[Mid-term efficacy evaluation of ABO incompatible living relative kidney transplantation based on protocol biopsy]

Objective: To evaluate the mid-term efficacy of ABO incompatible living donor kidney transplantation (ABOi-KT) based on the results of routine renal biopsy for transplantation. Methods: Retrospective collection of clinical data from 23 pairs of ABOi-KT donors and recipients at the First Affiliated Hospital of Sun Yat-sen University from July 2015 to November 2021. ABOi-KT was performed on recipients after desensitization treatment, and the results of routine kidney transplant biopsy at 1 week, 1 month, 3 months, 6 months, and 12 months after surgery were analyzed. Combined with blood type antibody levels and renal function recovery, the mid-term efficacy of ABOi-KT was evaluated. Results: Among the 23 recipients, there were 19 males and 4 females; age range from 19 to 47 years old [(29.6±6.7) years old], all underwent ABOi-KT successfully after receiving desensitization treatment. The follow-up time was (44.6±22.4) months, of which 22 cases were followed up for more than 1 year. The incidence rates of rejection reactions at 1 week, 1 month, 3 months, 6 months, and 12 months after surgery were 15.0% (3/20), 11.1% (1/9), 7.7% (1/13), 25.0% (3/12), and 12.5% (1/8), respectively. For receptors with rejection reactions, targeted anti-rejection therapy was performed based on clinical symptoms and various indicators. Borderline T cell mediated rejection (TCMR) can be converted to mild tubular inflammation after anti-rejection treatment. The positive rate of complement C4d in peritubular capillaries was 95.0% (19/20) one week after surgery, and the positive rate of complement C4d was 100% at 3 and 12 months after surgery. The cumulative survival rates at 1, 3, 5, and 7 years after surgery were all 100%. The cumulative survival rates at 1, 3, 5, and 7 years after kidney transplantation were 100%, 93.3%, 84.0%, and 84.0%, respectively. Except for 2 recipients who underwent transplantation in 2017 and experienced kidney failure at 30 and 49 months after surgery, all other transplanted kidneys survived. Conclusions: The results of routine renal transplant biopsy show that ABOi-KT has a good mid-term therapeutic effect. The pathological changes of ABOi-KT can be dynamically observed through routine renal transplant biopsy and targeted treatment for rejection reactions can be provided accordingly.

Associations of maternal serum concentration of iron-related indicators with birth outcomes in Chinese: a pilot prospective cohort study

BACKGROUND

Previous studies of maternal iron and birth outcomes have been limited to single indicators that do not reflect the comprehensive relationship with birth outcomes. We aimed to investigate the relationship between maternal iron metabolism and neonatal anthropometric indicators using comprehensive iron-related indicators.

METHODS

A total of 914 Chinese mother-child dyads were enrolled in this prospective study. Subjects' blood samples were collected at ≤ 14 weeks of gestation. Serum concentrations of iron-related indicators were measured by enzyme-linked immunosorbent assay (ELISA). Femur length was measured by B-ultrasound nearest delivery. Neonatal anthropometric indicators were collected from medical records.

RESULTS

After adjustment for potential covariates, higher iron (per one standard deviation, SD increase) was detrimentally associated with - 0.22 mm lower femur length, whereas higher transferrin (per one SD increase) was associated with 0.20 mm higher femur length. Compared with normal subjects (10th-90th percentiles), subjects with extremely high (> 90th percentile) iron concentration were detrimentally associated with lower femur length, birth weight, and chest circumference, and a higher risk of low birth weight, LBW (HR: 3.92, 95%CI: 1.28, 12.0). Subjects with high concentration of soluble transferrin receptor, sTFR and transferrin (> 90th percentile) were associated with higher femur length. Subjects with low concentration of iron and ferritin concentrations (< 10th percentile) were associated with a higher risk of LBW (HR: 4.10, 95%CI: 1.17, 14.3) and macrosomia (HR: 2.79, 95%CI: 1.06, 7.35), respectively.

CONCLUSIONS

Maternal iron overload in early pregnancy may be detrimentally associated with neonatal anthropometric indicators and adverse birth outcomes.

Associations of early pregnancy serum uric acid levels with risk of gestational diabetes and birth outcomes: a retrospective cohort study

BACKGROUND

Previous evidence suggests that higher blood uric acid (UA) levels are associated with adverse cardiovascular outcomes during pregnancy and subsequent birth outcomes. However, it has been relatively unclear whether these associations persist in normotensive pregnant women.

METHODS

The study was based on a retrospective analysis of 18,250 mother-infant pairs in a large obstetric center in China. Serum UA concentrations in early pregnancy (median: 17.6, IQR: 16.3, 18.6 gestational weeks) were assessed. Hyperuricemia was defined as ≥ one standard deviation (SD) of the reference value for the corresponding gestational age. Outcomes of gestational diabetes mellitus (GDM), preterm birth (PB), low birth weight (LBW), macrosomia, small for gestational age (SGA) and large for gestational age (LGA) were extracted from the medical records.

RESULTS

The mean maternal UA level was 0.22 ± 0.05 mmol/L, and 2,896 (15.9%) subjects had hyperuricemia. After adjustment for several covariates, UA was associated with several adverse outcomes. The ORs (95%CI) per one SD increase in serum UA concentration were 1.250 (1.136, 1.277) for GDM, 1.137 (1.060, 1.221) for PB, 1.134 (1.051, 1.223) for LBW, and 1.077 (1.020, 1.137) for SGA, respectively. Similar adverse associations were found between hyperuricemia and GDM, PB (ORs: 1.394 and 1.385, P < 0.001), but not for LBW, macrosomia, SGA, and LGA. Adverse associations tended to be more pronounced in subjects with higher BMI for outcomes including PB, LBW, and SGA (P interaction = 0.001-0.028).

CONCLUSION

Higher UA levels in early pregnancy were associated with higher risk of GDM, PB, LBW, and SGA in normotensive Chinese women.

Associations of Dietary Anthocyanidins Intake with Bone Health in Children: A Cross-Sectional Study

PURPOSE

Bone health and body composition share several common mechanisms like oxidative stress and inflammation. Anthocyanins have antioxidant and anti-inflammatory properties. We have reported that anthocyanins are associated with better body composition in children, but the associations with bone health have not been elucidated. We aimed to explore the association of anthocyanins with bone mineral content (BMC) and bone mineral density (BMD) at multiple sites in children.

METHODS

In this cross-sectional study, 452 Chinese children aged 6-9 years were recruited. A validated 79-item food frequency questionnaire was used to collect dietary information. BMC and BMD at multiple sites (whole body; whole body excluding head, WBEH; limbs; arms; legs) were measured by dual-energy X-ray.

RESULTS

Higher dietary intake of total anthocyanidins (per one standard deviation increase) was associated with a 1.28-13.6 g (1.31-1.60%, compared to median) higher BMC at all sites and a 3.61-6.96 mg (0.65-0.90%) higher BMD at the whole body, WBEH, and arm sites after controlling for a number of possible covariates. The results were similar and more pronounced for cyanidin, but not for delphinidin and peonidin. Higher dietary intake of cyanidin (per one standard deviation increase) was associated with a 1.33-15.4 g (1.48-1.68%) higher BMC at all sites and a 4.15-7.77 mg (0.66-1.00%) higher BMD at all sites except the legs. No statistically significant associations with BMC or BMD were found for dietary intake of delphinidin and peonidin.

CONCLUSIONS

Higher dietary intake of total anthocyanidins and cyanidins were associated with higher BMC and BMD in Chinese children.

[Research progress on the association of occupational antimony exposure with lung cancer and its carcinogenic mechanism]

Previous epidemiological studies suggested that occupational antimony exposure was associated with an increased risk of lung cancer. The evidence is sufficient for carcinogenicity of trivalent antimony in experimental animals, and strong mechanistic evidence has been observed in human primary cells and experinental systems. Thus, trivalent antimony has been classified as possibly carcinogenic to humans (Group 2A) by International Agency for Research on Cancer (IARC) , and the United States National Toxicology Program (NTP) classified Sb(2)O(3) as a human carcinogen. Antimony and its compounds could induce chromosome breakage and/or DNA damage. Oxidative damage of DNA under oxidative stress and inhibition of DNA damage repair may be the main mechanism of antimony carcinogenesis. This review summarizes the epidemiological investigation of occupational antimony exposure and lung cancer, as well as the experimental research progression on the carcinogenic effects of antimony exposure, and discusses the limitations of previous studies and future research directions.

