Pain prevalence in patients with chronic kidney disease.

BACKGROUND: The prevalence of pain in patients with chronic kidney diseases (CKD) is not known. In the current study, we aim to determine the prevalence of pain in CKD patients and its associations with various medical and psychosocial factors. METHODS: Consecutive CKD patients who were presented to the renal clinic at Olive View-UCLA Medical Center, a Los Angeles County tertiary referral center, over a 3-month period were interviewed on their medical and psychosocial histories and a history of pain including duration, severity and source. Chi2-testing for independence and binary logistic regression performed for the presence of pain and CKD stages as well as other medical and psychosocial factors were determined. A separate survey for pain was also done for 100 consecutive non-CKD patients who were presented to our ambulatory medicine clinic for routine care. RESULTS: 54.6% of 130 patients with known CKD interviewed were women. Any type of pain of at least a 2 week duration was reported in 72.9%. The most common source of pain was musculoskeletal. The presence of pain of less than a 2 week duration was associated with worse CKD stages (3 - 5 versus 1 - 2) and non-exercisers. Higher body mass index was associated with having pain lasting longer than a 2 week duration. Among patients who had pain, 33.8% used acetaminophen, 15.4% nonsteroidal anti-inflammatory drugs and 7.8% combination analgesics. In contrast to CKD patients, only 9% of non-CKD patients reported to have any type or duration of pain. CONCLUSIONS: Pain was much more prevalent among our CKD compared with non-CKD patients.

Disparities in the utilization of live donor renal transplantation.

Despite universal payer coverage with Medicare, sociodemographic disparities confound the care of patients with renal failure. We sought to determine whether adults who realize access to kidney transplantation suffer inequities in the utilization of live donor renal transplantation (LDRT). We identified adults undergoing primary renal transplantation in 2004-2006 from the United Network for Organ Sharing (UNOS). We modeled receipt of live versus deceased donor renal transplant on multilevel multivariate models that examined recipient, center and UNOS region-specific covariates. Among 41 090 adult recipients identified, 39% underwent LDRT. On multivariate analysis, older recipients (OR 0.62, 95% CI 0.56-0.68 for 50-59 year-olds vs. 18-39 year-old recipients), those of African American ethnicity (OR 0.54, 95% CI 0.50-0.59 vs. whites) and of lower socioeconomic status (OR 0.72, 95% CI 0.67-0.79 for high school-educated vs. college-educated recipients; OR 0.78, 95% CI 0.71-0.87 for lowest vs. highest income quartile) had lower odds of LDRT. These characteristics accounted for 14.2% of the variation in LDRT, more than recipient clinical variables, transplant center characteristics and UNOS region level variation. We identified significant racial and socioeconomic disparities in the utilization of LDRT. Educational initiatives and dissemination of processes that enable increased utilization of LDRT may address these disparities.

The link between lower serum magnesium and kidney function in patients with diabetes mellitus Type 2 deserves a closer look.

INTRODUCTION: We previously reported that lower serum magnesium levels [Mg2+] can be associated with more rapid decline in renal function in patients with diabetes mellitus Type 2 (DM2). We now report long-term renal outcomes of the same patient cohort. MATERIALS AND METHODS: Most recent serum creatinine (SCr) and routine urinary analyses (RUA) for the 550 DM2 patients from our original study were collected. DATA ANALYSIS: Patients with follow-up data were stratified according to the original study: Group 1 had initial [Mg2+] < or = 1.6 - 1.8 mg/dl, Group 3 > 1.8 - 2.0 mg/dl and Group 4 > 2.0 mg/dl. The change in renal function was defined by the ratio of the most recent to the initial SCr as well as slope of 1/SCr-versus-time. Any level of proteinuria detected from RUA provided evidence for overt proteinuria. Renal outcomes were analyzed for each defined patient group. RESULTS: SCr were available for 329 out of 550 patients (59.8%). The duration of follow-up ranged from 93.8 +/- 23.4 - 99.4 +/- 22.4 months among 5 groups. The ratios of the most recent to the initial SCr were 1.54 +/- 1.01, 1.28 +/- 0.51, 1.26 +/- 0.57 and 1.09 +/- 0.29 for Groups 1 - 4, respectively; where the differences between Groups 1, 2 and 3 against Group 4 were significant (p = 0.02, 0.001 and 0.007, respectively). Accordingly, the mean slope of 1/SCr-versus-time was the best for Group 4. RUA were available for 176 patients: 22.2%, 9%, 7.3% and none from Groups 1 to 4, respectively, developed overt proteinuria. CONCLUSION: Our follow-up data suggest a link between low [Mg2+] and worse renal outcomes in DM2 patients.

