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Biomedical subjects

J Steiger

Publications and source records attributed to J Steiger.

At least 19 recordsLinked to original sources
PubMed2002

[Manually-assisted laparoscopic donor nephrectomy].

The number of patients suffering from terminal renal failure awaiting kidney transplantation has continued to increase. Since the number of available cadaver donor kidneys has largely remained unchanged, a special publicity campaign achieved that almost one-half of the kidneys transplanted in Basle come from live donors. We performed a laparoscopic live donor nephrectomy in 14 patients between March 1998 and August 1999. Despite good experience regarding transplant function and patient satisfaction, the hand-assisted technique was introduced in 1999 because of the long average operating time of 230 min (200-270) and warm ischemia time of 7.5 min (4-9). In the 33 operations performed up to now, the average operating time and warm ischemia time could be significantly reduced to 185 min (135-240) and 2.4 min (1.5-4), respectively. Most recently, the technique of retroperitoneoscopic live donor nephrectomy was successfully employed in 4 patients and could possibly represent the method of choice for the future.

Adult↗
PubMed2002

[Renal biopsy: standard procedure of modern nephrology].

For more than 50 years, renal biopsy has been an important diagnostic procedure in modern nephrology. Increasing perfection of the biopsy technique has made the procedure very safe, with rare complications and few contraindications. Improved histological diagnostics and broader therapeutic possibilities have significantly expanded the indications. The most important indications are acute renal failure, proteinuria > 1 g/d (or 3 g/d) and nephritic urinary sediment. Complications with renal grafts provide additional indications for a renal biopsy. In addition, diabetes and monosymptomatic urinfindings (isolated haematuria) as well as pregnancy induced nephropathy are indications for a renal biopsy. The procedure is performed ambulatory or during a short hospital stay and the patient can usually be discharged after a monitoring period of eight hours.

Acute Kidney Injury↗
PubMed2001

Cytomegalovirus infection and graft rejection in renal transplantation.

BACKGROUND: Cytomegalovirus (CMV) infection and CMV disease have been associated with acute and chronic graft rejection. The introduction of the sensitive CMV antigenemia pp65 assay for detection of CMV infection allowed us to study the time course of CMV infection and acute rejection and the long-term outcome in renal transplant recipients with and without a CMV risk constellation. METHODS: Prospective single center study including 48 renal transplant recipients at risk for CMV infection (donor and/or recipient CMV seropositive) and a control group of 36 CMV seronegative recipients of CMV seronegative kidney donors. Evidence of CMV infection was monitored by the CMV antigenemia pp65 assay every 1 to 2 weeks and compared with the occurrence of acute rejection in the posttransplant period and graft function at 5 years. RESULTS: CMV infection developed in 83% (40/48) of patients of the CMV risk group within 4 months posttransplant. A total of 18 of patients experienced an acute rejection episode (control group 16/36; P=0.65). In 12/18 CMV infection followed rejection and in three patients antigenemia preceded the diagnosis of rejection. In three patients CMV antigenemia remained negative. Five-year follow up: Patient survival (44/48 vs. 31/36; P=0.48), graft survival (38/48 vs. 27/36; P=0.79), number of patients with at least one acute rejection episode: CMV risk group: 42.1%, control group 51% (P=0.46), serum creatinine: CMV risk group:130 +/- 66 micromol/iter, control group: 126 +/- 37 micromol/ liter (P=0.56), proteinuria: CMV risk group: 0.02 +/- 0.02 g/mmol creatinine, control group: 0.02 +/- 0.02 g/mmol creatinine (P=1.0). CONCLUSION: CMV infection within 4 months posttransplant, as defined by a positive antigenemia assay was not found to be a risk factor for acute graft rejection or chronic graft dysfunction at 5 years.

Adult↗
PubMed2001

Evidence for highly charged ion Coulomb crystallization in multicomponent strongly coupled plasmas.

Multicomponent non-neutral ion plasmas in a Penning trap consisting of Be(+) and highly charged Xe ions, having different mass-to-charge ratios than Be(+), are cooled to form strongly coupled plasmas by applying a laser-based collisional cooling scheme. The temperature of the plasma was determined from a Doppler broadened transition in Be(+). For the Xe ions, which are centrifugally separated from the Be, the Coulomb coupling parameter was estimated to be approximately 1000. Molecular dynamics simulations of the ion mixture show ordered structures, indicating crystallization of the Xe.

