Interaction of intracellular hydrogen peroxide accumulation with nitric oxide production in abscisic acid signaling in guard cells.

Reactive oxygen species and nitric oxide (NO•) concomitantly play essential roles in guard cell signaling. Studies using catalase mutants have revealed that the inducible and constitutive elevations of intracellular hydrogen peroxide (H2O2) have different roles: only the inducible H2O2 production transduces the abscisic acid (ABA) signal leading stomatal closure. However, the involvement of inducible or constitutive NO• productions, if exists, in this process remains unknown. We studied H2O2 and NO• mobilization in guard cells of catalase mutants. Constitutive H2O2 level was higher in the mutants than that in wild type, but constitutive NO• level was not different among lines. Induced NO• and H2O2 levels elicited by ABA showed a high correlation with each other in all lines. Furthermore, NO• levels increased by exogenous H2O2 also showed a high correlation with stomatal aperture size. Our results demonstrate that ABA-induced intracellular H2O2 accumulation triggers NO• production leading stomatal closure. ABBREVIATIONS: ABA: abscisic acid; CAT: catalase; cGMP: cyclic guanosine monophosphate; DAF-2DA: 4,5-diaminofluorescein-2 diacetate; H2DCF-DA: 2',7'-dichlorodihydrofluorescein diacetate; MeJA: methyljasmonate; NOS: nitric oxide synthetase; NR: nitrate reductase; POX: peroxidase; ROS: reactive oxygen species; SNAP: S-nitroso-N-acetyl-DL-penicillamine; SNP: sodium nitroprusside; NOX: NADP(H) oxidase.

The first identification and retrospective study of Severe Fever with Thrombocytopenia Syndrome in Japan.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a novel bunyavirus reported to be endemic in central and northeastern China. This article describes the first identified patient with SFTS and a retrospective study on SFTS in Japan. METHODS: Virologic and pathologic examinations were performed on the patient's samples. Laboratory diagnosis of SFTS was made by isolation/genome amplification and/or the detection of anti-SFTSV immunoglobulin G antibody in sera. Physicians were alerted to the initial diagnosis and asked whether they had previously treated patients with symptoms similar to those of SFTS. RESULTS: A female patient who died in 2012 received a diagnosis of SFTS. Ten additional patients with SFTS were then retrospectively identified. All patients were aged ≥50 years and lived in western Japan. Six cases were fatal. The ratio of males to females was 8:3. SFTSV was isolated from 8 patients. Phylogenetic analyses indicated that all of the Japanese SFTSV isolates formed a genotype independent to those from China. Most patients showed symptoms due to hemorrhage, possibly because of disseminated intravascular coagulation and/or hemophagocytosis. CONCLUSIONS: SFTS has been endemic to Japan, and SFTSV has been circulating naturally within the country.

[Serum amyloid A as a useful index of disease activity in polymyalgia rheumatica].

PURPOSE: To clarify the usefulness of measuring serum amyloid A (SAA) levels in patients with polymyalgia rheumatica (PMR), we compared this parameter to C-reactive protein (CRP). SUBJECTS AND METHODS: The study included 10 patients with PMR, who could be prospectively followed up from the start of prednisolone (PSL) treatment until the CRP level decreased to 1 mg/dl or less. When the CRP level decreased, the subjects were divided into the group in which the symptom persisted (n = 6) and those in which the symptom disappeared (n = 4). RESULTS: In the group in which the symptom persisted, both CRP and SAA levels were significantly higher. When the CRP level decreased, there was no significant difference in the CRP level between the two groups. However, the mean SAA level in the group in which the symptom persisted (137.8 micrograms/ml) was significantly higher than that in the group in which the symptom disappeared (21.8 micrograms/ml). On the initial consultation, there was a positive correlation between CRP and SAA (R = 0.77). The SAA level was more sensitive than the CRP level (y = 94.899 x -51.22). When the CRP level decreased, SAA was much more sensitive (y = 222.92 x +6.9121), suggesting the usefulness of SAA after the start of PSL treatment. CONCLUSION: SAA may be a useful parameter of PMR activity.

Clinical study of Japanese spotted fever and its aggravating factors.

