bluuebunny/crossref_metadata_2025 huggingface dataset:
Real‐time cine MRI of ventricular septal motion: A novel approach to assess ventricular coupling
Authors: Francone Marco , Dymarkowski Steven , Kalantzi Maria , Bogaert Jan
Published: February 2005

The purpose of this study was to assess the feasibility of magnetic resonance imaging (MRI) to evaluate in real‐time, the effects of respiration in ventricular septal motion and configuration in normal volunteers and cardiac patients. Real‐time cine MRI studies, using the steady‐state free precession (SSFP) technique, were performed in the cardiac short‐axis during operator‐guided deep inspiration and expiration in normal volunteers (N = 6), and in patients with constrictive pericarditis (CP; N = 6), restrictive cardiomyopathy (RCM; N = 4), chronic cor pulmonale (N = 5), and pericardial effusion. The respiratory effects on septal position and configuration during early ventricular filling were visually assessed. Results were compared with the short‐axis breath‐hold cine MRI studies, obtained at end‐inspiration. In CP patients, onset of inspiration led to a leftward inversion in four of six patients and flattening of the septum in two of six patients during early ventricular filling. Septal abnormalities progressively disappeared during the following heartbeats. A similar pattern was found in one of six patients with pericardial effusion. The above pattern was absent in RCM patients. Although septal flattening during early inspiration was also found in two of six normal volunteers, flattening was minimal compared to that in CP patients. In all cor pulmonale patients, septal flattening or inversion was present, but this was not influenced by respiratory motion. Real‐time cine MRI is a promising technique for determining the influence of respiration on septal motion and might be helpful in differentiating between different causes of impaired ventricular filling. J. Magn. Reson. Imaging 2005;21:305–309. © 2005 Wiley‐Liss, Inc.
Effect of free radical scavenger (tempol) on intrarenal oxygenation in hypertensive rats as evaluated by BOLD MRI
Authors: Li Lu‐Ping , Li Belinda S. Y. , Storey Pippa , Fogelson Laura , Li Wei , Prasad Pottumarthi
Published: February 2005

Purpose

To demonstrate a differential response following administration of a free radical scavenger, tempol, in kidneys of hypertensive compared to normotensive rats.

Material and Methods

Data were obtained in spontaneously hypertensive rats (SHR, N = 5). Wistar‐Kyoto rats (WKY, N = 6) were used as normotensive controls.

Results

Consistent with prior reports, SHRs show a significant response to tempol (R2*decreased from 40.56 ± 0.66 second−1 to 28.58 ± 0.6 second–1 in medulla, P < 0.05), while WKY rats exhibit a minimal change (R2* measuring 22.36 ± 4.38 second–1 pre‐tempol and 21.57 ± 4.78 second–1 post‐tempol, in medulla). The post‐tempol R2* in SHR was found to be comparable to pre‐tempol values in WKY rats, suggesting an improved medullary oxygenation in SHRs.

Conclusion

Based on both baseline R2* values and the differential effect of the free radical scavenger on renal medullary oxygenation, BOLD MRI can distinguish hypertensive from normal kidney in rats. J. Magn. Reson. Imaging 2005;21:245–248. © 2005 Wiley‐Liss, Inc.
Continuous arterial spin labeling using a train of adiabatic inversion pulses
Authors: Moffat Bradford A. , Chenevert Thomas L. , Hall Daniel E. , Rehemtulla Alnawaz , Ross Brian D.
Published: February 2005

Purpose

To develop a simple and robust magnetic resonance imaging (MRI) pulse sequence for the quantitative measurement of blood flow in the brain and cerebral tumors that has practical implementation advantages over currently used continuous arterial spin labeling (CASL) schemes.

Materials and Methods

Presented here is a single‐coil protocol that uses a train of hyperbolic secant inversion pulses to produce continuous arterial spin inversion for perfusion weighting of fast spin echo images. Flow maps of normal rat brains and those containing a 9L gliosarcoma orthotopic tumor model conditions were acquired with and without carbogen.

Results

The perfusion‐weighted images have reduced magnetization transfer signal degradation as compared to the traditional single‐coil CASL while avoiding the use of a more complex two‐coil CASL technique. Blood flow measurements in tumor and normal brain tissue were consistent with those previously reported by other CASL techniques. Contralateral and normal brain showed increased blood flow with carbogen breathing, while tumor tissue lacked the same CO2 reactivity.

Conclusion

This variation of the CASL technique is a quantitative, robust, and practical single‐coil method for measuring blood flow. This CASL method does not require specialized radiofrequency coils or amplifiers that are not routinely used for anatomic imaging of the brain, therefore allowing these flow measurements to be easily incorporated into traditional rodent neuroimaging protocols. J. Magn. Reson. Imaging 2005;21:290–296. © 2005 Wiley‐Liss, Inc.
Lateglacial and early Holocene palaeoclimatic reconstruction based on glacier fluctuations and equilibrium‐line altitudes at northern Folgefonna, Hardanger, western Norway
Authors: Bakke Jostein , Dahl Svein Olaf , Nesje Atle
Published: February 2005

