Impact of Presence of HBs Antigen and Anti-Hepatitis C Virus and Anti-Cytomegalovirus Antibodies on Transplanted Kidney Survival

INTRODUCTION

Infections are one of the most common complications after organ transplantation. Viral infections such as hepatitis type B (HBV) and C (HCV) or cytomegalovirus (CMV) infections are among the most serious ones. A high frequency of HBV and HCV infections has been recognized in kidney recipients. Viral infections play a special role in graft recipients because of clinical symptoms influencing graft function and recipient survival. Immunosuppressive treatment to decrease immunological reactions after organ transplantation may increase the risk of viral infections. The aim of this study was to evaluate the impact of the presence of HBs antigen and HCV and CMV antibodies on patient and graft survivals.

MATERIAL AND METHODS

Two hundred one enrolled kidney transplantation patients (96 women and 105 men) were treated with the same immunosuppressive regimen. Age, sex, and viral state (HBs antigen, anti-HCV and anti-CMV antibodies) were evaluated in every patient. Statistical analysis was performed with the Gompertz model, Kaplan-Meier curves and Cox proportional hazard tests.

RESULTS

The presence of HBs antigen was detected in 161 patients (20.4%), HCV antibodies in 61 recipients (30.3%); and CMV antibodies in 12 patients (5.9%). Eighty-seven recipients (43.4%) were seronegative. Average recipient age was 38.5 years.

CONCLUSION

Time of graft function was independent of the presence of HBs antigen or HCV or CMV antibodies.

Early Acid–Base Balance Disorders During Kidney Transplantation

INTRODUCTION

Reperfusion is a crucial moment in kidney transplantation. Resumption of blood flow is associated with many metabolic changes, which result from the kidney's initial condition and preservation. These biochemical alterations including the acid-base balance are the part of ischemia-reperfusion injury. The study's purpose was to examine acid-base balance during the first 30 minutes after reperfusion of the transplanted kidney.

MATERIALS AND METHODS

The 30 recipients (13 men, 17 women) averaged ages of 46 +/- 14 years. Measurements performed nine times (at 0, 1, 3, 5, 10, 15, 20, 25, and 30 minutes after unclamping renal vessels) included: gas analysis, expiratory Pco(2), tidal volume, and respiratory rate. The evaluation of the temporary acid-base balance was performed on the basis of common parameters: pH, Pco(2), [HCO(3)(-)], and base excess (BE). The patients were under general anesthesia with stable external conditions of O(2) saturation, heart rate, blood pressure, and temperature. Blood samples were analyzed using Corning 278 and 248 blood gas analyzer; vital parameters were recorded using Ohmeda 5250 RGM and Dräger Sulla 909V/Julian apparatus.

RESULTS

The analysis showed increasing metabolic acidosis with coexisting increase in blood Pco(2), changes that were most intense in the first minute of reperfusion. Decreasing mean pH index did not exceed physiologic limits, but the final mean values of [HCO(3)(-)] and BE were in most of cases below the limit. Increased expiratory air Pco(2) was most intense in the first 3 minutes reaching a maximum at about 15 minutes.

CONCLUSIONS

The beginning of reperfusion was the cause of increasing metabolic acidosis, which was partially compensated by blood buffers. Simultaneous increase in expiratory Pco(2), corresponding to the dynamics of acidosis, indicated the existence of respiratory compensation. Sudden increase in acidosis parameters may be the result of lactate accumulation during kidney ischemia. The decreased [HCO(3)(-)] may indicate postreperfusion kidney injury, which must be the subject of further research.

The Evaluation of Apoptosis and Reactive Oxygen Species in Hematopoietic Cells Derived From Heparinized Cadaveric Organ Donors Stored Short-Term at 4°C

Heparinized cadaveric organ donors are an important source of human organs and potentially of hematopoietic cells for transplantation purposes. The aim of this study was to evaluate the kinetics of programmed cell death in the hematopoietic cells harvested from these individuals and stored short-term at 4 degrees C. We also attempted to assess hematopoietic cell oxidation by measuring reactive oxygen species (ROS) generated by the mitochondria of stored cells. We found that these bone marrow cells harvested and stored at 4 degrees C for 7 days did not display a significant increase in programmed cell death. However, prolonged storage resulted in lower ROS production, indirectly giving evidence of activation of intracellular signaling proteins.

