Kidney function and its association to imminent, short- and long-term fracture risk-a longitudinal study in older women.

Reduced kidney function is associated with an increased fracture risk, although the relationship between an age-related decline and fractures needs further investigation. We followed kidney function and fracture risk for 10 years. A mild-moderate decline in kidney function was associated with fracture, but not in advanced age. INTRODUCTION: With age, kidney function declines. Though well known that chronic kidney disease is associated with increased fracture risk, the extent to which the typical age-related decline contributes is unclear. In the OPRA cohort, a longitudinal study of older non-selected women, we investigated the association between kidney function and fracture. METHODS: Cystatin C-based kidney function estimates were available at age 75 (n = 981) and 80 (n = 685). Women were categorized by kidney function: normal (CKD stages 1 and 2), mild-moderate (3a), poor (3b-5), and imminent, short- and long-term fracture risk investigated. BMD measurements and kidney function for risk prediction were also evaluated; women were categorized by both reduced kidney function (stages 3-5) and osteoporosis status. RESULTS: In the short term, 2-3 years, mild-moderate kidney dysfunction was associated with the highest risk increase: osteoporotic fractures (2 years HRadj 2.21, 95% CI 1.27-3.87) and also up to 5 years (between 75 and 80 years) (HRadj 1.51, 1.04-2.18). Hip fracture risk was similarly increased. This association was not observed from age 80 nor for women with poorest kidney function. Reduced kidney function was associated with higher risk even without osteoporosis (osteoporotic fracture; HRadj 1.66, 1.08-2.54); risk increased by having both osteoporosis and reduced function (HRadj 2.53, 1.52-4.23). CONCLUSION: Older women with mild-moderate reduction of kidney function are at increased risk of fractures, but not those with the worst function. Our findings furthermore confirm the value of osteoporosis assessment and it is possible that in this age group, age-related decline of kidney function has limited contribution compared with BMD.

Reduced kidney function is associated with BMD, bone loss and markers of mineral homeostasis in older women: a 10-year longitudinal study.

Kidney function decreases with age; however, the long-term influence on bone density (BMD) in older women already at risk of osteoporosis is unknown. We followed kidney function and bone loss for 10 years. Declining kidney function was adversely associated with bone loss and mineral homeostasis in old women, though it attenuated with advanced aging. INTRODUCTION: Existing studies do not fully address the relationship between kidney function and bone metabolism with advanced aging in Caucasian women. This study describes the association between kidney function, BMD, bone loss and bone metabolism in older women and provides a review of the available literature for context. METHODS: We studied participants from the OPRA cohort with follow-up after 5 and 10 years. Using plasma cystatin C (cysC), estimated glomerular function rate (eGFR) was evaluated at age 75 (n = 981), 80 (n = 685) and 85 (n = 365). Women were stratified into "normal" function (CKD stages 1-2), "intermediate" (stage 3a) and "poor" (stages 3b-5), and outcome measures-BMD, bone loss and markers of mineral homeostasis-were compared. RESULTS: Femoral neck (FN) BMD positively associated with kidney function at 75 years old ([Formula: see text] = 0.001, p = 0.028) and 80 years old ([Formula: see text] = 0.001, p = 0.001), although with small effect size. Prevalence of osteoporosis (FN T-score ≤ - 2.5) did not differ with kidney function. Measured at age 75, women with poor kidney function had higher annual percentage bone loss over 5 years compared to those with normal function (2.3%, 95% CI 1.8-2.8 versus 1.3%, 95% CI 1.1-1.5, p = 0.007), although not when measured from age 80 or 85. Additionally, markers of mineral homeostasis (PTH, phosphate, vitamin D, calcium), CRP and osteocalcin differed by kidney function. CONCLUSIONS: In old women, kidney function is associated with BMD, bone loss and altered mineral homeostasis; probably, a relationship attenuated in the very elderly.

Anti-Müllerian hormone, a Sertoli cell-derived marker, is decreased in plasma of male patients in all stages of chronic kidney disease.

