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Biomedical subjects

A Knight

Publications and source records attributed to A Knight.

At least 19 recordsLinked to original sources

The differential diagnosis of rhinorrhea.

Rhinorrhea disrupts the quality of life of a large segment of the population. The first step to treating it properly is to make an accurate diagnosis of its underlying cause. This is not always a simple proposition, however, because rhinorrhea has many causes that can easily be confused in clinical practice. Diagnosis has come to rely increasingly on testing, but test costs add significantly to the health-care burden. This article reviews the use of medical logic in the differential diagnosis of rhinorrhea and describes the relative usefulness of various testing methods.

Conjunctivitis

Membrane protein trafficking through the common apical endosome compartment of polarized Caco-2 cells.

By raising monoclonal antibodies to the apical surface of Caco-2 cells we have identified a membrane protein (p100) that internalizes and recycles constitutively between the apical plasma membrane and endosomes in the apical cytoplasm. By applying tracers bound to the transferrin receptor, which internalizes and recycles back to the basolateral border, we demonstrate that the apical endosomes containing p100 include a subset of multivesticular bodies (MVB), which are also accessible to proteins arriving from the basolateral endosome. Tracers bound to EGF receptors and alpha-2-macroglobulin, which internalize from the basolateral border and are degraded, probably in lysosomes, also pass through the p100-containing MVB. These studies therefore suggest that the apical cytoplasm of Caco-2 cells contains a population of MVB capable of receiving membrane proteins trafficking in from both apical and basolateral borders and then routing them to a variety of cell surface and intracellular destinations. The differential distribution of apical and basolateral tracers within the 50-nm-diameter tubules connected to these p100-positive apical MVB suggests that the destination of proteins trafficking from the MVB back to apical and basolateral surfaces is determined by the tubules to which they gain access.

Cell Polarity

One month treatment with the once daily oral beta 2-agonist bambuterol in asthmatic patients.

Bambuterol is a new long-acting oral bronchodilator for once daily use in patients with asthma. It is a prodrug of terbutaline, designed to be slowly metabolized to terbutaline. Results from comparative studies have shown that it has similar clinical efficacy to other oral bronchodilators, but less side-effects. The present study was aimed at verifying the 24 h effect duration of bambuterol, 10 and 20 mg in comparison with placebo during a one month treatment period. The study was conducted as a double-blind, randomized, parallel group placebo-controlled, multicentre trial. It started with a one week run-in period with placebo, when oral bronchodilators were withdrawn. At the end of this reference period, the patients were randomized to one of three treatments: placebo, bambuterol 10 mg, or bambuterol 20 mg, once daily in the evening. The treatment period lasted for 4 weeks. Four hundred and eighty seven patients with a mean age of 45 yrs were included. Mean baseline forced expiratory volume in one second (FEV1) and FEV1% of predicted were 2.05 l and 62%, respectively. Administration of 10 mg bambuterol resulted in a significant 24 h effect duration, expressed as an increase in mean daily morning and evening peak expiratory flow (PEF) (+11 l.min-1, adjusted means) throughout the study, as compared with placebo. Bambuterol, 20 mg, gave a significant 24 h effect duration in both FEV1 and morning and evening PEF as compared with placebo. Furthermore, the adverse events observed during the study were relatively few and mild.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral

beta-Scruin, a homologue of the actin crosslinking protein scruin, is localized to the acrosomal vesicle of Limulus sperm.

Scruin (alpha-scruin) is an actin bundling protein found in the acrosomal process of Limulus polyhemus sperm. We have cloned and sequenced a second scruin isoform from Limulus, beta-scruin, that is 67% identical to alpha-scruin. Northern and Southern analyses confirm that beta-scruin and alpha-scruin are encoded by distinct genes. The sequence of beta-scruin, like alpha-scruin, is organized into N- and C-terminal superbarrel domains that are characterized by a six-fold repeat of a 50 residue motif. Western analysis using rabbit polyclonal antisera specific for alpha- and beta-scruin indicate that beta-scruin, like alpha-scruin, is found in Limulus sperm but not blood or muscle. Both immunofluorescence microscopy and immunogold-EM localize beta-scruin within the acrosomal vesicle at the anterior of sperm but not in the acrosomal process. The function of beta-scruin in this membrane-bounded compartment that is devoid of actin is unknown. However, the location of beta-scruin together with the fact that it contains two putative beta-superbarrel structural folds, which are known to be catalytic domains in a number of proteins, suggests it may have a possible enzymatic role.

Acrosome

Multicenter trial of fluticasone propionate aqueous nasal spray in ragweed allergic rhinitis.

