Examining the association between serum free fatty acids and blood levels of testosterone.

BACKGROUND: Multiple studies have uncovered the effects that ingested fat has on human blood levels of testosterone. Yet, few reports have discussed the effect of circulating serum free fatty acids (FFAs). The present study aimed to explore the relationship between serum free fatty acids and blood levels of testosterone. METHODS: In total, 5719 adults were pooled from the database of the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2012. Based on multivariable-linear regression models, we employed a total of 30 FFAs to interpret the relationship of FFAs with blood levels of testosterone. Two models with covariate adjustments were designated for further evaluation and analysis. RESULTS: Capric acid [ß = -0.014, 95% confidence interval (CI) = -0.023, -0.004, P = 0.005], myristic acid (ß = -0.001, 95% CI = -0.001, 0.000, P ≤ 0.001), pentadecanoic acid (ß = -0.013, 95% CI = -0.018, -0.008, P ≤ 0.001), margaric acid (ß = -0.011, 95% CI = -0.017, -0.005, P ≤ 0.001) and alpha-linolenic acid (ß = -0.001, 95% CI = -0.002, 0.000, P = 0.004) in the fully adjusted model were significantly negatively correlated with the testosterone level inh obese men. In the fully adjusted model for the female analysis, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, myristoleic acid, oleic acid, nervonic acid and alpha-linolenic acid were found significantly associated with the testosterone level. CONCLUSIONS: Our findings indicate a significant negative correlation between serum FFAs and blood levels of testosterone. Furthermore, we reveal the essentiality of serum FFAs and their potential effects on the reduction of testosterone levels.

Clinicopathological features and course of cutaneous protothecosis.

BACKGROUND: Protothecosis is an uncommon infection caused by the achlorophyllic algae found more commonly in tropical areas. Only a limited number of cases have been reported. OBJECTIVE: We aimed to evaluate the clinicopathological features and treatment outcomes of cutaneous protothecosis. METHODS: We retrospectively identified 20 pathology-confirmed cases of cutaneous protothecosis based on skin biopsies in two tertiary medical centres in Taiwan from 1997 to 2015. RESULTS: The age of the patients at the time of diagnosis ranged from 48 to 85 years (mean age of 74 years). All lesions developed on the limbs. Twelve (60%) patients had adrenal insufficiency, but no patients had active malignancy at diagnosis. Interestingly, four (20%) patients had concurrent scabies infestation. Clinically, most lesions were erythematous plaques studded with punctate ulcers. Microscopically, the most common finding was granulomatous inflammation. Nineteen (95%) cases were successfully treated with itraconazole for 14-148 days with only one case of recurrence. Concomitant scabies should be suspected if pruritus is recalcitrant despite itraconazole treatment. CONCLUSION: Despite its rarity, cutaneous protothecosis has become more significant due to an increased prevalence of immunocompromised individuals. Steroid overuse or iatrogenic adrenal insufficiency predisposes individuals to high-risk infections. Neglecting the disease leads to a chronic and incurable state. Protothecosis should be suspected in chronic eczematous and ulcerative plaques on the limbs refractory to conventional antibacterial and antiviral treatments, especially in patients with adrenal insufficiency. Clinical suspicion should be confirmed by skin biopsies, and confirmed cases can be successfully treated with itraconazole.

Transcriptome analysis and anthocyanin-related genes in red leaf lettuce.

