Preclinical evaluation of a novel thermally sensitive co-polymer (LiftUp) for endoscopic resection.

Introduction: Endoscopic resection techniques can successfully resect large lesions either in "en bloc" fashion or in "piece-meal" technique by using a submucosal injection solution. The aim of this study was to evaluate the safety of a novel injectable, containing thermally sensitive co-polymer from ethylenoxide and propylenoxide (LiftUp) used as submucosal injection solution.Material and methods: We conducted an in vivo animal trial in the porcine model to evaluate the LiftUp gel in a preclinical setting and to study the effectiveness of mucosal lifting and the safety of the new injectable. In seven animals a total of 63 injections and endoscopic resections were carried out in different anatomical locations (esophagus, stomach and rectum). The resection sites were controlled endoscopically one and four weeks after resection and a histopathological evaluation of the resection sites was performed after four weeks.Results: The application of LiftUp was safe and there were no negative effects on wound healing after injection and resection. A major procedural complication rate (defined as perforation and major haemorrhage) of 3.2% was registered, which undercuts the anticipated mean complication rate of 4-8%. Furthermore, there was no necessity of reinjection after the initial submucosal injection in 90.5% and no procedural complications in 98.8%. The histopathological examination of the tissue samples indicated normal wound healing with granulation tissue and epithelialisation.Conclusion: The use of LiftUp as submucosal injection solution was feasible for different endoscopic resection techniques, with high and long-lasting elevation and fewer procedural adverse events than expected at trial planning. The new injectable is a practical advancement over the current state-of-the-art of submucosal injection and could fasten up the resection procedure and make endoscopic 'en bloc' resection safer.

Endoscopic full-thickness resection and clip defect closure in the colon with the new FTRD system: experimental study.

BACKGROUND: The benefit of endoscopic full-thickness resection is the improved diagnostic work-up with an integral wall specimen which allows a precise determination of the tumor or its precursor and its infiltration depth into the wall. MATERIALS AND METHODS: A new endoscopic full-thickness resection device (FTRD), which is a combination of a modified over-the-scope-clip (OTSC) system with an electrocautery snare, has been tested in an experimental setting. In eleven pigs, divided into three groups, endoscopic full-thickness resection was performed in the colon at one or two sites, respectively. Seven days (n = 7) or 28 days (n = 4) after the intervention, the animals were euthanized following endoscopic examination of the resection and clip application sites. Furthermore, two different clips were tested during these animal trials in order to evaluate the most effective clip design. RESULTS: The average diameter of the tissue resected with the FTRD was 3.1, 3.6, and 5.4 cm in the three groups. On follow-up endoscopy 7 days after the intervention, fibrin coating and stool residues were found at all clips, causing minor inflammatory reactions. However, the colon wall under the clip was non-inflamed. After 28 days, the serosa had primarily healed in all cases. There were also stool residues at all clips; however, no acute inflammatory reactions were seen anymore, due to complete healing. Histological assessment did not show any signs of dehiscence in the region of the scar, or ischemia in the clip area. In addition, no wound infections, such as abscess formation, were observed. CONCLUSIONS: This study demonstrates the safety and efficacy of the clip-and-cut technique using the new FTRD system. With the device, a local full-thickness colon resection can be easily created, and the resulting wall defect is reliably sealed by the endoluminal application of a modified OTSC clip.

Expression of the proliferation marker Ki-67 associates with tumour staging and clinical outcome in differentiated thyroid carcinomas.

