Receptor-selective analogs demonstrate NPY/PYY receptor heterogeneity in rat brain.

Neuropeptide Y (NPY) receptors are heterogeneous, consisting of at least two subclasses, Y1 and Y2. We sought evidence for differential expression of NPY receptor subtypes in the rat brain. Tissue was incubated with 125I-peptide YY (PYY) which labels NPY and PYY binding sites. The Y1-selective agonist, p[Pro34]NPY, and the Y2-selective agonist, pNPY 13-36, were used as displacing ligands. Autoradiographic analyses of regional receptor binding demonstrated heterogeneity across brain regions. We conclude that Y1- and Y2-receptors may be independently expressed in the brain. While the predominate NPY/PYY receptor subtype in the brain is Y2, there are also Y1-receptors in some brain regions such as the superficial layers of the parietal cortex.     

Passive immune hemolysis for detection of heat-labile enterotoxin produced by Escherichia coli isolated from different sources.

Fifty-one strains of Escherichia coli isolated from humans, swine, food, and water and identified as enterotoxinogenic by the Y-1 adrenal cell assay, were examined for heat-labile enterotoxin (LT) production by the passive immune hemolysis test. Cholera antitoxin, anti-choleragenoid and anti-LT were used as antisera. Cholera antitoxin was much more potent than anti-choleragenoid and LT antiserum in the detection of LT-positive strains. All strains isolated from pigs and sausage were negative in tests made with LT antiserum. A few strains isolated from humans, food, and water also gave negative results. These data showed that the passive immune hemolysis test is not as efficient as the Y-1 adrenal cell assay in the detection of enterotoxinogenic E. coli strains.     

A European study on the genetics of mite sensitization

BACKGROUND: Sensitization to mite allergens represents a prominent feature of atopy and an important predictor of bronchial asthma. OBJECTIVE: It was the intention of this study to define genetic loci linked to mite sensitization because these could represent the genetic basis of the important atopic component of asthma. METHODS: We studied a multiethnic white population of 99 families, including 224 sib pairs sensitized to Dermatophagoides pteronyssinus. A genome-wide candidate-region search was performed that covered potential asthma and atopy regions. RESULTS: As for nonparametric linkage (NPL) analysis, 14 of the candidate regions showed evidence for linkage (NPL > 2.0), and 4 of them showed prominent linkage (NPL > 3.0). However, there were substantial ethnic differences. Maximizing the LOD score analysis identified candidate regions with suspected dominant and recessive mode of inheritance. Furthermore, genetic imprinting models provided significant evidence for linkage in the 8p23 region and revealed potential maternal imprinting. The regions found are distinct to those in asthma searches that have been found to be linked to asthma, as well to other inflammatory diseases. In addition, we could not find linkage to the HLA region. By different cutoff points of the phenotype definition, the IL cluster showed evidence of being linked to the degree of sensitization rather than to sensitization per se. CONCLUSION: The results indicate that the genetic basis of the atopic component of asthma is different from that of the inflammatory component. Furthermore, it seems reasonable to assume that specific sensitizations are influenced by distinct genetic variants leading to their initiation versus those leading to their enhancement.     

Expression of ATM, p53, and the MRE11-Rad50-NBS1 complex in myoepithelial cells from benign and malignant proliferations of the breast

AIMS: To analyse the expression of proteins involved in DNA double strand break detection and repair in the luminal and myoepithelial compartments of benign breast lesions and malignant breast tumours with myoepithelial differentiation. METHODS: Expression of the ataxia telangiectasia (ATM) and p53 proteins was immunohistochemically evaluated in 18 benign and malignant myoepithelial tumours of the breast. Fifteen benign breast lesions with prominent myoepithelial compartment were also evaluated for these proteins, in addition to those in the MRE11-Rad50-NBS1 (MRN) complex, and the expression profiles were compared with those seen in eight independent non-cancer (normal breast) samples and in the surrounding normal tissues of the benign and malignant tumours examined. RESULTS: ATM expression was higher in the myoepithelial compartment of three of 15 benign breast lesions and lower in the luminal compartment of eight of these lesions compared with that found in the corresponding normal tissue compartments. Malignant myoepithelial tumours overexpressed ATM in one of 18 cases. p53 was consistently negative in benign lesions and was overexpressed in eight of 18 malignant tumours. In benign breast lesions, expression of the MRN complex was significantly more reduced in myoepithelial cells (up to 73%) than in luminal cells (up to 40%) (p=0.0005). CONCLUSIONS: Malignant myoepithelial tumours rarely overexpress ATM but are frequently positive for p53. In benign breast lesions, expression of the MRN complex was more frequently reduced in the myoepithelial than in the luminal epithelial compartment, suggesting different DNA repair capabilities in these two cell types.     

