Pulmonary alveolar proteinosis as a terminal complication in myelodysplastic syndromes: a report of four cases detected on autopsy

Secondary pulmonary alveolar proteinosis (PAP) is one of the complications of hematologic malignancy and immunosuppressive diseases. We encountered four cases of myelodysplastic syndrome (MDS) associated with PAP detected on autopsy. They consisted of two refractory anemia (RA) and two patients with refractory anemia with excess blasts in transformation (RAEBt) at the time of MDS diagnosis, but all of them developed leukemic phase and were resistant to chemotherapy at the time of pulmonary episodes. Of the four MDS patients, two also had pulmonary aspergillosis. Previously, 69 patients with PAP associated with hematologic disorders have been reported, but there have been only seven cases with MDS, including our four patients. Of the 69 reported cases of PAP in hematologic malignancies, 24/63 (38%) informative patients with infection had fungal infections of the lung; 2/7 (29%) MDS cases had fungal infection. We should, therefore, pay careful attention to this possibility in cases of MDS with lung complications, including PAP, especially in patients in the leukemic phase of MDS.     

Antiphospholipid syndrome and multiple ischemic strokes in a patient with myasthenia gravis

Little is known about ischemic stroke occurrence in patients with myasthenia gravis (MG), although antiphospholipid antibodies are detectable in many MG patients. A 47-year-old woman with a 20-year history of generalized MG had an acute onset of right hemiparesis. She had undergone thymectomy 10 years previously and was treated for phlebothrombosis of the lower extremity 3 years previously. Computed tomography (CT) demonstrated an old infarct in the left frontal lobe and a new lesion in the right parietal lobe. Multiple small cortical and subcortical infarcts were demonstrated on fluid attenuated inversion recovery (FLAIR) images. Thrombocytopenia (5.9 x 10(4)/microL), a prolonged activated partial thromboplastin time (aPTT; 50.2 sec), and an elevation of beta 2-IgG-glycoprotein I anticardiolipin antibodies (beta 2-GPIaCL; 55.7 U/mL) were observed. Neurological defects improved significantly over 2 weeks. She then was treated with oral prednisolone (30 mg/day) for 18 months, with resolution of laboratory abnormalities and no new cerebrovascular events or findings on imaging. We believe that our patient's multiple infarcts are caused by antiphospholipid antibodies and recommend glucocorticoid therapy to prevent recurrent of ischemic stroke in similar case.     

Visualization of pulmonary arteriovenous malformation by three dimensional computed tomography: a case report

Pulmonary arteriovenous malformation (PAVM) is an anomaly condition characterized by abnormal vascular communications between arteries and veins in the lungs. Hereby we describe a 60-year-old female with PAVM. Although the patient was asymptomatic, an abnormal round opacity was found on a chest X-ray film. Computed tomography (CT) of the lung disclosed nodules connected with enlarged vessels. Because PAVM was suspected, the patient was further evaluated by spiral CT coupled with three dimensional reconstruction of the images (3D-CT). As a result, PAVM was clearly visualized and invasive procedures such as angiography was not performed. The present case illustrates that 3D-CT is a diagnostic procedure of choice when PAVM is suspected.     

Combination chemotherapy with irinotecan and ifosfamide as second-line treatment of refractory or sensitive relapsed small cell lung cancer: a phase II study

This phase II study was conducted to investigate the efficacy and safety of irinotecan (CPT-11) and ifosfamide as second-line chemotherapy for relapsed small cell lung cancer (SCLC). Eligibility criteria included histologically or cytologically confirmed SCLC, prior chemotherapy including platinum + etoposide, and measurable or evaluable disease. CPT-11 (80 mg/m(2)) was administered intravenously on days 1, 8 and 15, while ifosfamide (1.5 g/m(2)) was given on days 1 through 3 every 4 weeks. Thirty-four patients (29 men) with a median age of 69 years (range 42-77) and a median Eastern Cooperative Oncology Group (ECOG) performance status of 1 (range 0-2) were enrolled. The response rate was 52.9% (95% confidence interval: 29.8-64.9%) with 2 complete responses and 16 partial responses. Our analyses of prognostic factors showed risk factors assessed before receiving second-line chemotherapy, which were the number of metastatic sites, performance status and the type of relapse. WHO grade 3-4 neutropenia was recorded in 52.9% of the patients, grade 3 diarrhea in 5.9%. The combination of CPT-11 and ifosfamide demonstrated clinical efficacy in relapsed SCLC with a favorable toxicity profile, particularly for performance status 0-1 and sensitive cases with only one metastatic site.     

Mutations of a novel human RAD54 homologue, RAD54B, in primary cancer.