Experiences in Kidney Transplantation With Duplicated Ureters

INTRODUCTION

The purpose of this study was to evaluate the complications of duplicated ureters in renal transplant recipients.

METHODS

Between 1983 and 2004, 12 patients (median age 34 years) received renal transplants from donors with duplicated ureters. In four patients the ureter to bladder anastomoses were performed separately according to the method described by MacKinnon, including two cases transplanted with ureteral catheters because of narrow widths. In the following cases of eight duplicated ureters an anastomosis was performed between the distal part of each ureter to form a common ureteral ostium, which was connected to the urinary bladder. A ureteral catheter was used to the splint ureterovesical anastomosis.

RESULTS

No graft loss to ureteral complications was observed. There was no ureteral necrosis in the postoperative period. No clinical symptoms of ureteral junction obstruction were revealed after removing the ureteral catheter. By ultrasound examination four patients showed a slight temporary pyelocaliectasis was observed and four patients developed temporary urinary fistulas.

CONCLUSION

Our ureterocystoneostomy procedures with duplicated ureters were safe and useful in kidney transplantation.

Pretransplant Nephrectomy in Patients With Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease and a frequent cause of end-stage renal failure. Transplantation in patients with ADPKD is associated with specific cyst-related problems, especially urinary tract infections (UTI). Although pretransplant nephrectomy has been applied in this group of patients, evidence of the benefits of this strategy is lacking. Therefore, we compared the outcomes and posttransplant complications among patients with or without pretransplant nephrectomy.

PATIENTS AND METHODS

ADPKD patients (73) transplanted from cadaveric donors were reviewed retrospectively with regard to posttransplant complications and outcomes. The groups either underwent pretransplant unilateral nephrectomy (n = 30) or were transplanted with native kidneys intact (n = 43).

RESULTS

Two patients underwent simultaneous bilateral nephrectomy due to a large size of the polycystic kidneys interfering with the transplant operation. Overall postransplant complications were more frequent in the group without nephrectomy (34% vs 20%); however, the difference was not statistically significant. Most complications were related to cyst infections with 3 deaths (12%) due to lethal septicemia in the group without nephrectomy. No infection-related deaths were noted in the group with pretransplant nephrectomy.

CONCLUSIONS

Graft and patient outcomes as well postransplant complications were similar in both groups, independent of previous nephrectomy. It seems that pretransplant unilateral nephrectomy should not be routine and has no advantage over transplantation with both native kidneys intact, although this conclusion is limited by the small number of patients. An Individualized approach should be applied especially when there has been a history of cyst-related infection.

Factors influencing low incidence of living donors for renal transplantation in Poland

PURPOSE OF THE STUDY

To answer the question: "Why are only 3.8% of kidney transplantations in Poland from living donors?"

MATERIAL AND METHODS

The research was conducted using data from anonymous polls addressed to family members of dialyzed patients (potential donors).

RESULTS

Almost everybody (98%) had heard about the possibility of treating renal insufficiency by kidney transplantation, but only 77% knew about the possibility of giving their own kidney to a related person. Merely 36% had been informed about this treatment method by a doctor. The most common fears within respondents were those of: health worsening after donating a kidney--45%, and the operation itself (taking an organ)--39%.

Organ procurements in West Pomerania in years 2000-2001

Year by year the actual number of transplanted organs has been growing in Poland. In the event of the Województwo Zachodniopomorskie (Western Pomeranian Province) the primary activities were focused on informing medical personnel at hospital departments about approaching donors through trainings for such medical personnel. Such activities resulted in both acceptance and support, especially by medical personnel of medium as well as lower ranks. Since 1983 two transplant units have been functioning in the Province: SPSK-2 and S. P. W. S. Z. in Szczecin, and since 2000 two co-ordination offices, too. Main result of our activities can be seen in the number of organs procured for transplantation. In 2000 we had 27.7 procurements per million (ppm), in 2001 there were 39.9 ppm.

