Structure and localization of the human gene encoding SR-BI/CLA-1. Evidence for transcriptional control by steroidogenic factor 1

The scavenger receptor, class B, type 1 receptor (SR-BI) mediates the selective transport of lipids from high density lipoprotein to cells. We describe the structure and subchromosomal location of human SR-BI and provide evidence that it is regulated by the transcription factor, steroidogenic factor 1 (SF-1). SR-BI resides on chromosome 12q24.2-qter, spans approximately 75 kilobase pairs, and contains 13 exons. RNA blot analysis of human tissues reveals an expression pattern similar to that described previously for rodents with the highest levels of mRNA in the adrenal gland, ovary, and liver. Unlike rodents, human SR-BI was expressed at high levels in the placenta. The transcription start site for SR-BI was mapped, and DNA sequence analysis revealed a binding site for SF-1 in the proximal 5'-flanking sequence. SF-1, an orphan member of the nuclear hormone receptor gene family, plays a key role in the regulation of steroidogenesis and is expressed at high levels in steroidogenic tissues. SF-1 binds to the SR-BI promoter in a sequence-specific manner, and efficient transcription from this promoter in adrenocortical Y1 cells is dependent on an intact SF-1 site. These data extend our understanding of SF-1 function within steroidogenic tissues and suggest that SR-BI, which serves to supply selected tissues with lipoprotein-derived lipids, is part of the repertoire of SF-1-responsive genes involved in steroidogenesis.

[ICAM-1 mRNA expression in the bronchial tissue of asthmatic guinea pigs]

To determine the expression of ICAM-1 mRNA in the bronchial tissue of asthmatic guinea pigs. The guinea pigs were divided randomly in to asthma, asthma treated with dexamethasone (DEX), and control groups. ICAM-1 expression was analyzed by in situ hybridization and the cellular infiltrate was evaluated by HE staining. In situ hybridization demonstrated ICAM-1 mRNA was mainly expressed in the cytoplasm of epithelial cells and endothelial cells. Compared with the control and DEX groups, a significant increase of ICAM-1 mRNA expression was observed in the bronchial tissue (P < 0.02 and 0.05 respectively). In asthmatic guinea-pigs, the intensity of ICAM-1 mRNA expression in bronchial tissue was correlated with total leucocyte infiltrate (P < 0.05). ICAM-1 expression in bronchial tissue may be related with the leucocyte infiltration and glucocorticoid may inhibit the expression of cell adhesion molecules.

The effect of erythromycin on the CYP3A component of sertindole clearance in healthy volunteers

The effect of erythromycin on the pharmacokinetic disposition of oral sertindole, a new antipsychotic compound, was investigated. Ten subjects who completed the study received a single 4-mg dose of sertindole without or with concomitant erythromycin 250 mg taken orally 4 times daily. Coadministration of sertindole and erythromycin led to a 33% decrease (P < 0.05) in mean (+/- SD) time to reach maximum plasma concentration (tmax) value and a 15% elevation (P < 0.05) in the mean maximum plasma concentration (Cmax) value of sertindole. The mean area under the concentration-time curve (AUC) value of sertindole did not change significantly in the presence of erythromycin (alone: 159 +/- 111 ng.hr/mL, in combination: 179 +/- 144 ng.hr/mL, P > 0.05). The presence of erythromycin also significantly increased the dehydrosertindole Cmax and AUC means by 16% and 21%, respectively, possibly due to inhibition of the CYP3A metabolic isozyme responsible for the elimination of this metabolite. The rate of absorption of sertindole and the rate of appearance of dehydrosertindole in the systemic circulation after a 4-mg sertindole single dose were slightly enhanced by concomitant dosing of erythromycin. In conclusion, there is a small but noticeable effect of erythromycin on the pharmacokinetic disposition of sertindole. The effects are believed to have little clinical significance.

Mortality from coronary heart disease and cardiovascular disease among adult U.S. Hispanics: findings from the National Health Interview Survey (1986 to 1994)

OBJECTIVES

We sought to estimate the coronary heart disease (CHD) and cardiovascular disease (CVD) mortality experience of U.S. Hispanics.

BACKGROUND

Limited information is available concerning the mortality from CHD among U.S. Hispanics, the nation's second largest minority group.

METHODS

The study used data from the National Health Interview Survey (1986 to 1994), including representative national samples of 246,239 non-Hispanic whites, 38,042 blacks and 14,965 Hispanics who were > or = 45 years old at baseline. Mean follow-up of mortality was 5 years (range 1 to 10).

RESULTS

During the follow-up period, 27,702 whites (11%), 4,976 blacks (13%) and 1,061 Hispanics (7%) died. Among men, the age-adjusted total mortality per 100,000 person-years was 3,089 in whites and 2,466 in Hispanics, and among women, it was 1,897 and 1,581 in whites and Hispanics, respectively. The Hispanic/white mortality rate ratio for CHD was 0.77 (95% confidence interval [CI] 0.64 to 0.93) and 0.82 (95% CI 0.66 to 1.01) for men and women, respectively. The rate ratio was 0.79 (95% CI 0.68 to 0.91) and 0.80 (95% CI 0.69 to 0.94), respectively, for mortality from cardiovascular diseases. Given the lower all-cause mortality in Hispanics, the proportion of total deaths due to CHD and CVD was similar between the two populations for the same gender and were, respectively, 29.7% and 44.7% in white men, 28.1% and 44.3% in Hispanic men, 24.9% and 43.2% in white women and 24.1% and 41% in Hispanic women.

CONCLUSIONS

These data from a cohort of a large national sample are consistent with vital statistics that show that all-cause, CHD and CVD mortality is approximately 20% lower among adult Hispanics than among whites in the United States.

Population analysis of the pharmacokinetics and pharmacodynamics of seratrodast in patients with mild to moderate asthma

BACKGROUND

Seratrodast, a potent thromboxane receptor antagonist, is approved in Japan for the treatment of asthma and currently is being developed in the United States.

METHODS

This was a phase II, randomized, double-blind, parallel-group, placebo-controlled 15-center study of seratrodast in patients with mild to moderate asthma. A total of 183 patients were randomly assigned to receive daily doses of either placebo, or 80 mg seratrodast, or 120 mg seratrodast for 8 weeks. Pharmacokinetic and pharmacodynamic modeling was carried out by means of the population approach. A two-compartment model with zero-order input and first-order elimination best fitted the plasma concentration-time data.

