Multiple risk factors of nasopharyngeal carcinoma: Epstein-Barr virus, malarial infection, cigarette smoking and familial tendency

A community-based case-control study was carried out to assess multiple risk factors and familial aggregation of nasopharyngeal carcinoma (NPC). All of the 347 pathologically-confirmed NPC new cases were serially recruited from the National Taiwan University Hospital, and healthy community controls one-to-one matched with cases on age, sex and residence were selected from household registration offices. NPC risk factors were obtained from the study subjects through standardized interviews according to a structured questionnaire. Levels of antibody to EBV-specific DNase (anti-EBV DNase) and IgA antibody to EBV viral capsid antigen (anti-EBV VCA) were determined by standard methods blindly. Multiple logistic regression analysis for matched data showed significant associations of NPC with high levels of anti-EBV DNase and anti-EBV VCA independently. The effect of cigarette smoking on NPC was modified by age. The older the age, the more striking the dose-response relation between cigarette smoking and NPC. There was no significant association between alcohol consumption and NPC. Malarial infection history was associated with NPC with an odds ratio of 2.2, but the association was significant in males only. First-degree relatives of NPC cases had a greater NPC-affected rate than those of matched healthy controls with a relative risk of 19.2, and the heritability of NPC was estimated as 0.60 (95% confidence interval = 0.55-0.64) based on the multifactorial inheritance model. Familial NPC cases were younger than sporadic cases, but environmental risk factors were similar in the two groups.

The hepatocyte protein synthesis defect induced by galactosamine involves hypomethylation of ribosomal RNA

D-galactosamine produces an early defect in protein synthesis, independent of its effects on RNA synthesis. Here we show that the defect in protein synthesis is inherent in purified ribosomal subunits in vitro. Further, galactosamine treatment is associated with an 85% decrease in methylation of ribosomal RNA, involving all sites (2'-0-ribose and base positions), intact ribosomes from galactosamine-treated animals can be methylated to a greater extent than control ribosomes and in vitro methylation restores their functional capacity. Statistical analyses of these data, along with those with a number of other hepatotoxins, reveal a correlation coefficient of r = 0.95 (p less than 0.003) between protein synthetic capacity and ribosomal RNA methylation, and linear regression accounts for more than 90% of the observed variation. In contrast, no relationship was found between nucleolar RNA methylation and protein synthetic capacity. A relationship of borderline statistical significance was found between messenger RNA methylation and protein synthetic capacity, but it does not appear consistent with results obtained after CCl4 intoxication. These results lend strong support to the notion that methylation status of ribosomal RNA is an important control for protein synthesis in quiescent hepatocytes and that net hypomethylation is a common response to such divergent hepatotoxins as CCl4, ethionine and D-galactosamine.

Variations in atrioventricular valve innervation in four species of mammals

In this series of studies, the innervation patterns of whole-mount preparations of bicuspid and tricuspid valves were studied by light microscopy in the mouse, rat, guinea pig, and opossum. The acetylcholinesterase-positive networks of nerve fibers showed many similarities in the basic patterns of valve innervation in all of the species studied, but several interspecies variations were observed. The basal zone of the valve adjacent to the fibromuscular atrioventricular ring displayed the most dense plexus of nerves, with acetylcholinesterase-positive fibers being seen across the width of the valve. In the intermediate zone of the valve, less dense plexuses of nerve fibers were found; and these were more numerous in the cuspal areas and less numerous in the intervening commissural areas. In the distal portions of the valve, nerve networks arborized extensively, with some of their nerve fibers extending toward the chordae tendineae and the free edges of the valve cusps. Only in the guinea pig and opossum did these fibers reach the free margin of the valve cusp, where they either ended directly as free nerve endings or lay parallel to the free edge of the cusp, often running between adjacent chordae tendineae. Although the patterns of innervation were similar in both bicuspid and tricuspid valves, the innervation density of the bicuspid valve was greater than that of the tricuspid valve for each species examined. A distinguishing feature of guinea pig and opossum tricuspid valves was that their chordae tendineae were relatively more prominent and more densely innervated than the bicuspid chordae tendineae. Free nerve endings with no light microscopic evidence of specialization were present throughout the bicuspid and tricuspid valves of all species studied. Some nerve endings in the opossum showed evidence of specialization, with brush-like arborizations leading to presumed free terminals seen chiefly in the distal zone of the valve cusps. Although some general tendencies were apparent, we have demonstrated that interspecies heterogeneity exists in the terminal networks of the atrioventricular valves of mouse, rat, guinea pig, and opossum.

