Stimulated photosynthesis of regrowth after fire in coastal scrub vegetation: Increased water or nutrient availability?

Fire-prone landscapes experience frequent fires, disrupting above-ground biomass and altering below-ground soil nutrient availability. Augmentation of leaf nutrients or leaf water balance can both reduce limitations to photosynthesis and facilitate post-fire recovery in plants. These modes of fire responses are often studied separately and hence rarely compared. We hypothesised that under severe burning, woody plants of a coastal scrub ecosystem would have higher rates of photosynthesis (Anet) than in unburned areas due to a transient release from leaf nutrient and water limitations, facilitating biomass recovery post-burn. To compare these fire recovery mechanisms in regrowing plants, we measured leaf gas exchange, leaf and soil N and P concentrations, and plant stomatal limitations in Australian native coastal scrub species across a burn sequence of sites at one year after severe fi, seven years following a light controlled fire, and decades after any fire at North Head, Sydney, Australia. Recent burning stimulated increases in Anet by 20% over unburned trees and across three tree species. These species showed increases in total leaf N and P as a result of burning of 28% and 50% for these macronutrients, respectively, across the three species. The boost in leaf N and P and stimulated leaf biochemical capacity for photosynthesis, alongside species-specific gs increases, together contributed to increased photosynthetic rates after burning compared to the long-unburned area. Photosynthetic stimulation after burning occurred due to increases in nutrient concentrations in leaves, particularly nitrogen, as well as stomatal opening for some species. The findings suggest that changes in species photosynthesis and growth with increased future fire intensity or frequency may be facilitated by changes in leaf physiology after burning. On this basis, species dominance during regrowth depends on nutrient and water availability during post-fire recovery.

Efficacy of a school-based education intervention on the consumption of fruits, vegetables and carbonated soft drinks among adolescents.

OBJECTIVES: To evaluate the efficacy of a school-based education intervention on the consumption of fruit, vegetables and carbonated soft drinks among adolescents. DESIGN: Cluster-randomised controlled trial. SETTING: Eight secondary schools from Dhaka, Bangladesh, participated in this trial and were randomly allocated to intervention (n 160) and control groups (n 160). PARTICIPANTS: A total of 320 students from 8th to 9th grades participated and completed the self-reported questionnaires at baseline, and at 8 and 12 weeks. The intervention included weekly classroom-based nutrition education sessions for students and healthy eating materials for students and parents. Repeated measures ANCOVA was used to assess the effects of the intervention. RESULTS: Daily fresh fruit intake was more frequent in the intervention (26 %) compared to the control group (3 %) at 12 weeks (p = 0·006). Participants from the intervention group also reported a significantly (P < 0·001) higher (49 %) proportion of fresh vegetable intake compared to the control group (2 %) at 12 weeks. Frequency of daily carbonated soft drinks intake decreased (25 %) in the intervention group at 12 weeks compared to baseline, while it remained unchanged in the control group; the interaction effect was observed significant (P = 0·002). CONCLUSION: Our school-based education intervention increased the daily frequency of fresh vegetables and fruit intake and decreased carbonated soft drink consumption among adolescents in the intervention group. There is a need for scaling up the intervention to engage students and empower them to develop healthy dietary habits.

Examining the Association between Sports Participation and Mental Health of Adolescents.

Sports participation has been linked to various health outcomes; however, there is scant literature exploring this relationship in developing countries. We used a mixed method approach to examine the association between sports participation and mental health of Bangladeshi adolescents (n = 320; 13-17 years; 59% boys) and to explore sports preferences and barriers to sports participation across genders. A survey collected team and non-team sports participation, depression, and life satisfaction. Focus groups (16 boys, 16 girls) explored preferences for, and barriers to, sports participation. Regression analysis showed that higher team and non-team sports participation were associated with lower depressive symptoms in boys (ß = -1.22, 95% CI:-2.55 to -0.10; ß = -2.50, 95% CI:-3.83 to -1.16, respectively), while greater participation in team sports was associated with less depression in girls (ß = -2.44, 95% CI:-4.63 to -0.24). Participation in team and non-team sports was positively associated with life satisfaction for boys and girls. Boys reported preferences for playing football and cricket, while girls favored skipping and running. Prolonged time on electronic devices was reported as barriers to sports participation in both genders. Furthermore, household chores, family restrictions, and unsafe environment were reported by girls. Participation in team sports may provide mental health benefits for both genders, while non-team sports may be more beneficial to boys than girls.

