The first histological observation of a C1 posterior arch defect

Deficiencies in the posterior arch of C1 have been well-studied with incidences ranging from 5.65% to 3% and five different classifications. Unfortunately, there is a paucity of information describing the detailed anatomy, muscle attachments, and histology of cases with a C1 posterior arch deficiency. We found a case of an isolated unilateral posterior arch defect in the 83-years-old male cadaver. Histology revealed that the posterior arch defect was filled with collagen fibers and fibrocartilaginous tissue without muscle or bony tissues. This is the first report detailing the histological findings of a posterior arch defect of C1.

Are the nerves supplying the anterior sacroiliac joint nociceptive?

BACKGROUND

Sacroiliac joint (SIJ) pain is often difficult to diagnose. Moreover, while its anatomical characteristics have been well studied, its innervation and the contributions of particular nerves remain controversial, especially in relation to posterior joint innervation. To our knowledge, previous studies have not investigated the presence of nociceptive fibres in the nerves innervating the anterior SIJ.

MATERIALS AND METHODS

Eight adult cadaveric sides underwent dissection of the anterior SIJ. Adjacent anterior rami were examined for branches to the anterior SIJ. Any branches contributing to the anterior SIJ were measured and then resected. These samples were fixed in formalin and substance P was identified immunohistologically.

RESULTS

On all sides, 1-2 small branches (mean diameter of 0.33 mm) arose from the posterior aspect of the L4 anterior ramus (12.5%), the L5 anterior ramus (62.5%), or simultaneously from both the L4 and L5 anterior rami (25%). These branches had a mean length of 13.5 mm. All histological samples contained nerve tissue. All samples of nerve fibres traveling to the anterior SIJ were positive for diffuse substance P reactivity. There were no histological differences between sides or sex. Each of the branches identified as travelling to the SIJ exhibited similar positivity for substance P.

CONCLUSIONS

This cadaveric study demonstrates that the anterior SIJ nerve fibres carry pain fibres. This new knowledge has application to patients with SIJ syndrome and to its various treatments including interventional approaches to SIJ pain.

MRI of cerebral micro-vascular flow patterns: A multi-direction diffusion-weighted ASL approach

The study and clinical assessment of brain disease is currently hindered by a lack of non-invasive methods for the detailed and accurate evaluation of cerebral vascular pathology. Angiography can detect aberrant flow in larger feeding arteries/arterioles but cannot resolve the micro-vascular network. Small vessels are a key site of vascular pathology that can lead to haemorrhage and infarction, which may in turn trigger or exacerbate neurodegenerative processes. In this study, we describe a method to investigate microvascular flow anisotropy using a hybrid arterial spin labelling and multi-direction diffusion-weighted MRI sequence. We present evidence that the technique is sensitive to the mean/predominant direction of microvascular flow in localised regions of the rat cortex. The data provide proof of principle for a novel and non-invasive imaging tool to investigate cerebral micro-vascular flow patterns in healthy and disease states.

Molecular epidemiologic analysis of a Pneumocystis pneumonia outbreak among renal transplant patients

Between 18 November and 3 December 2011, five renal transplant patients at the Department of Nephrology, Toho University Omori Medical Centre, Tokyo, were diagnosed with Pneumocystis pneumonia (PCP). We used molecular epidemiologic methods to determine whether the patients were infected with the same strain of Pneumocystis jirovecii. DNA extracted from the residual bronchoalveolar lavage fluid from the five outbreak cases and from another 20 cases of PCP between 2007 and 2014 were used for multilocus sequence typing to compare the genetic similarity of the P. jirovecii. DNA base sequencing by the Sanger method showed some regions where two bases overlapped and could not be defined. A next-generation sequencer was used to analyse the types and ratios of these overlapping bases. DNA base sequences of P. jirovecii in the bronchoalveolar lavage fluid from four of the five PCP patients in the 2011 outbreak and from another two renal transplant patients who developed PCP in 2013 were highly homologous. The Sanger method revealed 14 genomic regions where two differing DNA bases overlapped and could not be identified. Analyses of the overlapping bases by a next-generation sequencer revealed that the differing types of base were present in almost identical ratios. There is a strong possibility that the PCP outbreak at the Toho University Omori Medical Centre was caused by the same strain of P. jirovecii. Two different types of base present in some regions may be due to P. jirovecii's being a diploid species.

A rare case of dual origin of the left vertebral artery without convergence

A case of dual origin of the left vertebral artery was encountered in a dissection course for medical students in 2014. Two vertebral arteries were observed on the left side. One arose from the aortic arch between the origin of the left common carotid artery and the left subclavian artery, entered the transverse foramen of the 4th cervical vertebra, and coursed upward into the transverse foramen. The other arose from the left subclavian artery as expected, divided into two branches anterior to the cervical vertebrae, and entered the transverse foramina of the 6th and 7th cervical vertebrae. Both branches flowed into the anterior spinal artery. Moreover, as seen in other anomalies, 3 arterial fenestrations were observed in the cranial arteries. This case is extremely unique with respect to the following points: the 2 ipsilateral vertebral arteries did not combine to form 1 vertebral artery, the vertebral artery of subclavian artery origin entered the transverse foramen of the 7th cervical vertebra, and 3 fenestrations were observed in the intracranial arteries. This is a very suggestive case for neurosurgeons and radiologists who perform treatments involving the vertebral artery.

Disruption of Tacc3 function leads to in vivo tumor regression

The formation of the bipolar spindle is responsible for accurate chromosomal segregation during mitosis. The dynamic instability of microtubules has an important role in this process, and has been shown to be an effective target for cancer chemotherapy. Several agents that target non-microtubule mitotic proteins, including the motor protein Eg5, Aurora kinases and Polo-like kinases, are currently being developed as chemotherapeutic drugs. However, because the efficacies of these drugs remain elusive, new molecular targets that have essential roles in tumor cells are desired. Here, we provide in vivo evidence that transforming acidic coiled-coil-3 (Tacc3) is a potential target for cancer chemotherapy. Using MRI, we showed that Tacc3 loss led to the regression of mouse thymic lymphoma in vivo, which was accompanied by massive apoptosis. By contrast, normal tissues, including the thymus, showed no overt abnormalities, despite high Tacc3 expression. in vitro analysis indicated that Tacc3 depletion induced multi-polar spindle formation, which led to mitotic arrest, followed by apoptosis. Similar responses have been observed in Burkitt's lymphoma and T-ALL. These results show that Tacc3 is a vulnerable component of the spindle assembly in lymphoma cells and is a promising cancer chemotherapy target.

[Application of the lower partial sternotomy approach to patients who may need tracheostomy in the early period after cardiac surgery]

Recent good results of cardiovascular surgery have led to expansion of its indication to elderly patients and patients with serious complications. Such patients may have serious respiratory complications after cardiac surgery and need to undergo tracheostomy relatively early in the postoperative period. Although the full sternotomy approach is the standard in almost all cardiac surgeries, superficial and deep sternal infections are rather common after early tracheostomy in full sternotomy patients. The lower partial sternotomy approach is a safer and more useful procedure in patients who will need tracheostomy in the early period after cardiac surgery. We report on 2 patients who were successfully tracheostomized within a week after cardiac surgery, with a review of the literature.