B-cell epitopes in the immunodominant p34 antigen of mycobacterium avium ssp. paratuberculosis recognized by antibodies from infected cattle

Mycobacterium avium ssp. paratuberculosis (M. paratuberculosis) causes Johne's disease, a chronic and fatal enteritis in ruminants. In the last stage of the disease, antibody titres rise and levels of interferon-gamma decrease, suggesting that the host-immune response is switching from a T helper 1 (Th1) to a Th2 profile. In infected cattle, the membrane protein p34 elicits the predominant humoral response against M. paratuberculosis. To map the B-cell epitopes of this antigen, affinity-purified bovine antibodies against the carboxy-terminal region of p34 were used to screen a 12-mer phage display library. Several phage clones carrying peptides resembling fragments of p34 were affinity selected. Based on the predicted amino acid sequence, peptides were chemically synthesized, which demonstrated reactivity with serum from naturally infected and p34-vaccinated cattle. Immunization of mice with these peptides elicited an anti-p34 antibody response. Two B-cell epitopes were identified and characterized. Based on the reactivity and the type of immune response elicited, epitope A was determined to be conformational, whereas epitope B was demonstrated to be sequential. Both epitopes were shown to be present in p34 proteins from M. avium ssp. avium or M. paratuberculosis but absent from M. intracellulare, the other member of the M. avium complex. Furthermore, both epitopes were mapped to regions of p34 that display high variability when compared to homologous proteins from other mycobacterial species of public and animal health importance. We hypothesize that these variable regions of p34 may play a role in the immunobiology of M. paratuberculosis infections.

An optimization of isolation of early hematopoietic cells from heparinized cadaveric organ donors

Heparinized cadaveric organ donors are a potential source of hematopoietic cells for transplantation purposes. The aim of this study was to optimize the harvest of early hematopoietic cells from cadaver donors. Accordingly, we noticed that bone marrow cells harvested from cadaver donors should be resuspended in RPMI or Iscove's medium supplemented with heparin or ACD. Bags with harvested marrow should contain 20% atmosphere air during short-term storage/transportation. Finally, we noticed that BMMNC survive short-term storage better if the collected marrow is not depleted of erythrocytes.

Factors that impact on immediate graft function in patients after renal transplantation

Kidney transplantation has become therapy of choice for patients with end-stage renal failure. However, many factors may cause graft rejection or delayed graft function, both of which decrease the prognosis for graft survival. For transplantologists the most important endeavor is to eliminate factors responsible for shortening graft function and to find those predictive of immediate graft function. The aim of the study was to investigate which factors influence early graft function. We retrospectively reviewed 442 renal transplant patients performed between 1990 and 1995 in two Szezecin units. All patients received an identical immunosuppressive drug schedule. Three hundred twelve patients who displayed immediate graft function were included in the study group to analyze donor and recipient age and sex, etiology of ESRD, HLA compatibility AB0 and Rh compatibility cold ischemia time, warm ischemia time, antileukocytes antibodies (PRA), and period of dialysis therapy before transplantation. We observed statistical significance for HLA and AB0 compatibility, younger donor age, and shorter cold ischemia time as the most important factors predictive of early graft function and an improved prognosis for graft survival.

Postoperative adaptation of urinary bladder to variable volume of urine in the initial period following kidney transplantation

OBJECTIVES

Postoperative adaptation of urinary bladder is a process involving all patients after kidney transplantation that is facilitated by improve surgical techniques and new perioperative protocols.

METHODS

The study enrolled 102 kidney transplant recipients whose transplantations were performed between 2000 and 2002. The function of urinary bladder was examined: on the day of operation and 2, 4, 8, 12, 16, and 24 weeks following operation. Patients were assessed with respect to bladder adaptation in relation to the period of dialysis.

RESULTS

In patients undergoing dialysis up to 24 months, the maximum speed of flow increased from the 2nd week postoperation and regained normal values after 12 weeks. Volume of micturition, cystometric volume, and compliance regained proper values after 24 weeks of observation.

CONCLUSION

The findings confirm that adaptation of the bladder is faster among patients who have had dialysis for longer than 12 months. The most useful, economical, and noninvasive assessment of bladder function was obtained with uroflowmetry in combination with daily bladder diary.

