[The effects of low birth weight, gestational age on lung function in childhood]

OBJECTIVE

To evaluate the effects of low birth weight, gestational age on lung function in later childhood.

METHODS

Height, body weight and lung function were measured in a cohort of 35 children with low birth weight (aged 6 approximately 9 y) and 35 healthy controls matched for sex and age with normal birth weight. At the same time, we inquired their gestational age and passive smoking history. The correlation analysis was used to analyze the relationship between lung function in these children and birth weight and gestational age.

RESULTS

FVC, FEV(1), FEV(1)% pred, V(75), V(50), V(50%) Pred, (V(25%) Pred in children with low birth weight were significantly lower than those in children with normal birth weight (P < 0.05). The lung function statistically positively correlated with birth weight (r = 0.245 approximately 0.365, P < 0.05), but not with gestational age (P > 0.05).

CONCLUSION

Low birth weight was positively correlated with most lung function parameters in childhood.

[A cross-sectional study on the promotion and execution of "the practiced guidelines for the management of common malignant gynecological tumors"]

OBJECTIVE

To evaluate the promotion and execution of "the practice guidelines for the management of common malignant gynecological tumors (draft)" (guidelines).

METHODS

Cross sectional study was applied. All obstetricians and gynecologists (Obs/Gyns) who attended the Chinese Medical Association's Senior Workshop for Department Chairmen of Obstetrics and Gynecology were included.

RESULTS

Three hundred and fifty Obs/Gyns were inquired, while two hundred and eighty-one questionnaires were available. Ninety percent (253/281) of Obs/Gyns declared that they had read the guidelines, and 96.4% (271/281) of them thought it necessary to establish the guidelines. In those Obs/Gyns who read the guidelines, 87.7% (222/253) of them managed gynecological tumors according to the guidelines. In those who did not read the guidelines, most were obstetricians or worked in special hospitals, while all gynecological oncologists read the guidelines. In addition, there were still many suggestions on the guidelines.

CONCLUSION

The guidelines has been playing a role in the management of common malignant gynecological tumors and need to be revised regularly.

Brownian dynamics simulations of interaction between scorpion toxin Lq2 and potassium ion channel

The association of the scorpion toxin Lq2 and a potassium ion (K(+)) channel has been studied using the Brownian dynamics (BD) simulation method. All of the 22 available structures of Lq2 in the Brookhaven Protein Data Bank (PDB) determined by NMR were considered during the simulation, which indicated that the conformation of Lq2 affects the binding between the two proteins significantly. Among the 22 structures of Lq2, only 4 structures dock in the binding site of the K(+) channel with a high probability and favorable electrostatic interactions. From the 4 candidates of the Lq2-K(+) channel binding models, we identified a good three-dimensional model of Lq2-K(+) channel complex through triplet contact analysis, electrostatic interaction energy estimation by BD simulation and structural refinement by molecular mechanics. Lq2 locates around the extracellular mouth of the K(+) channel and contacts the K(+) channel using its beta-sheet rather than its alpha-helix. Lys27, a conserved amino acid in the scorpion toxins, plugs the pore of the K(+) channel and forms three hydrogen bonds with the conserved residues Tyr78(A-C) and two hydrophobic contacts with Gly79 of the K(+) channel. In addition, eight hydrogen-bonds are formed between residues Arg25, Cys28, Lys31, Arg34 and Tyr36 of Lq2 and residues Pro55, Tyr78, Gly79, Asp80, and Tyr82 of K(+) channel. Many of them are formed by side chains of residues of Lq2 and backbone atoms of the K(+) channel. Thirteen hydrophobic contacts exist between residues Met29, Asn30, Lys31 and Tyr36 of Lq2 and residues Pro55, Ala58, Gly79, Asp80 and Tyr82 of the K(+) channel. These favorable interactions stabilize the association between the two proteins. These observations are in good agreement with the experimental results and can explain the binding phenomena between scorpion toxins and K(+) channels at the level of molecular structure. The consistency between the BD simulation and the experimental data indicates that our three-dimensional model of Lq2-K(+) channel complex is reasonable and can be used in further biological studies such as rational design of blocking agents of K(+) channels and mutagenesis in both toxins and K(+) channels.

Influence of flanking sequence context on the mutagenicity of acetylaminofluorene-derived DNA adducts in mammalian cells

Site-specifically modified oligodeoxynucleotides were used to explore the influence of neighboring base sequence context on the mutagenic potential of N-(deoxyguanosin-8-yl)-2-acetylaminofluorene (dG-AAF) and N-(deoxyguanosin-8-yl)-2-aminofluorene (dG-AF) in mammalian cells. Oligodeoxynucleotides ((5)(')TCCTCCTNXNCTCTC, where X is dG-AAF, dG-AF, or dG and N is C, A, G, or T) with different bases flanking the lesion were incorporated into a single-strand shuttle plasmid vector and used to establish the mutational frequency and specificity of dG-AAF and dG-AF adducts in simian kidney (COS-7) cells. Vectors containing dG-AAF promote preferential incorporation of dCMP at the site of the lesion; misincorporation of dAMP and dTMP also was observed. Mutational frequencies range from 11 to 23%. High mutational frequencies (18-23%) were observed when G or T was positioned 5' to dG-AAF and a lower frequency (11%) when C was 5' to the lesion. dCMP was predominantly incorporated opposite the dG-AF adduct when C, A, or T was 5' to the lesion; dAMP and dTMP were misincorporated at a frequency of 2-4%. With G 5' to the lesion, the overall mutational frequency for dG-AF ranged between 11 and 70%; the highest value occurred when C was the 3' flanking base, and the predominant mutation event was G --> T transversion (59%). We conclude from these experiments that dG-AAF and dG-AF promote G --> T transversions and G --> A transitions in mammalian cells. The mutational frequency and specificity of dG-AF vary significantly, depending on the nature of the bases flanking the lesion.

[Influence of moderate hypothermia on the contents of 6-KETO-PGF1 alpha and TXB2 in brain tissues after cardiac arrest and resuscitation in dogs]

To investigate the effect of moderate hypothermia of whole brain (30 degrees C to 32 degrees C) on the levels of prostacyclin and thromboxane A2 in brain tissues after cardiac arrest and resuscitation. Twenty-one dogs were divided into four groups: Group A, nonischemic controls (n = 4); Group B, 15 minute cardiac arrest without reperfusion (n = 4); Group C, 15 minute cardiac arrest and standard resuscitation (n = 6); Group D, 15 minute cardiac arrest and moderate hypothermia (30 degrees C-32 degrees C). The results showed that as compared with those in Group A, the 6-Keto-PGF1 alpha levels remained substantially unchanged in Group C and D (P > 0.05), and the levels of TXB2 and TXB2/6-Keto-PGF1 alpha ratio increased significantly in Group C (P < 0.01), but both maintained basically stable in Group D (P > 0.05). In comparison with those in Group C, the levels of TXB2 and TXB2/6-Keto-PGF1 alpha ratio decreased dramatically (P < 0.01). It is concluded that the moderate hypothermia can depress the arachidonic acid metabolism and keep a certain balance between the activities of TXA2 and PGI2 during cerebral resuscitation.

