Outcome in children receiving continuous venovenous hemofiltration

OBJECTIVE

Continuous venovenous hemofiltration (CVVH) alone or with dialysis (D) has become an important supportive therapy for critically ill children with acute renal failure. Previous reports of pediatric patient outcome either mix CVVH/D with other renal replacement modalities or do not examine severity of illness. The current study examines only outcomes of children receiving CVVH/D using Pediatric Risk of Mortality (PRISM) scores to control for severity of illness.

PATIENTS

Twenty-one patients (mean age: 8.8 +/- 6.3 years; mean weight: 28.3 +/- 20.8 kg) received 22 courses of CVVH/D.

OUTCOMES

Nine (42.8%) of 21 patients survived. Nine (75%) of 12 deaths occurred within 25 days of pediatric intensive care unit (PICU) admission. Mean PRISM score at PICU admission and CVVH initiation were 13.1 +/- 5.8 and 15.4 +/- 8.9, respectively. Mean patient weight, age, PRISM score at PICU admission and at CVVH/D initiation, maximum pressor number, estimated glomerular filtration rate at CVVH/D initiation and change in mean airway pressure did not differ between survivors and nonsurvivors. The degree of fluid overload at CVVH/D initiation was significantly lower in survivors (16.4% +/- 13.8%) compared with nonsurvivors (34.0% +/- 21.0%), even when controlled for severity of illness by PRISM score. Mean cost of providing CVVH/D accounted for only 1% of total PICU cost per patient.

CONCLUSIONS

The pattern of early multiorgan system failure and death, minimal relative cost of CVVH/D provision, and potential for improved outcome with initiation of CVVH/D at lesser degrees of fluid overload are factors that may support early initiation of CVVH/D in critically ill children with acute renal failure.

Hemolytic-uremic syndrome during an outbreak of Escherichia coli O157:H7 infections in institutions for mentally retarded persons: clinical and epidemiologic observations

PURPOSE

To describe an outbreak of Escherichia coli O175:H7 infection resulting in a high rate of progression to hemolytic-uremic syndrome, and to attempt to identify predictors of and risk factors for progression.

DESIGN

Case-control study among employees and comparison of daily clinical features in two groups: infected residents with subsequent development of HUS and those who had no complications.

SETTING

Two institutions for retarded persons in Utah.

PATIENTS

Twenty residents with E. coli O157:H7 infection (13 culture confirmed, 2 probable, and 5 possible); HUS developed in 8, and 4 died. Thirty-one infected employees (3 with culture-confirmed, 6 with probable, and 22 with possible infection).

MEASUREMENTS AND MAIN RESULTS

In a case-control study among employees, infection was independently associated with eating ground beef from a single lot prepared at several barbecues and with close contact with a resident who had diarrhea. Five of eight residents in whom HUS developed had received trimethoprim-sulfamethoxazole, compared with none of seven who had no subsequent complications (p = 0.026); this finding may reflect antimicrobial treatment of patients with more severe illness. Compared with infected residents without complications, persons with HUS were younger (median age 13 vs 27 years, p = 0.043) and, by the third day of illness, had higher leukocyte counts (median 23.7 X 10(9)/L vs 9.1 X 10(9)/L, p = 0.018) and temperature (median 38.5 degrees C vs 37.0 degrees C, p = 0.016). Leukocytosis peaked on day 4, more than 24 hours before signs of HUS appeared.

CONCLUSIONS

Food-borne outbreaks of E. coli O157:H7 in institutions may have devastating effects. Leukocytosis and fever may precede and predict HUS in patients with E. coli O157:H7 infection.

