bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of locally injected interferon‐β on palatal mucoperiosteal wound healing
Authors: Cornelissen A. M. H. , Von den Hoff J. W. , Maltha J. C. , Kuijpers‐Jagtman A. M. 
Published: March 2003

AbstractBackground:   Wound contraction and scar formation in the palatal mucoperiosteum after cleft palate surgery impair maxillary growth. The aim of this study was to determine the effects of IFN‐β on palatal mucoperiosteal wound healing in growing rats.Methods:   Standardized wounds were made in the palatal mucoperiosteum of young rats. Either IFN‐β or vehicle were injected at the wound site between 4 and 29 days after wounding. The results were compared with control wounds. Tissue samples were collected at 8, 15, 30, and 60 days PW for biochemical and microscopic analysis.Results:   IFN‐β stimulated re‐epithelialization but did not reduce the number of myofibroblasts or scar tissue formation. Surprisingly, the injection of vehicle alone delayed the healing process.Conclusion:   IFN‐β might be suitable to stimulate re‐epithelialization but it does not reduce scar tissue formation in rat palatal wound healing. The injection of agents into palatal wounds might severely impair the healing process.
AgNOR count as objective marker for dysplastic features in oral leukoplakia
Authors: Chattopadhyay Amit , Ray Jay G. , Caplan Daniel J. 
Published: March 2003

AbstractBackground:   Dysplasia is an important feature of leukoplakia. Because agreement among oral pathologists is poor regarding lesional diagnosis, silver stainable nucleolar organizer regions (AgNORs) as replicatory markers may have a place in objectively characterizing dysplasia in tissue specimens.Methods:   We studied 41 normal oral epithelia, 51 oral leukoplakia (26 dysplastic, 25 non‐dysplastic), and 51 cases of squamous cell carcinoma specimens for their mean AgNOR counts.Results:   Mean AgNOR counts increased gradually from normal epithelium to non‐dysplastic to dysplastic leukoplakia to squamous cell carcinoma. Using ROC analysis, we determined a mean AgNOR count cut‐point (2.37) that can be used to distinguish between dysplastic and non‐dysplastic leukoplakia. The test had a sensitivity of 75% and specificity of 83% with area under the curve being 88%.Conclusions:  Mean AgNOR count could be a valuable criterion for defining objective parameters for diagnosis/determination of dysplasia distinguishing between dysplastic and non‐dysplastic leukoplakia.
Immunohistochemical detection of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in ameloblastomas
Authors: Kumamoto Hiroyuki , Yamauchi Kensuke , Yoshida Mitsuhide , Ooya Kiyoshi 
Published: March 2003

AbstractBackground:  To evaluate the roles of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in tumor progression, expression of MMP‐1, ‐2 and ‐9 and TIMP‐1 and ‐2 was analyzed in ameloblastomas as well as tooth germs.Methods:  Frozen tissue sections of seven tooth germs and 22 ameloblastomas were immunohistochemically examined using anti‐MMP‐1, ‐2 and ‐9 and anti‐TIMP‐1 and ‐2 antibodies.Results:  MMP‐1, ‐2 and ‐9 and TIMP‐1 and ‐2 were expressed strongly in mesenchymal components of tooth germs, and stromal cells of ameloblastomas. Immunoreactivity for MMP‐9 in stromal cells of ameloblastomas was significantly stronger than in mesenchymal cells of dental follicles and dental papillae. Dental laminae showed weak MMP‐2 expression in six tooth germs, MMP‐9 expression in two tooth germs and TIMP‐1 expression in six tooth germs. Some tumor cells showed weak MMP‐2 expression in 19 ameloblastomas, MMP‐9 expression in four ameloblastomas and TIMP‐1 expression in all cases. TIMP‐2 reactivity was prominently found in basement membrane zones of dental laminae in tooth germs, and tumor cell islands or nests in ameloblastomas.Conclusion:  Expression of MMPs and TIMPs was considered to be associated with interactions between epithelial cells and mesenchymal components in normal and neoplastic odontogenic tissues; these molecules might play a role in regulation of tumor progression in ameloblastomas as well as regulation of developmental processes in tooth germs.
Melanosome Capping of Keratinocytes in Pigmented Reconstructed Epidermis – Effect of Ultraviolet Radiation and 3‐Isobutyl‐1‐Methyl‐Xanthine on Melanogenesis
Authors: GIBBS SUSAN , MURLI SEEMA , DE BOER GERRIT , MULDER AAT , MOMMAAS A. MIEKE , PONEC MARIA 
Published: March 2003

