Glomerulonephritis after methicillin-resistant Staphylococcus aureus infection resulting in end-stage renal failure

A 58-year-old man developed proteinuria and renal dysfunction following pneumonia caused by methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin was administered, and prednisolone pulse therapy and plasmapheresis were performed. Subsequently, serum creatinine was decreased. Eight months later, creatinine and CRP were again elevated, and MRSA was detected. Vancomycin was again administered and plasmapheresis was performed. However, renal function was not improved and continuous hemodialysis was initiated. This case indicates that complete eradication of MRSA is necessary to treat MRSA-associated glomerulonephritis, and if this is not attained, a permanent loss of renal function occurs.

Renal metabolism of 3'-iodohippuryl N(epsilon)-maleoyl-L-lysine (HML)-conjugated Fab fragments

Renal localization of radiolabeled antibody fragments constitutes a problem in targeted imaging and radiotherapy. Recently, we reported use of a novel radioiodination reagent, 3'-[131I]iodohippuryl N(epsilon)-maleoyl-L-lysine (HML), that liberates m-iodohippuric acid before antibody fragments are incorporated into renal cells. In mice, HML-conjugated Fab demonstrated low renal radioactivity levels from early postinjection times. In this study, renal metabolism of HML-conjugated Fab fragments prepared by different thiolation chemistries and by direct radioiodination were investigated to determine the mechanisms responsible for the low renal radioactivity levels. Fab fragments were thiolated by 2-iminothiolane modification or by reduction of disulfide bonds in the Fab fragments, followed by conjugation with radioiodinated HML to prepare [131I]HML-IT-Fab and [125I]HML-Fab, respectively. In biodistribution studies in mice, both [131I]HML-IT-Fab and [125I]HML-Fab demonstrated significantly lower renal radioactivity levels than those of [125I]Fab. In subcellular distribution studies, [125I]Fab showed migration of radioactivity from the membrane to the lysosomal fraction of the renal cells from 10 to 30 min postinjection. On the other hand, the majority of the radioactivity was detected only in the membrane fraction at the same time points after injection of both [131I]HML-IT-Fab and [125I]HML-Fab. In metabolic studies, while [125I]Fab remained intact at 10 min postinjection, both HML-conjugated Fab fragments generated m-iodohippuric acid as a radiometabolite at the same postinjection time. [131I]HML-IT-Fab registered two radiometabolites (intact [131I]HML-IT-Fab and m-iodohippuric acid), whereas additional radiometabolites were observed with [125I]HML-Fab. This suggested that metabolism of both HML-conjugated Fab fragments would occur in the membrane fractions of the renal cells. The findings of this study reinforced our previous hypothesis that radiochemical design of antibody fragments that liberate radiometabolites that are excreted into the urine by the action of brush border enzymes would constitute a useful strategy to reduce renal radioactivity levels from early postinjection times.

3D-micro-MR angiography of mice using macromolecular MR contrast agents with polyamidoamine dendrimer core with reference to their pharmacokinetic properties

Four novel macromolecular MRI contrast agents, all of which had the same chemical composition but different molecular weights, were prepared using generation-3, -4, -5, and -6 polyamidoamine (PAMAM) dendrimers conjugated with a bifunctional diethylenetriaminepentaacetic acid derivative to change the blood retention, tissue perfusion, and excretion. Size-dependent changes in the pharmacokinetics were observed in the biodistribution study. (153)Gd-labeled generation-6 PAMAM-conjugates remained in the blood significantly longer than all of the other preparations (P < 0.001). The increase in blood-to-organ ratio of the preparations was found to correlate with increasing molecular size (P < 0.001). Additionally, 3D-micro MR images and angiography of mice of high quality and detail were obtained using PAMAM-(1B4M-Gd)x as a macro-molecular MRI contrast agent with a 1.5-T clinical MRI instrument. Numerous fine vessels of approximately 200 microm diameter were visualized on subtracted 3D-MR angiographms with G6D-(1B4M-Gd)(192). The quality of the images was sufficient to estimate the microvasculature of cancerous tissue for anti-angiogenesis therapy and to investigate knockout mice. Magn Reson Med 45:454-460, 2001.

Delayed (18)F-fluoro-2-deoxy-D-glucose positron emission tomography scan for differentiation between malignant and benign lesions in the pancreas

BACKGROUND

Positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D-glucose (FDG) has been used for the evaluation of various tumors, but accumulation in inflammatory lesions makes it a controversial modality. The aim of this study was to investigate the usefulness of delayed scanning in differentiation between malignant and benign lesions in the pancreas.

