Nitric oxide and aneurysm formation in Kawasaki disease

The objective of this study is to show that nitric oxide plays a role in the development of coronary artery abnormalities in Kawasaki disease. We examined nitrite + nitrate, biopterin and neopterin in 316 urine samples of 34 patients with Kawasaki disease, those of 24 patients with other diseases, and those of 25 healthy children acting as a control group, because urinary nitrite + nitrate are reportedly useful as markers of nitric oxide generation in vivo , and pathways for neopterin-biopterin synthesis and nitric oxide generation are tightly coupled. In our study, the children with Kawasaki disease excreted more urinary nitrite + nitrate and neopterin than did the healthy control group children and excreted abnormally high quantities more often than did the patients with other diseases. Good relationships were found between the urinary nitrite + nitrate levels and the urinary biopterin levels, and between these biopterin levels and the urinary neopterin levels. Nitric oxide is therefore thought to be generated in abnormally high quantities, and to be closely related to the pathology of Kawasaki disease and to the development of coronary artery abnormalities. The role of nitric oxide in Kawasaki disease should be further studied to elucidate the pathophysiology of the disease and to aid in the development of new treatments.     

Subependymoma of the septum pellucidum: Characterization by PET

We report the evaluation of a subependymoma of the septum pellucidum by positron emission tomography (PET) with analysis of ₁₈F-fluorodeoxyglucose (FDG)kinetics. The tumor showed exceedingly low rates of glucose metabolism (rCMRG1) and kinetic constants (K1, K2, and K3). This hypometabolism indicates low cellular density and slow growth.     

Evaluation of syringomyelia with three-dimensional constructive interference in a steady state (CISS) sequence

The purpose of this study was to evaluate a three-dimensional (3D) constructive interference in steady state (CISS) sequence in the assessment of syringomyelia. Eleven patients with syringomyelia were prospectively studied with magnetic resonance imaging. All patients underwent sagittal imaging with T1- and T2-weighted spin-echo (SE), and 3D-CISS sequences. The SE and 3D-CISS images, as well as multiplanar reconstruction (MPR) images of the 3D-CISS sequence, were analyzed with regard to image quality, degree of artifacts, visualization of the extent and internal structure of the syringomyelia, and contrast-to-noise ratio (CNR) of the fluid within the syringomyelia. Contrast between the spinal cord and cerebrospinal fluid (CSF), as well as delineation was significantly poorer for the T1-weighted SE sequence than for the 3D-CISS sequence (P < 0.01), while there was no significant difference between the T2-weighted SE sequence and the 3D-CISS sequence. Artifacts induced by CSF flow were significantly more for the T2-weighted SE sequence than for the 3D-CISS sequence (P < 0.01). Although the extent of syringomyelia was delineated equally among the three sequences in 9 of 11 patients, it was better for the 3D-CISS sequence than for the SE sequences in the remaining two. Septation and communication between the cavities were best detected by the 3D-CISS MPR images. The CNR of the 3D-CISS sequence was significantly higher than that of the SE sequence (P < 0.01). The 3D-CISS sequence demonstrates the extent and internal structures of syringomyelia better than conventional SE sequences and should be added to SE sequences in the evaluation of syringomyelia.     

Primary transitional cell carcinoma of prostate: a case report

A 67-year-old male was admitted with a three-month history of voiding difficulty. Prostate specific antigen remained within the normal limit. Under the diagnosis of benign prostatic hypertrophy, transurethral resection of prostate was performed. Pathological examination of the resected specimens of the prostate revealed transitional cell carcinoma. Two courses of systemic M-VAC (methotrexate, vinblastine, doxorubicin, cisplatin) chemotherapy were performed, followed by cystoprostatourethrectomy, pelvic lymphadenectomy, and ileal conduit construction. Now one year has elapsed, with no clinical signs of recurrence.     

