Oil blotting paper for formalin fixation increases endoscopic ultrasound-guided tissue acquisition-collected sample volumes on glass slides

OBJECTIVES

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is used for pathological diagnosis and obtaining samples for molecular testing, facilitating the initiation of targeted therapies in patients with pancreatic cancer. However, samples obtained via EUS-TA are often insufficient, requiring more efforts to improve sampling adequacy for molecular testing. Therefore, this study investigated the use of oil blotting paper for formalin fixation of samples obtained via EUS-TA.

METHODS

This prospective study enrolled 42 patients who underwent EUS-TA for pancreatic cancer between September 2020 and February 2022 at the Osaka International Cancer Institute. After a portion of each sample obtained via EUS-TA was separated for routine histological evaluation, the residual samples were divided into filter paper and oil blotting paper groups for analysis. Accordingly, filter paper and oil blotting paper were used for the formalin fixation process. The total tissue, nuclear, and cytoplasm areas of each sample were quantitatively evaluated using virtual slides, and the specimen volume and histological diagnosis of each sample were evaluated by an expert pathologist.

RESULTS

All cases were cytologically diagnosed as adenocarcinoma. The area ratios of the total tissue, nuclear, and cytoplasmic portions were significantly larger in the oil blotting paper group than in the filter paper group. The frequency of cases with large amount of tumor cells was significantly higher in the oil blotting paper group (33.3%) than in the filter paper group (11.9%) (p = 0.035).

CONCLUSIONS

Oil blotting paper can increase the sample volume obtained via EUS-TA on glass slides and improve sampling adequacy for molecular testing.

Immunoreactivity of TTF-1, GATA-3, CEA, and p16/Ki67 cocktail in Cellprep®-processed control samples: Comparison of long-term storage in vials and slides

INTRODUCTION

Cellprep® (CP) is a novel liquid-based cytology (LBC) system. This study aimed to assess the immunoreactivity of control samples stored long-term under two storage conditions using CP.

METHODS

The immunoreactivity in control samples was evaluated under two sample storage conditions: CP vial storage at room temperature (RT: 20-25°C) and CP slide storage in a refrigerator (2-6°C). Clinical samples as controls (total: positive/negative) were immunostained using thyroid transcription factor-1 (TTF-1) (20: 14/6), GATA binding protein 3 (GATA-3) (13: 10/3), carcinoembryonic antigen (CEA) (23: 15/8), and the p16/Ki67 cocktail (20: 12/8) markers. The first immunocytochemistry (ICC) was performed within 1 month using CP vials stored at RT. Samples stored in CP vials and on CP slides were used for the second (within 3-6 months) and third (within 6-11 months) ICCs. Compared with the first ICC, the concordance of immunoreactivity for the second and third ICCs was evaluated using the weighted kappa coefficient.

RESULTS

For TTF-1, CEA, and the p16/Ki67 cocktail markers, ICC controls had stable immunoreactivity for a minimum of 6 months when samples were stored in CP vials (kappa coefficients >0.8), whereas for GATA-3, they were for 3 months. On CP slides, only for the p16/Ki67 cocktail, ICC controls had stable immunoreactivity for at least 3 months (kappa coefficient >0.8).

CONCLUSION

Clinical samples as ICC controls revealed consistently more stable immunoreactivity in CP vials than on CP slides for TTF-1, GATA-3, CEA, and the p16/Ki67 cocktail markers.

Utility of needle biopsy in centrally located lung cancer for genome analysis: a retrospective cohort study

BACKGROUND

It is essential to collect a sufficient amount of tumor tissue for successful next-generation sequencing (NGS) analysis. In this study, we investigated the clinical risk factors for avoiding re-biopsy for NGS analysis (re-genome biopsy) in cases where a sufficient amount of tumor tissue could not be collected by bronchoscopy.

METHODS

We investigated the association between clinical factors and the risk of re-genome biopsy in patients who underwent transbronchial biopsy (TBB) or endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and required re-genome biopsy in cases enrolled in LC-SCRUM Asia, a prospective nationwide genome screening project in Japan. We also examined whether the frequency of re-genome biopsy decreased between the first and second halves of the enrolment period.

RESULTS

Of the 572 eligible patients, 236 underwent TBB, and 134 underwent EBUS-TBNA. Twenty-four TBBs required re-genome biopsy, and multivariate analysis showed that the risk of re-genome biopsy was significantly increased in lesions where the tumor lesion was centrally located. In these cases, EBUS-TBNA should be utilized even if the lesion is a pulmonary lesion. However, it should be noted that even with EBUS-TBNA, lung field lesions are at a higher risk of re-canalization than mediastinal lymph node lesions. It was also found that even when tumor cells were detected in rapid on-site evaluation, a sufficient amount of tumor tissue was not always collected.

CONCLUSIONS

For centrally located pulmonary mass lesions, EBUS-TBNA, rather than TBB, can be used to obtain tumor tissues that can be analyzed by NGS.

Sensitivity of cytology in liver tumor biopsy and its significance in the prompt clinical diagnosis of non-hepatocellular carcinoma

BACKGROUND

Cytology is a fast and simple modality for identifying malignancies and tumor histology. In this study, we analyzed the sensitivity of cytology for liver tumor biopsy and evaluated its potential for prompt clinical diagnosis.

METHODS

This retrospective study included patients who had concurrently undergone conventional cytology, on-site cytology, and histopathology for ultrasound-guided liver tumor biopsies. In the case of malignant tumors, malignancy was first diagnosed, then preliminary clinical diagnosis was established using histology based on cytology and clinical information, followed by histopathological diagnosis. Sensitivity of malignancy detection was evaluated by comparison with histopathological diagnosis.

RESULTS

Of the 191 tumors, 164 (85.9%) were malignant. The sensitivity of conventional cytology for malignancy detection was 97.6%. The sensitivity of non-hepatocellular carcinoma (non-HCC) (99.3%) detection was higher than that of the HCCs (87.5%; p = 0.001). The sensitivity of on-site cytology for malignancy detection was as high as that of conventional cytology. Similar to conventional cytology, the sensitivity of on-site cytology for non-HCC detection (99.3%) was higher than that for HCCs (79.2%; p < 0.001). In most cases of non-HCC tumors (126/140, 90.0%), accurate preliminary clinical diagnoses were obtained by combining on-site cytology with clinical information.

CONCLUSION

Cytology of liver tumor biopsy has high sensitivity for malignancy, especially in non-HCC tumors. On-site cytology can contribute to the prompt clinical diagnosis of non-HCC tumors when combined with clinical information. This approach may be a reassuring modality for patients with severely advanced cancers requiring prompt clinical diagnosis and quick initiation of treatment owing to their deteriorating health.

Usefulness of on-site cytology of liver tumor biopsy in specimen sampling for cancer genomic profiling test

AIM

Appropriate sample selection with a tumor fraction ≥20% without necrosis contamination is required for successful cancer genomic profiling (CGP). Rapid on-site evaluation (ROSE) is performed to assess adequate sampling.

