[Determination of normal temperature properties of refractory die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the normal temperature properties of the refractory die material compatible with slip casting core.

METHODS

to mix the die material at five different ratios (8/1, 7.5/1, 7/1, 6.5/1, and 6/1) and measure their solidification time with self-manufactured Vicker's needle; to prepare five cylindrical specimens (phi 10 x 15 mm) in different drying time for determining their compressive strength, and then to let another five specimens fire at 1000 degrees C four times for measuring the residual compressive strength at room temperature.

RESULTS

The setting time was 16.25 minutes (7.5/1), and the lower the powder-liquid ratio, the longer the setting time. The normal compressive strength was 25.32 MPa (drying 24 hours), while the longer the drying time, the higher the compressive strength achieved (P < 0.01). The residual compressive strength was 24 MPa.

CONCLUSION

The normal temperature properties of the refractory die material meet the demand of slip casting core of sintered powder.

Association of waist circumference with ApoB to ApoAI ratio in black and white Americans

BACKGROUND

Although numerous studies have demonstrated obesity as an aspect of the insulin resistance syndrome in cardiovascular disease (CVD), the mechanism is not clear. Central adiposity, acting through many CVD risk factors, including, plasma glucose, insulin, total cholesterol, low density lipoprotein-cholesterol (LDL-C) and lipoprotein moities-apolipoprotein B (ApoB), apolipoprotein A-I (ApoAI), by atherogenic and thrombotic mechanisms has been proposed as a possible mechanism. In this study, we examined the relationship between central fat distribution (defined by waist circumference) and the ratio of these lipoproteins (ApoB/ApoAI).

SUBJECTS AND METHODS

Association between ApoB/ApoAI ratio and waist circumference was compared in Blacks (n = 854) and Whites (n = 2552) using the NHANES III population-based samples. Correlation analyses and multiple regression analyses were used to determine the association between ApoB/ApoAI and waist circumference, controlling for age, body mass index (BMI), race, gender, plasma glucose, insulin, serum triglyceride and total cholesterol.

RESULTS

Adjusting for age, ApoB/ApoAI was significantly correlated with waist circumference (Black men: r = 0.38, White men: r = 0.26, Black women: r = 0.20, White women: r = 0.36) (all P < 0.01). Adjusting for age and triglyceride or insulin, waist circumference was also positively correlated with CVD risk factors including, ApoB, LDL-C, plasma glucose and fasting insulin, and inversely correlated with ApoAI and HDL-C in Blacks and Whites (P < 0.05). Overall, triglyceride and total cholesterol were the strongest predictors of ApoB/ApoAI in Blacks and Whites adjusting for age, BMI and insulin, than waist girth (P < 0.01).

CONCLUSIONS

The result of this study suggests the need to investigate ApoB/ApoAI as another possible facet in the insulin resistant syndrome.

[Determination of high temperature compressive strength and refractory degree of die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the high temperature properties of the refractory die material compatible with slip casting core.

METHODS

To prepare three cylindrical specimens (phi 10 x 15 mm) and determine their compressive strength at 1000 degrees C: to make four specimens in flat-topped cone for determining the practical refractory degree by decreasing the pressing temperatures in a sequence of 1420, 1400, 1350 and 1100 degrees C.

RESULTS

The compressive strength of this material was 17.8 MPa at 1000 degrees C. Its practical refractory degree was higher than 1100 degrees C.

CONCLUSION

The high temperature properties of the refractory die material that we developed meet the demand of slip casting core of sintered powder.

Socioeconomic status and morbidity in the last years of life

OBJECTIVES

This study evaluated the effect of socioeconomic status, as characterized by level of education, on morbidity and disability in the last years of life.

METHODS

The analysis used data from the National Health Interview Survey (1986-1990), with mortality follow-up through December 1991.

RESULTS

Among 10,932 decedents 50 years or older at baseline interview, educational attainment was inversely associated with long-term limitation of activity, number of chronic conditions, number of bed days, and days of short hospital stay during the year preceding the interview.