Death from metastatic donor-derived ovarian cancer in a male kidney transplant recipient.

Posttransplant malignancy developing in an allograft is an uncommon complication of organ transplantation. The tumor may represent malignant transformation of donor or recipient cells that were previously normal, metastatic malignancy of recipient origin or malignancy transmitted from organ donor to recipient. Establishing the origin of the malignancy is critical to treatment algorithms. It is generally believed allograft removal and immunosuppression withdrawal will lead to resolution of transmitted malignancies in cases where the renal allograft is the origin. We report a male patient who developed metastatic ovarian malignancy secondary to donor transmission.

Clinical pathways in general surgery. Development, implementation, and evaluation.

OBJECTIVES: To emphasize the importance of the view of business process management for development and implementation of clinical pathways, and to evaluate their effectiveness in reducing cost and effort as well as enhancing patient satisfaction. METHODS: We describe the development and implementation of pathways with methods of process management and the design and realization of an evaluation study in the setting of a surgical department. For this study 67 patients treated without clinical pathways were compared with 62 patients treated using pathways. RESULTS: The approach explicitly enhances the development and implementation of clinical pathways. The introduction of pathways reduces length of hospital stay, number of laboratory tests, number of consultations, and number of imaging procedures. Patient satisfaction is improved. CONCLUSIONS: Depending on design and setting, the introduction of clinical pathways may be a very promising method to improve the inpatient service at a hospital and so to react to the challenges of increasing competition in medical care.

Obesity and outcome following renal transplantation.

Single institution series have demonstrated that obese patients have higher rates of wound infection and delayed graft function (DGF), but similar rates of graft survival. We used UNOS data to determine whether obesity affects outcome following renal transplantation. From the UNOS database, we identified patients who underwent primary kidney-only transplantation between 1997 and 1999. Recipient and donor body mass index (BMI) was categorized as underweight (BMI < 18.5), normal (BMI 18.5-24.9), overweight (BMI 25-29.9), obese (BMI 30-34.9) or morbidly obese (BMI > or = 35). We correlated BMI with intermediate measures of graft outcome and overall graft survival, and created multivariate models to evaluate the independent effect of BMI on graft outcome, adjusting for factors known to affect graft success. The study sample comprised 27,377 recipients. Older age, female sex, African American race and increased comorbidity were associated with obesity (p < 0.001). Compared with normal weight patients, morbid obesity was independently associated with an increased risk of DGF (p < 0.001), prolonged hospitalization (p < 0.001), acute rejection (p = 0.006) and decreased overall graft survival (p = 0.001). Donor BMI did not affect overall graft survival (p > or = 0.07). Recipient obesity is associated with an increased risk of DGF and decreased graft survival following renal transplantation.

Lower serum magnesium levels are associated with more rapid decline of renal function in patients with diabetes mellitus type 2.

