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L Thomas

Publications and source records attributed to L Thomas.

At least 73 records · Page 4Linked to original sources
PubMed2003

Family risk factors for cannabis use: a population-based survey of Australian secondary school students.

The objective of this study was to investigate relationships between adolescent cannabis use and indices of parent - child attachment, family functioning and parent attitudes to drugs and delinquency. A total of 2848 year 9 and 2363 year 11 students participated in the Victorian Adolescent Health and Well-Being Survey (1999). The study was a school-based random sample of 535 metropolitan and rural, government and non-government secondary schools throughout Victoria, Australia. Cannabis use was defined as 'any' and 'weekly' use in the last 30 days. Multivariate logistic regression was used to identify independent associations between cannabis use and parent - child attachment, family functioning and parent attitudes to drugs and delinquency. Cannabis use in year 9 was associated with permissive parent attitudes to drugs and delinquency (any use: adjusted odds ratio (OR) = 8.1; weekly use: adjusted OR = 7.6), and was particularly sensitive to small changes in the quality of the parent - child relationship with risk increasing threefold for those describing their attachment as 'good' compared with 'very good' (any use: adjusted OR = 2.8, weekly use adjusted OR = 2.9). A similar, but more moderate pattern association was evident in year 11. After adjusting for other family and background factors, poor family functioning showed minimal association with level of cannabis use at both year levels. Results suggest that intervention efforts might sensibly target strengthening parent - children relationships and promoting less permissive parent attitudes to drug use.

Adolescent↗
PubMed2003

Relevance of vertical growth pattern in thin level II cutaneous superficial spreading melanomas.

Thin (<or=0.76 mm) level II cutaneous superficial spreading melanomas (SSMs) are known to be of excellent prognosis and very few recur, metastasize, or are lethal. Although many prognostic features at this stage have been studied, none appears to be statistically significant. The concept of tumor growth phase is correlated with Clark's level except for level II. SSM level II show either an invasive vertical growth phase or an invasive radial growth phase. The aim of our study (retrospective, multicenter, and case-control type) was to investigate the prognostic impact of vertical growth phase in thin level II cutaneous SSM. We identified 12 patients of poor outcome with complete initial excision. Each case was matched with three controls for gender, age, location, tumor thickness, and follow-up period since diagnosis. Independent pathologists studied all cases and controls. Univariate analyses were performed with a conditional logistic regression method. A kappa test was used to assess reproducibility between pathologists. Our study is the first and largest that shows that vertical growth phase is the only statistically significant prognostic factor for thin level II cutaneous SSM. We propose that growth phase evaluation (a minimum of eight serial sections being mandatory not to underdiagnose vertical growth phase) should be added to the recommendations for melanoma histologic report, at least for level II SSM.

Adult↗
PubMed2003

A prospective randomized multicentre phase III trial of fotemustine plus whole brain irradiation versus fotemustine alone in cerebral metastases of malignant melanoma.

The main objective of this prospective multicentre randomized phase III study was to compare a combined regimen of fotemustine plus whole brain irradiation with fotemustine alone in terms of cerebral response and time to cerebral progression in patients with melanoma cerebral metastases. Seventy-six patients were randomized to receive either fotemustine (arm A, n = 39) or fotemustine plus whole brain irradiation (arm B, n = 37). Fotemustine was administered intravenously at 100 mg/m(2) on days 1, 8 and 15, followed by a 5 week rest period, then every 3 weeks in non-progressive patients. In arm B, concomitant whole brain irradiation was performed at a total dose of 37.5 Gy (2.5 Gy/day on days 1-5 for three consecutive weeks). Although patients who received fotemustine alone had worse prognostic factors, there was no significant difference in cerebral response (arm A, 7.4%, arm B, 10.0%) or control rates (objective responses plus stable disease) after 7 weeks (arm A, 30%; arm B, 47%) or in overall survival (arm A, 86 days; arm B, 105 days). However, there was a significant difference in favour of arm B for the time to cerebral progression (P = 0.028, Wilcoxon test). In conclusion, fotemustine plus whole brain irradiation delayed the time to cerebral progression of melanoma cerebral metastases compared with fotemustine alone but without a significant improvement in terms of objective control or overall survival.

