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Biomedical subjects

H Blair

Publications and source records attributed to H Blair.

At least 19 recordsLinked to original sources
PubMed2001

Targeting polymerised liposome vaccine carriers to intestinal M cells.

Due to their transcytotic capability, intestinal M cells may represent an efficient potential route for oral vaccine delivery. We previously demonstrated that the lectin Ulex europaeus agglutinin 1 (UEA1, specific for alpha-L-fucose residues) selectively binds to mouse Peyer's patch M cells and targets 0.5 microm polystyrene microparticles to these cells. Using a gut loop model we now demonstrate that covalently-membrane-bound UEA1 similarly targets polymerised liposomes (Orasomes, approximately 200 nm diameter), potential biocompatable oral vaccine delivery vehicles, to mouse M cells. Targeting was inhibited by alpha-L-fucose while the co-entrapped adjuvant, monophosphoryl Lipid A (MPL), failed to exert any detrimental effect on UEA1-mediated M cell targeting. Lectin-mediated M cell targeting may thus permit the efficacy of mucosal vaccines to be enhanced if cellular relationship between particle binding and immune outcome can be established.

Animals↗
PubMed1998

Operative treatment of tertiary hyperparathyroidism: a single-center experience.

OBJECTIVE: To review the experience with the operative treatment of tertiary hyperparathyroidism (TH) from a single renal transplant center. SUMMARY BACKGROUND DATA: Most patients with chronic renal failure show evidence of secondary hyperparathyroidism by the time maintenance hemodialysis begins. Persistent secondary hyperparathyroidism (i.e., TH) requiring surgical intervention is uncommon in the authors' experience. METHODS: Charts of patients who underwent parathyroidectomy for TH were reviewed retrospectively. Information obtained included demographics, laboratory data, symptoms, operative procedure (including morbidity and mortality rates), and pathology. Comparisons of demographic data and allograft survival were made between the transplant population as a whole and a matched cohort group of patients. RESULTS: Thirty-eight patients from 4344 renal transplant procedures during a 29-year period required parathyroidectomy for TH. All patients had hypercalcemia; 20 were asymptomatic and 18 had varying symptoms. Mean time from renal transplantation to parathyroidectomy was 997 +/- 184 days, with a mean preoperative calcium level of 12.2 +/- 0.14 mg/dl. Total parathyroidectomy with parathyroid autograft was performed in 26 of 34 primary procedures. There were no deaths. The operative morbidity rate was 6% (wound separation and vocal cord hemiparesis, one each). Pathology was reported in all patients and recently reviewed in 28 patients. Twenty-four had diffuse hyperplasia and nine had nodular hyperplasia; one had an adenoma. Parathyroid glands diagnosed as nodular hyperplasia were significantly larger by total mass than those with diffuse hyperplasia. Comparison of allograft survival between the study group and a matched cohort group of patients revealed no difference in long-term graft survival. CONCLUSIONS: Operative intervention is recommended in patients with an asymptomatic increase in serum calcium to >12.0 mg/dl persisting for >1 year after the transplant, acute hypercalcemia (calcium >12.5 mg/dl) in the immediate posttransplant period, and symptomatic hypercalcemia.

Adult↗
PubMed1996

Radiofrequency catheter ablation of right ventricular outflow tachycardia in children and adolescents.

OBJECTIVES: The current study reviews the safety and efficacy of radiofrequency catheter ablation for the treatment of right ventricular outflow tachycardia in children and adolescents and describes a modified method for mapping the tachycardia focus. BACKGROUND: Although radiofrequency catheter ablation has proved highly effective for the treatment of supraventricular tachycardia during childhood and adolescence, its application in children with idiopathic right ventricular outflow tachycardia has been limited. METHODS: Six children (mean [+/- SD] age 10.6 +/- 2.4 years, range 6 to 16) with right ventricular outflow tachycardia underwent seven radiofrequency catheter ablation procedures. The mean tachycardia cycle length was 323 +/- 24 ms (range 300 to 360). Two multipolar catheters were positioned in the right ventricular outflow tract to map the tachycardia focus. RESULTS: Radiofrequency catheter ablation was successful in five (83%) of the six children (95% confidence interval 36% to 99%). At successful ablation sites, local endocardial activation time preceded the surface QRS onset by 46 +/- 5 ms (range 37 to 57), and there was concordance of the 12-lead pace map and the electrocardiogram (ECG) in 11 (one patient) to 12 ECG leads (four patients). One patient developed complete right bundle branch block during radiofrequency catheter ablation. There were no additional complications and no clinical recurrences over a mean follow-up period of 12.7 +/- 3.8 months (range 9 to 22). CONCLUSIONS: These results suggest that radiofrequency catheter ablation is a safe and effective treatment for right ventricular outflow tachycardia during childhood and adolescence. In addition, tachycardia mapping may be enhanced by use of a multipolar right ventricular outflow catheter technique.

Adolescent↗
PubMed1992

Bone maturation and resorption by peritoneal macrophages in noninsulin-dependent streptozocin-induced diabetes in the rat.

The existence of osteopenia in noninsulin-dependent diabetes mellitus (NIDDM) is controversial. In this regard rats with a diabetic condition that simulates NIDDM have normal bone mineral content. However, normal total mineral content in bones does not preclude abnormalities in more delicate functions in bones of rats with NIDDM (specifically, bone maturation and response of bone matrix to resorptive activity). To evaluate these functions, bone maturation was studied in tibias from 14-week old male and female rats with streptozocin-induced NIDDM and controls. The ability of macrophages to resorb bone was studied in bone particles that were obtained from femors of male rats with NIDDM and controls. The diabetic rats had the overt NIDDM condition for 8 weeks at the time of the study. We found that bone maturation/mineralization remained intact in the diabetic rats and that response of the bone particles that were obtained from their femors to the resorptive activity of macrophages was similar to that of the bone particles that were obtained from controls. These data suggest that in the rat, a diabetic condition that simulates NIDDM does not alter the physiologic functions of the bone matrix.

