Real-time imaging and detection of intracranial haemorrhage by electrical impedance tomography in a piglet model

The aim of this study was to use electrical impedance tomography (EIT) to detect and image acute intracranial haemorrhage (ICH) in an animal model. Blood was infused into the frontal lobe of the brains of anaesthetized piglets and impedance was measured using 16 electrodes placed in a circle on the scalp. The EIT images were constructed using a filtered back-projection algorithm. The mean of all the pixel intensities within a region of interest--the mean resistivity value (MRV)--was used to evaluate the relative impedance changes in the target region. A symmetrical index (SI), reflecting the relative impedance on both sides of the brain, was also calculated. Changes in MRV and SI were associated with the injection of blood, demonstrating that EIT can successfully detect ICH in this animal model. The unique features of EIT may be beneficial for diagnosing ICH early in patients after cranial surgery, thereby reducing the risk of complications and mortality.

Intrathecal sufentanil decreases the median effective dose (ED50) of intrathecal hyperbaric ropivacaine for caesarean delivery

BACKGROUND

The addition of opioid to local anaesthetics has become a well-accepted practice of spinal anaesthesia for caesarean delivery. Successful caesarean delivery anaesthesia has been reported with the use of a low dose of intrathecal hyperbaric ropivacaine coadministered with sufentanil. This prospective, double-blinded study determined the median effective dose (ED50) of intrathecal hyperbaric ropivacaine with and without sufentanil for caesarean delivery, to quantify the sparing effect of sufentanil on the ED50 of intrathecal hyperbaric ropivacaine.

METHODS

Sixty-four parturients undergoing elective caesarean delivery with combined spinal-epidural anaesthesia were randomized into two groups: Group R (ropivacaine) and Group RS (ropivacaine plus sufentanil 5 microg). The initial dose of ropivacaine was 13 mg in Group R and 10 mg in Group RS. The effective dose was defined as a T(6) level attained within 10 min and no supplemental epidural anaesthetic required during surgery. Effective or ineffective responses determined, respectively, a 0.3 mg decrease or increase of the dose of ropivacaine for the next patient using an up-down sequential allocation.

RESULTS

The ED50 of intrathecal ropivacaine was 11.2 mg [confidence interval (CI) 95%: 11.0-11.6] in Group R vs. 8.1 mg (CI 95%: 7.8-8.3) in Group RS. Motor block was markedly more intense in Group R than in Group RS, and the incidence of shivering was lower in Group RS than in Group R. There were no differences in the onset time of sensory block or motor block, in the incidence of hypotension, nausea and vomiting.

CONCLUSION

Intrathecal sufentanil 5 microg produced a 28% reduction of ED50 of intrathecal hyperbaric ropivacaine for caesarean delivery.

Treadmill running exercise results in the presence of numerous myofibroblasts in mouse patellar tendons

Mechanical loading is known to alter tendon structure, but its cellular mechanisms are unclear. This study aimed to determine the effect of mechanical loading on tendon cells in vivo. C57BL/6J female mice were used in a treadmill running study. The treadmill running protocol consisted of treadmill training for 1 week, followed by sustained moderate running at 13 m/min for 50 min/day, 5 days/week, for 3 weeks. Immunohistochemical staining of tendon sections of mice after treadmill running revealed that numerous cells in the tendon section expressed alpha-SMA, whereas in the tendon sections of control mice, only a few cells exhibited weak alpha-SMA signals. Furthermore, mouse patellar tendon cells (MPTCs) derived from treadmill running mice were generally larger in culture, proliferated faster, expressed a higher level of alpha-SMA, and formed more abundant stress fibers compared to MPTCs from control mice. In addition, MPTCs from treadmill running mice generated larger traction forces (169 +/- 66.1 Pa) than those from control mice (102 +/- 34.2 Pa). Finally, cells from treadmill running mice produced higher levels of total collagen (516.4 +/- 92.7 microg/10,000 cells) than their counterparts (303.9 +/- 34.8 microg/10,000 cells). Thus, mechanical loading via treadmill running increased the presence of myofibroblasts in mouse patellar tendons. As myofibroblasts are activated fibroblasts, their presence in the tendon following treadmill running indicates that they actively repair and remodel tendon tissue under strenuous mechanical loading, leading to known changes in tendon structure.

The effects of swimming exercise on high-fat-diet-induced steatohepatitis

AIM

The aim of this study was to assess the effects of swimming exercise on high-fat (HF) diet-induced steatohepatitis.

