bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of photosynthesis in Sorghum bicolor by ultraviolet radiation
Authors: Johnson Gregory A. , Day Thomas A. 
Published: March 2003

We assessed the influence of ultraviolet radiation (UV) on net photosynthetic CO2 assimilation rate (Pn) in Sorghum bicolor, with particular attention to examining whether UV can enhance Pn via direct absorption of UV and absorption of UV‐induced blue fluorescence by photosynthetic pigments. A polychromatic UV response spectrum of leaves was constructed by measuring Pn under different UV supplements using filters that had sharp transmission cut‐offs from 280 to 382 nm, against a background of non‐saturating visible light. When the abaxial surface was irradiated, Pn averaged 4.6% higher with the UV supplement that cut‐off UV at 311 nm, compared to lower and higher UV wavelength supplements. This former supplement differed from higher wavelength supplements by primarily providing more UV between 320 and 350 nm. To assess the possibility of direct absorption of UV by photosynthetic pigments, we measured the absorbance of extracted chlorophylls. Chlorophyll a had absorbance peaks at 340 and 389 nm that were 49 and 72% of that at the sorét peak. Chlorophyll b had absorbance peaks at 315 and 346 nm that were both 35% of that at the sorét peak. Since the epidermis transmits some UV, the strong UV absorbance of chlorophyll implies a potential role for irradiance beyond the bounds of the conventionally defined photosynthetically active radiation waveband (400–700 nm). To assess the role of absorption of UV‐induced blue fluorescence, we measured the UV‐induced fluorescence excitation and emission spectra of leaves. Abaxial excitation peaked at 328 nm, while emission peaked at 446 nm. In this analysis, we used our abaxial fluorescence excitation spectrum and the UV photosynthetic inhibition spectrum of Caldwell et al. (1986) to weight the UV irradiance with each cut‐off filter, thereby estimating the potential contribution of UV‐induced blue fluorescence to photosynthesis and the inhibitory effects of UV irradiance on photosynthesis, respectively. With a non‐saturating visible background, we estimate that the absorption of UV‐induced blue fluorescence and the direct absorption of UV by photosynthetic pigments maximally enhanced photosynthesis by about 1% each with the UV supplement that cut‐off UV at 311 nm. We suggest that a portion of the incident UV on the S. bicolor leaves was used to drive photosynthesis.
Preemptive treatment approach to cytomegalovirus (CMV) infection in solid organ transplant patients: relationship between compliance with the guidelines and prevention of CMV morbidity
Authors: Künzle N. , Petignat C. , Francioli P. , Vogel G. , Seydoux C. , Corpataux J.‐M. , Sahli R. , Meylan P.R.A. 
Published: March 2003

Abstract:Cytomegalovirus (CMV) remains a major cause of morbidity in solid organ transplant patients. In order to reduce CMV morbidity, we designed a program of routine virological monitoring that included throat and urine CMV shell vial culture, along with peripheral blood leukocyte (PBL) shell vial quantitative culture for 12 weeks post‐transplantation, as well as 8 weeks after treatment for acute rejection. The program also included preemptive ganciclovir treatment for those patients with the highest risk of developing CMV disease, i.e., with either high‐level viremia (>10 infectious units [IU]/106 PBL) or low‐level viremia (<10 IU/106 PBL) and either D+/R− CMV serostatus or treatment for graft rejection.During 1995–96, 90 solid organ transplant recipients (39 kidneys, 28 livers, and 23 hearts) were followed up. A total of 60 CMV infection episodes occurred in 45 patients. Seventeen episodes were symptomatic. Of 26 episodes managed according to the program, only 4 presented with CMV disease and none died. No patient treated preemptively for asymptomatic infection developed disease. In contrast, among 21 episodes managed in non‐compliance with the program (i.e., the monitoring was not performed or preemptive treatment was not initiated despite a high risk of developing CMV disease), 12 episodes turned into symptomatic infection (P=0.0048 compared to patients treated preemptively), and 2 deaths possibly related to CMV were recorded. This difference could not be explained by an increased proportion of D+/R− patients or an increased incidence of rejection among patients with episodes treated in non‐compliance with the program. Our data identify compliance with guidelines as an important factor in effectively reducing CMV morbidity through preemptive treatment, and suggest that the complexity of the preemptive approach may represent an important obstacle to the successful prevention of CMV morbidity by this approach in the regular healthcare setting.
Fetal porcine thymus engraftment, survival and CD4 reconstitution in αGal‐KO mice is impaired in the presence of high levels of antibodies against αGal
Authors: Rodriguez‐Barbosa Jose‐Ignacio , Zhao Yong , Houser Stuart , Zhao Guiling , Sykes Megan 
Published: March 2003

