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Biomedical subjects

S Howarth

Publications and source records attributed to S Howarth.

15 recordsLinked to original sources
PubMed2001

Stimulation of IL-8 release from epithelial cells by gas cooker PM(10): a pilot study.

OBJECTIVE: To measure the effect of matter collected by a method that has a 50% efficiency for particles with an aerodynamic diameter of 10 microm (PM10), generated by gas and electric cooking, on A549 epithelial cells with and without nitrogen dioxide (NO2). METHOD: Multiple indoor PM10 samples were collected on Teflon filters during the use of gas or electric cookers. Interleukin-8 (IL-8) concentrations were measured with a sandwich enzyme linked immunosorbent assay (ELISA) system. RESULTS: Treatment of A549 cells with PM10 generated from gas cooking resulted in increased concentrations of IL-8 compared with untreated cells; particles from the electric cooker had no effect. NO2 did not alter the concentration of IL-8. CONCLUSION: PM10 generated by gas cooking has the potential to cause proinflammatory effects in lung cells. This may have implications for susceptible people.

Air Pollution, Indoor↗
PubMed2001

Ultrafine particles and nitrogen oxides generated by gas and electric cooking.

OBJECTIVES: To measure the concentrations of particles less than 100 nm diameter and of oxides of nitrogen generated by cooking with gas and electricity, to comment on possible hazards to health in poorly ventilated kitchens. METHODS: Experiments with gas and electric rings, grills, and ovens were used to compare different cooking procedures. Nitrogen oxides (NO(x)) were measured by a chemiluminescent ML9841A NO(x) analyser. A TSI 3934 scanning mobility particle sizer was used to measure average number concentration and size distribution of aerosols in the size range 10-500 nm. RESULTS: High concentrations of particles are generated by gas combustion, by frying, and by cooking of fatty foods. Electric rings and grills may also generate particles from their surfaces. In experiments where gas burning was the most important source of particles, most particles were in the size range 15-40 nm. When bacon was fried on the gas or electric rings the particles were of larger diameter, in the size range 50-100 nm. The smaller particles generated during experiments grew in size with time because of coagulation. Substantial concentrations of NO(X) were generated during cooking on gas; four rings for 15 minutes produced 5 minute peaks of about 1000 ppb nitrogen dioxide and about 2000 ppb nitric oxide. CONCLUSIONS: Cooking in a poorly ventilated kitchen may give rise to potentially toxic concentrations of numbers of particles. Very high concentrations of oxides of nitrogen may also be generated by gas cooking, and with no extraction and poor ventilation, may reach concentrations at which adverse health effects may be expected. Although respiratory effects of exposure to NO(x) might be anticipated, recent epidemiology suggests that cardiac effects cannot be excluded, and further investigation of this is desirable.

Air Pollution, Indoor↗
PubMed1999

Platelet indices during normal pregnancy and pre-eclampsia.

Platelet count and mean platelet volume (MPV) were estimated in 349 normal pregnancies at various gestational stages, and in 30 cases of pre-eclampsia. A probability plot was constructed from these data using discriminant analysis of MPV versus platelet count for the pre-eclamptic versus normal pregnancies. The sensitivity for pre-eclampsia was 90% (27/30) and the specificity was 83.3%. This plot may be of use in confirming risk of pre-eclampsia.

Blood Platelets↗
PubMed1996

Rapid and sensitive detection of anti-Ro (SS-A) antibodies by indirect immunofluorescence of 60kDa Ro HEp-2 transfectants.