METHODS

Two groups of rats were fed a HF diet (35%; kcal) for 12 weeks, with one group remained sedentary (HF-Sed) and the other group swam (HF-Tr) during this entire period. A third group was fed a standard diet and remained sedentary for 12 weeks (SD-Sed). Swimming exercise (5 days/week) was initiated at the same time as the HF diet and was progressively increased, until it reached 90 min after 4 weeks.

RESULTS

At the end of the 12-week period, HF-Sed rats exhibited higher body weight (means +/- standard error [SE]: 492+/-40 vs 432+/-21 g; P<0.05), liver weight (16.21+/-2.23 vs 9.92+/-1.14 g; P<0.05), serum alanine aminotransferase (73.62+/-36.11 vs 27.16+/-4.62 U/L; P<0.05), aspartic aminotransferase (AST; 198.87+/-120.16 vs 120.16+/-19.09 U/L; P<0.05), nonesterified fatty acids (NEFA; 897.48+/-133.62 vs 437.5 micromol/L; P<0.05), triglyceride (0.92+/-0.1 vs 0.56+/-0.04 mmol/L; P<0.05), tumor necrosis factor (TNF)-a (21.74+/-2.93 vs 16.57+/-3.53 pg/mL; P < 0.05) as well as liver malondialdehyde (MDA; 5.3+/-1.45 vs 3.48+/-0.94 nmol/mg protein; P<0.05) and NEFA (305.47+/-69.23 vs 204.56+/-64.26 micromol/mg protein; P<0.05) than SD-Sed rats. All HF-Sed rats developed moderate to severe hepatic steatosis and steatohepatitis according to liver histological findings. Compared with HF-Sed, HF-Tr rats' hepatopathological manifestations of steatosis and inflammation were much attenuated, and their serum and liver parameters were all lower with the exception of serum AST.

CONCLUSION

It was concluded that swimming exercise might reduce the incidence of HF-diet-induced steatohepatitis.

Review article: anatomic double bundle anterior cruciate ligament reconstruction

The anterior cruciate ligament (ACL) consists of 2 bundles: a slightly larger anteromedial bundle and a posterolateral bundle, named according to their relative tibial insertion sites. Both bundles are crucial to knee stability. Although it is more technically demanding, a double bundle ACL reconstruction restores the knee biomechanics better and provides more rotational stability than a single bundle ACL reconstruction. Intermediate and long-term clinical investigation including the measurement of rotational laxity and the evaluation of osteoarthritic change is needed to confirm biomechanical and short-term clinical outcomes.

Smoking and tuberculosis among silicotic patients

The aim of the present study was to investigate the relationship between smoking and tuberculosis (TB) among high-risk silicotic patients in Hong Kong. A cohort of 435 silicotic patients tuberculin tested from 1995-2002 was prospectively followed-up until the end of 2005. Baseline characteristics were analysed with respect to positive tuberculin reaction (> or =10 mm) at baseline and subsequent development of TB. Smoking, alcohol use and body mass index were independent predictors of positive tuberculin reaction at baseline in multiple logistic regression analysis. Total cigarette pack-yrs did not demonstrate any significant effect. The annual incidences of TB were 1,841, 2,294 and 4,181 per 100,000 for never-, ex- and current smokers, respectively. On Cox proportional hazard analysis, current smokers have a significantly higher risk of TB than other silicotic patients (adjusted hazard ratio (95% confidence interval (CI)): 1.96 (1.14-3.35)) after controlling for age, alcohol use, tuberculin status, treatment for latent TB infection and other relevant background/disease factors. A significant dose-response relationship was also observed with the daily number of cigarettes currently smoked. Smoking cessation may reduce 32.4% (95% CI: 6.5-54.0) of the risk. Smoking increases the risk of both tuberculosis infection and subsequent development of the disease among silicotic patients.

Crystal structure of bis(1,10-phenanthroline-N,N′)silver(I) mononitrate, [Ag(C12H8N2)2][NO3]

C24H16AgN5O3, orthorhombic, Fddd (no. 70), a = 3.668(1) Å, b = 30.046(9) Å, c = 38.88(1) Å, V = 4284.2 Å3, Z = 8, Rgt(F) = 0.064, wRref(F2) = 0.198, T = 273 K.

Crystal structure of catena-aquatris(1H-imidazole-N)(μ-sulfato)copper(II), Cu(H2O)(C3H4N2)3(SO4)

C9H14CuN6O5S, monoclinic, P121/n1 (no. 14), a = 11.723(2) Å, b = 8.651(2) Å, c = 13.839(3) Å, β = 91.703(4)°, V = 1402.8 Å3, Z = 4, Rgt(F) = 0.046, wRref(F2) = 0.133, T = 296 K.