AIMS: Hypomagnesemia has been implicated in adversely affecting diabetic complications. This is a retrospective study designed to determine whether there is any association between serum magnesium concentration [Mg2+] and the rate of renal function deterioration, as determined by the slope of serum creatinine reciprocals versus time (1/SCr-vs-t), in patients with diabetes mellitus type 2 (DM2). MATERIALS AND METHODS: DM2 patients without known kidney disease seen at Olive View-UCLA Medical Center for any reason during January-March 2001 were included. For each patient, all available data from our electronic database for [Mg2+], hemoglobin A(1C) (HbA(1C), serum creatinine (SCr), lipid profiles, routine urinary analysis, as well as history of hypertension and pharmacy profiles were retrieved. The average of all parameters obtained and linear regression analyses for the slope of 1/SCr-vs-t plot were performed for each patient. Patients were stratified by gender and divided into four groups based on increasing [Mg2+]. Correlations between each parameter including the slope of 1/SCr-vs-t and the four magnesium groups were analyzed. RESULTS: 252 males and 298 females with a mean follow-up of 62.6 +/- 22.5 months were included. Patients belonging to lower [Mg2+] groups for both genders had significantly worse slopes of 1/SCr-vs-t plot independent of the presence of hypertension and use of ACEI/ARB, diuretics, HMG-CoA enzyme inhibitors or aspirin. In a multivariate regression analysis controlling for age, HbA(1C) and various components of the lipid profile, [Mg2+] remained an independent predictor for the slope of 1/SCr-vs-t. A trend for worse proteinuria based on routine urinary analysis was observed among patients belonging to the lowest [Mg2+] group. CONCLUSIONS: Lower [Mg2+] is associated with a faster renal function deterioration rate in DM2 patients.

Review article: current management of renal dysfunction in the cirrhotic patient.

The United Network for Organ Sharing database revealed that over the last 4-5 years, an average of 1800 patients were removed from the cadaveric waiting list annually because of patients' death and an additional 400-500 were removed from the list because of the severity of their illnesses. The pre-transplant evaluation process, therefore, requires careful and continued assessment of the patient's pulmonary, cardiac and renal function among others. This article describes a systematic approach to the evaluation and management of renal dysfunction complicating the course of advanced liver disease, the pathogenic mechanisms and current recommendations for the treatment of hepatorenal syndrome, and the indications for combined liver-kidney transplantation.

Sodium and water disturbances in patients with Sheehan's syndrome.

Sheehan's syndrome has been attributed to ischemic damage of the pituitary gland or hypothalamic-pituitary stalk during the peripartum period. Well-described clinical features of Sheehan's syndrome include hypothyroidism, adrenal insufficiency, hypogonadism, growth hormone deficiency, hypoprolactinemia, and different sodium and water disturbances. The occurrence of sodium and water disturbances associated with Sheehan's syndrome depends on the degree of pituitary damage, time of onset since the initial pituitary insult, and concurrent medical conditions that also may play a role in sodium and water balance. We present a patient with Sheehan's syndrome with severe chronic hyponatremia; discuss a potential problem in the patient's management; and review the literature for various sodium and water disturbances, including acute and chronic hyponatremia as well as overt and subclinical central diabetes insipidus. Although Sheehan's syndrome is more prevalent in developing countries, the increasingly large immigrant population within the United States warrants better awareness of this syndrome and its potential complicating sodium and water disturbances. Prompt diagnosis and an understanding of the pathogenic mechanisms of sodium and water disturbances associated with Sheehan's syndrome may avoid potential treatment-related complications.

The delta and delta ' subunits of the DNA polymerase III holoenzyme are essential for initiation complex formation and processive elongation.

delta and delta' are required for assembly of the processivity factor beta(2) onto primed DNA in the DNA polymerase III holoenzyme-catalyzed reaction. We developed protocols for generating highly purified preparations of delta and delta'. In holoenzyme reconstitution assays, delta' could not be replaced by delta, tau, or gamma, even when either of the latter were present at a 10,000-fold molar excess. Likewise, delta could not be replaced by delta', tau, or gamma. Bacterial strains bearing chromosomal knockouts of either the holA(delta) or holB(delta') genes were not viable, demonstrating that both delta and delta' are essential. Western blots of isolated initiation complexes demonstrated the presence of both delta and delta'. However, in the absence of chipsi and single-stranded DNA-binding protein, a stable initiation complex lacking deltadelta' was isolated by gel filtration. Lack of delta-delta' decreased the rate of elongation about 3-fold, and the extent of processive replication was significantly decreased. Adding back delta-delta' but not chipsi, delta, or delta' alone restored the diminished activity, indicating that in addition to being key components required for the beta loading activity of the DnaX complex, deltadelta' is present in initiation complex and is required for processive elongation.

