A multicentre randomized controlled trial of expectant management versus IVF in women with Fallopian tube patency.

BACKGROUND: Although observational studies suggest that IVF is more effective than no treatment for women with Fallopian tube patency, this has not been tested rigorously in a randomized controlled trial (RCT). METHODS: Eligible consenting couples planning their first treatment cycle in five Canadian fertility clinics received either IVF, within 90 days of randomization, or a period of 90 days with no treatment. Random allocation was stratified by female age and sperm quality, and administered using numbered, opaque, sealed envelopes. Follow-up assessed live birth and associated morbidity. RESULTS: Sixty-eight couples were randomized to a first cycle of IVF and 71 couples had 3 months without treatment. The live birth rates were 20/68 (29%) and 1/71 (1%), respectively. The single delivery in the untreated group was of twins, as were six of the 20 IVF deliveries (30%). An average of 2.0 embryos were transferred and no triplet pregnancies resulted. The relative likelihood of delivery after allocation to IVF was 20.9-fold higher than after allocation to no treatment [95% confidence interval (CI) 2.8-155]. The presence of abnormal sperm did not reduce this likelihood. Treating four women (95% CI 3-6) with one cycle of IVF is required to achieve a single additional birth. CONCLUSIONS: This study provides a valid and up-to-date comparison for policy makers and patients as they make choices around IVF, accurately measuring and confirming a major benefit from treatment.

Characterising doctor-parent communication in counselling for impending preterm delivery.

OBJECTIVE: To examine the counselling of women admitted to hospital in preterm labour. Such women and their partners are often asked to participate in difficult decisions including mode of delivery, fetal monitoring, and resuscitation. STUDY DESIGN: Questionnaire based descriptive study. STUDY SETTING: A tertiary level perinatal referral centre. PATIENTS: Forty-nine women in preterm labour at 22-30 weeks gestation, admitted in two separate periods between March 1997 and May 1999. INTERVENTION AND OUTCOME MEASURE: Within 24 hours of counselling, parents were asked to complete a questionnaire assessing recall of the management plan, desire for involvement in decision making, anxiety, and feelings of control over their health. A parallel questionnaire was completed by the clinicians. RESULTS: Parents and clinicians on recall agreed well about obstetric issues but poorly about neonatal issues. Overall 27% of parents felt: "I would prefer to have the doctors advise me, rather than asking me to decide". In 79% of cases, clinicians believed parents preferred advice rather than to make decisions, but in 45% of these, they misidentified those who wished to make their decisions. Anxiety levels for one third of the mothers were high, and associated with poorer concordance of recall between parents and clinicians. CONCLUSIONS: Serious deficiencies exist in parent-clinician encounters during extremely preterm labour. Concordance between parents and clinicians is poor and anxiety very high. A quarter of parents appear to prefer to relinquish decision making autonomy, but clinicians cannot correctly identify this subgroup. Standardised counselling in the perinatal period, using formal decision aids, should be investigated.

Chemokine RANTES promoter polymorphism affects risk of both HIV infection and disease progression in the Multicenter AIDS Cohort Study.

OBJECTIVE: To examine whether polymorphism in the RANTES gene is associated with HIV disease outcome. DESIGN: RANTES, a ligand of the major HIV co-receptor, CCR5, is known to block HIV-CCR5 interactions. Recently, two single nucleotide polymorphisms in the RANTES gene promoter region, designated -403G/A and -28C/G, have been described. Both polymorphisms can affect in-vitro promoter activity, and the RANTES -403A, -28G haplotype has been associated with a slower CD4 cell count decline rate in a Japanese cohort. METHODS: We compared RANTES compound genotype frequencies between HIV-positive and exposed-uninfected participants of the Multicenter AIDS Cohort Study (MACS) and rates of progression to AIDS for MACS seroconverters. RESULTS: We found that the two most common RANTES promoter compound genotypes, G1 (-403G/G, -28C/C) found in 67% of Caucasians, and G4 (-403G/A, -28C/C) found in 23% of Caucasians, were associated with altered risk of HIV transmission and progression, particularly in individuals who lacked the protective CCR5 mutation, CCR5delta32. In this study, individuals with a G4 compound genotype were more likely to acquire HIV than individuals with a G1 compound genotype (OR 1.72, P = 0.016) and the risk increased when individuals possessing CCR5delta32 were omitted from consideration (OR 2.13, P = 0.005). Among seroconverters lacking CCR5delta32, those who had the G4 compound genotype progressed significantly slower to AIDS-1993 than those with the G1 compound genotype (median time to AIDS 7.6 versus 5.4 years; RH 0.65; P = 0.007). CONCLUSIONS: These data implicate the RANTES-403A allele as a risk factor for HIV transmission and as a protective factor for HIV progression.