[Detection of bate 2-microglobulin fibronection and interleukin 2 content in patients with nasopharyngeal carcinoma]

OBJECTIVE

To study the clinical significance of detecting of beta 2-microglobulin (beta 2-MG). Fibronection (Fn) and interleukin 2 (IL-2) in patients with nasopharyngeal carcinoma.

METHOD

The levels of serum beta 2-MG and IL-2 in 32 patients with nasopharyngeal carcinoma were determined by radioimmunoassay, radial immunodiffusion and ELISA before and after radiotherapy.

RESULT

The levels of serum beta 2-MG in patients with nasopharyngeal carcinoma were significantly higher than that in controls (P < 0.05); but serum Fn and IL-2 in patients were significantly lower than that in controls (P < 0.05). The level of serum beta 2-MG decreased in patients after radiotherapy, but the serum Fn and IL-2 increased in patients after radiotherapy.

CONCLUSION

Detection of serum beta 2-MG, Fn and IL-2 was useful in clinical diagnosis and prognosis observation of nasopharyngeal carcinoma.

[Sixty years of study on ancient medical history]

The paper includes ten parts, viz. origin of medicine, division of historical periods in Chinese medicine, medical institution, history of preventive medicine, history of medicl disciplines and diseases, history of exchanges among China and foreign countries, history of medical education, history of minority medicine, studies on medical figures, works on Chinese medical history. It summarizes the brilliant achievements in the study of ancient Chinese medical history.

[A retrospective clinical study of 6539 cases of malignant oral-maxillofacial tumors]

OBJECTIVE

The aim of this study is to obtain the general information of post-operation malignant oral-maxillofacial tumor patients in forty-seven years.

METHODS

A total of 6539 patients with malignant oral-maxillofacial tumors in the hospital of stomatology, west china university of medical sciences, from 1953 to 2000 were retrospected.

RESULTS

The average age of patients with malignant oral-maxilloficial tumor is 48.7 years old. The ratio of male to female is 2.31:1. The most common original malignant tumors in this oral-maxillofacial region are malignant oral tumors, malignant maxillary tumors, malignant mandibular tumors, and malignant sialoma successively. As to the original tissues of tumors, there were 5869 cases of epithelial tumors, and made up 89.75% of all the investigated patients. Tumors came from lymphatic and hematopoietic systems and mesoderm were much less those came from epithelia. There were 4177 cases of squamous cell carcinomas and the percentage was 63.88%.

CONCLUSION

The incidence rate of malignant tumors in oral-maxillofacial region tends to increase, and the average age of patients also rose. The ratio of male to female decreases gradually. Epithelial tumors, especially squamous cell carcinomas are very common tumors happening in this region.

Autologous chondrocyte implantation of the knee: multicenter experience and minimum 3-year follow-up

OBJECTIVE

To determine clinical outcome and graft survivorship in patients undergoing autologous chondrocyte implantation (ACI) for the repair of chondral defects of the knee.

DESIGN

Prospective cohort study.

SETTING

19 centers in the United States.

PATIENTS

50 patients (37 males, 13 females). Mean age was 36 years (range: 19-53). Defects were grade III or IV with a mean size of 4.2 cm 2. All patients had a minimum of 36 months postoperative follow-up.

MAIN OUTCOME MEASUREMENTS

Clinician and patient evaluation based on the modified Cincinnati Knee Rating System. Graft failure was defined as replacement or removal of the graft due to mechanical symptoms or pain.

RESULTS

Clinician and patient evaluation indicated median improvements of 4 and 5 points, respectively, at 36 months following ACI (p < 0.001). Previous treatment with marrow stimulation techniques and size of defect did not impact the results with ACI. The most common adverse events reported were adhesions and arthrofibrosis and hypertrophic changes. Three patients had graft failure and required reimplantation or treatment with alternative cartilage repair techniques. Kaplan-Meier estimated freedom from graft failure was 94% at 36 months postoperatively (95% CI = 88-100%).

CONCLUSIONS

These results of this study indicate excellent graft survivorship using ACI as well as substantial improvement in functional outcome.