Male patients with terminal renal failure are often infertile and exhibit an abnormal sex hormone pattern in plasma. We studied patients in all chronic kidney disease (CKD) stages to determine plasma levels of anti-Müllerian hormone (AMH), a Sertoli cell-derived marker, and other sex hormones. Seventy-eight male patients with CKD stages 1-5 and a median age of 40 years (22-50 years), as well as 20 healthy controls with a median age of 37 years (26-44 years), were enrolled. The CKD patients were evenly distributed; 18 with CKD stages 1-2, 19 with CKD stage 3, 19 with CKD stage 4, and 22 with CKD stage 5. Cystatin C, follicle-stimulating hormone, luteinizing hormone, prolactin, sex hormone-binding globulin, testosterone, and AMH levels in plasma were analysed. AMH was analysed using the Ansh Labs UltraSensitive AMH assay. Several changes occurred in plasma levels of sex hormones in male patients with CKD. Plasma AMH levels were lower in CKD stages 1-4 by 30% (p = 0.041) and by 70% (p < 0.001) in CKD stage 5 compared with controls. Plasma luteinizing hormone and prolactin levels were higher and testosterone levels were lower compared with controls. The pathophysiological role of this reduction in AMH is unclear, but can be linked to altered Sertoli cell function.

Cystatin C identifies cardiovascular risk better than creatinine-based estimates of glomerular filtration in middle-aged individuals without a history of cardiovascular disease.

OBJECTIVES: Creatinine- and cystatin C-based estimates of renal function are considered to be cardiovascular disease (CVD) risk factors, but the clinical utility in middle-aged subjects without a history of CVD is controversial. DESIGN: We related plasma cystatin C and creatinine-based glomerular filtration rate (GFR) [MDRD, CKD-EPI-2009, and CKD-EPI-comb (a combination of creatinine and cystatin C)] to incident CVD, CVD mortality, all-cause mortality, and heart failure in 4650 middle-aged subjects without CVD. RESULTS: The hazard ratio (HR) per standard deviation increment (95% CI) of cystatin C predicted incident CVD (1.22, 1.11-1.33; P < 0.0001), CVD mortality (1.44, 1.24-1.66; P < 0.0001), all-cause mortality (1.15, 1.05-1.26; P = 0.002), and heart failure (1.27, 1.05-1.55; P = 0.02), whereas MDRD and CKD-EPI-2009 only predicted CVD mortality (0.79, 0.66-0.93; P = 0.006 and 0.78, 0.66-0.92; P = 0.003, respectively). Cystatin C led to a significant increase in the net reclassification improvement for all endpoints, except heart failure. Only within the quartile with the worst renal function were all measures related to all-cause and CVD mortality. The top 25% of cystatin C in the population significantly predicted risk of incident CVD and CVD mortality, whereas MDRD and CKD-EPI-2009 were predictors of CVD mortality only at a GFR < 60 mL/min/1.73 m(2) (11-13% of the population) and of incident CVD only at a GFR < 45 mL/min/1.73 m(2) (<1% of the population). CONCLUSION: Cystatin C is a better risk marker for CVD morbidity and mortality than creatinine-based GFR. Whether this is explained by cystatin C being a better marker for true GFR or through other effects of cystatin C remains to be shown.

Intensive care treatment of severe mixed metabolic acidosis.

We report a case of severe metabolic acidosis associated with acute renal failure and septicaemia following treatment with maximal therapeutic doses of metformin and diclofenac. On the second day of intensive care the patient deteriorated with respiratory insufficiency and abdominal pain during continuous renal replacement therapy. A laparoscopy revealed a perforated cholecystitis with abscess formation. The patient regained renal function and recovered. Intake of diclofenac 5 days before this episode could have been the main cause of renal insufficiency and metabolic acidosis in this patient and could also have delayed surgical treatment by masking early clinical signs of perforated cholecystitis. The renal failure may also have caused metformin and lactate to accumulate, contributing to the mixed pattern of metabolic acidosis. This case report describes a mixed organic and non-organic metabolic acidosis associated with acute renal failure, presumably resulting from a combination of drugs and diseases often found in the elderly - metformin for diabetes mellitus and a non-steroidal anti-inflammatory drug for cholecystolithiasis. Acid-base balance and electrolyte changes were rapidly normalized by continuous renal replacement therapy.

Serum cystatin C advantageous compared with serum creatinine in the detection of mild but not severe diabetic nephropathy.

