Pulmonary vein stenosis after catheter ablation of atrial fibrillation

BACKGROUND: This report describes the complication of pulmonary vein stenosis with resultant severe pulmonary hypertension that developed in 2 patients after successful catheter ablation of chronic atrial fibrillation. METHODS AND RESULTS: Three months after successful catheter ablation of atrial fibrillation, both patients developed progressive dyspnea and pulmonary hypertension. Both were found to have severe stenosis of all 4 pulmonary veins near the junction with the left atrium. Balloon dilation of the stenotic pulmonary veins was performed in these patients, with improvement in dyspnea and pulmonary hypertension. CONCLUSIONS: The complication of pulmonary vein stenosis is potentially life-threatening, and the application of radiofrequency current within the pulmonary veins with standard catheter technology should be avoided. This complication can be treated with balloon dilation, although the long-term course is unknown.     

Pain syndrome in gastroenterological practice: potentialities of evaluation

Qualitative and quantitative characteristics of chronic pain syndrome and their possible use in assessing analgetic effects of treatment were studied in 16, 49, 26 and 17 patients with gastric ulcer, duodenal ulcer, chronic pancreatitis, chronic colitis, respectively. Pain was measured with the use of McHill's questionnaire modification and visual-verbal-analog scale. In addition to routine analysis of the data from the respondents, graphic mean profiles of pain for each group have been devised. There were differences in quantitative parameters of pain syndrome depending on nosological unity and profiles of patients. The questionnaire proved rather informative in evaluation and gradation of analgetic effects of therapeutic factors in ulcer patients.     

Plasma osmolality and brain water content in a rat glioma model

Little is known about how intravenous fluids influence peritumoral edema formation. This experiment was designed to determine, in a rat glioma model, whether changes in plasma osmolality alter water content, as assessed by specific gravity (SpGr), in normal and neoplastic cerebral tissue. Cells cultured from an ethylnitrosourea-induced rat glioma were stereotactically implanted into the right striatum of Fischer 344 rats. A tumor growth interval of 21 days was allowed. In a second experiment, rats underwent a 60-second cortical freeze injury followed by 24 hours' recovery. In both experiments, rats were assigned to one of three groups: hypotonic (100 ml/kg of 0.2 mol/L NaCl in H2O, intraperitoneally; resultant plasma osmolality approximately 268 mOsm/kg); isotonic (no treatment; plasma osmolality approximately 298 mOsm/kg); or hypertonic (10 ml/kg of 1.0 mol/L NaCl in H2O, intraperitoneally; plasma osmolality approximately 342 mOsm/kg). Thirty minutes after fluid injection, regional SpGr was determined using a kerosene-bromobenzene gradient. In subsets of rats, the tissue morphology and blood-brain barrier permeability of Evans blue dye were assessed. Tissue within the freeze lesion was stained by Evans blue dye with sharp demarcation. Evans blue dye did not stain gliomatous tissue, and central necrosis was not histologically evident. In isotonic rats, glioma SpGr was reduced (1.0411 +/- 0.0012 g/ml) relative to the contralateral striatum (1.0437 +/- 0.0008 g/ml; P < 0.001). Despite this, a strong linear relation was observed for SpGr and plasma osmolality in both neoplastic and normal tissue. Within the freeze lesion in isotonic rats, SpGr was severely reduced (1.0335 +/- 0.0008 g/ml; P < 0.0001) compared with contralateral frontal cortex.(ABSTRACT TRUNCATED AT 250 WORDS)     

A study of the protein composition of the zona pellucida of mammalian oocytes and zygotes by a method of microelectrophoresis in polyacrylamide gel

It is known that drugs are not unlimitedly stable. Dilutions of the antineoplastic agent daunoblastin used in the clinic and experimental work, were examined, whether they could be stored for several days. By means of impulscytophotometry, spectral-photometric measurements, counting of surviving cells and estimation of DNA-synthesis after culturing pieces of tissue in the presence of daunoblastin it could be established that this drug, diluted even four days ago, still possesses sufficient activity.     

An investigation of wet-and dry-bulb psychrometry in metallic vapor-gas systems

Wet- and dry-bulb temperatures were measured for Hg-N₂ and Cd-H₂ systems in a high temperature psychrometer apparatus specially constructed for this purpose. The apparatus features a device termed a self-adjusting shield developed to minimize heat transfer by radiation. A correlation for the psychrometric ratio for spherical shaped wet bulbs was formulated and experimental results showed close agreement with the theoretical values calculated from the proposed correlation. Formerly Graduate Student, University of New South Wales, Formerly Associate Professor, University of New South Wales     

The effect of an electric field on the solidification of off-eutectic tin-lead composite alloys

The influence of an electric field upon the directional solidification of hypoeutectic and hypereutectic Sn-Pb composite alloys was studied. Equations were derived to account for the effect of electrotransport of solute in the liquid upon the solid composite composition. Experimental results support the theoretical predictions. Mixing in the liquid is more strongly influenced by unstable solute gradients than by current induced convection. Electrotransport shows limited promise as a method for control of the volume fraction fibre phase in the preparation of aligned composites by directional solidification.     

Measurement of integrated sensory-motor function following brain damage by a computerized preview tracking task

A preview tracking task has been developed which has particular application to neurological assessment and rehabilitation. Generated and monitored by a graphic display computer, it permits accurate global quantification of the upper-limb sensory-motor system. The incorporation of 'preview' into the tracking task is considered to significantly increase its effectiveness and relevance in relation to normal daily activities. Applied to three groups of normal subjects, several features of normal psychomotor performance and learning were identified or verified: hand dominance is not significant in overall arm control; learning does not completely plateau; increase in age (15-59 years) results in only a minor overall decrement in performance; an initial wide performance distribution decreases dramatically in subsequent sessions. Applied to brain-damaged patients, particularly head injury or stroke, the preview tracking task allows assessment at regular intervals enabling sensory-motor recovery curves to be generated. The potential of this technique, to help determine the efficacy of therapeutic procedures on the recovery process, is illustrated with the presentation of results from three brain-damaged patients demonstrating zero, significant and disjointed recovery of sensory-motor function. The usefulness of the preview tracking task can be expanded by combination with a less frequently applied but more component specific neurological assessment battery.     

Alkane contamination of lipids extracted fromLagenidium giganteum andLagenidium callinectes

Alkanes associated with the mycelia of the fungiLagenidium giganteum andL. callinectes were analyzed. Careful studies showed that these substances were contaminats derived from glass ware, media and solvents. No alkane biosynthesis or transformation was detected, indicating little or no alkane metabolism. The importance of using clean techniques, high-purity solvents and proper media controls was emphasized.