The use of an antifibrosis agent to improve muscle recovery after laceration

Muscle injuries are challenging problems in traumatology and the most frequent injuries in sports medicine. Muscle injuries are capable of healing, although slowly and occasionally with incomplete functional recovery. We observed that lacerated muscle undergoes a rapid process of regeneration, which is hindered by the development of fibrosis. Biologic approaches to enhance muscle regeneration and prevent fibrosis are being investigated to improve muscle healing after injuries. We observed that growth factors can improve muscle regeneration but cannot prevent muscle fibrosis. We investigated the use of an antifibrosis substance, decorin, as an approach to prevent fibrosis and thereby improve muscle healing after injury in murine muscle. We observed that direct injection of human recombinant decorin can efficiently prevent fibrosis and enhance muscle regeneration in the lacerated muscle. More importantly, decorin can improve the recovery of strength in the injured muscle to a level similar to that observed in normal noninjured muscle. These results suggest that injection of decorin improves both the muscle structure and the function of the lacerated muscle to near complete recovery. This study will contribute significantly to the development of strategies to promote efficient muscle healing and complete functional recovery after muscle injuries.

[Expression of VEGF-C and its correlation with cervical lymph nodes metastasis of oral cancers]

OBJECTIVE

Vascular endothelial growth factor C (VEGF-C) is known to be capable of inducing cell proliferation of lymphatic endothelia and development of lymphatic vessels. Thus, in the current study the expression of VEGF-C was investigated to understand the mechanism of lymphatic metastasis of oral cancer.

METHODS

VEGF-C protein expression in benign and malignant oral lesions was investigated with an immunohistochemical staining assay, followed by light microscopic examination and image analysis.

RESULTS

Immunohistostaining of VEGF-C was observed in normal, benign and malignant epithelia, as well as in some lymphatic vessels. The VEGF-C positive rate was significantly higher in squamous carcinomas than in normal tissues and benign lesions. It was also noted that in squamous carcinomas the expression level of VEGF-C correlated well with pathological grades and stages of lymph node metastasis, but not with clinical grades.

CONCLUSION

These findings suggest that VEGF-C may promote lymphatic metastasis of oral cancer, and it is possible to be used as a predictor for the lymphatic metastasis and prognosis of oral cancer.

[The function of benzol peroxide in the induction of Syrian golden hamster tongue carcinoma by chemical carcinogen]

OBJECTIVE

To testify the function of promoter(benzol peroxide) in the induced tongue carcinogenesis of Syrian golden hamster as well as the function of carcinogen (DMBA).

METHODS

In this study, group 1: 20% benzoyl peroxide in acetone solution was brushed to the right tongue border of Syrian golden hamster, followed by 0.5% 7, 12-dimethybenzanthrancene(DMBA) in acetone, twice a week, lasting 20 weeks. Group 2: 0.5% 7,12-dimethybenzanthrancene(DMBA) in acetone was painted on the right tongue border of golden Syrian hamster in the manner of group 1. Group 3: 20% benzoyl peroxide in acetone solution was used with mentioned methods.

RESULTS

Group 2: showed 90% (27/30) carcinogenesis-rate in tongue of Syrian golden hamster. While it was 100% (30/30) of induced tongue carcinoma and 3/30 lymph node metastasis was found in group 1. No tongue carcinogenesis was found in group 3. The former two groups had the manifestations of hyperplasia of epithelium cell, carcinoma in situ, invasive and cervical lymph node metastatic carcinoma in the process of experiment, but it was 2 weeks shorter in group 1 than that of group 2. Both groups had the same features under eye and light microscope. The samples were high-differentiated squamous cell carcinoma histologically through HE stain.

CONCLUSION

This study indicated that benzoyl peroxide could increase carcinogenesis of golden hamster tongue which induced by DMBA. Consideration of promoting agent should be taken in carcinogenesis as well as carcinogen.

[Treatment of hemangioma in oral and maxillofacial region with pingyangmycin injection]

OBJECTIVE

To investigate the indication and result in hemangioma in oral and maxillofacial region with Pingyangmycin injection.

METHODS

1282 patients (554 males and 728 females) with hemangioma in oral and maxillofacial region have been treated in our hospital during the 10-year period from May 1990 to March 1999. The patients range between 0.5-84 years old. Lip, cheek and tongue were usually involved. 1211 patients were treated with injection of Pingyangmycin(about 0.89 mg/ml) and dexamethasone (about 0.55 mg/ml), 1 time/1-2 weeks.

RESULTS

The curative rates of cavernous hemangioma and strawberry hemangioma were 93.87% and 84.90%, but that of plexiform hemangioma was 22.22% and those of portwine stain and central hemangioma of the jaws were 0%, respectively. Serious complications associated with Pingyangmycin injection, such as pulmonary fibrosis were not seen.