A 4-week multicenter, double-blind, placebo-controlled, parallel-group trial was carried out with 416 adults with ragweed allergic rhinitis to compare 200 micrograms of fluticasone propionate once daily and 100 micrograms of fluticasone propionate twice daily with placebo. Compared with placebo, both groups receiving fluticasone propionate had greater number of symptom free days (P < .01), lower median symptom scores (P < .01), and greater number of days not requiring rescue medications (P < .001). No significant differences for individual symptoms were found between the two fluticasone propionate groups except that those taking the twice daily dosage used less antihistamine (P < .01) and had greater number of days free of rescue medications (P < .05). Adverse events were comparable between the three groups. These results indicate that topical intranasal fluticasone propionate 200 micrograms once daily and 100 micrograms twice daily are both efficacious and well tolerated.

Administration, Intranasal

A modern disease.

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Air Pollution, Indoor

Can autoimmune mechanisms account for the genetic predisposition to schizophrenia?

Applications of molecular genetic techniques to schizophrenia have shown great initial promise but have then proved disappointing. In order to maximise chances of elucidating the genetic mechanism underlying schizophrenia, diverse strategies and diverse perspectives must be adopted. Most studies begin with the premise that, although schizophrenia may be a heterogeneous collection of diseases, some subtypes will be primarily single-gene disorders. We are concerned that this single-gene hypothesis may be incorrect. Schizophrenia research may benefit from application of knowledge from other disciplines and from other diseases which, in terms of epidemiology and apparent genetic mechanisms, bear some resemblance to schizophrenia.

Autoantibodies

Sustained improvement in asthma with long-term use of formoterol fumarate.

Inhaled formoterol fumarate, a long acting beta 2 agonist, produces bronchodilatation that is sustained for approximately 12 hours. To determine whether such bronchodilator effects are maintained and asthma control sustained during chronic administration, we monitored airflow indices and clinical control in 112 asthmatic patients who self administered formoterol twice daily for periods ranging from 9 to 12 months. Subjects were recruited immediately following completion of a 3-month double-blind comparison of formoterol, 12 micrograms, bid versus salbutamol, 200 micrograms, qid. Assessments were conducted at baseline, 3, 6, and 9 months, where baseline represents the final visit of the 3-month comparative study. Patients were asked to complete diary cards and twice daily PEFR for a 2-week period before each assessment. Throughout the follow-up study, there was no indication of worsening of asthma control or deteriorating lung function. For the patients who continued to receive formoterol, the previous improvement in asthma control and lung function was maintained at the level reached in the 3-month study. There was an improvement in flow rates and asthma symptoms in the group switched from salbutamol to formoterol by the first clinic visit. This improvement in asthma control and lung function was maintained over the subsequent 6 months. Formoterol was well tolerated during the study period. We conclude that prolonged use of formoterol fumarate twice daily results in sustained improvement in symptoms and flow rates in asthma with no evidence of tachyphylaxis.

Adolescent

Clinical evaluation of the efficacy and safety of noberastine, a new H1 antagonist, in seasonal allergic rhinitis: a placebo-controlled, dose-response study.

Noberastine (NOB), a new histamine H1 antagonist, has potent and specific peripheral antihistaminic activity. To evaluate the efficacy and safety of NOB in ragweed seasonal allergic rhinitis, 250 eligible patients were randomized to one of four parallel, double-blind treatment groups: NOB, 10, 20, and 30 mg, or placebo, each administered once daily for 3 weeks. Rescue medication was prohibited. Efficacy parameters included global response rate (percentage of responders), physician visit, patient-diary symptom scores, and onset of action. Efficacy analyses used alpha = 0.0167 (adjusted for multiple comparisons). Efficacy parameters demonstrated universal superiority of NOB therapy over placebo therapy with statistical significance achieved frequently; no statistically or clinically significant separation was demonstrated among NOB-treated groups. Global-response rates for all active-treatment groups (range, 62.7% to 71.1%) were statistically significantly greater than rates for the placebo-treated group (39.6%). Median time to first relief of symptoms was within 2 to 4 hours for NOB-treated groups versus 72 hours for the placebo-treated group. No significant abnormalities in safety parameters were ascribed to NOB treatment. Incidence and severity of adverse experiences of NOB-treated groups were comparable in incidence and severity to placebo treatment. NOB treatment did not appear to cause weight gain or sedation. Once-daily NOB, 10, 20, and 30 mg, is equally and highly effective and safe in the symptomatic management of seasonal allergic rhinitis compared to placebo.

