Characterization of three strains of Capnocytophaga canis isolated from patients with sepsis.

Capnocytophaga canimorsus and Capnocytophaga cynodegmi, both commensal bacteria in the oral cavities of dogs and cats, are zoonotic pathogens. In particular, C. canimorsus causes sepsis and fatal septic shock. Recently, a novel Capnocytophaga species, C. canis, was isolated from the oral cavities of healthy dogs. It is reportedly oxidase-negative and therefore considered avirulent in humans. In the present study, three strains of C. canis were isolated from Japanese patients with sepsis. All three strains, HP20001, HP33001 and HP40001, were oxidase-positive. Nucleotide sequence identities of the 16S rRNA gene of the three strains to the C. canimorsus type strain ATCC35979, C. cynodegmi type strain ATCC49044 and C. canis type strain LMG29146 were 96.9-97.0%, 96.9-97.0% and 99.7-99.8%, respectively. Multi-locus sequence analysis based on seven house-keeping genes, dnaJ, fumC, glyA, gyrB, murG, trpB and tuf, revealed that the oxidase-positive C. canis strains isolated in Japan and oxidase-negative strains of C. canis from canine oral cavities in Switzerland were clustered in different genetic subgroups. These results indicate that the virulence of C. canis strains in humans is associated with oxidase activity.

Sepsis Caused by Newly Identified Capnocytophaga canis Following Cat Bites: C. canis Is the Third Candidate along with C. canimorsus and C. cynodegmi Causing Zoonotic Infection.

Sepsis caused by a Capnocytophaga canis infection has only been rarely reported. A 67-year-old female with a past medical history of splenectomy was admitted to our hospital with fever and general malaise. She had been bitten by a cat. She showed disseminated intravascular coagulation and multi-organ failure because of severe sepsis. On blood culture, characteristic gram-negative fusiform rods were detected; therefore, a Capnocytophaga species infection was suspected. A nucleotide sequence analysis revealed the species to be C. canis, which was newly identified in 2016. C. canis may have low virulence in humans; however, C. canis with oxidase activity may cause severe zoonotic infection.

[Lower urinary tract dysfunction and neuropathological findings of the neural circuits controlling micturition in familial amyotrophic lateral sclerosis with L106V mutation in the SOD1 gene].

We report lower urinary tract dysfunction and neuropathological findings of the neural circuits controlling micturition in the patients with familial amyotrophic lateral sclerosis having L106V mutation in the SOD1 gene. Ten of 20 patients showed lower urinary tract dysfunction and 5 patients developed within 1 year after the onset of weakness. In 8 patients with an artificial respirator, 6 patients showed lower urinary tract dysfunction. Lower urinary tract dysfunction and respiratory failure requiring an artificial respirator occurred simultaneously in 3 patients. Neuronal loss and gliosis were observed in the neural circuits controlling micturition, such as frontal lobe, thalamus, hypothalamus, striatum, periaqueductal gray, ascending spinal tract, lateral corticospinal tract, intermediolateral nucleus and Onufrowicz' nucleus. Lower urinary tract dysfunction, especially storage symptoms, developed about 1 year after the onset of weakness, and the dysfunction occurred simultaneously with artificial respirator use in the patients.

Distinctive clinicopathological features of 2 large families with amyotrophic lateral sclerosis having L106V mutation in SOD1 gene.

A clinicopathological study of 2 families with familial amyotrophic lateral sclerosis was previously reported [1]. The present study continues to investigate these families, with detailed clinical, genetic, and neuropathological studies performed on 24 patients, including 5 autopsy cases of the families. A point mutation at codon 106 (L106V) in the copper/zinc superoxide dismutase-1 (SOD1) gene was identified in the families. Average age at onset was 52.0 ± 9.4 years, and initial symptoms were weakness and atrophy in the distal muscles of the lower extremities in most patients. Half of the patients showed neurogenic bladder (overactive bladder) and sensory impairment. The neurophysiological study showed peripheral/central conduction delay. Neuropathological examination revealed severe motor neuron loss with many bizarre reactive astrocytes in the spinal anterior horn. SOD1-immunopositive Lewy body-like hyaline inclusions and aggregation of neurofilaments were observed in the surviving anterior horn cells. Degeneration of the corticospinal tract was relatively minor. In addition, slight but diffuse gliosis was identified in the hypothalamus and medial nucleus of thalamus. Neurogenic bladder, sensory impairment, and degeneration of the hypothalamus and thalamus might be specific features in patients with familial amyotrophic lateral sclerosis with L106V mutation in the SOD1 gene.

Electrophysiological features of familial amyloid polyneuropathy in endemic area.

