A novel risk factor associated with colonization by Carbapenemase-Producing Enterobacteriaceae: Use of Proton Pump Inhibitors in addition to Antimicrobial Treatment

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Clinical Characteristics and Transmission of COVID-19 in Children and Youths During 3 Waves of Outbreaks in Hong Kong

IMPORTANCE: Schools were closed intermittently across Hong Kong to control the COVID-19 outbreak, which led to significant physical and psychosocial problems among children and youths. OBJECTIVE: To compare the clinical characteristics and sources of infection among children and youths with COVID-19 during the 3 waves of outbreaks in Hong Kong in 2020. DESIGN, SETTING AND PARTICIPANTS: This cross-sectional study involved children and youths aged 18 years or younger with COVID-19 in the 3 waves of outbreaks from January 23 through December 2, 2020. Data were analyzed from December 2020 through January 2021. MAIN OUTCOMES AND MEASURES: Demographic characteristics, travel and contact histories, lengths of hospital stay, and symptoms were captured through the central electronic database. Individuals who were infected without recent international travel were defined as having domestic infections. RESULTS: Among 397 children and youths confirmed with COVID-19 infections, the mean (SD) age was 9.95 (5.34) years, 220 individuals (55.4%) were male, and 154 individuals (38.8%) were asymptomatic. There were significantly more individuals who were infected without symptoms in the second wave (59 of 118 individuals [50.0%]) and third wave (94 of 265 individuals [35.5%]) than in the first wave (1 of 14 individuals [7.1%]) (P = .001). Significantly fewer individuals who were infected in the second and third waves, compared with the first wave, had fever (first wave: 10 individuals [71.4%]; second wave: 22 individuals [18.5%]; third wave: 98 individuals [37.0%]; P < .001) or cough (first wave: 6 individuals [42.9%]; second wave: 15 individuals [12.7%]; third wave: 52 individuals [19.6%]; P = .02). Among all individuals, 394 individuals (99.2%) had mild illness. One patient developed chilblains (ie, COVID toes), 1 patient developed multisystem inflammatory syndrome in children, and 1 patient developed post–COVID-19 autoimmune hemolytic anemia. In all 3 waves, 204 patients with COVID-19 (51.4%) had domestic infections. Among these individuals, 186 (91.2%) reported having a contact history with another individual with COVID-19, of which most (183 individuals [90.0%]) were family members. In the third wave, 18 individuals with domestic infections had unknown contact histories. Three schoolmates were confirmed with COVID-19 on the same day and were reported to be close contacts. CONCLUSIONS AND RELEVANCE: his cross-sectional study found that nearly all children and youths with COVID-19 in Hong Kong had mild illness. These findings suggest that household transmission was the main source of infection for children and youths with domestic infections and that the risk of being infected at school was small

Resisting Sleep Pressure:Impact on Resting State Functional Network Connectivity

In today's 24/7 society, sleep restriction is a common phenomenon which leads to increased levels of sleep pressure in daily life. However, the magnitude and extent of impairment of brain functioning due to increased sleep pressure is still not completely understood. Resting state network (RSN) analyses have become increasingly popular because they allow us to investigate brain activity patterns in the absence of a specific task and to identify changes under different levels of vigilance (e.g. due to increased sleep pressure). RSNs are commonly derived from BOLD fMRI signals but studies progressively also employ cerebral blood flow (CBF) signals. To investigate the impact of sleep pressure on RSNs, we examined RSNs of participants under high (19 h awake) and normal (10 h awake) sleep pressure with three imaging modalities (arterial spin labeling, BOLD, pseudo BOLD) while providing confirmation of vigilance states in most conditions. We demonstrated that CBF and pseudo BOLD signals (measured with arterial spin labeling) are suited to derive independent component analysis based RSNs. The spatial map differences of these RSNs were rather small, suggesting a strong biological substrate underlying these networks. Interestingly, increased sleep pressure, namely longer time awake, specifically changed the functional network connectivity (FNC) between RSNs. In summary, all FNCs of the default mode network with any other network or component showed increasing effects as a function of increased 'time awake'. All other FNCs became more anti-correlated with increased 'time awake'. The sensorimotor networks were the only ones who showed a within network change of FNC, namely decreased connectivity as function of 'time awake'. These specific changes of FNC could reflect both compensatory mechanisms aiming to fight sleep as well as a first reduction of consciousness while becoming drowsy. We think that the specific changes observed in functional network connectivity could imply an impairment of information transfer between the affected RSNs

