Improvement in early diagnosis of Japanese spotted fever by using a novel Rick PCR system

Rickettsia diseases, including Japanese spotted fever (JSF), are serious infections. Delayed diagnosis occasionally results in life‐threatening liver disorders and disseminated intravascular coagulation (DIC). Because of the shortness of the latent period, serological diagnosis is not preferable for early diagnosis of JSF. Until now, a polymerase chain reaction (PCR)‐based diagnosis method has been used for early diagnosis, and the sensitivity reaches as high as 90% using skin biopsy samples as we previously reported. On the other hand, the sensitivity of the same PCR method using blood samples is limited at less than 50%. In the present study, using peripheral blood samples, we developed a novel diagnostic method for JSF using a Rick PCR system with original PCR primers, showing improved sensitivity compared with the conventional nested PCR. It may constitute a preferable diagnostic tool for early and sensitive diagnosis of Rickettsia infection.     

Interaction of Necl‐4/CADM4 with ErbB3 and integrin α6β4 and inhibition of ErbB2/ErbB3 signaling and hemidesmosome disassembly

Nectin‐like molecule 4 (Necl‐4)/CADM4, a transmembrane cell–cell adhesion molecule with three Ig‐like domains, was shown to serve as a tumor suppressor, but its mode of action has not been elucidated. In this study, we showed that Necl‐4 interacted in cis with ErbB3 through their extracellular regions, recruited PTPN13 and inhibited the heregulin‐induced activation of the ErbB2/ErbB3 signaling. In addition, we extended our previous finding that Necl‐4 interacts in cis with integrin α₆β₄ through their extracellular regions and found that Necl‐4 inhibited the phorbol ester‐induced disassembly of hemidesmosomes. These results indicate that Necl‐4 serves as a tumor suppressor by inhibiting the ErbB2/ErbB3 signaling and hemidesmosome disassembly.     

Ultrafast thermally induced unfolding of RNase A.

A temperature jump (T-jump) method capable of initiating thermally induced processes on the picosecond time scale in aqueous solutions is introduced. Protein solutions are heated by energy from a laser pulse that is absorbed by homogeneously dispersed molecules of the dye crystal violet. These act as transducers by releasing the energy as heat to cause a T-jump of up to 10 K with a time resolution of 70 ps. The method was applied to the unfolding of RNase A. At pH 5.7 and 59 degrees C, a T-jump of 3-6 K induced unfolding which was detected by picosecond transient infrared spectroscopy of the amide I region between 1600 and 1700 cm-1. The difference spectral profile at 3.5 ns closely resembled that found for the equilibrium (native-unfolded) states. The signal at 1633 cm-1, corresponding to the beta-sheet structure, achieved 15 +/- 2% of the decrease found at equilibrium, within 5.5 ns. However, no decrease in absorbance was detected until 1 ns after the T-ump. The disruption of beta-sheet therefore appears to be subject to a delay of approximately 1 ns. Prior to 1 ns after the T-jump, water might be accessing the intact hydrophobic regions.     

A prospective clinical study of theophylline safety in 3810 elderly with asthma or COPD

A large-scale prospective study was conducted in 3810 Japanese elderly (> or =65 years old) patients with asthma or chronic obstructive pulmonary disease (COPD) who had been treated with sustained-release theophylline tablets (THEODUR) at a dose of 400 mg/day for 1-6 months, in principle. Among 3798 protocol-complying patients (mean age: 73.8 +/- 0.10 years, 1997 with COPD), 261 theophylline-related adverse events were observed in 179 (4.71%) patients. The 5 most frequently observed adverse events were "nausea" (40 episodes, 1.05%), "loss of appetite" (22 episodes, 0.56%), "hyperuricemia" (16 episodes, 0.42%), "palpitation" (15 episodes, 0.39%), and "increased alkaline phosphatase" (11 episodes, 0.28%). No convulsions were reported. Six patients had serious adverse events. The incidence of theophylline-related adverse events was higher in patients with hepatic disease (odds ratio: 1:1.81) and in patients with arrhythmia (odds ratio: 1:1.88). Blood drug concentration measurements in 736 patients indicated that the drug levels were < or =15 microg/ml in 641 patients (87.1%), and no correlation was noted between dose and theophylline-related adverse events. These results suggest that sustained-release theophylline can be used safely in elderly patients with asthma or COPD.     

A case of tuberculous pericarditis developing constrictive pericarditis

A case of constrictive pericarditis which developed after the onset of clinical manifestation of tuberculous pericarditis was reported. A 75-year-old male, complaining of anorexia, was admitted to our hospital. Adenosinedeaminase (ADA) level in pericardial effusion was found to be increased, and the culture of pericardial effusion was positive for tubercle bacilli. Diagnosed as having tuberculous pleuritis and pericarditis, he underwent chemotherapy for tuberculosis. However, massive pleural effusion developed later and pleural effusion drainage was carried out. Despite repeated drainage, pleural effusion continued to recur. Chest CT revealed apparent pericardial thickening, in addition, cardiac catheterization revealed elevation of mean right atrial pressure and marked deterioration of cardiac functions including decrease of cardiac output. These findings were compatible with constrictive pericarditis. After these investigations a diagnosis of constrictive pericarditis was established, and the patient underwent a pericardiectomy. Pathological examination of resected specimens revealed tuberculous inflammation.     

Expression of GPIV and Naka antigen on monocytes in Naka-negative subjects whose platelets lack GPIV

Summary. The platelet antigen Nak^a was once considered to be a platelet-specific alloantigen and is carried on platelet membrane glycoprotein (GP) IV. Recent studies suggest that Nak^a-negative subjects lack platelet GPIV. GPIV is an important adhesive receptor and expressed on the surface of monocytes as well as of platelets. In the present study, flow cytometry was used to detect GPIV and Nak^a antigen on the surface of monocytes. Nak^a antigen was expressed on monocytes as well as on platelets in Nak^a-positive subjects ( n = 6) (P-GPIV-positive subjects). To our surprise, monocytes of Nak^a-negative subjects ( n = 7) (P-GPIV-negative subjects) having no anti-Nak^a antibody in their serum expressed GPIV and Nak^a antigen to almost the same degree as did the monocytes of P-GPIV-positive subjects. Competitive experiments using OKM5 (a monoclonal antibody against GPIV) and anti-Nak^a antibody showed that the epitope of anti-Nak^a antibody on monocytes was very close to that of OKM5. In two P-GPIV-negative subjects having anti-Nak^a antibody in their serum, GPIV and Nak^a antigen were not expressed on the surface of either monocytes or platelets. These results indicate that the GPIV molecules and Nak^a antigen are expressed on the surface of monocytes in the majority of P-GPIV-negative subjects, but that in a very few P-GPIV-negative subjects neither GPIV nor Nak^a antigen is expressed on the surface of their monocytes. We hypothesize that P-GPIV-negative subjects who carry neither GPIV nor Nak^a antigen on their monocytes produce anti-Nak^a antibody as a result of transfusion or pregnancy.