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Biomedical subjects

S M Langan

Publications and source records attributed to S M Langan.

14 recordsLinked to original sources
PubMed2006

Randomized, double-blind, placebo-controlled prospective study of the efficacy of topical anaesthesia with a eutetic mixture of lignocaine 2.5% and prilocaine 2.5% for topical 5-aminolaevulinic acid-photodynamic therapy for extensive scalp actinic keratoses.

BACKGROUND: Photodynamic therapy (PDT) is an effective treatment modality for the treatment of extensive scalp actinic keratoses (AKs), but pain is a significant drawback when treating large areas with topical PDT using 5-aminolaevulinic acid (ALA) as sensitizer. A recent study has shown that use of tetracaine gel (Ametop) did not significantly reduce pain associated with PDT. OBJECTIVES: To assess the benefit of a eutetic mixture of lignocaine 2.5% and prilocaine 2.5% (Emla) on pain during topical ALA-PDT treatment of scalp AKs. METHODS: Fourteen men aged 59-83 years with extensive scalp AKs were recruited into a double-blind placebo-controlled study. Two treatment fields were defined (right and left frontal scalp) and were treated 2 weeks apart. These fields were randomized to receive either Emla or Aqueous cream as first or second treatment. ALA 20% cream was applied for 4 h. Topical anaesthesia or Aqueous cream was applied for 2 h. Pain was assessed using a visual analogue scale (0-100 mm) at 3, 6, 12 and 16 min. The instrument used for this was a blinded counter with one side reading 'no pain' to 'worst pain ever' with a numerical scale (0-100) on the reverse side. Pain scores were assessed looking at median and interquartile range and confidence intervals and calculating differences between treatment groups and analysing them using a paired t-test. RESULTS: Thirteen patients received treatment to both fields. No significant difference in mean pain scores was seen with the use of Emla cream compared with placebo during treatment of scalp AKs (P = 0.328). There was no significant difference in requirement for oral analgesia following PDT between the two groups (P = 0.06). CONCLUSIONS: Our data do not support the routine use of topical anaesthesia with Emla for topical PDT.

Aged↗
PubMed2006

An exploratory prospective observational study of environmental factors exacerbating atopic eczema in children.

BACKGROUND: Possible exacerbating factors are a major concern of parents of children with atopic eczema (AE). However, there is minimal evidence for their direct role in leading to disease flares. OBJECTIVES: To assess the association between 'trigger factors' and disease flares in AE. METHODS: Twenty-five children with AE were recruited. Participants completed diaries, recording severity and exposure to potential exacerbating factors (18 variables) over 28 days. Severity was assessed at baseline and study completion. The relationship between severity and exposures was assessed. RESULTS: At episode level, on the day of exposure (lag 0), hot weather correlated to increased scratch scores (P=0.043). At a lag of 2 days after exposure, damp weather was associated with raised scratch scores (P=0.027). At lag 3 days, elevated scratch scores were associated with sweating and stress (P=0.029 and 0.019, respectively). Outside damp was associated with elevated scores (P=0.001) at lag 4. Multivariate analysis of all significant variables showed that only damp at lag 4 was significantly associated with flares (P=0.039). CONCLUSIONS: This study suggests association between stress, damp and heat and disease flares. These findings need to be studied over a longer period, using objective exposure measures.

Adolescent↗
PubMed2006

What causes worsening of eczema? A systematic review.