CONCLUSION

Injection of Pingyangmycin is selective primary method for cavernous and strawberry hemangioma treatment.

[Autologous chondrocyte transplantation for treatment of cartilage defects of the knee joint. Clinical results]

Cartilage defects in the knee joint are common and have a bad tendency for healing due to the limited regeneration of hyaline cartilage. Surgeons have an ample choice of various operative treatment measures. Especially for the treatment of larger lesions first results of autologous chondrocyte transplantation (ACT) were published in 1994 [3]. Autologous chondrocytes are isolated from an arthoscopically harvested cartilage biopsy, cultured in vitro and implanted in the defect under a periostal flap in a second procedure. In an international multicenter study 1,051 patients treated with ACT between 6/95 and 12/98 were documented with follow-up examinations after 12 months (588 patients), 24 months (220 patients) and 36 months (40 patients). The majority of the defects (61.2%) were localized on the medial femoral condyle, measuring 4.6 cm2 and mostly described as grade III/IV lesions. The clinical evaluation was performed using a modified Cincinnati knee rating system independently for clinician and patient. Evaluations showed an increase from 3.35 to 6.25 after 24 months and from 3.10 to 6.77 in a scale from 1 (bad) to 10 (excellent). ACT favours defects of the femur with an improvement rate of 85%. Adverse events possibly related to ACT were described in 4.8% of the patients. Diagnostic second-look arthroscopies are included in the reoperation rate of 5.1%. The presented data indicate autologous chondrocyte transplantation as an effective and safe option for the treatment of large full thickness cartilage defects in the knee joint.

[Tissue engineering and gene therapy of the musculoskeletal system with muscle cells]

AIM

Muscle-based somatic gene therapy is a novel way to alleviate a biochemical deficiency.

METHOD

Muscle-derived cells are very promising in the field of gene therapy and tissue engineering. First, most muscle tissue is accessible by injection. Second, muscle tissue consists of multinucleated, postmitotic myofibers, which enable a long-term expression of the transduced gene. Third, muscle tissue can be biopsied easily. It is available in abundance and the biopsy does not compromise the health and function of the patient. Finally, muscle tissue is highly vascularized, which makes systemic delivery feasible.

RESULTS

Muscle-derived cells can promote muscle healing and bone healing. Implanted cells maintain a long-term transgene expression of therapeutic proteins. Isolated, muscle-derived stem cells can differentiate in osteoblasts.

CONCLUSION

Based on these characteristics, we present four possible applications: inherited muscular diseases, muscle injury, bone healing, and intraarticular disorders.

[Effect of electric field on optical radiation linewidth of free-carriers in quantum wells]

By using concepts as orbit, momentum and wave packet, the particles which move in a large range of space in solid state are described. According to the uncertainty relations in quantum mechanics, a formula of energy uncertainty of particles is derived. The formula indicates that electric field scatters carriers strongly and makes energy levels broaden largely. Applying the formula to GaAs/GaAlAs quantum wells with P-I-N structure, the calculated optical radiation linewidths are in agreement with measured photoluminescence linewidths.

Differential effects of exogenous interleukin-10 on cardiac allograft survival: inhibition of rejection by recipient pretreatment reflects impaired host accessory cell function

BACKGROUND

There have been conflicting reports of the influence of exogenous mammalian interleukin (IL)-10 on immune reactivity. These findings may reflect the pleiotropic effects of IL-10 on the functions of antigen-presenting cells and immune effector cells. The purpose of this study was to extend observations of the influence of the cytokine on organ allograft survival and to investigate its effects on the function of accessory and immune effector cells in a mouse cardiac transplant model.

METHODS

C3H (H2k) recipients of heterotopic vascularized B10 (H-2b) heart allografts were treated with recombinant (r) mouse IL-10 over a wide range of doses (0.2-200 microg/day), either before the transplant (days -3, -2, -1), peri-operatively (days -1, 0, 1), or after the transplant (days 0-6). Anti-donor cytotoxic T lymphocyte activity of host spleen and graft-infiltrating cells, and circulating complement-dependent cytotoxic antibody titers were determined by isotope release assays. Mixed leukocyte reactions were used to determine the influence of IL-10 on the function of antigen-presenting cells and allogeneic responder T cells.

