RENEB Inter-Laboratory Comparison 2021: Inter-Assay Comparison of Eight Dosimetry Assays

Tools for radiation exposure reconstruction are required to support the medical management of radiation victims in radiological or nuclear incidents. Different biological and physical dosimetry assays can be used for various exposure scenarios to estimate the dose of ionizing radiation a person has absorbed. Regular validation of the techniques through inter-laboratory comparisons (ILC) is essential to guarantee high quality results. In the current RENEB inter-laboratory comparison, the performance quality of established cytogenetic assays [dicentric chromosome assay (DCA), cytokinesis-block micronucleus assay (CBMN), stable chromosomal translocation assay (FISH) and premature chromosome condensation assay (PCC)] was tested in comparison to molecular biological assays [gamma-H2AX foci (gH2AX), gene expression (GE)] and physical dosimetry-based assays [electron paramagnetic resonance (EPR), optically or thermally stimulated luminescence (LUM)]. Three blinded coded samples (e.g., blood, enamel or mobiles) were exposed to 0, 1.2 or 3.5 Gy X-ray reference doses (240 kVp, 1 Gy/min). These doses roughly correspond to clinically relevant groups of unexposed to low exposed (0-1 Gy), moderately exposed (1-2 Gy, no severe acute health effects expected) and highly exposed individuals (>2 Gy, requiring early intensive medical care). In the frame of the current RENEB inter-laboratory comparison, samples were sent to 86 specialized teams in 46 organizations from 27 nations for dose estimation and identification of three clinically relevant groups. The time for sending early crude reports and more precise reports was documented for each laboratory and assay where possible. The quality of dose estimates was analyzed with three different levels of granularity, 1. by calculating the frequency of correctly reported clinically relevant dose categories, 2. by determining the number of dose estimates within the uncertainty intervals recommended for triage dosimetry (±0.5 Gy or ±1.0 Gy for doses <2.5 Gy or >2.5 Gy), and 3. by calculating the absolute difference (AD) of estimated doses relative to the reference doses. In total, 554 dose estimates were submitted within the 6-week period given before the exercise was closed. For samples processed with the highest priority, earliest dose estimates/categories were reported within 5-10 h of receipt for GE, gH2AX, LUM, EPR, 2-3 days for DCA, CBMN and within 6-7 days for the FISH assay. For the unirradiated control sample, the categorization in the correct clinically relevant group (0-1 Gy) as well as the allocation to the triage uncertainty interval was, with the exception of a few outliers, successfully performed for all assays. For the 3.5 Gy sample the percentage of correct classifications to the clinically relevant group (≥2 Gy) was between 89-100% for all assays, with the exception of gH2AX. For the 1.2 Gy sample, an exact allocation to the clinically relevant group was more difficult and 0-50% or 0-48% of the estimates were wrongly classified into the lowest or highest dose categories, respectively. For the irradiated samples, the correct allocation to the triage uncertainty intervals varied considerably between assays for the 1.2 Gy (29-76%) and 3.5 Gy (17-100%) samples. While a systematic shift towards higher doses was observed for the cytogenetic-based assays, extreme outliers exceeding the reference doses 2-6 fold were observed for EPR, FISH and GE assays. These outliers were related to a particular material examined (tooth enamel for EPR assay, reported as kerma in enamel, but when converted into the proper quantity, i.e. to kerma in air, expected dose estimates could be recalculated in most cases), the level of experience of the teams (FISH) and methodological uncertainties (GE). This was the first RENEB ILC where everything, from blood sampling to irradiation and shipment of the samples, was organized and realized at the same institution, for several biological and physical retrospective dosimetry assays. Almost all assays appeared comparably applicable for the identification of unexposed and highly exposed individuals and the allocation of medical relevant groups, with the latter requiring medical support for the acute radiation scenario simulated in this exercise. However, extreme outliers or a systematic shift of dose estimates have been observed for some assays. Possible reasons will be discussed in the assay specific papers of this special issue. In summary, this ILC clearly demonstrates the need to conduct regular exercises to identify research needs, but also to identify technical problems and to optimize the design of future ILCs.

RENEB Inter-Laboratory Comparison 2021: The FISH-Based Translocation Assay

Translocation analysis using fluorescence in situ hybridization (FISH) is the method of choice for dose assessment in case of chronic or past exposures to ionizing radiation. Although it is a widespread technique, unlike dicentrics, the number of FISH-based inter-laboratory comparisons is small. For this reason, although the current Running the European Network of Biological and Physical retrospective Dosimetry (RENEB) inter-laboratory comparison 2021 was designed as a fast response to a real emergency scenario, it was considered a good opportunity to perform an inter-laboratory comparison using the FISH technique to gain further experience. The Bundeswehr Institute of Radiobiology provided peripheral blood samples from one healthy human volunteer. Three test samples were irradiated with blinded doses of 0, 1.2, and 3.5 Gy, respectively. Samples were then sent to the seven participating laboratories. The FISH technique was applied according to the standard procedure of each laboratory. Both, the frequency of translocations and the estimated dose for each sample were sent to the coordinator using a special scoring sheet for FISH. All participants sent their results in due time. However, although it was initially requested to send the results based on the full analysis, evaluating 500 equivalent cells, most laboratories only sent the results based on triage, with a smaller number of analyzed cells. In the triage analysis, there was great heterogeneity in the number of equivalent cells scored. On the contrary, for the full analysis, this number was more homogeneous. For all three samples, one laboratory showed outlier yields compared to the other laboratories. Excluding these results, in the triage analysis, the frequency of translocations in sample no. 1 ranged from 0 to 0.013 translocations per cell, and for samples no. 2 and no. 3 the genomic mean frequency were 0.27 ± 0.03 and 1.47 ± 0.14, with a coefficient of variation of 0.29 and 0.23 respectively. Considering only results obtained in the triage analysis for sample no. 1, all laboratories, except one, classified this sample as the non-irradiated one. For sample no. 2, excluding the outlier value, the mean reported dose was 1.74 ± 0.16 Gy indicating a mean deviation of about 0.5 Gy to the delivered dose of 1.2 Gy. For sample no. 3 the mean dose estimated was 4.21 ± 0.21 Gy indicating a mean deviation of about 0.7 Gy to the delivered dose of 3.5 Gy. In the frame of RENEB, this is the second FISH-based inter-laboratory comparison. The whole exercise was planned as a response to an emergency, therefore, a triage analysis was requested for all the biomarkers except for FISH. Although a full analysis was initially requested for FISH, most of the laboratories reported only a triage-based result. The main reason is that it was not clearly stated what was required before starting the exercise. Results show that most of the laboratories successfully discriminated unexposed and irradiated samples from each other without any overlap. A good agreement in the observed frequencies of translocations was observed but there was a tendency to overestimate the delivered doses. Efforts to improve the harmonization of this technique and subsequent exercises to elucidate the reason for this trend should be promoted.

