ABSTRACT Seven Ehrlichia strains (six HF strains and one Anan strain) that were obtained from laboratory mice by intraperitoneally inoculating homogenates of adult Ixodes ovatus collected in Japan were characterized. 16S rRNA sequences of all six HF strains were identical, and the sequences were 99.7, 98.2, and 97.7% identical to those of Anan strain, Ehrlichia chaffeensis (human monocytic ehrlichiosis agent), and E. muris , respectively. Partial GroEL amino acid sequencing also revealed that the six HF strains had identical sequences, which were 99.0, 98.5, and 97.3% identical to those of E. chaffeensis , the Anan strain, and E. canis , respectively. All HF strains were lethal to mice at higher dosages and intraperitoneal inoculation, whereas the Anan or E. muris strain induced only mild clinical signs. Light and electron microscopy of moribund mice inoculated with one of the HF strains revealed severe liver necrosis and the presence of numerous ehrlichial inclusions (morulae) in various organs. The study revealed that members of E. canis genogroup are naturally present in Ixodes ticks. HF strains that can cause severe illness in immunocompetent laboratory mice would be valuable in studying the pathogenesis and the roles of both cellular and humoral immune responses in ehrlichiosis caused by E. canis genogroup.
Ultraviolet-sensitivelon − mutant ofEscherichia coli K-12 produced abundant polysaccharide when grown in a minimal medium at 37 C, but not when grown in a broth medium. The repression of polysaccharide synthesis in the broth-grownlon − andlon + cells was studied. The effects were largely dependent on the amino acid concentrations and on the requirements of the strain used. At 200 μg per ml of each of the essential amino acids, histidine, proline, and threonine, there was complete inhibition of polysaccharide synthesis. At 200 μg per ml the required amino acids, tryptophane and tyrosine promoted polysaccharide synthesis. Most amino acids inhibited cell growth at 200 μg per ml but the inhibiting effect was smaller at 400 μg per ml. Polysaccharide synthesis of cells was not correlated with the growth rate, and occurred even under non-growing conditions.
Humanin (HN) and S14G HN (HNG) are recently discovered polypeptides that rescue cells from death induced by multiple different types of familial Alzheimer's disease genes and by amyloid-beta. However, the cytoprotective activity of these peptides against other cell death-inducing stimuli remains unclear. In this study, we demonstrated, using three different methods (MTS assay, caspase-3 assay, and detection of DNA fragmentation), that both HN and HNG protect PC12 cells from death elicited by serum deprivation. This implies the potential of the peptides to rescue cells from a broad spectrum, if not all, of cell death-inducing factors. Further investigations on HN may lead the possible application of this peptide as therapeutic agent for the treatment of other neurodegenerative diseases.
A 19-year-old girl was admitted to our hospital with nausea, vomiting, hiccups, constipation and syncope. After hiccups or vomiting sinus arrest developed and lasted more than 5-8 seconds. She lost consciousness every one hour. Based on an electrocardiographic diagnosis of sick sinus syndrome (SSS), a temporary pacemaker was implanted. The next day, although her syncope and bradycardia disappeared, she had orthostatic tachycardia of over 120 beats/minute and swelling of the legs, which led to a diagnosis of postural orthostatic tachycardia syndrome (POTS). Neurologically, she showed the right-sided tongue deviation and parasympathetic system disorders revealed by coefficient of variation of R-R interval (CVR-R), the Achner eye-ball pressure test, the valsalva ratio, and the head-up-tilt test. Brain MRI disclosed a small hyperintense lesion on a T2-weighted image with gadolinium enhancement in the right dorsal medulla including the hypoglottis nucleus and the posterior nucleus of vagus. After steroid pulse therapy (methyl prednisolone 1 g/day×3 days, 5 times) was administered, this lesion became smaller and finally disappeared. Before the lesion disappeared, she was able to begin rehabilitation by wearing elastic stockings and treatment with midodrine hydrochloride. The following year, she developed other MRI-proven brain lesions, suggestive of demyelination. Such a spinal and temporal distribution of lesions led to a diagnosis of multiple sclerosis (MS). A case of POTS caused by MS has not been reported previously, however, MS often affects the medullary paraventricular regions associated with autonomic failures. Autonomic failures often prevent patients from experiencing early rehabilitations. We should promptly give symptomatic treatment against autonomic failures, which leads to good patient recovery not only in patient vitality but also functionality.