[Endoscopic ultrasonographic features of submucosal lesions of upper digestive tract suspected gastrointestinal stromal tumors and their correlation with progression and pathological risk grade of the lesions]

Objective: To investigate the endoscopic ultrasonographic (EUS) characteristics of submucosal lesions of upper digestive tract suspected gastrointestinal stromal tumors (GIST) and their correlation with biological behaviors and pathological risk grade of the tumors. Methods: Retrospective cohort study. The EUS findings, follow-up review, surgical treatment and pathological data of patients with suspected GIST at the Gastrointestinal Endoscopy Center of Peking University People's Hospital from January 2013 to April 2021 were collected. All samples were divided into follow-up group and treatment group based on the pathological condition and the patient's treatment intention. According to whether or not the tumor was enlarged in EUS, the follow-up group was divided into non-enlarged group and enlarged group. Paired T-test was used to compare the lesion size before and after follow-up, and logistic regression was used to analyze the risk factors of tumor enlargement. According to the treatment methods, the treatment group was further divided into endoscopic treatment group and surgical treatment group. According to the pathological results and risk grade, the treatment group was further divided into the low-risk group and the medium-risk group. The risk factors of pathological malignant risk were analyzed by logistic regression, and the tumor diameter of patients with moderate or above pathological risk was predicted by receiver operation characteristic (ROC) curve. The relationship between the findings of EUS and the progression and pathological risk of GIST were also explored. Results: Seventy-three cases including 23 males and 50 females, with an age of 58 (30-88) years, were included in the follow-up group, with a mean lesion diameter of (1.21±0.49) cm before follow-up, median follow-up interval of 33.8 months, and a lesion diameter of (1.18±0.49) cm after follow-up. There was no significant difference (all P>0.05) in lesion diameter between before and after follow-up. There was no significant difference (all P>0.05) between tumor enlargement group (18 cases, 24.7%) and non-enlargement group (55 cases, 75.3%). One hundred and thirty-eight cases, including 52 males and 86 females, with an age of 60 (19-84) years, were enrolled in the treatment group, with a mean EUS estimated diameter of (2.55±1.35) cm and pathological diameters of (3.43±2.42) cm. Ninety-five (68.8%) of these cases were pathologically confirmed as GIST while 43 cases were diagnosed as other tumor types, including 37 benign tumors and 6 malignant tumors. In multifactorial logistic regression analysis, only the increase of tumor diameter [OR (95%CI): 1.800 (1.172-2.766), P=0.007] was a risk factor for pathological intermediate or higher risk. The optimal tumor diameter for predicting pathological intermediate or higher risk using ROC curve analysis was 2.75 cm, with a sensitivity 71.4%, specificity 79.0%, Youden index 0.5 and area under ROC curve 0.807 (95%CI: 0.703-0.909). Conclusions: EUS is essential for assessing the risk of progression and malignancy of submucosal lesions of upper digestive tract suspected GIST. For lesions of small diameter, the interval of follow-up shall be relatively extended while the indication of treatment could be partially waived.

[Association between cognitive impairment and main metals among oldest old aged 80 years and over in China]

Objective: To identify the main metals involved in cognitive impairment in the Chinese oldest old, and explore the association between these metal exposures and cognitive impairment. Methods: A cross-sectional study was conducted on 1 568 participants aged 80 years and older from Healthy Aging and Biomarkers Cohort Study (2017 to 2018). Fasting venous blood was collected to measure the levels of nine metals (selenium, lead, cadmium, arsenic, antimony, chromium, manganese, mercury, and nickel). The cognitive function of these participants was evaluated by using the Chinese version of the Mini-Mental State Examination (CMMSE). The random forest (RF) was applied to independently identify the main metals that affected cognitive impairment. The multivariate logistic regression model and restricted cubic splines (RCS) model were used to further verify the association of the main metals with cognitive impairment. Results: The age of 1 568 study subjects was (91.8±7.6) years old, including 912 females (58.2%) and 465 individuals (29.7%) with cognitive function impairment. Based on the RF model (the out-of-bag error rate was 22.9%), the importance ranking of variables was conducted and the feature screening of five times ten-fold cross-validation was carried out. It was found that selenium was the metal that affected cognitive function impairment, and the other eight metals were not included in the model. After adjusting for covariates, the multivariate logistic regression model showed that with every increase of 10 μg/L of blood selenium levels, the risk of cognitive impairment decreased (OR=0.921, 95%CI: 0.889-0.954). Compared with the lowest quartile(Q₁) of blood selenium, the ORs (95%CI) of Q₃ and Q₄ blood selenium were 0.452 (0.304-0.669) and 0.419 (0.281-0.622) respectively. The RCS showed a linear dose-response relationship between blood selenium and cognitive impairment (P_nonlinear>0.05). Conclusion: Blood selenium is negatively associated with cognitive impairment in the Chinese oldest old.

Associations between thyroid function and gestational diabetes mellitus in Chinese pregnant women: a retrospective cohort study

BACKGROUND

Thyroid function is known to be closely linked with type 2 diabetes, but data on the association between thyroid function and gestational diabetes mellitus (GDM) are inconsistent.

METHODS

A total of 2849 pregnant women were included in this retrospective study. Serum concentrations of thyroid indicators (free tetraiodothyronine, FT4; thyroid-stimulating hormone, TSH; and thyroid peroxidase antibody, TPO Ab) were obtained from a clinical laboratory. The presence of GDM were drawn from medical records. The clinical subtypes of thyroid function (euthyroidism, subclinical hypothyroidism, hyperthyroidism, and isolated hypothyroxinemia) were categorized according to the thresholds of the 2.5^th/97.5^th and 10^th/90^th percentiles of TSH and FT4 concentrations. A concentration of > 34 IU/L was defined as indicating TPO Ab-positivity.

RESULTS

Two hundred and thirty-five (8.25%) of the 2849 women were TPO Ab-positive. Higher serum concentrations of FT4 (top vs. bottom tertiles) was found to be negatively associated with the risk of GDM. The corresponding odds (OR) values (top tertile vs. bottom tertile) were 0.71 [95% confidence interval (CI): 0.54, 0.93]. No significant associations were observed between the extremely 2.5^th/97.5^th or 10^th/90^th percentiles of FT4 concentration, TSH concentration, thyroid function subtypes (vs. euthyroidism), TPO Ab-positivity (vs. -negativity), and the GDM risk. The corresponding results remained similar when TPO Ab-positive subjects were excluded.

CONCLUSIONS

A negative association with the risk of GDM was observed for the highest FT4 concentrations tertile. No significant associations were found between the TSH concentration, thyroid function subtypes, TPO Ab positivity, and the GDM risk.

The Association of Gut Microbiota With Osteoporosis Is Mediated by Amino Acid Metabolism: Multiomics in a Large Cohort

CONTEXT

Several small studies have suggested that the gut microbiome might influence osteoporosis, but there is little evidence from human metabolomics studies to explain this association.

OBJECTIVE

This study examined the association of gut microbiome dysbiosis with osteoporosis and explored the potential pathways through which this association occurs using fecal and serum metabolomics.

METHODS

We analyzed the composition of the gut microbiota by 16S rRNA profiling and bone mineral density using dual-energy X-ray absorptiometry in 1776 community-based adults. Targeted metabolomics in feces (15 categories) and serum (12 categories) were further analyzed in 971 participants using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry.

RESULTS

This study showed that osteoporosis was related to the beta diversity, taxonomy, and functional composition of the gut microbiota. The relative abundance of Actinobacillus, Blautia, Oscillospira, Bacteroides, and Phascolarctobacterium was positively associated with osteoporosis. However, Veillonellaceae other, Collinsella, and Ruminococcaceae other were inversely associated with the presence of osteoporosis. The association between microbiota biomarkers and osteoporosis was related to levels of peptidases and transcription machinery in microbial function. Fecal and serum metabolomics analyses suggested that tyrosine and tryptophan metabolism and valine, leucine, and isoleucine degradation were significantly linked to the identified microbiota biomarkers and to osteoporosis, respectively.

CONCLUSION

This large population-based study provided robust evidence connecting gut dysbiosis, fecal metabolomics, and serum metabolomics with osteoporosis. Our results suggest that gut dysbiosis and amino acid metabolism could be targets for intervention in osteoporosis.

Gut microbiota, inflammation, and molecular signatures of host response to infection

Gut microbial dysbiosis has been linked to many noncommunicable diseases. However, little is known about specific gut microbiota composition and its correlated metabolites associated with molecular signatures underlying host response to infection. Here, we describe the construction of a proteomic risk score based on 20 blood proteomic biomarkers, which have recently been identified as molecular signatures predicting the progression of the COVID-19. We demonstrate that in our cohort of 990 healthy individuals without infection, this proteomic risk score is positively associated with proinflammatory cytokines mainly among older, but not younger, individuals. We further discover that a core set of gut microbiota can accurately predict the above proteomic biomarkers among 301 individuals using a machine learning model and that these gut microbiota features are highly correlated with proinflammatory cytokines in another independent set of 366 individuals. Fecal metabolomics analysis suggests potential amino acid-related pathways linking gut microbiota to host metabolism and inflammation. Overall, our multi-omics analyses suggest that gut microbiota composition and function are closely related to inflammation and molecular signatures of host response to infection among healthy individuals. These results may provide novel insights into the cross-talk between gut microbiota and host immune system.