Anti-Ro (SS-A) antibodies are important diagnostic markers for primary Sjögren's syndrome and systemic lupus erythematosus, but their detection by indirect immunofluorescence (IF) in the diagnostic laboratory is hindered by the low cellular abundance of 60kDa Ro protein (Ro60). The approach we used to overcome this problem was to transfect and over-express the Ro60 gene into HEp-2 cells. In this study we have used a mixture of Ro60 transfectants and untransfected HEp-2 cells (HEp-Ro60) as a substrate for IF-antinuclear antibody (ANA) testing in a hospital laboratory. Screening of 240 routine serum specimens identified 14 Ro transfectant-positive sera which were confirmed by counterimmunoelectrophoresis (CIE); 3 of these sera were ANA-negative on untransfected cells and regular HEp-2. A comparison of HEp-Ro60 and regular HEp-2 showed strong concordance of the different ANA patterns between the 2 substrates. No increase in background staining was observed on the Ro transfectants when reacted with normal human sera. A comparison between HEp-Ro60 and CIE for 53 sera from patients with primary Sjögren's syndrome showed that HEp-Ro60 were a sensitive and specific substrate for detection of anti-Ro antibodies. Masking of positive Ro transfectants was observed rarely in sera containing multiple ANA specificities, but the Ro60 staining on these transfectants were unmasked at higher serum dilutions. We conclude that HEp-Ro60 are a suitable substrate for IF-ANA in the routine laboratory and that they have the additional advantage over regular HEp-2 slides of being able to detect anti-Ro in ANA-negative sera. HEp-RO60 are also a valuable confirmatory test for sera giving equivocal precipitin reactions or ELISA results.

Adult↗
PubMed1993

Activated partial thromboplastin time reagents: an evaluation.

Nine automated, activated partial thromboplastin time (APTT) reagents were evaluated on an automated coagulometer, in comparison with a manual reagent. The study consisted of three separate stages: 1) to choose a reagent that had a working stability between 4 degrees C and 8 degrees C for seven days and heparin sensitivity between 0 and 0.8 iu/ml; ii) assessment of sensitivity to specific factor deficiencies, particularly factors VIII, IX, XI and XII using standardised plasma serially diluted with factor-deficient plasma; and iii) assessment of sensitivity to the presence of a lupus anticoagulant, from a known positive panel. Only one reagent fulfilled all the essential criteria as an acceptable replacement for the manual reagent.

Blood Coagulation Factors↗
PubMed1992

Evaluation of some prophylactic therapies for the idiopathic headshaker syndrome.

Eighteen horses affected by the idiopathic headshaker syndrome were studied in an owner assessed trial to test the efficacy of some prophylactic therapies. Riding the affected animal with a veil over the nostrils gave varying degrees of temporary relief in three of 10 horses. Local (intra-nasal) corticosteroid therapy was reported to be slightly effective in three of nine horses, but treatment with sodium cromoglycate, systemic corticosteroid, flunixin meglumine and an antihistamine were generally ineffective. Bilateral infraorbital neurectomy provided sustained relief in three of seven horses, but in one of these cases, a reaction at the neurectomy site necessitated another surgical procedure after six months. A fourth horse was reported to be slightly improved after neurectomy. A period of nasal irritation resulting in self-inflicted trauma was a common complication of this surgery.

Administration, Inhalation↗
PubMed1991

Squamous cell carcinoma of the equine external genitalia: a review and assessment of penile amputation and urethrostomy as a surgical treatment.

A retrospective analysis was performed on 48 cases of suspected neoplasia involving the equine external genitalia. Forty nine squamous cell carcinomata (SCC) and 23 squamous papillomata (SP) were identified. Two cases of epithelial hyperplasia and one case of habronemiasis were also recognised histopathologically. The glans penis was the most common site of tumour development accounting for 53 per cent of cases of SCC and 61 per cent of SP. The urethral diverticulum, urethral process or urethra was involved in 27.6 per cent (8/29) of cases of SCC. Twelve per cent (5/41) of cases of SCC were confirmed to have metastatic involvement of the local lymph nodes. Papillomata showing pre-malignant changes were identified in five cases. Seventy five per cent (36/48) of the animals presented were ponies. All were geldings, mean age 16.5 years. Penile amputation and urethrostomy, preputial ablation and proximal urethrostomy or local excision were used in the surgical management of these animals; three cases were inoperable and destroyed at presentation. Oedema, haemorrhage and stenosis of the urethrostomy site were encountered as post operative complications. Sixty six per cent (6/9) of animals with SCC of the glans penis (without urethral involvement), which had a known history over the follow up period, treated by penile amputation and urethrostomy survived for longer than 18 months. Similarly, of those with urethral involvement only 28.6 per cent (2/7) survived for a similar follow-up period. SCC not uncommonly affects the external genitalia of aged pony geldings and frequently the glans penis. If the lesion is identified before local metastasis occurs, penile amputation and urethrostomy is indicated and the prognosis is favourable.

