Chest complications in immunocompromised patients without acquired immunodeficiency syndrome (AIDS): differentiation between infectious and non-infectious diseases using high-resolution CT findings.

AIM: To differentiate between infectious and non-infectious diseases occurring in immunocompromised patients without acquired immunodeficiency syndrome (AIDS) using high-resolution computed tomography (HRCT). MATERIALS AND METHODS: HRCT images of 555 patients with chest complications were reviewed retrospectively. Infectious diseases (n=341) included bacterial pneumonia (n=123), fungal infection (n=80), septic emboli (n=11), tuberculosis (n=15), pneumocystis pneumonia (n=101), and cytomegalovirus pneumonia (n=11), while non-infectious diseases (n=214) included drug toxicity (n=84), infiltration of underlying diseases (n=83), idiopathic pneumonia syndrome (n=34), diffuse alveolar haemorrhage (n=8), and pulmonary oedema (n=5). Lung parenchymal abnormalities were compared between the two groups using the χ2 test and multiple logistic regression analysis. RESULTS: The χ2 test results showed significant differences in many HRCT findings between the two groups. Multiple logistic regression analysis results indicated the presence of nodules with a halo and the absence of interlobular septal (ILS) thickening were the significant indicators that could differentiate infectious from non-infectious diseases. ILS thickening was generally less frequent among most infectious diseases and more frequent among most non-infectious diseases, with a good odds ratio (7.887, p<0.001). The sensitivity and accuracy for infectious diseases in the absence of ILS thickening were better (70% and 73%, respectively) than those of nodules with a halo (19% and 48%, respectively), while the specificity in the nodules with a halo was better (93%) than that of ILS thickening (78%). CONCLUSIONS: The presence of nodules with a halo or the absence of ILS thickening tends to suggest infectious disease. Specifically, ILS thickening seems to be a more reliable indicator.

HRCT findings of collagen vascular disease-related interstitial pneumonia (CVD-IP): a comparative study among individual underlying diseases.

AIM: To identify characteristic high-resolution computed tomography (CT) findings for individual collagen vascular disease (CVD)-related interstitial pneumonias (IPs). MATERIALS AND METHODS: The HRCT findings of 187 patients with CVD, including 55 patients with rheumatoid arthritis (RA), 50 with systemic sclerosis (SSc), 46 with polymyositis/dermatomyositis (PM/DM), 15 with mixed connective tissue disease, 11 with primary Sjögren's syndrome, and 10 with systemic lupus erythematosus, were evaluated. Lung parenchymal abnormalities were compared among CVDs using χ2 test, Kruskal-Wallis test, and multiple logistic regression analysis. A CT-pathology correlation was performed in 23 patients. RESULTS: In RA-IP, honeycombing was identified as the significant indicator based on multiple logistic regression analyses. Traction bronchiectasis (81.8%) was further identified as the most frequent finding based on χ2 test. In SSc IP, lymph node enlargement and oesophageal dilatation were identified as the indicators based on multiple logistic regression analyses, and ground-glass opacity (GGO) was the most extensive based on Kruskal-Wallis test, which reflects the higher frequency of the pathological nonspecific interstitial pneumonia (NSIP) pattern present in the CT-pathology correlation. In PM/DM IP, airspace consolidation and the absence of honeycombing were identified as the indicators based on multiple logistic regression analyses, and predominance of consolidation over GGO (32.6%) and predominant subpleural distribution of GGO/consolidation (41.3%) were further identified as the most frequent findings based on χ2 test, which reflects the higher frequency of the pathological NSIP and/or the organising pneumonia patterns present in the CT-pathology correlation. CONCLUSION: Several characteristic high-resolution CT findings with utility for estimating underlying CVD were identified.

In-situ straining and time-resolved electron tomography data acquisition in a transmission electron microscope.

This paper reports the preliminary results of a new in-situ three-dimensional (3D) imaging system for observing plastic deformation behavior in a transmission electron microscope (TEM) as a directly relevant development of the recently reported straining-and-tomography holder [Sato K et al. (2015) Development of a novel straining holder for transmission electron microscopy compatible with single tilt-axis electron tomography. Microsc. 64: 369-375]. We designed an integrated system using the holder and newly developed straining and image-acquisition software and then developed an experimental procedure for in-situ straining and time-resolved electron tomography (ET) data acquisition. The software for image acquisition and 3D visualization was developed based on the commercially available ET software TEMographyTM. We achieved time-resolved 3D visualization of nanometer-scale plastic deformation behavior in a Pb-Sn alloy sample, thus demonstrating the capability of this system for potential applications in materials science.

