Effects of oral administration of timothy hay and psyllium on the growth performance and fecal microbiota of preweaning calves.

The objective of this study was to evaluate the effects of oral administration of fiber from the first week of life on the growth and hindgut environment of preweaning calves. Twenty newborn female Holstein calves were divided into 2 groups as control and treatment. Calves in both groups were reared under the same feeding program except for oral fiber administration. Timothy hay and psyllium were mixed at a 50-to-6 ratio as a treatment diet for oral fiber administration. Calves in the treatment group were orally administered 50 g of fiber daily from 3 to 7 d of age and 100 g of fiber from 8 d of age until weaning. Feed intake and occurrence of diarrhea were recorded daily, and body weight (BW) was recorded weekly for the individual calf. Fresh feces were collected from calves at 7, 21, 35, 49, and 56 d of age to analyze fermentation parameters and microbiota to characterize the hindgut environment. Higher fiber intake in the treatment group due to oral administration of timothy and psyllium did not affect the starter intake and achieved higher BW at 21 d of age. The fecal pH, total volatile fatty acid, lactate, and ammonia nitrogen concentrations were not affected by oral fiber administration; meanwhile, the molar proportion of propionate was higher in the treatment group at 7 d of age. The difference in fecal microbiota in the calves subjected to the oral administration of fiber was observed within 21 d of life; Lactobacillus spp. and Prevotella spp. showed higher abundance, whereas that of Clostridium perfringens was decreased. These higher abundances of beneficial bacteria and lower abundance of pathogenic bacteria during early life may partly explain the higher BW of calves in the treatment group at 21 d of age. Furthermore, no adverse effect was observed for the BW and health status in the treatment group throughout the preweaning period. Therefore, early fiber feeding via oral administration potentially contributes to improving the hindgut environment in newborn calves, which leads to better growth of calves during the early stage of life.

Noradrenergic excitation of a subpopulation of GABAergic cells in the basolateral amygdala via both activation of nonselective cationic conductance and suppression of resting K+ conductance: a study using glutamate decarboxylase 67-green fluorescent protein knock-in mice.

GABAergic interneurons play central roles in the regulation of neuronal activity in the basolateral nucleus of the amygdala (BLA). They are also suggested to be the principal targets of the brainstem noradrenergic afferents which are involved in the enhancement of the BLA-related memory. In addition, behavioral stress has been shown to impair noradrenergic facilitation of GABAergic transmission. However, the noradrenaline (NA) effects in the BLA have not been differentiated among medium- to large-sized GABAergic neurons and principal cells, and remain to be elucidated in terms of their underlying mechanisms. Glutamate decarboxylase 67 (GAD67) is a biosynthetic enzyme of GABA and is specifically expressed in GABAergic neurons. To facilitate the study of the NA effects on GABAergic neurons in live preparations, we generated GAD67-green fluorescent protein (GFP) knock-in mice, in which GFP was expressed under the control of an endogenous GAD67 gene promoter. Here, we show that GFP was specifically expressed in GABAergic neurons in the BLA of this GAD67-GFP knock-in mouse. Under whole-cell patch-clamp recordings in vitro, we identified a certain subpopulation of GABAergic neurons in the BLA chiefly on the basis of the electrophysiological properties. When depolarized by a current injection, these neurons, which are referred to as type A, generated action potentials at relatively low frequency. We found that NA directly excited type-A cells via alpha1-adrenoceptors, whereas its effects on the other types of neurons were negligible. Two ionic mechanisms were involved in this excitability: the activation of nonselective cationic conductance and the suppression of the resting K+ conductance. NA also increased the frequency of spontaneous IPSCs in the principal cells of the BLA. It is suggested that the NA-dependent excitation of type-A cells attenuates the BLA output for a certain period.

An Er:YAG laser bone cutting manipulator for precise rotational acetabular osteotomy.

Rotational acetabular osteotomy (RAO) has an important advantage in that surgical bony defects are reconstructed with a patients' own tissue. We propose a surgical robot for the RAO using Er:YAG laser irradiating mounted on iliac bone to operate RAO precisely and to reduce recovery and trauma. A water-cooling Er:YAG laser (30 J/cm/sup 2/, l=2.94 mum, 20 Hz, 200 msec) that used optical fiber was operated 4-8 irradiation-overlapping ratio. We kept the distance between the laser and the bone at 0.25 mm using force sensor and spring to maintain effective ablation. Swine scapulae were ablated and performance was evaluated. The manipulator was operated mounting on iliac bone to get a filed position whereby resulting in precise bone cutting. The precision of the manipulator was within 0.3 mm and the efficiency of laser bone ablations per unit time optimized to 0.21 mm/sup 3//secW at the overlapping ratio of the irradiation area was 0.8, meaning a given ablated area was irradiated five times. The troughs showed m charring at this condition and the temperature of the surface was raised to 41.3 degrees C and it lasted only 5 seconds. We are sure that this research will be applied to orthopedics in the near future.

A morphological study of the effects of ozone on rat lung. I. Short-term exposure.

In order to determine the effects of ozone on lungs and the course of cell renewal after damage, young male rats were exposed to 3 ppm of ozone for 4 hr. They were killed at 1, 6, 12, and 18 hr and 1, 2, 3, 4, 7, and 14 days after exposure. One hour before the killing, dividing cells were labeled with tritiated thymidine. Type 1 cells of centriacinar location and bronchiolar cells were severely damaged after exposure. Labeling indices of type 2 cells and bronchiolar nonciliated cells increased 1 day after exposure. Hyperplasia of type 2 cells and bronchiolar nonciliated cells was observed 2 and 3 days after exposure. Ciligenesis of bronchiolar ciliated cells occurred 4 days after exposure. Our study shows that injured type 1 cells are repaired by proliferation of type 2 cells and that injured bronchiolar ciliated and Clara cells are repaired by proliferation of bronchiolar nonciliated cells. These undifferentiated cells are probably progenitors of ciliated cells and Clara cells, and some nonciliated cells are in a transitional form between nonciliated and type 2 cells.