Noninvasive assessment of regulable transferred-p53 gene expression and evaluation of therapeutic response with FDG-PET in tumor model

The use of tumor-suppressor gene p53 as an anticancer therapeutic has been vigorously investigated. However, progress has met with limited success to date. Some major drawbacks are the difficulty in achieving controllable and efficient gene transfer as well as in analyzing the transferred gene expression in real time and the treatment response in a timely manner. Thus, development of novel gene transfer vector with a regulative gene expression system coupled with the reporter gene, by which transgene can be monitored simultaneously, is critical. Moreover, noninvasive imaging-based assessment of the therapeutic response to exogenous wild-type p53 gene transfer is crucial for refining treatment protocols. In this study, as a simple preclinical model, we constructed a doxycycline-regulated bidirectional vector harboring a reporter gene encoding red fluorescence protein and p53. Then, we determined the controllable and simultaneously coordinated expression of both proteins and the p53-mediated anticancer effects in vitro and in vivo. Next, we observed that cells or tumors with induced p53 overexpression exhibited decreased uptake of [(14)C]FDG in cellular assay and [(18)F]FDG in positron emission tomography (PET) imaging. Thus, by coupling with bidirectional vector, controllable p53 transfer was achieved and the capability of fluoro-2-deoxy-D-glucose (FDG)-PET to assess the therapeutic response to p53 gene therapy was evidently confirmed, which may have an impact on the improvement of p53 gene therapy.

Changes in apparent diffusion coefficients in the normal uterus during different phases of the menstrual cycle

This study investigated the apparent diffusion coefficients (ADCs) of the uterine zonal structures (myometrium, endometrium and junctional zone) among reproductive women, and their changes during the menstrual cycle. Magnetic resonance (MR) images of seven healthy females (aged 24-31 years) were obtained during the periovulatory, luteal and menstrual phases. Diffusion-weighted imaging (DWI) was performed with a single-shot echo-planar imaging (EPI) sequence in the midsagittal plane of the uterus using three b-values (b = 0, 500 or 1000 s mm(-2)). The ADC values of the three uterine zonal structures were measured on an ADC map by placing two regions of interest (ROI) on the corresponding zonal structures. The average changes of ADC values (intra-individual ADC value variation) over three menstrual phases were 0.41 x 10(-3) mm(2) s(-1) (range, 0.08-0.91) for myometrium, 0.55 x 10(-3) mm(2) s(-1) (0.35-0.84) for endometrium, and 0.40 x 10(-3) mm(2) s(-1) (0.18-0.59) for the junctional zone. The ADC values for myometrium and endometrium were lower in the menstrual phase, although there was some overlap of individual values. Interindividual variation in ADC value for a given zone or phase ranged from 0.48 x 10(-3) mm(2) s(-1) to 0.85 x 10(-3) mm(2) s(-1). Intermeasurement variation between the two ROIs ranged from 0 to 0.48 x 10(-3) mm(2) s(-1) per measurement. The magnitude of these variations was comparable to reported differences between malignant and non-malignant tissues. These preliminary results, from a small number of subjects, suggest that the menstrual cycle and individual variation in pre-menopausal women should be considered when interpreting the ADC values of uterine structures.

Hepatocyte Response to Continuous Low Dose-rate Radiation in Radioimmunotherapy Assessed by Micronucleus Assay

The response of hepatocytes to low dose-rate irradiation was examined in mice following the injection of radiolabelled monoclonal antibody. Mice were injected intravenously with an 131I-labelled monoclonal antibody 196-14 which recognizes CA125 antigen, and the effect of continuous low dose-rate irradiation on hepatocytes was assessed using the micronucleus assay. The frequency of micronuclei increased in a dose-dependent fashion, but it was lower than the frequency induced by conventional external X-rays which was determined immediately after the irradiation. A linear quadratic model (micronucleus frequency = aD+bD2+c) showed that the value of b decreased with low dose-rate irradiation from the radiolabelled antibody. It is concluded that the micronucleus assay is useful for the evaluation of the response of hepatocytes to irradiation in radioimmunotherapy.

Visualization of in vivo electroporation-mediated transgene expression in experimental tumors by optical and magnetic resonance imaging

In vivo electroporation (EP) is an efficient method for effective gene transfer and is highly expected for application in anticancer gene therapy. Non-invasive monitoring of gene transfer/expression is critical for optimal gene therapy. Here we report in vivo optical and high-field magnetic resonance imaging (MRI) of EP-mediated transgene expression in a tumor model. Initially, we observed spatio-temporal change in in vivo EP-mediated transgene expression by optical imaging using red fluorescence protein (RFP) as a reporter gene. Next, we constructed a dual-reporter plasmid carrying a gene-encoding MRI reporter ferritin heavy chain and RFP gene to visualize the intratumoral transgene expression by dual modality. Cells transfected with this plasmid showed lower signal intensity on in vitro T(2)-weighted cellular MRI and quantitatively increased the transverse relaxation rate (1/T(2)) compared with control cells. After conducting in vivo EP in an experimental tumor, the plasmid-injected region showed both fluorescent emissions in optical imaging and detectably lowered signal on T(2)-weighted MRI. The correlative immunohistological findings confirmed that both the reporter transgenes were co-expressed in this region. Thus, our strategy provides a platform for evaluating EP-mediated cancer gene therapy easily and safely without administering contrast agent or substrate.

The feasibility of sentinel node biopsy in the previously treated breast

PURPOSE

Sentinel lymph node biopsy (SNB) has been a standard technique in early breast cancer. However, it is not clear that the SNB procedure can be applied to second breast cancer or recurrence occurring in the previously treated breast. The purpose of this study was to clarify the feasibility of the SNB procedure in breast cancer occurring in the previously treated breast, and to investigate the factors related to altered lymphatic flow.

PATIENTS AND METHODS

Between April 2004 and December 2006, 1490 patients underwent the breast SNB procedure. Among them, 31 patients had a history of previous treatments in the same breast. Recent excision biopsy cases were not included in this group. All patients had previous breast-conserving surgery in the same breast. Sixteen patients had axillary dissection, 3 had SNB, and 12 had no axillary treatment. Ten patients had received radiation therapy to the breast and axilla. Visualization of axillary nodes, internal mammary nodes and contralateral axillary nodes was evaluated and compared with pathological results.

RESULTS

Axillary nodes were visualized in 23 patients, internal mammary nodes in 7 patients, and contralateral axillary nodes in 7 patients. The patients with previous axillary dissection exhibited altered lymph node distribution, but did not show involvement of contralateral axillary nodes. Visualization of contralateral axillary nodes occurred in 7 of the 10 patients with previous irradiation to breast irrespective of axillary dissection. Twenty-eight patients underwent SNB, 4 of whom showed cancer-positive nodes. Three patients were cancer-positive in non-ipsilateral axillary nodes (one patient showed positive opposite axillary node and two patients showed positive internal mammary nodes).