Adolescent

A three-month comparison of twice daily inhaled formoterol versus four times daily inhaled albuterol in the management of stable asthma.

We compared the efficacy of inhaled formoterol, a long-acting beta 2-agonist, with inhaled albuterol in 145 stable adult asthmatics in a 12-wk multicenter trial. Patients were allocated in randomized double-blind fashion to maintenance therapy with either formoterol 12 micrograms twice a day or albuterol 200 micrograms four times a day in addition to their other asthma medications. Patients were allowed to use "rescue" 100-micrograms albuterol puffs on an as-needed basis. Mean baseline FEV, in the morning before bronchodilator was 2.14 +/- 0.76 L and 1.98 +/- 0.71 L for the formoterol and albuterol groups, respectively, these values being used as baseline covariates in subsequent analysis of predrug and postdrug FEV1. Measured at each clinic visit, morning predrug FEV1 rose significantly with formoterol treatment and was significantly greater at all visits than in the albuterol group, the greatest difference being in Week 8 (2.40 +/- 0.77 versus 1.92 +/- 0.66 L, p less than 0.001). Morning FEV1 30 min postdrug was significantly higher in the formoterol group at Weeks 2 and 8, the trend not reaching statistical significance at other times. Diurnal variation in prebronchodilator peak flow rates was significantly reduced in the formoterol group throughout the trial (17 versus 42 L/min at Week 12, p less than 0.0001). The number of asthma episodes per week was significantly less in the formoterol group during Weeks 4, 8, and 12 as were the number of sleep disruptions during Weeks 2, 4, 6, 8, and 12. Significantly more rescue albuterol was required in the albuterol group by Week 2 and throughout the remainder of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation

A prospective randomized study of a modified technique of ultrafiltration during pediatric open-heart surgery.

Conventional ultrafiltration (UF) fails to reverse satisfactorily hemodilution and the rise in total body water (TBW) seen after cardiopulmonary bypass (CPB). We have modified the technique, timing, and placement of UF in the CPB circuit and in pilot studies observed controlled elevation of hematocrit and a significantly reduced rise in TBW. We have carried out a prospective randomized study in 50 children undergoing open-heart surgery, comparing modified UF (MUF) with nonfiltered controls. MUF was carried out for 10 minutes after completion of CPB to a hematocrit of 36-42. Fluid balance, TBW (by bioimpedance), and hemodynamics were recorded for 24 hours postoperatively. The results were analyzed using Mann-Whitney U test, comparing controls (n = 24) to ultrafiltered (n = 24). There was one death in each group. Blood loss (ml/kg/24 hr) was 19.5 median (range, 9-30) in the controls versus 12.5 (8-22) in MUF (p = 0.0002); blood transfused (ml/kg/24 hr) 15.5 (3-35) in controls versus 3 (0-11) in MUF (p = 0.0001); colloid transfused (ml/kg/24 hr) 12 (6-56) in controls versus 12 (0-28) in MUF (p = 0.18); percent rise in TBW 11.1 (4.3-16.8) in controls versus 4.0 (1.6-7.9) in MUF (p = 0.0001). There was rise in arterial blood pressure during MUF. Percent rise of systolic blood pressure was 1 (-4 to +9) in controls versus 49 (5-81) in MUF (p = 0.0001); percent rise in diastolic blood pressure 0 (-5 to +8) in controls versus 28 (3-47) in MUF (p = 0.0001). UF reduced the rise in TBW and donor blood requirement associated with CPB in children. The blood pressure rise observed during UF is as yet unexplained, but if proven safe the technique may permit donor blood-free cardiac surgery and prevent the accumulation of potentially dangerous excess tissue fluid.

Body Water

Autoantibodies against brain septal region antigens specific to unmedicated schizophrenia?

Health et al. (1989) reported that serum from 96% of unmedicated schizophrenic patients contained IgG autoantibodies specific for the septal region of rhesus monkey brain, compared with 0% of nonschizophrenic control subjects and 6% of schizophrenic patients who were on neuroleptic medication. Using the same technique of crossed immunoelectrophoresis, we have tried to replicate this finding. In contrast to the original report, we observed "positive" precipitin arcs with IgG concentrates from all 14 serum samples tested. The failure of immunoelectrophoretic methods to provide convincing evidence of pathogenic autoantibodies in schizophrenia in no way detracts from the hypothesis that autoimmune processes are involved in some forms of schizophrenia. Such methods have not proved useful in established autoimmune diseases such as Graves' disease and myasthenia gravis in which the pathogenic autoantibodies against cell-surface receptors can only be detected by assays which measure functional interactions with such receptors.

Adolescent