[Effect of basic fibroblast growth factor treatment on efficacy of adipose-derived mesenchymal stem cells in liver cirrhosis]

Objective: To observe the effect of basic fibroblast growth factor (bFGF) treatment on efficacy of adipose-derived mesenchymal stem cells (ADSCs) in cirrhotic rats. Methods: A rat model of liver cirrhosis was established via intraperitoneal injection of carbon tetrachloride (CCl(4)) for 10 weeks. Thirty SD rats were randomly divided into 3 groups (n = 10): control group served as group A, and 0.5ml of phosphate-buffered saline (PBS) was transfused into the tail vein; ADSCs single-dose transplantation group served as group B, and 1×10(6) ADSCs were transplanted into the tail vein; bFGF-treated ADSCs treatment group served as group C, and 1×10(6) bFGF-treated ADSCs were transplanted through tail vein. Liver function, pathological and cytokine changes, and the in vivo survival transformation condition of the transplanted cells were measured at one week after transplantation. F test and an independent sample t test were used. Results: bFGF treatment had significantly promoted the proliferation, differentiation and overexpression of hepatocyte growth factor (HGF) in ADSCs [ADSCs single: (2 137.16 ± 261.52) pg/ml vs. ADSCs (bFGF): (4 776.23 ± 532.44) pg/ml, P < 0.05]. The bFGF-treated ADSCs treatment group had statistically significant differences in promoting the recovery of liver function [alanine aminotransferase (ALT): ADSCs single (190.8 ± 34.98) vs. ADSCs (bFGF): (117.8 ± 35.81) pg/ml; aspartate aminotransferase (AST): ADSCs single (295.2 ± 33.71) U/L vs. ADSCs (bFGF): (183.8 ± 41.29) U/L, P ​​< 0.05). There was no statistically significant difference in serum albumin levels between the control group, ADSCs single group, and ADSCs (bFGF) group. Compared with the control group, the serum albumin level of ADSCs (bFGF) group was increased significantly (P < 0.05), and the difference between the control group and the ADSCs single transplantation group in improving liver regeneration and reducing liver damage was statistically significant (P < 0.05). Masson trichrome staining showed that the percentage of the liver fibrosis area in the bFGF-treated ADSCs treatment group was 6.78% ± 0.56%, which was significantly higher than that of the control and ADSCs single dose transplantation group (7.96% ± 0.64%) (P < 0.05). Western blot analysis showed that the expression of HGF protein in the bFGF-treated ADSCs treatment group was significantly up-regulated, while the expression of α-smooth muscle actin was significantly down-regulated, and the difference was significant in the ADSCs single transplantation group. A double fluorescent staining method showed that the numbers of stem cells implanted in the liver tissue of the bFGF-treated ADSCs treatment group were higher than that of the ADSCs single transplantation group. In-vitro cell experiments confirmed that bFGF had significantly promoted the overexpression of HGF in ADSCs. Conclusion: bFGF-treated ADSCs transplantation can significantly improve liver function and fibrosis as compared with ADSCs single-dose transplantation in cirrhotic rats.

[Individual irradiation dose trend and correlation analysis of nuclear medicine workers in a hospital]

Objective: To understand the personal dose level of nuclear medical workers in a hospital, and to provide basis for health management of nuclear medicine occupational population. Methods: From January 2014 to December 2018, 147 radiation workers in a hospital were selected as the monitoring objects, and the individual dose monitoring data were analyzed. The correlation between individual dose and clinical workload was analyzed. Results: The average annual personal dose of 147 staff members was below the national dose limit. Compared with the radiation department, the average annual personal dose of nuclear medical staff was higher, and the difference was statistically significant (P<0.05) . There was a positive correlation between the annual average personal dose and the corresponding injection workload (Rs=0.69, P<0.05) . Conclusion: The occupational exposure risk of nuclear medical technicians and nurses is high, and reasonable protective measures should be taken to reduce the radiation exposure dose. Conclusion The occupational exposure risk of nuclear medical technicians and nurses is high, and reasonable protective measures should be taken to reduce the radiation exposure dose.

Erythrocyte n-6 Polyunsaturated Fatty Acids, Gut Microbiota, and Incident Type 2 Diabetes: A Prospective Cohort Study

OBJECTIVE

To examine the association of erythrocyte n-6 polyunsaturated fatty acid (PUFA) biomarkers with incident type 2 diabetes and explore the potential role of gut microbiota in the association.

RESEARCH DESIGN AND METHODS

We evaluated 2,731 participants without type 2 diabetes recruited between 2008 and 2013 in the Guangzhou Nutrition and Health Study (Guangzhou, China). Case subjects with type 2 diabetes were identified with clinical and biochemical information collected at follow-up visits. Using stool samples collected during the follow-up in the subset (n = 1,591), 16S rRNA profiling was conducted. Using multivariable-adjusted Poisson or linear regression, we examined associations of erythrocyte n-6 PUFA biomarkers with incident type 2 diabetes and diversity and composition of gut microbiota.

RESULTS

Over 6.2 years of follow-up, 276 case subjects with type 2 diabetes were identified (risk 0.10). Higher levels of erythrocyte γ-linolenic acid (GLA), but not linoleic or arachidonic acid, were associated with higher type 2 diabetes incidence. Comparing the top to the bottom quartile groups of GLA levels, relative risk was 1.72 (95% CI 1.21, 2.44) adjusted for potential confounders. Baseline GLA was inversely associated with gut microbial richness and diversity (α-diversity, both P < 0.05) during follow-up and significantly associated with microbiota β-diversity (P = 0.002). α-Diversity acted as a potential mediator in the association between GLA and type 2 diabetes (P < 0.05). Seven genera (Butyrivibrio, Blautia, Oscillospira, Odoribacter, S24-7 other, Rikenellaceae other, and Clostridiales other) were enriched in quartile 1 of GLA and in participants without type 2 diabetes.

CONCLUSIONS

Relative concentrations of erythrocyte GLA were positively associated with incident type 2 diabetes in a Chinese population and also with gut microbial profiles. These results highlight that gut microbiota may play an important role linking n-6 PUFA metabolism and type 2 diabetes etiology.

Early pregnancy vitamin D and the risk of adverse maternal and infant outcomes: a retrospective cohort study

Background

Previous evidence has suggested that lower gestational vitamin D levels might increase the risks of adverse pregnancy and birth outcomes. The results remain inconsistent and require further exploration.

Methods

A total of 2814 Chinese mother-infant pairs were included in this retrospective cohort study. Serum concentrations of 25(OH)D were reviewed in early pregnancy (16.3 ± 2.3 weeks). Outcomes of maternal gestational diabetes mellitus (GDM), cesarean section, fetal distress, preterm birth, low birth weight (LBW), and macrosomia were extracted from the medical records. Cox regression analysis was used to explore these associations.

Results

In total, 19.3% of mothers were pregnant at an advanced age (≥35 years), and 40.3% of pregnant women had vitamin D deficiency (< 50 nmol/L). After adjusting for potential covariates, the hazard ratio (HR) (95% CI) per standard deviation (SD) increase of serum 25(OH)D concentrations was 0.86 (0.779, 0.951) for GDM, 0.844 (0.730, 0.976) for preterm birth, and 0.849 (0.726, 0.993) for LBW. Similar protective associations were found for GDM, cesarean section, and preterm birth for a better vitamin D status when compared with vitamin D deficiency.

Conclusion

Higher early pregnancy vitamin D was associated with a lower risk of GDM, cesarean section, preterm birth, and LBW.

Erythrocyte Membrane Polyunsaturated Fatty Acids Are Associated with Incidence of Metabolic Syndrome in Middle-Aged and Elderly People-An 8.8-Year Prospective Study

BACKGROUND

The total and specific types of polyunsaturated fatty acids (PUFAs) related to metabolic syndrome (MetS) remain inconsistent.

OBJECTIVE

We assessed the association of erythrocyte n-3 and n-6 PUFAs with MetS and the components of MetS in a cohort population.

METHODS

This prospective analysis included 2754 participants (aged 40-75 y) from the Guangzhou Nutrition and Health Study (2008-2019) in China. Erythrocyte PUFAs at baseline were measured using gas chromatography. MetS was assessed every 3 y according to the updated National Cholesterol Education Program Adult Treatment Panel III criteria. Multivariable Cox proportional hazard models were used to evaluate HRs and 95% CIs.

RESULTS

We identified 716 incident cases of MetS. The primary analyses showed that the HRs (95% CIs) of MetS (tertile 3 versus 1) were 0.67 (0.56, 0.80) for n-3 PUFAs and 0.70 (0.58, 0.85) for n-6 PUFAs (all Ps trend <0.001). The secondary outcomes showed that, higher erythrocyte very-long-chain (VLC) PUFAs [20:3n-3, docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), arachidonic acid (ARA), and 22:4n-6], but lower α-linolenic acid (ALA) and γ-linolenic acid (GLA), tended to be associated with lower incidences of MetS and its components; among individual MetS components, the associations of PUFAs were more pronounced for hypertriglyceridemia (HTG) and hypertension, followed by low high-density lipoproten (HDL) cholesterol. Significantly higher concentrations of n-3 PUFAs (total, DPA, and DHA) and n-6 PUFAs (total, ARA, and 22:4) were observed in participants with improved (versus progressed) status of MetS (all Ps trend ≤0.003).

CONCLUSION

This study reveals that higher erythrocyte VLC n-3 and n-6 PUFAs, but lower 18-carbon PUFAs (ALA and GLA), are associated with lower risks of MetS components (HTG, hypertension, and low HDL cholesterol) and thereby lower MetS incidence in Chinese adults.

Associations Between Maternal Thyroid Function and Birth Outcomes in Chinese Mother-Child Dyads: A Retrospective Cohort Study

OBJECTIVE

Although research suggests a close association between maternal thyroid function and birth outcomes, no clear conclusion has been reached. We aimed to explore this potential association in a retrospective cohort study.

METHODS

This study included 8985 mother-child dyads. The maternal serum free tetraiodothyronine (FT4), thyroid-stimulating hormone (TSH), and thyroid peroxidase antibody (TPO Ab) concentrations and birth outcome data were reviewed from medical records. Subjects with TPO Ab concentrations of >34 and ≤34 IU/ml were classified into the TPO Ab positivity (+) and TPO Ab negativity (-) groups, respectively.