Kidney and pancreas transplantation in the United States, 1999-2008: the changing face of living donation

The waiting list for kidney transplantation continued to grow between 1999 and 2008, from 41 177 to 76 089 candidates. However, active candidates represented the minority of this increase (36 951-50 624, a 37% change), while inactive candidates increased over 500% (4226-25 465). There were 5966 living donor (LD) and 10 551 deceased donor (DD) kidney transplants performed in 2008. The total number of pancreas transplants peaked at 1484 in 2004 and has declined to 1273. Although the number of LD transplants increased by 26% from 1999 to 2008, the total number peaked in 2004 at 6647 before declining 10% by 2008. The rate of LD transplantation continues to vary significantly as a function of demographic and geographic factors, including waiting time for DD transplant. Posttransplant survival remains excellent, and there appears to be greater use of induction agents and reduced use of corticosteroids in LD recipients. Significant changes occurred in the pediatric population, with a dramatic reduction in the use of LD organs after passage of the Share 35 rule. Many strategies have been adopted to reverse the decline in LD transplant rates for all age groups, including expansion of kidney paired donation, adoption of laparoscopic donor nephrectomy and use of incompatible LD.

Early initiation of peritoneal dialysis after surgical repair of congenital heart disease

The mortality rate of infants who require renal replacement therapy after surgical repair of congenital heart disease has been reported to be 30%-79%. We report our experience with early initiation of continuous manual peritoneal dialysis (CPD) to treat fluid overload in 20 consecutive critically ill children who underwent CPD post cardiotomy. CPD catheters were inserted at the discretion of the cardiothoracic surgeon. CPD was started for evidence of total body fluid overload with inadequate urine output, and stopped when negative fluid balance was achieved and urine output improved. Median age was 10 days (range 3-186 days), mean time to start CPD post-operatively was 22 h (range 5-40 h), and mean duration of CPD was 50 h (range 13-92 h). CPD resulted in mean ultrafiltration of 93 ml/kg per day (range 43-233 ml/kg per day). Net negative fluid balance was 106 ml/kg per day (range 49-273 ml/kg per day). During CPD, the mean number of inotropes decreased from 2.2 to 1.6 (P<0.05) and urine output increased from 2.2 to 3.9 ml/kg per hour (P<0.01). No patient died during CPD or had CPD discontinued due to adverse hemodynamic effects. The overall mortality rate was 20%. We conclude that early initiation of CPD can safely and effectively promote fluid removal in infants after repair of congenital heart disease, with a lower mortality rate than has previously been reported.

Global, regional, and national sex-specific burden and control of the HIV epidemic, 1990-2019, for 204 countries and territories: the Global Burden of Diseases Study 2019

BACKGROUND

The sustainable development goals (SDGs) aim to end HIV/AIDS as a public health threat by 2030. Understanding the current state of the HIV epidemic and its change over time is essential to this effort. This study assesses the current sex-specific HIV burden in 204 countries and territories and measures progress in the control of the epidemic.

METHODS

To estimate age-specific and sex-specific trends in 48 of 204 countries, we extended the Estimation and Projection Package Age-Sex Model to also implement the spectrum paediatric model. We used this model in cases where age and sex specific HIV-seroprevalence surveys and antenatal care-clinic sentinel surveillance data were available. For the remaining 156 of 204 locations, we developed a cohort-incidence bias adjustment to derive incidence as a function of cause-of-death data from vital registration systems. The incidence was input to a custom Spectrum model. To assess progress, we measured the percentage change in incident cases and deaths between 2010 and 2019 (threshold >75% decline), the ratio of incident cases to number of people living with HIV (incidence-to-prevalence ratio threshold <0·03), and the ratio of incident cases to deaths (incidence-to-mortality ratio threshold <1·0).

FINDINGS

In 2019, there were 36·8 million (95% uncertainty interval [UI] 35·1-38·9) people living with HIV worldwide. There were 0·84 males (95% UI 0·78-0·91) per female living with HIV in 2019, 0·99 male infections (0·91-1·10) for every female infection, and 1·02 male deaths (0·95-1·10) per female death. Global progress in incident cases and deaths between 2010 and 2019 was driven by sub-Saharan Africa (with a 28·52% decrease in incident cases, 95% UI 19·58-35·43, and a 39·66% decrease in deaths, 36·49-42·36). Elsewhere, the incidence remained stable or increased, whereas deaths generally decreased. In 2019, the global incidence-to-prevalence ratio was 0·05 (95% UI 0·05-0·06) and the global incidence-to-mortality ratio was 1·94 (1·76-2·12). No regions met suggested thresholds for progress.