Assessment of cell-signaling pathways in the regulation of mammalian target of rapamycin (mTOR) by amino acids in rat adipocytes.

Enhanced phosphorylation of the ribosomal protein s6 kinase, p70(s6k), and the translational repressor, 4E-BP1, are associated with either insulin-induced or amino acid-induced protein synthesis. Hyperphosphorylation of p70(s6k) and 4E-BP1 in response to insulin or amino acids is mediated through the mammalian target of rapamycin (mTOR). In several cell lines, mTOR or its downstream targets can be regulated by phosphatidylinositol (PI) 3-kinase; protein kinases A, B, and C; heterotrimeric G-proteins; a PD98059-sensitive kinase or calcium; as well as by amino acids. Regulation by amino acids appears to involve detection of levels of charged t-RNA or t-RNA synthetase activity and is sensitive to inhibition by amino acid alcohols. In the present article, however, we show that the rapamycin-sensitive regulation of 4E-BP1 and p70(s6k) in freshly isolated rat adipocytes is not inhibited by either L-leucinol or L-histidinol. This finding is in agreement with other recent studies from our laboratory suggesting that the mechanism by which amino acids regulate mTOR in freshly isolated adipocytes may be different than the mechanism found in a number of cell lines. Therefore we investigated the possible role of growth factor-regulated and G-protein-regulated signaling pathways in the rapamycin-sensitive, amino acid alcohol-insensitive actions of amino acids on 4E-BP1 phosphorylation. We found, in contrast to previously published results using 3T3-L1 adipocytes or other cell lines, that the increase in 4E-BP1 phosphorylation promoted by amino acids was insensitive to agents that regulate protein kinase A, mobilize calcium, or inhibit protein kinase C. Furthermore, amino acid-induced 4E-BP1 phosphorylation was not blocked by pertussis toxin nor was it mimicked by the G-protein agonists fluoroaluminate or MAS-7. However, amino acids failed to activate either PI 3-kinase, protein kinase B, or mitogen-activated protein kinase and failed to promote tyrosine phosphorylation of cellular proteins, similar to observations made using cell lines. In summary, amino acids appear to use an amino acid alcohol-insensitive mechanism to regulate mTOR in freshly isolated adipocytes. This mechanism is independent of cell-signaling pathways implicated in the regulation of mTOR or its downstream targets in other cells. Overall, our study emphasizes the need for caution when extending results obtained using established cell lines to the differentiated nondividing cells found in most tissues.

Cyclosporine and tacrolimus-associated thrombotic microangiopathy.

The development of thrombotic microangiopathy (TMA) associated with the use of cyclosporine has been well documented. Treatments have included discontinuation or reduction of cyclosporine dose with or without concurrent plasma exchange, plasma infusion, anticoagulation, and intravenous immunoglobulin G infusion. However, for recipients of organ transplantation, removing the inciting agent is not without the attendant risk of precipitating acute rejection and graft loss. The last decade has seen the emergence of tacrolimus as a potent immunosuppressive agent with mechanisms of action virtually identical to those of cyclosporine. As a result, switching to tacrolimus has been reported to be a viable therapeutic option in the setting of cyclosporine-induced TMA. With the more widespread application of tacrolimus in organ transplantation, tacrolimus-associated TMA has also been recognized. However, literature regarding the incidence of the recurrence of TMA in patients exposed sequentially to cyclosporine and tacrolimus is limited. We report a case of a living donor renal transplant recipient who developed cyclosporine-induced TMA that responded to the withdrawal of cyclosporine in conjunction with plasmapheresis and fresh frozen plasma replacement therapy. Introduction of tacrolimus as an alternative immunosuppressive agent resulted in the recurrence of TMA and the subsequent loss of the renal allograft. Patients who are switched from cyclosporine to tacrolimus or vice versa should be closely monitored for the signs and symptoms of recurrent TMA.

Overcorrection of hyponatremia: where do we go wrong?