METHODS

Forty-seven patients with suspected pancreatic carcinoma were studied by FDG-PET. All patients received approximately 370 megabequerels of FDG after a transmission scan, and an emission scan was performed 1 hour and 2 hours later for all patients. A subset of 19 patients was also scanned at 3 hours postinjection. The standardized uptake value (SUV) was determined, and the retention index was calculated by dividing the increase in the SUV between 1 hour and 2 hours postinjection by the SUV at 1 hour postinjection.

RESULTS

Of 27 malignant lesions, the SUVs of 22 lesions increased at 2 hours postinjection, whereas the FDG uptake in 17 of 20 benign lesions decreased. The SUVs at 3 hours postinjection were higher than those at 2 hours postinjection in 9 of 14 malignant lesions and in 2 of 5 benign lesions. Malignant lesions showed a higher retention index than benign lesions (mean +/- standard deviation: 12. 36 +/- 13.37 and -7.05 +/- 17.28, respectively; P < 0.0001). Applying an SUV of 2.5 at 1 hour postinjection with the cut-off value for the differentiation between malignant and benign lesions caused one false negative result and seven false positive results, with a diagnostic accuracy of 83.0% (39 of 47 patients). However, combining the retention index with the SUV obtained at 2 hours postinjection provided a higher diagnostic accuracy (91.5%; 43 or 47 patients) than the SUV alone. The false negative rate remained constant when the retention index was taken into account. Images at 3 hours postinjection usually were unhelpful in differentiating further between malignant lesions and benign lesions.

CONCLUSIONS

The current data suggest that delayed FDG-PET scanning at 2 hours postinjection may contribute to differentiation between malignant and benign lesions in the pancreas.

Delayed (18)F-fluoro-2-deoxy-D-glucose positron emission tomography scan for differentiation between malignant and benign lesions in the pancreas

BACKGROUND

Positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D-glucose (FDG) has been used for the evaluation of various tumors, but accumulation in inflammatory lesions makes it a controversial modality. The aim of this study was to investigate the usefulness of delayed scanning in differentiation between malignant and benign lesions in the pancreas.

METHODS

Forty-seven patients with suspected pancreatic carcinoma were studied by FDG-PET. All patients received approximately 370 megabequerels of FDG after a transmission scan, and an emission scan was performed 1 hour and 2 hours later for all patients. A subset of 19 patients was also scanned at 3 hours postinjection. The standardized uptake value (SUV) was determined, and the retention index was calculated by dividing the increase in the SUV between 1 hour and 2 hours postinjection by the SUV at 1 hour postinjection.

RESULTS

Of 27 malignant lesions, the SUVs of 22 lesions increased at 2 hours postinjection, whereas the FDG uptake in 17 of 20 benign lesions decreased. The SUVs at 3 hours postinjection were higher than those at 2 hours postinjection in 9 of 14 malignant lesions and in 2 of 5 benign lesions. Malignant lesions showed a higher retention index than benign lesions (mean +/- standard deviation: 12. 36 +/- 13.37 and -7.05 +/- 17.28, respectively; P < 0.0001). Applying an SUV of 2.5 at 1 hour postinjection with the cut-off value for the differentiation between malignant and benign lesions caused one false negative result and seven false positive results, with a diagnostic accuracy of 83.0% (39 of 47 patients). However, combining the retention index with the SUV obtained at 2 hours postinjection provided a higher diagnostic accuracy (91.5%; 43 or 47 patients) than the SUV alone. The false negative rate remained constant when the retention index was taken into account. Images at 3 hours postinjection usually were unhelpful in differentiating further between malignant lesions and benign lesions.

CONCLUSIONS

The current data suggest that delayed FDG-PET scanning at 2 hours postinjection may contribute to differentiation between malignant and benign lesions in the pancreas.

FDG-PET of autoimmune-related pancreatitis: preliminary results

The purpose of this retrospective study was to elucidate the fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) findings in autoimmune-related pancreatitis (AIP), which is a reversible chronic pancreatitis with an autoimmune cause. The study group comprised six patients with clinically diagnosed AIP. After 370 MBq (10 mCi) of FDG had been injected intravenously, the abdomen and/or the whole body was scanned at 1 h post injection in all patients, and scanning was repeated at 2 h in four patients. PET findings were evaluated visually and/or semiquantitatively using the standardized uptake value (SUV). In four of the six patients, PET demonstrated intense uptake in the whole pancreas, which appeared swollen on computed tomography, and the accumulation increased with time in three patients. In one patient, intense focal uptake in the pancreatic head was observed, and the accumulation decreased over time. In the remaining patient, no abnormal accumulation in the pancreas was observed. Follow-up PET scanning after steroid therapy was performed in three patients, and intense FDG uptake was no longer observed. Our preliminary data show that AIP can cause intense FDG uptake in the pancreas. This fact, and the benign status of the condition, should be kept in mind when making a diagnosis with FDG-PET in patients with pancreatic disorders.