This study aimed to analyze the transcriptome profile of red lettuce and identify the genes involved in anthocyanin accumulation. Red leaf lettuce is a popular vegetable and popular due to its high anthocyanin content. However, there is limited information available about the genes involved in anthocyanin biosynthesis in this species. In this study, transcriptomes of 15-day-old seedlings and 40-day-old red lettuce leaves were analyzed using an Illuminia HiseqTM 2500 platform. A total of 10.6 GB clean data were obtained and de novo assembled into 83,333 unigenes with an N50 of 1067. After annotation against public databases, 51,850 unigene sequences were identified, among which 46,087 were annotated in the NCBI non-redundant protein database, and 41,752 were annotated in the Swiss-Prot database. A total of 9125 unigenes were mapped into 163 pathways using the Kyoto Encyclopedia of Genes and Genomes database. Thirty-four structural genes were found to cover the main steps of the anthocyanin pathway, including chalcone synthase, chalcone isomerase, flavanone 3-hydroxylase, flavonoid 3'-hydroxylase, flavonoid 3',5'-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase. Seven MYB, three bHLH, and two WD40 genes, considered anthocyanin regulatory genes, were also identified. In addition, 3607 simple sequence repeat (SSR) markers were identified from 2916 unigenes. This research uncovered the transcriptomic characteristics of red leaf lettuce seedlings and mature plants. The identified candidate genes related to anthocyanin biosynthesis and the detected SSRs provide useful tools for future molecular breeding studies.

Identification of heat shock proteins via transcriptome profiling of tree peony leaf exposed to high temperature.

The tree peony leaf is an important vegetative organ that is sensitive to abiotic stress and particularly to high temperature. This sensitivity affects plant growth and restricts tree peony distribution. However, the transcriptomic information currently available on the peony leaf in public databases is limited. In this study, we sequenced the transcriptomes of peony leaves subjected to high temperature using the Illumina HiSeq TM 2000 platform. We performed de novo assembly of 93,714 unigenes (average length of 639.7 bp). By searching the public databases, 22,323 unigenes and 13,107 unigenes showed significant similarities with proteins in the NCBI non-redundant protein database and SWISS-PROT database (E-value < 1e-5), respectively. We assigned 17,340 unigenes to Gene Ontology categories, and we assigned 7618 unigenes to clusters of orthologous groups for eukaryotic complete genomes. By searching the Kyoto Encyclopedia of Genes and Genomes Pathway database, 8014 unigenes were assigned to 6 main categories, including 290 KEGG pathways. To advance research on improving thermotolerance, we identified 24 potential heat shock protein genes with complete open reading frames from the transcriptomic sequences. This is the first study to characterize the leaf transcriptome of tree peony leaf using high-throughput sequencing. The information obtained from the tree peony leaf is valuable for gene discovery, and the identified heat shock protein genes can be used to improve plant stress-tolerance.

Phenotypic heterogeneity in monogenic diabetes: the clinical and diagnostic utility of a gene panel-based next-generation sequencing approach.

Single gene mutations that primarily affect pancreatic ß-cell function account for approximately 1-2% of all cases of diabetes. Overlapping clinical features with common forms of diabetes makes diagnosis of monogenic diabetes challenging. A genetic diagnosis often leads to significant alterations in treatment, allows better prediction of disease prognosis and progression, and has implications for family members. Currently, genetic testing for monogenic diabetes relies on selection of appropriate individual genes for analysis based on the availability of often-limited phenotypic information, decreasing the likelihood of making a genetic diagnosis. We thus developed a targeted next-generation sequencing (NGS) assay for the detection of mutations in 36 genes known to cause monogenic forms of diabetes, including transient or permanent neonatal diabetes mellitus (TNDM or PNDM), maturity-onset diabetes of the young (MODY) and rare syndromic forms of diabetes. A total of 95 patient samples were analyzed: 19 with known causal mutations and 76 with a clinically suggestive phenotype but lacking a genetic diagnosis. All previously identified mutations were detected, validating our assay. Pathogenic sequence changes were identified in 19 out of 76 (25%) patients: 7 of 32 (22%) NDM cases, and 12 of 44 (27%) MODY cases. In 2 NDM patients the causal mutation was not expected as consanguinity was not reported and there were no clinical features aside from diabetes. A 3 year old patient with NDM diagnosed at 3 months of age, who previously tested negative for INS, KCNJ11 and ABCC8 mutations, was found to carry a novel homozygous mutation in EIF2AK3 (associated with Wolcott-Rallison syndrome), a gene not previously suspected because consanguinity, delayed growth, abnormal bone development and hepatic complications had not been reported. Similarly, another infant without a history of consanguinity was found to have a homozygous GCK mutation causing PNDM at birth. This study demonstrates the effectiveness of multi-gene panel analysis in uncovering molecular diagnoses in patients with monogenic forms of diabetes.