Transcriptional analysis of Marek's disease virus glycoprotein D, I, and E genes: gD expression is undetectable in cell culture

The various alphaherpesviruses, including Marek's disease virus (MDV), have both common and unique features of gene content and expression. The entire MDV U(s) region has been sequenced in our laboratory (P. Brunovskis and L. F. Velicar, Virology 206:324-338, 1995). Genes encoding the MDV glycoprotein D (gD), glycoprotein I (gI), and glycoprotein E (gE) homologs have been found in this region, although no gG homolog was found. In this work, transcription of the tandem MDV gD, gI, and gE genes was studied and found to have both unique characteristics and also features in common with other alphaherpesviruses. MDV gD could not be immunoprecipitated from MDV GA-infected duck embryo fibroblast cells by antisera reactive to its TrpE fusion proteins, while gI and gE could be. When the gD gene was subjected to in vitro-coupled transcription-translation, the precursor polypeptide was produced and could be immunoprecipitated by anti-gD. Northern blot, reverse transcriptase PCR, and RNase protection analyses have shown that (i) no mRNA initiating directly from the gD gene could be detected; (ii) a large but low-abundance 7.5-kb transcript spanning five genes, including the one encoding gD, was seen on longer exposure; and (iii) transcription of the gI and gE genes formed an abundant bicistronic 3.5-kb mRNA, as well as an abundant 2.0-kb gE-specific mRNA. Therefore, the MDV gD gene expression is down-regulated at the transcription level in MDV-infected cell culture, which may be related to the cell-associated nature of MDV in fibroblast cells. Compared to the highly gD-dependent herpes simplex virus and the other extreme of the varicella-zoster virus which lacks the gD gene, MDV is an intermediate type of alphaherpesvirus.

C1q arrests the cell cycle progression of fibroblasts in G(1) phase: role of the cAMP/PKA-I pathway

C1q may participate in the loss of connective tissue occurring in chronic inflammatory lesions. The hypothesis of a detrimental role of C1q on cell proliferation was tested on primary cultures of human fibroblasts (HFs). C1q suppressed the DNA synthesis of HF in response to platelet-derived growth factor (PDGF) with an IC(50) of 20 microg/ml, and blocked 78% of the cycling cells in G(1) phase. The C1q block did not involve production of inhibitory prostaglandin by the cells. Given that C1q elicits signals of the adenylyl cyclase pathway in HF, we examined cAMP-dependent mechanisms to understand how C1q inhibited the PDGF response. Whereas the C1q block was enhanced by agonist dibutyryl-adenosine 3', 5'-cyclic mono-phosphate (db-cAMP), antagonist adenosine 3', 5'-cyclic monophosphorotioate triethylammonium salt (Rp-cAMP) minimized it. C1q increased the level of cAMP-dependent protein kinase I (PKA-I) 4.5-fold, without altering the activation of the extracellular-regulated protein kinase (ERK) pathway. These results demonstrate that the interactions of C1q with HF cause growth arrest at the G(1) phase through mechanisms associated with a PKA-I dependent pathway.

[Expression of monocyte chemotacticp protein-1 in the eutopic endometrium of women with endometriosis]

OBJECTIVE

To examine the expression of monocyte chemotactic protein-1 (MCP-1) messenger ribonucleic acid (mRNA) in the endometrium of patients with and without endometriosis.

METHODS

A reverse transcription-polymerase chain reaction (RT-PCR) method was utilized to examine and quantitate MCP-1 mRNA expressions and levels in the eutopic endometrium. Thirty patients with endometriosis were included as study group, and 20 patients without endometriosis selected as control group.

RESULTS

26 (87%) of 30 samples of endometrium from patients with endometriosis expressed MCP-1 mRNA, 19 of which were strong expression, while 15 (75%) of 20 samples of endometrium from patients without endometriosis express MCP-1 mRNA (P > 0.05). When endometriosis were grouped by Revised American Fertility Society (RAFS) stages, there was no obvious correlation between stage and MCP-1 mRNA expression level (P > 0.05). Semi-quantitative PCR showed the expression level of MCP-1 in endometrium of patients with endometriosis were higher than those of patients without endometriosis (0.746 +/- 0.345 Vs 0.460 +/- 0.341 respectively, P < 0.05).

CONCLUSIONS

The MCP-1 mRNA is over expressed in the eutopic endometrium from patients with endometriosis, which may play some roles on the pathogenesis of endometriosis.

Phosphorylation of hepatic stimulator substance on mitogen-activated protein kinase in BEL-7402 hepatoma cells

OBJECTIVE

To obtain more insight into information of signal transduction of EGF-receptor-mediated pathway response to the stimulation of hepatic stimulator substance (HSS).

METHODS

HSS was extracted from weanling rat liver and partially purified. Bioactivity of HSS was confirmed with its ability to proliferate hepatoma cell in vitro. Meanwhile, a rat recombinant HSS vector was constructed and expressed in BL-21 E. Coli. Mitogen-activated protein kinase (MAPK) activation marked by phosphorylation at Thr202/Tyr204 was determined by Western blot.

RESULTS

The molecular weight of the biochemically purified HSS was found identically to that of the recombined HSS as expressed in the prokaryotic cells. After the treatment of HSS, cellular MAPK phosphorylation was initiated obviously at 15 min and maintained to 30 min. In comparison with EGF, MAPK phosphorylation as stimulated by HSS appeared less intensive and later time-kinetics as well. The HSS induction on cellular MAPK phosphorylation was gradually inhibited by PD98059, a specific inhibitor of MAPK kinase (MEK). A complete blockade was seen at 100 micromol/L of PD98059.

CONCLUSIONS

The involvement of HSS on MAPK activation implies that this liver-specific growth factor might take part in, either individually or as combined with other growth factors, the regulation of TPK signaling cascade during hepatocyte proliferation.

Secure optical storage that uses fully phase encryption

A secure holographic memory system that uses fully phase encryption is presented. Two-dimensional arrays of data are phase encoded. Each array is then transformed into a stationary white-noise-like pattern by use of a random-phase mask located at the input plane and another at the Fourier plane. This encrypted information is then stored holographically in a photorefractive LiNbO(3):Fe crystal. The original phase-encoded data can be recovered, by use of the two random-phase masks, with a phase-conjugate readout beam. This phase information can then be converted back to intensity information with an interferometer. Recording multiple images by use of angular multiplexing is demonstrated. The influence of a limited system bandwidth on the quality of reconstructed data is evaluated numerically. These computer simulation results show that a fully phase-based encryption system generally performs better than an amplitude-based encryption system when the system bandwidth is limited by a moderate amount.

