Effect of posterior hypothalamic knife cuts on the baroreflex and hemorrhage-induced hormonal responses.

We made posterior hypothalamic knife cuts in rats to transect the fibers of the medial forebrain bundle (MFB) at the level of the mammillary body. The role of the MFB in the baroreflex and hemorrhage-induced hormonal responses was then examined in the unanesthetized, freely moving condition. The slopes for the relationship between changes in pulse interval and mean arterial pressure (MAP) in the posterior-cut group were significantly steeper than those in the sham-cut group both when there were phenylephrine-induced increases in MAP (1.13 +/- 0.07 vs 0.86 +/- 0.10 msec/mmHg) and nitroprusside-induced decreases in MAP (1.16 +/- 0.10 vs 0.77 +/- 0.05 msec/mmHg). This result indicates that posterior cuts elevated baroreflex sensitivity when MAP was increased or decreased. The resting MAP was not changed, but the resting heart rate (HR) was lowered by the posterior cuts. Furthermore, the posterior cuts augmented hypotensive hemorrhage-induced bradycardia. Hypotensive hemorrhage (16-17 ml/kg) caused elevation of the plasma catecholamine, ACTH and vasopressin (AVP) levels, but the posterior cuts attenuated these hormonal responses. These results indicate that the fibers in the MFB have a tonic inhibitory effect on the baroreflex in the resting condition, and play a stimulatory role in hemorrhage-induced catecholamine, ACTH and AVP responses.</p

Diffuse X-Ray Scattering Measurement by Stationary Use of the Buerger Precession Camera

A photographic method for constructing the intensity contours of the diffuse X-ray scattering from a series of stationary photographs taken with the crystal and film rotated through successive angles is proposed, which is efficient for detecting the details of the intensity distribution. The transformation equations are derived to relate the coordinates on the film to those in the reciprocal lattice. A volume element of intensity measurement in reciprocal space, necessary for obtaining the integrated intensity or calculating the Fourier transforms of the intensity, is calculated

Electron Diffraction Study on Diffuse Scattering from Disordered Cu_3Au Alloy

A detailed study has been made on diffuse scattering from Cu_3Au alloy in the disordered state by electron diffraction, using single crystal evaporated films, in order to investigate the origin of the short-range order above T_c. Aspects of the diffuse scattering resemble in some respects those of superlattice reflections below T_c, which are related to the antiphase domain structure. From the present study, however, it has become clear that there is no direct relation between the short-range order state above Te and the antiphase domain structure below T_c. Behaviors of the diffuse scattering have been studied, the electron-atom ratio being changed by addition of Pd or In to Cu_3Au. Results obtained are well interpreted by the suggestion of Moss, indicating that the short-range order state revealed by the diffuse scattering originates from anomalies of energy of conduction electrons

Correlative Microdomain Model for Short-Range Ordered Alloy Structures : I. Diffraction Theory(Physics)

A diffraction theory is developed for diffuse scattering from disordered binary alloys with short-range order. It is based on a model of ordered microdomains embedded in a disordered matrix and interference effects between the domains are considered. There is a possibility that the fine structures of diffuse scattering as observed in the cases of Cu_3Au, CuAu and Cu_3Pd alloys result from the introduction of interdomain correlations. From experimental diffuse intensity values one can calculate the statistical distribution of microdomains in antiphase with one another

X-ray Diffraction Study of Static Distortion of the Host Zirconium Lattice in Interstitial Zr-O Solid Solutions(Physics)

Static distortions of the host zirconium lattice as caused by the interstitial oxygen atoms have been determined by X-ray diffraction for Zr-23.6 and 24.8 at.%O alloys. The arrangement of oxygen atoms in the former alloy is specified by the ZrO_x or ABC-type stacking structure and that in the latter by a statistical sequence of two kinds of oxygen layer, i.e. single A and double AB layers. The present work has proved that each zirconium atom shifts toward the adjacent oxygen atoms and the magnitude of the displacement is about 0.04 A for both the alloys. The anomalous dependence of the lattice constants on oxygen concentration is qualitatively explained by the local contraction in the c plane

