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Dive into the research topics where H. Bitter-Suermann is active.

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Featured researches published by H. Bitter-Suermann.


Pediatric Transplantation | 2001

Extravesical ureteroneocystostomy with and without internalized ureteric stents in pediatric renal transplantation

Christopher G. French; Philip D. Acott; John F. S. Crocker; H. Bitter-Suermann; J Lawen

Abstract: The use of ureteric double‐J stents and the Lich‐Gregoir (extravesical) technique of ureteroneocystotomy have both been shown to decrease the rate of urologic complications in adult kidney transplantation (Tx). There are, however, few studies of the systematic use of stents in pediatric renal Tx. Between 1991 and 1997, 32 consecutive pediatric renal transplant recipients routinely received a 6F‐12 cm indwelling double‐J stent and were studied prospectively. These patients were compared with 32 consecutive pediatric recipients in whom a stent was not used. The latter were transplanted between 1987 and 1991 and formed the control group. All patients had a Lich‐Gregoir ureteroneocystotomy. Stents were removed under general‐anesthetic cystoscopy 2–3 weeks after Tx. Immunosuppression for stented patients was polyclonal antibody induction, delayed (7–10 days) cyclosporin A, azathioprine, and prednisone. The control group received the same triple drug regimen but with no induction in 29 of the 32 patients. All patients were followed‐up with at least one ultrasound evaluation in the first month, and a renal scan and repeat ultrasound were performed if there was any rise in serum creatinine. In the stented group there were two patients with urinary leak and no obstructions. In the non‐stented group there were no leaks and one obstruction. There was no graft loss owing to urologic complications in either group. There were three cases of stent expulsion (all in girls) and one case of stent migration in the posterior urethra (a boy). The 1‐yr graft survival rate was 90.6% in the stented group and 65.6% in the non‐stented group. The prophylactic use of an indwelling ureteral stent in pediatric renal Tx did not reduce the risk of urinary leakage or obstruction. Stent migration is a common phenomenon and, while not a serious complication, is traumatic to children. Furthermore, removal of an internalized double‐J stent requires a general anesthetic. We recommend using a stent for selected patients only.


Transplantation | 1990

Rat liver preservation. I, The components of UW solution that are essential to its success

Yu Wm; Coddington D; H. Bitter-Suermann

A total of 278 orthotopic rat liver grafts, without arterialization, were performed, in an attempt to determine which of the individual components of UW solution are essential. Livers were preserved by in situ flushing and cold storage with the following results: 56% of rats survived for 1 week after 9 hr of preservation with UW solution as compared with 44% using Marshall solution, and 10% using Collins solution. Having established LD 50 for UW solution, we then omitted its components one at a time and found that omission of HES, raffinose, allopurinol, adenosine, phosphate buffer, or MgSO4 did not change survival after 9 hr of preservation. Omission of lactobionate, glutathione, and dexamethasone, respectively, resulted in decreased survival, whereas elimination of insulin surprisingly increased survival. In ensuing dose-response studies, the concentrations of lactobionate, glutahione, dexamethasone in UW solution proved to be optimal. Finally, livers were preserved with a solution containing only lactobionate, glutathione, dexamethasone, raffinose, and phosphate buffer, resulting in 53% animal survival, as compared with 56% for the unchanged UW solution. We conclude that UW solution can be simplified without loss of effectiveness in this model.


Transplantation | 1996

Infection concomitant with pediatric renal allograft rejection.

