Canine ureteral replacement with long acellular matrix tube: is it clinically applicable?

PURPOSE

We evaluated the effectiveness of acellular matrix used as a tube for replacement of a relatively long segment of the canine ureter.

MATERIALS AND METHODS

Acellular matrix was obtained by excision of the whole ureter of donor dogs that were sacrificed and not included in the study group. Retrieved ureters were treated to have complete cell lysis, while maintaining the fiber framework. The study included 10 mongrel dogs in which a 3 cm segment was excised from 1 ureter and replaced by a tube of acellular matrix of the same length and width. The new tube was sutured proximal and distal by watertight interrupted sutures around a 5Fr Double-J stent (Medical Engineering Corp., New York, New York) that remained for 6 weeks. Excretory urography was done 1 and 2 weeks after stent removal and the dogs were then sacrificed. Before sacrifice the ureter was exposed and carefully examined, and the whole specimen was excised for histopathological examination.

RESULTS

All dogs survived surgery except 1, which died 1 week postoperatively of a malpositioned stent and urinary ascites. There was no clinically apparent postoperative complications during the presence or after the removal of the ureteral stents. One week after stent removal excretory urography showed ipsilateral mild to moderate hydroureteronephrosis in 3 dogs and no dye excretion in 6 with a normal contralateral kidney. One week later no dye excretion was detected in all except 1 dog, which showed more radiological deterioration. At the time of sacrifice there was moderate to marked hydroureteronephrosis above the level of the new tube in all dogs. Although the graft was intact in all subjects, marked shrinkage was observed. On ureteral calibration there was significant narrowing of the lumen up to complete occlusion. At 8 weeks histopathological examination showed extensive fibrosis.

CONCLUSIONS

An acellular matrix tube is not able to replace a 3 cm segment of the canine ureter.

Effect of spontaneous closure of arteriovenous fistula access on cardiac structure and function in renal transplant patients

BACKGROUND/AIM

The effect of spontaneous closure of arteriovenous fistula (AVF) used for hemodialysis on the heart is not adequately studied. The aim of this study was to assess the effect of spontaneous AVF closure in the early period after renal transplantation on the patient's outcome.

METHODS

Seventeen patients (13 males, 4 females) who had their AVF thrombosed within the first month after transplantation were retrospectively compared to another well-matched and persistent AVF group of patients comprising of 34 patients (27 males, 7 females). Echocardiographic assessment was done before transplantation and at 1 year after transplantation.

RESULTS

In the thrombosed fistula group, there was a trend towards lower values of left ventricular end-systolic and end-diastolic diameters as well as end-systolic and end-diastolic volumes of the left ventricle, but it did not reach statistical significance. The persistent AVF group had significantly higher estimates for cardiac output and cardiac index (p < 0.05). Both groups were comparable for left ventricular mass, left ventricular mass index, and left ventricular systolic and diastolic functions. There was no difference regarding patient and graft survival in both groups.

CONCLUSION

Spontaneous AVF thrombosis did not offer a cardiac beneficial effect and routine fistula closure is not warranted.

Long-term results of a prospective randomized study comparing two different antireflux techniques in orthotopic bladder substitution

PURPOSE

We compared the long-term functional results following two different reflux prevention techniques in orthotopic ileal bladder substitution in a prospective controlled randomized study.

METHODS

The study included 60 patients for whom orthotopic bladder replacement was indicated. The treated patients were prospectively randomized into two groups: group I (30 patients) underwent ileal W neobladder with serous lined extramural tunnel and group II (30 patients) received hemi-Kock pouch with intussuscepted nipple valve. Laboratory evaluation included estimation of serum creatinine while radiological studies included IVU and voiding studies. Urodynamic evaluation was an integral part of our investigation.

RESULTS

Patients and tumor characteristics were comparable between both groups. No operative or postoperative mortality were observed in either. Early complications were encountered in 5 (16.7%) and 4 (13.3%) patients in the two treated groups respectively (p=0.72) and most were treated conservatively. Twenty patients in group I and 19 in group II were evaluable. The mean follow up was 73.9+/-6.6 and 72.9+/-5.6 months in the treated groups respectively. Day and night time continence was comparable between both groups. Ascending studies demonstrated reflux in 3 (7.7%) of the reimplanted units in group I versus 2 (5.3%) in group II (p=0.81); IVU showed uretero-ileal anastomotic strictures in 2 renal units with both the serous lined extramural tunnel (5.1%) and the ileal nipple valve (5.3%) techniques (p=0.98). One patient in group I had pouch stone compared with 5 in group II (p=0.08). Urodynamic characteristics were also comparable in both groups.