CONCLUSION

Previous axillary dissection or irradiation to the breast greatly influences lymphatic flow. Irradiation to the breast may be a strong factor for the visualization of contralateral axillary nodes. Despite the frequent alteration of lymphatic flow, SNB seems to be feasible in secondary or recurrent breast cancer patients.

Phase II clinical study of combination therapy with irinotecan and S-1(IRIS) for inoperable recurrent advanced colorectal cancer: Hokkaido Gastrointestinal Cancer Study Group study HGCSG-0302)

3589

Background: We planned to conduct a phase II clinical study of combination therapy with irinotecan and S-1, a new oral anticancer drug of the fluorinated pyrimidine type. We reported the interium reports of this study in colorectal cancer patients at GI cancer Symposium 2006. Methods: The antitumor effect was the primary endpoint, while the safety, progression-free survival time, and median survival time were the secondary endpoints. The subjects were untreated patients with inoperable advanced colorectal cancer aged 20–75 years. Irinotecan was administered at a dose of 100 mg/m2 (on days 1 and 15) as an intravenous infusion over 90 minutes, and oral S-1 (40 mg/m2) was administered after breakfast and dinner and then withdrawn for 2 weeks. Results: Forty patients were enrolled in the present study. There were 23 men and 17 women. The median age was 62 years (range: 34 to 74 years). Two patient showed grade 4 neutropenia, but the next course could be given safely after dose reduction. Three patients had grade 3 diarrhea, but therapy could be continued with addition of an antidiarrheal drug. No other serious adverse reactions occurred (either hematological or non-hematological), and all patients could receive therapy safely on an outpatient basis. Interim analysis suggested excellent results, with a response rate of 50%. To date, 231 cycles (median 8, range 1–19) have been administered. Median relative dose intensity was 97% for S-1 and 87% for irinotecan. 36 pts are evaluable for efficacy: RR was 47.2% (95% CI, 30.9–63.5%) and Disease Control Rate (PR + SD) was seen in 94.4% of pts. PFS of this regimen is 320 days. MST is not reached. Conclusions: IRIS therapy achieved a high response rate and could be given safely. These findings suggest that the therapy has potential as first-line treatment for inoperable advanced recurrent colorectal cancer. It seems that IRIS is a good treatment equal to FOLFIRI. In addition, this regimen could qualify as a candidate for future combination therapy with a molecular-targeting drug. The latest data will be reported at the meeting.

No significant financial relationships to disclose.

Positron emission tomography application for gynecologic tumors

Positron emission tomography (PET) using fluorine-18-fluoro-2-deoxy-d-glucose (FDG), which originated as a research tool to evaluate glucose metabolism in cancer tissues, has now become an essential imaging modality for determining the appropriate therapeutic management of various cancer patients. The clinical role of FDG-PET for gynecologic tumors has not been established yet, but FDG-PET has come to be considered one of the important imaging modalities for evaluating patients with gynecological cancers. The objective was to review the literature regarding the utility of FDG-PET in the clinical setting of gynecological malignancies. Many articles reported that FDG-PET could be used for staging and restaging in patients with uterine cervical cancer. Although there is limited data about the feasibility of FDG-PET for endometrial cancer, preliminary results for detecting recurrence were promising. Furthermore, FDG-PET has been reported as a useful imaging modality, especially for restaging, in ovarian cancer, although the prognostic value needs to be fully investigated. Currently, a combined PET/computed tomography scanner is available, and its clinical application has begun. It is expected that this modality will contribute to the management of gynecological cancers, as has been reported recently for other malignancies.

Evaluation of a fully automated system (RAISUS) for rapid identification and antimicrobial susceptibility testing of Staphylococci

RAISUS is a system for rapid bacterial identification and antimicrobial susceptibility testing. RAISUS and VITEK showed 97.8% and 75.9% agreement in identification of 45 Staphylococcus aureus strains and 58 coagulase-negative staphylococci (CoNS), respectively, and RAISUS and CLSI (formerly NCCLS) methods showed 87.2% and 87.9% agreement in the MICs for S. aureus and CoNS, respectively. RAISUS provided these data within 3.75 h, suggesting its utility for clinical bacteriological laboratories.

Delayed Esophageal Necrosis and Perforation Secondary to Thoracic Aortic Rupture: A Case Report and Review of the Literature

Delayed esophageal necrosis secondary to aortic rupture is extremely rare but potentially fatal. Although diagnostic techniques have improved, survival remains rare. The clinical and imaging features have not been characterized, as no large series have been reported since the advent of computed tomography (CT) and endoscopy. Moreover, as delayed esophageal necrosis secondary to aortic rupture is rarely anticipated, diagnosis is usually delayed. We recently encountered a case of this complication and present this along with a literature review, in order to facilitate early recognition and treatment. In many cases, hemodynamics remain relatively stable despite aortic rupture and the long interval between onset and operation. Dysphagia is therefore an important symptom that may indicate compression of the esophagus and subsequent esophageal necrosis. Preoperative total obstruction of the esophagus on barium swallow, endoscopy, or CT is also an important feature suggesting ischemic change of the esophagus. Endoscopy often reveals an annular ulcer suggestive of an ischemic process leading to necrosis. Death generally occurs from severe mediastinitis occurring after graft repair of the aorta. We recommend performing postoperative endoscopy after aortic surgery when preoperative obstruction of esophagus is found. If endoscopy reveals annular necrosis, surgical treatment involving esophagectomy and omental translocation should be performed expediently before perforation occurs.

Positron emission tomography application for gynecologic tumors

Positron emission tomography (PET) using fluorine-18-fluoro-2-deoxy-d-glucose (FDG), which originated as a research tool to evaluate glucose metabolism in cancer tissues, has now become an essential imaging modality for determining the appropriate therapeutic management of various cancer patients. The clinical role of FDG-PET for gynecologic tumors has not been established yet, but FDG-PET has come to be considered one of the important imaging modalities for evaluating patients with gynecological cancers. The objective was to review the literature regarding the utility of FDG-PET in the clinical setting of gynecological malignancies. Many articles reported that FDG-PET could be used for staging and restaging in patients with uterine cervical cancer. Although there is limited data about the feasibility of FDG-PET for endometrial cancer, preliminary results for detecting recurrence were promising. Furthermore, FDG-PET has been reported as a useful imaging modality, especially for restaging, in ovarian cancer, although the prognostic value needs to be fully investigated. Currently, a combined PET/computed tomography scanner is available, and its clinical application has begun. It is expected that this modality will contribute to the management of gynecological cancers, as has been reported recently for other malignancies.