Updated prostate imaging reporting and data system (PIRADS v2) recommendations for the detection of clinically significant prostate cancer using multiparametric MRI: critical evaluation using whole-mount pathology as standard of reference.

OBJECTIVES: To evaluate the recommendations for multiparametric prostate MRI (mp-MRI) interpretation introduced in the recently updated Prostate Imaging Reporting and Data System version 2 (PI-RADSv2), and investigate the impact of pathologic tumour volume on prostate cancer (PCa) detectability on mpMRI. METHODS: This was an institutional review board (IRB)-approved, retrospective study of 150 PCa patients who underwent mp-MRI before prostatectomy; 169 tumours ≥0.5-mL (any Gleason Score [GS]) and 37 tumours <0.5-mL (GS ≥4+3) identified on whole-mount pathology maps were located on mp-MRI consisting of T2-weighted imaging (T2WI), diffusion-weighted (DW)-MRI, and dynamic contrast-enhanced (DCE)-MRI. Corresponding PI-RADSv2 scores were assigned on each sequence and combined as recommended by PI-RADSv2. We calculated the proportion of PCa foci on whole-mount pathology correctly identified with PI-RADSv2 (dichotomized scores 1-3 vs. 4-5), stratified by pathologic tumour volume. RESULTS: PI-RADSv2 allowed correct identification of 118/125 (94 %; 95 %CI: 90-99 %) peripheral zone (PZ) and 42/44 (95 %; 95 %CI: 89-100 %) transition zone (TZ) tumours ≥0.5 mL, but only 7/27 (26 %; 95 %CI: 10-42 %) PZ and 2/10 (20 %; 95 %CI: 0-52 %) TZ tumours with a GS ≥4+3, but <0.5 mL. DCE-MRI aided detection of 4/125 PZ tumours ≥0.5 mL and 0/27 PZ tumours <0.5 mL. CONCLUSIONS: PI-RADSv2 correctly identified 94-95 % of PCa foci ≥0.5 mL, but was limited for the assessment of GS ≥4+3 tumours ≤0.5 mL. DCE-MRI offered limited added value to T2WI+DW-MRI. KEY POINTS: • PI-RADSv2 correctly identified 95 % of PCa foci ≥0.5 mL • PI-RADSv2 was limited for the assessment of GS ≥4+3 tumours ≤0.5 mL • DCE-MRI offered limited added value to T2WI+DW-MRI.

Development of a novel straining holder for transmission electron microscopy compatible with single tilt-axis electron tomography.

We have developed a newly designed straining specimen holder for in situ transmission electron microscopy (TEM) compatible with high-angle single tilt-axis electron tomography. The holder can deform a TEM specimen under tensile stress with the strain rate between 1.5 × 10(-6) and 5.2 × 10(-3) s(-1). We have also confirmed that the maximum tilt angle of the specimen holder reaches ±60° with a rectangular shape aluminum specimen. The new specimen holder, termed as 'straining and tomography holder', will have wide range potential applications in materials science.

Sex and the clinical value of body mass index in patients with clear cell renal cell carcinoma.

BACKGROUND: An increased body mass index (BMI) is significantly associated with favourable prognosis in renal cell carcinoma (RCC). This study investigated the associations among sex, BMI, and prognosis in clear cell RCC patients. METHODS: We retrospectively analysed 435 patients with clear cell RCC who underwent a nephrectomy. The associations among sex, BMI, clinicopathologic factors, and cancer-specific survival (CSS) were analysed. RESULTS: As a continuous variable, increased BMI was associated with higher CSS rate by univariate analysis in the whole population (hazard ratio, 0.888 per kg m(-2); 95% confidence interval, 0.803-0.982; P=0.021). A sub-population analysis by sex demonstrated that BMI was significantly associated with CSS in men (P=0.004) but not in women (P=0.725). Multivariate analysis revealed BMI to be an independent predictor of CSS in only men. CONCLUSION: Body mass index was significantly associated with clear cell RCC prognosis. However, the clinical value of BMI may be different between men and women.

Low-grade central osteosarcoma mimicking fibrous dysplasia: a report of two cases.

