Aramchol in patients with nonalcoholic steatohepatitis: a randomized, double-blind, placebo-controlled phase 2b trial

Nonalcoholic steatohepatitis (NASH), a chronic liver disease without an approved therapy, is associated with lipotoxicity and insulin resistance and is a major cause of cirrhosis and hepatocellular carcinoma. Aramchol, a partial inhibitor of hepatic stearoyl-CoA desaturase (SCD1) improved steatohepatitis and fibrosis in rodents and reduced steatosis in an early clinical trial. ARREST, a 52-week, double-blind, placebo-controlled, phase 2b trial randomized 247 patients with NASH (n = 101, n = 98 and n = 48 in the Aramchol 400 mg, 600 mg and placebo arms, respectively; NCT02279524 ). The primary end point was a decrease in hepatic triglycerides by magnetic resonance spectroscopy at 52 weeks with a dose of 600 mg of Aramchol. Key secondary end points included liver histology and alanine aminotransferase (ALT). Aramchol 600 mg produced a placebo-corrected decrease in liver triglycerides without meeting the prespecified significance (-3.1, 95% confidence interval (CI) -6.4 to 0.2, P = 0.066), precluding further formal statistical analysis. NASH resolution without worsening fibrosis was achieved in 16.7% (13 out of 78) of Aramchol 600 mg versus 5% (2 out of 40) of the placebo arm (odds ratio (OR) = 4.74, 95% CI = 0.99 to 22.7) and fibrosis improvement by ≥1 stage without worsening NASH in 29.5% versus 17.5% (OR = 1.88, 95% CI = 0.7 to 5.0), respectively. The placebo-corrected decrease in ALT for 600 mg was -29.1 IU l^-1 (95% CI = -41.6 to -16.5). Early termination due to adverse events (AEs) was <5%, and Aramchol 600 and 400 mg were safe, well tolerated and without imbalance in serious or severe AEs between arms. Although the primary end point of a reduction in liver fat did not meet the prespecified significance level with Aramchol 600 mg, the observed safety and changes in liver histology and enzymes provide a rationale for SCD1 modulation as a promising therapy for NASH and fibrosis and are being evaluated in an ongoing phase 3 program.

Fibroblast growth factor 23 as a risk factor for cardiovascular events and mortality in patients in the EVOLVE trial

INTRODUCTION

High mortality rates in patients with chronic kidney disease-mineral and bone disorder (CKD-MBD) receiving maintenance hemodialysis are largely due to cardiovascular (CV) events.

METHODS

We evaluated associations between MBD parameters, fibroblast growth factor 23 (FGF23) concentrations, and clinically adjudicated CV events from the Evaluation of Cinacalcet Hydrochloride Therapy to Lower Cardiovascular Events (EVOLVE) trial. Patients enrolled in EVOLVE, who had not experienced any study endpoints between randomization and week 20 with evaluable baseline and week 20 values for key laboratory parameters (parathyroid hormone, calcium, phosphate, and FGF23), were assessed. We used adjusted Cox proportional hazards regression models to estimate relative risk of outcomes (primary composite, all-cause mortality, and CV events) based on FGF23 and MBD parameters. Laboratory values were modeled with linear terms and using natural cubic splines with two degrees of freedom.

FINDINGS

For the primary endpoint, patients assessed (N = 2309) were followed up over a mean duration of 3.1 years, during which 1037 CV events (497 deaths, 540 nonfatal events) occurred. Adjusted models showed an association between FGF23 and the risk of CV events. Hazard ratio per log unit of FGF23 at week 20 was 1.09 [95% CI: 1.03-1.16], and the hazard ratio per log unit change in FGF23 from week 0 to week 20 was 1.09 [95% CI: 1.00-1.17].

DISCUSSION

Our data highlight FGF23 as an independent CV risk factor and potential biomarker and therapeutic target for patients with CKD-MBD receiving maintenance hemodialysis.

Estimated Life Expectancy and Income of Patients With Sickle Cell Disease Compared With Those Without Sickle Cell Disease

IMPORTANCE

Individuals with sickle cell disease (SCD) have reduced life expectancy; however, there are limited data available on lifetime income in patients with SCD.

OBJECTIVE

To estimate life expectancy, quality-adjusted life expectancy, and income differences between a US cohort of patients with SCD and an age-, sex-, and race/ethnicity-matched cohort without SCD.