CONCLUSION

The study provided evidence that the long-term functional results following serous lined extramural tunnel are as equal as the nipple valve. Furthermore, it spares the use of extra-bowel length, does not need staples and allows retrograde endoscopic procedures.

Tunica albuginea acellular matrix graft for treatment of Peyronie's disease--an experimental study in dogs

OBJECTIVE

To study the value of an acellular matrix graft of the tunica albuginea for reconstruction of the penis in cases of severe Peyronie's disease.

MATERIAL AND METHODS

In nine mongrel dogs, an acellular matrix graft of the tunica albuginea was used to cover a 30 x 10 mm2 tunical defect. Equal numbers of animals were sacrificed at 1, 3 and 6 months after surgery. Before death, an erection was induced by means of papaverine injection and cavernosography was performed. After death the penis was prepared for histopathological study.

RESULTS

All animals survived the surgery and none developed haematoma, wound infections or dehiscence. All dogs developed a straight, rigid erection. Cavernosography showed patent corpora cavernosa in all animals. The papaverine injection and cavernosographic results did not change over time. Inspection of the graft site and measurement of its length and width showed healing with no contracture. Histologically, the regenerated matrix appeared thicker than the neighbouring tunica albuginea in the 1-month group; otherwise the appearance was normal. Gradual orientation of the fibrocytes, capillaries and collagen fibres was demonstrated at 1 month and was complete at 3 and 6 months. Comparison between an implanted tunica at 6 months and a control tunica from a normal dog showed no significant histological difference.

CONCLUSION

A homologous acellular matrix graft of the tunica albuginea may be an alternative treatment for severe cases of Peyronie's disease.

Acellular Matrix Tube for Canine Urethral Replacement:: is It Fact or Fiction?

PURPOSE

We evaluated the results of acellular matrix used as a tube for replacement of a relatively long segment of the canine urethra.

MATERIALS AND METHODS

The study included 9 female and 5 male mongrel dogs in which a 3 cm segment of the whole urethral circumference was excised and replaced by a tube of acellular matrix of the same length and width. The acellular matrix was obtained by excision of the whole urethra of donor female dogs that were sacrificed and not included in the study group. The retrieved urethra was treated to have complete cell lysis with maintenance of the fiber framework. In all dogs the urethra was stented for 4 weeks. Ascending urethrogram was done after stent removal every month until the dogs were sacrificed. The dogs were sacrificed at a rate of 1 weekly for 4 weeks and then monthly. If urine retention occurred, ascending urethrogram was performed and the dog was sacrificed. Before sacrifice the urethra was exposed and carefully examined. The whole specimen was then excised for histopathological examination.

RESULTS

All dogs survived surgery and no postoperative complications were seen during urethral stenting. After stent removal all dogs had a urethral fistula and/or stricture, which increased in severity until urine retention occurred by the end of month 3. Exploration at 1, 2, 3 and 4 weeks showed an intact graft, although there was progressive shrinkage in length and urethral calibration also demonstrated progressive narrowing of the lumen. At 3 months there was marked shrinkage (length equaled 0.3 cm) and complete obliteration of the lumen. Histopathological examination showed progressive fibrosis, which was extensive by week 4.

CONCLUSIONS

Acellular matrix tube is not able to replace a 3 cm segment of canine urethra.

Comparison of Partial Urethral Replacement with Acellular Matrix versus Spontaneous Urethral Regeneration in a Canine Model

OBJECTIVE

To determine whether acellular matrix could be used for partial urethral replacement and to compare regeneration over acellular matrix versus normal spontaneous urethral regeneration.

MATERIALS AND METHODS

The study included 21 male mongrel dogs in which a 3-cm segment including half of the urethral circumference was excised. In 13 dogs (study group), the defect was covered by acellular matrix of the same length and width obtained from female mongrel dogs and prepared to have complete cell lysis with keeping of the fiber framework. In 8 dogs (control group), the urethral defect was not covered by any urethral tissue. In both groups, an 8F feeding tube was kept inside the urethra for a mean duration of 2 weeks. In the study group, dogs were sacrificed at 1 week, 2 weeks, 3 weeks and then one dog every month for 10 months. In the control group, one dog was sacrificed every month for 8 months.