OBJECTIVE: To determine whether serum cystatin C is more accurate than serum creatinine in the detection of diabetic nephropathy, also after adjustment for age. METHODS: Forty-one patients with type 1 and 82 patients with type 2 diabetes were evaluated with serum creatinine, serum cystatin C, and (51)Cr-EDTA clearance (reference method). Cystatin C was measured by a particle-enhanced turbidimetric method and creatinine by an enzymatic method. Statistical estimations were performed both without and with age adjustment created by z-scores for (51)Cr-EDTA clearance, creatinine, and cystatin C. The cut-off levels for glomerular filtration rate (GFR) ((51)Cr-EDTA clearance) were 60 and 80 mL min(-1) 1.73 m(-2), respectively, in absolute values and 80, 90 and 95% CIs, respectively, in age-adjusted values (z-scores). RESULTS: Estimations without age adjustment showed significantly (P = 0.0132) closer correlation for cystatin C (r = 0.817) versus (51)Cr-EDTA clearance as compared with creatinine (r = 0.678). However, when using age-adjusted values, the correlation for cystatin C and creatinine, respectively, versus (51)Cr-EDTA clearance did not differ. When comparing the diagnostic utilities for serum cystatin C versus serum creatinine in manifest renal impairment (GFR < 60 mL min(-1) 1.73 m(-2) or z-scores <-1.28 SD), there were no significant differences between the two markers whether age adjusted or not. However, for diagnosing mild nephropathy (GFR < 80 mL min(-1) 1.73 m(-2) or z-score -0.84 SD), serum cystatin C is significantly more useful. CONCLUSIONS: Serum cystatin C performed better compared with serum creatinine even when measured enzymatically, to detect mild diabetic nephropathy. However, serum creatinine was as efficient as serum cystatin C to detect advanced diabetic nephropathy.

Normalization of haemoglobin concentration with recombinant erythropoietin has minimal effect on blood haemostasis.

BACKGROUND: Elevation of haemoglobin (Hb) with recombinant erythropoietin (rHuEpo) in patients with chronic renal failure has raised concern of increased risk of thromboembolic diseases. In this study, a substudy of the Scandinavian multicentre trial, we examined the influence on haemostatic parameters of normalization of Hb levels from subnormal levels in patients with chronic renal failure. METHODS: Twenty-six patients, 17 males (before study start Hb 113+/-6 g/l) and nine females (Hb 111+/-8 g/l), with end-stage renal disease were included. Both dialysis and predialysis patients were included. After 3 months of rHuEpo therapy Hb levels reached 136+/-14 g/l for males and 128+/-13 g/l for females, and after 1 year 142+/-11 g/l and 126+/-14 g/l respectively. The increase in Hb was significant both at 3 months and 1 year, compared to baseline. At baseline, after 3 months and 1 year haemostatic and prothrombotic parameters were measured, including prothrombin complex test, activated partial thromboplastin time, platelet aggregation and retention, von Willebrand factor antigen, antithrombin, protein C, total and free protein S, activated protein C resistance, FV-Leiden mutation, D-dimers, plasminogen activator inhibitor-1 and prothrombin fragments 1+2 (PF 1+2). RESULTS: The only statistically significant change was a transient decrease in total levels of protein S at 3 months from 131 to 120% (P=0.0093). The free and active form of protein S showed no significant change. After 1 year the difference was not seen. CONCLUSIONS: Apart from a transient and clinically insignificant decrease in total protein S, we found no prothrombotic changes after normalization of Hb from subnormal levels. Our findings indicate that rHuEpo treatment may aim at normalizing Hb levels without significant effects on haemostatic parameters in patients with chronic renal failure compared to patients with subnormal Hb levels.

Long-term clinical effects of a peritoneal dialysis fluid with less glucose degradation products.

