Clinical Management of Gastrointestinal Disease in the Common Marmoset (Callithrix jacchus).

Gastrointestinal disease is a frequently encountered problem among captive common marmoset (Callithrix jacchus) colonies. Management can be challenging due to the number of etiologies responsible for gastrointestinal disease in this species, limitations on diagnostic capabilities, and lack of effective treatments. Understanding commonly described GI diseases in the captive marmoset can provide insight on the impact these diseases have on research studies and aid in the development of appropriate management strategies. A review of commonly encountered GI disease processes as well as routinely implicated causes of GI disease in the common marmoset are provided. Current strategies in clinical management of GI disease in the common marmoset, including approaches to colony health, diagnostic testing, and commonly employed treatments are discussed.

The adult oligodendrocyte can participate in remyelination.

Endogenous remyelination of the CNS can be robust and restore function, yet in multiple sclerosis it becomes less complete with time. Promoting remyelination is a major therapeutic goal, both to restore function and to protect axons from degeneration. Remyelination is thought to depend on oligodendrocyte progenitor cells, giving rise to nascent remyelinating oligodendrocytes. Surviving, mature oligodendrocytes are largely regarded as being uninvolved. We have examined this question using two large animal models. In the first model, there is extensive demyelination and remyelination of the CNS, yet oligodendrocytes survive, and in recovered animals there is a mix of remyelinated axons interspersed between mature, thick myelin sheaths. Using 2D and 3D light and electron microscopy, we show that many oligodendrocytes are connected to mature and remyelinated myelin sheaths, which we conclude are cells that have reextended processes to contact demyelinated axons while maintaining mature myelin internodes. In the second model in vitamin B12-deficient nonhuman primates, we demonstrate that surviving mature oligodendrocytes extend processes and ensheath demyelinated axons. These data indicate that mature oligodendrocytes can participate in remyelination.

Brachyury drives formation of a distinct vascular branchpoint critical for fetal-placental arterial union in the mouse gastrula.

How the fetal-placental arterial connection is made and positioned relative to the embryonic body axis, thereby ensuring efficient and directed blood flow to and from the mother during gestation, is not known. Here we use a combination of genetics, timed pharmacological inhibition in living mouse embryos, and three-dimensional modeling to link two novel architectural features that, at present, have no status in embryological atlases. The allantoic core domain (ACD) is the extraembryonic extension of the primitive streak into the allantois, or pre-umbilical tissue; the vessel of confluence (VOC), situated adjacent to the ACD, is an extraembryonic vessel that marks the site of fetal-placental arterial union. We show that genesis of the fetal-placental connection involves the ACD and VOC in a series of steps, each one dependent upon the last. In the first, Brachyury (T) ensures adequate extension of the primitive streak into the allantois, which in turn designates the allantoic-yolk sac junction. Next, the streak-derived ACD organizes allantoic angioblasts to the axial junction; upon signaling from Fibroblast Growth Factor Receptor-1 (FGFR1), these endothelialize and branch, forming a sprouting VOC that unites the umbilical and omphalomesenteric arteries with the fetal dorsal aortae. Arterial union is followed by the appearance of the medial umbilical roots within the VOC, which in turn designate the correct axial placement of the lateral umbilical roots/common iliac arteries. In addition, we show that the ACD and VOC are conserved across Placentalia, including humans, underscoring their fundamental importance in mammalian biology. We conclude that T is required for correct axial positioning of the VOC via the primitive streak/ACD, while FGFR1, through its role in endothelialization and branching, further patterns it. Together, these genetic, molecular and structural elements safeguard the fetus against adverse outcomes that can result from vascular mispatterning of the fetal-placental arterial connection.

Bronchiolitis in young female smokers.

BACKGROUND: Smoking is a growing concern among young women. However, the pulmonary effects of smoking in young female smokers in their 20's are unknown. OBJECTIVE: The purpose of this study was to determine whether young female smokers demonstrate smoking-related lung abnormalities such as bronchiolitis in their 20's. METHODS: We recruited young females (20-30 yr) from Izmir, Turkey; 29 smokers and 31 lifetime non-smokers. They were all asymptomatic. All subjects performed complete lung function measurements and underwent thoracic computed tomography (CT) scanning at suspended full inspiration using a Toshiba "Aquilion" multi-slice CT scanner. The CT images were analyzed using custom software (Emphylx-J) and published equations to calculate total lung volume, mean lung density, lung mass, and the extent of emphysema. CT images were also read semi-quantitatively for respiratory bronchiolitis and emphysema by 2 experienced chest radiologists. When there was substantial difference in scoring, a 3rd (independent) radiologist read the CT scans. Plasma biomarkers of smoking were also measured in these subjects. RESULTS: Although none of the subjects demonstrated emphysema on CT images, 41% of smokers (compared with only 15% of non-smokers) had evidence for respiratory bronchiolitis (with a score of 2 or more; p = 0.0301). There was a significant relationship between pack-years of smoking and the severity of respiratory bronchiolitis in smokers. Plasma interleukin (IL)-6 levels were also higher in smokers than in non-smokers (p = 0.028). Quantitative analysis for emphysema or airways disease on CT scans did not reveal any significant differences in the two groups with the exception of lung mass, which was higher in the smokers than in non-smokers. Lung function was similar between the two groups. CONCLUSION AND CLINICAL RELEVANCE: Young female smokers in their 20's and 30's demonstrate CT changes consistent with respiratory bronchiolitis and elevated plasma IL-6 levels. They also have "heavier" lungs compared with lifetime non-smokers. These data indicate that pathologic changes of smoking occur early in young female smokers in the absence of demonstrable airflow limitation or symptoms. Public health efforts to curb smoking in young women are clearly needed to reduce the burden of smoking related lung disease in women.