RENEB Inter-Laboratory Comparison 2021: The Dicentric Chromosome Assay

After large-scale radiation accidents where many individuals are suspected to be exposed to ionizing radiation, biological and physical retrospective dosimetry assays are important tools to aid clinical decision making by categorizing individuals into unexposed/minimally, moderately or highly exposed groups. Quality-controlled inter-laboratory comparisons of simulated accident scenarios are regularly performed in the frame of the European legal association RENEB (Running the European Network of Biological and Physical retrospective Dosimetry) to optimize international networking and emergency readiness in case of large-scale radiation events. In total 33 laboratories from 22 countries around the world participated in the current RENEB inter-laboratory comparison 2021 for the dicentric chromosome assay. Blood was irradiated in vitro with X rays (240 kVp, 13 mA, ∼75 keV, 1 Gy/min) to simulate an acute, homogeneous whole-body exposure. Three blood samples (no. 1: 0 Gy, no. 2: 1.2 Gy, no. 3: 3.5 Gy) were sent to each participant and the task was to culture samples, to prepare slides and to assess radiation doses based on the observed dicentric yields from 50 manually or 150 semi-automatically scored metaphases (triage mode scoring). Approximately two-thirds of the participants applied calibration curves from irradiations with γ rays and about 1/3 from irradiations with X rays with varying energies. The categorization of the samples in clinically relevant groups corresponding to individuals that were unexposed/minimally (0-1 Gy), moderately (1-2 Gy) or highly exposed (>2 Gy) was successfully performed by all participants for sample no. 1 and no. 3 and by ≥74% for sample no. 2. However, while most participants estimated a dose of exactly 0 Gy for the sham-irradiated sample, the precise dose estimates of the samples irradiated with doses >0 Gy were systematically higher than the corresponding reference doses and showed a median deviation of 0.5 Gy (sample no. 2) and 0.95 Gy (sample no. 3) for manual scoring. By converting doses estimated based on γ-ray calibration curves to X-ray doses of a comparable mean photon energy as used in this exercise, the median deviation decreased to 0.27 Gy (sample no. 2) and 0.6 Gy (sample no. 3). The main aim of biological dosimetry in the case of a large-scale event is the categorization of individuals into clinically relevant groups, to aid clinical decision making. This task was successfully performed by all participants for the 0 Gy and 3.5 Gy samples and by 74% (manual scoring) and 80% (semi-automatic scoring) for the 1.2 Gy sample. Due to the accuracy of the dicentric chromosome assay and the high number of participating laboratories, a systematic shift of the dose estimates could be revealed. Differences in radiation quality (X ray vs. γ ray) between the test samples and the applied dose effect curves can partly explain the systematic shift. There might be several additional reasons for the observed bias (e.g., donor effects, transport, experimental conditions or the irradiation setup) and the analysis of these reasons provides great opportunities for future research. The participation of laboratories from countries around the world gave the opportunity to compare the results on an international level.

Validity of ultrasound arterial wall vascularization for assessment of vascular inflammation

Background

Vascular inflammation plays a fundamental role in most vascular diseases including atherosclerosis and vasculitis syndrome, in which arterial wall vascularization (AWV) frequently develops. Visualization of AWV is informative in detecting the vascular inflammation but is challenging. A new ultrasound technique (superb micro-vascular imaging [SMI]) allows the detection of extremely low-velocity flows. We examined an availability of SMI for assessment of the instability of atherosclerotic plaques and the activity of Takayasu arteritis (TA).

Methods and results

The study consists of two independent and consecutive parts A and B, examined in carotid stenosis (A) and TA (B), respectively. In part A, 12 patients with symptomatic severe carotid stenosis (CS group) scheduled for carotid endarterectomy were enrolled. In six of 12 patients, preoperative ultrasonography with SMI showed intraplaque neovascularization at the plaque shoulder. Postoperatively, histopathology confirmed the neovessels at the corresponding sites of visualized AWV. SMI had a sensitivity of 67%, specificity of 90% for detection of AWV in CS group. In SMI analysis, false positive findings were caused by motion artifact and arterial wall calcification, and a false negative finding is attributed by intraplaque hemorrhage. In part B, 10 patients with TA were enrolled. All patients underwent 18F-FDG-PET/CT, and its vascular uptake were compared with AWV detected by SMI. Bilateral common carotid arteries (CCA), internal carotid arteries and common iliac arteries were examined by SMI. Active vascular 18F-FDG uptake (max SUV &gt;2.1) were found at five sites in three patients, which were not significantly correlated with the prevalence of macaroni sign, increase in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Of note, SMI revealed AWV at five sites corresponding to uptake of 18F-FDG, with a sensitivity/specificity of 100% and 98%, positive predictive value 71%, and a negative predictive value 100%.

Conclusion

SMI enables visualization of AWV at vulnerable plaque in CS patients and at 18F-FDG positive sites in TA patients. SMI has potential as a modality to detect the vascular inflammation.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research, Japan

Utility of superb microvascular imaging for assessment of foot perfusion in patients with critical limb ischemia

Background

Recently, an increasing attention has been paid to foot microcirculation in critical limb ischemia (CLI). Although skin perfusion pressure (SPP) is the most frequently used marker of microcirculation, SPP is often unmeasurable at the most ischemic site in the foot. A new ultrasound technique (superb micro-vascular imaging [SMI]) allows the detection of extremely low velocity flows and enables the quantitative verification as vascular index (VI). We examined the diagnostic value of SMI-based VI in assessing foot perfusion when planning endovascular treatment (EVT).

Methods

Consecutive 50 patients with CLI were enrolled. All cases underwent EVT for superficial femoral arteries. SMI-based VI of plantar, dorsal, medial heel, lateral heel and toe's area were obtained before and after EVT, and those were compared with SPP (plantar and dorsal) or ankle-brachial index (ABI) representing macrocirculation.

Results

Based on the six angiosomes concept, SMI enabled to visualize microcirculation in all subjects, but SPP was not feasible in 13% of all subjects at the most ischemic site. After EVT, ABIs were significantly increased from 0.64±0.19 to 0.85±0.27 (P=0.0003). Plantar SPP also increased from 39.6±20.4 mmHg to 58.5±27.1 mmHg (p=0.002). SMI-based VI significantly increased in each sites based on the six angiosomes concept. Of note, plantar SMI-based VI significantly increased from 5.1±3.2% to 10.6±6.6% (p&lt;0.0001), suggesting improvement of foot perfusion. Plantar SMI-based VI was well correlated with plantar-SPP both before and after EVT (p=0.002, r=0.663). Plantar VI was also informative in showing a rapid improvement of foot perfusion during EVT.

Conclusion

SMI enabled to visualize the foot microcirculation on the basis of angiosomes concept. SMI has potential as an alternative to SPP.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in -Aid for Scientific Reseach, Japan

CAPABILITIES OF THE ARADOS-WG03 REGIONAL NETWORK FOR LARGE-SCALE RADIOLOGICAL AND NUCLEAR EMERGENCY SITUATIONS IN ASIA

In 2015, the Asian Radiation Dosimetry Group established a regional network of biological dosimetry laboratories known as the ARADOS-WG03 (Working Group 03; Biological Dosimetry). A survey was conducted in 2017 to evaluate the capabilities and capacities of the participating laboratories for emergency preparedness and responses in large-scale nuclear and/or radiological incidents. The results of this survey were identified and assessed. The data provide important information on the current state of emergency cytogenetic biological dosimetry capabilities in the Asian region.

