Thermophilic ATP synthase has a decamer c-ring: indication of noninteger 10:3 H+/ATP ratio and permissive elastic coupling

In a rotary motor F(o)F(1)-ATP synthase that couples H(+) transport with ATP synthesis/hydrolysis, it is thought that an F(o)c subunit oligomer ring (c-ring) in the membrane rotates as protons pass through F(o) and a 120 degrees rotation produces one ATP at F(1). Despite several structural studies, the copy number of F(o)c subunits in the c-ring has not been determined for any functional F(o)F(1). Here, we have generated and isolated thermophilic Bacillus F(o)F(1), each containing genetically fused 2-mer-14-mer c (c(2)-c(14)). Among them, F(o)F(1) containing c(2), c(5), or c(10) showed ATP-synthesis and other activities. When F(1) was removed, F(o) containing c(10) worked as an H(+) channel but F(o)s containing c(9), c(11) or c(12) did not. Thus, the c-ring of functional F(o)F(1) of this organism is a decamer. The inevitable consequence of this finding is noninteger ratios of rotation step sizes of F(1)/F(o) (120 degrees /36 degrees ) and of H(+)/ATP (10:3). This step-mismatch necessitates elastic twisting of the rotor shaft (and/or the side stalk) during rotation and permissive coupling between unit rotations by H(+) transport at F(o) and elementary events in catalysis at F(1).     

Adriamycin binding assay: a valuable chemosensitivity test in human osteosarcoma

Summary The reliability of a simple method evaluating the pattern of subcellular binding of Adriamycin (Adriamycin binding assay, ABA) as an index of sensitivity was demonstrated in different primary cultures and in sensitive and resistant cell lines of human osteosarcoma. After exposure to Adriamycin (10 g/ml for 30 min at 37°C), living sensitive cells showed selective intranuclear uptake of the drug, whereas in resistant cells no distinct subcellular distribution was observed. The binding pattern of Adriamycin in sensitive and in highly resistant cells was inversely related to the expression of P-glycoprotein. However, low levels of resistance in vitro, not detectable by increased levels of expression of P-glycoprotein, were revealed by ABA. The use of ABA in combination with the estimate of P-glycoprotein expression is recommended in clinical practice as an accurate means for predicting the sensitivity of osteosarcoma to Adriamycin.This study was supported by a grant from the Associazione Italiana per la Ricerca sul Cancro (A.I.R.C.).     

Changes in pancreatic somatostatin content in spontaneously diabetic mice, as determined by radioimmunoassay and immunohistochemical methods.

A specific RIA for somatostatin (SRIF) was used to determine the SRIF content of the pancreas and hypothalamus in spontaneously diabetic C57BL/KsJ dbdb and C57BL/6J obob mice. In addition, SRIF- and glucagon-containing cells were examined in the pancreatic islets with an immunohistochemical technique. In dbdb mice, immunoassayable pancreatic SRIF content was increased, as was the number of SRIF- or glucagon-containing cells. In obob mice, immunoassayable pancreatic SRIF content was also increased, but no increase was noted in the number of SRIF- or glucagon-containing cells. The hypothalamic SRIF content of either strain was not different from that of controls. These results regarding pancreatic SRIF content were in accord with some but not all previous reports. These differences may be related to the age of the mice or to the conditions in which they were bred. The pancreatic SRIF increase in both dbdb and obob mice may be attributable to hyperglucagonemia, hyperglycemia, or a decrease in insulin action. Further work is necessary to clearly delineate the mechanism.     

Targeted deletion of the murine corneodesmosin gene delineates its essential role in skin and hair physiology