RESULTS

Compared with subjects in the normal group (0.1 ≤ TSH < 2.5 mIU/L and TPO Ab-), those with TSH concentrations of 2.5-4.0 mIU/L and TPO Ab- had a 0.65-fold lower risk of low birth weight (LBW). In contrast, those with TSH concentrations of >4.0 mIU/L, regardless of the TPO Ab status, had a 2.01-fold increased risk of LBW. Subclinical hypothyroidism, regardless of the TPO Ab status, was associated with a 1.94-fold higher risk of LBW when compared with that in subjects with euthyroidism and TPO Ab-. No other significant associations were observed.

CONCLUSION

A maternal TSH concentration of 2.5-4.0 mIU/L was associated with a lower risk of LBW when combined with TPO Ab-, whereas subjects with a TSH concentration of >4.0 mIU/L had an increased risk of LBW. Subclinical hypothyroidism appears to be associated with a higher risk of LBW.

[Relationship between expression of high-mobility group box-1 and inflammatory cytokines in patients with bone cancer pain]

Objective: To investigate the change and relationship between serum high-mobility group box-1(HMGB1) and related inflammatory cytokines level in patients suffer with bone metastatic pain. Methods: Collection of the bone cancer pain patients who received analgesic therapy the department of pain in The First Affiliated Hospital of Jiaxing University from November 2016 to August 2016. Serum concentration of HMGB1, the Receptor of Advanced Glycation Endproducts (RAGE), monocyte chemotactic protein-1(MCP-1), tumor necrosis factor -α (TNF-α), interleukin-1β (IL-1β), interleukin-10 (IL-10), interleukin-13 (IL-13), and transforming growth factor-β (TGF-β) levels were determined in 15 healthy individuals as healthy donor and 15 patients with bone metastatic pain by enzyme-linked immunosorbent (ELISA) . The healthy individuals and patients with bone metastatic pain were collected before treatment and on 7 d after the treatment. Results: The serum concentration of HMGB1 and RAGE were significantly increased in tumorous group compared with healthy group[(8.8±2.3) vs (1.9±1.1) μg/L,(231±16) vs (46±20) ng/L); t=7.10,12.44, both P<0.05], then decreased after analgesic therapy [(4.77±1.36) μg/L, (129.80±29.32) ng/L, t=7.10, 12.44, both P<0.05]. The serum concentration of proinflammatory cytokines such as MCP-1, TNF-α, and IL-1β were significantly increased in tumorous group when compared with healthy group, and decreased after analgesic therapy (all P<0.05). The expression of anti-inflammatory cytokines such as IL-10, IL-13, and TGF-β were significantly increased in tumorous group when compared with healthy group, and decreased after analgesic therapy (all P<0.05).Compared with healthy group, the levels of MCP-1/IL-10, MCP-1/IL-13, MCP-1/TGF-β, TNF-α/IL-10, TNF-α/IL-13, TNF-α/TGF-β, IL-1β/IL-10, IL-1β/IL-13, IL-1β/TGF-β were significantly increased in tumorous group (all P<0.05). Conclusion: HMGB1 may adjust the proinflammatory-anti-inflammatory system homeostasis to participate in the development of bone metastatic pain.

Erythrocyte membrane n-3 polyunsaturated fatty acids are inversely associated with the presence and progression of nonalcoholic fatty liver disease in Chinese adults: a prospective study

PURPOSE

Previous studies have shown that high-dose supplementation with n-3 polyunsaturated fatty acids (PUFAs) may benefit patients with nonalcoholic fatty liver disease (NAFLD), but the association of n-3 PUFAs with NAFLD among individuals with normal diets is only speculative. We investigated the cross-sectional and prospective associations between n-3 PUFAs and NAFLD in Chinese adults.

METHODS

This community-based prospective study included 3049 men and women (40-75 years) in Guangzhou, China, whose participants completed an NAFLD ultrasound evaluation and erythrocyte PUFA tests. A total of 2660 participants underwent the second NAFLD evaluation approximately 3 years later. α-Linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocytes were measured by gas chromatography.

RESULTS

After adjusting for potential confounders, we observed inverse associations between DHA, DHA + EPA, total n-3 PUFAs and the presence of NAFLD in the cross-sectional analysis. The adjusted odds ratios (95% confidence interval) of NAFLD for the highest (vs. lowest) tertile were 0.74 (0.61, 0.90) for DHA, 0.82 (0.67, 1.00) for EPA, 0.73 (0.60, 0.88) for DHA + EPA and 0.74 (0.61, 0.91) for total n-3 PUFAs  (all P values≤0.05). Over the average 3.12 years of follow-up, higher levels of DHA was associated with an improvement of NAFLD. The hazard ratio of improved NAFLD for the highest tertile was 1.18 (95% CI 1.09, 1.33) for DHA. Pathway analyses showed that favorable associations may be mediated by improvements in inflammatory markers (e.g., interleukin 1 beta and tumor necrosis factor alpha-like).

CONCLUSIONS

Erythrocyte membrane n-3 PUFAs are inversely associated with the presence and progression of NAFLD in Chinese adults.

TRIAL REGISTRATIONS

ClinicalTrials.gov NCT03179657.

Erythrocyte Saturated Fatty Acids and Incident Type 2 Diabetes in Chinese Men and Women: A Prospective Cohort Study

The association between circulating saturated fatty acids (SFAs) and incident type 2 diabetes (T2D) is reported in Western populations with inconsistent results, while evidence from Asian populations is scarce. We aimed to examine the associations between erythrocyte SFAs and incident T2D in a Chinese population. Between 2008 and 2013, a total of 2683 participants, aged 40⁻75 years, free of diabetes were included in the present analyses. Incident T2D cases were ascertained during follow-up visits. Gas chromatography was used to measure erythrocyte fatty acids at baseline. The Cox proportional hazards model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). During 13,508 person years of follow-up, 216 T2D cases were identified. Compared with the first quartile, multivariable-adjusted HRs (95% CIs) of the fourth quartile were 1.20 (0.82⁻1.76; p = 0.242) for myristic acid (14-carbon tail, zero double bonds; 14:0), 0.69 (0.48⁻0.99; p = 0.080) for palmitic acid (16:0), 1.49 (1.02⁻2.19; p = 0.047) for stearic acid (18:0), 1.46 (1.00⁻2.12; p = 0.035) for arachidic acid (20:0), 1.48 (0.99⁻2.22; p = 0.061) for behenic acid (22:0), and 1.08 (0.74⁻1.56; p = 0.913) for lignoceric acid (24:0). Our findings indicate that individual erythrocyte SFAs are associated with T2D in different directions, with 18:0 and 20:0 SFAs positively associated with the risk, whereas no convincing inverse association for 16:0 SFAs.

Role of free electrons in phosphorescence in n-type wide bandgap semiconductors

Long persistent phosphorescence is generally known as a phenomenon involving carrier traps induced by defects or impurities in crystals. In this paper, phosphorescence sustained for tens of minutes was found in intentionally undoped ZnO and it was proposed to be a universal phenomenon in wide bandgap semiconductors upon satisfying several conditions. A new model was built to understand this attractive phenomenon within the framework of the traditional trapping-detrapping model but it was modified by considering the free electrons in the conduction band as a significant contributor to the long persistent phosphorescence besides the electrons trapped by shallow donors. This model, explicitly expressed as I(t) ∝ [1 + M(1 - Fe^-γt)^-2]e^-γt, is not only capable of giving a quantitative description of the non-exponential decay of phosphorescence in a wide temperature range but also enables one to determine the depth of shallow donors in semiconductors. The participation of free electrons in phosphorescence was further confirmed by another carefully designed experiment. Thus, this study may represent significant progress in understanding phosphorescence.

[Dose-response relationship of ropivacaine for epidural block in early herpes zoster guided by CT]

Objective: To determine the dose-response relationship of ropivacaine for epidural block in early herpes zoster by CT guided. Methods: From January 2015 to February 2017, according to the principle of completely random digital table, 80 patients with early herpes zoster who were prepared for epidural block were divided into 4 groups(each group 20 patients): in group A the concentration of ropivacaine was 0.08%, in group B was 0.10%, in group C was 0.12% and in group D was 0.14%.Under CT guidance, epidural puncture was performed in the relevant section, mixing liquid 5.0 ml (with 10% iodohydrin)were injected into epidural gap.CT scan showed that the mixing liquid covered the relevant spinal nerve segmental.The numeric rating scale(NRS) values before treatment and at 30 minutes, the incidence of adverse reactions were recorded, and the treatment were evaluated. The response to ropivacaine for epidural block in early herpes zoster was defined as positive when the NRS values was less than or equal to one.The ED(50), ED(95) and 95% confidence interval (CI) of ropivacaine for epidural block in early herpes zoster guided by CT were calculated by probit analysis. Results: The NRS values before treatment were 5.00(4.00, 6.00), 5.00(4.25, 6.00), 5.50(5.00, 6.00) and 5.00(4.00, 6.00), the difference was no significant(Z=2.576, P=0.462). The NRS values at 30 minutes decreased and the effective rate of the treatment increased(χ(2)=8.371, P=0.004), following ropivacaine dose gradient increasing, they were 1.50(1.00, 2.00), 1.00(1.00, 2.00), 0.50(0.00, 1.00) and 0.00(0.00, 1.00), the difference was statistically significant (Z=17.421, P=0.001). There was one case in group C and four cases in group D were hypoesthesia, others were no significant adverse reactions occurred. The ED(50) and ED(95) (95%CI) of ropivacaine for epidural block in early herpes zoster guided by CT were 0.078%(0.015%-0.095%)and 0.157%(0.133%-0.271%), respectively. Conclusion: Ropivacaine for epidural block in early herpes zoster guided by CT is effective for neuropathic pain, with no significant adverse reactions.