An inflammatory pulmonary insult post-traumatic brain injury worsens subsequent spatial learning and neurological outcomes

BACKGROUND

Severe traumatic brain injury (TBI) patients are at high risk for early aspiration and pneumonia. How pneumonia impacts neurological recovery after TBI is not well characterized. We hypothesized that, independent of the cerebral injury, pneumonia after TBI delays and worsens neurological recovery and cognitive outcomes.

METHODS

Fifteen CD1 male mice were randomized to sham craniotomy or severe TBI (controlled cortical impact [CCI] - velocity 6 m/s, depth 1.0 mm) ± intratracheal lipopolysaccharide (LPS-2 mg/kg in 0.1 mL saline) as a pneumonia bioeffector. Neurological functional recovery by Garcia Neurologic Testing (GNT) and body weight loss were recorded daily for 14 days. On Days 6-14, animals underwent Morris Water Maze learning and memory testing with cued trials (platform visible), spatial learning trials (platform invisible, spatial cues present), and probe (memory) trials (platform removed, spatial clues present). Intergroup differences were assessed by the Kruskal-Wallis test with Bonferroni correction (p < 0.05).

RESULTS

Weight loss was greatest in the CCI + LPS group (maximum 24% on Day 3 vs. 8% [Sham], 7% [CCI], both on Day 1). GNT was lowest in CCI + LPS during the first week. Morris Water Maze testing demonstrated greater spatial learning impairment in the CCI + LPS group vs. Sham or CCI counterparts. Cued learning and long-term memory were worse in CCI + LPS and CCI as compared to Sham.

CONCLUSION

A pneumonia bioeffector insult after TBI worsens weight loss and mortality in a rodent model. Not only is spatial learning impaired, but animals are more debilitated and have worse neurologic performance. Understanding the adverse effects of pneumonia on TBI recovery is the first step d patients.

BIODOSIMETRY AND BIODOSIMETRY NETWORKS FOR MANAGING RADIATION EMERGENCY

Biological dosimetry enables individual dose reconstruction in the case of unclear or inconsistent radiation exposure situations, especially when a direct measurement of ionizing radiation is not or is no longer possible. To be prepared for large-scale radiological incidents, networking between well-trained laboratories has been identified as a useful approach for provision of the fast and trustworthy dose assessments needed in such circumstances. To this end, various biodosimetry laboratories worldwide have joined forces and set up regional and/or nationwide networks either on a formal or informal basis. Many of these laboratories are also a part of global networks such as those organized by World Health Organization, International Atomic Energy Agency or Global Health Security Initiative. In the present report, biodosimetry networks from different parts of the world are presented, and the partners, activities and cooperation actions are detailed. Moreover, guidance for situational application of tools used for individual dosimetry is given.

Cerebral Edema and Neurological Recovery after Traumatic Brain Injury Are Worsened if Accompanied by a Concomitant Long Bone Fracture

Progression of severe traumatic brain injury (TBI) is associated with worsening cerebral inflammation, but it is unknown how a concomitant bone fracture (FX) affects this progression. Enoxaparin (ENX), a low molecular weight heparin often used for venous thromboembolic prophylaxis, decreases penumbral leukocyte (LEU) mobilization in isolated TBI and improves neurological recovery. We investigated if TBI accompanied by an FX worsens LEU-mediated cerebral inflammation and if ENX alters this process. CD1 male mice underwent controlled cortical impact (CCI) or sham craniotomy with or without an open tibial FX, and received either ENX (1 mg/kg, three times/day) or saline for 2 days following injury. Randomization defined four groups (Sham, CCI, CCI+FX, CCI+FX+ENX, n = 10/group). Two days after CCI, neurological recovery was assessed with the Garcia Neurological Test (GNT); intravital microscopy (LEU rolling and adhesion, microvascular leakage) and blood hemoglobin levels were also evaluated. Penumbral cerebral neutrophil sequestration (Ly-6G immunohistochemistry [IHC]) were evaluated post-mortem. In vivo LEU rolling was greater in CCI+FX (45.2 ± 4.8 LEUs/100 μm/min) than in CCI alone (26.5 ± 3.1, p = 0.007), and was suppressed by ENX (23.2 ± 5.5, p = 0.003 vs. CCI + FX). Neurovascular permeability was higher in CCI+FX (71.1 ± 2.9%) than CCI alone (42.5 ± 2.3, p < 0.001). GNT scores were lower in CCI+FX (15.2 ± 0.2) than in CCI alone (16.3 ± 0.3, p < 0.001). Hemoglobin was lowest in the CCI+FX+ENX group, lower than in Sham or CCI. IHC demonstrated greatest polymorphonuclear neutrophil (PMN) invasion in CCI+FX in uninjured cerebral territories. A concomitant long bone FX worsens TBI-induced cerebral LEU mobilization, microvascular leakage, and cerebral edema, and impairs neurological recovery at 48 h. ENX suppresses this progression but may increase bleeding.

Clinical Experience of 123I-IMP Scintigraphy in Detecting Vertebral Bone Metastases of Hepatocellular Carcinoma

Although bone scintigraphy with 99mTc-MDP is a sensitive diagnostic method to detect bone metastasis, it is not specific for malignancy. A radioactive substance which accumulates specifically into metastatic lesions should be of value. 123I-IMP and bone scintigraphy with 99mTc-MDP were consecutively performed in patients with vertebral bone metastases from hepatocellular carcinoma and lumbar spondylosis deformans in a 7-day interval or shorter. The intensity of uptake was compared. Eighteen of the 20 metastatic lesions (90%) were classified as increased uptake areas in 123I-IMP scintigraphy. MDP-scintigraphy disclosed 16 metastatic lesions (80%), 9 as “hot” lesions (56%) and 7 as “cold” lesions (44%). 123I-IMP scintigraphy was negative in all 12 lesions of lumbar spondylosis deformans. Compared to MDP-scintigraphy, 123I-IMP scintigraphy was more sensitive in detecting vertebral bone metastases of hepatocellular carcinoma with smaller rates of false-positive and false-negative findings.

Chondroitin Sulfate Iron Colloid as MR Contrast Agent in Differentiation between Hepatocellular Carcinoma and Adenomatous Hyperplasia

Using a 1.5 T MR imaging unit, T1- and T2-weighted images were obtained before and after i.v. administration of chondroitin sulfate iron colloid (CSIC) in order to differentiate hepatocellular carcinoma (n = 20) from adenomatous hyperplasia without atypia (n = 16). Differentiation was made from the tumor-liver contrast to noise ratio (CNR) and visual evaluation of the nodule, with reference to signal intensity relative to that of the surrounding liver. The CNR of adenomatous hyperplasia was on T1-weighted images significantly decreased after CSIC administration (p < 0.01). On T2-weighted images, there was no significant difference in CNR after CSIC administration. On the other hand, the CNR of hepatocellular carcinoma was significantly increased after CSIC administration on both T1- and T2-weighted images (p < 0.01). CSIC reflects intratumor reticuloendothelial cellular functions, and is therefore useful in differentiating hepatocellular carcinoma from adenomatous hyperplasia without atypia.