CONCLUSIONS

Decedents with higher socioeconomic status experienced lower morbidity and disability and better quality of life even in their last years of life.

Association of nonspecific minor ST-T abnormalities with cardiovascular mortality: the Chicago Western Electric Study

CONTEXT

Minor electrocardiographic (ECG) ST-T abnormalities are common, but their prognostic importance has not been fully determined.

OBJECTIVE

To examine associations of single (1 time only) and multiple (2 times only and > or =3 times) nonspecific minor ST-T abnormalities in 5 years with long-term mortality due to myocardial infarction (MI), coronary heart disease (CHD), cardiovascular disease (CVD), and all causes in middle-aged men.

DESIGN

Prospective cohort study (29-year follow-up after 5 annual examinations).

SETTING AND PARTICIPANTS

A total of 1673 men employed at the Western Electric Company in Chicago, III, aged 40 to 55 years at entry, with no evidence of CHD and no major ECG abnormalities throughout the first 5-year period.

MAIN OUTCOME MEASURES

Minor ST-T abnormalities identified from annual resting ECGs and mortality ascertained from death certificates.

RESULTS

Of the 1673 men, 173 had evidence of isolated nonspecific minor ST-T segment abnormalities. During the follow-up period, there were 234 deaths due to MI, 352 deaths due to CHD, 463 deaths due to CVD, and 889 deaths due to all causes. For men with 3 or more annual recordings of minor ST-T abnormalities, risk of death due to MI, CHD, CVD, and all causes was significantly greater than for those with normal ECG findings. For men with 3 or more ECGs with minor ST-T abnormalities, relative risks (and 95% confidence intervals) adjusted for cardiovascular and other risk factors were 2.28 (1.16-4.49), 2.39 (1.39-4.12), 2.30 (1.44-3.68), and 1.60 (1.06-2.42), respectively, with a graded relationship between frequency of occurrence of ST-T abnormalities and mortality risk (linear trend, P< or =.007).

CONCLUSIONS

Persistent, minor, nonspecific ST-T abnormalities are associated with increased long-term risk of mortality due to MI, CHD, CVD, and all causes; the higher the frequency of occurrence of minor ST-T abnormalities, the greater the risk. These data underscore the potential value of including nonspecific ECG findings in the overall assessment of cardiovascular risk.

[Determination of major expansion properties of refractory die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

To determinate major expansion properties of refractory die material.

METHODS

The setting expansion ratio of refractory die material for slip casting core of sintered titanium powder at room temperature was performed, as well as thermal expansion ratio from room temperature to 800 degrees C.

RESULTS

The maximum setting expansion ratio in 2 hours reached 0.3407%; The final setting expansion ratio in 24 hours was 0.3117%; The mean thermal expansion coefficient was mainly in range of 8 x 10(-6)-11 x 10(-6)/degree C; The expansion property seemed very stable after sintering repeatedly and the small shrinkage after sintering could be compensated with the die spacer and setting expansion.

CONCLUSION

The expansion properties of the refractory die material that we synthesized can fulfil the application requirements of slip casting core of sintered titanium powder.

Self-reported health status and mortality in a multiethnic US cohort

The authors examined the relation between self-reported health status and mortality among the following racial/ethnic groups: Native Americans, Asian/Pacific Islanders, blacks, whites, and Hispanics. They pooled 1986-1994 data from the National Health Interview Survey to obtain information on more than 700,000 cohort participants. Although fewer than 5,000 Native Americans are included in this cohort, the data provide information previously unavailable for this group. Also included are almost 17,000 Asian/Pacific Islanders, over 90,000 blacks, and over 50,000 Hispanics. The authors found strong associations between self-reported health status and both socioeconomic status and subsequent mortality. A self-report of fair or poor health was associated with at least a twofold increased risk of mortality for all racial/ethnic groups. Even after adjustment for socioeconomic status and measures of comorbidity, a significant relation was found between self-reported health status and subsequent mortality. The authors found that self-reported health status is a strong prognostic indicator for subsequent mortality for both genders and all racial/ethnic groups examined. These results emphasize the utility of using simple filter questions in population research.

