[Based on a Markov model, cost-effectiveness analysis of influenza vaccination among people aged 60 years and older in Shenzhen].

Objective: To assess the cost-effectiveness of influenza vaccination among people aged 60 years and older in Shenzhen. Methods: A Markov state transition model was constructed to evaluate the cost-effectiveness of annual influenza vaccination for preventing influenza infection compared with no vaccination among the elderly from the social perspective. Allowing seasonal variation of influenza activity, the model followed a five-year cohort using weekly cycles. We employed once the Chinese gross domestic product (GDP) per capita in 2019 (70 892 yuan) as the willingness-to-pay (WTP) threshold and calculated the net monetary benefit (NMB) with costs and quality-adjusted life-years (QALYs) discounted at 5% annually. The impact of parameter uncertainty on the results was examined using one-way and probabilistic sensitivity analyses (PSA). Results: The base case amounted to approximately 35 yuan of cost-saving and a net gain of 0.007 QALYs. Correspondingly, the NMB was 529 yuan per vaccinated person. One-way sensitivity analyses showed that the NMB was relatively sensitive to changes in the attack rate of influenza and vaccine effectiveness. Based on the results of PSA with 1 000 Monte Carlo simulations, influenza vaccination had a probability of being cost-effective in 100% of the repetitions. Conclusions: The present study provides evidence that influenza vaccination is a cost-saving disease prevention strategy for people aged 60 years and older in Shenzhen.

[Analysis on clinical efficacy, safety and economy of Shaobei injection and elastic band ligation in the treatment of grade II or III hemorrhoids].

Objective: Currently, various treatments such as hemorrhoidectomy, ligation and sclerotherapy injection can be applied in grade II or III hemorrhoids. This study aims to compare the clinical efficacy, safety and economy between Shaobei injection and elastic band ligation in treating patients with grade II or grade III hemorrhoids. Methods: A retrospective cohort study was used. Clinical data of 60 patients with grade II or grade III hemorrhoids at Department of Anorectal Surgery of the Sixth Affiliated Hospital, Sun Yat-sen University between January 2019 and October 2019 were collected. Patients were divided into two groups according to surgical methods. Patients in the Shaobei group received Shaobei injection (n=28), and those in the ligation group received elastic band ligation (n=32). Inclusion criteria: (1) diagnosis of grade II or III hemorrhoid; (2) application of Shaobei injection or elastic band ligation; (3) age between 18-75 years old. Exclusion criteria: (1) comorbidity with anal fissure, anal fistula, anal sinusitis or other perianal diseases; (2) patients with mental disorder or poor compliance; (3) incomplete clinical or follow-up data. Recurrent rate, postoperative pain, anal edema, anal distension, total cost of hospitalization, length of hospitalization, and postoperative life quality EQ-5D-3L score were compared between the two groups at postoperative 6-month. Results: No significant difference was observed in the baseline data (including Nystrom hemorrhoid symptom score) between the two groups (all P>0.05), except gender ratio [male proportion: Shaobei 75% (21/28) vs. ligation 37.5%(12/32), χ(2)=8.485, P=0.004]. No significant difference in recurrent rate was found between the two groups [14.3% (4/28) vs. 9.4% (3/32), χ(2)=0.035, P=0.851]. Compared to the ligation group, Shaobei group showed less pain at postoperative day 1 [VAS median (range): 2 (1-6) vs. 3 (1-7), Z=2.814, P=0.005] and postoperative day 7 [VAS median (range): 0 (0-2) vs. 1 (0-4), Z=3.149, P=0.002]; lower anal edema ratio at postoperative day 1 [10.7% (3/28) vs. 34.4% (11/32), Z=4.673, P=0.037]; lower anal distension ratio at postoperative day 1 [7.1% (2/28) vs. 28.1% (9/32), Z=4.391, P=0.048]; less hospitalization cost [(6343.5±1444.1) yuan vs. (10 587.1± 1719.0) yuan, t=12.515, P<0.001] and shorter postoperative hospital stay [median (range): 1 (1-5) days vs. 3 (1-6) days, Z=5.879, P<0.001]. The EQ-5D-3L scores of two groups were significantly improved six months after treatment [Shaobei group: (0.90±0.16) vs. (0.73±0.14); ligation group: (0.91±0.13) vs. (0.74±0.10); both P<0.001], while there was no statistically significant difference between the two groups (t=0.130, P=0.897). No complications such as massive hemorrhage, infection, iatrogenic anal fistula, rectal stricture and local induration occurred after the injection. Conclusions: Shaobei injection is effective and safe in treating grade II or III hemorrhoids. Compared with elastic band ligation, it can reduce morbidity of complications and hospitalization expenses.

