Circulating Metabolic Hormones During the Peripubertal Period and Their Association with Testicular Development in Bulls     

LFC Brito  AD Barth  NC Rawlings  RE Wilde  DH Crews Jr    PS Mir  JP Kastelic 《Reproduction in domestic animals》2007,42(5):502-508

The objective of the present study was to characterize changes in serum metabolic hormones concentrations from 20 weeks before to 20 weeks post-puberty in bulls and to investigate the associations of metabolic hormones concentrations with testicular development. Leptin concentrations increased from 16 weeks before puberty to 8 weeks post-puberty and insulin concentrations increased from puberty to 8 weeks post-puberty. Growth hormone concentrations decreased after 4 weeks post-puberty, whereas IGF-I concentrations increased from 8 weeks before puberty to 8 weeks post-puberty. During this period, testicular growth was accelerated and testosterone secretion increased substantially, without any significant changes in gonadotropin secretion. Monthly circulating concentrations of leptin, IGF-I and insulin accounted for 63% of the variation in scrotal circumference and 59% of the variation in paired testes volume. In conclusion, the secretion of metabolic hormones was not associated with changes in gonadotropins concentrations. Furthermore, the associations of leptin, IGF-I and insulin concentrations with testes size indicated that these hormones might be involved in a gonadotropin-independent mechanism regulating the testicular development in peripubertal bulls.  相似文献   

Reply     

DH DAVIES  S. PIDFORD 《Australian veterinary journal》1991,68(12):411-411

  相似文献   

Production of pneumonia in gnotobiotic pigs with pure cultures of mycoplasma hyopneumoniae   总被引：3，自引：0，他引：3  

R T Hodges  A O Betts  A R Jennings 《The Veterinary record》1969,84(11):268-273

  相似文献   

Isolation of a virus from a cat sarcoma in an established canine melanoma cell line   总被引：2，自引：0，他引：2  

L Kasza  A H Hayward  A O Betts 《Research in veterinary science》1969,10(2):216-218

  相似文献   

Operative techniques and recurrence rates associated with gastric volvulus in the dog.     

W E Wingfield  C W Betts  R W Greene 《The Journal of small animal practice》1975,16(7):427-432

  相似文献   

Out-of-season breeding in sheep     

J E Betts  J E Newton  H L Denehy 《The Veterinary record》1969,84(14):358-359

  相似文献   

Pneumonia in gnotobiotic pigs produced by simultaneous inoculation of a swine adenovirus and mycoplasma hyopneumoniae   总被引：5，自引：0，他引：5  

L Kasza  R T Hodges  A O Betts  P C Trexler 《The Veterinary record》1969,84(11):262-267

  相似文献   

Postreplicative formation of cohesion is required for repair and induced by a single DNA break     

Ström L  Karlsson C  Lindroos HB  Wedahl S  Katou Y  Shirahige K  Sjögren C 《Science (New York, N.Y.)》2007,317(5835):242-245

Sister-chromatid cohesion, established during replication by the protein complex cohesin, is essential for both chromosome segregation and double-strand break (DSB) repair. Normally, cohesion formation is strictly limited to the S phase of the cell cycle, but DSBs can trigger cohesion also after DNA replication has been completed. The function of this damage-induced cohesion remains unknown. In this investigation, we show that damage-induced cohesion is essential for repair in postreplicative cells in yeast. Furthermore, it is established genome-wide after induction of a single DSB, and it is controlled by the DNA damage response and cohesin-regulating factors. We thus define a cohesion establishment pathway that is independent of DNA duplication and acts together with cohesion formed during replication in sister chromatid-based DSB repair.  相似文献   

Assessing land-surface-atmosphere coupling in the ERA-40 reanalysis with boreal forest data     

Alan K. Betts  John H. Ball  Alan G. Barr  T. Andy Black  J. Harry McCaughey  Pedro Viterbo   《Agricultural and Forest Meteorology》2006,140(1-4):365

This analysis uses long time-series of daily mean data from the three BERMS flux sites in central Saskatchewan to explore biases in ERA-40 at a close-by grid-point, and to study the relationships between surface variables and fluxes and cloud cover in the observed and model data sets. On the seasonal timescale the biases in ERA-40 of temperature and humidity are small, but the model has a high bias in evaporation, and except in mid-summer a low bias of reflective cloud, which gives a high bias in the surface downward net shortwave flux. In summer, on days with high observed cloud cover, the model has too little cloud, and a corresponding high sensible heat flux and a warm, dry bias; while on summer days when observed cloud is lower, the model biases are generally reversed. The internal relationships between near-surface relative humidity, linked to the mean lifting condensation level, cloud cover and the surface radiation fluxes are however very similar in model and data. Although cause and effect cannot be determined from these biases alone, given the complexity of the interactions, they suggest possible errors in both the land-surface model and the atmospheric cloud parameterizations.  相似文献   

Chronic cervical compressive myelopathy in horses: clinical correlations with spinal cord alterations     

JV YOVICH  RA LeCOUTEUR†  DH GOULD† 《Australian veterinary journal》1991,68(10):326-334

Histological examination was performed on the cervical spinal cord from 13 horses with chronic cervical compressive myelopathy of 4 to 29 months duration. Structural alterations were correlated with clinical features. At the level of compression, the spinal cord was grossly deformed. Histological alterations included nerve fibre swelling and degeneration, occasional spheroids, astrocytic gliosis, increased macrophage activity and increased perivascular collagen. Myelin degeneration or loss at the level of the compressive lesion was greatest in the ventral and lateral funiculi and less consistently present in the dorsal funiculi. Asymmetry of lesions in the dorsal funiculi was associated with asymmetry of clinical signs in 5 horses. Histological alterations in areas of Wallerian degeneration were similar to that at the level of spinal cord compression, except that perivascular collagen was not increased. Wallerian degeneration was present cranial to the compressed site in the superficial portions of the lateral funiculi and in the middle of the dorsal funiculi. Caudal to the compressed site it was present in the ventral funiculi adjacent to the ventral median fissure and in the middle of the lateral funiculi. Deformation of the spinal cord did not correlate with the severity or duration of clinical signs but was positively correlated with the amount of perivascular collagen increase. The amount of nerve fibre swelling was not correlated with the severity of clinical signs but was negatively correlated with their duration. A rapid loss of nerve fibres apparently occurred early in the course of compression, since there was a marked decrease in the amount of nerve fibre swelling and Marchi stained degenerating myelin with increasing clinical duration.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献