Identification of the receptor subtype involved in the analgesic effect of neurotensin

The neuropeptide neurotensin (NT) elicits hypothermic and naloxone-insensitive analgesic responses after brain injection. Recent pharmacological evidence obtained with NT agonists and antagonists suggests that these effects are mediated by a receptor distinct from the initially cloned high-affinity NT receptor (NTR1). The recent cloning of a second NT receptor (NTR2) prompted us to evaluate its role in NT-induced analgesia. Intracerebroventricular injections in mice of two different antisense oligodeoxynucleotides from the NTR2 markedly decreased NTR2 mRNA and protein and reduced NT-induced analgesia. This effect was specific, because NTR1 levels were unaffected, and sense or scramble oligodeoxynucleotides had no effect. Structure-activity studies revealed a close correlation between the analgesic potency of NT analogs and their affinity for the NTR2 and disclosed potent and selective agonists of this receptor. These data confirm that NTR1 is involved in the NT-elicited turning behavior and demonstrate that the NTR2 mediates NT-induced analgesia.     

Short communication: Diagnostic performance of on-farm bacteriological culture systems for identification of uterine Escherichia coli in postpartum dairy cows

The objectives of this study were to validate the performance of on-farm bacteriological culture systems for identification of Escherichia coli in the uterus of early postpartum dairy cows and to determine if an association is present between the results and the subsequent occurrence of puerperal metritis (PM). A prospective cohort study was conducted in one commercial Holstein dairy herd in which 400 cows were sampled between 24 and 48 h after parturition. Three bacteriological samples were obtained from the uterus of each cow and were cultured for identification of E. coli. One sample was cultured in a commercial bacteriology laboratory according to standard procedures for identification of E. coli and was considered as the reference test. The two other samples were cultured on the farm using the Tri-Plate (University of Minnesota, St. Paul, MN) and Petrifilm systems, and plate readings were done after 24 and 48 h of incubation (variables: Tri24h, Tri48h, Petri24h, Petri48h). Participating cows were followed until 21 days in milk to diagnose PM. The prevalence of PM and E. coli (from the reference test) in the cow population was 15.0 and 33.5%, respectively. Both on-farm culture systems were accurate compared with the reference test. The sensitivity and specificity were 97 and 100%, 99 and 100%, 100 and 92%, and 100 and 89% for Tri24h, Tri48h, Petri24h, and Petri48h, respectively. On-farm results for Tri24h, Tri48h, Petri24h, and Petri48h were associated with subsequent occurrence of PM. The results from this study support the use of the Tri-Plate and Petrifilm culture systems on dairy farms to identify the presence of E. coli in the uterus of postpartum cows.     

A randomized controlled trial on the effect of incomplete milking during the first 5 days in milk on reproductive performance of dairy cows

The main objective of the current study was to measure the effect of incomplete milking on luteal activity and on pregnancy hazard. We also aimed to study the effect of early-lactation hyperketonemia (i.e., β-hydroxybutyrate blood concentration ≥1.4 mmol/L during the first 3 wk in milk) on those reproductive outcomes. Multiparous Holstein cows (n = 853) from 13 commercial herds were enrolled in a randomized controlled trial. Cows were assigned to a control or a treatment group, incompletely milked (10–14 L of milk collected/d) from 1 to 5 DIM. Blood samples were collected once a week during weeks in milk 1 to 3 for β-hydroxybutyrate blood concentration, and a threshold of 1.4 mmol/L was used to define hyperketonemia. During weeks in milk 5 and 7, cows were sampled for progesterone blood concentration, and a threshold of 1 ng/mL was used to define luteal activity. Reproductive information and culling dates were obtained through herd records. Logistic regression models and survival analyses were used to assess the effect of treatment on luteal activity and on pregnancy hazard, respectively. Analogous models were used to investigate the effect of early-lactation hyperketonemia on reproductive outcomes. The odds of luteal activity for incompletely milked cows were 1.1 (95% confidence interval: 0.72–1.7) times those of conventionally milked cows. The effect of treatment on pregnancy hazard varied as a function of time, parity, and start of the breeding period. In second-parity cows that started the breeding period <55 d in milk, the pregnancy hazard (95% confidence interval) in incompletely milked cows was 576.3 (240.0–1,383.7), 36.9 (18.9–72.1), 6.8 (3.3–13.8), 2.5 (1.0–5.9), and 0.13 (0.07–0.26) times that of conventionally milked cows at 1 to 21, 22 to 43, 44 to 65, 66 to 87, and >87 d after the voluntary waiting period, respectively. The treatment did not have an effect on pregnancy hazard in cows in third parity or greater or in those starting the breeding period ≥55 d in milk. Early-lactation hyperketonemia was not associated with any of the reproductive outcomes. In conclusion, the incomplete milking protocol had no effect on luteal activity and had a positive effect on pregnancy hazard in second-parity cows in herds with a short voluntary waiting period (<55 d). We did not observe an effect of early-lactation hyperketonemia on luteal activity or on pregnancy hazard.     