MN/CA IX antigen as a potential target for renal cell carcinoma

MN/CA IX is considered as a carbonic anhydrase isoenzyme expressed in the normal alimentary tract in a tissue-specific manner. This antigen is activated in the majority of renal cell carcinomas (RCC) but not in the normal kidney tissues. Our previous study revealed that increase of malignant potential is related to down-regulation of MN/CA9. To investigate the mechanism of MN activation in RCC, we examined the methylation status of this gene (MN/CA9) in RCC cell lines (SKRC-1, 6, 10, 12, 14, 44, 59). Moreover, we analyzed the circulating blood of patients for the presence of RCC cells by RT-PCR, to determine whether detection of circulating RCC cells could be useful as a biomarker. CpG methylation was investigated at 7 CpG sites in the MN/CA9 5' region. Clear mRNA signals were observed in 5 cell lines (SKRC-1, 6, 10, 44, 59), e.g., MN/CA9 positive. These 5 MN-positive cell lines showed hypomethylation in the 5' region. In contrast, all CpG sites were methylated in the remaining 2 lines and 3 normal kidney tissue samples. These results suggest that hypomethylation in the 5' region may play an important role in the expression of MN/CA9 in RCC. RT-PCR analysis of blood samples from RCC patients revealed the presence of circulating MN-positive cancer cells in the blood. Although a significant correlation with tumor stage and grade was not observed, the analysis of blood samples from patients with metastases resulted in a high detection rate of 82%. These findings suggest the usefulness of MN/CA IX as a potential diagnostic marker for detection of RCC.     

Application of PET-MRI registration techniques to cat brain imaging

In positron emission tomography (PET) studies of diseased animals, it is very useful to have accurate anatomical information as a reference. In human studies, anatomical information is usually obtained from magnetic resonance imaging (MRI) of the subject with retrospective registration of the subject's PET image to the MRI. A number of PET-MRI registration techniques are used for this purpose. However, the utility of these methods has not been tested for animals image registration. This paper studies the feasibility of applying two currently used human brain PET-MRI registration techniques to cat brain images. METHODS: Three cats were anesthetized with isoflurane gas, and PET images were acquired with H(2)(15)O, benzodiazepine receptor ligand 11C-flumazemil (FMZ), dopamine receptor ligand 11C-nemonapride (NEM) and fluorodeoxy glucose (18F-FDG). The four PET scans were acquired consecutively within the same day while the cat remained fixed in the scanner. We also obtained T1-weighted and T2-weighted MRI of the cats in a 4.7 T unit. The PET images were registered to MRI using two human brain registration techniques: a semi-automatic method (SAM), which is a two-step method based on the extraction of the midsagittal plane, and an automatic method (AMIR) method that minimizes PET pixel variance within spatially connected segments determined by MRI. RESULTS: T2-weighted MRI provided better structural information than T1 MRI. FMZ did, while FDG or H(2)O PET images did not, provide a structural outline of the brain. The FMZ PET image was registered to MRI satisfactorily using SAM. The striatum visualized in nemonapride PET image re-sliced with the same parameters matched the striatum identified in T2-weighted MRI. Registration by AMIR was successful by inspection for FMZ, FDG or H(2)O PET images in only one of the three cats. The registration error of SAM was estimated to be less than 2 mm or 2 degrees. CONCLUSION: A satisfactory registration of FMZ-PET to T2-weighted MRI of the cat brain was obtained by a two-step manual registration technique. This will enhance the usefulness of PET in the field of cerebral pathophysiology.     