Twenty-eight patients with Japanese spotted fever were clinically investigated. The diagnosis was determined by confirming an increase of specific antibody. All patients were treated with minocycline, and all recovered, excluding one patient with a fulminant course. Fever and exanthema were observed in all patients, and an eschar was pointed out in 20 (71%) patients. The platelet count was 10 x 10(4)/microl or lower in 8 (28%) patients. The fibrin degradation product (FDP)-level was abnormally high, 10 microg/ml or more, in 16 (57%) patients. The creatine kinase (CK) value was high in 14 of 22 patients, suggesting the presence of myositis. The leukocyte count, FDP, C-reactive protein, and soluble interleukin 2 receptor (sIL2-R) levels were significantly higher in severe cases. In the group without concomitant steroid therapy, mean times of 54.7 h and 101.4 h were required to reduce the temperature to 38 degrees C and 37 degrees C or lower, respectively, after the initiation of tetracycline treatment. There were 6 severe cases: 1 with disseminated intravascular coagulation, 2 with multiorgan failure, 1 with acute respiratory distress syndrome, and 2 with meningoencephalitis. These severe cases formed a group that required 6 or more days to initiate therapy after the onset (P < 0.005 vs non-severe group), showing that delay in diagnosis and therapy is the major cause of aggravation. In the 2 patients complicated by multiorgan failure, the sIL2-R level, produced by activated lymphocytes, was 10,000 U/ml or higher, suggesting that an sIL2-R level of more than 10,000 U/ml can be used as a marker of poor prognosis. It may be better that moderate to severe cases are treated with minocycline plus short-term steroid therapy.

[A patient with polymyalgia rheumatica who exhibited fever as the main symptom for a long period].

We encountered a patient with polymyalgia rheumatica (PMR) who exhibited fever as the main symptom for a long period without muscular pain. As an etiological factor, the condition may have been associated with nonsteroidal anti-inflammatory drugs (NSAIDs). A 71-year-old man consulted our Department of Orthopedics for fever and lumbar pain, which initially developed in early September 2000. Administration of NSAIDs resulted in the disappearance of lumbar pain. However, fever persisted. The C-reactive protein (CRP) level was persistently high. Therefore, on October 5, 2000, the patient was referred to our department. At the outpatient clinic, a detailed examination was performed. However, the etiology could not be determined. Repeated administration of NSAIDs resulted in pyretolysis, and the dose of NSAIDs was decreased from January 31, 2001. Severe fever appeared again, and inflammatory reaction also exacerbated. On March 11, 2001, muscular pain involving the bilateral shoulders and forearms suddenly developed. For diagnostic treatment, administration of prednisolone (PSL) at 10 mg/day was started. Muscular pain rapidly disappeared. According to Bird's criteria, PMR was diagnosed. After the dose of PSL was decreased to 7.5 mg/day, the course is good. PMR should be considered as the etiology of idiopathic fever in elderly patients.

Fulminant Japanese spotted fever definitively diagnosed by the polymerase chain reaction method.

A 72-year-old man was admitted to the emergency ward in our hospital on July 20, 2001, because of consciousness disturbance, fever, generalized skin eruption, and severe general weakness beginning 7 days previously. Physical examination on admission revealed marked systemic cyanosis, erythema, and purpura. Laboratory findings indicated disseminated intravascular coagulation (DIC) and multiorgan failure (platelet count, 0.9 x 10(4)/micro l; fibrin degradation product, 110 micro g/ml; C-reactive protein, 22.6 mg/dl). Soluble interleukin 2-receptor (sIL-2R) was markedly increased to 14 710 U/ml. Blood gas analysis demonstrated severe metabolic acidosis. He was diagnosed with multiorgan failure due to DIC. Administration of heparin and sodium bicarbonate was started immediately, but respiratory failure was exacerbated and systemic spasm caused by encephalitis was noted. Although he was supported by an artificial ventilator, deterioration of metabolic acidosis occurred, and the blood pressure decreased to less than 60 mm Hg. He died 5.5 h after admission. The serological test showed no positive antibody titers against Orientia tsutsugamushi, Rickettsia japonica, or Rickettsia typhi. However, a specific DNA band derived from R. japonica was detected by the polymerase chain reaction (PCR) method using a primer from a blood clot. Therefore, he was definitively diagnosed as having Japanese spotted fever. The PCR method may be markedly useful for establishing a definitive diagnosis of Japanese spotted fever during the critical stage.