Optics of arthropod compound eye.

The extent to which light can escape from one ommatidium into its neighbors in the compound eye has been examined by recording from single receptors during stimulation of single facets. In the "apposition" eye of the drone honeybee and locust, optical interaction is extremely small. In the "superposition" eye of the crayfish, more than half the light captured by the average cell gets in through neighboring facets, even when screening pigments are in the fully lightadapted position.

Molecular characterisation of the 22q13 deletion syndrome supports the role of haploinsufficiency of SHANK3/PROSAP2 in the major neurological symptoms.

METHODS: The 22q13 deletion syndrome (MIM 606232) is characterised by moderate to profound mental retardation, delay/absence of expressive speech, hypotonia, normal to accelerated growth, and mild dysmorphic features. We have determined the deletion size and parent of origin in 56 patients with this syndrome. RESULTS: Similar to other terminal deletion syndromes, there was an overabundance of paternal deletions. The deletions vary widely in size, from 130 kb to over 9 Mb; however all 45 cases that could be specifically tested for the terminal region at the site of SHANK3 were deleted for this gene. The molecular structure of SHANK3 was further characterised. Comparison of clinical features to deletion size showed few correlations. Some measures of developmental assessment did correlate to deletion size; however, all patients showed some degree of mental retardation and severe delay or absence of expressive speech, regardless of deletion size. CONCLUSION: Our analysis therefore supports haploinsufficiency of the gene SHANK3, which codes for a structural protein of the postsynaptic density, as a major causative factor in the neurological symptoms of 22q13 deletion syndrome.

Validity of substance use self-reports in dually diagnosed outpatients.

OBJECTIVE: The purpose of this study was to assess the validity of self-reports of substance use among outpatients dually diagnosed with substance use disorder and either bipolar disorder or posttraumatic stress disorder. METHOD: Self-reports of substance use were compared with supervised urine samples collected on the same day for 55 subjects. RESULTS: Self-reports were highly valid. Only 4.7% of cases involved subjects not reporting substance use detected by urine screens. CONCLUSIONS: Self-reports of substance use may be highly valid in nonpsychotic, dually diagnosed outpatients under certain conditions, i.e., when patients are in treatment, when urine samples are collected with patients' prior knowledge, when patients are well-known to staff, and when honest self-reporting is encouraged.

Invagination of presynaptic ribbons in the fly's optic lobe following loss of their target neuron.

In the first optic neuropile of the housefly Musca, photoreceptor terminals innervate fixed clusters of interneurons, one of which is the monopolar cell L2; L2's synapses in turn feed back upon the terminals. We examined the ultrastructure of these feedback synapses following degeneration of their normal targets, the receptor terminals; this was accomplished by photo-ablating the receptor cells after intraretinal injections of sulforhodamine. Even when all the terminals degenerated, their deafferentated target cells, including L2, remained structurally intact for at least 14 d. Despite this lack of obvious trans-synaptic degeneration, L2's synaptic connections did alter. Presynaptic organelles of the feedback synapses, synaptic ribbons and associated synaptic vesicles, soon appeared in L2's cytoplasm, separating from their site of attachment at the presynaptic membrane by invagination. Similar free-floating organelles and vesicles also occurred in another monopolar cell, L4. They were also occasionally encountered in L2, in normal, newly emerged flies at a time when a naturally occurring loss of feedback synapses is greatest. We interpret the process of internalization that forms these floating ribbons to be the first step in synaptic loss which occurs spontaneously, and that the rate is enhanced in L2 when its main synaptic targets, the receptor terminals, degenerate.

Reactive synaptogenesis following degeneration of photoreceptor terminals in the fly's optic lobe: a quantitative electron microscopic study.

Following photo-ablation of receptor cells in the retina of the housefly's compound eye, their synaptic terminals degenerate with a timecourse which we have followed over 8 d. Degeneration deprives the monopolar interneurons in the first optic neuropile, the lamina, of their main synaptic input. Simultaneously it deprives one monopolar interneuron (L2) of one of its synaptic targets, as L2 makes numerous feedback synaptic contacts at which it is pre-synaptic upon receptor terminals. Because the feedback synapses are dyadic, input still remains available to the second element post-synaptic at the dyad, which does not degenerate. This element is T1, a higher-order interneuron from the next most proximal neuropile (the medulla). Some of the original feedback synaptic sites soon disappear as a consequence of the photo-ablation, but their loss is partly offset by the production of new synaptic contacts. The new pre-synaptic ribbons resemble those at the original sites except for being smaller. The sites are, moreover, monadic, with T1 now the sole post-synaptic partner. These results show that interneurons in the fly's lamina retain a dynamic capacity for synaptogenesis throughout much of adult life, normally a few weeks in Musca, and that during this synaptogenesis they re-enact the same cell preferences expressed earlier in development.