Treatment of congenital aneurysms of the left atrium and left atrial appendage

We report 2 cases of congenital aneurysm, 1 of the left atrium and 1 of the left atrial appendage. The patients were 14 and 27 years of age, respectively. Their common symptoms were paroxysmal palpitations and dyspnea. Diagnoses were suggested by chest radiographic films that revealed prominent convexity at the upper left border of the heart and were confirmed by echocardiography, which demonstrated a large cystic mass attached to the left atrium in each case. Aneurysmectomy was performed through a median sternotomy or a left thoracotomy, with cardiopulmonary bypass in 1 patient and without it in the other. Both patients were discharged, free of symptoms, in sinus rhythm. We conclude that echocardiography can provide a clear diagnosis and that aneurysmectomy is the treatment of choice.

Identification of Ce-AF-6, a novel Caenorhabditis elegans protein, as a putative Ras effector

Mammalian Ras proteins associate with multiple effectors, including Raf, Ral guanine nucleotide dissociation stimulator, phosphoinositide 3-kinase and AF-6. In the nematode Caenorhabditis elegans, LIN-45/Raf has been identified genetically as an effector of LET-60/Ras. To search for other effectors in C. elegans, we carried out a yeast two-hybrid screening for LET-60-associating proteins. The screening identified a novel protein, designated Ce-AF-6, which exhibited a strong structural homology with human AF-6, rat Afadin and Drosophila melanogaster Canoe and possessed both the Ras-associating (RA) domain and the PSD-95/DlgA/ZO-1 (PDZ) domain. Ce-AF-6 associated with human Ha-Ras in a GTP-dependent manner, with an efficiency comparable to that of human Raf-1 Ras-binding domain. When the effects of mutations of the Ras effector region residues were examined for associations with various effectors, Ce-AF-6 was found to possess a distinct and the most rigorous requirement for the effector region residues. These results strongly suggest that Ce-AF-6 is a putative effector of Ras that possesses a distinct recognition mechanism for association with Ras.

[Effect of crystalling temperatures on microstructure of dental glass-ceramic]

To know well the effect of crystalling temperature on the microstructure of dental glass-ceramic, the parameters of microstructure such as the type of crystal, crystal percentage, crystal size and crystal form were investigated by altering crystalling temperatures and using scanning electronic microscope, energy dispersive X-ray analysis and X-ray diffraction techniques. The results showed that the crystalline phase was identified to be tetrasilicic fluromica, and the promotion of crystalling temperature contributed to the increased crystal percentage, crystal size and the transformation of crystal form from 830 degrees C to 950 degrees C.

[Clinical and experimental study of Tongqiao tablet in treating catarrhal otitis media]

OBJECTIVE

To assess the effect of Tongqiao tablet (TQT) in treating catarrhal otitis media (COM).

METHODS

Ninety-six patients of COM were randomized into two groups, 52 patients in the treatment group were treated with TQT and 44 patients of the control group were treated with western medicine. Animal experiment study on effect of TQT was also carried out.

RESULTS

The total effective rate and the cure and markedly improved rate of the treatment group were 92.31% and 53.85% respectively, while those in the control group were 68.18% and 27.27% respectively, the difference between the two groups was significant statistically (P < 0.01). The effect of TQT was superior to that of the western medicine. Experimental study indicated that TQT had remarkable inhibiting effect on inflammation and granuloma formation.

CONCLUSION

TQT is an effective drug for treatment of COM.