Reconstructed pigmented epidermis was established by co‐seeding autologous melanocytes and keratinocytes onto a dermal substrate and culturing for up to 6 weeks at the air–liquid interface. Inspection of the tissue architecture revealed that melanocytes are regularly interspersed only in the basal layer and transfer melanosomes to the keratinocytes. We report for the first time, the in vitro formation of supranuclear melanin caps above the keratinocyte nuclei. The formation and abundance of these melanin caps could be enhanced by pigment modifiers such as ultraviolet light and 3‐isobutyl‐1‐methyl‐xanthine (IBMX). In untreated cultures, the capping was observed in the spinous layers after 6 weeks of culture, whereas after irradiation or supplementation of the culture medium with IBMX, the capping occurred already in the basal layer 2 weeks after initiation of the stimulus.In this study, we show that IBMX and ultraviolet irradiation stimulate pigmentation via different mechanisms. After supplementation of the culture medium with IBMX the increase in pigmentation was entirely due to the increase in melanocyte activity as observed by increased dendrite formation, melanin production and transport to the keratinocytes and was not due to an increase in melanocyte proliferation. In contrast, after UV irradiation, the increase in pigmentation was also accompanied with an increase in melanocyte proliferation as well as an increase in melanocyte activity.In conclusion, we describe the establishment of pigmented reconstructed epidermis with autologous keratinocytes and melanocytes that can be kept in culture for a period of at least 6 weeks. The complete program of melanogenesis occurs: melanosome synthesis, melanosome transport to keratinocytes, supranuclear capping of keratinocyte nuclei and tanning of the epidermis. This enables sustained application of pigment stimulators over a prolonged period of time and also repeated application of pigment stimulators to be studied.
Subjective intensity of pain during the treatment of periodontal lesions with the Vector™‐system
Authors: Braun Andreas , Krause Felix , Nolden Rolf , Frentzen Matthias 
Published: March 2003

The aim of this study was to measure subjective intensities of pain during the treatment of periodontal lesions with the Vector™‐system when compared to pain occurring during the treatment with conventional methods.Twenty patients, each of whom had three teeth with comparable periodontal pocket depths, were treated using three different methods: (i) scaling and root planing with hand instruments, (ii) cleaning with a conventional ultrasonic instrument (Siroson™S) and (iii) cleaning with the Vector™‐system. The subjective intensities of pain during the treatment were measured with an intermodal intensity comparison. A visual analog scale was used for the evaluation after the treatment.The results of the intermodal intensity comparison during treatment showed that the use of the Vector™‐system caused less pain than the cleaning with hand instruments or the conventional ultrasonic system (P < 0.05). The intermodal intensity comparisons of cleaning with hand instruments and cleaning with the conventional ultrasonic system were not significantly different (P > 0.05). These results could be confirmed by the visual analog scale.Using the Vector™‐system for cleaning periodontal lesions it is possible to reduce pain sensations compared to conventional methods. Using cleaning methods that cause less discomfort and pain, it might be possible to increase the patient's compliance during non‐surgical periodontal therapy and recall.
Effect of ultraviolet A on ornithine decarboxylase and metallothionein gene expression in mouse skin
Authors: Oguro Takiko , Yoshida Takemi 
Published: March 2003

