Pre-pregnancy body mass index, gestational diabetes mellitus, and gestational weight gain: individual and combined effects on fetal growth

Background

Pre-pregnancy body mass index (BMI), gestational diabetes mellitus (GDM), and gestational weight gain (GWG) are interlinked and may play a complex role in fetal growth. We aimed to examine the relationship between pre-pregnancy BMI, GDM, GWG, and fetal growth outcomes and explore the contribution of GDM and GWG to the relationship between Pre-pregnancy obesity/overweight and large-for-gestational-age (LGA) in a prospective cohort.

Methods

We prospectively recruited women in the first trimester and having one-step GDM screened with a 75-g oral glucose tolerance test between 24 and 28 weeks of gestation (n = 802). Outcomes included LGA, small-for-gestational-age (SGA), and preterm birth. To assess the individual and cumulative associations between pre-pregnancy BMI, GDM, GWG, and these outcomes, we used multivariate logistic regression analysis. Furthermore, we employed structural equation modeling (SEM) to investigate the mediating role of GDM and excessive GWG in the correlation between pre-pregnancy overweight/obesity and LGA.

Results

Pre-pregnancy obesity, GDM, and excessive GWG were all independently associated with increased odds of LGA. Inadequate GWG was associated with higher odds of preterm birth. Compared with women unexposed to pre-pregnancy overweight/obesity, GDM, or excessive GWG, women exposed any two conditions had higher odds for LGA (AOR 3.18, 95% CI 1.25-8.11) and women with coexistence of all had the highest odds for LGA (AOR 8.09, 95% CI 2.18-29.97). The mediation analysis showed that GDM explained 18.60% (p < 0.05) of the total effect of pre-pregnancy overweight/obesity on LGA, and GWG explained 17.44% (p < 0.05) of the total effect.

Conclusion

Pre-pregnancy obesity/overweight, GDM, and excessive GWG are associated with higher odds of fetal growth disturbances as individual factors and when they co-exist. The effect of pre-pregnancy overweight/obesity on LGA is partially achieved through GDM and excessive GWG.

Identifying critical genes and pathways of doxorubicin-induced cardiomyopathy via bioinformatics analysis

OBJECTIVE

The pathogenesis of doxorubicin (DOX) induced cardiomyopathy (DCM) is still uncertain. We aimed to identify the critical genes and pathways involved in DCM based on bioinformatics analysis.

MATERIALS AND METHODS

The GSE59672 and GSE23598 mice heart tissue microarray data were obtained from Gene Expression Omnibus (GEO) database. The "limma" package of R software was used to screen the differently expressed genes (DEGs). GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses were performed on DEGs by using "clusterProfiler" package in R software. The PPI (Protein - Protein Interaction) network of DEGs constructed by STRING online database and thereby the top 15 hub genes selected by cytoHubba in Cytoscape software. The hub genes interaction was performed by GeneMANIA online database. The "Corrplot" R package was employed to assess hub genes correlation.

RESULTS

Finally, a total of 492 and 501 DEGs were screened in GSE59672 and GSE23598 datasets, respectively. GO analyses revealed that DEGs were mainly involved in the regulation of extracellular matrix organization, metabolic process, regulation of collagen-containing extracellular matrix. KEGG pathway analyses indicated that DEGs were mainly involved in protein digestion and absorption, ECM-receptor interaction, phagosome, and p53 signaling pathway. Finally, the 8 hub genes were identified, including Col1a1, Col3a1, Col1a2, Col6a1, Ptprc, Tyrobp, Itgb2, and Ctss.

CONCLUSIONS

The present study identified a series of key genes, including Col1a1, Col3a1, Col1a2, Col6a1, Ptprc, Tyrobp, Itgb2, and Ctss. In addition, important pathways were also discovered. The results of this study may provide a novel molecular mechanism and potential therapeutic targets for DCM.

The implementation of target trial emulation for causal inference: a scoping review

OBJECTIVES

We aim to investigate the implementation of Target Trial Emulation (TTE) for causal inference, involving research topics, frequently used strategies, and issues indicating the need for future improvements.

STUDY DESIGN AND SETTING

We performed a scoping review by following the Joanna Briggs Institute (JBI) guidance and Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. A health research-focused librarian searched multiple medical databases, and two independent reviewers completed screening and extraction within covidence review management software.

RESULTS

Our search resulted in 1,240 papers, of which 96 papers were eligible for data extraction. Results show a significant increase in the use of TTE in 2018 and 2021. The study topics varied and focused primarily on cancer, cardiovascular and cerebrovascular diseases, and infectious diseases. However, not all papers specified well all three critical components for generating robust causal evidence: time-zero, random assignment simulation, and comparison strategy. Some common issues were observed from retrieved papers, and key limitations include residual confounding, limited generalizability, and a lack of reporting guidance that need to be improved.

CONCLUSION

Uneven adherence to the TTE framework exists, and future improvements are needed to progress applications using causal inference with observational data.

The Shear Stress-Regulated Expression of Glypican-4 in Endothelial Dysfunction In Vitro and Its Clinical Significance in Atherosclerosis

Retention of circulating lipoproteins by their interaction with extracellular matrix molecules has been suggested as an underlying mechanism for atherosclerosis. We investigated the role of glypican-4 (GPC4), a heparan sulfate (HS) proteoglycan, in the development of endothelial dysfunction and plaque progression; Expression of GPC4 and HS was investigated in human umbilical vein/artery endothelial cells (HUVECs/HUAECs) using flow cytometry, qPCR, and immunofluorescent staining. Leukocyte adhesion was determined in HUVECs in bifurcation chamber slides under dynamic flow. The association between the degree of inflammation and GPC4, HS, and syndecan-4 expressions was analyzed in human carotid plaques; GPC4 was expressed in HUVECs/HUAECs. In HUVECs, GPC4 protein expression was higher in laminar than in non-uniform shear stress regions after a 1-day or 10-day flow (p < 0.01 each). The HS expression was higher under laminar flow after a 1 day (p < 0.001). Monocytic THP-1 cell adhesion to HUVECs was facilitated by GPC4 knock-down (p < 0.001) without affecting adhesion molecule expression. GPC4 and HS expression was lower in more-inflamed than in less-inflamed plaque shoulders (p < 0.05, each), especially in vulnerable plaque sections; Reduced expression of GPC4 was associated with atherogenic conditions, suggesting the involvement of GPC4 in both early and advanced stages of atherosclerosis.