BACKGROUND: Glucose degradation products (GDPs) are cytotoxic in vitro and potentially toxic in vivo during peritoneal dialysis (PD). We are presenting the results of a two-year randomized clinical trial of a new PD fluid, produced in a two-compartment bag and designed to minimize heat-induced glucose degradation while producing a near neutral pH. The effects of the new fluid over two years of treatment on membrane transport characteristics, ultrafiltration (UF) capacity, and effluent markers of peritoneal membrane integrity were investigated and compared with those obtained during treatment with a standard solution. DESIGN: A two-group parallel design with 80 continuous ambulatory peritoneal dialysis patients was used. The patients were randomly assigned to either the new fluid (N = 40) or to a conventional one (N = 40), and were stratified with respect to age, diabetes, and time on PD. Peritoneal transport characteristics were assessed by the Personal Dialysis Capacity (PDCtrade mark) test at 1, 6, 12, 18, and 24 months after inclusion and by weighing the overnight bag daily. Infusion pain and handling were evaluated using a questionnaire. Peritoneal mesothelial and interstitial integrity were evaluated by analyzing overnight effluent dialysate concentrations of CA 125, hyaluronan (HA), procollagen-1-C-terminal peptide (PICP), and procollagen-3-N-terminal peptide (PIIINP) at 1, 6, 12, 18, and 24 months. RESULTS: The handling of the new two-compartment bag was considered easy, and there were no indications of increased discomfort with the new system. Furthermore, no changes in peritoneal fluid or solute transport characteristics were observed during the study period for either fluid, and neither were there any differences with regard to peritonitis incidence. However, significantly higher dialysate CA 125 (73 +/- 41 vs. 25 +/- 18 U/mL), PICP (387 +/- 163 vs. 244 +/- 81 ng/mL), and PIIINP (50 +/- 24 vs. 29 +/- 13 ng/mL) and significantly lower concentrations of HA (395 +/- 185 vs. 530 +/- 298 ng/mL) were observed in the overnight effluent during treatment with the new fluid. CONCLUSIONS: We conclude that the new fluid with a higher pH and less GDPs is safe and easy to use and has no negative effects on either the frequency of peritonitis or peritoneal transport characteristics as compared with conventional ones. Our results indicate that the new solution causes less mesothelial and interstitial damage than conventional ones; that is, it may be considered more biocompatible than a number of conventional PD solutions currently in use.

Cystine analyses of separate day and night urine as a basis for the management of patients with homozygous cystinuria.

Based on previous observations of the diurnal variation of urinary cystine excretion, the use of separate day and night urine collections was proposed. To improve the medical treatment of patients with cystinuria, this strategy was performed to guide the fluid intake and the administration of SH compounds (tiopronin, D-penicillamine, and MESNA).Twenty-six patients (19 treated with SH compounds and seven with alkalinization and hydration only) were followed during two 3.5-year periods. During Period 1, 24-h urine was collected and during Period 2, separate day and night urine was collected. There were 56 episodes of high urinary cystine supersaturation (> 1,200 micromol/l) during Period 2, 47% of which would have evaded detection with 24-h urine analysis. In comparison with Period 1, the urinary cystine concentration was lower (P < 0.05), and the urinary volume was higher (P < 0.05) during Period 2. Patients treated with tiopronin had reduced cystine excretion (P < 0.05) and at the end of Period 2, an increased dose of tiopronin, reflecting a more aggressive treatment. Furthermore, a reduced number of stone episodes and need of active stone removal (P < 0.05) was noted in the whole group of patients. Analyses of separate day and night urine samples can be used advantageously to reveal episodes of high supersaturation with cystine not detected in 24-h urine samples. Such a procedure might be useful for optimizing the treatment of patients with cystinuria.

The prognostic value of different forms of prostate specific antigen and their ratios in patients with prostate cancer.

OBJECTIVE: To assess the prognostic value for patient survival of different forms of PSA and ratios thereof, before treatment for prostate cancer, by considering the forms and ratios both as independent markers and by comparing them with other commonly used prognostic markers, e.g. tumour grade, local stage (T-stage) and absence or presence of skeletal metastases (M-stage). PATIENTS AND METHODS: Blood samples were collected consecutively from men diagnosed with prostate cancer at our department in 1988. From this group, 66 men were followed until death, or for >/=9 years. Twenty-five patients died from their prostate cancer and 21 from other causes during the follow-up period. Forty-eight patients received hormonal treatment, whereas 18 remained untreated or received no treatment for their cancer before they died from other causes. Assays measuring the serum levels of free prostate specific antigen (fPSA), PSA complexed to alpha1-antichymotrypsin (PSA-ACT), and total PSA (tPSA) were used to calculate the percentage of free to total PSA (f/tPSA) fPSA/ACT and ACT/tPSA at diagnosis. Based on the initial levels or ratios of the PSA forms, the patients were divided into three numerically comparable groups (tertiles) for survival analysis. Prognostic factors predicting patient survival were evaluated using univariate (Kaplan-Meier life-tables with the log-rank test) and multivariate techniques (Cox proportional hazards regression model). RESULTS: Univariate analysis using the log-rank test showed that the serum level of each molecular form of PSA, i.e. tPSA (P=0.001), PSA-ACT (P<0.001) and fPSA (P<0.001), as well as grade (P<0.001), T-stage (P=0.00355) and M-stage (P<0.001), provided statistically significant prognostic information. Log-rank tests showed that none of the ratios, i.e. f/tPSA, fPSA/ACT and ACT/tPSA, were informative of prognosis (P>0.05). However, in a multivariate analysis regression model, not only M-stage (risk ratio 4.2; P=0. 026) and grade (risk ratio 2.6; P=0.022), but also f/tPSA (risk ratio 1.8; P=0.037), provided significant prognostic information. CONCLUSION: The values of tPSA, fPSA and PSA-ACT, as well as grade and T- and M-stage, are all independent prognostic factors of prostate cancer survival. In a multivariate analysis, not only M-stage and grade but also f/tPSA provided significant prognostic information.