Low-grade central osteosarcoma is an unusual variant of conventional osteosarcoma. We present here two rare cases of low-grade central osteosarcoma resembling fibrous dysplasia. A 24-year-old woman diagnosed as fibrous dysplasia was treated with intra-lesional excision and curettage of the tumor but tumor recurred at 4 months after surgery. Distal femoral en-bloc resection was performed followed by arthroplasty with mega-prosthesis of the knee. A 57-year-old man diagnosed as central osteosarcoma was treated with wide excision of the tumor, followed by reconstruction with the vascularized fibula graft combined with an autogenous irradiated bone graft. Because of the difficulty in distinguishing low-grade central osteosarcoma from a benign lesion, open biopsy is needed to obtain a large tumor sample. Careful clinical and pathological evaluation is required to obtain a definite diagnosis. The treatment of low-grade central osteosarcoma is en-block resection with wide surgical margins.

Induction of murine AA amyloidosis by various homogeneous amyloid fibrils and amyloid-like synthetic peptides.

We investigated amyloid-enhancing factor (AEF) activity of amyloid fibrils extracted from amyloid-laden livers of mice, cow, cheetah, cat and swan. All amyloid fibrils were confirmed to be amyloid protein A (AA) by an immunohistochemical analysis. We found that these fibrils accelerated the deposition of amyloid in an experimental mouse model of AA amyloidosis. Furthermore, the degree of deposition was dependent on the concentration of fibrils. When we compared the minimal concentration of amyloid fibrils needed to induce deposition, we found that these fibrils showed different efficiencies. Murine amyloid fibril induced amyloid deposition more efficiently than cow, cat, cheetah or swan amyloid fibrils. These data suggest that amyloid deposition is preferentially induced by amyloid fibrils with the same primary sequence as the endogenous amyloid protein. We then analysed the AEF activity of synthetic peptides, synthesized corresponding to amino acids 1-15 of mouse SAA (mSAA), 2-15 of cow SAA (bSAA), 1-15 of cat SAA (cSAA), which was the same as cheetah, and the common amino acids 33-45 of these four SAA (aSAA). We found that mSAA, bSAA and cSAA formed amyloid-like fibrils in morphology and showed similar AEF properties to those of native amyloid fibrils. Although aSAA also formed highly ordered amyloid-like fibrils, it showed weaker AEF activity than the other synthetic fibrils. Our results indicate that amyloidosis is transmissible between species under certain conditions; however, the efficiency of amyloid deposition is species-specific and appears to be related to the primary amino acid sequence, especially the N-terminal segment of the amyloid protein.

Effects of bisphosphonate treatment on bone repair under immunosuppression using cyclosporine A in adult rats.

UNLABELLED: The effect of cyclosporine A on bone turnover remains unclear. Using adult rats with vascularized bone transplantation, we show that long-term cyclosporine A administration increases bone turnover and zoledronic acid treatment enhances the reconstruction of cyclosporine A-administered skeleton. Bisphosphonates might be efficacious in human bone repair under immunosuppression using cyclosporine A. INTRODUCTION: Bisphosphonate treatment effectively prevents bone loss after transplantation. However, recent evidence from gain- and loss-of-function experiments has indicated that calcineurin inhibitors, such as cyclosporine A (CsA), reduce bone turnover, and severely suppressed bone turnover might delay the union of human fractured bone. The purpose of this study was to investigate the effects of bisphosphonate treatment on the repair of CsA-administered skeleton. METHODS: After skeletal reconstruction by vascularized tibial grafting, adult recipient rats were treated with intramuscular CsA (10 mg/kg/day) and low-dose (0.2 microg/kg/week) or high-dose (2 microg/kg/week) subcutaneous zoledronic acid alone or in combination for 8 weeks. Biochemical parameters were measured in blood and urine. The reconstructed skeleton was analyzed using soft X-ray, histology, dual energy X-ray absorptiometry, and three-point bending test. RESULTS: CsA induced mild renal dysfunction, hyperparathyroidism and high bone turnover. High-dose zoledronic acid delayed cortical bone union at the distal host-graft junction, but its combination with CsA did not cause such a delay. High-dose zoledronic acid prevented CsA-induced bone loss and bone fragility in the reconstructed skeleton. CONCLUSION: In this rat model, long-term CsA administration increases bone turnover, at least partly, through hyperparathyroidism and high-dose zoledronic acid treatment does not impair the union of CsA-administered bone.

Demonstration of the shorter flagellin (flaA) gene of urease-positive thermophilic Campylobacter isolated from the natural environment in Northern Ireland.