OBJECTIVE: Although the prognosis of differentiated thyroid carcinoma (DTC) is excellent, with 10-year survival rates of about 90%, about one-third of patients experiences recurrent disease. We aimed to identify novel histological prognostic factors to optimize treatment and follow-up of patients at risks. DESIGN: Retrospective analysis of patients diagnosed from January 1990 to March 2004. SUBJECTS: A total of 93 patients diagnosed with DTC of which 67 with papillary and 26 with follicular histology. MEASUREMENTS: Analysis of immunohistochemical expression of somatostatin receptor (sst) subtypes 1-5, glucose transporter-1 (GLUT-1), receptor tyrosine kinase c-KIT, oestrogen and progesterone receptors, and proliferation marker Ki-67 and correlation with the patients' clinical outcome. RESULTS: DTC showed immunohistochemical expression of GLUT-1, C-KIT and progesterone receptor in a high percentage of cases (range: 57-80%). In contrast, the oestrogen receptor as well as the sst subtypes 1-5 was less frequently detected (range: 15-29%). Mean staining of the proliferation marker Ki-67 was 6% positive cells (range 0-20%). Ki-67 expression was significantly associated with tumour staging (ρ = 0·2076, P = 0·0459), whereas the other histopathological markers were not associated with gender, age, tumour entity, or tumour classification. Tumour staging and expression of Ki-67, oestrogen receptor and sst2, but of none of the other histopathological factors, independently predicted the clinical outcome 5 years after definitive treatment (P < 0·0001, P < 0·0001, P = 0·0004 and P = 0·0206, respectively). CONCLUSIONS: In patients with DTC, Ki-67 expression associates with tumour staging and clinical outcome.

Isolation of three stem cell lines from human sacrococcygeal teratomas.

Sacrococcygeal teratomas (SCTs) are benign tumours of the newborn with absolute indication for surgery directly after birth. We recently described the presence of stem cells positive for the stem cell markers nanog and Oct4 in SCTs. Here we report the isolation of three stem cell lines from three different SCTs. Cells were propagated in mesenchymal or in embryonic stem cell medium. Non-clonal homogeneous stem cell lines were obtained after two to three passages and characterized in vitro by immunocytochemistry, RT-PCR, western blot, FACS analysis, and metaphase spreads. The differentiation potential was tested in vitro and in vivo. The isolated cell lines, which we refer to as human sacrococcygeal teratoma stem cells (hSctSCs), express nanog, Oct4 and stella, and are negative for malignancy markers alpha-fetoprotein and carcinoembryonic antigen. They can be induced in vitro to express neuronal, osteogenic, and chondrogenic traits. After grafting in vivo, spontaneous integration into the neural crest of the chick embryo and teratoma formation in the nude mouse were obtained. Our results indicate that SCTs are derived from remnants of the epiblast-derived primitive streak, which in the human embryo normally regresses but forms teratomas in children affected with SCT. The hSctSCs therefore may be comparable to mouse epiblast-derived stem cells (EpiSCs) and share characteristic features with human embryonic stem (hES) cells. Thus, SCT tissue obtained after surgery appears to be a novel source for the generation of human stem cells without the ethical implications associated with hES cells.

CD8(+)/perforin/granzyme B(+) effector cells infiltrating cerebellum and inferior olives in gluten ataxia.

Up to 8% of patients with gluten sensitivity (GS) develop neurological symptoms such as ataxia, dementia, seizures or peripheral neuropathy. The underlying immunological mechanisms still remain to be elucidated. We here report the case of a 68-year-old male patient suffering from progressive ataxia and dementia associated with chronic diarrhea and both elevated IgG and IgA antigliadin-antibodies. At autopsy, frequent argyrophilic glial and neuronal inclusions within the basal nucleus of Meynert were considered as the structural correlative for the cognitive decline. Significant neuronal loss in the cerebellar cortex and the inferior olives was accompanied by infiltrating CD8(+)/perforin(+)/granzyme B(+) cells as well as reactive astrogliosis and microglial activation. These CD8(+) cytotoxic T and NK cells are likely to act as effector cells responsible for neuronal cell death in patients with gluten sensitivity and neurological disease and might therefore at least partly be responsible for cerebellar symptoms in gluten ataxia. In conclusion, our results, showing an absence of B- or plasma cells but multiple CD8(+) as well as granzyme B and perforin expressing cells in ataxia-associated brain areas, suggest that there are also prominent cytotoxic effects in neuropathogenesis of GS.

Human precision-cut liver tumor slices as a tumor patient-individual predictive test system for oncolytic measles vaccine viruses.