INTERPRETATION

Sub-Saharan Africa had both the highest HIV burden and the greatest progress between 1990 and 2019. The number of incident cases and deaths in males and females approached parity in 2019, although there remained more females with HIV than males with HIV. Globally, the HIV epidemic is far from the UNAIDS benchmarks on progress metrics.

FUNDING

The Bill & Melinda Gates Foundation, the National Institute of Mental Health of the US National Institutes of Health (NIH), and the National Institute on Aging of the NIH.

Comparison of tolmetin sodium and aspirin in the treatment of juvenile rheumatoid arthritis

The Pediatric Rheumatology Collaborative Study Group was established in 1973 to undertake systematic trials of new drugs in the treatment of juvenile rheumatoid arthritis. The first drug evaluated was tolmetin (1-methyl-5-p-toluoylpyrrole-2 acetic acid), a new nonsteroid anti-inflammatory agent. A four-week open trial with 30 patients and a subsequent 12-week double-blind trial against aspirin with 107 patients were conducted. Tolmetin and aspirin had equal anti-inflammatory and analgesic effects in the treatment of JRA. Elevations of transaminase values attributed to aspirin were not found with tolmetin. Adverse effects accompanying administration of tolmetin did not appear to be of major clinical significance.

Modulation of growth factors by growth hormone in children with chronic renal failure. The Southwest Pediatric Nephrology Study Group

Anthropometric measurements and circulating growth factors were studied serially in 44 prepubertal children with growth failure and chronic renal failure (GFR = 10 to 40 ml/min/1.73 m2) who were randomized to receive either recombinant human growth hormone (rhGH; N = 30) or no treatment (N = 14). RhGH was given as Nutropin, 0.05 mg/kg/day, and the studies were carried out at baseline and after 3 and 12 months. At baseline, serum insulin-like growth factor binding protein (IGFBP)-1 and -2 levels were, while IGFBP-3 levels were not, higher than those of children with normal renal function. In addition, height SDS at baseline correlated inversely with serum IGFBP-2 levels (r = -0.461, P = 0.0016), but did not correlate significantly with any other factor. After 12 months of study, the 30 children receiving rhGH showed: (i) greater increase in height (9.1 +/- 2.8 vs. 5.5 +/- 1.9 cm, P < 0.0001); (ii) increases in serum levels of IGF-I, IGF-II, free IGF-I, IGFBP-3 and acid labile subunit (ALS); (iii) a greater decrease in serum IGFBP-1 levels; and (iv) no significant difference in serum IGFBP-2 levels, when compared to the 14 control patients. The change in height SDS after 12 months of rhGH (+0.8) in the 30 treated children correlated significantly and positively with serum ALS, IGFBP-3, total IGF, IGF-I, IGF-II and free IGF-I levels measured during treatment. These observations suggest that, in children with growth failure associated with chronic renal failure: (i) IGFBP-2, and not IGFBP-3, is likely to be a growth inhibitor; (ii) rhGH stimulates catch-up growth in part by increasing serum levels of IGF peptides; and (iii) linear growth is influenced by the balance between growth stimulating IGFs and growth inhibitory IGFBPs.

Age and ethnicity affect the risk and outcome of focal segmental glomerulosclerosis

In patients with proteinuria, African-American (AA) ethnicity is reported to be a risk factor for focal segmental glomerulosclereosis (FSGS) and its progression to end-stage renal disease (ESRD). We reviewed our single-center experience to determine the probability of FSGS and its progression to ESRD based on ethnicity and age at presentation in children with proteinuria with or without nephrotic syndrome. Proteinuria without systemic disease or acute glomerulonephritis was the presenting feature in 17% (236/1,403) of children in the renal patient database of Texas Children's Hospital, Baylor College of Medicine. Histopathological diagnoses were established in 107 of 236 patients (45%). FSGS was identified in 65 patients, accounting for 28% of all patients with proteinuria and 61% of patients who underwent renal biopsy. FSGS was more prevalent in AA (45%) than in non-AA patients (22%) (P=0.001), and AA patients with FSGS were older at presentation (12.7+/-4.4 years) than non-AA patients (5.6+/-4.6 years) (P<0.001). Among patients who underwent renal biopsy, increasing age at presentation increased the probability of having FSGS in AA but not non-AA patients (P=0.04). Five-year actuarial renal survival of FSGS was worse in AA (8%) than in non-AA patients (31%) (P=0.01). These data suggest an increased risk and worse outcome of FSGS in AA compared with non-AA children.