Albumin-corrected calcium and ionized calcium in stable haemodialysis patients.

BACKGROUND: It is ionized calcium that is physiologically active and under homeostatic control; however, total calcium is more conveniently measured. Formulae for correction of calcium to account for albumin binding have not been validated in a dialysis setting. METHODS: We measured ionized calcium simultaneously with total calcium (t[Ca]), albumin, total protein and pH before dialysis in 50 stable outpatients and convalescent inpatients. RESULTS: Although 92% of patients were taking calcium supplements and 70% taking alphacalcidol, 11 patients (22%) had ionized hypocalcaemia. To facilitate comparison of calculated ionized calcium, measured total calcium (t[Ca]), and 'corrected' calcium (c[Ca]), with the criterion measure of ionized calcium, all measurements were converted to z scores, standardized on the normal range for each variable. Results are expressed as intraclass correlation coefficients (ICC: 0, all differences are due to error; 1, all differences are due to between patient variation). CONCLUSIONS: None of the published formulae greatly improved the test characteristics beyond simply using the total calcium. A correction formula in widespread use (Payne), quoted in reference texts, agreed less well with ionized calcium than did the unadjusted measured calcium. Correction formulae should be abandoned in favour of the use of uncorrected calcium. In cases of doubt, ionized calcium should be directly measured.

Randomized trial of a "stage-of-change" oriented smoking cessation intervention in infertile and pregnant women.

OBJECTIVE: To assess a "stage-of-change" oriented smoking cessation intervention for infertile and pregnant women, compared with standard of care. DESIGN: Randomized controlled trial. SETTING: Three university teaching hospitals in Hamilton, Ontario, Canada. PATIENT(S): Infertile women at their first visit to a tertiary referral infertility clinic (n = 94) and new patients seeking pre-natal care (n = 110) who had smoked >/= 3 cigarettes in the past six months. INTERVENTION(S): A three to five minute scripted intervention and booklet specific to the woman's "stage-of-change" in the smoking continuum, versus standard of care. Exhaled carbon-monoxide (CO) monitoring was used to validate exposure in both groups. MAIN OUTCOME MEASURE(S): Delta "stage-of-change" and rate of maintained cessation at 12 months post follow-up. RESULT(S): Intervention and control were similarly effective for infertile women: the rate of maintained cessation rose significantly from 4% to 24% over twelve months, with a mean delta "stage-of-change" 0.28. In prenatal women, neither approach was effective. Maintained cessation did not significantly change from 0 to 12 months (19% to 18%). Mean delta "stage-of-change" declined by -0.62. CONCLUSION(S): For infertile women, basic information describing the impact of smoking on fertility, along with exhaled CO monitoring and a more intensive intervention were both highly effective. In pregnant women neither approach was beneficial, with some evidence of post-partum relapse.

Acyclophostin: a ribose-modified analog of adenophostin A with high affinity for inositol 1,4,5-trisphosphate receptors and pH-dependent efficacy.