Inhibition of MEK sensitizes gastric cancer cells to TRAIL-induced apoptosis.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which has long been believed to be highly selective in inducing apoptosis in cancer cells, has turned out to be a molecule that induces a far more diverse range of effects. The aim of this study was to investigate whether or not ERK1/2 pathway is involved in antitumor effects of TRAIL on gastric cancer cells. In addition to activate the extrinsic and intrinsic apoptotic pathway, TRAIL also triggered the activation of ERK1/2. Inhibition of ERK1/2 signaling by MEK inhibitor U0126 promoted cell death via increased activation of caspases, drop in mitochondrial membrane potential and downregulation of XIAP, cIAP2 and Mcl-1. These results indicate that TRAIL-induced rapid activation of ERK1/2 may be a survival mechanism to struggle against TRAIL assault at the early stage, and inhibition of ERK1/2 signaling can sensitize gastric cancer cells to TRAIL-induced apoptosis.

The prognostic significance of APC gene mutation and miR-21 expression in advanced-stage colorectal cancer.

AIM: Colorectal cancer (CRC) is the second commonest cause of cancer death in Taiwan. Although numerous genes have been associated with tumorigenesis in colorectal cancer, only a few have been validated and used as biomarkers for predicting clinical outcome. The aim of this study was to analyse the association of APC gene mutation and miR-21 expression with clinical outcome in CRC patients. METHOD: In total, 195 colorectal cancer patients were enrolled in a single medical centre between 2003 and 2007. APC gene mutation and expression of APC and miR-21 were analysed by direct DNA sequencing and real-time reverse transcription polymerase chain reaction. The primary outcome included 5-year overall survival and univariate (Kaplan-Meier) and multivariate (Cox regression) analyses of prognostic factors. RESULTS: The results showed that 66 (33.8%) of 195 tumour tissues contained an APC mutation. The predominant APC gene variations were deletion mutations (50.0%). APC gene expression was low in CRC and negatively correlated with miR-21 expression and gene mutation. In advanced-stage cancer, patients with APC mutation/high miR-21 had poorer overall survival rates than those with APC mutation/low miR-21, APC wild-type/high miR-21 and APC wild-type/low miR-21. CONCLUSION: In Taiwan, downregulation of the APC gene in CRC correlated with gene mutation and miR-21 upregulation. APC mutation and miR-21 expression could be used to predict the clinical outcome of CRC, especially in patients with advanced disease.

Impending macrosomia: will induction of labour modify the risk of caesarean delivery?

OBJECTIVE: To compare the annual incidence rates of caesarean delivery between induction of labour and expectant management in the setting of macrosomia. DESIGN: This is a retrospective cohort study. SETTING: Deliveries in the USA in 2003. POPULATION: Singleton births of macrosomic neonates to low-risk nulliparous women at 39 weeks of gestation and beyond. METHODS: Women who had induction of labour at 39 weeks of gestation with a neonatal birthweight of 4000 ± 125 g (3875-4125 g) were compared with women who delivered (either induced or spontaneous labour) at 40, 41 or 42 weeks (i.e. expectant management), assuming an intrauterine fetal weight gain of 200 g per additional week of gestation. Similar comparisons were made at 40 and 41 weeks of gestation. Chi-square test and multivariable logistic regression analysis were used for statistical comparison. MAIN OUTCOME MEASURES: Method of delivery, 5-minute Apgar scores, neonatal injury. RESULTS: There were 132,112 women meeting the study criteria. In women whose labours were induced at 39 weeks and who delivered a neonate with a birthweight of 4000 ± 125 g, the frequency of caesarean was lower compared with women who delivered at a later gestational age (35.2% versus 40.9%; adjusted OR 1.25, 95% CI 1.17-1.33). This trend was maintained at both 40 weeks (36.1% versus 42.6%; adjusted OR 1.31, 95% CI 1.23-1.40) and 41 weeks (38.9% versus 41.8%; adjusted OR 1.16, 95% CI 1.06-1.28) of gestation. CONCLUSIONS: In the setting of known birthweight, it appears that induction of labour may reduce the risk of caesarean delivery. Future research should concentrate on clinical and radiological methods to better estimate birthweight to facilitate improved clinical care. These findings deserve examination in a large, prospective, randomised trial.