Congenital rubella infection: escape of one monozygotic twin with two amnions, one chorion, and single placenta

We report a 2 amnions, 1 chorion, single placenta, monozygotic identical twins, who were born by a mother with a subclinical rubella infection during the gestation; one twin had a congenital rubella infection, the other escaped from it. Both twins were premature and small for their gestational age at birth. They both had an intraventricular hemorrhage ascribed to prematurity. One had a strong positive rubella IgM antibody for more than 3 months and a persistent IgG antibody for more than 1 year. The other had a fading rubella IgG antibody within 3 months, and a negative IgM. The baby with the congenital infection of rubella did not have a defective appearance, but the auditory brain stem evoked potential test showed abnormal findings. In monozygotic identical twins, vessel communication usually exist and the escape of a twin from rubella is a rare condition; there have been only two such events reported in the English literature.

On multiple training for bidirectional associative memory

The minimal number of times for using a pair for training to guarantee recall of that pair among a set of training pairs is derived for a bidirectional associative memory.

[Right ventricular volumes and ejection fraction estimated by two-dimensional echocardiography]

The right ventricular volumes and ejection fraction (RVEF) obtained from two-dimensional echocardiography and from right ventricular angiography were compared in 20 patients with congenital heart disease. Single plane area-length method of apical four-chamber view was used to estimate echocardiographic right ventricular volumes and single plane right anterior oblique projection was used to calculate angiographic right ventricular volumes. The results showed that right ventricular volumes estimated by echocardiography correlated highly with that calculated by angiography, the correlation coefficients of end-diastolic volume, end-systolic volume and stroke volume were 0.983, 0.976, 0.973 respectively. Echocardiographic RVEF also correlated strongly with angiographic RVEF (r = 0.992, P less than 0.001), and there were no significant difference between the two methods (P greater than 0.05).

CONCLUSION

two-dimensional echocardiography can be used to accurately estimate right ventricular volumes and ejection fraction.

An epidemiological study of behaviour problems in school children in urban areas of Beijing

A total of 2432 primary school children, aged 7-14 yrs. in urban areas of Beijing, were evaluated with the Children's Behaviour Questionnaire developed by Rutter. The frequency of behaviour problems in primary school was 8.3%-7.4% antisocial behaviour and 0.62% neurotic behaviour. Behaviour problems were higher in boys than girls: antisocial behaviour was dominant in boys, while neurotic behaviour was common in girls. The frequency of behaviour problems varied significantly with the different social environments in which the children were brought up, but were not different between one-child families and those with more children.

[Research of the electrophysiological properties of isolated ventricular papillary muscle of rhesus]

The electrophysiological properties of cardiac muscle of rhesus (Macaca mulatta) by use of intracellular electrode technique has been described in this paper. Thirty papillary muscle from 8 rhesus were used for this research and 68 successful records had been obtained. The value of resting potential is -86.26 +/- 7.57 mV (M +/- SD). The configuration of the action potential is typical for the ventricular muscle of mammalian. The amplitude of action potential is 118.80 +/- 10.69 mV: over-shoot is 25.57 +/- 6.11mV. The APD20, APD50, APD80, APD100 is 184.33 +/- 64.04, 301.02 +/- 95.32, 382.17 +/- 125.81 and 436.33 +/- 122.39 ms, respectively. The maximum depolarization velocity of 0 phase is 101.20 +/- 17.59 V/s. The effective refractory period is 292.69 +/- 93.91ms. Comparing the results of the rhesus cardiac muscle with that of other mammalians, authors found that they were very similar. It is suggested that the results and analysis of its mechanism derived from investigation of other mammalian cardiac tissues are applicable to the human.

