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1.
Int J Cosmet Sci ; 45(6): 791-801, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37602524

ABSTRACT

OBJECTIVE: It is well established that exposure of human skin to airborne pollution, particularly in the form of particulate matter sized 2.5 µm (PM2.5 ), is associated with oxidative stress, DNA damage and inflammation, leading to premature signs of skin aging. Because much of the damage results from oxidative stress, we examined the effects of a topical composition containing three antioxidants in an in vitro model system to assess the potential for amelioration of premature aging. The use of multiple antioxidants was of interest based on the typical composition of therapeutic skincare products. It is important to determine the efficacy of multiple antioxidants together and develop a short-term assay for larger scale efficacy testing. METHODS: Normal human epidermal keratinocytes were exposed to a rural-derived source of PM2.5 in the presence and absence of an antioxidant mixture of resveratrol, niacinamide and GHK peptide. Endpoints related to inflammation, premature aging and carcinogenicity were monitored after 5 h of exposure and included IL-6, CXCL10, MMP-1 and NRF2. Differentially expressed genes were monitored by RNA-seq. RESULTS: Pre-treatment of keratinocytes with the antioxidant preparation in the absence of PM2.5 reduced baseline levels of MMP-1, IL-6 and CYP1A1 and reduced PM2.5 -induced increases in all four endpoints, MMP-1, IL-6, CXCL10 and CYP1A1. Antioxidants significantly increased NRF2 protein in the presence of PM2.5 , indicating a protective response. RNA-seq interrogation of antioxidant-treated cells further showed increased expression of NRF2 inducible genes. The expression of CYP1A1 and genes related to aryl hydrocarbon activation were induced by PM2.5 and suppressed by antioxidants. CONCLUSIONS: Specific signalling pathways known to be correlated with skin inflammation and aging were examined based on their suitability for use in efficacy testing for the prevention of skin damage due to ambient hydrocarbon pollution. Endpoints examined after only 5 h of exposure provide a useful method amenable to high through-put screening. The results obtained reinforce the concept that a multiple antioxidant preparation, topically applied, may reduce pro-inflammatory signalling and cellular damage and thereby reduce premature skin aging due to exposure to rural-derived airborne pollution.


OBJECTIF: Il est bien établi que l'exposition de la peau humaine à la pollution atmosphérique, en particulier sous forme de particules d'une taille de 2,5 µm (PM2,5 ), est associée à un stress oxydatif, à des dommages à l'ADN et à une inflammation entraînant des signes prématurés de vieillissement cutané. Étant donné que la plupart des dommages résultent du stress oxydatif, nous avons examiné les effets d'une composition topique contenant trois antioxydants dans un système de modèle in vitro afin d'évaluer le potentiel d'amélioration du vieillissement prématuré. L'utilisation de plusieurs antioxydants a été intéressante en raison de la composition typique des produits thérapeutiques de soin de la peau. Il est important de déterminer l'efficacité de plusieurs antioxydants combinés et de développer un test à court terme pour des tests d'efficacité à plus grande échelle. MÉTHODES: Des kératinocytes épidermiques humains normaux ont été exposés à une source de PM2,5 rurale en présence et en l'absence d'un mélange antioxydant de resvératrol, de niacinamide et de peptide GHK. Les critères d'évaluation liés à l'inflammation, au vieillissement prématuré et à la carcinogénicité ont été surveillés après 5 heures d'exposition et comprenaient l'IL-6, CXCL10, MMP-1 et le NRF2. Les gènes exprimés de manière différentielle ont été surveillés par séquençage de l'ARN. RÉSULTATS: Le prétraitement des kératinocytes par la préparation antioxydante en l'absence de PM2,5 a réduit les taux initiaux de MMP-1, IL-6 et de CYP1A1 et a réduit les augmentations induites par les PM2,5 dans les quatre critères d'évaluation, MMP-1, IL-6, CXCL10 et CYP1A1. Les antioxydants ont significativement augmenté la protéine NRF2 en présence de PM2,5 , ce qui indique une réponse protectrice. L'interrogation des séquences d'ARN des cellules traitées par antioxydants a également montré une expression accrue des gènes inductibles par NRF2. L'expression du CYP1A1 et des gènes liés à l'activation des hydrocarbures aryles a été induite par les PM2,5 et supprimée par les antioxydants. CONCLUSIONS: Les voies de signalisation spécifiques connues pour être corrélées à l'inflammation cutanée et au vieillissement ont été examinées en fonction de leur adéquation à l'utilisation dans les tests d'efficacité pour la prévention des lésions cutanées dues à la pollution des hydrocarbures ambiants. Les critères d'évaluation examinés après seulement 5 heures d'exposition fournissent une méthode utile pouvant être utilisée pour un dépistage à haut débit. Les résultats obtenus renforcent le principe selon lequel une préparation antioxydante multiple, appliquée par voie topique, peut réduire la signalisation pro-inflammatoire et les dommages cellulaires et ainsi réduire le vieillissement prématuré de la peau résultant de l'exposition à la pollution atmosphérique d'origine rurale.