Phosphorus availability and plants alter soil nitrogen retention and loss.

Availability of phosphorus (P) can directly and/or indirectly affect nitrogen (N) retention and loss from soil by stimulating microbial and plant root activities. However, it is not clear how P availability and plant presence interact on nitrous oxide (N2O) emission and nitrate (NO3-) leaching in soil. A mesocosm experiment was conducted to investigate the effect of P addition (0, 10 and 20 mg P kg-1) with and without plant presence (Phalaris aquatica, C3 grass) on N2O emission, NO3- leaching and 15N recovery. Our results showed large variation in N2O emission with significant increases after leaching events. We observed that initially low but later (after 53 days of sowing) high levels of P addition increased N2O emission rates, possibly by stimulating nitrifiers and/or denitrifiers in soil. Plant presence decreased N2O emission at times when plants reduced water and NO3- in the soil, but increased N2O emission at times when both water and NO3- in the soil were abundant, and where plants may have stimulated denitrification through supply of labile organic C. Furthermore, an increase in net N mineralization, possibly due to increased decomposition stimulated by root derived C, may also have contributed to the higher cumulative N2O emission with plant presence. P addition increased 15N recovery in soil, but reduced it in leachates, suggesting increased 15N fixation in microbial biomass. Our results showed that both P addition and plant presence stimulated N loss as N2O, but also increased N retention in the soil-plant system and thus reduced N loss through leaching.

Antidiuretic and antinatriuretic response to high salt load in normotensive Wistar-Kyoto rats: Role of alpha-1A-adrenoreceptors.

Altered renal adrenergic responses have been recognized as pathophysiological responses to high salt intake. This study aims to investigate the influence of 6 weeks of high salt diet on α1A -adrenoceptor regulation of renal tubular antinatriuretic and antidiuretic response in normal Wistar Kyoto rats. To achieve the above objective, antinatriuretic and antidiuretic response to phenylephrine was measured in the absence and presence of 5-methylurapidil (5-MeU) using the inulin clearance method. Systemic mean arterial blood pressure and renal haemodynamics were also measured simultaneously. Six weeks of high salt intake in Wistar-Kyoto (WKY) rats did not bring any significant increase in mean arterial blood pressure. WKY rat on high salt diet (WKYHNa) showed an exaggerated increase in absolute and fractional sodium excretion. There was a significant involvement of α1A -adrenoceptor in carrying out renal tubular antinatriuretic and antidiuretic response in Wistar Kyoto rats on normal sodium diet (WKYNNa). However, α1A -adrenoceptor played a minimal role in handling the tubular reabsorptive response in WKY rats on high salt diet.

Perceptual evaluation of tracheoesophageal speech: Is it a reliable tool?

Perceptual voice evaluation is a common clinical tool for rating the severity of vocal quality impairment. It has been used in research as a gold standard for comparison with acoustic and aerodynamics measurements. Nevertheless, it has disadvantages in the form of being time-consuming, a group of raters is needed and last but not the least it is a subjective manner of evaluation. Intraobserver and interobserver reliability is an important issue in perceptual evaluations. Different perceptual scales have been developed to describe the quality of a patient's voice but none is internationally accepted. Although not entirely comprehensive, perceptual evaluations will be used as a standard against which other measures will be evaluated. Data were collected by conducting a computer-aided search of the MED-LINE and PUBMED databases, supplemented by hand searches of key journals. More than 50 articles in the last three decades on the topic have been reviewed out of which approximately 31 were found to be relevant to this article.

