Modulation of apoptosis, tumorigenesity and metastatic potential with antisense H-ras oligodeoxynucleotides in a high metastatic tumor model of hepatoma: LCI-D20

BACKGROUND/AIMS

To investigate the effect of antisense H-ras DNA on tumorigenesity, apoptosis and metastasis of a high metastatic tumor model of human hepatocellular carcinoma in nude mice LCI-D20.

METHODOLOGY

LCI-D20 cells in primary culture were treated with 10 microns/L antisense oligodeoxynucleotide (ODN) drugs in vitro. 1.5 x 10(6) LCI-D20 cells with or without pretreatment were inoculated into each elevated subcutaneous (s.c.) flap in 14 nude mice, 6 animals for antisense H-ras oligodeoxynucleotide treated cells, 4 for H-ras non-specific antisense oligodeoxynucleotide treated cells, and the rest 4 for cells without pretreatment.

RESULTS

In in vitro cell culture study, 5-day continuous suppression of H-ras expression by antisense H-ras oligodeoxynucleotide resulted in significant inhibition of the proliferation of LCI-D20 cells (t = 31.529, P < 0.01). In situ end-labeling detection showed that apoptotic cell death was significantly increased in cells with 5-day treatment of antisense H-ras oligodeoxynucleotide (34.0 +/- 4.5%) in comparing with cells without treatment (2.5 +/- 1.2%, t = 13.434, P < 0.01) or treated with non-specific antisense oligodeoxynucleotide (4.8 +/- 1.4%, t = 12.453, P < 0.01) at the corresponding time. In the in vivo experiment, at week 6, no palpable tumor could be found in 50% (3/6) of animals receiving cells with pretreatment of antisense H-ras oligodeoxynucleotide, while 100% (4/4, 4/4) of animals in the 2 control groups developed palpable tumors. Tumor growth in antisense H-ras treated animals was significantly retarded in comparison with that of the untreated (t = 3.509, P < 0.01) or non-specific antisense oligodeoxynucleotide treated animals (t = 3.452, P < 0.01). 75% to 100% of animals in the 2 control groups developed lung metastases, while in antisense H-ras treated animals lung metastasis foci could not be found by random serial section and microscopy (u = 2.536, P < 0.01; u = 3.162, P < 0.01, respectively).

CONCLUSIONS

Specific inhibition of H-ras expression by antisense H-ras oligodeoxynucleotides could not only induce apoptotic cell death, inhibit the growth rate of LCI-D20 cells in vitro and in vivo, but also alter in vivo tumorigenesity and metastatic potential of LCI-D20 cells.

[Investigation of infiltration glass of the machinable infiltrated ceramic(MIC)]

To explore the manufacture arts and determine the properties of the infiltration glass of the MIC. In order to determine the glass forming range of the MIC infiltration glass, molten glass was prepared in Al2O3 crucibles by heating the components to 1450 degrees C. Thermal analytic device was employed to study the thermal properties of the glass. Its crystal phases after micro-crystallization were analyzed with XRD. Flexural strength was measured by means of 3-point bending test. The chemical components of MIC glass were determined. Conventional fluorophlogopite glass was converted into an infiltration glass with low viscosity, good infiltration capability and low fusing temperature by introducing B2O3, La2O3 and Li2O into the glass. Fluorophlogopite crystals formed after crystallization. Conventional mica glass can be changed according to the requirements of properties. Modified mica MIC glass in this study has good infiltration ability in Al2O3 matrix while remains machinability.

Synthesis and in vitro and in vivo functional studies of ortho-substituted phenylpiperazine and N-substituted 4-N-(o-methoxyphenyl)aminopiperidine analogues of WAY100635

WAY100635 (2), N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohe xanecarboxamide, is a silent serotonin 5-HT(1A) antagonist, which is now widely used to study the 5-HT(1A) receptor both in vivo and in vitro. In this paper, we describe the synthesis and in vitro (5-HT(1A) affinity and pA(2) values at guinea pig ileum strips) and in vivo (hypothermia and ultrasonic vocalization) pharmacology at the serotonin 5-HT(1A) receptor of several closely related analogues of 2. Test compounds 12 and 14, in which the arylpiperazine moiety of 2 has been replaced by an arylaminopiperidine moiety, showed no affinity or antagonistic activity at the 5-HT(1A) receptor. Substitution of the o-methoxy group of 2 by larger fluoroalkoxy or sulfonyloxy substituents did not alter the in vitro or in vivo pharmacology to any great extent; in vivo both the fluoropropyl analogue 5 and the triflate analogue 7 are equipotent to WAY100635 itself. The O-desmethyl analogue 3 proved to be the most potent antagonist at the serotonin 5-HT(1A) postsynaptic receptor sites in this series.