Double Contrast MR Imaging with Iron Colloid and Gd-DTPA in Cholangiocellular Carcinoma

Double contrast MR imaging with combined use of chondroitin sulfate iron colloid (CSIC) and Gd-DTPA was attempted in 3 cases of cholangiocellular carcinoma (CCC). In all cases, nonenhanced spin echo T1- and T2-weighted images, and T1-weighted images after i.v. injection of Gd-DTPA were obtained. Within one week, the MR sequences were repeated one hour after i.v. injection of CSIC. Double contrast (CSIC/Gd-DTPA) T1-weighted imaging was evaluated and compared with the other sequences in terms of tumor detectability, tumor spreading and tumor characterization. Double contrast MR imaging was comparable in tumor detectability and superior as to the evaluation of spreading and characterization to the other MR imaging modalities.

Chondroitin Sulfate Iron Colloid-Enhanced MR Imaging in Patients with Hepatocellular Carcinoma

Chondroitin sulfate iron colloid (CSIC) was used as an MR contrast agent for the detection of hepatocellular carcinoma (HCC). The findings of 25 surgically confirmed HCCs in 19 patients were retrospectively analyzed. T1-, T2- and proton density-weighted spin echo MR images were obtained before and after i.v. injection of 23.6 μM Fe/kg of CSIC. Unenhanced and CSIC-enhanced MR images and images obtained by CT during arterial portography (CT-AP) were correlated with surgical pathology findings. The sensitivities of CSIC-enhanced and unenhanced MR imaging, and CT-AP were 92%, 80%, and 88%, respectively. No significant differences were noted. Portal flow abnormalities demonstrated by CT-AP did not affect the detection of HCC by CSIC-enhanced MR imaging. CSIC-enhancement at MR imaging was a disadvantage in the detection of lesions less than 1 cm in diameter. CSIC-enhanced MR imaging is a supplemental method for the detection of HCC.

A case of splenic metastasis of ovarian cancer treated with complete laparoscopic splenectomy and transvaginal specimen extraction

A 61-year-old woman was diagnosed with right inguinal lymph node and splenic metastasis of ovarian serous cystadenocarcinoma. We performed right inguinal lymph node dissection and total laparoscopic splenectomy in the supine position followed by transvaginal specimen extraction (TVSE). First, using three ports, we extracted the right inguinal lymph node. We repaired the posterior wall of the inguinal canal using a mesh plug. We added two ports and displaced the spleen from the retroperitoneum and lifted it using a snake retractor, disconnecting the hilum using an automatic suturing device. Next, the posterior wall of the vagina was intraperitoneally incised. And an Alexis® laparoscopic system was inserted into the vagina. The cap maintained aeroperitoneum, a collection bag was inserted in the abdominal cavity via the vagina, and the spleen was collected. When the spleen was removed from the body, partial fragmentation of the organ was required in the bag. Organ fragmentation was performed only within the bag, and we made sure not to tear the bag. The vaginal wound was laparoscopically sutured. The patient had no operative complications and was able to actively ambulate at the first day after surgery due to a slight postoperative pain. Total laparoscopic splenectomy with TVSE in the supine position may be a safe and feasible method for selected female patients. This technique enables minimally invasive surgery for female patients with splenic disease.

Impairment of host resistance to helminthes with age in murine small intestine

Age-associated alterations of Th2 immune responses against nematode parasites are largely unknown. We investigated primary and memory responses against two types of gastrointestinal nematode parasites, Heligmosomoides polygyrus (Hp) and Nippostrongylus brasiliensis (Nb), in aged mice. The small intestinal gene expression of Th2 cytokines was almost unchanged after primary (Nb and Hp) and secondary infection (Hp) in aged mice in contrast to strongly increased small intestinal gene expression of Th2 cytokines in young (3-month-old) mice. Mucus production decreased (Nb), and worm expulsion was impaired (Nb and Hp) compared with the young mice. Immunofluorescent staining revealed that after Hp infection, the number of alternatively activated macrophages, which are induced by Th2 cytokines, was lower in the aged mice. On the other hand, the number of CD4(+) T cells recruited to the worm cysts was normal compared with the young mice. These results suggest that migration of CD4(+) T cells to the host-parasite interface is not affected by ageing. Alterations in Th2 immune responses in aged mice might be due to inappropriate or insufficient activation of CD4(+) T cells in the submucosa.

[A case of Barrett's esophageal carcinoma treated with combined therapy]

During a routine health examination, a 50-year-old man was found to have an elevated lesion at the esophagogastric junction. Poorly differentiated adenocarcinoma was diagnosed from the biopsy findings. Computed tomography showed metastases in the mediastinal, intra-abdominal, and paraaortic lymph nodes. The clinical stage diagnosis was cT2, cN4, cM0, cStage IVa. Combination chemotherapy with docetaxel, CDDP, and 5-FU (DCF) was started initially. After 2 courses of DCF, the primary lesion and mediastinal lymph nodes had decreased in size, but the intra-abdominal lymph node had grown. A curative operation with paraaortic lymph node dissection was considered possible; thus, video-assisted thoracoscopic surgery of the esophagus with 3-field lymph node dissection was performed. The final findings revealed Barrett's esophageal carcinoma, EG, 0-III,23×18 mm, mod-por, CT-pT1b (sm3) pN4, sM0, fStage IV. Histologically, the mediastinal lymph node metastases disappeared with chemotherapy, but no reduction was observed in the abdominal lymph nodes. After surgery, 2 courses of combination adjuvant chemotherapy with CDDP and 5-FU were administered along with 50 Gy of radiotherapy. Subsequently, the treatment was changed to tegafur-gimeracil-oteracil potassium alone on an outpatient basis. The patient remains recurrence free 22 months postsurgery.

[A case of small intestinal cancer in the efferent loop of roux-en Y reconstruction after total gastrectomy and liver metastases]

A 61-year-old woman, who had undergone total gastrectomy and distal splenopancreatectomy with Roux-en Y reconstruction for a gastric cancer 16 years earlier, was found primary small intestinal cancer located in intestinal loop of Roux- en Y in gastrointestinal endoscopy for abdominal pain. Computed tomography showed liver metastases which were 8 cm in diameter at lateral segment and 1 cm in diameter at segment 8 of the liver. In the operation, the small intestinal cancer was located in the ρ-anastomosis in the loop of Roux-en Y with the other jejunum fistula. We performed lateral segment hepatectomy, partial hepatectomy of segment 8, partial resection of small intestine including loop of ρ-Roux-en Y, partial resection of transverse colon, and restoration Roux-en Y again. We succeeded in preserving double tract anastomosis at duodenum. Histological examination revealed a moderately differentiated adenocarcinoma of the small intestine and segment 8 of the liver, and angiomyolipoma of lateral segment of the liver. It is extremely rare for small intestinal cancer to arise in a loop of Roux-en Y reconstruction caused by total gastrectomy.