Availability of an individualized preselection of oncolytic viruses to be used for virotherapy of tumor patients would be of great help. Using primary liver tumor resection specimens we evaluated the precision-cut liver slice (PCLS) technology as a novel in vitro test system for characterization of paramount tumor infection parameters of individual patients. PCLS slices from resection specimens of 20 liver tumor patients were cultivated in vitro for up to 5 days and infected with 5 different oncolytic measles vaccine virus (MeV) strains. Effectiveness of tumor infection was monitored by viral nucleocapsid (N) protein detection in immunofluorescence staining or Western blot analysis or by detection of GFP marker gene expression. MeV spreading in PCLS cultures was visualized by confocal microscopy. Oncolytic MeV vaccine particles were demonstrated to efficiently infect PCLS slices originating from different primary and secondary tumors of the liver with MeV strains Moraten/Edmonston Zagreb and AIK-C showing highest infection rates (75% of all tested tumor specimens). Employing mixed liver tissue slices (exhibiting both tumorous and non-tumorous tissue areas on one and the same sample) a distinct tumor area favouring pattern of MeV infections was observed being in accordance with our finding that primary human hepatocytes are also permissive to MeV particles, albeit at a much lower rate and with a much less pronounced cytopathic effect. Furthermore, confocal microscopy demonstrated virus penetration throughout tumor tissues into deep cell layers. In conclusion, the PCLS technology is suitable to perform a tumor-patient individualized preselection of oncolytic agents prior to clinical virotherapeutic applications.

MRI findings in deep and generalized morphea (localized scleroderma).

OBJECTIVE: Our objective was to describe the spectrum of MRI features in patients with deep and generalized morphea. CONCLUSION: Imaging features of morphea are not specific and usually overlap with those of other disorders involving the skin, fascia, and musculature, such as some types of fasciitis, myositis, and so forth. Nevertheless, the imaging features of morphea reflect pathomorphologic changes of this rare disorder and enable a complete assessment of the disease extent, including depth of infiltration and disease activity.

PD-1-PD-L1 pathway is involved in suppressing alloreactivity of heart infiltrating t cells during murine gvhd across minor histocompatibility antigen barriers.

BACKGROUND: Graft-versus-host disease (GVHD) is still a major cause of morbidity and mortality after allogeneic stem cell transplantation. GVHD mainly affects skin, liver, and intestine, whereas other organs usually are spared. In the present study, we wanted to investigate whether local regulatory T cells (Treg) or differential expression of immunomodulatory molecules contribute to organ specificity of GVHD. METHODS: In a murine B10.D2->BALB/c (both H-2) model, GVHD was induced by transplantation of 1x10 bone marrow and 1x10 spleen cells. We compared expression of T-cell and dendritic cell markers, CD40-CD40L, various B7 family members, FoxP3, and Th1/Th2 cytokines between ileum (GVHD-target organ) and heart (nontarget organ). RESULTS: GVHD was documented by an increase of CD4 T cells with accompanying tissue destruction in ileum but not in heart. We found a significantly increased expression of PD-L1 in heart on day 14 and 21 as well as of CTLA-4 on day 21 after transplantation, whereas all other molecules were not different between heart and ileum. In heart, PD-L1 was expressed on lymphoid cells, endothelial cells, CD8alpha+CD11c+DCs, and up-regulated during GVHD. In contrast, in the ileum only endothelial cells stained weekly positive for PD-L1. Furthermore, we could not find any evidence for the presence of Tregs in the heart. CONCLUSIONS: Our data indicate that immunomodulatory molecules such as PD-L1 rather than Tregs play pivotal roles in the tissue-specific regulation of alloresponses. Further studies are needed to refine the significance of the PD-L1 pathway in GVHD and its versatility for therapeutic intervention.

Syndrome of inappropriate antidiuretic hormone secretion and ectopic ACTH production in small cell lung carcinoma.

BACKGROUND: Small cell lung carcinoma (SCLC) is frequently associated with a paraneoplastic syndrome. CASE REPORT: We report on a rare case of SCLC presenting with syndrome of inappropriate antidiuretic hormone (SIADH) secretion and ectopic ACTH production. In accordance with the endocrine evaluation, immunohistochemical staining of the tumour was positive for ADH and ACTH. Chemotherapy with etoposide and carboplatin induced a nearly complete remission. CONCLUSION: Simultaneous secretion of ADH and ACTH is infrequently reported with only five cases described in the literature. SIADH in patients with ectopic ACTH syndrome may be underdiagnosed due to the antagonistic hormone actions of cortisol and ADH on renal sodium excretion.

