Effects of ONO-3708, an antagonist of the thromboxane A2/prostaglandin endoperoxide receptor, on platelet aggregation and thrombosis

The beneficial effects of an antagonist of the thromboxane A2/prostaglandin endoperoxide receptor, 7-[2 alpha,4 alpha-(dimethylmethano)-6 beta-(2-cyclopentyl-2 beta- hydroxyacetamido)-1 alpha-cyclohexyl]-5(Z)-heptenoic acid (ONO-3708) on thrombosis were examined. ONO-3708 at 0.1-3 microM inhibited the human platelet aggregation induced by thromboxane A2, prostaglandin H2, collagen, ADP (secondary phase) and epinephrine (secondary phase) without affecting prostanoid synthesis and the content of cyclic AMP in platelets. The in vivo effects, on coronary thrombosis in this case, were examined in two canine models. ONO-3708, 3 to 300 micrograms/kg i.v., prevented dose dependently the coronary thrombosis induced by partial obstruction of the coronary artery. ONO-3708, 3 micrograms/kg per min i.v., significantly prevented electrically stimulated coronary thrombosis without affecting systemic blood pressure and heart rate. These results indicate that the thromboxane A2/prostaglandin endoperoxide receptor could play an important role in the pathogenesis of thrombosis and that ONO-3708 may have therapeutic advantages in preventing thrombosis.     

Gd-DTPA-cascade-polymer: Potential blood pool contrast agent for MR imaging

Gadolinium-DTPA (diethylenetriaminepentaacetic acid)-cascade-polymer, a potential new blood pool contrast agent for magnetic resonance (MR) imaging, was compared with a known blood pool agent, Gd-DTPA-polylysine, in an animal model. The relative signal intensities of liver, renal cortex, pancreas, and trunk muscle were assessed in 12 pigs between 4 seconds and 120 minutes after injection of a 20 μmol/kg dose of each contrast agent, by using a FLASH (fast low-angle shot) sequence. Except for muscle, all tissues showed visible enhancement after injection of either contrast agent. After injection of Gd-DTPA-polymer, enhancement patterns in the liver, renal cortex, and pancreas were similar to those seen after injection of Gd-DTPA-polylysine. No statistically significant differences in enhancement between the two contrast agents were found at any time point. The authors conclude that the contrast kinetics of Gd-DTPA-cascade-polymer are similar to those of Gd-DTPA-polylysine and that this agent may also be used as a blood pool contrast agent for MR imaging.     

Eosinophilic fasciitis associated with Borrelia afzelii infection]

A 58-year-old woman suffered from stiffness, swelling, rubor and muscle pain in the extremities one month after she climbed a mountain in Kyushu, an island in southern Japan. On admission, mild proximal weakness was present in the extremities. Her range of motion in the extremities was limited due to firm skin and subcutaneous stiffness which was similar to scleroderma. She showed peripheral blood eosinophilia and hypergammaglobulinemia as well as a high erythrocyte sedimentation rate. An IgM antibody against Borrelia afzelii was positive. MRI of the skeletal muscles demonstrated enhancing fascia around the biceps brachii muscle, and a biopsy specimen revealed perivascular infiltration of mononuclear cells within the hypertrophic fascia. Eosinophilic infiltration was absent. We treated the patient with prednisolone, doxycycline and amoxicillin, which alleviated the symptoms. This is the first report to show that Borrelia afzelii was involved in eosinophilic fasciitis.     

A case of brachial amyotrophic diplegia accompanied with Sj?gren's syndrome presenting good response to immunotherapies in the early course of the disease]