Effect of vitamin A on the relationship between maternal thyroid hormones in early pregnancy and fetal growth: A prospective cohort study

Background

Fetal growth patterns are influenced by maternal thyroid function and vitamin A level during pregnancy. Vitamin A presents interactions with thyroid tissues and hormonal systems. We examined whether vitamin A status modified the associations of maternal thyroid hormones in early pregnancy and fetal growth outcomes among euthyroid pregnant women in a prospective cohort study (n = 637).

Methods

We performed multiple linear regression and multinomial logistic regression analysis to investigate the effects of thyroid hormones in early pregnancy on fetal growth according to different levels of serum vitamin A based on median value.

Results

A 1 pmol/L increase in maternal free triiodothyronine (FT3) levels was associated with an increased birth weight of 0.080 kg (p = 0.023) in women with lower maternal vitamin A levels in early pregnancy. Increased maternal free thyroxine (FT4) was associated with decreased odds for both small size for gestational age (SGA) [odds ratios (OR) = 0.66, 95% confidence interval (CI): 0.45–0.95] and large size for gestational age (LGA) (OR = 0.66, 95% CI: 0.45–0.98) in women with higher vitamin A level in early pregnancy after adjustment for maternal prepregnancy body mass index, gestational weight gain, maternal employed, parity, gestational week at sampling, and gestational diabetes mellitus.

Conclusions

In Chinese pregnant women without overt thyroid dysfunction, maternal FT4 in early pregnancy was positively associated with optimal fetal growth among women with higher serum vitamin A concentrations.

The Impacts of Prenatal Mental Health Issues on Birth Outcomes during the COVID-19 Pandemic: A Scoping Review

Background: The severity of the COVID-19 pandemic is likely to exacerbate mental health problems during the prenatal period and increase the risk of adverse birth outcomes. This review assessed the published literature related to the impacts of prenatal mental health issues on birth outcomes during the COVID-19 pandemic. Methods: This scoping review was conducted using PROSPERO, Cochrane Library, OVID Medline, Ovid EMBASE, OVID PsycInfo, EBSCO CINAHL, and SCOPUS. The search was conducted using controlled vocabulary and keywords representing the concepts “COVID19”, “mental health” and “birth outcomes”. The main inclusion criteria were peer-reviewed published articles from late 2019 to the end of July 2021. Results and Discussion: After removing duplicates, 642 articles were identified, of which two full texts were included for analysis. Both articles highlighted that pregnant women have experienced increasing prenatal mental health issues during the COVID-19 pandemic and, further, increased the risk of developing adverse births. This scoping review highlighted that there is a lack of research on the impact of prenatal mental health issues on birth outcomes during the pandemic. Conclusion: Given the severity of the COVID-19 pandemic and the burdens of prenatal mental health issues and adverse birth outcomes, there is an urgent need to conduct further research.

Vitamin B6 catabolism and lung cancer risk: results from the Lung Cancer Cohort Consortium (LC3)

BACKGROUND

Increased vitamin B6 catabolism related to inflammation, as measured by the PAr index (the ratio of 4-pyridoxic acid over the sum of pyridoxal and pyridoxal-5'-phosphate), has been positively associated with lung cancer risk in two prospective European studies. However, the extent to which this association translates to more diverse populations is not known.

MATERIALS AND METHODS

For this study, we included 5323 incident lung cancer cases and 5323 controls individually matched by age, sex, and smoking status within each of 20 prospective cohorts from the Lung Cancer Cohort Consortium. Cohort-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between PAr and lung cancer risk were calculated using conditional logistic regression and pooled using random-effects models.

RESULTS

PAr was positively associated with lung cancer risk in a dose-response fashion. Comparing the fourth versus first quartiles of PAr resulted in an OR of 1.38 (95% CI: 1.19-1.59) for overall lung cancer risk. The association between PAr and lung cancer risk was most prominent in former smokers (OR: 1.69, 95% CI: 1.36-2.10), men (OR: 1.60, 95% CI: 1.28-2.00), and for cancers diagnosed within 3 years of blood draw (OR: 1.73, 95% CI: 1.34-2.23).

CONCLUSION

Based on pre-diagnostic data from 20 cohorts across 4 continents, this study confirms that increased vitamin B6 catabolism related to inflammation and immune activation is associated with a higher risk of developing lung cancer. Moreover, PAr may be a pre-diagnostic marker of lung cancer rather than a causal factor.

Influence of hormone therapy or C. foetida extract on breast tenderness in postmenopausal women

OBJECTIVE

To evaluate the prevalence of breast tenderness in a population treated with menopausal hormone therapy (MHT) or Cimicifuga foetida extract.

METHODS

A prospective, randomized, controlled trial was conducted. Ninety-six postmenopausal women were randomly assigned to three groups: group A, 1 mg estradiol valerate daily plus 4 mg medroxyprogesterone acetate (MPA), days 19-30; group B, 1 mg estradiol valerate daily plus 100 mg micronized progesterone (MP), days 19-30; group C, 100 mg C. foetida extract daily. Breast tenderness was evaluated daily for 12 months.

RESULTS

Seventy-three patients completed the study. Group A had the highest prevalence of breast tenderness, while group C had the lowest. More than 50% of all participants reported no symptoms throughout the period. The participants in group A experienced a sharp increase in breast tenderness after treatment, but decreased after 1 month. No significant decline was found in the duration of pain in group B. The patients in group C reported no remarkable changes after 1 month. Compared to estrogen only, estrogen plus MPA/MP led to a higher incidence of prolonged breast symptoms.

CONCLUSIONS

Compared to MHT groups, C. foetida extract had the lowest prevalence of breast tenderness. Most participants experienced mild or no symptoms.

Association of plasma neopterin with risk of an inpatient hospital diagnosis of atrial fibrillation: results from two prospective cohort studies

BACKGROUND

Link between inflammation and atrial fibrillation (AF) has been increasingly recognized. Neopterin, a biomarker of cellular immune activation, may be associated with incident AF.

OBJECTIVE

To investigate the association between plasma neopterin levels and risk of an inpatient hospital diagnosis of AF, and to evaluate a joint association of neopterin and a nonspecific inflammatory marker C-reactive protein (CRP) in two prospective cohorts.

METHODS

We performed a prospective analysis from a community-based cohort (the Hordaland Health Study (HUSK), n = 6891), and validated the findings in a cohort of patients with suspected stable angina pectoris (the Western Norway Coronary Angiography Cohort (WECAC), n = 2022).