Adenophostin A is the most potent known agonist of D-myo-inositol 1, 4,5-trisphosphate [Ins(1,4,5)P3] receptors. Equilibrium competition binding studies with 3H-Ins(1,4,5)P3 showed that the interaction of a totally synthetic adenophostin A with both hepatic and cerebellar Ins(1,4,5)P3 receptors was indistinguishable from that of the natural product. At pH 8.3, a synthetic analog of adenophostin A (which we named acyclophostin), in which most elements of the ribose ring have been removed, bound with substantially higher affinity (Kd = 2.76 +/- 0.26 nM) than Ins(1,4,5)P3 (Kd = 7.96 +/- 1.02 nM) to the 3H-Ins(1,4,5)P3-binding sites of hepatic membranes. At pH 7, acyclophostin (EC50 = 209 +/- 12 nM) and Ins(1,4,5)P3 (EC50 = 153 +/- 11 nM) stimulated 45Ca++ release to the same maximal extent and from the same intracellular stores of permeabilized hepatocytes. Comparison of the affinities of a range of Ins(1,4,5)P3 and adenophostin analogs with their abilities to stimulate Ca++ release revealed that although all other agonists had similar EC50/Kd ratios, that for acyclophostin was significantly higher. Similar results were obtained with cerebellar membranes, which express almost entirely type 1 InsP3 receptors. When the radioligand binding and functional assays of hepatocytes were performed under identical conditions, the higher EC50/Kd ratio for acyclophostin was retained at pH 8.3, but it was similar to that for Ins(1,4,5)P3 when the assays were performed at pH 7. To directly assess whether acyclophostin was a partial agonist of hepatic Ins(1,4,5)P3 receptors, the kinetics of 45Ca++ efflux from permeabilized hepatocytes was measured with a temporal resolution of 80 ms using rapid superfusion. At pH 7, the kinetics of 45Ca++ release, including the maximal rate of release, evoked by maximal concentrations of acyclophostin or Ins(1,4,5)P3 were indistinguishable. At pH 8.3, however, the maximal rate of 45Ca++ release evoked by a supramaximal concentration of acyclophostin was only 69 +/- 7% of that evoked by Ins(1,4,5)P3. We conclude that acyclophostin is the highest affinity ribose-modified analog of adenophostin so far synthesized, that at high pH it is a partial agonist of inositol trisphosphate receptors, and that it may provide a structure from which to develop high-affinity antagonists of inositol trisphosphate receptors.

Lysine: N6-hydroxylase: stability and interaction with ligands.

Recombinant lysine:N6-hydroxylase, rIucD, which is isolated as an apoenzyme, requires FAD and NADPH for its catalytic function. rIucD preparations have been found to undergo time-dependent loss in monooxygenase function due to aggregation from the initial tetrameric state to a polytetrameric form(s), a process which is reversible by treatment with thiols. Ligand-induced conformational changes in rIucD were assessed by monitoring its CD spectra, DSC profile, and susceptibility to both endo- as well as exopeptidases. The first two methods indicated the absence of any significant conformational change in rIucD, while the last approach revealed that FAD, and its analog ADP, can protect the protein from the deleterious action of proteases. NADPH was partially effective and L-lysine was ineffective in this regard. Deletion of the C-terminal segment, either by treatment with carboxypeptidase Y or by mutagenesis of iucD, results in the loss of rIucD's monooxygenase activity. These findings demonstrate the crucial role of the C-terminal segment in maintaining rIucD in its native conformation.

Luminal Ca2+ regulates passive Ca2+ efflux from the intracellular stores of hepatocytes.

Ca2+ uptake into the intracellular stores of permeabilized hepatocytes was entirely dependent on ATP and substantially inhibited by either ionomycin or thapsigargin, although both were required for complete inhibition. Unidirectional efflux of 45Ca2+ after removal of ATP from cells loaded to steady state (1.60+/-0.12 nmol/10(6) cells) was monoexponential and occurred with a half-time of 103+/-10 s. However, the 45Ca2+ content of the stores did not return to their pre-ATP level, but reached a plateau at 0.12+/-0.04 nmol/10(6) cells. A similar amount of Ca2+ was trapped within the stores when Ca2+ uptake was prevented by thapsigargin and chelation of Ca2+; at all temperatures between 2 degreesC and 37 degreesC; and after stores had first been loaded with unlabelled Ca2+. Simultaneous addition of inositol 1,4,5-trisphosphate (InsP3) and inhibition of Ca2+ uptake reduced the amount of trapped Ca2+ to a level consistent with InsP3 rapidly and more completely emptying a fraction of the stores that could be only partially emptied by the passive leak. After dilution of the specific activity of the 45Ca2+ under conditions that maintained the steady-state activities of the pumps and leaks, the stores rapidly lost their entire 45Ca2+ content. We conclude that the channel responsible for mediating the leak of Ca2+ abruptly closes when the luminal [Ca2+] of the intracellular stores falls below a critical threshold corresponding to about 7% of their steady-state loading. Whereas InsP3 is capable of completely emptying a fraction of the stores, regulation of the passive leak by luminal [Ca2+] is likely to prevent it from completely emptying them; such regulation may ensure that the many other functions of Ca2+ within the endoplasmic reticulum are not compromised.