Follow-up assessment of the collateral circulation in patients with Kawasaki disease who underwent dipyridamole stress technetium-99m tetrofosmin scintigraphy

To assess the alteration of myocardial ischemic findings and the role of collateral vessels in patients with Kawasaki disease (KD), we used dipyridamole stress technetium-99m tetrofosmin (Tf) single photon emission computed tomography (SPECT). A comparison study of coronary angiography and dipyridamole stress (0.70 mg/kg) Tf-SPECT was repeated at least twice in 20 patients. The subjects included 7 patients with coronary stenosis, 1 with pre- and post-coronary artery bypass grafting (CABG) due to coronary stenosis, 1 with progression to coronary stenosis, and 11 with persistent coronary aneurysms. In the stenosis group, Tf-SPECT revealed that 6 of the 7 patients had some degree of ischemic findings, and 5 of these 6 did not show any change in their ischemic findings during follow-up. In 1 patient, the ischemic findings changed according to the collateral circulation changes. The patient who underwent CABG had pre-CABG ischemic changes that disappeared after CABG. In the patient whose coronary arteries progressed to stenosis, the ischemic findings progressed as the coronary stenosis progressed. In the persistent aneurysm group, there were no ischemic findings. In the future Tf-SPECT may become one of the most useful methods for monitoring the progressive changes of myocardial ischemia in KD.

Ectopically located gonads in a patient with mixed gonadal dysgenesis: detection by diffusion-weighted MRI

We report a case of mixed gonadal dysgenesis in which diffusion-weighted magnetic resonance imaging played a major role in the detection of ectopically located gonads. Magnetic resonance imaging may have a potential in detecting ectopically located gonads and may provide important information for the management of patients with mixed gonadal dysgenesis.

Morphological imaging in the localization of neuroendocrine gastroenteropancreatic tumors found by somatostatin receptor scintigraphy

PURPOSE

To evaluate the necessity of morphological images (MI) in reading somatostatin receptor scintigraphy (SRS) in patients with suspected neuroendocrine gastroenteropancreatic (GEP) tumors.

MATERIAL AND METHODS

A Japanese multicenter clinical trial of SRS was conducted in 40 patients with suspected GEP tumors. Three experienced radiologists interpreted the images in three separate sessions in a blinded manner (1: SRS images alone, 2: MI alone, 3: SRS and MI analyzed simultaneously), and the reading results of each session were compared. In addition, the diagnostic abilities of SRS, MI and SRS alone and simultaneous SRS and MI readings were compared for patients where final diagnosis was obtained.

RESULTS

SRS detected more suspected lesions (positive or inconclusive uptake) than morphological images did (51 vs 27 lesions), but included many physiological uptakes detected as positive or inconclusive uptakes. Combined reading of SRS and morphological images helped to correctly recognize these physiological uptakes, and also helped in determining the anatomical localization of the abnormal uptakes. Combined reading of SRS and morphological images gave the highest diagnostic impact.

CONCLUSION

The sensitivity of SRS with regard to GEP is high. However the specificity is very low. Morphologic imaging is necessary for the exclusion of physiological uptake and correct anatomic location of an abnormal tracer uptake. The combined reading of SRS and morphologic imaging studies gives the highest diagnostic impact.

Residual formaldehyde on plastic materials and medical equipment following low-temperature steam and formaldehyde sterilization

We measured the amount of residual formaldehyde on 16 plastic materials and five medical devices following low-temperature steam and formaldehyde (LTSF) sterilization, based on the European Standard EN14180. The amounts of formaldehyde residue on the plastic materials were compared with that on a filter paper of similar dimensions. The amount of residual formaldehyde on polyamide 6, polyurethane, natural rubber and polyacetal was higher (21.9, 15.2, 3.0 and 2.1 times, respectively) than that on the filter paper. The amount of formaldehyde recovered from a breathing circuit, anaesthesia circuit, oxygen tubing, airway tube and tweezers was 260, 240, 594, 56 and 0 microg, respectively, following LTSF sterilization. Our results emphasize the need to verify the main material composing the medical equipment before LTSF sterilization, as the amount of formaldehyde retrieved following sterilization varies according to the material used for construction.

Elastic moduli of thyroid tissues under compression

The aim of this study was to evaluate the elastic moduli of thyroid tissues under uniaxial compression and to establish the biomechanical fundamentals for accurate interpretation of thyroid elastograms. A total of 67 thyroid samples (24 samples of normal thyroid tissue, 2 samples of thyroid tissue with chronic thyroiditis, 12 samples of adenomatous goiter lesions and 7 samples of follicular adenoma, 19 samples of papillary adenocarcinoma (PAC) and 3 samples of follicular adenocarcinoma (FAC)) obtained from 36 patients who had received thyroid surgery were subjected to biomechanical testing within three hours after surgical resection at precompression strains of 5%, 10% and 20% and applied strains of 1%, 2%, 5% and 10% of sample height. As a result, the mean values of elastic moduli for benign thyroid lesions at all examined precompression levels were significantly higher than those for normal thyroid tissue measured at the same load (p<0.01). At low precompression (5%) and compression (1-2%) levels, benign thyroid nodule samples were 1.7 times harder than normal thyroid tissue. At high precompression (20%) and compression (10%) levels, this difference increased to 2.4 times. Stiffness of PAC samples was significantly higher than those for normal thyroid tissue and benign thyroid tumors measured at the same load (p<0.01). At low precompression (5%) and compression (1-2%) levels, PAC samples were 5.0 times harder than normal thyroid tissue. At high precompression (20%) and compression (10%) levels, this difference increased to 17.7 times. In contrast, samples of FAC were much softer than PAC (p<0.05) and were comparable in stiffness to normal thyroid tissues. The significant differences in the stiffness between normal thyroid tissue and thyroid tumors may provide useful information for accurate interpretation of thyroid elastograms.

Obstructed Coarctation in a Right Aortic Arch in an Adult Female

Coarctation of a right aortic arch is rare congenital anomaly. We report a rare case of a 24-year-old female with coarctation of the right aortic arch with aberrant left subclavian artery between the right common carotid and right subclavian arteries. The coarctation progressed into complete obstruction as the interruption of the aorta in adulthood. To prevent cerebral complications and progression to heart failure, surgical procedure was selected. Extraanatomical bypass grafting between the ascending and descending aorta was successfully performed using cardiopulmonary bypass. Some patients diagnosed with interruption of the aortic arch in adulthood might be displaying progression of undiagnosed coarctation, as our in case. Three-dimensional computed tomography was useful to detect the obstructive lesion and to determine the surgical approach and methods.

Williams syndrome associated with complete atrioventricular septal defect

Williams syndrome is a genetic disorder associated with characteristic facies, supravalvar aortic stenosis, peripheral pulmonary stenosis, mental retardation, hypertension, premature aging of skin, and congenital cardiac defects. Many cardiac defects such as bicuspid aortic valve, mitral valve regurgitation, coarctation of the aorta, and ventricular or atrial septal defects are linked to the syndrome. Complete atrioventricular septal defect has rarely been associated with Williams syndrome and only one necropsy case has been reported in the literature. The long term follow up of Williams syndrome associated with complete atrioventricular septal defect is reported. During a 10 year follow up period, the pressure gradient in the ascending aorta did not increase despite narrowing of the ascending aorta as identified on an aortogram.

Carotid artery intima-media thickness and brachial artery flow-mediated vasodilation in asymptomatic Japanese male subjects amongst apolipoprotein E phenotypes

BACKGROUND

Epidemiological studies suggest that apolipoprotein E (apoE) polymorphism influences plasma lipoprotein levels and the development of cardiovascular disease.

OBJECTIVE

To clarify the role of apoE polymorphism as a risk factor for early atherosclerosis.