RESULTS

In both cohorts, higher plasma levels of neopterin were associated with an increased risk of incident AF after adjustment for age, sex, body mass index, current smoking, diabetes, hypertension and renal function. The multivariable-adjusted hazard ratio (HR) (95% CI) per one SD increment of log-transformed neopterin was 1.20 (1.10-1.32) in HUSK and 1.26 (1.09-1.44) in WECAC. Additional adjustment for CRP did not materially affect the risk association for neopterin. The highest risk of AF was found among individuals with both neopterin and CRP levels above the median (HR: 1.54; 95% CI: 1.16-2.05 in HUSK and HR: 1.67; 95% CI: 1.11-2.52 in WECAC).

CONCLUSIONS

Our findings indicate an association of plasma neopterin with risk of an inpatient hospital diagnosis of AF, which remains after adjustment for traditional risk factors as well as for CRP. This study highlights a role of cellular immune activation, in addition to inflammation, in AF pathogenesis.

wblA, a pleiotropic regulatory gene modulating morphogenesis and daptomycin production in Streptomyces roseosporus

AIMS

The wblA gene, encoding a homologue of the WhiB family protein, was identified in the sequenced genome of daptomycin producer Streptomyces roseosporus. To explore the function of wblA, we construct wblA disruption strains, complemented strains and overexpression strains to test whether it can affect the production of secondary metabolites and morphogenesis.

METHODS AND RESULTS

We constructed disruption strains by homologous recombination in S. roseosporus. The disruption mutant of wblA could block aerial mycelium sporulation and enhance the production of daptomycin by 51%. In contrast, overexpression of wblA resulted in significantly decreased the yield of daptomycin. In agreement with it, the transcription of key daptomycin regulatory genes atrA, dptR2 and dptR3 and structural gene dptE remarkably increased in the wblA disruption mutant.

CONCLUSIONS

wblA plays a key role in control of daptomycin biosynthesis and is essential for sporulation. The disruption of wblA could accumulate the transcription level of some key genes involving in daptomycin biosynthesis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Daptomycin is an important antibiotic with potent activity against a variety of Gram-positive pathogens. This study demonstrates that valuable improvement in the yield of daptomycin can be achieved through modulating the expression of wblA transcription regulator.

Smoking, plasma cotinine and risk of atrial fibrillation: the Hordaland Health Study

BACKGROUND

Cigarette smoking has been identified as a major modifiable risk factor for coronary heart disease and mortality. However, findings on the relationship between smoking and atrial fibrillation (AF) have been inconsistent. Furthermore, findings from previous studies were based on self-reported smoking.

OBJECTIVE

To examine the associations of smoking status and plasma cotinine levels, a marker of nicotine exposure, with risk of incident AF in the Hordaland Health Study.

METHODS

We conducted a prospective analysis of 6682 adults aged 46-74 years without known AF at baseline. Participants were followed via linkage to the Cardiovascular Disease in Norway (CVDNOR) project and the Cause of Death Registry. Smoking status was assessed by both questionnaire and plasma cotinine levels.

RESULTS

A total of 538 participants developed AF over a median follow-up period of 11 years. Using questionnaire data, current smoking (HR: 1.41, 95% CI: 1.09-1.83), but not former smoking (HR: 1.03, 95% CI: 0.83-1.28), was associated with an increased risk of AF after adjustment for gender, age, body mass index, hypertension, physical activity and education. Using plasma cotinine only, the adjusted HR (95% CI) was 1.40 (1.12-1.75) for participants with cotinine ≥85 nmol L^-1 compared to those with cotinine <85 nmol L^-1 . However, the risk increased with elevated plasma cotinine levels until 1199 nmol L^-1 (HR: 1.55, 95% CI: 1.16-2.05 at the third group vs. the reference group) and plateaued at higher levels.

CONCLUSIONS

Current, but not former smokers, had a higher risk of developing AF. Use of plasma cotinine measurement corroborated this finding.

Efficacy and safety evaluation of Cimicifuga foetida extract in menopausal women

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of long-term treatment with Cimicifuga foetida extract in menopausal women.

METHODS

A prospective, randomized, controlled clinical trial was conducted. A total of 96 early postmenopausal women were randomly assigned to three groups: group A received 1 mg estradiol valerate daily plus 4 mg medroxyprogesterone acetate on days 19-30; group B received 1 mg estradiol valerate daily plus 100 mg micronized progesterone on days 19-30; group C received 100 mg C. foetida extract daily. The efficacy was evaluated. Safety parameters were recorded.

RESULTS

A total of 81 patients completed the treatment and follow-up visit. The modified Kupperman Menopausal Index scores decreased after 3 months in all groups. No significant changes were observed in the liver, renal function and components of metabolic syndrome in group C (p > 0.05). There were no significant differences in the incidences of metabolic syndrome among the three groups (p > 0.05). After 24 months, the endometrial thickness increased significantly in group B (p = 0.014), but not in the C. foetida extract group (p > 0.05).

CONCLUSIONS

C. foetida extract is safe and effective for the treatment of menopausal symptoms in postmenopausal women.

Determinants of second pregnancy among pregnant women: a hospital-based cross-sectional survey in China

OBJECTIVES

This study aimed to explore determinants of second pregnancy and underlying reasons among pregnant Chinese women.

DESIGN

The study was a population-based cross-sectional survey.

SETTING

16 hospitals in 5 provinces of Mainland China were included.

PARTICIPANTS

A total of 2345 pregnant women aged 18 years or above were surveyed face to face by investigators between June and August 2015.

MAIN OUTCOME MEASURES

The pregnancy statuses (first or second pregnancy) and reasons for entering second pregnancy.

RESULTS

A total of 1755 (74.8%) and 590 (25.2%) women in their respective first and second pregnancies were enrolled in this study. The most common self-reported reasons for entering second pregnancy among participants included the benefits to the first child (26.1%), love of children (25.8%), adoption of the 2-child policy (11.5%), concerns about losing the first child (7.5%) and suggestions from parents (7.5%). Pregnant women with low (prevalence ratio (PR) 1.96; 95% CI 1.62 to 2.36) and moderate education level (PR 1.97; 95% CI 1.65 to 2.36) were more likely to have a second pregnancy than their higher educated counterparts. Income was inversely associated with second pregnancy. However, unemployed participants (PR 0.79; 95% CI 0.66 to 0.95) were less likely to enter a second pregnancy than those employed. Women with moderate education were 3 times more likely to have a second child following the '2-child policy' than the low education level subgroup.