New antipsychotic agents with serotonin and dopamine antagonist properties based on a pyrrolo[2,1-b][1,3]benzothiazepine structure

The development of a synthetic approach to the novel pyrrolo[2, 1-b][1,3]benzothiazepine and its derivatives and their biological evaluation as potential antipsychotic drugs are described. In binding studies these compounds proved to be potent 5-HT2, D2, and D3 receptor ligands. The more potent benzothiazepine (+/-)-3b was resolved into its enantiomers by using HPLC techniques. In vitro testing confirmed that (-)-3b is a more potent D2 receptor ligand, maintaining high affinity for 5-HT2 receptors. In contrast, the (+)-3b enantiomer presents a 35 times higher affinity for 5-HT2 than for dopamine D2 receptors with a similar dopamine D1 receptor affinity to that of (-)-3b. Overall, (+)-3b shows an "atypical" neuroleptic binding profile, while (-)-3b has a more "classical" profile. Furthermore pharmacological and biochemical testing displayed that the novel benzothiazepine (+/-)-3b is able to increase the extracellular levels of dopamine in the rat striatum and causes a dose-related suppression of apomorphine-induced locomotor activity. At low doses (+/-)-3b does not induce catalepsy, showing atypical antipsychotic properties similar to those of olanzapine. These heterocyclic compouds represent new leads for the development of novel antipsychotic drugs with atypical properties.

Synthesis and pharmacological evaluation of benzofuran-acetamides as "antineophobic" mitochondrial DBI receptor complex ligands

A sries of novel benzofuran analogues of N,N-di-n-hexyl-2-phenylindole-3-acetamide (5, FGIN-1-27), a potent and highly specific mitochondrial DBI receptor complex ligand, were synthesized by a modified Fischer method and found in vitro and in vivo to be equally potent and selective as FGIN-1-27.

[The application of a Salmonella typhimurium biotyping method to the epidemiological surveys and surveillance]

In order to explore a new and effective means to the investigation and surveillance on Salmonella typhimurium infection, the authors applied a biotyping method of S. typhimurium invented by Duguid to the surveillance of nosocomial infection and tracing of infected case as well as cause of food-poisoning. Results showed that the major biotypes of strains isolated from children of acquired nosocomial infection with biotypes of strains from hospital environment and medical staff were quite similar. The biotype of cultures from the urine in a paralytic patient was the same as from the environment of the household and the wife's hands. The biotypes of strains identified from food-poison cases and leftovers was the same as isolated from ducks. It is believed that nosocomicial infection among children was caused by contamination of bacteria in hospital environment and carriers of medical staff. The urinary infection of a paralytic patient was due to environment pollution of the household, but not to nosocomial infection. The food-poisoning case was caused by the consumption of ducks infected with the bacteria.

Influence of left ventricular geometric patterns on prognosis in patients with or without coronary artery disease

OBJECTIVES

We sought to examine patterns of left ventricular (LV) geometry as determined by echocardiography and their association with mortality in patients with or without coronary artery disease (CAD).

BACKGROUND

The independent prognostic role of LV geometry remains uncertain.

METHODS

We performed a cohort study based on 988 consecutive patients who underwent both coronary arteriography for presumed CAD and echocardiography and were followed up for a mean of 9 years (range 5 to 13). Patients were classified into four LV geometry patterns: normal, concentric remodeling, eccentric LV hypertrophy (LVH) and concentric LVH.

RESULTS

Patients with concentric LVH consistently showed the largest increase in LV posterior wall and septal thickness and LV mass index, as well as relative wall thickness (RWT), regardless of status of the coronary arteries. This pattern conferred the highest risk of both all-cause and cardiac mortality. Eccentric LVH moderately increased the risk of death compared with normal geometry; no substantial increase in mortality was noted in patients with concentric remodeling. When LV index and RWT were analyzed as continuous measures and considered in the same Cox proportional hazards model, increases in LV mass were independently associated with risk, but this outcome was less clear for RWT.

CONCLUSIONS

In this series of patients referred to coronary angiography for suspected CAD, LVH conferred most of the predictive information from echocardiography. Patients with both LVH and abnormal RWT--concentric LVH--represent a group with the greatest mortality risk. Concentric remodeling may not be associated with increased risk of death because the predictive value of RWT is not as strong as for LV mass.

[Determination of linear sintering shrinkage rate of slip-casting infiltrated ceramic]

This study tested the linear sintering shrinkage (SS) rate of ceramic infiltrated with different glasses (Vita In-ceram, G I-I La, G I-II La, G I-II Ce), the results showed that the linear SS rate was 0.08%-0.32%, which occurred mainly in the firing stage of alumina (P < 0.05) and glass infiltration had no influences on the dimensional stability of ceramic(P > 0.05). It suggests that the effects of glass infiltration on the dimensional stability of GI glasses were comparable with that of Vita In-ceram.

