Diffusion tensor imaging of cingulum fibers in mild cognitive impairment and Alzheimer disease

BACKGROUND

Neuroimaging in mild cognitive impairment (MCI) and Alzheimer disease (AD) generally shows medial temporal lobe atrophy and diminished glucose metabolism and cerebral blood flow in the posterior cingulate gyrus. However, it is unclear whether these abnormalities also impact the cingulum fibers, which connect the medial temporal lobe and the posterior cingulate regions.

OBJECTIVE

To use diffusion tensor imaging (DTI), by measuring fractional anisotropy (FA), to test 1) if MCI and AD are associated with DTI abnormalities in the parahippocampal and posterior cingulate regions of the cingulum fibers; 2) if white matter abnormalities extend to the neocortical fiber connections in the corpus callosum (CC); 3) if DTI improves accuracy to separate AD and MCI from healthy aging vs structural MRI.

METHODS

DTI and structural MRI were preformed on 17 patients with AD, 17 with MCI, and 18 cognitively normal (CN) subjects.

RESULTS

FA of the cingulum fibers was significantly reduced in MCI, and even more in AD. FA was also significantly reduced in the splenium of the CC in AD, but not in MCI. Adding DTI to hippocampal volume significantly improved the accuracy to separate MCI and AD from CN.

CONCLUSION

Assessment of the cingulum fibers using diffusion tensor imaging may aid early diagnosis of Alzheimer disease.

Conversion factor for CT dosimetry to assess patient dose using a 256-slice CT scanner

Recent rapid progress in CT technology has yielded equipment with large numbers of detector rows and standard computed tomography dose index (CTDI) is therefore no longer an adequate integration range. An integration range of 300 mm is necessary to accurately measure dose under a nominal beam width of 128 mm due to scattered radiation. However, such a long phantom is inconvenient to use routinely in cone-beam CT patient dose checking. To assess patient dose accurately with standard dosimetry methods, we determined a conversion factor (CF) which was calculated from the weighted dose profile integral (DPI(w)) for the 300 mm integration range with a 300 mm long CTDI phantom using a 300 mm long ionization chamber divided by that for the 100 mm integration range with a standard CTDI phantom (140 mm long) with a 100 mm long chamber. CF values increase with increasing nominal beam width and effective energy in the range from 1.5 to 2.0. CF values can also be adapted for use with other CT systems as their dose profiles are thought to be analogous to those for the 300 mm phantom and are useful in any hospital situation to assess accurate patient doses using standard dosimetry methods.

Quantitative characterization of the corticospinal tract at 3T

BACKGROUND AND PURPOSE

White matter tract-specific imaging will probably become a major component of clinical neuroradiology. Fiber tracking with diffusion tensor imaging (DTI) is widely used, but variability is substantial. This article reports the ranges of MR imaging appearance and right-left asymmetry of healthy corticospinal tracts (CST) reconstructed with DTI.

METHODS

For 20 healthy volunteers, whole-brain DTI data were coregistered with maps of absolute T1 and T2 relaxation times and magnetization transfer ratio (MTR), all acquired at 3T. For each individual, the 2 reconstructed CSTs and their asymmetry were analyzed with respect to the number of fibers reconstructed; tract volume; and individual MR imaging parameters restricted to the tracts. Interscan variability was estimated by repeat imaging of 8 individuals.

RESULTS

Reconstructed fiber number and tract volume are highly variable, rendering them insensitive to abnormalities in disease. Individual tract-restricted MR imaging parameters are more constrained, and their population averages and normal ranges are reported. The average population asymmetry is generally zero; therefore, normal ranges for an index of asymmetry are reported. By way of example, CST-restricted MR imaging parameters and their asymmetries are shown to be abnormal in an individual with multiple sclerosis who had a lesion affecting the CST.

CONCLUSIONS

The results constitute a normative dataset for the following imaging parameters of the CST: T1, T2, MTR, fractional anisotropy, mean diffusivity, transverse diffusivity, and the 3 diffusion tensor eigenvalues. These data can be used to identify, characterize, and establish the significance of changes in diseases that affect the CST.

