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Histological Effects (histological + effects)

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Medical Sciences	57%

Selected Abstracts

Histological effects of tazarotene 0·1% cream vs. vehicle on photodamaged skin: a 6-month, multicentre, double-blind, randomized, vehicle-controlled study in patients with photodamaged facial skin

BRITISH JOURNAL OF DERMATOLOGY, Issue 6 2004
L.A. Machtinger
Summary Background, Topical tazarotene has been shown to offer efficacy in ameliorating multiple effects of photodamage. Objectives, To evaluate the histological effects of tazarotene cream on photodamaged skin. Methods, In this multicentre, double-blind, randomized, vehicle-controlled study, 50 patients with photodamaged facial skin (at least mild fine wrinkling and mottled hyperpigmentation, with at least one of these being moderate) were randomized to apply tazarotene 0·1% cream or vehicle cream to their face, once daily for 24 weeks. Results, Blinded assessments showed that tazarotene was less likely than vehicle to be associated with an increase in keratinocytic and melanocytic atypia, and more likely than vehicle to be associated with a reduction in atypia. Between-group comparisons in distribution of change from baseline categories of severity were in favour of tazarotene (P = 0·055 for keratinocytic atypia, P = 0·034 for melanocytic atypia, and P < 0·001 for the number of granular cell layers). Compared with vehicle, tazarotene was associated with an increase in epidermal polarity (P = 0·008) and epidermal thickness (P = 0·012), and a tendency for stratum corneum compaction. Tazarotene was also associated with widened intercellular spaces (reported as epidermal oedema) relative to vehicle (P < 0·001). Conclusions, Treatment of photodamaged skin with tazarotene is associated with an amelioration of keratinocytic and melanocytic atypia, an improvement in epidermal polarity, and an increase in epidermal thickness. [source]

Advanced fluorescence in situ hybridization to localize and quantify gene expression in Japanese medaka (Oryzias latipes) exposed to endocrine-disrupting compounds

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2009
June-Woo Park
Abstract In an earlier study, we described the development of fluorescence in situ hybridization (FISH) using confocal microscopy to localize and quantify gene expression in fish. Here, we report the results of FISH application to investigate effects of model endocrine-disrupting chemicals (EDCs), 17,-ethinylestradiol (EE2) and 17,-trenbolone (TB), on expressions of EDC-responsive genes in Japanese medaka (Oryzias latipes) at the cellular/tissue level paired with histological observation. Gene expressions of vitellogenin-II (Vit-II), androgen receptor (AR), and cytochrome P450 gonadal aromatase (CYP19a) were determined after exposure to 5, 50, or 500 ng/L of EE2 or 50, 500, or 5,000 ng/L of TB for 7 d. Exposure to the greatest concentration of EE2 or TB significantly reduced fecundity and caused histological alterations in gonads. 17,-Ethinylestradiol induced Vit-II expression in both male gonads and liver relative to controls and resulted in greater intensity of hematoxylin staining in hepatocytes, which was significantly correlated with Vit-II induction in liver. When exposed to EE2 at less than 50 ng/L, CYP19a expression associated with early stage oocytes was greater than that in controls. However, at 500 ng/L, this trend was reversed. The greater Vit-II expression in testis from all EE2 groups, and the lesser expression of CYP19a in ovaries from the 500 ng/L group, likely is related to changes in the number of cells in which these genes are predominantly expressed rather than to an increase in expression per cell. 17,-Trenbolone significantly induced AR expression in ovaries but did not alter AR expression in female liver. It was concluded that FISH combined with histology enables advanced elucidation of molecular effects of chemicals by associating changes in gene expression with certain tissues and/or cell types and allows these changes to be related to histological effects. [source]

Metamorphic inhibition of Xenopus laevis by sodium perchlorate: Effects on development and thyroid histology

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2005
Joseph E. Tietge
Abstract The perchlorate anion inhibits thyroid hormone (TH) synthesis via inhibition of the sodium-iodide symporter. It is, therefore, a good model chemical to aid in the development of a bioassay to screen chemicals for affects on thyroid function. Xenopus laevis larvae were exposed to sodium perchlorate during metamorphosis, a period of TH-dependent development, in two experiments. In the first experiment, stage 51 and 54 larvae were exposed for 14 d to 16, 63, 250, 1,000, and 4,000 ,g perchlorate/L. In the second experiment, stage 51 larvae were exposed throughout metamorphosis to 8, 16, 32, 63, and 125 ,g perchlorate/L. Metamorphic development and thyroid histology were the primary endpoints examined. Metamorphosis was retarded significantly in the first study at concentrations of 250 ,g/L and higher, but histological effects were observed at 16 ,g/L. In the second study, metamorphosis was delayed by 125 ,g/L and thyroid size was increased significantly at 63 ,g/L. These studies demonstrate that inhibition of metamorphosis readily can be detected using an abbreviated protocol. However, thyroid gland effects occur at concentrations below those required to elicit developmental delay, demonstrating the sensitivity of this endpoint and suggesting that thyroidal compensation is sufficient to promote normal development until perchlorate reaches critical concentrations. [source]

Effects of an ethanol,gasoline mixture: results of a 4-week inhalation study in rats