Establishment and characterization of a breast cancer cell line expressing Na+/I- symporters for radioiodide concentrator gene therapy

131I therapy is a widely accepted treatment for metastatic differentiated thyroid cancer. To investigate the feasibility of 131I therapy for breast cancer, we established breast cancer cells stably expressing Na-/I- symporter (NIS) gene that can be modulated and studied in vitro and in vivo.

METHODS

We transfected rat NIS genes into a human breast cancer cell line (MCF7) by electroporation. Iodide accumulation was evaluated under various extracellular concentrations of sodium and iodide, and iodide efflux was also assessed. Biodistribution and tumor imaging were studied using tumor-bearing mice.

RESULTS

A novel cell line (MCF3B), stably expressing the NIS gene, was established from MCF7. MCF3B took up 44 times more radioiodide in vitro than MCF7 did. Iodide uptake was completely inhibited by 1 mmol/L perchlorate and was dependent on external sodium and iodide concentrations. Iodide efflux from MCF3B cells was slower (half-life [T 1/2] > 27 min) than from FRTL5 thyroid cells (T 1/2 = 4 min). In the biodistribution study using MCF3B-xenografted mice, high tumor uptake of 125I was shown (16.73%) at 1 h after injection, and tumor-to-normal tissue ratios were also high (4.84-21.28), except in the stomach (0.47). However, the iodide accumulation in the tumor lessened with time, reaching less than 1% at 24 h after injection.

CONCLUSION

Our preliminary data indicate that NIS-based gene therapy may be applied by concentrating a lethal dose of radiation in tumor cells in vivo, but further investigation is necessary to determine a method of maintaining radioiodine in the cells to allow greater therapeutic effects.

[Histopathological study of the temporal bones in patients with primary carcinomas of the ear]

The most common symptoms of patients with carcinomas of the middle ear or mastoid are otorrhea, facial paralysis, and hearing loss, including a sensorineural element and vertigo. The latter two symptoms are indicators of inner ear damage. However, few reports have been made concerning the histopathological changes that occur in the inner ear in the presence of a tumor. The present study was performed to determine the pattern of tumor invasion in the inner ear and the histopathological changes that occur in the inner ear in cases of ear carcinomas. Temporal bone sections from five patients (age: #39-73 years; 3 males and 2 females) who died from a primary carcinoma of the ear were studied histologically. The following features were examined: 1) localization of the tumor in the temporal bone, 2) pattern of tumor invasion in the inner ear, 3) pathological changes in the inner ear, including the cochlea, vestibule and semicircular canals. Tumor cells were still present in the temporal bone sections of all the patients except one, even though the patients had received various treatments for the carcinoma, including radiation therapy, surgery and chemotherapy. Marked inflammatory and necrotic changes were observed in cases where the tumor had invaded the external auditory canal, middle ear cleft, internal auditory canal, and in some cases the inner ear. In cases where the tumor invaded the inner ear via the internal auditory canal rather than directly from the middle ear, the otic capsule is thought to have acted as a barrier against tumor invasion. In addition, marked degenerative changes throughout the entire inner ear structures were noted. These changes may have arisen from an attenuated blood supply to the inner ear as a result of pressure from the tumor in the internal auditory canal, tumor infiltration of the labyrinthine artery.

Monoclonal antibody-dendrimer conjugates enable radiolabeling of antibody with markedly high specific activity with minimal loss of immunoreactivity