CONCLUSIONS

1 in every 4 pregnant women is undergoing a second pregnancy. The benefits of the firstborn or the love of children were the key drivers of a second pregnancy. Low socioeconomic status was positively associated with a second pregnancy as well. The new 2-child policy will have an influence on China's demographics.

Association between matrix metalloproteinase-9 rs3918242 polymorphism and development of coronary artery disease in a Chinese population

We conducted a case-control study to investigate the role of one single nucleotide polymorphism of MMP-9 rs3918242 in the development of coronary artery disease. The rs3918242 was amplified with 435-bp DNA fragments using polymerase chain reaction coupled with restriction fragment length polymorphism. When compared with control subjects, patients with coronary artery disease had higher systolic and diastolic blood pressure, as well as higher triglycerides (P < 0.05), were more likely to suffer from diabetes mellitus, and had lower total cholesterol and high-density lipopolysaccharides. Using unconditional logistic analysis, we found that individuals with CT and TT genotypes were associated with increased risk of coronary artery disease in a co-dominant model, and the ORs (95%CI) were 1.50 (1.02-2.20) and 6.89 (2.51-23.41) for CT and TT, respectively. We observed that the T allele of rs3918242 was correlated with increased risk of coronary artery disease (OR = 1.88, 95%CI = 1.39-2.55). In conclusion, we suggest that the TT and CT genotypes and T allele of MMP-9 rs3918242 polymorphism is correlated with an increased risk of coronary artery disease in a Chinese population.

Development of a novel adenovirus-alphavirus hybrid vector with RNA replicon features for malignant hematopoietic cell transduction

To improve the expression levels of transgenes in malignant hematopoietic cells, we developed a novel adenoviral-alphavirus hybrid vector Ad5/F11p-SFV-GFP that contains a Semliki Forest Virus (SFV) replicon and chimeric fibers of Ad5 and Ad11p. Ad5/F11p-SFV-GFP infected >95% of K562, U937 or Jurkat cells and 23.65% of HL-60 cells, and led to moderate Enhanced Green Fluorescent Protein (EGFP) transgene expression intensity. The infection efficiency of Ad5/F11p-SFV-GFP in primary human leukemia cells ranged from 9.34-89.63% (median, 28.58%) at a multiplicity of infection (MOI) of 100, compared with only 3.37-44.54% (median, 10.42%) in cells infected by Ad5/F11p-GFP. Importantly, Ad5/F11p-SFV-GFP led to a significantly higher transgene expression level in primary leukemia cells, as indicated by the relative fluorescence intensity, compared to cells infected with Ad5/F11p-GFP. The increased expression of EGFP in Ad5/F11p-SFV-GFP-infected cells was associated with the accumulation of abundant subgenomic mRNA. Additionally, infection of K562, U937 or Jurkat cells by Ad5/F11p-SFV-GFP was significantly inhibited by blocking CD46 receptor; however, other factors may affect the gene-transfer efficiency of Ad5/F11p-SFV-GFP in primary leukemia cells. In conclusion, we successfully developed a novel adenoviral-alphavirus hybrid vector with RNA replicon features, which represents a promising vector for gene modifications during the production of cell-based vaccines for leukemia patients.

Berberine attenuates doxorubicin-induced cardiotoxicity in mice

This study investigated the effects of berberine, a natural alkaloid, on doxorubicin-induced cardiotoxicity in mice. Mice were injected intraperitoneally with saline 10 ml/kg (n = 10), doxorubicin 2.5 mg/kg (n = 10), 60 mg/kg berberine 1 h before doxorubicin 2.5 mg/kg (n = 10), or 60 mg/kg berberine alone (n = 10) every other day for 14 days. Body weight, general condition and mortality were recorded over the 14-day study period. Electro cardiography was performed before the start of treatment and after 14 days and plasma lactate dehydrogenase (LDH) activity was measured after 14 days. At the end of the study period the heart was excised and examined histologically. An increase in mortality, an initial decrease in body weight, increased LDH activity, prolongation of QRS duration and increased myocardial injury were seen in the doxorubicin-treated group compared with the saline control group. These changes were significantly attenuated by pretreatment with berberine. The study suggests that berberine may have a potential protective role against doxorubicin-induced cardiotoxicity in mice.

Cytokines produced by microwave-radiated Sertoli cells interfere with spermatogenesis in rat testis

Microwave radiation resulted in degeneration, apoptosis or necrosis in germ cells at different stages. The molecular mechanisms by which microwaves induce spermatogenesis disorder have not been completely understood. Sertoli cells play crucial roles in mammalian spermatogenesis. Cytokines produced by Sertoli cells play pleiotropic roles in different conditions. At physiologically low concentration, TNFα, IL-1β and IL-6 behave as survival factors; while under pathological condition, these cytokines can induce apoptosis in testis. The effects of cytokines produced by microwave-radiated Sertoli cells on spermatogenesis are poorly understood. The purpose of this study was to determine the effect of cytokines produced by microwave-radiated Sertoli cells on the germ cells. We focused the effect of TNFα, IL-1β and IL-6 on the germ cells. The results showed that TNFα, IL-1β and IL-6 were increased in Sertoli cells after exposure to microwave radiation. These up-regulated cytokines can induce apoptosis and lipid peroxidation in the membrane of germ cells. In addition, germ cell apoptosis was associated with the up-regulation of Bax/Bcl-2 and caspase-3. These results suggest that cytokines produced by microwave-radiated Sertoli cells may disrupt spermatogenesis. Our data provided novel insight into the injury mechanism of germ cells induced by microwave radiation.

Zinc intake and the risk of hyperglycemia among Chinese adults: the prospective Jiangsu Nutrition Study (JIN)

OBJECTIVE

To prospectively examine the associations between zinc intake, the zinc to heme iron ratio and the incidence of hyperglycemia in Chinese.

METHODS

We followed 1056 healthy adults aged 20 and older from 2002 to 2007. Dietary data were collected using 3-day food record and food frequency questionnaire. Hyperglycemia was defined as fasting plasma glucose > 5.6 mmol/l.

