Mycoplasma pneumoniae isolation and IHA antibody detection in patients with M. pneumoniae infection

Throat swab culture was compared with indirect hemagglutination (IHA) antibody detection for diagnosis of Mycoplasma pneumoniae infection. These two methods were tried on the patients several times for a long term after onset of the disease. For five years from 1982 to 1986 in Kanagawa prefecture, a total of 566 patients were tested and 141 (25%) were diagnosed as M. pneumoniae infection by either of the two test methods. Both culture and antibody detection were performed on 110 patients out of 141, revealing that 96 patients (87%) were positive by culture and 89 (81%) were positive by antibody detection. Most of the patients with M. pneumoniae infection showed positive culture within a week after onset of the disease, and half of the patients treated with antibiotics such as macrolides or tetracyclines showed positive for two or three months after the onset. Positive rate of IHA antibody detection in the patients with M. pneumoniae infection was 43% within a week after onset of the disease and reached the maximum (92%) in 15 to 21 days after the onset. The rate did not decrease to less than 70% three months after the onset. Geometric mean titer of the antibody reached the maximum at the same time as the antibody positive rate. Both antibody positive rate and geometric mean titer declined significantly four months after the onset. In general, IHA antibody of infants with M. pneumoniae infection increased satisfactorily day by day after onset of the disease. Nine percent of the patient with M. pneumoniae infection developed otitis media with effusion, and M. pneumoniae was isolated from two of six patient effusions.     

Diagnostic usefulness of KL-6 measurements in patients with pulmonary complications after administration of amiodarone

Amiodarone-induced pulmonary toxicity is one of the major complications in patients receiving administration of amiodarone. KL-6 is a useful indicator to evaluate the activity of interstitial pneumonitis. We studied the clinical utility of KL-6 as a marker for amiodarone-induced pulmonary toxicity. We investigated 6 patients in whom chest radiography revealed abnormal consolidations after administration of amiodarone from 1997 to 1999. All patients were male aged 56 to 76 years (mean 66 +/- 7 years). The indications for amiodarone included sustained ventricular tachycardia in 5 patients and atrial fibrillation in one patient with refractory heart failure. The mean left ventricular ejection fraction was 31 +/- 12% (22-52%). KL-6 levels were measured by a sandwich type enzyme immunoassay using a murine monoclonal antibody (KL-6 antibody), and the cutoff level was determined at 520 U/ml. Complications occurred from 17 days to 45 months after treatment with amiodarone. The KL-6 levels were abnormally high (2,100 and 3,000 U/ml) in 2 patients with amiodarone-induced pneumonitis but under the cutoff level in the non-pneumonitis patients. In one patient with amiodarone-induced pneumonitis, the KL-6 level increased from 695 to 2,100 U/ml concurrently with worsening interstitial changes shown by high resolution computed tomography. We conclude that KL-6 has practical uses as a marker for the detection and evaluation of amiodarone-induced pulmonary toxicity.     

Requirement of gp130 signaling for the AGM hematopoiesis

OBJECTIVE: Definitive hematopoiesis starts in the aorta-gonad-mesonephros (AGM) region during mouse development and remarkably expands in the liver at a later stage of ontogeny. gp130 is a signal transducing receptor component shared by all the IL-6 family cytokines, whose gene ablation in mouse results in the significant reduction in the fetal liver hematopoiesis. The present study aims to evaluate the role of gp130 signaling in the fetal mouse AGM hematopoiesis. METHODS AND MATERIALS: Mouse AGM regions from the wild-type and gp130-deficient mice on embryonic day 11.5 were dissociated and cultured with a mixture of cytokines, including one which activates gp130. Wild-type human gp130 and its mutant constructs were introduced into cultured gp130-deficient AGM cells using retrovirus system. To further analyze gp130 downstream signaling, a dominant-negative mutant of STAT3 was also introduced. RESULTS: The gp130 deficiency in the culture of fetal mouse AGM cells resulted in the failure of the expansion of the c-kit(+), Sca-1(+), and lineage markers(-) population. Such failure was rescued by introduction of a wild-type gp130 expression construct but not its mutant constructs having no ability to activate STAT3. In the normal AGM cell culture, introduction of a dominant-negative form of STAT3 in which Y(705) was changed to phenylalanine suppressed the expansion of hematopoietic cell colonies. CONCLUSION: gp130 plays an indispensable role in the expansion of hematopoietic precursor cells in the fetal mouse AGM. In particular, the activation of STAT3 by gp130 is found to be important in this process.     

