Duodenal erosions and ulcers in patients with pancreatobiliary obstruction

In order to determine whether obstructive pancreatobiliary lesions increase the risk of duodenal erosions and ulcers, the duodenal mucosa of patients with these lesions were prospectively examined before endoscopic retrograde cholangiopancreatography (ERCP). During the study period, 133 patients underwent ERCP for various reasons in the Department of Medicine, The Aga Khan University Hospital. One hundred and twenty-three patients were eligible for final analysis. Sixty-five patients with bilirubin ≥ 35 μmol/L and alkaline phosphatase ≥ 2.5 times normal levels along with radiological evidence of pancreatobiliary obstruction were included in the obstruction group. Fifty-eight patients who did not fulfil these criteria were used in the control group. Acid peptic lesions, which included erosions and ulcers, were seen in 16 patients of the obstruction group and four patients of the control group (P=0.016, odds ratio (OR) = 4.41). Patients with carcinoma of the pancreas had a greater number of lesions than the rest of the obstruction group (P= 0.001, OR=8.75). Individual variables like age, sex, serum bilirubin, alanine aminotransferase, alkaline phosphatase, amylase levels, and duration of jaundice did not increase the vulnerability to acid peptic injury. The degree of obstruction multiplied by duration of jaundice (alkaline phosphatase x days) increased the susceptibility for duodenal disease (P=0.047). From this data it was concluded that patients with obstructive pancreatobiliary lesions are more prone to acid peptic duodenal lesions.     

Dietary factors influencing levels of food antibodies and antigens in breast milk

The effect of a milk-free diet during late pregnancy and lactation, on levels of cows'milk specific antibodies and antigens in breast milk, was examined. Women with an allergic condition (defined as atopic) were randomly allocated to a milk-free diet ( n = 10) or an unrestricted diet ( n = 12). Twelve non-atopic women followed an unrestricted diet. A significant reduction ( p < 0.001) in β-lactoglobulin-specific immunoglobulin A and α-casein-specific immunoglobulin A levels was observed over the first 5 days in all groups. The mean level of β-lactoglobulin antigens in breast milk from women who adhered strictly to the milk-free diet was significantly lower than the levels of the atopic group on the unrestricted diet ( p < 0.02). The allergy incidence in the infants born in the atopic diet group was significantly lower compared with that of the atopic group on the unrestricted diet.     

高效液相色谱法测定马钱属植物中士的宁和马钱子碱的含量

高效液相色谱法测定马钱属植物中士的宁和马钱子碱的含量顾志平张曙明王春兰连文琰肖培根陈建民（中国医学科学院、中国协和医科大学药用植物研究所，北京１０００９４）马钱属植物我国产１０种，主要分布于广东、广西、海南、云南等省区。士的宁和马钱子碱是该属植物的主...     

A Satiety Quotient: A Formulation to Assess the Satiating Effect of Food

This paper introduces a satiety quotient (SQ) to assess the satiating effect of an eating episode. This procedure constitutes an improvement on previous measures by considering the satiating effects of the eating episode over time. A satiety quotient was calculated from data obtained from several studies involving the presentation of a preload/meal to young lean male and female subjects. Subjects were presented with preloads/meals of varying composition, and motivation to eat immediately prior to, and periodically following, the eating episode were measured. Food and fluids were not consumed whilst motivation to eat was measured in the post preload/meal period. The SQ was calculated by dividing the difference between ratings of motivation to eat before and after the eating episode (pre minus post) by the weight or energy content of intake during the episode. This quotient relates intake to the rate of return of motivation to eat in the post-ingestive period, a relationship which is not apparent on separate examination of the amount consumed or ratings of motivation to eat. Development of this satiety quotient is a further contribution to the evolution of the concept of quantifying satiating effects of foods, and provides additional information on the effects of food attributes on short-term appetite control.     

Spectroscopic analysis of [Trp3]-β-casomorphin analogs Comparative structure conformation-activity studies

A series of [3-tryptophan]-β-casomorphin-5([Trp³]-β-CM-5) analogs were investigated by circular dichroism (CD) and fluorescence spectroscopy to explore their structure-conformation properties in solution. In addition, the comparative opioid activities of these compounds were evaluated using the in vitro guinea pig ileum (GPI) and mouse vas deferens (MVD) assays. Specifically, the pentapeptide sequence of [Trp³]-β-CM-5, H-Tyr-Pro-Trp-Pro-Gly-OH (I) was modified at Pro-2 and Pro-4 by d -Pro substitutions to provide two diastereometric analogs, [Trp³-d -Pro-4]-β-CM-5 (II) and [d -Pro^2,4,Trp³]-β-CM-5 (III). In the GPI and MVD assays, β-CM-5 effected IC₅₀ values of 1.3 μm and 8.9 μm , respectively, which confirmed its known μ/δ-selectivity on these two peripheral opioid receptor subtypes. The potencies of compounds I, II, and III were 0.2, 2.0, and < 0.005 relative to β-CM-5 on the GPI assay. Compounds I and II exhibited pronounced μ/δ-selectivities (> 18.9- and 12.4-fold respectively), whereas compound III was essentially inactive in both the GPI and MVD assays. CD studies of β-CM-5 and its [Trp³]-β-CM-5 analogs showed striking differences in their near-UV and far-UV spectra in aqueous or organic solvents. In the far UV CD spectra, weak (20%) α-helicity (maximum at 193 nm and minima at 208 and 222 nm) for β-CM-5 was obtained in trifluoroethanol (TFE); however, none of the [Trp³]-β-CM-5 analogs showed such CD bands. Of potential relevance to γ-turn or C₇ secondary structure was the observation of a strong negative band at 245 nm for compounds II and III which was not solvent-dependent in H₂O or TFE, whereas compound I showed this CD band exclusively in TFE. In the near-UV CD at 275 nm (Trp electronic transition), the relative order of intensities of this band were determined for the [Trp³]-β-CM-5 compounds to be II > I > III, which was identical to their relative biological potencies in both the GPI and MVD assays. Fluorescence energy transfer (FET) experiments of compounds I-III provided the intramolecular distances (r) between their Tyr (donor) to Trp (acceptor) side-chains, by the Förster method, and were as follows: [Trp³]-β-CM-5, r = 10.6Å; [Trp³, d -Pro⁴]-β-CM-5, r = 9.6Å; and [d -Pro^2,4,Trp³]-β-CM-5, r = 11.0Å. A rank order correlation existed between the Tyr-Trp intramolecular distances and biological activity with shorter distance corresponding to higher biological potency. Furthermore, based on the fluorescence lifetime data analysis (Globals software) of the [Trp³]-β-CM-5 analogs, which were best fitted to a double exponential decay model, the relative ranking of long (> 1.5 ns) lifetime fractions of these three compounds was II > I > III. In summary, detailed spectroscopic analysis of three [Trp³]-β-CM-5 diastereomeric analogs by CD and FET have provided intriguing data indicating a possible structure conformation-activity relationship among these μ/δ-selective opioid-mimetic compounds.