Development of the digestive tract in the ostrich (Struthio camelus).

A study was conducted to investigate changes in the development of the gastrointestinal tract (GIT) in relation to body growth of growing ostriches. There was an 11-fold increase (P < 0.001) in body weight between 3 and 72 days of age. The relative (to body weight) weight of the proventriculus/gizzard, caeca and colon also increased (P < 0.001) with age. The relative weight of the small intestine peaked at 41 days of age and then tended to decline (P < 0.05) subsequently. The relative weight of the pancreas peaked at 27 days of age and remained fairly stable thereafter. The activities of chymotrypsin and lipase declined (P < 0.001) with age between 3 and 72 days. At 3 days of age, the protein content of the duodenal mucosal homogenate was higher (P < 0.001) than that of the jejunum or ileum, but at all subsequent periods the jejunal protein content was the highest. The protein content of the intestinal brush-border membrane was higher (P < 0.001) at the jejunum than at the duodenum or ileum. The specific activity of maltase declined (P < 0.001) with age in all three regions, most especially between 3 and 27 days of age. The activity of alkaline phosphatase (AP) at 41 and 55 days of age was higher (P < 0.001) in the duodenum than in the jejunum or ileum. The activity of AP fluctuated with age in the duodenum but there was a more defined decline (P < 0.001) with age in the jejunum and ileum. The relative protein content of the liver increased (P < 0.001) with age, with two peaks at 27 and 55 days of age. Arginase activity was not detected in the liver of 3-day old chicks and was not significantly affected by age between 27 and 72 days of age. The pattern of development observed is similar to that in growing poultry. There is, however, a need for evaluation at closer intervals in early life as well as an in-depth assessment of the morphometry of the intestinal mucosa.     

Estimation of intestinal permeability in healthy dogs using the contrast medium iohexol

Background: Iohexol is a nonradioactive marker that has been used successfully to test intestinal permeability in humans with inflammatory bowel disease. There is evidence in dogs that iohexol shares a similar permeability pathway as ⁵¹chromium‐EDTA, the gold standard marker. Objective: The objective of this study was to determine an optimal oral iohexol dosage for an intestinal permeability serum test (IPST) and to use the test to estimate intestinal permeability in healthy dogs. Methods: Eight clinically healthy dogs free of gastrointestinal, liver, and pancreatic disease were used in the study. Dosages of 0.25, 0.5, 1.0, 2.0, and 4.0 mL/kg of Omnipaque‐350 (iohexol) were administered to 2 dogs at weekly intervals. Iohexol concentration was determined in serum samples obtained hourly for 6 hours after administration by high‐performance liquid chromatography. Using the optimal dosage, iohexol was administered to 8 dogs twice, 6–36 days (mean 10 days) apart, and coefficients of variation (CVs) for iohexol concentration were calculated. Results: A dosage of 2.0 mL/kg was chosen as optimal for the IPST, based on ease of iohexol detection in serum, intestinal contrast, and clinical effects of iohexol. Following administration of this dose to healthy dogs, mean (±SD) serum iohexol concentrations were 8.74±4.38, 11.89±5.67, 12.40±5.47, 9.23±5.54, 7.61±5.13, and 5.27±2.67 μg/mL at 1, 2, 3, 4, 5, and 6 hours after iohexol administration, respectively. CVs between the 2 test days were 28–45%. Conclusions: Using the iohexol dosage established in this study, the iohexol IPST was easy to perform as a marker for intestinal permeability in dogs. Further studies to establish reference intervals and evaluate the diagnostic value of the iohexol IPST in dogs with gastrointestinal disease are warranted.     

First Report of the Root Lesion Nematode,Pratylenchus hippeastri,on Apple in South Africa

Journal of Plant Diseases and Protection - Root lesion nematodes (Pratylenchus spp.) are the most common plant-parasitic nematodes present in apple orchards in South Africa. During a survey...     

A haemagglutination and haemagglutination inhibition test for bluetongue virus

Haemagglutination of bluetongue virus (BTV) was demonstrated for the first time by making use of a purified preparation of the virus. The reaction was found to be independent of variations in the pH, temperature, buffer system and origin of the erythrocytes used in the test. A haemagglutination inhibition test, subsequently developed, was demonstrated to be serotype specific. The storage of the virus for indefinite periods was facilitated by lyophilization of BTV in the presence of a low concentration of sucrose.     

Partial and clearcut harvesting of dry Douglas-fir forests: Implications for small mammal communities

Dry Douglas-fir (Pseudotsuga menziesii) forests offer a wide range of timber and non-timber values, which may benefit from a balanced timber harvest by variable retention systems with conservation of biodiversity. A major component of biodiversity are forest floor small mammal communities whose abundance and diversity serve as ecological indicators of significant change in forest structure and function from harvesting activities. This study was designed to test the hypotheses that abundance, reproduction, and survival of (i) the southern red-backed vole (Myodes gapperi, formerly Clethrionomys gapperi), will decline; (ii) the deer mouse (Peromyscus maniculatus), will be similar; and (iii) the meadow vole (Microtus pennsylvanicus) and northwestern chipmunk (Tamias amoenus), will increase, with decreasing levels of tree retention. Small mammal populations were live-trapped from 1994 to 1997 in replicated sites of uncut forest, 20% and 50% volume removal by single tree selection, 20%, 35%, and 50% patch cuts based on openings of 0.1–1.6 ha, and small 1.6 ha clearcuts in Douglas-fir forest near Kamloops, British Columbia, Canada. M. gapperi dominated the small mammal community, starting with an abundance of 74–98 animals/ha with mean values ranging from 33 to 51 animals/ha. In the two post-harvest years, abundance, reproduction, and survival of M. gapperi populations were consistently similar among uncut forest and the various levels of tree retention. Thereafter, M. gapperi was seldom found on the small clearcuts. M. pennsylvanicus, T. amoenus, and P. maniculatus occurred predominantly in clearcut sites. As with other types of forest disturbance, responses to our treatments were species-specific. The most striking result was the high abundance and productivity of M. gapperi populations in a dry forest ecosystem, a novel result for this bio-indicator species of closed-canopy forest conditions. At least with respect to small mammals, the retention systems studied seem to enable timber extraction and maintenance of mature forest habitat in these dry fir ecosystems.     

Delayed sleep phase cases and controls

Background

Delayed sleep phase disorder (DSPD) is a condition in which patients have difficulty falling asleep before the early morning hours and commonly have trouble awakening before late morning or even early afternoon. Several studies have suggested that variations in habitual bedtime are 40–50% heritable.

Methods

We recruited a case series of 205 participants, along with 221 controls (DSPD-C) with normal sleep, roughly matched for age, gender, and ancestry. A representative sample of San Diego adults recruited some years before was already available to confirm the control group. Both DSPD and DSPD-C provided blood or saliva samples for DNA and completed extensive questionnaires about sleep habits, sleep history, family history, sleep quality, morningness-eveningness traits, depression, mania, and seasonality of symptoms. The DSPD group wore wrist actigraphs for a median of 13.2 days. The representative sample collected previously had undergone actigraphic recordings, from which 48 hours of data were generally available.

Results

The DSPD and DSPD-C samples showed almost no overlap on morningness-eveningness scores. DSPD cases went to bed and arose about 3 hours later than the DSPD-C and the representative sample. DSPD cases reported more difficulties with sleep, poorer sleep quality, and more depression, but there was no significant difference in a history of mania. DSPD cases reported more family history of late bedtimes, but female DSPD reported that their fathers' bedtimes were later than the fathers of male DSPD.

Conclusion

These results indicate a DSPD phenotype is familial and associated with unipolar depression.