Inactivation of Escherichia coli by O- water

AIMS

To clarify the effects of O(-) (atomic oxygen radical anion) water on the viability and morphological alteration of Escherichia coli.

METHODS AND RESULTS

O(-) water (OW) was prepared by bubbling of O(-)/argon (Ar) flux into deionized water. O(-) and hydrogen peroxide (H(2)O(2)) in the resultant OW were analysed by electron paramagnetic resonance and ultraviolet (UV) absorption spectroscopy. The population of E. coli treated by a typical OW of pH 4.30 +/- 0.20 [(2.5 +/- 0.8) x 10(-3) mmol l(-1) O(-); 0.5 +/- 0.2 mmol l(-1) H(2)O(2)) was reduced by more than 3 log CFU ml(-1) within 60 min at 30 degrees C. Through scanning electron microscopy observation, the OW-treated cells appeared dramatically collapsed. The release of nucleic acid induced by OW was identified by UV absorption spectroscopy.

CONCLUSIONS

O(-) water can result in inactivation of E. coli, nucleic acid release and cellular damage under the controlled laboratory conditions in excess of 15-30 min. Reactive oxygen species may play an important role in the inactivation process.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study first revealed that OW could inactivate E. coli, which may be potentially useful in developing a novel approach for the microbial decontamination of food, water or heat-sensitive material.

Tissue culture-induced locus-specific alteration in DNA methylation and its correlation with genetic variation in Codonopsis lanceolata Benth. et Hook. f

We have reported recently that tissue culture induced a high level of genetic variation at the primary nucleotide sequence in regenerants of medicinal plant Codonopsis lanceolata. It is not known, however, whether epigenetic variation in the form of alteration in DNA methylation also occurred in these plants. Here, we investigated possible alterations in level and pattern of cytosine methylation at the CCGG sites in the same set of regenerants relative to the donor plant, by the MSAP method employing a pair of isoschizomers, HpaII and MspI, which recognize the same restriction site but are differentially sensitive to cytosine methylation at the CCGG sites. A total of 1,674 MSAP profiles were resolved using 39 primer combinations. Of these, 177 (10.5%) profiles were polymorphic among the regenerants and/or between the regenerant(s) and the donor plant, in EcoRI + HpaII or EcoRI + MspI digest but not in both, indicating alteration in cytosine methylation patterns of specific loci, though their estimated total level of methylation remained more or less the same as the donor plant. Gel blot analysis validated most of the variant MSAP profiles as bona fide alteration in methylation patterns. Correlation analysis between the MSAP data and the previously reported ISSR and RAPD data revealed significant correlations, suggesting their possible intrinsic interrelatedness. Thirty-seven typical variant MSAP profiles were isolated and sequenced, of which 5 showed significant homology to known-function genes, 2 to chloroplast sequences, whilst the rest 30 did not find a match in the database.

Drug-induced changes in P450 enzyme expression at the gene expression level: a new dimension to the analysis of drug-drug interactions

Drug-drug interactions (DDIs) caused by direct chemical inhibition of key drug-metabolizing cytochrome P450 enzymes by a co-administered drug have been well documented and well understood. However, many other well-documented DDIs cannot be so readily explained. Recent investigations into drug and other xenobiotic-mediated expression changes of P450 genes have broadened our understanding of drug metabolism and DDI. In order to gain additional information on DDI, we have integrated existing information on drugs that are substrates, inhibitors, or inducers of important drug-metabolizing P450s with new data on drug-mediated expression changes of the same set of cytochrome P450s from a large-scale microarray gene expression database of drug-treated rat tissues. Existing information on substrates and inhibitors has been updated and reorganized into drug-cytochrome P450 matrices in order to facilitate comparative analysis of new information on inducers and suppressors. When examined at the gene expression level, a total of 119 currently marketed drugs from 265 examined were found to be cytochrome P450 inducers, and 83 were found to be suppressors. The value of this new information is illustrated with a more detailed examination of the DDI between PPARalpha agonists and HMG-CoA reductase inhibitors. This paper proposes that the well-documented, but poorly understood, increase in incidence of rhabdomyolysis when a PPARalpha agonist is co-administered with a HMG-CoA reductase inhibitor is at least in part the result of PPARalpha-induced general suppression of drug metabolism enzymes in liver. The authors believe this type of information will provide insights to other poorly understood DDI questions and stimulate further laboratory and clinical investigations on xenobiotic-mediated induction and suppression of drug metabolism.

Muscle-specific creatine kinase gene polymorphism and running economy responses to an 18-week 5000-m training programme

OBJECTIVE

To investigate the association between muscle-specific creatine kinase (CKMM) gene polymorphism and the effects of endurance training on running economy.

METHODS

102 biologically unrelated male volunteers from northern China performed a 5000-m running programme, with an intensity of 95-105% ventilatory threshold. The protocol was undertaken three times per week and lasted for 18 weeks. Running economy indexes were determined by making the participants run on a treadmill before and after the protocol, and the A/G polymorphism in the 3' untranslated region of CKMM was detected by polymerase chain reaction-restricted fragment length polymorphism (NcoI restriction enzyme).

RESULTS

Three expected genotypes for CKMM-NcoI (AA, AG and GG) were observed in the participants. After training, all running economy indexes declined markedly. Change in steady-state consumption of oxygen, change in steady-state consumption of oxygen by mean body weight, change in steady-state consumption of oxygen by mean lean body weight and change in ventilatory volume in AG groups were larger than those in AA and GG groups.

CONCLUSIONS

The findings indicate that the CKMM gene polymorphism may contribute to individual running economy responses to endurance training.

Genomic instability in phenotypically normal regenerants of medicinal plant Codonopsis lanceolata Benth. et Hook. f., as revealed by ISSR and RAPD markers

Codonopsis lanceolata Benth. et Hook. f., commonly known as bonnet bellflower, is a high-valued herb medicine and vegetable. In this study, a large number of plants were regenerated via organogenesis from immature seed-derived calli in C. lanceolata by a simple and efficient method. Compared with the mother donor plant, the regenerated plants did not exhibit visible phenotypic variations in six major morphological traits examined at the stage of one-season-maturity under field conditions. To gain insight into the genomic stability of these regenerated plants, 63 individuals were randomly tagged among a population of more than 2,000 regenerants, and were compared with the single mother donor plant by two molecular markers, the inter-simple sequence repeats (ISSR) and randomly amplified polymorphic DNA (RAPD). Apparent genomic variation was detected in the 63 regenerants, whereas preexisting heterozygosiy in the donor plant was deemed minimal by testing 30 seedlings germinated from selfed seeds of the same donor plant. The percentages of polymorphic bands (PPB) in the ISSR and RAPD analysis were respectively 15.7 and 24.9% for the 63 regenerated plants. Cluster analysis indicates that the genetic similarity values calculated on the basis of RAPD and ISSR data among the 64 plants (63 regenerated and one donor) were respectively 0.894 and 0.933, which allow classification of the plants into distinct groups. Nineteen randomly isolated bands underlying the changed RAPD or ISSR patterns were sequenced, and three of them showed significant homology to known-function genes. Detailed pairwise sequence comparison at one locus between the donor plant and a regenerant revealed that insertion of two short (24 and 19 bp) stretches of nucleotides in the regenerated plant relative to the donor plant occurred in an apparently stochastic manner.

Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities

We have previously demonstrated that the serine/threonine protein phosphatase-1 (PP-1) plays an important role in promoting cell survival. However, the molecular mechanisms by which PP-1 promotes survival remain largely unknown. In the present study, we provide evidence to show that PP-1 can directly dephosphorylate a master regulator of apoptosis, p53, to negatively modulate its transcriptional and apoptotic activities, and thus to promote cell survival. As a transcriptional factor, the function of p53 can be greatly regulated by phosphorylation and dephosphorylation. While the kinases responsible for phosphorylation of the 17 serine/threonine sites have been identified, the dephosphorylation of these sites remains largely unknown. In the present study, we demonstrate that PP-1 can dephosphorylate p53 at Ser-15 and Ser-37 through co-immunoprecipitation, in vitro and in vivo dephosphorylation assays, overexpression and silence of the gene encoding the catalytic subunit for PP-1. We further show that mutations mimicking constitutive dephosphorylation or phosphorylation of p53 at these sites attenuate or enhance its transcriptional activity, respectively. As a result of the changed p53 activity, expression of the downstream apoptosis-related genes such as bcl-2 and bax is accordingly altered and the apoptotic events are either largely abrogated or enhanced. Thus, our results demonstrate that PP-1 directly dephosphorylates p53, and dephosphorylation of p53 has as important impact on its functions as phosphorylation does. In addition, our results reveal that one of the molecular mechanisms by which PP-1 promotes cell survival is to dephosphorylate p53, and thus negatively regulate p53-dependent death pathway.

Antitumor effect of antisense ODC adenovirus on human prostate cancer cells

Ornithine decarboxylase (ODC), the first enzyme of polyamine biosynthesis, was found to increase in cancer cells, especially prostate cancers. Some chemotherapeutic agents aimed to decrease ODC expression showed inhibitory effects on cancer cells. In this study, we examined the effect of adenoviral-transduced antisense ODC on prostate cancer cells. An adenovirus carrying antisense ODC (rAd-ODC/Ex3as) was infected to prostate cancer cells PC-3 and LNCap. Expression of ODC and concentration of polyamines in cells were determined by Western blotting and HPLC. MTT (3-(4,5-methylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay was used to analyze the effect on cell growth. Cell cycle was evaluated by FCM and cellular invasion by Matrigel invasion assay. A nude mouse xenograft model was used to examine tumorigenicity. Expression of ODC in PC-3 and LNCap cells were reduced to 45 and 59%, and three polyamines were also decreased by the rAd-ODC/Ex3as treatment. Consequently, cell growth was substantially inhibited and cell cycle arrested at G1 phase. Matrigel invasion assay showed relatively low invasion. Marked suppression of tumor formation was observed in the xenograft model. This study suggests that rAd-ODC/Ex3as has the antitumor effect on the human prostate cancer cells.

[Expression of vascular endothelial growth factor and nm23 as prognostic factors in nasopharyngeal carcinoma]

OBJECTIVE

To evaluate the prognostic significance of vascular endothelial growth factor (VEGF) and nm23 expression for patients with nasopharyngeal carcinoma(NPC).

METHODS

From Jan. 1991 to Dec. 1995, 75 NPC patients treated in Department of Radiotherapy & Chemotherapy, Zhongnan Hospital of Wuhan University, with follow-up of more than 4 yrs, were selected to enter this study. Specimens of 75 NPC were studied by immunohistochemical staining for VEGF and nm23. The immunohistochemical data were correlated with development of locoregional failure, distant metastasis and survival.

RESULTS

Positive expression of VEGF and negative expression of nm23 were found in 54.7% and 56% of NPC specimens. Positive expression of VEGF and negative expression of nm23 correlated with the development of distant metastasis (P = 0.0181; P = 0.0091) and shorter survival (P = 0.0136; P = 0.0207). No association was observed with locoregional failure. No association was observed between the expression of VEGF and the expression of nm23.Cox proportional hazard model was used to compare the various factors and found the VEGF and nm23 expression were significant prognostic factors for patients with NPC.

CONCLUSION

The results of the study show that the VEGF and nm23 expression are significant prognostic factors for patients with NPC and indicate that expression of VEGF and nm23 may be useful in identifying patients who may benefit from systemic chemotherapy or other novel treatment strategies.

[Optimization of synthetic culture condition on lignin biodegradation ability of alkaliphilic ligninolytic bacteria using orthogonal experimental design]

The effects of seven single culture factors on lignin biodegradation ability of alkaliphilic ligninolytic bacteria strain 6 in alkaline liquid medium (pH approximately 10.5) with compounded carbons were optimized using orthogonal experiments. The result showed the seven single culture factors promote the activities of Laccase and MnP and the degradation rate of wheat straw lignin in varying degrees. The synthetic result was analysised. The optimal synthetic condition was static culture (10 days culture period), 37 degrees C, the initial pH10.6, 1 g/L sugar (the starting carbons), wheat straw lignin (the second carbons, wheat straw powder 20 g/L, added into on the fourth day after inoculation), 1.2 g/L NH4NO3 (nitrogen), 0.3% detergent T-80, 70 ml medium/250 ml flask.

Potassium channel blocker TEA prevents CA1 hippocampal injury following transient forebrain ischemia in adult rats

It has been recently reported that potassium channel increases activities in CA1 pyramidal neurons of rat hippocampus following transient forebrain ischemia. To understand the role of the enhanced potassium current in the pathogenesis of neuronal damage after ischemia, we examined the effects of tetraethylammonium (TEA) and 4-aminopyridine (4-AP) on the neuronal injury of CA1 region induced by 15 min forebrain ischemia using a four-vessel occlusion model. Adult rats received intracerebroventricular administration of either TEA or 4-AP after ischemia or TEA before ischemia and once each day for 7 days. In the postischemic TEA treated-rats, the neuronal injury in hippocampal CA1 region was significantly less than that of the controls. In contrast, neither preischemic infusion of TEA nor postischemic treatment of 4-AP had any neuroprotective effects. The present study demonstrates that postischemic application of TEA protects hippocampal CA1 pyramidal neurons against ischemic insult, suggesting that potassium channels may play important roles in the pathogenesis of CA1 neuronal death after transient forebrain ischemia.

Relationship between age and effect of early and long-term captopril treatment in patients with acute myocardial infarction

OBJECTIVE

To analyse the relationship between age and treatment with captopril after acute myocardial infarction (AMI).

METHODS

In a randomized trial, 822 patients with a first AMI received conventional medical treatment, including intravenous thrombolytic therapy and oral aspirin or metoprolol, and then were randomly allocated to captopril [dosage from the first 6.25 mg to 25 mg/t.i.d, 209 younger patients (< or = 64 years), 269 elderly patients (65-75 years)] or conventional treatment only (131 younger patients, 213 elderly). Survival in the four groups was calculated with the Kaplan-Meier method. Multivariate analysis was performed to understand the degree that multi-variables (including age) affect survival in patients taking captopril in the hospital or during long term follow-up.

RESULTS

The survival of patients who took captopril correlated significantly with age (P < 0.001). The survival of the elderly patients on captopril treatment did increase (P < 0.0001), but not of the younger ones (P > 0.05) during hospitalization. During follow-up, the survival of patients who took captopril correlated insignificantly with age (P > 0.05), but both the elderly and the younger patients have good survival rates (all P < 0.01) and lower cardiac events (all P < 0.01) when they took captopril.

CONCLUSIONS

Captopril exerts a weak effect on the younger patients but a beneficial effect on the elderly patients during hospitalization after AMI. However, there is no difference between the younger and the elderly in the prognosis, both having good survival and lower cardiac events when they take captopril long term during follow-up.

Effect of long-acting isosorbide-5-mononitrate administration on large artery distensibility in patients with essential hypertension

To evaluate the clinical efficacy of long-acting nitrates, isosorbide-5-mononitrate (IS-5-MN), on large artery distensibility in patients with essential hypertension. Large arterial distensibility was assessed by automatic noninvasive measurement of the carotid-femoral pulse wave velocity (PWV). Seventeen patients aged 62.53+/-7.94 years (mean+/-SD) with essential hypertension undering long-term antihypertensive therapy were studied in this trial. PWV was measured 2 weeks and 4 weeks after oral administration of IS-5-MN (30 mg once daily) with previous therapy. There was no significant difference in systolic blood pressure, diastolic blood pressure, pulse pressure or heart rate at 2 weeks and 4 weeks after treatment compared with baseline. The carotid-femoral PWV decreased significantly at 2 and 4 weeks after treatment (p<0.05, p< 0.05, respectively). Long-acting nitrates have potential value in improving large arterial distensibility in patients with essential hypertension independent of blood pressure alteration. It might be used as an effectively additive drug in hypertension control.