Northern Folgefonna (c. 23 km2), is a nearly circular maritime ice cap located on the Folgefonna Peninsula in Hardanger, western Norway. By combining the position of marginal moraines with AMS radiocarbon dated glacier‐meltwater induced sediments in proglacial lakes draining northern Folgefonna, a continuous high‐resolution record of variations in glacier size and equilibrium‐line altitudes (ELAs) during the Lateglacial and early Holocene has been obtained. After the termination of the Younger Dryas (c. 11 500 cal. yr BP), a short‐lived (100–150 years) climatically induced glacier readvance termed the ‘Jondal Event 1’ occurred within the ‘Preboreal Oscillation’ (PBO) c. 11 100 cal. yr BP. Bracketed to 10 550–10 450 cal. yr BP, a second glacier readvance is named the ‘Jondal Event 2’. A third readvance occurred about 10 000 cal. yr BP and corresponds with the ‘Erdalen Event 1’ recorded at Jostedalsbreen. An exponential relationship between mean solid winter precipitation and ablation‐season temperature at the ELA of Norwegian glaciers is used to reconstruct former variations in winter precipitation based on the corresponding ELA and an independent proxy for summer temperature. Compared to the present, the Younger Dryas was much colder and drier, the ‘Jondal Event 1’/PBO was colder and somewhat drier, and the ‘Jondal Event 2’ was much wetter. The ‘Erdalen Event 1’ started as rather dry and terminated as somewhat wetter. Variations in glacier magnitude/ELAs and corresponding palaeoclimatic reconstructions at northern Folgefonna suggest that low‐altitude cirque glaciers (lowest altitude of marginal moraines 290 m) in the area existed for the last time during the Younger Dryas. These low‐altitude cirque glaciers of suggested Younger Dryas age do not fit into the previous reconstructions of the Younger Dryas ice sheet in Hardanger. Copyright © 2005 John Wiley & Sons, Ltd.
Evidence for an extreme climatic event on Achill Island, Co. Mayo, Ireland around 5200–5100 cal. yr BP
Authors: Caseldine C. , Thompson G. , Langdon C. , Hendon D.
Published: February 2005

A range of detailed palaeoenvironmental analyses carried out on a series of three peat profiles from Achill Island, Co. Mayo, western Ireland, reveal evidence for an extreme climatic event, probably a storm or series of storms, around 5200–5100 cal. yr BP that caused the deposition of an extensive layer of silt across blanket peat. This event followed a period of relatively dry climate during which Neolithic communities expanded in the region. There was a subsequent period of continuing dry conditions allowing extensive colonisation of the peat by Pinus before a shift to wetter conditions characteristic of the later Holocene. The extreme climatic event is possibly linked to human abandonment of the area comparable to that observed from the work on the internationally significant Céide Fields in the same region. Copyright © 2005 John Wiley & Sons, Ltd.
Pheochromocytoma and functional paraganglioma syndrome: No longer the 10% tumor
Authors: Elder Elisabeth Edström , Elder Grahame , Larsson Catharina
Published: February 2005

Pheochromocytomas and abdominal paragangliomas are catecholamine‐producing tumors of the sympathetic nervous system, while head and neck paragangliomas are non‐secreting tumors of parasympathetic origin. Recent developments in clinical and molecular research on these tumor forms have significantly clarified their genetic backgrounds and challenged the view of “pheochromocytoma as the 10% rule tumor.” Firstly, a larger proportion of these tumors are today discovered in normotensive patients during imaging carried out for other reasons than suspicion of pheochromocytoma. Secondly, although the differential diagnosis between malignant and benign tumors remains a challenge, the risk of malignancy well exceeds the classical 10% in patients with extra‐adrenal disease, and/or carriers of germ‐line SDHB mutations. Finally, up to a third of patients carry a germ‐line mutation in a gene predisposing to pheochromocytoma and/or paraganglioma. Identification of a constitutional mutation in RET, VHL, SDHD, or SDHB has implications for clinical screening and follow‐up for both the patient and for relatives at risk who can be identified by screening for the same mutation. Genetic testing in apparently sporadic cases is therefore regarded as beneficial, especially in patients diagnosed before 50 years of age, and in patients with bilateral, multifocal, malignant and/or extra‐adrenal disease. J. Surg. Oncol. 2005;89:193–201. © 2005 Wiley‐Liss, Inc.
Surgical treatment of non‐functioning pancreatic islet cell tumors
Authors: Kouvaraki Maria A. , Solorzano Carmen C. , Shapiro Suzanne E. , Yao James C. , Perrier Nancy D. , Lee Jeffrey E. , Evans Douglas B.
Published: February 2005

Pancreatic endocrine tumors (PETs) are rare neoplasms originating from the amine precursor uptake and decarboxylation (APUD) stem cells. Although the majority of PETs are sporadic, they frequently occur in familial syndromes. PETs may cause a variety of functional syndromes or symptoms of local progression if they are non‐functional. General neuroendocrine tumor markers are highly sensitive in the diagnostic assessment of a PET. Imaging studies for tumor localization and staging include computer tomography (CT) scan, magnetic resonance imaging (MRI), In111‐octreotide scan, MIBG, and endoscopic ultrasonography (EUS). Treatment of PETs often requires a multi‐modality approach; however, surgical resection remains the only curative therapy for localized (non‐metastatic) disease. Treatment of metastatic disease includes biologic agents, cytotoxic chemotherapy, and liver‐directed therapies. J. Surg. Oncol. 2005;89:170–185. © 2005 Wiley‐Liss, Inc.
From incidentaloma to adrenocortical carcinoma: The surgical management of adrenal tumors
Authors: Shen Wen T. , Sturgeon Cord , Duh Quan‐Yang
Published: February 2005

In this article we review the management of benign and malignant adrenal tumors, with an emphasis on oncologic concerns. Concise, logical guidelines for the diagnosis and operative treatment of incidentalomas, aldosteronomas, adrenal Cushing syndrome, virilizing and feminizing adrenal tumors, isolated adrenal metastases, and adrenocortical carcinoma are provided. We also discuss the choice of optimal surgical approach for performing adrenalectomy (laparoscopic, open, hand‐assist). J. Surg. Oncol. 2005;89:186–192. © 2005 Wiley‐Liss, Inc.
Multiple endocrine neoplasia type 1
Authors: Doherty Gerard M.
Published: February 2005