For the purpose of radioimmunotherapy, labelling of monoclonal antibody with high specific activity is often necessary, especially when using a radionuclide with a shorter half-life. Polyamine dendrimers (PAMAM) are novel synthetic polymeric molecules with large numbers of amine residues on their spherical surface. In order to bind large numbers of radiometals to single antibody molecules, the generation-4 PAMAM (G4), which has 64 amines, was conjugated with 43 molecules of 2-(p-isothiocyanatobenzyl)-6-methyl-diethylene triamine penta-acetic acid (1B4M), a derivative of DTPA. This product [G4-(1B4M)43] was then conjugated with OST7, a murine monoclonal IgG1. We evaluated the achievable specific activity for 111In labeling, immunoreactivity, biodistribution, and tumor targeting in mice of the 111In- or 153Gd-OST7-G4-(1B4M)43 as compared with radiolabeled OST7-1B4M or 56C-1B4M. The maximum specific activity of 111In-OST7-G4-(1B4M)43 and 111In-OST7-1B4M was 470 and 8.7 GBq/mg (12,700 and 263 mCi/mg), respectively. Immunoreactivity of radiolabeled OST7-G4-(1B4M)43 and OST7-1B4M, as determined by the binding to KT005 cells expressing the antigen, was respectively 91% and 84% of that of 125I-labelled OST7. Biodistribution studies for preparations with maximum specific activity in normal mice 3 h after injection showed that 111In- or 153Gd-OST7-G4-(1B4M)43 cleared faster from the blood and accumulated more in the liver than did 111In- or 153Gd-OST7-1B4M. The dendrimer 1B4M [G4-(1B4M)64] itself showed similar saturation effects with metals. The radioactivity in all the other organs reflected the rapid clearance of radioactivity from the blood. 153Gd-OST7-G4-(1B4M)43 showed specific accumulation in the KT005 tumor. In conclusion, we could successfully bind 49 times as many metal atoms to an antibody molecule as is possible with conventional metal labeling for indium and gadolinium, and did so with minimal loss of immunoreactivity. When we achieved radiolabeling with maximum specific activity, Gd conjugate showed better biodistribution than In conjugate.

Deletion 7p in gastric MALT lymphoma

Deletion of the long arm of chromosome 7 has been related to loss of tumor suppressor genes which may constitute a primary step of carcinogenesis in many kinds of malignancies, including low-grade B-cell lymphoma. However, deletion of the short arm of chromosome 7, del(7p), in low-grade B-cell lymphoma has not been reported. Here, we report a case of gastric MALT lymphoma with the chromosome aberration del(7p) which progressed in spite of eradication of Helicobactor pylori. Deletion 7p may represent a new karyotypic change that is possibly related to autonomous growth of MALT lymphoma.

Avidin chase can reduce myelotoxicity associated with radioimmunotherapy of experimental liver micrometastases in mice

Myelotoxicity is the main factor which decides the maximum tolerated dose (MTD) in radioimmunotherapy (RIT). Since bone marrow is mostly irradiated from blood radioactivity, enhancing the clearance of unbound circulating radiolabeled antibody is important to reduce myelotoxicity and to increase the MTD. We applied the avidin chase method, which was devised to obtain high tumor-to-background ratios in tumor-targeting, to RIT of experimental liver micrometastases and evaluated its influence on the side effects and therapeutic outcome. Seven days after intrasplenic injection of human colon cancer LS174T cells, nude mice were intravenously injected with biotinylated (131)I-labeled anti-CEA monoclonal antibody (MAb) (24 - 38 microg, 11.1 MBq). Mice of the chase group then received an intravenous injection of avidin twice (24 and 30 h, 72 - 115 microg each). Biodistribution, side effects (white blood cell counts and body weight change), and short- and long-term therapeutic effects were determined. Avidin chase markedly accelerated the clearance of radiolabeled MAb from the blood (P < 0.0001) and normal tissues, resulting in milder leukocytopenia and body weight loss, both of which recovered earlier than in the non-chase group (P < 0.01). The tumor uptake of radiolabeled MAb was also decreased by avidin chase, but the metastases-to-background ratios were increased. Avidin chase gave the therapeutic gain ratio of 1.89. Treated groups with and without avidin chase showed significant therapeutic effects compared to the non-treated group. There was no significant difference in the therapeutic effects between the two treated groups. Avidin chase effectively reduced the side effects of RIT and should increase the MTD.

Anticonvulsant actions of nefiracetam on epileptic EL mice and their relation to peripheral-type benzodiazepine receptors

Anticonvulsant actions of the nootropic drug nefiracetam were studied using EL mice, an animal model of epilepsy, in which peripheral-type benzodiazepine receptors (PBRs) might be involved in their epileptogenesis. Nefiracetam, when administered orally t o EL mice, inhibited convulsions induced by the PBR agonist, Ro 5-4864, with an ED(50) of 17.2 mg/kg, whereas it did not inhibit the drug-induced convulsions in control DDY mice. When administered intravenously (i.v.) to DDY mice, nefiracetam and other piracetam-like nootropics inhibited the Ro 5-4864-induced convulsions in the sequence of nefiracetam>aniracetam>>oxiracetam, piracetam. Spontaneous EL mouse seizures were also inhibited by these nootropics with a similar rank order of potencies. Binding studies for PBRs, performed on crude membranes of brain tissues of these mice, revealed that [3H]Ro 5-4864 and [3H]PK 11195 bindings were both inhibited by micromolar concentrations of nootropic agents in the sequence of nefiracetam> aniracetam>>oxiracetam, piracetam. The results suggest that nefiracetam may exert an anticonvulsant action through interacting with a low-affinity type of PBR in the brain, and could be developed as a promising therapeutic drug for neurological disorders including epilepsies.