DESIGN

Using a high-resolution ultrasound method, we investigated the association between apoE phenotypes, carotid intima-media thickness (CCA-IMT), and flow-mediated dilation in the brachial artery (brachial-FMD) in 96 healthy asymptomatic Japanese men (mean +/- SD age, 50 +/- 8 years).

RESULTS

Serum cholesterol and LDL-cholesterol levels in subjects with E3E4 were highest and those with E2E3 were lowest (P < 0.05 and P < 0.05, respectively). The CCA-IMT in E3E4 subjects (0.76 +/- 0.17 mm) was greater than that in E2E3 and E3E3 (0.61 +/- 0.15 and 0.64 +/- 0.14 mm, respectively; P < 0.01). In contrast, there was no difference between brachial-FMD and apoE phenotypes (P=0.15). By univariate analysis, CCA-IMT was positively correlated with age (r=0.51, P < 0.01), LDL-chol/HDL-chol ratio (r=0.37, P < 0.01), triglycerides (r=0.23, P < 0.05), and negatively correlated with HDL-cholesterol (r=-0.31, P < 0.01). An association between CCA-IMT and the presence of E4 allele was also found (P < 0.05). Logistic regression analysis revealed that the presence of E4 allele was a higher risk for increased IMT (relative risk of 4.4, 95% CI 1.5-12.5), even after adjustment for age, LDL-cholesterol, blood pressure and other known risk factors. A negative correlation between brachial-FMD and CCA-IMT was also found in all subjects (r=-0.21, P < 0.05), being most apparent in the E3E4 subjects (r=-0.53, P < 0.02).

CONCLUSION

ApoE4 phenotype was independently associated with an increased risk of carotid atherosclerosis and elevated LDL-cholesterol levels in asymptomatic middle-aged Japanese men.

[Pitfall of modified ultrafiltration in pediatric cardiac surgery]

Since June, 1998, modified ultrafiltration (MUF) was performed for 92 consecutive children who underwent cardiac surgery using cardiopulmonary bypass, except those with atrial septal defect. Among 92 cases, MUF could not be completed in two cases because of the accident that many air bubbles were found in the arterial line of the CPB circuit. The causes of such trouble were discussed.

Simultaneous quantification of prostaglandins in human synovial cell-cultured medium using liquid chromatography/tandem mass spectrometry

A liquid chromatographic-tandem mass spectrometric (LC/MS-MS) method was developed for the simultaneous quantification of prostaglandin (PG) E(2), PGF(2alpha), 6-keto-PGF(lalpha) and thromboxane (TX) B(2). These eicosanoids and their deuterium derivatives, using as internal standards, were extracted by solid-phase extraction and analyzed using LC/MS-MS in the selected reaction-monitoring (SRM) mode. A good linear response over the range of 10 pg to 10 ng for each eicosanoid was demonstrated. The accuracy of added eicosanoids ranged from 94.1 to 106.6% and coefficients of variation ranged from 0.62 to 7.8%. Furthermore, we applied this method for the determination of eicosanoids in the human synovial cell-cultured medium, stimulated by lipopolysaccharide (LPS). LPS produced each eicosanoid and they increased in a time-dependent manner. The production levels after 24 h stimulation were 6-keto-PGF(1alpha) > PGE(2) > TXB(2) >> PGF(2alpha). This simultaneous quantification method is so useful to clarify the function of synovial cells in rheumatoid arthritis (RA).

Pharmacokinetics and enhancement patterns of macromolecular MR contrast agents with various sizes of polyamidoamine dendrimer cores

Four macromolecular contrast agents are synthesized to visualize small vessels by MRI using generation-3 (G3D), -4 (G4D), -5 (G5D), and -6 (G6D) polyamidoamine dendrimers conjugated to chelated gadolinium (Gd). The pharmacokinetics, enhancement patterns, and the ability of these constructs to visualize fine vessels is evaluated by dynamic MRI in relationship to their size. Gd-G6D and -G5D exhibit a prolonged high vascular (ventricular) signal intensity (SI) with high ventricle-to-organ SI ratios. The initial high vascular SI with Gd-G4D decreases to a value as low as that obtained with Gd-G3D and Gd-dimeglumine-diethylenetriaminepentaacetic acid (Gd-DTPA). Gd-G5D, -G4D, and -G3D show high renal SIs, and Gd-DTPA prominently enhances the skin. Gd-G6D and -G5D present fine vasculature significantly more clearly than Gd-G3D and -DTPA (P < 0.005). As the molecular size increases, the excretion of the 153Gd-conjugates is retarded. In conclusion, Gd-G6D and -G5D are retained in the blood and present fine vessels with high quality and detail, and should be adequate for visualizing small tumor vasculature.

Micro-MR angiography of normal and intratumoral vessels in mice using dedicated intravascular MR contrast agents with high generation of polyamidoamine dendrimer core: reference to pharmacokinetic properties of dendrimer-based MR contrast agents

Pharmacokinetic characteristics of intravascular macromolecular magnetic resonance imaging (MRI) contrast agents with polyamidoamine dendrimer cores smaller than generation-7 were previously studied in the literature. To evaluate the effects of greater hepatic uptake on the pharmacokinetics of the larger generation dendrimers, the MRI contrast agents GxD-(1B4M-Gd)(2(x+2)) were synthesized with generation-7, -8, and -9 polyamidoamine dendrimers and 2-(p-isothiocyanatobenzyl)-6-methyl-diethylenetriaminepentaacetic acid (1B4M). Their pharmacokinetic characteristics in mice were compared with that of G6D-(1B4M-Gd)(256). In biodistribution and dynamic micro-MRI studies, significantly less renal accumulation of G7D-(1B4M-Gd)(512), G8D-(1B4M-Gd)(1024), and G9D-(1B4M-Gd)(2048) was shown compared to G6D-(1B4M-Gd)(256) (P < 0.01). There was a significantly greater accumulation of G8D-(1B4M-Gd)(1024) and G9D-(1B4M-Gd)(2048) in the liver compared to G6D-(1B4M-Gd)(256) and G7D-(1B4M-Gd)(512) (P < 0.01). The highest blood retention of all dendrimer-based MRI contrast agents was exhibited by G7D-(1B4M-Gd)(512) (P < 0.01). The normal and intratumoral fine vessels of approximately 100 microm diameter were visualized in normal or tumor-bearing mice by high resolution three-dimensional-micro-MR angiographs with G7D-(1B4M-Gd)(512) and G8D-(1B4M-Gd)(1024) with good vessel-to-soft tissue contrast. In summary, increased accumulation in the liver with concomitant decreased uptake in the kidney was caused by increased molecular sizes of the dendrimer-based MRI contrast agents.