Amputation, Surgical↗
PubMed1990

Mortality in elderly patients admitted for respite care.

OBJECTIVE: To determine whether admitting elderly patients to hospital to give temporary relief to their carers is associated with increased mortality. DESIGN: Prospective multicentre study comparing the mortality of patients admitted on a one off or rotational basis with that experienced while they were awaiting admission. SETTING: A wide range of urban and rural district general, geriatric or long stay, and general practitioner hospitals. PATIENTS: 474 Patients aged 70 or over who had 601 admissions. MAIN OUTCOME MEASURE: Death. RESULTS: 16 (3.4%) Of the 474 patients (2.7% of all 601 admissions) died while in hospital during an average stay of 15.7 days whereas 23 (4.9%) patients died while awaiting admission (average waiting time was 34.2 days). The 16 deaths in hospital and the 23 deaths during the longer waiting period correspond to death rates of 19.9 and 12.5 per 10,000 person days respectively. The difference between these of 7.4 is not statistically significant (95% confidence interval -3.6 to 18.3). The estimated relative risk of dying in hospital is 1.59 but the 95% confidence interval is wide (0.84 to 3.01). CONCLUSION: Although the death rates are slightly higher in those admitted to hospital for relief care than in those awaiting admission, the difference was not significant, and the death rate in both groups was reassuringly small.

Aged↗
PubMed1984

Reticulo-endothelial function in glomerulonephritis.

IgG- and C3b-coated erythrocytes were used to investigate splenic Fc-receptor function and hepatic C3b-receptor function by measurements of their blood clearance. Most patients with glomerular disease including those who were HLA, A1, B8, DR3 had normal Fc-receptor function. Occasional individuals with persistent glomerulonephritis had delayed clearance unrelated to disease activity. In rapidly progressive glomerulonephritis, the phenomenon of 'reticulo-endothelial blockade' was confirmed. C3b-receptor function was normal in most patients with persistent glomerulonephritis. A defect in splenic Fc-receptor function hepatic C3b-receptor function is unlikely to underlie persistent glomerulonephritis.

Adult↗
PubMed1984

Antibody profiles of sera giving different nuclear staining patterns.

Antibodies to three major antigens of the non-histone or saline-extractable nuclear antigen (ENA) complex were sought by counterimmunoelectrophoresis (CEP) in three groups of sera which gave different patterns in the immunofluorescence test for antinuclear antibodies (ANA). Precipitins, mainly anti RNP and anti SS-B, were found most commonly (61%) in 70 sera with a speckled ANA pattern but were less frequent (8%) in 61 sera with a homogeneous ANA pattern and exceptional (1%) in 72 sera which showed fibrillar ANA staining. Rim staining was an insensitive indicator of nDNA antibody. An enzyme immunoassay (EIA), specific for anti-SS-B was more sensitive than CEP and identified this antibody in 28 sera, compared with 18 for CEP.

Adult↗
PubMedDate not supplied

Management of major depression in the primary care setting.

BACKGROUND: Patients treated in community clinics, particularly those of minority status, may rely more heavily on primary care physicians (PCPs) for the diagnosis and management of depression. We wished to determine how PCPs in a community clinic setting initially manage patients newly diagnosed with major depression. METHODS: 698 patients were screened for major depression by the Structural Clinical Interview for DSM-III-R in a community-based primary care health center. Forty outpatients (29 Hispanic) were found to suffer from major depression. A letter explaining positive findings was sent to the patients' PCPs. Medical record charts were reviewed 3 months later to determine the PCP's management following the diagnosis. RESULTS: Of the 38 patients who remained in the study at 3 months, 20 (53%) received no intervention from the PCP by the end of 3 months after diagnosis, and of these, 14 were Hispanic. Five (13%) were prescribed an antidepressant by the PCP. Nine (24%) were referred to mental health services for medication, psychotherapy or combination treatment. Four (11%) were prescribed an antidepressant and then referred to mental health services. Differences between management of Hispanic and non-Hispanic patients were not statistically significant. CONCLUSIONS: Independent screening by psychiatrists in primary care settings may not be adequate enough to ensure appropriate management of depression by PCPs. Possible explanations may include time constraints during primary care visits, patient and/or physician reticence, and insufficient education of PCPs about depression.

Adult↗