The PCR amplicons (about 1450 bp in length) of flaA gene fragments of 11 isolates of urease-positive thermophilic Campylobacter (UPTC) isolated from the natural environment not including wild birds in Northern Ireland were demonstrated to be shorter than those of C. jejuni 81116 and six isolates of C. jejuni and C. coli (about 1700 bp) isolated in Northern Ireland and Japan. When the nucleotide lengths of the possible open reading frame (ORF) of the flaA genes were determined, those from the 11 UPTC isolates were estimated to be 1464-1503 bp, and those from the six C. jejuni and C. coli isolates and C. jejuni 81116 strain to be 1716-1728 bp. Nucleotide sequence and deduced amino acid sequence alignments of the possible ORFs demonstrated that the ORFs from the 11 UPTC isolates lack about 80 amino acid residues, mainly from the approximate residue numbers 390-470 of the large variable region in the flaA protein of the seven isolates of C. jejuni and C. coli, and do not have any internal termination codons. High amino acid sequence similarity of both amino- and carboxy-termini of the ORFs of the flaA gene was demonstrated between the 11 isolates of UPTC and the 7 isolates of C. jejuni and C. coli. The 11 UPTC isolates examined were strongly suggested to possess a shorter flaA gene without any internal termination codons.

Long-term follow-up of large flat colorectal tumors resected endoscopically.

BACKGROUND AND STUDY AIM: When a large flat colorectal tumor is excised by piecemeal endoscopic resection, it is not possible to obtain suitable specimens for histopathological examination to assess whether the resection has been complete. We prospectively analysed follow-up colonoscopy examinations of endoscopic polypectomy resection sites for residual lesions. PATIENTS AND METHODS: A total of 24 patients with large flat colorectal tumors were treated using an endoscopic submucosal saline injection technique. The resection site was prospectively examined for residual lesions using a magnifying colonoscope, at 3, 6, 12 and 24 months postoperatively. RESULTS: None of the 5 patients who underwent en bloc resection exhibited residual lesions postoperatively. Of the 19 patients who underwent piecemeal resection, one died of an asthma attack and 18 were followed up. Residual lesions were detected in four of these 18 patients (three adenomas and one cancer), which were resected endoscopically. When the tumor was resected endoscopically en bloc and was judged histologically to be completely resected, residual lesions were not detected at follow-up. However, residual lesions were detected in 22.2 % of patients 3 months after initial resection when polyps were resected piecemeal. After treatment, residual lesions were detected in two patients (11.1 %) at 24 months. CONCLUSION: After piecemeal endoscopic resection for large flat colorectal tumors, it is necessary to follow-up and remove residual lesions endoscopically every 3 months until they all are removed.

flaA-like sequences containing internal termination codons (TAG) in urease-positive thermophilic Campylobacter isolated in Japan.

AIMS: To demonstrate two flaA-like sequences containing two internal termination codons (TAG) in two Japanese strains of urease-positive thermophilic Campylobacter (UPTC). METHODS AND RESULTS: A primer pair of A1 and A2, which ought to generate a product of approx. 1700 bp of the flaA gene for Campylobacter jejuni, was used to amplify products of approx. 1450 bp for two Japanese strains of UPTC, CF89-12 and CF89-14. After molecular cloning and sequencing, the nucleotide sequences of the amplicons from the two strains were found to be 1461 bp in length and to have nucleotide sequence differences in relation to each other at four nucleotide positions, respectively. CONCLUSIONS: Nucleotide and amino acid sequence alignment and homology analysis demonstrated that the polymerase chain reaction (PCR) amplicons from the two Japanese strains have approx. 83% nucleotide and 80% amino acid sequence homology to the possible open reading frame of the flaA gene of UPTC NCTC 12892. SIGNIFICANCE AND IMPACT OF THE STUDY: Surprisingly, both PCR amplicons from the Japanese UPTC have two internal termination codons (TAG) at nucleotide positions from 775 to 777 and 817 to 819, respectively.

A new rabbit model for the study on cervical compressive myelopathy.

Development process and pathology of myelopathy due to chronic spinal cord compression have not been fully elucidated. This study was conducted in order to establish an experimental model which can efficiently produce myelopathy and be useful in the studies on myelopathy due to chronic spinal cord compression. Under electrophysiological monitoring of the spinal cord, anterior compression was produced on C5 using a plastic screw. Two weeks later, a plastic plate was inserted under the C5 arch. For the subsequent 10 months on average, walking pattern and MR images were periodically monitored. Before the sacrifice, electrophysiological test was performed and then histopathological examination was done. Palsy appeared at 5 months on average after the addition of posterior compression. Mean compression ratio of the spinal cord calculated on MR images was 34%. All animals with compression showed a high intramedullary signal intensity, and the mean contrast-to-noise ratio (CNR) in the compressed area was 49%. Electrophysiological test showed a significant decrease in the amplitude of spinal cord evoked potentials (SCEPs) at the given compression level. Histology showed flattening of the anterior horn, disappearance and necrosis of anterior horn cells in the gray matter; and demyelination and axonal degeneration in the white matter. The antero-posterior compression produces the condition of spinal canal stenosis. Repeated antero-posterior compression to the spinal cord is important in establishing myelopathy. The present animal model was evaluated to be useful in the studies on myelopathy.