Adult↗
PubMed2003

Oral calcitriol: a new therapeutic agent in cutaneous lichen sclerosis.

BACKGROUND: Lichen sclerosus remains an elusive disease with an uncertain relationship to morphea and scleroderma. The disorder has been difficult to treat, with no consistent and reproducible efficacious therapy. Recently, a beneficial effect of treatment with oral calcitriol (1-25 dihydroxyvitamin D3) in patients with scleroderma or morphea was described. This fact could be ascribed to the immunomodulatory effects of calcitriol observed in vitro and to inhibition of fibroblastic growth. Because of the success of calcitriol in localized scleroderma, we attempted this therapy in a patient with LS. OBSERVATION: One patient with cutaneous generalized LS resistant to different therapeutics was treated with calcitriol in an oral daily dose of 0.5 mcg. After 6 months of treatment, the skin extensibility increased, and the lesions improved. The improvement persisted after discontinuation of therapy during a follow-up period of one year. The only side effect was hypercalciuria, which resolved with dose reduction. CONCLUSION: Calcitriol has shown a beneficial effect in scleroderma and morphea during open studies. A case is reported of a patient with LS who had a dramatic response to calcitriol. Double blind, placebo-controlled trials are needed to assess the therapeutic value of calcitriol in patients with LS.

Administration, Oral↗
PubMed2003

[Hypomelanosis of Ito in a girl with Trisomy 13 mosaicism: a cytogenetic study].

BACKGROUND: Hypomelanosis of Ito was first described by Ito in 1952 as incontinentia pigmenti achromians. The consistent feature of the disease is a characteristic cutaneous hypopigmentation area following the lines of Blaschko, but the clinical manifestations are varied and hypomelanosis of Ito is regarded as a neurocutaneous syndrome. Hypomelanosis of Ito is sporadic but is probably a non-specific expression of chromosomal mosaicism; we report a case with four clones. CASE REPORT: We report the case of a 26 year-old woman with neurocutaneous hypomelanosis of Ito and Trisomy 13 mosaicism. She also exhibited skeletal and ophthalmologic disorders. Immunohistology revealed a PS100 and Melan A decrease in hypopigmented skin. Cytogenetic study of normal and hypopigmented skin fibroblasts showed mosaicism with four clones. DISCUSSION: This is the third case of Trisomy 13 mosaicism associated with hypomelanosis of Ito, although other anomalies on chromosome 13 have been described. Happle published "phylloid" pigmented cases, which are mainly associated with Trisomy 13. This is the first observation of four-clone mosaicism and can be explained by successive mutations during embryogenesis. Anomalies on chromosomes 5,6 and 21 have never been described. The definition of hypomelanosis of Ito is not well established and the disease is presently included in a group of "pigmentary dysplasia" with genetic mosaicism.

Adult↗
PubMed2002

[Legionellosis in HIV-1 infected patients. 4 case reports].

INTRODUCTION: Contrary to patients exhibiting cellular immunodepression, legionellosis is rare in HIV-infected patients. We report 4 cases. OBSERVATIONS: Four men aged 41 to 48 were infected by HIV-1. Three of them were treated with antiretroviral therapy. The clinical and biological manifestations were unspecific. Evolution was favourable with adapted antibiotic therapy (erythromycine for three patients and ciprofloxacine for the fourth). COMMENTS: Legionella pneumophila serotype Lp1 remains the principle etiological agent. Frequent use of contrimoxazole in prophylaxis against pneumocystosis and toxoplasmosis, macrolides, rifamycines and fluoroquinolones in the preventive and curative treatment of mycobacterioses, and the relative conservation of monocyte/macrophage function and immune repair with efficient antiretroviral therapy, may explain the low prevalence of this disease in HIV infections.