JOURNAL OF APPLIED TOXICOLOGY, Issue 3 2005
I. Chu
Abstract The inhalation toxicity of an ethanol,gasoline mixture was investigated in rats. Groups of 15 male and 15 female rats were exposed by inhalation to 6130 ppm ethanol, 500 ppm gasoline or a mixture of 85% ethanol and 15% gasoline (by volume, 6130 ppm ethanol and 500 ppm gasoline), 6 h a day, 5 days per week for 4 weeks. Control rats of both genders received HEPA[sol ]charcoal-filtered room air. Ten males and ten females from each group were killed after 4 weeks of treatment and the remaining rats were exposed to filtered room air for an additional 4 weeks to determine the reversibility of toxic injuries. Female rats treated with the mixture showed growth suppression, which was reversed after 4 weeks of recovery. Increased kidney weight and elevated liver microsomal ethoxyresorufin- O -deethylase (EROD) activity, urinary ascorbic acid, hippuric acid and blood lymphocytes were observed and most of the effects were associated with gasoline exposure. Combined exposure to ethanol and gasoline appeared to exert an additive effect on growth suppression. Inflammation of the upper respiratory tract was observed only in the ethanol,gasoline mixture groups, and exposure to either ethanol and gasoline had no effect on the organ, suggesting that an irritating effect was produced when the two liquids were mixed. Morphology in the adrenal gland was characterized by vacuolation of the cortical area. Although histological changes were generally mild in male and female rats and were reversed after 4 weeks, the changes tended to be more severe in male rats. Brain biogenic amine levels were altered in ethanol- and gasoline-treated groups; their levels varied with respect to gender and brain region. Although no general interactions were observed in the brain neurotransmitters, gasoline appeared to suppress dopamine concentrations in the nucleus accumbens region co-exposed to ethanol. It was concluded that treatment with ethanol and gasoline, at the levels studied, produced mild, reversible biochemical hematological and histological effects, with some indications of interactions when they were co-administered. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Fractional deep dermal ablation induces tissue tightening,

LASERS IN SURGERY AND MEDICINE, Issue 2 2009
Zakia Rahman MD
Abstract Background and Objective Due to the significant risk profile associated with traditional ablative resurfacing, a safer and less invasive treatment approach known as fractional deep dermal ablation (FDDAÔ) was recently developed. We report the results of the first clinical investigation of this modality for treatment of photodamaged skin. Study Design/Materials and Methods Twenty-four subjects received treatments on the inner forearm with a prototype fractional CO2 laser device (Reliant Technologies Inc., Mountain View, CA) at settings of 5,40 mJ/MTZ and 400 MTZ/cm2. Clinical and histological effects were assessed by study investigators 1 week, 1 month, and 3 months following treatment. Thirty subjects were then enrolled in a multi-center study for treatment of photodamage using the same device. Subjects received 1,2 treatments on the face and neck, with energies ranging from 10 to 40 mJ/MTZ and densities ranging from 400 to 1,200 MTZ/cm2. Study investigators assessed severity of post-treatment responses during follow-up visits 48 hours, 1 week, 1 month, and 3 months following treatment. Using a standard quartile improvement scale (0,4), subjects and investigators assessed improvement in rhytides, pigmentation, texture, laxity and overall appearance 1 and 3 months post-treatment. Results Clinical and histologic results demonstrated that fractional delivery of a 10,600 nm CO2 laser source offers an improved safety profile with respect to traditional ablative resurfacing, while still effectively resurfacing epidermal and dermal tissue. Forearm and facial treatments were well-tolerated with no serious adverse events observed. Eighty-three percent of subjects exhibited moderate or better overall improvement (50,100%), according to study investigator quartile scoring. Conclusions FDDAÔ treatment is a safe and promising new approach for resurfacing of epidermal and deep dermal tissue targets. Lasers Surg. Med. 41:78,86, 2009. © 2009 Wiley-Liss, Inc. [source]

Histological effects of tazarotene 0·1% cream vs. vehicle on photodamaged skin: a 6-month, multicentre, double-blind, randomized, vehicle-controlled study in patients with photodamaged facial skin

ROSIGLITAZONE, AN AGONIST OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA, PREVENTS CONTRALATERAL TESTICULAR ISCHAEMIA,REPERFUSION INJURY IN PREPUBERTAL RATS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2007
Mustafa Inan
SUMMARY 1Rosiglitazone plays a positive role in the reparation of ischaemia,reperfusion (I/R) injury in different tissues. Thus, we examined its biochemical and histological effects on the contralateral testes to determine whether exogenous rosiglitazone affords any protection against testicular damage. 2Forty-eight prepubertal male Wistar-Albino rats were divided into six groups. Testicular torsion was created by rotating the right testis 720° in a clockwise direction for 5 h in all groups except group I, which was the sham-control group. In group II, bilateral orchiectomy was performed following the torsion period. After detorsion both testes were removed in the fifth hour in group III and on the seventh day in group IV. In group V, one-shot rosiglitazone (4 mg/kg) was administered 40 min before detorsion and both testes were removed following the torsion period. In group VI, rosiglitazone was administered (4 mg/kg) 40 min before detorsion and for 7 days, and then both testes were harvested. The tissue levels of malondialdehyde (MDA) were measured and mean testicular biopsy score (MTBS) and mean seminiferous tubule diameter (MSTD) were examined. Immunoexpression of endothelial nitric oxide synthase (eNOS) in testes tissues was investigated by immunohistochemical studies. 3In the contralateral testis, the MTBS and MSTD values of group VI were significantly higher than those in group IV. Immunohistochemically, mild eNOS immunostaining was present in the germ cells of the contralateral testes in group IV after I/R. In group VI, intense eNOS immunoreactivity was seen in the contralateral testes. 4Rosiglitazone reduces contralateral testicular damage formed after unilateral testicular torsion and alleviates the oxidative events. [source]