Phosphorylation of Ku dictates DNA double-strand break (DSB) repair pathway choice in S phase.

Multiple DNA double-strand break (DSB) repair pathways are active in S phase of the cell cycle; however, DSBs are primarily repaired by homologous recombination (HR) in this cell cycle phase. As the non-homologous end-joining (NHEJ) factor, Ku70/80 (Ku), is quickly recruited to DSBs in S phase, we hypothesized that an orchestrated mechanism modulates pathway choice between HR and NHEJ via displacement of the Ku heterodimer from DSBs to allow HR. Here, we provide evidence that phosphorylation at a cluster of sites in the junction of the pillar and bridge regions of Ku70 mediates the dissociation of Ku from DSBs. Mimicking phosphorylation at these sites reduces Ku's affinity for DSB ends, suggesting that phosphorylation of Ku70 induces a conformational change responsible for the dissociation of the Ku heterodimer from DNA ends. Ablating phosphorylation of Ku70 leads to the sustained retention of Ku at DSBs, resulting in a significant decrease in DNA end resection and HR, specifically in S phase. This decrease in HR is specific as these phosphorylation sites are not required for NHEJ. Our results demonstrate that the phosphorylation-mediated dissociation of Ku70/80 from DSBs frees DNA ends, allowing the initiation of HR in S phase and providing a mechanism of DSB repair pathway choice in mammalian cells.

Prevalence and determinants of metabolic syndrome among newly diagnosed type 2 diabetic subjects according to different criteria.

BACKGROUND AND AIM: Metabolic syndrome (MS) is becoming a serious global public health problem. The prevalence of MS differs in different population by using different definitions. Present study aimed to find out the prevalence and determinants of MS among newly diagnosed type 2 diabetes (NDT2D) according to different criteria. SUBJECTS AND METHODS: This cross-sectional analytic study was conducted among 281 subjects selected purposively from the OPD of BIRDEM. Information on lifestyle factors and disease history were collected using a semi-structured questionnaire by face to face interview. The three definitions of MS used in this study are from the International Diabetes Federation (IDF), a modified version of the ATP III criteria for Asian populations (modified ATP III) and World Health Organization (WHO) criteria. Adjusted odds ratio and confidence limit were generated through logistic regression. RESULTS: The overall prevalence of metabolic syndrome among the study subjects according to modified ATPIII, WHO and IDF criteria were 79% (95% CI: 74.2-83.8), 81% (95% CI: 76.4-85.6) and 68% (95% CI: 62.6-73.5) respectively. The prevalence of metabolic syndrome among female were higher compared to males in all the criteria's. Female gender (OR=5.93), family history of diabetes (OR=1.92), overweight (OR=6.2), and obesity (OR=5.13) were found as important confounders associated with metabolic syndrome. CONCLUSION: The prevalence of the metabolic syndrome among NDT2D is considerably higher in our population which may indicate considerable risk of cardiovascular diseases in future. Female gender, family history of diabetes, overweight and obesity are important confounders of MS in this population.

The transcription factor TFII-I promotes DNA translesion synthesis and genomic stability.

Translesion synthesis (TLS) enables DNA replication through damaged bases, increases cellular DNA damage tolerance, and maintains genomic stability. The sliding clamp PCNA and the adaptor polymerase Rev1 coordinate polymerase switching during TLS. The polymerases Pol η, ι, and κ insert nucleotides opposite damaged bases. Pol ζ, consisting of the catalytic subunit Rev3 and the regulatory subunit Rev7, then extends DNA synthesis past the lesion. Here, we show that Rev7 binds to the transcription factor TFII-I in human cells. TFII-I is required for TLS and DNA damage tolerance. The TLS function of TFII-I appears to be independent of its role in transcription, but requires homodimerization and binding to PCNA. We propose that TFII-I bridges PCNA and Pol ζ to promote TLS. Our findings extend the general principle of component sharing among divergent nuclear processes and implicate TLS deficiency as a possible contributing factor in Williams-Beuren syndrome.