RESULTS

During the 5 years of follow-up, we documented 125 incident cases of hyperglycemia. Zinc intake alone was not associated with the risk of hyperglycemia. The zinc to heme iron ratio was inversely associated with the risk of hyperglycemia: odds ratios (OR, 95% CI) across increasing quartiles of the zinc to heme iron ratio were 1.00, 0.78(0.44-1.37), 0.40(0.19-0.83), and 0.21(0.08-0.54)(p for trend= 0.001). Adjustment for lifestyle covariates did not significantly change the associations.

CONCLUSIONS

This cohort study suggests that the zinc to heme iron intake ratio was significantly associated with a decreased risk of hyperglycemia in Chinese adults.

Effects of selenium and iodine deficiency on bone, cartilage growth plate and chondrocyte differentiation in two generations of rats

OBJECTIVE

The purpose of the current study was to investigate the roles of combined selenium and iodine deficiency in bone development as a possible experimental model of Kashin-Beck osteoarthropathy.

METHODS

Sprague-Dawley rats (n=48) were randomly divided into selenium deficiency (-Se+I), iodine deficiency (+Se-I), combined selenium and iodine deficiency (-Se-I), and selenium and iodine sufficient (+Se+I) groups. Growth of bone and cartilage, and the expression of type X collagen (ColX) and parathyroid hormone-related peptide (PTHrP) were measured in two generations of rats (F(0) and F(1)).

RESULTS

The tibial length in -Se-I rats was significantly shorter in F(1) generation. In +Se-I of F(1) rats, the thickness of the growth plate cartilage, and the proliferative zone was smaller, while in -Se-I rats the growth plate, and the proliferative and hypertrophic zones were also thinner in F(1) generation. In articular cartilage, ColX expression was increased in the deep zone in -Se-I rats of F(0) generation, and in -Se+I, +Se-I and -Se-I rats of F(1) generation. PTHrP expression was increased in the middle zone of -Se+I, +Se-I and -Se-I rats of both F(0) and F(1) generations. In the growth plate cartilage, ColX and PTHrP were expressed in the hypertrophic zone. ColX expression was significantly weaker in -Se+I and -Se-I rats in both F(0) and F(1) generations, while PTHrP expression was stronger in -Se+I, +Se-I and -Se-I rats in both F(0) and F(1) animals.

CONCLUSIONS

Combined selenium and iodine deficiency impaired the growth of bone and cartilage. The changes in the expression of ColX and PTHrP induced by combined selenium and iodine deficiency were compatible to measurements of ColX and PTHrP in Kashin-Beck osteoarthropathy.

A review of 227 cases of small papillary thyroid carcinoma

AIMS

To review differences in biological aggressiveness, clinical behaviors or selected surgical treatments between the PMC and the slightly larger PTC of 1.0<T<or=2.0 cm.

METHODS

Two hundred and twenty-seven cases of papillary thyroid carcinoma not larger than 2.0 cm, diagnosed and treated at the Kuma Hospital, Kobe, Japan, with a 10-year follow-up from 1992 to 2003, were reviewed.

RESULTS

The small PTCs demonstrated excellent outcomes, and persistent/recurrent disease was identified in only nine patients (4%). None of the patients died of the disease. A multivariate analysis revealed that massive extrathyroidal extension at presentation was the only independent prognostic factor for locoregional recurrence. Subdivision into PMCs and slightly larger tumors (1<T<or=2 cm) did not affect the excellent outcomes, but the patients in the latter subgroup received more lymph node surgery and displayed more aggressive clinico-histological features such as higher rates of extrathyroidal extension, lymph node metastasis, loss of polarity, invasive growth pattern and loss of cohesiveness.

CONCLUSIONS

Small PTC not larger than 2.0 cm could be considered as favorable a prognosis as PMC.

Agro-climatic classification systems for estimating the global distribution of livestock numbers and commodities

Investment in agricultural research in developing countries is being increasingly targeted at those agro-climatic zones and issues where the economic and environmental benefits may be expected to be greatest. This first requires that the zones themselves be defined, along with information on domestic livestock numbers and commodity output within agro-climatic zones in different countries. Different methods for classifying agro-climatic zones were compared. These included methods based on estimated length of growing period (LGP) using rainfall and temperature data, the ratio of precipitation to potential evapotranspiration (PET), and on more detailed agronomic models, remote sensing data and land use information. Zonation based on LGP has already been linked to existing national livestock data. By defining agro-climatic zones and relating concentrations of livestock populations to those of humans, it is possible to make realistic estimates of livestock populations and the production of livestock commodities for most developing countries. Detailed agro-climatic analyses of Mainland East Asia and Sri Lanka have recently been undertaken using the GROWEST agronomic model. Using this model as the basis of agro-climatic classification appears to be significantly superior, particularly in temperate environments, to approaches based solely on LGP. Different ways of subdividing countries and continents into agro-climatic or agro-ecological zones (AEZs) are reviewed in this paper. In addition, we show how the numbers of production and commodities from domestic livestock can be allocated to such zones. We also indicate how some of this information can be applied.

[Inhibitive effects of lip repair on maxillary growth in patients with complete unilateral cleft lip and palate]

OBJECTIVE

The aim of this study was to assess the isolated effects of lip repair on inhibition of maxillary growth in patients with complete unilateral cleft lip and palate.

METHODS

The lateral cephalometric analysis were applied to 20 patients with unilateral cleft lip and palate who only had lip repaired in childhood, 32 patients with unilateral cleft lip and palate who had both lip and palate repaired in childhood, as well as 37 normal Chinese of the same age as controls.

RESULTS

Both complete unilateral cleft lip and palate groups had almost the same significant degree of maxillary retrusion compared with the normal control group.

CONCLUSION

Lip repair is one of important factors that could inhibit maxillary growth in patients with complete unilateral cleft lip and palate.

[Complications of third ventriculostomy for hydrocephalus]

OBJECTIVE

To explore the reason of complications of third ventriculostomy and the method for reducing complications.

METHODS

Fifteen third ventriculostomies and the related complications were analyzed retrospectively.

RESULTS

Two patients had ventricular infection, one subdural fluid collection, one obstraction of fenestration site by neoplasm, one delayed herniation due to hematoma-occupied third ventricle. The complications were due to the inferior quality of the equipment and poor experience.

CONCLUSIONS

Advanced equipment and understanding of possible complications can reduce complications.

[The effect of lip repair on maxillary growth in patients with complete unilateral cleft lip and(or) palate]

OBJECTIVE

To investigate the different effects of lip repair on maxillary growth among patients with cleft lip and(or) palate, and also the possible mechanisms accounting for that differences.