An intraoperative sentinel lymph node identification in breast cancer patients guided by near-infrared fluorescence imaging: Preliminary results

10776

Background: Recently, radioactive tracer, a vital dye, or a combination of both has been applied to detect intraoperative sentinel lymph nodes (SLN) in early breast cancers. In this study, we present a novel method in SLN identification that provides with high detection and low false-negative rates. Methods: This study enrolled 19 patients with a tumor less than 3 cm in diameter. Their mean age was 49.6 years. Preoperative TNM stage was I in 13 cases, IIa in 4, and IIb in 2, respectively. Initially the combination dye of indocyanine green and indigocarmine was injected subdermally in the areolar. Fluorescence imaging (photodynamic eye: Hamamatsu Photonics Co.) was obtained using a charge coupled device camera with a cut filter as the detector, and light emitting diodes at 760 nm as the light source. Subcutaneous lymphatic channels draining from the areola to the axilla or other directions were visible by fluorescence imagings immediately. After incising the axillary skin on the disappeared point of fluorescence image, SLN was then dissected under the guidance of fluorescence. Results: In all patient, lymphatic channels and SLN were successfully visualized. SLN was observed before skin incision in two patients. The number of fluorescence SLN ranged from 2 to 11 (mean: 5.5) and blue dyed SLN ranged from o to 6 (mean: 2.3). In the latter, SLN was not identified in one patient. Six patients had lymph node metastases pathologically. All of them were recognized by fluorescence imagings, however, in two patients LN with metastasis were not identified by a vital dye. There were no intra- or postoperative complications associated with SLN identification. Conclusions: This method is feasible and safe to detect SLN intraoperatively with less invasive, real-time observation and no requirement of training. We hope that this method will provide with high detection and low false-negative rates in SLN navigation surgery.

No significant financial relationships to disclose.

Improved motion compensation in 3D-CT using respiratory-correlated segment reconstruction: diagnostic and radiotherapy applications

Conventional respiratory-gated CT and four-dimensional CT (4DCT) are disadvantaged by their low temporal resolution, which results in the inclusion of anatomic motion-induced artefacts. These represent a significant source of error both in radiotherapy treatment planning for the thorax and upper abdomen and in diagnostic procedures. In particular, temporal resolution and image quality are vitally important to accurate diagnosis and the minimization of planning target volume margin due to respiratory motion. To improve both temporal resolution and signal-to-noise ratio (SNR), we developed a respiratory-correlated segment reconstruction method (RS) and adapted it to the Feldkamp-Davis-Kress algorithm (FDK) with a 256 multidetector row CT (256MDCT). The 256MDCT scans approximately 100 mm in the craniocaudal direction with a 0.5 mm slice thickness in one rotation. Data acquisition for the RS-FDK relies on the assistance of a respiratory sensing system operating in cine scan mode (continuous axial scan with the table stationary). We evaluated the RS-FDK for volume accuracy and image noise in a phantom study with the 256MDCT and compared results with those for a full scan (FS-FDK), which is usually employed in conventional 4DCT and in half scan (HS-FDK). Results showed that the RS-FDK gave a more accurate volume than the others and had the same SNR as the FS-FDK. In a subsequent animal study, we demonstrated a practical sorting process for projection data which was unaffected by variations in respiratory period, and found that the RS-FDK gave the clearest visualization among the three algorithms of the margins of the liver and pulmonary vessels. In summary, the RS-FDK algorithm provides multi-phase images with higher temporal resolution and better SNR. This method should prove useful when combined with new radiotherapeutic and diagnostic techniques.

Genetic characterisation of spontaneous ankylosing arthropathy with unique inheritance from Fas-deficient strains of mice

BACKGROUND

The spontaneous onset of macroscopic arthropathy in the ankle of the particular F1 mice descended from two Fas-deficient strains of mice; a mutant substrain of MRL/Mp.Fas(lpr) (MRL/rpl) and C3H/He.Fas(lpr) (C3H/lpr) was recently observed.

AIM

To histopathologically characterise and genetically interpret the unique inheritance mode of disease in this arthropathy model.

METHODS

MRL/rpl, C3H/lpr, (MRL/rpl x C3H/lpr; MC) F1, (C3H/lpr x MRL/rpl; CM) F1 and MCF2 mice were bred under specific pathogen-free conditions. Histopathological grade of arthropathy was determined at 6 months by examination under a light microscope. To search for a linkage locus to the arthropathy, the whole genome of selected 48 male MCF2 mice with 71 polymorphic microsatellite markers was scanned, followed by quantitative trait locus analysis.

RESULTS

The incidence of microscopically defined arthropathy in the male and female MCF1 groups was 100% and 19.4%, respectively. No incidence was observed in the parental strains, MRL/rpl and C3H/lpr, and in CMF1 mice. In the MCF1 mice, the arthropathy mainly affected the ankle joints and was histopathologically characterised by marked entheseal proliferation with chondrocytic differentiation and ossification in the ankle joints, the manifestations similar to ankylosing enthesitis reported previously. An MRL/rpl-derived autosomal dominant susceptibility locus was mapped in the distal of D7Mit68 (60 cM) to the ankylosis onset.

