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Biomedical subjects

S Lester

Publications and source records attributed to S Lester.

At least 19 recordsLinked to original sources
PubMed2005

Sub-clinical infection and asymptomatic carriage of Cryptococcus gattii in dogs and cats during an outbreak of cryptococcosis.

Since 1999, Cryptococcus gattii has emerged as an important pathogen of humans and animals in British Columbia, Canada. Nasal swabs and serum samples were collected from dogs and cats residing within the Coastal Douglas Fir biogeoclimatic zone on Vancouver Island, where clinical cases have been reported. Deep and superficial nasal fungal cultures of 280 dogs and 94 cats identified four (4.3%) cats and three (1.1%) dogs with C. gattii serotype B in their nasal cavity. Serum samples collected from 266 dogs and 84 cats identified six (7.1%) cats and two (0.8%) dogs with a positive cryptococcal antigen titer. Overall cats were 4.4 times more likely than dogs to be positive on one or both tests. Identification of sub-clinical infection and nasal colonization is an important step in the characterization of the outbreak of clinical cryptococcosis on Vancouver Island.

Animals↗
PubMed2005

Follow-up study of dogs and cats with asymptomatic Cryptococcus gattii infection or nasal colonization.

The pathogenesis of Cryptococcus spp. infection following nasal colonization is unclear. This article reports follow-up data on a cohort of seven cats and five dogs identified in a previous study as sub-clinically infected with Cryptococcus spp. or colonized by C. gattii. Two cats progressed to clinical disease within four to six months of initial detection of antigenemia and nasal cavity colonization. The ten other animals remained asymptomatic but many were repeatedly positive on cryptococcal antigen testing or nasal fungal culture suggesting protracted infection or colonization. The results indicate that asymptomatically infected animals may clear the organism, remain sub-clinically infected or progress to clinical disease. Factors influencing the transition from exposure to disease require further investigation.

Animals↗
PubMed2004

Oral oestrogen and combined oestrogen/progestogen therapy versus placebo for hot flushes.

BACKGROUND: Hot flushes and night sweats are common symptoms experienced by menopausal women. Hormone therapy (HT), containing oestrogens alone or oestrogens together with progestogens in a cyclic or continuous regimen, is often recommended for their alleviation. OBJECTIVES: To examine the effect of oral HT compared to placebo on these vasomotor symptoms and the risk of early onset side-effects. SEARCH STRATEGY: We searched the Cochrane Menstrual Disorders Group and Subfertility Group trials register (searched May 2002). This register is based on regular searches of MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, the handsearching of 20 relevant journals and conference proceedings, and searches of several key grey literature sources. We also contacted all relevant pharmaceutical companies, The Journal of the International Menopause Society and Climacteric. SELECTION CRITERIA: Double-blind, randomised, placebo-controlled trials of oral HT for at least three months duration. DATA COLLECTION AND ANALYSIS: Study quality and outcome data were assessed independently. Random effects models were considered appropriate due to the variety of trial methodologies. The meta-analyses were explored for sensitivity to trial quality and therapy duration. Symptom frequency and severity were assessed separately, together with withdrawals and side-effects. Frequency data were analysed using the Weighted Mean Difference (WMD) between treatment and placebo outcomes. For severity data, odds ratios were estimated from the proportional odds model. From 115 references originally identified, 24 trials meeting the selection criteria were included in the review. Study participants totaled 3,329. Trial duration ranged from three months to three years. MAIN RESULTS: There was a significant reduction in the weekly hot flush frequency for HT compared to placebo (WMD -17.92, 95% CI -22.86 to -12.99). This was equivalent to a 75% reduction in frequency (95% CI 64.3 to 82.3) for HT relative to placebo. Symptom severity was also significantly reduced compared to placebo (OR 0.13, 95% CI 0.07 to 0.23). Withdrawal for lack of efficacy occurred significantly more often on placebo therapy (OR 10.51, 95% CI 5.00 to 22.09). Withdrawal for adverse events, commonly breast tenderness, oedema, joint pain and psychological symptoms, was not significantly increased (OR 1.25, 95% CI 0.83 to 1.90), although the occurrence of any adverse events was significantly increased for HT (OR 1.41, 95% CI 1.00 to 1.99). In women who were randomised to placebo treatment, a 57.7% (95% CI 45.1 to 67.7) reduction in hot flushes was observed between baseline and end of study. REVIEWERS' CONCLUSIONS: Oral HT is highly effective in alleviating hot flushes and night sweats. Therapies purported to reduce such symptoms must be assessed in blinded trials against a placebo or a validated therapy because of the large placebo effect seen in well conducted randomised controlled trials, and also because during menopause symptoms may fluctuate and after menopause symptoms often decline. Withdrawals due to side-effects were only marginally increased in the HT groups despite the inability to tailor HT in these fixed dose trials. Comparisons of hormonal doses, product types or regimens require analysis of trials with these specific "within study" comparisons.

