Intrinsic conduction maximizes cardiopulmonary performance in patients with dual chamber pacemakers.

Dual chamber pacemaker programmability allows the possibility of atrially-tracked ventricular pacing in patients who would otherwise have intrinsic atrioventricular (AV) conduction. Thirteen patients with permanent AV sequential pacemakers (ages 50-79) were evaluated with paired exercise tests to determine the cardiopulmonary effects of pacemaker induced right ventricular activation compared with normal AV and intraventricular conduction. Peak oxygen uptake (VO2), oxygen pulse (O2P), respiratory rate (RR), and respiratory exchange ratio (RER) were determined using breath-by-breath analysis of expired gases.

Temporal variations in cold sensitivity of root growth in cold-stored white spruce seedlings.

We examined effects of soil temperature on the number of roots produced by white spruce (Picea glauca (Moench.) Voss) seedlings during the first month of growth following 0-30 weeks of storage in darkness at -2 degrees C. After storage, seedlings were planted in pots and placed in a controlled-environment chamber with a constant air temperature of 11 degrees C and a 16-h photoperiod.

Steric stabilization of microspheres with grafted polyethylene oxide reduces phagocytosis by rat Kupffer cells in vitro.

Sterically stabilized polyethylene oxide-polystyrene copolymer microspheres, (PS-PEO) and charge stabilized polystyrene (PS) microspheres of similar size (1 micron) were prepared in order to compare their uptake by cultured rat Kupffer cells isolated by centrifugal elutriation. The uptake of the sterically stabilized particles was found to be much less than that for the charge stabilized control. The uptake of microspheres stabilized with covalently grafted PEO was lower or equivalent to that of control microspheres stabilized by the adsorption of the non-ionic PEO-polypropylene oxide (PPO-PEO) surfactant Poloxamer 238 or Methoxy-PEO.

Hemodynamic consequences of desmopressin administration after cardiopulmonary bypass.

Desmopressin acetate is used to reduce blood loss after cardiac surgery. However, there have been reports that hypotension can occur with infusion of desmopressin and that postoperative blood loss is not reduced. In this randomized, double-blinded study, we investigated the effects of desmopressin on hemodynamics, coagulation, and postoperative blood loss in patients undergoing primary elective coronary artery bypass grafting (CABG).

Possible impairment of the sympathetic nervous system response to postprandial hypotension in elderly hypertensive patients.

In a randomised, single-blind, cross-over study, the effects of a high carbohydrate meal or 'no meal' on BP, pulse rate, blood glucose, plasma insulin and catecholamine levels were assessed in eight fit, untreated, elderly hypertensive subjects. A significantly greater fall in supine (P = 0.006) and erect (P = 0.

A comparison of inhaled beclomethasone dipropionate and nedocromil sodium as additional therapy in asthma.

We have compared the effects of inhaled beclomethasone dipropionate (BDP) 400 micrograms day-1 with inhaled nedocromil sodium (NDS) 16 mg day-1 as additional therapy in adults with asthma not fully controlled by regular beta-2-agonist inhalers with, or without, oral theophyllines. Seventeen subjects were entered into a 2-week baseline phase, and subsequently in a double-blind crossover fashion into two 8-week phases of daily BDP or NDS. Subjects recorded daily peak expiratory flow rates, morning and evening (PEF am and pm), symptom scores and beta-2-agonist inhaler use.

The effect of infused fat emulsions on reticuloendothelial function in the rabbit.

The effect of the infusion of different fat emulsions (Intralipid and MCT/LCT mixtures) on the reticuloendothelial function of the rabbit has been investigated. Emulsions containing 20% dispersed triglyceride were administered over 6 h to a total of 3 g/kg body weight. The extent of blockade of the reticuloendothelial system was measured using a labelled probe in the form of technetium-99m labelled albumin microspheres.

Learning disabilities: an appraisal of Rorschach response patterns.

Recent developments with the Rorschach invite research concerning cognitive and coping styles of learning disabled students. This study, based on an N of 25 (12 learning disabled and 13 controls), was designed to assess group differences in perceptual accuracy, self-concept, and reactivity. Analysis showed that learning disabled students represent a diverse population for which highly individualized understanding is required if appropriate schooling strategies are to be devised.

Methylphenidate and baseball playing in ADHD children: who's on first?

The effects of 0.3 and 0.6 mg/kg methylphenidate were analyzed in a double-blind, placebo-controlled, cross-over study in which 17 boys (ages 7.

Drug therapy in patients with recent stroke.

At present the treatment of the acute stroke is limited to managing the consequences of the primary event and attempting secondary prevention. The routine use of agents to reverse the cause or ameliorate the effects of stroke appears to be very controversial, and the value of secondary preventative measures is still far from clear. A large number of therapeutic trials have been performed in the past with no clear advantage for any drug.

Crystallization and preliminary X-ray analysis of porcine synovial collagenase.

Crystals of porcine synovial collagenase suitable for an X-ray structure analysis have been obtained. The crystals belong to space group I4, with unit cell dimensions a = b = 160.0 A, c = 53.

Defective lysosomal egress of free sialic acid (N-acetylneuraminic acid) in fibroblasts of patients with infantile free sialic acid storage disease.

Egress of free NeuAc from normal lysosome-rich granular fractions was assessed at NeuAc concentrations of up to 221 pmol/hexosaminidase unit, achieved by exposure of growing fibroblasts to 40-125 nM N-acetylmannosamine for up to 7 days. The normal velocity of NeuAc egress increased with NeuAc loading and with temperature, exhibiting a Q10 of 2.4, characteristic of carrier-mediated transport.

Investigation of osteopaenia in anorexia nervosa.

Sixty-nine female patients, mean age 27.5 years (range 20-40), with a past or current history of anorexia nervosa (DSM III-R) had spinal trabecular bone density assessed by single energy quantitative CT scan. Current exercise and dietary calcium levels were assessed by detailed questionnaires and categorized.

Carrier-mediated transport of monoiodotyrosine out of thyroid cell lysosomes.

Monoiodotyrosine (MIT) crosses the lysosomal membrane of rat FRTL-5 thyroid cells by a carrier-mediated process. In egress studies, MIT lost from inside lysosomes was quantitatively recovered outside lysosomes as MIT, indicating that the compound was transported intact across the lysosomal membrane. In uptake studies, [125I]MIT entry required intact lysosomes and exhibited saturation kinetics.

Focal inpatient treatment planning.

Focal Inpatient Treatment Planning (FITP) is a new method of organizing and choosing among the many data available to the inpatient clinician. FITP emphasizes one Focal Problem, provides criteria for defining it, makes it possible to formulate the problem in operational language, channels free-ranging case discussion into workaday terms, invites the clinician to make explicit a sophisticated view of pathogenesis; including developmental, dynamic, and contextual factors, and ties formulation to intervention through explicit objectives. By requiring language that is jargon-free and accessible to patients and parents, FITP fosters empathy and alliance between the treatment community and the domain of the patient.