Mucosal mast cell counts correlate with visceral hypersensitivity in patients with diarrhea predominant irritable bowel syndrome

Background and Aim: Although increased mast cells in the gut and their role in visceral hypersensitivity in irritable bowel syndrome have been postulated, this relationship remains unclear. Our aim was to determine whether a relationship exists between the number of mucosal mast cells in the gut and visceral hypersensitivity. Method: Eighteen patients with diarrhea predominant irritable bowel syndrome (D‐IBS) (eight females, 10 males aged 25–65 years; mean 42.6 years) with symptoms meeting the Rome‐II criteria, and 15 healthy controls (five females, 10 males aged 31–57 years; mean 41.4 years) were recruited. Participants completed a questionnaire for bowel symptoms and psychological distress. Colonic mucosal mast cells were identified immunohistochemically and quantified by image analysis, and maximally tolerable pressures were evaluated using barostat test. Results: Numbers of mast cells were significantly greater in the terminal ileum, ascending colon and rectum of D‐IBS patients compared with controls (P < 0.01). A multivariate analysis of the barostat test showed that maximally tolerable pressures of D‐IBS patients were significantly lower than those of controls (P < 0.01). When patients were divided into the rectal hypersensitivity (+) and (–) groups by the distension level of 34 mmHg, mast cell counts were significantly higher in the rectal hypersensitivity (–) group than in the rectal hypersensitivity (+) group for the terminal ileum, ascending colon and rectum (P < 0.05, respectively). Conclusions: Rectal sensitivity was enhanced in D‐IBS patients with moderately increased mucosal mast cells, but it was attenuated in patients with markedly increased ones. This study might provide evidence for an important role of mast cells in visceral hypersensitivity.     

Architecture of the Atrial Musculature In and Around the Triangle of Koch:

Atrial Fibers. Introduction : Recent studies suggest that atrial fibers in the approaches to the AV node form part of the dual pathways recognized electrophysiologically in patients with AV nodal reentrant tachycardia (AVNRT). Our aim was to determine, by gross dissection, the arrangement of the superficial musculature in the area of the triangle of Koch In normal hearts and in hearts with documented AVNRT. hoping to ascertain anatomic features that might contribute to the debate.
Methods and Results : We used blunt dissection to study the architecture of the superficial atrial musculature in 16 autopsied hearts from adults who died of noncardiac disease. A well-defined pattern of architecture of muscle fibers was found in the region of the triangle of Koch, showing marked variations in 7 of the 16 specimens. The relationship of these fibers to the histologically specialized AV node was confirmed by histology in three cases. Two hearts from patients with known AVNRT, treated by ablation in one, were examined further histologically. These sections showed that the site of ablation was well distant from the histologically discrete AV node.
Conclusion : The variability in the arrangement of the superficial atrial muscle fibers in the area of the triangle of Koch may be one of the factors influencing the route for impulses entering the AV node. Lesions that ablate nodal reentry are within these atrial fibers rather than the histologically specialized AV node.     

Hydroxocobalamin. I. Blood Levels and Urinary Excretion of Vitamin B12 in Man After a Single Parenteral Dose of Aqueous Hydroxocobalamin, Aqueous Cyanocobalamin and Cyanocobalamin Zinc-Tannate Complex

A single intramuscular injection of 500 or 1000 µg. of hydroxocobalamin to17 individuals resulted in a 1.8- to 4.1-times higher mean serum vitamin B₁₂blood level, respectively, 5 hours after injection; a 4.6- and 12.8-times higherlevel 24 hours after injection; a 2.4- and 5.2-times higher level 72 hours afterinjection, and a 1.6- and 2.4-times higher level by the 2nd through the 4thweek after injection than identical doses of cyanocobalamin administered to19 individuals. The vitamin B₁₂ blood levels following i.m. administration of500 or 1000 µg. of hydroxocobalamin were significantly higher during the first24 and 48 hours, respectively, than they were after a cyanocobalamin zinc-tannate complex given to 17 individuals at identical doses.

After a single i.m. injection of 500 or 1000 µg. of hydroxocobalamin, anaverage of only 16 per cent and 27 per cent, respectively, of the vitamin B₁₂was lost in the 72-hour urines, as compared to 60 per cent and 69 per cent,respectively, after identical doses of cyanocobalamin. These differences, again,were highly significant statistically.

The results of these studies give evidence of a slower rate of urinary excretion of hydroxocobalamin as compared to that of cyanocobalamin, and ofits ability to build up consistently higher and more prolonged vitamin B₁₂levels in the blood.

Submitted on June 6, 1961 Accepted on August 1, 1961     

Pseudo-Pacemaker Syndrome Following Inadvertent Fast Pathway Ablation for Atrioventricular Nodal Reentrant Tachycardia

Pseudo-Pacemaker Syndrome After AV Nodal Ablation. Atrioventricular nodal reentrant tachycardia that is refractory to drug treatment has recently been treated with radiofrequency catheter ablation. In this case report we describe a patient with atrioventricular nodal reentrant tachycardia in whom radiofrequency ablation of slow pathway was attempted, with inadvertent damage to the fast pathway. The patient developed marked first-degree atrioventricular block associated with symptoms mimicking pacemaker syndrome.     