Subject(s)
Aging, Premature , Antioxidants , Humans , Antioxidants/pharmacology , Antioxidants/metabolism , Matrix Metalloproteinase 1/metabolism , Aging, Premature/metabolism , NF-E2-Related Factor 2/metabolism , NF-E2-Related Factor 2/pharmacology , Cytochrome P-450 CYP1A1/metabolism , Cytochrome P-450 CYP1A1/pharmacology , Interleukin-6/metabolism , Interleukin-6/pharmacology , Keratinocytes , Particulate Matter/toxicity , Oxidative Stress , Resveratrol/pharmacology , Dust , Inflammation
2.
Langenbecks Arch Surg ; 408(1): 267, 2023 Jul 06.
Article in English | MEDLINE | ID: mdl-37410251

ABSTRACT

BACKGROUND: This study aims to determine the most accurate appendicitis scoring system and optimal cut-off points for each scoring system. METHODS: This single-centred prospective cohort study was conducted from January-to-June 2021, involving all patients admitted on suspicion of appendicitis. All patients were scored according to the Alvarado score, Appendicitis Inflammatory Response (AIR) score, Raja Isteri Pengiran Anak Saleha (RIPASA) score and Adult Appendicitis score (AAS). The final diagnosis for each patient was recorded. Sensitivity and specificity were calculated for each system. Receiver operating characteristic (ROC) curve was constructed for each scoring system, and the area under the curve (AUC) was calculated. Optimal cut-off scores were calculated using Youden's Index. RESULTS: A total of 245 patients were recruited with 198 (80.8%) patients underwent surgery. RIPASA score had higher sensitivity and specificity than other scoring systems without being statistically significant (sensitivity 72.7%, specificity 62.3%, optimal score 8.5, AUC 0.724), followed by the AAS (sensitivity 60.2%, specificity 75.4%, optimal score 14, AUC 0.719), AIR score (sensitivity 76.7%, specificity 52.2%, optimal score 5, AUC 0.688) and Alvarado score (sensitivity 69.9%, specificity 62.3%, optimal score 5, AUC 0.681). Multiple logistic regression revealed anorexia (p-value 0.018), right iliac fossa tenderness (p-value 0.005) and guarding (p-value 0.047) as significant clinical factors independently associated with appendicitis. CONCLUSION: Appendicitis scoring systems have shown moderate sensitivity and specificity in our population. The RIPASA scoring system has shown to be the most sensitive, specific and easy-to-use scoring system in the Malaysian population whereas the AAS is most accurate in excluding low-risk patients.