Adherence to the 2006 American Heart Association's Diet and Lifestyle Recommendations for cardiovascular disease risk reduction is associated with bone mineral density in older Chinese

This cross-sectional study investigated the association between the modified 2006 American Heart Association Diet and Lifestyle Recommendations (AHA-DLR) and bone mineral density in Chinese adults. We found that better adherence to the AHA-DLR associated with higher bone mineral density (BMD) at multiple sites.

INTRODUCTION

Accumulating evidence shows that cardiovascular disease (CVD) and osteoporosis are associated with each other, yet little research has focused on whether strategies to reduce CVD risk could also benefit bone health. We aimed to assess the association between adherence to the modified 2006 American Heart Association Diet and Lifestyle Recommendations (AHA-DLR) and BMD in Chinese adults.

METHODS

We included 2092 women and 1051 men aged 40-75 years in this community-based cross-sectional study. Dietary information was assessed using a 79-item food frequency survey through face-to-face interviews at baseline (2008-2010) and 3 years later (2011-2013). Adherence to the AHA-DLR was assessed using modified diet and lifestyle scores (American Heart Association Diet and Lifestyle Score (AHA-DLS)) adjusted for bone health. BMD for the whole body, lumbar spine, total hip, femur neck, and trochanter sites was measured using dual-energy X-ray absorptiometry in 2011-2013.

RESULTS

After adjusting for potential covariates, greater adherence to the modified AHA-DLS was positively and dose-dependently associated with BMD. The mean BMD was 1.93-3.11% higher in quartile 4 (vs. 1) (all p values <0.01) at multiple sites. Five-unit increases in the modified AHA-DLS score were associated with 4.20-6.07, 4.44-8.51, and 3.36-4.67 mg/cm² increases in BMD at multiple sites for the total subjects, males, and females, respectively (all p values <0.01).

CONCLUSIONS

Better adherence to the AHA-DLR shows protective associations with BMD at multiple sites in the middle-aged and elderly Chinese population.

The association between urinary sodium to potassium ratio and bone density in middle-aged Chinese adults

The joint effect of sodium and potassium on bone health remains uncertain. We examined the associations between urinary excretion of sodium, potassium, and their ratio and bone mineral density (BMD), and reported an inverse association between urinary sodium-to-potassium ratio and BMD in women, but not in men.

INTRODUCTION

Several studies have suggested that a higher sodium or lower potassium intake is associated with poor bone health. However, few studies have examined their joint effects. We examined the associations of urinary excretion of sodium, potassium, and the sodium-to-potassium ratio with BMD in Chinese adults.

METHODS

This community-based, cross-sectional study included 2202 women and 1063 men (40-75 years) in Guangzhou, China. The BMD of the whole body, lumbar spine, and hip sites were measured by dual-energy x-ray absorptiometry. The concentrations of sodium, potassium, and creatinine of the fasting morning first-void urine sample were measured, and creatinine-adjusted values were then used for further analyses. General information was collected via face-to-face interviews.

RESULTS

For women, after multivariable adjustment, the urinary sodium-to-potassium ratio was inversely associated with BMD at the whole body, total hip, trochanter, and intertrochanter (all p trend <0.05). The mean BMD differences between extreme quartiles ranged from 1.50 to 2.98 % at these sites (all p < 0.05). Similar, but less significant, associations were observed for urinary sodium/creatinine, for which the only significant difference was found at the trochanter (2.00 %, p = 0.016). We did not find any significant associations of BMD with urinary potassium in women and with urinary sodium/creatinine, potassium/creatinine, or their ratio in men.

CONCLUSION

Our findings suggest that the urinary sodium-to-potassium ratio, but not individual creatinine-adjusted values of sodium or potassium, is a good predictor of BMD in women, but not in men.

[Expression of enterotoxigenic Bacteroides fragilis and polyketide synthase gene-expressing Escherichia coli in colorectal adenoma patients]

OBJECTIVE

To investigate the distribution of various bacteria in adenoma tissue of colorectal adenoma (T/CRA), normal colonic mucosa tissue adjacent to the adenoma (N/CRA), and healthy colonic mucosa tissue (N/H) by comparing the number of total bacteria, Bacteroides fragilis (BF), enterotoxigenic Bacteroides fragilis (ETBF), polyketide synthase (pks) gene-expressing Escherichia coli(E.coli)(pks(+) E. coli)among the above 3 types of tissues.

METHODS

A total of 36 patients diagnosed with colorectal adenoma by colonoscopy and pathology in Department of Gastroenterology, Peking University People's Hospital from September 2011 to September 2013 were selected into this study. T/CRA and N/CRA tissues from the 36 patients and N/H tissues from 18 healthy controls were collected for DNA extraction. The number of total bacteria, BF, ETBF, pks(+) E. coli was detected by quantitative real time PCR, and their correlation with colorectal adenoma was analyzed.

RESULTS

(1) The number of total bacteria decreased gradually from N/H, N/CRA, to T/CRA, with the median values being 3.18×10(8,) 1.57×10(8,) and 7.91×10(7) copies/g, respectively, and with significant difference among the three groups and between each two groups (all P<0.01). (2) The content of BF decreased gradually from N/H, N/CRA, to T/CRA, the median values being 6.03×10(5,) 4.28×10(4,) and 5.48×10(3) copies/g, respectively, and with significant difference among the three groups and between each two groups (all P<0.01). (3) The toxin content produced by ETBF increased from N/H, N/CRA, to T/CRA, the relative expression being 1.73±0.30, 6.15±1.52, and 8.54±1.80, respectively. Significant difference was found between the T/CRA and N/H tissue (P=0.003), but not between any other two groups. (4) The expression of clbB in pks(+) E.coli was highest in T/CRA colonic tissue (2.96±0.28), followed by the N/CRA (2.79±0.19) and N/H tissue (1.06±0.08). Significant difference was found between T/CRA and N/H tissues, as well as between N/CRA and N/H tissues (both P<0.001), but not between T/CRA and N/CRA tissues.

CONCLUSIONS

The number of total bacteria is markedly reduced in the colonic mucosa of CRA patients compared to normal people, while the expressions of ETBF and pks(+) E.coli are significantly increased. Such changes in total bacterial, ETBF and pks(+) E.coli concentrations in colonic mucosa may be related to the tumorigenesis of colorectal adenoma.

Analysis of two sling procedures using polypropylene mesh for treatment of stress urinary incontinence

OBJECTIVES

To evaluate and compare the surgical outcome between the innovative tension-free vaginal tape (TVT) and conventional pubovaginal sling (PVS) procedures using polypropylene mesh.

METHODS

Eighty consecutive women with urodynamic stress urinary incontinence (SUI), who chose to undergo either a TVT (n=23) or a PVS (n=57) procedure using polypropylene mesh based on financial consideration, were recruited for this study. The surgical results were analyzed and compared subjectively and objectively.

RESULTS

The mean follow-up interval was 23 months for the TVT and 20 months for the PVS procedure (P=0.062). Postoperatively, SUI (91.3% vs. 93.0%), concomitant urge symptoms (85.0% vs. 85.3%) and the negative impact of incontinence and urogenital distress on patients' quality of life (79.8% vs. 77.8%) (77.4% vs. 68.8%) had improved markedly. After a multivariable logistic regression analysis, the treatment outcome of SUI was found to be independent of the main effects of patient age, parity, concurrent gynecological surgeries, intrinsic sphincter deficiency, previous failed incontinence surgeries, and concomitant urge symptoms. However, it was significantly related to treatment procedures (TVT vs. PVS) and their interaction with patient body mass index (BMI). Based on the fitted logistic model, we see that TVT performs better than PVS when BMI is less than 27.27 kg/m2, and the advantage of TVT decreases as BMI increases.

CONCLUSION

Both TVT and PVS procedures using polypropylene mesh are effective treatment modalities for female SUI. However, TVT was not as effective in treating overweight or obese women as PVS.

Adherence to the Mediterranean diet is associated with a higher BMD in middle-aged and elderly Chinese

Previous studies showed that better adherence to the Mediterranean diet (MD) is associated with lower risk of chronic diseases, but limited data are available on bone health. We investigated the association of the MD with bone mineral density (BMD) in Chinese adults. We included 2371 participants aged 40–75 years in this community-based cross-sectional study. Dietary information was assessed at baseline and a 3-year follow-up. Alternate Mediterranean diet (aMed) scores were calculated. BMD was determined at the second survey. After adjusting for potential covariates, higher aMed scores were positively and dose-dependently associated with BMD (all P-trends < 0.05). The BMD values were 1.94% (whole body), 3.01% (lumbar spine), 2.80% (total hip), 2.81% (femur neck), 2.62% (trochanter), and 2.85% (intertrochanter) higher in the quintile 5 (highest, vs. quintile 1) aMed scores for all of the subjects (all P-values < 0.05). Similar associations were found after stratifying by gender (P-interaction = 0.338–0.968). After excluding the five non-significant components of vegetables, legumes, fish, monounsaturated to saturated fat ratio, and alcohol intake from the aMed scores, the percentage mean differences were substantially increased by 69.1–150% between the extreme quintiles. In conclusion, increased adherence to the MD shows protective associations with BMD in Chinese adults.