Multiple endocrine neoplasia‐1 (MEN‐1) is an autosomal dominant inherited syndrome that occurs due to inactivating mutations of the MEN1 gene locus, coding for a tumor‐suppressor protein, menin. The components of MEN‐1 are hyperparathyroidism due to multiple parathyroid adenomas, pancreatic neuroendocrine tumors, and pituitary adenomas, in addition to some less common neoplastic manifestations. Care of people with MEN‐1 requires knowledge of the problems that may arise, and the best approaches to detect and care for the manifestations of this incurable, but manageable, disease. J. Surg. Oncol. 2005;89:143–150. © 2005 Wiley‐Liss, Inc.
Role of 131I in the treatment of well differentiated thyroid cancer
Authors: Woodrum Derek T. , Gauger Paul G.
Published: February 2005

131I is an integral component in postsurgical management of well‐differentiated thyroid cancer (WDTC), which includes papillary and follicular types. 131I is used postsurgically to either destroy remaining thyroid tissue (thyroid ablation) or to treat recurrence and metastases (radioiodine therapy). 131I is no longer a routine diagnostic modality, but it is widely used for remnant ablation after thyroidectomy for WDTC > 1 cm, under conditions of thyroxine withdrawal. It is generally—though not unanimously—accepted that postsurgical radioiodine is the most powerful method by which to lengthen disease‐free survival. 131I cannot be used if the residual thyroid remnant is large; many surgeons therefore perform near‐total or total thyroidectomy for all WDTC > 1 cm. Since 1997, radioiodine treatment has been performed in outpatient settings, where side effects are common, but mild and transient. Secondary screening is by physical exam, thyroglobulin measurements, and 131I diagnostic whole‐body scans. This is performed under conditions of thyrotropin stimulation, which is accomplished either by thyroxine withdrawal or administration of recombinant human thyrotropin. While most cancers are well treated with radioiodine, some advanced cancers may no longer take up radioiodine, rendering them resistant to treatment. For these cancers, redifferentiation therapy and molecular target‐specific medicines hold future promise for improved treatment. J. Surg. Oncol. 2005;89:114–121. © 2005 Wiley‐Liss, Inc.
Light diffraction by a subwavelength circular aperture
Authors: Chang Che-Wei , Sarychev A K , Shalaev V M
Published: February 2005

Diffraction of normally incident light by a
subwavelength circular aperture is calculated analytically. The
aperture is opened on a perfectly conducting planar screen with
infinitesimal thickness. In our model, the aperture is replaced by
uniform magnetic currents and charges. The model allows one to
obtain the normalized cross section for the aperture radius up to
half of the wavelength, which exceeds the 0.2 wavelength limit of
the Bethe-Bouwkamp's dipole model
[1-3]. Also, in addition to
reproducing the (ka)4 dependence, which is characteristic of
the dipole mode, our uniform field model explains the transmission
enhancement obtained in Abajo's numerical simulation
[4].
Splitting of the middle hepatic vein in full-right full-left splitting of the liver
Authors: Broering Dieter C. , Bok Pamela , Mueller Lars , Wilms Christian , Rogiers Xavier
Published: February 2005

Full-right/full-left splitting of the liver offers a chance to overcome the severe shortage of donor organs. During this procedure, the splitting surgeons are always faced with the question of how to share the middle hepatic vein (MHV), since this vein drains parts of both halves of the liver. Consequently, we developed a procedure that splits the MHV, thus creating an MHV on both grafts. In this short article, we report on this splitting technique and our first initial experience. (Liver Transpl 2005;11:350–352.)
Can a leukocyte depletion filter (LDF) reduce the risk of reintroduction of hepatocellular carcinoma cells?
Authors: Gwak Mi Sook , Lee Kwang-Woong , Kim Shi Yeon , Lee Jihyun , Joh Jae Won , Kim Sung Joo , Lee Hwan Hyo , Park Jean Wan , Kim Gaab Soo , Lee Suk-Koo
Published: February 2005

During liver transplantation for hepatocellular carcinoma (HCC) patients, HCC could theoretically be introduced into the systemic circulation when salvaged blood is used with an autotransfusion device. Several reports have shown that some types of leukocyte depletion filters (LDFs) could completely reduce the risk for reintroducing some types of tumor cells. In this study, we tested the ability of the LDF (RCEZ1T, Pall Biomedical Co, NY, USA) to reduce the risk for reintroducing HCC cells in vitro by using a very sensitive detection method. We divided the test group into 6 groups: group I was 10 cells, group II was 20 cells, group III was 2 × 103 cells, group IV was 2 × 105 cells, group V was 2 × 106 cells, and group VI was 2 × 107 cells. The counted cells in 200 mL saline were passed through the RCEZ1T using the force of gravity. To identify the presence of cells, the pellet was resuspended, and polymerase chain reaction (PCR) was performed. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a housekeeping gene, was used as a primer. In groups I and II, the HCC cells were completely filtered in all experiments. However, in groups III, IV, and V, the HCC cells were not completely filtered in a few of the repeated experiments, with the unfiltered rate of tumor cells being between 8% and 20%. In group VI, the HCC cells were not completely filtered in all the repeated experiments. In conclusion, the RCEZ1T filter markedly reduced the risk for reintroduction of HCC cells. However, at high HCC cell load the filter cannot completely remove all the tumor cells. Further studies are required to assess the impact in clinical settings. (Liver Transpl 2005;11:331–335.)
Short-term administration of (-)-epigallocatechin gallate reduces hepatic steatosis and protects against warm hepatic ischemia/reperfusion injury in steatotic mice
Authors: Fiorini Ryan N. , Donovan Jennifer L. , Rodwell David , Evans Zachary , Cheng Gang , May Harold D. , Milliken Charles E. , Markowitz John S. , Campbell Crystal , Haines Julia K. , Schmidt Michael G. , Chavin Kenneth D.
Published: February 2005