22q13 deletion syndrome.

We have recently collected clinical information on 37 individuals with deletion of 22q13 and compared the features of these individuals with 24 previously reported cases. The features most frequently associated with this deletion are global developmental delay, generalized hypotonia, absent or severely delayed speech, and normal to advanced growth. Minor anomalies include dolicocephaly, abnormal ears, ptosis, dysplastic toenails, and relatively large hands. As with many terminal deletions involving pale G-band regions, the deletion can be extremely subtle and can go undetected on routine cytogenetic analysis. In fact, 32% of the individuals in our study had previous chromosome analyses that failed to detect the deletion. Eight of 37 individuals had deletion of 22q13 secondary to an unbalanced chromosome translocation. In the newborn, this deletion should be considered in cases of hypotonia for which other common causes have been excluded. In the older child, this syndrome should be suspected in individuals with normal growth, profound developmental delay, absent or delayed speech, and minor dysmorphic features. We recommend high-resolution chromosome analysis and fluorescence in situ hybridization studies, or molecular analysis to exclude this diagnosis.

Anti-adhesive coating for glass microelectrodes.

A simple procedure is described for coating the tips of glass micropipette electrodes with a durable thin film of a commercially available anti-adhesive agent (Antispread). This lowers the surface tension of the electrode glass, and helps reduce damage and distortion to tissue, by preventing the microelectrode from sticking permanently to cell membranes. In controlled trials, the coating actually increased the probability that nearby cells could be recorded from successively by about 30%. Electrode resistance increased only very slightly (on average by 8%) as a result of the coating. Coated electrodes yielded excellent long-term penetrations of small visual cells, and in addition allowed these to be dye-filled in the normal way. The coating may have applications in all situations where prevention of wetting by tissue is desirable.

PHYLOGENY OF THE SUBFAMILIES OF THE FAMILY BRACONIDAE (HYMENOPTERA: ICHNEUMONOIDEA): A REASSESSMENT.

Abstract- The recently published phylogeny of Braconidae by Quicke and van Achterberg is reassessed. Character-state definitions and character polarities are evaluated, and more rigorous methods are suggested. Our results indicate that there are many more parsimonious solutions to their data set, the consensus of which differs substantially from their results. Based on our reassessment, little can be said about the relationships among braconid subfamilies. Consensus trees show the cyclostomes as a largely unresolved basal grade. The two other major lineages which have been proposed, the helconoids and microgastroids, are somewhat better resolved, but not consistently so. Relationships among the helconoids vary considerably depending on the parameters used for parsimony analysis.

Mechanical, morphological and biochemical adaptations of bone and muscle to hindlimb suspension and exercise.

The influences of weightbearing forces on the structural remodeling, matrix biochemistry, and mechanical characteristics of the rat tibia and femur and surrounding musculature were examined by means of a hindlimb suspension protocol and highly intensive treadmill running. Female, young adult, Sprague-Dawley rats were designated as either normal control, sedentary suspended, or exercise suspended rats. For 4 weeks, sedentary suspended rats were deprived of hindlimb-to-ground contact forces, while the exercise suspended rats experienced hindlimb ground reaction forces only during daily intensive treadmill training sessions. The suspension produced generalized atrophy of hindlimb skeletal muscles, with greater atrophy occurring in predominantly slow-twitch extensors and adductors, as compared with the mixed fiber-type extensors and flexors. Region-specific cortical thinning and endosteal resorption in tibial and femoral diaphyses occurred in conjunction with decrements in bone mechanical properties. Tibial and femoral regional remodeling was related to both the absence of cyclic bending strains due to normal weightbearing forces and the decrease in forces applied to bone by antigravity muscles. To a moderate extent, the superimposed strenuous running counteracted muscular atrophy during the suspension, particularly in the predominantly slow-twitch extensor and adductor muscles. The exercise did not, however, mitigate changes in bone mechanical properties and cross-sectional morphologies, and in some cases exacerbated the changes. Suspension with or without exercise did not alter the normal concentrations of collagen, phosphorus, and calcium in either tibia or femur.

The fate of prostaglandin A1-5,6-3H in the rat.

