ELIMIMATION OF RANDOM DEFACTS IN AEROSPACE MATERIALS

１．ＩｎｔｒｏｄｕｃｔｉｏｎＤｅｖｅｌｏｐｍｅｎｔｓｉｎｒｏｔａｔｉｎｇｐａｒｔｓｏｖｅｒｔｈｅｐａｓｔｄｅｃａｄｅｈａｖｅｎｏｔｓｅｅｎｔｈｅｅｘｔｅｎｓｉｖｅｉｎｔｒｏｄｕｃｔｉｏｎｏｆｎｅｗｍａｔｅｒｉａｌｓ,ｂｕｔｒａｔｈｅｒｔｈｅｍｏｒｅｒｉｇｏｒｏｕｓａｐｐｌｉｃａｔｉｏｎｏｆｅｘｉｓｔｉｎｇａｌｌｏｙｓａｓｏｕｒｕｎｄｅｒｓｔａｎｄｉｎｇｏｆｔｈｅｓｅｒｖｉｃｅｃｏｎｄｉｔｉｏｎｓａｎｄｍｅｃｈａｎｉｃａｌｒｅｑｕｉｒｅｍｅｎｔｓｈａｓｂｅｃｏｍｅｄｅｅｐｅｒ．Ｔｈｅｔｗｏｅｓｓｅ…     

N-glycosylation of recombinant human interferon-gamma produced in different animal expression systems

Recombinant human interferon-gamma (IFN-gamma) was expressed in Chinese hamster ovary cells, baculovirus-infected Sf9 insect cells and the mammary gland of transgenic mice. The N-linked carbohydrate populations associated with both Asn25 and Asn97 glycosylation sites were characterized by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) in combination with exoglycosidase array sequencing. A site-specific analysis of dual (2N) and single (1N) site-occupancy variants of IFN-gamma derived from Chinese hamster ovary cells showed that N-glycans were predominantly of the complex bi- and triantennary type. Although Asn25-linked glycans were substituted with a core fucose residue, Asn97 N-glycans were predominantly non-fucosylated, and truncated complex and high-mannose oligosaccharide chains were also evident. Transgenic mouse derived IFN-gamma exhibited considerable site-specific variation in N-glycan structures. Asn25-linked carbohydrates were of the complex, core fucosylated type, Asn97-linked carbohydrates were mainly of the oligomannose type, with smaller proportions of hybrid and complex N-glycans. Carbohydrates associated with both glycosylation sites of IFN-gamma from Sf9 insect cells were mainly tri-mannosyl core structures, with fucosylation confined to the Asn25 site. These data demonstrate the profound influence of host cell type and protein structure on the N-glycosylation of recombinant proteins.     

Studies of the coronary circulation in Chagas' heart disease

Pathogenesis of chronic Chagas' heart disease may include various disturbances in the coronary circulation, that could be responsible for the myocardial lesions seen in human hearts and in experimental models of the disease. In this paper we critically reviewed the anatomical and functional abnormalities described in chronic chagasic patients, pertaining to the so-called vascular pathogenetic theory of Chagas' disease. The epicardial coronary arteries are usually free of significant obstructive disease in nonselected groups of chagasic patients examined at autopsy or by coronary angiography. However, chagasic patients who were studied after an episode of acute myocardial infarction, show the same patterns of atherosclerotic coronary artery disease seen in the general nonchagasic population. Studies of chagasic patients with angiographically normal coronary arteries, by several scintigraphy methods, revealed myocardial perfusion abnormalities which may be caused by the microcirculatory derangements described in animals experimentally infected with the T. cruzi. Since hypoperfusion has been detected in regions with normal or mildly impaired wall motion, it is likely that the microvascular disturbances precede and may be causative mechanism for the subsequent myocardial damage. We speculate that hibernating ventricular areas may occur in chagasic patients, on the basis of the evidence gathered from these studies. Recent investigations of chronic patients with Chagas' disease and chest pain showed attenuation of the vasomotor responses to physiological and pharmacological stimuli, in the epicardial coronary arteries.     