Background: Ultraviolet A (UVA) is known to induce the expression of many stress responsive genes due to the generation of reactive oxygen species (ROS). However, UVA's role in inducing metallothionein (MT) gene expression has not been studied. Furthermore, our group demonstrated that UVA enhanced 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐mediated induction of ornithine decarboxylase (ODC) activity in mouse skin (1).Methods: We examined the interaction of UVA, TPA and antioxidants on the induction of MT and ODC mRNA in mouse skin. Female CD‐1 mice were exposed to UVA (19 J/cm2) and total RNA was isolated from the skin. Northern blot analysis for MT and ODC mRNAs was performed. ODC activity in mouse epidermis was also determined in some experiments.Results: UVA induced MT mRNA in mouse skin; however, it did not increase ODC mRNA. 1,4‐Diazabicyclo‐[2,2,2]‐octane (DABCO), a singlet oxygen scavenger, reduced UVA‐mediated induction of MT mRNA by 40%. The data suggest that ROS produced by UVA exposure may contribute to its ability to induce MT mRNA. UVA slightly enhanced TPA‐mediated ODC mRNA induction, while it enhanced ODC enzyme activity 70%. UVA additively intensified TPA‐mediated MT mRNA induction. α‐Tocopherol pretreatment inhibited the induction of ODC enzyme activity by TPA treatment combined with UVA exposure (TPA+UVA); however, α‐tocopherol had less of an inhibitory effect on ODC mRNA induction by TPA+UVA. Curcumin, a plant pigment, dramatically inhibited both TPA‐ and TPA+UVA‐induced expression of ODC and MT genes.Conclusions: These results demonstrate that UVA can induce MT gene expression and enhance TPA‐induced ODC and MT gene expression. The data further suggest that these effects are partially mediated by ROS.
Repair of cyclobutyl pyrimidine dimers in human skin: variability among normal humans in nucleotide excision and in photorepair
Authors: Sutherland Betsy M. , Hacham Haim , Bennett Paula , Sutherland John C. , Moran Michael , Gange R. W. 
Published: March 2003

Background/Aims: Photoreactivation (PR) of cyclobutyl pyrimidine dimers (CPD) in human skin remains controversial. Recently Whitmore et al. (1) reported negative results of experiments using two photorepair light (PRL) sources on UV‐irradiated skin of volunteers. However, their PRL sources induced substantial levels of dimers in skin, suggesting that the additional dimers formed could have obscured PR. We met a similar problem of dimer induction by a PRL source. We designed and validated a PRL source of sufficient intensity to catalyse PR, but that did not induce CPD, and used it to measure photorepair in human skin.Methods and Results: Using a solar simulator filtered with three types of UV‐filters, we found significant dimer formation in skin, quantified by number average length analysis using electrophoretic gels of isolated skin DNA. To prevent scattered UV from reaching the skin, we interposed shields between the filters and skin, and showed that the UV‐filtered/shielded solar simulator system did not induce damage in isolated DNA or in human skin. We exposed skin of seven healthy human volunteers to 302 nm radiation, then to the improved PRL source (control skin areas were kept in the dark for measurement of excision repair).Conclusions: Using a high intensity PRL source that did not induce dimers in skin, we found that three of seven subjects carried out rapid photorepair of dimers; two carried out moderate or slow dimer photorepair, and three did not show detectable photorepair. Excision repair was similarly variable in these volunteers. Subjects with slower excision repair showed rapid photorepair, whereas those with rapid excision generally showed little or no photoreactivation.
Acute effects of UVB radiation on the proliferation and differentiation of keratinocytes
Authors: Lee J. H. , An H. T. , Chung J. H. , Kim K. H. , Eun H. C. , Cho K. H. 
Published: March 2003

Purpose: The effects of UVB radiation on the proliferation and differentiation of epidermal keratinocytes were investigated with respect to timing, dosage, and repeated exposures.Methods: Nine healthy volunteers were placed into three subgroups and exposed to UVB radiation on buttock skin using a Waldmann UV 800 unit fitted with Philips TL‐20W/12 fluorescent lamps. Three volunteers were given 2 MED of UVB and biopsied at: pre‐exposure, 24, 48 and 72 h after UVB exposure. For three volunteers, 1 MED, 2 MED, 3 MED of UVB were applied. After 48 h, biopsies were taken from non‐irradiated and irradiated sites. Finally, three volunteers received 1 MED of UVB daily for 5 days, and the non‐irradiated and irradiated sites were biopsied 48 h after the final exposure. The expression of proliferation and differentiation markers by keratinocytes were detected by immunohistochemical staining, and the results were analysed quantitatively by image analysis.Results: The expression of proliferation and differentiation markers was observed prominently 48 h after irradiation. Higher doses of UVB caused an increase in proliferation and differentiation marker expression. Repeated exposures potentiated the effect of UVB radiation.Conclusion: UVB irradiation concomitantly promotes epidermal proliferation and differentiation. Responses were maximal 48 h after irradiation. This effect of UVB increases linearly according to dose and repetition.
Visual discrimination testing of ultraviolet transmitting and ultraviolet blocking acrylic thermoplastics
Authors: Kucenic Michael J. , Patel Manisha , Feldman Steven R. , Liguori Anthony , Fleischer Alan B. 
Published: March 2003

