NMDA receptor-dependent and metabotropic glutamate receptor-dependent forms of long-term depression coexist in CA1 hippocampal pyramidal cells

The development and maturation of the endolymphatic sac (ES) and duct (ED) were studied in the newt Cynops pyrrhogaster. The ES first appears as an oval capsule at the dorsal-medial tip of the otic vesicle at stage 39, about 11 days after oviposition. The ES consists of polymorphous epithelial cells with a minimum of cytoplasm. The intercellular space (IS) between the epithelial cells is narrow and has a smooth surface. At stage 44, the size of the ES increases as many vacuoles in the IS become filled. At stage 46, 18 days after oviposition, the ES elongates markedly and a slit-like lumen is found in the ES. The epithelium contains a few cell organelles which are scattered in the cytoplasm. The vacuoles in the IS are fused, which expands the IS. Two days later (stage 48), floccular material (endolymph) is present in the expanded lumen. The IS dilates and has a wide and irregular appearance. At stage 50, approximately 26 days after oviposition, the ES extends and expands significantly and crystals (otoconia) can now be seen in the widened lumen of the ES. The cytoplasm of the cuboidal epithelial cells contains an abundance of vesicles surrounded by ribosomes and Golgi complexes. Intercellular digitations are formed in the expanded IS. At stage 54, the ES forms a large bellow-like pouch. Numerous otoconia accumulate in the lumen. Free floating cells and cell debris can be seen in the lumen at this stage. The epithelial cells contain numerous cytoplasmic organelles which are evenly distributed in the cytoplasm. Granules are found in the apical and lateral cytoplasm. The IS is loose and displays a labyrinthine appearance. The primitive ED first appears as a connection between the ES and the saccule but no lumen is present inside at stage 39. At stage 46, a narrow lumen is formed in the ED, which corresponds to the formation of the ES lumen. At stage 50, as the ED extends, floccular material is seen in the lumen. At stage 54, the ED bears numerous microvilli on its luminal surface. Otoconia and endolymph are present in the ED. Tight junctions between the epithelial cells are formed at stage 46. A fully developed intercellular junctional complex is produced at stage 54. Based on the development of the ES and ED, the maturation of function of the ES and ED are discussed.     

Anxiety disorders of childhood, Implications for adult psychopathology

Although the exact path of acquisition remains incompletely understood, research supports the association between anxiety disorders in children and psychopathologic conditions in adults. This article addresses this relationship; reviews findings on the temperamental profile and behavioral inhibition, which may be an early identifiable childhood predictor of later anxiety disorders; and discusses the importance of early intervention.     

Novel diffusion cell for in vitro transdermal permeation, compatible with automated dynamic sampling

The development of a new diffusion cell for in vitro transdermal permeation is described. The so-called Kelder cells were used in combination with the ASPEC system (Automatic Sample Preparation with Extraction Columns), which is designed for the automation of solid-extractions (SPE). Instead of SPE columns, 20 Kelder cells were placed in the racks. This allowed automatic sampling of up to 20 cells for 24 h in a dynamic mode. The cells consist of an inlet compartment, a donor compartment and a receptor compartment. The size and the depth of the inlet compartment were important to avoid entrapment of air bubbles in the receptor compartment. The Kelder cells mimic blood flow beneath the skin by replacement of the permeating drug every 2 min. Hence sink condition are more easily maintained than with the static Franz diffusion cell. The performance of the cells was tested with permeation experiments using atropine as a model drug permeating through an artificial membrane (Silastic). The use of this skin model minimized the variability in permeation of atropine as compared with human skin.     

The influence of advanced age on the outcome of assisted reproduction

This study investigates within-subject variations and associations of salivary viscosities and flow rates in a test panel of healthy adults. After several practice sessions, unstimulated and stimulated whole saliva samples were collected 5 times daily (at 0800, 1100, 1400, 1700, and 2000 h) from 30 university students. There was a significant within-subject variation in viscosity and flow rate of unstimulated saliva (P<0.001). Intra-item correlations were significantly different for salivary flow rates (r= 0.82 for unstimulated, r= 0.88 for stimulated, P< 0.001) and viscosity of unstimulated saliva (r= 0.54, P< 0.05), but viscosity of stimulated saliva was different in this respect. Our results indicate that there is a significant within-subject variation in viscosity of unstimulated saliva.     