Renovascular disease and renal insufficiency--diagnosis and treatment.

Renovascular disease as cause of end-stage renal disease has become more frequent during the last decade. In order to minimize the need for dialysis treatment non-invasive screening for the disease is needed. However, both ultrasonic duplex scanning and renal scintigraphy are not sufficient for detection of all stenosis. Furthermore, there is little data on non-invasive tests in patients with renal insufficiency. Renal arteriography is the gold standard for detection of renovascular disease. One disadvantage is the risk of contrast-agent induced acute renal insufficiency. This problem can be avoided using carbon dioxide angiography. In the near future spiral computed tomography and magnetic resonance angiography may be alternatives for identifying patients with renovascular disease. Ischaemic nephropathy is potentially curable. Percutaneous transluminal renal angioplasty is first line treatment in most cases. Intervention often results in improvement or preservation of renal function which is very important in order to avoid chronic dialysis.

Similar treatment success rate after renal transplantation in diabetic and nondiabetic patients due to improved short- and long-term diabetic patient survival.

In the early era of transplantation, it was common practice to exclude diabetic patients since the outcome in such cases was usually poor. At our center in Malmö, Sweden, diabetic nephropathy was never regarded as a contraindication. During the 22-year period from 1972 to 1993, 223 renal allografts were transplanted in 189 uremic diabetics, representing 24% of all renal transplant recipients (n = 788). The two subgroups - patients with and without diabetes - did not differ significantly in graft survival rates for the 22-year period, which was characterized by a successive improvement in the success rate that was especially striking in the diabetic nephropathy subgroup. Among transplantations performed before 1988, the overall patient survival rate was significantly lower in the diabetic subgroup than in the remainder. After 1988 (when a series of new procedures had been adopted), the patient survival rate in the diabetic subgroup was similar to that in the nondiabetic subgroup, a similarity that persisted for at least 5 years. The 1st year post-transplant mortality rate was reduced in diabetic patients from 24% before 1988 to 0% in those transplanted after 1988. In the 22-year period as a whole, cardiovascular or cerebrovascular events were the most common cause of death in both subgroups; the risk of cardiovascular or cerebrovascular death was reduced after 1988, and the rates were similar in both subgroups. The improved success rate of renal transplantation in patients with diabetic nephropathy supports continuation of the renal transplant program, which is based on careful management of the early stages of the disease.

Free and complexed prostate-specific antigen (PSA): in vitro stability, epitope map, and development of immunofluorometric assays for specific and sensitive detection of free PSA and PSA-alpha 1-antichymotrypsin complex.

Generation of 15 monoclonal antibodies (MAbs) allowed construction of epitope maps and specific two-site immunofluorometric assays for free prostate-specific antigen (PSA) and PSA complexed with alpha 1-antichymotrypsin (ACT). Close correlation of PSA concentrations obtained with the use of different assays of free PSA suggested extensive similarity in immunodetection of free PSA in serum. Assays of the PSA-ACT complex overestimated the concentration of PSA-ACT in serum because of nonspecific adsorbance of ACT or cathepsin G-complexed ACT to the solid phase. This interference was substantially decreased in the presence of heparin. In studying the stability of purified PSA and PSA-ACT complexes formed in vitro, we found that the free PSA was stable during storage for 4 weeks at 35 degrees C, whereas PSA-ACT complexes largely dissociated in these conditions. The instability of PSA-ACT complexes was counteracted by storage at low temperatures, by adjusting the pH of the storage buffer between 6.8 and 7.4, and through addition of 100-1000-fold molar excess of native ACT. The ease of calibration and the accuracy of free PSA assays in comparison with assays of the PSA-ACT complex suggest that measurements of free to total PSA most accurately reflect the inverse of the proportion of PSA complexed to ACT in serum.

