Effectiveness of ultraviolet C-light in eliminating microbial pathogens from stethoscopes used in the Neonatal Intensive Care Unit of East Avenue Medical Center

Background@#Instruments used to examine infected patients may be contaminated by disease- causing microorganisms during contact. If these instruments are not sterilized properly prior to being used on other patients, pathogen transfer may occur via this route. Stethoscopes are the most commonly used equipment by healthcare providers. Microbes and viruses may be transmitted from one patient to another and from healthcare worker to patient via stethoscope membranes.@*Objective@#To determine the effectiveness of ultraviolet c-light in eliminating microbial pathogens from stethoscopes used in the Neonatal Intensive Care Unit of East Avenue Medical Center.@*Methodology@#This is a two-arm, double blind, randomized controlled trial. The minimum sample size computed for this study was 26 stethoscopes. Thirteen (13) stethoscopes each were randomly allocated to Ultraviolet C (Group A) and standard of care (Group B) groups.@*Data Analysis@#Summary statistics were reported in tables as means, standard deviations, percentages and frequencies min-max for quantitative discrete outcome measures or percentages for qualitativemeasures.@*Results@#The predominant microbial pathogens colonized in the stethoscopes were different species of Coagulase Negative Staphylococcus (CONS) namely: Staphylococcus Heamolyticus (34.62%), Staphyloccocus Epidermidis (26.92%) and Staphylococcus Hominis (19.23%). Both UVC light and standard of care were equally effective in decreasing the CFUS on the stethoscopes. There was no significant difference in the post-test colony-forming units (CFUs) between the two groups (t = .594, p >.05).@*Conclusion@#UVC light sterilization is comparative to the standard of care in eliminating microbial pathogens. It works faster and is more reliable, durable and cost-effective. It is recommended as an alternative method for decontaminating stethoscopes used at the EAMC-NICU due to its numerous advantages.Keywords: ultraviolet c light, neonatal intensive care unit, stethoscope

Influence of maxadilan on human adipose-derived stem cells / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the effect of maxadilan, which specifically activates pituitary adenylate cycla-se-activating polypeptide type I receptor (PAC1 receptor), on the proliferation, apoptosis and differentiation potential of human adipose-derived stem cells ( ASCs) .METHODS:ASCs from human adipose tissue were isolated by enzymatic di-gestion and cultured.ASCs were confirmed by the analysis of the markers for cell phenotypes by flow cytometry ( FCM) and adipogenic/osteogenic induction.The effect of maxadilan on ASCs viability was analyzed by CCK-8 assay and FCM.ASCs were irradiated by ultraviolet C ( UVC) at 254 nm and the absorbance of apoptotic ASCs induced by various doses of UVC was measured by CCK-8 assay.ASCs were exposed to 702 J/m2 UVC for 24 h to induce apoptosis.The effect of maxadilan on ASC apoptosis was analyzed by FCM and the determination of caspase 3 and caspase 9 levels.RESULTS:Adipose-de-rived stem cells were confirmed by the detection of the positive expression of cell phenotypes including CD29, CD44, CD59 and CD105 by FCM.The data of CCK-8 assay revealed that ASCs treated with maxadilan (80 nmol/L) had the strongest ability of proliferation.The data of FCM also demonstrated that the addition of 80 nmol/L maxadilan to ASCs in experimen-tal group markedly improved the proliferation capacity of the cells compared with control group (P<0.05).The apoptosis of ASCs exposed to 702 J/m2UVC was dramatically inhibited by the treatment with maxadilan (80 nmol/L).Such process involved the caspase signaling pathway including caspase 3 and caspase 9.There was statistical significance (P<0.05) between experiment group ( ASCs irradiated by UVC and supplemented with maxadilan) and control group ( ASCs only irra-diated by UVC) .Meanwhile, adipogenic and osteogenic differentiation potentials were both positive in experiment group and control group.CONCLUSION:Maxadilan promotes proliferation and inhibits apoptosis of the ASCs.The differentia-tion potential of ASCs toward adipogenic and osteogenic lineages wouldn’ t be altered by maxadilan.Maxadilan would bene-fit to growth and expansion of ASCs in vitro.

Influence of ultraviolet C bystander effect on inflammatory response in A375 cell on subsequent exposure to ultraviolet C or hydrogen peroxide.

Ultraviolet C (UVC) irradiation (λ: 200-280 nm) causes release of several secretory cytokines responsible for inflammation. Our objective was to investigate whether inflammatory response was also induced in bystander cells. For this purpose, the conditioned medium containing the released factors from UVC irradiated A375 cells was used in this study to evaluate the expression of inflammatory markers, such as tumour necrosis factor alpha (TNFα), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) and p38 mitogen-activated protein kinase (p38 MAPK) in its bystander cells. Inflammatory responses in bystander cells subjected to further irradiation by UVC or other damaging agent like H2O2 were also examined. It was observed that TNFα, NFκB and p38 MAPK were not induced in UVC-bystander cells, but their expression was suppressed in the UVC-bystander cells treated with UVC or H2O2. This lowering in inflammatory response might be due to smaller depletion in the reduced glutathione (GSH) content present in these treated bystander cells. The study indicated that UVC-induced bystander effect was an intrinsic protective response in cells, capable of suppressing inflammation induced in cells on exposure to damaging agents.