Hepatic steatosis increases the extent of cellular injury incurred during ischemia/reperfusion (I/R) injury. (-)-Epigallocatechin gallate (EGCG), the major flavonoid component of green tea (

camellia sinensis

) is a potent antioxidant that inhibits fatty acid synthase (FAS) in vitro. We investigated the effects of EGCG on hepatic steatosis and markers of cellular damage at baseline and after I/R injury in

ob

/

ob

mice. Animals were pretreated with 85 mg/kg EGCG via intraperitoneal (ip) injection for 2 days or oral consumption in the drinking water for 5 days before 15 minutes of warm ischemia and 24 hours of reperfusion. After EGCG administration, total baseline hepatic fat content decreased from baseline. Palmitic acid and linoleic acid levels also were reduced substantially in all ECGC-treated animals before I/R. Alanine aminotransferase (ALT) levels decreased in all EGCG-treated animals compared with control animals after I/R. Histologic analysis demonstrated an average decrease of 65% necrosis after EGCG administration. EGCG administration also increased resting hepatic energy stores as determined by an increase in cellular adenosine triphosphate (ATP) with a concomitant decrease in uncoupling protein 2 (UCP2) before I/R. Finally, there was an increased level of glutathione (GSH) in the EGCG-treated mice compared with the vehicle-treated mice both at baseline and after I/R. In conclusion, taken together, this study demonstrates that treatment with ECGC by either oral or ip administration, significantly protects the liver after I/R, possibly by reducing hepatic fat content, increasing hepatic energy status, and functioning as an antioxidant. (Liver Transpl 2005;11:298–308.)
Herpes zoster infection after liver transplantation: A case-control study
Authors: Levitsky Josh , Kalil Andre , Meza Jane L. , Hurst Glenn E. , Freifeld Alison
Published: February 2005

Prior case series have suggested that herpes zoster (HZ) after orthotopic liver transplantation (OLT) may lead to serious complications due to visceral involvement. We sought to determine the incidence, risk factors, and long term outcomes of HZ after OLT. Clinical data from September 1993 to April 2004 were collected on all cases of HZ after OLT, and at the same post-OLT time points in age, gender, and transplant-year–matched HZ-negative controls. Risk factors for HZ infection and long-term outcomes were compared between cases and controls. A total of 29 patients developed HZ at a median of 4.9 years (range .5–12.9) after OLT. All HZ infections except 1 were localized to a single dermatome. Only 8 (28%) were hospitalized and 16 (55%) were treated with oral antivirals alone. No patients developed visceral involvement or died of HZ infection. No risk factors for HZ infection were identified on multivariate analysis. Of the long-term outcomes, the estimated 10-year survival was lower (

P

= .05) for cases than controls. The lower survival in HZ cases was not directly attributable to HZ infection. In conclusion, this study is the largest series on HZ after OLT. HZ is neither a common nor a serious infection after OLT and can be managed with antiviral therapy with a low likelihood of visceral dissemination. (Liver Transpl 2005;11:320–325.)
Microchimerism after liver transplantation: Absence of rejection without abrogation of anti-donor cytotoxic T-lymphocyte–mediated alloreactivity
Authors: Bettens Florence , Tiercy Jean-Marie , Campanile Nathalie , Giostra Emiliano , Majno Pietro , Rubbia Laura , Roosnek Eddy , Mentha Gilles , Villard Jean
Published: February 2005

Microchimerism (MC) is defined by the persistence of <1% circulating donor cells resulting from cell migration from the graft; MC may play a role in the induction of unresponsiveness to allogeneic tissues, or may be merely the consequence of the graft's acceptance following immunosuppression. To analyze early MC (7 patients) and late MC (12 patients) following a liver transplantation, we designed a sensitive and semiquantitative nested polymerase chain reaction (PCR) protocol based on the detection of incompatible human leukocyte antigen (HLA)-DRB1 donor alleles. MC was measured in multiple PCR samples and expressed as percent positive PCRs / time point. The detection level was 1 donor cell / 105 patient cells. All patients had detectable early MC, ranging from 5 to 100% positive PCRs in the 1st 3 months after transplantation. The kinetic analysis demonstrated that MC decreased during the 1st year in 6 of 7 patients. All of the 4 patients with the lowest MC had rejection episodes, vs. none among the 3 patients with MC >50%. However, cytotoxic T-lymphocyte reactivity (CTL) against HLA class I donor antigens could be demonstrated 1 year posttransplant in 2 patients with a high level of early MC. MC is a dynamic process, which is easily detectable <3 months after liver transplantation. In conclusion, a correlation between the level of early MC and the absence of rejection episodes was observed. However, high levels of early MC did not abrogate the persistence of an alloreactive response measured

in vitro

1 year after transplantation, which suggests that MC did not lead to clonal deletion of donor-specific CTL. (Liver Transpl 2005;11:290–297.)
MARS treatment for a patient presenting with acquired hepatic glutamine synthetase deficiency after orthotopic liver transplantation
Authors: Chiu Alexander , Tam Sidney , Au Wing Yan , Chan See Ching , Liu Chi Leung , Fan Sheung Tat
Published: February 2005