Osteopontin regulates anabolic effect in human menopausal osteoporosis with intermittent parathyroid hormone treatment.

UNLABELLED: In this pilot study, we demonstrated that women with osteopontin (OPN) over-expression show less resistance to postmenopausal osteoporosis than women with normal OPN levels. We hypothesized that the levels of plasma OPN could be used as a treatment indicator for intermittent parathyroid hormone (PTH)-treated menopausal osteoporosis. We demonstrated that plasma OPN levels could be used as a biomarker for early treatment response. INTRODUCTION: Animal studies indicate that OPN-deficient mice are resistant to ovariectomy induced osteoporosis. Our pilot study also demonstrated women with OPN over expression may show less resistance to postmenopausal osteoporosis. The role of plasma OPN in PTH1-34-treated osteoporosis remains unclear. METHODS: From September 2005 to September 2006, 31 menopausal women over 45 years of age with severe osteoporosis were enrolled in our study. Subjects were treated with PTH1-34 subcutaneously at a dose of 20 µg/day. Plasma OPN levels and BMD of the lumbar spine and hip were measured using ELISA and dual-energy X-ray absorptiometry at baseline, 3, 6, and 9 months. Response to the treatment was assessed by the sequential change in bone mineral density and OPN expression using a general linear mixed model. RESULTS: The plasma OPN decreased sequentially and significantly throughout the 9-month treatment course from 20.75 ± 5.36 to 11.2 ± 4.37 ng/ml (p < 0.001). The sequential improvement in the T-score and Z-score was significant in the lumbar spine but not in the hip area. In the lumbar spine, when the plasma OPN decreased by 1 ng/ml the T-score increased by 0.0406 and the Z-score increased by 0.0572 of lumbar spine. CONCLUSION: OPN levels are related to the anabolic effect of PTH in human postmenopausal osteoporosis. Plasma OPN levels could be used as a biomarker for early treatment response.

Perinatal morbidity associated with late preterm deliveries compared with deliveries between 37 and 40 weeks of gestation.

OBJECTIVE: To estimate the risk of short-term complications in neonates born between 34 and 36 weeks of gestation. DESIGN: This is a retrospective cohort study. SETTING: Deliveries in 2005 in the USA. POPULATION: Singleton live births between 34 and 40 weeks of gestation. METHODS: Gestational age was subgrouped into 34, 35, 36 and 37-40 completed weeks of gestation. Statistical comparisons were performed using chi-square test and multivariable logistic regression models, with 37-40 weeks of gestation designated as referent. MAIN OUTCOME MEASURES: Perinatal morbidities, including 5-minute Apgar scores, hyaline membrane disease, neonatal sepsis/antibiotics use, and admission to the intensive care unit. RESULTS: In all, 175,112 neonates were born between 34 and 36 weeks in 2005. Compared with neonates born between 37 and 40 weeks, neonates born at 34 weeks had higher odds of 5-minute Apgar <7 (adjusted odds ratio [aOR] 5.51, 95% CI 5.16-5.88), hyaline membrane disease (aOR 10.2, 95% CI 9.44-10.9), mechanical ventilation use >6 hours (aOR 9.78, 95% CI 8.99-10.6) and antibiotic use (aOR 9.00, 95% CI 8.43-9.60). Neonates born at 35 weeks were similarly at risk of morbidity, with higher odds of 5-minute Apgar <7 (aOR 3.42, 95% CI 3.23-3.63), surfactant use (aOR 3.74, 95% CI 3.21-4.22), ventilation use >6 hours (aOR 5.53, 95% CI 5.11-5.99) and neonatal intensive-care unit admission (aOR 11.3, 95% CI 11.0-11.7). Neonates born at 36 weeks remain at higher risk of morbidity compared with deliveries at 37-40 weeks of gestation. CONCLUSIONS: Although the risk of undesirable neonatal outcomes decreases with increasing gestational age, the risk of neonatal complications in late preterm births remains higher compared with infants delivered at 37-40 weeks of gestation.