Subject(s)
Appendicitis , Adult , Humans , Prospective Studies , Appendicitis/diagnosis , Appendicitis/surgery , Sensitivity and Specificity , ROC Curve , Hospitalization , Appendectomy , Acute Disease
3.
Heliyon ; 8(10): e11070, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36303936

ABSTRACT

Emphysematous pyelonephritis (EP) is an uncommon condition involving acute severe necrotising infection in the renal parenchyma, perinephric space and collecting system, with a mortality rate of up to 13%. A 62-year-old male with poorly controlled diabetes mellitus presented with severe epigastric pain and shortness of breath for three days. A computed tomography scan revealed class 3B EP, which failed medical therapy and percutaneous drainage. He underwent a nephrectomy and achieved an excellent clinical recovery. Septic shock and uncontrolled diabetes mellitus are two risk factors that lead to a poorer prognosis. Class 3B EP with failed medical therapy and percutaneous drainage would benefit from nephrectomy.

4.
Clin Case Rep ; 9(10): e04797, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34631061

ABSTRACT

A colo-appendico-duodenal fistula is a rare occurrence that results from extrapulmonary tuberculosis (TB) complications, especially in the endemic region.

5.
Pan Afr Med J ; 38: 398, 2021.
Article in English | MEDLINE | ID: mdl-34381542

ABSTRACT

Situs inversus totalis is the complete transpositioning of thoracoabdominal viscera into a mirror image of the normal configuration. Choledochal cyst is the congenital cystic dilation of the biliary tract. Both these conditions coexisting in a patient is extremely rare. We hereby present a case of type IC choledochal cyst in a patient with situs inversus totalis presenting with biliary sepsis secondary to choledocholithiasis. Also detailed are the management and operative strategies employed to deal with this rare entity.


Subject(s)
Choledochal Cyst/diagnosis , Choledocholithiasis/complications , Sepsis/etiology , Situs Inversus/diagnosis , Adult , Biliary Tract Diseases/diagnosis , Biliary Tract Diseases/pathology , Choledochal Cyst/pathology , Female , Humans , Sepsis/diagnosis , Situs Inversus/pathology
6.
Int J Drug Policy ; 97: 103333, 2021 11.
Article in English | MEDLINE | ID: mdl-34175526

ABSTRACT

BACKGROUND: Sexualised drug use (SDU) has been identified as a major risk factor for HIV, as well as other mental health comorbidities among gay, bisexual and other men who have sex with men (GBMSM). While multiple studies have been conducted on the topic, few have explored the role of trauma in underpinning experiences of SDU among substance use treatment-experienced GBMSM. This qualitative study investigates life histories of trauma, and proposes a framework to better situate the factors driving SDU among treatment-experienced GBMSM. METHODS: We conducted semi-structured in-depth interviews with 33 purposively-sampled GBMSM with a history of SDU, and seeking treatment for it in Singapore. Interview topics included participants' experiences and life histories of SDU, substance use, incarceration, trauma, as well as stories of resilience and ongoing recovery from SDU. Interviews were audio-recorded, transcribed, coded, and analysed using inductive thematic analysis, from which a trauma-informed framework was developed. RESULTS: Participants firstly articulated the positive and desired aspects of SDU, such as its utility in allowing them to achieve positive emotional states, sexual enhancement, and feelings of connectedness and intimacy. Participants also described how SDU, in contrast, was used as a coping mechanism to deal with emotional and situational 'precipitants', including dealing with loneliness and a low self-esteem, sexual shame and social anxiety, as well as general stressful situations. Participants also articulated how such precipitants were underpinned by experiences of trauma, including those relating to HIV-related stigma, racism, sexual violence, death and loss, neglect, as well as internalised homophobia. Next, participants illustrated how such trauma were in turn reinforced by several 'preconditions', including the accessibility of substances, emphasis on sexual capital, and lack of access to mainstream support structures in the gay male community, alongside general sociolegal barriers to accessing care. CONCLUSIONS: This study proposes the role of trauma and the preconditions underpinning them in motivating SDU among a sample of largely substance use treatment-experienced GBMSM in Singapore. Interventions that provide support for GBMSM seeking treatment for SDU should provide trauma-informed care to address the complex barriers to treatment effectiveness.