New selective and potent 5-HT(1B/1D) antagonists: chemistry and pharmacological evaluation of N-piperazinylphenyl biphenylcarboxamides and biphenylsulfonamides

A series of new analogues of N-[4-methoxy-3-(4-methylpiperazin-1-yl)phenyl] 2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)biphenyl-4-carboxamide (1; GR127935) as potent and selective 5-HT(1B/1D) antagonists were synthesized and evaluated pharmacologically. Their receptor binding profiles were comparable to that of 1. The 1,3,4-oxadiazole isomer 2 and the 4'-aminocarbonyl and 4'-amidinyl analogues (9 and 10) of 1 had higher affinities at the rat 5-HT(1B) receptor (IC(50) = 0.93, 1. 3, and 0.5 nM, respectively) and calf 5-HT(1D) receptor (IC(50) = 37, 10, and 3 nM, respectively) than did 1 (1.6 and 52 nM for rat 5-HT(1B) and calf 5-HT(1D) receptors, respectively). In the functional in vitro testing of 5-HT(1B/1D) antagonistic properties, 2, 9, 10, 11b (O-demethylated derivative of 2), 13a (O-methylsulfonyl analogue of 2), and 16 (which differs from 2 with a sulfonamide linker) showed more pronounced effects in the K(+)-induced 5-HT release in the cortex of guinea pig than did 1 and 3 (SB224289). Compounds 2, 9, and 10 were equally potent as 1 in rabbit saphenous vein model (pA(2) > 9). A biochemical study of 2 with in vivo microdialysis in the rat brain showed that it is capable of augmenting citalopram (a selective serotonin reuptake inhibitor, SSRI) induced 5-HT release in rat ventral hippocampus, while preventing the decrease in acetylcholine release elicited by citalopram administration. The molecular structure of 2 was determined by single-crystal X-ray analysis. The log P and log D values of these compounds were calculated. This study contributes to the SAR study of N-piperazinylphenyl biphenylcarboxamides as selective and potent 5-HT(1B/1D) antagonists.

Quality of the last year of life of older adults: 1986 vs 1993

CONTEXT

The population is aging and life expectancy is increasing, but whether morbidity and disability late in life also increase is unknown.

OBJECTIVE

To examine whether the use of health care services, disability and cognitive function, and overall quality of life in the year before death among older adults has changed over time.

DESIGN AND SETTING

The 1986 and 1993 National Mortality Followback Surveys, which were probability samples of all deaths in the United States with response rates of next of kin of 90% and 88% for those aged 65 years and older.

PARTICIPANTS

Next of kin were asked to report the health status of a total of 9179 decedents who were 65 years and older in 1986 and 6735 in 1993, representing 1.5 and 1.6 million decedents aged 65 years and older.

MAIN OUTCOME MEASURES

Days of hospital or nursing home stays, number and length of disability in 5 activities of daily living, duration of impairment in 3 measures of cognitive function, and an overall sickness score among individuals aged 65 through 84 years and those aged 85 years and older.

RESULTS

Women used significantly fewer hospital and nursing home services in the last year of life in 1993 vs 1986 (mean reduction, 3.3 nights for both age groups for hospital services; mean reduction 18.4 nights for nursing home for women aged 65-84 years and 42.3 nights for women > or =85 years). Men had no changes except those aged 85 years and older had a decline in nursing home nights of 32.6. The proportion of women aged 85 years and older with restriction of at least 2 activities of daily living decreased from 62.5% in 1986 to 52.1% in 1993 (P<.01), and those with normal cognitive function increased from 50.3% to 56.2% (P<.05). Their mean overall sickness score decreased and quality-of-life improved. Among women aged 65 through 84 years, the number with normal cognitive function increased and the mean sickness score decreased, but those with at least 2 activities of daily living impairments increased and the overall quality of life declined. A similar pattern of change was found in the oldest-old men except that cognitive function worsened. Most parameters for men aged 65 through 84 years did not change significantly.