Rodriguez‐Barbosa JI, Zhao Y, Houser S, Zhao G, Sykes M. Fetal porcine thymus engraftment, survival and CD4 reconstitution in αGal‐KO mice is impaired in the presence of high levels of antibodies against αGal. Xenotransplantation 2003; 10: 24–40. © Blackwell Munksgaard, 2003Xenospecific T‐cell tolerance can be induced among murine and human T‐cells by porcine thymic grafting. However, anti‐α 1,3‐galactosyltranserase (αGal) (Galα1–3Galβ1–4GlcNAc‐R) natural antibodies (NAbs) pose a major barrier to porcine xenografts in humans. We used αGal knockout (KO) and μ chain KO mice to explore the effect of natural anti‐αGal and other xenoantibodies on porcine thymic engraftment and to examine the potential of thymic tissue to tolerize anti‐αGal antibody‐producing cells.Thymectomized [adult thymectomy (ATX)] non‐immunized and rabbit red blood cell (RRBC) pre‐transplant immunized αGal‐KO (knockout), wild‐type (WT) and μ chain KO B6 mice were treated with 3Gy total body irradiation (TBI), and T and natural killer (NK) cell depleting monoclonal antibodies (mAbs). These conditioned mice were grafted with fetal porcine thymus and liver (FP THY/LIV) tissue under the kidney capsule. Flow cytometric analysis was performed to follow CD4 reconstitution as a measure of FP THY engraftment and function. Only mice with >10% CD4+ peripheral blood lymphocytes (PBL) were considered successfully engrafted. Enzyme‐linked immunosorbent assay (ELISA) was used to assess the kinetics of immunoglobulin M (IgM) and IgG anti‐αGal antibodies. Anti‐pig antibodies were monitored by flow cytometry (FCM).FP THY engrafted successfully in most of the immunoglobulin deficient mice (11 out of 12, 92%) and the outcome was similar in WT B6 controls (8 out of 12, 67%). Non‐immunized αGal‐KO mice grafted with FP THY had a similar success rate (7 out of 11) to that observed in non‐immunized αGal‐WT controls (2 out of 4). In contrast, αGal‐KO mice immunized pre‐transplant with RRBC, then grafted with FP THY/LIV, showed a significant reduction in the success of thymic grafting (2 out of 9, 22%) compared with pre‐transplant immunized WT controls (4 out of 7; 57%) and non‐immunized αGal‐KO mice (7 out of 11, 64%). Anti‐Gal and anti‐pig antibody levels were not markedly augmented by porcine thymus grafts in mice with successful thymus grafts.FP THY engraftment is impaired in the presence of high levels of anti‐αGal xenoantibodies. However, low levels of anti‐αGal antibodies and other mouse anti‐pig NAbs appear not to play a major role in the rejection of FP THY. Although grafting FP THY expressing the αGal epitope did not tolerize B cells producing anti‐αGal antibodies in a T‐cell independent manner, it prevented T‐cell dependent sensitization by inducing T‐cell tolerance to porcine antigens.
Thymic selection revisited: how essential is it?
Authors: Von Boehmer Harald , Aifantis Iannis , Gounari Fotini , Azogui Orly , Haughn Loralee , Apostolou Irina , Jaeckel Elmar , Grassi Fabio , Klein Ludger 
Published: March 2003