RESULTS AND CONCLUSIONS

The pharmacokinetics of seratrodast were linear after single and multiple dosing for 8 weeks. The population estimates for oral clearance and apparent volume of distribution were 8.5 ml/hr/kg and 43.3 ml/kg, respectively. All pharmacokinetic parameters (the oral central compartment clearance, the volumes of distribution of the central and peripheral compartments, and the intercompartmental clearance) were estimated with a precision of 10% or less and were found to be associated with body weight. The residual variability was 30%. The values of oral clearance estimated in this study in male patients were similar to those previously estimated in healthy male subjects. Seratrodast at a dose of 120 mg daily produced an increase in forced expiratory volume in 1 second (FEV1) from baseline that was linearly correlated with its plasma concentrations. The average slope of the concentration-effect relationship was 0.222% and 0.470% per microgram/ml after single and multiple dosing, respectively. Interpatient variability in response was mainly affected by the initial severity of the disease. A lower percentage of predicted FEV1 (i.e., more severe obstruction) was associated with higher slopes, and greater increases in FEV1.

Evaluation of the effect of fluconazole on the pharmacokinetics of ritonavir

The effects of fluconazole on the pharmacokinetics of the HIV protease inhibitor ritonavir were investigated after multiple dosing in an open-label study. In this randomized, two-period crossover study, eight healthy subjects received ritonavir alone (200 mg every 6 hr for 4 days) and ritonavir with fluconazole (400 mg on day 1, 200 mg every day on days 2-5) with a 2-week washout period. Ritonavir plasma concentrations were measured during the final four ritonavir dosing intervals (24 hr) and a 12-hr washout period. There were statistically significant increases in ritonavir C(max) and AUC0-24 (p < 0.02), with concurrent administration of fluconazole compared with administration of ritonavir alone. The difference between regimens in C(min) was marginally statistically significant (p = 0.089), and t(max) and beta were not statistically significantly different. Although some ritonavir parameters were affected by fluconazole, mean increases in C(max) and AUC were < or = 15% for the 24-hr period, and only 7-19% for individual dose intervals. Thus, the pharmacokinetics of ritonavir may be influenced only to a small extent when administered with fluconazole. These changes are probably of limited clinical significance and do not necessitate dosage adjustment of ritonavir when fluconazole is added to the regimen.

Pharmacokinetics of sertindole in healthy young and elderly male and female subjects

OBJECTIVE

The pharmacokinetic disposition of oral sertindole, a new selective antipsychotic compound, in young and elderly male and female subjects was investigated.

STUDY DESIGN

A total of 46 subjects (12 young males, 11 elderly males, 11 young females, and 12 elderly females) received 4 mg/day sertindole (once a day; days 1 through 3) for 3 consecutive days, 8 mg/day sertindole for 3 consecutive days (days 4 through 6), and 12 mg/day sertindole for 10 consecutive days (days 7 through 16).

RESULTS

Age and gender did not appear to have any effect on the plasma binding of sertindole, despite a lower albumin concentration in elderly subjects. After multiple dosing of 12 mg sertindole, the mean peak plasma concentration (Cmax) values for young and elderly female subjects were 20% and 31% higher than those observed for male subjects of comparable age (p < 0.05). The mean values for area under the plasma concentration-time curve [AUC(0-24)] of female subjects were 29% higher than those observed in male subjects of similar age (p < 0.05). There were no statistically significant age-related differences in Cmax and AUC(0-24) (or apparent total plasma clearance), and there were no gender- or age-related differences for the elimination rate constant or values for apparent volume of distribution during the terminal elimination phase after the last 12 mg dose on day 16 (p > 0.05).

CONCLUSIONS

There are no differences between young and elderly subjects in the absorption and elimination of sertindole. The higher Cmax and AUC values in females may be a result of a higher extent of absorption or a dependence of sertindole clearance on lean body mass.

Optically heterodyned 25-GHz true-time-delay lines on thick LD-3 polymer-based planar waveguides

Synthesis of the LD-3 electro-optic polymer has resulted in a highly reliable nonlinear organic material. Such a success has been impeded from further progress because the LD-3 films produced thus far are too thin (<0.5 mum) to form a waveguide. Further details of material synthesis have to be studied to solve this problem. We report the formation of thick LD-3 films ranging from 1.2 to 2.4 mum by introducing cyclopentanone as the new solvent in polymer synthesis. The formation of multimode planar waveguides on silicon with a waveguide loss of approximately 1.3 dB/cm at 1.3 mum is demonstrated. Preliminary studies aimed at forming true-time-delay lines are conducted by use of various waveguide lengths in conjunction with an optical heterodyne technique. Waveguide settings equivalent to different true-time-delay lines with a delay time of up to 0.27 ns and a base bandwidth of 25 GHz are demonstrated with a signal-to-noise ratio of 15 dB.

[Effects of cytokines on somatostatin in nude mice bearing human renal cell carcinoma]

We studied the relationship between the production of SS and treatment with cytokines and a new method for the treatment of renal cell carcinoma. 4.4 x 10(6)RCC94616 cells were injected subcutaneously into the back of nude mice. Five groups with TNF, IL-2, rIFN, TNF + IL-2, TNF + rIFN and controls were randomly divided according to the mean diameter of experimental tumor. After the last injection of cytokines, 0.5-0.8 ml blood, 1g tumor tissue, para-tissue and normal tissue were havested respectively. Contents of SS were tested by radioimmunoassay. In the treatment groups with cytokines, the concentration of SS was changed, siginificantly increased in the TNF + IL-2 group (P < 0.01). The effect on distribution of SS by cytokines may also be mediated by the regulation of human immunity and antitumor activity. It may be suggested that the method of TNF + IL-2 + SS is best to treat renal cell carcinoma.