A 74-year-old woman suffered from progressive muscle atrophy and weakness of her arms since she was seventy two years old. Before referral to our department, she was diagnosed as having cervical spondylotic myeloradiculopathy and received spinal fusion. Though spinal decompression was successful, muscle weakness of her upper limbs were progressive even after the surgery. On admission, neurological examinations revealed marked atrophy and weakness of her bilateral upper limbs with absent deep tendon reflexes showing man-in-the-barrel syndrome. Her lower extremities had normal muscle strength, but fasciculations were seen in her all four limbs. Electrophysiologically, motor nerve conduction velocity was almost normal but the amplitude was remarkably decreased, conduction block was not detected, and electromyography showed neurogenic patterns on her all extremities. Spinal progressive musclar atrophy (SPMA) accompanied with Sj?gren's syndrome was the likely diagnosis. Because 50 kDa anti-neuronal antibodies were found in her serum, we assumed that anterior horn cells were impaired by an autoimmune mechanism. Thus we treated her with corticosteroid pulse therapy, plasma exchange (PE) and intravenous immunoglobulin infusion therapy (IVIG). Although steroid pulse therapy only had a minimal effect, PE and IVIG promoted a remarkable improvement on her weakness, and the effect lasted for about three months. This is the first case of SPMA with Sj?gren's syndrome which showed good response to PE and IVIG in the early course of the disease. We considered that some SPMA-like motor neuron syndrome accompanied with autoimmune features may require immunomodulating therapies.     

Differences between T-cell reactivities to major myelin protein-derived peptides in opticospinal and conventional forms of multiple sclerosis and healthy controls

In Japanese, susceptibility to the conventional form of multiple sclerosis (C-MS) is associated with the HLA-DRB1*1501-DRB5*0101 haplotype while susceptibility to the opticospinal form of MS (OS-MS) is associated with HLA-DPA1*0202-DPB1*0501. To clarify the characteristics of T cells autoreactive to myelin proteins in each MS subtype, we established T-cell lines reactive to such myelin antigens as myelin basic protein (MBP), proteolipid protein (PLP) and myelin oligodendrocyte glycoprotein (MOG) from 5 of 10 OS-MS patients, 6 of 11 C-MS patients and 7 of 13 healthy controls (HCs), and T-cell epitopes and their restriction molecules were determined. We found that (a) intermolecular epitope spreading was found to be significantly more frequent in MS patients than in HCs (P=0.0128), (b) intramolecular epitope spreading also tended to occur more frequently in MS patients than in HCs (P=0.0584), (c) in OS-MS, HLA-DR-restricted and MOG-autoreactive T cells were more frequently established as compared with those reactive to MBP or PLP epitopes and (d) in C-MS, HLA-DQ-restricted and PLP-autoreactive T cells dominated those autoreactive to MBP or MOG epitopes. A DPB1*0501-restricted MBP-reactive T-cell clone from a patient with OS-MS provided evidence that the first HLA class II anchor amino acid of peptide bound to disease-susceptible DP5 molecule was distinct from that for the DR2 molecule. Taken together, these differences in specificities of myelin-autoreactive T cells between C-MS and OS-MS as well as the difference in the anchor motif of the binding peptides between each MS subtype-susceptible HLA class II molecule may contribute to the development of distinct clinical phenotypes.     

Novel missense mutations in the human lysosomal sialidase gene in sialidosis patients and prediction of structural alterations of mutant enzymes

Three novel missense mutations in the human lysosomal sialidase gene causing amino acid substitutions (P80L, W240R, and P316S) in the coding region were identified in two Japanese sialidosis patients. One patient with a severe, congenital form of type 2 sialidosis was a compound heterozygote for 239C-to-T (P80L) and 718T-to-C (W240R). The other patient with a mild juvenile-onset phenotype (type 1) was a homozygote for the base substitution of 946C-to-T (P316S). None of these mutant cDNA products showed enzymatic activity toward an artificial substrate when coexpressed in galactosialidosis fibroblastic cells together with protective protein/cathepsin A (PPCA). All mutants showed a reticular immunofluorescence distribution when coexpressed with the PPCA gene in COS-1 cells, suggesting that the gene products were retained in the endoplasmic reticulum/Golgi area or rapidly degraded in the lysosomes. Homology modeling of the structural changes introduced by the mutations predicted that the P80L and P316S transversions cause large conformational changes including the active site residues responsible for binding the sialic acid carboxylate group. The W240R substitution was deduced to influence the molecular surface structure of a limited region of the constructed models, which was also influenced by previously identified V217M and G243R transversions. Received: Stptember 21, 2001 / Accepted: November 2, 2001     

Postmortem Stability of SARS-CoV-2 in Nasopharyngeal Mucosa

Analyses of infection chains have demonstrated that severe acute respiratory syndrome coronavirus 2 is highly transmissive. However, data on postmortem stability and infectivity are lacking. Our finding of nasopharyngeal viral RNA stability in 79 corpses showed no time-dependent decrease. Maintained infectivity is supported by virus isolation up to 35 hours postmortem.     