Effect of UV-C on thylakoid arrangement, pigment content and nitrogenase activity in the cyanobacterium Microchaete sp.

The effect of UV-C radiation on thylakoid arrangement, chlorophyll-a and carotenoid content and nitrogenase activity of the cyanobacterium Microchaete sp. was studied. Chlorophyll-a and carotenoid content increased gradually up to 48 h of UV-C exposure but declined with longer exposures. Nitrogenase activity decreased moderately with 6 to 12 h exposure and decreased substantially afterwards. When cells exposed to UV-C for 12 to 24 h, grown under fluorescent light for 144 h, nitrogenase activity increased to levels greater than in the control cells. The exposure of UV-C treated cells to fluorescent light, however, did not result in recovery of pigment content. In Microchaete sp. cells treated with UV-C for 144 h, thylakoid membranes became dense, were aggregated into bundles, and were surrounded by spaces devoid of cytoplasm.

Effect of ultraviolet C irradiation on expression of basic fib roblast growth factor of wound in rats / 中华物理医学与康复杂志

Objective To investigate the influence o f ultraviolet C (UVC) irradiation of different doses on expression of basic fibrob last growth factor (bFGF) in granulation tissues of wound in rats. MethodsThirty Wistar rats were recruited and three wounds wer e made in each rat. The UVC irradiation of different doses (60mJ/cm2 and 15mJ/ cm2) were performed daily in two of the three wounds in each rat, respectively , and the UVC irradiation lasted for three days. The expression of bFGF both at the mRNA level and the protein level were observed by the methods of in situ hyb ridization and immunohistochemistry at 7 days, 14 days, 21 days after wound was made, respectively. ResultsAt the 7 days after woun d was made, the expression of bFGF in irradiation groups were higher than that i n the control group ( P

L-hydroxyproline changes in rats' skin induced by ultraviolet C irradiation / 中国康复理论与实践

@#ObjectiveTo investigate the L-hydroxyproline (L-Hyp) changes in rats' skin after exposed to different doses of ultraviolet C irradiation (UVC) and the effect of UVC radiation on collagen synthesis.MethodsAfter the animal model was set up, each male Wistar rat was made three fresh skin wounds, and three skin wounds of rats were divided into the 15 MED UVC irradiation (15mJ/cm2),60 MED UVC irradiation (60mJ/cm2) and control (without UVC irradiation). Then the chemistry method was utilized to research changes of L-Hyp contents of the granulation.ResultsFrom the 21st to the 28th day after UVC irradiation, contents of L-Hyp in the 15 MED group were higher than that in controls (P<0.05). While at the 28th day, L-Hyp level in the 60 MED group increased greatly and was higher than that in other two groups (P<0.01).ConclusionUVC irradiation increases L-Hyp level in rat's wound skin, so it accelerates the collagen synthesis and is helpful to promote wound healing, and the effect of 60 MED dose is superior to that of 15 MED.

Effect of ultraviolet C irradiation on expression of transforming growth factor β in wound / 中国康复理论与实践

@#ObjectiveTo study the effect of ultraviolet C(UVC) irradiation at different doses on expression of transforming growth factor β(TGF-β) of granulation tissues in wound. MethodsAfter dosing 15mJ/cm2 or 60mJ/cm2 UVC on wound of rats, the expression of TGF-β were observed at both the mRNA level and the protein level by the methods of in situ hybridization and immunohistochemistry respectively. Results At the 7th day after UVC irradiation, the expression of TGF-β in the 15mJ/cm2 group were higher than that in 60mJ/cm2 group and controls (P<0.05)at both the mRNA and the protein level. On the 21st day, the level of TGF-β mRNA in the 60mJ/cm2 group was higher than that in the other two groups(P<0.05).Conclusions At the early stage of wound healing,the treatment of 15mJ/cm2 UVC irradiation promots the expression of TGF-β and might be useful for accelerating wound healing. The level of TGF-β mRNA was up-regulated at the later stage at the dose of 60mJ/cm2 UVC irradiation.

Effect of ultraviolet C irradiation on the expression of basic fibroblast growth factor in gunshot wounds in limbs / 解放军医学杂志

Objective To investigate the effect of different irradiation doses of ultraviolet C ray(UVC)on the expression of basic fibroblast growth factor(bFGF)in granulation tissue of gunshot wound in rabbit limbs.Methods After giving 30mJ/cm2 or 60mJ/cm2 UVC to the gunshot wound of soft tissue of limbs,the expression of bFGF was observed both at the mRNA level and the protein level by the methods of in situ hybridization and immunohistochemistry,respectively.Results On the 7th day after UVC irradiation,the expression of bFGF in UVC-treated groups was significantly higher than that in control group(P