Exercise-induced oxidative stress before and after vitamin C supplementation

Vitamin C (ascorbic acid) was supplemented (1 g/day) for 1 day and 2 weeks in the same subjects. Plasma thiobarbituric acid reacting substances (TBARS) and oxygen radical absorbance capacity (ORAC) before and after 30 min submaximal exercise were measured. Different vitamin C supplementations did not affect resting TBARS or ORAC. Following 30 min exercise, values for TBARS were 12.6 and 33% above rest with 1 day and 2 weeks of vitamin C supplementation, respectively, compared to 46% higher with placebo. ORAC did not significantly change (11%) after exercise with a placebo, nor when subjects were given vitamin C supplements for 1 day or 2 days (4.9% and 5.73%, respectively). TBARS:ORAC, a ratio representing oxidative stress, increased 32% (p < .05) with placebo compared to 5.8 and 25.8% with vitamin C supplements for 1 day and 2 weeks, respectively. It was concluded that exercise-induced oxidative stress was highest when subjects did not supplement with vitamin C compared to either 1 day or 2 weeks of vitamin C supplementation.

Structure of the human gene encoding sterol regulatory element binding protein 2 (SREBF2)

Sterol-regulatory element binding protein (SREBP) 1 and SREBP2 are ubiquitously expressed transcription factors that play key roles in the regulation of cholesterol and fatty acid metabolism. SREBP1 and SREBP2 share approximately 47% sequence identity and map to chromosomes 17 and 22, respectively. The gene encoding SREBP1 (SREBF1) has been cloned and characterized. In this paper we describe the gene structure and 5'-flanking sequence of SREBF2. SREBF2 spans 72 kb and is composed of 19 exons and 18 introns. The locations of the exon/intron boundaries of SREBF2 are remarkably similar to those of SREBF1, but SREBF2 is approximately 2.8 times larger in size. The 5'-flanking regions of SREBF2 and of two alternatively spliced forms of SREBF1, SREBF1a and SREBF1c, were sequenced, and the SREBF2 transcription start site was determined. A perfect 10-bp sterol regulatory element (SRE)-1 sequence was present in the promoter region of SREBF2. No SRE-1 was identified in the 5'-flanking sequences of either SREBF1a or SREBF1c, but several E-box sequences were present in SREBP1c. Thus, analysis of the 5'-flanking regions provides support that these two transcription factors, though similar in their coding sequence and overall gene structure, have different physiological roles. Finally, evidence is presented for the presence of another expressed gene of unknown function located 500 bp upstream of SREBF2.

Complete regression of established murine hepatocellular carcinoma by in vivo tumor necrosis factor alpha gene transfer

BACKGROUND & AIMS

Although tumor necrosis factor (TNF)-alpha possesses a potent antitumor activity, systemic administration of TNF-alpha causes severe side effects. To circumvent this, the efficacy of tumor cell-targeted TNF-alpha gene therapy was investigated.

METHODS

Murine hepatocellular carcinoma (HCC) cells were infected with MNSM-Alb e/p-TNF-alpha retroviruses carrying the murine TNF-alpha gene under the transcriptional control of the murine albumin gene promoter, and antitumor effects induced by TNF-alpha gene transfer were examined in vitro and in vivo.

RESULTS

Although MNSM-Alb e/p-TNF-alpha retrovirally infected HCC cells showed the same in vitro cell growth as parental HCC cells, they lost their tumorigenicity when implanted in syngeneic mice and induced tumor immunity against parental HCCs. The retrovirally infected HCC cells also significantly inhibited the tumorigenicity of previously implanted parental HCCs. Furthermore, intratumoral administration of MNSM-Alb e/p-TNF-alpha retroviruses showed the antitumor effect against established HCCs, resulting in significantly prolonged survival periods. Most importantly, intratumoral implantation of MNSM-Alb e/p-TNF-alpha retroviral-producing cells completely abrogated established HCCs in mice.

CONCLUSIONS

These results indicate the potential efficacy of transferring the TNF-alpha gene via retroviral vectors directly into tumors for gene therapy against HCCs.

The pharmacokinetic and pharmacodynamic interaction between zileuton and terfenadine

OBJECTIVES

The effects of zileuton on terfenadine pharmacokinetics, and the effects of terfenadine alone and the combination on the duration of the QTc interval and the morphology of the TU complex were examined.

METHODS

The study was double-blind, randomized, placebo-controlled, two period cross-over in 16 healthy volunteers. During each period, subjects received 60 mg of terfenadine every 12 h on days 1 to 7 and 600 mg of either zileuton or placebo for zileuton every 6 h on days 1 to 10. Blood samples were obtained on days 7 to 10 and serial ECGs were performed on days -1 and 7 in both periods.

RESULTS

The combination of zileuton and terfenadine was well tolerated. Coadministration of zileuton with terfenadine resulted in a significant increase in the mean AUC and Cmax of terfenadine by approximately 35% and the mean AUC and Cmax of carboxyterfenadine by approximately 15%. The maximum concentration of terfenadine observed in the study was 9.6 ng.ml-1. The addition of zileuton to terfenadine did not result in significant changes in the evaluated ECG-recordings (QTc interval and morphology of TU complex). The difference in means for both maximum and average QTc interval was very small (< or = 2.3 ms), and there were no clinically significant changes in individual values.

CONCLUSIONS

The relatively small pharmacokinetic effect of zileuton on terfenadine metabolism, with no change in the QTc interval, is unlikely to be of clinical significance. The interaction is minimal in comparison to the background variability of the population.

Antioxidant and prooxidant behavior of flavonoids: structure-activity relationships

The antioxidant and prooxidant behavior of flavonoids and the related activity-structure relationships were investigated in this study using the oxygen radical absorbance capacity assay. Three different reactive species were used in the assay: 2,2'-azobis(2-amidino-propane) dihydrochloride, a peroxyl radical generator; Cu(2+)-H2O2, mainly a hydroxyl radical generator; and Cu2+, a transition metal. Flavonoids including flavones, isoflavones, and flavanones acted as antioxidants against peroxyl and hydroxyl radicals and served as prooxidants in the presence of Cu2+. Both the antioxidant and the copper-initiated prooxidant activities of a flavonoid depend upon the number of hydroxyl substitutions in its backbone structure, which has neither antioxidant nor prooxidant action. In general, the more hydroxyl substitutions, the stronger the antioxidant and prooxidant activities. The flavonoids that contain multiple hydroxyl substitutions showed antiperoxyl radical activities several times stronger than Trolox, an alpha-to copherol analogue. The single hydroxyl substitution at position 5 provides no activity, whereas the di-OH substitution at 3' and 4' is particularly important to the peroxyl radical absorbing activity of a flavonoid. The conjugation between rings A and B does not affect the antioxidant activity but is very important for the copper-initiated prooxidant action of a flavonoid. The O-methylation of the hydroxyl substitutions inactivates both the antioxidant and the prooxidant activities of the flavonoids.