Renal deposition of cytomegalovirus antigen in immunoglobulin-A nephropathy

Renal biopsy specimens from patients with various glomerular disorders were examined by indirect immunofluorescence microscopy with three different heterologous antibodies directed against cytomegalovirus and two heterologous antibodies against herpes simplex virus (HSV) type 1. All 31 samples from patients with immunoglobulin-A (IgA) nephropathy, 1 of 12 with systemic lupus erythematosus (SLE), and 1 of 5 with Henoch-Schönlein purpura (HSP) showed mesangial staining with cytomegalovirus antiserum, whereas no sample from 37 patients with other forms of glomerulonephritis was positive. Antigens of herpes simplex virus I were demonstrated in samples from 4 of 31 patients with IgA nephropathy, 1 of 12 patients with SLE, 1 of 5 patients with HSP, and 1 of 37 patients with other glomerular diseases. The consistent finding of glomerular cytomegalovirus antigen in IgA nephropathy suggests but does not prove that the virus has a role in the aetiology of this disorder.

Ambulatory blood pressure monitoring and interdialytic weight gain in children receiving chronic hemodialysis

Volume overload appears to induce hypertension in hemodialysis patients, yet studies of the effect of hydration status on interdialytic blood pressure (BP) have yielded contradictory results. We measured interdialytic BP by ambulatory BP monitoring (ABPM) during inpatient fluid restriction in 12 children receiving chronic hemodialysis to describe the overall BP pattern and to determine the effect of weight gain on BP change. Weight was measured on admission and four times each day. For each weight, casual BP was measured and compared with the mean of 3 hours of ABPM surrounding the weight measurement. Sleep BP decreased from daytime BP by 6% for systolic BP (SBP) and 11% for diastolic BP (DBP). Sleep loads were greater than daytime loads (P < 0.01) for SBP (53% v 28%) and DBP (57% v 27%). Overall, 58% (7 of 12) of the patients had sleep SBP load greater than 50%, and 67% (8 of 12) of the patients had sleep DBP load greater than 50%. Casual and ABPM measurements of BP showed moderate correlations for SBP (r = 0.51) and DBP (r = 0.46) and mean differences between methods of 6.3 +/- 13.2 mm Hg and -1.4 +/- 12.6 mm Hg, respectively. Increases in interdialytic weight were positively associated with increases in SBP (r = 0.41; P < 0.001), and interdialytic BP changes varied closely with corresponding weight changes. We conclude that in children receiving chronic hemodialysis: (1) sleep BP decreases are attenuated and sleep BP loads are elevated, (2) casual BP correlates poorly with ABPM, and (3) interdialytic weight and BP are related.

Osterix enhances BMSC-associated osseointegration of implants

Cellular and molecular events in osseointegration at the dental implant surface remain largely unknown. We hypothesized that bone marrow stromal cells (BMSCs) participate in this process, and that osterix (Osx) promotes implant osseointegration. To prove this hypothesis, we tracked double-labeled BMSCs in implantation sites created in nude mice transplanted with these cells. We also inserted implants into the femurs of our established transgenic mice after local administration of viruses encoding Osx, to determine the osteogenic effects of Osx. Immunohistochemical results demonstrated that BMSCs can recruit from peripheral circulation and participate in wound healing and osseointegration after implantation. Microcomputed tomography (microCT) analysis revealed an increased bone density at the bone-to-implant interface in the Osx group, and histomorphometric analysis indicated an elevated level of bone-to-implant contact in the Osx group. We concluded that exogenous BMSCs participate in the osseointegration after implantation, and that Osx overexpression accelerates osseointegration.