Administration, Oral↗
PubMed2004

Reliability of a new measure of H-reflex excitability.

OBJECTIVE: This study examined the intraclass reliability of different measures extracted from Hoffmann reflex (H-reflex) stimulus-response curve that are used to assess neuromuscular excitability. The following measures were compared: (1) the peak-to-peak amplitude of the H-reflex at a stimulus intensity associated with 5% of the maximum M-wave; (2) the slope of the regression line of the H-reflex stimulus-response curve; and (3) the peak of the first derivative of the H-reflex stimulus-response curve, a new measure introduced in this paper. METHODS: The H-reflex was elicited in the soleus for 24 subjects (12 males and 12 females) on 5 separate days. Vibration was applied to the Achilles tendon prior to stimulation to test the sensitivity of the measures on test day 4. The stimulus intensity was gradually increased from below the threshold for an H-reflex response to above the maximum M-wave (Mmax) response. The means of 5 evoked potentials at each intensity level were used to create both the H-reflex and M-wave stimulus-response curves for each subject across test days. Determination of reliability involves the consideration of both the stability and consistency of the measures. A repeated measures analysis of variance evaluated the stability of the group means across test sessions. The consistency of scores within individuals was determined by calculating the intraclass correlation coefficient (ICC). Calculation of the 95% confidence interval of estimation was used to assess significant differences between ICCs. RESULTS: The H-reflex measures were both stable and consistent across the first 3 test days. Achilles tendon vibration resulted in a profound reduction (59-70%) on test day 4, and then there was a return to baseline levels on test day 5. The ICC for H-reflex at a stimulus intensity associated with 5% of the maximum M-wave was 0.85. The ICC for the slope of the regression line of the H-reflex stimulus-response curve was 0.79, while it was 0.89 for the peak of the first derivative of the H-reflex stimulus-response curve. However, there was no statistical significance (P>0.05) between the 3 EMG measures of the H-reflex arc. Maximum M-wave amplitude had an ICC of 0.96 attesting to careful methodological controls. CONCLUSIONS: The peak of the first derivative of the H-reflex stimulus-response curve was shown to have comparable sensitivity and reliability as other more established measures. SIGNIFICANCE: The first derivative of the H-reflex stimulus-response curve provides the rate of change, rather than amplitude, making it a robust measure of reflex arc excitability. The higher ICC for the first derivative offers greater statistical power, which is of practical significance.

Achilles Tendon↗
PubMed2004

Complications of exploratory coeliotomy in 70 cats.

Records of all cats that had undergone exploratory coeliotomy at the University of Edinburgh during the period November 1995 to July 2002 were reviewed. Seventy records were retrieved. There were 30 cats in which infection or inflammatory disorders predominated, 17 cats with neoplasia, three cats with trauma and 20 cats with other disorders. Exploratory coeliotomy was performed for diagnostic purposes in 28 cats (40 per cent), treatment in 34 cats (49 per cent) and for diagnosis and treatment in eight cats (11 per cent). Methods of intraoperative diagnosis included incisional biopsy of abdominal organs (52 cats), cytology (two cats), microbiology (17 cats) and gross appearance (17 cats). Fifty-eight cats (83 per cent) survived the hospitalisation period. Complications occurred in 18 cats (26 per cent) and were related to anaesthesia (four cats), the underlying disease process (15 cats), surgery (five cats) and were undetermined in one cat.