Predicted sodium concentrations [Na(+)] based on traditional calculations for the correction of hyponatremia often do not match treated [Na(+)], for various reasons. In many situations, hyponatremia is corrected at unexpectedly rapid rates. The authors present an analysis of two cases of overly rapid correction of hyponatremia despite apparently appropriate management based on initial evaluations. The mistakes involved are discussed and simple calculations demonstrated to prove that the overcorrections did not occur at random. Overcorrection in one case involved miscommunications between the emergency room and admitting physicians regarding the amount of saline and potassium already administered to the patient. Unexpected hypoosmotic polyuria was responsible for overcorrection in the other case. Overcorrection of hyponatremia may be preventable in many cases. In general, overcorrection of hyponatremia is caused by either "too much salt (Na(+) + K(+)) gained" or "too much water lost." Recognizing common pitfalls will enable physicians to avoid overcorrection and its attendant risk of fatal osmotic demyelinating syndrome (ODS).

Metabolism of O6-propyl and N6-propyl-carbovir in CEM cells.

The metabolism of O6-propyl-carbovir and N6-propyl-carbovir, two selective inhibitors of HIV replication, has been evaluated in CEM cells. Both compounds were phosphorylated in intact cells to carbovir-5'-triphosphate. The metabolism of these two agents was inhibited by deoxycoformycin and mycophenolic acid, but not erythro-9-(2-hydroxy-3-nonyl)adenine. No evidence of the 5'-triphosphate of either compound was detected in CEM cells.

Renal abnormalities in sickle cell disease.

Renal abnormalities in sickle cell disease. Sickle cell nephropathy is indicated by sickled erythrocytes, with the consequent effects of decreased medullary blood flow, ischemia, microinfarct and papillary necrosis. Impaired urinary concentrating ability, renal acidification, hematuria, and potassium secretion are also found. There may be a causal relationship between an increase in nitric oxide synthesis and experimental sickle cell nephropathy, and some studies have indicated that the progression of sickle cell nephropathy is hemodynamically mediated. Although there are many studies showing that proteinuria, nephrotic syndrome, chronic progressive renal failure, and acute renal failure syndromes are the outcome of this disease, the pathogenic mechanism(s) and potential therapies remain to be elucidated. Survival of patients with sickle cell nephropathy who progress to end-stage renal disease (ESRD) is equal to non-diabetic ESRD patients, and graft survival rates are also similar for those who undergo renal transplantation. This article presents a historical review of the glomerular and tubular disorders associated with sickle cell nephropathy, and reviews therapeutic indications to slow its progression. Further research is needed.

The kidney in liver transplantation.

Early recognition and determination of the cause of renal failure in patients with ESLD can be difficult because of the potential interplay among various factors and the wide array of differential diagnoses. A systematic approach, however, assists clinicians to identify common and potentially reversible causes of ARF. It is crucial to distinguish patients with functional renal failure, such as HRS, from those with advanced irreversible renal disease. Isolated liver transplantation is the treatment of choice for the former, and CLKT may be a therapeutic option for the latter. Because of the ever-increasing shortage of donor organs, CLKT must be used judiciously. Kidney biopsy may resolve diagnostic dilemmas. Management of renal complications post-OLT remains a challenge for the physician caring for transplant patients. Modification of nephrotoxic immunosuppressive regimens to avoid postoperative ARF/CRI has met with variable results. Azathioprine has been used in place of cyclosporine. Therapy with polyclonal antilymphocyte preparations or anti-OKT3 monoclonal antibodies (Orthoclone) should be reserved for patients with delayed graft function and for the treatment of acute rejection. The routine use of these agents as prophylactic therapy is not recommended. Data on the impact of renal insufficiency on patient and allograft outcome are inconsistent. Nonetheless, the authors' literature review suggests that renal failure associated with sepsis and, except for patients with HRS, renal failure requiring dialysis are the most consistent features associated with a worse outcome. The need for preoperative or postoperative dialysis has no adverse effect on survival in patients with HRS. On long-term follow-up, despite a greater percentage of patients reaching ESRD in patients with HRS compared with their non-HRS counterparts, the overall outcome in patients with HRS following OLT is favorable. In patients with HRS requiring prolonged dialysis (i.e., greater than 4 weeks), however, irreversible renal failure may develop, necessitating CLKT. Ideally, timely referral of patients for OLT may avoid this complication and obviate the need for double organ transplantation.