METHOD

This retrospective study included 54 patients who underwent CGP using liver tumor biopsy specimen with ROSE.

RESULT

The sampling success rate (98.1%) was higher than the previously reported 77.5%-88.9%. ROSE was performed once in 51 patients and twice in three patients; for those undergoing ROSE twice, the first ROSE was negative for malignancy, or showed few tumor cells with necrotic cell contamination, while the second ROSE obtained from another location showed abundant malignant cells. In these patients, the CGP was successful using the second specimen, though the first sample did not meet the required criteria for CGP test.

CONCLUSION

Performing ROSE during liver tumor biopsy may be useful for CGP test sampling because ROSE prevents sampling errors and contributes to adequate sampling.

Boring biopsy with rapid on-site evaluation for gastric gastrointestinal stromal tumor: A pilot study

One of 4 patients (25%) and 2 of 3 patients (67%) were correctly diagnosed by conventional and hot boring biopsies, respectively. The median procedure time of conventional and hot boring biopsies was 21 (range, 13-33) and 17 (range, 16-23) min, respectively. Rapid on-site evaluation was performed totally 12 times in 7 patients. The positive and negative predictive values of rapid on-site evaluation for gastrointestinal stromal tumor were 0.5 (0.12-0.88) and 1.0 (0.42-1.00), respectively.

Utility of p16/Ki67 double immunocytochemistry for detection of cervical adenocarcinoma

BACKGROUND

Although the incidence of cervical adenocarcinoma has consistently increased, especially among young women, there is no established best means for screening. This study evaluated the screening efficacy of CINtec PLUS (CINtec; p16/Ki67 double immunocytochemistry) expression in cervical glandular cells.

METHODS

Cervical cytology was examined using abnormal glandular cells. The CINtec status of 100 samples with corresponding surgically resected specimens and 11 samples that exhibited negative results for intraepithelial lesion or malignancy at follow-up was analyzed. Additionally, 31 negative samples containing benign glandular cells were included.

RESULTS

Of the 142 samples, CINtec status was diffusely positive in 74, focally positive in 24, and negative in 44. The 74 diffusely positive samples included 70 adenocarcinomas (62 cervical, seven uterine, and one ovarian) and four cases of high-grade cervical intraepithelial neoplasia. The 24 focally positive samples included 15 adenocarcinomas (seven cervical, seven uterine, and one fallopian tube) and nine without malignancy. The 44 negative samples included nine adenocarcinomas (five uterine and four cervical) and 35 without malignancy. The sensitivity, specificity, positive predictive value, and negative predictive value of the CINtec diffusely or focally positive cases for cervical adenocarcinomas were 94.5%, 58.0%, 70.4%, and 90.9%, respectively. In CINtec diffusely positive cases, the respective values were 84.9%, 82.6%, 83.8%, and 83.8%, and in women aged ≤39 years the values were 90.6%, 89.5%, 93.5%, and 85.0%, respectively.

CONCLUSIONS

CINtec may support efficient detection of cervical adenocarcinomas.

Conventional Direct Smear Yields Diagnostic Indicators of Gastric-Type Mucinous Carcinoma Compared with Cytomorphological Features Identified by Liquid-Based Cervical Cytology

INTRODUCTION

Gastric-type mucinous carcinoma (GAS) of the uterine cervix is an adenocarcinoma subtype with a gastric phenotype that poses diagnostic pitfalls in cervical screening cytology because of its blunt morphologic atypia and the limited utility of human papillomavirus testing and ancillary immunochemical staining. Despite the recent widespread uptake of liquid-based cytology (LBC) systems, the cytomorphological features of GAS in LBC samples and the differential features between GAS and usual-type endocervical adenocarcinoma (UEA) remain unclear.

METHODS

Eight GAS cases, all of which were surgically treated following histological confirmation, were examined. Direct Papanicolaou-stained smears and LBC samples were reviewed and compared with 10 UEA cases as controls. Featured cytomorphological findings were as follows: background (mucinous, inflammatory, or necrotic), cell crowding (size of neoplastic cell clusters), cytoplasm (golden mucin and cell border), and nuclei (nuclear chromatin and nucleoli).

RESULTS

Of 18 adenocarcinomas, 16 were detected against a non-mucinous background in LBC samples, most of which were accompanied by mild to moderate inflammation. Clusters comprising >300 neoplastic cells were identified in both GAS and UEA in conventional smears (CSs), while no LBC samples harboured clusters as large as these. Cell borders of GAS were more distinct than those of UEA in CSs (p < 0.001), although fewer populations of neoplastic clusters revealed distinct cell borders in both GAS and UEA in LBC samples. Three of 8 and 2 of 8 GAS cases had golden mucin in CSs and in LBC samples, respectively, which was not detected in UEA at all. Nucleoli against fine nuclear chromatin were more pronounced in GAS than in UEA on CS (p = 0.03), although the difference between GAS and UEA was not apparent in LBC samples.

DISCUSSION/CONCLUSION

This study demonstrated that the diagnostic clues to detect GAS using the conventional approach, namely distinct cell borders and prominent nucleoli, are not useful for excluding UEA in LBC samples. Conventional cervical smears may indicate a diagnosis of GAS; however, specific high-risk HPV detection approaches, such as HPV test or immunocytochemical p16/Ki-67 dual staining, are desirable to differentiate GAS from UEA in the setting of LBC with ambiguous cytomorphological features.

Detection of pagetoid urothelial intraepithelial neoplasia extending to the vagina by cervical screening cytology: a case report with renewed immunochemical summary

Background

Pagetoid spread of urothelial carcinoma (UC) to the lower genital tract is quite a rare and diagnostically challenging condition. Pagetoid urothelial intraepithelial neoplasia extending to the vagina is difficult to diagnose, especially in remote recurrences without symptomatic or macroscopic lesions typical to Paget disease. However, its identification by cervical screening cytology is important because UC is often characterized by a long history of relapse.

Case presentation

A 68-year-old Japanese postmenopausal woman developed brown vaginal discharge after radical cystectomy for bladder cancer (high-grade UC, pT2a pN0 cM0 [Union for International Cancer Control, 8th edition]) concomitant with focal in-situ UC in the urethra. She had a history of left renal pelvis UC, which was surgically removed 9 months before the radical cystectomy. Gynecologic examination of the lower genital tract was unremarkable although cervical screening cytology demonstrated severely atypical cells with pleomorphism repeatedly. Cervical colposcopy and diagnostic conization revealed no cervical neoplasm. In retrospect, immunocytochemical p16/Ki-67 dual staining for the previous cervical screening was negative for p16 labeling, and the neoplastic cells were positive for cytokeratins 7 and 20, p63, and GATA binding protein 3. No high-risk human papillomavirus genotype was identified by an automated DNA chip system using liquid-based cytology samples. Eleven months post-cystectomy, punch biopsy of the vulva and vagina confirmed intraepithelial UC in the juxtaposed squamous epithelium with pagetoid spread demonstrating positivity for specific urothelial markers: uroplakins II and III and thrombomodulin. Concurrent invasive malignancy was ruled out, and CO₂ laser vaporization of the vulvar and vaginal lesion was performed. The patient remained alive without evidence of invasive malignancy for 14 months after the radical cystectomy for bladder cancer.