Biological Dosimetry by the Triage Dicentric Chromosome Assay - Further validation of International Networking

Biological dosimetry is an essential tool for estimating radiation doses received to personnel when physical dosimetry is not available or inadequate. The current preferred biodosimetry method is based on the measurement of radiation-specific dicentric chromosomes in exposed individuals' peripheral blood lymphocytes. However, this method is labour-, time- and expertise-demanding. Consequently, for mass casualty applications, strategies have been developed to increase its throughput. One such strategy is to develop validated cytogenetic biodosimetry laboratory networks, both national and international. In a previous study, the dicentric chromosome assay (DCA) was validated in our cytogenetic biodosimetry network involving five geographically dispersed laboratories. A complementary strategy to further enhance the throughput of the DCA among inter-laboratory networks is to use a triage DCA where dose assessments are made by truncating the labour-demanding and time-consuming metaphase-spread analysis to 20 to 50 metaphase spreads instead of routine 500 to 1000 metaphase spread analysis. Our laboratory network also validated this triage DCA, however, these dose estimates were made using calibration curves generated in each laboratory from the blood samples irradiated in a single laboratory. In an emergency situation, dose estimates made using pre-existing calibration curves which may vary according to radiation type and dose rate and therefore influence the assessed dose. Here, we analyze the effect of using a pre-existing calibration curve on assessed dose among our network laboratories. The dose estimates were made by analyzing 1000 metaphase spreads as well as triage quality scoring and compared to actual physical doses applied to the samples for validation. The dose estimates in the laboratory partners were in good agreement with the applied physical doses and determined to be adequate for guidance in the treatment of acute radiation syndrome.

The effect of nicorandil on small intestinal ischemia-reperfusion injury in a canine model

BACKGROUND

It has been shown that nicorandil, which has both ATP-sensitive K+ (KATP) channel opener-like and nitrate-like properties, has an organ-protective effect in ischemia-reperfusion injury in several experimental animal models.

AIMS

We evaluate the effectiveness of nicorandil on warm ischemia-reperfusion injury of the small intestine in a canine model.

METHODS

Eighteen beagle dogs were divided into three groups: the control group (n=6); the nicorandil group (n=6), to which nicorandil was injected intravenously before the ischemia; and the glibenclamide group (n=6), to which glibenclamide, which closes the KATP channel and does not suppress the nitrate effect of nicorandil, was orally administered, and then nicorandil was injected in the same manner as in the nicorandil group. Both the superior mesenteric artery and vein were clamped for 2 h. Superior mesenteric artery blood flow, small intestinal mucosal tissue blood flow, intramucosal pH, and histopathological analyses were compared among the three groups.

RESULTS

Superior mesenteric artery blood flow, mucosal tissue blood flow and pHi after reperfusion were significantly maintained in the nicorandil in comparison with the control and the glibenclamide groups. The histopathological findings showed less severe mucosal damage after reperfusion in the nicorandil group compared with the other two groups. Between the control group and the glibenclamide group, no significant differences were observed in all those parameters.

CONCLUSION

This study suggests that nicorandil has a protective effect on small intestinal IR injury, and activation of KATP channels plays an important role in inhibiting small intestinal IR injury.

[Intramucosal colorectal carcinomas treated by surgical resection]

Stage 0 colorectal cancer was found only in the innermost lining of the colon and rectum. Treatments for an early stage colorectal cancer were available including endoscopic polypectomy, endoscopic mucosal resection (EMR) and trans-anal or -sacral local excision, laparoscopy-assisted colectomy and open colectomy. Our study indicated that endoscopic therapy for the early stage colorectal cancer was more advantageous than the conventional operative treatment. Although EMR should be applied for intramucosal carcinomas, 11 intramucosal carcinomas were treated by a surgical resection due to several limitations at our institution.

Hemoperfusion with polymyxin B-immobilized fiber column improves liver function after ischemia-reperfusion injury

AIM: To investigate the usefulness of direct hemoperfusion with a polymyxin B-immobilized fiber column (DHP-PMX therapy) for warm hepatic ischemia-reperfusion (I/R) injury after total hepatic vascular exclusion (THVE) using a porcine model.

METHODS: Eleven Mexican hairless pigs weighing 22-38 kg were subjected to THVE for 120 min and then observed for 360 min. The animals were divided into two groups randomly: the DHP-PMX group (n = 5) underwent DHP-PMX at a flow rate of 80 mL/min for 120 min (beginning 10 min before reperfusion), while the control group did not (n = 6). The rate pressure product (RPP): heart rate × end-systolic arterial blood pressure, hepatic tissue blood flow (HTBF), portal vein blood flow (PVBF), and serum aspartate aminotransferase (AST) levels were compared between the two groups.

RESULTS: RPP and HTBF were significantly (P < 0.05) higher in the DHP-PMX group than in the control group 240 and 360 min after reperfusion. PVBF in the DHP-PMX group was maintained at about 70% of the flow before ischemia and differed significantly (P < 0.05) compared to the control group 360 min after reperfusion. The serum AST increased gradually after reperfusion in both groups, but the AST was significantly (P < 0.05) lower in the DHP-PMX group 360 min after reperfusion.

CONCLUSION: DHP-PMX therapy reduced the hepatic warm I/R injury caused by THVE in a porcine model.

Direct hemoperfusion with a polymyxin B-immobilized cartridge in intestinal warm ischemia reperfusion

AIM: To investigate the effectiveness of direct hemoperfusion with polymyxin B-immobilized fibers (DHP-PMX therapy) on warm ischemia-reperfusion (I/R) injury of the small intestine.

METHODS: The proximal jejunum and distal ileum of mongrel dogs were resected. Warm ischemia was performed by clamping the superior mesenteric artery (SMA) and vein (SMV) for 2 h. Blood flow to the proximal small intestine was restored 1 h after reperfusion, and the distal small intestine was used as a stoma. The experiment was discontinued 6 h after reperfusion. The dogs were divided into two groups: the DHP-PMX group (n = 6, DHP-PMX was performed for 180 min; from 10 min prior to reperfusion to 170 min after reperfusion) and the control group (n = 5). The rate pressure product (RPP), SMA blood flow, mucosal tissue blood flow, and intramucosal pH (pHi) were compared between the two groups. The serum interleukin (IL)-10 levels measured 170 min after reperfusion were also compared.

RESULTS: The RPP at 6 h after reperfusion was significantly higher in the PMX group than in the control group (12 174 ± 1832 mmHg/min vs 8929 ± 1797 mmHg/min, P < 0.05). The recovery rates of the SMA blood flow at 1 and 6 h after reperfusion were significantly better in the PMX group than in the control group (61% ± 7% vs 44% ± 4%, P < 0.05, and 59% ± 5% vs 35% ± 5%, P < 0.05, respectively). The recovery rate of the mucosal tissue blood flow and the pHi levels at 6 h after reperfusion were significantly higher in the PMX group (61% ± 8% vs 31% ± 3%, P < 0.05 and 7.91 ± 0.06 vs 7.69 ± 0.08, P < 0.05, respectively). In addition, the serum IL-10 levels just before DHP-PMX removal were significantly higher in the PMX group than in the control group (1 569 ± 253 pg/mL vs 211 ± 40 pg/mL, P < 0.05).