Patient compliance in mobile screening mammography

RATIONALE AND OBJECTIVES: We assessed the follow-up behavior of women who had abnormal results of screening mammograms taken on a mobile van. METHODS: A retrospective cohort study was conducted between 1988 and 1991 of all women served by a mobile mammography van in rural North Carolina. Compliance with radiologist recommendations for follow-up was assessed through review of patient records and mail surveys of patients with incomplete records. RESULTS: Compliance was 44% for negative or benign mammograms, 57% for indeterminate mammograms, and 62% for probably malignant or malignant mammograms. Women who had a previous mammogram or had a malignant finding were more likely to comply with follow-up recommendations (p < .0001) than women with normal or benign results and no history of mammography. Compliers and noncompliers did not differ with respect to family history of breast cancer or personal history of breast discomfort. CONCLUSION: Compliance with recommendations in this setting was lower than expected. This may be because rural women using mobile van mammography have limited access to the resources needed for appropriate follow-up. Further research is needed to examine explanations for poor compliance in this setting.     

A conundrum in molecular toxicology: molecular and biological changes during neoplastic transformation of human cells

The process of multistage carcinogenesis lends itself to the concept that the effects of carcinogens are mediated through dose-related, multi-hit, linear changes. Multiple in vitro model systems have been developed that are designed to examine the cellular changes associated with the progression of cells through the different stages in the process; however, these systems may have inherent limitations due to the cell lines used for these studies, the manner of assessing the effects of the carcinogens, and the subsequent growth and differentiation of the exposed cells. Each of these variables results in increasing levels of uncertainty relative to the correlation of the events with the actual process of human tumor development. Therefore, the prediction of the ultimate effect of any carcinogen is difficult. Moreover, relationships between individual biological endpoints resulting from carcinogen treatment appear at best to be approximations. The presence of an activated carcinogen inside the cell can give rise to multiple outcomes, only some of which may be critical events. For example, site-specific modification of the 12th and 13th codons of H-ras is different than that in the adjacent 14th and 15th codons. It is interesting to speculate what effect these differences might have on a biological outcome, e.g., transformation to anchorage-independent growth. The use of different model systems to examine the effects of activated carcinogens also creates additional problems. Comparisons of in vitro transformed cells with similar cells isolated from human tumors indicate that the culture environment appears to influence the expression of a particular phenotype, in that human tumor cells in culture express many of the same parameters as those found in cells transformed with carcinogens in vitro. If the process of transformation is linear, then less aggressive phenotypes should progress to a more aggressive transformed stage. However, in carcinogen-transformed human cells, the populations exhibit phenotypic diversity in that many of the transformed cells differentiate and fail to continue to divide in culture. Historically, we have assumed only a limited role for epigenetic modulation of molecular changes that occur during progression; however, our data suggest quite strongly that nonmalignant tumor populations can be converted to a more malignant phenotype without additional mutations taking place and, conversely, malignant populations can be downregulated to a nontumorigenic phenotype. Tumor cell plasticity is not only a fundamental characteristic of diverse types of human tumors, but also appears as an integral characteristic of carcinogen-transformed cells in vitro.     

Practical guidelines for the assessment and treatment of selective mutism

OBJECTIVE: To provide practical guidelines for the assessment and treatment of children with selective mutism, in light of the recent hypothesis that selective mutism might be best conceptualized as a childhood anxiety disorder. METHOD: An extensive literature review was completed on the phenomenology, evaluation, and treatment of children with selective mutism. Additional recommendations were based on clinical experience from the authors' selective mutism clinic. RESULTS: No systematic studies of the phenomenology of children with selective mutism were found. Reports described diverse and primarily noncontrolled treatment approaches with minimal follow-up information. Assessment and treatment options for selective mutism are presented, based on new hypotheses that focus on the anxiety component of this disorder. Ongoing research suggests a role for behavior modification and pharmacotherapy similar to the approaches used for adults with social phobia. CONCLUSION: Selectively mute children deserve a comprehensive evaluation to identify primary and comorbid problems that might require treatment. A school-based multidisciplinary individualized treatment plan is recommended, involving the combined effort of teachers, clinicians, and parents with home- and clinic-based interventions (individual and family psychotherapy, pharmacotherapy) as required.     

Synovial sarcoma of the suboccipital region of the neck

A synovial sarcoma (SS) is an uncommon malignant soft-tissue tumor, which in spite of its name does not arise from synovial tissue. It is so named because of its histologic similarity to synovium. An SS originates from mesenchyme, not from synoviocytes and usually manifests as a biphasic tumor with both malignant-epithelial and spindle-cell components. Monophasic epithelial and spindle-cell presentations may cause a diagnostic dilemma. Diagnosis should include immunocytochemistry using cytokeratin and/or epithelial membrane antigen; vimentin further helps to eliminate any histologic confusion. These tumors are most commonly found in the extremities. When located near a joint, invasion occurs only by secondary extension. Rarely are SSs found in the neck, especially in the posterior aspect, as reported here.