Conclusions

To detect recurrent pagetoid urothelial intraepithelial neoplasia with pagetoid spread in the lower genital tract, pathologists should recognize the history of prior UC with special attention to absence of p16 labeling in cervical cytology as a pointer to the diagnosis of urothelial cancer. Using further biopsy and immunohistochemical confirmation of UC relapse, investigation to rule out invasive malignancies and careful follow-up throughout the patient’s lifetime is recommended.

Evaluation of preoperative positron emission tomography with computed tomography (PET-CT) for detecting lymph node metastasis in gynecologic carcinoma

5593

Background: To evaluate the sensitivety, specificity, and accuracy of PET-CT for detecting lymph node metastasis in gynecologic carcinoma. Methods: Between May 2007 to August 2008, 36 consecutive patients (pts) with cervical carcinoma, endometrial carcinoma and epithelial ovarian carcinoma were enrolled. All pts underwent PET-CT prior to the surgery of systematic pelvic and paraaortic lymphadenectomy. For pathological metastatic lymph nodes, the size of intranodal tumor deposits (maximum diameter of metastatic foci in each lymph node) were recorded. Results: The total number of pelvic lymph nodes (PLNs) plus paraaortic lymph nodes (PANs) removed was 2426. The median number of removed lymph nodes (LNs) was 67 each pts (range: 25 to 102). The number of involvement LNs was 79 (3.5%). The sensitivity, specificity and accuracy of preoperative PET-CT to detect LN metastasis were 24%, 99.9%, and 97.5%, respectively. The sensitivity of PLNs and PANs were 39.5% and 7.3%, respectively. The sensitivity of squamous cell carcinoma (SCC) were 35.7%, that of adenocarcinoma were 8.1%. FDG-PET detected 100% of intranodal tumor deposits > or =10 mm, whereas tumor deposits smaller than 5 mm were not detected. Conclusions: The results of our study revealed 76% underdiagnosis (overlooking) in evaluation of preoperative PET-CT in LN metastasis. Particularly, tumor deposits smaller than 5 mm were not detected at all. Using PET-CT for detecting small LN metastasis in gynecologic carcinoma may be unreliable so far. However we found that PLNs are comparatively easy to be detected than PANs, and SCC are comparatively easy to be detected than adenocarcinoma. The improved usability and application of PET-CT for detecting LN metastasis in gynecologic carcinoma have to keep researching constructively.

No significant financial relationships to disclose.

Pulmonary clearance of aerosolized 99mTc-DTPA in sarcoidosis I patients

AIM

Sarcoidosis frequently affects the lungs of patients. Pulmonary clearance scintigraphy with Technetium-99m-diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) aerosol may assess pulmonary involvement of sarcoidosis patients. The study investigated early pulmonary involvement of sarcoidosis I patients by assessing the pulmonary clearance of inhaled (99m)Tc-DTPA aerosol and the character of pulmonary clearance though systemic steroid therapy.

METHODS

The pulmonary clearance of (99m)Tc-DTPA aerosol was investigated in 24 patients with suspected stage I sarcoidosis and 20 non-smoking healthy controls over 18 months. The radiological finding was evaluated by chest computed radiography (CR) and high resolution computed tomography (HRCT) and the histological diagnosis was performed by transbronchial lung biopsy and/or Scalen node biopsy. The sarcoidosis I patients with ocular involvement underwent 1 year-systemic steroid therapy and were followed up over totally 18 months.

RESULTS

The histological diagnosis was proved in 13 out of the 24 patients that had no lung filed involvement on CR and HRCT. Accelerated pulmonary clearance of (99m)Tc-DTPA was observed in 10 out of the 13 sarcoidosis I patients. Nine out of 13 sarcoidosis I patients underwent systemic steroid therapy due to ocular involvement and the accelerated pulmonary clearance responded to therapy and improved in all of the 9 over 18 months.

CONCLUSIONS

Acceleration of (99m)Tc-DTPA pulmonary clearance may be observed in sarcoidosis I patients and the acceleration will respond to systemic steroid therapy. Pulmonary clearance scintigraphy with (99m)Tc-DTPA aerosol may be useful for assessing pulmonary involvement before radiological changes emerge and sarcoidosis I patients with accelerated pulmonary clearance may undergo systemic steroid treatment.

Comparison of patient doses in 256-slice CT and 16-slice CT scanners

The 256-slice CT-scanner has been developed at the National Institute of Radiological Sciences. Nominal beam width was 128 mm in the longitudinal direction. When scanning continuously at the same position to obtain four-dimensional (4D) images, the effective dose is increased in proportion to the scan time. Our purpose in this work was to measure the dose for the 256-slice CT, to compare it with that of the 16-slice CT-scanner, and to make a preliminary assessment of dose for dynamic 3D imaging (volumetric cine imaging). Our group reported previously that the phantom length and integration range for dosimetry needed to be at least 300 mm to represent more than 90% of the line integral dose with the beam width between 20 mm and 138 mm. In order to obtain good estimates of the dose, we measured the line-integral dose over a 300 mm range in PMMA (polymethylmethacrylate) phantoms of 160 mm or 320 mm diameter and 300 mm length. Doses for both CT systems were compared for a clinical protocol. The results showed that the 256-slice CT generates a smaller dose than the 16-slice CT in all examinations. For volumetric cine imaging, we found an acceptable scan time would be 6 s to 11 s, depending on examinations, if dose must be limited to the same values as routine examinations with a conventional multidetector CT. Finally, we discussed the studies necessary to make full use of volumetric cine imaging.

Effect of calcium trisodium DTPA in rats with puncture wound contaminated by 90Y-chloride

The efficacy of diethylenetriaminepentaacetate calcium trisodium (CaNa(3)DTPA) in a dose of 34.7 micromol kg(-1) as a function of its route of administration was investigated in rats with a puncture wound contaminated by (90)Y-chloride at a concentration of 2.55 MBq kg(-1). Approximately 60% of (90)Y-chloride at a puncture wound was absorbed into the body of rats over 72 h post-puncture and radioactivity in femoral bone increased during the timed-release of (90)Y. Intravenous administration of CaNa(3)DTPA (systemic treatment) at 15 min post-puncture reduced (90)Y at a puncture wound and in bone up to 75.6 and 84.3% of controls, respectively. Direct infiltration of CaNa(3)DTPA into a puncture wound site (local treatment) at 15 min post-puncture diminished radioactivity at the puncture wound and in bone up to 34.9 and 52.5% of controls, respectively. Thus, prompt local treatment may be effective for removing (90)Y from a puncture wound and minimising (90)Y-distribution to bone compared with systemic treatment.