Cervical muscle response to trunk flexion in whiplash-type lateral impacts

The purpose of this study was to determine the response of the cervical muscles to increasing low-velocity, whiplash-type lateral impacts when the occupant is seated out of the recommended driving position (neutral posture). Twenty healthy volunteers were subjected to left lateral impacts of 4.1, 7.7, 10.5, and 13.7 m/s² acceleration, with their trunk flexed by 45° and laterally flexed to the right and left also by 45° at the time of impact. Bilateral electromyograms of the sternocleidomastoids, trapezii, and splenii capitis were recorded. Under these conditions of trunk-flexed postures, in a left lateral impact, muscle responses were of generally low magnitude with the trunk flexed to either the left or right. Even at the highest acceleration of 13.7 m/s², all muscles generated less than 37% of their known maximal voluntary contraction electromyogram. Also, in these left lateral impacts, the right splenius capitis showed a greater EMG response than the left splenius capitis regardless of whether the subject was flexed to the right or left at the time of impact. The right splenius capitis (the one contralateral to the left lateral impact direction) was more active than its counterpart. Compared to what is known for EMG responses with an occupant in the neutral posture, the right sternocleidomastoid (usually the most active muscle in a left lateral collision) was significantly less-active with trunk flexion than with neutral posture conditions (P<0.01). In the absence of bodily impact, the flexed trunk posture does not produce a biomechanical response that would increase the likelihood of cervical muscle injury in low velocity lateral impacts, and may lessen the risk of injury for some muscles.     

The Helix aspersa (brown garden snail) allergen repertoire

BACKGROUND: Ingestion of snails can induce strong asthmatic or anaphylactic responses, mainly in house-dust-mite-sensitized patients. The aim of this study was to identify the Helix aspersa (Hel a), Theba pisana (The p) and Otala lactea (Ota l) allergens and the extent of their cross-reactivity with the Dermatophagoides pteronyssinus (Der p) mite. PATIENTS AND METHODS: In 60 atopic patients, skin prick tests (SPT) to snail and D. pteronyssinus, total and specific IgE, specific IgE immunoblots, RAST and immunoblot inhibition assays were performed. RESULTS: Mean total IgE was >1,000 kU/l. Mean specific IgE (class 6 for Der p and class 2 for Hel a) SPT were positive in 44 patients for snail and in 56 for mite. Isoelectric focusing (IEF) and SDS-PAGE followed by immunoblotting of H. aspersa extract enabled the identification of 27 and 20 allergens, respectively. Myosin heavy chains from snails (molecular weight >208 kDa) disclosed two major allergens. Hel a and Der p RAST were strongly inhibited by their homologous extracts, with Hel a RAST being inhibited by the Der p extract to a much greater extent (72.6%) than the inverse (5.6%). A complete inhibition of the immunoblots by their homologous extract was obtained. However, Hel a extract did not inhibit Der p IEF separated recognition. On the other hand, mite extract extensively inhibited snail immunoblots from both IEF and SDS-PAGE separations. Immune detection on chicken, pig, rabbit, cow and horse myosins did not reveal any IgE cross recognition with snail. CONCLUSIONS: In most cases of snail allergy, mite appeared to be the sensitizing agent. Nevertheless, snails may also be able to induce sensitization by themselves. This hypothesis is supported by the finding of specific IgE to Hel a in 2 patients who did not show specific IgE to Der p, and one of them was suffering from asthma after snail ingestion.     

