Wheat endosperm cell walls: Spatial heterogeneity of polysaccharide structure and composition using micro-scale enzymatic fingerprinting and FT-IR microspectroscopy

Micro-scale enzymatic fingerprinting and FT-IR microspectroscopy were used to investigate changes of polysaccharide structure and composition in cell walls from wheat endosperm. These methods were applied to transverse and longitudinal sections of wheat grains harvested at maturity and 270°D. Principal component analysis treatment of the data revealed marked differences in the (1,3)-(1,4)-beta-glucans (BG)/arabinoxylans (AX) ratio and in the structure of AX depending on both cell position in the grain and stage of development. Cell walls close to the germ were enriched in BG in both developing and mature grain. AX in developing grain were characterized by a higher proportion of di-substitution by arabinose as compared to mature grain AX. In addition, AX in mature grains exhibited a different structure depending on prismatic or central origin of cell walls in the grain. These results indicated a high spatial and temporal control of the biosynthesis of AX and BG in wheat endosperm.     

Resistance to Meloidogyne chitwoodi,M. fallax and M. hapla in wild tuber-bearing Solanum spp.

Summary Over 5000 plants from 64 tuber-bearing wild Solanum spp. have been individually screened for resistance to Meloidogyne chitwoodi, M. fallax and M. hapla. Seedlings were analyzed by means of counting number of egg masses and resistance was verified by retesting low-scoring plants using stem cuttings. Resistance to both M. chitwoodi and M. fallax was observed in S. bulbocastanum, S. cardiophyllum, S. brachistotrichum, S. fendleri and S. hougasii. Only in S. chacoense and to a lesser extent in S. stoloniferum and S. gourlayi differential results between M. chitwoodi and M. fallax were observed. Resistance to M. hapla was found in S. bulbocastanum, S. brachistotrichum, S. cardiophyllum, S. arnezii, S. chacoense, S. tarijense, S. boliviense, S. gourlayi, S. microdontum, S. sparsipilum, S. spegazzinii, S. sucrense, S. acaule and S. hougasii. The occurrence of resistance in wild Solanum species in relation to their taxonomic status and the implications for introgression of resistance into S. tuberosum are discussed.     

Familial aortic aneurysm in Leonberg dogs

A thoracic aortic aneurysm was diagnosed in a 6-month-old male Leonberg dog by use of radiography, transthoracic and transesophageal echocardiography, and magnetic resonance imaging. The aneurysm was associated with a twisted ascending aorta and dilatation of several other thoracic arteries (pulmonary trunk, brachiocephalic trunk, and left subclavian artery). Histologic examination of the aorta revealed cystic medial necrosis, with disruption of the elastic network, collagen fibers, and the muscle glycoprotein fibrillin-1. The dam and sire of the dog and 8 littermates were examined by use of transthoracic echocardiography. The sire and 1 male littermate also had an aneurysm of the ascending aorta. To the authors' knowledge, this is the first report of familial aortic aneurysm in dogs.     

Use of the ventrodorsal myelographic view to predict lateralization of extruded disk material in small-breed dogs with thoracolumbar intervertebral disk extrusion: 104 cases (2004-2005)

OBJECTIVE: To determine whether the ventrodorsal myelographic view can be used to accurately predict the circumferential location of extruded disk material in dogs with thoracolumbar intervertebral disk extrusion (IVDE) and to describe paradoxical contrast obstruction (PCO). DESIGN: Retrospective case series. ANIMALS:104 dogs with Hansen type I IVDE. Procedures-Ventrodorsal myelographic views were reviewed, and contrast patterns were categorized according to 8 predetermined patterns. Agreement among observers was compared, and the predicted location of extruded disk material was compared with surgical findings. RESULTS: Agreement regarding myelographic pattern and location of extruded disk material was moderate (kappa = 0.74 and 0.80, respectively) among the 4 observers. Ninety-three (89%) dogs had myelographic evidence of lateralized extrusion, and in 83 of the 93 (89%), predicted location of extruded disk material matched the surgically confirmed location. In 33 of the 40 (83%) dogs with bilateral contrast column gaps of unequal length, disk material was found to be located on the side with the shorter, rather than the longer, contrast gap, a phenomenon described as PCO. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the ventrodorsal myelographic view could be used to predict the circumferential location of extruded disk material in dogs with thoracolumbar IVDE more often than previously reported. The PCO phenomenon may be useful in determining the side of lateralization when contrast material does not outline the extruded disk material.     

Presence of residual material following mini-hemilaminectomy in dogs with thoracolumbar intervertebral disc extrusion

Presence of residual material following mini-hemilaminectomy in dogs (n = 9) with spontaneous thoracolumbar intervertebral disc extrusion was prospectively investigated. Volume of extruded disc material within the vertebral canal and the proportion of residual material were determined using pre- and post-operative magnetic resonance imaging. The degree of spinal cord compression, proportion of extradural material considered hemorrhage, and invasion of the articular facets were also determined. Residual material was identified in 44% of the mini-hemilaminectomies. The median percentage of residual material calculated was 7.7% of the preoperative volume. No observed effect of surgical side or site, proportion of extradural material considered hemorrhage, patient weight, and duration of clinical signs was detected.     

