Inhibitory Effect of Glycerin on Vibrio parahaemolyticus and Salmonella

In a study of the effect of glycerin in transport media on Vibrio parahaemolyticus and Salmonella, it was found that a concentration of 30% glycerin was highly inhibitory for V. parahaemolyticus and to a lesser degree for Salmonella. The incorporation of peptone or human feces in media did not reduce the inhibitory effect of glycerin. In media with 15% glycerin, viable counts of V. parahaemolyticus and Salmonella increased after 24 hr of incubation both in the presence and absence of feces. Due to the concurrent increase in the total bacterial count in the media containing feces, no enrichment effect was noted.     

Immunolocalization of β-1-4-galactan and its relationship with lignin distribution in developing compression wood of Cryptomeria japonica

Compression wood (CW) contains higher quantities of β-1-4-galactan than does normal wood (NW). However, the physiological roles and ultrastructural distribution of β-1-4-galactan during CW formation are still not well understood. The present work investigated deposition of β-1-4-galactan in differentiating tracheids of Cryptomeria japonica during CW formation using an immunological probe (LM5) combined with immunomicroscopy. Our immunolabeling studies clearly showed that differences in the distribution of β-1-4-galactan between NW (and opposite wood, OW) and CW are initiated during the formation of the S₁ layer. At this stage, CW was strongly labeled in the S₁ layer, whereas no label was observed in the S₁ layer of NW and OW. Immunogold labeling showed that β-1-4-galactan in the S₁ layer of CW tracheids significantly decreased during the formation of the S₂ layer. Most β-1-4-galactan labeling was present in the outer S₂ region in mature CW tracheids, and was absent in the inner S₂ layer that contained helical cavities in the cell wall. In addition, delignified CW tracheids showed significantly more labeling of β-1-4-galactan in the secondary cell wall, suggesting that lignin is likely to mask β-1-4-galactan epitopes. The study clearly showed that β-1-4-galactan in CW was mainly deposited in the outer portion of the secondary cell wall, indicating that its distribution may be spatially consistent with lignin distribution in CW tracheids of Cryptomeria japonica.     

The reversibility of intestinal immune expulsion effects on adult Nippostrongylus brasiliensis

An attempt has been made to study the extent and nature of the damage occurring in adult Nippostrongylus brasiliensis undergoing immune expulsion from the rat. It was found that worms are not killed nor irreparably damaged when being rejected. On transfer into naive second recipient rats the rate of re-establishment of worms previously incubated in immune rat recipients for 4-17 hr was high (68-69%) and comparable to that shown by worms from normal recipient rats (48-56%). Similarly, worms taken on days 10, 11, and 12 of a primary infection, already passed to the distal half of the small intestine due to immune expulsion effects, on transfer into naive recipient rats re-established themselves well (rates varying from 62 to 80%) compared to those harvested from their normal habitat in the proximal half of the small intestine (rates varying from 44 to 87%). Worm damage is associated with decreased motility and impaired locomotion capacity. The phenomenon of mucosal trapping occurs during expulsion, but merely to the extent of some 30% of the worm population. It is suggested that in principle, worms subjected to immune expulsion are in a state of acute, transient metabolic crisis. The present results support the enteroallergic indirect mechanism for worm rejection.     

Adhesion of lymphoid cell lines to fibronectin-coated substratum: Biochemical and physiological characterization and the identification of a 140-kDa fibronectin receptor

Little information is available on the interaction between lymphocytes and fibronectin (fn). To gain a better understanding on this issue we examined the adhesion of 12 lymphoid cell lines, each exhibiting different phenotypic characteristics, to fn-coated substratum. Of the cell lines tested, five that adhered to fn possessed B-cell characteristics, while neither the T-cell lines nor the pre-B-cell line adhered. The physiology and biochemistry of adhesion of a B-cell line, MOPC 315, were examined in detail. Our results indicated that (1) the adhesion was a specific and time-dependent process, (2) the adhesion was temperature-dependent and inhibited by metabolic inhibitors, such as KCN and 2-deoxyglucose, (3) the presence of cycloheximide and pretreatment of cells with trypsin inhibited adhesion, (4) a 140-kDa surface protein was immunoprecipitated by anti-fn receptor antibodies, (5) the presence of divalent cations was essential for adhesion, (6) the presence of colchicine had no effect on adhesion, while cytochalasin B partially inhibited adhesion, and (7) the treatment of cells by both phorbol 12-myristate 13-acetate and calcium ionophore A23187 enhanced adhesion. In this study, we have established the interaction between lymphoid cell lines and fn. Such an interaction might play an important role in the behavior of lymphocytes in tissues.     