Disaccharide polyphosphates based upon adenophostin A activate hepatic D-myo-inositol 1,4,5-trisphosphate receptors.

The glyconucleotides adenophostin A and B are the most potent known agonists at type 1 inositol trisphosphate [Ins(1,4,5)P3] receptors, although their stuctures differ markedly from that of Ins(1,4,5)P3. Equilibrium competition binding with [3H]Ins(1,4,5)P3 and unidirectional 45Ca2+ flux measurements were used to examine the effects of adenophostin A in hepatocytes, which express predominantly type 2 Ins(1,4,5)P3 receptors. Both Ins(1,4,5)P3 (Kd = 8.65 +/- 0.98 nM) and adenophostin A (Kd = 0.87 +/- 0.20 nM) bound to a single class of [3H]Ins(1,4,5)P3-binding site and each fully mobilized the same intracellular Ca2+ pool; although, adenophostin A (EC50 = 10.9 +/- 0.7 nM) was more potent than Ins(1,4,5)P3 (EC50 = 153 +/- 11 nM). Working on the assumption that it is the phosphorylated glucose component of the adenophostins that mimics the critical features of Ins(1,4,5)P3, we synthesized various phosphorylated disaccharide analogs containing this structure. The novel disaccharide-based analogs, sucrose 3,4,3'-trisphosphate [Sucr(3,4,3')P3], alpha,alpha'-trehalose 3,4,3',4'-tetrakisphosphate [Trehal(3,4,3',4')P4], alpha,alpha'-trehalose 2,4,3', 4'-tetrakisphosphate [Trehal(2,4,3',4')P4], and methyl 3-O-(alpha-d-glucopyranosyl)-beta-d-ribofuranoside 2,3', 4'-trisphosphate [Rib(2,3',4')P3], were all able to mobilize the same intracellular Ca2+ pool as Ins(1,4,5)P3 and adenophostin A; although, none was as potent as adenophostin A. The rank order of potency of the analogs, adenophostin A > Ins(1,4,5)P3 approximately Rib(2,3',4')P3 > Trehal(2,4,3',4')P4 > Glc(2',3,4)P3 approximately Trehal(3,4,3',4')P4 > Sucr(3,4,3')P3, was the same in radioligand binding and functional assays of hepatic Ins(1,4,5)P3 receptors. Both Rib(2,3',4')P3, which was as potent as Ins(1,4,5)P3, and Trehal(2,4,3',4')P4 bound with significantly higher affinity ( approximately 27 and approximately 3-fold, respectively) than the only active carbohydrate agonist of Ins(1,4,5)P3 receptors previously examined [Glc(2',3,4)P3]. We conclude that phosphorylated disaccharides provide novel means of developing high-affinity ligands of Ins(1,4,5)P3 receptors.

Incremental Ca2+ mobilization by inositol trisphosphate receptors is unlikely to be mediated by their desensitization or regulation by luminal or cytosolic Ca2+.

The kinetics of Ins(1,4,5)P3 (InsP3)-stimulated Ca2+ release from intracellular stores are unusual in that submaximal concentrations of InsP3 rapidly release only a fraction of the InsP3-sensitive Ca2+ stores. By measuring unidirectional 45Ca2+ efflux from permeabilized rat hepatocytes, we demonstrate that such quantal responses to InsP3 occur at all temperatures between 2 and 37 degrees C, but at much lower rates at the lower temperatures. Preincubation with submaximal concentrations of InsP3, which themselves evoked quantal Ca2+ release, had no effect on the sensitivity of the stores to further additions of InsP3. The final Ca2+ content of the stores was the same whether they were stimulated with two submaximal doses of InsP3 or a single addition of the sum of these doses. Such incremental responses and the persistence of quantal behaviour at 2 degrees C indicate that InsP3-evoked receptor inactivation is unlikely to be the cause of quantal Ca2+ mobilization. Reducing the Ca2+ content of the intracellular stores by up to 45% did not affect their sensitivity to InsP3, but substantially reduced the time taken for each submaximal InsP3 concentration to exert its full effect. These results suggest that neither luminal nor cytosolic Ca2+ regulation of InsP3 receptors are the determinants of quantal behaviour. Our results are not therefore consistent with incremental responses to InsP3 depending on mechanisms involving attenuation of InsP3 receptor function by cytosolic or luminal Ca2+ or by InsP3 binding itself. We conclude that incremental activation of Ca2+ release results from all-or-nothing emptying of stores with heterogeneous sensitivities to InsP3. These characteristics allow rapid graded recruitment of InsP3-sensitive Ca2+ stores as the cytosolic InsP3 concentration increases.