The amygdala and Alzheimer's disease: positron emission tomographic study of the cholinergic system

The primary transmitter deficit is cholinergic in Alzheimer's disease (AD), and the amygdala receives a major cholinergic projection from the nucleus basalis of Meynert (Ch4), which may play an important role in the retention of affective conditioning and/or memory consolidation. We measured brain acetylcholinesterase (AChE) activity in 54 patients with AD and in 22 normal controls by positron emission tomography and N-[(11)C]methylpiperidin-4-yl acetate to characterize the cholinergic pathology in AD. The k(3) values were calculated as an index of AChE activity in a three-compartment model analysis using the metabolite-corrected arterial input function. The k(3) values were highly significantly reduced by 20% in the cerebral neocortex (P <0.0001 in the two-tailed t test), 14% in the hippocampus (P <0.001), and 33% in the amygdala (P <0.0001) in AD patients compared with normal controls. The k(3) values were significantly correlated with the Mini-Mental State Examination scores in both the cerebral cortex (P <0.001) and the amygdala (P <0.05) in AD patients, supporting the cholinergic hypothesis of cognitive dysfuncion in AD. Further studies are required, however, to elucidate the specific role of the cholinergic deficit in the amygdala in the emotional and behavioral symptoms in AD.

11C-choline PET for the detection of bone and soft tissue tumours in comparison with FDG PET

We assessed and compared the usefulness of C-choline positron emission tomography (PET) with that of 2-[ F]fluoro-2-deoxy-D-glucose (FDG) PET for the differentiation between benign and malignant bone and soft tissue tumours. A total of 43 patients with 45 lesions were included. C-choline PET and FDG PET were performed from 5 and 40 min, respectively, after injection of 275-370 MBq tracer. PET data were evaluated by using the standardized uptake value (SUV) and were analysed according to the pathological data. C-choline uptake in malignancies was 4.9+/-2.1 (n=14), which was significantly higher than that in benign lesions (2.5+/-1.7, n=31) (P <0.0001). The sensitivity, specificity and accuracy of C-choline PET were 100%, 64.5% and 75.6%, respectively, when 2.59 of the SUV was used as the cut-off value. The FDG uptake in malignancies was 5.1+/-4.2 (n=14) and was also significantly larger than that in benign lesions 2.9+/-2.9 (n=31) (P<0.003). The sensitivity, specificity and accuracy of FDG PET were 85.7%, 41.9% and 55.6%, respectively (cut-off=1.83). The C-choline uptake in the lesions correlated with FDG uptake ( r=0.61, P<0.003). In receiver operating characteristic (ROC) analysis, the area under the ROC curve for C-choline PET (area=0.847) was higher than that for FDG PET (area=0.717). This study showed that C-choline PET was superior to FDG PET in differentiation between malignant and benign lesion in bone and soft tissue tumours. C-choline PET might be useful as a screening method for malignant bone and soft tissue tumours.

Distinctly abnormal brain metabolism in late-onset ornithine transcarbamylase deficiency

OBJECTIVE

To assess alterations in brain metabolites in patients with late-onset ornithine transcarbamylase deficiency (OTCD).

METHODS

Six unrelated, asymptomatic Japanese late-onset OTCD patients were analyzed by proton MRS ((1)HMRS) using a point-resolved spectroscopy technique (repetition and echo times, 5000 and 30 ms). Localized spectra for the centrum semiovale were acquired and absolute metabolite concentrations were calculated using an LCModel.

RESULTS

Compared with age-matched controls, N-acetylaspartate and creatine concentrations were normal in all patients. The glutamine (Gln) plus glutamate concentration was increased in four patients, which progressed in proportion to the clinical stage. myo-inositol (mI) could not be detected in five symptomatic patients. A decreased choline (Cho) concentration was detected in two clinically severe patients. (1)HMRS after liver transplantation in one patient revealed the normalization of all metabolites.

CONCLUSION

These findings suggest progression of neurochemical events in OTCD, i.e., mI depletion and Gln accumulation followed by Cho depletion, which is reverse of that in hepatic encephalopathy, i.e., Cho depletion followed by mI depletion and Gln accumulation.

Oncological diagnosis using positron coincidence gamma camera with fluorodeoxyglucose in comparison with dedicated PET

The purpose of this study was to compare the utility of a dual-head positron coincidence detection gamma camera (PCD) with that of dedicated positron emission tomography (PET) in the imaging of various malignancies using (18)F-fluorodeoxyglucose (FDG). 25 patients with known or suspected malignancies at various sites underwent imaging with both methods, and diagnostic performance on a lesion basis was compared. Tumour lesions were analyzed visually and semi-quantitatively using the ratio of tumour-to-background counts (T/B ratio). FDG PCD and FDG PET visually detected 34 (72.3%) lesions and 37 (78.7%) lesions, respectively. The mean T/B ratio and standard deviation (SD) of FDG PCD was 3.5+/-3.3, significantly lower than that of FDG PET (8.4+/-7.1, p<0.001). When tumour lesions were less than 2.0 cm in diameter, the sensitivity of FDG PCD was 37.5%, significantly inferior to that of FDG PET (50.0%, p<0.01). Sensitivity between FDG PCD and FDG PET in lesions of more than 2.0 cm diameter showed no statistically significant difference. This study indicates that FDG imaging with a dual-head coincidence detection gamma camera can provide suitable diagnostic performance for lesions greater than 2.0 cm diameter, but performed significantly worse than dedicated PET for lesions smaller than this.

Brain N-acetylaspartate is elevated in Pelizaeus-Merzbacher disease with PLP1 duplication

OBJECTIVE

To assess alterations in brain metabolites of patients with Pelizaeus-Merzbacher disease (PMD) with the proteolipid protein gene 1 (PLP1) duplications using quantitative proton MRS.

METHODS

Five unrelated male Japanese patients with PMD with PLP1 duplications were analyzed using automated proton brain examination with the point resolved spectroscopy technique (repetition and echo time of 5,000 and 30 msec). Localized spectra in the posterior portion of the centrum semiovale were acquired, and absolute metabolite concentrations were calculated using the LCModel.

RESULTS

Absolute concentrations of N-acetylaspartate (NAA), creatine (Cr), and myoinositol (MI) were increased by 16% (p < 0.01), 43% (p < 0.001), and 31% (p < 0.01) in patients with PMD as compared with age-matched controls. There was no statistical difference in choline concentration.

CONCLUSION

The increased concentration of NAA, which could not be detected by previous relative quantitation methods, suggests two possibilities: axonal involvement secondary to dysmyelination, or increased cell population of oligodendrocyte progenitors. Elevated Cr and MI concentrations may reflect the reactive astrocytic gliosis. Our study thus emphasizes the importance of absolute quantitation of metabolites to investigate the disease mechanism of the dysmyelinating disorders of the CNS.

Epidemiological study on improving the QOL and oral conditions of the aged--Part 2: Relationship between tooth loss and lifestyle factors for adults men

Oral health in early- and mid-adulthood is essential for the improvement of one's QOL, this study was investigated to include an epidemiological analysis of the relationship between tooth loss and life style, such as smoking, regular exercise, and the food habits of approximately 2,000 employees. Compared with the group with mild or no periodontal disease (CPI of 0, 1, or 2), the frequency of tooth loss in the group with advanced periodontal disease (CPI of 4) was 2.00 times (odds ratio, 2.00; 95% confidence limit, 1.37 to 2.93). The probability of tooth loss showed statistical significance in relation to smoking, alcohol drinking, and frequency of meals. Compared with non-smokers, the probability that current smokers will lose teeth is 1.53 times greater (odds ratio, 1.53; 95% confidence limit, 1.20 to 1.96). It was concluded that periodontal disease and smoking must be averted for preventing tooth loss.