Dispersion population models discrete in time and continuous in space

We analyze a discrete-time model of populations that grow and disperse in separate phases. The growth phase is a nonlinear process that allows for the effects of local crowding. The dispersion phase is a linear process that distributes the population throughout its spatial habitat. Our study quantifies the issues of survival and extinction, the existence and stability of nontrivial steady states, and the comparison of various dispersion strategies. Our results show that all of these issues are tied to the global nature of various model parameters. The extreme strategies of staying-in place and going-everywhere-uniformly are compared numerically to diffusion strategies in various contexts. We approach the mathematical analysis of our model from a functional analysis and an operator theory point of view. We use recent results from the theory of positive operators in Banach lattices.     

No effect of isolation on blood pressure and daily electrolyte excretion in rats

The effects of isolation stress on mean blood pressure (BP) and on body weight, water and food intake as well as on urine flow, urinary sodium and potassium excretion were studied in CFY and Long Evans rats. During a 7 day isolation period, food and water intake as well as urine flow, urinary sodium and potassium excretion, as expressed for 100 g body weight, were not changed in either group. Body weight increased similarly in isolated (38 +/- 2 g) and aggregated (41 +/- 5 g) CFY rats. Compared to group housed rats, BP in male CFY animals was not increased after a 7 day isolation (111 +/- 3 vs 111 +/- 3 mmHg, NS). In additional experiments high sodium intake by physiological saline drinking slightly elevated blood pressure but failed to induce arterial hypertension in isolated rats (118 +/- 2 vs 121 +/- 3 mmHg, NS). We conclude that, contrary to some reports from other laboratories, isolation stress has no detectable effect on BP and/or water and electrolyte balance.     

The ontogeny of the vascular cambium inGinkgo biloba roots

Observation was made on early ontogeny of vascular cambium in the developing root ofGinkgo biloba L. After completion of root elongation, the vascular meristem gradually acquires cambial characteristics. Strips of the periclinal division of cells in transverse section are observed on the inner side of phloem when the primary xylem and phloem in the stele have been established. The strips are united into a continuous layer between phloem and xylem. In tangenital section, the procambium shows a homogeneous structure, which is initially composed of short cells with transverse end walls and subsequently, of long cells with tapering ends. Then, the procambium is organized into two systems of cells; axial strands of short cells with transverse end walls resulting from the sporadic transverse divisions of long cells, and long cells with tapering ends. Still later, the short cells are divided frequently in a trasverse plane exhibiting one or a few cells in width and several decades of cells in height, while the long cells are elongated. The frequency of transverse divisions of the short cells decreases in subsequent stages. Eventually, the short cells in axial strands are vertically separated from one another by the elongation of neighboring long cells and by the decrease in the frequency of transverse divisions of short cells themselves. Cambial initials occur in two forms; ray initials a few cells in height and one cell in width derived from the short cells, and fusiform initials with tapering ends derived from the long cells.     

The effect of high pressure sodium vapor lamps on the rat

The effect of high pressure sodium vapor lamps and daylight-simulating fluorescent lights on the growth, hematology, and behavior of Sprague-Dawley rats has been investigated. Rats weaned under the sodium vapor lamps had slightly heavier adrenals than those exposed to the daylight lamps when the two lighting systems were equalized either for total irradiance or for scotopic illuminance. However, no differences were observed in the tail-flick response, hot plate response, or swimming endurance of rats housed under the two lighting conditions. No consistent differences were seen in the hemoglobin, red and white cell count, hematocrit, and mean cell volume between rats weaned under the high pressure sodium vapor lamps and daylight-simulating fluorescent lights.     

Time course of denervation diuresis and natriuresis in the anaesthetized rat

The effect of unilateral renal sympathectomy on renal excretion of water and sodium was studied in three groups of Inactin-anaesthetized rats: 1-3, 4-19, and 20-35 weeks after denervation. Increased sodium excretion from the denervated kidney in the absence of changes in GFR was observed up to 35 weeks following renal denervation. Thus, in a functional sense, renal reinnervation may have only been partial during the time interval studied.