CONCLUSION: DHP-PMX therapy reduced warm I/R injury of the small intestine. IL-10 may play a role in inhibiting I/R injury during DHP-PMX therapy.

Epithelioid Variant of Pleomorphic Liposarcoma in a Heifer

A case of epithelioid variant of liposarcoma in a 31-month-old Japanese Black heifer is described. The tumour mass, which formed in the subcutis of the left cheek, was excised surgically, but this was followed by recurrence and metastasis to lymph nodes. The primary tumour was composed of sheets of lipid-laden cells, and anaplastic larger cells with eosinophilic or amphophilic cytoplasm were occasionally seen. In addition to vimentin and S-100 protein expression in the majority of tumour cells, squamous and non-squamous cytokeratins (CKs) were present, mainly in the larger cells, which predominated in the metastatic lesions. The expression of CKs was considered to be evidence of epithelioid differentiation.

Abdominal aortic aneurysm repair in a patient with a congenital solitary pelvic kidney. A case report

Abdominal aortic aneurysm (AAA) is rarely associated witha congenital pelvic kidney. To date only 11 cases have been reported in the literature in which a solitary pelvic' kidney was associated in only 1 patient. Repair of thesaneurysm is technically demanding because the abnormal origin of the renal arteries presents the problem of renal ischemia duringaortic cross-clamping. We report a case of a 77-year-old man who was found to have an AAA associated with a congenital solitary pelvic kidney. An abdominal aortography dearly showed 2 aberrant renal arteries, one of which originated from the aortic wall just above the aortic bifurcation and the other from the left common iliac artery. At surgery, we found other associated anomalies including malrotation of the gut and a left undescended testis. The surgical procedure consisted of an aneurysmorrhaphy followed by a tube graft replacement with therenal arteries being left intact to the distal aortic wall or below. Renal preservation during aortic cross-clamping was achieved by direct perfusion of the upper renal artery with cold lactated Ringer's solution together with topical cooling with ice slush. The patient's postoperative course was uneventful. Urinary output was satisfactory and serum creatinine level remained unchanged throughout his hospital stay. The renal preservation method used in this case was simple and effective.

Gene arrangement at the Rhesus blood group locus of chimpanzees detected by fiber-FISH

The Rhesus (Rh) blood group system in humans is encoded by two genes with high sequence homology. These two genes, namely, RHCE and RHD, have been implied to be duplicated during evolution. However, the genomic organization of Rh genes in chimpanzees and other nonhuman primates has not been precisely studied. We analyzed the arrangement of the Rh genes of chimpanzees (Pan troglodytes) by two-color fluorescence in situ hybridization on chromatin DNA fibers (fiber-FISH) using two genomic DNA probes that respectively contain introns 3 and 7 of human RH genes. Among the five chimpanzees studied, three were found to be homozygous for the two-Rh-gene type, in an arrangement of Rh (5'-->3') - Rh (3'<--5'). Although a similar gene arrangement can be detected in the RH gene locus of typical Rh-positive humans, the distance between the two genes in chimpanzees was about 50 kb longer than that in humans. The remaining two chimpanzees were homozygous for a four-Rh-gene type, in an arrangement of Rh (5'-->3') - Rh (3'<--5') - Rh (3'<--5') - Rh (3'<--5') within a region spanning about 300 kb. This four-Rh-gene type has not been detected in humans. Further analysis of other great apes showed different gene arrangements: a bonobo was homozygous for the three-Rh-gene type; a gorilla was heterozygous for the one-Rh- and two-Rh-gene types; an orangutan was homozygous for the one-Rh-gene type. Our findings on the intra- and interspecific genomic variations in the Rh gene locus in Hominoids would shed further light on reconstructing the genomic pathways of Rh gene duplication during evolution.

A case of intraoperative acute aortic dissection caused by cannulation into an axillary artery

Severe atherosclerotic disease of the ascending aorta is one of the risk factors of dissection of the ascending aorta and cerebral embolism during cardiac operations with cardiopulmonary bypass. Aortic dissection is rare, but once it happens, the mortality rate is high. For the patient with severely atherosclerotic or strongly calcified aorta, we should avoid cannulation into the aorta or clamping of it. In this case, we experienced aortic dissection although we chose the arterial cannulations into the axillary arteries because of the strong calcification of the ascending aorta and the abdominal aorta. The dissection was caused by the cannulation into the axillary artery. Transesophageal echocardiography (TEE) showed the dissection during the operation and the ascending aorta was replaced soon. Early diagnosis and treatment saved the patient. This case showed the following points: 1) cannulation into an axillary artery is not always safe; 2) TEE is very useful to detect the complicated dissection during operation; 3) replacement of the ascending aorta alone can be one of the choices for the treatment of aortic dissection caused by cannulation into an axillary artery.

Assignment of 118 novel cDNAs of cynomolgus monkey brain to human chromosomes

In order to isolate genes that may not be represented in current human brain cDNA libraries, we have sequenced about 20,000 sequence tags of cDNA clones derived from cerebellum and parietal lobe of cynomolgus monkeys (Macaca fascicularis). We determined the entire cDNA sequence of approximately 700 clones whose 5'-terminal sequences showed no homology to annotated putative genes or expressed sequence tags in current databases of genetic information. From this, 118 clones with sequences encoding novel open reading frames of more than 100 amino acid residues were selected for further analysis. To localize the genes corresponding to these 118 newly identified cDNA clones on human chromosomes, we performed a homology search using the human genome sequence and fluorescent in situ hybridization. In total, 108 of 118 clones were successfully assigned to specific regions of human chromosomes. This result demonstrates that genes expressed in cynomolgus monkey are highly conserved throughout primate evolution, and that virtually all had human homologs. Furthermore, we will be able to discover novel human genes in the human genome using monkey homologs as probes.

[Grafting and concomitant left ventricular myotomy-myectomy in a patient with coronary artery disease associated with hypertrophic obstructive cardiomyopathy]

A 44-year-old man complained of chest oppression and systolic murmur. Echocardiography showed subaortic stenosis with outflow gradient of 135 mmHg, interventricular septal thickness of 21 mm, left ventricular posterior wall thickness of 11 mm, and 2/4 mitral regurgitation. Selective coronary angiography demonstrated 75% stenosis in left anterior desending branch. Coronary artery revasculization comcomitant with left ventricular myotomy-myectomy was performed. He had a good recovery from operation, and was discharged in 19th days in NYHA class I. Echocardiography one month after operation showed mild outflow pressure gradient, light systolic anterior motion of mitral anterior leaflet, and 1/4 mitral regurgitation. Careful operative management, including myocardial protection, avoiding perporation of ventricular septum, and postoperative medical care are mandatory to this group of patients. The use of cathecholamine and Ca-blocker will be attentioned because of the increasing the left ventricular pressure gradient.