Controlled proteolytic degradation of specialized junctional structures, corneodesmosomes, by epidermal proteases is an essential process for physiological desquamation of the skin. Corneodesmosin (CDSN) is an extracellular component of corneodesmosomes and, although considerable debate still exists, genetic studies have suggested that the CDSN gene in the major psoriasis-susceptibility locus (PSORS1) may be responsible for susceptibility to psoriasis, a human skin disorder characterized by excessive growth and aberrant differentiation of keratinocytes. CDSN is also expressed in the inner root sheath of hair follicles, and a heterozygous nonsense mutation of the CDSN gene in humans is associated with scalp-specific hair loss of poorly defined etiology. Here, we have investigated the pathogenetic roles of CDSN loss of function in the development of skin diseases by generating a mouse strain with targeted deletion of the Cdsn gene. Cdsn-deficient mouse skin showed detachment of the stratum corneum from the underlying granular layer and/or detachment within the upper granular layers due to the disrupted integrity of the corneodesmosomes. When grafted onto immunodeficient mice, Cdsn-deficient skin showed rapid hair loss together with epidermal abnormalities resembling psoriasis. These results underscore the essential roles of CDSN in hair physiology and suggest functional relevance of CDSN gene polymorphisms to psoriasis susceptibility.     

Clinical presentation of community-acquired Chlamydia pneumoniae pneumonia in adults

STUDY OBJECTIVE: To investigate the clinical presentation of community-acquired Chlamydia pneumoniae pneumonia in adults. DESIGN: Prospective study. SETTING: Kawasaki Medical School Hospital, Kawasaki Medical School Kawasaki Hospital, and Kurashiki Daiichi Hospital in Japan. PARTICIPANTS: Forty patients with community-acquired pneumonia with C pneumoniae as the only pathogen identified admitted to three hospitals between April 1996 and March 2001 and their clinical presentations were compared to patients with Streptococcus pneumoniae and Mycoplasma pneumoniae pneumonia. MEASUREMENTS: The diagnosis of C pneumoniae infection was based on isolation and serologic testing of antibodies by the microimmunofluorescence test. RESULTS: The clinical presentations, except for shortness of breath, were similar for the three major etiologic agents. The mean temperature of C pneumoniae patients on hospital admission was 37.9 degrees C, which was lower than that of patients with S pneumoniae and M pneumoniae. The mean WBC count on hospital admission was lower in the patients with C pneumoniae (mean, 9,100/microL) than in those with S pneumoniae pneumonia but higher than in those with M pneumoniae pneumonia. No patients required respiratory support or admission to an ICU, and no deaths occurred among the C pneumoniae pneumonia patients. CONCLUSIONS: Our results indicate that C pneumoniae pneumonia as a single etiologic agent is mild and that the underlying conditions and clinical symptoms closely resemble those of S pneumoniae pneumonia. However, the physical examinations, laboratory findings, and prognostic factors of the C pneumoniae patients resembled those of patients with M pneumoniae pneumonia.     

Clinicopathological analysis of lung cancer resembling malignant pleural mesothelioma

OBJECTIVE: The aim of this study was to evaluate the clinicopathological features of lung cancer resembling malignant pleural mesothelioma. METHODOLOGY: The seven patients studied had tumours showing an extensive pleural growth pattern, and were chosen from 1516 lung cancer patients diagnosed at two affiliated hospitals over a 17-year period. RESULTS: Histologically, five of these lung cancers were adenocarcinomas, one was a small cell carcinoma, and one a large cell carcinoma. Tumour markers such as carcinoembryonic antigen (CEA) were elevated in six patients at admission. However, a clinical diagnosis was difficult and these cancers could only be distinguished from malignant pleural mesothelioma by thoracentesis in two cases, pleural biopsy in two, thoracotomy in two, and in case 7 at autopsy. Treatment consisted of chemotherapy or radiation therapy in four patients, but with little clinical effect. The mean survival time was 6.7 months, which is much less than for true malignant pleural mesothelioma. CONCLUSIONS: Lung cancer resembling malignant pleural mesothelioma is most frequently observed in patients with adenocarcinoma, which is suspected to occur peripherally. To distinguish pseudomesotheliomatous carcinoma from malignant pleural mesothelioma in patients with diffuse pleural thickening and effusion, requires adequate tissue sampling by thoracotomy or video-assisted thoracoscopic surgery and a panel of immunohistochemical stains.     

Risk factors for early death in patients undergoing treatment for multiple myeloma

The survival time of myeloma patients improved from a few months to many years after treatment with melphalan. Perhaps chemotherapy more intensive than melphalan-prednisolone should be administered to patients at risk of early death. Therefore, early death must be accurately predicted. We analyzed 93 patients with recently diagnosed myeloma and found that 13 (14%) died within 6 months (early death). The most common cause of death was bacterial and fungal pneumonia when myeloma became uncontrollable. The response to conventional chemotherapy was poorer in patients at high risk of early death than the control group. Multivariate analysis showed that the serum level of beta-2 microglobulin was the only value that predicted early death.     

