Exclusion from proximal 11q of a common gene with megaphenic effect on atopy

We have typed three markers on proximal 11q in 131 random families with three or more children studied for atopy. A summary map that includes the FCER1B candidate was constructed. Using a 2-locus disease model, we performed combined segregation and linkage analysis of three models, none of which suggested linkage. Nine marker loci on other chromosomes were also negative. In the regions swept by these 12 markers we cannot rule out a rare gene, perhaps of large effect, nor a common gene of small effect. However, a common gene of large effect is excluded. These results and alternative strategies are discussed in the perspective of inconsistent evidence for a major atopy gene.     

A Hemodynamically Responsive Antitachycardia System: Theoretical Bases for Design

Current antitachycardia systems such as the automatic implantable cardioverter/defibrillator (AICD), detect tachyarrhythmias primarily by sensing rate and thereby perform inadequately in differentiating hemodynamically stable from unstable arrhythmias. As a result, these devices may discharge during stable tachycardias (such as sinus tachycardia), causing discomfort to the patient and depleting the device's limited energy supply. If a parameter which could reflect the particular hemodynamic state of a tachycardia were incorporated into the sensing algorithm of these systems, function may be more hemodynamically precise and discharge specificity may be improved.     

Visual event-related potentials in first-episode psychotic patients and their relatives

We conducted a comprehensive examination of the sensory visual event-related potential (ERP) of psychiatric patients and their relatives using a methodology that improves upon those used previously by other investigators. One hundred thirty-five patients at the onset of their first psychotic episode, 146 first-degree relatives of these patients, and 113 normal controls were exposed to light flashes of four different intensities while their ERPs were recorded from three central scalp sites. For most analyses, various ERP amplitude measures did not discriminate the different psychiatric groups or their relatives either from one another or from the normal controls. These findings indicate that patients with schizophrenia, schizophreniform disorder, and affective disorder at the early stage of their illness do not display significant deficits in the processing and regulation of simple sensory visual stimulation.     

ANTIDIURETIC HORMONE IN BRONCHOGENIC CARCINOMA

Immunoactive antidiuretic hormone (ADH) was measured by radioimmunoassay in the plasma, lung tumours and metastatic tumours of nineteen patients with bronchogenic carcinoma. Ten patients had hyponatraemia and carcinoma of the small oat cell type. Plasma ADH measured in nine of these patients ranged from 11--270 pg/ml and was elevated above the normal range (4.6--6.2 pg/ml) in all subjects. ADH-immunoreactive material was detectable in all primary lung tumours (range 9--1080 pg/mg wet weight, n = 7) and metastases (range 5--63 pg/mg wet weight, n = 9) obtained from the hyponatraemic patients. A statistical relationship existed between plasma and tumour ADH concentration in six patients where both measurements were performed. Three patients had small cell carcinomas (two oat cell and one anaplastic) without overt hyponatraemia. ADH-like material was detectable in the lung tumours (18 and 1.1 pg/mg wet weight) and liver metastases (4 and 1.0 pg/mg wet weight) of two patients but not in the third. Four of the remaining patients had squamous cell carcinomas and two had adenocarcinomas. None had hyponatraemia. ADH-like material was undetectable in all lung tumours, metastatic tumours and uninvolved tissue from these patients. ADH extracted from the pituitaries of four patients ranged from 6400--13200 pg/mg wet weight. ADH immunoreactive extracts of six lung tumours and nine metastases (all oat cell) showed the same pattern on elution from a Sephadex G-25 column. A large peak, which made up 65% of the total activity, was eluted in the same position as synthetic arginine vasopressin and contained comparable amounts of immunoreactive and bioactive ADH. Two smaller peaks (8 and 27% of total activity) were eluted in positions of higher molecular weight and contained more immunoreactive than bioactive ADH. In contrast, three of four pituitary extracts showed only a single peak which eluted in the same position as marker vasopressin.     