CONCLUSION

The MCF1 mice stably develop spontaneous ankylosing disorders in the ankle, with a male predominance. The unique inheritance mode of ankylosis is possibly interpreted by the genetic interaction between the autosomal dominant locus and a Y-linked locus.

Spontaneous formation of vanadium "molecules" in a geometrically frustrated crystal: AlV2O4

We investigated the charge-ordered (CO) state in spinel AlV2O4 by electron diffraction, synchrotron x-ray diffraction, and magnetic measurements. It was found that the CO structure appearing below 700 K is characterized by the formation of V clusters (heptamers), each of which is consisting of 7 vanadium atoms and is in a spin-singlet state as a total. Theoretical consideration indicates that this unique molecularlike V heptamer is stabilized by a strong bonding of vanadium t(2g) orbitals.

Volumetric coronary angiography using the 256-detector row computed tomography scanner: comparison in vivo and in vitro with porcine models

PURPOSE

To investigate the feasibility of volumetric cine imaging in human cardiac studies by comparing in vivo and in vitro coronary angiography using a 256-detector row computed tomography (CT) without ECG gating.

MATERIAL AND METHODS

The left and right coronary arteries of two domestic pigs were scanned in vivo and in vitro in cine mode using the 256-detector row CT. The device scanned approximately 100 mm in the cranio-caudal direction with one rotation, with a slice thickness of 0.5 mm.

RESULTS

The coronary arteries could be observed to the third-degree branches in vitro, but could be visualized clearly only to the proximal portion (first-degree or second-degree branches) in vivo.

CONCLUSION

Application of cardiac volumetric cine imaging with 256-detector row CT may be a promising means of obtaining diagnostic information and has potential for adoption to human studies.

Current management of treatment-induced bone loss in women with breast cancer treated in the United Kingdom

New therapeutic options in breast cancer have improved survival but consequently increase the relevance of late complications. Ovarian suppression/ablation and aromatase inhibitors (AI) in the adjuvant setting have improved outcome, but have clinically important adverse effects on bone health. However, investigation and management of cancer treatment-induced bone loss (CTIBL) is poorly defined with no national guidance. In 2004, a questionnaire was sent to over 500 breast surgeons and oncologists who treat breast cancer within the United Kingdom. The questionnaire evaluated access to bone densitometry and specialist expertise as well as attitudes to investigation of CTIBL and anticipated changes in the use of AI for postmenopausal early breast cancer. A total of 354 completed questionnaires were received, 47 from clinicians not currently treating breast cancer. Of the 307 evaluable questionnaires, 164 (53%) were from breast surgeons, 112 (36%) from clinical oncologists and 31 (10%) from medical oncologists. Although most respondents recognised that CTIBL was the responsibility of the treating breast team, investigations for CTIBL are limited even though most had adequate access to bone densitometry; 98 (32%) had not requested a DXA scan in the last 6 months and 224 (73%) had requested fewer than five scans. In all, 235 (76%) were not routinely investigating patients on AI for bone loss. A total of 277 (90%) felt that their practice would benefit from national guidelines to manage these patients, and the majority (59%) had little or no confidence in interpreting DXA results and advising on treatment. This questionnaire has highlighted clear deficiencies in management of CTIBL in early breast cancer. The development of national guidelines for the management of these patients and educational initiatives for breast teams are urgently required.

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

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

Establishment of a mass-production system for NADP using bacterial inorganic polyphosphate/ATP-NAD kinase

The inorganic polyphosphate/ATP-dependent NAD kinase (Ppnk) of Mycobacterium tuberculosis was applied to the mass-production of NADP from NAD and inorganic polyphosphate (metaphosphate). When Ppnk purified from recombinant Escherichia coli cells overexpressing the M. tuberculosis Ppnk was used, 30 mM (27 g/l) NADP was produced from 50 mM NAD and 100 mg/ml metaphosphate at 37 degrees C and pH 7.0. The recombinant E. coli cells were immobilized in polyacrylamide gel, and treated with acetone to render the cells permeable to substrates and products. When acetone-treated immobilized cells were used, 16 mM (14 g/l) NADP was produced from 50 mM NAD and 100 mg/ml metaphosphate at 37 degrees C and pH 7.0. The isolation of NADP formed in the reaction mixture was easy because of the absence of by-products (ATP degradation compounds), and this NADP production system using purified Ppnk or immobilized recombinant E. coli cells expressing Ppnk is thought to be feasible in the production of NADP on an industrial scale.