Practical Bayesian inference using mixtures of mixtures

Discrete mixtures of normal distributions are widely used in modeling amplitude fluctuations of electrical potentials at synapses of human and other animal nervous systems. The usual framework has independent data values yj arising as yj = mu j + xn0 + j, where the means mu j come from some discrete prior G(mu) and the unknown xno + j's and observed xj, j = 1,...,n0, are Gaussian noise terms. A practically important development of the associated statistical methods is the issue of nonnormality of the noise terms, often the norm rather than the exception in the neurological context. We have recently developed models, based on convolutions of Dirichlet process mixtures, for such problems. Explicitly, we model the noise data values xj as arising from a Dirichlet process mixture of normals, in addition to modeling the location prior G(mu) as a Dirichlet process itself. This induces a Dirichlet mixture of mixtures of normals, whose analysis may be developed using Gibbs sampling techniques. We discuss these models and their analysis, and illustrate them in the context of neurological response analysis.

Construction of retroviral vectors to induce strong hepatoma cell-specific expression of cytokine genes

Continuing advances in molecular biology have provided tools for a promising approach to the treatment of cancer. Among the various strategies of gene therapy for cancer, many are aimed at killing tumour cells indirectly by the induction or reinforcement of a host immune response by gene transduction of various cytokines, major histocompatibility complex or immune accessory molecules. In the present study, we selected the tumour necrosis factor-alpha, interleukin-2 and interleukin-3 genes as potential cytokine genes to induce antitumour effects. We constructed retroviral vectors carrying these cytokine genes under the control of the murine albumin enhancer and promoter and retrovirally transduced these genes into hepatoma and non-hepatoma cell lines. Strong expression of the cytokine genes was induced in transduced hepatoma cells, while no evident expression was detected in transduced non-hepatoma cells. These results demonstrate the hepatoma-specific expression of cytokine genes and imply the feasibility of in vivo gene transfer into hepatomas without affecting any other tissues. Furthermore, these cytokine genes were expressed much more intensively when they were derived from the albumin enhancer and promoter than when derived from the simian virus 40 early region promoter. These results indicate that transcriptional regulatory sequences specific for the target tissues could be preferable to viral promoters for the gene therapy of cancer.

[Pearl and mother-of-pearl powder in health-care]

Based on pharmacological studies in files, mice and rats, the powder of sea pearl (Pteria martensii), mother-of-pearl and freshwater pearl has been proved to have tonic, anti-aging and anti-radiative actions. The effect of the sea pearl and mother-of-pearl powder is higher than that of freshwater pearl powder.

[Angioscopic in-situ arterial bypass for lower extremity revascularization]

The authors' initial experience of angioscopic in-situ arterial bypass of 37 extremities reveals that angioscopy can be used to assist complete valvular ablation and precise location and ligation of tributaries of saphenous vein grafts, avoiding postoperative arterial-venous fistula and warm ischemic injury to grafts. Angioscopy is also used to perform intraoperative completion inspection of the grafts and anastomoses. The designed biocomposite graft and common ostium technique promotes the usage rate of the limited autogenous vein grafts and enlarges the diameter of grafts and blood flow through the distal anastomosis. Because of the above new series of procedures, the extremity salvage rate in this study was 34/37 limbs. During the follow-up period of 2-18 months, all anastomoses were patent. The preoperative ankle and toe pressure of 3.5 +/- 0.2 kPa and 2.0 +/- 0.1 kPa respectively rose to 5.4 +/- 0.1 kPa and 3.8 +/- 0.2 kPa postoperatively. We conclude that angioscopic in-situ arterial bypass surgery is of practical value and specially advantageous in lower extremity revascularization.

Complementation of mutation in acyl-CoA:cholesterol acyltransferase (ACAT) fails to restore sterol regulation in ACAT-defective sterol-resistant hamster cells

A previously described mutant line of Chinese hamster ovary cells, designated SRD-4, fails to synthesize cholesteryl esters, owing to a deficiency in the activity of acyl-CoA:cholesterol acyltransferase (ACAT). These cells also fail to suppress low density lipoprotein receptors or cholesterol synthesizing enzymes in the presence of 25-hydroxycholesterol. In the current studies we show that SRD-4 cells have three defects: 1) a point mutation in one allele at the ACAT locus that changes codon 265 from Ser to Leu, resulting in an inactive enzyme; 2) a silent allele at the other ACAT locus that does not produce detectable mRNA; and 3) a mutation, as yet undefined, that abolishes the ability of 25-hydroxycholesterol to inhibit the cleavage of both sterol regulatory element binding proteins (SREBP-1 and SREBP-2). Correction of the ACAT deficiency by transfection of a wild-type cDNA failed to restore inhibition of SREBP cleavage by 25-hydroxycholesterol, indicating that the ACAT deficiency and the sterol regulatory defect are caused by independent mutations. These data provide further insight into the interplay between ACAT activation and inhibition of SREBP cleavage by 25-hydroxycholesterol, and they indicate that these two processes can be disrupted independently by mutation.

Effect of isothermal radiofrequency radiation on cytolytic T lymphocytes

Previous in vitro studies provide evidence that RF electromagnetic radiation modulates proliferation of human glioma, lymphocytes, and other cell types. The mechanism of RF radiation cell proliferation modulation, as well as mechanisms for effects on other cell physiologic endpoints, are not well understood. To obtain insight regarding interaction mechanisms, we investigated effects of RF radiation exposure on interleukin 2 (IL-2) -dependent proliferation of cytolytic T lymphocytes (CTLL-2). After exposure to RF radiation in the presence or absence of IL-2 cells were cultured at various physiological concentrations of IL-2. Treatment effects on CTLL-2 proliferation were determined by tritiated thymidine incorporation immediately or 24 h after exposure. Exposure to 2450 MHz RIF radiation at specific absorption rates (SARs) of greater than 25 W/kg (induced E-field strength 98.4 V/m) induced a consistent, statistically significant reduction in CTLL-2 proliferation, especially at low IL-2 concentrations. At lower SARs, 2450 MHz exposure increased CTLL-2 proliferation immediately after exposure but reduced 24 h postexposure proliferation. RF radiation effects depended on the mitotic state of the cells at the time of exposure. Comparison of the effects of temperature elevation and RF radiation indicated significant qualitative and quantitative differences.