Carbon disulfide at a Chinese viscose factory external and internal exposure assessment

This article presents the results of carbon disulfide exposure measurements in a Chinese viscose rayon factory. The objectives of the study were to identify the external exposure levels at a large factory and to investigate the 2-thiothiazolidine-4-carboxylic acid (TTCA) concentrations in the urine of the subjects who were exposed to carbon disulfide in the working place atmosphere. The metabolism of carbon disulfide in the exposed subjects was also studied in order to demonstrate the best points in time for the internal exposure sampling. The measurement of the amount of personal exposure to carbon disulfide in the air of the workplace was performed by GC-FPD; the presence of TTCA in the workers urine was analyzed by use of a modified HPLC method. The kinetics of TTCA excretion was studied by analyses at different time-points both during and after exposure to carbon disulfide in the subjects. A total of 155 personal samples were obtained. The carbon disulfide concentration in the staple viscose hall was 13.72 +/- 1.12 mg m-3 in terms of the geometric mean +/- geometric standard deviation, and was 20.05 +/- 1.33 mg m-3 in the filament spinning hall. The TTCA values in the subjects who worked in the staple spinning hall were 1.18 +/- 0.43 mg g-1 creatinine and 1.07 +/- 0.38 mg g-1 creatinine for subjects working in the filament spinning hall. The best time for TTCA sampling is at the end of the working shift, the TTCA excretion was stable for a period of 4-12 h after exposure of the subjects to the carbon disulfide. It might be that the Chinese have different anthropometric characteristics; a sampling bias may therefore appear among different races.

High internight reliability of computer-measured NREM delta, sigma, and beta: biological implications

BACKGROUND

Computer analysis of the sleep electroencephalogram (EEG) waveforms is widely employed, but there have been no systematic studies of its reliability.

METHODS

The most commonly used computer methods are power spectral analysis with the fast-Fourier transform (FFT) and period amplitude analysis (PAA) with zero cross or zero first derivative half-wave measurement. We applied all three computer methods to the digitized EEG of 16 normal subjects who underwent 5 consecutive nights of baseline (placebo) recording. We evaluated the internight reliability of three non-rapid eye movement (NREM) frequency bands of special importance to sleep research: delta (0.3-3 Hz), sigma (12-15 Hz), and beta (15-23 Hz).

RESULTS

Both FFT and the two methods of PAA gave excellent internight reliability for delta and sigma. Even a single night of recording correlated highly (r >.9) with the 5-night mean. Beta reliability was lower but still highly significant for both the PAA and the FFT measures.

CONCLUSIONS

Computer-analyzed sleep EEG data are highly reliable. Period amplitude methods demonstrate that wave incidence and period as well as amplitude are reliable, indicating that the reliability of composite measures (FFT power, PAA integrated amplitude) is not solely based on individual differences in EEG amplitude. The high internight stability of NREM delta indicates that it possesses traitlike characteristics and is relatively independent of day-to-day variations in state.

[Effects of different catechins on cell cycle arrest and induction of apoptosis in LoVo cells]

OBJECTIVE

To investigate the effects of green tea (-)-epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin-3-gallate (ECG)and (-)-epicatechin (EC) on the cell cycle arrest and induction of apoptosis in human colon carcinoma LoVo cell line.

METHODS

The cytotoxicity, cell cycle arrest and apoptosis-associated alterations in morphology and biochemistry were examined using the tetrazolium salt reduction (MTT) assay, gel electrophoresis, transmission electron microscope and flow cytometry after treatment of LoVo cells with the four catechins.

RESULTS

Treatment of LoVo cells with EGCG and EGC resulted in the growth suppression and induction of apoptosis in a time- and concentration-dependent manner. ECG and EC, however, did not have the same effects. In addition, the four catechins had different effects on the cell cycle of LoVo cells. Treatment with EGCG, EGC and ECG caused LoVo cells arrest at G1 phase in the cell cycle progression, whereas EC resulted in an arrest at S phase.

CONCLUSIONS

The cytotoxicity of the four catechins to LoVo cells is significantly different. The difference is associated with their effects on cell cycle and induction of apoptosis in LoVo cells.

Differences of four catechins in cell cycle arrest and induction of apoptosis in LoVo cells

(-)-Epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin-3-gallate (ECG), and (-)-epicatechin (EC) were found to have different cytotoxicities to human colon carcinoma LoVo cells. EGCG and EGC suppressed the growth of LoVo cells in dose-dependent manner; ECG and EC, however, had no obvious effects. At lower concentrations, EC did seem to promote slight proliferation. Similarly, EGCG and EGC, rather than ECG and EC, were found to induce apoptosis in LoVo cells. Moreover, EGCG, EGC, and ECG arrested G(1) phase in the cell cycle progression, whereas EC resulted in S phase arrest. We suggest that there are differences in the cytotoxicities of the four catechins to LoVo cells. They exert the effects by inducing apoptosis and regulating the cell cycle.

PLAG1 fusion oncogenes in lipoblastoma

Lipoblastomas are pediatric neoplasms resulting from transformation of adipocytes. These benign tumors are typically composed of adipose cells in different stages of maturation within a variably myxoid matrix, and they contain clonal rearrangements of chromosome band 8q12. Because lipoblastomas resemble embryonic adipose tissue, characterization of their transforming mechanisms might reveal biological pathways in physiological adipogenesis. Herein, we demonstrate that lipoblastoma chromosome 8q12 rearrangements bring about promoter-swapping events in the PLAG1 oncqgene. We show that the hyaluronic acid synthase 2 (HAS2) or collagen 1 alpha 2 (COL1A2) gene promoter regions are fused to the entire PLAG1 coding sequence in each of four lipoblastomas. PLAG1 is a developmentally regulated zinc finger gene whose tumorigenic function has been shown previously only in epithelial salivary gland cells. Our findings reveal that PLAG1 activation, presumably resulting from transcriptional up-regulation, is a central oncogenic event in lipoblastoma.

[The diagnostic and prognostic values of assay of serum vascular endothelial growth factor in epithelial ovarian cancer]

OBJECTIVE

To detect the level of the preoperative serum vascular endothelial growth factor (VEGF) in patients with epithelial ovarian cancer, and to evaluate the correlation between preoperative serum VEGF level and prognosis of epithelial ovarian cancer.

METHODS

Forty-one patients with epithelial ovarian cancer (EOC), 10 patients with borderline ovarian tumor (BOT), and 25 women with benign ovarian tumor (BET) were included as three study groups, while 20 healthy women were selected as a control group. Enzyme-linked immunosorbent assay (ELISA) was utilized to measure the serum VEGF level.