Journal Article↗
PubMed2001

Diagnostic yield of bronchoalveolar lavage following renal transplantation.

Organ transplant recipients are at high risk of infectious pulmonary complications. In this retrospective study, the diagnostic yield of bronchoalveolar lavage (BAL) was evaluated in renal transplant recipients. The results were analysed in special regard to the clinical presentation of pulmonary infections and the possible impact of new immunosuppressive agents. Over a 5-year period 91 BAL were performed in 71 renal transplant recipients. Microorganisms were isolated from 69% of BAL (63/91): bacteria 32%; cytomegalovirus (CMV) 27%; Pneumocystis carinii (PC) 22%; other viruses 9% (HSV; EBV, RSV, adenovirus, HHV8); Aspergillus fumigatus 1%. Total cell counts and neutrophil counts in BAL were significantly elevated in bacterial infection, whereas BAL positive for PC showed eosinophilia (P<0.05). There was no association between clinical symptoms and the radiological pattern of infiltrates and the type of infection. Immunosuppression containing tacrolimus or mycophenolate mofetil was associated with a significantly higher percentage of PC and CMV infections compared to cyclosporin-based immunosuppression (65% vs. 30%, P<0.005). A considerable number of PC and CMV infections occurred beyond 6 months after transplantation. In conclusion, BAL has a high diagnostic yield in renal transplant recipients. Infection with CMV and PC should also be considered beyond 6 months after transplantation, and prophylaxis for opportunistic infections should be given if the immunosuppression is intensified.

Adult↗
PubMed2001

Polyomavirus BK nephropathy in a kidney transplant recipient: critical issues of diagnosis and management.

Diagnosis of polyomavirus BK nephropathy and treatment by low-dose immunosuppression may be optimized by using surrogate markers, such as the detection of viral inclusion bearing cells in the urine and polyomavirus BK DNA in plasma by polymerase chain reaction. These markers were used prospectively in the management of a 44-year-old woman and led to the diagnosis of polyomavirus BK nephropathy at an early stage. The management was complicated by the concurrence of acute allograft rejection. Two treatment steps were initiated: antirejection therapy consisting of methylprednisolone for 3 days followed by lowering of the maintenance immunosuppression. This treatment resulted in a return of the serum creatinine concentration to the baseline of 1.6 mg/L, clearance of polyomavirus BK from plasma, and disappearance of viral inclusion bearing cells from the urine. After 2 months of stable allograft function, a control biopsy confirmed the resolution of polyomavirus BK nephropathy. Histologic signs of acute interstitial rejection were found and preemptively treated by methylprednisolone without altering the baseline regimen. Allograft function remained stable without evidence of recurrent polyomavirus BK nephropathy. This case shows the value of surrogate markers used in a prospective fashion for diagnosis and management of polyomavirus BK nephropathy with concurrent rejection.

Adult↗
PubMed2000

Evolution and etiology of cardiovascular diseases in renal transplant recipients.

The mortality rates for CVDs in transplant recipients are greater than those in the general population (13). CVDs are a major cause of both patient and graft loss in renal transplant recipients, and improving cardiovascular health may help to extend both patient and graft survival. A complication of chronic renal failure, CVDs are frequently present in patients being considered for transplantation. Pretransplant screening, based on risk stratification, may detect pre-existing disease and identify patients likely to benefit from therapeutic strategies designed to reduce CVDs prevalence. Further studies are needed to better define the risk factors for CVDs in the renal transplant population and to evaluate the effectiveness of risk modification on the related morbidity and mortality. Risk-factor management initiated early in the course of chronic renal failure might reduce the burden of CVDs in both dialysis and transplant populations.

Adult↗
PubMed2000

[Hematuria and proteinuria--old names, new horizons].

