Insights into the genetic architecture of morphological traits in two passerine bird species.

Knowledge about the underlying genetic architecture of phenotypic traits is needed to understand and predict evolutionary dynamics. The number of causal loci, magnitude of the effects and location in the genome are, however, still largely unknown. Here, we use genome-wide single-nucleotide polymorphism (SNP) data from two large-scale data sets on house sparrows and collared flycatchers to examine the genetic architecture of different morphological traits (tarsus length, wing length, body mass, bill depth, bill length, total and visible badge size and white wing patches). Genomic heritabilities were estimated using relatedness calculated from SNPs. The proportion of variance captured by the SNPs (SNP-based heritability) was lower in house sparrows compared with collared flycatchers, as expected given marker density (6348 SNPs in house sparrows versus 38 689 SNPs in collared flycatchers). Indeed, after downsampling to similar SNP density and sample size, this estimate was no longer markedly different between species. Chromosome-partitioning analyses demonstrated that the proportion of variance explained by each chromosome was significantly positively related to the chromosome size for some traits and, generally, that larger chromosomes tended to explain proportionally more variation than smaller chromosomes. Finally, we found two genome-wide significant associations with very small-effect sizes. One SNP on chromosome 20 was associated with bill length in house sparrows and explained 1.2% of phenotypic variation (VP), and one SNP on chromosome 4 was associated with tarsus length in collared flycatchers (3% of VP). Although we cannot exclude the possibility of undetected large-effect loci, our results indicate a polygenic basis for morphological traits.

Single dipole evanescently coupled to a multimode waveguide.

We consider a single dipole evanescently coupled to a cylindrical multimode waveguide. The emission rate into the waveguide is calculated as a function of the waveguide diameter and the dipole orientations, and the result is confirmed by finite-difference-time-domain simulations. We show that as the guide radius increases, the coupling to a given mode decreases but new decay channels to higher order modes open up to increase the density of states. This study gives insight for designing waveguide-based single photon sources that exploit superposition of transverse modes.

Detrimental role for CD4+ T lymphocytes in murine diffuse peritonitis due to inhibition of local bacterial elimination.

BACKGROUND: Abdominal sepsis due to intestinal leakage of endogenous gut bacteria is a life-threatening condition. In healthy individuals, T lymphocytes have essential functions in balancing the immune response to the commensal gut flora. AIM: To determine how T lymphocytes shape the process of diffuse faecal peritonitis. METHODS: In colon ascendens stent peritonitis (CASP), a clinically relevant mouse model of diffuse peritonitis, the kinetics of systemic T cell activation were investigated by assessment of activation markers. CD4(+) T cells were then depleted with monoclonal antibodies, and survival, bacterial dissemination and cytokine concentrations were measured. T cell receptor signalling was blocked with tacrolimus. RESULTS: In diffuse peritonitis, CD4(+) T cells, both Foxp3(-) and Foxp3(+), became systemically involved within hours and upregulated CTLA-4 and other activation markers. Depletion of the CD4(+) T cells enhanced local bacterial clearance from the peritoneal cavity, reduced bacterial dissemination and improved survival. This was accompanied by increased immigration of granulocytes and macrophages into the peritoneum, indicating that CD4(+) T cells inhibit the local innate immune response. Blockade of T cell receptor (TCR) signalling by tacrolimus did not influence the survival in this peritonitis model, showing that the inhibitory effects of the CD4(+) T lymphocytes were independent of TCR-mediated antigen recognition. CONCLUSION: In diffuse peritonitis caused by commensal gut bacteria the CD4(+) T lymphocytes exert a net negative effect on the local anti-bacterial defence, and thereby contribute to bacterial dissemination and poor outcome.

Immunolocalization of the protease kallikrein in the colon.

Colon kallikrein was localized in the goblet cells of cat and man by a variety of immunocytochemical techniques. No evidence of this enzyme was found in other sites in this organ. The possible physiological significance of kallikrein in the gastrointestinal tract and of the many related serine proteases is discussed.