Abdominal Injuries↗
PubMed2004

Fas gene promoter polymorphisms in primary Sjögren's syndrome.

BACKGROUND: Fas mediated apoptosis may be important in the pathogenesis of primary Sjögren's syndrome (pSS). OBJECTIVE: To examine genetic variation in the promoter region of the Fas gene in pSS. METHODS: Two single nucleotide polymorphisms at positions -1377(G/A) and -670(G/A) in the Fas gene promoter were genotyped by PCR-SSP in 101 patients with pSS and 108 Caucasoid controls. RESULTS: No significant differences in allele or genotype frequencies were detected between the patients with pSS and controls. However, significant associations were observed with Ro/La autoantibody negative patients, who display milder and later onset disease. The -670A allele was more frequent in Ro/La autoantibody negative patients than in Ro/La autoantibody positive patients (p = 0.04). CONCLUSION: This study does not confirm an earlier report of an association between pSS and the Fas promoter -670G allele. However, the results suggest that genetically determined variability in Fas expression may modulate Ro/La autoantibody responses in patients with pSS.

Antibodies, Antinuclear↗
PubMed2003

Central hemimaxillectomy and reconstruction using a superficial temporal artery axial pattern flap in a domestic short hair cat.

A 2-year-old, neutered male domestic short hair cat presented with a large mass involving the right upper lip and underlying gingiva. A previous attempt at mass excision had failed, and the histopathological diagnosis was reported to be a fibrosarcoma. The cat was otherwise in good health.A central hemimaxillectomy was performed with extensive soft-tissue dissection and maxillofacial reconstruction achieved using an axial pattern flap based on the superficial temporal artery. This is the first reported clinical case of the use of the superficial temporal artery axial pattern flap in the cat. Histopathology identified a periodontal fibromatous epulis.

Animals↗
PubMed2002

Risk-based evaluation of postmortem inspection procedures for pigs in Australia.

The results of traditional (incision) and risk-based (visual) postmortem inspection procedures were compared on groups of approximately 30,000 pigs. The performance characteristics used as a basis for comparison included the non-detection rates of grossly detectable abnormalities, the microbiological contamination rates of carcases and boned product, the association of reactive lymph nodes with carcase condemnation and the achievement of 'finished product standards' for 'wholesomeness'. It was estimated that 6 per cent of all cases of abscessation and 28 per cent of all cases of arthritis were undetected by the traditional method, and the comparable figures for the risk-based procedure were 19 per cent and 39 per cent. However, when the rates of contamination of undetected abnormalities with foodborne hazards and other carcase contamination parameters were taken into account, it was concluded that both inspection systems were likely to result in a very similar level of consumer protection. Any increase in potential exposure to foodborne hazards in the abnormalities undetected by risk-based inspection would be insignificant in comparison with the potential exposure to foodborne hazards resulting from contaminated 'normal' lymph nodes and carcase surfaces. There were no statistically significant differences between the two procedures in the contamination rates of pre-chill carcases or boned retail products with Salmonella and Yersinia species.

Animals↗
PubMed2002

Immunoglobulin kappa light chain gene alleles are not associated with primary Sjögren's syndrome.

The immunoglobulin kappa (Km) light chain gene is polymorphic and is believed to play a role in the pathology of infectious and autoimmune diseases. Polymorphisms within the constant region of the Km gene encode three alleles designated Km1, Km1,2 and Km3. Previous studies using serological detection of Km allotypes reported associations between specific Km allotypes, systemic lupus erythematosus and the presence of anti-La antibodies, yet these findings were not confirmed in other studies. In order to more precisely define any associations between Km alleles and anti-Ro/La antibodies we used the polymerase chain reaction and restriction fragment length polymorphisms for Km genotyping in a large cohort of patients with primary Sjögren's syndrome (SS). No associations were observed between specific Km alleles and primary SS when compared with a control population, nor within serologically defined subsets of SS patients. We conclude that Km alleles are not associated with primary SS or the Ro/La autoantibody response.