RESULTS

The serum VEGF levels in patients with EOC were higher than those in patients with BOT, or with BET, or those in healthy women. The median and ranges of serum VEGF levels were as follows: EOC: median 415.0 pg/ml, range 110-2,120 pg/ml; BOT: median 312.5 pg/ml, range 100-1,250 pg/ml; BET: median 170 pg/ml, range 70-925 pg/ml; healthy women: median 165 pg/ml, range 100-735 pg/ml. When median preoperative serum VEGF levels were grouped by tumor stages, histological grade of tumor cells, histological type of the tumor, lymph node involvement, and omentum involvement, significant correlations between serum levels of VEGF and histological grade, lymph node involvement and omentum involvement were found. The patients with high serum VEGF appeared to be accompanied with poor 3-year survival.

CONCLUSIONS

Preoperative serum VEGF levels seemed to be correlated with the malignant behavior of ovarian cancer, which might provide some prognostic value.

Independence of sleep EEG responses to GABAergic hypnotics: biological implications

GABAergic hypnotics are known to depress non-rapid eye movement delta and rapid eye movements and to stimulate non-rapid eye movement sigma (spindles) and beta EEG. This study addressed the question of whether the magnitudes of these effects are significantly correlated. Data were from a study in 16 normal subjects whose sleep was recorded for five nights under placebo and for three nights each under zolpidem (10 mg), triazolam (0.25 mg) and temazepam (30 mg). EEG was analyzed with both period-amplitude and power spectral (FFT) analysis. The magnitudes of the EEG and eye movement density responses were not significantly correlated for any of the three drugs. It is therefore unlikely that sleep responses to GABAergic drugs can be explained by the common cellular action (increased chloride conductance) of these drugs. We suggest that the sleep EEG responses are manifestations of complex (but consistent) interactions of excitation and inhibition in large brain systems although certain aspects of these responses (e.g. the different time courses of delta vs sigma and eye movement responses) may reflect molecular adaptations. A separate observation in this study was the strong traitlike characteristics of the sleep variables studied. These variables were highly correlated across nights of baseline sleep; in addition, individual differences in baseline sleep were significantly retained on the third night of temazepam administration.

Association of smoking and personality with a polymorphism of the dopamine transporter gene: results from a community survey

In studies that used mixed volunteer samples, Lerman et al. [1999: Health Psychol 18:14-20] and Sabol et al. [1999: Health Psychol 18:7-13] reported on an association of smoking with a polymorphism of the dopamine transporter gene. We attempted to replicate this association in a nonvolunteer community sample of 861 Caucasians. No associations were found with either smoking initiation or smoking cessation. Sabol et al. [1999] also reported on an association of the dopamine transporter polymorphism with the personality trait of novelty seeking. However, we failed to find any associations with a range of personality traits, including a scale of fun seeking that correlates with novelty seeking. These negative findings suggest that either the original associations are not replicable or that any association is very small.

[Analysis of refractive state after excimer laser photorefractive keratectomy in myopia]

OBJECTIVE

To evaluate refractive state after excimer laser photorefractive keratectomy (PRK) in patients with myopia.

METHODS

234 cases(391 eyes) followed up for two years were divided into two groups, group I: mild and moderate myopia(< or = -6.00 D), 228 eyes; group II: High myopia(> -6.00 D), 163 eyes. The refractive state of patients at three, six, twelve and twenty-four months postoperatively were monitored.

RESULTS

At two years after photorefractive keratectomy (PRK), refractive regression (> -0.5 D), overcorrection(> 1.00 D), undercorrection(> 1.00 D), postoperative residual astigmatism postoperative astigmatism and hyperopia shift in group I were 1.7%, 4.4%, 5.7%, 12.8%, 7.4% and 7.5% respectively, while in high myopia group were 15.9%, 4.9%, 23.3%, 29.7%, 31.1% and 6.7% respectively.

CONCLUSION

The results prove that photorefractive keratectomy is an effective, precise, stable and safe method for correction of mild and moderate myopia, but insufficient for high myopia.

[Design and optimization of a centrifugal pump for CPCR]

Requirements for an optimal centrifugal pump, the vital component in the equipment for cardiopulmonary cerebral resuscitation(CPCR), have been presented. The performance of the Sarns centrifugal pump (Sarns, Inc./3M, Ann arbor, MI, U.S.A) was tested. The preliminarily optimized model for CPCR was designed according to the requirements of CPCR and to the comparison and analysis of several clinically available centrifugal pumps. The preliminary tests using the centrifugal pump made in our laboratory(Type CPCR-I) have confirmed the design and the optimization.

Association of a functional polymorphism of the monoamine oxidase A gene promoter with personality and psychiatric symptoms

A functional polymorphism in the promoter of the monoamine oxidase gene has recently been described by Sabol et al. This polymorphism is a strong candidate for associations with personality traits and psychiatric symptoms. We report relevant data from a general population sample of 850 Caucasian Australians. We found no associations with anxiety and depression symptoms, with personality traits that predispose to anxiety (neuroticism, behavioral inhibition, negative affect) or to a personality trait related to antisocial behavior (psychoticism).

Pharmacokinetics of bis(t-butyl-SATE)-AZTMP, a bispivaloylthioethyl prodrug for intracellular delivery of zidovudine monophosphate, in mice

The pharmacokinetics of a bispivaloylthioethyl prodrug of zidovudine monophosphate (AZTMP), bis(t-butyl-SATE)-AZTMP, and intracellular conversion of the prodrug to AZTMP were characterized following intravenous (i.v.) and oral (p.o.) administration of the prodrug to mice. Concentrations of bis(t-butyl-SATE)-AZTMP, AZTMP and zidovudine (AZT) in blood, red blood cells, plasma, brain and lymph nodes were determined by HPLC. Following i.v. administration of bis(t-butyl-SATE)-AZTMP, concentrations of the prodrug declined rapidly with low levels of the prodrug detected until 4 h. Both bis(t-butyl-SATE)-AZTMP and AZTMP were detected in brain 3 min after dosing. AZTMP was found in both plasma and peripheral red blood cells, peaking at approximately 30 min and remaining detectable until 2 h. No AZTMP was detected in lymph nodes. Compared to the pharmacokinetics of AZT following its i.v. administration, i.v. administration of bis(t-butyl-SATE)-AZTMP produced lower peak concentrations of AZT in plasma, peripheral red blood cells, brain and lymph nodes. However, terminal half-lives of AZT were significantly prolonged following administration of the prodrug. Following p.o. administration of bis(t-butyl-SATE)-AZTMP, neither the prodrug nor AZTMP were detectable in whole blood. The conversion of AZT from bis(t-butyl-SATE)-AZTMP in plasma and peripheral red blood cells following p.o administration was 12.1% of that following i.v. administration of the prodrug. Bis(t-butyl-SATE)-AZTMP demonstrated promising potential for intracellular delivery of AZTMP. The prodrug also prolonged the retention of AZT in mice, and particularly increased delivery of AZT to the lymphatic and central nervous systems.