CONCLUSIONS

Men and women at least 85 years old in the US experienced a better overall quality of life in the last year of life in 1993 than those in 1986. Most measures for men and women aged 65 through 84 years improved or did not change.

Prostatic levels of tocopherols, carotenoids, and retinol in relation to plasma levels and self-reported usual dietary intake

This study evaluated how prostatic levels of antioxidants relate to plasma levels and self-reported usual dietary intake. Definition of these relations may aid in interpreting studies of antioxidant exposure and prostate cancer risk. Between July 1996 and April 1997, plasma and prostatic tissue levels of tocopherols, carotenoids, and retinol were measured in 47 men undergoing radical prostatectomy or transurethral prostatectomy at Loyola University Medical Center, Maywood, Illinois, and an affiliate hospital. Dietary intake was measured by using a 122-item version of the Block Health Habits and History Questionnaire, and correlations were assessed with Pearson's coefficients. Prostatic levels of tocopherols and carotenoids (but not retinol) were significantly correlated with plasma levels (r= 0.31-0.56, p < 0.05-0.0001); the strongest correlations were associated with lycopene, beta-carotene, and gamma-tocopherol (0.56, 0.54, and 0.52, respectively; p < 0.0001). Relative concentrations of tocopherols and carotenoids in prostate tissue were proportionate to those in plasma. No correlation between prostatic levels and reported dietary intake was observed (r = -0.09 to 0.16, p < not significant). Adjustment for energy intake, body mass index, and serum lipids did not impact these relations. These results suggest that plasma levels of tocopherols and carotenoids better reflect prostatic exposure than self-reported usual dietary intake.

Effect of anti-cardiac myosin antibody on prognosis of patients with acute myocardial infarction

To study whether there was an anti-cardiac myosin antibody (AMA) in serum of patients with myocardial infarction (AMI), relationship between AMA and the prognosis in patients with AMI was investigated. In 67 patients with acute AMI, AMA was assayed by ELISA and left ventricular structure and cardiac function were examined by echocardiography at the end of the first week after infarction and during a 6-month follow-up. The patients with AMI were divided into AMA-positive group and AMA-negative group. The parameters of left ventricular end-diastolic function and prognosis were compared between the two groups. Results showed that the AMA was positive in 18 patients with AMI, with a positive rate of 26.87%, while it was negative in 20 health donors. The locations of myocardial infarction in the two groups were similar. There were significant differences in Killip class I (22.22% vs 55.10%, P < 0.05), decreasing of wall motion and ventricular aneurysm (92.85% vs 37.5%, P < 0.01) between the positive group and the negative group. During a 6-month follow-up, the mortality was higher in AMA positive group than in AMA negative group (38.89% vs 10.20%, P < 0.05). It is concluded that AMA can be detected in serum of patients with AMI and can serve as an important autoimmune marker. The autoimmune response might take place in AMI. AMA was associated with the left ventricular remodeling and the prognosis of AMI.

[Determination of plasma homocysteine by high performance liquid chromatography with fluorescence detection]

This article report a highly sensitive method specific for the determination of homocysteine in plasma by high performance liquid chromatography with fluorescence detection. Half mL plasma with 100 microL 0.11 mol/L sodium borohydride in 50 mmol/L Tris-HCl (pH 9.0) was kept at 30 degrees C for 30 min, and then 0.5 mL 0.5 mol/L perchloric acid was added. After the mixture was kept at room temperature for 10 min and centrifuged at 15,000 r/min for 10 min, 0.5 mL aliquots of the supernatant solution was pipetted into another vial containing 0.1 mL 3 mmol/L Bromobimane in 1.0 mol/L Na2EDTA (pH 7.0) and 0.7 mL of 90 mmol/L ammonium bicarbonate buffer containing 1.43 mol/L Na2EDTA, pH 8.0. The content was mixed, kept at 37 degrees C for 30 min and centrifuged at 15,000 r/min for 10 min. Then 10 microL aliquots of the supernatant solution was injected into a high performance liquid chromatograph with fluorescence detector. The chromatographic conditions were as follows: an ODS column (4.6 mm i.d. x 150 mm, 5 microns), was eluted with a flow rate of 1.0 mL/min. The fluorescence detector was operated at lambda ex 365 nm and lambda em 475 nm. Mobile phase frompump A was 3% methanol containing 0.25% acetic acid. In gradient elution program the methanol from pump B was as follows: 0-8 min, 5%; 8-15 min, 5%-12%; 15-20 min, 12%; 20-30 min, 12%-20%; 30-32 min, 20%; 32-35 min, 20%-100%; 35-40 min, 100%; 40-43 min, 100%-5%; 43-45 min, 5%. The method proved to be linear in the range of 2.5-80.0 mumol/L with a regression coefficient of 0.9988. The minimum detection limit was 0.5 mumol/L, the recoveries were 94.0%-112.0%, and the RSD values were less than 5.6%.