Impact of selected factors on early graft function in patients after renal transplantation

Transplantation is the best treatment for end-stage renal diseases. For transplantologists, it is most important to know the factors that worsen graft survival prognosis. The aim of the study was to investigate factors predictive of graft loss and shortened graft survival. We retrospectively reviewed 442 renal transplant patients between 1990 and 1995 in two Szczecin units, all of whom received a triple-drug immunosuppressive regimen. One hundred thirty patients showed graft disorders such as delayed graft function or primary nonfunction. The occurrence of these disorders was examined as a function of donor and recipient age and sex, cause of ESRD, HLA compatibility, ABO and Rh compatibility, cold ischemia time, warm ischemia time, antileukocyte antibody level (PRA), and period of dialysis therapy before transplantation. The study showed that a high maximal PRA level, incompatibility for ABO group, and a longer warm ischemia time increase the probability of early graft function disorders.

Variations in temperature of the donor kidney during cold ischemia time and subsequent assessment of reperfusion using the application of thermovision camera

Cold ischemia time (CIT) and graft reperfusion events are important nonimmunological factors that influence kidney graft function. The optimal temperature for the organs during CIT ranges from 4 degrees C to 8 degrees C. However, preservation of the designated temperature is usually not controlled during standard storage procedures. Aspects of initial graft reperfusion are usually assessed indirectly. Better evaluation of the effectiveness of the early blood supply may improve the surgical outcome. The aim of the study was to monitor the temperature during CIT in the kidney and surrounding area and subsequently to assess graft reperfusion using thermography. Temperature values of the area surrounding the kidney were registered during 8 organ procurements. We observed that the area surrounding the kidney displayed the optimal temperature range only during the first 5 minutes of CIT; later the temperature oscillated between 1 degrees C and 3.5 degrees C. The study proved that the temperature of the preservation fluid is frequently below prescribed. Analysis of the thermograms of 40 transplanted kidneys with the use of a thermovision camera ThermaCAM SC500 showed usefulness of this method to assess reperfusion and blood distribution in the transplanted kidney.

Freedom from rejection and stable kidney function are excellent criteria for steroid withdrawal in tacrolimus-treated kidney transplant recipients

OBJECTIVES

This prospective, randomized, multicentre study investigated the efficacy and safety of two tacrolimus-based regimens and their potential to withdraw steroids.

METHODS

In total 489 patients were randomised to receive either tacrolimus and MMF (n = 243) or tacrolimus and azathioprine (n = 246) concomitantly with steroids in both treatment groups. The initial oral dose of tacrolimus was 0.2 mg/kg/day, MMF dose was 1 g/day, azathioprine was administered at 1-2 mg/day. Steroids were tapered from 20 mg/day to 5 mg/day. From month 3 onwards, steroids were withdrawn in patients who were free from steroid-resistant rejection and who had serum creatinine concentrations < 160 mumol/L. Study duration was 6 months.

RESULTS

Patient survival at month 6 was 98.3% (Tac/MMF/S) and 98.4% (Tac/Aza/S), graft survival at 6 month was 95.0% (Tac/MMF/S) and 93.5% (Tac/Aza/S). The 6-month incidences of biopsy-proven acute rejection were 18.9% (Tac/MMF/S) compared with 26.8% (Tac/Aza/S), p = 0.038. The 6-month incidences of steroid-resistant acute rejection were 2.1% (Tac/MMF/S) and 4.9% (Tac/Aza/S), p = ns. At the end of month 3, steroid withdrawal was performed in 60.5% (Tac/MMF/S) and 48.8% (Tac/Aza/S) of patients, p < 0.01. During months 4-6, 2.7% of patients in the Tac/MMF group had a biopsy-confirmed acute rejection compared with 0.8% of patients in the Tac/Aza group. In patients who continued to receive steroids, the incidences of biopsy-proven acute rejections during months 4-6 were 3.5% (Tac/MMF/S) and 7.1% (Tac/Aza/S). At study end, the steroid-free patients had an excellent kidney function, the median serum creatinine concentration was 119.5 mumol/L (Tac/MMF) and 115.1 mumol/L (Tac/Aza); the median serum creatinine of the total study group was 130.5 mumol/L (Tac/MMF/S) and 132.8 mumol/L (Tac/Aza/S).

CONCLUSION

Both tacrolimus regimens are efficacious and safe. The combination of Tacrolimus and MMF achieved a lower rejection rate and permitted a higher proportion of steroid-free patients. The overall incidence of acute rejection was low and kidney function was good.