Association of dietary consumption and serum levels of vitamin A and β-carotene with bone mineral density in Chinese adults

BACKGROUND

Former studies suggested an adverse effect of hypervitaminosis A on bone health, while the effects of retinol and its precursor (β-carotene) remain uncertain in populations consuming vitamin A (VA) mainly from plant sources.

OBJECTIVE

We investigated the association of serum, dietary retinol, and β-carotene with bone mineral density (BMD) in Chinese adults.

METHODS

We recruited 2101 women and 1053 men (aged 40-75 years) in Guangzhou, China. Dietary intake was assessed through face-to-face interviews with food-frequency questionnaires at baseline and 3 years later. Serum levels of retinol and β-carotene were determined by HPLC using a baseline specimen, and the BMD for the whole body (WB), lumbar spine (LS), total hip (TH), and femur neck (FN) were measured using dual energy X-ray absorptiometry at follow-up.

RESULTS

In general, greater levels of serum retinol, β-carotene, and the β-carotene-to-retinol ratio were associated with a higher BMD after adjustment for potential covariates in the total sample. BMD values in the top (vs. bottom) quartile were increased by 2.06% (TH) for retinol; 2.87% (WB), 2.51% (LS), 3.10% (FN) for β-carotene; 2.21% (WB) and 2.05% (FN) for the β-carotene-to-retinol ratio in the total sample (all p<0.05). A significant positive association with BMD was observed for dietary intake of β-carotene and total VA in retinol equivalents at the hip sites in the total sample.

CONCLUSION

Higher circulating and dietary levels of VA and β-carotene and higher serum β-carotene-to-retinol ratios were positively associated with BMD in Chinese adults consuming relatively low levels of VA, mainly from plant foods.

Donor factors predictive for poor outcomes of living donor kidney transplantation

INTRODUCTION

The aim of this study was to explore donor risk factors that predict the poor outcomes after living donor kidney transplantation.

METHODS

We retrospectively analyzed our 219 living donor kidney transplantations collecting donor age and gender, graft glomeular filtration rate (GFR), human leukocyte antigen (HLA) typing, recipient age and gender, acute rejection episodes chronic rejection, and 1-year serum creatinine level. Patient and graft survivals were calculated using the Kaplan-Meier analysis. Independent donor risk factors affecting graft survival and 1-year serum creatinine level were analyzed using Cox regression and logistic regression.

RESULTS

One-, 3-, 5-year patient and graft survivals were 98.6%, 98.1%, and 97.4% and 97.7%, 95.0%, and 92.2%, respectively. Acute rejection rate was 12.8%, and chronic rejection, 4.1%. If donor age was over 50 years, there were significantly increased incidences of acute and chronic rejection (χ(2) were 5.385 and 5.039; P < .05). Univariate analysis showed donor age > 50 years, graft GFR < 35 mL/min, female to male, HLA mismatch > 3 loci to be risk factors for an abnormal 1-year serum creatinine. Logistic multivariate regression revealed donor age > 50 years, female to male, and graft GFR before transplant < 35 mL/min to be independent risk factors for an abnormal 1-year serum creatinine level (odds ratio values 5.928, 2.489, and 6.993, respectively; P < .05). Cox multivariate regression demonstrated that graft GFR before transplant < 35 mL/min was an independent risk factor for long-term graft survival (relative risk value = 6.984; P = .004).

CONCLUSION

Older donor, female to male, and insufficient graft GFR before transplantation are predictive factors for poor outcomes of living donor kidney transplantations.

Major QTL for Fusarium crown rot resistance in a barley landrace

Fusarium crown rot (FCR) is a serious cereal disease in semi-arid regions worldwide. In assisting the effort of breeding cultivars with enhanced resistance, we identified several barley genotypes with high levels of FCR resistance. One of these genotypes, AWCS079 which is a barley landrace originating from Japan, was investigated by developing and assessing three populations of recombinant inbred lines. Two QTL, one located on the long arm of chromosome 1H (designated as Qcrs.cpi-1H) and the other on 3HL (designated as Qcrs.cpi-3H), were found to be responsible for the FCR resistance of this genotype. Qcrs.cpi-1H is novel as no other FCR loci have been reported on this chromosome arm. Qcrs.cpi-3H co-located with a reduced height (Rht) locus and the effectiveness of the former was significantly affected by the latter. The total phenotypic variance explained by these two QTL was over 60 %. Significant effects were detected for each of the QTL in each of the three populations assessed. The existence of these loci with major effects should not only facilitate breeding and exploitation of FCR-resistant barley cultivars but also their further characterization based on fine mapping and map-based gene cloning.

Characterization of a QTL affecting spike morphology on the long arm of chromosome 3H in barley (Hordeum vulgare L.) based on near isogenic lines and a NIL-derived population

Traits related to spike morphology (SM), including grain density (GD), spike length (SL) and awn length (AL), are of central importance in cereal improvement. A recent study based on a two-row landrace of barley, TX9425, detected QTL controlling all of the three traits in a similar region on the long arm of chromosome 3H. To further characterize this chromosomal region, 12 pairs of near isogenic lines (NILs) for GD were generated from two populations between TX9425 and two different commercial cultivars. A population consisting of 1,028 lines segregating primarily for the target region was also developed using materials generated during the production of these NILs. Results from the analysis of the NILs and the NIL-derived population showed that these three traits were likely controlled by a single-locus which was mapped to a 2.84 cM interval between two SSR markers, GBM1495 and HVM33. Across the 12 pairs of NILs, the presence of the 3HL locus increased GD by 53.4 %, reduced SL and AL by 38.8 % and 62.7 %, respectively. In the NIL-derived population, the presence of the 3HL locus increased GD by 64.6 %, reduced SL and AL by 33.7 % and 62.6 %, respectively. An interesting question arising from this research is why some loci such as the one reported here affect several SM-related traits while others appear to affect one of these traits only. The NILs and the NIL-derived population generated in this study will help answer such questions by providing the germplasm to enable cloning and comparative analysis of the genes responsible for these SM-related traits.

Morphological variation of mutant sunflowers (Helianthus annuus) induced by space flight and their genetic background detection by SSR primers

After sunflower seeds were exposed to space conditions, various mutant plants were screened from the descendent plants. The morphological characters of plants changed in flower color from golden to yellow, light yellow, or even to yellowish green. The ligulate petals of the unisexual floret broadened, or became thin, while the short tubular petals of bisexual floret elongated to some extent, or even turned into semi-ligulate petals or ligulate petals, making the phenotype of the whole inflorescence like a chrysanthemum. The shape and thickness of leaves varied in some of these plants. Absolute sterile plants in mutant plants were found to possess neither normal bisexual florets nor unisexual florets, but the "pseudo-floret" only consisted of pieces of shield-like bracts on protuberant floral disc. Thirty-five pairs of simple sequence of repeat primers were used to detect the genetic variation of the plants, and the results showed that only a variation was tested in the mutant plants from 4 primers. The different PCR products obtained were extracted for sequencing and alignment analysis, and the aligned results showed that the DNA sequence changed by deletion, insertion and replacement that occurred at some sites. The results proved the high mutagenic efficacy of space flight, and ways of DNA transformation due to space conditions.

Overactive bladder in Taiwanese women: re-analysis of epidemiological database of community from 1999 to 2001

AIMS

To update our previous computerized epidemiological data according to the new taxonomy, we re-evaluated and re-analyzed the data using the current definitions of lower urinary tract symptoms (LUTS) which were approved and published by the ICS in 2002 and 2010 according to patient perception. Further, we divided overactive bladder (OAB) symptoms into OAB dry and OAB wet to assess their prevalence percentages by using the current definitions.

METHODS

OAB syndrome in our computerized database was re-defined as having the following storage symptoms present, that is, frequency, urgency, nocturia, urgency incontinence, or stress urinary incontinence (SUI). The prevalence of OAB syndrome was determined with a different taxonomy for those five storage symptoms either singly or in combination. OAB symptoms which were probably associated with mixed incontinence were either ignored or excluded.

RESULTS

The prevalence of OAB syndrome varied from 34.76% to 28.33% to 20.95% using different classifications of the above five storage symptoms. The prevalence of OAB wet symptoms increased with advancing age and this finding was consistent with three different definitions.

CONCLUSIONS

The prevalence of OAB using the current definition is slightly higher than the result found in our previous published data using a defective classification system of OAB symptoms. The effects of mixed symptoms and probable misclassification cannot be overlooked because many women with OAB (with or without urgency incontinence) might also have SUI.

Immunoreactivities of human nonmetastatic clone 23 and p53 products are disassociated and not good predictors of lymph node metastases in early-stage cervical cancer patients

OBJECTIVE

To assess the relation between expressions of human nonmetastatic clone 23 (nm23-H1) and p53 in cervical cancer, their relationships with lymph node metastasis, and further to examine their predictive of lymph node metastases.