Influence of the I/D polymorphism of the angiotensin-converting enzyme gene on the outcome of microalbuminuria in essential hypertension

The objective of the present study was to analyze the influence of the I/D polymorphism of the ACE gene on the outcome of microalbuminuria in essential hypertensive patients who were receiving antihypertensive treatment. One hundred thirty-six essential hypertensive patients who were <50 years old and had never previously received treatment with antihypertensive drugs were included in the study. During a 3-year period, patients received nonpharmacological treatment consisting of moderate salt restriction and a low-calorie diet they were obese, with or without a regimen of antihypertensive drugs based on beta-blockers or ACE inhibitors. Hydrochlorothiazide was added when necessary to maintain the blood pressure goal of <135/85 mm Hg. At the beginning of the study and at yearly intervals, systolic and diastolic blood pressures (SBP and DBP, respectively), 24-hour urinary albumin excretion (UAE), renal function, and biochemical profile measurements were made. The insertion/deletion (I/D) polymorphism of the ACE gene was determined through the use of polymerase chain reaction. The variables used in the statistical analysis were the measurements at the start of the study and the increase or decrease detected during the follow-up, estimated as individual specific regression line slope values. At baseline, no differences in blood pressure or UAE values were observed among genotypes. Likewise, the genotype or allele frequency was not significantly different between normoalbuminurics and microalbuminurics. After the 3 treatment years, significant reductions in SBP, DBP, and UAE were found (SBP 151.6+/-17.3 reduced to 137.2+/-14.3 mm Hg, P<0.001; DBP 96.6+/-8.9 reduced to 84.5+/-9.8 mm Hg, P<0.001; UAE 36.7+/-71.5 reduced to 28.3+/-78.6 mg/24 h, P<0. 05). The slopes of these parameters over time did not differ significantly among genotypes. The slope of SBP was the main factor related to the slope of logUAE (P<0.003). A significant positive correlation coefficient between the SBP and logUAE slopes was observed for the DD patients (r=0.57, P<0.0001) but was absent in patients carrying the I allele (II r=-0.03, P=NS; I/D r=0.01, P=NS). Follow-up studies should be used to achieve a better understanding of the impact of candidate gene polymorphisms on the development of hypertension-induced organ damage. Assessment of the I/D polymorphism of the ACE gene may identify subjects who require a greatly lowered blood pressure to prevent organ damage and to reduce hypertension-associated complications and death.

Value of quantitative analysis of serum cTnT in diagnosis of cardiac disease and myocardial injury

Serum cTnT, CK-MB and LD1 were measured in 30 patients with AMI, 76 patients with VMC, 12 patients who had undergone operation without cardioplegia, 16 patients who had received open heart operation, 15 patients who had undergone thoracotomy for non-heart surgery and 55 healthy people. Concentration of serum cTnT was 0.057 +/- 0.056 microgram/L in healthy people, 0.069 +/- 0.032 microgram/L in patients who underwent thoracotomy for non-heart surgery, 0.328 +/- 0.472 microgram/L in patients with VMC, 0.388 +/- 0.279 microgram/L in patients with DCM, 4.259 +/- 4.619 micrograms/L in patients with AMI, 8.55 +/- 6.78 micrograms/L in patients who had undergone operation without cardioplegia and 16.03 +/- 6.01 micrograms/L in heart operation patients. In patients with VCM and DCM, serum cTnT was more specific and sensitive than CK-MB and LD1 for diagnosing myocardial injury. In patients with AMI and heart operation patients, the increasing multiple of serum cTnT was obviously higher than that of CK-MB and LD1. 72 h after heart operation, cTnT was still higher than normal, while CK-MB had returned to normal level. Serum cTnT had higher specificity and sensitivity and longer diagnostic period in diagnosing myocardial injury. Moreover, cTnT assay could indicate the degree of myocardial injury. So, quantitative analysis of cTnT can be used as a routine examination in the diagnosis of myocardial injury.