Somatostatin receptor expression in a parathyroid hormone-related peptide-secreting pancreatic neuroendocrine tumour causing severe hypercalcaemia.

BACKGROUND: Humoral hypercalcaemia is a common complication of malignancy with parathyroid hormone-related protein (PTHrP) as a major cause. Breast and lung cancer are relatively common sources of ectopic PTHrP secretion leading to increased osteoclastic bone resorption. CASE REPORT: We report the rare case of a 40-year-old man with severe hypercalcaemia due to a PTHrP-secreting poorly differentiated endocrine carcinoma of the pancreas. On immunohistochemistry, the tumour was positive for PTHrP and somatostatin receptors sst1, sst2, and sst3, whereas sst4 and sst5 were not detected. We demonstrate the transient improvement of hypercalcaemia after adding octreotide to the treatment mainstays in hypercalcaemia of malignancy (fluid repletion, administration of bisphosphonates, loop diuretics, and glucocorticoids). CONCLUSION: To the best of our knowledge, this is the first report showing somatostatin receptor expression in a PTHrP-secreting pancreatic neuroendocrine tumour.

Prevention of carotid artery restenosis after sirolimus-coated stent implantation in pigs.

BACKGROUND AND PURPOSE: To test the feasibility of self-expanding drug-coated nitinol stents for prevention of restenosis in an animal model. Stent implantation in the carotid artery (CA) has been shown to be feasible for treatment of CA stenosis. Even though the restenosis rate in CA is reported to be lower than in the coronary and peripheral arteries, problems may arise with increasing numbers of treated patients and lengthier follow-up. METHODS: After predilatation with 8-mm balloons, 8 Goettinger minipigs were randomly selected to receive a sirolimus-eluting self-expanding nitinol stent (7 mm/80 mm) as well as the same stent without sirolimus/polymer coating in the right or left CA. Aspirin was given starting 3 days before the intervention and administered for an additional 4 weeks. Clopidogrel was administered for 10 days. RESULTS: After 6 weeks, 2 subacute occlusions were observed in both groups. In the remaining vessels, the neointima was significantly reduced by sirolimus/polymer-coated stents (5.9+/-2.5 versus 0.7+/-1.0 mm2). CONCLUSIONS: Sirolimus self-expanding nitinol stents may be an effective tool in reducing neointimal formation in CA.

Choroid plexus tumors differ from metastatic carcinomas by expression of the excitatory amino acid transporter-1.

Tumors of the choroid plexus (CPTs) are rare neoplasms of neuroectodermal origin usually arising in pediatric patients. However, CPT may occur at any age, and their distinction from metastatic carcinomas is often difficult in adult cases. Because CPTs frequently show focal glial differentiation, we now investigated 35 CPTs (19 males and 16 females 0.3-70 years old; median age, 25.0 years), including 21 choroid plexus papillomas (CPPs), 5 atypical CPP, and 9 choroid plexus carcinomas regarding their expression of the excitatory amino acid transporter-1 (EAAT1, corresponding to rodent GLAST/GLAST-1) by immunohistochemistry. In addition, 77 metastatic carcinomas, including 64 adenocarcinomas with mostly papillary formations, derived from different organs were examined. Of the 35 CPTs, 23 (66%) showed membranous EAAT1 expression in variable numbers of tumor cells, including all atypical CPP and 3 of 9 choroid plexus carcinomas (33%). None of the metastatic carcinomas showed membranous immunostaining. Excitatory amino acid transporter-1 expression in CPT was significantly age dependent (P < .0001), with the proportion of EAAT1-positive tumor cells increasing with age, but not sex dependent. There was a highly significant difference between EAAT1 expression in CPT and in metastatic carcinomas (P < .0001). Establishing a cutoff value of 1% immunoreactive tumor cells served in adult cases to distinguish CPT from metastatic adenocarcinomas with 100% specificity and 70% sensitivity and was associated with positive and negative predictive values of 100% and 91%, respectively. Our findings indicate that EAAT1 immunohistochemistry may be useful in differentiating CPT from metastatic carcinomas.