Philip D. Acott; Spencer H. S. Lee; H. Bitter-Suermann; Joseph Lawen; John F. S. Crocker

Renal allograft rejection episodes are frequent in children and often lead to allograft failure. Frequent association of fever with rejection in our transplant program provoked a prospective evaluation of concurrent infection during rejection episodes. Because cytomegalovirus has an established role in rejection and allograft survival, evaluation of cytomegalovirus and other herpes viruses (human simplex virus type 1, varicella, Epstein-Barr virus, and human herpes virus type 6 [HHV-6]) was undertaken in addition to standard bacterial investigation. A total of 37 patients were followed over a 30-month period. Six of eight rejection episodes were associated with herpes viruses (HHV-6, n = 6, and Epstein-Barr virus, n = 1). Three of the herpes-group-associated rejection episodes were treated with antiviral therapy in addition to pulse steroid treatment, with full recovery. The three patients with HHV-6-associated rejection episodes who were treated with pulse steroids, but no antiviral therapy, developed chronic allograft rejection. The recipients response to allograft antigens may be influenced by concomitant herpes infection, and specific antiviral therapy appears to be indicated when infection is confirmed in association with rejection. An antiviral treatment program coupled with modulation of standard antirejection immunotherapy has the potential to improve morbidity and mortality in the pediatric renal transplant population.


Transplantation | 1993

Reduction by combination prophylactic therapy with CMV hyperimmune globulin and acyclovir of the risk of primary CMV disease in renal transplant recipients.

David L. Nicol; Allan S. MacDonald; Philip Belitsky; Spencer Lee; Allan D. Cohen; H. Bitter-Suermann; Joseph Lowen; Alice Whalen

CMV-seronegative recipients of kidneys from CMV-seropositive donors (D+/R+) are at highest risk for developing clinical CMV disease. Even with routine prophylactic use of low-dose acyclovir we had a CMV disease incidence of 26% (5/19) in these patients. Published studies using either acyclovir or CMV hyperimmune globulin (HIG) alone as prophylaxis have also shown clinical disease in 20-30% of D+/R+ patients--less than controls but still significantly greater than in comparable CMV+ recipients (R+). The purpose of this study was to determine whether the risk of primary CMV disease in D+/R- patients was reduced by prophylaxis with combined CMV-HIG and low-dose acyclovir as follows: CMV-HIG (Immuno) 1 ml/kg i.v. immediately prior to transplantation and at 3-week intervals for 6 months; acyclovir 600 mg/day p.o. for 3 months. A total of 361 consecutive renal transplants were studied prospectively. All D+/R- pts (n = 73) received CMV-HIG and acyclovir, the others (91 D+/R+, 74 D-/R+, 123 D-/R-) received only low-dose acyclovir. The incidence of clinical CMV disease, CMV-related graft loss, graft and patient survival, and the influence of ALG and OKT-3 were analyzed and compared between groups. Of the 361 patients only 18 (5%) developed CMV disease, with 5 CMV-related graft losses. CMV disease occurred in only 10% of the D+/R- patients, lower than in previously reported studies. Significantly the incidence was as low as in CMV+ recipients of kidneys from both CMV+ (6%) and CMV- (7%) donors. Use of OKT-3 for steroid-resistant rejection increased the risk of developing CMV disease: 11/50 (22%) receiving OKT-3 developed CMV disease vs. only 7/311 (2%) who did not (P < 0.001); 11/18 (61%) with CMV disease had received OKT-3. ALG induction immunosuppression did not increase the risk of CMV in patients who subsequently received OKT-3. No patient developed CMV disease after discontinuing prophylaxis. There were no complications related to either CMV-HIG or acyclovir use. Compared with all other patients, the D+/R- group had superior graft survival at 1 and 3 years (94% vs. 87% and 86% vs. 74%, P < 0.05) but similar patient survival. Combined CMV-HIG and low-dose acyclovir appear to be better than either agent alone in preventing primary CMV disease in CMV- patients who receive CMV+ kidneys. Low-dose oral acyclovir (600 mg/day) may be as effective in preventing CMV disease as higher-dose prophylactic regimens, at least when accompanied by CMV-HIG.(ABSTRACT TRUNCATED AT 400 WORDS)