Fluoroquinolone resistance in hematopoietic stem cell transplant recipients with infectious complications

The infectious complications are an important cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients. Our retrospective study has the objective to evaluate the incidence, clinical and bacteriologic features of documented infections in these patients. The frequency of infectious complications was analysed in 42 patients with hematologic malignancies who received HSCT from January to December 2002 at Pisa General Hospital. Thirty-three patients underwent autologous HSCT and 9 received allogeneic HSCT. All patients received acyclovir, fluconazole and fluoroquinolones as prophylactic regimen. A total of 38 infectious episodes were recognized in 22 patients during the early post-HSCT period (N=27) and in the late post-HSCT period (N=11). Infectious complications rate correlated positively with the deepness and length of neutropenia in the early period. There were 21 episodes of sepsis (the majority by coagulase negative staphylococci), 2 pneumonias and 1 vertebral osteomyelitis. All staphylococcus strains were, in vitro, resistant to oxacillin and ciprofloxacin and 8 out of 15 gram negative rods were resistant to ciprofloxacin. Most of the infectious complications were cured with appropriated antimicrobial therapy and/or with engraftment and, in 4 cases, with central catheter removal. One patient developed a positive CMV antigenemia; a pre-core mutant form of HBV reactivation was diagnosed in another patient. No cases of invasive fungal infections were recognised. Five patients died but only one from infection (septic shock). Pneumonia was a coexisting cause of death in 2 patient in the late period. We can conclude that most of infectious complications, that occurred in the early period post-HSCT were due to coagulase negative staphylococci and gram negative rods resistant to ciprofloxacin. For this reason, the usefulness of fluoroquinolone prophylaxis in HSCT recipients should be reevaluated.

Ferromagnetic microstructure in double exchange manganites

Ferromagnetic (FM) microstructures in double-exchange manganites, La0.825Sr0.175MnO3, were examined by low-temperature Lorentz microscopy. It was found that the FM domains with the stripe pattern were in the FM metallic phase of La0.825Sr0.175MnO3. The FM insulator phase induced by the substitution of Al ions for Mn in La0.825Sr0.175MnO3 was characterized as a complex mixture of the characteristic FM domains, which consists of three types of FM domains: the stripe domains, the plate-shaped domains and the complicated wavy domains. It is suggested that this mixture of different types of FM domains breaks the coherence of the electric conductivity and gives rise to the insulating character in Al doped La0.825Sr0.175MnO3.

Bone remodeling at the iliac crest can predict the changes in remodeling dynamics, microdamage accumulation, and mechanical properties in the lumbar vertebrae of dogs

We previously demonstrated that suppression of bone remodeling allows microdamage to accumulate, thereby leading to reduced bone toughness in dog bone. In this study we evaluated the relationships between bone remodeling at the iliac crest and skeletal activation frequency, microdamage accumulation, or biomechanical properties of lumbar vertebrae using the same dogs to determine whether bone remodeling at the iliac crest can predict damage accumulation and mechanical parameters of the lumbar spine following treatment with antiresorptive agents. Thirty-six female beagles, 1 to 2 years old, were divided into three groups. The control group was treated daily for 12 months with saline vehicle. The remaining two groups were treated daily with oral risedronate at a dose of 0.5 mg/kg/day, or alendronate at 1.0 mg/kg/day orally. The doses of these bisphosphonates were 5 to 6 times the clinical doses approved for treatment of osteoporosis in humans. After sacrifice, the right ilium and L2 vertebra were assigned to histomorphometry. The left ilium and L3 vertebra were used for microdamage analysis. The L4 vertebra was mechanically tested to failure in compression, and bone toughness calculated from the stress-strain curve. There was a strong positive relationship for activation frequency (Ac.f) between ilium and lumbar vertebrae (r2 = 0.82; P < 0.0001). Iliac crest Ac.f underestimates Ac.f in L2, but L2 Ac.f reaches a minimum threshold and does not decline further when iliac crest Ac.f is below 0.10/yr. Microdamage (Cr.S.Dn) accumulation at the ilium was significantly associated with increased microdamage accumulation in the L3 lumbar vertebra (r2 = 0.43, P < 0.0001). The data also show that bisphosphonate treatment increased Cr.S.Dn at a faster rate in L3 than in the iliac crest. Although bisphosphonate treatment decreased bone toughness in L4, this decrease demonstrated no relationship to decreased Ac.f in the ilium. These results clearly indicate that bone remodeling data obtained from iliac crest biopsy could be used to estimate the activation frequency and microdamage burden in the vertebral column.

[Histophenotypical variants of squamous cell carcinoma of the skin]

Cutaneous squamous cell carcinoma (SCC) is, in its most frequent presentation, a moderately aggressive neoplastic disease. It can, however, present in a moltitude of clinico-pathological variants, some of which are characterized by a more malignant attitude. It is important to determine which tumors, among the various histophenotypes, are high risk in order to establish the appropriate treatment and follow-up. Histologic subtype has been considered as a possible variable in determining the prognosis of cutaneous SCC. We report our experience with 3 cases of peculiar variants of cutaneous SCC.