Effects of early life undernutrition in artificially-reared rats: 3. Further studies of growth and behaviour.

Four groups of rat pups were reared: mother-reared control (well-fed) and undernourished (MRC, MRU) and artificially-reared control and undernourished (ARC, ARU). AR rats were fed expressed rats' milk (days 5-7), mixtures of rats milk and milk substitute (days 8-16), and milk substitute only (days 17-20) by intermittent infusion via a gastric cannula. Undernutrition, imposed from 5-25 days, was effected initially by underfeeding the mother (MRU) or by infusing restricted quantities of milk (ARU). Weaning was at 21 days and undernutrition from 21-25 days was by restricting the supply of solid food. All rats were fed ad lib from 25 days. From 18 weeks, male rats were subjected to 3 tests of behaviour: spontaneous alternation, conditioned food preference, and visual discrimination (Lashley stand). There were negative effects of both undernutrition and artificial rearing on body growth in weight and length. For two aspects of behaviour, preference for carbohydrate relative to protein (greater in U rats) and latency to jump (longer in U rats) the effects of early undernutrition were the same in both MR and AR animals. Hence, these effects cannot have been mediated through alterations in maternal care.

Fluctuations in responses to diazepam during the oestrous cycle in the mouse.

Administration of diazepam (0.28 mg/kg, IP; 60 min) to male mice or to female mice at oestrus or dioestrus increased the number of transitions made between the light and dark chambers of a test apparatus, a presumed anxiolytic action. However, the same dose of diazepam had no effect on light/dark transitions at late dioestrus, proestrus, or metoestrus II. At metoestrus I, this test dose of diazepam induced a decrease in the number of light/dark transitions and significant changes in other test parameters indicative of an increase in fearfulness or light aversion. Concentrations of diazepam in the brain after intraperitoneal injection were not influenced by the stage of the oestrous cycle, suggesting that the observed changes in responses to diazepam reflect changes in sensitivity to this drug rather than alterations in distribution or metabolism. The results indicate a physiological influence of ovarian steroid hormones on sensitivity to the benzodiazepine tranquilisers.

Laparoscopic management of a small bowel perforation caused by a toothpick.

A 58-year-old man underwent an emergency laparoscopic procedure for small bowel perforation with peritonitis after the ingestion of a wooden toothpick. Treatment consisted of laparoscopic removal of the foreign body, followed by lavage of the abdominal cavity and laparoscopic closure of the perforation, including omentoplasty. The patient recovered from peritonitis and was discharged from the hospital on day 14 after the operation.

Maternal vocalisations and other sounds in the fetal lamb's sound environment.

In a first experiment a miniaturised radio hydrophone was implanted inside the amniotic sac in three pregnant ewes and recordings were made from 3 weeks before the lambs were born until they had emerged; these recordings showed that the sound of the mother's voice was slightly louder when picked up by the hydrophone inside the amniotic sac than when picked up by a microphone beside her flank and that sounds recorded during labour included long and loud low frequency sounds associated with contractions, and an increase, compared with before labour, in the incidence of sounds produced by the maternal cardiovascular system and by breathing. Over the last 3 weeks of gestation the attenuation of sounds from outside the mother decreased at frequencies between 500 and 4000 Hz, but not below or above those frequencies. In a second experiment the bleats of 23 pregnant ewes were recorded; their lambs were taken at birth and tested with the sound of either their own mother's bleats, or with bleats from an alien ewe. Heart rate changes which occurred during playback of maternal and alien bleats differed significantly, but only on the occasion when each lamb heard its first bleat, postnatally.

Coverage of enterococci in community acquired secondary peritonitis: results of a randomized trial.

