Structure and optical properties of ZnSeO alloys with O composition up to 6.4%

II–VI-O type alloy semiconductor ZnSeO (O composition up to 6.4%) is grown by molecular beam epitaxy. O composition increases with O₂ flow rate. Several XRD peaks are observed when O composition is 2–4%, indicating phase separation. Growth at low temperature results in higher O composition. Photoluminescence intensity of ZnSeO lattice matched to GaAs is much stronger than that of ZnSe and peak shifts to lower energies with increasing O composition. Photoreflectance spectroscopy is performed to investigate the band gap energy. The band gap energy investigated by photoreflectance decreases with increasing O composition due to large band gap bowing even when phase separation occurs. The bowing parameter is estimated as 8.4 eV.     

CO2 and gadopentetate dimeglumine as alternative contrast agents for malfunctioning dialysis grafts and fistulas

BACKGROUND: Hemodialysis grafts and native fistulas are frequently evaluated angiographically utilizing iodinated contrast material to determine the cause of malfunction. Occasionally, patients are not able to receive iodinated contrast material due to a history of previous severe allergic reaction or concern that iodinated contrast material could worsen renal function requiring premature initiation of permanent dialysis. We set out to test the feasibility of gadopentetate dimeglumine as an alternative contrast agent in conjunction with carbon dioxide (CO2) angiography in the evaluation and treatment of hemodialysis grafts and native fistulas in patients who have a contraindication to iodinated contrast material. METHODS: Six patients with a malfunctioning hemodialysis graft and native fistula were evaluated. Four patients were successfully evaluated using carbon dioxide and gadopentetate dimeglumine. Two additional patients underwent balloon angioplasty using gadopentetate dimeglumine alone as the alternative contrast agent. RESULTS: All six patients successfully were evaluated and treated using gadopentetate dimeglumine either alone or as a supplement to CO2 angiography. Five of these patients had lesions successfully treated using gadopentetate dimeglumine alone or in combination with CO2 as the angiographic contrast agents. One patient underwent a successful diagnostic angiogram using gadopentetate dimeglumine and CO2 as alternative contrast agents and was subsequently treated with surgical revision. The gadopentetate dimeglumine angiograms identified the arterial anastomosis and more clearly identified stenotic lesions and venous outflow anatomy compared to carbon dioxide angiograms. CONCLUSION: Gadopentetate dimeglumine is useful as an alternative contrast agent in conjunction with CO2 in patients with malfunctioning hemodialysis grafts and fistulas, who have a contraindication to the administration of iodinated contrast material.     

Gadolinium-based contrast and carbon dioxide angiography to evaluate renal transplants for vascular causes of renal insufficiency and accelerated hypertension

PURPOSE: To evaluate the utility and potential nephrotoxicity of gadolinium-based contrast angiography when used with carbon dioxide angiography in renal transplant patients with suspected vascular causes of renal insufficiency and/or accelerated hypertension. MATERIALS AND METHODS: Thirteen consecutive renal transplant patients with suspected vascular causes of renal insufficiency and/or accelerated hypertension were evaluated with gadolinium-based contrast and CO2 angiography with use of digital subtraction techniques. Stenotic lesions were treated with angioplasty with/or without stent placement. No iodinated contrast agents were used. Serum creatinine levels were obtained before and at 24 and 48 hours after the procedure. An increase in creatinine levels greater than 0.5 mg/dL (44 micromol/L) was considered significant. RESULTS: Nine patients were studied for renal insufficiency, two for accelerated hypertension, and two for both. All 13 studies were considered diagnostic. Significant stenoses were treated in four patients with angioplasty with or without stent placement. Two patients had progression of their renal insufficiency. One of these patients underwent biopsy and was found to have both acute and chronic rejection. The other patient underwent cardiac catheterization 2 days after a transplant renal artery angioplasty. In the remaining nine patients with renal insufficiency (creatinine range, 1.8-3.9 mg/dL [159-345 micromol/L]; mean, 2.7 mg/dL [239 micromol/L]), renal function improved or did not worsen. CONCLUSION: Based on this limited study, gadolinium-based contrast angiography appears to be a promising supplement to CO2 angiography for the diagnosis and treatment of vascular lesions in patients with renal transplant insufficiency and/or accelerated hypertension. Further study is necessary to determine safety, optimal gadolinium dosage, and imaging parameters.     

