bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoprotective Effect of Black Tea Extracts Against UVB‐induced Phototoxicity in Skin
Authors: Zhao Jifu , Jin Xinho , Yaping E , Zheng Zai S. , Zhang Yu J. , Athar Mohammad , DeLeo Vincent A. , Mukhtar Hasan , Bickers David R. , Wang Zhi Y. 
Published: January 2008

AbstractIn previous studies, we showed that green tea and black tea extracts and their major polyphenolic constituents protect against UVB light‐induced carcinogenesis in murine skin. All of these studies required chronic administration of tea extracts or specific constituents either topically or orally. However, it is not known whether acute or subchronic administration of black tea extracts or constituents can ameliorate UVB‐induced early effects in skin. In the present study, cultured keratinocytes and mouse and human skin were employed to assess the effect of both oral and topical administration of standardized black tea extract (SBTE) and its two major polyphenolic subtractions namely BTF1 and BTF2 against UVB‐induced photodamage. In SKH‐1 hairless mice, topical application of SBTE (0.2 mg/cm2) prior to UVB exposure (180 mJ/cm2) resulted in 40% reduced incidence and 64% reduced severity of erythema and 50% reduction in skinfold thickness by day 6 when compared to nontreated UVB‐exposed animals. The SBTE was also effective in protecting against UVB‐induced erythema in human volunteers. Administration of SBTE 5 min after UVB irradiation was similarly effective in reducing UVB‐induced inflammation in both murine and human skin. The major polyphenolic subfractions, BTF1 and BTF2, were also effective in protecting in mouse skin. The SBTE subfractions inhibited UVB‐induced tyrosine phosphorylation of epidermal growth factor receptor (EGFR). The UVB irradiation of human epidermoid carcinoma cells resulted in 3.3‐fold induction of tyrosine phosphorylation of EGFR. Pretreatment with BTF1 and BTF2 reduced tyrosine phosphorylation of EGFR by 53% and 31%, respectively. The UVB‐mediated enhanced expression of the early response genes, c‐fos and c‐jun in human epidermal keratinocytes was reduced in a dose‐dependent manner by SBTE. Topical application of SBTE was also effective in reducing accumulation of c‐fos and p53 proteins by 82% and 78%, respectively, in UVB‐exposed mouse skin. These data provide evidence that constituents of black tea can abrogate UVB‐induced erythema and associated early events in murine and human skin.
5‐Aminolevulinic Acid Photosensitization of Dysplastic Barrett's Esophagus: A Pharmacokinetic Study
Authors: Ackroyd Roger , Brown Nicola , Vernon David , Roberts David , Stephenson Timothy , Marcus Stuart , Stoddard Christopher , Reed Malcolm 
Published: January 2008

AbstractPhotodynamic therapy (PDT) using 5‐aminolevulinic acid (ALA)‐induced protoporphyrin IX (PpIX) may have a role in the treatment of dysplastic Barrett's esophagus. Before ALA‐induced PDT can be used clinically, optimum treatment parameters must be established. In this study of 35 patients, the issues of drug dosage, time interval between drug and light delivery and side effects of oral ALA administration are addressed. Spectrofluoro‐metric analysis of tissue samples demonstrates that oral ALA administration induces porphyrin accumulation in esophageal tissues, with maximum levels at 4–6 h. High‐performance liquid chromatography confirms the identity of this porphyrin as PpIX, and fluorescence microscopy analysis demonstrates that it preferentially accumulates in the esophageal mucosa, rather than in the underlying stroma. Side effects of ALA administration included malaise, headache, photosensitivity, alopecia, transient derangement of liver function, nausea and vomiting. Fewer side effects and less hepatic toxicity was seen with 30 mg/kg than 50 mg/kg ALA. In conclusion, oral ALA administration induces preferential PpIX accumulation in the esophageal mucosa, with peak PpIX fluorescence noted at 4 h and minimal systemic toxicity at a dose of 30 mg/kg.
Solvent Dependence of the Fluorescence Lifetimes of Xanthene Dyes
Authors: Magde Douglas , Rojas Gail E. , Seybold Paul G. 
Published: January 2008