Complex formation between protein C inhibitor and prostate-specific antigen in vitro and in human semen.

Protein C inhibitor (PCI), a serine-proteinase inhibitor first purified from human blood plasma, occurs at high concentrations (3-4 microM) in seminal fluid in both a high-molecular-mass and low-molecular-mass form. Immunochemical data have previously suggested that PCI in seminal plasma forms complexes with the most abundant serine proteinase in semen, prostate-specific antigen (PSA). To provide a structural characterization of the PCI target, immunodetected as PSA, a procedure was developed to isolate low-molecular-mass and high-molecular-mass-forms of PCI from seminal fluid. The high-molecular-mass form of PCI, recognized by monoclonal antibodies against PSA, was dissociated by alkaline treatment into the low-molecular-mass form of PCI and a 33-kDa protein identified as PSA by 25 conclusive steps of N-terminal sequence analysis. We developed a sensitive immunofluorometric assay (IFMA) to measure PCI-PSA complexes in body fluids and investigated the rate at which purified PSA may form complexes with purified PCI. Formation of complexes detected by this IFMA and the appearance of SDS-stable approximately 90-kDa complexes paralleled loss of PSA activity recorded with chromogenic substrates. The rate of complex formation was slow compared to that reported for PCI and activated protein C, but was enhanced up to sixfold in the presence of heparin. Less than 10% of the initial PSA activity remained after 3 h incubation with a sevenfold molar excess of PCI and in the presence of heparin. In freshly collected ejaculates, the rate of PCI-PSA complex formation measured by IFMA was similar to that observed between the purified proteins, and paralleled the appearance of SDS-stable complexes by immunoblotting. During gel dissolution in freshly collected ejaculates, approximately 40% of immunodetected PCI becomes complexed to PSA. Although PCI is a slow inhibitor of PSA, complexes between PCI and PSA are detected at levels that correspond to an inactivation of up to 5% of the PSA activity in the ejaculate.

Serum prostate specific antigen complexed to alpha 1-antichymotrypsin as an indicator of prostate cancer.

Prostate specific antigen (PSA) in serum has recently been shown to occur in complex with alpha 1-antichymotrypsin and as an approximately 30 kDa. noncomplexed molecular form. We characterized PSA by 3 different assays in samples from 144 patients with benign prostatic hyperplasia (BPH) and 121 with carcinoma of the prostate. One of these noncompetitive assays measured total PSA by detecting PSA complexed to serine proteinase inhibitors and the noncomplexed molecular form, a second measured only PSA in complex with alpha 1-antichymotrypsin, whereas a third detected the noncomplexed form. PSA in complex with alpha 1-antichymotrypsin was the predominant form in all patient sera. Noncomplexed PSA constituted a minor fraction that was significantly smaller in patients with untreated prostate cancer than in those with BPH (p < 0.0001). The proportion of noncomplexed PSA does not correlate to the serum concentration of PSA or that of alpha 1-antichymotrypsin. In men with a serum PSA concentration of less than 10 micrograms./l. the combination of assays measuring total PSA immunoreactivity, the noncomplexed molecular form and PSA in complex with alpha 1-antichymotrypsin may facilitate discrimination between prostate cancer and BPH.

Protein C inhibitor in human body fluids. Seminal plasma is rich in inhibitor antigen deriving from cells throughout the male reproductive system.