Cerebral metabolic impairment in patients with obstructive sleep apnoea: an independent association of obstructive sleep apnoea with white matter change

OBJECTIVES

To determine the relation between severity of obstructive sleep apnoea (OSA) and degree of cerebral metabolic impairment.

METHODS

Fifty five patients with habitual snoring and excessive daytime sleepiness underwent standard overnight polysomnography and magnetic resonance spectroscopy separately. Proton MR spectra were measured with two dimensional chemical shift imaging (repetition time; 1500 ms, echo time; 135 ms). Severity of cerebral metabolic impairment was assessed by the N-acetylaspartate (NAA)/choline ratios for the cerebral cortex and white matter. Severity of OSA was assessed by the apnoea-hypopnoea index (AHI) and the minimum value of peripheral oxyhaemoglobin saturation. All patients were evaluated for the presence or absence of comobidities including hypertension, cardiac disease, diabetes mellitus, and hyperlipidaemia. Univariate analysis of variance (ANOVA) and mulitple linear regression analysis were used for statistical analyses.

RESULTS

Univariate ANOVA disclosed significant effects of AHI, age, and the presence or absence of hypertension on the NAA/choline ratio for cerebral white matter (p=0.011, p=0.028, p=0.0496, respectively). The AHI had a significant negative association with the NAA/choline ratio for cerebral white matter, independent of age and the presence or absence of cardiac disease, in the final multivariate regression model (standardised partial regression coefficient=-0.417, p<0.001). No significant relation was found between severity of OSA and the NAA/choline ratio for the cerebral cortex. Age alone had a significant effect on the NAA/choline ratio for the cerebral cortex on univariate ANOVA (p<0.001) and a significant negative association with the NAA/choline ratio for the cerebral cortex in the regression model (r=-0.552, p<0.001).

CONCLUSIONS

A significant relation exists between AHI and the degree of metabolic impairment in cerebral white matter in patients with OSA.

Chromosomal instability in chromosome band 12p13: multiple breaks leading to complex rearrangements including cytogenetically undetectable sub-clones

During fluorescence in situ hybridization (FISH) analysis of metaphase cells from 70 patients with lymphoid and myeloid hematologic malignancies and chromosomal rearrangements involving band 12p13, we identified nine patients (four with lymphoid malignancies, four with myeloid malignancies and one with biphenotypic leukemia) who showed more complicated rearrangements than we had expected from conventional cytogenetic study. In six patients, multiple breaks occurred in small segments of 12p with subsequent translocations and insertions of these segments into other chromosomes, sometimes to unexpected regions. In three patients additional chromosome breaks resulted in a sub-clone which was cytogenetically indistinguishable from the main clone in each patient based on the cytogenetic analysis. These subtle molecular events were detected exclusively in a region covering TEL/ETV6 and KIP1/CDKN1B. Seven of nine had a previous history of chemo/radiotherapy; all the patients showed complex karyotypes, even though they were newly diagnosed with leukemia. Survival data were available in five patients, and all survived less than 6 months. These findings suggest that the 12p13 region, especially the above-mentioned region, is genetically unstable and fragile. It is likely that multiple chromosome breaks were induced through mutagens used in chemo/ radiotherapy, and are associated with a sub-group of patients with an extremely bad prognosis.

First confirmed canine case of Ehrlichia canis infection in Japan

An 11-year-old castrated Pekinese dog that had been moved from Indonesia to Japan eight years previously was diagnosed with an Ehrlichia canis infection by haematological characteristics (normocytic anaemia, mild thrombocytopenia and hypergammaglobulinaemia) and serological findings (antibody titre to E canis 1:3,200 or more). The dog did not respond to treatment with tetracycline and died from renal failure. The diagnosis was confirmed postmortem by pathological evaluation and polymerase chain reaction (PCR) followed by sequencing of the 16S rRNA gene. Typical morulae of Ehrlichia were detected in the cytoplasm of macrophages in spleen tissue by immunohistological staining. Ehrlichia-like organisms were also detected in the spleen by electron microscopy. E canis-specific PCR analysis of DNA extracted from the spleen gave a positive signal, and sequence analysis of the fragment revealed that it was identical to part of the 16s rRNA gene of E canis. The dog was the first confirmed clinical case of E canis infection in Japan.

Comparative FISH mapping of the ancestral fusion point of human chromosome 2

It is known that human chromosome 2 originated from the fusion of two ancestral primate chromosomes. This has been confirmed by chromosome banding and fluorescence in-situ hybridization (FISH) with human chromosome-2-specific DNA libraries. In this study, the order of 38 cosmid clones derived from the human chromosome region 2q12-q14 was exactly determined by high-resolution FISH in human chromosome 2 and its homologous chromosomes in chimpanzees (Pan trogrodydes, 2n=48) and cynomolgus monkeys (Macacafascicularis, 2n = 42). This region includes the telomere-to-telomere fusion point of two ancestral ape-type chromosomes. As a result of comparative mapping, human chromosome region 2q12-q14 was found to correspond to the short arms of chimpanzee chromosomes 12 and 13 and cynomolgus monkey chromosomes 9 and 15. It is noted that no difference was detected in the relative order of the cosmid clones between human and chimpanzee chromosomes. This suggests that two ancestral ape-type chromosomes fused tandemly at telomeres to form human chromosome 2, and the genomic organization of this region is thought to be considerably conserved. In the cynomolgus monkey, however, the order of clones in each homologue was inverted. In addition to cosmid mapping, two chromosome-2-specific yeast artificial chromosome (YAC) clones containing the fusion point were identified by FISH.

Comparison of various techniques of iron oxide-enhanced breath-hold MR imaging of hepatocellular carcinoma

The purpose of our study is to compare qualitatively and quantitatively the abilities of various superparamagnetic iron oxide (SPIO)-enhanced breath-hold magnetic resonance imaging (MRI) techniques to detect hepatocellular carcinoma (HCC). Eight patients with HCCs were imaged. The images were obtained with conventional T2-weighted spin-echo imaging (CSE), half-Fourier single-shot turbo spin-echo (HASTE), single-shot gradient-echo type echo planar imaging (GE-EPI), and single-shot spin-echo type echo planar imaging (SE-EPI) before and after SPIO administration. The liver signal-to-noise ratios (SNRs) in CSE and each EPI sequence were significantly decreased after SPIO administration. GE-EPI had the highest decrease ratio (DR) of liver SNR, followed by SE-EPI (TE=98), SE-EPI (TE=28), CSE, and HASTE in this order. The relative contrasts with GE-EPI and SE-EPI (TE=98) were significantly higher than that with CSE after SPIO administration. On receiver operating characteristic (ROC) analysis, diagnostic accuracy did not differ significantly among the pulse sequences after SPIO administration. GE-EPI and SE-EPI (longer TE) were useful for SPIO-enhanced breath-hold MRI performed to detect HCC.

Low serum lipids suggest severe bone marrow failure in children with aplastic anemia

BACKGROUND

Significantly low serum lipid levels are occasionally seen at the time of diagnosis in children with aplastic anemia (AA). The aim of the present study was to clarify the pathologic and clinical significance of pretreatment serum lipid levels in AA.