Background: Visual perception has hindered the development of blinded, placebo‐controlled ultraviolet light exposure conditions in humans. New acrylic thermoplastics that block or transmit ultraviolet light have visual properties that may provide a solution.Methods: In a series of triangle taste tests, 60 subjects were tested for the ability to visually perceive ultraviolet light transmission by two of four types of acrylic thermoplastics.Results: Forty‐six of sixty (67%) subjects were unable to visually detect ultraviolet light transmitting acrylics among ultraviolet blocking acrylics in both an ambient light background condition and an ambient light background condition with ultraviolet A light supplementation.Conclusion: Acrylic thermoplastics allow for the production of blinded, placebo‐controlled ultraviolet light exposure conditions by eliminating visual discrimination differences between active and control groups.
Photopheresis affects the course of experimental allergic encephalomyelitis in Lewis rat
Authors: Chabannes D. , Besnier D. P. , Esnault V. L. M. 
Published: March 2003

Background/Purpose: The mechanism responsible for the beneficial effects of extracorporeal photochemotherapy (ECP) remains unknown. In the rat model of experimental allergic encephalomyelitis (EAE), the transfer of encephalitogenic cells (EAE cells) induces transient passive EAE, followed by resistance to subsequent disease induction through immunization with central nervous system antigens (active EAE).Methods: We tested whether ECP exerts its therapeutic effect by inducing an immune response targeted on circulating pathogenic T‐lymphocytes, which results from their increased immunogenicity. We compared the potential of untreated versus ECP‐treated encephalitogenic cells to transfer passive EAE and protect against active induction of the disease. The UVA irradiation conditions were derived from intensive ECP protocols used in human clinical studies.Results: Animals receiving untreated cells showed clinical symptoms following cell transfer but not after subsequent immunisation, whereas those receiving ECP‐treated cells remained healthy following cell transfer but experienced clinical symptoms after subsequent immunisation. However, these symptoms were less marked than in control naive rats.Conclusion: Under these ECP protocol conditions, ECP‐treated cells have no greater active stimulatory potential for the recipient immune system than untreated cells, since they are less effective at triggering the response that causes the resistant state to active EAE. We suggest that intensive ECP protocol may have deleterious effects with a risk of relapses after treatment discontinuation. The search for the irradiation threshold that would inhibit the T‐cell pathogenic properties, but retain their ability to educate the immune system, remains a major research challenge.
Phototoxicity to diuretics and antidiabetics in the cultured keratinocyte cell line HaCaT: evaluation by clonogenic assay and single cell gel electrophoresis Comet assay)
Authors: Selvaag Edgar , Petersen Anita B. , Gniadecki Robert , Thorn Tine , Wulf Hans Christian 
Published: March 2003

Background: Potential phototoxicity has been described for a number of drugs and chemical substances. Psoralens, chlorpromazines and fluoroquinolones have been described as inducing photomutagenicity and photocarcinogenicity in vitro and in vivo. We wanted to investigate oral antidiabetics and diuretics for potential phototoxicity and possible DNA damage in the HaCaT cell line.Methods: The oral antidiabetics tolbutamide, glibenclamide and glipizide, and the diuretics bendroflumethiazide, butizide, furosemide, hydrochlorothiazide and trichlormethiazide were dissolved in DMSO to final concentrations of 1 mM, 0.1 mM, and 0.01 mM, incubated together with the cells, and exposed to UVA1 (23 or 48 J/cm2). Cell survival was evaluated in a clonogenic assay and phototoxic DNA damage was investigated by single cell gel electrophoresis (comet assay). To investigate possible inhibiting effects of antioxidants, L‐ascorbic acid and α‐tocopherol were added at a final concentration of 1 mM 24 h before treatment with the drugs.Results: Bendroflumethiazide, furosemide, hydrochlorothiazide, trichlormethiazide and tolbutamide induced dose‐dependent phototoxicity in the clonogenic assay. Cells incubated with bendroflumethiazide, tolbutamide and glibenclamide and irradiated with UVA1 demonstrated increased oxidative DNA damage, revealed as alkali‐labile sites in the comet assay. Pretreatment with L‐ascorbic acid or α‐tocopherol suppressed the UVA‐induced DNA damage in cells incubated with 1 mM bendroflumethiazide, furosemide, glibenclamide, glipizide, tolbutamide or trichloromethiazide.Conclusion:  Several oral antidiabetics and diuretics show phototoxic effects in the HaCaT cell line. Inhibiting effects of antioxidants point towards involvement of reactive oxygen species in phototoxic DNA damage, suggesting a link between the phototoxic and photocancerogenic potential of the sulfonamide‐derived oral antidiabetic and diuretic drugs. Excessive exposure to UV light may be deleterious for patients treated with oral antidiabetic and diuretic drugs.
Positive effect of using calcipotriol ointment with narrow‐band ultraviolet B phototherapy in psoriatic patients
Authors: Rim Jong‐Hyun , Choe Yong‐Beom , Youn Jai‐Il 
Published: March 2003