Life under nutrient limitation in oligotrophic marine environments: an eco/physiological perspective of Sphingopyxis alaskensis (formerly Sphingomonas alaskensis)

The oceans of the world are nutrient-limited environments that support a dynamic diversity of microbial life. Heterotrophic prokaryotes proliferate in oligotrophic regions and affect nutrient transformation and remineralization thereby impacting directly on the all marine biota. An important challenge in studying the microbial ecology of oligotrophic environments has been the isolation of ecologically important species. This goal has been recognized not only for its relevance in defining the dynamics of community composition, but for enabling physiological studies of competitive species and inferring their impact on the microbial food web. This review describes the successful isolation attempts of the ultramicrobacterium, Sphingopyxis alaskensis (formerly described as Sphingomonas alaskensis) using extinction dilution culturing methods. It then provides a comprehensive perspective of the unique physiological and genetic properties that have been identified that distinguish it from typical copiotrophic species. These properties are described through studies of the growth phase and growth rate control of macromolecular synthesis, stress resistance and global gene expression (proteomics). We also discuss the importance of integrating ecological and physiological approaches for studying microorganisms in marine environments.

Identification of neutralizing and nonneutralizing epitopes in the porcine reproductive and respiratory syndrome virus GP5 ectodomain

After infection of swine with porcine reproductive and respiratory syndrome virus (PRRSV), there is a rapid rise of PRRSV-specific nonneutralizing antibodies (NNA), while neutralizing antibodies (NA) are detectable not sooner than 3 weeks later. To characterize neutralizing epitopes, we selected phages from a 12-mer phage display library using anti-PRRSV neutralizing monoclonal antibody (MAb) ISU25-C1. In addition, phages carrying peptides recognized by swine antibodies with high seroneutralizing titer were isolated after subtracting from the library those clones binding to swine anti-PRRSV serum with no neutralizing activity. Two epitopes located in the ectodomain of PRRSV GP5 were identified. One of these epitopes, which we named epitope B, was recognized both by neutralizing MAb ISU25-C1 and swine neutralizing serum (NS) but not by swine nonneutralizing serum (NNS), indicating that it is a neutralizing epitope. Epitope B is sequential, conserved among isolates, and not immunodominant. Antibodies directed against it are detected in serum late after infection. In contrast, the other epitope, which we named epitope A, is hypervariable and immunodominant. Antibodies against it appear early after infection with PRRSV. This epitope is recognized by swine NNA but is not recognized by either neutralizing MAb ISU25-C1 or swine NA, indicating that it is not involved in PRRSV neutralization. During infection with PRRSV, epitope A may act as a decoy, eliciting most of the antibodies directed to GP5 and delaying the induction of NA against epitope B for at least 3 weeks. These results are relevant to the design of vaccines against PRRSV.

Sphingomonas alaskensis strain AFO1, an abundant oligotrophic ultramicrobacterium from the North Pacific

Numerous studies have established the importance of picoplankton (microorganisms of < or =2 microm in length) in energy flow and nutrient cycling in marine oligotrophic environments, and significant effort has been directed at identifying and isolating heterotrophic picoplankton from the world's oceans. Using a method of diluting natural seawater to extinction followed by monthly subculturing for 12 months, a bacterium was isolated that was able to form colonies on solid medium. The strain was isolated from a 10(5) dilution of seawater where the standing bacterial count was 3.1 x 10(5) cells ml(-1). This indicated that the isolate was representative of the most abundant bacteria at the sampling site, 1.5 km from Cape Muroto, Japan. The bacterium was characterized and found to be ultramicrosized (less than 0.1 microm(3)), and the size varied to only a small degree when the cells were starved or grown in rich media. A detailed molecular (16S rRNA sequence, DNA-DNA hybridization, G+C mol%, genome size), chemotaxonomic (lipid analysis, morphology), and physiological (resistance to hydrogen peroxide, heat, and ethanol) characterization of the bacterium revealed that it was a strain of Sphingomonas alaskensis. The type strain, RB2256, was previously isolated from Resurrection Bay, Alaska, and similar isolates have been obtained from the North Sea. The isolation of this species over an extended period, its high abundance at the time of sampling, and its geographical distribution indicate that it has the capacity to proliferate in ocean waters and is therefore likely to be an important contributor in terms of biomass and nutrient cycling in marine environments.