AbstractFluorescence lifetimes of Ave representative xanthene dye species‐the rhodamine B zwitterion (RB=), the rhoda‐mine B cation (RB+), the rhodamine 6G cation (R6G+), the rhodamine 101 zwitterion (R101) and the fluorescein dianion (F2‐)‐were measured in H2O, D2O and in a series of alcohol solvents ranging from methanol to octanol. The lifetimes of both RB= and RB+ increased markedly as the solvent was varied from water to octanol. In contrast, the lifetimes of R6G+ and R101± decreased slightly over the alcohol series and that of F2‐ increased only slightly in the same series. For all the dyes studied the fluorescence lifetimes observed in D2O were slightly longer than those in H2O. Possible causes for the variations observed are discussed.
Pharmacokinetics, Tissue Distribution and Photodynamic Therapy Efficacy of Liposomal‐Delivered Hypocrellin A, a Potential Photosensitizer for Tumor Therapy
Authors: Wang Zhi‐Jin , He Yu‐Ying , Huang Chao‐Guo , Huang Jin‐Sheng , Huang Ying‐Cai , An Jing‐Yi , Gu Ying , Jiang Li‐Jin 
Published: January 2008

AbstractHypocrellin A, from Hypocrella bambusae, is a novel photosensitizer of high singlet oxygen quantum yield for photodynamic therapy (PDT). Tissue distributions were studied in tumor‐bearing mice as a function of time following administration. The tumor model was S‐180 sarcoma transplanted into one hind leg of male Kunming mice; hypocrellin A (HA) was delivered to the mice by intravenous injection of 5 mg/kg of body weight as a suspension either as a unilamellar liposome or in dimethyl sulfoxide (DMSO)‐solubilized saline. The HA was isolated from several tissues and organs, as well as tumors and peritumoral muscles and skin. Quantitation was performed by a high‐performance liquid chromatographic technique with detection that utilizes the native fluorescence of HA. Independent of the delivery system, the dye was retained in tumors at higher concentrations than in normal tissues, except for kidney, liver, lung and spleen. The dye retention in tumors was high and was vehicle dependent. For the liposomal system, the maximal accumulation in tumor and maximal ratios of dye in tumor versus peritumoral muscle and skin occurred 12 h post‐injection; for the DMSO saline system, the maximal ratio occurred earlier, 6 h postadministration. Liposomal delivery improved the selective accumulation of the dye in tumor with higher maximal levels in tumor and higher ratios of tumor‐to‐muscle and tumor‐to‐skin. Levels of dye were very low or not detectable in the brain. The PDT efficacy of HA in the liposome and DMSO saline systems was determined by evaluating the tumor volume regression percent. The PDT efficacy of HA in liposomes was highest when light treatment was performed at 12 h postinjection, consistent with the highest retention of HA in tumors. Similarly, the maximal PDT efficacy in DMSO saline was attained at 6 h postinjection, the highest HA retention point in tumor. Moreover, the peak PDT efficacy of HA in liposomes was much higher than that of HA in DMSO saline and even hematoporphyrin mono‐methylether.
A Critical Role for Dermal Mast Cells in Cis‐Urocanic Acid‐induced Systemic Suppression of Contact Hypersensitivity Responses in Mice
Authors: Hart Prue H. , Grimbaldeston Michele A. , Swift Georgina J. , Hosszu Emma K. , Finlay‐Jones John J. 
Published: January 2008