HLA-DRB1 gene polymorphism in patients with dilated cardiomyopathy

To probe into the genetic background and immunopathogenesis of dilated cardiomyopathy (DCM), HLA-DRB1 gene polymorphism in 68 patients with DCM and 175 normal control subjects were analyzed by using the polymerase chain reaction/sequence specific primer (PCR/SSP) techniques. It was found that the frequencies of HLA-DRB1* 15 and HLA-DRB1* 03 alleles were significantly lower in DCM patients than those in normal controls (14.71% vs 29.71% and 4.41% vs 15.43%, respectively), the relative risks (RR) in the DCM patients being 0.41 and 0.25, respectively, all P < 0.05. However, the frequencies of HLA-DRB1* 11 and HLA-DRB1* 12 alleles were significantly higher in the DCM patients than in controls (29.4% vs 12.00% and 36.76% vs 12.57%, respectively) with the RR in the DCM patients being 3.06 and 4.04, respectively, all P < 0.01. These findings further demonstrated that immunogenetics might play a predominant pathogenetic role in partial DCM patients.

RA-GEF, a novel Rap1A guanine nucleotide exchange factor containing a Ras/Rap1A-associating domain, is conserved between nematode and humans

A yeast two-hybrid screening for Ras-binding proteins in nematode Caenorhabditis elegans has identified a guanine nucleotide exchange factor (GEF) containing a Ras/Rap1A-associating (RA) domain, termed Ce-RA-GEF. Both Ce-RA-GEF and its human counterpart Hs-RA-GEF possessed a PSD-95/DlgA/ZO-1 (PDZ) domain and a Ras exchanger motif (REM) domain in addition to the RA and GEF domains. They also contained a region homologous to a cyclic nucleotide monophosphate-binding domain, which turned out to be incapable of binding cAMP or cGMP. Although the REM and GEF domains are conserved with other GEFs acting on Ras family small GTP-binding proteins, the RA and PDZ domains are unseen in any of them. Hs-RA-GEF exhibited not only a GTP-dependent binding activity to Rap1A at its RA domain but also an activity to stimulate GDP/GTP exchange of Rap1A both in vitro and in vivo at the segment containing its REM and GEF domains. However, it did not exhibit any binding or GEF activity toward Ras. On the other hand, Ce-RA-GEF associated with and stimulated GDP/GTP exchange of both Ras and Rap1A. These results indicate that Ce-RA-GEF and Hs-RA-GEF define a novel class of Rap1A GEF molecules, which are conserved through evolution.

Mortality among US adult Asians and Pacific Islanders: findings from the National Health Interview Surveys and the National Longitudinal Mortality Study

OBJECTIVES

To assess the mortality of the adult Asian and Pacific Islander population in the United States.

METHODS

Cohort study using data from the National Health Interview Survey (1986 to 1994) and the National Longitudinal Mortality Study. Deaths were ascertained by matching the National Death Index with average follow-ups of 5.3 and 9 years, respectively, for the two studies.

RESULTS

Respondents from the pooled National Health Interview Surveys included 532,794 non-Hispanic whites, 94,242 blacks, 52,725 Hispanics, and 16,936 Asians and Pacific Islanders, all of whom were at least 18 years of age at baseline. The National Longitudinal Mortality Study included 373,397 non-Hispanic whites, 41,262 blacks, 23,356 Hispanics, and 8,390 Asians and Pacific Islanders. Overall age-standardized mortality was the lowest in Asians/Pacific Islanders, whose risk of death was about 40% lower than whites'. Adjustment for differences in education levels had a minimal influence on the mortality advantage in Asians/Pacific Islanders.

CONCLUSIONS

Longitudinal cohorts provide an important source of health status information on Asians and Pacific Islanders. These two studies from representative national samples suggest that overall mortality is substantially lower among Asians and Pacific Islanders than in all other major ethnic groups.