RESULTS

All dogs survived the procedure. In the study group, 10 dogs underwent urethrogram; 8 were normal, 1 had diverticulum and 1 had relative narrowing. In the control group, 6 dogs underwent urethrogram; 5 were normal and 1 showed relative narrowing. Histopathological examination of the study group showed gradual regeneration over the acellular matrix with normal appearance at 20 weeks. In the control group, normal healing was observed at 2 months and thereafter.

CONCLUSION

Regeneration of all components of the urethra can occur gradually over acellular matrix and is complete at 20 weeks. Regeneration of a urethral defect 3-cm long including half of the urethral lumen is possible with or without acellular matrix.

Generation of Ag-specific cytotoxic T lymphocytes by DC transfected with in vitro transcribed influenza virus matrix protein (M1) mRNA

BACKGROUND

Application of DC transfected with tumor Ag RNA is promising for DC-based tumor immunotherapy. In this study, Ag-specific cytotoxic T lymphocytes (CTL) were generated by priming lymphocytes with DC transfected with in vitro transcribed (IVT) influenza virus matrix protein M1 (M1) mRNA.

METHODS

Human UC blood-CD34+ cell-derived DC were transfected with IVT mRNA encoding either the enhanced green fluorescence protein (EGFP), or M1 by square-wave electroporation. DC were confirmed to have typical morphology and phenotype. DC transfected with IVT EGFP mRNA were analyzed with the FACScan flow cytometer, to confirm the efficiency of this transfection method. On Days 7, 14, 21 and 28 after the start of DC culture, DC were harvested and electroporated with M1 mRNA. The transfected DC were co-cultured with autologous UC blood CD34- cells. One week after the fourth priming of autologous CD34 negative cells with M1 mRNA electroporated DC, Ag-specific CTL activity was evaluated. To prepare target cells, M1 mRNA was added to autologous DC 48 h prior to CTL assays.

RESULTS

Our CTL assays results indicate that UC blood CD34+ cell-derived DC transfected with M1 mRNA by electroporation stimulated Ag-specific CTL responses that are capable of recognizing and lysing autologous DC loaded with M1 mRNA. M1 mRNA transfected DC-primed CTL showed a significant cytotoxic activity against M1 mRNA loaded autologous DC, while nearly baseline cytotoxic activity was recorded for the M1 mRNA unloaded DC.

DISCUSSION

Our results showed that mRNA-transfected DC are potent stimulators of T-cell immunity in vitro. In addition, mRNA-loaded DC can function as targets in CTL cytotoxicity assays, which offer a practical substitute for tumor cells in assays to test the immunological effects of specific Ags.

A Comparative Study of the JAM Test and51Cr‐Release Assay to Assess the Cytotoxicity of Dendritic Cells on Hematopoietic Tumor Cells

Dendritic cells (DCs) are potent antigen presenting cells and possess a direct anti-tumor cytotoxic ability. Nevertheless, the mechanism of anti-tumor cytotoxicity by DCs and the methods for its evaluation are not fully elucidated. In order to clarify this mechanism of cytotoxicity, we examined the ability of DCs 1) to suppress [3H] thymidine (3H-TdR) uptake by tumor cells; 2) to induce cytolysis on 51Cr-labeled tumor cells; 3) and to induce DNA fragmentation on 3H-TdR labeled tumor cells (JAM test). Cytolysis and DNA fragmentation are markers of necrotic and apoptotic mechanisms of cytotoxicity in vitro, respectively. DCs inhibited approximately 38.6% to 54.8% of the growth of B4D6, NB4, U937, and Daudi cells as evaluated by the uptake of 3H-TdR. However no cytolysis was verified by 51Cr-release assay. On the other hand, cytotoxicity rates found using the JAM test ranged from 3 to 81% depending on the cell line and the effector to target cell ratio. The discrepancy of cytotoxicity between 51Cr-release assay and the JAM test may be due to the phagocytosis of apoptotic tumor cells or the absorption of released 51Cr by DCs surrounding the target cells. In conclusion, the JAM test was more sensitive than the 4-h and the 10-h 51Cr-release assay to investigate cytotoxicity mediated by DCs toward hematopoietic tumor cell lines in vitro.