AbstractMany studies have implicated cu‐urocanic acid (cu‐UCA) in UVB‐induced immunomodulation. The strongest evidence came from studies in mice whereby a cis‐UCA antibody blocked UVB‐induced suppression of de‐layed‐type hypersensitivity responses. Furthermore, in several studies, the cis‐UCA antibody at least partially reversed UVB suppression of contact hypersensitivity responses. Previous reports suggested that cis‐UCA was immunomodulatory through its effects on keratinocytes, Langerhans cells, fibroblasts, T lymphocytes, natural killer cells and monocytes/macrophages. As dermal mast cells were recently demonstrated to be critical to UVB‐induced systemic suppression of certain delayed‐type and contact hypersensitivity responses, we investigated whether they were involved in the processes by which cu‐UCA was immunomodulatory. Not only was there a correlation between dermal mast cell prevalence and the degree of susceptibility of different strains of mice to the immunomodulatory effects of cis‐UCA, there was also a functional link. Mast cell‐depleted Wf/Wf mice were rendered susceptible to immunomodulation by cis‐UCA injected subcutaneously only after their dorsal skin had been reconstituted with bone marrow‐derived mast cell precursors. These studies suggest that mast cells are critical to the processes by which cis‐UCA suppresses systemic contact hypersensitivity responses to the hapten, trinitrochlorobenzene, in mice.
Bromohypericins Are Potent Photoactive Antiviral Agents
Authors: Hudson Jim B. , Delaey Els , de Witte Peter A. 
Published: January 2008

AbstractSeveral hypericin derivatives, previously shown to have interesting light‐mediated biological activities, were evaluated for antiviral activities against herpes simplex virus and influenza virus. Three brominated hypericins, the di‐bromo‐ and tetrabromo‐derivatives and the natural compound gymnochrome B were all very active against both viruses, particularly herpes simplex virus, although light was required in all cases for maximum activity. The di‐bromohypericin was the most potent, under standard assay conditions, gymnochrome B was approximately as active as hypericin itself and tetrabromohypericin significantly less so. Surprisingly, hexamethylhypericin, which is known to have potent anti‐protein kinase (PK) C activity, as well as anticell proliferation properties, showed no antiviral activity at all. The compounds were also evaluated in different serum concentrations. All the active compounds were inhibited by increasing concentrations of serum, but to different degrees, such that their relative antiviral potencies changed to some extent Thus, in summary, there was no correlation between antiviral and anti‐PK or anticellular activities, and consequently it is not possible at present to define those structural features of hypericin‐type molecules that are required for their various biological activities.
Photodynamic Effectiveness and Vasoconstriction in Hairless Mouse Skin after Topical 5‐Aminolevulinic Acid and Single‐ or Two‐fold Illumination
Authors: de Veen Nynke , Hebeda Konnie M. , de Bruijn Henriëtte S. , Star Willem M. 
Published: January 2008

AbstractSeveral options were investigated to increase the efficacy of photodynamic therapy (PDT) using protoporphyrin IX (PpIX) induced by topically applied 5‐aminolevulinic acid (ALA). Hairless mice with normal skin or UVB‐light‐induced skin changes were used as a model. In the first part of the study animals were illuminated immediately (t = 4) or 6 h (t = 10, PpIX fluorescence maximum) after the end of a 4 h ALA application. A total incident light fluence of 100 J/cm2 (514.5 nm) was delivered at a fluence rate of 100 or 50 mW/cm2. The PDT‐induced damage to normal skin was more severe after treatment at t = 10 than at t = 4. Illumination at 50 mW/ cm2 caused significantly more visible damage than the same light fluence given at 100 mW/cm2. For UVB‐illu‐minated skin, different intervals or fluence rates made no significant difference in the severity of damage, although some qualitative differences occurred. In situ fluence rate measurements during PDT indicated vasoconstriction almost immediately after the start of the illumination. A fluorescein exclusion assay after PDT demonstrated vasoconstriction that was more pronounced in UVB‐treated skin than in normal skin. The second part of the study examined the effect of two illuminations. The first illumination bleaches the PpIX fluorescence. At the start of the second illumination, new PpIX had been formed. Light of 514.5 nm was delivered at 100 mW/cm2 to a total incident light fluence of 200 J/cm2 at t = 4 (single illumination) or 100 J/cm2 at t = 4 plus 100 J/cm2 at t = 10. There was no visual difference in skin damage between 100 and 200 J/cm2 single illumination. Two‐fold illumination (100 + 100 J/cm2) caused significantly more skin damage, indicating a potentially successful option for increasing the efficacy of topical ALA‐PDT.
Phosphorylation of Sp1 in Response to DNA Damage by Ataxia Telangiectasia-Mutated Kinase
Authors: Olofsson Beatrix A. , Kelly Crystal M. , Kim Jiyoon , Hornsby Stephen M. , Azizkhan-Clifford Jane 
Published: January 2008