Anthropometric indices of obesity and type 2 diabetes in Bangladeshi population: Chandra Rural Diabetes Study (CRDS).

BACKGROUND: Obesity is a risk factor for type 2 diabetes (DM); however, no study has specially assessed the anthropometric indices as predictors of diabetes in rural Bangladeshi population. OBJECTIVE: To identify markers for diabetes through body mass index (BMI), waist circumference (WC), waist hip ratio (WHR) and waist height ratio (WHtR) and identify the optimal cut-off values suitable for Bangladeshi adult population. METHODS: A total of 2293 subjects aged ≥20 years from rural Bangladesh were randomly recruited to participate in a population-based, cross sectional survey. Age adjusted data for anthropometric indices and diabetes risk were assessed and their relationships were examined. RESULTS: Age adjusted prevalence of DM in men and women were 9.5% and 7.0%, respectively. Both men and women with DM had a higher rate of general obesity (defined by BMI) and central obesity (defined by WC, WHR and WHtR) than non-diabetic subjects. In both men and women the most sensitive indice was WHR for predicting DM. The appropriate cut-offs values for WHR to predict DM in men and women were 0.93 and 0.87, respectively. WC of 82 cm for both sexes was appropriate to predict DM. Those of BMI and WHtR were 21.2 kg/m2, 21.8 kg/m2 and 0.53, 0.54 in men and women, respectively. CONCLUSIONS: Compared with BMI, measures of central obesity, WHR, WC, WHtR showed a better association with the risk of DM for both sexes in rural Bangladeshi population. Follow-up studies are needed for validifying these cut-offs values.

Pattern and predictors of dyslipidemia in patients with type 2 diabetes mellitus.

Dyslipidemia is a major risk factor for macro-vascular complications in patients with type 2 diabetes mellitus (T2DM). Present study explored pattern and predictors of dyslipidemia in Bangladeshi T2DM patients. The cross-sectional study is conducted among 366 consecutive eligible T2DM patients aged >30 years, BIRDEM diabetic hospital, during July-to-December 2010. Physical examination, diabetic profile, lipid profile and serum createnine was performed. Adjusted odds ratio and confidence limit were generated through binary logistic regression. Most frequent form (59.3%) of dyslipidemia is low HDL. Duration of T2DM is significantly correlated with TC (P<0.05), HDL (P<0.05) and LDL (P<0.05) in both male and female. Glycemic control in terms of HbA1c >7% appeared as predictor of dyslipidemia (P<0.01). Duration T2DM is associated with increased risk of having higher TC (P<0.05), LDL (P<0.05) and lower HDL (P<0.01) and does not seem to affect triglyceride (P>0.05). T2DM with comorbid hypertension seems to predict hyper tri-glyceridemia and lower HDL. Both TC-HDL ratio and LDL-HDL ratio appeared as good predictor of all four parameters of dyslipidemia (P<0.01). The characteristic features of diabetic dyslipidemia are low HDL, high triglyceride and LDL cholesterol level. Low HDL level is the most frequent type of abnormality. Poor glycemic control, prolonged duration, coexisting hypertension predicts dyslipidemia in T2DM.