MATERIALS AND METHODS

nm23-H1 and p53 expression profiles were visualized by immunohistochemistry in early-stage cervical cancer specimens.

RESULTS

Immunoreactivities of nm23-H1 and p53 were disassociated. The independent variables related with lymph node metastases were grade of cancer cell differentiation (p < 0.029) and stromal invasion (p < 0.039). Sensitivity, specificity, positive and negative predictive values, and accuracy for lymph node metastasis were calculated to be 91.7%, 13.5%, 25.6%, 83.3%, and 32.7% for nm23-H1 and 66.7%, 51.4%, 30.8%, 82.6%, and 55.1% for p53.

CONCLUSION

Nm23-H1 and p53 are disassociated and not good predictors of lymph node metastases in early-stage cervical cancer patients. However, stromal invasion and cell differentiation can predict lymph node metastasis.

Hematopoietic stem cell mobilization after rat partial orthotopic liver transplantation

BACKGROUND

On the basis of the recently recognized potential of hematopoietic stem cells (HSC) to give rise to hepatocytes, we investigated the possibility that HSC could be mobilized and home to the injured liver promoting tissue repair after 50% partial orthotopic liver transplantation (PLTx) in the rat.

METHODS

Using sex-mismatched (female to male) syngeneic SD rats, we performed 50% PLTx or whole orthotopic liver transplantation (WLTx) versus 50% partial hepatectomy (PHx) and sham operation (O). Elements with stem cell markers were detected in peripheral blood (PB) and in the liver. Liver injury and regeneration were estimated. The sex-determining region for Y chromosome gene (SRY) was used to define cell origin by in situ hybridization in liver sections.

RESULTS

Comparison of WLTx and PHx groups showed a lower survival rate (50%), in the PLTx group were (P<.05). Further, the liver injury was more serious and the levels of serum biochemical parameters were higher. Compared with PHx groups, on days 3 and 5 postoperatively, the mitosis index and the expression of PCNA were lower among the PLTx groups. Compared with WLTx and sham operation groups, beta2m-/Thy-1.1+, CD34+ cells in PB in PLTx groups and PHx were increased on day 1 postoperatively and decreased on the following days. Compared with PHx groups, beta2m-/Thy-1.1+, CD34+ cells were higher in PLTx. The CD34-, c-kit-, and Thy-1.1-positive cells detected in portal tract areas peaked during 3 to 5 days postoperatively in PLTx. Few SRY+ cells were detected in PLTx liver grafts.

CONCLUSIONS

beta2m-/Thy-1.1+ and CD34+ stem cells mobilized after PLTx and PHx may be related to the reduced-size liver. Few HSC are involved in liver regeneration in PLTx.

Factors that affect recurrence after anterior colporrhaphy procedure reinforced with four-corner anchored polypropylene mesh

The purpose of this study was to evaluate the effectiveness of the anterior colporrhaphy procedure reinforced with four-corner anchored polypropylene mesh in patients with severe (stage III or IV) anterior vaginal prolapse. Thirty-eight consecutive women were enlisted for this prospective study. The procedure consisted of an extensive vaginal dissection to join the vesicovaginal and retropubic space and an anchoring of a polypropylene mesh patch between the two Arcus Tendineus Fasciae Pelvis in a tension-free manner. The mean age of the study group was 63 (33-80) years. The success rate was 87% (33/38) at a mean follow-up interval of 21 (12-29) months. A total of eight (100%) patients were also cured of concomitant stress incontinence (five overt and three occult type) with an additional tension-free vaginal tape (TVT) operation. During follow-up, there were five de-novo stress incontinence cases (16.7%) and four vaginal erosions of mesh (10.5%). Four clinical variables--diabetes mellitus, recurrent anterior vaginal prolapse, chronic cough and vaginal erosions of mesh--were found to have a significant correlation with an unsatisfactory surgical result with large values of hazard ratios found by survival analysis. We concluded that the anterior colporrhaphy procedure reinforced with four-corner anchored polypropylene mesh was effective for most, but failed in some patients who had specific risk factors within short convalescence periods. Concomitant stress incontinence can be successfully treated by a TVT operation in combination with the anterior colporrhaphy procedure reinforced with four-corner anchored polypropylene mesh. However, the anterior colporrhaphy procedure may itself have adverse effects on urethral sphincter function.

Human Ca2+/calmodulin-dependent protein kinase kinase beta gene encodes multiple isoforms that display distinct kinase activity

Ca(+2)/calmodulin-dependent protein kinases (CaMKs) are activated upon binding of Ca(+2)/calmodulin. To gain maximal activity, CaMK I and CaMK IV can be further phosphorylated by an upstream kinase, CaMK kinase (CaMKK). We previously isolated cDNA clones encoding human CaMKK beta isoforms that are heterogeneous in their 3'-sequences (Hsu, L.-S., Tsou, A.-P., Chi, C.-W., Lee, C.-H., and Chen, J.-Y. (1998) J. Biomed. Sci. 5, 141-149). In the present study, we examined the genomic organization and transcription of the human CaMKK beta gene. The human CaMKK beta locus spans more than 40 kilobase pairs and maps to chromosome 12q24.2. It is organized into 18 exons and 17 introns that are flanked by typical splice donor and acceptor sequences. Two major species of transcripts, namely the beta1 (5.6 kilobase pairs) and beta2 (2.9 kilobase pairs), are generated through differential usage of polyadenylation sites located in the last and penultimate exons. Additional forms of CaMKK beta transcripts were also identified that resulted from alternative splicing of the internal exons 14 and/or 16. These isoforms display differential expression patterns in human tissues and tumor-derived cell lines. They also exhibit a distinct ability to undergo autophosphorylation and to phosphorylate the downstream kinases CaMK I and CaMK IV. The differential expression of CaMKK beta isoforms with distinct activity further suggests the complexity of the regulation of the CaMKK/CaMK cascade and an important role for CaMKK in the action of Ca(+2)-mediated cellular responses.

[Study on the construction of standard D1S549 allelic ladder via molecular cloning and its genetic polymorphism in Chinese three populations]

OBJECTIVE

To resolve the problem of the accuracy and standardization of STR-PCR typing in forensic practice, we have designed a new method to produce standard D1S549 allelic ladder.

METHODS

Eight different PCR amplified D1S549 allelic fragments were isolated from the gel, eluted into the distilled water and re-amplified by PCR. The purified allelic fragments were then blunt-end subcloned individually into the pUC plasmid vectors and transfected into competent E. coli DH5 alpha cells.

RESULTS

The sequencing results confirmed that the size and the construe of the inserts were correct. The recombinant plasmids DNA with 8 inserts were then used as templates for re-amplification to generate D1S549 standard ladder, with which the genetic polymorphisms of D1S549 locus in Chinese Han population in chengdu, Hui population in Gansu and Wei population in Xinjiang were studied.

CONCLUSION

The results showed that the standard ladder made via this method is excellent, and D1S549 locus is robust for genetic research and forensic application.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

Disruption of cochlear potentials by chemical asphyxiants. Cyanide and carbon monoxide

While ischemia, hypoxic hypoxia, and carbon monoxide (CO) have received extensive study designed to characterize mechanisms by which they disrupt cochlear function, little data are available concerning cyanide's potential to disrupt auditory function. In this study, disruption of the compound action potential (CAP) and endocochlear potential (EP) by cyanide and CO was compared in rats treated with potassium cyanide (KCN) (7 mg/kg ip), saline, CO (35 ml/kg ip), and air. Acute KCN administration significantly suppressed CAP and EP transiently. The effect was seen initially on EP with CAP impairment occurring a few minutes later. Acute CO injection also suppressed the CAP significantly, but the effect was far smaller, occurred later in time, and lasted longer than the effect of KCN. The effect of CO on EP was equivocal. There was a good correspondence between blood cyanide levels and impairment of cochlear function; carboxyhemoglobin (HbCO) levels were elevated during the period when cochlear function was impaired, but recovery of cochlear function preceded the return of normal oxyhemoglobin. Both KCN and CO had somewhat preferential effects on high-frequency tones. Repeated cyanide administration caused a persistent CAP threshold elevation despite the rapid recovery of EP and CAP observed following acute KCN administration. The data suggest that acute KCN administration has a prominent disruptive effect at the stria vascularis presumably by disrupting the electron transport chain in this metabolically active structure. The principal target for acute CO ototoxicity in the cochlea is probably not the stria vascularis.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

NMDA receptor blockage protects against permanent noise-induced hearing loss but not its potentiation by carbon monoxide

While a clear role has been proposed for glutamate as a putative neurotransmitter at the inner hair cell type I spiral ganglion cell synapse, the possible role of excessive glutamate release in cochlear impairment and of NMDA receptors in such a process is uncertain. The present study compares the protective effects of (+)-MK-801, an NMDA receptor antagonist, and the relatively inactive isomer (-)-MK-801 against permanent noise-induced hearing loss (NIHL). The study also asks whether (+)-MK-801 can protect against the NIHL potentiation by carbon monoxide (CO). Rats (n = 6) were exposed to 100-dB, 13.6-kHz octave-band noise for 2 h after receiving injection of (+)-MK-801 hydrogen maleate (1 mg/kg), (-)-MK-801 hydrogen maleate (1 mg/kg), or saline. Other groups of animals were exposed to the combination of noise and CO (1200 ppm) after receiving (+)-MK-801 or saline. Additional subjects received (+)-MK-801, saline or CO exposure alone. Compound action potential (CAP) threshold sensitivities were compared 4 weeks after the exposures. The results show significant protection by (+)-MK-801 against the permanent CAP threshold elevation induced by noise alone, but no protective effect of (-)-MK-801. (+)-MK-801 produced limited protection against threshold shifts induced by the combination of noise and CO. Outer hair cell (OHC) loss was not protected by (+)-MK-801 administration. The data suggest that NMDA receptor stimulation may play a role in NIHL resulting from fairly mild noise exposure. The data do not support a role for NMDA receptor stimulation in the potentiation of NIHL that results from simultaneous exposure to CO and noise.