Tea consumption and bone health in Chinese adults: a population-based study.

Tea is a worldwide drink with controversial effect on bone health. The sex-specific associations are unrevealed among general population. This study showed that prolonged moderate tea consumption benefited bone health in women, while no additional benefit with stronger tea. However, tea consumption was not associated with bone health in men. INTRODUCTION: Tea consumption has been shown a potentially beneficial effect on bone health in postmenopausal women. However, little is known about such association in men, and whether stronger tea instead harms bone health due to elevated urinary excretion of calcium associated with caffeine in the tea. The aim of this study was to examine the association between various metrics of tea consumption and bone health. METHODS: The present study included 20,643 participants from the China Kadoorie Biobank (CKB), who have finished both baseline survey (2004-2008) and a re-survey (2013-2014). They were aged 38-86 years at re-survey. Tea consumption was self-reported at both baseline and re-survey. Bone mineral density (BMD) was measured using calcaneal quantitative ultrasound once at re-survey. RESULTS: Compared with non-consumers, prolonged weekly tea consumers in women was associated with higher calcaneus BMD measures, with ß (95% CI) of 0.98 (0.22, 1.74) for BUA, 4.68 (1.74, 7.61) for SOS, and 1.95 (0.81, 3.10) for SI. Among prolonged weekly tea consumers, no linear increase in BMD measures with the amount of tea leaves added was observed. The SOS and SI were higher in consumers with tea leaves 3.0-5.9 g/day than in those with < 3.0 g/day, but were reduced to non-significant for those with ≥ 6.0 g/day. Tea consumption was not associated with calcaneus BMD measures in men. CONCLUSION: Prolonged moderate tea consumption benefited bone health in women but not in men. For stronger tea consumption with more tea leaves added, neither benefit nor harm to bone health was observed.

A novel noninvasive algorithm for the assessment of liver fibrosis in patients with chronic hepatitis B virus infection.

Several noninvasive blood biomarkers have been established for the assessment of liver fibrosis in patients with chronic hepatitis B virus (HBV) infection, but their clinical performance remains inconclusive. Here, we compared the diagnostic performance of these biomarkers and developed a novel algorithm for assessing liver fibrosis. Six hundred and sixteen chronically HBV-infected and treatment-naïve patients who underwent liver biopsy were enrolled and randomly divided into training (N=410) and internal validation cohorts (N=206). One hundred and fifty-nine patients from another centre were recruited as an external validation cohort. Receiver operating characteristic (ROC) curves were used to analyse the performance of the gamma-glutamyltransferase-to-platelet ratio (GPR), red cell volume distribution width-to-platelet ratio (RPR), FIB-4 index, aspartate aminotransferase-to-platelet ratio index (APRI) and HBV DNA level against liver histology, and a novel algorithm was developed using the recursive partitioning and regression tree (RPART) method. In the training cohort, the area under the ROC curve of FIB-4 was significantly higher than that of APRI (P=.038) but was comparable to those of GPR, RPR and HBV DNA; however, the performance of the biomarkers was similar among the validation cohort. The established RPR-HBV DNA algorithm performed better in the training cohort than any individual blood biomarker, and the corresponding sensitivity, specificity, positive predictive value and negative predictive value were 63%, 90%, 72% and 80%, respectively. In the internal and external validation cohorts, the performance of the algorithm in assessing liver fibrosis was also superior to that of other biomarkers. These results suggest that the established RPR-HBV DNA algorithm might improve the diagnostic accuracy of liver fibrosis in treatment-naïve patients with chronic HBV infection, although additional studies are warranted to confirm these findings.

Effect of Lung Transplantation on Health-Related Quality of Life in the Era of the Lung Allocation Score: A U.S. Prospective Cohort Study.