Multiple arteries in live donor renal transplantation: surgical aspects and outcomes

PURPOSE

This retrospective study describes the surgical techniques and outcomes of live donor renal allografts with multiple arteries.

MATERIALS AND METHODS

Between 1976 and 2000, 1,200 consecutive live donor renal transplants were done, including 1,087 with single (group 1) and 113 with multiple (group 2) arteries. Intracorporeal in situ anastomotic techniques were used for 94 grafts with multiple arteries, while ex vivo techniques were used for 19. During in situ surgery each one of the multiple arteries was anastomosed separately to an individual artery. In ex vivo surgery 2 or more arteries were joined together on the bench to form a common stem, which was then anastomosed to an iliac artery or the aorta.

RESULTS

Patient and graft survival were comparable in groups 1 and 2. The 2 groups were comparable regarding complications, including arterial bleeding, hematoma, renal artery stenosis, acute rejection, new onset hypertension, acute tubular necrosis and urological complications. Mean serum creatinine +/- SD at 1 year was 1.4 +/- 0.5 and 1.5 +/- 0.6 mg./dl., and at 5 years it was 1.8 +/- 1 and 2.1 +/- 1.4 mg./dl. for the 2 groups, respectively. The difference was only significant at 1 year (p = 0.02). Graft and patient survival, and the incidence of the described complications were comparable for the ex vivo bench anastomotic techniques and intracorporeal in situ techniques in the group with multiple renal arteries.

CONCLUSIONS

The use of multiple arteries in renal allografts does not adversely affect patient or graft survival. It is not associated with an increased rate of complications except for significantly higher mean serum creatinine at 1 year. Extracorporeal bench surgery was as effective as intracorporeal surgery for the anastomosis of multiple renal arteries with no increase in the incidence of relevant complications.

Vascular complications after live donor renal transplantation: study of risk factors and effects on graft and patient survival

We evaluated the incidence and management of vascular complications after live donor renal transplantation. Possible risk factors and their effects on patient and graft survival were also assessed.

MATERIALS AND METHODS

A total of 1,200 consecutive live donor renal transplants were performed in 1,152 patients at a single institution. The incidence of different types of vascular complications were determined and correlated with relevant risk factors. The impact on patient and graft survival was also studied.

RESULTS

There were 34 vascular complications (2.8%). Stenotic or thrombotic complications were recorded in 11 cases (0.9%), including renal artery stenosis in 5 (0.4%), renal artery thrombosis in 5 (0.4%) and renal vein thrombosis in 1 (0.1%). Hemorrhagic complications were observed in 23 patients (1.9%). Although no risk factors could be identified that were related to stenotic or thrombotic complications, grafts with multiple renal arteries were significantly associated with hemorrhagic complications (p = 0.04). Stenotic and thrombotic complications as well as hemorrhagic complications were significantly associated with subsequent biopsy proved acute tubular necrosis (p <0.001). The mean 5-year patient and graft survival rates +/- SD for those with vascular complications were 71.9% +/- 1.9% and 41.6% +/- 8.9% compared with 86.3% +/- 1.1% and 76.8% +/- 1.4% for the remainder of our transplant population, respectively (p <0.001). The deleterious impact on survival was not only observed in recipients with thrombotic or stenotic crises, but also in those with hemorrhagic sequelae.

CONCLUSIONS

Hemorrhagic crises are as serious as the stenotic and thrombotic complications affecting patient and graft survival. Because they are a significant factor in the development of hemorrhagic complications, grafts with multiple renal arteries should be managed critically.

High-energy transurethral microwave thermotherapy: symptomatic vs urodynamic success

OBJECTIVE

To evaluate the subjective and objective treatment results of high-energy transurethral microwave thermotherapy (TUMT) for symptomatic benign prostatic hyperplasia (BPH), and investigate the possible variables for predicting symptomatic and/or urodynamic success.

PATIENTS AND METHODS

Between October 1998 and October 2000, 40 men with BPH underwent high-energy TUMT using the Targis device (Urologix, Inc., Minneapolis, MN, USA). Evaluation after treatment included a clinical determination of the symptom score, a urodynamic assessment by peak flow rate and pressure-flow, magnetic resonance imaging (MRI), transrectal ultrasonography and endoscopy. The objective and subjective success was correlated with several variables before, during and after treatment.