The cervix-ripening effect of 15-methyl-prostaglandin F2 alpha methyl ester before vacuum aspiration for termination of early pregnancy in primigravidae

A double blind clinical trial on prostaglandin for cervix ripening prior to vacuum aspiration for termination of early pregnancy in primigravidae was carried out in 68 patients with 6-11 week's gestation. The patients were randomly treated with either 1.0 mg of 15-methyl-prostaglandin F2 alpha methyl ester vaginal suppository or a placebo suppository. A mean cervical dilation to 6.6 mm was achieved with minimal side effects in the prostaglandin group as against 4.3 mm in the placebo group. The 15-methyl-prostaglandin F2 alpha methyl ester suppository technique seems to be effective, safe and simple in ripening the cervix for termination of early pregnancy in primigravidae.

The herbal medicine tian ma gou teng yen alters the development of high blood pressure in the spontaneously hypertensive rat

In this study, the effect of the herbal prescription Tian Ma Gou Teng Yen (TGY), which is traditionally used to treat certain diseases associated with elevated arterial pressure (AP), on the general development of hypertension was investigated in the spontaneously hypertensive rat (SHR). An aqueous extract of TGY was given orally (0.5 ml/100g body weight) to 5 week old SHR twice a day for six consecutive days followed by one day without herbal therapy. The herbal prescription was administered until the SHR were 16 weeks of age. Administration of TGY significantly altered the development and prevented hypertension in SHR. On the other hand, heart rate, body weight, food and water intake, and urine volume and electrolytes were not altered. These data suggest that the effect of TGY on AP was through an action of TGY on sympathetic vasomotor activity.

Efficacy of a mass hepatitis B vaccination program in Taiwan. Studies on 3464 infants of hepatitis B surface antigen-carrier mothers

To evaluate the efficacy of the mass hepatitis B vaccination program in Taiwan in interrupting perinatal hepatitis B virus transmission, 3464 randomly selected 18-month-old infant vaccinees born to hepatitis B surface antigen-carrier mothers were recruited from 9697 eligible infants during a six-month period of the program. They were divided into ten groups according to maternal infectivity and compliance with the vaccination schedule. Serum samples were tested for hepatitis B surface antigen, antibody to hepatitis B surface antigen, and antibody to hepatitis B core antigen. In 786 infants who had highly infectious mothers and who received hepatitis B immune globulin and vaccine on schedule, the protective efficacy was about 85%. The efficacy seemed to be slightly lower in those immunized off schedule. Overall, 11% of infants still carried hepatitis B surface antigen, and 81% of the infants had antibody to hepatitis B surface antigen that exceeded 10 mIU/mL in more than 90% of them. The geometric mean titers of antibody to hepatitis B surface antigen were more than 200 mIU/mL in every group of infants. We conclude that the mass vaccination program is efficacious in preventing perinatal hepatitis B virus transmission and the chronic carrier state; most infant vaccinees have adequate levels of protective antibody at 18 months of age. This program is extremely significant in the control of hepatitis B virus infection in Taiwan.

Optical isomers of some piperidine-derived hemicholinium congeners containing secondary alcohol groups: preparation and biological activities

Previous publications on the title compounds, 1 and 2 ('A-4' and 'A-5'), reported pharmacological data on what were probably mixtures of optical isomers of unknown composition. The compounds can exist as an enantiomeric pair as well as a diastereomeric meso isomer. In the present work, all possible stereoisomers (meso and dextrorotatory and levorotatory isomers) of the piperidine derivatives 'A-4' and 'A-5' have been isolated, identified, and characterized, and pharmacological data have been obtained on all products. In all of the bioassays conducted, optical isomers of each structure exhibited similar qualitative and quantitative effects. We conclude that the stereochemical nature of the chiral centers bearing secondary alcohol groups in these molecules does not play a critical role in interactions with in vivo receptors, and therefore that the alcohol groups in 'A-4' and 'A-5' are not prime sites of interaction(s) with receptor(s).