Cost analysis of dialysis treatments for end-stage renal disease (ESRD).

The cost of alternative dialysis modalities for the treatment of end-stage renal disease (ESRD) was evaluated, using a societal viewpoint, in a regional nephrology program in south-western Ontario. The dialysis treatments compared were hospital hemodialysis, home hemodialysis, self-care hemodialysis, and continuous ambulatory peritoneal dialysis (CAPD). The participants were all patients treated by the same dialysis modality for the fiscal year April 1990 to March 1991. Fully allocated costs are expressed in 1993 Canadian dollars. The average costs per patient year were $88,585 for hospital hemodialysis, $55,593 for self-care hemodialysis, $44,790 for CAPD, and $32,570 for home hemodialysis. The dialysis treatment costs were $54,929 for hospital hemodialysis, $43,313 for self-care hemodialysis, $31,918 for CAPD, and $26,048 for home hemodialysis. These data quantify the magnitude of the differences between fully-allocated costs among the dialysis modalities in a regional nephrology program in Canada. The methodology used in this economic analysis can be applied to programs which differ in structure and scale. The breakdown of dialysis treatment costs into overhead, support department, personnel, supplies, and medication identifies potential areas for cost reduction strategies.

Effect of recombinant human erythropoietin on hospitalization of hemodialysis patients.

The effect of recombinant human erythropoietin (EPO) on hospitalization of patients with end-stage renal disease (ESRD) was evaluated in a controlled clinical trial. A cohort of 67 new hemodialysis patients prescribed EPO shortly after the clinical availability of EPO were the treatment group. The control group was a cohort of 67 new hemodialysis patients matched for clinical center, age, cardiovascular disease and transfusion history. These patients had not been prescribed EPO as they had started hemodialysis prior to the clinical availability of EPO. There were 21 pairs without hospitalization and 46 pairs with at least 1 member of the pair experiencing hospitalization. Among the latter group, the median follow-up was 174 and 184 days for the EPO and control patients respectively. For all hospitalizations, those treated with EPO were hospitalized 15.3 days per year compared to 23.2 days for the control patients. The difference (EPO-control) was -7.9 days (95% CI: -21.0; 7.8) for all cause hospitalization. For hospitalizations due to cardiac, infectious disease and gastrointestinal disease, the differences were 1.6, 1.8 and 1.2 days favouring EPO treated patients. For hospitalizations related to vascular access complications, the difference was 0.9 days favoring the control group. All other causes favoured EPO treated patients by 4 days. There had been 58 hospitalizations in the EPO group compared to 97 in the control group. The mean duration of hospitalization was 8.0 days for the EPO and 9.6 for the control group. The direction and magnitude of the change in all cause hospitalization represents an improvement in morbidity and an important decrease in health resource utilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Participatory control in chronic hospital-based hemodialysis patients.

The purpose of this study was to determine chronic hospital-based hemodialysis patients' perceptions of control over selected aspects of hemodialysis care and to compare the patients' ratings with the global ratings of nurses caring for them. Two versions of a 14-item Hemodialysis Control Questionnaire (HCQ) were developed, one for patients (HCQ-P) and one for nurses (HCQ-N). Forty-seven patients and 32 nurses rated both perceived and desired control for each aspect of hemodialysis care on the HCQ. Reasons for their ratings were elicited and recorded. High test-retest reliability was established for both perceived and desired control on the HCQ-P and the desired control component of the HCQ-N. Patients rated their overall perceived and desired control as moderate, likewise the nurses' global score for desired control was rated as moderate. Item-by-item analysis revealed that nurses overestimated the patients' desired control over technical aspects of care but underestimated the patients' desire for more control over nontechnical aspects of care. The content analysis of the verbatim responses supported the quantitative findings.

Probability of thrombosis of vascular access among hemodialysis patients treated with recombinant human erythropoietin.