Archive | 1990

Rat liver preservation

W. Yu; D. Coddington; H. Bitter-Suermann

The mechanisms by which cold preservation solutions exert their protective effects are only partially understood. The consequences of mixing different solutions, with presumably different modes of action, may be additive and beneficial or may be deleterious. It is commonplace in clinical liver preservation to use Ringers lactate (RL), Eurocollins (EC), and University of Wisconsin (UW) solution in sequence for washout of blood, precooling, and cold storage of the organ. In this study, 114 Sprague Dawley rats received orthotopic liver transplants that were flushed in various sequences with RL, EC, and UW solutions. One-week animal survival served as the criterion of preservation success. The results demonstrated that liver preservation with UW solution alone is significantly superior (P<0.01) to any combination of RL, EC, and UW solutions and may explain some of the instances of primary nonfunction in clinical liver transplantation.


Transplant International | 1990

Rat liver preservation. II. Combining UW solution with Eurocollins solution or Ringer's lactate abrogates its protective effect.

W. Yu; D. Coddington; H. Bitter-Suermann

Abstract. The mechanisms by which cold preservation solutions exert their protective effects are only partially understood. The consequences of mixing different solutions, with presumably different modes of action, may be additive and beneficial or may be deleterious. It is commonplace in clinical liver preservation to use Ringers lactate (RL), Eurocollins (EC), and University of Wisconsin (UW) solution in sequence for washout of blood, precooling, and cold storage of the organ. In this study, 114 Sprague Dawley rats received orthotopic liver transplants that were flushed in various sequences with RL, EC, and UW solutions. One‐week animal survival served as the criterion of preservation success. The results demonstrated that liver preservation with UW solution alone is significantly superior (P < 0. 01) to any combination of RL, EC, and UW solutions and may explain some of the instances of primary nonfunction in clinical liver transplantation.


The Journal of Urology | 1987

Repeat Cadaver Kidney Transplantation Using Cyclosporine a Immunosuppression

Peter Anderson; Philip Belitsky; H. Bitter-Suermann; Alan D. Cohen; Alan S. MacDonald

Repeat cadaver kidney transplantation using azathioprine immunosuppression carried a higher risk of graft loss than primary transplants. We analyzed the results of repeat cadaver kidney grafting with cyclosporine A immunosuppression. A total of 33 cyclosporine A-treated patients received the second kidney transplant at varying intervals after failure of the first transplant. Graft survival at 1 year was 66 per cent. A concurrent group of 189 cyclosporine A-treated first cadaver kidney recipients had a 1-year graft survival rate of 75 per cent, although this better result was not statistically significant (p greater than or equal to 0.25). A historical group of 31 azathioprine-treated second graft recipients had a significantly worse 1-year graft survival rate of 45 per cent compared to the cyclosporine A second graft group (p less than 0.1). Patient age, sex, early first graft loss, interval between transplants and the presence of panel reactive antibodies were not factors in predicting second graft outcome. A complete DR mismatch appeared to worsen the second transplant survival. These findings indicate that early graft survival of cyclosporine A-treated repeat cadaveric transplants is acceptable and is better than azathioprine-treated first or second grafts.


Liver Transplantation | 2001

Orthotopic liver transplantation using low-dose tacrolimus and sirolimus

Vivian C. McAlister; Kevork M. Peltekian; Dickran Malatjalian; Shannon Colohan; Sara MacDonald; H. Bitter-Suermann; Allan S. MacDonald


Microsurgery | 1995

Development of a mouse aortic transplant model of chronic rejection

J. Koulack; Vivian C. McAlister; C. A. Giacomantonio; H. Bitter-Suermann; Allan S. MacDonald; Timothy D.G. Lee


Clinical Immunology and Immunopathology | 1996

Importance of minor histocompatibility antigens in the development of allograft arteriosclerosis.

Joshua Koulack; Vivian C. McAlister; M.A. MacAulay; H. Bitter-Suermann; Allan S. MacDonald; Timothy D.G. Lee

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Vivian C. McAlister

University of Western Ontario

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J Lawen

Dalhousie University

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Bryce Kiberd

Queen Elizabeth II Health Sciences Centre

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