Rubella seroepidemiology and estimations of the catch-up immunisation rate and persistence of antibody titers in pregnant women in Taiwan.

OBJECTIVE: To examine rubella seroepidemiology, and estimate rates of catch-up immunisation and persistence of antibody titers in pregnant women in Taiwan after mass immunisation. DESIGN: A retrospective study. SETTING: Two medical centres and four regional hospitals specialising in obstetric care. SAMPLE: A total of 43,640 prenatal rubella test results for pregnant women from 2001 to 2008. METHODS: Rubella immunoglobulin G (IgG) antibody assay. MAIN OUTCOME MEASURES: Seronegativity, rate of catch-up immunization, and antibody decline. RESULTS: The seronegativity was 10.9% in all pregnant women. Immigrant women had higher seronegativity than indigenous women (OR 2.86; 95% CI 2.65, 3.01). Indigenous women born prior to implementation of the vaccination programmes were more susceptible (20.1%) to rubella infection than were women born thereafter (6.7%). Rates of seropositive conversion were low in both Taiwanese-born and foreign-born women (11.5 and 30.7%, respectively). The rubella antibody titers for vaccinated Taiwanese women in the 1971-1976 and after-1976 birth cohorts declined by 0.6 and 2.3% per year, respectively. CONCLUSIONS: This study demonstrates high seronegativity of older indigenous and immigrant women, a low catch-up immunisation rate, and the persistence of rubella antibodies in Taiwan after mass vaccination. Our study suggests that a single dose of rubella vaccine in teenagers effectively increased rubella seropositivity during their childbearing years. This finding is useful for countries that lack the resources necessary for a two-dose regimen. We recommend free rubella antibody tests to women of childbearing age and free vaccination as required. All postpartum women testing negative for rubella antibodies should be vaccinated before they leave hospital.

Diagnosis and morbidity of placenta accreta.

OBJECTIVE: To examine the diagnostic precision of ultrasound examination for placenta accreta in women with placenta previa and to compare the morbidity associated with accreta to that of previa alone. METHODS: This was a retrospective cohort study of all women with previa with/without accreta examined at the University of California, San Francisco (UCSF) between 2002 and 2008. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of ultrasound examination for the diagnosis of accreta were calculated and compared with results from similar studies in the literature. Univariable analysis was used to compare clinical outcomes. RESULTS: The PPV of an ultrasound diagnosis of accreta was 68% and NPV was 98%. Ultrasound had a sensitivity of 89.5%. Compared with previa alone, accreta had an odds ratio (OR) of 89.6 (95% CI, 19.44-412.95) for estimated blood loss > 2 L, an OR of 29.6 (95% CI, 8.20-107.00) for transfusion and an OR of 8.52 (95% CI, 2.58-28.11) for length of hospital stay > 4 days. CONCLUSION: Placenta accreta is associated with greater morbidity than is placenta previa alone. Ultrasound examination is a good diagnostic test for accreta in women with placenta previa. This is consistent with most other studies in the literature.

Increased serum osteopontin is a risk factor for osteoporosis in menopausal women.

SUMMARY: Osteopontin (OPN)-deficient mice are resistant to ovariectomy-induced osteoporosis. Therefore, we hypothesized that women with OPN overexpression may show less resistance to postmenopausal osteoporosis. In this study, we first demonstrated that serum OPN levels could be used as a biomarker for the early diagnosis of osteoporosis in postmenopausal women. INTRODUCTION: Animal studies indicate that OPN-deficient mice are resistant to ovariectomy-induced osteoporosis. METHODS: From 2004 to 2006, 124 women over the age of 45 were enrolled in a menopausal group, while another 95 women, from 25 to 45 years of age with regular menstruation, were enrolled into a childbearing age group. The serum concentrations of OPN were calculated using the enzyme-link immunosorbent assay method, and bone mineral densities were determined with dual energy X-ray absorptiometry. RESULTS: Serum OPN levels had a significant positive correlation with age (menopausal group, p < 0.0001) and a negative correlation with body weight, height, hip bone mineral density, and T-scores in the menopausal group. In contrast, there was a positive correlation with the E2 concentration and height, but there was no significant association with the above variables in the childbearing age group. Additionally, high serum OPN levels (>14.7 ng/ml) was a significant risk factor causing menopausal osteoporosis (odds ratio = 2.96, 95% confidence interval, 1.055-8.345). CONCLUSION: Serum OPN levels could be used as a biomarker for the early diagnosis of osteoporosis in postmenopausal women.