Factors associated with knowledge about breastfeeding among female garment workers in Dhaka city

Background: Knowledge about breastfeeding among women is very important for healthy children.The present study aims to determine the level of knowledge and factors associated with knowledgeon breastfeeding among female garment workers in a selected garment factory in Dhaka city.Methods: A cross-sectional study was conducted among 200 female garment workers in thereproductive age group (15–49 years). Data were collected through a pre-tested questionnaireusing the face-to-face interview method. Bivariate and multivariate analysis was done to determinethe association between sociodemographic variables and knowledge on breastfeeding.Results: The study showed that, overall the level of knowledge regarding breastfeeding is very poor(88%) among the study subjects. Most of the respondents have very poor knowledge regardingadvantages of exclusive breastfeeding (89%) and breastfeeding (100%). In contrast, a majorityhave good knowledge on duration of exclusive breastfeeding (74%) and breastfeeding (66%). Nosignificant association was found between the knowledge score of breastfeeding with remainingsocio-demographic variables like age, marital status, family income and expenditure. Education issignificantly (p<0.001) associated with a higher total knowledge score of breastfeeding. Womenwith secondary level of education had a significantly higher (p<0.001) level of total knowledgescore than other categories (illiterate, primary and higher secondary) of education.Conclusion: A large proportion of female garment workers had inadequate knowledge regardingbreastfeeding. It is also important that health education on breastfeeding is urgently provided tothe female garments workers of Bangladesh

Akt promotes post-irradiation survival of human tumor cells through initiation, progression, and termination of DNA-PKcs-dependent DNA double-strand break repair.

Akt phosphorylation has previously been described to be involved in mediating DNA damage repair through the nonhomologous end-joining (NHEJ) repair pathway. Yet the mechanism how Akt stimulates DNA-protein kinase catalytic subunit (DNA-PKcs)-dependent DNA double-strand break (DNA-DSB) repair has not been described so far. In the present study, we investigated the mechanism by which Akt can interact with DNA-PKcs and promote its function during the NHEJ repair process. The results obtained indicate a prominent role of Akt, especially Akt1 in the regulation of NHEJ mechanism for DNA-DSB repair. As shown by pull-down assay of DNA-PKcs, Akt1 through its C-terminal domain interacts with DNA-PKcs. After exposure of cells to ionizing radiation (IR), Akt1 and DNA-PKcs form a functional complex in a first initiating step of DNA-DSB repair. Thereafter, Akt plays a pivotal role in the recruitment of AKT1/DNA-PKcs complex to DNA duplex ends marked by Ku dimers. Moreover, in the formed complex, Akt1 promotes DNA-PKcs kinase activity, which is the necessary step for progression of DNA-DSB repair. Akt1-dependent DNA-PKcs kinase activity stimulates autophosphorylation of DNA-PKcs at S2056 that is needed for efficient DNA-DSB repair and the release of DNA-PKcs from the damage site. Thus, targeting of Akt results in radiosensitization of DNA-PKcs and Ku80 expressing, but not of cells deficient for, either of these proteins. The data showed indicate for the first time that Akt through an immediate complex formation with DNA-PKcs can stimulate the accumulation of DNA-PKcs at DNA-DSBs and promote DNA-PKcs activity for efficient NHEJ DNA-DSB repair.

Persistently bound Ku at DNA ends attenuates DNA end resection and homologous recombination.

DNA double strand breaks (DSBs) are repaired by non-homologous end joining (NHEJ) or homologous recombination (HR). The DNA cell cycle stage and resection of the DSB ends are two key mechanisms which are believed to push DSB repair to the HR pathway. Here, we show that the NHEJ factor Ku80 associates with DSBs in S phase, when HR is thought to be the preferred repair pathway, and its dynamics/kinetics at DSBs is similar to those observed for Ku80 in non-S phase in mammalian cells. A Ku homolog from Mycobacterium tuberculosis binds to and is retained at DSBs in S phase and was used as a tool to determine if blocking DNA ends affects end resection and HR in mammalian cells. A decrease in DNA end resection, as marked by IR-induced RPA, BrdU, and Rad51 focus formation, and HR are observed when Ku deficient rodent cells are complemented with Mt-Ku. Together, this data suggests that Ku70/80 binds to DSBs in all cell cycle stages and is likely actively displaced from DSB ends to free the DNA ends for DNA end resection and thus HR to occur.

Factors associated with knowledge about breastfeeding among female garment workers in Dhaka city.