Measurement of oil mists by a portable sampler and subjective symptoms among machine workers: a field investigation of machine workshops

Machine oils are widely used in metal processing and many workers are exposed to oil mists in the work environment. Some investigators have pointed out such health hazards due to prolonged exposure to oil mist as respiratory disorders, dermatitis, and possible carcinogenesis. In Japan, a permissible limit of oil mists of 3 mg/m3 was recommended in 1977 by the Japan Association of Industrial Health (JAIH) mainly based on the hazardous effects on the respiratory system. After this recommendation was made, only a few studies have been made on the measurement of oil mists and on the health effects in machine workers to determine whether the permissible limit is justifiable or not. In the present study, the levels of oil mists in the air of machine workshops were measured together with personal exposure levels by personal samplers. Oil mists were collected by a sampler head with 2 stages which enabled differentiation of distribution of particulates between larger than 10 microns and 2-10 microns in size. Oil components collected on the stainless steel stages were washed out by sonication in CCl4 solution and measured by an oil meter with infra-red spectrometry against a standard solution of heavy oil class B according to procedures reported elsewhere by the authors. Questionnaire surveys were also conducted on 308 male machine workers composed of 221 workers exposed to oil mists and 87 nonexposed controls. The questions were composed of five items about air quality in the work environment and 18 subjective symptoms during work and daily lives. The symptoms included nasopharyngeal, muco-dermal, gastrointestinal and neuro-muscular symptoms. Statistical analysis was made by the Manthel-Haenszel method for a comparison of "yes" rates of complaints between the exposed and the non-exposed by adjusting the underlying confounding factor of age distribution. 1. The levels of oil mists measured here ranged from 94 to 813 micrograms/m3 in the ambient air and from 107 to 483 micrograms/m3 of personal exposure. There was no obvious difference between the level in the ambient air and that of personal exposure. All these measured levels were under the permissible limit (3 mg/m3) recommended by JAIH in 1977. 2. The observed distribution of particulate size of oil mists from 2 to 10 microns referred to as respirable size was 32.8 +/- 16.1% generated from the grinding machines using water-soluble type of machine oils and 50.0 +/- 12.4% from those using insoluble type.(ABSTRACT TRUNCATED AT 400 WORDS)     

Clinical, immunological and MRI features of myelitis with atopic dermatitis (atopic myelitis)

In order to clarify the characteristic features of myelitis with atopic dermatitis (AD), we compared the clinical, immunological and MRI findings between 14 myelitic patients with AD and 12 myelitic patients without AD. The myelitic patients with AD showed the following distinct features, compared with those without AD. (1) A preferential involvement of the cervical cord, as shown by neurologic as well as MRI examinations (14/14 vs. 5/12; P=0.0012), (2) paresthesia/dysesthesia as the predominant symptoms and a rare occurrence of definite muscle weakness (0/14 vs. 5/12; P=0.0120) and dysuria (1/14 vs. 8/12; P=0.0029), (3) a lower Expanded Disability Status Scale score (mean, 1.5 vs. 3.5; P=0.0018), (4) normal cerebrospinal fluid (CSF) findings including those for the IgG index and oligoclonal IgG bands and (5) a persistence of neurologic symptoms and MRI lesions during the follow-up periods (mean, 17 months). In addition, both the serum total IgE level and the frequency of specific IgE to Dermatophagoides farinae were significantly higher in the myelitic patients with AD (median IgE=1266 U/ml, specific IgE 14/14) than in those without AD (145 U/ml, P=0.0034 and 8/12, P=0.0331, respectively) and in 40 healthy controls (86 U/ml, P<0.0001 and 12/40, P<0.0001, respectively). Since myelitis with AD has distinct features and atopy to mite antigens appears to be the underlying cause of this condition, it may therefore be a distinct subtype of myelitis.