RESULTS

Recipient pre-transplant administration of IL-10 (days -3, -2, -1) prolonged graft survival at all doses tested. Donor pretreatment with IL-10 (25 microg/day; days -3, -2, -1) was also effective, but less. A pre-transplant or perioperative course of IL-10, however, did not significantly affect the immunosuppressive action of tacrolimus given on days 0-6. If given only after the transplant, IL-10 either had no effect on graft survival or (at high dosage) accelerated rejection and prevented the immunosuppressive effect of cyclosporine. Pretransplant treatment of graft recipients with IL-10 reduced splenic anti-donor cytotoxic T lymphocyte activity and the incidence of graft-infiltrating CD8+ cells. There was no significant effect on circulating alloantibody titers. MLR assays revealed that preincubation of responder cells, but not stimulator spleen cells with IL-10, inhibited T cell proliferation, whereas addition of IL-10 after the start of culture modestly enhanced proliferation. Preincubation of purified T responders with IL-10 showed no inhibitory effect.

CONCLUSION

The modest and opposing effects of exogenous IL-10 on organ allograft survival are dependent on timing and dosage. Recipient pretreatment prolongs graft survival. This finding, together with the MLR results, suggest that IL-10 inhibits the function of host immune accessory cells and that the direct pathway of alloantigen presentation may be less susceptible to inhibition by IL-10.

[Diagnosis and treatment of central hemangioma of mandible]

OBJECTIVE

To investigate methods of diagnosis and treatment of hemangiomas of the mandible.

METHODS

Nineteen cases of central hemangioma of the mandible treated in our department from 1971 to 1997 were studied retrospectively. Fourteen patients received surgical treatment in which ten patients had received complete curettage of the lesion and the other four had received part resection of the mandible.

RESULTS

The most common signs and symptoms of this lesion were hypermobility of teeth and episodes of spontaneous hemorrhage from the surrounding gingival sulcus. Selective angiography was significant in the diagnosis of this lesion. Fourteen patients received surgical treatment and thirteen lesions were removed completely, except that one died of massive bleeding at the operation and DIC on the next day.

CONCLUSION

Selective angiography is useful to diagnosis the central hemangioma of mandible, and the complete curettage of the hemangiomas in the body of mandible is the most appropriate operation for children. At the same time, ligature of the inferior alveolar artery can reduce the risk of bleeding during operation.

Trafficking of APC from liver allografts of Flt3L-treated donors: augmentation of potent allostimulatory cells in recipient lymphoid tissue is associated with a switch from tolerance to rejection

Livers transplanted across major histocompatibility complex (MHC) barriers in mice are normally accepted without recipient immune suppression, and induce a state of functional tolerance. However, markedly increasing functional dendritic cells (DC) in the 'passenger leucocyte' population by donor pretreatment with the hematopoietic growth factor Flt3-ligand (Flt3L; 10 microg/day for 10 days) results in acute allograft rejection. In this study, molecular, immunohistochemical and flow cytometric analysis of donor cell traffick into recipient lymphoid tissue 24 h after liver transplantation (C57BL/10 [H2b]-->C3H [H2k]) was performed. In addition, the capacity of donor-derived cells in these tissues to stimulate host T cell proliferation was examined. Reverse transcriptase polymerase chain reaction analysis revealed increases in donor genomic DNA in both thymi and spleens of mice given livers from Flt3L-treated donors compared to controls. Donor MHC class II+ (IAb+) cells in spleens were strikingly elevated (10-fold) in the former group. Two-colour flow cytometry revealed a similar increase in donor-derived H-2Kb+/I-Ab+ cells, and in the incidence of donor leucocytes expressing CD40, CD80, and CD86. CD11c+ DC comprised approximately 40% of the I-Ab+ cells in spleens of mice given livers from Flt3L-treated donors. These changes were associated with the presence, in spleens, of potent allostimulatory activity for naive recipient strain T cells, that was not observed in normal liver recipients. Elicitation of allograft rejection, associated with enhanced trafficking of stimulatory donor antigen-presenting cells (APC), in particular DC, suggests that normal liver graft survival and tolerance induction may be linked to failure/counter-regulation of APC-driven stimulation of effective anti-donor T cell responses.

Prevention and restoration of second-set liver allograft rejection in presensitized mice: the role of "passenger" leukocytes, donor major histocompatibility complex antigens, and host cytotoxic effector mechanisms

BACKGROUND

The aim was to determine whether sublethal donor total body irradiation (TBI) might be as effective as lethal TBI in preventing mouse second-set liver allograft rejection, and to evaluate the role of passenger leukocytes, donor major histocompatibility complex (MHC) antigens, and host effector mechanisms in the response to livers from sublethally irradiated donors.