Characterization of insulin-like growth factor binding protein-3 in chronic renal failure serum

IGF-binding protein-3 (IGFBP-3), usually found as glycosylated 41- and 38-kD forms, is the major serum IGFBP during extrauterine life. In normal serum IGFBP-3 binds one IGF peptide and one acid-labile (alpha) subunit in a high-molecular-weight (MW) complex of 150 kD. By RIA, an excess of IGFBP-3 is present in chronic renal failure (CRF) serum, where it reportedly accumulates at low MW (25-55 kD) rather than as part of the 150-kD complex. To further evaluate IGFBP-3 forms in CRF, sera were obtained from seven healthy adolescents and seven adolescents with CRF. By RIA, IGFBP-3 levels were higher in CRF than normal sera (15.4 +/- 2.2 versus 10.1 +/- 2.1 micrograms/mL). High-MW (150-kD) fractions of CRF and normal sera, obtained by neutral size-exclusion chromatography, had equal amounts of IGFBP-3 by RIA. However, a second RIA peak of IGFBP-3, present in low-MW (35-kD) fractions of CRF but not normal sera, could account for the higher IGFBP-3 levels of CRF serum. [125I]IGF ligand blots of whole serum and serum fractions, either with or without prior precipitation by IGFBP-3 antiserum, found levels of 41- and 38-kD IGFBP-3 forms to be similar between CRF and normal whole sera and located these forms in the high-MW (150-kD) fractions of CRF and normal sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic endothelin-1 blockade reduces sympathetic nerve activity in rabbits with heart failure

Endothelin-1 (ET-1) is elevated in chronic heart failure (CHF). In this study, we determined the effects of chronic ET-1 blockade on renal sympathetic nerve activity (RSNA) in conscious rabbits with pacing-induced CHF. Rabbits were chronically paced at 320–340 beats/min for 3–4 wk until clinical and hemodynamic signs of CHF were present. Resting RSNA and arterial baroreflex control of RSNA were determined. Responses were determined before and after the ET-1 antagonist L-754,142 (a combined ETA and ETB receptor antagonist, n = 5) was administered by osmotic minipump infusion (0.5 mg · kg−1 · h−1 for 48 h). In addition, five rabbits with CHF were treated with the specific ETA receptor antagonist BQ-123. Baseline RSNA (expressed as a percentage of the maximum nerve activity during sodium nitroprusside infusion) was significantly higher (58.3 ± 4.9 vs. 27.0 ± 1.0, P < 0.001), whereas baroreflex sensitivity was significantly lower in rabbits with CHF compared with control (3.09 ± 0.19 vs. 6.04 ± 0.73, P < 0.001). L-754,142 caused a time-dependent reduction in arterial pressure and RSNA in rabbits with CHF. In addition, BQ-123 caused a reduction in resting RSNA. For both compounds, RSNA returned to near control levels 24 h after removal of the minipump. These data suggest that ET-1 contributes to sympathoexcitation in the CHF state. Enhancement of arterial baroreflex sensitivity may further contribute to sympathoinhibition after ET-1 blockade in heart failure.

Non-invasive intravascular monitoring in the pediatric hemodialysis population

Assessment of dry weight in pediatric hemodialysis (HD) patients is difficult, since small fluid shifts may result in dialysis-associated morbidity (DAM) and children may not verbalize complaints. Achieving dry weight is critical since chronic fluid overload can result in hypertension and left ventricular hypertrophy. To determine if non-invasive monitoring of hematocrit (NIVM) is useful in preventing DAM in pediatric HD patients, we reviewed 200 HD treatments performed with or without NIVM (no NIVM). DAM was defined as an "event" (e.g., hypotension, headache, cramping) that required nursing intervention. Patient age, weight, and gender were similar in both groups. Desired ultrafiltration was obtained in both groups. The event rate was lower in NIVM than no NIVM for all treatments (0.22 vs. 0.3, P = 0.07) and significantly lower in patients < 35 kg (0.25 vs. 0.47, P = 0.01). The second event rate (fraction of treatments with one event that had a subsequent event occurring at least 15 min later) was lower with NIVM (P < 0.01). For the NIVM group, events in the first 90 min occurred when blood volume changed > 8% per hour; 71% of events (43/60) at 90-240 min occurred when blood volume changed > 4% per hour. NIVM decreases DAM in pediatric HD patients, especially those < 35 kg. Ultrafiltration with blood volume change < 8% per hour is safe in the 1st h and < 4% after 1 h reduces DAM in children.