We report a 48-year-old man presenting with refractory hyperammonemia after orthotopic liver transplantation. On investigation he was found to have acquired hepatic glutamine synthetase deficiency, a rare condition that occurs after organ transplantations. The patient was started on continuous venovenous hemofiltration treatment, but the hyperammonemia did not respond. The patient was then subjected to molecular adsorption recirculation system (MARS) therapy and the ammonia level gradually improved with successive treatments. In conclusion, the response was unlikely due to the hemofiltration component of MARS alone but more probably due to the removal of putative albumin-bound toxin by the adsorption circuit that had ameliorated the internal milieu of the graft and reversed the enzyme deficiency. (Liver Transpl 2005;11:353–355.)
Use of Alemtuzumab and Tacrolimus Monotherapy for Cadaveric Liver Transplantation
Authors: Calne Roy Y.
Published: February 2005

We have proposed that the mechanisms of alloengraftment and variable acquired tolerance can be facilitated by minimum posttransplant immunosuppression. It was further suggested that the efficacy of minimalistic treatment could be enhanced by preoperative recipient conditioning with an antilymphoid antibody preparation. A total of 76 adults (38 hepatitis C virus [HCV], 38 HCV) were infused with 30 mg alemtuzumab before primary cadaveric liver transplantation and maintained afterward on daily monotherapy unless breakthrough rejection mandated additional agents. In stable patients, the intervals between tacrolimus doses were lengthened (“spaced weaning”) after approximately 4 months. Eighty-four contemporaneous nonlymphoid-depleted liver recipients (58 HCV, 26 HCV) were treated with conventional postoperative immunosuppression. The overall incidence of rejection was similar with the two strategies of immunosuppression. With follow-ups of 14 to 22 months, patient and primary graft survival in HCV cases are 97% and 90%, respectively, with alemtuzumab depletion plus minimal immunosuppression versus 71% and 70%, respectively, under conventional immunosuppression. In HCV recipients, current patient and graft survival in the alemtuzumab-pretreated group are 71% and 70% versus 65% and 54%, respectively, under conventional treatment. With both strategies of immunosuppression, the adverse effect of preexisting HCV on survival parameters and graft function already was significant at the 1-year milestone, but its extent was not evident until the second year. With or without HCV, 62% of the 64 surviving lymphoid-depleted patients are on spaced immunosuppression, and four patients receive no immunosuppression. Lymphoid depletion with alemtuzumab and minimalistic maintenance immunosuppression is a practical strategy of liver transplantation in HCV recipients but not HCV recipients. Transplantation. 2004 Oct 15;78(7):966–71.
The development of food allergy after liver transplantation
Authors: Boyle Robert J. , Hardikar Winita , Tang Mimi L.K.
Published: February 2005

The acquisition of new food allergy after orthotopic liver transplantation is now a well described phenomenon, mainly reported in children. The etiology of this phenomenon is at present unclear, but has been ascribed by some to tacrolimus treatment. Here we report a case of liver transplant acquired food allergy (LTAFA) in a child who received a split liver graft. The case is remarkable for the absence of new food allergy in the adult recipient of the same graft. This suggests that host-specific factors play an important role in the development of food allergy after liver transplantation, and emphasizes the predisposition that children have toward this phenomenon. Possible mechanisms underlying the development of food allergy after liver transplantation are discussed. In conclusion, tacrolimus treatment alone cannot account for LTAFA. Host factors such as the maturity of immune regulatory mechanisms are likely to play a critical role in the development of new food allergy after a liver transplant. (Liver Transpl 2005;11:326–330.)
Hepatic venous outflow reconstruction in right live donor liver transplantation
Authors: Malago Massimo , Molmenti Ernesto P. , Paul Andreas , Nadalin Silvio , Lang Hauke , Radtke Arnold , Liu Chao , Frilling Andrea , Biglarnia Reza , Broelsch Christoph E.
Published: February 2005

The increasing experience with live donor liver transplantation has allowed for the identification of potential morbidities associated with technical considerations. Technical graft failure can be associated with both inflow and outflow vascular compromise. Although the latter has not always been given the relevance of the former, evidence pointing to its pivotal role continues to mount. We believe that impaired venous outflow was a cause of previously unexplained graft failures during our initial experience. Based on this observation, we developed a technique to prevent the “choking” of the graft at the outflow anastomosis with the inferior vena cava (IVC). The enhanced outflow via a

cloaca maximum

is achieved by reconstructing the graft vessels with preserved veins or arteries (usually iliac vessels are used) from a blood-group-identical or blood-group-compatible deceased organ donor. Alternatively, hepatic vein or portal vein obtained from the resected native liver can be used. The reconstructed common outflow is anastomosed to a triangular opening of the IVC. Such enhanced outflow provides optimal venous drainage, especially during the early phase of growth of the graft. (Liver Transpl 2005;11:364–365.)
Immunosuppression in liver transplantation: Beyond calcineurin inhibitors
Authors: Fung John , Kelly Dympna , Kadry Zakiyah , Patel-Tom Kusum , Eghtesad Bijan
Published: February 2005

Although calcineurin inhibitors (CNIs) remain the mainstay of immunosuppression in liver transplantation (LTX), their long-term toxicity significantly contributes to morbidity and mortality. The elucidation of mechanisms of alloimmunity and leukocyte migration have provided novel targets for immunosuppression development. The toxicities of these agents differ from that of the CNI and act additively or synergistically. CNI avoidance protocols in LTX have not been achieved routinely; however, pilot trials have begun to delineate the limitations and promises of such approaches. CNI–sparing protocols appear to be much more promising in balancing the early need for minimizing rejection while tapering doses and minimizing long-term toxicity. (Liver Transpl 2005;11:267–280.)
New hepatic vein reconstruction in left liver graft
Authors: Takemura Nobuyuki , Sugawara Yasuhiko , Hashimoto Takuya , Akamatsu Nobuhisa , Kishi Yoji , Tamura Sumihito , Makuuchi Masatoshi
Published: February 2005