RESULTS

All patients completed at least 1 year of follow-up after TUMT as monotherapy. The symptom score improved from a median (range) of 20.5 (11-28) initially to 9 (0-28) (P < 0.001). Twenty-two patients (55%) had a marked and 11 (28%) a moderate response, giving an overall subjective success rate of 83%. Similarly, there was a significant improvement in peak flow rate, from 9.2 (4.4-13.4) to 15 (3.3-22.9) mL/s (P < 0.001). Twenty-one patients (53%) had a maximum flow rate of > 15 mL/s while in eight (20%) it was 10-15 mL/s. Only 20 patients changed from unobstructed on the pressure-flow nomogram, i.e. an overall objective success rate of 50%. Gadolinium-enhanced T1-weighted MRI 1 week after treatment showed a median (range) perfusion defect of 20.7 (5.5-76.6)% of the total gland volume. Despite this persisting in all patients, a well-defined cavity was apparent in only in seven (18%) at the final evaluation. Cystoscopy 1 month after therapy showed evidence of necrotic tissue occupying the prostatic fossa in all patients. Younger patients were more likely to be urodynamically successful, and a higher grade of obstruction predicted symptomatic success.

CONCLUSION

High-energy TUMT can induce considerable necrosis of the prostate, as shown by MRI and cystoscopy. Although there was an adequate improvement in most patients' symptoms, there was a successful urodynamic change to unobstructed in only half the patients. Younger patients and those with a higher grade of obstruction were more likely to have urodynamic and symptomatic success, respectively.

Urological complications after living-donor renal transplantation

OBJECTIVE

To determine the incidence and management of urological complications after 1200 consecutive live-donor renal transplantations, all of which were carried out in one centre; the possible risk factors and the effect on patient and graft survival were also assessed.

PATIENTS AND METHODS

Data were retrieved from an electronic database; the incidence of urological complications was determined, and correlated with relevant risk factors by univariate and multivariate analysis. The effect on patient and graft survival was assessed using Kaplan-Meier statistics.

RESULTS

There were 100 complications in 96 patients (8%); urinary leaks occurred in 37, ureteric strictures in 23 and lymphoceles causing ureteric obstruction in 17. Percutaneous needle biopsy was complicated by haematuria and clot anuria in six patients. Late complications included 11 cases of stones, four of bladder malignancy and two of haemorrhagic cystitis. There was evidence that the age of the recipients (< 10 years), method of establishing urinary continuity (uretero-ureteric anastomosis) and a high dose of steroids had an independent positive effect on the incidence of urological complications. However, their development did not influence graft or patient survival.

CONCLUSION

When there is meticulous attention to the technical details, renal transplantation should incur few urological complications. Early intervention with percutaneous drainage reduces morbidity and the likelihood loss of graft function. Proper and prompt management should not affect the graft and/or the patient's survival.

Activation of hepatic NKT cells and subsequent liver injury following administration of alpha-galactosylceramide

It has been established that alpha-galactosylceramide (alpha-GalCer), a glycolipid, is recognized by natural killer T (NKT) cells together with the monomorphic MHC-like antigen, CD1d, in mice and humans. In this study, we examined how NKT cells are modulated by in vivo administration of alpha-GalCer in mice. When 2 microg (or more)/mouse of alpha(-GalCer was injected i.p., the majority of NKT cells disappeared in the liver and spleen, possibly undergoing apoptosis, on day 1. At this time, NKT cytotoxicity seen in liver lymphocytes also disappeared. In parallel with this numerical and functional change of NKT cells, there was always concomitant hepatocyte damage, as shown by histology and elevated levels of transaminases. Subsequently, the number and function of NKT cells continued to increase from day 3 to day 7. The response seen in hepatic (and splenic) NKT cells did not occur in thymic NKT cells. All these phenomena induced in the liver did not appear in NKT-deficient mice such as beta2-microglobulin(-/-) and CD1d(-/-) mice. These results shed further light on the in vivo interaction between NKT cells and alpha-GalCer in mice.