Effects of zinc sulphate on ethanol- and indomethacin-induced ulceration and changes in prostaglandin E2 and histamine levels in the rat gastric glandular mucosa

The effect of zinc sulphate on stomach ulceration produced by ethanol and indomethacin was examined in rats. Oral or intraperitoneal pretreatment with zinc sulphate (20 mg/kg, expressed as zinc ion) strongly prevented ethanol-, but not indomethacin-induced gastric glandular ulceration. Indomethacin given beforehand did not influence the protective action of zinc sulphate against ethanol-evoked lesions. Ethanol decreased histamine levels, whereas indomethacin reduced the prostaglandin E2 (PGE2) content in the gastric glandular mucosa. The alcohol also elevated the histamine content in gastric secretion. Zinc sulphate reversed the ethanol-induced changes in histamine levels in both mucosa and secretion, but did not modify PGE2 reduction by indomethacin. Zinc sulphate also antagonised protein leakage from the stomach following ethanol administration. It is concluded that gastric ulceration by the currently employed doses of ethanol and indomethacin is caused by different mechanisms. Zinc sulphate prevents histamine-mediated lesions produced by the alcohol, but not ulceration due to PGE2 depletion by indomethacin.link_to_subscribed_fulltex

Mucosal nitric oxide is not responsible for the hemodynamic changes induced by nicotine in rat stomachs

It has been shown that chronic nicotine treatment decreases gastric mucosal blood flow (GMBF). The mechanism for this action is still not defined. In this study, nicotine treatment (5, 25 or 50 μg/ml drinking water) for 10 days dose dependently reduced the GMBF and volume of hemoglobin but increased ethanol-induced gastric damage. These effects were potentiated by N(ω)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase inhibitor, L-arginine but not the D-analog restored the actions of L-NAME, indicating that the selective action of L-NAME. However, the potentiating actions of L-NAME were significantly attenuated in the nicotine-pretreated rats. When the basal mucosal NO synthase (both iNOS and cNOS) activity and its second messenger cyclic GMP levels were measured, no difference was found between the nicotine and the non-nicotine groups. Furthermore, high dose of L-arginine could not reverse the action of nicotine. These findings suggest that the adverse action of chronic nicotine treatment on GMBF and lesion formation is probably mediated through a NO independent mechanism.link_to_subscribed_fulltex

Pathogenesis of nicotine treatment and its withdrawal on stress-induced gastric ulceration in rats

Previous studies showed that cigarette smoking was closely associated with gastric ulceration. People usually smoke under stress conditions, and together, these could induce more gastric damage. In the present study, we aimed to study the effects of nicotine administration and its withdrawal on stress-induced gastric ulceration in rats. Male Sprague-Dawley rats were given nicotine (25 or 50 μg/ml) for 10 days and then withdrawn for 2, 4 or 6 days. They were subjected to cold-restraint stress for 2 h after nicotine treatment or after nicotine withdrawal, and then killed. The results indicated that both nicotine treatment and its withdrawal potentiated stress-induced gastric damage. The mucosal glutathione (GSH) and mucus levels were reduced by stress and decreased further by nicotine. The prostaglandin E2 concentration remained unchanged. To conclude, the adverse effect of nicotine on stress ulceration was prostaglandin E2-independent but mediated by the depression of glutathione and mucus levels in the gastric mucosa. © 2002 Elsevier Science B.V. All rights reserved.link_to_subscribed_fulltex

The study of p16 and p15 gene methylation in head and neck squamous cell carcinoma and their quantitative evaluation in plasma by real-time PCR