The incidence of hepatic venous stenosis is higher in partial liver transplantation. New methods for hepatic venous reconstruction in left liver transplantation, which secure wide anastomosis, were devised and are reported here. In the graft, the right side of the middle hepatic vein or the left side of the left hepatic vein was cut longitudinally and a rectangular-shaped vein patch was attached for venoplasty. In the recipient, after the left and middle hepatic veins were joined, the right side of the middle hepatic vein was cut toward the closed right hepatic vein, making a horizontal cavotomy for anastomosis. Of 92 patients who underwent conventional hepatic vein reconstruction, 3 were complicated by hepatic venous stenosis (median follow-up 43 months). By contrast, there were no hepatic vein complications in the 20 patients who underwent the new technique (7 months). The current method appears to be technically feasible for outflow reconstruction in left liver graft transplantation. (Liver Transpl 2005;11:356–360.)
New Spiro‐Functionalized Polyfluorenes: Synthesis and Properties
Authors: Grisorio Roberto , Mastrorilli Piero , Nobile Cosimo Francesco , Romanazzi Giuseppe , Suranna Gian Paolo , Acierno Domenico , Amendola Eugenio
Published: February 2005

Summary: The synthesis of several new spirocycloalkane functionalized polyfluorenes is described. Poly[2,7‐(9,9‐dioctylfluorene)‐alt‐2′,7′‐spiro(cyclohexane‐1,9′‐fluorene)] (PF1), poly[2,7‐(9,9‐dioctylfluorene)‐co‐2′,7′‐spiro(cyclohexane‐1,9′‐fluorene)] (PF2), poly{2′,7′‐bis[(9,9‐dioctylfluoren‐2‐yl)]‐spiro(cyclohexane‐1,9′‐fluorene)‐7,7‐diyl} (PF3), poly[2,7‐(9,9‐dioctylfluorene)‐alt‐2′,7′‐spiro(cyclopropane‐1,9′‐fluorene)] (PF4) and poly[2,7‐(9,9‐dioctylfluorene)‐co‐2′,7′‐spiro(cyclopropane‐1,9′‐fluorene)] (PF5) were synthesized by Pd(0) and Ni(0) mediated coupling reactions. All polymers were characterized by NMR, UV‐vis, DSC‐TGA and PL. Efficient prevention of interchain interactions by the spirocyclohexane moieties guarantees pure blue emission from pristine PF1–3 as revealed by solid state PL spectra. On the other hand, solid state PL spectra of PF4 and PF5 are characterized by an additional emission band in the green region. Thermal annealing on PF1–3 at 150 °C under nitrogen atmosphere does not cause any substantial changes in their solid state PL spectra, whereas after carrying out the same treatment for 20 h at 110 °C under air the polymers show a low‐energy emission band in the green region which is presumably brought about by chemical modifications.

Structure of spiro‐functionalized polyfluorenes synthesized in this study.

magnified image

Structure of spiro‐functionalized polyfluorenes synthesized in this study.
Modification of Polyacrylonitrile Particles and Grafted Films with Oxazolines
Authors: Cabrera Andrés , Böhme Liz M. , Schmidt‐Naake Gudrun
Published: February 2005

Summary: Oxazoline functionalities were introduced onto the surface of polyacrylonitrile particles and polyacrylonitrile‐grafted films by the catalyzed reaction of a substituted aminoalcohol with the nitrile groups. The resulting oxazoline group was reacted with methyl triflate to use the resulting oxazolinium salt as initiator for the ring opening grafting of 2‐ethyl‐2‐oxazoline. The products were characterized with Fourier transform infrared spectroscopy (FTIR), elemental analysis, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The modification of polyacrylonitrile with the substituted aminoalcohol achieves high conversions. Conversely, the amount of grafted 2‐ethyl‐2‐oxazoline is low. The results show that controlled levels of 2‐oxazolines or polyoxazolines can be incorporated onto the surface of polyacrylonitrile.

Reaction of a nitrile group to form an oxazoline functionality.

magnified image

Reaction of a nitrile group to form an oxazoline functionality.
In vivo assessment of absolute perfusion and intracapillary blood volume in the murine myocardium by spin labeling magnetic resonance imaging
Authors: Streif Jörg U. G. , Nahrendorf Matthias , Hiller Karl‐Heinz , Waller Christiane , Wiesmann Frank , Rommel Eberhard , Haase Axel , Bauer Wolfgang R.
Published: February 2005