Presence of the cfxA gene in Bacteroides distasonis

In this study we investigated the presence of the cfxA gene (encoding a class A beta-lactamase) in 73 strains of the Bacteroides fragilis group belonging to the species B. distasonis (34), B. vulgatus (14), B. thetaiotaomicron (8), B. merdae (6), B. caccae (9) and B. ovatus (2) isolated from human intestinal microflora of healthy children and adults. Employing specific primers to the cfxA gene, a 312-bp amplified fragment was obtained in 2 strains of B. vulgatus and 9 strains, the majority from children, of B. distasonis. The expression of this enzyme was analysed by determining the MICs to cefoxitin and cefotaxime and values varied from 2 to >256 microg/ml of both cefoxitin and cefotaxime. Sequence analysis of the amplicons corresponding to the cfxA gene from B. distasonis and B. vulgatus revealed identical sequences between these isolates and high similarity with other beta-lactamase genes of anaerobes such as cfxA of B. vulgatus (99%) and cfxA2 of Prevotella intermedia (99%), both sequences of which deposited in Genbank under accession numbers U38243 and AF118110, respectively. However, a fragment obtained from a B. distasonis strain (EC17-4) showed a unique RFLP profile and 87% nucleotide similarity with cfxA and cfxA2 genes. These results seem to suggest a dissemination of these resistance determinants among Bacteroides species.     

Anatomic study of the tricuspid valve in children

We performed an anatomic study of the right atrioventricular valve in children under one year of age using a conservative method of dissection of the heart valve. The main aspects studied were the number of cusps and their morphometric characteristics, such as the width of the base and the depth of the cusps. Other parameters studied were the number of papillary muscles, number of tendinous cords, and diameter of the fibrous ring and the last one were divided in three regions, anterior, posterior and septal for localization of cusps. Our results showed that the number of cusps varied from two to four. Three cusps was the commonest finding and the fourth cusp, if present, was classified as anterolateral in location. The anterior and septal cusps had bases bigger than those of the posterior and anterolateral cusps; the septal cusp was deeper than the others; and the number of tendinous cords was greater for the anterior and septal cusps than for the posterior and anterolateral cusps. In addition, the posterior region showed great variability: in 35.7% it was occupied by undeveloped valve tissue and the posterior valve in these cases was located anteriorly.     

Chronic treatment of female rhesus monkeys with low doses of the antiprogestin ZK 137 316: establishment of a regimen that permits normal menstrual cyclicity

Large doses of antiprogestin typically disrupt menstrual cyclicity. A chronic low-dose regimen of the potent new antiprogestin ZK 137 316, which permits continued menstrual cyclicity but alters gonadal- reproductive tract activity, was established. Rhesus monkeys received vehicle (n = 6) or 0.01 (n = 8), 0.03 (n = 8) or 0.1 (n = 5) mg ZK 137 316/kg body weight daily for five menstrual cycles (C-1 to C-5). Oestradiol, progesterone and gonadotrophin profiles were normal during cycles involving vehicle and 0.01 and 0.03 mg ZK 137 316/kg body weight. In the 0.1 mg/kg group, mid-cycle oestradiol and gonadotrophin surges, and subsequent progesterone production, were absent in C-3 and C-5. Ovarian cyclicity was accompanied by timely menstruation in the vehicle and 0.01 mg/kg groups. By C-3, half the animals in the 0.03 mg/kg group and all animals in the 0.1 mg/kg group were amenorrhoeic. A corpus luteum was noted during the mid-luteal phase of C-5 in the vehicle, 0.01 mg/kg and 0.03 mg/kg groups. Large antral and cystic follicles were evident in the 0.1 mg/kg group. Thus, a daily treatment with 0.01 mg/kg ZK 136317 permitted normal menstrual cyclicity in macaques. While the daily administration of 0.03 mg/kg ZK 136 317 allowed ovarian cyclicity, menstruation was disrupted in some animals. Increasing the dose to 0.1 mg/kg antagonized pituitary function and resulted in anovulation and amenorrhoea. A chronic low-dose regimen of the antiprogestin ZK 137 316, which permits normal ovarian/menstrual cyclicity, has potential as a contraceptive in women.