METHODS

A questionnaire seeking precise data about AA in pediatric patients, including the initial laboratory data at the time of onset of AA and the clinical course of these patients, was sent to 18 institutes in Japan; 13 institutes responded to the questionnaire. In this retrospective study, data concerning hematologic examination and serum lipids were available for analysis in 127 children with AA. Serum lipoprotein patterns were analyzed using conventional agarose electrophoresis in eight patients. In order to elucidate the cause of hypolipidemia in AA, we assayed serum macrophage colony stimulating factor (M-CSF), which is well known to have apparent cholesterol-lowering activity, by using an enzyme-linked immunosorbent assay in seven patients with hypocholesterolemia and compared the results with those obtained in patients with iron-deficiency anemia (IDA).

RESULTS

We found that pretreatment total cholesterol (TC) and triglyceride levels in the serum correlated well with counts of both nucleated cells and hemopoietic cells in the bone marrow (BM) and were inversely correlated with the lymphocyte ratio in both the BM and peripheral blood. Patients with serum TC lower than 150 mg/dL showed a poor response to any form of therapy except BM transplantation. There was no difference in the serum lipoprotein patterns between the controls and patients examined. The serum M-CSF level was significantly higher in patients with TC levels lower than 150 mg/dL compared with controls.

CONCLUSIONS

These results indicate that the pretreatment serum lipid level may reflect hematopoietic activity within the BM and can help to predict the therapeutic response of each case of AA to treatment with immunosuppressive drugs, corticosteroids and anabolic steroids. These results also indicate that M-CSF may be one of the contributing causes of the hypocholesterolemia that occurs in both AA and IDA.

Relationship between hypersomnia and respiratory disorder during sleep in Prader-Willi syndrome

To assess whether hypersomnia in Prader-Willi syndrome (PWS) patients is related to the respiratory disorder during sleep (RDDS), we made a systematic evaluation regarding the relationship between the two disorders in three patients. All patients showed hypersomnia manifested as the long duration of night sleep and shortened sleep latencies of multiple sleep latency test. Although magnetic resonance imaging and laboratory studies revealed obstruction of the upper airway and mild increase of esophageal pressure during sleep, the number of other apneic episodes or awakenings was not as frequent. From the above results, we speculate that the mechanism of excessive daytime sleepiness in PWS is not caused by RDDS and quite resembles that of essential hypersomnia.

Profound hypothermia and low flow cardiopulmonary bypass in resectioning a massive facial arteriovenous malformation

A 44-year-old woman underwent resection of a massive facial arteriovenous malformation under profound hypothermia and low-flow cardiopulmonary bypass. A left ventricular vent through a small left anterior thoracotomy avoided ventricular distention associated with peripheral cannulation. Low-dose aprotinin was used to improve hemostasis. These techniques thus show promise for the safe application of profound hypothermic cardiopulmonary bypass in noncardiovascular operations.

The Density Profiles of the Dark Matter Halo Are Not Universal

We perform a series of high-resolution N-body simulations designed to examine the density profiles of dark matter halos. From 12 simulated halos ranging in mass from 2x1012 to 5x1014 h-1 M middle dot in circle (represented by approximately 1 million particles within the virial radius), we find a clear systematic correlation between the halo mass and the slope of the density profile at 1% of the virial radius, in addition to the variations of the slope among halos of similar mass. More specifically, the slope is approximately -1.5, -1.3, and -1.1 for galaxy-, group-, and cluster-mass halos, respectively. While we confirm the earlier simulation results that the inner slope is steeper than the universal profile originally proposed by Navarro, Frenk, & White, this mass dependence is inconsistent with several analytical arguments attempting to link the inner slope with the primordial index of the fluctuation spectrum. Thus, we conclude that the dark matter density profiles, especially in the inner region, are not universal.

Gene organization and rearrangements at the human Rhesus blood group locus revealed by fiber-FISH analysis

The human Rhesus (Rh) blood group locus is composed of two highly homologous genes, the RHD and RHCE genes on chromosome 1, encoding the D, C/c, and E/e antigens in common Rh-positive phenotypes. In general, the RHD gene is either absent or grossly deleted in Rh-negative individuals. In this study, gene organization at the RH locus of Japanese donors with different serological phenotypes was directly analyzed by two-color fluorescence in situ hybridization on DNA fibers released from their lymphocytes (fiber-FISH) and by using DNA probes of introns 3 and 7 of the RHCE and RHD genes. Six Rh-positive samples (two with the D+C-c+E+e-, two with the D+C+c-E-e+, and two with the D+C+c+E+e+ phenotype) showed the presence of two RH genes within a region of less than 200 kb on chromosome 1p36.1. Of great interest was the finding that the genes were arranged in the antidromic order of the telomere -RHCE (5'--> 3') -RHD (3'-->5') - centromere. On the other hand, two typical Rh-negative samples (D-C-c+E+e+) showed the presence of only one RHCE gene, as expected. Moreover, further analysis combined with a locus-specific assay of three Rh-negative samples (D-C+c+E+e+, D-C+c+E-e+, and D-C+c-E-e+) showed the possible presence of the RHD gene(s) and complex rearrangements, including partial deletion, duplication, and recombination, in this region; these could be responsible for the Rh-negative phenotype.

Fatal air embolism as a complication of CT-guided needle biopsy of the lung

A CT-guided needle lung biopsy carries a risk of potential air embolization. We present a rare case of air embolization after this procedure. Postmortem CT revealed air in the cerebral arteries and the left ventricle. This complication is extremely rare; however, it becomes fatal when it happens. Several points to prevent this fatal complication are discussed.

Measurement of cerebral mean transit time by dynamic susceptibility contrast magnetic resonance imaging

OBJECTIVE

To determine whether direct measurement of mean transit time from pixels over in-plane vessels on high spatial resolution echo planar imaging is a reliable method for quantitative assessment of cerebral circulation.

METHODS AND MATERIALS

Dynamic susceptibility contrast studies were performed using high spatial resolution echo planar imaging (echo time, 60 ms; field of view, 256 x 192-270 x 203 mm; matrix size, 256 x 192; slice thickness, 4 mm) in ten healthy subjects. Forty sequential measurements of five images between the level of the middle cerebral arteries and that of the centrum semiovale were acquired every 1.5 s before, during, and after intravenous injection of 0.12 mmol/kg of gadopentetate dimeglumine. Mean transit times were calculated from the results of gamma variate fitting to the measured deltaR2* data of the middle cerebral arteries, cerebral cortex and white matter.

RESULTS

The calculated true mean transit times for cerebral cortex and white matter varied greatly among individuals and from side to side even in a given individual. The fitness of regression models for the deltaR2* curves of the middle cerebral arteries was significantly lower than those for cerebral cortex and white matter.

CONCLUSION

Direct measurement of mean transit time from pixels over in-plane vessels was not sufficiently accurate for quantitative assessment of cerebral circulation, probably because the echo planar imaging we used had spatial resolution and dynamic range insufficient for determination of mean transit time for in-plane vessels.