Gene Frequency↗
PubMed2001

Oral oestrogen replacement therapy versus placebo for hot flushes.

BACKGROUND: Hot flushes and night sweats are common symptoms experienced by menopausal women. Hormone replacement therapy (HRT), containing oestrogens alone or oestrogens together with progestogens in a cyclic or continuous regimen, is often recommended for their alleviation. OBJECTIVES: To examine the effect of oral HRT compared to placebo on these vasomotor symptoms and the risk of early onset side-effects. SEARCH STRATEGY: As developed by the Menstrual Disorders Group and Subfertility group of the Cochrane Collaboration. SELECTION CRITERIA: Double-blind, randomised, placebo-controlled trials of oral HRT therapy for at least three months duration. DATA COLLECTION AND ANALYSIS: Study quality and outcome data were assessed independently. Random effects models were considered appropriate due to the variety of trial methodologies. The meta-analyses were explored for sensitivity to trial quality and therapy duration. Symptom frequency and severity were assessed separately, together with withdrawals and side-effects. Frequency data were analysed using the Weighted Mean Difference (WMD) between treatment and placebo outcomes. For severity data, odds ratios were estimated from the proportional odds model. From 99 references originally identified, 21 trials meeting the selection criteria were included in the review. Study participants totalled 2,511. Trial duration ranged from three months to three years. MAIN RESULTS: There was a significant reduction in the weekly hot flush frequency for HRT compared to placebo (WMD -17.46, 95% CI -24.72, -10.21). This was equivalent to a 77% reduction in frequency (95% CI 58.2, 87.5) for HRT relative to placebo. Symptom severity was also significantly reduced compared to placebo (OR 0.13, 95% CI 0.08, 0.22). Withdrawal for lack of efficacy occurred significantly more often on placebo therapy (OR 17.25, 95% CI 8.23, 36.15). Withdrawal for adverse events, commonly breast tenderness, oedema, joint pain and psychological symptoms, was not significantly increased for HRT therapy (OR 1.38, 95% CI 0.87, 2.21). In women who were randomised to placebo treatment, a 50.8% (95% CI 41.7, 58.5) reduction in hot flushes was observed between baseline and end of study. REVIEWER'S CONCLUSIONS: Oral HRT is highly effective in alleviating hot flushes and night sweats. Therapies purported to reduce such symptoms must be assessed in blinded trials against a placebo or a validated therapy. Withdrawals due to side-effects were only marginally increased in the HRT groups despite the inability to tailor HRT in these fixed dose trials. Comparisons of hormonal doses, product types or regimens require analysis of trials with these specific "within study" comparisons.

Administration, Oral↗
PubMed2001

Genomic diversity of natural killer cell receptor genes in three populations.

We report the distribution of genes encoding 11 killer cell immunoglobulin-like receptors (KIR) and 2 CD94:NKG2 receptors, in 32 Caucasians, 67 Australian Aborigines and 59 Vietnamese. The inhibitory and the activating KIR genes were found at different frequency in the three populations. No correlation was found between the polymorphism of the KIR genes and the HLA specificities of the tested samples. The most significant KIR associations were 2DL2 with 2DS2; 2DL2 with 2DS3 and 3DL1 with 2DS4 in all three study groups. In Caucasians and Vietnamese 2DS2 was associated with 2DS3 and 2DS1with 3DS1. KIR 2DL1 was strongly associated with three other KIRs: 2DL3, 3DL1 and 2DS4 in Aborigines. The distribution of the KIR phenotypes was different in the three populations. The AA1 phenotype was frequent in Vietnamese (42.4%) and Caucasians (31.2%), but very rare in Aborigines (1.5%). In contrast, the BB7 phenotype was very common for Aborigines (22.4%) and was absent in the two other groups. Our data demonstrate that different associations and putative KIR haplotypes could be distinguished in different populations.

Gene Frequency↗
PubMed2001

The alpha folate receptor is highly activated in malignant pleural mesothelioma.