Simultaneous determination of zidovudine and its monophosphate in mouse plasma and peripheral red blood cells by high-performance liquid chromatography

Novel prodrugs for the intracellular delivery of zidovudine monophosphate (AZTMP) have recently been designed. To investigate the bioconversion and pharmacokinetic profiles of these compounds, an analytical method for the simultaneous determination of zidovudine (AZT) and AZTMP in mouse plasma and peripheral red blood cells was developed. Mouse whole blood samples were treated with TBAHS, EDTA and NaH2PO4, and separated into plasma and red blood cell portions. Samples were processed by solid-phase extraction using Bond Elut C18 cartridges. Chromatography was performed using an Hypersil ODS column and a mobile phase of 2.9% (v/v) acetonitrile and 97.1% (v/v) phosphate buffer, pH 7.50, with UV detection at 267 nm. The average extraction recoveries of AZTMP and AZT in plasma were approximately 85% and 97% over their linear ranges of 0.05-5 microg/ml and 0.125-25 microg/ml, respectively. Extraction recoveries of AZTMP and AZT from peripheral red blood cells averaged 56 and 69% over their linear ranges of 0.125-5 microg/ml and 0.125-25 microg/ml, respectively. The accuracy of the assay was 90-100%. The intra- and inter-day variations of the assay were less than 14%. The analytical method was found to be applicable, reliable and suitable for pharmacokinetic studies.

[Exploration on features of early medical activities of Miao nationality]

The Miao Minority medicine has a long history, and it originated thousands of years ago. The features of the Miao Minority medicine in the early age include all kinds of herbs which were very popular. Thus, a long-term "combination of witch and doctor" period existed in the early age of Miao Minority. This striking feature has great influence in the Miao Minority medicine, and this influence goes on until today. The Miao Minority doctors were good at external treatment in the early age. The above three points are worth studying, constituting the distinct traditional features of the Miao Minority medicine.

[Effects of mild hypothermia on Na(+)-K+ ATPase and lipid peroxidation in canine brain tissue following cardiac arrest and resuscitation]

The effect of mild hypothermia on Na(+)-K+ ATPase and lipid peroxidation in canine brain tissue following a 18-minute cardiac arrest and resuscitation for 8 hours were studied. Mild hypothermia improved the restoration of the activity of Na(+)-K+ ATPase, LDH, protect the activity of SOD, decrease the loss of GSH, but not completely blocked the ischemia reperfusion induced lipid peroxidation.

[Efficacy of epimedium compound pills in the treatment of the aged patients with kidney deficiency syndrome of ischemic cardio-cerebral vascular diseases]

One hundred-twenty aged patients with kidney deficiency syndrome of ischemic cardio-cerebral vascular diseases were treated with Epimedium compound granules. The results showed that after therapeutic period the total and marked effective rates were 96.7%, 39.5% respectively in treatment group. The rates of improvement were 70% in electrocardiogram of the patients with coronary heart diseases, and 75% in electro-encephalogram of the patients with cerebral arterosclerosis. The therapeutic effectiveness in treatment group was better than that in control group treated with Su-Guan-Bian. According to experimental observation, the therapeutic effectiveness was related to the facts that Epimedium compound granules lower blood lipid have anti-free radicals and adjust balance between prostacyctin I2 and thromboxane A2(TXA2/PGI2).

[Development of a control and monitor system for the cardiopulmonary cerebral resuscitation(CPCR) device]

A novel idea in developing cardiopulmonary-cerebral resuscition(CPCR) device has been developed, using a combination of membrane artificial lung(oxygenator), mild-hypothermia, and centrifugal blood pump technologies. A control system for the CPCR has been introduced, using converter control and sensor monitor, with 8031 chips as the controller. Pressure, flow rate and temperature monitors were installed in the system. Two modes of blood pump regulation have been adopted, i.e. continous flow and pulsatile flow. The in vitro evaluation tests showed that the two modes were reasonable and feasible.

COMT and DRD3 polymorphisms, environmental exposures, and personality traits related to common mental disorders

In a community sample of 2,327 Caucasians, we tested the hypotheses that polymorphisms in the COMT and DRD3 genes are associated with personality traits conferring vulnerability to anxiety, depression, or alcohol misuse, or with current symptoms of these; and that the association is stronger in persons who also have been exposed to stressor experiences. To conserve resources and to allow replication, the genetic analysis was undertaken in two stages. For the COMT polymorphism, no statistically significant associations were found in the first sample of 862 persons. The remainder of the sample was therefore not analysed for that gene. For the DRD3 polymorphism, those in the first sample with at least one of the Ser(9) alleles had significantly higher scores in neuroticism (p=0.006) and behavioral inhibition (p=0.003). There was a trend, failing to meet the 1% significance criterion, for those with this genotype also to have higher depression and anxiety. The groups did not differ in alcohol use. In persons with the Ser(9) allele who were also exposed to stressors, there was a higher level of depression at the 5% level; and the depression level was higher in homozygotes. But when the remainder of the sample (1,465) was analysed, none of the associations reached statistical significance. We conclude that neither the COMT nor DRD3 polymorphisms are associated with anxiety, depression, or alcohol abuse. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:102-107, 2000

Comparison of the mutagenic properties of 8-oxo-7,8-dihydro-2'-deoxyadenosine and 8-oxo-7,8-dihydro-2'-deoxyguanosine DNA lesions in mammalian cells

The comparative mutagenicity of 8-oxo-7,8-dihydro-2'-deoxyadenosine (8-oxodA) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) was explored using simian kidney (COS-7) cells. Oligodeoxynucleotides ¿5'-TCCTCCT- G(1)X(2)CCTCTC or 5'-TCCTCCTX(1)G(2)CCTCTC (X = dA, dG, 8-oxodA or 8-oxodG) containing 8-oxodA or 8-oxodG positioned within codon 60 or 61 of the non-coding strand of human c-Ha-ras1 gene were inserted into a single-stranded phagemid shuttle vector. The vector was replicated in COS-7 cells and the progeny plasmids were used to transform Escherichia coli DH10B. The transformants were analyzed by oligodeoxynucleotide hybridization and DNA sequence analysis to establish the mutation frequency and specificity. When 8-oxodA was positioned at X(1), targeted A(oxo)-->C transversions were detected; the mutation frequency was 1.2%. When 8-oxodA was positioned at X(2), one targeted mutant among 416 colonies screened (an A(oxo)-->G transition) was detected. Thus, the mutation frequency and spectrum of 8-oxodA depend on the sequence context of the lesion. The mutation frequency of 8-oxodG at X(1) and X(2) was 5.2 and 6.8%, respectively. G(oxo)-->T transversions dominated the spectrum, accompanied by small numbers of G(oxo)-->A transitions and G(oxo)-->C transversions. We conclude that 8-oxodA has mutagenic potential in mammalian cells, generating A-->C transversions. However, when tested under similar conditions, the mutation frequency of 8-oxodA is at least four times lower than that of 8-oxodG.