The process of deterioration of peripheral nerve function in familial amyloid polyneuropathy (FAP) with amyloidogenic transthyretin (ATTR) Val30Met has not been systematically evaluated hitherto. We performed nerve conduction studies in 69 patients with FAP with ATTR Val30Met from one of the endemic areas in Japan. Sensory conduction velocity (SCV), motor conduction velocity (MCV), the size of the compound muscle action potential (CMAP) and distal latency (DL) were measured in the ulnar and tibial nerves. SCV was evaluated using the orthodromic method with needle recording electrodes. These electrophysiological parameters were compared with clinical stage of FAP and duration of neuropathy. When subjects noted minimal neuropathic symptoms only in the feet, motor and sensory nerve function in both the hands and feet had already been disturbed. Sensory nerve action potential on the foot disappeared more rapidly than CMAP. CMAP on foot muscle rapidly decreased during the initial 2 years and completely disappeared within 10 years. The duration of illness and deterioration parameters (CMAP of the abductor digiti minimi muscle, MCV and SCV of the ulnar nerve and DL of both ulnar and tibial nerves) were linearly correlated. CMAP was the most sensitive and reliable parameter to evaluate motor nerve degeneration in FAP.

The safety of transcranial magnetic stimulation with deep brain stimulation instruments.

OBJECTIVES: Transcranial magnetic stimulation (TMS) has been employed in patients with an implanted deep brain stimulation (DBS) device. We investigated the safety of TMS using simulation models with an implanted DBS device. METHODS: The DBS lead was inserted into plastic phantoms filled with dilute gelatin showing impedance similar to that of human brain. TMS was performed with three different types of magnetic coil. During TMS (1) electrode movement, (2) temperature change around the lead, and (3) TMS-induced current in various situations were observed. The amplitude and area of each evoked current were measured to calculate charge density of the evoked current. RESULTS: There was no movement or temperature increase during 0.2 Hz repetitive TMS with 100% stimulus intensity for 1 h. The size of evoked current linearly increased with TMS intensity. The maximum charge density exceeded the safety limit of 30 muC/cm(2)/phase during stimulation above the loops of the lead with intensity over 50% using a figure-eight coil. CONCLUSIONS: Strong TMS on the looped DBS leads should not be administered to avoid electrical tissue injury. Subcutaneous lead position should be paid enough attention for forthcoming situations during surgery.

Size variance of motor evoked potential at initiation of voluntary contraction in palsy of conversion disorder.

AIM: To investigate the efficacy of transcranial magnetic stimulation (TMS) with a cue signal for the objective diagnosis of palsy of conversion disorder (CD). METHODS: Ten patients with palsy of CD, nine with amyotrophic lateral sclerosis (ALS), and eight control subjects were examined. Motor evoked potential (MEP) was recorded from the abductor digiti minimi muscle under three conditions: at rest, during tonic contraction, and with an audio cue signal. In the cue signal paradigm, subjects were asked to perform ramp-and-hold contraction in response to a cue signal. RESULTS: MEP size increased in the cue signal paradigm in both controls and patients with ALS, but was not obvious in some CD patients. This was likely due to variance among trials in the cue signal paradigm in each CD patient. The coefficients of variance (CV) among trials in the cue signal paradigm were 15 +/- 4.3 in controls, 25 +/- 11 in ALS, and 70 +/- 40 in CD. CONCLUSIONS: CV of MEP size with cue signal was larger in CD than in controls (P < 0.005) and in ALS patients (P < 0.01). The size variance among MEP trials with the cue signal is a supportive parameter for the diagnosis of CD.

Ten-year follow-up of peripheral nerve function in patients with familial amyloid polyneuropathy after liver transplantation.

BACKGROUND: The electrophysiological long-term effects of liver transplantation on peripheral nerve function in patients with familial amyloid polyneuropathy (FAP) have not been evaluated. METHODS: Eight FAP patients with a proven ATTRVal30Met gene were observed for 10 years after liver transplantation. We performed repeated measurement of maximal motor nerve conduction velocity (MCV), distal latency, size of compound muscle action potential (CMAP) and maximal sensory nerve conduction velocity (SCV) in both the ulnar and tibial nerves. We also recorded the coefficients of variance in the R-R interval on the electrocardiogram (CV(R-R)). RESULTS: Some autonomic symptoms subsided but motor and sensory symptoms 10 years after transplantation were either slightly improved or almost the same as before surgery in 7 of 8 patients. These 7 have returned to their previous social lives including their jobs. The MCV of the tibial nerve slightly improved, and other parameters of motor and sensory nerve function and CV(R-R) did not show any deterioration during the 10-year observation period. CONCLUSIONS: Liver transplantation can halt the progression of peripheral neuropathy in FAP patients.