Prognostic significance of serum creatinine and uric acid in older Chinese patients with isolated systolic hypertension

We examined the relation of serum creatinine and uric acid to mortality and cardiovascular disease in older (aged >/=60 years) Chinese patients with isolated systolic hypertension (systolic/diastolic blood pressure >/=160/<95 mm Hg). We used Cox regression to correlate outcome with baseline serum creatinine and uric acid measured in 1880 and 1873, respectively, of the 2394 patients enrolled in the placebo-controlled Systolic Hypertension in China (Syst-China)

TRIAL

Median follow-up was 3 years. In multiple Cox regression analysis with adjustment for gender, age, active treatment, and other significant covariates, serum creatinine was significantly associated with a worse prognosis. The relative hazard rates (95% CIs) associated with a 20-micromol/L increase in serum creatinine for all-cause, cardiovascular, and stroke mortality were 1.16 (1.05 to 1.27, P=0.003), 1.15 (1.01 to 1.31, P=0.03), and 1.37 (1.13 to 1.65, P=0.001), respectively. In a similar analysis, which also accounted for serum creatinine, serum uric acid was also significantly and independently associated with excess mortality of cardiovascular disease and stroke. The relative hazard rates associated with a 50-micromol/L increase of serum uric acid were 1.14 (1.02 to 1.27, P=0.02) for cardiovascular mortality and 1.34 (1.14 to 1.57, P<0.001) for fatal stroke. In conclusion, in older Chinese patients with isolated systolic hypertension, serum creatinine and serum uric acid were predictors of mortality.

Modified lactone/carboxylate salt equilibria in vivo by liposomal delivery of 9-nitro-camptothecin

The lactone stability of camptothecins is critical for their anticancer activity. A stable liposomal 9-nitro-camptothecin formulation was developed to circumvent the drawbacks of low aqueous solubility and lactone instability and to provide sustained release of the agent in blood circulation. The potential merits of the formulation were demonstrated by its profoundly improved lactone stability in vivo, favorable pharmacokinetic and biodistribution characteristics in rats, and enhanced preclinical efficacy in tumor-bearing athymic mice.

Temperature-sensitive transformation by an Abelson virus mutant encoding an altered SH2 domain

Abelson murine leukemia virus (Ab-MLV) encodes the v-Abl protein tyrosine kinase and induces transformation of immortalized fibroblast lines and pre-B cells. Temperature-sensitive mutations affecting the kinase domain of the protein have demonstrated that the kinase activity is absolutely required for transformation. Despite this requirement, mutations affecting other regions of v-Abl modulate transformation activity. The SH2 domain and the highly conserved FLVRES motif within it form a phosphotyrosine-binding pocket that is required for interactions between the kinase and cellular substrates. To understand the impact of SH2 alterations on Ab-MLV-mediated transformation, we studied the Ab-MLV mutant P120/R273K. This mutant encodes a v-Abl protein in which the beta B5 arginine at the base of the phosphotyrosine-binding pocket has been replaced by a lysine. Unexpectedly, infection of NIH 3T3 or pre-B cells with P120/R273K revealed a temperature-dependent transformation phenotype. At 34 degrees C, P120/R273K transformed about 10-fold fewer cells than wild-type virus of equivalent titer; at 39.5 degrees C, 300-fold fewer NIH 3T3 cells were transformed and pre-B cells were refractory to transformation. Temperature-dependent transformation was accompanied by decreased phosphorylation of Shc, a protein that interacts with the v-Abl SH2 and links the protein to Ras, and decreased induction of c-Myc expression. These data suggest that alteration of the FLVRES pocket affects the ability of v-Abl to interact with at least some of its substrates in a temperature-dependent fashion and identify a novel type of temperature-sensitive Abelson virus.

Risks of smoking in treated and untreated older Chinese patients with isolated systolic hypertension

OBJECTIVES

To examine the health risks associated with smoking and blood pressure in Chinese hypertensive patients and to compare the benefit of antihypertensive drug treatment with the risk attributable to smoking.

METHODS

We used multiple Cox regression to correlate outcome with blood pressure and smoking status in 2284 older (aged > or = 60 years) patients enrolled in the Systolic Hypertension in China (Syst-China) Trial (systolic/diastolic blood pressure > or = 160/< 95 mmHg).

RESULTS

Median follow-up was 3.0 years. After adjustment for sex, age, active antihypertensive treatment and various entry characteristics, the relative hazard rates associated with smoking more than 20 cigarettes per day were 2.04 (P = 0.04), 4.66 (P < 0.001) and 4.74 (P = 0.002) for all-cause, noncardiovascular and cancer mortality, respectively. With similar adjustments applied, the relative hazard rates for total (fatal and non-fatal) stroke associated with smoking 10-20 and more than 20 cigarettes per day were 1.78 (P = 0.04) and 2.23 (P = 0.03), respectively. Furthermore, both smoking and systolic blood pressure were associated with higher risk of stroke. Compared with the overall risk in the whole group, treating 1,000 patients for 5 years prevented 40 [95% confidence interval (CI), 5-75] strokes in smokers as well as never smokers. Prognosis in never smokers and past smokers was similar. Quitting smoking had the potential to prevent 51 (95% CI, -21 to 122) strokes in untreated hypertensive patients and to prevent 45 (95% CI, - 14 to 104) additional strokes in treated patients, over and above the effects of antihypertensive treatment. If, in addition to stroke, non-cardiovascular mortality was also accounted for, the estimated absolute benefit of quitting smoking increased to 69 (95% CI, -18 to 155) and 97 (95% CI, 23-171) events in the untreated and the treated group, respectively.

CONCLUSIONS

In elderly Chinese patients, smoking was a risk factor for all-cause, non-cardiovascular and cancer mortality, as well as fatal and non-fatal stroke. The potential benefits of antihypertensive treatment and quitting smoking were approximately similar. In our view, these findings are important in terms of public health policies and health economics.

Enhancement in activities of large conductance calcium-activated potassium channels in CA1 pyramidal neurons of rat hippocampus after transient forebrain ischemia

It has been reported previously that the neuronal excitability persistently suppresses and the amplitude of fast afterhyperpolarization (fAHP) increases in CA1 pyramidal cells of rat hippocampus following transient forebrain ischemia. To understand the conductance mechanisms underlying these post-ischemic electrophysiological alterations, we compared differences in activities of large conductance Ca(2+)-activated potassium (BK(Ca)) channels in CA1 pyramidal cells acutely dissociated from hippocampus before and after ischemia by using inside-out configuration of patch clamp techniques. (1) The unitary conductance of BK(Ca) channels in post-ischemic neurons (295 pS) was higher than that in control neurons (245 pS) in symmetrical 140/140 mM K(+) in inside-out patch; (2) the membrane depolarization for an e-fold increase in open probability (P(o)) showed no significant differences between two groups while the membrane potential required to produce one-half of the maximum P(o) was more negative after ischemia, indicating no obvious changes in channel voltage dependence; (3) the [Ca(2+)](i) required to half activate BK(Ca) channels was only 1 microM in post-ischemic whereas 2 microM in control neurons, indicating an increase in [Ca(2+)](i) sensitivity after ischemia; and (4) BK(Ca) channels had a longer open time and a shorter closed time after ischemia without significant differences in open frequency as compared to control. The present results indicate that enhanced activity of BK(Ca) channels in CA1 pyramidal neurons after ischemia may partially contribute to the post-ischemic decrease in neuronal excitability and increase in fAHP.