The plasma concentrations, tissue distribution and excretion of prostaglandin A1 (PGA1) and related metabolites have been determined in rats, following the intravenous injection of a single dose of PGA1-5,6-3H. Urinary and faecal excretion accounted for averages of 25 and 43% of the administered dose of PGA1, respectively. Oxidative cleavage of the carboxyl side chain of PGA1 appeared to be a major metabolic pathway in the rat. PGA1-5,6-3H was deemed unsuitable for metabolism studies in man, in view of the significant loss of tritium label from the prostaglandin;

The effects of subcutaneous injections of sodium selenate on blood composition and milk yield in dairy cows.

Three groups of four lactating cows received a subcutaneous injection of 0 . 05, 0 . 10 and 0 . 15 mg Se/kg body weighty respectively administered as sodium selenate. A fourth group was injected with saline. In all the cows injected with sodium selenate, the concentration of Se in blood increased rapidly and was significantly higher than in control cows for two days in the group receiving the lowest dose and for 182 days (the duration of the experiment) in the two other groups. The activity of glutathione peroxidase in blood increased slowly in all cows injected with sodium selenate and was significantly greater than in control cows after 15, 22 and 29 days respectively, and remained significantly greater for 63, 91 and 182 days respectively. In a second experiment a single subcutaneous injection of 0 . 15 mg Se/kg body weight had no effect on the mean milk yield of 37 animals (19 . 1 kg/day) compared with the milk yield of a similar group of control animals (19 . 1 kg/day) during 70 days. The concentration of Se in milk was significantly higher on the first (168 microgram/litre) and second (69 microgram/litre) day after injection than in control animals (mean 26 microgram/litre).

Survey of lameness in British dairy cattle.

During 1977 a survey was undertaken by practising veterinary surgeons of the incidence of different lesions causing lameness in dairy cattle. Forty-eight veterinary practices participated and they treated 7526 cases of lameness in 1821 herds. The average incidence of lameness among all cows was 5.5 per cent and the annual incidence among practices ranged from 1.8 to 11.8 per cent. Most lesions (88.3 per cent) occurred in the feet; the commonest were foul of the foot (16.7 per cent), white line abscess (15.6 per cent), sole ulcer (13.6 per cent), punctured sole and pus (10.4 per cent) and underrun heel (8.7 per cent). These proportions varied in different parts of the country. Eighty-four per cent of foot lesions occurred in the hind feet and of these lesions 85 per cent occurred in the outer claw; 42 per cent of foot lesions occurred in abnormally shaped claws. The remaining 11.7 per cent of lesions occurred in the legs and trunk, 76 per cent of which occurred in the hindlimb. Trauma was the main cause of leg lesions, which occurred most frequently in the joints and ligaments.

Changes in geometrical and biomechanical properties of immature male and female rat tibia.

Tibial geometry and mechanical properties in male and female rapidly growing rats were measured to provide comparative data for spaceflight, exercise, or disease experiments that use immature rats as an animal model. A total of 68 immature Sprague-Dawley rats (43-58 d of age) were divided into 8 groups according to age and sex. Tibial length and middiaphysial cross-sectional data were analyzed, and tibial mechanical properties were obtained via three-point bending tests to failure. Results indicated that tibial geometry and mechanical properties were changed significantly during this 15-d period of rapid growth, with male rats having greater increases than female rats. Both male and female tibial lengths nevertheless increased significantly during this growth period, as did middiaphysical cross-sectional area. Tibial flexural rigidity increased significantly for both sexes during this growth period. The male tibiae changed primarily in structural characteristics, but some material properties also changed with age. In the female rats, however, the major changes in mechanical properties of the tibia were attributable only to structural changes in the bone.

Does bupivacaine irrigation of third molar sockets reduce postoperative pain? A double blind controlled trial.

A double blind controlled randomised trial suggested that irrigation of third molar sockets with bupivacaine 0.75% produces significant reduction in pain scored on the first post-operative morning (p less than 0.01). However, this technique produces no significant reduction in opiate or oral analgesic consumption.

Do local analgesics injected at the time of third molar removal under general anaesthesia reduce significantly post operative analgesic requirements? A double-blind controlled trial.

A prospective, controlled, randomised, double-blind trial suggested that: 1. The use of bupivacaine 0.5% plain and prilocaine 3% with felypressin 0.03 i.u./ml. as peroperative local analgesics reduce postoperative pain scores recorded on the first postoperative morning (P less than 0.05). 2. Bupivacaine 0.5% plain reduces postoperative opiate requirements (P less than 0.025). 3. Patients do not find peroperative bilateral inferior alveolar and lingual nerve blocks with buccal infiltrations significantly unpleasant. Thus peri-operative bupivacaine 0.5% is a valuable adjunct to third molar removal under general anaesthesia.

Absorption, tissue distribution, and excretion of 3H-labeled arbaprostil in the male rat.