DESIGN, SETTING, AND PARTICIPANTS

Cohort simulation modeling was used to (1) build a prevalent SCD cohort and a matched non-SCD cohort, (2) identify utility weights for quality-adjusted life expectancy, (3) calculate average expected annual personal income, and (4) model life expectancy, quality-adjusted life expectancy, and lifetime incomes for SCD and matched non-SCD cohorts. Data sources included the Centers for Disease Control and Prevention, National Newborn Screening Information System, and published literature. The target population was individuals with SCD, the time horizon was lifetime, and the perspective was societal. Model data were collected from November 29, 2017, to March 21, 2018, and the analysis was performed from April 28 to December 3, 2018.

MAIN OUTCOMES AND MEASURES

Life expectancy, quality-adjusted life expectancy, and projected lifetime income.

RESULTS

The estimated prevalent population for the SCD cohort was 87 328 (95% uncertainty interval, 79 344-101 398); 998 were male and 952 were female. Projected life expectancy for the SCD cohort was 54 years vs 76 years for the matched non-SCD cohort; quality-adjusted life expectancy was 33 years vs 67 years, respectively. Projected lifetime income was $1 227 000 for an individual with SCD and $1 922 000 for a matched individual without SCD, reflecting a lost income of $695 000 owing to the 22-year difference in life expectancy. One study limitation is that the higher estimates of life expectancy yielded conservative estimates of lost life-years and income. The analysis only considered the value of lost personal income owing to premature mortality and did not consider direct medical costs or other societal costs associated with excess morbidity (eg, lost workdays for disability, time spent in the hospital). The model was most sensitive to changes in income levels and mortality rates.

CONCLUSIONS AND RELEVANCE

In this simulated cohort modeling study, SCD had societal consequences beyond medical costs in terms of reduced life expectancy, quality-adjusted life expectancy, and lifetime earnings. These results underscore the need for disease-modifying therapies to improve the underlying morbidity and mortality associated with SCD.

The Generalized Data Model for clinical research

BACKGROUND

Most healthcare data sources store information within their own unique schemas, making reliable and reproducible research challenging. Consequently, researchers have adopted various data models to improve the efficiency of research. Transforming and loading data into these models is a labor-intensive process that can alter the semantics of the original data. Therefore, we created a data model with a hierarchical structure that simplifies the transformation process and minimizes data alteration.

METHODS

There were two design goals in constructing the tables and table relationships for the Generalized Data Model (GDM). The first was to focus on clinical codes in their original vocabularies to retain the original semantic representation of the data. The second was to retain hierarchical information present in the original data while retaining provenance. The model was tested by transforming synthetic Medicare data; Surveillance, Epidemiology, and End Results data linked to Medicare claims; and electronic health records from the Clinical Practice Research Datalink. We also tested a subsequent transformation from the GDM into the Sentinel data model.

RESULTS

The resulting data model contains 19 tables, with the Clinical Codes, Contexts, and Collections tables serving as the core of the model, and containing most of the clinical, provenance, and hierarchical information. In addition, a Mapping table allows users to apply an arbitrarily complex set of relationships among vocabulary elements to facilitate automated analyses.

CONCLUSIONS

The GDM offers researchers a simpler process for transforming data, clear data provenance, and a path for users to transform their data into other data models. The GDM is designed to retain hierarchical relationships among data elements as well as the original semantic representation of the data, ensuring consistency in protocol implementation as part of a complete data pipeline for researchers.

Modeling the consequences of recurrences after trastuzumab treatment of HER2+ early-stage breast cancer

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Background: The study objective was to estimate the long-term consequences of recurrences following treatment with trastuzumab (TRA) among women with HER2+ early stage breast cancer (BC) in the United States (US). Methods: A simulation model was constructed to estimate the following outcomes for each combination of hormone receptor (+/-) and nodal (+/-) status: number of recurrences, direct medical cost and indirect cost attributed to recurrences. The number of women aged ≥18 years with newly diagnosed HER2+ BC between 2018 and 2037 was estimated using SEER incidence rates (assumed constant over time) and from US Census data and accounted for the proportion of women utilizing adjuvant TRA by nodal status and age (assumed constant over time). The recurrence rate to any regional, distant or contralateral site was based on the long-term follow-up of the HERceptin Adjuvant (HERA) trial (expected 20-year recurrence proportions of 27.6% for TRA and 36.7% without TRA). Medical and pharmacy costs due to a recurrence were based on a 3-year study of metastatic BC patients treated with HER2 targeted agents. Beyond year 3, cost increased by 4.5% per year. The indirect costs of recurrences included loss of income from early retirement valued at the mean hourly wage, work absenteeism ($6,960/year), and reduced productivity while at work ($3,456/year). Non-cancer related mortality was estimated using SEER data. Results: We estimated that there would be 411,373 incident cases of early stage BC who would receive adjuvant TRA treatment from 2018 to 2037. Following each annual cohort for 20 years, we estimated that there would be 112,700 recurrences after TRA treatment and 149,674 recurrences without TRA treatment. The 20-year direct medical costs of recurrences were estimated to be $28.2 and $37.5 billion with and without TRA, respectively and the indirect costs were estimated to be $4.1 and $5.6 billion with and without TRA, respectively. Conclusions: Although TRA reduced recurrences by 25% in our 20-year model, there was a substantial number of recurrences. Future research will assess the clinical and economic impact of newer HER2 directed therapies in the adjuvant (pertuzumab, T-DM1) and extended adjuvant (neratinib) setting.