Summary:Intrathymic T cell development represents one of the best studied paradigms of mammalian development. Lymphoid committed precursors enter the thymus and the Notch1 receptor plays an essential role in committing them to the T cell lineages. The pre‐T cell receptor (TCR), as an autonomous cell signaling receptor, commits cells to the αβ lineage while its rival, the γδTCR, is involved in generating the γδ lineage of T cells. Positive and negative selection of immature αβTCR‐expressing cells are essential mechanisms for generating mature T cells, committing them to the CD4 and CD8 lineages and avoiding autoimmunity. Additional lineages of αβT cells, such as the natural killer T cell lineage and the CD25+ regulatory T cell lineage, are formed when the αβTCR encounters specific ligands in suitable microenvironments. Thus, positive selection and receptor‐instructed lineage commitment represent a hallmark of the thymus. Ectopically expressed organ‐specific antigens contribute to thymic self–nonself discrimination, which represents an essential feature for the evolutionary fitness of mammalian species.
Oral administration of milk from cows immunized with human intestinal bacteria leads to significant improvements of symptoms and signs in patients with oral submucous fibrosis
Authors: Tai Y. S. , Liu B. Y. , Wang J. T. , Sun A. , Kwan H. W. , Chiang C. P. 
Published: March 2003

Abstract:Background: Previous studies have shown that the local and systemic upregulation of fibrogenic cytokines and downregulation of antifibrotic cytokine are central to the pathogenesis of oral submucous fibrosis (OSF). The milk from cows immunized with human intestinal bacteria (immune milk) contains an anti‐inflammatory component that may suppress the inflammatory reaction and modulate cytokine production. Therefore, it was decided to test whether immune milk may have some beneficial effects on controlling the symptoms and signs in OSF patients.Methods: In this preliminary study, 26 OSF patients who received immune milk treatment (45 g of immune milk powder twice a day) for 3 months and oral habit intervention were included in the experimental group. Another 20 OSF patients who received only oral habit intervention served as the control group.Results: We found that the interincisor distance was significantly improved (≧3 mm of the baseline measurement) in 18 of the 26 (69.2%) OSF patients in the experimental group at exit. However, in the control group none of the OSF patients had an increase in interincisor distance greater than 2 mm. In addition, disappearance or significant improvement of symptoms at exit was observed in 80% (16/20) of the patients with intolerance to spicy foods (P<0.001) and 72.2% (13/18) of the patients with xerostomia (P<0.005) in the experimental group, compared with 17.6% (3/17) of the patients with improvement of intolerance to spicy foods and 15.4% (2/13) of the patients with improvement of xerostomia in the control group. Partial regression of concomitant oral leukoplakia or erythroplakia (judged from the size reduction of the lesions) at exit was noted in 71.4% (5/7) of the patients in the experimental group (P<0.05), compared with none (0/5) of the patients with improvement in the control group.Conclusion: We conclude that oral administration of immune milk leads to significant improvements of symptoms and signs in OSF patients.
Detection of TP53 mutation in ameloblastoma by the use of a yeast functional assay
Authors: Shibata Toshiyuki , Nakata Daichi , Chiba Itsuo , Yamashita Tetsuro , Abiko Yoshihiro , Tada Mitsuhiro , Moriuchi Tetsuya 
Published: March 2003

AbstractBackground:   Mutations in TP53 have been observed in a variety of tumors including oral lesions, though there are no reports in ameloblastomas. The purpose of the study was to examine the TP53 status of ameloblastomas using newly developed yeast functional assay whose accuracy and sensitivity has been proven to be higher than those of the previous DNA structure‐based methods such as single strand conformation polymorphism (SSCP) analysis.Methods:   TP53 status was analyzed by yeast functional assay and DNA sequencing in 12 cases of ameloblastoma which were diagnosed histologically and represented the clinical features of a benign tumor. After the extraction of RNA from the frozen tissue samples without microdissection, reverse transcription (RT)–PCR was carried out and these samples were used. The assay can detect mutations of p53 mRNA between codons 67 and 347 by the DNA‐binding activity of the protein and reveal them as red colonies.Results:   One case of 47‐year‐old male gave 17% red colonies of yeast and the other 11 cases gave 5.4% (mean; range, 3–8%). To confirm this result, we obtained other nine samples from the case of 17% red colonies, which contained or did not contain tumor tissues, and analyzed them by the assay. Seven samples that were histologically negative for tumor cells gave 4.7% red colonies (mean; range, 1–7%). Two samples that were histologically positive for tumor cells gave 20 or 46% of red colonies. The p53 plasmids were recovered from the red colonies of these three samples showing high red colony ratios and were subjected to sequencing analysis after purification. In all these samples, the same clonal mutation of TGT (Cys) 238 TAT (Tyr) was demonstrated.Conclusions:  These results suggest that TP53 mutation may be involved in molecular pathogenesis in a subset of ameloblastomas, though it is infrequent.
Oral manifestations of an HIV positive cohort in the era of highly active anti‐retroviral therapy (HAART) in South London
Authors: Eyeson J. D. , Tenant‐Flowers M. , Cooper D. J. , Johnson N. W. , Warnakulasuriya K. A. A. S. 
Published: March 2003