Association of breast tumor susceptibility gene products BRCA1 and BRCA2 with the RAD51 recombination protein suggested that cancer could arise through defects in recombination. The identification of NBS1, responsible for Nijmegen breakage syndrome, from the MRE11/RAD50 recombination protein complex also supports this hypothesis. However, our mutation analysis revealed that known members of the RAD52 epistasis group are rarely mutated in human primary cancer. Here we describe the isolation of a novel member of the SNF2 superfamily, characterized with sequence motifs similar to those in DNA and RNA helicases. The gene, designated RAD54B, is significantly homologous to the RAD54 recombination gene. The expression of RAD54B was high in testis and spleen, which are active in meiotic and mitotic recombination. These findings suggest that RAD54B may play an active role in recombination processes in concert with other members of the RAD52 epistasis group. RAD54B maps to human chromosome 8q21.3-q22 in a region associated with cancer-related chromosomal abnormalities. Homozygous mutations at highly conserved positions of RAD54B were observed in human primary lymphoma and colon cancer. These findings suggest that some cancers arise through alterations of the RAD54B function.     

Efficient drug delivery to atherosclerotic lesions and the antiatherosclerotic effect by dexamethasone incorporated into liposomes in atherogenic mice

In order to confirm the efficacy of dexamethasone (DXM) incorporated into liposomes (DXM-liposomes) on atherosclerosis, drug delivery to atherosclerotic lesions and the antiatherosclerotic effect by DXM-liposomes were investigated in atherogenic mice. DXM-liposomes were prepared with egg yolk phosphatidylcholine, cholesterol and dicetylphosphate in a lipid molar ratio of 7/2/1 by the hydration method and then adjusted to three different particle sizes to clarify the influence of particle size on the drug delivery to atherosclerotic lesions and the effect on atherosclerosis. The particle sizes of DXM-liposomes were 519 nm (L500), 202 nm (L200) and 68.6 nm (L70), respectively. In both size, DXM concentration and DXM/lipid molar ratio in DXM-liposomes suspension were 1 mg DXM/ml and 0.134 mol DXM/mol total lipids, respectively. Atherogenic mice used as an experimental model develop an atherosclerotic lesion in the aorta and they were prepared by feeding an atherogenic diet for 14 weeks. The aortic pharmacokinetics of DXM-liposomes was examined by intravenous administration to atherogenic mice. The aortic uptake clearance of DXM in atherogenic mice treated with L200 was 2.6--3.2 fold greater than that in animals treated with L500, L70 or free DXM (f-DXM). Furthermore, the effects of DXM-liposomes on atherosclerosis were examined by intravenous administration to atherogenic mice once a week from 8 to 14 weeks. The antiatherosclerotic effects of DXM-liposomes were evaluated by determination of the aortic cholesterol ester (CE) level. The aortic CE level in atherogenic mice treated with L200 (55 microg DXM/kg) was significantly lower than that in animals treated with PBS. The antiatherosclerotic effect of L200 (55 microg DXM/kg) was significantly more potent than that of f-DXM (550 microg DXM/kg). These findings suggest that efficient delivery of DXM to the atherosclerotic lesions by L200 induces an excellent antiatherosclerotic effect at a lower dose. Therefore, L200 may be useful in the development of drug delivery systems for atherosclerotic therapy.     

Effects of depletion of dihydropyrimidine dehydrogenase on focus formation and RPA phosphorylation

Gimeracil, an inhibitor of dihydropyrimidine dehydrogenase (DPYD), partially inhibits homologous recombination (HR) repair and has a radiosensitizing effect as well as enhanced sensitivity to Camptothecin (CPT). DPYD is the target protein for radiosensitization by Gimeracil. We investigated the mechanisms of sensitization of radiation and CPT by DPYD inhibition using DLD-1 cells treated with siRNA for DPYD. We investigated the focus formation of various kinds of proteins involved in HR and examined the phosphorylation of RPA by irradiation using Western blot analysis. DPYD depletion by siRNA significantly restrained the formation of radiation-induced foci of Rad51 and RPA, whereas it increased the number of foci of NBS1. The numbers of colocalization of NBS1 and RPA foci in DPYD-depleted cells after radiation were significantly smaller than in the control cells. These results suggest that DPYD depletion is attributable to decreased single-stranded DNA generated by the Mre11/Rad50/NBS1 complex-dependent resection of DNA double-strand break ends. The phosphorylation of RPA by irradiation was partially suppressed in DPYD-depleted cells, suggesting that DPYD depletion may partially inhibit DNA repair with HR by suppressing phosphorylation of RPA. DPYD depletion showed a radiosensitizing effect as well as enhanced sensitivity to CPT. The radiosensitizing effect of DPYD depletion plus CPT was the additive effect of DPYD depletion and CPT. DPYD depletion did not have a cell-killing effect, suggesting that DPYD depletion may not be so toxic. Considering these results, the combination of CPT and drugs that inhibit DPYD may prove useful for radiotherapy as a method of radiosensitization.