Hemodynamic Responses to Rapid Pacing: A Model for Tachycardia Differentiation

The hemodynamic responses to rapid atrial and ventricular pacing were examined in 10 closed-chest anesthetized dogs in an attempt to distinguish hemodynamically stable from unstable tachycardias. Pressure monitoring catheters were placed in the femoral artery, right atrium, and right ventricle to measure mean arterial pressure, mean right atrial pressure, and mean right ventricular pressure at baseline heart rate and after rapid high right atrial and right ventricular apex pacing. Pressures recorded during rapid pacing (average of the pressures at 30 and 60 seconds of pacing) at pacing rates of 180, 250, and 280/minute were compared to those recorded initially at baseline heart rates. Rapid right ventricular apex pacing resulted in significant increases in mean right atrial pressure (from 6 ± 1 mmHg (mean ± standard error) to 12 ± 1 mmHg, a 100% increase, P < 0.001) and mean right ventricular pressure (from 11 ±1 mmHg to 16 ± 1 mmHg, a 45% increase, p < 0.02) with marked hemodynamic compromise (mean arterial pressure decreased from 85 ± 6 mmHg to 50 ± 6 mmHg, a 41% decrease, P < 0.01). These parameters remained stable (no statistically significant difference from baseline) during high right atrial pacing. In half of the dogs high right atrial pacing at rates 250 resulted in atrioventricular Wenckebach. Thus, it is concluded that mean right atrial pressure and mean right ventricular pressure may be useful in distinguishing hemodynamically significant tachycardias, and in the future design of antitachycardia devices.     

The SdaBlood Group Antigen in Tissues and Body Fluids

Abstract. In man the Sd^aantigen is present in most secretions with the greatest concentration in urine. There is little difference in the amount of Sd^asubstance in the urine of newborn infants, pregnant women and normal adults but there is a much greater amount in the saliva of newborn infants than in adults. Approximately half the people whose red cells group as Sd(a-) secrete Sd^asubstance in the urine. Anti-Sd^aantibody is present in 50% of Sd(a-) non-secretors of Sd^asubstance, though most of these antibodies only react with the strongest Sd(a +) cells. The greatest Sd^aactivity has been found in human meconium, guinea pig urine and guinea pig kidney. Activity can be detected in the urine of many animal species. The kidneys of 5 bird species did not contain Sd^a.     

Left Septal Atrial Tachycardias: Electrocardiographic and Electrophysiologic Characterization of a Paraseptal Focus

Left Septal Atrial Tachycardias. Objective: The objective was to characterize the electrocardiographic and electrophysiological features of focal atrial tachycardia (FAT) originating from the left septum (LS). Background: FAT is recognized to occur at predefined anatomic locations rather than randomly throughout the atria. We describe the ECG and EP features of ATs originating from the LS as an important site for apparent perinodal tachycardias. Methods: Nine patients presenting with LS FAT from a consecutive series of 384 underwent EP/RFA for symptomatic FAT. Results: The mean age was 56 ± 12 years; 7 female with symptoms for 36 ± 28 months. P wave morphology (PWM) was negative/positive in lead V1 and across the precordial leads and negative or negative/positive in inferior leads in all patients. Tachycardia was incessant in 6 out of 9 patients with a mean tachycardia cycle length 421 ± 56 milliseconds. His A was ahead of P wave in all patients (mean ?15 ± 5 milliseconds) and earlier than CS proximal (mean 4 ± 9 milliseconds). Successful acute focal ablation achieved at a mean of 31 ± 12 milliseconds ahead of P wave with no recurrences at a mean follow‐up of 30 ± 28 months. Conclusion: Although the left septum is an uncommon site for focal AT an awareness of this location for harboring foci is particularly important when mapping apparently right‐sided septal tachycardias. (J Cardiovasc Electrophysiol, Vol. 24, pp. 413‐418, April 2013)