Subject(s)
HIV Infections , Pharmaceutical Preparations , Sexual and Gender Minorities , Substance-Related Disorders , HIV Infections/epidemiology , Homosexuality, Male , Humans , Male , Sexual Behavior , Singapore/epidemiology , Substance-Related Disorders/epidemiology
7.
Am J Case Rep ; 22: e930967, 2021 Jun 17.
Article in English | MEDLINE | ID: mdl-34135299

ABSTRACT

BACKGROUND A rectal foreign body (RFB) can be stigmatizing for patients and present a dilemma for the treating physician. Removal can be challenging owing to the variety of objects introduced. The goals of therapy are to safely remove the RFB and to minimize injury to the bowel. CASE REPORT A 22-year-old man was referred from a district hospital to our institution after being unable to remove a self-inflicted RFB after sexual gratification. He was hemodynamically stable with a soft and nontender abdomen. A mass was felt in the suprapubic region. Abdominal radiography revealed a well-defined radiolucent object in the pelvic region, which was consistent with a lubricant bottle. No sign of bowel obstruction or perforation was observed. The RFB was successfully retrieved by a combination of transrectal digital manipulation and directed gentle abdominal pressure, allowing for descent of the RFB and transanal traction at the bedside. Various approaches have been described for removal of a RFB, from simple bedside strategies to open surgery for complicated cases. Endoscopy and minimally invasive techniques have also demonstrated a role in formulating a tailored approach. CONCLUSIONS We describe a successful retrieval of an RFB at the bedside, avoiding unnecessary open surgery.


Subject(s)
Foreign Bodies , Adult , Endoscopy , Foreign Bodies/diagnostic imaging , Foreign Bodies/surgery , Humans , Male , Young Adult
8.
Oman Med J ; 36(2): e239, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33768970

ABSTRACT

Perivascular epithelioid cell tumors (PEComas) are a family of rare mesenchymal tumors with discrete histological and immunohistochemical characteristics. Even rarer among them are cutaneous and subcutaneous PEComas. We describe a 34-year-old woman who presented with a large anterior abdominal subcutaneous lesion showing intact overlying skin and no obvious invasion of the abdominal musculature. A wide local excision was performed. Histopathology revealed a solitary tumor measuring 75 × 55 × 90 mm with epithelioid cells in nests with thin fibrovascular septa and spindle cells. Resection margins were clear with no invasion to the skin or rectus sheath. Tumor cells were positive for HMB-45 but negative for other markers. This is the largest subcutaneous PEComa reported to date.

9.
Vet Clin Pathol ; 43(2): 295-302, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24731193

ABSTRACT

BACKGROUND: Limited availability of diagnostic cytopathologic material may preclude additional diagnostic techniques. Tissue transfer allows for preparation of additional slides from a single original slide. Information pertaining to the application of the tissue transfer technique in veterinary cytopathology is lacking. OBJECTIVES: The objectives were to evaluate the application of the tissue transfer technique on Quick Dip-stained veterinary cytologic smears and to assess if a selection of histochemical and immunocytochemical stains, and PCR analyses could be performed on transferred material. METHODS: Archived Quick Dip-stained canine lymph node aspirate smears from previously diagnosed lymphoma cases were utilized to validate and optimize the tissue transfer technique. In this technique, diagnostic material is lifted from the original stained slide, is divided and transferred to multiple new slides. Histochemical stains such as Gram, periodic acid Schiff, Congo red, and Ziehl-Neelson, immunohistochemistry for CD3 and PAX5, and PCR for cryptococcal and mycobacterial organisms were selectively performed on transferred material. RESULTS: The tissue transfer technique was simple, and transferred Quick Dip-stained material retained cellular morphology. Histochemical and immunohistochemical stains, and PCR analysis yielded reliable results when performed on the additional smears produced by this technique. CONCLUSIONS: The tissue transfer technique was simple and easy to perform on previously Quick Dip-stained cytology smears. Cellular detail was preserved and multiple additional ancillary diagnostic techniques were facilitated, such as histochemical and immunohistochemical stains, and PCR analysis.