AbstractBackground: Human Immunodeficiency Virus (HIV) infection is associated with oral manifestations of diagnostic and prognostic importance. With the advent of Highly Active Anti‐retroviral Therapy (HAART) there is anecdotal evidence to suggest that the prevalence of oral lesions has declined. The number of prevalence studies, carried out in the era of HAART is, however, meagre. Our aim was to study the prevalence of the oral manifestations of HIV in a population, predominantly on HAART, attending a Genito‐Urinary Medicine Centre in South London.Methods: This cross sectional study included 203 adult volunteers, comprising 76% males and 24% females. One third of the subjects were from the predominantly African or Afro‐ Caribbean ethnic minority groups resident in London. The relationship between the prevalence of oral lesions and demographic variables, therapeutic regimes, viral load and CD4 counts were evaluated.Results: One hundred (49%) of the patients had no detectable oral lesions. Oral lesions detected most frequently included oral hairy leukoplakia (9.9%), HIV associated periodontal diseases (9.9%) and oral candidiasis (4.9%). Three subjects had multiple papillomatous growths. Most cases (n = 17/20) of oral hairy leukoplakia were in individuals with a detectable (> 400 copies/ml) plasma RNA viral load. The majority (n = 8/10) of our patients with oral candidiasis had a plasma RNA viral load > 10,000 copies/ml and half (n = 5/10) had a CD4 count < 200 cells/mm3. Logistic regression analysis suggested that the presence of an oral lesion was not associated with any demographic features except for periodontal diseases which were associated with tobacco smoking (P = 0.023).Conclusions: The prevalence of so called ‘strongly associated’ oral lesions of HIV is low in this South London HIV‐infected population on HAART, and the relative frequency is different from that cited in the literature from the pre‐HAART era. The oral lesions detected were found mostly in people with low CD4 counts and high HIV‐1 RNA viral loads, suggesting they were very immunocompromised, not on, or declining therapy, or that their therapy was failing.
Invasive front grading: reliability and usefulness in the management of oral squamous cell carcinoma
Authors: Sawair Faleh A. , Irwin Christopher R. , Gordon Derek J. , Leonard Alan G. , Stephenson Mike , Napier Séamus S. 
Published: March 2003

AbstractBackground:  The value of histological grading was examined with emphasis on reliability of assessment in 102 cases of intraoral squamous cell carcinoma from Northern Ireland with known outcome.Methods:  Two pathologists independently graded the invasive tumour front blinded to the stage and outcome.Results:  Intraobserver agreement was acceptable but interobserver agreement was not satisfactory. The degree of keratinisation was assessed most consistently while nuclear polymorphism was the least reliable feature. Multivariate survival analysis showed that the total grading score was associated with overall survival while the pattern of tumour invasion was the most valuable feature in estimating regional lymph node involvement. The number of positive lymph nodes was strongly associated with regional relapse, while the treatment modality and status of the surgical margins correlated with local relapse.Conclusions:  Grading of selected features in OSCC is reliable and can facilitate treatment planning.
Eumelanin is a Major Determinant for2‐Amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) Incorporation into Hair of Mice
Authors: Hegstad Solfrid , Reistad Ragnhild , Haug Line S. , Alexander Jan 
Published: March 2003