Epigenetic silencing of the p16 and p15 genes by promoter methylation are commonly observed in human epithelial malignancies, including head and neck squamous cell carcinomas (HNSCC). In this study, a methylation-specific polymerase chain reaction (MSP) was used to evaluate the methylation status of the p16 and p15 genes in 73 HNSCC surgical specimens. p16 and p15 gene methylation was also examined in 29 paired metastatic lymph nodes and 29 paired histologically, normal resection margin mucosae. The quantity of cell-free methylated p16 and p15 DNA in the plasma samples of 20 HNSCC patients and 24 healthy controls was also examined using a fluorescence-based real-time PCR assay. The frequencies of p16 and p15 methylation in the primary tumour were 49% and 60%, respectively. Concordant methylation of p16 and p15 in tumour samples and metastatic lymph nodes was found in 59 and 38% of cases, respectively. A significantly higher prevalence of p15 methylation was found in histologically-normal surgical margin epithelia of HNSCC patients with chronic smoking and drinking habits compared with non-smokers and non-drinkers. In addition, methylated p16 and p15 DNA levels were significantly higher in the plasma of HNSCC patients (mean 56 copies/ml plasma and 65 copies/ml plasma, respectively) compared with normal controls (mean 6 copies/ml plasma and 16 copies/ml plasma, respectively). In conclusion, promoter methylation of the p16 and p15 genes is involved in the pathogenesis of HNSCC and may be related to chronic smoking and drinking. The differential levels of methylated p16 and p15 DNA in plasma might be potential useful markers in screening high-risk populations for early HNSCC and monitoring their treatment response. © 2003 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

The study of p16 and p15 gene methylation in head and neck squamous cell carcinoma and their quantitative evaluation in plasma by real-time PCR

Epigenetic silencing of the p16 and p15 genes by promoter methylation are commonly observed in human epithelial malignancies, including head and neck squamous cell carcinomas (HNSCC). In this study, a methylation-specific polymerase chain reaction (MSP) was used to evaluate the methylation status of the p16 and p15 genes in 73 HNSCC surgical specimens. p16 and p15 gene methylation was also examined in 29 paired metastatic lymph nodes and 29 paired histologically, normal resection margin mucosae. The quantity of cell-free methylated p16 and p15 DNA in the plasma samples of 20 HNSCC patients and 24 healthy controls was also examined using a fluorescence-based real-time PCR assay. The frequencies of p16 and p15 methylation in the primary tumour were 49% and 60%, respectively. Concordant methylation of p16 and p15 in tumour samples and metastatic lymph nodes was found in 59 and 38% of cases, respectively. A significantly higher prevalence of p15 methylation was found in histologically-normal surgical margin epithelia of HNSCC patients with chronic smoking and drinking habits compared with non-smokers and non-drinkers. In addition, methylated p16 and p15 DNA levels were significantly higher in the plasma of HNSCC patients (mean 56 copies/ml plasma and 65 copies/ml plasma, respectively) compared with normal controls (mean 6 copies/ml plasma and 16 copies/ml plasma, respectively). In conclusion, promoter methylation of the p16 and p15 genes is involved in the pathogenesis of HNSCC and may be related to chronic smoking and drinking. The differential levels of methylated p16 and p15 DNA in plasma might be potential useful markers in screening high-risk populations for early HNSCC and monitoring their treatment response. © 2003 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

Comparison of the time to perceived exertion in cycling with different warm-up procedures

This study investigated the effect of active, passive, and no warm-up on the time of reaching 75% of maximu exertion in cycling ergometry testing. The study adopted a randomized repeated measures design. A total of 20 able-bodied adults (11 males, 9 females) were tested in three sessions in random order, namely active warm-up, passive warm-up, and no warm-up. Active warm-up comprised active stretching of thigh muscles, treadmill running, and cycling on an ergometer at low intensity. Passive warm-up comprised passive stretching, hot pack, and massage to both thighs. All subjects underwent cycling ergometry testing with a constant work output in each session. The main outcome measure was the time to reach a level of 15 in the rate of perceived exertion (RPE). Results showed a significant difference (p=0.04) in the exercise time before reaching RPE 15 among the three conditions. Post hoc analysis revealed that subjects had longer exercise time after passive warm-up than active warm-up and no warm-up (p=0.05 and p=0.04, respectively). This result suggests that passive warm-up prior to exercise could lengthen exercise time before subjects reach a high level of perceived exertion in cycling.Department of Rehabilitation Science