Under the U.S. Lung Allocation Score (LAS) system, older and sicker patients are prioritized for lung transplantation (LT). The impact of these changes on health-related quality of life (HRQL) after transplant has not been determined. In a single-center prospective cohort study from 2010 to 2016, we assessed HRQL before and repeatedly after LT for up to 3 years using the SF12-Physical and Mental Health, the respiratory-specific Airway Questionnaire 20-Revised, and the Euroqol 5D/Visual Analog Scale utility measures by multivariate linear mixed models jointly modeled with death. We also tested changes in LT-Valued Life Activities disability, BMI, allograft function, and 6-min walk test exercise capacity as predictors of HRQL change. Among 211 initial participants (92% of those eligible), LT improved HRQL by all 5 measures (p < 0.05) and all but SF12-Mental Health improved by threefold or greater than the minimally clinically important difference. Compared to younger participants, those aged ≥65 improved less in SF12-Physical and Mental Health (p < 0.01). Improvements in disability accounted for much of the HRQL improvement. In the LAS era, LT affords meaningful and durable HRQL improvements, mediated by amelioration of disability. Identifying factors limiting HRQL improvement in selected subgroups, especially those aged ≥65, are needed to maximize the net benefits of LT.

HER2 status in gastric cancers: a retrospective analysis from four Chinese representative clinical centers and assessment of its prognostic significance.

BACKGROUND: HER2 has a predictive value in gastric cancer. However, its association with prognosis remains uncertain. The aim of our study was to estimate the HER2-positive rate in Chinese gastric cancers, compare the classical fluorescence in situ hybridization (FISH) method with the novel bright-field dual color silver-enhanced in situ hybridization (DSISH) detection system, and evaluate the relationship between the HER2 status and prognosis. PATIENTS AND METHODS: Seven hundred and twenty-six resected gastric cancers separately from four clinical centers in China were examined for HER2 by immunohistochemistry (IHC), FISH, and DSISH. RESULTS: The HER2-positive rate was 13%. The consistency between FISH and DSISH results was high (99%; κ = 0.958; P < 0.001). Tumor heterogeneity and polysomy were the main reasons for inconsistency. There was no significant difference in the 3-year overall survival (OS) between HER2-positive and -negative patients (P = 0.959). Multivariate analysis showed that HER2 was not an independent prognostic factor. CONCLUSION(S): HER2 overexpression and amplification occur in a significant number of Chinese gastric cancer patients. Given the obvious advantages and high consistency with FISH, DSISH was superior for evaluating HER2 amplification in gastric cancer. HER2 was not a prognostic factor for gastric cancer in our study.

Dose point kernel simulation for monoenergetic electrons and radionuclides using Monte Carlo techniques.

Monte Carlo (MC) simulation has been commonly used in the dose evaluation of radiation accidents and for medical purposes. The accuracy of simulated results is affected by the particle-tracking algorithm, cross-sectional database, random number generator and statistical error. The differences among MC simulation software packages must be validated. This study simulated the dose point kernel (DPK) and the cellular S-values of monoenergetic electrons ranging from 0.01 to 2 MeV and the radionuclides of (90)Y, (177)Lu and (103 m)Rh, using Fluktuierende Kaskade (FLUKA) and MC N-Particle Transport Code Version 5 (MCNP5). A 6-µm-radius cell model consisting of the cell surface, cytoplasm and cell nucleus was constructed for cellular S-value calculation. The mean absolute percentage errors (MAPEs) of the scaled DPKs, simulated using FLUKA and MCNP5, were 7.92, 9.64, 4.62, 3.71 and 3.84 % for 0.01, 0.1, 0.5, 1 and 2 MeV, respectively. For the three radionuclides, the MAPEs of the scaled DPKs were within 5 %. The maximum deviations of S(N←N), S(N←Cy) and S(N←CS) for the electron energy larger than 10 keV were 6.63, 6.77 and 5.24 %, respectively. The deviations for the self-absorbed S-values and cross-dose S-values of the three radionuclides were within 4 %. On the basis of the results of this study, it was concluded that the simulation results are consistent between FLUKA and MCNP5. However, there is a minor inconsistency for low energy range. The DPK and the cellular S-value should be used as the quality assurance tools before the MC simulation results are adopted as the gold standard.

Prenatal counseling--implications of the cultural background of pregnant women on information processing, emotional response and acceptance.