METHODS

The lateral cephalometric analysis was applied to 84 Chinese patients with unilateral cleft lip and(or) palate at the early stage of permanent dentition, which included 32 UCLA, 20 UCLP (CP unrepaired), and 32 UCLP, and 37 normal Chinese of the same age as controls.

RESULTS

The patients with unilateral cleft lip and palate who had lip repaired while the palate was left unrepaired exhibited the similar inhibition on maxillary growth to those who had both lip and palate repaired but the patients with unilateral cleft lip and alveolus had much less inhibition on their maxilla.

CONCLUSIONS

The cleft and tissue defect of patients with cleft lip and palate might be the main cause that induced the inhibitive effects of lip repair on maxillary growth.

[Relationship between the expression of Bax and apoptosis induced by hyperthermia in BcaCD885 cells]

OBJECTIVE

This study aimed to investigate the role of Bax gene in apoptosis induced by hyperthermia in BcaCD885 cells.

METHODS

After inducing apoptosis through hyperthermia, the expression of Bax protein and mRNA were examined with FCM antibody analysis and RT-PCR technique respectively.

RESULTS

Up regulation of Bax protein was noted after hyperthermia. The correlation coefficient r between the apoptotic rate and the expression Bax protein was 0.9240. The expression of Bax mRNA was also raised after hyperthermia.

CONCLUSION

Hyperthermia acting as an external signal may up-regulates expression of Bax gene and then induces apoptosis in BcaCD885 cells.

[Long-term follow-up results of microsurgical treatment for glossopharyngeal neuralgia]

OBJECTIVE

To discuss effective surgical methods for the treatment of glossopharyngeal neuralgia.

METHODS

During 1986 - 1998, 21 patients with glossopharyngeal neuralgia were treated microsurgically. Of whom, 5 patients were treated by microvascular decompression (MVD), 4 by MVD combined with rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve root, and 12 by rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve root.

RESULTS

Neuralgia disappeared in all patients postoperatively. In 3 patients, occasional coughing episodes occurred postoperatively. One of the 3 patients also suffered from mild hoarseness and swallowing difficulty. All patients were followed up on average 7.2 years with no recurrence.

CONCLUSIONS

MVD, rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve and their combination are effective for the treatment of glossopharyngeal neuralgia. Operative methods should be chosen according to the following two points: compression of nerve roots by affected vessels or not; and the condition of compression.

Development of surgical confocal scanning microscope for intra-operative imaging of brain tumors using near infrared fluorescence: technical note

We developed a confocal laser scanning microscope for intra-operative imaging of brain tumors using near infrared fluorescence. The quality of near infrared images of Indocyanine Green (ICG) was compared with the surgical confocal scanning (SCS) microscope and a conventional charge-coupled device (CCD) camera; we compared images of a tube filled with ICG, which was located in the mouse brain. Compared to the CCD camera, the SCS microscope could obtain a more precise image of ICG fluorescence through the brain tissue. In addition, the SCS microscope could image ICG fluorescence clearly in a relatively light room because of elimination of stray light, while the CCD camera required high darkness to obtain ICG images. The present SCS microscope can give useful intra-operative imaging of brain tumors, particularly detection of residual tumor tissues that extend into normal brain tissues.

[Identification of telomerase activity in the experimental carcinogenesis of oral cavity]

OBJECTIVE

Telomerase is a ribonucleoprotein enzyme which synthesizes telomere DNA repeat sequences and maintain stably telomere length. The activity of telomerase may be necessary for the growth of immortalized cells overcoming cellular senescence. The researches have shown that telomerase activities are associated with most cancers. The purpose of the study is to detect the development of telomerase activity during golden hamster cheek pouch carcinogenesis induced by DMBA.

METHODS

First, 52 golden hamsters were divided into 2 groups. Four of them were not done any special treatment and were killed after 3 days. The others were covered with DMBA on the surface of cheek pouch on one side in order to induce carcinogenesis, the other side of cheek pouch was treated as the control. Then, the 48 golden hamsters were divided into 4 groups and were killed in 7, 10, 14 and 20 weeks. The telomeric repeat amplification protocol (TRAP) based on PCR and ELISA was used to analysis the activity of telomerase.

RESULTS

1. The expression of telomerase activity existed in normal cheek pouch mucosa of golden hamsters, which meant that telomerase played an important role on controlling cell proliferation. 2. The level of telomerase activity gradually increased while hyperplasia and dysplasia was observed in the cheek pouch mucosa covered with DMBA. It reached its top at a later premalignant period and gradually decreased after that. 3. There was negative correlation between the degree the telomere length was shortened and the activity of telomerase (r = -0.9654), and there was positive correlation between the reduced rate of telomere length and the activity of telomerase (r = 0.9471).

CONCLUSION

The activity of telomerase is one of important factors that can effect the stability of telomere length and plays a crucial role in the progression of oral cancer. So the activity of telomerase is an early molecular marker of carcinogenesis.

[The method of time series modeling and its application in the spectral analysis of lubricating oil]

In this paper, we discuss the applications of time series modeling method in the analysis of lubricating oil of mechanical equipment. We obtained satisfactory results by applying AR model to perform time series modeling and forecasting analysis to the collected spectral analysis data of the air engine. So we have built a practical method for state monitoring and trouble forecasting of mechanical equipment.

Effects of aging on language-activated cerebral blood oxygenation changes of the left prefrontal cortex: Near infrared spectroscopy study

The use of positron-emission tomography (PET) has shown a variety of age-related alterations in neuronal activity in elderly patients. Near infrared spectroscopy (NIRS) has shown a multiplicity of evoked cerebral blood oxygenation (CBO) changes during cognitive performance. To evaluate the effects of aging on the CBO changes, we compared the CBO changes induced by cognitive tasks between young adults and older adults by using NIRS. Twenty-six participants performed 6 cognitive tasks to evaluate differences among young adults (mean age+/-SD, 28.8+/-4.4 years) and older adults (50.7+/-8.0 years). We monitored CBO changes in the left prefrontal cortex. We classified several common patterns of the NIRS parameter change and compared the frequency of each pattern in both groups. In both groups, the most common NIRS parameter change was an increase in oxyhemoglobin (Oxy-Hb) and total-hemoglobin (Total-Hb), with a decrease in deoxyhemoglobin (Deoxy-Hb). The frequency of this pattern in the older group, however, was considerably lower than in the young group (P<.01). In addition, decreases of Oxy-Hb and Total-Hb during the tasks were more common in the older groups, (P<.0001), suggesting a decrease of regional cerebral blood flow during the tasks. Age effects varied for specific tasks, with results being significant for verbal fluency and reading, (P<.05). During all tasks, older subjects were less likely than younger subjects to have the typical pattern of increases in Oxy-Hb and Total-Hb. In addition, compared with younger subjects, older subjects had a greater frequency of decreases in Oxy-Hb and Total-Hb. The overall results, as well as results for specific tasks, suggest that functional reorganization or alteration of CBO responses may occur during aging.