Tumor targeting and imaging of intraperitoneal tumors by use of antisense oligo-DNA complexed with dendrimers and/or avidin in mice

To establish an effective nonviral gene delivery and a corresponding imaging method for i.p.-disseminated tumors, various oligonucleotide-carrier complexes were synthesized, and their in vitro and in vivo properties were examined. The 20-mer multiamino-linked oligonucleotide (oligo), synthesized as antisense against the c-erbB-2 sequence, and the 3'-biotinylated form of the same oligonucleotide (oligo-Bt) were (111)In labeled through a diethylenetriaminepentaacetic acid chelate. (111)In-oligo was mixed with generation 4 polyamidoamine dendrimer (G4) or with biotinylated G4 (G4-Bt), which are positively charged to form electrostatic complexes. (111)In-oligo/G4-Bt and (111)In-oligo-Bt were conjugated to avidin ((111)In-oligo/G4-Av and (111)In-oligo-Av, respectively). (111)In-oligo/G4, (111)In-oligo/G4-Av, (111)In-oligo-Av, and carrier-free (111)In-oligo (2.96 kBq/22.4-45.9 ng of oligo) were examined for internalization in vitro in human ovarian cancer cells (SHIN3). Biodistribution of (111)In-oligo-carrier complexes or (111)In-oligo was examined in normal (n = 4-7) or i.p. SHIN3 tumor-bearing (n = 6-10) mice 2-24 h after i.p. injection (74 kBq/125-300 ng). Scintigraphy of i.p. tumor-bearing and normal mice was performed at various times postinjection of (111)In-oligo-carrier complex or (111)In-oligo (1.85 MBq/2.2 ng). (111)In-oligo-carrier complexes bound to the tumor cells were internalized at a rate of 34-56% at 24 h. In vivo, G4, G4-Av, and Av significantly enhanced tumor delivery of (111)In-oligo [9.1, 14.5, and 24.4% of injected dose per g of tissue (ID/g) at 24 h; P < 0.05, < 0.01, and < 0.0001, respectively] compared with delivery without carrier (0.8% ID/g). Scintigrams of (111)In-oligo delivered to the i.p.-disseminated tumors by the carriers were successfully obtained. In conclusion, G4, G4-Av, and Av can effectively deliver (111)In-oligo to i.p.-disseminated tumors. (111)In-oligo-carrier complexes also have potential as tracers for imaging and monitoring of gene delivery.

(99m)Tc-sestamibi retention characteristics during pharmacologic hyperemia in human myocardium: comparison with coronary flow reserve measured by Doppler flowire

The aim of the study was to investigate the increase in myocardial (99m)Tc-methoxyisobutylisonitrile (sestamibi) retention in humans during pharmacologic vasodilation.

METHODS

For calculation of the increase in (99m)Tc-sestamibi retention during hyperemia, baseline and adenosine triphosphate (ATP)-induced hyperemic stress sestamibi studies were performed using a same-day rest-stress protocol. On the injection of sestamibi, left ventricular dynamic data were obtained for 90 s. The increase in sestamibi retention from baseline to hyperemia was calculated by the formula [abstract: see text] where Cm(h)(t) and Cm(b)(t) are myocardial counts on the tomographic image, and Cb(b)(tau) and Cb(h)(tau) are the left ventricular blood-pool counts during the first transit of sestamibi at baseline and during hyperemia, respectively. Coronary flow increase during intravenous ATP stress was measured using intracoronary Doppler flow guide wire and compared with the scintigraphic results of 28 measurements in 22 patients.

RESULTS

Sestamibi retention increased as coronary flow velocity increased but plateaued at >2.5-3 times baseline flow velocity. The relationship between the increase in sestamibi retention (Y) and the increase in flow (X) is expressed as follows: Y = 0.44 + 0.60X - 0.068X(2) (r = 0.82).

CONCLUSION

In humans, the increase in (99m)Tc-sestamibi myocardial retention underestimates coronary flow reserve, particularly at high flow rates. Knowledge of these tracer retention characteristics will contribute to a more comprehensive understanding of the manner and interpretation of stress sestamibi imaging.

Positive effects of polyethylene glycol conjugation to generation-4 polyamidoamine dendrimers as macromolecular MR contrast agents

Macromolecules conjugated with polyethylene glycol (PEG) acquire more hydrophilicity, resulting in a longer half-life in circulation and lower immunogenicity. Two novel conjugates for MRI contrast agents were synthesized from a generation-4 polyamidoamine dendrimer (G4D), 2-(p-isothiocyanatobenzyl)-6-methyl-diethylenetriaminepentaacetic acid (1B4M), and one or two PEG molecules with a molecular weight of 20000 Da (PEG(2)-G4D-(1B4M-Gd)(62) (MW: 96 kD), PEG(1)-G4D-(1B4M-Gd)(63) (MW: 77 kD)). Their pharmacokinetics, excretion, and properties as vascular MRI contrast agents were evaluated and compared with those of G4D-(1B4M-Gd)(64) (MW: 57 kD). PEG(2)-G4D-(1B4M-Gd)(62) remained in the blood significantly longer and accumulated significantly less in the liver and kidney than the other two preparations (P < 0.01). Although the blood clearance was slower, PEG(2)-G4D-(1B4M-Gd)(62) was excreted more readily without renal retention than the other two preparations. In conclusion, the positive effects of PEG conjugation on a macromolecular MRI contrast agent were found to be prolonged retention in the circulation, increased excretion, and decreased accumulation in the organs.

Novel liver macromolecular MR contrast agent with a polypropylenimine diaminobutyl dendrimer core: comparison to the vascular MR contrast agent with the polyamidoamine dendrimer core

As MRI contrast agents, more hydrophobic molecules reportedly accumulate in the liver and thus are potentially useful as liver MRI contrast agents. In this study, a generation-4 polypropylenimine diaminobutane dendrimer (DAB-Am64), which is expected to be more hydrophobic than the generation-4 polyamidoamine dendrimer (PAMAM-G4D), was used to synthesize a conjugate with 2-(p-isothiocyanatobenzyl)-6-methyl-diethylenetriaminepentaacetic acid (1B4M) [DAB-Am64-(1B4M-Gd)(64)] for complexing Gd(III) ions. This DAB conjugate quickly accumulated in the liver and its characteristics were studied and compared with those of a PAMAM conjugate [PAMAM-G4D-(1B4M-Gd)(64)], which is known to be a useful vascular MRI contrast agent, in regard to its availability as a liver MRI contrast agent. DAB-Am64-(1B4M-Gd)(64) accumulated significantly more in the liver and less in blood than PAMAM-G4D-(1B4M-Gd)(64) (P < 0.001). Contrast-enhanced MRI with DAB-Am64-(1B4M-Gd)(64) was able to homogeneously enhance liver parenchyma and visualize both portal and hepatic veins of 0.5 mm diameter in mice. In conclusion, DAB-Am64-(1B4M-Gd)(64) is a good candidate for a liver MRI contrast agent.