INTRODUCTION: The increasing number of enterococcal infections in hospitals and reports about the development of resistance of these bacteria make it necessary to review their importance as co-pathogens in secondary peritonitis. MATERIALS AND METHODS: A prospective randomized controlled trial on primary therapy of secondary peritonitis was carried out in six centers comparing cephalosporin-based antibiotic therapy to acylaminopenicillin-based therapy. RESULTS: Enterococci were only cultured in 6 of 110 cases from the abdomen and were found in only 5 cases of postoperative complications. No differences were found between penicillin-based vs. cephalosporin-based therapy. CONCLUSION: The study supports the view that these bacteria continue to play a minor role in secondary peritonitis. The point has to be emphasized, however, that the patients under study were in relatively good condition (APACHE II median 9 for cephalosporins and 10 for penicillins) and that postoperative cases of peritonitis were excluded.

Results from a signal detection analysis approach to the study of lasting effects of early life undernutrition on the behaviour of rats.

Rats were undernourished from birth to 45 days of age, first by underfeeding their mothers (50% of ad libitum diet) and then, from weaning at 25 days, by feeding the pups a restricted diet. They were fed ad libitum from 45 days till the start of behavioural testing at 29 weeks. Eleven well-fed control (C) and 10 previously undernourished (PU) male rats were trained to discriminate a brief decrement in light intensity. A response during this period was rewarded with food (a 'hit'); a response during an equivalent period in the absence of the signal (a 'false alarm') was penalised by delaying the onset of the next signal. Both groups of rats learned an easy discrimination equally well, but when the discrimination was made more difficult the PU rats required longer test sessions that C rats, made both more hits and more false alarms and had a higher responsivity index, indicating that the PU rats were more highly motivated than the C rats under this condition. Session duration increased on the more difficult discrimination; consequently time of day of testing changed somewhat and more for some rats than others. This may have been a confounding factor on the difficult discrimination and was specifically investigated in a follow-up experiment with the same rats. The results suggest that time may have been a conditioned stimulus and that the influence of this factor differed between C and PU rats.

[Changing of renal endothelium-dependent vascular reactivity by cyclosporin A]. / Modification de la réactivité vasculaire rénale endothélium-dépendante par la ciclosporine A.

Clinical use of the immunosuppressant cyclosporine A (CSA) is hampered by its nephrotoxicity. The renal vascular resistance is increased, may be as a consequence of a deleterious effect of the drug on the vascular endothelial cell function. The renal effects of a subchronic treatment with CSA (50 mg/kg/d, sc, 18 days), or olive oil vehicule (1 ml/kg), were studied in normotensive male Wistar rats. Creatinine clearance was measured on 24 h urine collection before the right kidney of the animals was isolated and perfused in an open circuit at 6 ml/min with Tyrode's solution. Renal vasodilator responses to acetylcholine (ACH, 10(-10) to 10(-7) M) and sodium nitroprusside (NP, 3 x 10(-9) to 3 x 10(-6) M) were studied after reestablishment of a renal vascular tone by a continuous perfusion of noradrenaline (NA, 10(-7) M). ACH was more potent than NP to induce renal vasodilation (EC50 = 0.57 +/- 0.05 x 10(-9) M, n = 8, vs 3.42 +/- 0.29 x 10(-8) M, n = 5), but both drugs reversed the NA-induced vasoconstriction by near 90%. L-NAME (3 x 10(-5) M) had no effect on NP-induced renal relaxation but suppressed responses to low concentrations of ACH and decreased by half its Emax (47 +/- 17%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Ileus in extensive intra-abdominal calcinosis after peritonitis]. / Ileus bei ausgedehnten intraabdominellen Verkalkungen nach Peritonitis.

We report on a case of extensive intraabdominal calcifications resulting from previous bacterial peritonitis. The patient suffered from an obstructive ileus. Relaparotomy was performed and the calcifications resected. To avoid recurrence, radiotherapy (15 Gy) and indomethacin were given. A literature review revealed only two cases of intraabdominal calcifications following peritonitis.