Antioxidant capacity in different tissues of young and old rats

The antioxidant capacity in heart, liver, lung, and kidney was studied in young (6 months) and old (22 months) male Fischer 344 rats, using the oxygen radical absorbance capacity (ORAC) assay system with two different reactive oxygen species (ROS) generators. The results indicated that liver in old rats had significantly lower peroxyl radical absorbance capacity (ORACROO), units/g wet wt), but higher hydroxyl radical absorbance capacity (ORACOH), units/mg protein) than in young rats. The decreased liver ORACROO in the old rats was mainly due to the loss of cytosol protein, while the increased liver ORACOH in the old rats was a result of an increased resistance of cytosol proteins to the attack of ROS. This conclusion was further supported by the finding that the contribution of nonprotein fraction of liver cytosol to the ORACOH of the cytosol decreased with age. No effect of age was found on either ORACROO or ORACOH in other tissues. The antioxidant capacity for both ORACROO and ORACOH, was usually high in liver and kidney but low in lung and heart.

Short stature and risk of mortality and cardiovascular disease: negative findings from the NHANES I epidemiologic follow-up study

OBJECTIVES

This study sought to examine the relation between body height and incidence of myocardial infarction, coronary heart disease, overall mortality and mortality from cardiovascular disease.

BACKGROUND

An association between short stature and increased risk of fatal and nonfatal cardiovascular disease has been observed in several studies, attracting considerable attention.

METHODS

We used data from the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-Up Study, a prospective study of a large random sample of the U.S. population, to examine the association between height and risk of four end points.

RESULTS

Baseline data were collected from 1971 to 1975 for 13,031 respondents (5,296 men, 7,735 women), and the average follow-up period was 13 years, through 1987. Height was inversely associated with risk of all four of the end points studied in both men and women. However, after adjustment for age and years of education in Cox proportional hazards analyses, the relation no longer existed. Using the same adjustment procedures, persons in the lowest height quintile had no increase in risk compared with those in the highest category. The findings were consistent for men and women, blacks and whites and different age groups.

CONCLUSIONS

Data from this study in a national sample do not support the hypothesis of an inverse height-heart disease relation.

Experimental and theoretical studies of vessel contrast-to-noise ratio in intracranial time-of-flight MR angiography

CNR studies were performed for human intracranial vessels in 3D MRA data sets. The CNR dependency of different imaging parameters, such as flip angle, field of view, echo time, repetition time, and echo readout symmetry, was studied for vessels in the region of the circle of Willis. A theoretical model was developed for MR vascular imaging based on the Bloch equations and Fourier imaging theory. This model predicts the MR image intensity of vessels from basic subject parameters, such as the relaxation times of blood and stationary tissue, vessel dimension, and flow velocity, and the parameters of the imaging technique, such as flip angle, voxel volume, repetition time, and echo time. For most experiments, the model was found to fit the experimental results well. The validity of this model allows the optimization of imaging parameters to maximize vessel CNR in MR angiography.

Antioxidant capacity decreases during growth but not aging in rat serum and brain

The objective of this study was to evaluate the effects of growth and aging on the antioxidant capacities of rat serum and brain, by using two different reactive oxygen species (ROS) generators and two different methods of expressing the results. The antioxidant capacity was determined by using the oxygen radical absorbance capacity (ORAL) assay. The protein content of serum increased significantly during the growth period of day 1 to 6 months of age. The protein content in brain (cortex and cerebellum) extract also tended to increase with the growth. The antioxidant capacity of serum decreased during growth, if the ORAC values were expressed on the basis of serum protein concentration. The antioxidant capacity in brain cortex and cerebellum declined significantly during growth, regardless of which ROS generator was used in the ORAC assay or how the results were expressed (units/ml or units/mg protein). Therefore, the rat pups had higher antioxidant capacity than the adult and old rats. The low plasma antioxidant capacity reported in premature neonates may simply result from a low protein concentration of the plasma, which occurs in neonates. No aging effect was observed on the antioxidant capacity of serum and brain in the adult and old rats.

Automated assay of oxygen radical absorbance capacity with the COBAS FARA II

Reactive oxygen species are of interest in biology and medicine because of evidence relating them to aging and disease processes. A relatively simple but sensitive and reliable method for quantifying the oxygen radical absorbance capacity (ORAC) of antioxidants in biological tissues has been automated for use with the COBAS FARA II centrifugal analyzer with a fluorescence-measuring attachment. In this assay, beta-phycoerythrin (beta-PE) is used as an indicator protein, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as a peroxyl radical generator, and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) as a calibrator for antioxidant activity. This assay is unique because the reaction goes to completion so that both inhibition time and inhibition degree are considered in quantifying ORAC (micromoles of Trolox equivalent per liter or per gram of tissue). This method can be used not only for serum but also other tissue and food samples and is suitable for application to a range of nutritional and clinical conditions.

Automated assay of oxygen radical absorbance capacity with the COBAS FARA II

Reactive oxygen species are of interest in biology and medicine because of evidence relating them to aging and disease processes. A relatively simple but sensitive and reliable method for quantifying the oxygen radical absorbance capacity (ORAC) of antioxidants in biological tissues has been automated for use with the COBAS FARA II centrifugal analyzer with a fluorescence-measuring attachment. In this assay, beta-phycoerythrin (beta-PE) is used as an indicator protein, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as a peroxyl radical generator, and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) as a calibrator for antioxidant activity. This assay is unique because the reaction goes to completion so that both inhibition time and inhibition degree are considered in quantifying ORAC (micromoles of Trolox equivalent per liter or per gram of tissue). This method can be used not only for serum but also other tissue and food samples and is suitable for application to a range of nutritional and clinical conditions.