Epidemiological study on improving the QOL and oral conditions of the aged--Part 1: The relationship between the status of tooth preservation and QOL

In part 1 of this epidemiological study, a survey was conducted for all senior citizens aged 70 and over who resided in a mountainous village in the mid-section of Hyogo Prefecture. It focused on the relationship among the number of existing teeth, life environment, health status, and activities of daily living; and the correlation between oral status and QOL was analyzed. The daily activities of individuals were compared between those having one or more teeth and others who were totally edentulous. Subsequently, it was found that for both males and females, the odds ratio was significantly high for the dentulous individuals, in comparison with edentulous individuals, to exhibit a behavior indicative of a better QOL (such as "opportunity for conversation with family members or others)", "regular physical activities", and "attend meetings or group outings"). The result of this survey indicates that the presence of teeth is very closely related to one's daily activities. It was concluded that preventing tooth loss is vital for maintaining the masticatory function; so to prevent tooth loss, periodontal disease must be averted.

Kinetic analysis of [(11)C]MP4A using a high-radioactivity brain region that represents an integrated input function for measurement of cerebral acetylcholinesterase activity without arterial blood sampling

N -[(11)C]methylpiperidin-4-yl acetate ([(11)C]MP4A) is an acetylcholine analog. It has been used successfully for the quantitative measurement of acetylcholinesterase (AChE) activity in the human brain with positron emission tomography (PET). [(11)C]MP4A is specifically hydrolyzed by AChE in the brain to a hydrophilic metabolite, which is irreversibly trapped locally in the brain. The authors propose a new method of kinetic analysis of brain AChE activity by PET without arterial blood sampling, that is, reference tissue-based linear least squares (RLS) analysis. In this method, cerebellum or striatum is used as a reference tissue. These regions, because of their high AChE activity, act as a biologic integrator of plasma input function during PET scanning, when regional metabolic rates of [(11)C]MP4A through AChE (k(3); an AChE index) are calculated by using Blomqvist's linear least squares analysis. Computer simulation studies showed that RLS analysis yielded k(3) with almost the same accuracy as the standard nonlinear least squares (NLS) analysis in brain regions with low (such as neocortex and hippocampus) and moderately high (thalamus) k(3) values. The authors then applied these methods to [(11) C]MP4A PET data in 12 healthy subjects and 26 patients with Alzheimer disease (AD) using the cerebellum as the reference region. There was a highly significant linear correlation in regional k(3) estimates between RLS and NLS analyses (456 cerebral regions, [RLS k(3) ] = 0.98 x [NLS k(3) ], r = 0.92, P < 0.001). Significant reductions were observed in k(3) estimates of frontal, temporal, parietal, occipital, and sensorimotor cerebral neocortices (P < 0.001, single-tailed t-test), and hippocampus (P = 0.012) in patients with AD as compared with controls when using RLS analysis. Mean reductions (19.6%) in these 6 regions by RLS were almost the same as those by NLS analysis (20.5%). The sensitivity of RLS analysis for detecting cortical regions with abnormally low k 3 in the 26 patients with AD (138 of 312 regions, 44%) was somewhat less than NLS analysis (52%), but was greater than shape analysis (33%), another method of [(11)C]MP4A kinetic analysis without blood sampling. The authors conclude that RLS analysis is practical and useful for routine analysis of clinical [(11)C]MP4A studies.

Long-term assessment of posttransplant renal prognosis with 31 P magnetic resonance spectroscopy

BACKGROUND

31P-magnetic resonance spectroscopy (MRS) has been widely used to study pretransplantation renal viability, and although some had discussed posttransplant renal viability, no one has examined long-term posttransplant renal prognosis. We discuss the use of 31P-MRS to assess the long-term prognosis from the time when MRS was performed.

METHODS

We studied 20 patients with renal allografts. 1.5 Tesla clinical magnetic resonance imaging (MRI) and 15 cm surface coil was used for 31P-MRS. Localized 31P-MRS was done using image selected in vivo spectroscopy (ISIS) method. Individual peaks were fitted by Lorenzian line-shapes with a least square method and peak area ratios were calculated.

RESULTS

A beta-adenosine triphosphate/inorganic phosphate (beta-ATP/Pi) ratio >1.2 had sensitivity of 92.8%, specificity of 100%, and accuracy of 95% for predicting 3-year renal survival; a beta-ATP/Pi ratio >1.2 had sensitivity of 90.9%, specificity of 66.7%, and accuracy of 76.9% for predicting 5-year renal survival. We compared 31P-MRS spectra data between the survived group and failed group. The survived group had significantly higher beta-ATP/Pi, alpha-ATP/Pi, and phosphodiester (PDE)/Pi ratios than the failed group.

CONCLUSIONS

We discussed the beta-ATP/Pi value as a parameter for predicting long-term survival of a transplanted kidney from the time when MRS was performed. A value above 1.2 suggests a high probability of 3-year renal survival, whereas a value over 2.5 indicates that the transplanted kidney could survive over 5 years. 31P-MRS may be useful for predicting long-term survival of transplanted kidneys, but additional studies are needed.

Age-related reduction of extrastriatal dopamine D2 receptor measured by PET

Although the aging effect of dopamine D2 receptor in the striatum is well-documented, the effect of age on the extrastriatal dopamine D2 receptor has not been fully examined. Since the density of extrastriatal dopamine D2 receptor is very low, suitable ligands are limited. In this study, we used [11C]FLB 457 to quantify the extrastriatal dopamine D2 receptor in the living human brain. Twenty-seven healthy male subjects aged from 21 to 82 years participated in the positron emission tomography study. Extrastriatal [11C]FLB 457 binding was quantified with a reference tissue model using cerebellum as a reference region. Binding potentials corresponding to Bmax/Kd were used to evaluate age-related change. We found age-related decreases of D2 receptor binding in all measured extrastriatal regions. The decrease of D2 receptor binding was 13.8% per decade in frontal cortex, 12.0% in temporal cortex, 13.4% in parietal cortex, 12.4% in occipital cortex, 12.2% in hippocampus, and 4.8% in thalamus. These findings suggest that the amounts of D2 receptor declines in all brain regions as part of the normal aging process.