Feasibility of cardiac cryoablation using a transvenous steerable electrode catheter

BACKGROUND AND PURPOSE: Accurate contouring of the clinical target volume (CTV) is a fundamental prerequisite for successful conformal radiotherapy of prostate cancer. The purpose of this study was to investigate intra- and inter-observer variability in contouring prostate (P) and seminal vesicles (SV) and its impact on conformal treatment planning in our working conditions. MATERIALS AND METHODS: Inter-observer variability was investigated by asking five well-trained radiotherapists of contouring on CT images the P and the SV of six supine-positioned patients previously treated with conformal techniques. Short-term intra-observer variability was assessed by asking the radiotherapists to contour the P and SV of one patient for a second time, just after the first contouring. The differences among the inserted volumes were considered for both intra- and inter-observer variability. Regarding intra-observer variability, the differences between the two inserted contours were estimated by taking the relative differences in correspondence to the CT slices on BEV plots (antero-posterior and left-right beams). Concerning inter-observer variability, the distances between the internal and external envelopes of the inserted contours (named projected diagnostic uncertainties or PDUs) and the distances from the mean inserted contours (named mean contour distances or MCDs) were measured from BEV plots (i.e. parallel to the CT slices). RESULTS: Intra-observer variability was relatively small (the average percentage variation of the volume was approximately 5%; SD of the differences measured on BEV plots within 1.8 mm). Concerning inter-observer variability, the percentage SD of the inserted volumes ranged from 10 to 18%. Differences equal to 1 cm in the cranio-caudal extension of P + SV were found in four out of six patients. The largest inter-observer variability was found when considering the anterior margin in the left-right beam of P top (MCD = 7.1 mm, 1 SD). Relatively high values for MCDs were also found for P bottom, for the posterior and lateral margins of P top (2.6 and 3.1 mm, respectively, I SD) and for the anterior margin of SV (2.8 mm, 1 SD). Relatively small values were found for P central (from 1.4 to 2.0 mm, 1 SD) and the posterior margin of SV (1.5 mm, 1 SD). CONCLUSIONS: The application of larger margins taking inter-observer variability into account should be taken into consideration for the anterior and the lateral margins of SV and P top and for the lateral margin of P. The impact of short-term intra-observer variability does not seem to be relevant.     

Hierarchical strategy for protein folding and design: synthesis and expression of T4 lysozyme gene and two putative folding mutants

A T4 lysozyme-coding DNA sequence of 495 bp was chemically synthesizedand cloned by ligation of 26 deoxyribooligo-nucleotide fragmentsin two steps with a linearized plasmid followed by transformation.On selection by colony hybridization and DNA sequence analysis,clone pTLY.10 was identified to contain a complete T4 lysozymesynthetic DNA. On expression under lac-promoter, unfused T4lysozyme was obtained in {small tilde}4–6% yield. Thedesign and synthesis of two putative folding mutants, flexible(Gly-Gly-Gly) and rigid (Asn-Asp-Gly) at position 73-74-75,were based on hierarchical principles. Both mutants lost enzymaticactivity of the wildtype. These results are readily understandableif the hierarchical organization of the structure is taken intoaccount. A possible explanation is that the catalytic sitesare blocked in both mutants.     

Effects of limited food intake on the obese-hyperglycemic syndrome

In ob/ob mice a 12-wk period of food restriction led to a reduced rate of somatic growth and a decreased lean body mass, along with small but reliable reductions in systemic immunoreactive insulin levels and evidence of increased insulin sensitivity. However, no effects of limited access to food were noted on the basal hyperglycemia, the elevated percent carcass lipid, or on the significantly higher levels of serum corticoids that occur in obese animals. These data indicate that hyperphagia alone is not responsible for the maintenance of many of the commonly reported characteristics of the obese-hyperglycemic syndrome, but do not exclude the contribution of factors secondary to the quantity of ingested food. Additionally, the present data lend support to recent work suggesting that chronic hyperinsulinemia or an elevated set point of total carcass lipid may be instrumental in the development of this syndrome.     

Lumbo-sciatica and chemonucleolysis

Three patients are described, each having a malignant bone tumor associated with inflammatory episodes in the adjacent joint. Two of these were sarcomas of the lower end of the femur, and one a metastatic carcinoma in the distal end of the radius. Histologically, the synovium exhibited moderate and non-specific signs of inflammation near the malignant tissue. These cases illustrate the possibility of diagnostic error, either clinically or on microscopic examination of small specimens, especially in punch biopsies.     

Electrophysiological and neuropharmacological study of tectoreticular pathways in lampreys

Tectoreticular (TR) cells along the diencephalic-mesencephalic border are the origin of prominent crossed and uncrossed pathways that project to the middle (MRRN) and posterior (PRRN) rhombencephalic reticular nuclei in juvenile and adult lampreys [I.C. Zompa, R. Dubuc, Diencephalic and mesencephalic projections to rhombencephalic reticular nuclei in lampreys, Brain Res. (1998) in press.]. This study investigated the synaptic contacts between TR axons and the reticular cells. Intracellular recordings were carried out in reticular neurones (n=124) while microstimulating the TR regions. Tectoreticular inputs were recorded in all reticular cells studied (248 PSPs); although stronger responses were evoked in the MRRN neurones. The majority of responses were excitatory, but increasingly mixed and inhibitory when recorded in the middle and caudal part of the reticular nuclei. The excitation had the shortest onset latencies and sharpest slopes measured in both reticular nuclei, while the inhibition was longer and smoother. The characteristics of TR inputs to different reticular cell types is also presented. The transmission of evoked responses was isolated to the crossed and uncrossed TR pathways by studying the effects of 1% Xylocaine ejections and surgical lesions. The TR inputs were transmitted to reticular cells through monosynaptic and polysynaptic contacts. The synaptic transmission involved excitatory amino acids, acting through AMPA and NMDA receptors, while the inhibition was glycinergic. Comparisons with other sensory systems in lampreys are discussed.