The absolute perfusion and the intracapillary or regional blood volume (RBV) in murine myocardium were assessed in vivo by spin labeling magnetic resonance imaging. Pixel‐based perfusion and RBV maps were calculated at a pixel resolution of 469 × 469 μm and a slice thickness of 2 mm. The T1 imaging module was a segmented inversion recovery snapshot fast low angle shot sequence with velocity compensation in all three gradient directions. The group average myocardial perfusion at baseline was determined to be 701 ± 53 mL (100 g · min)−1 for anesthesia with isoflurane (N = 11) at a mean heart rate (HR) of 455 ± 10 beats per minute (bpm). This value is in good agreement with perfusion values determined by invasive microspheres examinations. For i.v. administration of the anesthetic Propofol, the baseline perfusion decreased to 383 ± 40 mL (100 g · min)−1 (N = 17, P < 0.05 versus. isoflurane) at a mean heart rate of 261 ± 13 bpm (P < 0.05 versus isoflurane). In addition, six mice with myocardial infarction were studied under isoflurane anesthesia (HR 397 ± 7 bpm). The perfusion maps showed a clear decrease of the perfusion in the infarcted area. The perfusion in the remote myocardium decreased significantly to 476 ± 81 mL (100 g · min)−1 (P < 0.05 versus sham). Regarding the regional blood volume, a mean value of 11.8 ± 0.8 vol % was determined for healthy murine myocardium under anesthesia with Propofol (N = 4, HR 233 ± 17 bpm). In total, the presented techniques provide noninvasive in vivo assessment of the perfusion and the regional blood volume in the murine myocardium for the first time and seem to be promising tools for the characterization of mouse models in cardiovascular research. Magn Reson Med 53:584–592, 2005. © 2005 Wiley‐Liss, Inc.
Implementation issues of multivoxel STEAM‐localized 1H spectroscopy
Authors: Théberge Jean , Menon Ravi S. , Williamson Peter C. , Drost Dick J.
Published: February 2005

Single‐voxel STEAM‐localized spectroscopy studies of neuropsychiatric patients yield high‐quality data at short echo times, but are often limited to only a few regions of interest due to the linear increase of acquisition time with the number of regions examined. A multivoxel STEAM approach increases the number of regions of interest examined with a less than linear increase in acquisition time. Several implementation issues were considered, especially the signal contribution of outer voxel stimulated echoes (OVSE), which can lead to systematic errors in the quantification of relative metabolite concentrations. The relative signal contribution of OVSEs was found to be as great as 30% in phantoms. Gradient polarity switching completely canceled the contribution of OVSEs. A two‐voxel STEAM approach produces phantom and in vivo data quality comparable to single‐voxel STEAM in practically half the time. Quantification precision and accuracy are preserved in phantoms and in vivo. Magn Reson Med 53:713–718, 2005. © 2005 Wiley‐Liss, Inc.
Sodium magnetic resonance imaging of diuresis: Spatial and kinetic response
Authors: Maril Nimrod , Margalit Raanan , Mispelter Joel , Degani Hadassa
Published: February 2005

Renal function is highly correlated with the sodium concentration gradient along the corticomedullary axis. The application of 3D high‐resolution sodium magnetic resonance imaging (MRI) provided a means to quantify in vivo the spatial and temporal changes in renal tissue sodium concentration under normal and diuretic conditions. A detailed, pixel‐by‐pixel analysis of the intact rat kidney sodium MR images yielded a quantitative measure of the corticomedullary sodium gradient before and at early and later times after the administration of two distinct diuretic agents, furosemide and mannitol. Furosemide, a loop diuretic, induced a fivefold reduction in the cortical‐outer medullary sodium gradient, whereas mannitol, an osmotic diuretic, did not affect this gradient. Both diuretics induced a 50% decrease in the sodium concentration of the inner medulla; however, mannitol exerted its effect twice as fast as furosemide with a 2.5‐min exponential decay constant. These specific changes were attributed to the different mechanism of action and site of activity of each diuretic agent. Thus, high‐resolution 23Na MRI offers a unique, noninvasive tool for functional imaging of the kidney physiology. Magn Reson Med 53:545–552, 2005. © 2005 Wiley‐Liss, Inc.
Gradual changes in the apparent diffusion coefficient of water in selectively vulnerable brain regions following brief ischemia in the gerbil
Authors: Lythgoe Mark F. , Thomas David L. , King Martin D. , Pell Gaby S. , van der Weerd Louise , Ordidge Roger J. , Gadian David G.
Published: February 2005

Although selective vulnerability and delayed neuronal death following global ischemia have been recognized in both the human and animal brain, the underlying mechanisms of cell damage are not fully understood. In this study we investigated the time‐dependent changes of the apparent diffusion coefficient (ADC) of water and cerebral blood flow (CBF) in a classic animal model of selective vulnerability and delayed neuronal death, using magnetic resonance (MR) diffusion‐ and perfusion‐weighted imaging. CBF was monitored using the noninvasive MR arterial spin labeling method called flow‐sensitive alternating inversion recovery (FAIR). Bilateral common carotid occlusion was induced for 5 min, followed by 10 hr of reperfusion in a gerbil model. The most notable finding was that the lateral portion of the striatum in the basal ganglia exhibited a prolonged and gradual ADC decrease throughout the study following reperfusion. This pattern was not exhibited within the cortex. It is suggested that regions known to exhibit so‐called delayed cell death progress to infarction via a gradual process that can be monitored by MR diffusion‐weighted imaging (DWI). Magn Reson Med 53:593–600, 2005. © 2005 Wiley‐Liss, Inc.
In vivo method for correcting transmit/receive nonuniformities with phased array coils
Authors: Wang Jinghua , Qiu Maolin , Constable R. Todd
Published: February 2005

Phased array coils are finding widespread applications in both the research and the clinical setting. However, intensity nonuniformities with such coils can reduce the potential benefits of these coils, particularly for applications such as tissue segmentation. In this work, a method is described for correcting the nonuniform signal response based on in vivo measures of both the transmission field of body coil and the reception sensitivity of phased array coils, separately. For a uniform phantom, the reception sensitivity can be calculated using both Bloch equations and transmission field maps. For a heterogeneous object such as a brain, a minimal contrast acquisition must be obtained to map the receiver nonuniformities. This transmit field/receiver sensitivity (TFRS) approach is compared with the standard methods of using the body coil to obtain a reference scan and low‐pass filtering. The quantitative comparison results shows that the TFRS approach provides superior results in correcting intensity nonuniformities for a uniform phantom. This approach reduces the ratio between signal intensity SD of an image and its mean intensity from approximately 21% before correction to 13% after correction. Results are also shown demonstrating the utility of this approach in vivo with human brain images. The method is general and can be applied with most pulse sequences, any coil combination for transmission and reception, and in any anatomic region. Magn Reson Med 53:666–674, 2005. © 2005 Wiley‐Liss, Inc.
Vessel size imaging in humans
Authors: Kiselev V. G. , Strecker R. , Ziyeh S. , Speck O. , Hennig J.
Published: February 2005