Abstract:Mice with different hair pigmentation were studied to evaluate the role of melanin in the incorporation of 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) into hair. Mice C57BL/6J‐c2j/+ (white), C57BL/6J‐Ay (yellow), C57L/J (grey), C57BR/cdJ (brown) and C57BL/6J (black) were dosed with PhIP: 7–9 days old (total amount: 0.006 or 0.58 mg/kg b.wt., for 4 days) and adults (total amount 50 mg/kg b.wt. during 8 weeks). Hair was collected either 30 days after the last PhIP administration (new‐born mice) or 8 weeks after the first administration (adult mice). PhIP was incorporated into black hair to a greater extent than into brown, grey, yellow and non‐pigmented hair. The concentration of PhIP in the hair of new‐born mice exposed to 0.58 mg PhIP/kg b.wt. were (mean±S.D.): 328±135 (black), 134±41 (brown), 9.1±1.2 (yellow) and 5.2±1.4 (white) ng/g hair. The PhIP concentrations in the hair of adult mice exposed to 50 mg/kg b.wt. were: 4750±1449 (black), 810±235 (brown), 541±119 (grey), 35.5±4.6 (yellow) and 21.6±8.8 (white) ng/g, and the eumelanin hair concentration in the same animals decreased in a similar pattern. A linear relationship (r2=1.00, P<0.0001) between the relative PhIP incorporation and the eumelanin concentration in hair was found.
Polychromatic phototest as a prognostic tool for polymorphic light eruption
Authors: Leroy D. , Dompmartin A. , Faguer K. , Michel M. , Verneuil L. 
Published: March 2003

Background: Diagnosis of polymorphic light eruption (PLE) is based on the patient’s history, the morphology of the lesions and the results of phototesting. Skin lesions of PLE can be provoked by repetitive UVB or UVA irradiation. However, about 20% of the patients with PLE have negative phototests. As 24% of the patients with PLE go into remission, it was of interest to search for a link between the results of the phototests and the evolution of the photodermatosis.Methods: Forty patients with PLE were recruited and repetitive phototests were performed. To ensure a good reproducibility of the phototests, one to three phototests were performed on each patient at different stages of the disease including the period when the PLE had gone into remission.Results: Except for one patient, there was a good reproducibility of the repetitive polychromatic phototests: in each patient, the tests remained positive or negative throughout the disease. After long‐term follow‐up, two different subgroups were identified: 30 patients with active PLE and 10 patients in remission. There were no clinical differences between these two groups apart from the age of onset and the clinical lesions of the PLE. PLE began at an earlier age in the patients in remission and presented mainly with a plaque‐type eruption. In total, 52.5% of the patients had at least one positive polychromatic phototest. Phototests were positive only in patients with active disease. All the patients in remission had negative phototests.Conclusions: Repetitive phototests could be a prognostic marker for PLE. Two subtypes of PLE were identified on the basis of phototest results: the benign form of PLE with negative phototests, which tends to go into remission, and the more severe and more chronic PLE, with positive phototests.
Ultraviolet‐filtering properties of commonly used tissue cell culture plasticware
Authors: Brown Douglas B. , Peritz Adam E. , Uitto Jouni , Gasparro Francis P. 
Published: March 2003

Background: Fluorescent sunlamps are a common source of ultraviolet radiation (UVR) for photobiology research. However, these lamps emit a significant amount of biologically “irrelevant” wavelengths that, if not removed, can drastically skew results and perhaps lead to mistaken conclusions regarding human photobiology. The use of a cellulose triacetate sheet (Kodacel) to filter the shorter ultraviolet wavelengths has become the accepted standard in photobiology. Over time, the transmission characteristics of this sheet may be altered due to photochemical changes. In addition, in vitro experiments utilizing filtered fluorescent sunlamps require the removal of plastic tissue cell culture lids, increasing the possibility of contamination.Methods: We evaluated the transmission characteristics of various commercially available plastic lids used in tissue cell cultures. In addition, we used a biological system containing the human elastin promoter/chloramphenicol acetyltransferase reporter gene construct to compare the effects of filtering from these plastic lids.Results: Here, we demonstrate that the transmission of UVR and the biological response through plastic culture dish lids is similar to that of Kodacel.Conclusion: Although this is an improvement for in vitro experiments, further improvements can be made using more realistic UVR sources, e.g. UVA‐340 lamps, which mimic the short wavelengths of sunlight.