Extensive intraglomerular thrombi of monoclonal IgM-kappa in a patient with malignant lymphoma

We describe an 80-year-old man who developed malignant lymphoma (ML) complicated by extensive intraglomerular thrombi of immunoglobulin M (IgM)-kappa monoclonal immunoglobulin. The clinical picture was characterized by nephrotic syndrome and systemic lymphadenopathy. Laboratory examination showed mild anemia and a small amount of monoclonal IgM-kappa in the blood. The histopathologic findings and surface immunoglobulin analysis of the lymph node biopsy specimen were consistent with CD5-positive diffuse large B-cell (type, IgM-kappa) lymphoma. The subsequent renal biopsy showed a massive deposition of amorphous material in the glomerular capillary lumens, subendothelial areas, and mesangium. Nodular glomerulosclerosis was not found. An immunofluorescent study showed that the deposits consisted of IgM-kappa monoclonal immunoglobulin. Ultrastructurally, the deposits were composed of granular electron-dense material. Chemotherapy was effective for both the ML and nephrotic syndrome, and the patient's urine analysis results returned to normal. The histopathologic manifestations of this case are rare, and the pathogenesis of these glomerular lesions was obviously associated with ML.

Evaluation of pancreatic islet cell tumors by fluorine-18 fluorodeoxyglucose positron emission tomography: comparison with other modalities

PURPOSE

Pancreatic islet cell tumors are potentially malignant tumors and are often difficult to detect with current imaging modalities. Positron emission tomography (PET) using fluorine-18-labeled fluorodeoxyglucose (FDG) is an imaging technique with high sensitivity for malignant tumors. The aim of this study was to assess the feasibility of FDG PET to detect pancreatic islet cell tumors.

METHODS

Nineteen lesions of histologically proved islet cell tumors were evaluated in 12 patients (5 men, 7 women; ages 22 to 77 years). FDG uptake was analyzed semiquantitatively as a standardized uptake value. The diagnostic accuracy of PET was compared with that of US, CT, and MRI.

RESULTS

Of 19 lesions, 8 showed positive PET results (standardized uptake value > 2.3), and localization was indicated in 2 lesions. In nine tumors that were not detected by PET, seven were small tumors ranging from 1.5 to 8 mm in diameter and were not identified by other imaging methods. The sensitivity rate of PET was 53%, whereas those of US, CT, and MRI were 53%, 50%, and 53%, respectively.

CONCLUSION

Our data suggest that FDG PET has a limitation in that it does not detect some small-sized islet cell tumors, mainly depending on their size, but it has potential utility as a complementary modality for other imaging techniques.

[A case of collapsing variant of FSGS]

We report a case of collapsing variant of FSGS. An 82-year-old man without HIV-1 infection or a history of intravenous drug abuse was admitted to our hospital with the chief complaints of acute onset of generalized edema and loss of appetite. Laboratory findings were consistent with nephrotic syndrome. He developed acute renal insufficiency. Initially, we suspected minimal change nephrotic syndrome and started steroid pulse therapy but the nephrotic syndrome was refractory and a renal biopsy was performed. The pathologic findings were judged to be consistent with a collapsing variant of focal segmental glomerulosclerosis (FSGS). This form was described by Weiss et al. in 1986 as a clinically and pathologically distinct variant of FSGS. Valeri et al. further reported that the incidence of this idiopathic collapsing type of FSGS which is devoid of evidence of HIV-1 infection or intravenous drug abuse has progressively increased over the past two decades. They reported that cyclosporin is effective for the treatment of this type of FSGS with a remission rate of about 30%. The present case also had a nearly complete remission after 2 month-cyclosporin treatment. In Japan, no adult case of this type of FSGS has been reported according to our review of the literature.

A spectrum of clinicopathological features of nephropathy associated with POEMS syndrome

BACKGROUND

In POEMS syndrome, substantial involvement of the kidney can occur and is reflected by proteinuria, haematuria, renal dysfunction, and renal failure requiring dialysis therapy. The mechanism by which renal dysfunction is induced and progresses to end-stage renal disease remains obscure. A pathogenic role of cytokines and growth factors has recently been implicated.