Neodymium:YAG 30-W cw Laser Side Pumped by Three Diode Laser Bars

A theoretical calculation of pump power deposition in a direct water-cooled Nd:YAG laser rod, side pumped by three diode laser bars is presented. The pumping cavity design provides a nearly uniform pump profile. More than 30-W cw output power with optical-to-optical efficiencies of more than 30% are obtained.

Direct enantiomeric separation of mianserin and 6-azamianserin derivatives using chiral stationary phases

The direct enantiomeric separation of mianserin and 6-azamianserin and some of their derivatives, respectively, by means of HPLC using two different chiral selectors was investigated. For the cellulose-based Chiralcel OD column, a strong dependence of the lipophilicity of the compounds tested on the retention behaviour was observed. To some extent, this was also found for the enantiomeric separation on the amylose-based Chiralpak AD column. In some cases a complementary behaviour of these two phases was observed: racemic mixtures that could not be separated by one column could be resolved by the other one.

Mortality and optimal body mass index in a sample of the US population

In this paper, the authors model the nonmonotonic relation between body mass index (BMI) (weight (kg)/height2 (m2)) and mortality in 13,242 black and white participants in the NHANES I Epidemiologic Follow-up Study in order to estimate the BMI at which minimum mortality occurs. The BMI of minimum mortality was 27.1 for black men (95% confidence interval (CI) 24.8-29.4), 26.8 for black women (95% CI 24.7-28.9), 24.8 for white men (95% CI 23.8-25.9), and 24.3 for white women (95% CI 23.3-25.4). Each confidence interval included the group average. Analyses conducted by smoking status and after exclusion of persons with baseline illness and persons who died during the first 4 years of follow-up led to virtually identical estimates. The authors determined the range of values over which risk of all-cause mortality would increase no more than 20% in comparison with the minimum. This interval was nine BMI units wide, and it included 70% of the population. These results were confirmed by parallel analyses using quantiles. The model used allowed the estimation of parameters in the BMI-mortality relation. The resulting empirical findings from each of four race/sex groups, which are representative of the US population, demonstrate a wide range of BMIs consistent with minimum mortality and do not suggest that the optimal BMI is at the lower end of the distribution for any subgroup.

The impact of obesity and body fat distribution on ambulatory blood pressure in children and adolescents

To assess the relationship between obesity, body fat distribution, and blood pressure in children and adolescents, various measures of obesity and the waist-to-hip circumference ratio were related to casual and ambulatory blood pressure as measured using a SpaceLabs 90207 monitor during a regular school day. Seventy obese and 70 nonobese children aged 6 to 16 years were included in the study. Regardless of the time period analyzed (24 h, daytime, or nighttime), ambulatory blood pressure and casual blood pressure were significantly higher among the obese children. The differences in systolic blood pressure observed between the groups were attributable to the presence of obesity as estimated by the ponderal index and by skinfold thickness. Similarly, systolic and diastolic loads, as an assessment of high blood pressure values over 24 h, were significantly higher in the obese children when compared to the loads for the nonobese children. Waist-to-hip circumference ratio was independently associated, (in multiple regression analysis) with systolic blood pressure, whether during 24 h, daytime, or nighttime periods, after controlling for age, sex, current height, ponderal index, and tricipital skinfold thickness. This study demonstrates that obesity is a determinant of ambulatory and casual blood pressure. Since obese children with a predominantly abdominal fat mass show higher blood pressure values, evaluation of body fat distribution in children may help to identify subjects more susceptible to developing hypertension later in life.

Alterations of oncogenes, tumor suppressor genes and growth factors in hepatocellular carcinoma: with relation to tumor size and invasiveness

OBJECTIVE

To make a better understanding of the molecular mechanisms involved in recurrence and metastasis of the hepatocellular carcinoma (HCC), some invasion related oncogenes, and growth factors have been investigated.