Intestinal metaplasia and gastric carcinoma: A histological study of 198 gastrectomy specimens

One hundred and ninety-eight consecutive gastrectomy specimens (78 gastric carcinomas, 120 benign lesions) were reviewed and examined to study the relation between intestinal metaplasia (IM) and gastric carcinomas (GC). IM was classified as complete (type I) and incomplete (types II and III) depending on the types of mucin secreted. Only type III IM was found to be significantly associated with GC ( P = 0.0005) when GC was treated as a group in contrast to non-neoplastic lesions. On subdivsion into different types of GC, such association was only found in the intestinal type but not the diffuse type. The significance of the association between type III IM and the intestinal type GC is discussed. In addition, dysplasia was significantly associated with GC and not with benign lesions ( P < 0.005).     

Alpha1-Adrenergic Receptor Modulation of Repolarization in Canine Purkinje Fibers

Alpha-Agonists and Repolarization. Introduction: Alpha-adrenergic receptor stimulation increases contractility and prolongs repolarization. These effects are modulated by α₁-adrenergic receptor-mediated inhibition of transsarcolemmal potassium currents.
Methods and Results: We used standard microelectrode techniques to study the actions of 4-aminopyridine (4-AP), which blocks the transient outward current, I_to, and WAY-123,398, which blocks the delayed rectifier, I_k, on canine Purkinje fiber action potential prolongation induced by phenylephrine. At a basic cycle length of 1 second, phenylephrine (0.1 to 10 μ) dose-dependently prolonged action potential duration at 90% repolarization (APD₉₀) from 331 ± 10 msec to 400 ± 12 msec (P < 0.05) at phenylephrine, 10 μ. Phenylephrine did not change phase 1 or plateau height. 4-AP (0.1 mM) decreased phase 1 magnitude, shifted plateau height to more positive potentials (from 0.1 ± 1.8 mV to 14.3 ± 1.1 mV [P < 0.05]), and shortened APD₉₀ from 318 ± 9 msec to 294 ± 8 msec (P < 0.05). 4-AP did not block phenylephrine effects on APD₉₀, which increased, at 10 μ phenylephrine, from 294 ± 8 msec to 342 ± 6 msec (P < 0.05). In contrast, WAY-123,398 (0.1 μ) prolonged APD₉₀ from 360 ± 6 msec to 452 ± 6 msec (P < 0.05), and had no effect on plateau height. In the presence of WAY-123,398, phenylephrine no longer increased APD_9o.
Conclusion: (1) Agents that block I_to shorten APD in Purkinje fibers; and (2) the α-agonist mediated increase of APD in canine Purkinje fibers can be explained by inhibition of I_k.     

Stenotic bicuspid aortic valve associated with a ventricular septal defect in an adult presenting with congestive heart failure: a rare observation

This report is concerned with an adult presenting with stenoticbicuspid aortic valve associated with a ventricular septal defect(VSD). The association between aortic regurgitation (AR) andVSD has often been described, but that between a stenosed aorticvalve and VSD has been rarely observed, although bicuspid aorticvalves and ventricular septal defects are probably the two mostcommon congenital heart defects. The development of congestiveheart failure in the presented case was considered to be dueto an increase in the left to right shunt through the VSD. Thiswas attributable to a progressive elevation in left ventricularpressure as a result of the development, with age, of stenosisof the bicuspid aortic valve.     

The contribution of preterm birth and intrauterine growth restriction to childhood undernutrition in Tanzania

Objectives were to examine the growth patterns of preterm and growth‐restricted infants and to evaluate the associations of prematurity and intrauterine growth restriction (IUGR) with risk of stunting, wasting and underweight. Data from a cohort of HIV‐negative pregnant women–infant pairs were collected prospectively in Tanzania. Small for gestational age [SGA, birthweight (BW) <10th percentile] was used as proxy for IUGR. Anthropometry was measured monthly until 18 months. Length‐for‐age (LAZ), weight‐for‐length (WLZ), and weight‐for‐age (WAZ) z‐scores were calculated using the 2006 World Health Organization (WHO) Child Growth Standards. Stunting, wasting and underweight were defined as binary outcomes using a cut‐off of z‐scores. Multivariate Cox proportional hazard models were used to assess the associations between preterm and SGA to time to stunting, wasting and underweight. The study included 6664 singletons. Preterm and appropriate for gestational age (AGA) infants had slightly better nutritional status than term‐SGA infants and despite some catch‐up growth, preterm‐SGA infants had the poorest nutritional status. The gap in LAZ and WAZ z‐scores among the groups remained similar throughout the follow‐up. Compared with term‐AGA babies, relative risk (RR) of stunting among preterm‐AGA babies was 2.13 (95% confidence interval (CI) 1.93–2.36), RR among term‐SGA was 2.21 (95% CI 2.02–2.41) and the highest risk was among the babies who were both preterm and SGA (RR = 7.58, 95% CI 5.41–10.64). Similar magnitude of RR of underweight was observed among the three groups. Preterm and SGA infants should be closely monitored for growth failure. Intervention to reduce preterm and SGA birth may lower risk of undernutrition in resource‐limited settings.