HEPARINIZED CADAVERIC ORGAN DONORS (HCOD)???A POTENTIAL SOURCE OF HEMATOPOIETIC CELLS FOR TRANSPLANTATION AND GENE THERAPY1

BACKGROUND

Hematopoietic stem cells (HSC) from unrelated HLA-matched heparinized cadaveric organ donors (HCOD) are a new potential source of cells for transplantation and gene therapy. In addition, these cells could also be used as adjuvant therapy to increase microchimerism and graft tolerance after transplantations of various solid organs. Our purpose was to develop an efficient method for harvesting hematopoietic cells from HCODs,

METHODS

Bone marrow cells were harvested from pelvic bones and/or vertebral bodies from 50 adult HCODs before or up to 3 hr after disconnecting the donor from the respirator. Subsequently, we evaluated the hematological and gasometric parameters of aspirated marrow samples as well as the proliferative potential, viability, and expression of CD34 and AC133 antigens on these cells.

RESULTS

We noticed that up to 2-3 hr after disconnecting the donor from the respirator bone marrow cavities do not clot and remain uninfected and that it is possible to aspirate bone marrow mononuclear cells in quantities sufficient to perform allotransplantation. Nevertheless, due to the developing hypoxia and acidosis of the hematopoietic microenvironment the number and proliferative potential of CD34+ and AC133+ cells gradually decreases. Hence, to obtain viable early hematopoietic cells, bone marrow should be aspirated without delay; optimally before HCOD is disconnected from the respirator or at the very latest 2 hr after organ harvest.

CONCLUSIONS

Collectively, our results show that early hemopoietic cells may be efficiently harvested from HCOD in large quantities and used for research and/or transplantation purposes. We postulate to create an international network of banks in which hemopoietic stem cells from HCODs could be preserved for therapeutic purposes.

Chemical control stability in patients with obstructive sleep apnea

The role of chemical control instability in the pathogenesis of obstructive sleep apnea (OSA) is not clear. We studied 32 patients with OSA during sleep while their upper airway was stabilized with continuous positive airway pressure. Twelve patients had repetitive OSA whenever they were asleep, regardless of body position or sleep stage, and were classified as having severe OSA (apnea-hypopnea index [AHI] = 88 +/- 19). The remaining 20 patients had sporadic OSA or repetitive OSA for only part of the time (mild/moderate OSA; AHI = 27 +/- 16). Susceptibility to periodic breathing (PB) was assessed by gradually increasing controller gain, using proportional assist ventilation. The increase in loop gain (LG) at each assist level was quantified from the ratio of assisted tidal volume (VT) to the VT obtained during single-breath reloading tests (VT amplification factor [VTAF]). Nine of 12 patients with severe OSA developed PB, with recurrent central apneas, whereas only six of 20 patients in the mild/moderate group developed PB (p < 0.02). This difference was observed despite the subjection of the mild/moderate group to greater amplification of LG; the highest values of VTAF in the mild/moderate and severe groups were 2.7 +/- 1.0 and 1.9 +/- 0.7, respectively (p < 0.01). We conclude that the chemical control system is more unstable in patients with severe OSA than in patients with milder OSA. We speculate that this may contribute to the severity of OSA, at least in some patients.

Specific growth rate plays a critical role in hydrogen peroxide resistance of the marine oligotrophic ultramicrobacterium sphingomonas alaskensis strain RB2256

The marine oligotrophic ultramicrobacterium Sphingomonas alaskensis RB2256 has a physiology that is distinctly different from that of typical copiotrophic marine bacteria, such as Vibrio angustum S14. This includes a high level of inherent stress resistance and the absence of starvation-induced stress resistance to hydrogen peroxide. In addition to periods of starvation in the ocean, slow, nutrient-limited growth is likely to be encountered by oligotrophic bacteria for substantial periods of time. In this study we examined the effects of growth rate on the resistance of S. alaskensis RB2256 to hydrogen peroxide under carbon or nitrogen limitation conditions in nutrient-limited chemostats. Glucose-limited cultures of S. alaskensis RB2256 at a specific growth rate of 0.02 to 0.13 h(-1) exhibited 10,000-fold-greater viability following 60 min of exposure to 25 mM hydrogen peroxide than cells growing at a rate of 0.14 h(-1) or higher. Growth rate control of stress resistance was found to be specific to carbon and energy limitation in this organism. In contrast, V. angustum S14 did not exhibit growth rate-dependent stress resistance. The dramatic switch in stress resistance that was observed under carbon and energy limitation conditions has not been described previously in bacteria and thus may be a characteristic of the oligotrophic ultramicrobacterium. Catalase activity varied marginally and did not correlate with the growth rate, indicating that hydrogen peroxide breakdown was not the primary mechanism of resistance. More than 1,000 spots were resolved on silver-stained protein gels for cultures growing at rates of 0.026, 0.076, and 0.18 h(-1). Twelve protein spots had intensities that varied by more than twofold between growth rates and hence are likely to be important for growth rate-dependent stress resistance. These studies demonstrated the crucial role that nutrient limitation plays in the physiology of S. alaskensis RB2256, especially under oxidative stress conditions.