AIDS-Related Opportunistic Infections↗
PubMed2002

Role of 12-lipoxygenase and oxidant stress in hyperglycaemia-induced acceleration of atherosclerosis in a diabetic pig model.

AIMS/HYPOTHESIS: We previously showed that vascular smooth muscle cells and endothelial cells cultured under high glucose conditions produced more 12(S)-hydroxyeicosatetraenoic acid (12-HETE), the 12-lipoxygenase (12-LO) product of arachidonate metabolism, relative to normal glucose. Because the lipoxygenase (LO) pathway has been associated with oxidant stress and the pathogenesis of atherosclerosis, we now examined 12-LO activation in vivo in a pig model of diabetes-induced accelerated atherosclerosis which displays human characteristics. METHODS: The animal model was developed in pigs who were fed a normal or high fat diet and given streptozotocin injections to produce normolipemic-normoglycaemic (NLNG), normolipemic-hyperglycaemic (NLHG), hyperlipemic-normoglycaemic (HLNG) and hyperlipemic-hyperglycaemic (HLHG) pigs. Tissue samples were obtained from key arterial beds to examine 12-LO expression at 20 weeks after the pigs began their diet. RESULTS: All HG pigs maintained threefold higher serum glucose concentrations. The HL groups developed atherosclerosis but diabetic HLHG pigs showed markedly accelerated atherosclerosis (twofold) relative to non-diabetic HLNG pigs. Immunostaining showed progressive increases in 12-LO in arteries in the order NLNG, NLHG, HLNG and HLHG. Leukocyte-type 12-LO protein (immuno-blotting) as well as mRNA expression (by competitive PCR) in abdominal and coronary arteries were significantly greater in HLHG pigs than in all the other three groups. Furthermore, increased oxidant stress was observed in monocytes from NLHG and HLNG pigs, and greatly potentiated in HLHG pigs. CONCLUSIONS/INTERPRETATION: These results are consistent with the hypothesis that 12-LO activation plays a key role in accelerated atherosclerosis due to diabetes and hyperlipemia.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed2002

[Systemic lupus erythematosus in Martinique: an epidemiologic study].

PURPOSE: To review epidemiological and clinical aspects of systemic lupus erythematosus (SLE) in Martinique, French West Indies. METHODS: Cases of SLE were identified by attending physicians. Patients who presented with at least four of the criteria defined by the American College of Rheumatology were included. Determination of incidence and prevalence included the new cases arising during the 1990-1999 period and 1999 population census results. Probability of survival was based on the use of the Kaplan-Meier estimator. RESULTS: Two hundred and eighty-six patients were studied, including 265 females (92.7%). The average annual incidence was 4.7 cases per 100,000 inhabitants (95% confidence interval [CI]: 2.5-6.9). The prevalence for 1999 was 64.2 cases per 100,000 inhabitants (CI: 56.2-72.2). The mean age at onset was 30 years. Eleven percent of all patients had at least one parent with SLE. Renal disease was present in 139 patients (48.6%), and neurological disorders were diagnosed in 70 patients (24.5%). Patients tested positive for the following antibodies: anti-Sm (37.1%), anti-RNP (58.7%), anti-SSA (47.2%). Mean survival time was: 96.4% (CI: 94.1-98.7) at 5 years, 91.8% (CI: 87.9-95.7) at 10 years. Survival was significantly reduced in patients with end-stage renal disease (n = 40, chi 2 = 6.96, P < 0.01). CONCLUSION: The high incidence of SLE in Martinique and the immunological characteristics of patients were found to be similar to those described in other populations of African descent. The frequency of renal disease and survival rates were identical to those reported in Caucasians.

Adolescent↗
PubMed2002

[First surgery followed by vaginal curietherapy in small-volume uterine cervix cancer: an alternative to the association of uterovaginal curietherapy and surgery].

