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Four patients with environmental reduplication, a specific form of spatial disorientation and confabulation are described. The patients maintained that their hospital rooms were located in their homes. Each patients had evidence of right frontal or right parietal injury based upon computed tomography, neurosurgery, and neuropsychological testing. The factors associated with environmental reduplication were: impaired spatial perception and visual memory, inability of the patients to recognise the inconsistency between their believed location and their actual location, confusion soon after admission to hospital, and a strong desire to be at home. [ABSTRACT FROM AUTHOR]

A middleaged woman with a four year history of behavioural change including episodes of catatonia is described. Despite a persistently abnormal electroencephalogram, the patient was diagnosed repeatedly as suffering from a primary psychiatric disorder. Neurological examination and psychological testing suggested frontal lobe dysfunction, which was confirmed by the finding of isolated frontal lobe atrophy on computed axial tomography. [ABSTRACT FROM AUTHOR]

The goal of rehabilitation for stroke patients in this research was to improve the volitional coordination of the swing phase and stance phases of gait. Functional neuromuscular stimulation (FNS) is a promising rehabilitation tool for restoring motor control. For our gait training protocols, FNS systems with surface electrodes were impractical. For the rehabilitation protocols that we defined, available implantable electrode designs did not meet desired criteria regarding fracture rate, invasiveness of placement procedures, and maintenance of position at the motor point. The criteria for the new intramuscular (IM) electrode design included minimally invasive electrode placement technique, accurate placement of electrodes, good muscle selectivity, consistency of muscle activation, good position maintenance of the electrode at the motor point, comfortable stimulus, and practical donning time for the system. A percutaneous electrode was designed for placement beneath the skin at the motor point of seven paralyzed or paretic muscles in the lower limb. A single-helical coil lead, a double-helical coil electrode, and fine wire barbs were design features that enhanced the anchoring capability of the electrode. A polypropylene core enhanced electrode durability. Implantation tools were custom-designed to enable accurate electrode placement without incision. We studied 17 subjects with a total of 124 electrodes. With the use of IM electrodes, FNS was provided for 1,413.8 electrode months. During this time, no instances of infection occurred. The measure of electrode integrity showed a 99% electrode survival rate. Throughout the treatment protocols, 93% of the electrodes delivered a good muscle response; 7% (nine electrodes) moved from the motor point and delivered a poor muscle response during the treatment protocol. Anchoring performance was higher for electrodes implanted in muscles that moved the hip (96.0%) and ankle joints (97.45%) compared with electrodes implanted in muscles that moved the knee joint (88.5%). Ninety-seven percent of the electrodes delivered a comfortable stimulus. Three percent delivered a stimulus that was uncomfortable at therapeutic levels and therefore were not used. We achieved gains in subject impairment and disability measures. The system proved to be practical for use in both clinical and home environments.

From October 1989 to June 1993, we captured and sampled 110 coyotes (Canis latrans) for various diseases in Yellowstone National Park, Wyoming (USA). Prevalence of antibodies against canine parvovirus (CPV) was 100% for adults (> 24 months old), 100% for yearlings (12 to 24 months old), and 100% for old pups (4 to 12 months old); 0% of the young pups (< 3 months old) had antibodies against CPV. Presence of antibodies against canine distemper virus (CDV) was associated with the age of the coyote, with 88%, 54%, 23%, and 0% prevalence among adults, yearlings, old pups, and young pups, respectively. Prevalence of CDV antibodies declined over time from 100% in 1989 to 33% in 1992. The prevalence of canine infectious hepatitis (ICH) virus antibodies was 97%, 82%, 54%, and 33%, for adults, yearlings, old pups, and young pups, respectively. The percentage of coyotes with ICH virus antibodies also declined over time from a high of 100% in 1989 to 31% in 1992, and 42% in 1993. Prevalence of antibodies against Yersinia pestis was 86%, 33%, 80%, and 7%, for adults, yearlings, old pups, and young pups, respectively, and changed over time from 57% in 1991 to 0% in 1993. The prevalence of antibodies against Francisella tularensis was 21%, 17%, 10%, and 20%, for adults, yearlings, old pups, and young pups, respectively. No coyotes had serologic evidence of exposure to brucellosis, either Brucella abortus or Brucella canis. No coyotes were seropositive to Leptospira interrogans (serovars canicola, hardjo, and icterohemorrhagiae). Prevalence of antibodies against L. interrogans serovar pomona was 7%, 0%, 0%, and 9%, for adults, yearlings, old pups, and young pups, respectively. Antibodies against L. interrogans serovar grippotyphosa were present in 17% of adults and 0% of yearlings, old pups, and young pups. Many infectious canine pathogens (CPV, CDV, ICH virus) are prevalent in coyotes in Yellowstone National Park, with CPV influencing coyote pup survival during the first 3 months of life; eight of 21 transmitted pups died of CPV infection in 1992. The potential impact of these canine pathogens on wolves (C. lupus) reintroduced to Yellowstone National Park remains to be documented.

The effect of the local anesthetic QX222 on the kinetics of miniature end-plate currents (MEPC)and acetylcholine-induced end-plate current fluctuations was studied in voltage-clamped frog cutaneous pectoris neuromuscular junctions. The rate constants for a kinetic scheme of local anesthetic blockage of end-plate channels were calculated from the MEPC decay parameters. At 18 degrees C the blocking rate constant was 1.1 +/- 0.3 x 10(7) exp (-0.009 +/- 0.003 x V)s -1M-1, and the unblocking rate constant was 5.7 +/- 0.6 exp (0.011 +/- 0.002 x V)s -1. The dissociation constant was close to 10 microM at -80 mV. End-plate fluctuations indicated that the local anesthetic QX222 lowered the effective single-channel conductance, suggesting a finite blocked state conductance that was calculated to be 1.6 pS. The apparent differences between QX222 interaction with end-plate and extrajunctional channels are discussed.

The effect of the local anesthetic QX222 on the kinetics of miniature endplate currents and acetylcholine induced endplate current fluctuations was studied in voltage clamped cutaneous pectoris muscle of Rana pipiens. Both the endplate current fluctuation spectra and the miniature endplate current decay consisted of two or three components depending upon the holding potential and local anesthetic concentration. The cutoff frequency of each spectral component was equal to the decay rate of its corresponding constituent of the miniature endplate current. Comparison of the relative amplitudes of the spectral and miniature endplate components indicated that QX222 did not act by creating two kinetically distinct populations of acetylcholine receptors. QX222 action could be explained by alteration of the acetylcholine receptors such that they sequentially change conformation form one open state to another. A specific case in which QX222 binds to the open state of the acetyl-choline receptor creating a blocked state, was found to account for the observed relationship between the relative amplitudes of the miniature endplate current and spectral components, as well as the previously observed voltage and concentration sensitivity of the decay rates of endplate current components.