The relation of contrast‐enhanced transverse relaxation rates R2* and R2 provides in vivo mapping of the mean caliber of cerebral vessels. This technique is referred to as vessel size imaging (VSI). Here a quantitative assessment of the vessel caliber in brain tumor patients is presented. The obtained mean vessel size shows sensitivity to the tumor type. A theoretical analysis is given to elucidate the morphological information content of VSI in the context of vessel architecture. The simplification of the theory underlying the data processing results in a systematic overestimation of the vessel caliber. An increase in the magnetic susceptibility of the contrast agent allows for quantitatively more accurate measurements. Quantitative VSI must include measurements of the regional diffusion coefficient and absolute determination of the regional cerebral blood volume. Magn Reson Med 53:553–563, 2005. © 2005 Wiley‐Liss, Inc.
Theory of susceptibility‐induced transverse relaxation in the capillary network in the diffusion narrowing regime
Authors: Frøhlich A. F. , Østergaard L. , Kiselev V. G.
Published: February 2005

The transverse relaxation effect of deoxyhemoglobin compartmentalization in erythrocytes in the capillary network is investigated using an analytical approach. The capillaries are modeled as long arrays of paramagnetic spheres, simulating the individual red blood cells. Calculations are performed in the diffusion narrowing regime, which holds for the native blood paramagnetism at moderate fields up to about 1.5 T, for the free induction decay, the Hahn spin‐echo, and the Carr–Purcell–Meiboom–Gill sequence. The commonly used model of capillaries as homogeneously magnetized cylinders is shown to underestimate the capillary contribution to the susceptibility‐induced relaxation rate by up to 55%. This results in a noticeable change in the predicted deoxyhemoglobin concentration needed to cause the variation in the transverse relaxation rate observed in functional MRI and may affect subsequent quantification of physiological parameters derived from the BOLD signal. Furthermore, the model for the individual red blood cells (RBCs) represents a framework for investigating the effects of interspecies and intersubject variations in hematocrit, RBC deoxyhemoglobin concentration, and cell size on the relaxation rate. The results agree within their validity domain with previous Monte Carlo simulations. Magn Reson Med 53:564–573, 2005. © 2005 Wiley‐Liss, Inc.
MR imaging of biodegradable polymeric microparticles: A potential method of monitoring local drug delivery
Authors: Chen Hunter H. , Le Visage Catherine , Qiu Bensheng , Du Xiangying , Ouwerkerk Ronald , Leong Kam W. , Yang Xiaoming
Published: February 2005

Gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) was encapsulated into biodegradable, bioadhesive polymeric microparticles to enable noninvasive monitoring of their local intravesical delivery with MRI. The microparticles were characterized by contrast agent encapsulation and release kinetics, T1 relaxation rates, and contrast enhancement in vivo. The level of Gd‐DTPA loading into microparticles was 14.3 ± 0.6 μg/mg polymer. The measured T1 relaxation rates of the microparticles showed a direct dependence on Gd‐DPTA content. Both 1.5T and 4.7T MR scanners were used to image murine bladders instilled intravesically with Gd‐DTPA‐loaded particles in vivo. MR images showed ring‐shaped regions of enhancement inscribing the bladder wall, which were attributed to the microparticles that were preferentially adherent to the mucosa lining the urothelium. The images of controls exhibited no such enhancement. The normalized signal intensities measured from post‐instillation images were significantly greater (P < 0.05) than those in the pre‐instillation images. Contrast enhancement was observed for at least 5 days after the initial instillation, although the enhancement decreased due to microparticle degradation or mucosa renewal. The localized distribution of biodegradable, bioadhesive microparticles encapsulating Gd‐DTPA was successfully visualized with MRI in vivo, allowing particle‐mediated delivery to be temporally and spatially monitored noninvasively. Magn Reson Med 53:614–620, 2005. © 2005 Wiley‐Liss, Inc.
Particle conservation in the hot‐carrier solar cell
Authors: Würfel P. , Brown A. S. , Humphrey T. E. , Green M. A.
Published: February 2005

In conventionalp–njunction solar cells, carrier multiplication by impact ionisation, is negligible, owing to the low temperature of the electron–hole pairs. This leads to particle conservation between the net number of absorbed photons and the number of electron–hole pairs withdrawn from the cell. In hot‐carrier solar cells, in which electrons are at a high temperature by assuming suppression of electron–phonon scattering, such particle conservation leads to peculiar results. Numerical calculations show that entire current–voltage characteristics with meaningful values of temperature and chemical potential do not exist. If the energy at which electron–hole pairs are extracted is smaller than the average energy of absorbed photons, the temperature of the electrons and holes becomes much larger than the tem perature of the sun. When the extraction energy is larger than the average energy of the absorbed photons, an entire current–voltage curve cannot always be obtained. It follows that impact ionisation and Auger recombination cannot be neglected when the thermal energy of the electron–hole pairs is comparable to the bandgap of the absorber. Accounting for these processes results in current–voltage characteristics that are well behaved. Copyright © 2005 John Wiley & Sons, Ltd.