METHODS

We reviewed cases of 52 Japanese patients with confirmed renal pathology who were reported in the literature, and personally analysed renal tissues from 22 subjects including nine patients of our own. Interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) were measured in our cases.

RESULTS

Despite relatively mild renal symptomatology, about half of the cases had azotaemia with creatinine levels above 1.5 mg/dl and the BUN/creatinine ratio markedly raised by volume contraction or wasting. One-tenth of patients were placed on haemodialysis because of advanced or end-stage renal disease. Bilateral and unilateral contracted kidneys were found in four and two cases respectively. Pathological analyses disclosed two major changes: glomerular alterations and endarteritis-like lesions of renal small arteries. The former included glomerular enlargement, cellular proliferation, mesangiolysis and marked swelling of endothelial-mesangial cells. This structural disorganization led to a reduction in renal function to some degree by impairing the glomerular circulation. Vasculopathy of the small artery probably resulted in progressive renal damage and ultimately to kidney contraction. Serum IL-6 was elevated in about 40% of cases. IL-6 levels were found to be high in the ascites of three patients who were examined. In different studies, an increased level of VEGF was found in the peripheral blood (75-100%; overall 92.3%), but no apparent correlation with glomerular alterations was observed.

CONCLUSION

POEMS nephropathy can be one cause of end-stage renal disease with variable intrarenal pathological changes of a microangiopathic nature which have differential influences on renal function. A pathogenic role for VEGF in POEMS syndrome appears to be likely, but its causal relation to the nephropathy awaits further investigation.

Evaluation of intraoperative radiation therapy for unresectable pancreatic cancer with FDG PET

This investigation was undertaken to evaluate 18F-labeled fluorodeoxyglucose (FDG) PET in monitoring patients after intraoperative radiotherapy (IORT) for unresectable pancreatic cancer and to compare its usefulness with CT.

METHODS

FDG PET was performed in 12 consecutive unresectable ductal adenocarcinoma patients before (n = 12) and after IORT (0.7-11.9 mo, n = 14). In the follow-up period, FDG PET results after IORT were divided into three groups: early (0-2.0 mo after IORT, n = 7), intermediate (2.1-4.0 mo, n = 5) and delayed period (4.1 mo or later, n = 2). FDG uptake at 60 min after injection of 185 MBq FDG under fasting conditions was analyzed with standardized uptake value (SUV). Three parameters, the highest SUV in the tumor, the area of tumor showing SUV of more than 2.0 and the average SUV in the tumor area were calculated. Ratios of each parameter after IORT to that before IORT were defined as residual uptake ratio (RUR)-1, -2 and -3, respectively. Tumor regression after IORT was evaluated with CT as tumor size ratio (TSR) every 2 mo.

RESULTS

Results of RUR-1 and -3 were consistent with tumor size measured by CT. They decreased in 10 patients with partial response and increased in 2 patients with no change, although these 2 patients had abscesses. RUR-3 decreased consistently as 0.65+/-0.33 in 2 mo, 0.51+/-0.39 in 4 mo and 0.24 in 4 mo or later after IORT, respectively. RUR-1 decreased in early period, but demonstrated no change through the remaining periods. There were discrepancies between the results of RUR-2 and those of the other RURs. CT results revealed a slow decrease in tumor size, because TSR was 0.91 +/-0.10, 0.76+/-0.11 and 0.70+/-0.18 in 2, 4 and 6 mo after IORT, respectively. RUR-3 was smaller than TSR at 2 mo (P < 0.05) and 4 mo (P = 0.056). These results indicate that the measurement of the average SUV in the tumor area with FDG PET could evaluate the local response of pancreatic cancer after IORT earlier and more markedly than with CT.

CONCLUSION

FDG PET was useful in monitoring patients after IORT, because the decrease of metabolism in pancreatic tumor could be detected earlier than the decrease in tumor size.

Asialoglycoprotein receptor scintigraphy in evaluation of auxiliary partial orthotopic liver transplantation

The purpose of this study was to evaluate asialoglycoprotein receptor scintigraphy in the post-transplant monitoring of liver graft and native liver functions in recipients of auxiliary partial orthotopic liver transplantation (APOLT) from living donors.

METHODS

We performed 36 asialoglycoprotein receptor scintigraphies on 13 patients who had undergone APOLT for noncirrhotic metabolic liver diseases or for small-for-size grafts. The portal vein of the native liver was separated in 12 patients. Anterior dynamic images including the heart and both livers were obtained for 16 min after intravenous injection of 99mTc-diethylenetriamine pentaacetic acid-galactosyl human serum albumin (GSA), and thereafter static SPECT images of both livers were obtained. Uptake rates from the blood to the graft and to the native liver were determined separately by Patlak plot graphical analysis. Relative uptake of GSA by the graft was calculated from transverse SPECT images. The relative volume of the graft liver was determined by CT.