Simian immunodeficiency virus (SIV) infection of a rhesus macaque induces SIV-specific CD8(+) T cells with a defect in effector function that is reversible on extended interleukin-2 incubation

A vigorous expansion of antigen-specific CD8(+) T cells lacking apparent effector function was observed in a rhesus macaque acutely infected with the simian immunodeficiency virus (SIV) strain SIVmac239. Antigen-specific CD8(+) T cells were identified using antigenic-peptide class I major histocompatibility complex tetramers. As many as 8.3% of CD8(+) cells recognized the Mamu-A*01-associated SIV epitope Gag(181-189) (CTPYDINQM); however, these cells demonstrated no effector function when presented with peptide-incubated targets, as measured by intracellular cytokine staining for gamma interferon (IFN-gamma), interleukin-2 (IL-2) production, or direct cellular lysis. Similar results were observed with three other SIV peptide antigens. Nonresponsiveness did not correlate with apoptosis of the CD8(+) cells, nor were cells from this macaque impaired in their ability to present peptide antigens. Associated with the nonresponsive state was a lack of IL-2 production and decreased IL-2 receptor expression. Exogenous IL-2 treatment for 1 week in the absence of antigenic stimulation restored antigen-specific responses and the quantitative correlation between tetramer recognition and antigen-responsive IFN-gamma secretion. This case report suggests a regulatory mechanism that may impede the effector function of antigen-specific T cells during acute infection with SIV or human immunodeficiency virus in some cases. This mechanism may participate in the failure of the immune system to limit infection.

Filarial infections increase susceptibility to human immunodeficiency virus infection in peripheral blood mononuclear cells in vitro

Because helminth infections and human immunodeficiency virus (HIV) coexist in areas where the spread of AIDS is most dramatic, their in vitro interaction was explored. Cryopreserved peripheral blood mononuclear cells (PBMC) from patients with filarial infections (n=24) and from unexposed control subjects (n=12) were depleted of CD8 T cells and were infected with macrophage (M)- and T cell-tropic viruses. A trend toward increased HIV replication in PBMC from filaria-infected patients was observed. Furthermore, PBMC from 6 filaria-infected patients before antifilarial treatment were significantly more susceptible to replication of M-tropic virus than their posttreatment PBMC (P=.03). No intergroup differences were found in the surface expression of HLA-DR, CD25, CCR5, CXCR4, CCR3 on CD4 T cells, or monocytes before infection. PBMC from filaria-infected patients produced less RANTES (P=.02) but more intracellular interleukin-4 than those of control subjects. Thus, PBMC from persons with filarial infections appear to have enhanced susceptibility to HIV-1 infection mediated by an undetermined mechanism.

Laparoscopic lymphocele drainage after renal transplantation

The formation of a lymphocele in small pelvis following renal transplantation is a well-known complication. Although various non-operative methods are available, laparotomy with transperitoneal internal drainage has been the gold standard for the treatment of lymphoceles. In 1991, internal drainage of a renal transplant lymphocele was performed for the first time laparoscopically. Nine patients with symptomatic lymphoceles were treated using laparoscopic technique, between July 1995 and November 1999 in the Surgical Department of the District Hospital in Szczecin. In 8 patients, the laparoscopic approach was successful and no further therapy was required. In one case, the videoscopic procedure had to be converted to open surgery. Operative time ranged from 15 to 60 minutes. The postoperative course was uneventful in all nine cases. Laparoscopic method of treatment of a renal transplant lymphocele combines the efficiency of internal surgical drainage, with the minimal invasiveness of non-operative techniques. It reduces postoperative pain, shortens length of hospitalisation and convalescence, and has a similar recurrence rate to open surgery.