Distribution of lysosome-associated membrane proteins-1 and -2, and cathepsin D in eosinophilic granular bodies: possible relationship to cyst development in pilocytic astrocytomas.

Pilocytic astrocytomas are usually cystic; cyst formation within these tumours may result in increased intracranial pressure, due to the effect of their mass, and contribute to cerebral damage. Eosinophilic granular bodies (EGBs) are produced abundantly in pilocytic astrocytomas but their role in disease progression remains unknown. Immunohistochemistry studies showed EGBs to exhibit pronounced reactivity to antibodies against lysosome-associated membrane proteins (LAMP)-1 and LAMP-2, and the lysosomal enzyme cathepsin D. Both LAMP-1 and LAMP-2 showed peripheral rim and granular staining patterns. The EGBs were scattered widely across cysts and, where EGBs aggregated in clusters, were usually close to areas of fluid in the cysts. Most EGBs had nuclei either attached or close by, indicating that the EGBs may be derived from anucleated astrocytes. The results suggest that EGBs, together with other factors, may play a role in the development of cysts in pilocytic astrocytomas.

Medical waste production at hospitals and associated factors.

This study was conducted to evaluate the quantities of medical waste generated and the factors associated with the generation rate at medical establishments in Taiwan. Data on medical waste generation at 150 health care establishments were collected for analysis in 2003. General medical waste and infectious waste production at these establishments were examined statistically with the potential associated factors. These factors included the types of hospital and clinic, reimbursement payment by National Health Insurance, total number of beds, bed occupancy, number of infectious disease beds and outpatients per day. The average waste generation rates ranged from 2.41 to 3.26kg/bed/day for general medical wastes, and 0.19-0.88kg/bed/day for infectious wastes. The total average quantity of infectious wastes generated was the highest from medical centers, or 3.8 times higher than that from regional hospitals (267.8 vs. 70.3Tons/yr). The multivariate regression analysis was able to explain 92% of infectious wastes and 64% of general medical wastes, with the amount of insurance reimbursement and number of beds as significant prediction factors. This study suggests that large hospitals are the major source of medical waste in Taiwan. The fractions of medical waste treated as infectious at all levels of healthcare establishments are much greater than that recommended by the USCDC guidelines.

Comprehensive characterization of indoor airborne bacterial profile.

This is the first detailed characterization of the airborne bacterial profiles in indoor environments. Two restaurants were selected for this study. Fifteen genera of bacteria were isolated from each restaurant and identified by three different bacterial identification systems including MIDI, Biolog and Riboprinter. The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant. Most bacteria identified were representative species of skin and respiratory tract of human, and soil. Although the bacterial levels in these two restaurants were below the limit of the Hong Kong Indoor Air Quality Objective (HKIAQO) Level 1 standard (i.e., < 500 cfu/m3), the majority of these bacteria were opportunistic pathogens. These results suggested that the identity of airborne bacteria should also be included in the IAQ to ensure there is a safety guideline for the public.

Xeroderma pigmentosum group C gene expression is predominantly regulated by promoter hypermethylation and contributes to p53 mutation in lung cancers.