Inferior Outcomes on the Waiting List in Low-Volume Pediatric Heart Transplant Centers

Low case volume has been associated with poor outcomes in a wide spectrum of procedures. Our objective was to study the association of low case volume and worse outcomes in pediatric heart transplant centers, taking the novel approach of including waitlist outcomes in the analysis. We studied a cohort of 6482 candidates listed in the Organ Procurement and Transplantation Network for pediatric heart transplantation between 2002 and 2014; 4665 (72%) of the candidates underwent transplantation. Candidates were divided into groups according to the average annual transplantation volume of the listing center during the study period: more than 10, six to 10, three to five, or fewer than three transplantations. We used multivariate Cox regression analysis to identify independent risk factors for waitlist and posttransplantation mortality. Of the 6482 candidates, 24% were listed in low-volume centers (fewer than three annual transplantations). Of these listed candidates in low-volume centers, only 36% received a transplant versus 89% in high-volume centers (more than 10 annual transplantations) (p < 0.001). Listing at a low-volume center was the most significant risk factor for waitlist death (hazard ratio [HR] 4.5, 95% confidence interval [CI] 3.5-5.7 in multivariate Cox regression and HR 5.6, CI 4.4-7.3 in multivariate competing risk regression) and was significant for posttransplantation death (HR 1.27, 95% CI 1.0-1.6 in multivariate Cox regression). During the study period, one-fourth of pediatric transplant candidates were listed in low-volume transplant centers. These children had a limited transplantation rate and a much greater risk of dying while on the waitlist.

Natural logarithmic estimates of Kt/V in the pediatric hemodialysis population

The natural logarithm formula for Kt/V proposed by Daugirdas is recognized as a valid and simple alternative to formal urea kinetic modeling (UKM) in adults receiving hemodialysis. No data have been published to validate the use of this formula in infants, children, and adolescents. We compared Kt/V derived by formal UKM with the natural logarithmic formula for 103 treatments in 21 pediatric end-stage renal disease patients receiving chronic hemodialysis. Values for Kt/V derived by formal UKM ranged from 0.65 to 2.06. Patients ranged in age from 1.8 to 22.5 years and in dry weight from 10.2 to 82.5 kg. The largest percent error between the two methods for any data point was less than 6%. The total error (absolute value percent error + 2 SD) was less than 6% across the entire range of dry weights. Our data show excellent agreement between formal UKM and the natural logarithm formula for Kt/V in pediatric hemodialysis patients, even those weighing less than 30 kg. These results support the use of the natural logarithm formula as a valid alternative to formal UKM in children. The simplicity of this formula should allow for the use of Kt/V as the best measure to study the relationship between delivered dialysis dose and outcomes in children.

Acyclovir prophylaxis of varicella in children with renal disease receiving steroids

Varicella, or chickenpox, is very communicable and has been shown to be transmitted to nearly 90% of household contacts. Severe varicella infections with fatal complications have been noted in children receiving corticosteroids despite the administration of varicella-zoster immune globulin (VZIG). The use of post-exposure acyclovir prophylaxis in immunocompetent children exposed to a household contact with varicella has been shown to decrease the transmission rate of varicella significantly. We studied the safety and efficacy of acyclovir prophylaxis as an adjunctive preventive measure in 8 children (10 separate exposures) receiving corticosteroids for renal disease. Four children (6 separate exposures) served as controls. No adverse reactions were reported with the acyclovir prophylaxis. The maximum change between pre- and study serum creatinine levels was 0.1 mg/dl. None of the 8 patients who received acyclovir prophylaxis developed chickenpox. One of these 8 patients developed humoral immunity to varicella despite the absence of clinical infection. One of 4 patients who received VZIG prophylaxis alone developed chickenpox. These data support the use of acyclovir prophylaxis as an adjunctive measure to VZIG for the prevention of potentially serious varicella infection in children receiving steroids.