Characteristic cellular composition of germinal centers

We established the method of isolating individually encapsulated germinal centers (GCs) from immunized spleen and analyzed single cell suspension of GCs by flowcytometry. In GCs, the high frequency of sIgG+ cells (29%) and sIgA+ cells (5%) was detected. Two-color flowcytometry analysis showed that GCs contained 27% of sIgM-IgG+ cells, in which isotype switch from IgM to IgG had occurred, and 5% of Bu1-IgG+ cells, which were differentiating into plasma cells. On the other hand, sIgM-IgG+ and Bu1-IgG+ cells were not detected in the bursa, which contained 95% of B cells and only 1% of T cells. CD4+ but not CD8+ T cells were detected in the light zone of GCs and these CD4+ T cells are supposed to play a key role in isotype switching and differentiation into plasma cells in GCs. These results clearly demonstrate that GCs provide a site for isotype switching and differentiation into plasma cells.     

Comparison of two pre-anaesthetic medetomidine doses in isoflurane anaesthetized sheep

OBJECTIVE: To compare the sedative, anaesthetic-sparing and arterial blood-gas effects of two medetomidine (MED) doses used as pre-anaesthetic medication in sheep undergoing experimental orthopaedic surgery. STUDY DESIGN: Randomized, prospective, controlled experimental trial. ANIMALS: Twenty-four adult, non-pregnant, female sheep of various breeds, weighing 53.9 +/- 7.3 kg (mean +/- SD). METHODS: All animals underwent experimental tibial osteotomy. Group 0 (n = 8) received 0.9% NaCl, group L (low dose) (n = 8) received 5 microg kg(-1) MED and group H (high dose) (n = 8) received 10 microg kg(-1) MED by intramuscular (IM) injection 30 minutes before induction of anaesthesia with intravenous (IV) propofol 1% and maintenance with isoflurane delivered in oxygen. The propofol doses required for induction and endtidal isoflurane concentrations (F(E')ISO) required to maintain anaesthesia were recorded. Heart and respiratory rates and rectal temperature were determined before and 30 minutes after administration of the test substance. The degree of sedation before induction of anaesthesia was assessed using a numerical rating scale. Arterial blood pressure, heart rate, respiratory rate, FE'ISO, end-tidal CO2 (FE'CO2) and inspired O2 (FIO2) concentration were recorded every 10 minutes during anaesthesia. Arterial blood gas values were determined 10 minutes after induction of anaesthesia and every 30 minutes thereafter. Changes over time and differences between groups were examined by analysis of variance (anova) for repeated measures followed by Bonferroni-adjusted t-tests for effects over time. RESULTS: Both MED doses produced mild sedation. The dose of propofol for induction of anaesthesia decreased in a dose-dependent manner: mean (+/-SE) values for group 0 were 4.7 (+/-0.4) mg kg(-1), for group L, 3.2 (+/-0.4) mg kg(-1) and for group H, 2.3 (+/-0.3) mg kg(-1)). The mean (+/-SE) FE'ISO required to maintain anaesthesia was 30% lower in both MED groups [group L: 0.96 (+/-0.07) %; group H: 1.06 (+/-0.09) %] compared with control group values [(1.54 +/- 0.17) %]. Heart rates were constantly higher in the control group with a tendency towards lower arterial blood pressures when compared with the MED groups. Respiratory rates and PaCO2 were similar in all groups while PaO2 increased during anaesthesia with no significant difference between groups. In group H, one animal developed a transient hypoxaemia: PaO2 was 7.4 kPa (55.7 mmHg) 40 minutes after induction of anaesthesia. Arterial pH values and bicarbonate concentrations were higher in the MED groups at all time points. CONCLUSION AND CLINICAL RELEVANCE: Intramuscular MED doses of 5 and 10 microg kg(-1) reduced the propofol and isoflurane requirements for induction and maintenance of anaesthesia respectively. Cardiovascular variables and blood gas measurements remained stable over the course of anaesthesia but hypoxaemia developed in one of 16 sheep receiving MED.     

Reproductive performance of camels (Camelus dromedarius) under pastoral management and its influence on herd development

Camels (Camelus dromedarius) produce milk and offspring and provide transport in pastoral husbandry systems in the Afro-Asian dryland belt. The aim of the present study was to investigate the reproductive performance of camels kept under pastoral management in northern Kenya. Using the Progeny History surveying technique, data were collected from 471, 287 and 416 adult Rendille, Gabra and Somali female camels including data on 1506, 789 and 1206 parturitions, respectively. Surveys took place from January to December 1995, but data refer to the 15-year production period preceding the survey. Age at first calving (AFC) was 58.4±1.0 months (LSMeans±S.E.), 63.0±1.1 months and 68.4±1.3 months for the Somali, Rendille and Gabra camels, respectively.The mean calving interval was similar for all three populations with 27.3±0.6 months (LSMeans±S.E.) for Rendille camels, 28.0±0.6 months for Gabra (n=500) and 28.4±0.6 months for Somali camels. The annual calving rate varied between 33% and 46% in the Somali, 19% and 44% in the Gabra and 8% and 86% in the Rendille camel population. Calf mortality rate averaged 25%, 22% and 27% in Rendille, Gabra and Somali camel calves, respectively, and showed highest variation between the years in the Rendille system (5% to 60%).The number of adult breeding females increased by about 20% over a simulation period of 10 years using the status quo reproductive parameters and by about 70% with improved AFC and CI (excluding AFC>78 months and CI>36 months). The results reveal the usual and unusual variation in the reproductive parameters over different years and in the different systems. It is concluded that eliminating unusual variation is a promising way to enhance herd development and reduce risk in the production systems.