Low‐energy extracorporeal shock wave therapy enhances skin wound healing in diabetic mice: A critical role of endothelial nitric oxide synthase

Low‐energy extracorporeal shock wave (LE‐ESW) treatment has been shown to accelerate wound repair; however, the mechanisms of treatment remain unclear. In the present study, we addressed the role of endothelial nitric oxide synthase (eNOS). A single LE‐ESW treatment accelerated the healing of wounds in diabetic mice caused by the injection of streptozotocin. This accelerated healing was accompanied by the increased expression of eNOS and vascular endothelial growth factor (VEGF) and the generation of new vessels at the wound tissues. These results raised the possibility that eNOS may be involved in the beneficial effects of LE‐ESW treatment. To address this possibility, we compared the effects of this treatment between mice with a genetic disruption of eNOS knockout (eNOS‐KO mice) and wild‐type (WT) control mice. Interestingly, the LE‐ESW‐induced acceleration of wound closure and the increase in VEGF expression and neovascularization was significantly attenuated in eNOS‐KO mice compared with WT mice. Considered collectively, these results showed that eNOS was induced at the wound tissues by LE‐ESW treatment and played a critical role in the therapeutic effects of this treatment by accelerating the wound healing by promoting VEGF expression and neovascularization.     

Antiepileptic Effects of MK-801, a Noncompetitive NMDA-Receptor Antagonist, in the Low-Frequency Kindling Model of Epilepsy

Abstract: We assessed the acute effect of MK-801 (0.05–0.7 mg/kg), a noncompetitive NMDA-receptor antagonist, on hippocampus-kindled seizures induced with low-frequency (2 Hz) electrical stimulations. MK-801 dose-dependently increased the seizure threshold (PNT, the number of stimulating pulses required for the triggering of epileptic dterdischarge), whereas most of the previous studies which assessed the effect of MK-801 on kindled seizures could not detect the elevation of seizure threshold by MK-801. In addition MK-801 decreased the severity of induced seizures at low doses at which previous studies could not detect the antiepileptic effect of MK-801, suggesting that the low-frequency kindling technique might be a more sensitive and reliable model of epilepsy than the conventional high-frequency kindling technique.     

Pharmacokinetic Analysis of the Absorption Enhancing Action of Decanoic Acid and Its Derivatives in Rats

The enhancing action of decanoic acid (C1O) and its derivatives on mucosal absorption of phenolsulfonphthalein (PSP) in the jejunum or colon was analyzed using pharmacokinetics in rats. After administration of a solution containing PSP and an enhancer [C10, 2-hydroxydecanoic acid (2-OHC10), or 3-hydroxydecanoic acid (3-OHC10)] into the jejunal or colonic loop, the amounts of PSP and enhancer remaining in the loop and/or plasma PSP concentration were determined periodically. 2-OHC10 exhibited a greater absorption enhancing potency than C10, while 3-OHC10 was less effective. Disappearance of residual PSP from the loop ceased after complete absorption of the enhancer. The enhancer-induced disappearance rate constant of PSP correlated well with the product of the enhancer disappearance rate and its capacity to sequester calcium ions. In conclusion, the enhancement of PSP mucosal absorption by C10 and its derivatives is consistent with a pharmacokinetic model, assuming that the enhanced membrane permeability of PSP depends on the enhancer disappearance kinetics from the loop and its calcium ion sequestration capacity.     

Effects of sensory stimulation on respiratory cardiac cycle variability in humans

The effects of the phase of respiration on the response of respiratory cardiac cycle variability to sensory stimulation were studied in five healthy young male subjects. Transcutaneous electrical stimulation of the ulnar nerve or hand-grip exercise was applied during inspiration or expiration. Although both electrical stimulation and hand-grip exercise depressed respiratory cardiac cycle variability, the nature of the depression differed according to where in the respiration cycle the stimuli were applied. The amplitude of respiratory cardiac cycle variation was significantly decreased when either stimulus was applied during expiration (P < 0.05), and was unchanged when applied during inspiration (P > 0.05). These findings would suggest that cardiac vagal efferent activity was effectively inhibited by sensory stimulation during expiration, but was not inhibited by such stimulation during inspiration. This mechanism may account, in part, for the known suppression of respiratory cardiac cycle variability during exercise. Present address: Department of Biomechanics and Physiology, Faculty of Liberal Arts, University of Yamaguchi, Yamaguchi City, 1677-1 Yoshida, Yamaguchi 753, Japan     

Purification of human muscle satellite cells by flow cytometry

To purify satellite cells directly from human muscle biopsies, we have developed a method based on size separation of dissociated cells by flow cytometry. Immediately after tryptic dissociation of human muscle biopsies and elimination of erythrocytes, microscopic observation and flow cytometry analysis of cell suspensions revealed two populations of cells differing in size and nucleocytoplasmic ratio. Clonal cultures of these two cell types with a manual procedure demonstrated that only the small cells were myogenic satellite cells. Flow cytometry-sorting and analysis of the small cell population showed that (1) all sorted cells contained desmin immediately after dissociation and plating; (2) more than 98% of the cells expressed the 5.1.H11 epitope after 2 weeks of proliferation in culture; and (3) 90% of the sorted cells were able to form myotubes when cultivated at low density or in clonal cultures. Thus, human muscle satellite cells can be directly purified from human muscle samples using flow cytometry. © 1993 John Wiley & Soncs, Inc.     

Circadian rhythms of ethanol consumption by mice: A simple computer analysis for chronopharmacology

On the assumption that a sinusoidal curve adequately describes the circadian rhythm of food or fluid consumption by mice, the whole daily pattern can be derived from a few observations. Examples are presented to show that the assumption is valid. This simple curve-fitting by computer is also applicable to analysis of blood levels of drugs administered in the food or drinking fluid. The method should be useful for estimating the magnitude of daily fluctuations in pharmacological variables, including drug intake rates and circulating drug levels.     

Physical properties and ease of operation of a wireless intraoral x-ray sensor.

OBJECTIVE: A wireless CMOS (CDR Wireless) system was evaluated based on its physical properties and ease of operation. STUDY DESIGN: The physical properties were assessed by dose-response curve, modulation transfer function, and detective quantum efficiency tests. The range of signal receptivity between the sensor and the antenna was also determined. The time required to make a radiograph was measured. Using a visual analog scale (VAS), 10 test patients were asked to evaluate the discomfort caused by having the sensor inserted and placed in the mouth. An intraoral x-ray film packet and a wired CDR sensor were also evaluated for comparison with the wireless system. RESULTS: The physical properties of the wireless system and the wired CDR sensor were essentially equal. The antenna could receive the signal up to 3.5 m from the sensor. The wireless CMOS system required less time to perform the radiographic task than the other methods studied. The VAS scores for the wireless and wired CDR sensors were comparable. CONCLUSIONS: The CDR Wireless sensor has equivalent physical properties to its wired counterpart and may be more convenient to use.