BACKGROUND: Flares of eczema are attributed to many factors, often with minimal scientific evidence. OBJECTIVES: Systematically to search, summarize and critically appraise the scientific evidence to support the roles of individual 'flare factors' in eczema. METHODS: We searched Medline from 1966 until 20 April 2005 to identify relevant articles for inclusion in this review. No language restrictions were imposed. All study designs were included and were ranked according to the strength of evidence. Experimental and provocation studies were restricted to those using a double-blind design. We included randomized controlled trials if they were provocation studies. Meta-analysis was not possible due to differences in study populations and methodology. The studies are therefore described qualitatively. RESULTS: The roles of foodstuffs (13 studies), house dust mite (three), other aeroallergens (two), seasonality (two), bacterial infections (one), textiles (three), detergents (one), sunlight (one) and stress (two) were assessed in different study populations, using a variety of study designs. All studies were performed on selected groups and only four were longitudinal in design. Collectively, these studies provide some evidence that certain foods, house dust mite, stress and seasonal factors are relevant causes of disease worsening in certain subgroups with eczema. No good evidence could be found to support the role of detergents, textiles and irritants in causing worsening of eczema. CONCLUSIONS: Despite anecdotal lists in textbooks and review articles, very little good evidence exists for 'flare factors' in eczema. The focus of all of the included studies was on disease worsening rather than clinically relevant flares. Studies of longitudinal design are required to clarify the roles of these and other putative flare factors in eczema.

Allergens↗
PubMed2006

The many faces of secondary syphilis: a re-emergence of an old disease.

There has been a recent dramatic re-emergence of syphilis in the UK. This article describes the varied clinical manifestations of secondary syphilis and describes the diagnosis and current guidelines for treatment, especially in association with human immunodeficiency virus infection.

AIDS-Related Opportunistic Infections↗
PubMed2003

Dermatomyositis associated with angiotropic lymphoma.

We describe a 64-year-old man with dermatomyositis sine myositis who presented with unusual cutaneous plaques and nodules. Initial investigations failed to reveal evidence of malignancy. Eighteen months later he became systemically unwell and repeat biopsies from the nodules confirmed angiotropic T-cell lymphoma. Cutaneous lymphoma is rarely reported with dermatomyositis and in the previously reported cases, mycosis fungoides was the variant seen. This is the first report of angiotropic T-cell lymphoma associated with dermatomyositis.

Antineoplastic Agents, Hormonal↗
PubMed1985

Purification and initial characterization of ubiquitin from the higher plant, Avena sativa.

Ubiquitin is a highly conserved, 76-amino acid polypeptide recently demonstrated to be involved in ATP-dependent protein degradation in mammalian cells. From immunoblot analyses with anti-human-ubiquitin antibodies we have detected the presence of free ubiquitin in green leaves, etiolated shoots, and dry seeds of the higher plant, oats (Avena sativa L.). We also find that crude oat extracts contain protease(s) that rapidly degrade both oat and human ubiquitin (t1/2 approximately 10 min at 27 degrees C). This proteolysis apparently cleaves ubiquitin at the carboxyl-terminal glycine dipeptide and results in inactivation of the molecule with respect to ligation but does not affect its mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Using homogenization conditions that preclude this proteolysis (low pH and the addition of the protease inhibitor p-chloromercuribenzoate) and immunoblotting as an assay for the protein, a procedure for the purification of ubiquitin from etiolated oat shoots was developed. Characterization of purified oat ubiquitin by absorption spectra, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing, radioimmunoassay with anti-human-ubiquitin antibodies, and kinetic analyses using the ubiquitin activating enzyme isolated from rabbit liver indicates that this protein is remarkably similar to the mammalian form. Small differences between the oat and human proteins have been observed by amino acid compositional analyses indicating that the two forms are not totally homologous. Immunoblotting of crude oat extracts has revealed the presence of high molecular weight proteins recognized by anti-ubiquitin antibodies that represent ubiquitin-protein conjugates formed in vivo. Taken together, these data provide evidence that higher plants contain a ubiquitin-dependent proteolytic pathway that is mechanistically identical to that present in animals.

Amino Acids↗
PubMed1985

Vitamin E, vitamin A and essential fatty acid status of patients hospitalized for anorexia nervosa.