The intergenic spacer region between the 16S and 23S rRNA genes of Mycoplasma haemomuris, previously classified as 'Haemobartonella muris', was amplified by PCR and sequenced for analysis of the primary and secondary structures of the RNA transcript. The spacer region consisted of 219 base-pairs and lacked the spacer tRNA gene. A hypothetical secondary structure predicted in the RNA transcript of the spacer region was tentatively assigned box A and box B loci peculiar to the members of the Mycoplasma. Mycoplasma haemomuris and the other species of the genus Mycoplasma are consistent with these characteristics of the spacer region.
Guillain-Barré syndrome (GBS) cases are generally monophasic, and recurrence is rare. However, the pathogenesis and pathophysiology of recurrent GBS remain to be fully elucidated. There are few detailed reports of patients who have been infected twice with Campylobacter jejuni and have developed GBS twice. We herein report a case of recurrent GBS in a 21-year-old man with a history of GBS caused by C. jejuni infection at 19 years old. Although our patient was reinfected with C. jejuni, several different anti-ganglioside antibodies were identified, and the clinical manifestations were more severe than those in the first GBS episode. We compared the anti-ganglioside antibodies and nerve conduction studies findings between the two GBS episodes. This case suggested that different antibodies are involved and produce different symptoms even when C. jejuni infection is the trigger in recurrent episodes.
Chitosan salts with two medical organic acids having phenyl groups (salicylic and gentisic acids) exhibited fiber diffraction patterns of a new type of crystal which does not compare with known types I and II. The crystals, called type III salts, showed a fiber repeat of 2.550 nm and a meridional reflection at the 5th layer line. These results coupled with a conformational analysis indicate the chain conformation of chitosan with the salts to be a 5/3 helix, this helix differing from those of type I (an extended two-fold helix) and type II (a relaxed two-fold helix or a 4/1 helix). The fiber patterns of all the type III salts were similar. This observation has also been found with type II salts and is an indication that the acid ions are not arranged in regular positions in the crystals. A comparison of solid-state 13C-NMR spectra of the gentisic acid salt and the aspirin salt, which could not be crystallized, suggests that, in the latter salt, the chitosan molecules also formed a 5/3 helix.
Accumulating evidence indicates an association of Alzheimer's disease (AD) with the metabolic syndrome (MetS), characterized by visceral fat accumulation with insulin resistance and altered secretion of adipocytokines such as adiponectin and leptin. The renin-angiotensin system (RAS) regulates blood pressure and insulin resistance. Recent studies suggest that the RAS plays crucial roles in cognitive functions and that adipocytokines exert neuroprotective activity in the brain. We investigated whether RAS blockers (RASB) affect adipocytokines and cognitive function in patients with AD.We studied 78 patients with a diagnosis of probable AD according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition and 106 nondemented control subjects who visited our clinic with a main complaint of headache or dizziness. We examined retrospectively the effects of RASB on adipocytokines and cognitive decline in patients with AD who were divided into three groups: hypertension treated with RASB (HT-RASB; n = 17), hypertension treated with other antihypertensive drugs (HT-other; n = 34), and no hypertension (non-HT; n = 27).The HT-RASB group had a significantly higher serum leptin level and a relatively larger visceral fat area than the other groups, because of the bias toward patients with MetS in this group. The HT-RASB group also had a significantly lower immunoreactive insulin level, a relatively low homeostasis model assessment as an index of insulin resistance, and a relatively high serum adiponectin level among the three groups. Cognitive decline, estimated on the basis of the mean annual decline using the Hasegawa Dementia Scale score was significantly low in the HT-RASB group.Treatment with RASB might modulate serum adipocytokines and glucose homeostasis, potentially slowing cognitive decline in patients with AD.
Abnormalities of both motor and sensory nerve action potentials, similar to those found in demyelinating polyneuropathy, may occur in patients with amyotrophic lateral sclerosis (ALS). We analyzed the clinical features of unusual ALS patients with demyelinating polyneuropathy (DPN) to delineate the characteristics and outcomes of this rare condition. We reviewed three ALS patients with DPN who were confirmed to meet the electrophysiological nerve conduction criteria for DPN among 157 patients with ALS. At the initial neurological examination, one patient had both subjective sensory symptoms and abnormal results of sensory examinations, and one patient had sensory symptoms. Motor weakness of the limbs was present in all patients, and fasciculation was present in two patients. Anti-GalNAc-GD1a IgG antibodies were evident in one. Sural nerve biopsy showed a moderate, marginal reduction in myelin thickness, and teased fiber analysis revealed segmental demyelination and remyelination, but axonal degeneration was found in one patient. The mean interval from disease onset to respiratory failure or death in our three patients and seven previously documented ALS patients with DPN was 43.1 ± 18.7 months. Our findings suggest that survival in ALS with DPN is similar to that in classic ALS.