Mediastinal germ cell tumor complicated by visceral hemangiomatosis

This report describes an extremely rare combination of mediastinal germ cell tumor and visceral hemangiomatosis in a 17-year-old boy who initially presented with chest pain and dyspnea. He was treated with chemotherapy consisting of cisplatin, cyclophosphamide, bleomycin, vinblastine, and dactinomycin followed by surgery. Multiple low-density nodules developed in the spleen three weeks later, suggesting metastases from the primary tumor, but the resected specimen showed cavernous hemangiomas within the splenic parenchyma. The patient died of recurrence of germ cell tumor 19 months after the initial treatment. Postmortem examination disclosed multiple hemangiomas in the lung and liver similar to those in the spleen.     

Proliferative potential and apoptosis in rat glioma cell lines after hyperthermia

The proliferative potential of cultured rat glioma cells (C6 and 9L) was evaluated after hyperthermia using immunohistochemical staining with bromodeoxyuridine (BrdU) and Ki-67 monoclonal antibodies. Apoptosis was assessed by in situ end-labeling of deoxyribonucleic acid breaks. Both BrdU and Ki-67 labeling indexes decreased with increasing hyperthermia time. The decrease of the Ki-67 labeling index was not as great as that of the BrdU labeling index. The number of apoptotic cells increased with time after hyperthermia. These results indicate that the antitumor effect of hyperthermia may reflect the induction of apoptosis in the cells within the cell cycle, and the resultant reduction of the proliferative potential of surviving cells, especially in the S phase.     

Severe antecollis during antipsychotics treatment: a report of three cases

1. The authors report on three patients with severe antecollis that developed after chronic treatment with antipsychotics. These patients had been treated with neuroleptics for their delusions and hallucinations. Antecollis is a rare form of tardive dystonia that has drawn little attention. To our knowledge, there have been no reports on this disorder. 2. The patients developed the symptom after receiving a number of antipsychotics for 4 months to 14 years. Neither discontinuation of antipsychotics nor administration of anticholinergic agents affected the symptom. 3. Although spontaneous improvement of dystonia was obtained after several months without any specific treatment in one patient, the symptom persisted for several years in another. The last patient could not be followed after discharge from our hospital since she and her family did not come to the hospital. 4. Severe antecollis may cause disturbances in various functions, such as vision, speaking and swallowing. Forward bending of the neck may cause inspiratory obstruction. Severe antecollis may not be unusual and psychiatrists should be aware of this symptom in routine clinical practice.     

CDR3 size spectratyping and sequencing of spectratype-derived TCR of spinal cord T cells in autoimmune encephalomyelitis

To characterize the nature of autoimmune disease-inducing T cells in the target organ, oligoclonal expansion of spinal cord T cells of Lewis rats with experimental autoimmune encephalomyelitis (EAE) was examined by complementarity-determining region 3 (CDR3) size spectratyping. It is known that TCR of in vitro-established myelin basic protein-specific T cell clones and lines have a short CDR3 and that the amino acid sequence in this region is highly preserved. On the basis of these findings, we analyzed 22 spectratypes of the TCR beta-chain (Vbeta1-20). Among them, only Vbeta8.2 and Vbeta17 showed oligoclonal expansion of TCR with a short CDR3 at the early stage of EAE. More interestingly, the spectratype profile of Vbeta8.2 seen at the early stage was preserved throughout the course of EAE, whereas that of Vbeta17 became more diverse at the peak stage of the disease. Analysis of nucleotide and predicted amino acid sequences of Vbeta8.2 CDR3 derived from the spectratypes revealed that the clones with CASSDSSYEQYFGPG, which is one of the representative sequences of encephalitogenic T cell clones, constituted the predominant population not only at the early stage but also at the peak and recovery stages (71, 71, and 60%, respectively). These findings imply that although the phenotype of T cells in the target organ diversifies as the autoimmune disease progresses, disease-associated TCR spectratype(s) are preserved throughout the course of the disease. Thus, CDR3 size spectratyping is a powerful tool for the screening of disease-inducing T cells in an autoimmune disease of unknown pathomechanism.     

Yield stress of a copper single crystal containing B2O3 particles

The yield stress of a copper single crystal containing vitreous B₂O₃ particles was measured as a function of temperature (77–1073 K) and strain rate (5.6 × 10^–6–5.6 × 10^–4sec^–1). Although the B₂O₃ particles in the copper matrix are a plastically non-deformable solid at low temperatures, they became liquid-like at high temperatures, above approximately 550 K. The yield stress of the Cu-B₂O₃ alloy at low temperatures was explained by the Orowan mechanism and the modulus-corrected yield stress of the Cu-B₂O₃ alloy at 1073 K was about four-fifths of the values at low temperatures. It was found that the liquid B₂O₃ particles could be the effective hardening centres even at high temperatures. At 873 and 1073 K, the yield stresses of the Cu-B₂O₃ alloy varied with the logarithm of the strain rates.