Successful use of Tesio catheters in pediatric patients receiving chronic hemodialysis

Semipermanent venous catheters remain the most commonly used access for chronic hemodialysis (HD) in pediatric patients. The recent availability of Tesio catheters in 7 and 10 F has expanded available HD catheter options for children and adolescents. We report our experience with Tesio catheter survival, complications, and effect on dialysis adequacy in comparison to standard dual-lumen (DL) catheters in our pediatric HD patients. Demographic data were similar between the two groups. Overall actuarial survival was significantly longer for Tesio versus DL catheters (46% versus 0% at 1 year; P = 0.003). A comparison of smaller catheters (7 F Tesio catheter, 8 or 10 F DL catheter) showed that smaller Tesio catheters had a significantly longer survival (median survival, 244 versus 13 catheter-days; P < 0.01). Tesio 10 F catheters also survived significantly longer than the larger 11.5 and 12 F DL catheters (P < 0.02). Catheter sepsis occurred less frequently with Tesio catheters (one episode/20 catheter-months) than DL catheters (one episode/5 catheter-months) despite the longer duration of Tesio catheters. Adequate dialysis (single-pool Kt/V > 1.2) was delivered with the same frequency, but for a longer duration with Tesio catheters (76% +/- 32% over 100 monthly measurements versus DL catheter, 57% +/- 45% over 54 monthly measurements). Our clinical practice was to replace cuffed catheters when adequate dialysis could not be delivered. We conclude that Tesio catheters provide superior performance compared with DL catheters in terms of catheter survival, infection rates, and duration of adequate performance.

Use of cyclosporine in pediatric renal transplant recipients

Cyclosporine and prednisone were used in combination to produce immunosuppression in 18 pediatric recipients of renal allografts. Ten children received cadaveric kidneys and eight received kidneys from living related donors. With a mean follow-up of 16.5 months (range 7 to 33 months), the patient survival rate is 100% (18 of 18) and the graft survival rate is 83% (15 of 18). Two grafts were lost for nonimmunologic reasons. Currently the group mean (+/- SE) serum creatinine concentration is 1.22 +/- 0.11 mg/dl and creatinine clearance is 69.3 +/- 4.79 ml/min/1.73 m2. Cyclosporine nephrotoxicity has not caused irreversible allograft injury nor led to graft loss in this population. The incidence of treated rejection episodes has been 39% (seven of 18). Only 39% (seven of 18) of children have required hospital readmissions since the initial transplant discharge. There have been no opportunistic infections. In the 15 children with functioning grafts, some linear growth has occurred in 10 of 11 prepubertal and two of four postpubertal patients. Cyclosporine and prednisone have constituted a safe, efficacious immunosuppressive regimen for pediatric renal allograft recipients. Longer follow-up will be necessary to confirm whether these advantages persist beyond 2 years.

Particle size determination by automated microscopical imaging analysis with comparison to laser diffraction

A rapid and precise microscopical analysis technique for the determination of particle size distribution has been developed. Particle size distribution was determined with a Carl Zeiss Axioplan microscope equipped with a computer-controlled image analysis system. Area and volume measurements were performed on a number of particles and plotted against Feret's diameter to yield a distribution histogram. This technique was then applied to several compounds of pharmaceutical interest, and the resulting histograms were compared with histograms determined with a laser diffraction instrument. The reproducibility of the microscopical determination was good and the agreement between the two determinations was dependent on the crystalline shape.

Intermittent clean catheterization: an alternative to diversion in continent transplant recipients with lower urinary tract dysfunction

A total of 3 renal transplant recipients who were candidates for urinary diversion underwent successful transplantation using a planned program of intermittent clean catheterization. The urinary tract dysfunction was caused by a lower motor neuron neurogenic bladder, prune belly syndrome and myelodysplasia. The patients remain dry between catheterizations and maintain serum creatinine levels of 1.1, 0.8 and 0.5 mg. per cent, respectively, with a followup of 6 to 25 months. There has been only 1 urinary tract infection during 42 patient-months at risk while on self-catheterization. Pre-transplant urologic evaluation and patient education are mandatory. The ideal candidate for intermittent clean catheterization is a patient with a low pressure bladder that fails to empty and who is continent between catheterizations. Intermittent clean catheterization is a safe and effective alternative to diversion in continent transplant recipients with lower urinary tract dysfunction.