An assay was developed for the measurement of human protein C inhibitor antigen (PCI) in blood plasma and other biological fluids. Both native PCI, modified inhibitor, and complexes of inhibitor with activated protein C or plasma kallikrein could be measured with the assay. Inhibitor antigen concentrations were found to be very high in seminal plasma (greater than 200 mg/liter), more than 40 times the concentration of PCI found in blood plasma. The inhibitor in seminal plasma was unable to form complexes with activated protein C. Gel filtration and immunoblotting findings indicated that the inhibitor in seminal plasma is present in a high molecular mass complex or cleaved to its modified form. As PCI antigen was absent from seminal plasma of patients with dysfunctional seminal vesicles, the seminal vesicle glands would appear to be the major source of seminal plasma PCI, a conclusion supported by immunohistochemical demonstration of the presence of PCI epitopes in the secretory epithelium of the seminal vesicles. Specific PCI immunoreactivity was also shown to be present in the testes, the epididymis glands, and the prostate, suggesting the inhibitor to have a complex or multiple function in the male reproductive system. Conclusive evidence of a local synthesis of PCI in the four male sex glands was provided by Northern blot analysis of RNA from these organs.

Prostate-specific antigen in serum occurs predominantly in complex with alpha 1-antichymotrypsin.

Immunologic measurements of the serum concentration of prostate-specific antigen (PSA), an abundant prostatic-secreted serine proteinase, are frequently used to monitor patients with prostate cancer, though it has not been ascertained whether this immunoreactivity represents a PSA zymogen, the active proteinase, or PSA complexed to extracellular proteinase inhibitors. To characterize the PSA immunoreactivity in serum, we used monoclonal antibodies produced against PSA and a polyclonal rabbit IgG against alpha 1-antichymotrypsin in the design of three noncompetitive PSA assays: assay T, which detected PSA both when present as the active proteinase and when complexed to alpha 1-antichymotrypsin; assay F, which recognized the active proteinase but most poorly detected PSA complexed to alpha 1-antichymotrypsin; and assay C, which was specific for PSA complexed to alpha 1-antichymotrypsin. We used the three assays to measure PSA immunoreactivity in 64 patients' sera and in the effluent after gel chromatography of sera from four patients. This identified an 80- to 90-kDa complex between PSA and alpha 1-antichymotrypsin as the predominant fraction of the PSA immunoreactivity in blood plasma; an immunoreactive 25- to 40-kDa compound was the minor fraction.

In vivo comparative evaluation of hemodialysis tubing plasticized with DEHP and TEHTM.

The migration of plasticizers from blood lines was studied in 11 patients with chronic renal failure on hemodialysis for a period of six months. Di-2-ethylhexylphthalate (DEHP), the conventional plasticizer, was compared with tri-2-ethylhexyltrimellitate (TEHTM). A liquid chromatography method for quantitative determination of DEHP and TEHTM in human blood plasma is described. During treatment with tubing containing DEHP, the plasma level of DEHP rose from 0.10 micrograms/ml (less than 0.05-0.17 n = 11) to 0.70 micrograms/ml (0.30-1.6 n = 11). When the patients were changed to tubing containing TEHTM, the concentration of DEHP was below or close to the detection limit and TEHTM could not be detected. No adverse events of either tubing were found as regards acute toxic effects, performance or applicability.

Enzymatic activity of prostate-specific antigen and its reactions with extracellular serine proteinase inhibitors.

Prostate-specific antigen (PSA) is one of the three most abundant prostatic-secreted proteins in human semen. It is a serine proteinase that, in its primary structure, manifests extensive similarities with that of the Arg-restricted glandular kallikrein-like proteinases. When isolated from semen by the addition of chromatography on aprotinin-Sepharose to a previously described procedure, PSA displayed chymotrypsin-like activity and cleaved semenogelin and the semenogelin-related proteins in a rapid and characteristic pattern, but had no trypsin-like activity. About one third of the purified protein was found to be enzymatically inactive, due to cleavage carboxy-terminal of Lys145. Active PSA formed SDS-stable complexes with alpha 1-antichymotrypsin, alpha 2-macroglobulin-analogue pregnancy zone protein. PSA formed inhibitory complexes with alpha 1-antichymotrypsin at a molar ratio of 1:1, a reaction in which PSA cleaved the inhibitor in a position identical to that reported from the reaction between chymotrypsin and alpha 1-antichymotrypsin. The formation of stable complexes between PSA and alpha 1-antichymotrypsin occurred at a much slower rate than that between chymotrypsin and alpha 1-antichymotrypsin, and at a similar or slightly slower rate than that between PSA and alpha 2-macroglobulin. When added to normal blood plasma in vitro, active PSA formed stable complexes both with alpha 2-macroglobulin and alpha 1-antichymotrypsin. This complex formation may be a crucial determinant of the turnover of active PSA in intercellular fluid or blood plasma in vivo.