Axl-gas6 interaction counteracts E1A-mediated cell growth suppression and proapoptotic activity

The adenovirus type 5 early region 1A gene (E1A) has previously been known as an immortalization oncogene because E1A is required for transforming oncogenes, such as ras and E1B, to transform cells in primary cultures. However, E1A has also been shown to downregulate the overexpression of the Her-2/neu oncogene, resulting in suppression of transformation and tumorigenesis induced by that oncogene. In addition, E1A is able to promote apoptosis induced by anticancer drugs, irradiation, and serum deprivation. Many tyrosine kinases, such as the epidermal growth factor receptor, Her-2/Neu, Src, and Axl, are known to play a role in oncogenic signals in transformed cells. To study the mechanism underlying the E1A-mediated tumor-suppressing function, we exploited a modified tyrosine kinase profile assay (D. Robinson, F. Lee, T. Pretlow, and H.-J. Kung, Proc. Natl. Acad. Sci. USA 93:5958-5962, 1996) to identify potential tyrosine kinases regulated by E1A. Reverse transcription (RT)-PCR products were synthesized with two degenerate primers derived from the conserved motifs of various tyrosine kinases. A tyrosine kinase downregulated by E1A was identified by analyzing the AluI-digested RT-PCR products. We isolated the DNA fragment of interest and found that E1A negatively regulated the expression of the transforming receptor tyrosine kinase Axl at the transcriptional level. To study whether downregulation of the Axl receptor is involved in E1A-mediated growth suppression, we transfected axl cDNA into E1A-expressing cells (ip1-E1A) to establish cells that overexpressed Axl. The Axl ligand Gas6 triggered a greater mitogenic effect in these ip1-E1A-Axl cells than in ip1-E1A control cells and protected the Axl-expressing cells from serum deprivation-induced apoptosis. These results indicate that downregulation of the Axl receptor by E1A is involved in E1A-mediated growth suppression and E1A-induced apoptosis and thereby contributes to E1A's antitumor activities.

[A comparative study of finger plethysmography and aortic pressure for monitoring the effect of external counterpulsation]

Invasive pressure detecting and monitoring of aortic root was conducted in 20 volunteers so as to study the effect of Enhanced External Counterpulsation (EECP) on aortic pressure and finger plethysmography. The results demonstrated that the changes of aortic diastolic pressure linearly related to the counterpusation's bladder pressure, and the aortic augmentation increased to the top of 168.56 mmHg with a D/S ratio of 2.75(amplitude ratio of diastolic waveform and systolic waveform, D/S ratio) following the bladder pressure of 0.45 Kg/cm2. With the increase of bladder pressure, the dp/dt of aortic augmentation elevated gradually, but a down-regulating trend was seen in systolic waveform. During EECP, the starting time of plethysmographic augmentation had a mean delay of 108.20 +/- 25.70 ms comparing with that of aortic augmentation. The duration between the starting time of aortic systolic waveform and that of finger plethysmogram was arround 96.69 +/- 38.70 ms. When the bladder pressure changed, no significant difference was observed among them. The D/S ratio of finger plethysmographic waveform changed in concord with that of aortic pressure with the promotion of bladder pressure. Therefore, a relationship between aortic D/S ratio (Y) and plethysmographic D/S ratio (x) was constructed by the linear regression analysis: Y = 0.376 + 0.457X. It can be concluded that EECP has significant effects on aortic D/S ratio, aortic peak augmentation and its dp/dt value. Finger plethysmography, to date, still plays important roles in monitoring and controlling EECP work safely and effectively.

Synchronous, dual-wavelength, injection-seeded amplification of 5-ns pulses in a flash-lamp-pumped Ti:sapphire laser

The outputs of two cw diode lasers are coupled into a flash-lamp-pumped Ti:sapphire laser cavity for regenerative amplification. Slices of each seed beam are simultaneously trapped in the cavity and amplified for approximately 33 round trips. The output is a 4.7-ns pulse, the total pulse energy is 110 mJ, and linewidths are only 50% greater than the Fourier-transform limit. The timing jitter between the pulses at the two wavelengths is less than +/-75 ps , and their relative energy is controlled by adjustment of the seed power of the cw diode lasers. Gain competition between the two frequencies does not lead to instabilities.

[Investigation of aluminum oxide matrix of the machinable infiltrated ceramic(MIC)]

OBJECTIVE

To explore the effects of different powder/liquid ratio during the procedure of aluminum oxide slip preparation on the properties and microstructure of the machinable infiltrated ceramic(MIC) aluminum matrice.

METHODS

PI alpha-Al2O3 powder was employed in this study. Aluminum slip with different powder/liquid ratios of 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5 and 10.5 was prepared separately. Specimens were slip-casted and pre-fired, and whose physical properties were determined and morphology of specimens was examined under scanning electromicroscope.

RESULTS

The packing density increased while the linear shrinkage decreased, when the powder/liquid ratio increased. Elevated pre-firing temperature resulted in higher flexural strength of the matrice. The matrice demonstrated porous morphology under electromicroscope, and neck-fusion between Al2O3 particles was observed and increased with elevated prefiring temperature.