Positron emission tomographic measurement of brain acetylcholinesterase activity using N-[(11)C]methylpiperidin-4-yl acetate without arterial blood sampling: methodology of shape analysis and its diagnostic power for Alzheimer's disease

N-[11C]methylpiperidin-4-yl acetate ([11C]MP4A) is a radiotracer that has been used successfully for the quantitative measurement of acetylcholinesterase (AChE) activity in the human brain with positron emission tomography (PET) using a standard compartment model analysis and a metabolite-corrected arterial input function. In the current study, the authors evaluated the applicability of a simple kinetic analysis without blood sampling, namely shape analysis. First, the authors used computer simulations to analyze factors that affect the precision and bias of shape analysis, then optimized the shape analysis procedure for [11C]MP4A. Before shape analysis execution, the later part of dynamic PET data except for the initial 3 minutes were smoothed by fitting to a bi-exponential function followed by linear interpolation of 8 data points between each of adjacent scan frames. Simulations showed that shape analysis yielded estimates of regional metabolic rates of [11C]MP4A by AChE (k3) with acceptable precision and bias in brain regions with low k3 values such as neocortex. Estimates in regions with higher k3 values became progressively more inaccurate. The authors then applied the method to [11C]MP4A PET data in 10 healthy subjects and 20 patients with Alzheimer's disease (AD). There was a highly significant linear correlation in regional k3 estimates between shape and compartment analyses (300 neocortical regions, [shape k3] = 0.93 x [NLS k3], r = 0.89, P < 0.001). Significant reductions in k3 estimates of frontal, temporal, parietal, occipital, and sensorimotor cerebral cortices in patients with AD as compared with controls were observed when using shape analysis (P < 0.013, two-tailed t-test), although these reductions (17% to 20%) were somewhat less than those obtained by compartment analysis (22% to 27%). The sensitivity of shape analysis for detecting neocortical regions with abnormally low k3 in the 20 patients with AD (92 out of 200 regions, 46%) also was somewhat less than compartment analysis (136 out of 200 regions, 68%). However, taking its simplicity and noninvasiveness into account, the authors conclude that quantitative measurement of neocortical AChE activity with shape analysis and [11C]MP4A PET is practical and useful for clinical diagnosis of AD.

Effect of donepezil on brain acetylcholinesterase activity in patients with AD measured by PET

Acetylcholinesterase (AChE) activities in the brain of three patients with AD were measured once before and once during donepezil treatment (5 mg/d in two patients, 3 mg/d in one patient) using PET and N-[11C]methylpiperidin-4-yl acetate. Donepezil reduced k(3) values, an index of AChE activity, in the cerebral cortex by 39 +/- 5%. All patients showed some degree of symptomatic improvement, and it was concluded that this improvement was likely caused by improved cholinergic activity by inhibition of AChE in the brain.

Dose relationship of limbic-cortical D2-dopamine receptor occupancy with risperidone

RATIONALE

It has been suggested that the antipsychotic effect of antipsychotics is mediated by the antagonism of the dopamine D2 receptor in the limbic-cortical regions. Risperidone has an atypical property, but its effect on limbic-cortical regions has not been evaluated.

OBJECTIVES

In this study, we examined the relationship among doses of risperidone and limbic-cortical dopamine D2 receptor occupancy using positron emission tomography.

METHODS

Seven patients with schizophrenia were scanned during the steady state with risperidone. Their occupancies in limbic-cortical regions were determined using positron emission tomography with [11C]FLB 457.

RESULTS

The average occupancy ranged from 38% to 80% on doses of 1-6 mg/day. The saturation curve plotted against the drug level fit the data well.

CONCLUSIONS

Our results demonstrate that the D2 receptor occupancy with risperidone in the limbic-cortical regions seems to be similar to that of previous reports regarding the striatum, and it would be comparable to that of typical antipsychotics.

Trihalomethane removal by activated carbon fiber

For the safety of drinking water, trihalomethanes are removed by adsorption onto activated carbon fiber from single-component solutions. The amounts adsorbed onto adsorbents with large surface area and/or pore volume were small. Stronger surface hydrophobicity of adsorbent was correlated with a larger amount of trihalomethanes adsorbed. A trihalomethane with bromine was adsorbed to a greater extent than that with chlorine. The differences in the amounts adsorbed among trihalomethanes can be explained by the polarity of trihalomethane molecules. The amount of trihalomethanes adsorbed was mainly dominated by the strength of hydrophobicity of activated carbon fibers.

Adenosine-induced coronary flow reserve in Watanabe heritable hyperlipidemic rabbits

The Watanabe heritable hyperlipidemic (WHHL) rabbit develops coronary atherosclerosis and hypercholesterolemia because of a genetic deficiency of low-density lipoprotein receptors and is therefore a good animal model for studying the relationships of coronary atherosclerosis, hypercholesterolemia and coronary flow reserve. The aim of the present study was to assess myocardial perfusion at baseline and during adenosine infusion (0.2 mg x kg(-1) x min(-1)) in 8 WHHL rabbits (13.8+/-0.5 months) with 13N-ammonia, small-animal positron emission tomography (PET) and colored microspheres. Results were compared with those from 6 age-matched Japanese white rabbits. Plaque distribution was also examined in the extramural coronary arteries. All 8 WHHL rabbits had coronary plaques, with 6 showing multiple plaques. Mean global myocardial blood flow (ml x min(-1) x g(-1)) did not differ significantly between control and WHHL groups both at baseline (3.67+/-0.72 vs 4.26+/-1.12 ml x min(-1) x g(-1), p=NS) and with adenosine (7.92+/-2.00 vs 9.27+/-2.91 ml x min(-1) x g(-1), p=NS), nor did coronary flow reserve (2.16+/-0.37 vs 2.18+/-0.41, p=NS). None showed evidence of regional perfusion abnormalities by visual and semiquantitative analyses of PET images. It was concluded that WHHL rabbits preserve adenosine-induced coronary flow reserve despite coronary atherosclerosis and hypercholesterolemia, suggesting that a compensatory mechanism develops in this animal model.

Tumor uptake of radioiodinated anti-human pulmonary surfactant-associated protein monoclonal antibody PE10 in nude mice bearing human pulmonary adenocarcinoma in combination with an unlabeled preload

This study assessed the potential use of radioimmunoscintigraphy of pulmonary alveolar Type II cells tumor with the radiolabeled anti-human surfactant-associated protein (SP) monoclonal antibody (MAb) PE 10 in combination with preloads of unlabeled MAb. The in vitro binding of iodine-125 ((125)I)-labeled MAb PE 10 (1 microg), which had a specific radioactivity of 400 MBq/mg, on human pulmonary papillary adenocarcinoma NCI-H441 cells that produced SP was investigated. In NCI-H441 tumor-bearing nude mice, the tumor uptake of (125)I-MAb PE 10 (5 microg) was examined in combination with preloads of unlabeled MAb PE 10 (0, 5, 10, and 50 microg). An isotype-matched unassociated murine MAb was used as a control both in vitro and in vivo. (125)I-MAb PE 10 showed specific cell binding compared with (125)I-control MAb. Tumor uptake of (125)I-MAb PE 10 in vivo reached a peak of 4.97+/-0.33% injected dose per gram (%ID/g) at 48 h postinjection. Preloads of 5 and 10 microg unlabeled MAb PE 10 significantly enhanced tumor uptake at 48 h postinjection ( 5.94+/-0.29% ID/g and 5.72+/-0.29% ID/g, respectively), whereas preload of 50 microg unlabeled MAb PE 10 significantly decreased tumor uptake ( 2.75+/-0.32% ID/g) at 48 h. Preload of 5 microg unlabeled MAb PE 10 significantly increased the tumor-to-blood radioactivity ratio at 48 h ( 2.39+/-0.16). Preloads of unlabeled control MAb did not cause any significant change in tumor uptake. Immunohistochemistry showed the intracellular and pericellular patterns of SP expression in tumor cells. In conclusion, radioimmunoscintigraphy with MAb PE 10 labeled with a gamma-emitting radioiodine such as (123)I might be a useful means of targeting pulmonary alveolar Type II tumor cells in combination with preloading with an optimal dose of the unlabeled MAb.