GNB1L, a gene deleted in the critical region for DiGeorge syndrome on 22q11, encodes a G-protein beta-subunit-like polypeptide

CATCH 22 syndromes, which include DiGeorge syndrome and Velocardiofacial syndrome, are the most common cause of congenital heart disease which involve microdeletion of 22q11. Using a strategy including EST searching, PCR amplification and 5'-RACE, we have cloned a 1487 bp cDNA fragment from human heart cDNA library. The cloned GNB1L cDNA encodes a G-protein beta-subunit-like polypeptide, and the GNB1L gene is located in the critical region for DiGeorge syndrome. A comparison of GNB1L cDNA sequence with corresponding genomic DNA sequence revealed that this gene consists of seven exons and spans an approximately 60 kb genomic region. Northern blot analysis revealed GNB1L is highly expressed in the heart.

Arg485Lys polymorphism of factor V increases the risk of coronary artery disease in a Chinese population

OBJECTIVE

To explore the relationship between genetic variation in coagulation factor V and the occurrence of coronary arterial disease (CAD).

METHODS

Unrelated 86 patients with CAD and 102 healthy controls were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) to detect variations in the entire twenty-five exons of the factor V gene.

RESULTS

Polymorphisms in exon 4 [642 G-->T (Ser156)], exon 10 [1628 G-->A (Arg485Lys)], exon 13 [4070 A-->G (His1299Arg)] and exon 16 [5380 G-->A (Val1736Met)] were documented. The study also identified a novel polymorphism in exon 2 (327 A-->G) which did not result in amino acid residue substitution. The Leiden mutation (Arg506Gln) was not detected in any of our 188 subjects. Among the 5 polymorphisms, the allele frequency of 1628 G-->A was significantly different between CAD patients and controls (0.69 vs 0.81, chi 2 = 6.908, P < 0.01). This is the first report of this finding in a Chinese population.

CONCLUSION

1628 G-->A polymorphism is associated with CAD and it may be a risk factor for CAD morbidity in the Chinese population.

Breast cancer risk in relation to adipose concentrations of organochlorine pesticides and polychlorinated biphenyls in Long Island, New York

To assess a possible etiological role of organochlorine compounds in breast cancer development on Long Island, a high-risk region of New York State, concentrations of organochlorine pesticides and polychlorinated biphenyls (PCBs) were measured in the adipose tissue of 232 women with breast cancer and 323 hospital controls admitted to surgery for benign breast disease or non-breast-related conditions. Seven pesticide residues and 14 PCB congeners were assayed via a supercritical fluid extraction method followed by gas chromatography with electron capture detection. After adjustment for age and body mass index, which were strongly correlated with organochlorine levels, adipose concentrations of 1,1-dichloro-2,2-di(4-chlorophenyl)ethylene, total pesticides, and total polychlorinated biphenyls (PCBs) did not differ significantly between cases and controls. The relative abundance of individual pesticide species and PCB congeners was similar in cases and controls. Odds ratios adjusted for age, BMI, hospital, and race gave no evidence of a dose-response for 1,1-dichloro-2,2-di(4-chlorophenyl)ethylene, total pesticides, or total PCBs, whether stratified by estrogen receptor status or not. Breast cancer risk among Long Island residents was not elevated compared with residents of the adjacent New York City borough of Queens. We did not confirm a previously reported association between breast cancer risk and levels of PCB congener 118 (2,3',4,4',5-pentachlorobiphenyl), nor did we observe an association with the most abundant congener 153 (2,2',4,4',5,5'-hexachlorobiphenyl), a strong inducer of phase I enzymes that was reported recently to have estrogenic properties. Only PCB congener 183 (2,2',3,4,4',5',6-heptachlorobiphenyl), which is also an inducer, was significantly associated with risk, with an adjusted odds ratio of 2.0 (95% confidence interval, 1.2-3.4) in women with adipose levels >5.67 ng/g; the biological importance of this observation is unclear without confirmation in additional studies. Although neither the present nor other studies have provided convincing evidence of an association between body burden of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane and PCBs with cancer of the breast, these compounds are rated as "possible" and "probable" human carcinogens, respectively, by the International Agency for Research on Cancer. Investigations of associations with cancer at other sites should be carried out.

Reversal of aberrant splicing of beta-thalassaemia allele (IVS-2-654 C-->T) by antisense RNA expression vector in cultured human erythroid cells

The antisense fragment targeting the aberrant splice sites of the beta-thalassaemia allele, IVS-2-654 C-->T (beta654), pretranscript was cloned into the mammalian expression vector, pcDNA3. The recombinant construct, pCMVA, was then used to repair the defective splicing of the beta654 mutant pretranscript in cultured beta654 erythroid cells by the lipofectin-mediated DNA transfection method. The total RNA was extracted at given time points after transfection and the effect of antisense RNA was studied by reverse transcription polymerase chain reaction (RT-PCR)-mediated mRNA quantitative assay, as well as globin chain microbiosynthesis. The antisense fragment transcribed from pCMVA effectively improved the beta654 splicing pattern in cultured erythroid cells. The level of correctly spliced transcript increased from 0.19 (day 0 after transfection) to 0.58 (day 8) in beta654/beta654 homozygous erythroid cells, and from 0.45 (day 0) to 0.83 (day 8) in beta654/betaA heterozygous erythroid cells, as determined by the ratio of normally spliced beta-globin transcript over total beta-globin transcript. Correspondingly, the ratios of globin chain biosynthesis (beta/alpha) increased from 0.16 (day 0) to 0.52 (day 8) in beta654/beta654 erythroid cells, and from 0.39 (day 0) to 0.84 (day 8) in beta654/betaA erythroid cells. Antisense RNA had no significant effect on the splicing pattern in betaA/betaA erythroid cells. The splicing pattern in transfected cells with pCMVA showed significant changes compared with that in untransfected cells and that in transfected cells with the control antisense fragment (human SRY gene sequence). In addition, we did not observe side-effects on cytological features after the introduction of pCMVA. All these results indicated that the antisense RNA transcribed from the mammalian expression vector pCMVA could efficiently and specifically suppress the aberrant splicing pattern of beta654 mutant pretranscript and restore the correct splicing pathway in vivo, leading to the improvement of globin chain biosynthesis in thalassaemic cells.

Identification and functional expression of four isoforms of ATPase II, the putative aminophospholipid translocase. Effect of isoform variation on the ATPase activity and phospholipid specificity

ATPase II, a vanadate-sensitive and phosphatidylserine-dependent Mg(2+)-ATPase, is a member of a subfamily of P-type ATPase and is presumably responsible for aminophospholipid translocation activity in eukaryotic cells. The aminophospholipid translocation activity plays an important physiological role in the maintenance of membrane phospholipid asymmetry that is observed in the plasma membrane as well as the membranes of certain cellular organelles. While the preparations of ATPase II from different sources share common fundamental properties, such as substrate specificity, inhibitor spectrum, and phospholipid dependence, they are divergent in several characteristics. These include specific ATPase activity and phospholipid selectivity. We report here the identification of four isoforms of ATPase II in bovine brain. These isoforms are formed by a combination of two major variations in their primary sequences and show that the structural variation of these isoforms has functional significance in both ATPase activity and phosholipid selectivity. Furthermore, studies with the phosphoenzyme intermediate of ATPase II and its recombinant isoforms revealed that phosphatidylserine is essential for the dephosphorylation of the intermediate. Without phosphatidylserine, ATPase II would be accumulated as phosphoenzyme in the presence of ATP, resulting in the interruption of its catalytic cycle.

Redox modulation of large conductance calcium-activated potassium channels in CA1 pyramidal neurons from adult rat hippocampus

Redox regulation of BK(Ca) channels was studied in CA1 pyramidal neurons of adult rat hippocampus by using inside-out configuration of patch clamp. Intracellular application of oxidizing agent 5, 5'-dithio-bis(2-nitrobenzoic acid) (DTNB) markedly increased activity of BK(Ca) channels and this stimulating action persisted even after washout. In contrast, the reducing agent dithiothreitol (DTT) had no apparent effects on channel activity but could reverse the pre-exposure of DTNB-induced enhancement. The increase in channel activity produced by DTNB was due to shortened closed time as well as prolonged open time. The effects exerted by another redox couple glutathione disulphide and its reducing form were similar as DTNB and DTT. The present results indicate that BK(Ca) channels in CA1 pyramidal neurons can be modulated by intracellular redox potential, and that augmentation of BK(Ca) channels by oxidative stress might contribute to the postischemic electrophysiological alterations of CA1 pyramidal neurons.