Activation of hepatic NKT cells and subsequent liver injury following administration of alpha-galactosylceramide

It has been established that alpha-galactosylceramide (alpha-GalCer), a glycolipid, is recognized by natural killer T (NKT) cells together with the monomorphic MHC-like antigen, CD1d, in mice and humans. In this study, we examined how NKT cells are modulated by in vivo administration of alpha-GalCer in mice. When 2 microg (or more)/mouse of alpha(-GalCer was injected i.p., the majority of NKT cells disappeared in the liver and spleen, possibly undergoing apoptosis, on day 1. At this time, NKT cytotoxicity seen in liver lymphocytes also disappeared. In parallel with this numerical and functional change of NKT cells, there was always concomitant hepatocyte damage, as shown by histology and elevated levels of transaminases. Subsequently, the number and function of NKT cells continued to increase from day 3 to day 7. The response seen in hepatic (and splenic) NKT cells did not occur in thymic NKT cells. All these phenomena induced in the liver did not appear in NKT-deficient mice such as beta2-microglobulin(-/-) and CD1d(-/-) mice. These results shed further light on the in vivo interaction between NKT cells and alpha-GalCer in mice.

Nocturnal enuresis in men with an orthotopic ileal reservoir: urodynamic evaluation

PURPOSE

We evaluated the urodynamic features of enuretic and continent patients with an orthotopic neobladder.

MATERIALS AND METHODS

Included in our study were 100 men with an orthotopic hemi-Kock or W neobladder and a minimum followup of 1 year. Of the patients 50 were completely continent day and night, and 50 had enuresis without evidence of an underlying organic etiology, such as stones, reflux or urethral stricture.

RESULTS

Univariate analysis showed significantly higher pressure and a larger volume of post-void residual urine in the men with enuresis. In addition, maximum urethral pressure, maximum flow and compliance were decreased in the enuretic group compared to the continent group. Multivariate analysis revealed that post-void residual urine volume, frequency and maximum amplitude of uninhibited contractions are the most critical parameters affecting nocturnal continence.

CONCLUSIONS

The cystometric parameters significantly associated with nocturnal enuresis in patients with an orthotopic reservoir are post-void residual urine volume, frequency and maximum amplitude of uninhibited contractions. Urethral pressure and flow parameters did not sustain significance on multivariate analysis.

[Demonstration of HFE polymorphism in German patients with hereditary hemochromatosis]

BACKGROUND AND OBJECTIVE

Hereditary haemochromatosis (HH) is the most common genetically determined disease of the white population which by iron overload causes multiorgan functional impairment. Recently the gene for HH (HFE gene) has been located on chromosome 6. The development of HH is thought to be caused by two point mutations that lead to an amino acid exchange of tyrosine for cysteine on codon 282 (Cys282Tyr) and of histidine by aspargic acid on codon 63 (His63Asp).

PATIENTS AND METHODS

75 patients with phenotypically confirmed HH were examined genetically. The analysis of the HFE-gene mutation was done on genomic DNA by restriction digestion with the restriction enzymes Rsal and Mbol.

RESULTS

Homozygosity for the Cys282Tyr mutation was found in 66 (88%) of the patients, while two were heterozygous. Of seven patients with wild-type sequence of the amino acid position 282, three (43%) had a His63Asp exchange. Overall only four patients had neither of the two mutations.

CONCLUSIONS

Because of different geographical distributions, a knowledge of the mutation rate is important for patients with HH. to assess the diagnostic value of the gene test. For the first time gene analysis makes it possible to diagnose HH before clinically significant iron overload occurs. It may further improve prognosis of the disease by early application of therapeutic blood-letting.

Dendritic cells stimulate the expansion of PML-RAR alpha specific cytotoxic T-lymphocytes: its applicability for antileukemia immunotherapy

Dendritic cells (DC), the most potent "professional" antigen-presenting cells, hold promise for improving the immunotherapy of cancer. In this study, we investigated the ability of normal donor DC pulsed ex vivo with 12 mer PML-RAR alpha (A) peptide (SGAGEAAIETQS) to generate peptide specific autologous cytotoxic T-lymphocytes. The peptide pulsed DC-primed peripheral blood lymphocytes (PBL) displayed significantly higher cytotoxic activity compared with that of peptide non-pulsed DC-primed PBL against peptide-pulsed autologous macrophages (P<0.001). Both CD8+ and CD4+ T lymphocytes were involved in the effector cell populations. The PML-RAR alpha peptide-pulsed DC-primed T-cells were significantly superior in their production of GM-CSF and TNF-alpha, compared with peptide non-pulsed DC-primed T-cells. These intriguing preclinical studies, suggest that PML-RAR alpha pulsed-DC could be a promising immunotherapeutic modality for patients with acute promyelocytic leukemia.