Gradually advanced diagnostic standards for the analysis of urine specimens during the last years led to improved clinical arguments providing important clues. Unnecessary diagnostic procedures like IVP or cytoscopy in suspected glomerular hematuria may for instance be prevented, the patients comfort enhanced and costs reduced. A possible diagnostic algorithm in a case with suspected urologic pathology is shown.

Algorithms↗
PubMed2000

Undergraduate medical education: tendencies and requirements in a rapidly developing Europe.

This study pinpoints the necessity to constantly monitor local approaches in undergraduate medical education on an inter-European scale. Traditional undergraduate medical curricula need restructuring to account for the increasing amount of medical knowledge and rapid changes and developments in societies, nosology, therapy and IT. European undergraduate medical curricula should be harmonized not egalized, with a focus on inter-European sharing of resources, mobility, credit (allocation, accumulation and transfer), definition of European and trans-European mission statements, identification of quality metrics, advice on dealing with conflicting aims such as specialization and generalization, on communicating core knowledge instead of providing overabundance of information, and on introducing multifaceted teaching and learning methods, as well as providing strategies for life long learning. Sound medical education can no longer and nowhere be considered under the autonomous auspices of individual Medical Schools or national philosophies. It has to be perceived and structured as a competitive and flexible approach which promotes life long learning of teachers, students, physicians and other related staff with international awareness. It is stressed that student and staff mobility, as well as virtual mobility in the form of worldwide available teaching modules and expertise have to be incorporated into national medical curricula. This is to guarantee up-to-date education in support of patient demands, future professionality and competitiveness of students, physicians and Public Health System institutions. The formal approaches of traditional subject related curricula as well as problem based learning must be linked with quality approved state of the art ODL, evaluated international CME strategies and training in the utilization of IT in preparation of lifelong learning. Strategies for the use of IT need updating on a regular basis to diminish the gap between undergraduate and postgraduate medical education. General European perspectives of medical education are discussed in relation to ECTS, ODL, compulsory credited and evaluated CME and relicensing of physicians. Prime features of ETM--the most reputed and well-known European medical CME initiative fostering quality assured international awareness are described and recommended for local and nationwide implementation. Specific links of the Bonn undergraduate medical curriculum with credited and evaluated CME and imminent European strategies are detailed. The authors conclude that European universities not adapting at least some of the outlined curricular necessities will rapidly lose their competitiveness compared to other national and international Medical Schools. Harmonized European ethical mission statements and consequent utilization of IT deserve special considerations in this context.

Computer-Assisted Instruction↗
PubMed1999

Blood eosinophilia in tacrolimus-treated patients: an indicator of Pneumocystis carinii pneumonia.

BACKGROUND: Pneumocystis carinii pneumonia (PcP) in immunocompromised patients is suggested if the following symptoms develop: dyspnea, fever, and interstitial infiltrates on chest x-ray. We observed a significant blood eosinophilia in kidney recipients with PcP under immunosuppressive treatment with tacrolimus. METHODS: Blood eosinophil counts of kidney recipients under immunosuppression with tacrolimus suffering from PcP were compared to eosinophil counts of patients without evidence of PcP and to patients showing PcP under immunosuppression with cyclosporine. RESULTS: PcP-positive patients treated with tacrolimus showed a significantly higher blood eosinophil count compared to PcP-positive patients treated with cyclosporine (P=0.01), and to patients under immunosuppression with tacrolimus without PcP, respectively (P=0.006). Eosinophilia preceded the time of a definitive PcP diagnosis by bronchoalveolar lavage and decreased after successful treatment. CONCLUSIONS: An increasing blood eosinophil count can be an indicator of P. carinii pneumonia in patients under immunosuppressive therapy with tacrolimus.

Adult↗
PubMed1998

IL-2 and IL-4 double knockout mice reject islet allografts: a role for novel T cell growth factors in allograft rejection.