PURPOSE: Providing information about prenatal diagnosis (PND) that leads to an informed decision is ethically and psychologically challenging, especially in an intercultural context. The aim was to investigate cultural differences in information processing, test interpretation, evaluation of an established information leaflet, emotional response during screening and acceptance of PND. MATERIALS AND METHODS: This prospective study compared 30 pregnant Turkish immigrants with 30 women from Switzerland and countries within the European Union (EU). They completed a questionnaire prior to (T1) and after risk assessment between 11-14 weeks (T2) and after receiving the results (T3). The questionnaire focused on the perception of, experiences with and knowledge about the risk assessment and included the hospital anxiety and depression scale (HADS). χ(2) tests were used for dichotomous variables and Student's t-tests for scores on perception, experience, knowledge, depression and anxiety. Groups were compared over time by 2-factorial ANOVA. RESULTS: Regarding the 6 questions on knowledge, the rate of correct answers was between 32.2% and 62.5% at T1 and 35.1% and 75.0% at T2. The Turkish women's knowledge level was significantly lower. They rated the information leaflet as less helpful and found the counseling significantly more unsettling. The acceptance of PND was higher in Turkish women. CONCLUSION: Considering the information and knowledge deficits, informed consent was not given in every case, especially in Turkish women. Nevertheless, the acceptance of PND was good. Further studies will have to focus on counseling strategies that take into account the specific needs and expectations of pregnant women with different cultural backgrounds.

Day-case diagnostic and interventional peripheral angiography: 10-year experience in a radiology specialist nurse-led unit.

We describe a prospective evaluation of the safety of peripheral angiography procedures performed on day-case patients in a dedicated radiological nurse-led and administrated unit. Patients referred for peripheral vascular angiography, over a 10-year period, were pre-assessed by a radiology specialist nurse in a nurse-led clinic. Radiologists performed all procedures, whereas radiology specialist nurses were responsible for patient care before, during and after angiography and during the 24 h follow-up. Procedures were divided into diagnostic or interventional; complications were divided into immediate or delayed (24 h follow-up) either requiring hospital admission (major) or day-case unit management (minor). Patient acceptability was assessed using a standard questionnaire. Cost analysis was also performed. 401 day-case peripheral angiography procedures (144 diagnostic and 257 interventional) were performed in 310 patients. 109/401 (27.2%) procedures were performed on patients with diabetes mellitus. In diagnostic studies, 16/144 (11.1%) immediate and 6/144 (4.2%) delayed complications occurred whereas, in interventional studies, 65/257 (25.3%) immediate and 13/257 (5.1%) delayed complications were noted. A major complication occurred in 17/257 (6.6%) of patients in the interventional group and 3/144 (2.1%) in the diagnostic group. Puncture site haematoma was the most common complication. Nurse-led care was acceptable to the patient, with a high level of patient satisfaction seen. In conclusion, day-case diagnostic and interventional peripheral angiography procedures can be performed safely in a specialist nurse-led and administrated unit, with complication rates being within the accepted guidelines.

Assessment of baseline toxicity of mono-cyclic aromatic compounds by pseudomonas initial oxygen uptake assay.

The objective of this study was to develop quantitative structure-activity relationships (QSARs) for the toxicity of mono-cyclic aromatic compounds in the Pseudomonas putida initial oxygen uptake assay. The QSARs were developed using response-surface based on descriptors for chemical hydrophobicity (logP) and electrophilicity (LUMO). The model log (Ki(-1)=0.434 (+/-0.011) log P-0.389 (+/-0.013) LUMO - 2.13(+/-0.031); n=155, r2=0.941, r2(adj)=0.940, s=0.119, F=1206 led us to conclude that the polar and non-polar narcotics were statistically indistinguishable. Pentafluorophenol, pentachlorophenol and most dinitrophenols classified as weak acid respiratory uncouplers in literature fit well into this model when they were treated as their corresponding phenoxides. This latter result suggests that the action mechanism of these phenols should be reevaluated.

Analysis of cost and assessment of computerized patient record systems in Japan based on questionnaire survey.

PURPOSE: The purpose of this study was to clarify the implementation and maintenance costs of a computerized patient record (CPR) system by means of a questionnaire survey. Moreover, the benefits of CPR systems were evaluated to determine their contribution to enhancing the quality of medical care and hospital management. METHODS: Data were collected by a questionnaire survey mailed out to participants. RESULTS: The per-bed mean cost for implementation was 14,308 dollars (range: 3538-38,077 dollars). The mean annual maintenance cost for the CPR system was 457,615 dollars (range: 39,769-2,307,692 dollars). The multivariate analysis (Hayashi's Quantification Type I) revealed high partial correlation coefficients between implementation cost and the CPR system maker. In addition, the multiple correlation coefficient for four factors (CPR system maker, number of servers, institution type and implementation date) in predicting implementation cost was 0.798. Over 60% of respondents replied that their satisfaction with the CPR system was 'very high' or 'high.' Eighty-two percent of the hospitals responded positively that CPR systems improve the quality of medical care, and 70% felt that the systems help prevent medical errors. CONCLUSIONS: Our findings indicate that the maker of CPR system, number of servers, institution type and implementation date had a strong influence on per-bed implementation costs in that order. Finally, it was found that CPR systems were considered effective for hospital administration and medical examinations, based on the high assessments of the results of installing a CPR system.