PURPOSE: Evaluate the results of the treatment of small uterine cervix cancer with the association of surgery and postoperative vaginal brachytherapy, without unfavourable prognostic factors. PATIENTS AND METHODS: After radical hysterectomy with lymphadenectomy, 29 women (mean age: 44 years) with carcinoma < 25 mm (26 stage IB1, 3 IIA, mean size: 15 mm) were treated by post-operative prophylactic vaginal brachytherapy using low dose rate. Ovarian transposition was performed at the surgical time in 14 young women (mean age 35 years). RESULTS: The actuarial specific survival rates at 5 and 10 years were 100% and 90% respectively, with a mean follow-up 75 months. Only one local recurrence was observed. The rate of grade 1 post-operative complication was 7%. The conservation rate of the ovarian function was 85% for young women. CONCLUSION: Treatment of small volume uterine cervix cancer using first surgery and post-operative vaginal brachytherapy is a reliable therapeutic option. The results in terms of specific survival and complications are the same with those after standard association of preoperative uterovaginal brachytherapy and surgery.

Adult↗
PubMed2002

Mutation analysis of the STK11/LKB1 gene and clinical characteristics of an Australian series of Peutz-Jeghers syndrome patients.

Peutz-Jeghers syndrome (PJS) is a rare cancer predisposition, which is characterized by the presence of hamartomatous polyposis and mucocutaneous pigmentation. A significant proportion of both familial and sporadic forms of this disorder are associated with mutations in the STK11 (serine/threonine kinase 11)/LKB1 gene. In this report we present a series of Australian PJS cases, which suggest that mutations in the STK11 gene do not account for many families or patients without a family history. The most likely explanation is either the presence of another susceptibility gene or genetic mosaicism in the non-familial patients.

AMP-Activated Protein Kinase Kinases↗
PubMed2002

Lymphomatoid papulosis: a localized form with acral pustular involvement.

We report a localized form of lymphomatoid papulosis (LyP) presenting as pustular papules of the hands. The histopathology revealed a moderate inflammatory infiltrate composed of atypical pleomorphic large lymphocytes with atypical mitosis and large nuclei. Epidermotropism could be observed. These atypical cells expressed CD4 and CD30. Laboratory examinations and bone marrow explorations remained negative. The clinical presentation of this case of LyP is unusual. Only histopathological features allowed to diagnose LyP. The knowledge that LyP may be associated with neoplasia or lymphoma underlines the need for a long-term follow-up of these patients.

Hand Dermatoses↗
PubMed2002

Plasma leptin concentration in fetal sheep during late gestation: ontogeny and effect of glucocorticoids.

The ontogeny and developmental control of plasma leptin concentration in the fetus are poorly understood. The present study investigated plasma leptin concentration in chronically catheterized sheep fetuses near term, and in neonatal and adult sheep. The effect of glucocorticoids on plasma leptin in utero was examined by fetal adrenalectomy and exogenous cortisol or dexamethasone infusion. In intact, untreated fetuses studied between 130 and 140 d (term, 145 +/- 2 d), plasma leptin concentration increased in association with the prepartum cortisol surge. Positive relationships were observed between plasma leptin in utero and both gestational age and plasma cortisol. Plasma leptin was also inversely correlated with fetal p(a)O(2). The ontogenic rise in plasma leptin was abolished by fetal adrenalectomy. In intact fetuses at 123-127 d, plasma leptin was increased by infusions of cortisol (3-5 mg kg(-1)d(-1), +127 +/- 21%) for 5 d and dexamethasone (45-60 microg kg(-1)d(-1), +268 +/- 61%) for 2 d. However, the cortisol-induced rise in plasma leptin was transient; by the fifth day of infusion, plasma leptin was restored to within the baseline range. These findings show that, in the sheep fetus, an intact adrenal gland is required for the normal ontogenic rise in plasma leptin near term. Furthermore, fetal treatment with exogenous and endogenous glucocorticoids increases circulating leptin concentration in utero.

