Anaphylactic colonic hypersecretion in cow's milk sensitized guinea-pigs depends upon release of Interleukin-1, prostaglandins and mast cell degranulation

Methods: The effect of β-lactoglobulin (β-LGI) challenge on net water movements into the proximal colon and the role of Interleukin-1 (IL-1), prostaglandins and mast cell degranulation on the challenge-induced net water changes were assessed in vivo using isolated colonic loops in anaesthetized guinea-pigs immunized to bovine milk. Results: β-lactoglobulin challenge infused into the colonic loop during 30 min reversed the net water flux into a net secretion during the period of antigen infusion. Doxantrazole, a mast cell stabilizing agent, administered 120 min before challenge infusion, suppressed challenge-induced hypersecretion. Similarly recombinant IL-1 receptor antagonist protein abolished the antigen-induced colonic secretory effect. Indomethacin, a prostaglandin synthesis inhibitor, administered 20 min prior to antigen infusion, significantly (P < 0.05) reduced, but did not abolish, the challenge-induced colonic secretory effect. Conclusions: These results suggest that IL-1 plays an important role in antigen challenge-induced colonic hypersecretion which involves mast cell degranulation and prostaglandin release.     

Reference values of gastric intramucosal pH in children

To determine the reference values of gastric intramucosal pH (pHi) by tonometry in paediatric patients, we studied 17 children (nine males, eight females) with no systemic or gastrointestinal disease, aged six months to 12 years undergoing minor reconstructive surgery. Following anaesthetic induction a sigmoid tonometry catheter was inserted (Tonometrics, Inc.) into the stomach of the patients under direct vision. All children were normoventilated and were haemodynamically stable. After an equilibration period of 30 min, gastric pHi was calculated by applying the Henderson-Hasselbalch equation on the Pco ₂ obtained with the tonometer and the bicarbonate from the arterial blood gas analysis. The mean gastric pHi in our patients was 7.35±0.06 (sd ). The normal pHi in the general population is estimated to be 7.31–7.40, with a confidence interval of 99%. No correlation was found between pHi and arterial pH, bicarbonate or base excess. Under conditions of normal ventilation and haemodynamic stability, healthy children during general anaesthesia have gastric intramucosal values similar to those of adults.     

Accuracy of five electronic foramen locators with different operating systems: an ex vivo study

Objective:

The aim of this study was to evaluate, ex vivo, the precision of five electronic root canal length measurement devices (ERCLMDs) with different operating systems: the Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApex A-15, and the possible influence of the positioning of the instrument tips short of the apical foramen.

Material and Methods:

Forty-two mandibular bicuspids had their real canal lengths (RL) previously determined. Electronic measurements were performed 1.0 mm short of the apical foramen (-1.0), followed by measurements at the apical foramen (0.0). The data resulting from the comparison of the ERCLMD measurements and the RL were evaluated by the Wilcoxon and Friedman tests at a significance level of 5%.

Results:

Considering the measurements performed at 0.0 and -1.0, the precision rates for the ERCLMDs were: 73.5% and 47.1% (Root ZX), 73.5% and 55.9% (Mini Apex Locator), 67.6% and 41.1% (Propex II), 61.7% and 44.1% (iPex), and 79.4% and 44.1% (RomiApex A-15), respectively, considering ±0.5 mm of tolerance. Regarding the mean discrepancies, no differences were observed at 0.0; however, in the measurements at -1.0, the iPex, a multi-frequency ERCLMD, had significantly more discrepant readings short of the apical foramen than the other devices, except for the Propex II, which had intermediate results. When the ERCLMDs measurements at -1.0 were compared with those at 0.0, the Propex II, iPex and RomiApex A-15 presented significantly higher discrepancies in their readings.

Conclusions:

Under the conditions of the present study, all the ERCLMDs provided acceptable measurements at the 0.0 position. However, at the -1.0 position, the ERCLMDs had a lower precision, with statistically significant differences for the Propex II, iPex, and RomiApex A-15.     

The cell cycle in psoriasis

The cell cycle has been determined in eight in-patients with psoriasis. The cell cycle time for the germinative cell compartment has been found to be 91 h, and the turnover time for the epidermal compartment, beneath the keratin layer to be 120 h (5 days). The duration of the S phase (DNA synthesis) has been found to be 10 h, and that for mitosis 30 min. If it is accepted that the turnover time for the keratin layer is 2 days, then the turnover time for the epidermis in psoriasis is 7 days, and not 3–4 days as previously described.     

EFFECT OF RETINOIC ACID IN PSORIASIS, II

Summary.— Clinical and histological features and mitotic counts have been studied in the lesions of 11 patients with psoriasis who were treated with topically applied retinoic acid ointment for a period of 3 months.
Serial biopsies were taken at monthly intervals from treated lesions in all 11 patients and from lesions treated with the unmedicated ointment base in 9.
There was no significant difference between treated and placebo groups regarding any of the parameters studied. Irritant effects of the retinoic acid were prominent in 7 patients.
The significance of these results is discussed in the light of the known mechanism of action of retinoic acid.     

Acrodermatitis Acidemica: Experience of 5 Years in Andalusia

Letters to the Editor are welcomed for publication (subject to editing). Letters must be signed by all authors, and must not exceed two pages of text including references. Letters should not duplicate material submitted or published in other journals. Prepublication proofs will not be provided.     

Alterations of colonic motility after oral administration of prostaglandin E1 analogue misoprostol in man

This study describes the motor changes observed in human colon under normal feeding schedule, after administration of a single oral does of misoprostol, a PGE₁ synthetic analogue. Fourteen patients (3 men, 11 women, mean age 45±7 years), with chronic abdominal pain but without any detectable organic digestive disease were studied. The colonic motor activity was recorded by endoluminal electromyography during 218-h recording sessions over 2 consecutive days. Misoprostol 600 μg or placebo was randomly administered in double-blind manner either on the first or the second day of the recording period. In 8 patients, misoprostol was administered orally 1 h before the dinner (17.30 hours) and in 6 patients at the beginning of the night-time (23.00hours). Meals were standardized and scheduled during the whole recording session in the same way for all patients. After placebo, colonic response to feeding was characterized by an increase in colonic motor activity mainly concerning the percentage of time occupied by long spike bursts (LSBs =+232%) and migrating long spike bursts (MLSBs =+214%) (p < 0.05). Short spike burst activity (SSBs) was not affected by feeding. Administered before the meal, misoprostol (600 μg) strongly reduced percentage of time occupied by the LSBs activity during post-cibal period (-46%) when compared to placebo (P < 0.01). On the contrary, MLSBs and SSBs activities were similar in post-prandial period after placebo and misoprostol. Administration of misoprostol during the nighttime did not affect the basic colonie myoelectrical pattern when compared to placebo. We conclude that an oral administration of misoprostol before a meal alters the colonic response to feeding, mainly the contractile activity of LSBs.