BACKGROUND: Knowledge about breastfeeding among women is very important for healthy children. The present study aims to determine the level of knowledge and factors associated with knowledge on breastfeeding among female garment workers in a selected garment factory in Dhaka city. METHODS: A cross-sectional study was conducted among 200 female garment workers in the reproductive age group (15-49 years). Data were collected through a pre-tested questionnaire using the face-to-face interview method. Bivariate and multivariate analysis was done to determine the association between sociodemographic variables and knowledge on breastfeeding. RESULTS: The study showed that, overall the level of knowledge regarding breastfeeding is very poor (88%) among the study subjects. Most of the respondents have very poor knowledge regarding advantages of exclusive breastfeeding (89%) and breastfeeding (100%). In contrast, a majority have good knowledge on duration of exclusive breastfeeding (74%) and breastfeeding (66%). No significant association was found between the knowledge score of breastfeeding with remaining socio-demographic variables like age, marital status, family income and expenditure. Education is significantly (p<0.001) associated with a higher total knowledge score of breastfeeding. Women with secondary level of education had a significantly higher (p<0.001) level of total knowledge score than other categories (illiterate, primary and higher secondary) of education. CONCLUSION: A large proportion of female garment workers had inadequate knowledge regarding breastfeeding. It is also important that health education on breastfeeding is urgently provided to the female garments workers of Bangladesh.

Acoustic analysis of tracheo-oesophageal voice in male total laryngectomy patients.

INTRODUCTION: The aim of this study was to test the null hypothesis that voice parameters of post-laryngectomy patients using tracheo-oesophageal (TO) prosthetic valves are similar to those of normal laryngeal subjects. METHODS: Thirty total laryngectomy patients and thirty normal controls were subjected to acoustic analysis of single voice recordings using a sustained vowel. Acoustic parameters including fundamental frequency, jitter, shimmer, harmonics-to-noise ratio and maximum phonation time were analysed. RESULTS: Poorer values were found as well as larger variability for all the voice parameters for the total laryngectomy patients using TO voice compared with those of normal subjects. There were statistically significant differences (p<0.05) for all studied parameters between the TO and normal speech. CONCLUSIONS: Alaryngeal speech with TO voice prosthesis is not yet comparable to laryngeal speech.

Dexamethasone reduces pain, vomiting and overall complications following tonsillectomy in adults: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Tonsillectomy is one of the most common surgical procedures, but there is debate whether systemic steroids should be used to reduce pain and post-operative complications. OBJECTIVE OF REVIEW: To determine whether peri-operative steroids reduce post-tonsillectomy pain and complications in adults. TYPE OF REVIEW: Systematic review and meta-analysis of randomised controlled trials. SEARCH STRATEGY: We searched MEDLINE (1950-2010), EMBASE (1980-2010), CINAHL (1981-2010), Web of Science, ProQuest, metaRegister, Conference Proceedings Citation Index, the Cochrane Library and reference lists of relevant studies. EVALUATION METHOD: Two reviewers independently selected trials and extracted data on their quality, characteristics and results. Trials included adults (age >16 years) undergoing elective tonsillectomy where peri-operative steroids were used, and the results were compared with control or placebo. RESULTS: There were seven randomised controlled trials (580 patients) reporting post-operative pain. Meta-analysis demonstrates that dexamethasone in adults reduces the pain level experienced in the first post-tonsillectomy day [standard mean difference (SMD): -0.63, 95% CI: -1.13 to -0.12] with significant heterogeneity (I(2) = 84%, P < 0.00001). Sub-group analysis to explore heterogeneity demonstrated this reduction in pain was mostly with high total dose steroids (total >10 mg over first 24 h post-operatively; SMD: -1.48, 95% CI: -2.17 to -0.79, P < 0.00001), especially when given both intra-operatively and post-operatively. There was no significant effect with low doses (SMD: -0.12, 95% CI: -0.36 to 0.13, P = 0.35). There were three trials (231 patients) that reported post-operative nausea and vomiting, three other trials (270 patients) reporting on bleeding and three trials (401 patients) reporting other complications (infections and odynophagia). There was a significant reduction in post-operative nausea and vomiting (RR: 0.53, 95% CI: 0.36 to 0.80, P = 0.002, I(2) = 26%) and bleeding (RR: 0.45, 95% CI: 0.25 to 0.80, P = 0.007, I(2) = 0%), but the reduction in the other complications did not reach statistical significance (RR: 0.69, 95% CI: 0.48 to 1.01, P = 0.06, I(2) = 0%). Pooling of these complications (post-operative nausea and vomiting, bleeding, infections and odynophagia) shows that in six trials (501 patients), the use of dexamethasone significantly reduced post-operative complications following tonsillectomy in adults (RR: 0.59, 95% CI: 0.49 to 0.71, P < 0.00001, I(2) = 0%), when compared with placebo or control. CONCLUSIONS: Dexamethasone reduces pain, post-operative nausea and vomiting, bleeding and overall post-operative complications in adults undergoing tonsillectomy. However, the effect of the dose of dexamethasone on post-operative pain and whether dexamethasone reduces bleeding require further research.