Cyclosporin-A increases synthesis of 1,25-dihydroxyvitamin D3 in the rat and mouse

We have previously observed elevated serum 1,25-dihydroxyvitamin D3 [1,25-(OH)2D] levels in male rats treated with oral cyclosporin-A (CsA). This elevation was independent of changes in PTH, ionized calcium, or phosphate. This paper investigates the potential sources and mechanisms for this increase in both rats and mice. Kidney homogenates from rats treated for 14 days with (15 mg/kg) had a significant increase in 25-hydroxyvitamin D (25OHD)-24-hydroxylase (24-hydroxylase) activity (149 +/- 20 vs. 89 +/- 16 fmol/mg.min; P less than 0.05), but nonsignificant increases in 25OHD-1 alpha-hydroxylase (1 alpha-hydroxylase) activity compared to controls. Kidney homogenates from C57b16J mice after the administration of 30-50 mg/kg CsA for 3 days revealed a linear dose-related increase in renal 1 alpha-hydroxylase (r = 0.96; P less than 0.05), which became significant with doses of 30 mg/kg CsA or more (P less than 0.05). To investigate the source of this 1,25-(OH)2D production, serum 1,25-(OH)2D was measured before and 48 h after bilateral nephrectomy in rats receiving CsA for 16 days. The percent decrease in serum 1,25-(OH)2D values was not significantly different in CsA-treated and untreated rats (33.9 +/- 4.9% vs. 47.5 +/- 4.9%), indicating little or no contribution from nonrenal sources. Studies of MCRs and production rates (PRs) revealed that the elevated 1,25-(OH)2D values were due to enhanced production and not altered clearance (PR, 12.4 +/- 1.2 vs. 19.1 +/- 1.9 fmol/mg.min; P less than 0.01). CsA increases 1 alpha-hydroxylase activity and produces significant elevations in serum 1,25-(OH)2D levels in both rats and mice. This increase may have an impact on bone mineral metabolism and immune modulation in postorgan transplantation patients.     

Vanadyl‐TrBR4‐Catalyzed Oxidative Polymerization of Diphenyl Disulfide

A newly established catalyst system for oxygen‐oxidative polymerization of diphenyl disulfide is reported. Combination of vanadyl compounds (e.g., VO(acac)₂) and triphenylmethylium tetrakis(pentafluorophenyl)borate (TrB(C₆F₅)₄) proceeds the polymerization to give poly(1,4‐phenylene sulfide) (PPS) at 100 °C. When triphenylmethylium tetrafluoroborate (TrBF₄) is applied with vanadyl tetraphenylporphyrin (VO(TPP)) or N,N′‐(ethylenebis(salicylideneaminato))oxovanadium (VO(salen)), PPS is also given via polymerization under conditions near 160 °C. Combination of the vanadyl complex and the borate affords the first protic‐acid‐free catalytic system for the polymerization of the disulfide, suggesting the overall reaction to produce PPS and H₂O from O₂ and protons that are eliminated from the monomer.

     

Clusters of proliferating endothelial cells and smooth muscle cells in rabbit carotid arteries

Schwarz and Benditt found clustering of replicating cells in aortic endothelium in 1976 and discussed how homeostasis of the arterial wall is maintained through this nonrandom distribution of replicating cells. However, it is still unclear how cells of vascular walls turnover. In order to address this issue, we evaluated distribution of the cells in mitotic cycle, labeled by Ki67‐immunostaining, in serial histological sections of twelve carotid arteries of six adult male Japanese rabbits. As a result, a total of 1713 Ki67‐positive endothelial cells (ECs) and 1247 Ki67‐positive smooth muscle cells (SMCs) were identified. The Ki67‐positivity rate in ECs and SMCs were about 0.048% and 0.0027%, respectively. Many of the Ki67‐positive cells clustered in two (EC, 37%; SMC, 33%), three to four (EC, 8%; SMC, 28%), and five to eight cells (EC, 5%; SMC, 10%). Clusters having more than eight cells were not found. Thus, it can be speculated that the cell division of proliferating ECs and SMCs occur four times at most. These novel findings offer great insights for better understanding of the mechanism that underlies cell number regulation of the blood vessel.     

Type 1 Autoimmune Pancreatitis Extending along the Main Pancreatic Duct: IgG4-related Pancreatic Periductitis

We herein report a unique form of autoimmune pancreatitis (AIP) spreading along the main pancreatic duct (MPD). A 70-year-old man was referred for a small lesion at the pancreatic neck, accompanying an adjacent cyst and dilated upstream MPD. Four years earlier, health checkup images had shown a pancreatic cyst but no mass lesion. Endoscopic ultrasonography showed a contrast-enhanced, tumorous lesion, mainly occupying the MPD. With a preoperative diagnosis of ductal neoplasms mainly spreading in the MPD, Whipple''s resection was performed. The resected specimens showed MPD periductitis with IgG4-related pathology, indicating type 1 AIP. Clinicians should practice caution concerning the various AIP forms.     

Development of Epstein-Barr virus-associated gastric cancer: Infection,inflammation, and oncogenesis

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) cells originate from a single-cell clone infected with EBV. However, more than 95% of patients with gastric cancer have a history of Helicobacter pylori (H. pylori) infection, and H. pylori is a major causative agent of gastric cancer. Therefore, it has long been argued that H. pylori infection may affect the development of EBVaGC, a subtype of gastric cancer. Atrophic gastrointestinal inflammation, a symptom of H. pylori infection, is observed in the gastric mucosa of EBVaGC. Therefore, it remains unclear whether H. pylori infection is a cofactor for gastric carcinogenesis caused by EBV infection or whether H. pylori and EBV infections act independently on gastric cancer formation. It has been reported that EBV infection assists in the onco-genesis of gastric cancer caused by H. pylori infection. In contrast, several studies have reported that H. pylori infection accelerates tumorigenesis initiated by EBV infection. By reviewing both clinical epidemiological and experimental data, we reorganized the role of H. pylori and EBV infections in gastric cancer formation.