Abstract
Sp1, a transcription factor that regulates expression of a wide array of essential genes, contains two SQ/TQ cluster domains, which are characteristic of ATM kinase substrates. ATM substrates are transducers and effectors of the DNA damage response, which involves sensing damage, checkpoint activation, DNA repair, and/or apoptosis. A role for Sp1 in the DNA damage response is supported by our findings: Activation of ATM induces Sp1 phosphorylation with kinetics similar to H2AX; inhibition of ATM activity blocks Sp1 phosphorylation; depletion of Sp1 sensitizes cells to DNA damage and increases the frequency of double strand breaks. We have identified serine 101 as a critical site phosphorylated by ATM; Sp1 with serine 101 mutated to alanine (S101A) is not significantly phosphorylated in response to damage and cannot restore increased sensitivity to DNA damage of cells depleted of Sp1. Together, these data show that Sp1 is a novel ATM substrate that plays a role in the cellular response to DNA damage. (Mol Cancer Res 2007;5(12):1319–30)
INFANT-VENTILATOR INTERACTION CAN AFFECT CEREBRAL BLOOD FLOW IN PRETERM INFANTS: COMPARISON BETWEEN 2 MODES
Authors: El-Moneim Ehab Saoud Abd , Hans-Otto Fuerste , Markus Krueger , Elmagd Ali Abou , Brandis Matthias , Schulte-Moenting Jürgen , Hentschel Roland 
Published: January 2008

INTRODUCTION: Disturbance of cerebral blood flow (CBF) has been associated with neonatal brain injury. Because CBF is greatly influenced by mechanical ventilation, it is important to consider the effect of ventilation mode on CBF. We have shown that pressure-support ventilation combined with volume-guarantee mode (PSV-VG) would lower ventilation pressures and improve infant-ventilator synchrony when compared with synchronized intermittent mandatory ventilation (SIMV).
OBJECTIVE: Our aim was to compare the effect of PSV-VG and SIMV on CBF.
METHODS: To study an on/off effect, 33 preterm infants (mean gestational age: 26.6 ± 2.2 weeks) were switched from SIMV to PSV-VG and back again to SIMV. By using Doppler techniques, anterior cerebral artery pulsatility index (PIaca), superior vena cava flow (SVCF), and aortic minute distance (MDao) were measured in each phase. Infants were grouped according to patency of ductus arteriosus.
RESULTS: When the duct was closed, the PIaca decreased significantly (P = .002), which indicates higher CBF, SVCF increased by 20.1% ± 7.4% (P = .01), and MDao increased by 14.6% ± 4.1% (P = .007) during PSV-VG. In the group with patent ductus arteriosus, although MDao decreased by 10.5% ± 4.4% (P = .04) during PSV-VG, the PIaca and SVCF remained constant. We also observed noticeable changes in the pattern of SVCF Doppler waveform as infant-ventilator interaction changed with switching the ventilation mode. Such pattern changes are described here for the first time.
CONCLUSIONS: The interaction between the ventilation mode, the shunt across the duct, and probably CBF autoregulation determines the effect of mechanical ventilation on CBF. Studying the SVCF Doppler waveform pattern may be a useful tool for assessing ventilator-patient interaction.
AMNIOTIC FLUID TRANSFORMING GROWTH FACTOR β AND THE DEVELOPMENT OF NEONATAL CHRONIC LUNG DISEASE
Authors: Ichiba Hiroyuki , Saito Mika , Yamano Tsunekazu 
Published: January 2008