Identification of a novel isopeptidase with dual specificity for ubiquitin- and NEDD8-conjugated proteins

Covalent conjugation of proteins by ubiquitin or ubiquitin-like molecules is an important form of post-translational modification and plays a critical role in many cellular processes. Similar to the concept of phosphorylation and dephosphorylation, these conjugates are regulated by a large number of deconjugating enzymes. Here, we report the cloning of a 2,141-base pair DNA fragment from human placenta cDNA library by a strategy that involves expressed sequence tag data base searching, polymerase chain reaction, and rapid amplification of cDNA ends. Nucleotide sequence analysis revealed that the cloned cDNA contains an open reading frame of 1,143 base pairs encoding a novel protease, USP21, which is composed of 381 residues with a calculated molecular mass of 43 kDa. The human USP21 gene is located on chromosome 1q21 and encodes a member of the ubiquitin-specific protease family with highly conserved Cys and His domains. The activity and specificity of USP21 were determined by using a COS cell expression system in vivo. We showed that USP21 is capable of removing ubiquitin from ubiquitinated proteins as expected. Furthermore, USP21 is capable of removing NEDD8 from NEDD8 conjugates but has no effect on Sentrin-1 conjugates. As expected from its biochemical activity, overexpression of USP21 has a profound growth inhibitory effect on U2OS cells. Thus, USP21 is the first ubiquitin-specific protease shown to have dual specificity for both ubiquitin and NEDD8 and may play an important role in the regulation of cell growth.

Ubiquitin-like proteins: new wines in new bottles

Ubiquitin is a small polypeptide that covalently modifies other cellular proteins and targets them to the proteasome for degradation. In recent years, ubiquitin-dependent proteolysis has been demonstrated to play a critical role in the regulation of many cellular processes, such as cell cycle progression, cell signaling, and immune recognition. The recent discovery of three new ubiquitin-like proteins, NEDD8, Sentrin/SUMO, and Apg12, has further broadened the horizon of this type of post-translational protein modification. This review will focus on the biology and biochemistry of the Sentrin/SUMO and NEDD8 modification pathways, which are clearly distinct from the ubiquitination pathway and have unique biological functions.

Regulation of microphthalmia-associated transcription factor MITF protein levels by association with the ubiquitin-conjugating enzyme hUBC9

The basic helix-loop-helix/leucine zipper (bHLH/ZIP) microphthalmia-associated transcription factor (MITF) regulates transcription of genes encoding enzymes essential for melanin biosynthesis in melanocytes and retinal pigmented epithelial cells. To determine how MITF activity is regulated, we used the yeast two-hybrid system to identify proteins expressed by human melanoma cells that interact with MITF. The majority of clones that showed positive interaction with a 158-amino-acid region of MITF containing the bHLH/ZIP domain (aa 168-325) encoded the ubiquitin conjugating enzyme hUBC9. The association of MITF with hUBC9 was further confirmed by an in vitro GST pull-down assay. Although hUBC9 is known to interact preferentially with SENTRIN/SUMO1, in vitro transcription/translation analysis demonstrated greater association of MITF with ubiquitin than with SENTRIN. Importantly, cotransfection of MITF and hUBC9 expression vectors resulted in MITF protein degradation. MITF protein was stabilized by the proteasome inhibitor MG132, indicating the role of the ubiquitin-proteasome system in MITF degradation. Serine 73, which is located in a region rich in proline, glutamic acid, serine, and threonine (PEST), regulates MITF protein stability, since a serine to alanine mutation prevented hUBC9-mediated MITF (S73A) degradation. Furthermore, we identified lysine 201 as a potential ubiquitination site. A lysine to arginine mutation abolished MITF (K201R) degradation by hUBC9 in vivo. Our experiments indicate that by targeting MITF for proteasome degradation, hUBC9 is a critical regulator of melanocyte differentiation.

Soluble cell adhesion molecules in patients with acute coronary syndrome

OBJECTIVE

To observe the changes in serum soluble intercellular adhesion molecule type-1 (ICAM-1), vascular cell adhesion molecule type-1 (VCAM-1), E-selectin and von Willebrand factor (vWf) in patients with acute coronary syndrome.

METHODS

Serial venous blood samples were taken from 21 patients with acute myocardial infarction (AMI) before and 4, 8, 12, 24, 48 and 72 h after thrombolytic treatment or direct PTCA. One blood sample was drawn from 16 patients with unstable angina and 16 control subjects. Serum concentrations of ICAM-1, VCAM-1, E-selectin and vWf were determined using a double antibody sandwich enzyme-linked immunosorbent assay.

RESULTS

Serum levels of ICAM-1, VCAM-1, E-selectin and vWf were higher in patients with acute coronary syndrome than in controls. Patients with AMI and successful reperfusion therapy had a significant reduction in the serum concentration of ICAM-1 and E-selectin at 24 and 48 h, VCAM-1 at 24 and 72 h and vWf at 12, 24, 48 and 72 h, but had peak in serum levels of ICAM-1 and E-selectin at 4 h. The number of diseased coronary arteries was not related to the levels of ICAM-1, VCAM-1 and E-selecin.

CONCLUSION

The serum concentration of soluble cell adhesion molecules was elevated significantly in patients with acute coronary syndrome. Successful reperfusion therapy was associated with a reduction in the serum concentrations of soluble cell adhesion molecules in patients with AMI.

Identification of a superimmunoglobulin gene family member overexpressed in benign prostatic hyperplasia

BACKGROUND

Benign prostate hyperplasia (BPH), a nonmalignant disease with an increasing rate of occurrence associated with advancing age, requires auxiliary markers to help identify its presence and distinguish its progression from prostate cancer.

METHODS

Hybridoma technology was used to generate an antibody against a BPH antigen, which was subsequently characterized by Western blot analysis, sequence homology, and RT-PCR.

RESULTS

A BPH-associated protein, designated P25/26, was identified that showed a strong sequence similarity with superimmunoglobulin family members, overexpressed in BPH, with lower expression observed in both normal and prostate cancer tissues.

CONCLUSIONS

Further studies appear warranted to assess the role that this and other superimmunoglobulin family members may have in the pathogenesis of BPH, and to determine if these glycoproteins have any clinical utility in the differential diagnosis or therapeutic monitoring of BPH.

Differential regulation of sentrinized proteins by a novel sentrin-specific protease

Sentrin-1, also called SUMO-1, is a protein of 101 residues that is distantly related to ubiquitin and another ubiquitin-like protein, NEDD8. Here we report the cloning of a novel sentrin-specific protease, SENP1, which has no homology to the known de-ubiquitinating enzymes or ubiquitin C-terminal hydrolases. However, SENP1 is distantly related to the yeast Smt3-specific protease, Ulp1. A COS cell expression system was used to demonstrate the activity of SENP1 in vivo. When HA-tagged sentrin-1 was co-expressed with SENP1, the higher molecular weight sentrin-1 conjugates were completely removed. Surprisingly, the major sentrinized band at 90 kDa remained intact. The disappearance of the high molecular weight sentrin-1 conjugates also coincided with an increase in free sentrin-1 monomers. SENP1 is also active against proteins modified by sentrin-2, but not those modified by ubiquitin or NEDD8. In addition, sentrinized PML, a tumor suppressor protein that resides in the nucleus, was selectively affected by SENP1, whereas sentrinized RanGAP1, which is associated with the cytoplasmic fibrils of the nuclear pore complex, remained intact. The inability of SENP1 to process sentrinized RanGAP1 in vivo is most likely due to its nuclear localization because SENP1 is active against sentrinized RanGAP1 in vitro. The identification of a nuclear-localized, sentrin-specific protease will provide a unique tool to study the role of sentrinization in the biological function of PML and in the pathogenesis of acute promyelocytic leukemia.