Solitary pulmonary nodules: association between signal characteristics in dynamic contrast enhanced MRI and tumor angiogenesis.

PURPOSE: To estimate the association between signal characteristic of dynamic enhanced MRI using curve types and angiogenesis in solitary pulmonary nodules. MATERIALS AND METHODS: Thirty-six patients with a solitary pulmonary nodule (SPN) ranging in size from 6 to 37 mm (median 17 mm) underwent dynamic contrast enhanced MRI with a time interval of 10 s over a total period of 4 min. Resulting from the time-intensity curves four different enhancement curve profiles (A-D) were defined: type A with strong increase followed by early washout, type B with strong increase without washout, type C with slow increase and type D without relevant increase. Maximum peak (Pmax), slope of the first bolus transit (slope) and washout were calculated. Microvessel densities (MVD) were counted at the margins and at the center of the nodules. The mean MVD of each nodule was calculated. Enhancement characteristics were correlated with MVD grouped by diagnosis and by curve types. Curve types were correlated with the score of vascular endothelial growth factor (VEGF). RESULTS: The frequency of malignancy was 55% (20/36). Using curve types for differentiation between malignant and benign SPN, the sensitivity, specificity and accuracy were 100%, 75% and 89%, respectively. The correlation between Pmax and MVD(mean) for all nodules was moderate (r(s)=0.4, P=0.02). A relevant correlation was found between Pmax and MVD(margin) in curve type A (r(s)=0.63; P=0.04) and Pmax and MVD(mean) in curve type C (r(s)=0.86; P=0.006). No positive correlation was found between Pmax and MVD (mean, center and margin) in curve type B. No significant correlation was found for slope and washout. VEGF score correlated positively with curve types (r(s)=0.67; P<0.001). CONCLUSION: A relevant association between perfusion curve profiles and angiogenesis was found in malignant nodules having early washout and in benign lesion with a slow increase of enhancement. In cases of strong signal increase without washout additional factors for enhancement must be considered. The use of curve profiles could allow for the estimation of the extent of VEGF.

Cytomegalovirus pneumonia after stem cell transplantation: correlation of CT findings with clinical outcome in 30 patients.

OBJECTIVE: The purpose of our study was to assess the correlation between early high-resolution CT findings of cytomegalovirus (CMV) pneumonia in patients with blood disorders and their clinical outcomes. CONCLUSION: The initial high-resolution CT findings in immunocompromised patients with CMV pneumonia seem to predict the patient's outcome being unfavorable in those forms of disease beginning mostly bilaterally as diffuse or patchy ground-glass opacity followed by progressive air-space consolidation. Also, a change in the CT morphology of pulmonary lesions toward diffuse ground-glass opacity seems to correlate with an unfavorable disease course.

Spontaneous thoracic air-leakage syndrome in patients following allogeneic hematopoietic stem cell transplantation: causes, CT-follow up and patient outcome.

OBJECTIVE: The purpose of this article is to describe and illustrate the acute and follow-up imaging features, clinical constellation and outcome of patients with thoracic air-leakage syndrome following allogeneic hematopoietic stem cell transplantation (allo-HCT). METHODS: Patients with evidence of thoracic air-leakage, i.e. spontaneous pneumomediastinum, spontaneous pneumothorax or interstitial emphysema after allo-HCT were retrospectively identified by a chart review. Acute and follow-up morphology, duration and patient outcome were analyzed on CT (HRCT or MSCT with HR-reconstructions). Correlation was made with histological results of transbronchial biopsy. RESULTS: The 6 patients included (3 male and 3 female, 14-64 years old) with thoracic air-leakage after allo-HCT all had histologically proven bronchiolitis obliterans (BO) or bronchiolitis obliterans organizing pneumonia (BOOP). Thoracic air-leakage consisted of spontaneous pneumomediastinum associated with active invasive pulmonary aspergillosis (IPA) in 4/6 and spontaneous pneumothorax or interstitial emphysema each in 1/6 patients. Duration of thoracic air-leakage was 7-135 days. Of the patients with spontaneous pneumomediastinum, 3/4 died of IPA. One patient survived until complete regression of spontaneous pneumomediastinum. One patient died 7 days after spontaneous pneumothorax and one survived developing chronic interstitial emphysema. CONCLUSION: In all cases, thoracic air-leakage was associated to BO or BOOP. In the majority of cases with additional IPA, thoracic air-leakage is more indicative for severity of pulmonary disease than a life-threatening entity itself.