B-cell lymphoproliferation and lymphomagenesis are associated with clonotypic intracellular terminal regions of the Epstein-Barr virus

We analyzed 17 B-cell lineages cloned from two patients with infectious mononucleosis and found that different B-cell lineages exhibited notable variation in the length of the fused Epstein-Barr virus (EBV) terminal region on intracellular EBV episomes. EBV termini in different B-cell clones from the same person differed by as many as 15 to 20 reiterations of the ca. 500-base-pair terminal repeat sequence. In contrast, analysis of seven B-cell lineages cloned from a patient with a fatal, oligoclonal lymphoma revealed that three of the cell clones had the same-sized EBV terminal region. These three clones had previously been shown, by immunoglobulin gene analysis, to be metastatic daughter cells descended from a common progenitor. Similarity of the EBV terminal regions in the three daughter clones suggested that EBV infected the progenitor cell before proliferation and metastasis. Individual, EBV-infected cells from a single individual showed sufficient heterogeneity in their EBV termini to allow use of terminal fragment size as a clonal marker in studies addressing the contribution of EBV to the clonal pathogenesis of tumors with which this virus has been associated.

Study of different phases in growth cycle of human bone marrow cells and their growth speed, using rat-human cell hybridization, premature chromosome condensation, and sister chromatid differentiation techniques

The cytokinetic activity of bone marrow cells is an indication of hemopoietic status. In the routine examination of bone marrow smears, only M phase can be identified, whereas the different phases of the remainder of the cell cycle are not possible to determine. However, by using premature chromosome condensation and bromodeoxyuridine differential staining techniques, cell stage and cell kinetics can be easily determined. Ninety-eight samples of human bone marrow were collected, cells were hybridized with mitotic M3 cells, and 5016 randomly selected hybrid cells were analyzed for cell stage. Our data demonstrated that 80.37% of the cells were in G1 phase, 12.66% were in S phase, 5.29% were in G2 phase, and 1.68% were in M phase. In specimens that had been cultured for 48 h in the presence of bromodeoxyuridine, 57.46% had completed at least two rounds of DNA replication. In 72-h specimens, 69.27% of the cells had completed at least two S phases. In 96-h specimens, 2S and 2S+ cells occupied 74% of the cell population. The use of cell hybridization techniques, premature chromosome condensation, and bromodeoxyuridine-dependent differential staining revealed the phases of the cell cycle distinctly, as well as the kinetics of cell growth.

Cloning and characterization of a human ribosomal protein gene with enhanced expression in fetal and neoplastic cells

Hepatocellular carcinoma is strongly associated with hepatitis B virus carrier patients who usually have HBV sequences integrated in the chromosomal DNA of liver cells. To assess the possible effects of HBV regulatory sequences (e.g., the enhancer) on expression of neighboring host genes we have screened for cellular genes that are both overexpressed and adjacent to integrated HBV sequences in hepatocellular carcinoma cells. The cloned cDNA for one such gene encodes a protein similar to the E. coli L-3 ribosomal protein which is thought to play a role in mRNA binding to the ribosome. The protein encoded by the cDNA localizes to the nucleolus and is also found in ribosomes; possibly it is the mammalian homologue of L-3 (MRL3). The expression of MRL3 is higher in colon carcinoma and lymphoma cell lines than in normal liver, placenta and diploid fibroblasts, and is also higher in fetal than in adult liver. Therefore, MRL3 overexpression seems to be a property of rapidly dividing cells and is not directly linked to oncogenesis.

Borderline immunodeficiency in male homosexuals: is life-style contributory?

Results of our study suggest that white Southern male homosexuals without clinical evidence of AIDS who patronize "gay bars" may have significant zinc deficiency and moderately depressed T-helper/T-suppressor cell ratios. No single causative factor could be identified to explain the significantly low zinc and elevated copper levels measured in whole blood, as well as the depressed OKT4/OKT8 cell ratios. Seventy-four percent of the homosexual male subjects were "recreational" drug abusers, 81% used inhalant nitrites routinely, and 41% routinely treated themselves with antibiotics. Eighty-one percent practiced active and/or passive penile-oral insertion, and 55.5% practiced both active and passive anal intercourse. Of the latter, 19% reported anal bleeding. Clinically inapparent, though statistically significant, borderline immunodeficiency and aberrant zinc and copper levels may be a consequence of multiple factors comprising the gay bar life-style.