Dopamine induces cell death, lipid peroxidation and DNA base damage in a catecholaminergic cell line derived from the central nervous system

Dopamine can be autoxidized to superoxides and quinones. Superoxides can form hydroxyl radicals that are highly reactive with lipids, proteins and DNA leading to neuronal damage and cell death. We used a clonal catecholaminergic cell line (CATH.a) derived from the central nervous system to evaluate the effects of dopamine on cell death, lipid peroxidation and DNA base damage. Dopamine produces cell death in CATH.a cells and this is associated with an increase in annexin binding, which is an early indicator of apoptosis. Incubation of CATH.a cells with deferoximine, an iron chealator, partially antagonizes dopamine-induced cell death. In CATH.a cells, dopamine produces an increase in both lipid peroxidation, as measured by cis-parinaric acid fluorescence, and DNA oxidative base damage, as measured by 8-hydroxy-2'-deoxyguanosine formation. Cell death was inhibited 84-92% by the hydrophilic antioxidants, dithiothreitol, L-cysteine, and N-acetylcysteine. The lipophilic vitamins, retinol and vitamin E and the vitamin E analog, Trolox, inhibited dopamine-induced cell death by 18-33%. The lipophilic antioxidants probucol, propyl glycol and butylated hydroxyanisone had no inhibitory effect on dopamine-induced cell death. These data suggest that damage to DNA and lipids may be partially responsible for dopamine-induced cell death in CATH.a cells.

Chinese trial on isolated systolic hypertension in the elderly. Systolic Hypertension in China (Syst-China) Collaborative Group

BACKGROUND

In 1988, the Systolic Hypertension in China (Syst-China) Collaborative Group initiated the placebo-controlled Syst-China trial to investigate whether antihypertensive drug treatment could reduce the incidence of fatal and nonfatal stroke in older Chinese patients with isolated systolic hypertension.

OBJECTIVES

To explore (1) whether the benefits of active treatment were evenly distributed across 4 strata, prospectively defined according to sex and previous cardiovascular complications, and (2) whether the morbidity and mortality results were influenced by age, level of systolic or diastolic blood pressure (BP), smoking or drinking habits, or diabetes mellitus at enrollment.

METHODS

Eligible patients had to be 60 years or older with a sitting systolic BP of 160 to 219 mm Hg and diastolic BP less than 95 mm Hg. After stratification for center, sex, and previous cardiovascular complications, 1253 patients were assigned to active treatment starting with nitrendipine (10-40 mg/d), with the possible addition of captopril (12.5-50.0 mg/d), and/or hydrochlorothiazide (12.5-50 mg/d). In the 1141 control patients, matching placebos were used similarly.

RESULTS

Male sex, previous cardiovascular complications, older age, higher systolic BP or lower diastolic BP, living in northern China, smoking, and diabetes mellitus significantly and independently increased the risk of 1 or more of the following end points: total or cardiovascular mortality, all fatal and nonfatal cardiovascular end points, all strokes, and all cardiac end points. In the placebo-control group diabetes raised the risk of all end points 2- to 3-fold (P< or =.05). However, active treatment reduced the excess risk associated with diabetes to a nonsignificant level (P values ranging from .12-.86) except for cardiovascular mortality (P = .04). Cox regression with adjustments applied for significant covariates suggested that active treatment may reduce total mortality more (P = .06) in women and stroke more (P = .07) in men and that it may provide better protection against cardiac end points in nonsmokers than smokers (P = .04). Otherwise, the benefits of active treatment were equally manifest, regardless of the enrollment characteristics of the patients, and regardless of whether active treatment consisted of only nitrendipine or of nitrendipine associated with other active drugs.

CONCLUSIONS

In elderly Chinese patients with isolated systolic hypertension, stepwise antihypertensive drug treatment, starting with the dihydropyridine calcium channel blocker nitrendipine, improved prognosis. The benefit was particularly evident in diabetic patients; for cardiac end points it tended to be larger in nonsmokers. Otherwise, the benefit of active treatment was not significantly influenced by the characteristics of the patients at enrollment in the trial.

Proteinchip(R) surface enhanced laser desorption/ionization (SELDI) mass spectrometry: a novel protein biochip technology for detection of prostate cancer biomarkers in complex protein mixtures

Improving early detection, diagnosis, treatment monitoring and prognosis of cancer will require rapid and high throughput detection, identification, and measurement of multiple biomarkers. In this study, we demonstrate the versatility of the innovative SELDI ProteinChip(R) MS technology for the rapid, reproducible and simultaneous identification of four well-characterized prostate cancer-associated (PCA) biomarkers, prostate specific antigen (free and complexed forms), prostate specific peptide, prostate acid phophatase and prostate specific membrane antigen in cell lysates, serum and seminal plasma. Proteins corresponding to the mass of these biomarkers could readily be captured and detected using either chemically defined or antibody coated ProteinChip(R) arrays. Several (yet to be identified) proteins were found upregulated in cell lysates of pure populations of PCA cells procured by laser capture microdissection (LCM) when compared with mass spectra of normal cell lysates. Coupling LCM with SELDI provides tremendous opportunities to discover and identify the signature proteins associated with each stage of tumor development. Collectively, these observations demonstrate the potential of SELDI for the discovery and simultaneous detection of and clinical assay development for PCA biomarkers in complex biological mixtures.

Comparison of some antineoplastic drugs on inhibiting thrombin catalizing fibrinogen clotting in vitro

OBJECTIVE

To classify the effect of thrombin, the key enzyme which enables fibrinogen to form fibrin (fibrinogen clotting) on the formation of metastasis by comparing the inhibition of some antineoplastic drugs on fibrinogen clotting in vitro.

METHODS

Time intervals of different drugs to reach a maximum OD (340 nm) data in fibrinogen solution added with thrombin were used in this work.

RESULTS

It was found that L-4-oxalysine (8-40 micrograms/ml) and arabinosyl cytosine (10-50 micrograms/ml) could inhibit the effect of thrombin by extending the fibrinogen clotting time to 100%-150% (P < 0.001) and 61%-100% (P < 0.001) while the other antimetastatic drugs razoxane, probimane, adriamycin, harringtonine homoharringtonine and alpha-anordrin at the treatment concentrations showed no such activity. The positive rate of drugs to thrombin activity was approximately 25%.

CONCLUSION

It suggests that L-4-oxalysine and arabinosyl cytosine may even exhibit antimetastatic effect through thrombin-fibrinogen pathway, and thrombin might operate in tumor metastasis for only limited step but crucial to fibrin formation in tumor nodules.

Identification of the activating and conjugating enzymes of the NEDD8 conjugation pathway

NEDD8 is a ubiquitin-like molecule that can be covalently conjugated to a limited number of cellular proteins, such as Cdc53/cullin. We have previously reported that the C terminus of NEDD8 is efficiently processed to expose Gly-76, which is required for conjugation to target proteins. A combination of data base searches and polymerase chain reaction cloning was used to identify a cDNA encoding human UBA3, which is 38% identical to the yeast homologue, 22% identical to human UBA2, and 19% identical to the C-terminal region of human UBE1. The human UBA3 gene is located on chromosome 3p13 and gave rise to a 2.2-kilobase pair transcript that was detected in all tissues. Human UBA3 could be precipitated with glutathione S-transferase (GST)-NEDD8, but not with GST-ubiquitin or GST-sentrin-1. Moreover, human UBA3 could form a beta-mercaptoethanol-sensitive conjugate with NEDD8 in the presence of APP-BP1, a protein with sequence homology to the N-terminal half of ubiquitin-activating enzyme. We have also cloned human UBC12 and demonstrated that it could form a thiol ester linkage with NEDD8 in the presence of the activating enzyme complex. Identification of the activating and conjugating enzymes of the NEDD8 conjugation pathway should allow for a more detailed study of the role of NEDD8 modification in health and disease.