Effect of dopamine D3 receptor blockade on renal function and glomerular size in diabetic rats.

Dopamine D2-like receptors, including D2, D3, and D4 receptors, are involved in the regulation of glomerular hyperfiltration due to diabetes mellitus. These hemodynamic alterations represent a risk factor for the later development of diabetic nephropathy. The aim of the present study was to determine whether the D3 receptor subtype modulates the diabetes-induced increase in glomerular filtration rate (GFR) in rats. Renal function was studied in Sprague-Dawley rats 14 days after induction of a moderate diabetes mellitus (DM) by streptozotocin and in non-diabetic controls (CON). Rats were orally treated either with the peripherally acting, selective dopamine D3 receptor antagonist BSF 135170 (BSF, 10 mg/kg per day for 2 weeks) or with vehicle (VHC). Perfusion-fixed kidneys were used for estimation of glomerular volume. In conscious rats, which were treated with BSF, the DM-induced increase in fluid intake, urinary output, and renal sodium excretion was significantly less pronounced than in the vehicle group (DM-VHC). In the clearance experiments, GFR in CON was about 0.84+/-0.04 ml/min per 100 g body weight. The DM-VHC group presented a significant glomerular hyperfiltration (1.09+/-0.04 ml/min per 100 g body weight). Treatment with BSF significantly lowered GFR towards levels of CON. The estimated glomerular volume was 0.73+/-0.03 x 10(6) microm3 in the CON-VHC group and 0.86+/-0.04 x 10(6) microm3 in the DM-VHC animals. Interestingly, treatment with BSF decreased the glomerular volume in both groups. Irrespective of BSF treatment, kidney wet weight related to body weight was about 36% higher in DM animals compared with CON animals. We conclude that dopamine D3 receptors represent a target for the modulation of diabetes-induced glomerular hyperfiltration. Therefore, the results encourage the testing of the possible beneficial effects of long-term D3 receptor blockade on the development of diabetic nephropathy.

Increased Postoperative Bleeding Risk among Patients with Local Flap Surgery under Continued Clopidogrel Therapy.

PURPOSE: The purpose of the study was to evaluate the influence of a continued antiplatelet therapy with clopidogrel on postoperative bleeding risk in patients undergoing skin tumor resection and reconstruction with local flaps or skin grafts under outpatient conditions. PATIENTS AND METHODS: The authors designed and implemented a retrospective clinical cohort study at the General Hospital Balingen. The primary endpoint was the bleeding ratio in patients with clopidogrel treatment in comparison to patients without any anticoagulant or antiplatelet therapy. Wound healing was evaluated on days 1, 3, 5, 7, 10, and 14. RESULTS: 650 procedures were performed, 123 of them under continued clopidogrel therapy. There were significantly more postoperative bleeding complications among patients with continued antiplatelet therapy. Regarding the whole study population, malignant lesions, a larger defect size, and skin grafts were accompanied by a higher rate of bleeding incidents. However, there were no significant findings in the univariate analysis of the clopidogrel group. All bleeding incidents were easily manageable. CONCLUSION: Despite an increased bleeding ratio among patients under continued clopidogrel therapy, the performance of simple surgical procedures can be recommended. However, cautious preparation and careful hemostasis are indispensable.

Experimental thermoradiotherapy in malignant hepatocellular carcinoma.