CONCLUSION

MIC is a kind of easy-manipulated material with high packing density, optimum porosity and lower linear shrinkage, so it may be an ideal aluminum matrix for infiltrated ceramic.

Pressure tuning of thermal lensing for high-power scaling

A new concept is introduced whereby thermal stresses generated through the pumping process are canceled by an applied force. By use of a Nd:YVO(4) disk laser as a model system, significant reduction of thermal lensing and deformation is demonstrated as a function of applied pressure, and the output power (19 W TEM(00)) is limited only by the available pump power.

[Pharmacognostic identification of Ampelopsis grossedentata]

Pharmacognostic identification of Ampelopsis grossedentata was carried out by studying its microscopic characteristics, UV spectra and TLC. The results may provide a scientific basis for the comprehensive development and utilization of the drug.

Substituted coumarins as esterase-sensitive prodrug moieties with improved release rates

Our laboratory has recently reported a coumarin-based prodrug system for the preparation of esterase-sensitive prodrugs of amines, peptides, and peptidomimetics. However, the release from this prodrug system was undesirably slow for some drug moieties. In this report, we describe the synthesis and evaluation of several substituted coumarin-based prodrugs of model amines with significantly increased release rates.

Prediction of coronary heart disease mortality in blacks and whites: pooled data from two national cohorts

Statistical models used to predict personal risk of death from coronary heart disease (CHD) have been based on studies among white populations. We compared the predictive functions derived from black and white men and women, using the pooled data of 2 national cohorts: the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study and the Second National Health and Nutrition Examination Survey (NHANES II) Mortality Study. The participants included 6,937 white men, 940 black men, 9,202 white women, and 1,463 black women aged 30 to 74 years who were free of CHD at baseline. The 2 cohorts were followed for 20 and 15 years, respectively. There were no significant differences between blacks and whites in the magnitude of the Cox coefficients for most of the personal risk factors (i.e., age, systolic blood pressure, serum total cholesterol, smoking, and diabetes mellitus status) for men and women. The receiver operating characteristic (ROC) analyses, with all risk factors considered collectively, suggest that the models have similar ability to rank personal relative risk among blacks and whites. The areas under the ROC curve were 0.77 and 0.76 for white and black men, respectively, and 0.84 and 0.82 for white and black women, respectively. However, the equation derived from white men overestimated the 15-year cumulative CHD mortality in black men by about 60%. Thus, predictive functions derived from 1 demographic group (e.g., whites) can be applied to another subgroup (e.g., blacks) to rank personal risk. However, prediction of absolute risk is less accurate.

New (sulfonyloxy)piperazinyldibenzazepines as potential atypical antipsychotics: chemistry and pharmacological evaluation

A series of 2- or 8-trifluoromethylsulfonyloxy (TfO) and 2- or 8-methylsulfonyloxy (MsO) 11-piperazinyldibenzodiazepines, -oxazepines, and -thiazepines were synthesized and evaluated in pharmacological models for their potential clozapine-like properties. In receptor binding assays, the 2-TfO analogues (18a, GMC2-83; 24, GMC3-06; and previously reported GMC1-169, 9a) of the dibenzazepines have profiles comparable to that of clozapine, acting on a variety of CNS receptors except they lack M1 receptor affinity. Introduction of 2-TfO to clozapine leads to compound 9e (GMC61-39) which has a similar binding profile as that of clozapine including having M1 receptor affinity. Interestingly, the MsO analogues, as well as the 8-TfO analogues, have no or weak dopaminergic and serotonergic affinities, but all 8-sulfonyloxy analogues do have M1 affinities. In behavioral studies performed to indicate the potential antipsychotic efficacy and the propensity to induce EPS, 2-TfO analogues blocked effectively the apomorphine-induced climbing in mice in a dose-dependent manner with ED50 values (mg/kg) of 2.1 sc for 9a, 1.3 po for 18a, 2.6 sc for 24, and 8.2 sc for 9e. On the other hand, they showed a clear dose separation with regard to their ED50 values (mg/kg) for indicating catalepsy in rats (>44 sc for 9a, 28 po for 18a, 30 sc for 24, and >50 sc for 9e, respectively), thus implicating a more favorable therapeutic ratio (K/A, ED50 climbing/ED50 catalepsy) in comparison with typical neuroleptics such as haloperidol and isoclozapine. Furthermore, compound 18a was also demonstrated to be an orally potent DA antagonist with an ED50 value of 0.7 mg/kg po in the ex vivo L-DOPA accumulation model. The present study contributes to the SAR of 11-piperazinyldibenzazepines, and the 2-TfO analogues of 11-piperazinyldibenzazepines are promising candidates as clozapine-like atypical antipsychotics with low propensity to induce EPS.