Structure and expression of human mitochondrial adenylate kinase targeted to the mitochondrial matrix.

The previously isolated cDNA encoding human adenylate kinase (AK) isozyme 3 was recently renamed AK4. Consequently, human AK3 cDNA remains to be identified and we have little information about the functional relationship between human AK3 and AK4. In pursuit of the physiological roles of both the AK3 and AK4 proteins, we first isolated an authentic human AK3 cDNA and compared their expression. Nucleotide sequencing revealed that the cDNA encoded a 227-amino-acid protein, with a deduced molecular mass of 25.6 kDa, that shares greater homology with the AK3 cDNAs isolated from bovine and rat than that from human. We named the isolated cDNA AK3. Northern-blot analysis revealed that AK3 mRNA was present in all tissues examined, and was highly expressed in heart, skeletal muscle and liver, moderately expressed in pancreas and kidney, and weakly expressed in placenta, brain and lung. On the other hand, we found that human AK4 mRNA was highly expressed in kidney, moderately expressed in heart and liver and weakly expressed in brain. Western-blot analysis demonstrated expression profiles of AK3 and AK4 that were similar to their mRNA expression patterns in each tissue. Over expression of AK3, but not AK4, in both Escherichia coli CV2, a temperature-sensitive AK mutant, and a human embryonic kidney-derived cell line, HEK-293, not only produced significant GTP:AMP phosphotransferase (AK3) activity, but also complemented the CV2 cells at 42 degrees C. Subcellular and submitochondrial fractionation analysis demonstrated that both AK3 and AK4 are localized in the mitochondrial matrix.

Vascular amyloid of unknown origin and senile transthyretin amyloid in the lung and gastrointestinal tract of old age: histological and immunohistochemical studies.

The histological and immunohistochemical characteristics and the incidence of amyloid deposits in the tissues of the lung and gastrointestinal tract were investigated in 64 autopsied individuals who were 80 years and older (age range: 80-92 years; mean: 83.3 years). Immunohistochemical examination was performed with antibodies against amyloid A, transthyretin, immunoglobulin lambda and kappa light chain amyloid fibril proteins, beta2-microglobulin, beta protein, apolipoprotein AI, apolipoprotein AII, atrial natriuretic peptide, apolipoprotein E, and amyloid P component. Transthyretin amyloid fibril protein (ATTR) deposits were observed in five cases (7.8%). Gastrointestinal amyloid deposits of unknown origin were observed in the veins of the gastrointestinal tract in 26 cases (40.6%). This amyloid was regarded as portal amyloid with respect to distribution pattern. Pulmonary vascular amyloid deposits of unknown origin were observed in 12 cases (18.8%). These amyloid deposits were found mainly in medium-sized veins in the lungs and did not react with any antibodies against amyloid fibril proteins except apolipoprotein E and amyloid P component. Eleven of the 26 cases (42.3%) showing portal amyloid also showed pulmonary vascular amyloid of unknown origin. The pulmonary vascular amyloid deposits were similar to the portal amyloid deposits with respect to their morphological features and their relation to elastic fibers in the vessels. Further morphological investigation and biochemical analysis of the pulmonary vascular amyloid and portal amyloid will resolve questions of their origins and relation.

Useful polyclonal antibodies against synthetic peptides corresponding to immunoglobulin light chain constant region for immunohistochemical detection of immunoglobulin light chain amyloidosis.