Mismatch extension by Escherichia coli DNA polymerase III holoenzyme.

The in vitro fidelity of Escherichia coli DNA polymerase III holoenzyme (HE) is characterized by an unusual propensity for generating (-1)-frameshift mutations. Here we have examined the capability of HE isolated from both a wild-type and a proofreading-impaired mutD5 strain to polymerize from M13mp2 DNA primer-templates containing a terminal T(template).C mismatch. These substrates contained either an A or a G as the next (5') template base. The assay allows distinction between: (i) direct extension of the terminal C (producing a base substitution), (ii) exonucleolytic removal of the C, or (iii), for the G-containing template, extension after misalignment of the C on the next template G (producing a (-1)-frameshift). On the A-containing substrate, both HEs did not extend the terminal C (<1%); instead, they exonucleolytically removed it (>99%). In contrast, on the G-containing substrate, the MutD5 HE yielded 61% (-1)-frameshifts and 6% base substitutions. The wild-type HE mostly excised the mispaired C from this substrate before extension (98%), but among the 2% mutants, (-1)-frameshifts exceeded base substitutions by 20 to 1. The preference of polymerase III HE for misalignment extension over direct mismatch extension provides a basis for explaining the in vitro (-1)-frameshift specificity of polymerase III HE.

Amino acid effects on translational repressor 4E-BP1 are mediated primarily by L-leucine in isolated adipocytes.

Previous studies indicated that amino acids may activate the protein kinase activity of the target of rapamycin (TOR) and thereby augment and/or mimic the effects of insulin on protein synthesis, p70(S6k) phosphorylation, and multicellular clustering in adipocytes. To identify the individual amino acids responsible for these effects, the present study focused on the TOR substrate and translational repressor 4E-BP1. A complete mixture of amino acids stimulated the phosphorylation of 4E-BP1, decreasing its association with eukaryotic initiation factor eIF-4E. Studies on subsets of amino acids and individual amino acids showed that L-leucine was the amino acid responsible for most of the effects on 4E-BP1 phosphorylation; however, the presence of other amino acids was required to observe a maximal effect. The stimulatory effect of leucine was stereospecific and not mimicked by other branched chain amino acids but was mimicked by the leucine metabolite alpha-ketoisocaproate (alpha-KIC). The effect of alpha-KIC, but not leucine, was attenuated by the transaminase inhibitor (aminooxy)acetate. The latter result indicates that the effects of alpha-KIC required its conversion to leucine. Half-maximal stimulation of 4E-BP1 phosphorylation occurred at approximately 430 microM; therefore, the response was linear within the range of circulating concentrations of leucine found in various nutritional states.

The base substitution and frameshift fidelity of Escherichia coli DNA polymerase III holoenzyme in vitro.

We have investigated the in vitro fidelity of Escherichia coli DNA polymerase III holoenzyme from a wild-type and a proofreading-impaired mutD5 strain. Exonuclease assays showed the mutD5 holoenzyme to have a 30-50-fold reduced 3'-->5'-exonuclease activity. Fidelity was assayed during gap-filling synthesis across the lacId forward mutational target. The error rate for both enzymes was lowest at low dNTP concentrations (10-50 microM) and highest at high dNTP concentration (1000 microM). The mutD5 proofreading defect increased the error rate by only 3-5-fold. Both enzymes produced a high level of (-1)-frameshift mutations in addition to base substitutions. The base substitutions were mainly C-->T, G-->T, and G-->C, but dNTP pool imbalances suggested that these may reflect misincorporations opposite damaged template bases and that, instead, T-->C, G-->A, and C-->T transitions represent the normal polymerase III-mediated base.base mispairs. The frequent (-1)-frameshift mutations do not result from direct slippage but may be generated via a mechanism involving "misincorporation plus slippage." Measurements of the fidelity of wild-type and mutD5 holoenzyme during M13 in vivo replication revealed significant differences between the in vivo and in vitro fidelity with regard to both the frequency of frameshift errors and the extent of proofreading.