Crystallization of a soluble, catalytically active form of Escherichia coli leader peptidase

Leader peptidase, a novel serine protease in Escherichia coli, catalyzes the cleavage of the amino-terminal leader sequences from exported proteins. It is an integral membrane protein containing two transmembrane segments with its carboxy-terminal catalytic domain residing in the periplasmic space. Here, we report a procedure for the purification and the crystallization of a soluble non-membrane-bound form of leader peptidase (delta 2-75). Crystals were obtained by the sitting-drop vapor diffusion technique using ammonium dihydrogen phosphate as the precipitant. Interestingly, we have found that the presence of the detergent Triton X-100 is required to obtain crystals sufficiently large for X-ray analysis. The crystals belong to the tetragonal space group P4(2)2(1)2, with unit cell dimensions of a = b = 115 A and c = 100 A, and contain 2 molecules per asymmetric unit. This is the first report of the crystallization of a leader (or signal) peptidase.

Inaccuracy of self-reported weights and heights among American Indian adolescents

To determine the accuracy of self-reported weights and heights and of relative weight status in a sample of American Indian adolescents, a survey was conducted in middle and high schools on or near three Indian reservations-Navajo, Choctaw, and Blackfeet. Self-reported weights and heights were compared with measured weights and heights. Participants were 12 through 19 years old. (N = 806, 47.4% male). Overall, both boys and girls underreported weight (mean difference = self-reported - measured mean values)(-3.4 +/- 13.1 and -4.6 +/- 13.0 lb, respectively) and overreported height (0.6 +/- 2.1 and 0.2 +/- 2.6 in, respectively) However, underweight boys and girls overreported weight (normal: -1.6 +/- 7.9 and -1.4 +/- 6.3; overweight: -7.5 +/- 17.9 and -11.6 +/- 19.0 lb, respectively). Although correlations between measured and reported weight, height, and body mass index (BMI) were high, the sensitivity of relative weight categories based on BMI using self-reported weight and height compared with measured weight and height was poor: 66.7% for underweight (BMI < 15th percentile, based on a national reference population), 88.9% for normal weight, and 73.6% for overweight (> 85th percentile). These results call into question the accuracy of self-reported weight and height measurements among American Indian youth and are similar to findings among non-American Indian adolescents. Therefore, their use in prevalence studies should be avoided, and they should be used cautiously in other types of epidemiologic studies.

Study of the role of vitamin B12 and folinic acid supplementation in preventing hematologic toxicity of zidovudine

A prospective, randomized study was conducted to evaluate the role of vitamin B12 and folinic acid supplementation in preventing zidovudine (ZDV)-induced bone marrow suppression. Seventy-five human immunodeficiency virus (HIV)-infected patients with CD4+ cell counts < 500/mm3 were randomized to receive either ZDV (500 mg daily) alone (group I, n = 38) or in combination with folinic acid (15 mg daily) and intramascular vitamin B12 (1000 micrograms monthly) (group II, n = 37). Finally, 15 patients were excluded from the study (noncompliance 14, death 1); thus, 60 patients (31 in group I and 29 in group II) were eligible for analysis. No significant differences between groups were found at enrollment. During the study, vitamin B12 and folate levels were significantly higher in group II patients; however, no differences in hemoglobin, hematocrit, mean corpuscular volume, and white-cell, neutrophil and platelet counts were observed between groups at 3, 6, 9 and 12 months. Severe hematologic toxicity (neutrophil count < 1000/mm3 and/or hemoglobin < 8 g/dl) occurred in 4 patients assigned to group I and 7 assigned to group II. There was no correlation between vitamin B12 or folate levels and development of myelosuppression. Vitamin B12 and folinic acid supplementation of ZDV therapy does not seem useful in preventing or reducing ZDV-induced myelotoxicity in the overall treated population, although a beneficial effect in certain subgroups of patients cannot be excluded.

Abbreviated moment-compensated phase encoding

To achieve correct spatial location of blood vessels, first order gradient moment nulling applied to the phase encoding axes can be used. However, gradient moment nulling prolongs echo time (TE), which may degrade the flow image in regions of complex flow. The fact that abbreviated moment compensated phase-encoding (AMCPE) can be used to apply partial flow compensation to the phase-encoding axes to prevent spatial misregistration of vessels without requiring the use of long echo times or using arbitrary chosen TE is demonstrated. AMCPE defines two cutoff lines in k-space. The flow-induced phase is completely compensated for values between the cutoff lines and partially compensated beyond the cutoff lines. The AMCPE technique has been tested on both a flow phantom and a human volunteer. The AMCPE images from both the in vivo and the in vitro study demonstrate correctly imaged flow. Computer simulations have been performed to analyze the penalty caused by the incomplete flow compensation. The result shows that the ripple artifacts due to the incomplete flow compensation are unobservable when 60%-70% of k-space is completely flow compensated.

[Synthesis of S(+)-2-(4-isobutylphenyl) propionic acid by asymmetric hydrolysis of microbial enzyme. II. Reaction conditions and product extraction]

Trichosporon cutaneum 158 exhibited higher sterospecificity to hydrolyze substrate ibuprofen ester. Among the five chosen substrate, asymmetric hydrolysis of methyl ester or isopropyl ester formed S(+)-ibuprofen of 97% ee. While ethyl ester not only gave ee 93% but also showed the highest hydrolytic activity. The optimum pH range for asymmetric hydrolysis was 6.5-7.0. Ability of resolusion was stabler in the range of temperature 28-37 degrees C. This yeast produced intracellular enzyme. Hydrolysis can be carried out by powered cells treated by iced-acetone to improve the specificity of resolution. The product S(+)-ibuprofen can be got with acid-base reaction and organic solvent extraction, unreacted esters can be recovered simultaneously.

Protein oxidation and aging. I. Difficulties in measuring reactive protein carbonyls in tissues using 2,4-dinitrophenylhydrazine

A current hypothesis explaining the aging process implicates the accumulation of oxidized protein in animal tissues. This hypothesis is based on a series of reports showing an age-dependent increase in protein carbonyl content and an age-dependent loss of enzyme function. This hypothesis is also supported by the report of a novel effect of N-tert-butyl-alpha-phenylnitrone (PBN) in reversing these age-dependent changes. Here we specifically study the method that was used to measure reactive protein carbonyls in tissues. This method uses 2,4-dinitrophenylhydrazine (DNPH) and includes a washing procedure. Our results indicate that reactive protein carbonyls in normal crude tissue extracts cannot be reliably measured by this method, although it does reliably measure reactive carbonyls in purified proteins which have been oxidatively modified in vitro. The nucleic acids in tissues could be a major problem encountered in the assay. Using the streptomycin sulfate treatment combined with a dialysis step, we were successful in removing most nucleic acids from a crude tissue extract, but then the reactive carbonyl level in the crude tissue extract was too low to be reliably measured. This streptomycin sulfate treatment procedure, however, had no effect on the reactive carbonyl measurement of an oxidized protein sample. The unwashed free DNPH was another major problem in the assay because of its very strong absorption around 370 nm, where reactive carbonyls were quantitated. Nevertheless, on using the procedure described in the literature to measure total "reactive carbonyls" in rat liver and gerbil brain cortex, no change with age or PBN treatment was found. Then, we investigated a HPLC procedure which uses sodium dodecyl sulfate in the mobile phase but this was also found to be unsuitable for the reactive protein carbonyl assay in tissues.