Novel intravascular macromolecular MRI contrast agent with generation-4 polyamidoamine dendrimer core: accelerated renal excretion with coinjection of lysine

One of the major limitations to macromolecular MRI contrast agents (MRI-CAs) is their slow clearance and associated decreased excretion of gadolinium (Gd(III)). The effect of coinjecting lysine to accelerate renal excretion of a macromolecular MRI-CA (generation-4 PAMAM dendrimer (G4D-(1B4M-Gd)64)) was investigated. The biodistribution and urine and fecal excretion in athymic mice was evaluated with and without lysine coinjection. 3D-dynamic-micro-MRI with G4D-(1B4M-Gd)64 was obtained with and without lysine coinjection, and the serial signal intensity (SI) change in the blood and organs was evaluated. When lysine was coinjected, urinary excretion of G4D-(1B4M-Gd)64 increased 5.4-fold compared to that without lysine, resulting in decreased renal accumulation of G4D-(1B4M-Gd)64 from 150% to 40% injected dose per gram (P < 0.001). On dynamic MRI with G4D-(1B4M-Gd)64, when lysine was coinjected, the kidney-to-blood SI ratio was significantly lower than that obtained without lysine (P < 0.001). When lysine was coinjected, the G4D-(1B4M-Gd)64 was excreted from the kidney intact.

3D MR angiography of intratumoral vasculature using a novel macromolecular MR contrast agent

Noninvasive methods to visualize blood flow in the intratumoral vasculature have not previously been studied. In the present study, the use of a novel intravascular MR contrast agent with a generation-6 polyamidoamine dendrimer core (G6-(1B4M-Gd)192; MW: 175kD) was investigated, and the vasculature in experimental tumors was visualized using 3D MR angiography (MRA). Xenografted tumors in nude mice of two different histologies-KT005 (human osteogenic sarcoma) and LS180 (human colon carcinoma)-were used to obtain 3D MRA using G6-(1B4M-Gd)192 and Gd-DTPA. The contrast MR sectional images were correlated with the corresponding histological sections. The intratumoral vasculature in the KT005 tumor was clearly visualized by 3D MRA, which became more evident with the growth of the tumor xenograft. In contrast, the intratumoral vasculature in the LS180 tumor was sparser and much less developed than that in KT005 tumors. Blood vessels with a diameter as small as 100 microm based on histology were visualized using 0.033 mmol Gd/kg of G6-(1B4M-Gd)192. In conclusion, intratumoral vasculature with a 100-microm diameter was visualized better using 3D MRA with G6-(1B4M-Gd)192 than with Gd-DTPA.

Dynamic micro-magnetic resonance imaging of liver micrometastasis in mice with a novel liver macromolecular magnetic resonance contrast agent DAB-Am64-(1B4M-Gd)(64)

DAB-Am64-(1B4M-Gd)(64) is a newly synthesized macromolecular liver magnetic resonance imaging (MRI) contrast agent with a polypropylenimine diaminobutane (DAB) dendrimer conjugated with a bifunctional diethylenetriaminepentaacetic acid (DTPA) derivative for complexing Gd(III) atoms. The characteristics of DAB-Am64-(1B4M-Gd)(64), which quickly accumulated in the liver, have been reported recently. In the present study, the dynamic micro-MRI with DAB-Am64-(1B4M-Gd)(64) was obtained in the mouse liver metastasis model using colon carcinoma cells to evaluate the ability to visualize the micrometastatic tumors compared with that using Gd-DTPA. The dynamic micro-MRI with DAB-Am64-(1B4M-Gd)(64) was able to homogeneously enhance the normal liver parenchyma and visualize micrometastatic tumors of 0.3-mm diameter in the liver of the mice with better contrast than that with Gd-DTPA. In conclusion, DAB-Am64-(1B4M-Gd)(64) is a new liver MRI contrast agent potentially useful for diagnosis of micrometastasis in the liver.

Avidin-dendrimer-(1B4M-Gd)(254): a tumor-targeting therapeutic agent for gadolinium neutron capture therapy of intraperitoneal disseminated tumor which can be monitored by MRI

Peritoneal carcinomatosis is a late stage in cancer progress, for which no effective therapeutic modality exists. Targeting therapeutic agents to disseminated lesions may be a promising modality for treating peritoneal carcinomatosis. Gadolinium ((157,155)Gd) is known to generate Auger and internal conversion electrons efficiently by irradiation with a neutron beam. Auger electrons from neutron-activated Gd(III) are strongly cytotoxic, but only when Gd(III) atoms have been internalized into the cells. In the present investigation, we have developed a quickly internalizing tumor-targeting system to deliver large quantities of Gd(III) atoms into tumor cells to generate the Auger emission with an external neutron beam. Simultaneously, one would be able to image its biodistribution by MRI with a shortened T1 relaxation time. Avidin-G6-(1B4M-Gd)(254) (Av-G6Gd) was synthesized from generation-6 polyamidoamine dendrimer, biotin, avidin, and 2-(p-isothiocyanatobenzyl)-6-methyl-diethylenetriaminepentaacetic acid (1B4M). The Av-G6Gd was radiolabeled with Gd(III) doped with (153)Gd. All of the 1B4M's on the conjugate were fully saturated with Gd(III) atoms. An in vitro internalization study showed that Av-G6Gd accumulated and was internalized into SHIN3 cells (a human ovarian cancer) 50- and 3.5-fold greater than Gd-DTPA (Magnevist) and G6-(1B4M-Gd)(256) (G6Gd). In addition, accumulation of Gd(III) in the cells was detected by the increased signal on T1-weighted MRI. A biodistribution study was performed in nude mice bearing intraperitoneally disseminated SHIN3 tumors. Av-G6Gd showed specific accumulation in the SHIN3 tumor (103% ID/g) 366- and 3.4-fold greater than Gd-DTPA (0.28% ID/g, p < 0.001) and G6Gd (30% ID/g, p < 0.001) 1 day after i.p. injection. Seventy-eight percent of the tumor-related radioactivity of Av-G6Gd in the SHIN3 tumor was located inside the cells. The SHIN3 tumor-to-normal tissue ratio was greater than 17:1 in all organs and increased up to 638:1 at 1 day after i.p. injection. In conclusion, a sufficient amount (162 ppm) of Av-G6Gd was accumulated and internalized into the SHIN3 cells both in vitro and in vivo to kill the cell using (157/155)Gd with external irradiation with an appropriate neutron beam while monitoring with MRI. Thus, Av-G6Gd may be a promising agent for Gd neutron capture therapy of peritoneal carcinomatosis. This reagent also has the potential to permit monitoring of its pharmacokinetic progress with MRI.

Primary diffuse tracheobronchial amyloidosis: radiologic findings

Reports detailing the radiologic features of tracheobronchial amyloidosis are scant and typically describe only the computed tomography findings of this disease. No reports have described the magnetic resonance (MR) findings of tracheobronchial amyloidosis. With this case, the authors describe the radiologic findings in a patient with diffuse tracheobronchial amyloidosis, focusing particularly on the MR and bone scintigraphy findings in this disease.

Enhancement of the therapeutic outcome of radio-immunotherapy by combination with whole-body mild hyperthermia

To enhance the effect of radio-immunotherapy for solid cancers, whole-body mild hyperthermia was added, and its effects on the pharmacokinetics of radiolabelled antibody, outcome of radio-immunotherapy, and radiosensitivity of the tumour were investigated. Nude mice bearing human colon cancer xenografts were heated to 40 degrees C for 3 or 6 h. After heating, mice received intravenous (i.v.) injections of [131I]-labelled anti-carcinoembryonic antigen (CEA) monoclonal antibody. Although 6-h heating did not alter the biodistribution of the radiolabelled antibody, and alone did not show any therapeutic effect on tumour growth, when combined with radio-immunotherapy, the therapeutic effect on tumour growth was significantly enhanced. Three-hour heating also significantly enhanced the effect of radio-immunotherapy. Colony formation assay showed that the radiosensitivity of the tumour was significantly enhanced after heating, which was achieved by a reduction of the hypoxic fraction of the tumour. In conclusion, the addition of whole-body mild hyperthermia significantly enhanced the therapeutic effect of radio-immunotherapy by increasing the radiosensitivity of the tumour.

