Induction of tumor regression by passive transfer of antibody from mice vaccinated with anti-idiotype antibodies resembling a human renal cell carcinoma-associated antigen

We have shown that six different internal image antiidiotype antibodies (Ab2) raised against the combining site of the murine monoclonal antibody G250 (MAbG250; Abl), which specifically reacts with a human renal cell carcinoma (RCC)-associated antigen, induce antigen specific humoral and cellular responses in mice. These six Ab2 can be divided into four mutually exclusive groups: (1) NUH31 and NUH51, (2) NUH44 and NUH82, (3) NUH71, and (4) NUH91. Immunization with NUH82 or NUH91 resulted in Ab3 sera that gave complete protection against tumor challenge. In this study, we tested the antitumor efficacy of NUH82- and NUH91-induced mouse sera (Ab3 sera; Ab3-82 and Ab3-91) in mice with established subcutaneous human RCC xenografts. Mice were treated 3 times per week by intraperitoneal injection of Ab3 sera (0.2 ml) or MAbG250 (250 μg) for 6 weeks. Treatment of NU12 human RCC xenografts of approximately 20 mm(3) expressed as tumor size index (TSI) with NUH-Ab3 sera or MAbG250 resulted in significant tumor growth inhibition compared with tumors treated with Ab3 sera from mice immunized with control immunoglobulin (Ab3-MOPC). In all Ab3-NUH treated mice, tumors stabilized or disappeared completely. In contrast, Ab3-MOPC treatment did not result in any antitumor effects. Tumor remnants in Ab3-NUH treated animals contained viable tumor cells surrounded by infiltrating mouse cells, whereas no infiltration was observed in control tumors. These findings demonstrate that Ab3 sera obtained from NUH82- or NUH91-immunized mice are very effective in eradicating established RCC [i.e., Ab2 vaccination may be able to eradicate (minimal) residual disease in RCC patients].     

Pupillary responses in normal subjects following auditory stimulation

To clarify pupillary responses of humans following auditory stimuli, we studied both eyes of 61 normal subjects using a computed pupillograph. Unilateral auditory stimulation elicited pupillary dilatation in all cases. Pupillary responses were classified according to duration as being either “long” or “short”. The duration of dilatation was 1530±320 ms (mean±SD) in the longlasting group (n=45) and 850±250 ms in the short-lasting group (n=16). The latency time for dilatation was 460±80 ms. Both eyes of each subject showed the same response. Two drops of 10% guanethidine, a sympathetic blocking agent, were applied to one eye of 3 subjects. Although the early phase of dilatation was barely affected, the late phase was inhibited, as seen in long-lasting dilatation. The short-lasting response was unaffected. We conclude that the long-lasting response consists of an early pupillary dilatation due to inhibition of parasympathetic nervous activity and a late dilatation due to excitation of sympathetic activity. The short-lasting response is produced only by inhibition of the parasympathetic component.     

Post-traumatic pituitary apoplexy--two case reports

A 60-year-old female and a 66-year-old male presented with post-traumatic pituitary apoplexy associated with clinically asymptomatic pituitary macroadenoma manifesting as severe visual disturbance that had not developed immediately after the head injury. Skull radiography showed a unilateral linear occipital fracture. Magnetic resonance imaging revealed pituitary tumor with dumbbell-shaped suprasellar extension and fresh intratumoral hemorrhage. Transsphenoidal surgery was performed in the first patient, and the visual disturbance subsided. Decompressive craniectomy was performed in the second patient to treat brain contusion and part of the tumor was removed to decompress the optic nerves. The mechanism of post-traumatic pituitary apoplexy may occur as follows. The intrasellar part of the tumor is fixed by the bony structure forming the sella, and the suprasellar part is free to move, so a rotational force acting on the occipital region on one side will create a shearing strain between the intra- and suprasellar part of the tumor, resulting in pituitary apoplexy. Recovery of visual function, no matter how severely impaired, can be expected if an emergency operation is performed to decompress the optic nerves. Transsphenoidal surgery is the most advantageous procedure, as even partial removal of the tumor may be adequate to decompress the optic nerves in the acute stage. Staged transsphenoidal surgery is indicated to achieve total removal later.     

Purification and Partial Characterization of an Indomethacin Hydrolyzing Enzyme from Pig Liver

Purpose. Indomethacin is well known to be metabolized via O-demethylation and N-deacylation. In this paper we found an enzyme involved in the hydrolysis of amide-linkage of indomethacin and partially characterized it as well as its substrate specificity. Methods. An indomethacin hydrolyzing enzyme was purified to homogeneity from pig liver microsomes using columns of Q-Sepharose, Red-Sepharose and Blue-Sepharose. The enzyme activity was assayed by measuring of -chlorobenzoic acid liberated from indomethacin by HPLC. Results. The purified enzyme effectively hydrolyzed the amide linkage in indomethacin but not those in -naphthylacetate and -nitrophenylacetate, which are typical substrates for carboxylesterase. The subunit molecular mass of the enzyme was 65 kDa according SDS-polyacrylamide gel electrophoresis. The Michaelis constant (Km) and maximum velocity (Vmax) values for indomethacin were 67.8 µM and 9.02 nmol/min/mg protein, respectively. The amino acid sequence analysis of the enzyme after cyanogen bromide cleavage showed high homology with a mouse carboxylesterase isozyme designated as ES-male. The activity of indomethacin hydrolysis was relatively high in the pig, rabbit and human liver homogenate, but not in those from rat and mouse. On the other hand, purified human liver carboxylesterases pl 5.3 and 4.5, and pig liver carboxylesterases have no catalytic activity for indomethacin. Conclusions. These results indicate that the hydrolysis of amide-linkage of indomethacin in humans would be associated with an enzyme similar to the indomethacin hydrolyzing enzyme from pig liver microsomes described here.     

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.