METHODS

B10 (H2b) donors received various doses of TBI at different times before their livers were transplanted orthotopically into normal or donor skin-presensitized C3H (H2k) recipients. The influence of irradiation on graft non-parenchymal cells (NPC) was determined by monoclonal antibody staining, and flow cytometric analysis. Hematopoietic cells within the grafts were reconstituted by intravenous infusion of syngeneic or third-party bone marrow cells. Allograft survival was determined in recipients that received no treatment, or that were given spleen cells from either normal B10 donors, or MHC class I - or class II-deficient mice syngeneic with the donors. Cytotoxic activity of graft-infiltrating cells and host spleen cells, and complement-dependent cytotoxic alloantibody titers were determined by isotype release assays.

RESULTS

The protective effect of donor TBI was observed both at lethal (9.5 Gy) and sublethal doses (5 and 3 Gy; graft median survival time: >100 days). Extended delay in liver transplantation, allowing hematopoietic recovery and graft reconstitution eliminated the effect. Liver NPC were reduced about 80% within 24 hr of 3 Gy TBI, with a selective reduction in the incidence of B cells. The NPC-depleted livers underwent accelerated rejection when donor (but not third-party) spleen cells (5 x 10(7) were administered systemically to the recipient immediately after graft revascularization. Spleen cells from MHC class I-deficient (but not MHC class II-deficient) mice failed to fully restore accelerated rejection of TBI liver grafts. Freshly isolated graft NPC, or spleen cells from TBI liver recipients, harvested 4 days after transplantation, exhibited lower, donor-specific cytotoxic activity than cells from mice given normal livers. Recipients of TBI livers also showed much lower serum complement-dependent cytotoxic alloantibody titers.

CONCLUSIONS

By substantially depleting "passenger leukocytes," sublethal donor TBI undermines anti-donor cell-mediated and humoral immune reactivity and inhibits second-set liver allograft rejection in presensitized recipients. The interval between irradiation and transplantation is important in conferring resistance to rejection. Expression of MHC class I on donor leukocyte infusions is important for overcoming resistance to second-set rejection induced by donor irradiation.

Evidence for a role of IL-17 in organ allograft rejection: IL-17 promotes the functional differentiation of dendritic cell progenitors

IL-17 is a T cell-derived cytokine that stimulates stromal cells and macrophages to secrete proinflammatory cytokines. We hypothesized that IL-17 might play a role in alloimmune responses, and that interference with its activity might suppress allograft rejection. IL-17R:Fc or control IgG was added at the start of mouse MLR or was administered i.p. (100-500 microg/day) for different durations post-transplant to murine recipients of MHC-mismatched cardiac allografts. IL-17R:Fc (50-200 microg/ml) markedly inhibited T cell proliferation in vitro and significantly prolonged nonvascularized cardiac allograft median survival time from 13 to 20 days (100 microg/day; days 0 and 1) or to 19 days (100-300 microg/day; days 0-4). Survival of vascularized grafts was also extended significantly from 10.5 to 19 days by IL-17R:Fc (500 microg/day; days 0-6). To address a possible mechanism by which IL-17 may promote alloreactivity, we examined the influence of IL-17 on the differentiation and function of bone marrow-derived cells propagated in granulocyte-macrophage CSF with or without IL-4 to promote dendritic cell (DC) growth. A minor proportion of CD11c+ DC expressed the IL-17R. IL-17 promoted the maturation of DC progenitors, as evidenced by increased cell surface expression of CD11c, costimulatory molecules (CD40, CD80, CD86), and MHC class II Ag, and allostimulatory capacity. IL-17 had a lesser effect on the phenotype and function of more fully differentiated myeloid DC. These findings suggest a role for IL-17 in allogeneic T cell proliferation that may be mediated in part via a maturation-inducing effect on DC. IL-17 appears to be a novel target for therapeutic intervention in allograft rejection.

Systemic administration of anti-interleukin-10 antibody prolongs organ allograft survival in normal and presensitized recipients

BACKGROUND

Systemic administration of cellular interleukin (IL)-10 at a dose of 100 microg/day for 1 week after transplantation accelerates mouse cardiac allograft rejection across MHC barriers. This effect is associated with enhancement of donor-specific cytotoxic T lymphocyte and alloantibody (alloAb) titers. To further evaluate the in vivo role of IL-10, we tested the influence of a neutralizing anti-IL-10 monoclonal antibody (mAb) in both normal and donor (skin) presensitized mouse organ allograft recipients.