Intrastromal corneal ring segments for low myopia: a report by the American Academy of Ophthalmology.

OBJECTIVE: This document describes intrastromal corneal ring segments (Intacs) inserts technology and examines the evidence to answer the key question about whether the treatment is safe and effective in correcting low myopia. METHODS: A literature search that was conducted in September 2000 retrieved 13 relevant citations, and the reference lists of these articles were consulted for additional citations. Panel members reviewed this information and articles were rated according to the strength of evidence. RESULTS: Prospective multicenter phase II and III clinical trials (Level II evidence rating) of Intacs inserts for myopia of -1.00 to -3.00 diopters (D), with a maximum of +1.00 D of astigmatism, enrolled a total of 452 subjects, with a total of 454 surgical attempts. The results from phase II and phase III were pooled for much of the analysis. At 1 year, 97% of patients who completed follow-up had 20/40 or better uncorrected visual acuity (UCVA). Seventy-four percent of patients had 20/20 or better UCVA. Ninety-two percent of eyes were within +/-1 D of intended refractive correction, and 69% were within 0.5 D of intended refractive correction. At 3 months, 90% of patients had less than 1.0 D of change from the previous examination performed at 1 month. The ocular complication rate, which was defined as clinically significant events but not resulting in permanent sequelae, was 11% at 12 months. The adverse event rate was 1.1%, defined as a serious event if untreated. Nearly 9% of patients requested to have their inserts removed and a total of 3.8% of patients required a secondary surgical intervention. CONCLUSIONS: To date, evidence suggests that low myopia (-1 to -3 D) in a well-defined group of patients who have a stable manifest refraction and less than +1.0 D of astigmatism can be treated with Intacs inserts with a reasonable assurance of safety and effectiveness. Additional clinical research is needed to determine the long-term effectiveness of treatment and the comparative safety, effectiveness, and costs with other treatment modalities, including laser-assisted in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).

UPBEAT: the impact of a psychogeriatric intervention in VA medical centers. Unified Psychogeriatric Biopsychosocial Evaluation and Treatment.

BACKGROUND: The Unified Psychogeriatric Biopsychosocial Evaluation and Treatment (UPBEAT) program provides individualized interdisciplinary mental health treatment and care coordination to elderly veterans whose comorbid depression, anxiety, or alcohol abuse may result in overuse of inpatient services and underuse of outpatient services. OBJECTIVES: To determine whether proactive screening of hospitalized patients can identify unrecognized comorbid psychiatric conditions and whether comprehensive assessment and psychogeriatric intervention can improve care while reducing inpatient use. DESIGN: Randomized trial. SUBJECTS: Veterans aged 60 and older hospitalized for nonpsychiatric medical or surgical treatment in 9 VA sites (UPBEAT, 814; usual care, 873). MEASURES: The Mental Health Inventory (MHI) anxiety and depression subscales, the Alcohol Use Disorder Identification Test (AUDIT) scores, RAND 36-Item Health Survey Short Form (SF-36), inpatient days and costs, ambulatory care clinic stops and costs, and mortality and readmission rates. RESULTS: Mental health and general health status scores improved equally from baseline to 12-month follow-up in both groups. UPBEAT increased outpatient costs by $1,171 (P <0.001) per patient, but lowered inpatient costs by $3,027 (P = 0.017), for an overall savings of $1,856 (P = 0.156). Inpatient savings were attributable to fewer bed days of care (3.30 days; P = 0.016) rather than fewer admissions. Patients with 1 or more pre-enrollment and postenrollment hospitalizations had the greatest overall savings ($6,015; P = 0.069). CONCLUSIONS: UPBEAT appears to accelerate the transition from inpatient to outpatient care for acute nonpsychiatric admissions. Care coordination and increased access to ambulatory psychiatric services produces similar improvement in mental health and general health status as usual care.

Women's participation in developing west China.