Adrenalectomy↗
PubMed2002

Contrasting effects of different levels of food intake and adiposity on LH secretion and hypothalamic gene expression in sheep.

Body reserves (long-term) and food intake (short-term) both contribute nutritional feedback to the hypothalamus. Reproductive neuroendocrine output (GnRH/LH) is stimulated by increased food intake and not by high adiposity in sheep, but it is unknown whether appetite-regulating hypothalamic neurons show this differential response. Castrated male sheep (Scottish Blackface) with oestradiol implants were studied in two 4 week experiments. In Experiment 1, sheep were fed to maintain the initial body condition (BC) score of 2.0+/-0.00 (lower BC (LBC), n=7) or 2.9+/-0.09 (higher BC (HBC), n=9), and liveweight of 43+/-1.1 and 59+/-1.6 kg respectively. LBC and HBC sheep had similar mean plasma LH concentration, pulse frequency and amplitude, but HBC animals had higher mean plasma concentrations of insulin (P<0.01), leptin (P<0.01) and glucose (P<0.01). Gene expression (measured by in situ hybridisation) in the hypothalamic arcuate nucleus (ARC) was higher in LBC than HBC sheep for neuropeptide Y (NPY; 486% of HBC, P<0.01), agouti-related peptide (AGRP; 467%, P<0.05) and leptin receptor (OB-Rb; 141%, P<0.05), but lower for cocaine- and amphetamine-regulated transcript (CART; 92%, P<0.05) and similar between groups for pro-opiomelanocortin (POMC). In Experiment 2, sheep with initial mean BC score 2.4+/-0.03 and liveweight 55+/-0.8 kg were fed a liveweight-maintenance ration (low intake, LI, n=7) while sheep with initial mean BC score 2.0+/-0.03 and liveweight 43+/-1.4 kg were fed freely so that BC score increased to 2.5+/-0.00 and liveweight increased to 54+/-1.4 kg (high intake, HI, n=9). Compared with LI, HI sheep had higher mean plasma LH (P<0.05), baseline LH (P<0.01) and pulse amplitude (P<0.01) and showed a trend towards higher pulse frequency. Although there were no differences in final mean plasma concentrations, there were significant increases over time in mean concentrations of insulin (P<0.001), leptin (P<0.05) and glucose (P<0.001) in HI sheep. Gene expression for AGRP in the ARC was higher in HI than LI animals (453% of LI; P<0.05), but expression levels were similar for NPY, OB-Rb, CART and POMC. Thus, the hypothalamus shows differential responses to steady-state adiposity as opposed to an increase in food intake, in terms of both reproductive neuroendocrine activity and hypothalamic appetite-regulating pathways. Differences in hypothalamic gene expression were largely consistent with contemporary levels of systemic leptin and insulin feedback; however, increased nutritional feedback was stimulatory to GnRH/LH whereas constant high feedback was not. The hypothalamus therefore has the ability to retain a nutritional memory that can influence subsequent responses.

Adipose Tissue↗
PubMed2002

[Dermatoscopy of pigmented lesions].

Dermoscopy is a simple to use in vivo method for the early diagnosis of malignant melanoma and the differential diagnosis of pigmented skin lesions. It has been shown to increase diagnostic accuracy over clinical visual inspection in the hands of an experienced physician. This paper is a review of the principles of Dermoscopy as well as recent technological developments.

Algorithms↗
PubMed2001

Toll-like receptor-4 is expressed by macrophages in murine and human lipid-rich atherosclerotic plaques and upregulated by oxidized LDL.

