Motor cortex neuroplasticity associated with lingual nerve injury in rats

The aim of this study was to determine if lingual nerve trauma affects the features of face primary motor cortex (MI) defined by intracortical microstimulation (ICMS). The left lingual nerve was transected in adult male rats by an oral surgical procedure; sham rats (oral surgery but no nerve transection) as well as naive intact rats served as control groups. ICMS was applied at post-operative days 0, 7, 14, 21, and 28 to map the jaw and tongue motor representations in face MI by analyzing ICMS-evoked movements and electromyographic activity recorded in the genioglossus (GG) and anterior digastric (AD) muscles. There were no statistically significant effects of acute (day 0) nerve transection or sham procedure (p?>?0.05). The surgery in the sham animals was associated with limited post-operative change; this was reflected in a significant (p?<?0.05) increase in the number of GG sites in left MI at post-operative day 14 compared to day 0. However, nerve transection was associated with significant increases in the total number of AD and GG sites in left or right MI or specifically the number of GG sites in rats at post-operative days 21 or 28 compared to earlier time periods. There were also significant differences between nerve-transected and sham groups at post-operative days 7, 14, or 21. These findings suggest that lingual nerve transection is associated with significant time-dependent neuroplastic changes in the tongue motor representations in face MI.     

Motor cortex neuroplasticity associated with lingual nerve injury in rats

The aim of this study was to determine if lingual nerve trauma affects the features of face primary motor cortex (MI) defined by intracortical microstimulation (ICMS). The left lingual nerve was transected in adult male rats by an oral surgical procedure; sham rats (oral surgery but no nerve transection) as well as naive intact rats served as control groups. ICMS was applied at post-operative days 0, 7, 14, 21, and 28 to map the jaw and tongue motor representations in face MI by analyzing ICMS-evoked movements and electromyographic activity recorded in the genioglossus (GG) and anterior digastric (AD) muscles. There were no statistically significant effects of acute (day 0) nerve transection or sham procedure (p > 0.05). The surgery in the sham animals was associated with limited post-operative change; this was reflected in a significant (p < 0.05) increase in the number of GG sites in left MI at post-operative day 14 compared to day 0. However, nerve transection was associated with significant increases in the total number of AD and GG sites in left or right MI or specifically the number of GG sites in rats at post-operative days 21 or 28 compared to earlier time periods. There were also significant differences between nerve-transected and sham groups at post-operative days 7, 14, or 21. These findings suggest that lingual nerve transection is associated with significant time-dependent neuroplastic changes in the tongue motor representations in face MI.     

Peripheral nerve compression associated with low-voltage electrical injury without associated significant cutaneous burn.

Although peripheral-nerve injury has been described as clearly related to electrical injury, that electrical injury is usually associated with third- and often fourth-degree burns. The report presented here describes three cases of low-voltage electrical injury with associated peripheral-nerve symptoms but without clinically significant cutaneous burns. The symptoms and clinical findings resembled peripheral-nerve compression. The presence of these symptoms and findings in the upper- and lower-extremities and the presence of bilateral involvement suggest a systemic electrical injury that resembles a peripheral neuropathy. Symptoms were relieved by the decompression of nerves at multiple sites in each extremity. Perineurial fibrosis was identified at the time of nerve decompression. It is proposed that the electrical injury causes maximal heat production at areas of minimal limb cross-sectional area. In these areas, the peripheral nerve is in close proximity to bone and fibrous tissue. This results in perineurial fibrosis and symptoms of a compressive peripheral neuropathy.     

Examination for sexual assault: Is the documentation of physical injury associated with the laying of charges? A retrospective cohort study

BACKGROUND: Few studies have examined whether there is an association between individual medical findings and legal outcome in cases of sexual assault. This study was undertaken to determine the relation between the extent of documented physical injury and a positive legal outcome in cases of sexual assault and to determine other factors associated with the laying of charges in such cases. METHODS: In this retrospective cohort study, the authors reviewed the charts and medicolegal reports for all cases of sexual assault that were handled by the BC Women''s Sexual Assault Service in 1992 for which a police report had been filed. Information on patients'' characteristics, the nature of the assault and the extent of injury was extracted from these records. A system for scoring clinical injury was developed by 4 of the physicians at the Sexual Assault Service, and a clinical injury score was assigned for each case by one physician. The relation between the outcome (in terms of whether charges were laid) and the circumstances of the case was examined by logistic regression. RESULTS: A total of 95 cases with complete medical records and information about legal outcome were identified during the 1992 calendar year. After adjustment for income level and the patient''s knowledge of the assailant (either as an acquaintance or as his or her partner), the odds ratio (OR) for charge-laying in a sexual assault case with documented moderate to severe injury was 3.33 (95% confidence interval [CI] 1.06-10.42). Socioeconomic status above the group median (defined as annual income greater than $21,893) (OR 3.26, 95% CI 1.09-9.71) and knowledge of the assailant (OR 4.58, 95% CI 1.52-13.79) were also associated with charge-laying. Presence of genital injury per se, age of the patient and detection of sperm by microscopy at the time of examination were not associated with the laying of charges. INTERPRETATION: The results of this study show that the extent of documented injury is associated with the laying of charges in cases of sexual assault. However, many questions remain about the effectiveness of the medical component of gathering such evidence.     