PIP: In China, the underdeveloped economy of the west has limited women's employment opportunities compared with their counterparts in the eastern and central region. Most women workers are engaged in agricultural production offering few opportunities for career development. Education, awareness of participation, fertility level, and health conditions are the compounding factors that hindered women's employment. According to a 10% sampling survey of the 4th population census in 1990, a high percentage of illiterates and semi-illiterates and a high dropout rate among girl students are noted. Moreover, a survey of maternal mortality rates indicated that the rate in west China was still far higher than that in central and eastern areas. In the context of its fertility, it is evident that the average age at first marriages and childbirth for women are considerably lower than the national average, while the percentage of women having multiple children is markedly higher than the national level. The paper proposes the following: improve education for women, especially girls; promote gender equality; publicize and implement the family planning policy; and increase spending on improving young girls' nutrition and on acquisition of medical equipment in western China for a balanced national economic development.^ieng

Cardiac rehabilitation participation predicts lower rehospitalization costs.

The effect of participation in cardiac rehabilitation on medical costs was determined by measuring hospitalization charges for cardiac admissions over a 3-year period in 580 post-coronary event patients (58% after coronary bypass surgery, 42% after myocardial infarction), of whom 230 entered a cardiac rehabilitation program and 350 did not. Baseline left ventricular ejection fraction was similar in entrants and nonentrants (59.9% vs 59.5%). Over the 1 to 46-month follow-up period (mean 21 months), per capita hospitalization charges for participants in cardiac rehabilitation were $739 lower than charges for nonparticipants ($1197 +/- 3911 vs $1936 +/- 5459, p = 0.022). This was due to both a lower incidence of hospitalizations and lower charges per hospitalization. Inasmuch as groups differed with regard to age, sex, diagnostic category, and smoking status, data were adjusted for these baseline differences by means of analysis of covariance. Rehospitalization charges remained significantly higher in nonparticipants (p = 0.015). Because physician charges were not measured, the cost differential between groups is underestimated. Results of this study show an association between participation in comprehensive cardiac rehabilitation and lowered cardiac rehospitalization costs in the years after an acute coronary event.

Dose parameters of 125I and 192Ir seed sources.

As mandated by an NCI brachytherapy contract, we measured dosimetric parameters for 192Ir seeds and two models of 125I seeds. Measurements were with LiF powder in a water-equivalent phantom. Data were corrected for background, sample mass, and finite detector volume. Selected parameters were also investigated through Monte Carlo calculations. Results are presented in terms of a dose parametrization that is described in detail, and are compared to published data. Our results agreed well with published data for relative quantities such as radial and angular dose dependence. Our measured value for the 192Ir dose factor was 4.55 cGy(H2O) cm2 mCi-1 h-1, also in good agreement with commonly used values. However, the measured dose factors for 125I seed models 6702 and 6711 were 1.18 and 1.06 cGy(H2O) cm2 mCi-1 h-1, values well below those in general use.

Improved dose distribution with customized I-125 source loading in temporary interstitial implants.

I-125 sources are being used in temporary interstitial implants of various sites. Radiation safety considerations favor its use over other available radioisotopes. Cost containment is achieved by using the same sources for a number of patients. Loading I-125 seeds into implant catheters at our institutions permit customized source arrangement to optimize the implant dose patterns. Clinical examples are given for which the dose distributions achieved with customized source loading are superior to those achievable with standard Ir-192 ribbons.

Low-cost frequency-stabilized CO(2) laser using 4.3-microm saturated fluorescence.

A frequency-stabilized CO(2) laser using the saturated fluorescence technique was constructed. Stainless-steel rods were used to support the cavity, and a thermoelectrically cooled PbSe detector monitored the 4.3-microm fluorescence from a low-pressure CO(2) absorption cell. Stabilization of the CO(2) laser at the center of the saturation dip was achieved with the absorption cell inside or outside the laser cavity. The frequency stability is estimated to be better than 3.5 x 10(-9).

Assessment of the anti-tumor potential of glutathione.

This study assesses the effect of reduced glutathione (GSH) on regenerating liver, 3'-methyl-4-dimethylaminoazobenzene (3'-MDAB) hepatocarcinogenesis, and normal and transformed hepatocytes in vitro. GSH administered intragastrically caused only a 30% reduction in thymidine incorporation into liver DNA at 24 h after partial hepatectomy; there was no apparent effect on RNA and protein synthesis. Furthermore, in 3'-MDAB induced hepatocarcinogenesis, all GSH-treated animals developed hepatocyte nodules, and serum alpha-fetoprotein (AFP) levels were not reduced. In vitro, GSH was shown to be cytotoxic to both normal and transformed hepatocytes at serum concentrations under 10%. GSH inhibited [3H]thymidine incorporation slightly in 2 transformed hepatocyte lines, but not in normal hepatocytes.