T cell growth factors (TCGFs) play a critical role in allograft rejection by promoting the activation and proliferation of alloreactive T cells. To determine whether IL-2 and IL-4 are of quintessential importance in allograft rejection and to identify possible alternative TCGFs, we have bred IL-2(-/-) and IL-4(-/-) double knockout (DKO) mice and studied islet allograft rejection using the DKO mice as allograft recipients. Although mononuclear leukocytes from DKO mice did not mount a proliferative response in vitro in response to anti-CD3 stimulation, crude islet allografts were vigorously rejected by DKO mice (mean survival time 17 +/- 7, n = 8) as compared with wild-type controls (mean survival time 13 +/- 4, n = 7). Treatment of DKO mice with anti-CD3 or rapamycin markedly prolonged the islet allograft survival. An analysis of intragraft cytokine gene transcripts showed robust expression of IL-7 and IL-15. In contrast, intragraft IL-9 gene transcripts were not detected in either wild-type or DKO mice. Provision of exogenous IL-2, IL-4, IL-7, or IL-15, but not IL-9, supports the proliferation of anti-CD3 activated DKO splenic leukocytes in vitro. Blocking the common gamma c of IL-2 receptor, a shared essential signaling component by receptors for IL-2, IL-4, IL-7, IL-9, and IL-15, prolonged the survival of islet allografts in DKO mice. Hence, a T cell dependent allograft rejection enabled by rapamycin-sensitive signals or signals mediated by binding of the gamma c chain occurs in the absence of both IL-2 and IL-4. Non-T cell-derived TCGFs, especially IL-7 and IL-15, may play an active role in supporting allograft rejection.

Animals↗
PubMed1998

Prenatal ethanol exposure differentially alters behavior in males and females on the elevated plus maze.

Rodents prenatally exposed to ethanol demonstrate hypothalamic-pituitary-adrenal and behavioral hyperactivity to a variety of stressful situations. The present study examined both behavioral and corticosterone (CORT) responses to the elevated plus maze (+-maze), an anxiety- or fear-provoking task. Sprague-Dawley male and female offspring from fetal ethanol-exposed (E), pair-fed (PF), and ad libitum-fed control (C) groups were tested at 60 to 90 days of age. In experiment 1, behavior was measured in animals exposed to the +-maze for 5 min on two consecutive days; 2 weeks later, both behavioral and CORT responses were measured in animals confined to the open and closed arms of the maze for 20 min. In experiment 2, animals were placed in an open field (OF) for 5 min before a single 5-min exposure to the +-maze. Factor analysis of the scored behaviors from the two experiments indicated two main factors, designated "exploration" and "fear." E males and females both exhibited higher levels of exploratory behaviors when placed directly on the +-maze from their homecages without prior exposure to the OF, compared with C males and females. In addition, when confined to the closed arms of the +-maze, E males and females demonstrated higher levels of activity, compared with C males and females. After OF exposure, however, both E males and females demonstrated lower levels of exploratory behaviors than C males and females, and E females also had increased CORT levels, compared with PF and C females. Interestingly, E females, but not E males, showed an increase in fear-related behaviors on the +-maze, compared with controls, regardless of prior OF exposure. These data demonstrate that prenatal ethanol exposure may differentially affect both behavioral and hormonal responses of males and females in an aversive behavioral task and suggest that there may be a sex difference in the sensitivity of the mechanism(s) underlying these responses.

Animals↗
PubMed1997

CTLA4Ig attenuates accelerated rejection (presensitization) in the mouse islet allograft model.

BACKGROUND: Sensitization to donor antigens is a problem of growing magnitude in clinical transplantation. At a molecular level, this is due to the interaction between antigen bearing antigen-presenting cells and recipient T cells and involves both antigen presentation and co-stimulation. METHODS: Allogeneic islet transplantation was performed using DBA/2J donors and B6AF1 recipients. Four weeks before transplantation, recipient animals were given donor-specific transfusion (DST) alone, DST + CTLA4Ig, DST + control IgG, or no treatment. Graft loss was defined as a blood glucose >300 mg/100 ml. RESULTS: Administration of DST + control IgG 4 weeks before transplantation resulted in accelerated rejection due to presensitization (median survival time of 8 days, compared with 14.5 days for the no-treatment group). Animals treated with CTLA4Ig in combination with DST had a median survival time of 12 days, compared with 8 days for DST + IgG. CONCLUSIONS: CTLA4Ig attenuates the tempo of accelerated rejection in this islet allograft model of presensitization, but does not prolong allograft survival as compared with no treatment.

Abatacept↗