Effect of the Japanese Herbal Kampo Medicine Dai-Kenchu-To on Postoperative Adhesive Small Bowel Obstruction Requiring Long-Tube Decompression: A Propensity Score Analysis

Adhesive small bowel obstruction (ASBO) is an adverse consequence of abdominal surgery. Although the Kampo medicine Dai-kenchu-to is widely used in Japan for treatment of postoperative ASBO, rigorous clinical studies for its use have not been performed. In the present retrospective observational study using the Japanese diagnosis procedure combination inpatient database, we selected 288 propensity-score-matched patients with early postoperative ASBO following colorectal cancer surgery, who received long-tube decompression (LTD) with or without Dai-kenchu-to administration. The success rates of LTD were not significantly different between Dai-kenchu-to users and nonusers (84.7% versus 78.5%; P = .224), while Dai-kenchu-to users showed a shorter duration of LTD (8 versus 10 days; P = .012), shorter duration between long-tube insertion and discharge (23 versus 25 days; P = .018), and lower hospital charges ($23,086 versus$26,950; P = .018) compared with Dai-kenchu-to nonusers. In conclusion, the present study suggests that Dai-kenchu-to is effective for reducing the duration of LTD and saving costs

Effect of acute ether or restraint stress on plasma corticotropin-releasing hormone, vasopressin and oxytocin levels in the rat.

Ether and restraint stress-induced peripheral plasma corticotropin releasing hormone (CRH), arginine vasopressin (AVP), oxytocin (OXY) and adrenocorticotropin (ACTH) levels were measured by radioimmunoassays. Plasma CRH, AVP, OXY and ACTH rose to approximately twice the level of control rats 2 min after the onset of a 1-min exposure to ether. Plasma CRH rose further 5 min after the onset of ether stress, while plasma AVP and OXY returned to the baseline levels at 5 min. Plasma CRH, OXY and ACTH showed significant elevation 2 min after the onset of restraint stress, while plasma AVP did not show a significant change. Plasma OXY and ACTH rose further 5 min after the onset of restraint stress, whereas plasma CRH returned to baseline levels. CRH and OXY concentrations in the hypothalamic median eminence decreased 5 min after the onset of ether exposure and restraint, while the AVP concentration did not differ from control levels. The results, including the discrepancy between plasma CRH and ACTH 5 min after stress, suggest that CRH in the peripheral plasma is derived from both hypothalamic and extrahypothalamic tissues. The levels of stress-induced CRH in the peripheral plasma were sufficient to stimulate ACTH release. These results suggest that ether and restraint stress elevate plasma CRH shortly after the onset of the stress, and that this elevation in the plasma CRH level is at least partly responsible for stress-induced ACTH secretion.</p

Comparison of the Effects of Intra-Third Ventricular Administration of Interleukin-1 or Platelet Activating Factor on ACTH Secretion and the Sympathetic-AdrenomeduIIary System in Conscious Rats

The effects of centrally administered interleukin-1 beta (IL-1) or platelet activating factor (PAF) on adrenocorticotropin (ACTH) and catecholamine secretion, blood pressure and heart rate were examined to determine if these agents stimulate similarly the hypothalamic-pituitary-adrenal (HPA) axis or the sympathetic-adrenomedullary system. Intra-third ventricular administration of IL-1 (50, 200 ng) evoked significant ACTH secretion. Centrally administered IL-1 (50 ng) elevated plasma noradrenaline and adrenaline levels, systolic blood pressure and heart rate. Plasma ACTH, noradrenaline and adrenaline levels were also increased by the higher dose (200 ng) of IL-1 while systolic blood pressure and heart rate were not affected. Intra-third ventricular administration of 9 micrograms of PAF elevated the plasma ACTH level while 3 micrograms of PAF did not stimulate ACTH secretion. Neither dose of centrally administered PAF affected any plasma catecholamine level or systolic blood pressure. These results suggest that central IL-1 stimulates both the HPA axis and the sympathetic-adrenomedullary system, that a higher dose of IL-1 stimulates a mechanism to antagonize the elevation of blood pressure and heart rate and that central PAF is not involved in the control of the sympathetic-adrenomedullary system. Thus, IL-1 and PAF do not interact in the brain, although they interact peripherally.</p