[Role of lymphadenectomy in the treatment of Merkel-cell tumors in i and ii stages]

Merkel cell carcinoma (MCC) is a rare, malignant skin cancer, exhibiting neuroendocrine differentiation, with a significant incidence of locoregional lymph nodal involvement (40%-73%). The accepted staging system classifies MCC as: stage I, localized skin disease; stage II, regional lymph node disease; stage III, metastatic disease. The clinical differentiation of stage I and II patients is difficult and understaging is frequent. Surgery, as first approach, represents the leading treatment for this neoplasm and, depending on stage consists in: local wide excision for stage I patients and local excision and lymphadenectomy for stage II. In our experience, lymphadenectomy, included in the initial treatment of all stage II patients, seemed to influence positively the prognosis. In comparing stage related recurrence and survival rates the results we obtained were better in stage II patients, where lymphadenectomy was included in the initial treatment than in stage I subjects, who received local excision alone as first treatment and lymphadenectomy as secondary treatment for nodal recurrence (overall recurrence rate 86% vs 20%, survival rate 71% vs 80% in stage I vs stage II patients). The performance of lymphadenectomy for stage I MCC could be reconsidered both for a more reliable staging of the disease and for a positive impact on recurrence and survival rates.

Augmentation of post transplant immunity: antigen encounter at the time of hematopoietic stem cell transplantation enhances antigen-specific donor T-cell responses in the post transplant repertoire

After transplant, the immune system is reconstituted by cells derived from both hematopoietic stem cells and peripheral expansion from differentiated donor T cells. After transplant, immune function is poor despite transplantation of mature lymphocytes from immune-competent donors. We tested the hypothesis that early antigen encounter at the time of cell transplant would improve the desired donor T-cell responses. Two independent models of peptide-specific T-cell responses were studied. The model for CD4 cells employed T cells from transgenic (Tg) DO11.11 mice that constitutively express the T-cell receptor for the class II-restricted ovalbumin peptide 323-339. The model for CD8 cells employed non-Tg H2-Db-restricted T-cell responses to the influenza nucleoprotein peptide 366-374. As measured both functionally and by direct imaging of T cells using clonotypic reagents, encounter with specific antigen at the time of T-cell transplantation led to clonal expansion of donor T cells and preservation of donor T-cell function in the post transplant immune environment. Antigen-specific donor T-cell function was poor if antigen encounter was delayed or omitted. Severe parent>F1 graft-versus-host reactions blocked the effect of early antigen exposure. Vaccination of transplant recipients against microbial or leukemia antigens may be worthy of study.

Regimen-related toxicity following reduced-intensity stem-cell transplantation (RIST): comparison between Seattle criteria and National Cancer Center Common Toxicity Criteria (NCI-CTC) version 2.0

Acute regimen-related toxicity (RRT) is minimal in reduced-intensity stem-cell transplantation (RIST). However, the Seattle RRT grading (Bearman et al), developed in the context of conventional-intensity transplantation, is frequently applied to RIST. We compared the National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 2.0 with the Seattle criteria after RIST in 86 patients. RRT within 30 days of transplant graded by both sets of criteria were significantly associated with the outcome confirming the predictive value of both the systems. A total of 15 patients died of disease progression, and 12 of transplant-related mortality: RRT (n = 2), graft-versus-host disease (GVHD) (n = 7), infection (n = 1), and others (n = 2). GVHD-related deaths primarily resulted from infections after steroid treatment (n = 6) and bronchiolitis obliterans (n = 1). This study shows that NCI-CTC is appropriate in toxicity evaluation of RIST, and that its application to RIST enables a toxicity comparison between RIST and other types of cancer treatments. Since GVHD is a significant problem in RIST, modifications are required to evaluate immunological complications following RIST.

Bronchoalveolar lymphocytosis correlates with human T lymphotropic virus type I (HTLV-I) proviral DNA load in HTLV-I carriers

BACKGROUND

A study was undertaken to investigate the pathogenesis of pulmonary involvement in human T lymphotropic virus type I (HTLV-I) carriers.

METHODS

The bronchoalveolar lavage (BAL) cell profile of 30 HTLV-I carriers (15 asymptomatic HTLV-I carriers (AHCs) and 15 symptomatic HTLV-I carriers (SHCs)) with chronic inflammatory diseases of respiratory tract and eight patients with HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) was investigated. The HTLV-I proviral deoxyribonucleic acid (DNA) load in peripheral blood mononuclear cells (PBMCs) and BAL fluid from HTLV-I carriers was estimated using the quantitative polymerase chain reaction method and the correlation between the lymphocyte number in BAL fluid and the HTLV-I proviral DNA load in PBMCs and BAL fluid was examined.