Molecular cloning and characterization of human AOS1 and UBA2, components of the sentrin-activating enzyme complex

Sentrin-1/SUMO-1 is a novel ubiquitin-like protein, which can covalently modify a limited number of cellular proteins. Here we report the identification of the sentrin-activating enzyme complex, which consists of two proteins AOS1 and UBA2. Human AOS1 is homologous to the N-terminal half of E1, whereas human UBA2 is homologous to the C-terminal half of E1. The human UBA2 gene is located on chromosome 19q12. Human UBA2 could form a beta-mercaptoethanol-sensitive conjugate with members of the sentrin family, but not with ubiquitin of NEDD8, in the presence of AOS1. Identification of human UBA2 and AOS1 should allow a more detailed analysis of the enzymology of the activation of ubiquitin-like proteins.

Brain-derived and glial cell line-derived neurotrophic factors protect a catecholaminergic cell line from dopamine-induced cell death

Brain-derived neurotrophic factor (BDNF) promotes the survival of dopaminergic neurons in primary cultures and protects these neurons from the neurotoxic effects of 6-hydroxydopamine. The protective mechanism of BDNF on neurotoxicity was evaluated using CATH.a cells, a clonal catecholaminergic cell line derived from the central nervous system. Dopamine produced a dose-dependent cell death in CATH.a cells. Treatment of CATH.a cells with BDNF or glia cell line-derived neurotrophic factor (GDNF) reduced dopamine-induced cell death by approximately 60-70%. Nerve growth factor, basic fibroblast growth factor, neurotrophin-4/5 and insulin had no protective effect on dopamine-induced cell death. Dopamine decreased the activity of superoxide dismutase and the levels of glutathione in the CATH.a cells and these decreases were reversed by BDNF. In addition, BDNF treatment alone increased superoxide dismutase activity by 108%. These results suggest that BDNF may safeguard CATH.a cells from dopamine-induced cell death by maintaining or enhancing components of the cell, which protect from oxidative stress.

Reversal of aberrant splicing of beta-thalassemia allele by antisense RNA in vitro and in vivo

OBJECTIVE

To investigate the reversal of aberrant splicing of beta-thalassemia allele (IVS-2-654 C-->T, beta 654) by antisense RNA in vitro and in vivo.

METHODS

The vector expressing antisense RNA which targeted against the aberrant splice sites of beta 654 pre-mRNA was constructed in pcDNA3, and then used to repair the defective splicing of the mutant pre-mRNA in an in vitro transcription and splicing system, as well as in HeLa beta 654 cells and cultured beta 654 erythroid cells by lipid-mediated DNA-transfection method. The effect of the antisense RNA was identified by RT-PCR mediated mRNA quantitative assay as well as globin chain microbiosynthesis.

RESULTS

The antisense RNA decreased the aberrant splicing product and restored the correct splicing pattern in vitro and in vivo efficiently. In the in vitro transcription and splicing system, the level of normally spliced mRNA [beta/(beta + beta*)] increased from 0.25 to 0.60. In cultured HeLa beta 654 cells, the level of beta/(beta + beta*) increased from 0.07 to 0.43 on the 15th day after transfection. In cultured beta 654 erythroid cells, the level of mRNA [beta/(beta + beta*)] increased from 0.19 to 0.58 on the 8th day after transfection in beta 654/beta 654 erythroid cells, from 0.02 to 0.38 in beta 654/beta 41-42 erythroid cells, and from 0.45 to 0.83 in beta 654/beta A erythroid cells, respectively. Correspondingly, the ratios of globin chain (beta/alpha) biosynthesis increased from 0.16 to 0.52 on the 8th day after transfection in beta 654/beta 654 erythroid cells, 0.05 to 0.36 in beta 654/beta 41-42 erythroid cells, and 0.42 to 0.81 in beta 654/beta A erythroid cells, respectively. The splicing pattern did not show significant changes as compared to the untreated, as well as to the control antisense fragment.

CONCLUSIONS

Antisense RNA transcribed from the expression vector described here could efficiently suppress the aberrant splicing pattern of beta 654 mutant mRNA and restore the correct splicing pathway in vitro and in vivo, leading to the improvement of globin chain biosynthesis in thalassemic cells. Our antisense strategy provides an alternative approach to the gene therapy of beta-thalassemia.

Comparison of active treatment and placebo in older Chinese patients with isolated systolic hypertension. Systolic Hypertension in China (Syst-China) Collaborative Group

BACKGROUND

Isolated systolic hypertension occurs in around 8% of Chinese people aged 60 years or older. In 1988, the Systolic Hypertension in China (Syst-China) Collaborative Group started to investigate whether active treatment could reduce the incidence of stroke and other cardiovascular complications in older patients with isolated systolic hypertension.

METHODS

All patients were initially started on masked placebo. After stratification for centre, sex and previous cardiovascular complications, alternate patients (n=1253) were assigned nitrendipine at 10-40 mg daily, with the addition of captopril at 12.5-50.0 mg daily or hydrochlorothiazide at 12.5-50.0 mg daily, or both, if a sufficient blood pressure fall was not obtained. In the remaining 1141 control patients, matching placebos were administered similarly.

RESULTS

At entry, sitting blood pressure averaged 170.5 mmHg systolic and 86.0 mmHg diastolic, age averaged 66.5 years and total serum cholesterol was 5.1 mmol/l. After 2 years of follow-up, sitting systolic and diastolic blood pressures had fallen by 10.9 mmHg and 1.9 mmHg in the placebo group and by 20.0 mmHg and 5.0 mmHg in the active treatment group. The intergroup differences were 9.1 mmHg systolic (95% confidence interval 7.6-10.7 mmHg ) and 3.2 mmHg diastolic (95% confidence interval 2.4-4.0). Active treatment reduced total strokes by 38% (from 20.8 to 13.0 endpoints per 1000 patient-years, P=0.01), all-cause mortality by 39% (from 28.4 to 17.4 endpoints per 1000 patient-years, P=0.003), cardiovascular mortality by 39% (from 15.2 to 9.4 endpoints per 1000 patient-years, P=0.03), stroke mortality by 58% (from 6.9 to 2.9 endpoints per 1000 patient-years, P=0.02), and ail fatal and nonfatal cardiovascular endpoints by 37% (from 33.3 to 21.4 endpoints per 1000 patient-years, P=0.004).

CONCLUSIONS

Antihypertensive treatment prevents stroke and other cardiovascular complications in older Chinese patients with isolated systolic hypertension. Treatment of 1000 Chinese patients for 5 years could prevent 55 deaths, 39 strokes or 59 major cardiovascular endpoints.

Molecular cloning of cDNA encoding the alpha unit of CNGC gene from human fetal heart

Cyclic nucleotide-gated ion channels (CNGCs) play crucial roles in visual and olfactory signal transduction. As a first step to explore the presence of a CNGC gene in human heart, we cloned a human heart CNGC gene. The sequence consists of 111 bp 5' non-coding region and a 2064 bp open reading frame which is followed by a 459 bp 3' non-coding region. The predicted protein consists of 688 amino acids with a short highly charged segment rich in lysine and glutamate. Sequence comparison indicates that the human heart cDNA is almost identical to the retinal rod photo receptor CNGC cDNA. However, the human cardiac cDNA is lacking a 205 bp Alu fragment in the 5'-uncoding region, has a glutamic acid residue at amino acid position 129, and has a replacement of glutamic acid with a lysine residue at amino acid position 99. Data obtained with northern blot analysis confirm the presence of RNA for the CNGC alpha chain. This channel might play a role in cyclic nucleotide-mediated cellular processes, such as the inotropic effect in the heart.