RESULTS

The relative uptake of GSA by the graft was higher or increased more rapidly than the relative volume of the graft in 8 of 11 patients with no severe complications concerning the graft. The relative uptake by severely damaged graft liver in 2 patients was much lower than the relative volume. The uptake rate of GSA by the graft was low in these 2 patients. The uptake rate by the native liver decreased when the portal vein was separated.

CONCLUSION

The relative uptake of GSA was a better indicator of graft liver function than was anatomic volume. The uptake rate provided additional independent information of each liver. Asialoglycoprotein receptor scintigraphy is useful for distinguishing and monitoring the graft and native liver functions in patients who had undergone APOLT.

Electrophysiological studies on the mechanism for enhanced intestinal transport of water-soluble compounds by antibiotic peptide bacitracin

Bacitracin is an antibacterial cyclic dodecapeptide produced by Bacillus licheniformin. Besides antibacterial activity, it is reported to have a protease inhibitory activity and an absorption enhancing action. Here we determined the effects of bacitracin on transport of water-soluble dye fluoresceinisothiocyanate (FITC)-dextran across the rat intestinal mucosal membrane using an electrophysiological technique. Bacitracin enhanced the intestinal mucosal-to-serosal transport of FITC-dextran in concentration-dependent and pH-dependent manners. In particular, the addition of bacitracin to the mucosal side led to a remarkable enhancement of FITC-dextran transport across the colonic membrane. Furthermore, its exhibition of transport enhancement required the existence of metal divalent cations, Ca2+ and Mg2+, in the mucosal compartment. Electrophysiological study using voltage-clamp technique revealed that a relatively lower concentration of bacitracin (5 mM) enhanced the transport of 6-carboxyfluorescein via a paracellular pathway in the colonic membrane and higher concentration of bacitracin (20 mM) affects both transcellular and paracellular routes, resulting in significant enhancement of 6-carboxyfluorescein across the colonic membrane. These findings might provide the useful information for enhancing the intestinal transport of poorly absorbable drugs by bacitracin which has multiple functions.

Radioimmunotherapy of human glioma xenografts in nude mice by indium-111 labelled internalising monoclonal antibody

The potential of 111Indium (111In)-labelled internalising anti-integrin alpha 3 antibody GA17 in the radioimmunotherapy of human glioblastoma xenografts in nude mice was investigated. A radioisotope retention assay showed a rapid release of radioiodine from the glioblastoma cells after the binding of 125I-GA17, whilst 111In-GA17 was retained in the cells for a longer time period. The glioblastoma xenografts showed a high and prolonged uptake of 111In-GA17, and tumour uptake of 125I-GA17 was lower and decreased with time. In the mice which received two injections of 18.5 MBq of 111In-GA17, the growth of the subcutaneous tumour was significantly suppressed compared with the untreated group and mice injected with an 111In-labelled control antibody. These results indicate that GA17 was internalized into the glioblastoma cells and that 111In was retained within the cancer cells. The injection of a high-dose of 111In-GA17 can suppress the growth of tumour xenografts in nude mice.

Inhibition of peripheral blood lymphocyte apoptosis by soluble fas ligand in patients with hepatocellular carcinoma

We monitored apoptosis of peripheral blood lymphocytes (PBL) obtained from patients with various degrees of chronic viral hepatitis, including hepatocellular carcinoma (HCC), in vitro and quantitated the serum levels of soluble Fas ligand (FasL) by ELISA. There was no difference in mean percent PBL mortality. However, in HCC patients, the variance was significantly high (P<0.05), and, unexpectedly, a negative association was found between the PBL mortality and the serum soluble FasL levels (P=0.035). These results suggest the inhibitory effect of serum soluble FasL on apoptosis of PBL, which may explain the induction of immunological abnormalities with the development of HCC.