Analysis of Variance↗
PubMed1985

Asthma and urticaria induced by seminal plasma in a woman with IgE antibody and T-lymphocyte responsiveness to a seminal plasma antigen.

A patient with asthma urticaria and angioedema induced by allergy to seminal plasma was examined at intervals for 10 years. Before treatment her anaphylactic susceptibility to seminal plasma was manifested by very strong prick-test responses, IgE antibody to an allergenic fraction of seminal plasma determined by RAST, and by antigen-induced histamine release from her blood leucocytes. The skin test and in vitro lymphocyte tests indicated concomitant delayed hypersensitivity to the same allergen. The patient's lymphocytes treated with seminal plasma allergen fraction showed much increased incorporation of thymidine, and also synthesis of a product (NIF) that inhibited migration of neutrophils from a normal donor. The allergen fraction of seminal plasma had about five components in the range of 20 000-40 000 daltons molecular weight; the major fraction binding IgE appeared to be a glycoprotein. The patient was successfully desensitized by injections of her husband's seminal plasma. Desensitization was not associated with persistent amounts of antigen-specific IgG antibodies.

Animals↗
PubMed1983

Junctional automatic ectopic tachycardia: new proposed treatment by transcatheter His bundle ablation.

Three infants with junctional automatic ectopic tachycardia (JET) were seen over an 8-month period. Each had decreased left ventricular function. Two were treated with amiodarone, which together with propranolol reduced the tachycardia rate 10 to 40 bpm, but did not result in sinus rhythm. One patient died suddenly at home, as had 50% of our patients with JET treated with conventional medication. Two patients were treated by transcatheter ablation of the bundle of His and implantation of an atrial synchronous pacemaker. Neither has had subsequent tachycardia or required drugs. One patient resumed sinus rhythm and does not use his pacemaker. The other patient has complete AV block and continues to use her pacemaker. This aggressive approach to this lethal dysrhythmia offers hope for prevention of the former bad prognosis.

Amiodarone↗
PubMed1982

Oxidation of tyrosine to dopachrome by peroxidase isolated from murine melanoma.

Peroxidase, isolated from B16 mouse melanoma, converted tyrosine to dopachrome in the presence of either dopa or dihydroxyfumarate co-factor. A suspended homogenate of cloned, cultured B16 mouse melanoma cells also showed peroxidatic conversion of tyrosine to dopachrome in the presence of dihydroxyfumarate co-factor. The findings confirm previous histochemical, autoradiographic-histochemical, and EM-histochemical studies showing that melanoma peroxidase can convert tyrosine to melanin.

Animals↗
PubMed1977

A trial of ICI 74,917 in seasonal allergic rhinitis.

Twenty-four patients with seasonal allergic rhinitis were treated in a randomized double-blind trial of 6 weeks' duration, using either ICI 74,917 (0.5 mg in each nostril four times a day) or an identical placebo aerosol. Four patients receiving placebo were withdrawn from the trial because of the deteriorationin their rhinitis. The twelve patients using ICI 74,917 were protected as assessed by a combined total symptom score, which was statistically significant (P less than 0.05), from weeks 1 to 4 when the pollen counts were highest.

Adolescent↗
PubMed1977

Natural history of childhood asthma. 20-year follow-up.

Of 417 asthmatic children seen in hospital from 1941 to 1947, only 208 (50%) were still attending the hospital and were available for long-term follow-up, whereas a 91% follow-up was achieved from a personal follow-up of 267 asthmatic children seen in an East London group practice from 1948 to 1952 and followed for more than 20 years to December 1972. 125 patients (52%) were almost or completely symptom free; 51 (21%) had never had any symptom-free period for longer than 6 months; a further 63 (27%) had a remission of symptoms for 3 years before relapsing. 7 patients died, 3 due to their asthma. The final prognosis was influenced by the severity of the asthma at onset, by breast feeding, by the presence of associated atopic disease, and by a positive family history of atopic disease in first-degree relatives. It was uninfluenced by the age of onset of the asthma, by the sex of the patients, or by skin testing results. Short-term follow-up of such patients will fail to include those patients whose asthma remits and subsequently relapses.

Age Factors↗
PubMed1976

Intranasal beclomethasone dipropionate in seasonal rhinitis in general practice.

Thirty-five patients with seasonal allergic rhinitis were treated in a double-blind comparative trial in and East London Group Practice with either beclomethasone dipropionate (50 micrograms in each nostril four times a day) or a placebo aerosol preparation identical in appearance. There was a statistically significant difference in favour of intranasal beclomethasone dipropionate (P less than 0-05).

Administration, Intranasal↗
PubMed1975

A double blind trial of a 2% solution of sodium cromoglycate in perennial rhinitis.

Nineteen patients with perennial rhinitis were studied in a double blind crossover trial of 8 weeks duration using a 2% solution of sodium cromoglycate and placebo. Nasal smears, blood counts and serum IgE levels were carried out to determine whether any changes occurred with either the active or placebo formulations. Clinically, thirteen patients were greatly improved with the active solution, four showed no change and two became worse. Eosinophils in the nasal secretions were generally reduced during the administration of active solution but remained unchanged with the placebo.

Adolescent↗