RESULTS

The percentage of lymphocytes in BAL fluid was increased (>18%) in 11 of 30 HTLV-I carriers although there was no significant difference compared with control subjects. In HTLV-I carriers the lymphocyte number in BAL fluid correlated well with the copy number of HTLV-I proviral DNA in PBMCs. In addition, the copy number of HTLV-I proviral DNA in BAL fluid correlated well with the number of lymphocytes (both CD4+ and CD8+ cells) in BAL fluid.

CONCLUSIONS

These findings suggest that pulmonary lymphocytosis can occur in a subset of HTLV-I carriers without HAM/TSP and that the increased HTLV-I proviral DNA load may be implicated in the pathogenesis of pulmonary involvement in HTLV-I carriers.

Expression of cholesteryl ester transfer protein (CETP) in germinal centre B cells and their neoplastic counterparts

AIMS

Cholesteryl ester transfer protein (CETP) is known to facilitate the transfer of lipids between plasma lipoproteins. Previous studies on human tissues have determined that the spleen contains large amounts of CETP mRNA, while the exact location of CETP in such organs remains unknown. In the present study, our aim was to locate CETP protein expression at the cellular level in human normal and neoplastic lymphoid organs.

METHODS AND RESULTS

In-situ hybridization (ISH) and immunohistochemistry were applied to pathology specimens. A specific rabbit anti-CETP antibody was used for immunohistochemical analysis, together with another CETP-specific monoclonal antibody. A riboprobe for ISH was derived from CETP cDNA. Immunohistochemically, CETP was localized in germinal centre B cells and a proportion of marginal zone B cells. ISH showed that CETP mRNA was located mostly in the same areas. When 141 malignant lymphomas of various subtypes were studied, high expression of CETP, equivalent to that found in normal germinal centre B cells, was demonstrated in lymphoma subtypes that are currently regarded as the neoplastic counterparts of primarily germinal centre B cells.

CONCLUSION

CETP localizes B cells in germinal centres, a proportion of post-germinal centre B cells and their neoplastic counterparts.

Nano-sized domains related to dielectric anomaly in YFe2O4-delta

We examined microstructures related to the charge ordering in YFe2O4-delta, by transmission electron microscopy. It is found that two types of characteristic diffuse scatterings appear at room temperature. One is characteristic diffuse streaks elongated along the [0001] direction through the (1/3 1/3 2/3 0)-type reciprocal positions and the other is diffuse spots at (1/3 - eta 1/3 - eta 2/3 + 2eta 0)-type incommensurate positions (eta approximately 0.066). Real-space images revealed that the former diffuse scattering is related to nano-domains due to the charge ordering and the latter one is related to those due to vacancy ordering. The presence of the nano-sized domains should be strongly related to the dielectric anomalies found in YFe2O4-delta.

Japanese multicenter phase II and pharmacokinetic study of rituximab in relapsed or refractory patients with aggressive B-cell lymphoma

BACKGROUND

To evaluate the efficacy and feasibility of rituximab monotherapy in Japanese patients with relapsed or refractory aggressive B-cell lymphoma.

PATIENTS AND METHODS

Sixty-eight patients were treated with rituximab at 375 mg/m(2) by eight consecutive weekly infusions. Pretreatment variables affecting overall response rate (ORR) and progression-free survival (PFS) and the relationship between pharmacokinetic parameters and efficacy were analyzed.

RESULTS

The ORRs of 68 enrolled patients and 57 eligible patients were 35% [95% confidence interval (CI) 24% to 48%] and 37% (95% CI 25% to 51%), respectively. Median PFS of 53 evaluable patients was 52 days, whereas time to progression of 21 eligible responders was 245 days. Mild to moderate infusion-related toxicities were observed frequently at the first infusion, but all of them were reversible. Elevated lactate dehydrogenase (LDH) and refractoriness to prior chemotherapy were unfavorable factors affecting ORR and PFS (P <0.01). Serum trough levels of rituximab and area under the concentration-time curve for responders were higher than for non-responders (P <0.05).

CONCLUSIONS

Eight consecutive weekly infusions of rituximab have significant anti-lymphoma activity for relapsed or refractory aggressive B-cell lymphoma. Several pretreatment variables and serum rituximab levels are useful for predicting its efficacy.