INTRODUCTION: Chorioamnionitis can initiate fetal lung injury and result in neonatal chronic lung disease (CLD). Although neonates with CLD have higher amniotic fluid concentrations of proinflammatory cytokines, overexpression of transforming growth factor β (TGF-β) also seems to be important in the pathogenesis of neonatal CLD.
OBJECTIVE: Our goal was to investigate how TGF-β is related to fetal lung injury induced by chorioamnionitis.
METHODS: Forty-four amniotic fluid samples were obtained at delivery from preterm infants (median gestational age: 28 weeks; median birth weight: 908 g). TGF-β and interleukin 6 (IL-6) concentrations in amniotic fluid were measured with enzyme-linked immunosorbent assays.
RESULTS: TGF-β concentration in amniotic fluid correlated with IL-6 concentration (P &lt; .0001). Both TGF-β and IL-6 concentrations in amniotic fluid increased with increasing histologic severity of chorioamnionitis (each P &lt; .0001). Coexisting presence of neonatal CLD and histologic chorioamnionitis was associated with significantly higher amniotic fluid TGF-β and IL-6 concentrations than presence of neonatal CLD without histologic chorioamnionitis or absence of both (mean TGF-β level: 454.3 vs 119.2 vs 151.8 pg/mL [P &lt; .0001]; mean IL-6 level: 5.14 vs 0.99 vs 1.64 ng/mL [P = .0005]). Both TGF-β and IL-6 concentrations in amniotic fluid correlated with duration of neonates' need for oxygen administration (each P &lt; .0001).
CONCLUSIONS: Amniotic fluid TGF-β may be important in chorioamnionitis-induced fetal lung injury that results in neonatal CLD.
INFANT OUTCOME AFTER ANTENATAL STEROIDS IN PRETERM PREGNANCIES WITH ABSENT UMBILICAL END-DIASTOLIC FLOW
Authors: Murila Florence , Feng Susan , Robertson Michael , Yu Victor , Wallace Euan 
Published: January 2008

INTRODUCTION: Absence of the end-diastolic flow (EDF) is associated with adverse neonatal outcome. Administration of β-methasone to women with a pregnancy complicated by absent EDF is associated with the transient return of EDF in up to 70% of cases.
OBJECTIVE: We aimed to compare the hospital outcome of preterm infants for whom the absent EDF returned after antenatal administration of β-methasone with those for whom the absent EDF did not return.
METHODS: At Monash Medical Center, 80 pregnant women with absent EDF were given 2 intramuscular 11.4-mg doses of β-methasone 24 hours apart. In the majority of pregnancies, EDF returned after β-methasone treatment. The preterm infants born to these 80 pregnant women had their hospital outcome ascertained retrospectively. Statistical analysis was performed by using the χ2 and Mann-Whitney rank-sum tests.
RESULTS: The 51 infants for whom the EDF returned were compared with the 29 for whom the EDF did not return. There were no significant differences in their gestational age, birth weight, or resuscitation and ventilation needs. The former group was less acidotic at birth (mean pH: 7.4 vs 7.3 [P &lt; .05]; and mean base excess: −3 vs −5 mmol/L [P &lt; .05]). There was no significant difference in the incidence of respiratory disease, intraventricular hemorrhage, necrotizing enterocolitis, and mortality rates.
CONCLUSIONS: Preterm infants born after return of an absent EDF after the administration of antenatal β-methasone were less acidotic at birth, but their hospital morbidity and mortality rates were not significantly improved compared with those for whom the absent EDF did not return.
PERIPHERAL BLOOD COUNT FOR DENGUE SEVERITY PREDICTION: A PROSPECTIVE STUDY IN THAI CHILDREN
Authors: Eu-Ahsunthornwattana Nanthakorn , Eu-ahsunthornwattana Jakris , Thisyakorn Usa 
Published: January 2008