Parallel comparative trial of amlodipine and nitrendipine monotherapy in patients with essential hypertension

OBJECTIVES

To compare the blood pressure effects of two dihydropyridine calcium channel blockers, amlodipine and nitrendipine, in 488 patients with essential hypertension.

METHODS

The study used a randomized, single-blind design of 4 weeks' duration conducted at four medical centres in China. Patients were randomized to receive either amlodipine monotherapy (5-10 mg once daily; n = 334) or nitrendipine (10 mg twice or three times daily; n = 1 54). Blood pressure was evaluated by standard blood pressure measurements before and after treatment, and by 24 h ambulatory blood pressure monitoring in a subgroup of patients (n = 18).

RESULTS

Both systolic and diastolic blood pressures were reduced from baseline after 4 weeks of amlodipine and nitrendipine monotherapy. Diastolic blood pressure was reduced by 14.4% in the amlodipine group, which was significantly better than the 13.0% reduction in the nitrendipine group (P< 0.05). In addition, blood pressure response rates were significantly better with amlodipine monotherapy than with nitrendipine monotherapy. In the subgroup of patients undergoing 24 h ambulatory blood pressure monitoring, both systolic and diastolic blood pressure were reduced from baseline in the amlodipine and nitrendipine groups. Adverse effects were generally mild, with dizziness, flushing, palpitation, headache, drowsiness and ankle oedema being the most common. Rushing and headache were more frequent in the nitrendipine group than in the amlodipine group (P< 0.05 for flushing and P<0.01 for headache).

CONCLUSIONS

Amlodipine monotherapy reduced blood pressure more effectively than nitrendipine monotherapy in patients with essential hypertension and was associated with fewer adverse events.

Ethnic differences in red blood cell sodium/lithium countertransport and metabolic correlates of hypertension: an international collaborative study

Arterial hypertension is frequently associated with metabolic abnormalities. An abnormal activity of the erythrocyte sodium/lithium countertransport (Na/Li CT), an ion transport system under strong genetic control, is also found in people with hypertension and concomitant metabolic abnormalities. However, little information exists with regard to these clinical associations in different racial groups. The aim of this international collaborative study was to investigate Na/Li CT and the metabolic correlates of hypertension in two comparable samples of normotensive and hypertensive populations in the cities of Naples, Italy, and Shanghai, China, using identical, carefully standardized techniques. Blood pressure, anthropometric and metabolic variables, Na/Li CT, and 24-h urinary Na and K excretion were measured in untreated essential hypertensive (HPT) and normotensive (NT) individuals selected by age (35-60 years), body mass index (BMI; < 30 kg/m2), and blood pressure (BP; HPT, DBP > or = 95 mm Hg; NT, DBP < 90 mm Hg). The analysis of variance with adjustment for age was used to compare the groups. In the Neapolitan population, hypertensive individuals had higher serum triglyceride (P < .05) and uric acid levels (P < .001) than the normotensive group and also had a reduced glucose tolerance (P < .01) and an enhanced insulin response to the oral glucose tolerance test (OGTT) (P < .05). No such differences were seen between normotensive and hypertensive Chinese participants. The Neapolitan population (both NT and HPT) had a higher BMI (P < .01) than their Chinese peers. In the comparison of hypertensive patients in Shanghai and in Naples, the Neapolitans were heavier (P < .001), had a lower HDL/total cholesterol ratio (P < .01), an elevated fasting blood glucose (P < .05), and also a higher glucose (P < .001) and insulin response (P < .001) to OGTT. By contrast, they showed a significantly lower urinary Na/K ratio (P < .001). Na/Li CT was significantly increased in HPT both in Naples (286 +/- 24 v 224 +/- 13 micromol/L RBC x h; P < .05, M +/- SE) and in Shanghai (388 +/- 45 v 265 +/- 30 micromol/L RBC x h; P < .05). Furthermore, Na/Li CT was significantly and inversely associated with HDL cholesterol both in the Neapolitan (P < .01) and in the Chinese (P < .05) population, whereas it was directly correlated with serum triglyceride (P < .001) and serum uric acid (P = .001) only in the Neapolitan population. These results indicate that essential hypertension is associated with a higher prevalence of obesity, impaired glucose tolerance, and hyperinsulinemia in Naples than in Shanghai; and Na/Li CT is linked to both high blood pressure and metabolic abnormalities in the Italian sample, whereas it is an isolated marker of hypertension in the Chinese sample.

Relative abundance of organochlorine pesticides and polychlorinated biphenyls in adipose tissue and serum of women in Long Island, New York

Some organochlorine pesticides (OCPs) and PCBs are under investigation as possible risk factors for breast cancer because of their estrogenic properties and widespread presence in the environment. It is important to know whether adipose tissue used by some investigators and serum assays used by others can provide comparable information on body burden. Concentrations of seven OCPs or their breakdown products as well as 14 PCB congeners were measured in the adipose tissue and serum of 293 women enrolled as controls in a case-control study of environmental factors for breast cancer in Long Island, New York, a high-risk region. Adipose OCP/PCB levels were measured using a supercritical fluid extraction method developed by the authors. 1,1-Dichloro-2,2-di(4-chlorophenyl)ethylene (p,p'-DDE) was detected in all adipose and serum samples; two chlordane derivatives, beta-hexachlorocyclohexane (a lindane isomer) and hexachlorobenzene, were detected in at least 92% of adipose samples. The di-ortho hexachlorinated PCB congeners 2,4,5,2',4',5'-hexachlorobiphenyl and 2,3,4,2',4',5'-hexachlorobiphenyl were detected in all adipose and over 98% of serum samples. 1,1-Dichloro-2,2-di(4-chlorophenyl)ethylene comprised 77% of total pesticide residues in adipose and 71% in serum. 2,4,5,2',4',5'-Hexachlorobiphenyl comprised 24% of adipose and 21% of serum PCBs. The relative concentration patterns of the 14 PCB congeners were similar to those reported in other human studies and were also typical of patterns reported in environmental samples from various biota, including mammals and birds, but differed substantially from patterns reported in occupationally exposed workers. All adipose-serum correlations for pesticides and most PCBs were statistically significant. Either serum or adipose OCP/PCB levels of a variety of environmental organochlorine compounds may serve as useful biomarkers of body burden.

[The use of pediculated super-long randomized flap in repairing soft tissue defects of the head and neck]

A double-pediculated randomized flap of the shoulder and thorax was designed. The flap was transferred to cover the wound on the recipient area. The wound on the donor site was closed directly or covered by split skin graft. From January 1990 to January 1997, this method was used in 10 patients. After operation, a six month to three year following up indicated that the flaps were completely survived and the soft tissue defects of the head and neck were repaired. As a consequence, the pediculated super-long randomized flap was effective in repairing soft tissue defect.

Cardiac protection by long-term treatment with captopril in patients with acute myocardial infarction

OBJECTIVES

To assess the effects of long-term angiotensin-converting enzyme (ACE) inhibitor treatment with captopril on cardiac function in acute myocardial infarction (AMI).

METHODS

One hundred and one patients with AMI who were admitted to hospital within 72 hours of the onset of symptoms with no cardiogenic shock were randomly allocated to captopril (n = 52; group I) and conventional treatment (n = 49; group II). Left ventricular (LV) systolic performance and diastolic transmitral flow velocity profiles were assessed by Doppler echocardiography at admission (1.2 +/- 1.1 days), before discharge (27 +/- 10 days) and during follow-up (363 +/- 31 days).

RESULTS

At one year follow-up, in group I LV end-diastolic volume decreased, and ejection fraction increased due to a disproportionate decrease in end-systolic volume. The incidence of cardiac dilatation was reduced. LV early diastolic filling velocity (E) increased and late atrial filling velocity (A) decreased, resulting in an elevation of E/A ratio. However, the mean values of LV systolic and diastolic functional parameters were unchanged in group II.

CONCLUSIONS

Long-term treatment with captopril exerts a beneficial effect on cardiac protection for patients with AMI.