Brain acetylcholinesterase activity in Alzheimer disease measured by positron emission tomography

Brain acetylcholinesterase activity was measured in 14 patients with Alzheimer disease and 14 age-matched control subjects by positron emission tomography with a radioactive acetylcholine analogue. Kinetic analysis was performed to calculate k3, an index of acetylcholinesterase activity. The k3 values were significantly reduced in the neocortex, hippocampus, and amygdala of all patients with Alzheimer disease, suggesting a loss of cholinergic innervation from the basal forebrain. Most profound reductions of k3 values were observed in the temporal (-30%) and parietal cortices (-31%), although reductions of k3 values were relatively uniform in the cerebral neocortex. This technique may be a powerful tool for early diagnosis of Alzheimer disease and also for therapeutic monitoring of acetylcholinesterase inhibitors in Alzheimer disease.

Characteristics of Nonafluorobutyl Methyl Ether (NFE) Adsorption onto Activated Carbon Fibers and Different-Size-Activated Carbon Particles

The characteristics of adsorption of 1,1,1,2,2,3,3,4,4-nonafluorobutyl methyl ether (NFE), a chlorofluorocarbon (CFC) replacement, onto six different activated carbon; preparations (three activated carbon fibers and three different-sized activated carbon particles) were investigated to evaluate the interaction between activated carbon surfaces and NFE. The amount of NFE adsorbed onto the three activated carbon fibers increased with increasing specific surface area and pore volume. The amount of NFE adsorbed onto the three different-sized-activated carbon particles increased with an increase in the particle diameter of the granular activated carbon. The differential heat of the NFE adsorption onto three activated carbon fibers depended on the porosity structure of the activated carbon fibers. The adsorption rate of NFE was also investigated in order to evaluate the efficiency of NFE recovery by the activated carbon surface. The Sameshima equation was used to obtain the isotherms of NFE adsorption onto the activated carbon fibers and different-sized-activated carbon particles. The rate constant k for NFE adsorption onto activated carbon fibers was larger for increased specific surface area and pore volume. The rate of NFE adsorption on activated carbons of three different particle sizes decreased with increasing particle diameter at a low initial pressure. The adsorption isotherms of NFE for the six activated carbons conformed to the Dubinin-Radushkevich equation; the constants BE(0) (the affinity between adsorbate and adsorbent) and W(0) (the adsorption capacity) were calculated. These results indicated that the interaction between the activated carbon and NFE was larger with the smaller specific surface area of the activated carbon fibers and with the smaller particle diameter of the different-sized-activated carbon particles. The degree of packing of NFE in the pores of the activated carbon fibers was greater than that in the pores of the granular activated carbons. Copyright 2000 Academic Press.

Progressive loss of cortical acetylcholinesterase activity in association with cognitive decline in Alzheimer's disease: a positron emission tomography study

We measured brain acetylcholinesterase activity in 30 patients with Alzheimer's disease (AD) and 14 age-matched controls by positron emission tomography (PET) and using a carbon 11-labeled acetylcholine analogue. Seven AD patients had repeat PET scans. The k3 values were calculated as an index of acetylcholinesterase activity in a three-compartment analysis using the metabolite corrected arterial input function. Twenty-eight of the 30 AD patients (14 each in the early and late onset subgroups) were retained in the study so as to equalize the range and average severity of cognitive impairment within the early and late onset subgroups. The k3 values were significantly reduced in the neocortex, hippocampus, and amygdala in the early onset AD patients, although the k3 values were significantly reduced only in the temporoparietal cortex and amygdala in the late onset AD patients. In the longitudinal study, all 7 repeat AD patients showed further reduction of cortical k3 values in the second PET scans, with a mean interval of 2 years, suggesting a progressive loss of the ascending cholinergic system from the nucleus basalis of Meynert in AD. In 37 AD patients, there was a highly significant correlation between the cortical k3 values and Mini-Mental State Examination scores, supporting the cholinergic hypothesis in AD.

[A cross-sectional study on the relationship of plasma fibrinogen concentration and age, physical fitness, lifestyle and health examinations of healthy Japanese males]

The intention of this study was to examine the determinants of plasma fibrinogen concentrations in healthy Japanese male workers. A cross-sectional study was conducted in 1998 among 1,044 (male 975, female 69) employees aged 30-59 years in Osaka, Japan. The overall mean value of plasma fibrinogen concentration was 236.4 +/- 47.6 mg/dl. There was a dose-response relationship between cigarette smoking and plasma fibrinogen concentration. Plasma fibrinogen concentration was associated with age, body weight, body mass index, white blood cell count and CPITN score, and inversely associated with serum HDL cholesterol in male nonsmokers. Plasma fibrinogen was not related to physical exercise, alcohol consumption or dietary factors. This study confirms the relationship of known coronary risk factors to plasma fibrinogen concentration in Japanese male factory workers, and suggests that smoking and periodontal disease are related to plasma fibrinogen concentrations.

Activity of platelet-activating-factor-acetylhydrolase and the nitric oxide metabolite level in the plasma of pregnant women who develop transient hypertension during later pregnancy

It is reported that plasma platelet-activating-factor-acetylhydrolase (PAF-AH) is elevated in patients with essential hypertension. In this study, plasma PAF-AH activity was measured during pregnancy and after delivery to examine the relationship between plasma PAF-AH activity and the development of transient hypertension (TH) during pregnancy. Moreover, in order to examine the involvement of endothelial injury in TH, the plasma level of nitric oxide metabolite (NOx; NO2+NO3) was measured. The plasma PAF-AH activity in 51 pregnant women was consecutively measured in the 1st, 2nd and 3rd trimesters of gestation, and after delivery. Forty-one cases were normal pregnancies and 10 cases were complicated by TH later during pregnancy. The PAF-AH activity in the normal pregnancy group decreased in the 2nd trimester of gestation compared with the 1st trimester, but was elevated in the TH group. The incidence of elevation of PAF-AH in the TH group was significantly (7/10; 70.0%; P<0.01, Chi-squared test) higher than in the normal pregnancy group (9/41; 22.0%). The plasma NOx levels in the 2nd trimester were higher than those in the 1st trimester in both the normotensive and TH group (P<0.05 for both comparisons). The 51 patients were classified into two groups according to the change in the PAF-AH in the 2nd trimester: group A consisted of 35 patients whose PAF-AH activity did not increase, and group B consisted of 16 patients whose PAF-AH activity increased. The incidence of development of TH during later pregnancy in group B was significantly (7/16; 43.8%; P<0.01, Chi-squared test) higher than in group A (3/35; 8.6%). Hypertension developed after 36 weeks' gestation in all patients in the TH group. The results of the present study suggest that changes in PAF metabolism may relate to regulation of blood pressure in pregnant women whose pregnancy is complicated with TH, whereas NO metabolism does not differ between women with TH and those having a normal pregnancy.