[Hereditary hemochromatosis--new developments after discovery of the HFE gene]

Hereditary hemochromatosis (HH) is an autosomal recessive disorder of iron metabolism, resulting in an increased iron deposition and multiorgan failure. Recently a candidate gene of HH, termed HFE, has been identified on chromosome 6, coding for a protein homologous to major histocompatibility complex (MHC) class I molecules. Two mutations of the hemochromatosis gene leading to an exchange of cysteine to tyrosine at aminoacid 282 and histidine to asparagine at aminoacid 63, are retained responsible for the development of hereditary hemochromatosis. The Cys282Tyr-mutation disrupts a disulfid bond and thus abrogates binding of the mutant HFE-protein to beta 2-microglobulin and its presentation on the cell surface. The His63Asp-mutation seems to play a role in pH-regulated dissociation of the transferrin receptor/transferrin complex in the lysosome. Mutations of the HFE-protein alter the affinity of the transferrin receptor for its ligand transferrin and may thus cause an intracellular accumulation of iron. Knowledge of the responsible gene allows a molecular diagnosis of HH. The new genetic marker can be used for screening and confirmation of HH reducing the need for confirmatory liver biopsies. Compared to standard screening parameters like ferritin and transferrin saturation genetic testing will allow the diagnosis of HH in an early, asymptomatic state before iron accumulation has occurred. As a normal life expectancy of patients with HH can be achieved if iron reduction is initiated early, genetic testing may thus be of great benefit for patients with HH.

Activation of autologous or HLA-identical sibling cytotoxic T lymphocytes by blood derived dendritic cells pulsed with tumor cell extracts

This study describes the effect of dendritic cells (DC) pulsed with tumor cell extracts on the induction and activation of autologous and HLA-identical sibling tumor cell specific cytotoxic T lymphocytes (CTL). The subjects of the study were patients with hematological malignancies (acute myeloid leukemia, acute lymphoblastic leukemia, and multiple myeloma), and stem cell transplant donors. Although lymphocytes primed with non-pulsed DC did not show definite cytotoxic activity against autologous or HLA-identical sibling patient tumor cells, both autologous and HLA-identical sibling CTL activated by DC pulsed with tumor cell extracts demonstrated markedly significant killing activity against tumor cells in the fashion of higher cytotoxicity with the increase of effector:target ratio (p<0.05). These findings reveal that DC pulsed with tumor cell extracts could be efficiently applicable in anti-tumor immunotherapy for patients with hematological malignancies.

Generation of bcr-abl specific cytotoxic T-lymphocytes by using dendritic cells pulsed with bcr-abl (b3a2) peptide: its applicability for donor leukocyte transfusions in marrow grafted CML patients

Dendritic cells (DC), the most potent 'professional' antigen-presenting cells, hold promise for improving the immunotherapy of cancer. In this study, we investigated the ability of normal donor DC pulsed ex vivo with 12 mer bcr-abl (b3a2) peptide to generate b3a2-specific autologous or HLA-identical sibling donor's cytotoxic T-lymphocytes (CTL). DC that were grown from normal peripheral blood adherent cells or purified DC precursors in the presence of GM-CSF and IL-4, were pulsed with b3a2-peptide then were induced to become mature and functional cells by the addition of TNF-alpha. These peptide-pulsed mature DC elicited a potent b3a2-specific CTL response in vitro. The b3a2-peptide pulsed DC-primed peripheral blood lymphocytes (PBL) displayed significantly higher cytotoxic activity compared with peptide non-pulsed DC-primed PBL against target cells, which are b3a2 positive marrow cells derived from HLA-identical sibling chronic myelogenous leukemia (CML) patient, or peptide-pulsed autologous macrophages (P < 0.001). In addition, the b3a2 peptide-pulsed DC-primed and non-pulsed DC-primed PBL showed no cytotoxic response against peptide non-pulsed autologous macrophages. These findings revealed that normal donor PBL pre-immunized with b3a2-peptide pulsed autologous DC could increase the graft-versus-leukemia effect without exaggerating graft-versus-host-disease. Both CD8+ and CD4+ T lymphocytes were shown to be involved in the effector cell populations. The b3a2 peptide-pulsed DC-primed T cells were significantly superior in their production of GM-CSF and TNF-alpha compared with peptide non-pulsed DC-primed T cells. These intriguing preclinical results imply the feasibility of developing b3a2 peptide-DC based protocol for in vitro sensitization of normal donor leukocytes before donor leukocyte transfusions for patients with CML, who relapsed after HLA-matched sibling bone marrow transplantation.