Function of erbB receptors and DNA-PKcs on phosphorylation of cytoplasmic and nuclear Akt at S473 induced by erbB1 ligand and ionizing radiation.

BACKGROUND AND PURPOSE: In the present study effect of erbB2 as well as DNA-PKcs on ionizing radiation (IR)- and erbB1 ligand-induced phosphorylation of Akt at S473 in cytoplasmic and nuclear fractions was investigated. MATERIALS AND METHODS: DNA-PKcs proficient and deficient syngeneic colon carcinoma sublines of HCT116 and the glioblastoma cell lines MO59K and MO59J as well as the lung carcinoma cell line A549 were used. Akt-S473 phosphorylation was investigated in cells pre-treated with pharmacological inhibitors or transfected with siRNA by immunoprecipitation, Western blotting and confocal microscopy after different stimuli, i.e., ligands and IR. RESULTS: IR-induced phosphorylation of Akt in both MO59K and MO59J cell lines but not in HCT116 cells was DNA-PKcs dependent. In A549 cells, IR-induced phosphorylation of nuclear Akt-S473 was dependent on erbB1, erbB2, and DNA-PKcs. EGF induced phosphorylation of nuclear Akt-S473 in a DNA-PKcs and erbB2 independent manner. CONCLUSION: Data indicate that the function of DNA-PKcs on IR-induced Akt-S473 phosphorylation is cell line specific. IR-induced, but not EGF-induced phosphorylation of cytoplasmic and/or nuclear Akt-S473 is erbB2 dependent.

Involvement of DNA-dependent protein kinase in normal cell cycle progression through mitosis.

The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) plays an important role in DNA double-strand break (DSB) repair as the underlying mechanism of the non-homologous end joining pathway. When DSBs occur, DNA-PKcs is rapidly phosphorylated at both the Thr-2609 and Ser-2056 residues, and such phosphorylations are critical for DSB repair. In this study we report that, in addition to responding to DSBs, DNA-PKcs is activated and phosphorylated in normal cell cycle progression through mitosis. Mitotic induction of DNA-PKcs phosphorylation is closely associated with the spindle apparatus at centrosomes and kinetochores. Furthermore, depletion of DNA-PKcs protein levels or inhibition of DNA-PKcs kinase activity results in the delay of mitotic transition because of chromosome misalignment. These results demonstrate for the first time that DNA-PKcs, in addition to its role in DSB repair, is a critical regulator of mitosis and could modulate microtubule dynamics in chromosome segregation.

Oral mucositis in head and neck cancer.

This module explores the risk factors, pathogenesis and development of oral mucositis. It considers the early diagnosis and accurate management of oral mucositis in head and cancer patients undergoing treatment.