Candidate EPA, NIOSH method for determining carbon disulfide in air with capillary gas chromatography by orthogonal design

This paper describes a candidate NIOSH EPA method for the determination of carbon disulfide in the air of workplaces with capillary gas chromatography using an orthogonal design. This method is designed to replace the packed column of the NIOSH method with a capillary column. The first part of this work concerned the setup of the method, particularly the choice of chromatographic parameters and finding their main favorable working ranges. The second part, using the statistical method orthogonal design, focused on optimizing the GC conditions, which were: column temperature, T(c) = 90 degrees C; injector temperature, T(i) = 140 degrees C; U section detector temperature, FPDU = 160 degrees C; L section detector temperature, FPDL = 210 degrees C; flow rate of carrier gas, F(c) = 20 cm/s; split ratio = 1/70; and injection volume = 1 microL. The quality control test showed that the coefficient of intra-day variation (CV) was 2.21%. A good logarithm linear correlation between the standard solutions and their peak areas was obtained. In general, the method reported here seems a valid candidate for a NIOSH EPA method due to its high precision and accuracy.

Role of reactive oxygen species in acetylcholine-induced preconditioning in cardiomyocytes

We examined the ability of ACh to mimic ischemic preconditioning in cardiomyocytes and the role of ATP-sensitive potassium (KATP) channels and mitochondrial reactive oxygen species (ROS) in mediating this effect. Chick embryonic ventricular myocytes were studied in a flow-through chamber while flow rate, pH, PO2, and PCO2 were controlled. Cell viability was quantified with propidium iodide (5 microM), and production of ROS was measured using 2', 7'-dichlorofluorescin diacetate. Data were expressed as means +/- SE. Preconditioning with 10 min of ischemia followed by 10 min of reoxygenation or 10 min of ACh (1 mM) followed by a drug-free period before 1 h of ischemia and 3 h of reoxygenation reduced cell death to the same extent [preconditioning 19 +/- 2% (n = 6, P < 0.05) ACh 21 +/- 5% (n = 6, P < 0.05) vs controls 42 +/- 5% (n = 9)]. Like preconditioning, ACh increased ROS production threefold before ischemia [0.60 +/- 0.16 (n = 7, P < 0.05) vs. controls, 0.16 +/- 0. 03 (n = 6); arbitrary units]. Protection and increased ROS production during ACh preconditioning were abolished with 5-hydroxydecanoate (5-HD, 100 microM), a selective mitochondrial K(ATP) channel antagonist, and the thiol reductant 2-mercaptopropionyl glycine (2-MPG, 1 mM), an antioxidant [cell death: 5-HD+ACh 37 +/- 7% (n = 5), 2-MPG+ACh 47 +/- 6% (n = 6); ROS signals: 5-HD+ACh 0.09 +/- 0.03 (n = 5), 2-MPG+ACh 0.01 +/- 0.04 (n = 4)]. In addition, ACh-induced ROS signaling was blocked by the mitochondrial site III electron transport inhibitor myxothiazol (0.02 +/- 0.07, n = 5). These results demonstrate that activation of mitochondrial K(ATP) channels and increased ROS production from mitochondria are important intracellular signals that participate in ACh-induced preconditioning in cardiomyocytes.

[Clinical study on keratoplasty with corneal cryopreservation]

PURPOSE

To evaluate the clinical application value of the corneal cryopreservation in keratonosus.

METHODS

32 patients with keratonosus treated by corneal transplantation were clinically observed.

RESULTS

In 32 keratonosus cases, 59.37% (19 cases) of the grafts remained transparant; in 24 corneal ulcer preforation cases, 45.83% (11 cases) of the grafts were transparent, all eyeballs(100%) were remained.

CONCLUSION

Corneal cryopreservation can be a practical, effective method in the treatment of keratonosus in district hospitals.

Cloning and characterization of a family of cDNAs from human histiocyte macrophage cells encoding an arginine-rich basic protein related to the 70 kD U1-snRNP splicing factor

This paper describes the cloning and characterization of five cDNA members of a novel family of mRNAs, termed hm-1, isolated from human U937 macrophage cells. Two family members (clones 46 and 11) show complete mRNA features [including ribosome binding sites (RBS), polyadenylation signals, and poly(A) tails], and encode the same protein (designated HM-1), but differ substantially in their 5' untranslated regions. The three other cDNAs (clones 20, 60, and 38) appear to represent partial cDNAs. The protein sequences deduced from the five hm-1 cDNAs are identical (some truncated), except for one Trp --> Cys substitution. Full-length HM-1 is 246 amino acids long, has a predicted MW of 29431, is rich in arginine residues, has a pI of 10.25, and a mean hydrophobicity index of -1.23. HM-1 contains no obvious hydrophobic N-terminal cleavable signal sequence, and no potential N-glycosylation sites, but does contain three highly conserved motifs present in U1-70K splicing factors, and contains numerous C-terminal Arg/Asp and Arg/Glu dipeptides characteristic of "RD" family members that function as regulators of mRNA splicing. Northern hybridizations indicate that hm-1 is a family of mRNAs differentially expressed in a variety of human tissues.

Haploinsufficiency of CBFA2 causes familial thrombocytopenia with propensity to develop acute myelogenous leukaemia

Familial platelet disorder with predisposition to acute myelogenous leukaemia (FPD/AML, MIM 601399) is an autosomal dominant disorder characterized by qualitative and quantitative platelet defects, and propensity to develop acute myelogenous leukaemia (AML). Informative recombination events in 6 FPD/AML pedigrees with evidence of linkage to markers on chromosome 21q identified an 880-kb interval containing the disease gene. Mutational analysis of regional candidate genes showed nonsense mutations or intragenic deletion of one allele of the haematopoietic transcription factor CBFA2 (formerly AML1) that co-segregated with the disease in four FPD/AML pedigrees. We identified heterozygous CBFA2 missense mutations that co-segregated with the disease in the remaining two FPD/AML pedigrees at phylogenetically conserved amino acids R166 and R201, respectively. Analysis of bone marrow or peripheral blood cells from affected FPD/AML individuals showed a decrement in megakaryocyte colony formation, demonstrating that CBFA2 dosage affects megakaryopoiesis. Our findings support a model for FPD/AML in which haploinsufficiency of CBFA2 causes an autosomal dominant congenital platelet defect and predisposes to the acquisition of additional mutations that cause leukaemia.