Expression patterns of costimulatory molecules on cells derived from human hematological malignancies

In order to elucidate the possibility of costimulatory molecules-mediated immuno or immuno-gene therapy for human hematological malignancies, we analyzed 30 hematopoietic cell lines and cells obtained from 48 patients with hematological malignancies for the expression of costimulatory molecules such as CD80 and CD86. The 30 hematopoietic cell lines were composed of 4 cell lines derived from the patients with T-cell acute lymphoblastic leukemia (T-ALL), 3 from Philadelphia chromosome positive ALL (Ph1+ALL), 8 from acute myeloblastic leukemia (AML), 3 from acute promyelocytic leukemia (APL), 8 from chronic myeloid leukemia at blast crisis (CML-BC), 3 from Burkitt's lymphoma and one from follicular cell lymphoma. The expression of CD80 or CD86 was frequent on cell lines derived from the patients with CML-BC or Burkitt's lymphoma, while it was rare on cell lines from T-ALL. Subsequently we analyzed the cells obtained from 48 patients with hematological malignancies, which consisted of 6 samples from patients with ALL, 30 from AML, 2 from CML-BC, 3 from B-cell lymphoma and one from each acute mixed leukemia (AMixL), adult T cell leukemia (ATL), T-cell large granular lymphocytic leukemia (T-LGL leukemia), chronic lymphocytic leukemia (CLL), myelodysplastic syndrome (MDS)-RAEB in T, multiple myeloma (MM) or T-cell lymphoma. Among all the 48 cases, all cases except one case with CLL and two with B cell lymphoma were demonstrated to be negative for CD80 on the neoplastic cells. CD86 and HLA-DR were shown to be expressed in 50% and 88% of total 48 cases respectively. In 30 AML samples, CD86 was positive in 15 cases (50%), which was sharply in contrast with the finding that CD80 was not detected in any AML samples. HLA-DR was expressed in 25 AML samples (83%). We also treated seven human hematopoietic cell lines with IFN-gamma, IL-12 or IL-15 and observed whether these cytokines could induce or enhance the expression of CD40, CD54, CD58 and HLA-DR as well as CD80 and CD86. The present study demonstrated that the expression of CD86 could be upregulated not only by IFN-gamma, but also by IL-12 or IL-15 in some cell lines. These findings suggested the possibility that the absence of CD80 on neoplastic cells may be associated with the lack of efficient anti-tumor immunity in most patients with hematological malignancies and that the immuno or immuno-gene therapy manipulating the expression of costimulatory molecules such as CD80 may be a useful treatment modality for hematological malignancies.

Mitochondrial genomic markers confirm the presence of the camel strain (G6 genotype) of Echinococcus granulosus in north-western China

Twenty-eight isolates of E. granulosus, collected from humans at surgery, and a range of intermediate hosts, including sheep, cattle and camels from abattoirs in North and South Xinjiang Uygur Autonomous Region, People's Republic of China, were analysed for DNA sequence variation within regions of the mitochondrial cytochrome c oxidase I (COI) and NADH dehydrogenase subunit I (NDI) genes. The isolates were categorized into 2 distinct and uniform genotypic groupings, based on the sequences obtained, and the data clearly indicated that the camel/dog strain (G6 genotype) of E. granulosus as well as the cosmopolitan, common sheep strain (G1 genotype) occur in north Xinjiang. The presence of the camel strain has thus been confirmed in Xinjiang but it is evident from this and a previous molecular genetic survey of E. granulosus isolates from north-western China that the common sheep strain is the most predominant in the region. From the public health perspective, the majority of infected livestock will act as reservoirs of human infection there. During the course of the study, a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay, based on the NDI sequence variation, was developed that allows rapid discrimination of the G1 and G6 genotypes.