VGLUT2 controls heat and punctuate hyperalgesia associated with nerve injury via TRPV1-Cre primary afferents

Nerve injury induces a state of prolonged thermal and mechanical hypersensitivity in the innervated area, causing distress in affected individuals. Nerve injury-induced hypersensitivity is partially due to increased activity and thereby sustained release of neurotransmitters from the injured fibers. Glutamate, a prominent neurotransmitter in primary afferents, plays a major role in development of hypersensitivity. Glutamate is packed in vesicles by vesicular glutamate transporters (VGLUTs) to enable controlled release upon depolarization. While a role for peripheral VGLUTs in nerve injury-induced pain is established, their contribution in specific peripheral neuronal populations is unresolved. We investigated the role of VGLUT2, expressed by transient receptor potential vanilloid (TRPV1) fibers, in nerve injury-induced hypersensitivity. Our data shows that removal of Vglut2 from Trpv1-Cre neurons using transgenic mice abolished both heat and punctuate hyperalgesia associated with nerve injury. In contrast, the development of cold hypersensitivity after nerve injury was unaltered. Here, we show that, VGLUT2-mediated glutamatergic transmission from Trpv1-Cre neurons selectively mediates heat and mechanical hypersensitivity associated with nerve injury. Our data clarifies the role of the Trpv1-Cre population and the dependence of VGLUT2-mediated glutamatergic transmission in nerve injury-induced hyperalgesia.     

Entropy changes associated with a nerve impulse

In this paper the problem of entropy changes in a nerve fibre when an action potential is taking place is analysed. A probability field associated with the ionic distribution in the axoplasma and the extracellular space is defined. The total variation of its entropy can be computed on the basis of Gibbs' distribution of ions in the system. The final formula deduced for the entropy variation allows computations based on experimental data for the giant axon and the myelinated fibre. It represents at the same time a derivation of Brillouin's neguentropy principle of information in the particular case of the nerve.     

Experimental candidiasis associated with liver injury

In an attempt to perform a further investigation on the proposal that an increasing susceptibility to Candida infection in liver injury may be related to unsaturated transferin level (UIBC) and/or to a total amount of transferrin represented by TIBC, we conducted experimental candidiasis using mice with galactosamine-induced liver injury and investigated the effect of preadministration of transferrin prior to inoculation of Candida albicans. Final mortality was 10% in the mice without liver injury and without transferrin (Group 1) and ones with liver injury and with transferrin (Group 3). By contrast a 50% mortality was given in ones only with liver injury (Group 2). The TIBCs in Groups 1 and 3 were significantly higher than that in Group 2. The UIBCs in Groups 2 and 3, although there was no significant difference between them, were significantly lower than that in Group 1. This study confirmed that transferrin (TIBC) may have a direct deterring effect on systemic Candida infection and the decreased TIBC in the liver injury enhances the growth of C. albicans.     

CAP1 was associated with actin and involved in Schwann cell differentiation and motility after sciatic nerve injury

Adenylate cyclase-associated protein 1 (CAP1), a member of cyclase-associated proteins that regulating actin dynamics, was shown to regulate actin filaments, localize to dynamic actin structures and mediate such processes as establishment of cell polarity, motility, morphogenesis, receptor-mediated endocytosis and mRNA location. But little is known about the role of CAP1 during peripheral nervous system injury. Here, we found the spatiotemporal protein expression of CAP1 after sciatic nerve crush. After crush, CAP1 had an increased protein expression level, reached a peak at about day 5 and then returned to the normal level at 4 weeks, similar to Oct-6. Besides, in 5-day injured tissue, using double immunofluorescent staining we found CAP1 had a colocalization with S100 and Oct-6. In vitro, during the process of cAMP-induced Schwann cells differentiation, we observed enhanced expression of CAP1 and P0. Specially, CAP1-specific siRNA-tranfected SCs did not show significant actin structure which form cellure surface tension and protrusion shape after cAMP treatment. And we observed the interaction of CAP1 with actin and that CAP1-specific siRNA-transfected SCs had a decreased motility and migration. Together, all these data indicated that the change of CAP1 protein expression was associated with Schwann cells motility and differentiation after the crush of sciatic nerve.     

Unusual fractures associated with osteoporosis in premenopausal women.

Two premenopausal women (aged 40 and 34 years) and multiple undisplaced, often asymptomatic fractures of the femurs, ribs, metatarsals and other bones. The fractures, which appeared on roentgenograms as transverse radiolucent zones with variable callus formation, healed slowly or not at all despite treatment with calcium and vitamin D. They resembled pseudofractures (Looser''s transformation zones) radiologically, but the biochemical and histologic findings were those of idiopathic osteoporosis rather than osteomalacia. Since neither patient had been subjected to unusual stress it was concluded that the fractures had resulted from normal activity in abnormal bone.     

Flow parameters associated with hydrodynamic cell injury

Two flow parameters are proposed for the analysis of flows that have potential to damage animal cells. They are the state of stress (characterized by the second invariant of the stress tensor) and the flow classification parameter R(D) (which is related to the possibility of stress relaxation). We consider the flow that occurs when a 1.7-mm bubble collapses at a liquid interface. Using these two parameters, we show the regions in which the flow is strong in terms of high hydrodynamic stresses and elongation characteristics. (c) 1994 John Wiley & Sons, Inc.