BACKGROUND: Inflammation is implicated in atherogenesis and plaque disruption. Toll-like receptor 2 (TLR-2) and TLR-4, a human homologue of drosophila Toll, play an important role in the innate and inflammatory signaling responses to microbial agents. To investigate a potential role of these receptors in atherosclerosis, we assessed the expression of TLR-2 and TLR-4 in murine and human atherosclerotic plaques. METHODS AND RESULTS: Aortic root lesions of high-fat diet-fed apoE-deficient mice (n=5) and human coronary atherosclerotic plaques (n=9) obtained at autopsy were examined for TLR-4 and TLR-2 expression by immunohistochemistry. Aortic atherosclerotic lesions in all apoE-deficient mice expressed TLR-4, whereas aortic tissue obtained from control C57BL/6J mice showed no TLR-4 expression. All 5 lipid-rich human plaques expressed TRL-4, whereas the 4 fibrous plaques and 4 normal human arteries showed no or minimal expression. Serial sections and double immunostaining showed TLR-4 colocalizing with macrophages both in murine atherosclerotic lesions and at the shoulder region of human coronary artery plaques. In contrast to TLR-4, none of the plaques expressed TLR-2. Furthermore, basal TLR-4 mRNA expression by human monocyte-derived macrophages was upregulated by ox-LDL in vitro. CONCLUSIONS: Our study demonstrates that TLR-4 is preferentially expressed by macrophages in murine and human lipid-rich atherosclerotic lesions, where it may play a role to enhance and sustain the innate immune and inflammatory responses. Moreover, upregulation of TLR-4 in macrophages by oxidized LDL suggests that TLR-4 may provide a potential pathophysiological link between lipids and infection/inflammation and atherosclerosis.

Animals↗
PubMed2001

Sero-prevalence and mother-to-infant transmission of hepatitis E virus among pregnant women in the United Arab Emirates.

OBJECTIVES: (1) To study the prevalence of HEV infection in a cohort of pregnant women in the United Arab Emirates (UAE). (2) The rate of mother-to-infant transmission. METHOD: Sera of 469 pregnant women residing in the UAE was tested for anti-HEV with ELISA and for HEV-RNA by polymerase chain reaction (PCR). Neonatal cord-blood and infant blood was similarly tested for anti-HEV and HEV-RNA. Out of these 469 women, 33% were UAE nationals (Group A) and Egyptians (Group B), respectively, and 34% were from the Indian sub-continent (Group C). RESULTS: Out of 469 mothers 93 (20%) were anti-HEV positive and 28 (30%) of these 93 were HEV-RNA positive and symptomatic with on-going infection. The prevalence of anti-HEV was significantly increased amongst Groups B and C (Group A:B, P<0.001; Group A:C, P<0.001). Twelve of these 28 symptomatic women developed acute hepatic disease and two died undelivered, thus, were excluded from further study. Six of the remaining 10 women had non-fulminant acute viral hepatitis and four developed fulminant hepatic failure, of which one died in the early post-partum period. The remaining 16 women had mild symptomatic disease with complete recovery as did the remaining nine women with acute illness. Of the 10 babies born to mothers with acute disease, two were pre-term, three had anicteric hepatitis and two babies were born with hypothermia and hypoglycaemia and died within 48h. Noteworthy is the fact that, the 26 infants born to the 26 HEV-RNA positive mothers developed acute/on-going clinical infection and were HEV-RNA positive. Apart from the two early neonatal deaths, the remaining 24 infants had full recovery. No infant of the other mothers were symptomatic or had HEV-RNA. Thus, the mother-to-infant transmission was 100%. The remaining 65 sero-positive women remained asymptomatic with no evidence of clinical infection, continued to be HEV-RNA negative and delivered at term. Their infants had no evidence of infection and were sero-negative by 9 months of age, suggesting transplacental transmission of IgG antibodies. CONCLUSIONS: There is a high prevalence of anti-HEV among pregnant women residing in the UAE. Twelve of infected women developed fulminant/acute hepatitis resulting in three fatalities. Evidence suggests significant vertical transmission of HEV among HEV-RNA positive mothers with appreciable perinatal morbidity and mortality. Excluding mothers with acute hepatic disease, Breast-feeding appears to be safe in HEV sero-positive mothers.

Adult↗