Cerebral blood oxygenation changes induced by auditory stimulation in newborn infants measured by near infrared spectroscopy

Recent neuronal activation studies on newborns using functional MRI or near infrared spectroscopy (NIRS) have suggested that the increase in O2 consumption accompanying neuronal activation exceeds the increase in O2 delivery in the visual cortex during photic stimulation. In the present study, we evaluated the cerebral blood oxygenation (CBO) changes induced by auditory stimulation in the frontal lobe of newborns using NIRS. We studied 28 newborns; the postnatal age at CBO measurements was 3.1+/-0.3 days (mean+/-S.E.M.). We measured concentration changes of deoxyhemoglobin (Deoxy-Hb), oxyhemoglobin (Oxy-Hb), and total hemoglobin (Total-Hb) induced by auditory (music) stimulation in the bilateral frontal lobes of the newborns. Twenty-six (92.9%) out of 28 subjects showed increases of Oxy-Hb and Total-Hb during the stimulation. In these subjects, 17 (60.7%) subjects showed an increase of Deoxy-Hb associated with increases of Oxy-Hb and Total-Hb, while nine (32.1%) subjects showed a decrease of Deoxy-Hb. Although the direction of the Deoxy-Hb differed, these two groups did not differ for Oxy-Hb and Total-Hb (P > 0.05). Two (7.1%) subjects showed other changes. The frontal lobe of newborns shows CBO responses similar to those observed in the visual cortex, specifically neuronal activation causes an increase of Deoxy-Hb associated with increases of Oxy-Hb and Total-Hb. These results support the hypothesis that increments in O2 consumption exceed increments in O2 delivery during neuronal activity in newborns.

Continuous suction surgical cottonoid for microneurosurgery

A new suction device for microneurosurgery is presented. A surgical cottonoid is covered with a polyethylene film so that vacuum power is maintained throughout the length of the cottonoid. One end is connected to a vacuum pump via a plastic tube. Five to 10 mm of the surgical cottonoid are exposed for suctioning at the other end of the cottonoid. The suction surgical cottonoid is flexible and safe, avoiding tissue damage. In addition, the surgeon can manipulate the exposed cottonoid at the tip as any other surgical cottonoid.

[Evaluation of the effectiveness nine years after primary immunization with local produced plasma-derived hepatitis B vaccine]

OBJECTIVE

To observe the effectiveness of hepatitis B vaccine nine years after primary immunization.

METHODS

A randomized, controlled and double-blinded trial was designed with 126 children primarily immunized with local produced plasma-derived hepatitis B vaccine nine years ago and 135 placebo-control children aged five to nine years. All the children were followed-up, their blood samples collected and their disease occurrence examined. Their hepatitis B surface antigen (HBsAg), antibody against hepatitis B core antigen (anti-HBc) and antibody against hepatitis B surface antigen (anti-HBs) were tested. Causes of lowering in their antibodies were analyzed with multivariate methods.

RESULTS

During the nine-year follow-up, 4% to 19% of the study subjects dropped out. In the ninth year after immunization (T108), anti-HBs positive rate in the vaccinees and their geometric mean titer (GMT) (65.3% and 5.47, respectively) were still significantly higher than those in the placebo-controls (28.3% and 1.46, respectively), but significantly lower than those in the 6th year after immunization (T72). Multivariate analysis for the causes of lowering in the antibody during the 4th, 6th and 9th year after immunization showed that antibody titer in the vaccines first year after immunization (T12) was a crucial factor for the persistence of the antibody, and natural booster might also played a certain role in it. In the T108, one clinical case of hepatitis B occurred in the placebo control group, but no cases in the vaccinees found, with a protection rate of 81.4% from HBV infection and 84.6% from HBsAg positive-coversion, similar to those in the T72.

CONCLUSION

The effectiveness of HB vaccine still existed nine years after primary immunization, and no booster dose was needed so far.

Language-activated cerebral blood oxygenation and hemodynamic changes of the left prefrontal cortex in poststroke aphasic patients: a near-infrared spectroscopy study

BACKGROUND AND PURPOSE

In normal subjects, regional cerebral blood flow (rCBF) is greatly increased by neuronal activity, whereas the cerebral metabolic rate for O2 is increased only slightly. However, it is not clear what kinds of cerebral blood oxygenation and hemodynamic changes can be induced by language activities in language-relevant areas of poststroke aphasics. In the present study, we investigated the difference in the changes of cerebral blood oxygenation and hemodynamics in the left prefrontal cortex induced by language activities between normal subjects, poststroke nonaphasic patients, and nonfluent aphasic patients using near-infrared spectroscopy (NIRS).

METHODS

Twenty-nine participants performed speech tasks, such as confrontational naming, to evaluate changes among poststroke nonfluent (Broca's) aphasia patients (10 cases; mean+/-SEM, 56.9+/-2.2 years), age-matched normal subjects (13 cases; 50.7+/-2.2 years) and poststroke nonaphasic patients (6 cases; 52.5+/-3.9 years). The optodes of NIRS were placed over the left prefrontal cortex. We analyzed the NIRS parameter (oxyhemoglobin [oxy-Hb], deoxyhemoglobin [deoxy-Hb], and total hemoglobin [total-Hb]) changes by qualitative pattern analysis of the parameter changes and quantitative analysis of the parameter values among the groups.

RESULTS

The most common NIRS parameter change was an increase in oxy-Hb and total-Hb, with a slight decrease or no change in deoxy-Hb in the normal subjects (5 of 13 cases, 38.5%) and the nonaphasic cerebrovascular disease (CVD) patients (3 of 6 cases, 50.0%). In contrast, the most common pattern in the aphasic patients was an increase of deoxy-Hb, with an increase of oxy-Hb and total-Hb (5 of 10 cases, 50%). However, this pattern was observed in only 3 of 13 cases (23.1%) in the normal subjects and 1 of 6 cases (16.7%) in the nonaphasic CVD patients. The mean (+/-SEM) changes of deoxy-Hb of the aphasic patients, the normal subjects, and the nonaphasic CVD patients were 0.78+/-0.29, 0.06+/-0.16, and -0.18 +/- 0.22, respectively. The statistical analysis demonstrated a significant effect for deoxy-Hb (P<0.05), with the aphasic patients differing significantly from the normal subjects and the nonaphasic CVD patients, while the 2 nonaphasic groups did not differ from each other.