Tumour enhancement with newly developed Mn-metalloporphyrin (HOP-9P) in magnetic resonance imaging of mice

The purpose of the study is to evaluate the tumour enhancing characteristics and biodistribution of a newly developed metalloporphyrin derivative, HOP-9P (13, 17-bis (1-carboxypropionyl) carbamoylethyl-3, 8-bis (1-phenylpropyloxyethyl)-2,7,12,18-tetra- methyl-porphynato manganese (III)). Seven mice bearing SCC VII tumours were imaged using T1-weighted conventional spin echo magnetic resonance images before and 5 min, 2 h and 24 h after intravenous injection of 0.1 mmol/kg of HOP-9P. For the acquired images, signal intensities of the tumour, muscle and oil-phantom were measured. Then, tumor/oil and tumor/muscle signal intensity ratios were calculated. Nineteen mice were sacrificed before or after the administration of HOP-9P (at 5 min, 2 h and 24 h), and the biodistribution of manganese in the tumour, muscle, liver, blood and kidneys was measured using optical emission spectrometers and was expressed as micrograms of manganese per gram of tissue. The tumour/muscle signal intensity ratio at 24 h (3.18 +/- 0.34) was significantly higher than precontrast ratio (1.77 +/- 0.20) (P < 0.05). The biodistribution assessment of manganese demonstrated that HOP-9P gradually and consistently accumulated in the tumour to reach the highest concentration at 24 h (3.49 +/- 1.22 micro gMn/g). It is concluded that HOP-9P is a potential tumour-specific MR contrast agent.

Clinical Value of Positron Emission Tomography with FDG for Recurrent Ovarian Cancer

OBJECTIVE

Recurrence is often a major problem for patients who have undergone surgery for ovarian cancer. This prospective study was undertaken to evaluate the clinical contribution of positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) for recurrent ovarian cancer.

SUBJECTS AND METHODS

Twenty-four women who had undergone surgery or chemoradiotherapy for histopathologically proven ovarian cancer were enrolled in this study. Ovarian cancer was thought to have recurred in 12 of these women because of evidence on conventional imaging modalities or tumor marker measurements (group A). Clinical findings for the remaining 12 women showed them to be disease-free (group B). PET findings for the women were compared with the final diagnoses obtained by histopathology or by clinical follow-up. The clinical contribution of PET was assessed by evaluating whether PET yielded information complementing the findings of conventional modalities and by examining its impact on treatment.

RESULTS

PET gave valuable information for seven of 12 patients in group A in addition to the information obtained from findings on conventional imaging, and treatment was affected in five patients. On the other hand, in group B, additional information was obtained in only three of 12 patients, and treatment of only one patient was affected. Overall sensitivity, specificity, and accuracy of conventional imaging modalities were 72.7%, 75.0%, and 73.3%, respectively, and these rates improved to 92.3%, 100.0%, and 94.4%, respectively, by considering both conventional imaging modalities and PET findings.

CONCLUSION

Our preliminary data suggest that whole-body PET with FDG can be a complementary modality for following up patients who have had ovarian cancer, especially patients believed to be at risk for recurrence.

Appearance of vascular endothelial growth factor (VEGF) in femoral head in the growing rat

In this study, we examined the appearance of vascular endothelial growth factor (VEGF) in the femoral head of the growing rat using an immunocytochemical technique. Our results showed VEGF-immunopositive cells existed in the inner region and peripheral region of the femoral head at each developmental stage. In the 19-day-old fetus, immunopositive mesenchymal cells were demonstrated in the peripheral region of the femoral head. At 1 to 10 days after birth, VEGF immunoreactivities were observed in the osteoblasts, osteoclasts, periosteum, perichondrium and cartilage matrix of the femur. At 15 days after birth, VEGF immunoreactive chondrocytes appeared in the apex area of the femoral head. In this stage, the femoral head is still constituted by chondrocytes and no apparent vascular formation has been observed. Thereafter, the immunopositive chondrocytes in the femoral head increased in number. The penetration of capillaries was recognized within the ligament of the femoral head at 60 days after birth. The results indicate that some chondrocytes in the femoral head produce VEGF before the beginning of ossification, and that VEGF may play an important role in the penetration of blood vessels into the femoral head from the ligament of the femoral head.

(99m)Tc-HYNIC-derivatized ternary ligand complexes for (99m)Tc-labeled polypeptides with low in vivo protein binding

6-Hydrazinopyridine-3-carboxylic acid (HYNIC) is a representative agent used to prepare technetium-99m ((99m)Tc)-labeled polypeptides with tricine as a coligand. However, (99m)Tc-HYNIC-labeled polypeptides show delayed elimination rates of the radioactivity not only from the blood but also from nontarget tissues such as the liver and kidney. In this study, a preformed chelate of tetrafluorophenol (TFP) active ester of [(99m)Tc](HYNIC)(tricine)(benzoylpyridine: BP) ternary complex was synthesized to prepare (99m)Tc-labeled polypeptides with higher stability against exchange reactions with proteins in plasma and lysosomes using the Fab fragment of a monoclonal antibody and galactosyl-neoglycoalbumin (NGA) as model polypeptides. When incubated in plasma, [(99m)Tc](HYNIC-Fab)(tricine)(BP) showed significant reduction of the radioactivity in high molecular weight fractions compared with [(99m)Tc](HYNIC-Fab)(tricine)(2.) When injected into mice, [(99m)Tc](HYNIC-NGA)(tricine)(BP) was metabolized to [(99m)Tc](HYNIC-lysine)(tricine)(BP) in the liver with no radioactivity detected in protein-bound fractions in contrast to the observations with [(99m)Tc](HYNIC-NGA)(tricine)(2.) In addition, [(99m)Tc](HYNIC-NGA)(tricine)(BP) showed significantly faster elimination rates of the radioactivity from the liver as compared with [(99m)Tc](HYNIC-NGA)(tricine)(2.) Similar results were observed with (99m)Tc-labeled Fab fragments where [(99m)Tc](HYNIC-Fab)(tricine)(BP) exhibited significantly faster elimination rates of the radioactivity not only from the blood but also from the kidney. These findings indicated that conjugation of [(99m)Tc](HYNIC)(tricine)(BP) ternary ligand complex to polypeptides accelerated elimination rates of the radioactivity from the blood and nontarget tissues due to low binding of the [(99m)Tc](HYNIC)(tricine)(BP) complex with proteins in the blood and in the lysosomes. Such characteristics would render the TFP active ester of [(99m)Tc](HYNIC)(tricine)(BP) complex attractive as a radiolabeling reagent for targeted imaging.