Protein oxidation and aging. II. Difficulties in measuring alkaline protease activity in tissues using the fluorescamine procedure

A current hypothesis explaining the aging process implicates the accumulation of oxidized protein in animal tissues. This is primarily based on a series of reports showing an age-dependent increase in protein carbonyl content and an age-dependent decrease in the activities of enzymes, especially of alkaline proteases, which preferentially degrade oxidatively modified protein. Recently, this hypothesis was strongly supported by the report of a novel effect of the spin-trapping compound N-tert-butyl-alpha-phenylnitrone (PBN) in reversing these age-dependent changes. However, we found that the reactive protein carbonyls could not be reliably measured in tissues by using the 2,4-dinitrophenylhydrazine procedure described in the PBN study. We now focus on the alkaline protease activity assay and show that alkaline protease activity cannot be reliably measured in crude tissue extracts by using the fluorescamine procedure also described in the PBN study. We were, however, able to reliably measure a protease activity in crude tissue extracts at alkaline pH by using a synthetic fluorogenic peptide substrate, but no effect of aging or PBN treatment was found on the protease activity in rat brain cortexes. Thus, the reported age-dependent changes in protein carbonyl formation and alkaline protease activity remain to be confirmed.

Characterization of a soluble, catalytically active form of Escherichia coli leader peptidase: requirement of detergent or phospholipid for optimal activity

Leader peptidase is a novel serine protease in Escherichia coli, which functions to cleave leader sequences from exported proteins. Its catalytic domain extends into the periplasmic space and is anchored to the membrane by two transmembrane segments located at the N-terminal end of the protein. At present, there is no information on the structure of the catalytic domain. Here, we report on the properties of a soluble form of leader peptidase (delta 2-75), and we compare its properties to those of the wild-type enzyme. We find that the truncated leader peptidase has a kcat of 3.0 S-1 and a Km of 32 microM with a pro-OmpA nuclease A substrate. In contrast to the wild-type enzyme (pI of 6.8), delta 2-75 is water-soluble and has an acidic isoelectric point of 5.6. We also show with delta 2-75 that the replacement of serine 90 and lysine 145 with alanine residues results in a 500-fold reduction in activity, providing further evidence that leader peptidase employs a catalytic serine/lysine dyad. Finally, we find that the catalysis of delta 2-75 is accelerated by the presence of the detergent Triton X-100, regardless if the substrate is pro-OmpA nuclease A or a peptide substrate. Triton X-100 is required for optimal activity of delta 2-75 at a level far below the critical micelle concentration. Moreover, we find that E. coli phospholipids stimulate the activity of delta 2-75, suggesting that phospholipids may play an important physiological role in the catalytic mechanism of leader peptidase.

The translocation of negatively charged residues across the membrane is driven by the electrochemical potential: evidence for an electrophoresis-like membrane transfer mechanism

The role of the membrane electrochemical potential in the translocation of acidic and basic residues across the membrane was investigated with the M13 procoat protein, which has a short periplasmic loop, and leader peptidase, which has an extended periplasmically located N-terminal tail. For both proteins we find that the membrane potential promotes membrane transfer only when negatively charged residues are present within the translocated domain. When these residues are substituted by uncharged amino acids, the proteins insert into the membrane independently of the potential. In contrast, when a positively charged residue is present within the N-terminal tail of leader peptidase, the potential impedes translocation of the tail domain. However, an impediment was not observed in the case of the procoat protein, where positively charged residues in the central loop are translocated even in the presence of the membrane potential. Intriguingly, several of the negatively charged procoat proteins required the SecA and SecY proteins for optimal translocation. The studies reported here provide insights into the role of the potential in membrane protein assembly and suggest that electrophoresis can play an important role in controlling membrane topology.

In vivo or in vitro administration of the nitrone spin-trapping compound, n-tert-butyl-alpha-phenylnitrone, (PBN) reduces age-related deficits in striatal muscarinic receptor sensitivity

Previous research has indicated that age-related reductions in muscarinic (m) (e.g. oxotremorine, Oxo) agonist enhancement of striatal K(+)-evoked dopamine release (K(+)-ERDA) and decreased IP3 release upon m receptor (mAChR) agonist stimulation are partially the result of deficits in signal transduction (ST). The present experiments were carried out to test the hypothesis that these age-related ST deficits occur as a result of free radical-induced alterations in membranes containing receptor-G protein complexes. To test this hypothesis, the effects of in vivo and in vitro administration of the nitrone trapping agent, n-tert-butyl-alpha-phenylnitrone (PBN), on the Oxo-enhancement of K(+)-ERDA were examined. Results showed that: both in vivo (10 mg/kg/2 x day PBN i.p./14 days) in vitro (incubation of striatal slices 0-100 microM PBN/30 min) applications of PBN were effective in ameliorating age-related deficits in Oxo-enhanced K(+)-ERDA. The results of the in vivo administration of PBN indicate that the loss of mAChR sensitivity in aging may be the result of oxidative stress that can be restored by this nitrone trapping agent. These findings show that reductions of endogenous or exogenous free radicals may alter one important biomarker of aging, i.e. the loss of sensitivity in mAChR systems. However, these results, when considered along with those obtained with in vitro administration indicate that in addition, PBN may have acute effects (e.g. perhaps membrane structural alterations) which can also improve mAChR responsiveness.