A group of 17 patients hospitalized for anorexia nervosa was assessed for nutritional status with respect to the essential fatty acids and vitamins E and A. Plasma aliquots available from blood drawn upon hospital admission were frozen and later extracted for total lipids. The total lipids were then fractionated by thin layer chromatography to isolate the phospholipids (PL). The fatty acid profile of both total plasma and PLs was determined by gas chromatography. High pressure liquid chromatography was used to quantitate the tocopherol isomers and retinol (vitamins E and A, respectively). The anorexic patients showed below normal weight-for-height, decreased percent body fat, and a high incidence of secondary amenorrhea. Of the four tocopherol isomers measured, only the beta + gamma fraction was significantly lower than the normal value (0.16 +/- .06 mg/dl vs 0.25 +/- 0.51 mg/dl, p less than .001). The essential fatty acids, linoleate and linolenate, were lower in the PL fraction of the anorexic group (linoleate, 19.35 +/- 5.65 vs 24.96 +/- 2.24, p less than .01); linolenate, none detected vs 0.16 +/- 0.13, p less than .05). Other indicators of essential fatty acid status differed from the normal group in the direction of deficiency (total omega 6, 31.44 +/- 7.41 vs 37.42 +/- 3.40, p less than .05; 20:4 omega 6/18:2 omega 6, 0.49 +/- 0.14 vs 40 +/- 0.02, mean +/- standard deviation, p less than .01). Eicosatrienoic acid, however, was not detected in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1984

Relationship between the severity of experimental diabetes and altered lung phospholipid metabolism.

Glucose intolerance was induced in rats by iv infusion of streptozotocin (STZ) in doses of 30, 40, 50, and 100 mg/kg. Serum glucose concentrations were elevated versus controls and weight gains were reduced in a dose-dependent fashion up to 50 mg/kg. Urine outputs and blood urea nitrogen (BUN) values were higher than control values in the animals treated with 40 and 50 mg/kg and serum albumin concentrations were decreased after infusion with 50 mg STZ/kg. Lung phosphatidylcholine (PC) concentrations and dry-to-wet weight ratios were unchanged by STZ treatment, while lung protein and disaturated phosphatidylcholine (DSPC) concentrations were depressed in the 50-mg/kg group. Animals surviving treatment with 100 mg/kg demonstrated increased fasting blood glucose levels, BUN values, and 48-hr urine outputs, and decreased lung protein levels. However, these alterations were less than those found in the 50-mg/kg animals. Pulmonary concentrations of PC, DSPC, and lung dry-to-wet weight ratios were unchanged. It was found advantageous to express the results relative to fasting blood glucose levels. This demonstrated that urine output and BUN values increased and weight gain decreased with rising glucose concentrations, but serum albumin decreased only in moderate and severe hyperglycemia. Fasting glucose concentrations greater than 400 mg/dl were associated with reduced lung DSPC and protein levels, while pulmonary PC and dry-to-wet weight ratios demonstrated no change with increasing hyperglycemia.

Animals↗
PubMed1983

The effects of insulin and hyperglycemia on surfactant phospholipid synthesis in organotypic cultures of type II pneumocytes.

Organotypic cultures of fetal type II epithelial cells were incubated in media containing insulin at concentrations ranging from 10 to 400 microunits/ml. Exposure to insulin resulted in increased glucose uptake from the media and in the rate of glucose conversion to CO2. Furthermore, both glucose uptake and CO2 production were dependent on the glucose concentration in the media. Surfactant and residual phosphatidylcholine fractions were isolated from the organotypic cultures by sucrose density centrifugation. The presence of low doses of insulin (10-25 microunits/ml) caused a significant increase in the incorporation of glucose into both surfactant and residual phosphatidylcholine. Insulin at levels of 100 microunits/ml or higher resulted in a significant decrease in glucose incorporation into both phosphatidylcholine fractions. Increasing the media glucose concentration from 5.6 to 20 mM caused a 2- to 2.5-fold increase in glucose utilization for surfactant and residual phospholipid synthesis, but did not produce any significant changes in choline incorporation into either surfactant or residual phosphatidylcholine. The addition of 400 microunits/ml of insulin to media containing 20 mM glucose, however, resulted in a 20% decrease in choline incorporation into surfactant phosphatidylcholine but had no effect on choline incorporation into residual phosphatidylcholine. These results suggest that insulin is an important hormone regulating fetal lung maturation and that hyperinsulinemia may be responsible for the delayed lung development in infants of diabetic mothers.

Animals↗