METHODS

Heart or liver transplants were performed from B10 (H2b) donors to C3H (H2k) recipients. Anti-IL-10 mAb (SXC.I) was administered intravenously in a single injection or repeated once daily injections. Cytotoxic activity of graft-infiltrating cells was determined by 51Cr-release assay. Circulating alloAb levels were quantified by complement-dependent cytotoxicity and flow cytometry.

RESULTS

Survival of vascularized B10 cardiac allografts in normal recipients was prolonged significantly in the mAb-treated groups. A single injection of 1 mg of anti-IL-10 mAb immediately after heart transplantation gave a similar graft median survival time to repeated injections of lower dose mAb (0.5 mg/day for 6 days after transplantation) (Ig isotype control 11 days; single mAb injection 18 days; multiple injection 20 days). In presensitized recipients, anti-IL-10 mAb from days 0 to 6 significantly prolonged survival of both cardiac and orthotopic liver grafts. Graft median survival time was extended from 5 to 10 days and from 4 to 11 days, respectively. Prolongation of liver allograft survival in presensitized recipients was associated with suppression of circulating alloAb levels and with significant reductions in the incidence of B220+ cells in both grafts and recipient spleens.

CONCLUSIONS

The data support an adverse role of anti-IL-10 in allograft rejection; it seems that by reducing alloAb responses, anti-IL-10 mAb may have potential for use as a therapeutic immunosuppressant, particularly in presensitized organ allograft recipients.

Donor pretreatment with Flt-3 ligand augments antidonor cytotoxic T lymphocyte, natural killer, and lymphokine-activated killer cell activities within liver allografts and alters the pattern of intragraft apoptotic activity

BACKGROUND

Liver allografts are accepted across major histocompatibility complex (MHC) barriers in mice and induce donor-specific tolerance without requirement for immunosuppressive therapy. There is evidence that passenger leukocytes may play a key role in tolerance induction. Flt-3 ligand (FL) is a recently cloned hematopoietic cytokine that strikingly augments functional dendritic cells (DCs) within lymphoid and nonlymphoid tissue.

METHODS

The expression of costimulatory molecules and MHC class II antigen on DCs isolated from livers of FL-treated B10 (H2b) mice (10 microg/day; 10 days) was examined by flow cytometric analysis, and their allostimulatory activity assessed in primary mixed leukocyte cultures. B10 livers from FL-treated donors were transplanted orthotopically into naive C3H (H2k) recipients. Donor cells (MHC class II+) in recipient spleens were identified by immunohistochemistry. Antidonor cytotoxic T lymphocyte activity, and both natural killer and lymphokine-activated killer cell activities of graft nonparenchymal cells and host splenocytes were determined using isotope release assays. Apoptotic activity within liver grafts was determined by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling.

RESULTS

DCs isolated from livers of FL-treated donor mice exhibited increased cell surface expression of CD40, CD80, CD86, and IAb, and augmented T cell allostimulatory activity compared with controls. Within 24 hr of organ transplantation, the numbers of donor IAb+ cells within recipient spleens was augmented substantially compared with normal liver recipients. Livers from FL-treated donors were rejected acutely (median survival time, 5 days), whereas control B10 liver allografts survived >100 days. Nonparenchymal cells from rejecting grafts 4 days after transplantation exhibited increased antidonor cytotoxic T lymphocyte, natural killer, and lymphokine-activated killer cell activities compared with cells from spontaneously accepted grafts. This augmented cytotoxic reactivity was associated with histologic evidence of injury to bile duct epithelium and vascular endothelium that was not readily evident in controls.

CONCLUSION

Thus, although normal livers provide allostimulatory signals sufficient to elicit an antidonor immune response, regulatory mechanisms that may include apoptosis of graft-infiltrating T cells, and that are overcome by augmenting the number of functional donor DCs, may account for inherent liver tolerogenicity.

[Implementing a relatively rigorous algorithm of dynamic EIT problem on the modified FEM model]

We deduced a relatively rigorous algorithm of dynamic EIT problem-general inverse algorithm, and implemented it on the computer FEM model. Images which can show the changing of the resistivity(i.e. dynamic resistivity images) were gained. Also we modified the ordinary FEM model according to the characteristic of the EIT problem and implemented the general inverse algorithm on the modified model. The ill-posed condition of the forward matrix based on the modified model was fairly improved. It can be seen from the results that the general inverse algorithm with modified FEM model is an algorithm better than the back-projection algorithm in terms of object locating, image definition, and the ability of dealing with complex object and noise.