INTRODUCTION: Dengue viral infection has a wide range of severity levels and requires different levels of medical attention. Early severity prediction using clinical features is difficult. Certain lymphocytic subtypes can be used to predict severity; we postulate that peripheral blood counts can also predict severity, which would be more useful in smaller rural hospitals.
OBJECTIVE: We aimed to compare the peripheral blood counts between patients with mild dengue infection and those with severe dengue infection and identify simple yet sensitive early severity predictors.
METHODS: We enrolled 91 patients with serologically confirmed dengue infection who were admitted to King Chulalongkorn Memorial Hospital. Their leukocytic counts on admission were compared. Potential predictors were identified by using receiver-operating-characteristic analysis.
RESULTS: Compared with patients with mild infection, those with severe infection (dengue hemorrhagic fever grade II or worse) had a higher leukocyte count (3580 vs 3050 cells per μL; P = .04), and fewer had leukopenia on admission (70% vs 89%; P = .03). They also had a lower percentage of “typical” lymphocytes (24% vs 40%; P = .02). Two predictors were identified; either one classified ∼19% of all admitted patients as being at low risk. Typical lymphocyte counts of &lt;40% excluded patients with mild disease with 89% sensitivity and 24% specificity (negative predictive value: 77%; positive predictive value: 45%). A combination of parameters [(white blood cells per μL) + 470 × (% typical lymphocytes) + 5 × (atypical lymphocytes per μL) ≥−14 950] improved the sensitivity and specificity to 92% and 26% (negative predictive value: 82%; positive predictive value: 46%).
CONCLUSIONS: The absence of leukopenia and a low percentage of typical lymphocytes predict severe dengue illness. Simple hematologic parameters may be used to reduce unnecessary admissions of patients with suspected dengue infection in the absence of more sophisticated predictors.
RE-TREATMENT AND RISK FACTORS OF REFRACTORY KAWASAKI DISEASE
Authors: Du Zhong-Dong , Zhao Di , Du Junbao 
Published: January 2008

OBJECTIVE: The objective of this study was to evaluate the incidence and risk factors of children with refractory Kawasaki disease (KD).
METHODS: All children with KD were analyzed in Beijing from 2000 through 2004. Risk factors were analyzed by logistic regression. Refractory KD was defined as persistent fever of ≥38.5°C 36 hours after initial intravenous immunoglobulin (IVIg) treatment.
RESULTS: A total of 1052 patients (aged 1 month to 13.8 years) with IVIg treatment were included; of them, 135 did not respond to IVIg treatment, with an incidence of 12.8%. Refractory KD occurred more frequently in children who received 1 g/kg per day IVIg for 2 days (20.9%) than in those who received a single dose of 2 g/kg (9.9%) or 400 to 600 mg/kg per day for 4 days (8.7%). Logistic regression revealed that erythrocyte sedimentation rate, alanine aminotransferase, white blood cell count, serum albumin, time from onset to IVIg treatment, and IVIg dosage were independent risk factors for refractory KD. Children with refractory KD were re-treated: 8 received 2 g/kg IVIg, with 5 (62.5%) responding; 114 received 1 g/kg IVIg, with 35 (30.7%) responding; and 11 received 400 to 600 mg/kg IVIg, with (9.1%) responding. In addition, 2 received corticosteroids, with 2 responding.
CONCLUSIONS: The incidence of refractory KD in Beijing is 12.8%. A 2-g/kg dose of IVIg is probably the best re-treatment option for refractory KD.