Simultaneous determination of ephedrine, pseudoephedrine, norephedrine and methylephedrine in Kampo medicines by high-performance liquid chromatography

A simultaneous high-performance liquid chromatographic method for the determination of ephedrine, pseudoephedrine, norephedrine and methylephedrine (ephedrine alkaloids) in Kampo medicines which contain Ephedrae Herba was established. The analysis can be accomplished within 25 min with a Wakosil-II 5C18 HG column by isocratic elution using a mixture of water, acetonitrile and sodium dodecyl sulfate (65:35:0.4) as the mobile phase at a flow-rate of 1.0 ml min(-1), and detection at 210 nm. The detection limits of ephedrine alkaloids are 0.37-1.06 microM per injection (5 microl). This method was applied to analyze the quantities in eight Kampo decoctions; Mao-to, Makyo-yokukan-to, Makyo-kanseki-to, Yokuinin-to, Sho-seiryu-to, Keima-kakuhan-to, Kakkon-to and Kakkon-to-ka-senkyu-sin'i. The concentration (per Ephedrae Herba gram) of ephedrine alkaloids was higher in the Makyo-kanseki-to decoction than in the others. Calcium sulfate from Gypsum Fibrosum raised ephedrine alkaloids dissolution in the Makyo-kanseki-to decoction.

A novel immunoscintigraphy technique using metabolizable linker with angiotensin II treatment

Immunoscintigraphy is a tumour imaging technique that can have specificity, but high background radioactivity makes it difficult to obtain tumour imaging soon after the injection of radioconjugate. The aim of this study is to see whether clear tumour images can be obtained soon after injection of a radiolabelled reagent using a new linker with antibody fragments (Fab), in conditions of induced hypertension in mice. Fab fragments of a murine monoclonal antibody against human osteosarcoma were labelled with radioiodinated 3′-iodohippuryl N-ɛ-maleoyl-L-lysine (HML) and were injected intravenously to tumour-bearing mice. Angiotensin II was administered for 4 h before and for 1 h after the injection of radiolabelled Fab. Kidney uptake of ¹²⁵I-labelled-HML-Fab was much lower than that of ¹²⁵I-labelled-Fab radioiodinated by the chloramine-T method, and the radioactivity of tumour was increased approximately two-fold by angiotensin II treatment at 3 h after injection, indicating high tumour-to-normal tissue ratios. A clear tumour image was obtained with ¹³¹I-labelled-HML-Fab at 3 h post-injection. The use of HML as a radiolabelling reagent, combined with angiotensin II treatment, efficiently improved tumour targeting and enabled the imaging of tumours. These results suggest the feasibility of PET scan using antibody fragment labelled with ¹⁸F-fluorine substitute for radioiodine. © 1999 Cancer Research Campaign

Intratumoral distribution of radiolabeled antibody and radioimmunotherapy in experimental liver metastases model of nude mouse

The biodistribution and intratumoral distribution of radiolabeled anticarcinoembryonic antigen (CEA) monoclonal antibody in experimental liver metastases and the therapeutic effect of 131I-labeled anti-CEA antibody on the metastases were studied.

METHODS

Three weeks after an intrasplenic injection of human colon cancer cells, mice received an intravenous injection of 125I- or 111In-labeled anti-CEA antibody F33-104. The biodistribution and tumor penetration of radiolabeled antibody were examined by using quantitative autoradiography. To evaluate the therapeutic effect, 5.55, 9.25 or 11.1 MBq (150, 250 or 300 microCi) 131I-labeled F33-104 were injected into groups of mice that had micrometastases smaller than 1 mm. Control groups were injected with phosphate-buffered saline or 131I-labeled control antibody. Mice were killed 3 wk later to determine the size of liver metastases.

RESULTS

1251-labeled F33-104 showed a high accumulation in the liver metastases (percentage of injected dose per gram of metastases [%ID/g] >24%, metastasis-to-liver ratio >9.8, metastasis-to-blood ratio >2.1); however, its accumulation was heterogeneous or peripheral in the nodules more than 1 mm in diameter. When the antibody dose was increased, antibody penetration was improved, but tumor uptake of radioactivity and specificity ratios decreased. In mice with large metastases, radioactivity in the normal tissue was lower than that in mice with small metastases, resulting in higher metastasis-to-background ratios. 111In-labeled antibody showed even higher tumor uptake than 125I-labeled antibody (>51 %ID/g). Metastases formation was suppressed in a dose-dependent manner by 131I-labeled F33-104 injection (5 of 8 mice had no macroscopic tumor after an injection of 5.55 MBq (150 microCi), and all mice had no visible metastasis after an injection of 9.25 or 11.1 MBq [250 or 300 microCi]), whereas tumor progression was seen in the control groups.

CONCLUSION

Liver metastases had easy accessibility to the antibody. Micrometastases of less than 0.5 mm in diameter showed homogeneous intratumoral distribution of injected antibody and were successfully treated with 131I-labeled antibody. Very high uptake and satisfactory metastasis-to-liver ratios with 111In-labeled antibody suggest that the use of a radiometal with high beta-energy, such as 90Y or 188Re, is preferable for the successful radioimmunotherapy of metastases larger than 1 mm.