Seizure frequency and bilateral temporal abnormalities: a proton magnetic resonance spectroscopy of temporal lobe epilepsy

Proton magnetic resonance spectroscopy ((1)H-MRS) was performed in seven healthy volunteers and 17 patients with temporal lobe epilepsy (TLE) to clarify the correlation of the severity of epilepsy with bilateral temporal changes in N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine + phosphocreatine (Cr). Despite unilateral EEG focus, bilateral temporal reduction in NAA /(Cho + Cr) was revealed in patients with intractable seizures. The potential for seizure generation correlated with the NAA /(Cho + Cr) reduction not only on the ipsilateral side but also on the contralateral side. Proton MRS proved to be a useful measurement for obtaining important information about the neuronal changes as well as the lateralization of the epileptogenic focus in TLE patients.

Reduction of Iron(III) Ion by Activated Carbon Fiber

The mechanisms of adsorption of iron(II) ion, iron(III) ion, and reduced iron(III) ion onto an activated carbon fiber and the ability of carbon fibers to reduce iron(III) ion were investigated on the basis of the amounts of iron ion adsorbed. The amount of iron(II) ion adsorbed onto the activated carbon fiber increased with increasing adsorption temperature. Iron(II) ion was more easily removed by the activated carbon fiber than iron(III) ion. Iron(III) ion was adsorbed onto the activated carbon fiber after being reduced to iron(II) ion. The reduction ability of A-20 was stronger than that of A-10 because the hydrophilic groups of A-20 were larger than those of A-10. It is concluded that the activated carbon fiber has a reduction effect on iron(III) ion and that the reduction effect of the activated carbon fiber depended on the number of hydrophilic groups on the activated carbon fiber. Copyright 2000 Academic Press.

Uptakes and images of 38K in rabbit heart, kidney, and brain

The purpose of this study was to evaluate the kinetics and image quality of positron-emitting 38K (half-life, 7.6 min) and high-resolution small-animal PET in the heart, kidney, and brain of rabbits.

METHODS

Studies were performed with 18 closed-chest anesthetized rabbits at baseline and during infusions of adenosine (0.2 mg/kg/min) and propranolol (0.5-1.0 mg/kg intravenously) using high-resolution small-animal PET. 38K was injected intravenously and dynamic PET imaging of the heart, kidney, or brain was performed for 3 min. Colored microspheres were injected into the left ventricle to measure organ blood flow. Arterial blood was withdrawn directly from the femoral artery, and, after the animals were killed, 38K activities in each organ were measured directly with a well counter. Uptake of 38K was calculated by dividing the 38K activities in each organ by the integral of the input function. The extraction fraction of 38K was estimated by dividing the uptake of 38K in each organ by the organ blood flow, measured by microspheres.

RESULTS

The left ventricular myocardium and kidney were clearly visualized, but there was no visual 38K uptake in the brain. For the heart, kidney, and brain, respectively, average blood flow was 2.91 +/- 1.29, 5.49 +/- 0.71, and 0.57 +/- 0.11 mL/min/g, and the extraction fraction of 38K at baseline was 0.55 +/- 0.13, 0.48 +/- 0.13, and 0.022 +/- 0004. The Renkin-Crone model fit the relation between myocardial extraction and flow under a wide range of myocardial blood flow (r = 0.89).

CONCLUSION

38K is a suitable tracer for noninvasively showing the potassium kinetics of the heart, kidney, and brain by PET imaging.

CaNa2EDTA for improvement of radioimmunodetection and radioimmunotherapy with 111In and 90Y-DTPA-anti-CEA MAbs in nude mice bearing human colorectal cancer

111In and 90Y, dissociated from 111In-labeled-monoclonal antibody (MAb) and 90Y-labeled MAb, may cause deterioration of the image quality in radioimmunodetection (RID) and undesirable irradiation of nontargeted tissue in radioimmunotherapy (RIT), respectively. The aim of this study was to investigate any improvement in RID and RIT with 111In-MAb and 90Y-MAb by pre- and postadministration of calcium disodium ethylenetriaminetetraacetic acid (CaNa2EDTA).

METHODS

Murine MAb F33-104 against carcinoembryonic antigen (CEA) was labeled with 111In or 90Y by the diethylenetriamine pentaacetic (DTPA)-anhydride method. The influence of CaNa2EDTA on loss of radioactivity from 111In-MAb or 90Y-MAb in serum was investigated in vitro. The effects of CaNa2EDTA, administered before and after 111In-MAb or 90Y-MAb, on the biodistribution of radioactive isotopes in nude mice bearing human colon adenocarcinoma LS 180 tumor expressing CEA, or human pulmonary carcinoma PC 9 tumor expressing no CEA, were then examined. As a control, 0.9% NaCl was used in both the in vitro and in vivo studies.

RESULTS

CaNa2EDTA did not cause any decrease in levels of radioactivity of radiolabeled MAbs. Pre- and post-treatment with CaNa2EDTA reduced radioctivity in both specific and nonspecific tumors at 72 h after 111In-MAb injection resulting in an increase of the specific tumor-to-nonspecific tumor radioactivity ratio. The levels of hepatic and renal radioactivity were also subsequently decreased by CaNa2EDTA. On the other hand, CaNa2EDTA pre- and post-treatment reduced levels of bony, hepatic, and renal radioactivity at 24, 72, and 72 h, respectively, after 90Y-MAb injection, although it had no effect on tumor radioactivity.

CONCLUSION

Pre- and post-treatment with CaNa2EDTA would be of great use in humans who undergo RID or RIT with 111In-MAb and 90Y-MAb accompanied by disassociation of the labeled radionuclides.

Competitive Adsorption of Chloroform and Iron Ion onto Activated Carbon Fiber

Chloroform in tap water has been a significant problem because it may be a carcinogenic substituent. Iron ion exists in tap water because of dissolution from iron water pipes. Iron ions in tap water cause discoloration and a bad odor. The isotherms of chloroform and iron ion adsorption onto activated carbon fibers in a single solution (chloroform or iron ion) and in a binary mixture solution (chloroform and iron ion) were investigated to estimate the competitiveness between chloroform and iron ions. The amount of adsorbed iron ions increased with increasing pore volume of the activated carbon fibers, while that of chloroform decreased. The amount of chloroform adsorbed onto the activated carbon fibers in the binary mixture solution was greater than that in the single solution. These results indicate that the adsorption of chloroform and iron ion onto activated carbon fibers could be competitive. Copyright 1999 Academic Press.