CONCLUSIONS

The present results demonstrate a multiplicity of language-activated cerebral blood oxygenation and hemodynamic changes in the left prefrontal cortex in the nonaphasic and aphasic groups. The increase of deoxy-Hb with increases of oxy-Hb and total-Hb in the aphasics during language tasks suggests that the left prefrontal cortex of the aphasics utilizes more oxygen than the nonaphasics during language tasks. Finally, functional MRI, which images the activation area in the brain by detecting the reduced concentration of deoxy-Hb during neuronal activation, should be performed on the patients with cerebral dysfunction, giving special consideration to the possible multiplicity of the rCBF and cerebral oxygen metabolism responses to functional tasks.

[Transsphenoidal microsurgery for pituitary adenoma: analysis of 3 fatal cases]

To prevent severe postoperative complications and increase the survival rate of patients with pituitary adenoma after transsphenoidal microsurgery, 3 fatal cases were analysed in terms of clinical features and caused of death. They included (1) the too deeply inserted suction apparatus with resultant midbrain damage; (2) bleeding from residual tumor into aphragma sellae and dura mater, entering the subarachnoid, causing spasm of the brain vessels. In order to avoid complication, it is necessary to follow strictly the rules for transsphenoidal microsurgery and improve surgical skills.

Noninvasive optical imaging of the subarachnoid space and cerebrospinal fluid pathways based on near-infrared fluorescence

The authors have developed a noninvasive optical method to image the subarachnoid space and cerebrospinal fluid pathways in vivo based on the near-infrared fluorescence of indocyanine green (ICG). The ICG was bound to purified lipoproteins (ICG-lipoprotein) and injected into the subarachnoid space of neonatal and adult rats. The ICG fluorescence was detected by a cooled charge-coupled device camera. After injection of ICG-lipoprotein into the cerebral subarachnoid space of the neonatal rat, ICG fluorescence was clearly detected at the injection site through the skull and skin. The ICG fluorescence was observed in the cerebellum and the lumbar spinal cord 1 and 8 hours postinjection, respectively. After injection of ICG-lipoprotein into the lumbar spinal subarachnoid space of an adult rat, ICG fluorescence was observed from the injection site to the thoracic levels along the spinal subarachnoid space. In addition, with the rat's head tilted downward, ICG fluorescence had extended to the cerebral subarachnoid space by 1 hour postinjection. The ICG fluorescence imaging of the cerebral subarachnoid space demonstrated an increase in fluorescence intensity around the lambdoid suture and the forebrain. On dissection of the rat brain the former location was identified as the supracerebellar cistern and the latter as the olfactory cistern. The results of this study are the first to demonstrate that an optical technique is applicable to imaging of the subarachnoid space and cerebrospinal fluid pathways in vivo. In addition, ICG-lipoprotein provides a sensitive optical tracer for imaging extravascular biological structures. Finally, ICG fluorescence imaging does not require an intricate imaging system because ICG is localized near the surface of the body.

Determination of alpha-difluoromethylornithine in blood by microdialysis sampling and capillary electrophoresis with UV detection

A procedure is described for the analysis of alpha-difluoromethylornithine (DFMO), an anti-cancer agent, in plasma microdialysis (MD) samples. DFMO has been shown to be effective alone or in combination with other agents in the treatment of several cancers. Precolumn derivatization of DFMO with naphthalene-2,3-dicarboxaldehyde-cyanide (NDA-CN) in pH 10.0 borate buffer results in the rapid formation of a stable mono-derivatized product (N-substituted 1-cyanobenz[f]isoindole, CBI), which is UV active. An analytical method has been developed to separate CBI-DFMO from NDA-CN derivatization products of 20 standard amino acids using capillary electrophoresis (CE). This method is then employed for the determination of DFMO in plasma microdialysis samples. Separation of DFMO from other components in the dialysate was achieved within 20 min. The response for DFMO in Ringer's solution was linear over the range of 1.2 x 10(-6) to 1.6 x 10(-4) M after derivatization. The detection limit of DFMO in the plasma dialysate is 5 microM using UV detection at 254 nm. This method has been proven to have adequate sensitivity for quantitation of DFMO in i.v. microdialysate samples and has been successfully applied to monitoring the pharmacokinetics of DFMO by CE-UV.

[Preparation method for compound Hirudo oral liquid]

The extraction efficiency of alcohol, water and alcohol followed by water for Hirudo and the principal constituents of compound Hirudo oral liquid were compared with the extraction rate of nitric substances and pharmacological activity as the evaluation marker. Based on results of the above experiments, a new preparation method for the oral liquid was established.

Continuous in vivo monitoring of amino acid neurotransmitters by microdialysis sampling with on-line derivatization and capillary electrophoresis separation

A separation-based biosensor has been developed that is capable of near-real-time analysis of aspartate and glutamate with a temporal resolution of less than 2 min in anesthetized or awake, freely moving animals. The instrument consists of a microdialysis sampling system, an on-line reactor, an injection interface, and a CE-LIF system. Primary amine analytes are derivatized with NDA/CN following microdialysis sampling using an on-line reactor to produce fluorescent CBI derivatives. The reaction takes approximately 1 min. The derivatized sample then travels to a microinjection valve which alternately sends CE running buffer and reacted microdialysis sample to the CE column via an injection interface. The interface allows a controllable volume of 10-20 nL to be injected onto the CE separation capillary. Separation of aspartate and glutamate from the other amino acids present in the microdialysis sample was achieved within 70 s. Detection limits for glutamate and aspartate using laser-induced fluorescence detection were 0.1 microM. The linear dynamic range was acceptable for the determination of aspartate and glutamate in dialysate samples where the levels are between 1 and 10 microM. Full automation of the system was achieved by computer control of the valve, the interface, and the data collection system. The performance of this system was demonstrated in an anesthetized rat by monitoring ECF levels of aspartate and glutamate released in brain after stimulation with high concentrations of K+.