Clinical significance of cytomegalovirus (CMV) antigenemia in the prediction and diagnosis of CMV gastrointestinal disease after allogeneic hematopoietic stem cell transplantation

To evaluate the clinical significance of a cytomegalovirus (CMV) antigenemia assay in the prediction and diagnosis of CMV gastrointestinal (CMV-GI) disease after hematopoietic stem cell transplantation (HSCT), 19 allogeneic HSCT recipients developing CMV-GI disease were retrospectively reviewed. All patients were monitored by a CMV antigenemia assay, at least once weekly after engraftment. The median onset of CMV-GI disease occurred 31 days post transplant (range: 19-62). Only four of 19 patients (21%) developed a positive CMV antigenemia test before developing CMV-GI diseases. Although all 19 patients subsequently developed positive CMV antigenemia tests during their clinical courses, the values remained at a low-level in nine (47%) patients. Among the 14 patients in whom results of real-time polymerase chain reaction (PCR) were available, seven (50%) yielded positive results of real-time PCR before developing CMV-GI disease. In contrast to the values of CMV antigenemia, all 14 patients exclusively yielded high viral loads (median: 2.8 x 10(4) copies/ml plasma). We conclude that CMV antigenemia testing has limited value in prediction or early diagnosis of CMV-GI disease, and that real-time PCR could have a more diagnostic significance.

Holoprosencephaly--topologic variations in a liveborn series: a general model based upon MRI analysis

We present an MRI-based anatomic analysis of a series of 9 human brains, representing lobar, semilobar and alobar forms of holoprosencephaly. The analysis of these variable forms of the malformation is based upon a topologic systematics established in a prior analysis of a homogeneous set of semilobar malformations. This systematics has the dual advantage that it serves both as a uniform reference for qualitative description and as a quantitative descriptive base for mathematical correlations between parameters of topology and of growth and development. Within this systematics, the prosencephalic midline is divided from caudal to rostral into diencephalic (DD-right and left, subthalamus through suprachiasmatic junction with telencephalon), telencephalic (TT-right and left, suprachiasmatic border of telencephalon midline to hippocampal commissure) and diencephalic-telencephalic (DT-right and left-hippocampal commissure through temporal limb of choroid fissure) segments. The topologic abnormality of the initial semilobar series was expressed in an orderly rostral to caudal gradient along the TT segment. In each malformation, normal midline topology began with a small posterior corpus callosum. Although the topologic anomaly in the present series invariably also involved the TT segment, this involvement was not continuous and was variably associated with anomalies of the DD in 6 and unilaterally of the DT in 1 brain. In the present as well as with the earlier series of HPE malformations but not in "normative brains," total telencephalic growth is strongly correlated with the length of the midline telencephalic segment. We propose that this system of analysis will be sensitive to the developmental stage and locus of expression of genetic and non-genetic determinants of the formal origin of HPE. For all of the present series, karyotype anlyses were normal. Mutations in the Shh and Zic2 genes were excluded in 2 cases.

Late hemorrhagic cystitis after reduced-intensity hematopoietic stem cell transplantation (RIST)

We reviewed medical records of 256 patients to investigate the frequency and characteristics of hemorrhagic cystitis (HC) associated with reduced-intensity stem cell transplantation (RIST) as opposed to conventional stem cell transplantation (CST); 137 patients underwent CST and 119 RIST. Diagnosis of HC was made based on two or more episodes of sterile, macroscopic hematuria with normal coagulation profiles, without any evidence of renal stones or genitourinary malignancy. Actuarial frequency of HC development in RIST group was 7.6% (9/119), which gave a cumulative annual incidence of 11.7%. In CST group, 13 of 137 patients (9.5%) developed HC, giving an estimated annual incidence of 9.7%. The probability of developing HC was similar between the two groups (P=0.77). The viral etiologies of HC, adenovirus (n=12) and BK virus (n=2), were documented in eight patients after RIST and in six after CST. HC was milder and of a shorter duration, with less blood transfusion requirements, in RIST group than in CST group. A multivariate analysis revealed that HC was associated with antiadenovirus antibody positivity in the recipients, total dose of busulfan, and chronic GVHD. Although HC following RIST is less severe than that following CST, it is still a significant problem.

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Cerebellar hemangioendothelioma

We report a 26-year-old woman with cellular hemangioendothelioma that may be the third case diagnosed as cerebellar hemangioendothelioma. The tumor was composed of numerous vascular channels lined by endothelial cells and aggregates of large round endothelial cells. Transitional cells were also present. The large round cells were positive for CD34 and vimentin in their abundant cytoplasm that contained 1 or some red blood cells, revealing intracytoplasmic lumina. The patient remains free of disease over 5 years after tumor resection.