For the immunohistochemical detection of immunoglobulin (Ig) light chain amyloidosis on formalin-fixed, paraffin-embedded tissue sections, we prepared polyclonal antibodies against synthetic peptides corresponding to positions 118-134 of Ig lambda light chain and positions 116-133 of Ig kappa light chain. Nineteen cases of systemic Ig lambda light chain amyloidosis (Alambda amyloidosis), 10 cases of systemic Ig kappa light chain amyloidosis (Akappa amyloidosis), one case of immunohistochemically unclassified systemic amyloidosis and five cases of localized Alambda amyloidosis were tested with these antibodies. Anti-lambda (118-134) antiserum and the affinity-purified antibody both reacted with 18 of the 19 cases of systemic Alambda amyloidosis and all cases of localized Alambda amyloidosis, although the immunoexpression was somewhat variable in intensity in different areas within the same specimen in both systemic and localized amyloidosis. The signal intensities in plasma cells and serum reacted for anti-lambda (118-134) antiserum were weaker than signals obtained with commercially available anti-Ig lambda light chain antibodies. Anti-kappa (116-133) antiserum and the affinity-purified antibody reacted with nine of the 10 cases of systemic Akappa amyloidosis. We conclude that these antibodies against synthetic peptides corresponding to the Ig light chain constant region are useful for the classification of amyloidosis on formalin-fixed, paraffin-embedded tissue sections.

Suppression of a squamous cell carcinoma (SCC)-related serpin, SCC antigen, inhibits tumor growth with increased intratumor infiltration of natural killer cells.

Squamous cell carcinoma (SCC) antigen (SCCA), a member of the ovalbumin serine proteinase inhibitor family, serves as a circulating marker of squamous cell carcinoma (SC). One of the SCCAs, SCCA1, has been suggested to play a role in the attenuation of apoptosis in vitro and in the augmentation of tumor growth in vivo. In the present study, the infection of a SCC cell line (SKG IIIa) with recombinant retrovirus that expressed the antisense SCCA mRNA suppressed expression of SCCA in vitro. Local administration of this retrovirus into tumors by inoculation in nude mice suppressed tumor growth. Treatment of tumor tissue in vivo is also associated with increased numbers of apoptotic tumor cells and large mononuclear cells in the tumor. To test the possible role of SCCA in the infiltration of large mononuclear cells, we analyzed the effect of SCCA1 on migration of natural killer (NK) cells induced by monocyte-chemoattractant protein-1 in vitro. SCCA1 suppressed migration of NK cells completely, and this inhibitory effect was lost by mutation of the reactive site loop of SCCA1. These results suggest that antisense SCCA may suppress the growth of SCC in vivo not only by the augmentation of intracellular apoptosis but also by the increased infiltration of NK cells into the tumor.

Chlamydia pneumoniae in atherosclerotic and nonatherosclerotic tissue.

The positivity rate and localization of Chlamydia pneumoniae were investigated in atherosclerotic and nonatherosclerotic tissues by immunohistochemistry, polymerase chain reaction, and cell culture. In total, 67 atheromatous plaques from Japanese symptomatic patients and 110 nonatherosclerotic tissues and organs were evaluated. Of these, 62% of atherosclerotic plaques from symptomatic patients were infected with C. pneumoniae compared with just 2% of nonatherosclerotic tissues. Immunohistochemically stained C. pneumoniae were found most often in smooth muscle cells, less often in macrophages, and in a few endothelial cells.

Mesoblastic nephroma in adulthood: a case report.

BACKGROUND: Mesoblastic nephroma is an uncommon renal tumor of infancy and rarely occurs in adults. We report an adult case of mesoblastic nephroma. METHODS: A 50-year-old woman was found incidentally to have a right renal mass by abdominal ultrasonography. Computed tomography and magnetic resonance imaging revealed a heterogeneous tumor and angiography showed a mixture of hypervascularity and hypovascularity. Right radical nephrectomy was performed. RESULTS: The tumor was an encapsulated yellowish solid mass. Microscopically, the tumor was composed of spindle cell proliferation. Atypia and mitoses were not identified. Among the tumor cells, there were tubular arranged epithelial elements. CONCLUSION: The patient was free of recurrence 14 months postoperatively. Mesoblastic nephroma is classified as a benign tumor but recurrence and malignant formation of this tumor have been reported so regular postoperative follow up is required.

Coronary arteriovenous fistulas with giant aneurysm: two case reports.

Coronary arteriovenous fistulas are rare, particularly in association with coronary aneurysms. Two rare cases of patients with coronary arteriovenous fistulas and giant aneurysmal formation are described. A right coronary fistula that drained into the superior vena cava was demonstrated in one patient. The remaining patient had a documented left coronary fistula that drained into a main pulmonary artery and had evidence of several plexal vessels that transversed through the pulmonary trunk and toward the pericardial reflex. Under cardiopulmonary bypass, the fistulas and plexal vessels were successfully ligated without any injury to the native coronary circulation.