Background/purpose: The successful use of narrow‐band ultraviolet B (UVB) phototherapy for the management of psoriasis has prompted the examination of various combination treatments with narrow‐band UVB. However, there have been contradictory reports on the effect of the calcipotriol–narrow‐band UVB combination. This study was performed to compare the clinical efficacy of the calcipotriol–narrow‐band UVB combination with narrow‐band UVB alone.Methods: Of the 28 psoriasis patients, 10 were treated with the calcipotriol–narrow‐band UVB and 18 with narrow‐band UVB alone. Phototherapy was done once daily three times a week and the dose was gradually increased in a stepwise fashion by 0.05 J/cm2. At the end of therapy, overall efficacy was classified according to the chosen grading system.Results: On assessing the therapeutic results using the criteria selected, 90.0% patients (n = 9) in the calcipotriol–narrow‐band UVB group and 61.1% patients (n = 11) in the narrow‐band UVB group showed grade IV at the end of therapy. The calcipotriol–narrow‐band UVB group showed more rapid improvement at the early stage. The final and total UVB dose were slightly lower in the calcipotriol–narrow‐band UVB group but no significant difference was observed with respect to the total number of irradiations, duration of treatment, final UVB dose or total cumulative UVB dose required to reach grade IV in both groups (P > 0.05). The pattern of adverse effects was similar in both groups with a slightly higher frequency in the calcipotriol–narrow‐band UVB group.Conclusion: Our results demonstrated that the total cumulative UVB dose required to reach grade IV was not significantly different in both groups, although it was slightly lower in the calcipotriol–narrow‐band UVB group. However, a higher percentage of patients attained grade IV at the end of therapy in the combination group and this therapy was more effective in reducing the Psoriasis Area and Severity Index early in treatment. More studies are warranted to confirm these results.
Melatonin reduces nitric oxide level during ischemia but not blood–brain barrier breakdown during reperfusion in a rat middle cerebral artery occlusion stroke model
Authors: Pei Z. , Fung P. C. W. , Cheung R. T. F. 
Published: March 2003

Abstract: Melatonin is a potent antioxidant and free radical scavenger. Previously, we showed that a single injection of melatonin before ischemia significantly reduced the infarct volume in both permanent and 3‐hr middle cerebral artery occlusion (MCAO) rat stroke models. Nitric oxide (NO) and other free radicals play an important role in the pathogenesis of cerebral ischemia, and they have been postulated to mediate the breakdown of the blood–brain barrier (BBB) during ischemia. In this study, we evaluated the influence of melatonin, given at 30 min before MCAO, on brain NO concentration and BBB breakdown. Brain NO concentration was measured at 15 min of MCAO using electron paramagnetic resonance spectroscopy. BBB breakdown at 3 hr of reperfusion following 3 hr of MCAO was assessed using Evans blue extravasation. The relative brain NO concentration was increased to 141.69 ± 9.71% (mean ± S.E.M.; n = 9) at 15 min of MCAO. Treatment with melatonin at 1.5, 5, or 50 mg/kg significantly reduced the brain NO concentration to 104.20 ± 11.20% (n = 8), 55.67 ± 5.58% (n = 11), and 104.86 ± 12.56% (n = 9), respectively. Melatonin at 5 mg/kg did not affect Evans blue extravasation. Our results suggest that a single injection of melatonin protects against focal cerebral ischemia partly via inhibition of ischemia‐induced NO production and that this regimen does not prevent BBB breakdown following ischemia–reperfusion.