Detraining from total body exercise ergometry in individuals with spinal cord injury

Fibroblast-mediated cytokine gene therapy has proven to be a promising strategy for restoring hematopoiesis following repeated chemotherapy. Interleukin 3 (IL-3) and interleukin 6 (IL-6) can synergistically promote the recovery of hematopoiesis following chemotherapy. In this investigation, combined use of fibroblast-mediated IL-3 and IL-6 gene therapy was tested for hematopoietic effects on mice with or without 5-fluorouracil administration. The results demonstrated that combined therapy with IL-3 gene-modified NIH3T3 cell (NIH3T3-IL-3) and IL-6 gene-modified fibroblast NIH3T3 cell (NIH3T3-IL-6) implantation achieves obvious stimulation of hematopoiesis in normal mice and accelerates recovery of hematopoiesis. In normal mice the quantities of platelets, neutrophils, and total white blood cells in peripheral blood increased significantly after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells. The numbers of colony-forming unit (CFU) granulocyte/macrophage (CFU-GM) and CFU megakaryocyte (CFU-MK) formed by stem cells in bone marrow was significantly higher after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells than after the implantation of NIH3T3-IL-3 alone, NIH3T3-IL-6 alone, or neomycin gene-modified NIH3T3 cells. In hematopoiesis-depressed mice induced by preinjection with 5-fluorouracil at the dose of 150 mg/kg before cell implantation, the platelets, neutrophils, and white blood cells showed accelerated recovery, and the numbers of CFU-GM and CFU-MK formed by bone marrow cells were also markedly higher after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells than in control groups. Our data show that combined use of fibroblast-mediated IL-3 and IL-6 gene therapy may be of clinical relevance for the recovery of hematopoietic depression for patients after chemotherapy.     

Photoacoustic ultrasound: pulse production and detection of 0.5% Liposyn

Theoretical predictions and experimental measurements of photoacoustic pulse production within a 0.5% solution of Liposyn, a highly scattering, optical propagation medium, are reported. A simple model for photoacoustic energetics is developed that predicts photoacoustic signal pressure as a function of depth within a turbid medium following surface irradiation from an infrared source. The model is valid for very short irradiation duration. The model predicts that the acoustic pressure produced at a distance r from the center of a small, highly absorbing sphere of radius R consists of two, opposite polarity pulses, one originating from the near and one from the far side of the sphere. The magnitude of these biphasic pulses is expected to be proportional to the energy fluence (E) incident on the surface of the sphere and to the ratio, R/r. Furthermore, the energy fluence (E) that reaches the sphere is roughly proportional to e-mu effZ, where mu eff is the effective attenuation coefficient of the turbid medium and Z is the depth of the embedded sphere below the irradiated surface. The variation of E with depth within the absorber and biphasic acoustic pulse production have been verified experimentally. Further experiments demonstrate that a small (3-mm diameter), highly absorbing sphere can be detected and localized at a depth of 37.5 mm within a 0.5% solution of Liposyn with a spatial resolution of 1 x 6 mm2, using a biologically safe level of infrared irradiation (lambda = 1064 nm) and a conventional ultrasound transducer (frequency = 2.25 MHz). These results suggest that photoacoustic ultrasound imaging may have application to biologic systems such as the human breast.     

An evaluation of ruminally degradable intake protein and metabolizable amino acid requirements of feedlot calves

Ruminally degradable intake protein (DIP) and metabolizable indispensable amino acid (MIAA) requirements of feedlot steers were evaluated. Dietary treatments consisted of isocaloric 80% concentrate steam-flaked corn-based diets containing either .8% urea, 1.5% fish meal (FM), 3.0% FM, 4.5% FM, or 4.5% soybean meal (SBM). Treatment effects on characteristics of ruminal and total tract digestion were evaluated using four Holstein steers (249 kg) with cannulas in the rumen and proximal duodenum. Ruminal digestibility of OM (RDOM; P < .05) and feed N (P < .01) and microbial N flow (MNF; P < .01) to the small intestine were greater with urea as the supplemental N source. The level of DIP was closely associated (R2 = .89) with MNF. Postruminal digestibility of OM was greater (P < .05) for FM than for urea-supplemented diets, compensating for lower RDOM. There were no treatment effects (P > .10) on DOM. As the level of FM was increased, MIAA increased linearly (P < .01). Intestinal MIAA were similar (P > .10) for urea- and SBM-supplemented diets. Treatment effects on 56-d growth performance were evaluated using 100 medium-framed crossbred steers (231 kg). Daily weight gain (linear effect; P < .01), DM intake (linear effect; P < .10), feed efficiency (linear effect; P < .05), and diet NE (linear effect; P < .05) increased with level of FM supplementation. Daily weight gain (P < .10) and DM intake (P < .05) were greater for urea- than for SBM-supplemented diets. Using bovine tissue as the reference protein, the biological value (based on chemical score) of the intestinal chyme protein averaged 73%; methionine was first-limiting. There was a close association (R2 = .99) between methionine supply to the small intestine and observed/expected dietary NE. The metabolizable methionine requirement (MMETR, g/d) of medium-framed feedlot steers can be reliably predicted from measures of BW and ADG (MMETR = 1.565 + .0234ADG[268 - (29.4 x .0557BW(.75)ADG(1.097))/ADG] + .0896BW(.75)). There was a very close association (R2 = .89) between DIP and MNF (MNF = 13.7DIP - .66DIP(2) + 25.9). At maximal observed synthesis, DIP accounted for 76% of the MNF. A minimum of 100 g DIP/kg of total tract digestible OM was required to maximize RDOM and MNF.