Subject(s)
Dog Diseases/pathology , Lymphoma/pathology , Specimen Handling/veterinary , Animals , Bacteria/cytology , Bacteria/genetics , Bacteria/isolation & purification , Biopsy, Fine-Needle/veterinary , Dogs , Ferrets , Fungi/cytology , Fungi/isolation & purification , Immunohistochemistry/veterinary , Liver/pathology , Lymph Nodes/pathology , Skin/microbiology , Skin/pathology , Specimen Handling/methods
10.
Prev Med ; 57 Suppl: S21-3, 2013.
Article in English | MEDLINE | ID: mdl-23313791

ABSTRACT

OBJECTIVE: The aim of this study was to evaluate the accuracy of hysteroscopic impression for diagnosing benign and malignant endometrial pathology. METHOD: This is a retrospective cross-sectional study involving case records of 412 patients who underwent hysteroscopy with diagnostic dilatation and curettage (D&C) at the University of Malaya Medical Centre from January 2009 to August 2011, and cases with records of previous hysteroscopies (2007-2008). Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, likelihood ratios (LR) and post-test probabilities of hysteroscopy were calculated. D&C was set as the 'gold standard'. RESULTS: Hysteroscopy and histology results were concordant in 366 (88.8%) subjects. Sensitivity, specificity, PPV and NPV were high exceeding 80%. Moderate sensitivity for endometrial hyperplasia (64.4%, 95% CI=49.8%-76.8%) with moderate PPV for malignancy (62.1%, 95% CI=44.0%-77.3%) due to misdiagnosing hyperplasia as malignant was observed. PPV for leiomyoma was reduced (83.3%, 95% CI=60.8%-94.2%) despite 100% sensitivity, due to D&C false negatives. High positive LR (>10) and low negative LR (<0.2) were observed generally except for endometrial hyperplasia (0.36). Hysteroscopy had moderate positive post-test probability for malignancy (0.62) but effective in ruling out malignancy (negative post-test probability=0.00). CONCLUSION: Hysteroscopy is accurate for diagnosing focal and malignant endometrial pathology but only moderate for hyperplasia. Endometrial sampling is recommended for all cases especially when suspecting hyperplasia or malignancy.


Subject(s)
Endometrium/pathology , Hysteroscopy/standards , Uterine Diseases/diagnosis , Cross-Sectional Studies , Dilatation and Curettage/standards , Dilatation and Curettage/statistics & numerical data , Endometrial Hyperplasia/diagnosis , Endometrial Hyperplasia/pathology , Endometrial Neoplasms/diagnosis , Endometrial Neoplasms/pathology , Female , Humans , Hysteroscopy/statistics & numerical data , Leiomyoma/diagnosis , Leiomyoma/pathology , Middle Aged , Retrospective Studies , Sensitivity and Specificity , Uterine Diseases/pathology
11.
Photochem Photobiol ; 84(2): 350-5, 2008.
Article in English | MEDLINE | ID: mdl-18179621

ABSTRACT

Green tea chemoprevention has been a focus of recent research, as a polyphenolic fraction from green tea (GTP) has been suggested to prevent UV radiation-induced skin cancer. Recently, it was demonstrated that GTP reduced the risk for skin cancer in a murine photocarcinogenesis model. This was accompanied by a reduction in UV-induced DNA damage. These effects appeared to be mediated via interleukin (IL)-12, which was previously shown to induce DNA repair. Therefore, we studied whether GTP induction of IL-12 and DNA repair could also be observed in human cells. KB cells and normal human keratinocytes were exposed to GTP 5 h before and after UVB. UVB-induced apoptosis was reduced in UVB-exposed cells treated with GTP. GTP induced the secretion of IL-12 in keratinocytes. The reduction in UV-induced cell death by GTP was almost completely reversed upon addition of an anti-IL-12-antibody, indicating that the reduction of UV-induced cell death by GTP is mediated via IL-12. The ability of IL-12 to reduce DNA damage and sunburn cells was confirmed in "human living skin equivalent" models. Hence the previously reported UV-protective effects of GTP appear to be mediated in human cells via IL-12, most likely through induction of DNA repair.