Reduced DNA repair capability is associated with developing lung cancer, especially in nonsmokers. XPC participates in the initial recognition of DNA damage during the DNA nucleotide excision repair process. We hypothesize that inactivation of XPC by promoter hypermethylation may play an important role in the reduction of DNA repair capability to cause p53 mutation during lung carcinogenesis. In this report we demonstrate that hypermethylation of 17 CpG islands between -175 and -1 of the XPC promoter correlates very well with XPC expression levels in eight lung cancer cell lines. When cells with hypermethylated XPC promoters were treated with the demethylating agent 5-aza-2'-deoxycytidine, XPC expression was de-repressed. Interestingly, XPC hypermethylation was found in 4 of 5 (80%) lung cancer cell lines harbored p53 mutation, but not observed in two lung cancer cells which had a wild-type p53 gene. Among the analysis of the hypermethylation status of 158 lung tumors, XPC hypermethylation is more common in nonsmokers (39 of 94, 41%) than in smokers (14 of 64, 22%; P=0.010). Additionally, XPC hypermethylation is more often with G --> T or G --> C mutations in the p53 gene. To verify whether XPC inactivation is involved in the occurrence of p53 mutation, XPC gene of A549 cells was knockdown by a small interference RNA and then XPC-inactivated cells were treated with benzo[a]pynrene for different passages. Surprisingly, G --> T mutation in p53 gene at codon 215 was indeed detected in XPC-inactivated A549 cells of passages 15 and confirmed by loss of transcription activity of mdm2. These results show that hypermethylation of the XPC promoter may play a crucial role in XPC inactivation, which may partly contribute to the occurrence of p53 mutations during lung tumorigenesis, especially nonsmokers.

Biophysical and histological determinants underlying natural firing behaviors of splanchnic sympathetic preganglionic neurons in neonatal rats.

Isolated thoracic spinal cords of neonatal rats spontaneously generate splanchnic sympathetic nerve discharge (SND) with a quasiperiodic rhythm approximately 1-Hz. Using in vitro nerve-cord preparations that retained T6-T12 spinal segments, we investigated whether the natural firing behavior of sympathetic preganglionic neurons (SPNs) encoded the SND rhythm and what were the main biophysical and histological determinants of SPN firing. Under extracellular recording conditions, electrical stimulation of splanchnic nerves elicited antidromic responses in 212 SPNs. Among them, 92 SPNs were quiescent; 120 active SPNs had an average firing rate of 0.72+/-0.04 Hz, which was close to the quasiperiodic rhythm of SND. SPNs with rhythmic burst firing were rare. Probability plots of interspike intervals were constructed to extract mathematical features underlying SPN firing. Most active SPNs (88%) had a firing well described by unimodal Gaussian, suggesting a predominantly tonic pattern with normal variations. Biophysical properties of 112 SPNs were measured under whole-cell recording conditions. The charging time constant, tau, is positively correlated with the average firing rate. Histological properties were examined in 45 SPNs with intracellular diffusion of Lucifer Yellow or biocytin. SPNs with pyramidal somata and multipolar dendrites tend to be spontaneously active. In contrast, those with bipolar somata and fewer dendritic branches were quiescent in firing. These observations suggest that activity levels of SPNs are correlated with their capacity for temporal and spatial summation of synaptic inputs. How the seemingly tonic firing of individual SPNs is integrated into whole-nerve SND with quasiperiodic rhythms is discussed.

Disinfection of Legionella pneumophila by photocatalytic oxidation.

Photocatalytic oxidation (PCO) was proven to be efficacious in the inactivation of Legionella pneumophila serogroup 1 Strains 977, 1009, 1014 and ATCC 33153. The local (Strains 997, 1009 and 1014) and ATCC (Strain 33153) strains showed sensitivity differences towards PCO. The inactivation mechanisms of PCO were investigated by transmission and scanning electron microscopy by which PCO was found to disintegrate the cells eventually. Before the disintegration, there was lipid peroxidation of outer and cytoplasmic membrane causing holes formation and leading to the entry of OH into the cells to oxidize the intracellular components. Fatty acid profile analysis found that the amount of saturated, 16-carbon branched-chain fatty acid, which is predominant in Legionella, decreased in the surviving populations from PCO. A relationship between the amount of this fatty acid and the PCO sensitivity of the tested strains was also observed. Mineralization of cells by PCO was proven by total organic carbon analysis.