OBJECTIVE: To determine whether the folate receptor gene is overexpressed in malignant pleural mesothelioma. METHODS: Differential display analysis was performed with fresh frozen RNA obtained from normal lung, pleura, and mesothelioma. Sixty differentially expressed genes were identified and characterized. One gene that was over-expressed in mesothelioma versus normal tissue was the human alpha folate receptor. In situ hybridization with antisense probes designed on the basis of the sequence of the folate receptor was performed with frozen sections from 61 patients (33 epithelial and 28 mixed or sarcomatoid tumors) with malignant pleural mesothelioma. The controls included normal pleura, normal lung, other cancers, and sense controls for all of the tumors. Northern analysis with a folate receptor probe and immunohistochemical analysis with anti-alpha folate receptor antibodies were also performed. RESULTS: Forty-four (72%) of the 61 mesothelioma tumors were found to have between 2-fold and 4-fold higher mRNA expression of the folate receptor when compared with the control tissues. The histologic type of the tumor did not affect the rate of folate receptor activation. Northern analysis and immunohistochemical experiments confirmed these findings. CONCLUSIONS: A majority of mesothelioma tumors examined overexpress the alpha folate receptor protein when compared with normal adjacent tissues. This finding may help explain the observations that antifolate drugs have activity in the treatment of mesothelioma. It also encourages further study of folate receptor-related treatment strategies in this malignancy.

Carrier Proteins↗
PubMed2001

The utility of ultrasonographically guided large-core needle biopsy: results from 500 consecutive breast biopsies.

Five hundred ultrasonographically guided large-core needle breast biopsies of solid masses were performed in 446 women. Histopathologic results were correlated with imaging findings. Ultrasonographically guided large-core needle biopsy resulted in diagnosis of malignancy (n = 124) or severe atypical ductal hyperplasia (n = 4) in 128 lesions (26%). In the remaining 372 lesions (74%), ultrasonographically guided large-core needle biopsy yielded benign pathologic results. Follow-up of more than 1 year (n = 225), results of surgical excision (n = 50), or both were obtainable in 275 (74%) of the benign lesions. No malignancies were discovered at surgical excision or during follow-up of this group of benign lesions. There were no complications related to large-core needle biopsy that required additional treatment. Ultrasonographically guided large-core needle biopsy is a safe and accurate method for evaluating breast lesions that require tissue sampling.

Adolescent↗
PubMed2001

Oral estrogen replacement therapy versus placebo for hot flushes: a systematic review.

OBJECTIVE: To examine the effectiveness of oral hormone replacement therapy (HRT) with regard to hot flushes and night sweats, which are vasomotor symptoms commonly experienced by menopausal women. METHODS: Double-blind, randomized, placebo-controlled trials of oral HRT for at least 3 months' duration and reporting vasomotor outcomes were identified using a search strategy developed by the Menstrual Disorders Group and Subfertility Group of the Cochrane Collaboration. Twenty-one trials meeting the selection criteria were included in the review. Study participants totalled 2511. Trial duration ranged from 3 months to 3 years. RESULTS: There was a significant reduction in the weekly hot flush frequency for HRT compared with placebo (weighted mean difference -17.46, 95% confidence interval (CI) -24.72 to -10.21). This was equivalent to a 77% reduction in frequency (95% CI 58.2-87.5) for HRT relative to placebo. Symptom severity was also significantly reduced compared with placebo (odds ratio (OR) 0.13, 95% CI 0.08-0.22). Withdrawal for lack of efficacy occurred significantly more often with placebo therapy (OR 17.25, 95% CI 8.23-36.15). Withdrawal for adverse events, commonly breast tenderness, edema, joint pain and psychological symptoms, was not significantly increased for HRT (OR 1.38, 95% CI 0.87-2.21). In women who were randomized to placebo treatment, a 50.8% (95% CI 41.7-58.5) reduction in hot flushes was observed between baseline and the end of the study. CONCLUSIONS: Oral HRT is highly effective in alleviating hot flushes and night sweats. Owing to the marked effect seen with placebo treatment, it is important to compare therapies purported to alleviate vasomotor symptoms with a placebo or an established therapy.

Administration, Oral↗