Control of carrier density by self-assembled monolayers in organic field-effect transistors

Organic thin-film transistors are attracting a great deal of attention due to the relatively high field-effect mobility in several organic materials. In these organic semiconductors, however, researchers have not established a reliable method of doping at a very low density level, although this has been crucial for the technological development of inorganic semiconductors. In the field-effect device structures, the conduction channel exists at the interface between organic thin films and SiO(2) gate insulators. Here, we discuss a new technique that enables us to control the charge density in the channel by using organosilane self-assembled monolayers (SAMs) on SiO(2) gate insulators. SAMs with fluorine and amino groups have been shown to accumulate holes and electrons, respectively, in the transistor channel: these properties are understood in terms of the effects of electric dipoles of the SAMs molecules, and weak charge transfer between organic films and SAMs.

Evaluation of neuronal cell death after a new global ischemia model in infant mice

For the first time we set up a new model for global ischemia in the infant mice, and time-dependent changes of the blood-brain barrier (BBB) disruption and neuronal cell death were investigated in detail. Infant C57/B16 mice (postnatal 13 days) were anesthetized with inhalation of sevoflurane in N2O/O2 (70/30%) and were subjected to global ischemia by bilateral common carotid artery occlusion (CCAO) for 25 minutes. Disruption of BBB was noted at 4 hours and increased up to 24 hours after the injection of 2% Evan's Blue in the transient CCAO (tCCAO) model. Evaluation of neuronal cell death was determined with toluidine blue staining. Morphological changes of neurons after tCCAO were clearly observed in the hippocampal CA1 region but were slightly detected in the CA3 region. However, there were no morphological changes in the hippocampal dentate gyrus, the neocortex, the striatum and the hypothalamus. The number of survival neurons in the CA1 was significantly decreased at 2 days and sustained up to 4 days after tCCAO. These data indicate that this method is very useful to induce selective vulnerability in mouse hippocampus, and it provides a reliable ischemic model in infant mice.

Analysis of sensitization to carboxymethylcellulose: Identification of high risk group using ELISA and histamine release experiment

OBJECTIVE AND DESIGN

Carboxymethylcellulose (CMC) has been considered to be inert and is commonly used as an additive in medicines, foods and cosmetics. However, we experienced a patient who developed an anaphylactic reaction to CMC after an upper gastrointestinal examination using a barium meal containing CMC. Therefore, we examined the incidence of sensitization by CMC in healthy subjects, and categorized the high risk group prone to developing anaphylactic response to CMC.

METHODS

An ELISA for detecting CMC-specific IgE antibody was developed using serum from the patient as a positive control. In the ten subjects exhibiting high anti-CMC IgE among 387 normal populations, histamine release from isolated leukocytes was performed.

RESULTS

Five of ten subjects with a high IgE titer showed a significant CMC-induced histamine release from leukocyte preparations in vitro as observed in the patient, and were classified as high risk group. There was a correlation between sensitization by CMC and that by Japanese cedar pollen. The incidence of sensitization in females was 2.4 fold higher than that in males.

CONCLUSIONS

The combination of ELISA and histamine release experiment made it possible to identify the high risk group for developing anaphylactic response. The administration of high dose CMC as a suspending agent in barium sulfate or injectable corticosteroids to this group should be avoided to prevent anaphylactic reactions in the clinic.

Feasibility of reduced intensity hematopoietic stem cell transplantation from an HLA-matched unrelated donor

To evaluate the feasibility of reduced intensity stem cell transplantation (RIST) with bone marrow from a matched unrelated donor (MUD), we retrospectively investigated 20 patients with hematological disorders who received RIST in the Tokyo SCT consortium from January 2000 to October 2002. The preparative regimens were fludarabine-based (150-180 mg/m(2), n=18) or cladribine-based (0.77 mg/kg, n=2). To enhance engraftment, antithymocyte globulin (ATG) and 4 or 8 Gy total body irradiation (TBI) were added to these regimens in nine and 11 patients, respectively. GVHD prophylaxis was cyclosporine with or without methotrexate. In all, 19 achieved primary engraftment. Three developed graft failure (one primary, two secondary), and five died of treatment-related mortality within 100 days of transplant. Seven of the 19 patients who achieved initial engraftment developed grade II-IV acute GVHD, and seven of 13 patients who survived >100 days developed chronic GVHD. At a median follow-up of 5.5 months, estimated 1-year overall survival was 35%. Compared with a TBI-containing regimen, an ATG-containing regimen was associated with a high risk of graft failure (30 vs 0%, P=0.0737). This study supports the feasibility of RIST from MUD; however, procedure-related toxicities remain significant in its application to patients.