The objective was to evaluate the effect of the treatment of anemia with recombinant human erythropoietin (EPO) on thrombosis of the vascular access used for hemodialysis. The research design was a prospective cohort study comparing EPO-treated hemodialysis patients with a comparison group matched for type of vascular access, clinical center, and age. All patients commencing hemodialysis in the study centers between March 1988 and July 1991 were eligible if either a graft or fistula had been used as a first permanent vascular access. There were 64 matched fistula pairs and 38 matched graft pairs. There were more patients with a history of cardiovascular disease in the EPO group than in the comparison group for both fistulae and grafts, 34 versus 14% for the former and 37 versus 5% for the latter. There was no difference between EPO and comparison groups with respect to time to first thrombosis of fistula, 11.3 versus 10.6%, respectively, by thrombosis of grafts among those treated with EPO--33.6 versus 11.2% (P = 0.02). EPO treatment does not increase the probability of fistula thrombosis, but there is an association with an increased probability of graft thrombosis.

Effect of high-flux hemodialysis on cardiac structure and function among patients with end-stage renal failure.

The effect of high flux hemodialysis on left ventricular function in ESRD patients was evaluated in a double blind, single cross-over, study comparing conventional to high flux hemodialysis. The subjects were 21 stable chronic hemodialysis patients. Ten were randomly allocated to the conventional-high flux sequence and 11 to the reverse sequence. The conventional membrane was the CD 3,500 or 4,000; the high flux membrane was the Duoflux (Althin Medical Inc., Miami Lakes, Fla.). Both were cellulose acetate and both were sterilized with ethylene oxide. The dialysate bicarbonate and sodium were held constant for the study. The ultrafiltration rates were 3.5-5.0 ml/h/mm Hg transmembrane pressure for the conventional and 15 ml/h/mm for the high flux membrane. The beta-2-microglobulin sieving coefficient was 0 for conventional and 0.27 for the high-flux membrane. The modest improvements in estimates of systolic function suggest a cardiac advantage in high-flux dialysis, the clinical impact of which requires further study.

The quality of life in renal transplantation--a prospective study.

Methodologically sound measures of quality of life are required to judge accurately the impact of successful renal transplantation on patient well-being. The time trade-off (TTO) method is a reproducible and valid measure which we used to prospectively assess changes in the quality of life of 27 patients on maintenance dialysis who subsequently underwent renal transplantation. TTO scores approaching 0 signify a very poor quality of life, while scores approaching 1 represent perfect health. Of 98 dialysis patients who completed baseline TTO interviews, 31 consecutive patients subsequently received 28 cadaveric and 3 living related kidney transplants. Four of 31 patients did not complete a second TTO assessment, because of death in 2 patients and graft loss in 2 others. The remaining 27 patients completed a second TTO interview an average of 30.9 months following transplantation (range 1.5-52, 95% confidence interval [CI] 24.4-37.5) and formed the study cohort. At the time of study the mean serum creatinine for the cohort was 173 mumol/L (range 90-290, 95% CI 152-195 mumol/L). The employment rate rose 27% following transplantation (P = 0.10); but when males alone were analyzed, a significant increase of 38% (P = 0.048) was noted. During the dialysis period, the mean baseline TTO score was 0.41 (95% CI 0.33-0.49), confirming the observations of others. Following transplantation, the mean TTO score rose to 0.74 (95% CI 0.67-0.81), a difference that is statistically significant (P < 0.001). The mean increase in TTO score observed as a result of successful transplantation was 0.33 (95% CI 0.26-0.40). This magnitude of improvement was found in 20 of 27 patients (74%), whose TTO scores lay within or above the 95% CI (0.26-0.40) for the mean change in score of 0.33. One patient's score fell, while the remaining 6 patients had improvements in their TTO score which fell below the lower 95% CI value (0.26) for the mean change in score. We conclude that the 95% CI of 0.26-0.40 identifies a range in which clinically important improvements in quality of life will be found for the majority of patients receiving successful kidney transplants.

The natural history of asymptomatic urolithiasis.