Subject(s)
DNA Damage/drug effects , DNA/radiation effects , Interleukin-12/physiology , Phenols/pharmacology , Tea/chemistry , Ultraviolet Rays , Cell Line, Tumor , Humans
12.
Cell Biol Int ; 30(11): 903-9, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16904918

ABSTRACT

Normal human dermal fibroblasts have a limited life-span in vitro and stop proliferation after a fixed number of cell divisions. This process by which cells stop proliferation is called senescence. Senescence is also characterized by a decrease in the total cell number. In this study, we characterized an increase in cell death in normal human dermal fibroblasts in vitro as a function of increasing cell passage. With increasing passage, human fibroblasts showed an increase in the number of dead cells and increased DNA fragmentation as determined by flow cytometry. Serial passage of human fibroblasts also resulted in mitochondrial dysfunction, represented by a loss of mitochondrial membrane potential. The apoptotic markers caspase-3 and cytochrome c were both found to increase in senescent cells. These results suggest the activation of an apoptotic pathway within a population of human fibroblasts as a function of cell passage.


Subject(s)
Apoptosis , Cellular Senescence , Dermis/cytology , Fibroblasts/cytology , Caspase 3/metabolism , Cell Cycle , Cell Survival , Cells, Cultured , Cytochromes c/metabolism , Cytoplasm/metabolism , DNA Fragmentation , Humans , Membrane Potentials/physiology , Mitochondrial Membranes/metabolism , beta-Galactosidase/metabolism
13.
J Cosmet Sci ; 57(2): 203-4, 2006.
Article in English | MEDLINE | ID: mdl-16758568

ABSTRACT

Aspirin(acetyl salicylate) has long been used as an analgesic. Salicylic acid has been reported to have anti-inflammatory properties. These activities include inhibiting activity of cox-1, cox-2, and NF-kb. In addition, salicylic acid has also been shown in some systems to induce Hsp70. We have demonstrated that salicylic acid inhibits UVB-induced sunburn cell formation, as well as increase the removal of UVB induced TT dimer formation in living skin equivalents. Given these protective properties of salicylic acid, we propose the use of salicylic acid as a topical therapeutic to protect the skin from sun damage.


Subject(s)
Keratolytic Agents/pharmacology , Salicylic Acid/pharmacology , Skin/drug effects , Skin/radiation effects , Sunburn/prevention & control , Ultraviolet Rays/adverse effects , Adult , Cell Survival/drug effects , Cell Survival/physiology , Cell Survival/radiation effects , HSP70 Heat-Shock Proteins/metabolism , Humans , Keratinocytes , Skin/metabolism , Transcription Factor RelA/metabolism
14.
Phytother Res ; 20(3): 178-83, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16521105

ABSTRACT

Cat's Claw (Uncaria tomentosa) water extracts, essentially free of oxindole alkaloids, have been shown to possess a broad spectrum of biological activity including DNA repair enhancement and antiinflammatory properties. These two biological mechanisms are key molecular targets to develop treatments that protect skin exposed to ultraviolet light from the sun. Because C-Med-100, a Cat's Claw water extract, is the only documented natural source of components that can up-regulate simultaneously both DNA repair and antiinflammation, its ability to modulate DNA repair in human skin organ cultures was undertaken. For this purpose skin cultures were treated with or without 5 mg/mL C-Med-100, irradiated with 0-100 mJ/cm2 UVB, and microscopically analysed for necrosis as well as the level of pyrimidine dimers using immunofluorescent TT-dimer antibody staining. The data clearly demonstrated that co-incubation with C-Med-100 reduced skin cell death from UV exposure, and this protection was accounted for by a concomitant increase in DNA repair. Based on these results, it was concluded that C-Med-100 was a natural plant extract worthy of further consideration as a sunscreen product.