[Comparative study of ultrasonic detection of popliteal vein reflux]

The venous valve undergoes more destruction and malfunction, and the quantity and duration of venous valvular reflux are larger and longer. On the basis of this mechanism, we detected the popliteal vein reflux duration and various influencing factors with duplex ultrasound. The reflux duration longer than 0.5 secand was verified as the evidence of primary venous insufficiency (PVI) in the detection of 40 cases. The detecting method recommended by us is that with standing position, and pneumatic compression 10. 67kPa (80mmHg) applied to calf, the reflux duration through popliteal venous valves is detected by using both pulsed-wave Doppler scanning and color-flow Doppler scanning. With the rates of sensitivity (92%), specificity (100%), and accuracy (94%), this noninvasive, quantitative, and easily handled method showed a very good diagnostic value.

Synergistic insertion of two hydrophobic regions drives Sec-independent membrane protein assembly

We have studied the membrane insertion of two proteins from the inner membrane of Escherichia coli, both with two transmembrane segments connected by a short periplasmic loop: the M13 procoat protein and a mutant "inverted" leader peptidase. Neither molecule depends on the Sec machinery for insertion. We show that the introduction of a charged residue in the second transmembrane segment completely blocks insertion of both proteins. In contrast, a Sec-dependent procoat mutant, where the periplasmic region has been lengthened, inserts into the membrane even in the presence of a charged residue in the second hydrophobic domain. In addition, a large deletion within the second transmembrane domain of the leader peptidase mutant allows membrane translocation, but only under conditions where the SecA protein is functional. Furthermore, we show that the first hydrophobic domain is required for insertion of the short periplasmic loop of the "inverted" leader peptidase. These results suggest that Sec-independent insertion occurs by a synergistic entry of the two neighboring hydrophobic domains into the lipid bilayer.

Translocation of N-terminal tails across the plasma membrane

Previously we have shown that the first hydrophobic domain of leader peptidase (lep) can function to translocate a short N-terminal 18 residue antigenic peptide from the phage Pf3 coat protein across the plasma membrane of Escherichia coli. We have now examined the mechanism of insertion of N-terminal periplasmic tails and have defined the features needed to translocate these regions. We find that short tails of up to 38 residues are efficiently translocated in a SecA- and SecY-independent manner while longer tails are very poorly inserted. Efficient translocation of a 138 residue tail is restored and is Sec-dependent by the addition of a leader sequence to the N-terminus of the protein. We also find that while there is no amphiphilic helix requirement for N-terminal translocation, there is a charge requirement that is needed within the tail; an arginine and lysine residue can inhibit or completely block translocation when introduced into the tail region. Intriguingly, the membrane potential is required for insertion of a 38 residue tail but not for a 23 residue tail.

Reduction of partial-volume artifacts with zero-filled interpolation in three-dimensional MR angiography

Partial-volume artifacts reduce vessel contrast and continuity (especially in small vessels) in magnetic resonance (MR) angiography. The authors applied zero-filled (band-limited) interpolation to three-dimensional (3D) MR angiograms to reduce partial-volume artifacts. They demonstrated that zero-filled interpolation can also be implemented by means of voxel shifting in real space. Voxel-shifted interpolation is much less computer memory intensive than conventional zero-filled interpolation. They numerically simulated the contrast loss due to partial-volume artifacts and contrast recovery obtained with zero-filled interpolation. Zero-filled interpolation in all three orthogonal directions was applied to 3D MR angiography data sets from 29 human studies. These studies were obtained with the three commonly used 3D MR angiography techniques: 3D time of flight, multislab 3D time of flight, and 3D phase contrast. A substantial improvement in vessel contrast and vessel continuity was observed in all cases.

Familial aggregation of cardiovascular diseases in African-American pedigrees

Familial aggregation of cardiovascular diseases and diabetes has been consistently demonstrated. However, virtually all of the evidence on the familial patterns of these diseases has come from white population samples. This study evaluates the level of familial excess risk among first degree relatives of 232 African-American pedigrees which included 1,420 individuals recruited from the Chicago, IL, area. Excess disease risk was observed among relatives (parents and offsprings) of affected probands compared to relatives of unaffected probands for coronary heart disease (odds ratio [OR] = 5.30; 95% confidence interval [CI] = 2.51-11.23); hypertension (OR = 1.98; CI = 1.41-2.80); stroke (OR = 3.24; CI = 1.08-9.70); and diabetes (OR = 2.95; CI = 1.55-5.62). The results of this study clearly show that coronary heart disease, hypertension, stroke, and diabetes aggregate in some African-American families and not others. Unaffected relatives of persons suffering from these diseases should be encouraged to have their blood pressure, lipid, and blood glucose levels measured at frequent intervals. These recommendations are particularly urgent in African-American communities because of the disproportionately high morbidity and mortality experienced from cardiovascular diseases and diabetes.

Determinants of incident non-insulin-dependent diabetes mellitus among blacks and whites in a national sample. The NHANES I Epidemiologic Follow-up Study

The excess incidence of non-insulin-dependent diabetes mellitus noted among African Americans in the past two decades may be attributable to variations in the distribution of specific risk factors, or the impact of these risk factors may differ by ethnicity or sex. Over the 16 years (1971-1987) of the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study, 880 incident cases of diabetes mellitus developed among 11,097 white and black participants who were between the ages of 25 and 70 years at baseline. There were substantial differences among the four race/sex groups with respect to age at baseline, as well as marked differences in the distribution of several major risk factors for diabetes, including obesity, subscapular and triceps skinfold thickness, blood pressure, income, activity, and educational level. The age-adjusted incidence of diabetes over the course of the study was 15.0% among black women, while it was 10.9% among black men. White women and men experienced similar, more moderate risks of 7.0% and 6.9%, respectively. The 100% excess risk among black women and the 50% excess among black men can in large measure explain the recent marked increase in diabetes rates in the black community. Furthermore, at nearly every level of obesity, blacks had a higher risk of diabetes than whites, suggesting that other factors contributed to risk. A significant interaction between race and body mass index (weight (kg)/height(m)2) was likewise demonstrated in multivariate analysis. Baseline age, race, body mass index, and ratio of subscapular skinfold to triceps skinfold were significantly related to incident diabetes, both overall and in separate models for men and women; in the entire cohort and in women alone, blood pressure, activity level, and education also contributed to risk. Other interactions were tested but were not found to be important. Despite sampling difficulties and inconsistencies in the data, the NHANES I Epidemiologic Follow-up Study provides evidence that the associations of anthropometric and sociodemographic variables with diabetes may vary among subgroups which have different mean levels and distributions of these risk factors.