An inception cohort of 107 patients was reviewed to establish the natural history of asymptomatic urolithiasis. With an over-all mean followup of 31.6 months, 73 patients (68.2%) remained asymptomatic and were censored at the time of the last clinical visit. A symptomatic event developed in 34 patients (31.8%). Spontaneous passage occurred in 16 patients (15.0%), endoureteral removal was done in 6 (5.6%), percutaneous nephrostolithotomy was done in 3 (2.8%) and 9 (8.4%) were referred for therapeutic lithotripsy. Cumulative 5-year probability of a symptomatic event developing was 48.5%. A linear association was identified between the development of a symptomatic event and the number of previous stones as well as the number of asymptomatic stones at identification. A significant burden of illness is associated with an expectant strategy as an approach to asymptomatic urolithiasis. Of the patients who had a symptomatic event 47% had spontaneous stone passage, while 26.5% required urological intervention and 26.5% were referred for therapeutic lithotripsy. Prophylactic extracorporeal shock wave lithotripsy, although often advocated, has associated risks and is not always a benign procedure. A randomized controlled trial is required to evaluate properly the role of prophylactic lithotripsy versus an expectant strategy.

Effect of high-flux hemodialysis on quality of life and neuropsychological function in chronic hemodialysis patients.

The objective was to evaluate the effect of high-flux hemodialysis on quality of life, intra- and interdialytic symptoms and neuropsychological function. The study was double-blind single cross-over with random allocation to order of treatment. The patients were stable adult hospital hemodialysis patients. Both the conventional and high-flux membranes were cellulose acetate, the dialysate was bicarbonate, and dialysate sodium was held constant. The high-flux membrane had an ultrafiltration rate of 15 ml/h/mm Hg transmembrane pressure, a B12 clearance of 88 ml/min and a beta 2-microglobulin clearance of 11.4 ml/min. The values of the conventional membrane were 3.5-5.0, 34-45 and negligible. Each treatment period was 4 months. Twenty-two patients completed both phases of the cross-over. The KT/V value was higher during high-flux than conventional treatment; 1.42 versus 1.27(p < 0.05). There were no differences between high-flux and conventional treatment with respect to quality of life. Symptoms during dialysis were less severe during high-flux than conventional treatment for 12/14 items. Only 3 items reached statistical significance (0.05 > p > 0.01) and none were clinically significant. Symptoms between dialyses were less severe during high-flux than conventional treatment for 18/20 items. No single item had a statistically significant improvement but 3 had clinically important improvement. Among the 23 neuropsychological variables, none demonstrated statistically significant changes.

A comparison of evaluative indices of quality of life and cognitive function in hemodialysis patients.

In the setting of end-stage renal disease, the reproducibility and responsiveness of three health-related quality-of-life instruments were evaluated. The Time Trade Off instrument (TTO) is a generic instrument used to evaluate the utility of a health state. The Hemodialysis Quality-of-Life questionnaire (HQL) is a disease-specific instrument. A series of function-specific tests evaluated neurocognitive function. The TTO and HQL instruments are patient centric in that patient values define the health status while the neurocognitive function tests reflect the values of healthcare professionals. Forty-seven chronic hemodialysis patients participated. Those with adequate dialysis, defined as a Kt/V (a measure of small solute removal during hemodialysis) above 1.0 were maintained at the level for two administrations of the three instruments separated by six to eight weeks. The test-retest intraclass correlation coefficient exceeded 0.90 for all five domains of the HQL questionnaire and exceeded 0.70 for nine neurocognitive function tests. Patients with inadequate dialysis (Kt/V less than 0.8) had Kt/V increased to above 1.0. The TTO was not responsive. For the HQL questionnaire, an item was considered responsive if a 1-point improvement, on a 7-point Likert type scale, occurred significantly more often among those with an improvement in hemodialysis treatment compared to those without improvement. Only one item had such a change and therefore the HQL cannot be considered responsive.(ABSTRACT TRUNCATED AT 250 WORDS)

Dialyzer re-use--a multiple crossover study with random allocation to order of treatment.

A multiple crossover research study was used to evaluate the effect of dialyzer re-use on fever, blood leaks, serum urea and creatinine values and symptoms. Each of 6 crossover periods consisted of 4 weeks on either single-use or re-use, 1 week washout, 4 weeks on the alternative treatment and 1 week washout. The re-use consisted of 6 uses of each dialyzer and the washout weeks consisted of 3 single-use sessions. Analysis of paired observations within rather than between patients showed no effects of time (i.e. among crossover periods 1 through 6) or number of re-uses (i.e. among uses 1 through 6). There was no significant difference for temperature change during dialysis, blood leak rate, or the serum urea and creatinine values before the first dialysis of each washout period. There were no differences for symptoms of pruritus, cramps, nausea, headache, chest pain, backache or fatigue. There were no clinical advantages or disadvantages associated with dialyzer re-use.