METHODS

The studies were separately carried out, the results of which were summarized in this article with relation to tumor size and invasiveness of HCC.

RESULTS

The aberration rates of p53 and CDKN2 in HCC were 45.9% and 36.4% respectively, which were higher in invasive HCC compared with non-invasive HCC. H-ras expression was positive in 29.3% of HCC, which was associated with recurrence and extrahepatic metastasis of HCC. Intralesional injection of H-ras antisense gene markedly inhibited the tumor growth and metastasis of HCC in nude mice. The positive rates of transforming growth factor (TGF)-alpha, epidermal growth factor receptor (EGFR) and c-erbB-2 were 45.7%, 47.1% and 92.3% respectively. The expression of EGFR was closely related to TGF-alpha, which was related to HCC recurrence. But no obvious difference of TGF-alpha or c-erbB-2 expression was found between HCC with and without recurrence, or with and without extrahepatic metastasis. Expression of nm23/tissue inhibitor of metalloproteinase (TIMP)-2 was positively associated with the prognosis of HCC patients (Log-rank, P < 0.001). The alterative rates of above-mentioned genes and growth factors in small HCC were slightly lower than that in large ones, but no significant difference was shown except the p53 mutation.

CONCLUSIONS

The p53/CDKN2 mutation, over-expression of H-ras/EGFR, were associated with the invasiveness and recurrence of HCC. H-ras antisense gene might be of potential implication in the control of HCC recurrence and metastasis. Expression of nm23/TIMP-2 was closely related to the prognosis of HCC patients. Biological characteristics remained critical points to the prognosis even in small HCC.

Identification of PLC210, a Caenorhabditis elegans phospholipase C, as a putative effector of Ras

Mammalian Ras proteins regulate multiple effectors including Raf, Ral guanine nucleotide dissociation stimulator (RalGDS), and phosphoinositide 3-kinase. In the nematode Caenorhabditis elegans, LIN-45 Raf has been identified by genetic analyses as an effector of LET-60 Ras. To search for other effectors in C. elegans, we performed a yeast two-hybrid screening for LET-60-binding proteins. The screening identified two cDNA clones encoding a phosphoinositide-specific phospholipase C (PI-PLC) with a predicted molecular mass of 210 kDa, designated PLC210. PLC210 possesses two additional functional domains unseen in any known PI-PLCs. One is the C-terminal Ras-associating domain bearing a structural homology with those of RalGDS and AF-6. This domain, which could be narrowed down to 100 amino acid residues, associated in vitro with human Ha-Ras in a GTP-dependent manner and competed with yeast adenylyl cyclase for binding Ha-Ras. The binding was abolished by specific mutations within the effector region of Ha-Ras. The other functional domain is the N-terminal CDC25-like domain, which possesses a structural homology to guanine nucleotide exchange proteins for Ras. These results strongly suggest that PLC210 belongs to a novel class of PI-PLC, which is a putative effector of Ras.

The relation between income and mortality in U.S. blacks and whites

Differential mortality exists in the United States both between racial/ethnic groups and along gradients of socioeconomic status. The specification of statistical models for processes underlying these observed disparities has been hindered by the fact that social and economic quantities are distributed in a highly nonrandom manner throughout the population. We sought to provide a substantive foundation for model development by representing the shape of the income-mortality relation by racial/ethnic group. We used data on black and white men and women from the longitudinal component of the National Health Interview Survey (NHIS), 1986-1990, which provided 1,191,824 person-years of follow-up and 12,165 mortal events. To account for family size when considering income, we used the ratio of annual family income to the federal poverty line for a family of similar composition. To avoid unnecessary categorizations and prior assumptions about model form, we employed kernel smoothing techniques and calculated the continuous mortality surface across dimensions of adjusted income and age for each of the gender and racial/ethnic groups. Representing regions of equal mortality density with contour plots, we observed interactions that need to be accommodated by any subsequent statistical models. We propose two general theories that provide a foundation for more elaborate and testable hypotheses in the future.