PURPOSE: The human liver is known to be a relatively radiosensitive organ that develops clinically relevant late radiation hepatitis subsequent to whole liver treatment with total doses above 30 Gy in conventional fractionation. Experimental data, as well as clinical series, have demonstrated that hyperthermia of solid tumors in addition to radiotherapy enhances tumor growth inhibition and tumor control probability. We therefore developed an experimental model for combined radiotherapy and hyperthermia of the liver in transplantable rat Morris hepatoma 3924A. METHODS AND MATERIALS: A cube of approximately 8 mm(3) was implanted subcapsularly into the middle liver lobe of 59 male syngenic ACI rats weighing approximately 180-200 g. On Day 16 after tumor implantation, irradiation of the tumor-bearing liver with either 0 Gy/25 Gy/35 Gy/45 Gy total dose in 10 fractions +/- hyperthermia (target temperature 40-42 degrees C) twice a week was initiated. Energy deposition was monitored by temperature probes in the liver and esophagus of the rats. Determination of tumor volume with magnetic resonance imaging was performed 2 to 5 weeks after the end of therapy. The tumor growth rates could be estimated for 44 rats. If the growth rate was positive (37 rats), the inverse of the growth rate was interpreted as the time to 10-fold tumor volume. Otherwise the maximum observation time was considered as a censored value in a parametric survival analysis. RESULTS: Intrahepatic temperature probes showed a temperature plateau of greater than 40 degrees C after 5 to 8 min subsequent to initiation of hyperthermia. The target temperatures could be maintained for at least 22 min > or =40 degrees C and 10 min > or =41 degrees C, respectively. Median plateau temperature in liver, esophagus, and epicutaneously was 41.2 degrees C (standard deviation [SD] 0.7 degrees C; range 38.2 to 43.3 degrees C), 40.4 degrees C (SD 1.08 degrees C; range 38.9 to 41.8 degrees C), and 40.8 degrees C (SD 0.8 degrees C; range 38.2 to 42.7 degrees C), respectively. Elevation of the temperature in the esophagus correlated with intrahepatic temperatures in the range of 39-42 degrees C, r = 0.957. The increase in time to 10-fold tumor volume for each step of irradiation dosage was by 34% (95% confidence interval [CI] 20% to 49%) without hyperthermia and by 60% (95% CI 47% to 80%) with hyperthermia (p < 0.0001). CONCLUSION: Treatment outcome after experimental percutaneous thermoradiotherapy in intrahepatically implanted Morris hepatoma 3924A was related to total dose of irradiation and concurrently administered regional hyperthermia. An increased radiosensitivity due to hyperthermia (<42 degrees C) has to be assumed.

Organ-specific T cell receptor repertoire in target organs of murine graft-versus-host after transplantation across minor histocompatibility antigen barriers.

BACKGROUND: Minor histocompatibility antigens (miHags) are recognized by alloreactive cytotoxic donor T lymphocytes and trigger potent immune reactions such as graft-versus-host disease (GvHD) after major histocompatibility complex-matched transplantation. Our study focuses on tissue-specific T-cell responses to miHag-encoded peptides in GvHD target organs during the first 30 days in a murine transplant model. METHODS: Complementarity determining region (CDR)3-size spectratyping was used to study T cell receptor (TCR) repertoires in recipient skin, liver, ileum, colon, spleen, and heart. RESULTS: GvHD occurred as early as day 14 and was proven by histology in skin, liver, ileum, and colon. The heart was histologically not affected by GvHD but showed endomyocardial "quilty lesions." Two distinct patterns of TCR diversities could be identified. In skin, a restricted V beta usage in combination with all J beta segments contrasted with a complete V beta repertoire in intestinal organs combined with a restricted J beta usage. Interestingly, TCR repertoire in the heart was almost identical with intestinal CDR3-size patterns. Persisting clones were found in skin from day 9 to 30. In intestine and heart, identical sequences were obtained from several organs on day 14 and 21, but no persistence of CDR3 sequences could be observed. CONCLUSIONS: These results suggest that in the skin a limited number of persisting T cell clones maintains GvHD, whereas in the intestine, temporary expansions of different clones may fuel the process of GvHD. Strategies that eliminate tissue-specific T cells on the basis of their activational status rather than their V beta expression but at the same time preserve a broad, overall TCR repertoire will help to increase the efficacy and safety of allogeneic stem cell transplantation.