Subject(s)
Cat's Claw/chemistry , DNA Repair/drug effects , Phytotherapy , Plant Extracts/pharmacology , Skin/drug effects , Sunscreening Agents/pharmacology , Animals , Cells, Cultured , Esters , Fluoroimmunoassay/methods , Humans , Mice , Mice, Inbred C57BL , Necrosis/pathology , Organ Culture Techniques , Plant Bark/chemistry , Plant Extracts/chemistry , Plant Extracts/toxicity , Pyrimidine Dimers/analysis , Pyrimidine Dimers/metabolism , Quinic Acid/analysis , Skin/radiation effects , Sunscreening Agents/chemistry , Sunscreening Agents/toxicity , Ultraviolet Rays/adverse effects , Uncaria/chemistry , Uncaria/toxicity
15.
J Cosmet Sci ; 55(2): 149-55, 2004.
Article in English | MEDLINE | ID: mdl-15131726

ABSTRACT

Human skin, and its isolated cells, respond to insults with a variety of repair and protective mechanisms. One such mechanism is the production of heat shock proteins (HSPs). Heat shock proteins help the other cellular proteins fold correctly into their active three-dimensional structures. Therefore, they can enhance the survival of cells under harsh, denaturing conditions. In order to develop a means of promoting the heat shock response to prepare the skin to withstand insult, we are investigating materials that appear to protect the skin biologically. One such material is vitamin D3 and its precursors. We have observed that keratinocytes treated with 7-dehydrocholesterol (7-DHC), a precursor of vitamin D3, have increased levels of protein and mRNA for heat shock proteins. In addition, we observed that topically applied 7-DHC increases the minimal dose of UVB required to induce erythema. These data suggest that 7-DHC can induce heat shock proteins in skin keratinocytes and that they will be more resistant to UVB insult.


Subject(s)
Dehydrocholesterols/pharmacology , Epidermis/drug effects , Heat-Shock Proteins/metabolism , Keratinocytes/drug effects , Cells, Cultured , Epidermal Cells , Epidermis/metabolism , Humans , Keratinocytes/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism
16.
J Invest Dermatol ; 122(2): 484-91, 2004 Feb.
Article in English | MEDLINE | ID: mdl-15009734

ABSTRACT

Salen-manganese complexes exhibit powerful superoxide dismutase and catalase activity, with pharmacologic efficacy in several oxidative-stress-associated disease models. Ultraviolet (UV) B not only induces direct DNA damage, but also generates oxidative stress. EUK-134, a salen-manganese complex, might therefore confer a direct protection against UVB-induced oxidative stress and consequently alleviate UVB-damage-induced signal transduction. We investigated the effect of EUK-134 on the UVB-induced accumulation and stabilization of the p53 protein. p53 plays a central role in the UVB response, both as sensor of UVB damage and as a mediator of a protective response. Cells treated with EUK-134 before UVB irradiation showed a significantly lower accumulation of the p53 protein in a concentration-dependent fashion. Furthermore, EUK-134 severely reduced N-terminal phosphorylation of p53. The extracellular signal-regulated kinase ERK and the stress-activated kinases JNK and p38 have been implicated in the UVB-induced N-terminal phosphorylation and accumulation of p53. Pre-treatment with EUK-134 inhibited the UVB-induced activation of these mitogen-activated protein kinase (MAPK) pathways. We hypothesize that EUK-134, by direct protection of the membrane from UVB-induced oxidative damage, reduces oxidative stress induced MAPK signaling and consequently lowers the level of p53 induction. The protection conferred by EUK-134 resulted in a significant increase in cell survival following UVB irradiation.