Immunological and molecular analysis of B lymphocytes in low-grade MALT lymphoma of the stomach. Are there any useful markers for predicting outcome after Helicobacter pylori eradication?

Background: Background: Although Helicobacter pylori eradication is effective in treating low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma, the condition in some patients deteriorates even after the eradication. Therefore, it is important to predict the disease outcome before starting H. pylori eradication. We investigated the usefulness of flow cytometry, quantifying CD19- and CD20-positive B lymphocytes in MALT lymphoma tissue, for predicting the disease outcome after H. pylori eradication. Methods: Tissue specimens from 14 patients with H. pylori-positive low-grade gastric MALT lymphoma were examined by histology, Southern blotting, and flow cytometry before therapy. Serum levels of soluble interleukin (IL)-2 receptor were also measured. The relationship between the data and the prognosis after H. pylori eradication was analyzed. Results: Remission occurred in 10 of the 14 patients. The condition in the 4 remaining patients deteriorated even after H. pylori eradication. The percentages of CD19- and CD20-positive cells in MALT lymphoma tissue from the patients in remission were both significantly lower than those in the tissue from patients not in remission. Indeed, 4 of the 5 patients in whom both CD19- and CD20-positive cells accounted for more than 50% of the total number of lymphocytes had gastrectomy, whereas all patients in whom both CD19- and CD20-positive cells accounted for less than 50% of the total number of lymphocytes achieved remission. Although immunoglobulin gene rearrangement was present in all patients operated on, there were also 6 patients whose MALT lymphoma was ameliorated in spite of the presence of gene rearrangement. The serum level of soluble IL-2 receptor was in the normal range in all patients tested. Conclusions: Analysis of mature B-cell markers in MALT lymphoma tissue is more useful than the examination of immunoglobulin gene rearrangement or serum levels of soluble IL-2 receptor in predicting the outcome of low-grade gastric MALT lymphoma after H. pylori eradication. Received: January 5, 2001 / Accepted: November 2, 2001     

Assay of specific anti-Chlamydia pneumoniae antibodies by ELISA method. 3. Setting of serological criteria]

"HITAZYME C. pneumoniae" (or "HITAZYME CPN", for short) is a diagnostic reagent that has been recently developed by adopting an ELISA method for detection of anti-Chlamydia pneumoniae (C. pneumoniae) antibodies. When this reagent is used under a current diagnostic standard that has been set as a provisional standard, however, high antibody positive rates are often produced for both IgG and IgA even using the specimens of healthy persons. So, it is difficult to distinguish C. pneumoniae-infected patients from healthy persons. Therefore, this time, we tried to establish a new diagnostic standard by setting up of special cut-off values for a single serum and rise rates of antibody titers for paired sera to improve the accuracy for diagnosis of C. pneumoniae infection. For a single serum testing, we set a special cut-off value at ID 3.00 for both IgG and IgA, so that most healthy persons fall within the range of the "negative" zone. This value was based on the calculation of "Mean+2SD" using measurement results (or IDs) of healthy persons. When this cut-off value was applied, the rate of > or = ID 3.00 for either IgG or IgA was 7.6% for healthy persons, and 64.9% for infected patients. (The rate reached 76.4% when the highest IDs of multiple specimens taken from each patient for this test were used in calculation) As a diagnostic standard for a single serum, therefore, it was defined that: "If ID is 3.00 or greater for IgG and/or IgA, it is highly likely that the case has an acute or a present infection." Using paired sera, we could confirm almost a linear relationship between the results by HITAZYME CPN and those by micro-IF method. Under micro-If method, if the antibody titer increases four times or greater using paired sera, acute infection is diagnosed. As it was found that the four-fold increase in antibody titer corresponds to the increase of 1.35 in ID for IgG and 1.00 for IgA, we defined a diagnostic standard for paired sera as follows: "If ID increases by 1.35 or greater for IgG, and/or if ID increases by 1.00 or greater for IgA, the case may be diagnosed as acute infection."