Sevoflurane does not inhibit human platelet aggregation induced by thrombin

BACKGROUND: Sevoflurane reportedly inhibits adenosine diphosphate-induced platelet aggregation by suppressing thromboxane A2 formation. The increase in intracellular calcium concentration that fosters platelet aggregation, however, is also induced by other cell signaling pathways, such as activation of the production of inositol 1,4,5-triphosphate by thrombin. The current study aimed to clarify the net influence of sevoflurane on thrombin-induced platelet aggregation. METHODS: Washed platelets were stimulated by thrombin after incubation with 0.5, 1.0, or 1.5 mM sevoflurane, halothane, or isoflurane. Aggregation curves were measured by an aggregometer. Intracellular calcium concentration was measured fluorometrically using fura-2. Calcium mobilization via plasma membrane calcium channels and the dense tubular system was assessed differentially. Intracellular inositol 1,4,5-triphosphate was measured by radioimmunoassay. RESULTS: Halothane significantly suppressed aggregation ratios at 5 min compared with those in controls (89 +/- 7%) to 71 +/- 10% (1.0 mM) and 60 +/- 11% (1.5 mM) and the increase in intracellular calcium concentration (controls, 821 +/- 95 nM vs. 440 +/- 124 nM [1.0 mM] or 410 +/- 74 nM [1.5 mM]). Halothane also significantly inhibited release of calcium from the dense tubular system (controls, 220 +/- 48 nM vs. 142 +/- 31 nM [1.0 mM]). Neither sevoflurane nor isoflurane produced a net change in aggregation ratios, intracellular calcium concentration, or calcium mobilization. Halothane (1 mM) significantly suppressed inositol 1,4,5-triphosphate concentrations, whereas neither 1 mM isoflurane nor 1 mM sevoflurane had any effect. CONCLUSIONS: Although sevoflurane has been reported to inhibit human platelet aggregation induced by weak agonists such as adenosine diphosphate, it does not inhibit human platelet aggregation induced by strong agonists such as thrombin.     

Indocyanine green (TCG) clearance as a monitor to evaluate right heart function

Systemic venous return to the heart is disturbed as a result of right heart failure. ICG clearance is known to be influenced by hepatic venous return to the right atrium. Under a hypothesis that right heart function could be evaluated by ICG clearance test, patients with mitral valve disease (Group M, n = 29), aortic valve disease (Group A, n = 16), ischemic heart disease (Group CABG, n = 19) were studied. Preoperative K-ICG (normal range > 0.17) in the Group M was significantly lower than those in the Group A and Group CABG (0.097 +/- 0.037 vs 0.166 +/- 0.032 and 0.171 +/- 0.027, p < 0.05). In the Group M, patients who underwent tricuspid annuloplasty (TAP) had significantly lower K-ICG than the others (0.077 +/- 0.026 vs 0.113 +/- 0.038, p < 0.05). Postoperatively, K-ICG of TAP patients significantly increased (0.092 +/- 0.031, p < 0.05) when compared to their preoperative value. ICG clearance test was useful to quantify the right heart function, especially in the postoperative evaluation.     

A case of congenital cystic adenomatoid malformation of the lung in a 4-year-old child

A case of congenital cystic adenomatoid malformation (CCAM) of the lung is reported. A 3-year-old boy was admitted for elevation of infiltrative shadow in the right lower lung field on a chest X-ray. The clinical diagnosis was emphysematous bullae with inflammation. After 6 months, he had recurrent infected bullae, and was admitted. He received chemotherapy with antibiotics prior to the operation. Right lower lobectomy was performed on February 2, 1998. The resected lung was composed of multiple cysts with thin wall measuring 10-60 mm in diameter. The histological examination of specimen revealed CCAM (Stocker type I), which is rare in this age. The patient has been well for 16 months postoperatively.     

Label-free metabolic imaging of non-alcoholic-fatty-liver-disease (NAFLD) liver by volumetric dynamic optical coherence tomography

Label-free metabolic imaging of non-alcoholic fatty liver disease (NAFLD) mouse liver is demonstrated ex vivo by dynamic optical coherence tomography (OCT). The NAFLD mouse is a methionine choline-deficient (MCD)-diet model, and two mice fed the MCD diet for 1 and 2 weeks are involved in addition to a normal-diet mouse. The dynamic OCT is based on repeating raster scan and logarithmic intensity variance (LIV) analysis that enables volumetric metabolic imaging with a standard-speed (50,000 A-lines/s) OCT system. Metabolic domains associated with lipid droplet accumulation and inflammation are clearly visualized three-dimensionally. Particularly, the normal-diet liver exhibits highly metabolic vessel-like structures of peri-vascular hepatic zones. The 1-week MCD-diet liver shows ring-shaped highly metabolic structures formed with lipid droplets. The 2-week MCD-diet liver exhibits fragmented vessel-like structures associated with inflammation. These results imply that volumetric LIV imaging is useful for visualizing and assessing NAFLD abnormalities.