and 11 months. In addition, the Bmax of [3H]dizocilpine (MK-801, channel blocker for N-methyl-D-aspartic acid receptor/channel) binding in the cerebral cortex was age-dependently decreased in P/8 but not in R/1. These results suggest that synaptic dysfunctions in the glutamatergic system occur in the CNS of SAM-P/8.

Age-related changes in NMDA-induced [3H]acetylcholine release from brain slices of senescence-accelerated mouse

From the brain slices of normal mice (ddY strain, subcloned from dd strain in National Institute of Health in Japan), N-methyl-D-aspartic acid (NMDA) at 0.01-1 mM evoked [3H]acetylcholine (ACh) release in a concentration dependent manner. [3H]ACh release evoked by 1 mM NMDA was significantly inhibited by 2-amino-5-phosphonovaleric acid (APV), phencyclidine (PCP) and 5-methyl-10,11-dihydroxy-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801). The effects of NMDA were not seen in the Ca2+ free medium and were inhibited by physiological concentration (0.83 mM) of Mg2+. NMDA seems to cause ACh release from nerve terminals through the receptor-ion channel mediated mechanism in the mouse brain. Based upon these results, we determined the activity of a high K(+)- or NMDA-evoked [3H]ACh release using prone/8 strain of senescence-accelerated mouse (SAM-P/8) (a murine model of accelerated aging and memory dysfunction) and SAM-resistance/1 strain (SAM-R/1) (normal aging mice as the control) and these release activities were compared between both strains and during aging. [3H]ACh release evoked by 30 mM KCl was significantly lower than that of age-matched SAM-R/1 at 9 and 12 months. NMDA evoked the [3H]ACh release at 2, 6, 10 and 14 months in R/1 mice. In SAM-P/8 mice the activity of NMDA-evoked release was seen at 2 months, but markedly decreased afterwards. Nonsignificant difference was observed on the uptake of [3H]choline and on the spontaneous release of [3H]ACh between SAM-P/8 and SAM-R/1 strains, and during aging.(ABSTRACT TRUNCATED AT 250 WORDS)

A heparin-binding protein from neuroblastoma cells: immunological comparison to beta-amyloid precursor protein

1. beta-Amyloid precursor protein cross-reactive polypeptides were detected in the membrane extracts of a mouse neuroblastoma cell line, NB41A3. Four immunoreactive polypeptide bands were observed on western blots of a cell membrane extract. Their molecular weights as estimated by polyacrylamide gel electrophoresis ranged from 89.1 to 41 kDa. 2. After heparin affinity chromatography, two of these polypeptides strongly cross-reacted with an antibody that recognizes Alzheimer beta-amyloid precursor protein. 3. From the heparin binding fraction, these protein were further separated by reverse-phase high-performance liquid chromatography. A cross-reactive protein was isolated.

Effects of repeated administrations of facteur thymique sérique (FTS) on biochemical changes related to aging in senescence-accelerated mouse (SAM)

Superoxide dismutase (SOD) activity,malondialdehyde (MDA) content and monoamine oxidase B (MAO-B) activity were measured in the brain, liver and kidney of a normal aging strain (R/1) and an accelerating aging strain (P/8) senescence-accelerated mice (SAM) at 9-10 months of age, and the effects of facteur thymique sérique (FTS) were examined. The activity of Cu,Zn-SOD in the kidney and MAO-B in the liver was significantly low and high in SAM-P/8 compared to SAM-R/1. FTS enhanced the activity of Mn-SOD and Cu,Zn-SOD in the kidney of SAM-P/8 and Cu,Zn-SOD activity in the brain of both SAM-P/8 and SAM-R/1. It decreased the activity of MAO-B in the liver and the contents of malondialdehyde (MDA) in the brain and kidney of SAM-P/8. Thus, FTS affects the biochemical factors related to senescence in SAM-P/8, a particular senescent animal model, and may thus possibly be effective as an anti-senescent medicine.