[Supercritical-CO2 fluid extraction of fatty oils from Perilla frutescens seeds and pharmacological study]

Fatty oils from the seeds of Perilla frutescens were extracted by supercritical-CO2 fluid or petroleum ether and its quality was analyzed by GC-MS method. Pharmacological action of lowering blood-lipid for the oils was studied. The results showed that the technology of supercritical-CO2 extraction of the oils of P. frutescens seeds is superior than that of petroleum ether and the oil from SFE-CO2 have the action of lowering blood-lipid with low toxicity.

[Effects of long-term exposure to lower concentration of carbon disulfide on cardiovascular system of workers in a viscose rayon factory]

An epidemiological cross-sectional study was conducted on 99 workers exposed to lower concentration of carbon disulfide in a viscose rayon factory for a long time and 28 non-exposed ones in the same factory. Blood pressure, serum lipoproteins and electrocardiograph were detected. The results showed that neither diastolic blood pressure nor systolic one between exposed group and control group was obviously different All indicators of serum lipids and lipoproteins were not significantly different except the lipoprotein(a) of exposed group was significantly higher than that of control group, and the risk of abnormal electrocardiogram in the workers exposed to carbon disulfide was 1.1 times of those non-exposed ones but with no statistical significance. The results suggest that lipoprotein(a) can be used as a sensitive indicator for the cardiotoxic effects of carbon disulfide.

[DNA content and cell cycle phase analysis in uterine sarcomas and its clinical significance]

OBJECTIVE

To investigate the relationship among DNA content, cell cycle phase analysis with the clinical-pathological features and prognosis of uterine sarcomas.

METHODS

DNA content and cell cycle phase analysis were performed on 75 paraffin-embedded specimens of uterine sarcomas using flow cytometry.

RESULTS

Both the aneuploidy rate and DNA index (DI) in specimens from advanced stage and poorly-differentiated cases were significantly higher than those in specimens from early stage and well-differentiated cases (P < 0.05). S-phase fraction (SPF) and proliferation index (PI) were significantly higher in advanced stage than those in early stage (P < 0.05). The 5-year suvival rates for DNA aneuploid and diploid patients were 27% and 76%, respectively (P < 0.01). The 5-year suvival rates for patients with a SPF > 20% and those with SPF < or = 20% were 10% and 56% respectively (P < 0.01).

CONCLUSION

DI, SPF, PI and clinical stage are the most important factors affecting the prognosis.

[Clinical observation of hysteroscopic electric resection: an analysis of 36 patients with abnormal uterine bleeding]

OBJECTIVE

To assess the efficacy and influences of hysteroscopic electrosurgery in treating abnormal uterine bleeding (AUB).

METHODS

36 women with AUB received hysteroscopic transcervical resection of the endometrium or intrauterine lesions with a continuous flow resectoscope.

RESULTS

The complications rate was 8.3%. 32 patients were followed for 4 to 12 months. Menstrual symptoms ameliorated in 82.4% of the patients. 5.9% of the women became amenorrhoeic. 58.8% had only spotting, 17.6% recovered normal period. 6 out of the 8 cases with dysmenorrhea had relieved their pain. Satisfactory rate of the procedure was 76.5%. Two patients received hysterectomy later for recurrent uterine bleeding.

CONCLUSION

Hysteroscopic electrosurgery is an effective procedure in treating abnormal uterine bleeding. But its long-term efficacy is yet to be identified. When improving the technique and basic knowledge, the indications should be given appropriatly.

Efficacy of recombinant methioninase in combination with cisplatin on human colon tumors in nude mice

The present treatment of colon cancer is based on 5-fluorouracil (5-FU). Despite promising results of combining leucovorin or levamisole with 5-FU, the 5-year survival rate of patients with advanced colon cancer has not increased significantly. Colon tumors in vitro have been shown previously to have an elevated requirement for methionine, suggesting a new therapeutic target. In this study, targeting the methionine dependence of colon tumors is effected by recombinant methioninase (rMETase), alone and in combination with cisplatin (CDDP). In vitro results demonstrated that CDDP and rMETase act synergistically on the human colon cancer cell line SW 620, with a combination index (CI) of 0.45, as well as on the human colon cancer cell line Colo 205 with a CI of 0.7. Human colon cancer lines HCT 15, HT 29, Colo 205, and SW 620 growing in nude mice were treated with rMETase to determine an effective dose for depletion of tumor methionine. rMETase at 15 units/g/day for 5 days depleted tumor methionine in all four tumor types to approximately 30% of untreated control. rMETase alone arrested growth of HCT 15 and HT29 in nude mice for 1 week after treatment termination. Colo 205 and SW 620 were partially arrested by rMETase. However, CDDP in combination with rMETase resulted in tumor regression of Colo 205 and growth arrest of SW 620 in nude mice. The ratio of the treated:control group (T:C) tumor weights for Colo 205 was 8% when CDDP was given on day-5, followed by treatment on days 5-9 with rMETase. This treatment schedule resulted in two of the six animals having no detectable tumor when the experiment was terminated on day 16. SW620 was resistant to CDDP alone and only partially sensitive to rMETase alone. However, when SW 620 was treated with rMETase from days-5 to -9 and CDDP on day-5, tumor growth was arrested. The results demonstrate that rMETase used simultaneously in combination with CDDP had significant antitumor efficacy in colon cancer in vitro and in vivo. The data suggest a novel and promising therapeutic approach by targeting the elevated methionine dependence of colon cancer.

Platelet-activating factor receptor mRNA is localized in eosinophils and epithelial cells in rat small intestine: regulation by dexamethasone and gut flora

Platelet-activating factor (PAF) is a potent mediator involved in bowel injury. We investigated PAF receptor transcription and its mRNA localization in the small intestine of normal (conventionally fed) and germ-free rats, by competitive polymerase chain reaction (PCR) and in situ hybridization. A dose of PAF (1.5 microg/kg, i.v.) insufficient to cause gross bowel injury was injected into rats. Some rats were pretreated with dexamethasone (1 mg/kg). We found: (1) PAF receptor (PAF-R) mRNA localized predominantly in lamina propria eosinophils and in epithelial cells; (2) PAF increased PAF-receptor signals in the epithelial cells; (3) Dexamethasone depleted eosinophils in the intestine and markedly decreased PAF-receptor transcripts; the response to PAF was also weaker than control rats; (4) Germ-free rats had less PAF-R mRNA than normal rats, and showed a weaker response to PAF than conventionally fed rats. Thus, we conclude: (1) PAF receptor mRNA is constitutively expressed in the epithelium and in lamina propria eosinophils in the intestine. (2) PAF-R transcription is up-regulated by PAF and gut flora, mostly in the epithelium. (3) PAF-R transcription is down-regulated by glucocorticoids, mainly as a result of eosinophil depletion. These results suggest a functional role for PAF receptors both in host defence and the inflammatory response in the small intestine.