Black-white differences in disability and morbidity in the last years of life

To assess black-white differences in disability and morbidity in the last years of life, the authors analyzed data from the National Health Interview Survey from 1986 to 1994, with mortality follow-up through December 1995. A baseline household interview was conducted for 10,187 decedents aged 50 years and over within 2 years before death. Data collected included long-term limitation of activity, number of chronic conditions, number of bed days, doctor visits, and days of short hospital stay during the year preceding the interview. For both blacks and whites, educational attainment was inversely associated with disability/morbidity indices. Black decedents had greater morbidity compared with whites, and this difference was consistent across educational levels. Adjustment for education reduced the black-white difference in limitation of activity score by 32%, bed days by 59%, and hospital stay days by 40%. This study from a national representative US sample indicates that black decedents experienced greater disability/morbidity and worse quality of life through their last few months or years of life. Educational attainment was associated with morbidity before death and accounted for much of the black-white difference.

[Capillary free zone electrophoresis of globin chains]

OBJECTIVE

To introduce a new technique for rapid separation of globin chains from clinical samples.

METHODS

The authors used the uncoated capillary and the electrophoresis buffer which contained 100mmol/L NaH2PO4 +7mmol/L urea +1% Triton X-100 +1% 2-mercaptoethanol +0.25% PEG-600. Capillary free zone electrophoresis was employed in analyzing the hemoglobin-water solutions which were made from HbA control and 74 clinical blood samples. The globin chains were separated from the samples.

RESULTS

IN 40 minutes, five globin chains: alpha, beta, Ggamma, delta, Agamma were separated clearly by capillary free zone electrophoresis using nanolitres of sample. In electrophoresis figure the baselines were stable and the peaks were clear. The time coefficient of variation (CV) was under 3%, and the area CV below 4%. Also, The authors measured the relative concentration of globin chains from 60 normal cases and 14 thalassemia patients.

CONCLUSION

The capillary free zone electrophoresis for the separation of globin chains from clinical samples has been successfully achieved. It is a rapid, simple and sensitive technique suitable for rapid diagnosis of hemoglobinopathies.

How generalizable are coronary risk prediction models? Comparison of Framingham and two national cohorts

BACKGROUND

Previous models used to predict individual risk of death from coronary heart disease (CHD) were developed from data of 3 decades ago from the Framingham Heart Study. CHD mortality rates have declined markedly since that period as a result of improvement in both risk factor status and medical interventions. Generalization of the results from this one study to the population at large remains a matter of concern. We compared predictive functions derived from the major risk factors for CHD from Framingham and 2 more recent national cohorts, the First and Second National Health and Nutrition Examination Survey (NHANES I and NHANES II).

METHODS AND RESULTS

The participants included 1846 men and 2323 women 35 to 69 years of age and free of CHD at the fourth examination (1954 to 1958) from the Framingham Study; 2753 men and 3858 women from the NHANES I (1971 to 1975); and 2655 men and 3050 women from NHANES II (1976 to 1980). The 3 cohorts were monitored for 24, 20, and 15 years, respectively. Significant heterogeneity existed among studies in the magnitude of the Cox coefficients for the individual factors (ie, age, systolic blood pressure, serum total cholesterol, and smoking status), especially among men. When risk factors were considered collectively, however, functions derived from and applied to different cohorts had a similar ability to rank individual risk. The areas under the receiver operating characteristic curves were 0. 71 to 0.76 in men and 0.76 to 0.81 in women when different risk functions were applied to their own population or to a second population. The cumulative CHD survival observed in women in the 2 national cohorts was close to what was predicted from the Framingham equation. However, Framingham overestimated the cumulative CHD mortality rates in men in NHANES I and NHANES II.

CONCLUSIONS

The Framingham risk model for the prediction of CHD mortality rates provides a reasonable rank ordering of risk for individuals in the US white population for the period 1975 to 1990. However, prediction of absolute risk is less accurate.