[A study of genetic polymorphism of the STR locus D2S441 in Chinese Han population in Chengdu]

Using PCR and PAG, followed by silver staining, the tetrameric STR D2S441 locus was studied in 260 unrelated Chinese individuals living in Chengdu. 9 alleles and 26 genotypes were observed. The range of fragment size was 131 bp to 155 bp. The genotype distribution of D2S441 locus in Han population was in accordance with Hardy-Weinberg equilibrium. Family survey confirmed Mendelian inheritance of alleles. The discriminating power (Dp), observed heterozygosity (H), polymorphism information content (PIC) and power of exclusion (PE) were 0.9084, 0.7885, 0.7390 and 0.5778 respectively. The results demonstrated that this locus was highly polymorphic and could be used for forensic identification and paternity testing.

Predicting exposure conditions that facilitate the potentiation of noise-induced hearing loss by carbon monoxide

Hearing loss is the most common occupational disease in the United States, with noise serving as the presumed causative agent in most instances. This investigation characterizes the exposure conditions that facilitate the potentiation of noise-induced hearing loss (NIHL) by carbon monoxide (CO). Auditory function was compared in rats exposed 4 weeks earlier to noise alone, CO alone, combined exposure, and air in the exposure chamber. This interval between exposure and auditory threshold assessment was selected to permit recovery of temporary threshold shifts. The compound action potential (CAP) threshold evoked by pure tone stimuli was used as a measure of auditory sensitivity. The no adverse effect level (NOAEL) with respect to potentiation of NIHL was found to be 300 ppm CO. Potentiation of NIHL by CO increases linearly as CO concentration increases between 500 -1500 ppm. Benchmark dose software (version 1. 1B) published by the U.S. EPA National Center for Environmental Assessment was employed to determine a benchmark concentration of CO that produced either a 5-dB potentiation of NIHL or an increase in auditory threshold equivalent to 10% of the effect of noise alone. The lower bound for these benchmark concentrations were 320 and 194 ppm CO, respectively. Unlike CO dose, the relationship between noise severity and potentiation of NIHL by CO shows a nonlinear relationship. The greatest potentiation was observed at moderate noise exposures (100 dB, 2-h, octave band-limited noise, or OBN) that produce limited permanent threshold shifts. Repeated exposures to 95-dB noise for 2-h periods in combination with 1200 ppm CO also yielded potentiation of NIHL, though such effects were not observed following a single combined exposure. These results underscore the potential risk of hearing loss from combined exposure to noise and CO, and the risks associated with repeated exposure.

Low-level toluene disrupts auditory function in guinea pigs

Toluene appears to have adverse effects on the human auditory system, but it is difficult to estimate its potency since it is commonly present in the workplace in combination with noise exposure; workplace noise exposures are often highly variable. Studies designed to assess toluene ototoxicity specifically have been limited to high-dose studies in a single laboratory animal model, the rat. Here permanent hearing loss has been observed at concentrations of 1000 ppm toluene and greater after inhalation exposure for 5 days, 6 h/day. The OSHA threshold limit value for toluene is only 100 ppm. The current study focuses on the onset of toluene ototoxicity acutely in the guinea pig and in adducing a mechanism of effect. In this study, evidence is presented for the impairment of auditory function by toluene in the guinea pig, at a concentration substantially lower than that used for studying permanent impairment in the rat. The impaired function was correlated with reduced energy metabolism in outer hair cells. Assessment of auditory function was made using distortion product otoacoustic emissions (DPOAE) with subsequent measurement of succinate dehydrogenase (SDH) staining density in hair cells using surface preparations. Temporary disruption of auditory function in guinea pigs is seen in subjects exposed to 250, 500, and 1000 ppm toluene for 8 h/day, 5 day/week for 1 and 4 weeks. Concentrations as low as 250 ppm toluene were able to disrupt auditory function acutely in the guinea pig, and 500 and 1000 ppm toluene produced greater acute dysfunction. SDH staining suggests that reduced enzyme activity in the midfrequency region of the cochlea occurs acutely following toluene exposure. Although the auditory dysfunction progressed between 1 and 4 weeks of exposure, a permanent loss did not develop for these subjects and hair cell death was not seen. The current study identifies early evidence of auditory system impairment in the guinea pig at low toluene concentration and evidence for impairment of energy production in hair cells. While even a transient auditory impairment has implications for workplace safety, additional study on the transition from such acute effects to permanent impairment is essential.

Succinate dehydrogenase (SDH) activity in hair cells: a correlate for permanent threshold elevations

Hair cell loss is often used as a histological correlate of hearing loss. However, the histological and the physiological data are not always well correlated. This paper investigates the use of succinate dehydrogenase (SDH) activity in the hair cells as a marker of cellular dysfunction and so the loss of auditory sensitivity. In our previous studies, potentiation of noise-induced auditory threshold elevation by carbon monoxide (CO) was observed [Chen and Fechter, 1999; Chen et al., 1999]. However, its histological basis is still unclear. In this study, rats were exposed to 100-dB octave-band noise (center frequency=13.6 kHz, 2 h) or to the combination of the noise and CO (1200 ppm). Threshold elevation of compound action potential (CAP) and cochlear histological changes were assessed 4 weeks after exposure. The noise alone caused CAP threshold elevations with little if any or without hair cell loss. However, the SDH activity in the hair cells decreased after the exposure. The SDH reduction, especially in the inner hair cells, was well related to the loss of auditory sensitivity. The combined exposure to noise and CO caused more severe CAP threshold elevation and SDH activity reduction than did the noise alone and it also caused significant outer hair cell loss. However, across all the test frequencies, neither the hair cell loss nor the SDH reduction alone had good correlation to the reduction of the auditory sensitivity. Under this situation, CAP threshold elevation seemed to follow OHC loss at high frequencies and to follow SDH reductions in the IHCs at low frequencies, where no hair cell loss occurred.

Characterization of the ototoxicity of difluoromethylornithine and its enantiomers

Difluoromethylornithine (DFMO) is an irreversible inhibitor of ornithine decarboxylase (ODC), the essential enzyme in mammalian polyamine biosynthesis (Pasic et al., 1997, Arch. Otolaryngol. Head Neck Surg. 123[12], 1281-1286). This cancer chemotherapeutic agent has significant ototoxic potential. Because the DFMO enantiomers differ in their ability to block ODC, the present study was designed to compare the ototoxic potential of each enantiomer with the racemic form of this drug for the rat and guinea pig. Determining differential ototoxicity of the enantiomers is one preliminary step in determining the optimal form of DFMO to use in human cancer chemotherapy. Daily intubation with D,L-DFMO does not produce any auditory dysfunction in rats with doses between 200 mg/kg/day and 1. 2 g/kg/day for up to 8 weeks, despite the fact that doses of 800 and 1200 mg/kg/day depressed body weight gain. In contrast to the data observed in rats, substantial ototoxicity was observed when guinea pigs were injected ip with doses of D,L-DFMO between 500 mg/kg/day and 1 g/kg/day. D,L-DFMO produced loss of compound action potential sensitivity, but not of cochlear microphonic amplitude. This finding correlated with histological data revealing loss of both outer and inner hair cells in the cochlea with inner more affected than outer hair cells, particularly in the basal turn. Higher exposure doses (2-3 g/kg/day) resulted in significant general toxicity including impaired growth and some mortality. When the enantiomers were evaluated in the guinea pig, it was found that 1 g/kg/day D-DFMO did not produce any significant hearing impairment, whereas 1 g/kg/day of the L-enantiomer of DFMO generated a threshold shift that surpassed that of 1 g/kg/day of the D,L-DFMO treatment.

Neural responses to the onset of voicing are unrelated to other measures of temporal resolution

Voice onset time (VOT) is a temporal cue that can distinguish consonants such as /d/ from /t/. It has previously been shown that neurons' responses to the onset of voicing are strongly dependent on their static spectral sensitivity. This study examined the relation between temporal resolution, determined from responses to sinusoidally amplitude-modulated (SAM) tones, and responses to syllables with different VOTs. Responses to syllables and SAM tones were obtained from low-frequency neurons in the inferior colliculus (IC) of the chinchilla. VOT and modulation period varied from 10 to 70 ms in 10-ms steps, and discharge rates elicited by stimuli whose amplitude envelopes were modulated over the same temporal interval were compared. Neurons that respond preferentially to syllables with particular VOTs might be expected to respond best to the SAM tones with comparable modulation periods. However, no consistent agreement between responses to VOT syllables and to SAM tones was obtained. These results confirm the previous suggestion that IC neurons' selectivity for VOT is determined by spectral rather than temporal sensitivity.