Subject(s)
Keratinocytes/metabolism , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/radiation effects , Organometallic Compounds/pharmacology , Salicylates/pharmacology , Tumor Suppressor Protein p53/metabolism , Cell Survival/drug effects , Cell Survival/radiation effects , Cells, Cultured , Humans , Keratinocytes/cytology , Keratinocytes/radiation effects , Mitogen-Activated Protein Kinases/metabolism , Organometallic Compounds/chemistry , Oxidative Stress/drug effects , Phosphorylation/drug effects , Salicylates/chemistry , Ultraviolet Rays , p38 Mitogen-Activated Protein Kinases
17.
South Med J ; 95(1): 72-7, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11827248

ABSTRACT

BACKGROUND: Exercise is integral to the management of type 2 diabetes. Unfortunately, the majority of adults with type 2 diabetes do not engage in regular exercise. METHODS: Three hundred patients with type 2 diabetes were randomly selected from a patient pool of diabetic patients encountered in 1996 at the Department of Veterans Affairs Medical Center in New Orleans, Louisiana. Medical records from October 1996 to June 1999 were reviewed. Information about exercise, alcohol intake, smoking, medications, laboratory results, and other variables was extracted from medical records. Patients with mean glycosylated hemoglobin (HbA1c) < 8.0 (good diabetic control) were compared with those who had poor diabetic control (mean (HbA1c) > or = 8.0). The effect of exercise in the management of type 2 diabetes was assessed. RESULTS: After adjustment for other variables, patients without exercise had an odds ratio of 2.71 (95% CI, 1.38-5.32) for poor diabetic control compared with patients with exercise. CONCLUSIONS: These findings suggest that exercise by itself is important for type 2 diabetes management.


Subject(s)
Diabetes Mellitus, Type 2/physiopathology , Diabetes Mellitus, Type 2/therapy , Exercise/physiology , Adult , Aged , Case-Control Studies , Diabetes Mellitus, Type 2/blood , Glycated Hemoglobin/analysis , Health Status , Humans , Hypoglycemic Agents/therapeutic use , Life Style , Middle Aged , Odds Ratio , Random Allocation , Regression Analysis , Veterans
18.
Article in English | MEDLINE | ID: mdl-11803255

ABSTRACT

Ultraviolet irradiation of normal human keratinocytes induces a cytotoxic effect. The chromophore for this effect is believed to be genomic DNA. However, DNA damage is known to be repaired in UVB irradiated keratinocytes. The trigger for this DNA repair is potentially damaged DNA itself. To test the hypothesis that damaged DNA can induce the host cell's own DNA repair mechanism, we treated the keratinocytes with the damaged DNA and evaluated its cytoprotective effects. We have observed that fragmented calf thymus DNA irradiated and damaged with a UVC light can induce a protective effect in cultured human keratinocytes. Keratinocytes treated with UVC damaged DNA fragments are less susceptible to UVB irradiation-induced cell death as measured by neutral red uptake. Unirradiated exogenous DNA did not induce this protective effect. Similar protective effects can be seen with irradiated salmon sperm DNA. UVC damaged DNA fragments induced 60% increase in protection in human HaCaT keratinocyte in culture to the cell death induced by UVB. Similar protection was observed with UVC irradiated oligothymidylic acid (dT3-dT5) which increased the survival of human HaCaT keratinocytes after UVB irradiated by 50%. Isolated mononucleotides, irradiated or not, do not increase UVB survivability. Cellular DNA synthesis was greatly inhibited by UVB, becoming undetectable at 40 mJ/cm(2). Exogenous treatment with damaged fragments causes immediate and significant inhibition of total cellular DNA synthesis. This inhibition was dose dependent. Cells that undergo damage to their DNA are known to inhibit endogenous DNA synthesis via p53 suppressor gene activation. This is believed to allow them sufficient time to repair the host DNA. The cellular response to exogenous damaged DNA may be a similar mechanism.


Subject(s)
Cytoprotection/physiology , DNA/pharmacology , Keratinocytes/physiology , Animals , Cattle , Cell Survival/drug effects , Cell Survival/radiation effects , Cytoprotection/drug effects , DNA/physiology , DNA/radiation effects , DNA Fragmentation/physiology , DNA Fragmentation/radiation effects , Dose-Response Relationship, Drug , Dose-Response Relationship, Radiation , Humans , Keratinocytes/drug effects , Keratinocytes/radiation effects , Ultraviolet Rays
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