A single dose of arbaprostil-11 beta-3H (4 micrograms/kg) was administered orally to male rats. A maximum plasma radioactivity concentration equivalent to 2.5 to 2.8 nanograms of the prostaglandin per ml was reached at 30 minutes and was maintained until 120 minutes after drug administration. The plasma drug disappearance half-life was 2.6 hours. These results along with data from tissue distribution studies suggested a rapid uptake of radiolabeled arbaprostil by the glandular stomach tissue followed by an apparent zero-order release of drug-related radioactivity from this tissue "reservoir" into the plasma. Drug-related radioactivity was excreted rapidly, with 96 to 99% of the urinary excretion and 82 to 97% of the fecal excretion being completed within 24 hours. A total of 49.6 +/- 3.5% of the orally administered dose was excreted in the urine and 46.7 +/- 3.9% in the feces. No radioactive residues were detected in the animals at the end of the 120 hour specimen collection period. The metabolic stability of the 11 beta-tritium label and the suitability of arbaprostil-3H for use in human studies was demonstrated.

Isolation and characterization of urinary metabolites of arbaprostil in the rat.

The urinary metabolites of arbaprostil-3H in the male rat were profiled, isolated, and purified. Their structures were deduced by gas chromatography/mass spectrometry (GC/MS) studies after conversion to the methyl ester-methoxime-trimethylsilyl ether derivatives, aided by GC with simultaneous radioactivity monitoring. The identified metabolites accounted for over 91% of the urinary excretion products. beta-oxidation of the carboxy side-chain of arbaprostil to 15-methyl-tetranor PGE1 appeared to be the most significant metabolic pathway. Conversion to the dinor A and B derivatives and further beta-oxidation of these to the 15-methyl-tetranor A and B metabolites also appeared to occur. C-19-hydroxylated tetranor A and B derivatives of arbaprostil-3H were excreted in the urine. No conjugated urinary metabolites were evident.

Isolation and characterization of the urinary metabolites of arbaprostil in the male dog after intravenous administration.

The profile of urinary metabolites of 3H-arbaprostil was characterized in the male dog after intravenous administration. The major metabolites were purified and their structures deduced by gas chromatography/mass spectrometry (GC/MS) studies after conversion to the methyl ester-methoxime-trimethylsilyl ether derivatives, aided by GC with simultaneous radioactivity monitoring. The identified metabolites accounted for 96% of the urinary excretion products. beta-Oxidation of the carboxy side-chain of arbaprostil to 15-methyl-2,3,4,5-tetranor PGE1, via the 15-methyl-2,3-dinor PGE2 intermediate, appeared to be the most significant metabolic pathway. In contrast to the rat, the following were observed in the dog: glucuronic acid conjugation of the 15-methyl-2,3,4,5-tetranor PGE, and PGA metabolites; detection of the 15-methyl-2,3-dinor PGE2 intermediate; absence of 19-hydroxyl-15-methyl-2,3,4,5-tetranor PGA, and PGB metabolites; oxidation at C-20; and excretion of some parent drug.

Prognostic value of coronary multidetector CT angiography in patients with an intermediate probability of significant coronary heart disease.

The aim of this study was to determine the prognostic value of coronary multidetector CT angiography (MDCTA) in patients with an intermediate pre-test probability of significant coronary artery disease (CAD). Patients who underwent 64-slice coronary MDCTA and met the selection criteria were identified and assessed for intermediate pre-test probability. Coronary MDCTA scans were preceded by calcium scoring, whereas all MDCTA scans were interrogated for the presence of plaque composition and the distribution and degree of stenosis. Significant stenosis was classified as being >50% of the luminal diameter. All patients were followed up for the occurrence of (i) cardiac death, (ii) non-fatal myocardial infarction, (iii) unstable angina requiring hospital admission and (iv) revascularisation. 138 patients were included (follow-up of 19.9 months); of these, 8 had a cardiac event (all revascularisations) and all had a positive coronary MDCTA. Patients with normal coronary arteries or non-significant stenosis suffered no cardiac events during follow-up. There were significant differences between the two groups regarding the presence of significant stenosis (p<0.001), the presence of plaque (p = 0.011) and a calcium score >10 (p = 0.003); 36.4% of patients with significant stenosis underwent revascularisation. In conclusion, this is the first UK study to investigate survival data in a population of intermediate-risk patients with no prior history of CAD who were investigated with coronary MDCTA. Coronary MDCTA can confidently rule out significant CAD in the intermediate-risk population and guide risk factor modification in patients with demonstrated coronary atheroma.