Mutagenic properties of the 8-amino-2'-deoxyguanosine DNA adduct in mammalian cells

The DNA adduct 8-amino-2'-deoxyguanosine (8-amino-dG) is found in liver DNA of rats treated with the hepatocarcinogen 2-nitropropane. Site-specifically modified oligodeoxynucleotides were used to explore the mutagenic potential of 8-amino-dG in simian kidney (COS-7) cells. Oligodeoxynucleotides (5'-TCCTCCTX1G2CCTCTC and 5'-TCCTCCTG1X2CCTCTC, X = dG or 8-amino-dG) with the lesion positioned at codon 60 or 61 of the non-coding strand of the human c-Ha- ras1 gene were inserted into single-stranded phagemid vectors and transfected into COS-7 cells. The progeny plasmid obtained was used to transform Escherichia coli DH10B. Transformants were analyzed by oligodeoxynucleotide hybridization and DNA sequencing to establish the mutation frequency and spectrum produced by the modified base. The correct base, dCMP, was incorporated preferentially opposite 8-amino-dG at X1and X2. When 8-amino-dG was at X1, targeted GNH2-->T transversions were detected, along with smaller numbers of GNH2-->A transitions and GNH2-->C transversions. When the adduct was at X2, only GNH2-->T transversions were observed. The frequencies of targeted mutation at X1and X2were 2.7 and 1.7%, respectively. Mutation frequency and mutagenic spectrum were sequence context dependent. In addition, non-targeted G-->T transversions, accompanied by some G-->A transitions, were detected 5' to 8-amino-dG when the lesion was at X2. We conclude that 8-amino-dG is a mutagenic lesion, generating G-->T and G-->C transversions and G-->A transitions in mammalian cells.

[Serum sex hormone and urinary metabolites of male workers exposed to carbon disulfide]

Serum luteotropic hormone(LH), follicle-stimulating hormone (FSH), prolectin(PRL) and testosterone (T) were determined by radioimmunoassay methods in 50 workers exposed to carbon disulfide(CS2) in a viscose rayon factory. Urinary excretion of 2-thio-thiazolidine-4-carboxilic acid (TTCA) in workers by the end of work shift was analyzed with modified high-performance liquid chromatography. The working conditions of the factory had not been changed since 1950s. The concentration of CS2, determined by Multigas Monitor (type 1320) in workplace, was (14.4 +/- 4.62) mg/m3. The results showed that: (1) serum FSH of CS2 group (10.04 +/- 7.35)IU/L was significantly higher than that of control group (7.50 +/- 7.07 IU/L), PRL of CS2 group (5.72 +/- 4.18) ng/L was significantly lower than that of control group (6.89 +/- 4.64 ng/L). Serum LH was declined with the increase of time exposed to CS2, (2) urinary TTCA in CS2 group was 1.072 +/- 1.013 mg/g Cr. Serum FSH was declined with the increase of TTCA excretion. The results suggested that the function of endocrine system was disturbed in workers exposed to CS2.

[Retreatment after excimer laser photorefractive keratectomy]

OBJECTIVE

To evaluate the efficacy and safety of reoperation of residual myopia because of regression, undercorrection with or without coexisting severe corneal haze after excimer laser photorefractive keratectomy (PRK).

METHODS

A VISK 20/20 excimer laser was used to treat myopia of -1.00 to -16.50 diopters (spherical equivalent) at corneal plane. 35 patients (51 eyes) who had residual myopia because of regression, undercorrection with or without coexisting severe corneal haze after initial PRK were retreated by using PRK and phototherapeutic keratectomy.

RESULTS

At 12 months after retreatment, the rates of uncorrected visual acuity more than or equal to 10/20 or 20/20 were 82.6% and 39.1% respectively, 100.0% and 50.0% in myopia up to -6.00 D, 73.3% and 33.3% in myopia of -6.25 to -16.50 D respectively. 86.3% of eyes were within +/- 1.00 diopters of desired emmetropia. Corneal haze after retreatment was not greater than that observed after initial procedures.

CONCLUSIONS

The residual myopia because of regression, undercorrection with or without severe corneal haze after initial PRK can be successfully retreated. Although the therapeutic result of retreatment of PRK is less successful than that of the initial procedure, retreatment appears to enhance it.

[Study on measuring method of pulse oxygen saturation in clinical monitor]

In this paper, a measuring system of pulse oxygen saturation is presented, which is based on the Lambert-beer Principle, using the relative intensities at two wavelengths in the red and infrared ranges. In order to meet the special demand of continuous clinical physiological monitoring, two circuits and appropriate algorithms are designed, one circuit, a feedback circuit controlled by micro-controller, automatically regulates the base line of signal, another circuit is a controlled integral circuit which automatically regulates the amplitude of waveforms. As the result, the drift of base line in this system, especially the effects caused by the physiological differences of human bodies, which will deteriorate the system, have been reduced. The system is satisfactory to clinical monitoring.

[Detection of Epstein-Barr viral genome in tumor cells of Warthin's tumor of parotid gland]

OBJECTIVE

To evaluate the relations between Warthin's tumors of salivary gland and Epstein-Barr virus (EBV).

METHODS

75 cases of salivary gland Warthin's tumor and 20 cases of normal salivary gland tissue were examined for to detect EBV genoma by using the polymerase chain reaction (PCR) of DNA, 62 cases of single Warthin's tumor and 13 cases of multiple/bilateral Warthin's tumor's.

RESULTS

EBV DNA was detected in 13 cases of single Wathin's tumors, 9 cases of multiple/bilateral Warthin's tumor and 3 cases of normal salivary gland.

CONCLUSION

There was a close relationship between EBV and multiple/bilateral Warthin's tumors.

[Significance and changes of plasma endothelin in patients undergone upper abdominal surgery]

We observed the changes of plasma endothelin, hemodynamic and electrocardiogram in twelve patients undergone upper abdominal surgery under epidural anesthesia. The results showed that mean artery pressure, heart rate, cardiac output, cardiac index, systemic vascular resistance, maximum left atrial pressure, maximum ascendant speed of artery systolic pressure and mean ascendant speed of artery systolic pressure were all significantly lower during intraab-dominal exploration than that of preanesthesia (P < 0.01). Mean artery pressure and systemic vascualr resistance kept low levels to the end of operation. Plasma endothelin was significantly higher at 1 hour after skin resection than that of preanesthesia (P < 0.01) and was apparently negative related with cardiac output(CO) and cardiac index(CI) during exploration(CO r = -0.9221; CI r = -0.8768), two patients' with myocardial ischemia were specially higher. We conclude that plasma endothelin is closely related with cardiac function and myocardial ischemia during operation.