Modeling longer-term efficacy of neratinib in the extended adjuvant setting for early-stage breast cancer

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Background: Long-term efficacy in the extended adjuvant setting requires a long follow-up. In the ExteNET trial, neratinib was given for a year and invasive disease-free survival (iDFS) assessed at 2 and 5 years. In women with HER2+ hormone receptor positive (HR+) cancer who initiated neratinib, the observed difference in iDFS between neratinib and placebo at 5 years (4.5%) was greater than at 2 years (3.7%). The objective of these analyses was to extrapolate the effect of neratinib on iDFS beyond 5 years in patients with HER2+/HR+ early stage breast cancer who initiated treatment after receiving adjuvant trastuzumab. Methods: We analyzed the 5-year follow-up of the ExteNET trial using flexible spline-based parametric survival models to project iDFS risk at 10 years. Analyses included only HR+ patients. Several model specifications were explored including various combinations of the following variables: treatment as a time varying covariate, nodal status (0, 1-3, ≥4 nodes), and months from last trastuzumab treatment to randomization. The regression models included different combinations of interaction terms, either a proportional hazards or a proportional odds (PO) link function, and either 2 or 6 knots. The model fit was compared using Akaike Information Criterion (AIC). Results: In general, the fit statistics among the 16 models were comparable; however, the model with the lowest AIC included no interaction terms, 2 knots, and the PO link function. The mean iDFS event rate at 10 years was estimated to be 12.2% for neratinib and 18.9% for placebo for a difference of 6.8% (range across 16 models: 6.8%-7.8%). The recurrence rate and the difference between treatment groups were largest in women with ≥4 positive nodes. Conclusions: Based on these analyses, the projected 10-year difference in iDFS between placebo and neratinib patients seems likely to persist. However, because the data was limited to 5 years, we could not include the effect of hormonal therapy cessation. Also, low event rates in the node negative group may require longer follow-up to evaluate. In absence of longer-term data for neratinib, flexible parametric survival modeling of the iDFS suggests that the effect of neratinib therapy may remain stable.

Quality adjusted life year gains associated with administration of recombinant tissue-type plasminogen activator for treatment of acute ischemic stroke: 1998-2011

BACKGROUND

Intravenous recombinant tissue-type plasminogen activator (r-tPA) is an approved treatment for select patients with acute ischemic stroke (AIS). Data indicate r-tPA improves functional outcome three months after AIS compared with placebo. This study models the increase in quality adjusted life years (QALYs) associated with r-tPA compared with similar patients not treated with r-tPA.

METHODS

Hospital discharge data for AIS and r-tPA were obtained from the Nationwide Inpatient Sample from 1998 to 2011. Discharge location (home, rehabilitation, long-term care, death) was mapped to modified Rankin Scale (mRS) scores based on National Institute of Neurological Disorders and Stroke (NINDS) Study Group Part 1 and 2 clinical studies. The mRS scores were mapped to relative risk of death and QALYs obtained from the literature. The model estimated expected survival and QALYs by age, gender and mRS for patients receiving r-tPA. Life expectancy and QALYs for patients not receiving r-tPA were estimated based on discharge location and mRS for placebo patients in the NINDS study.

RESULTS

AIS discharges declined from over 635,000 in 1998 to over 593,000 in 2011. A total of 183,235 patients received r-tPA. Utilization of r-tPA increased from 1% of AIS patients in 1998 to over 4% in 2011. Estimated projections for QALYs gained from utilization of r-tPA to QALYS without r-tPA were just under 240,000 for the 13 years and with no discounting, and just over 165,000 assuming 3% annual discounting. In the most conservative scenario, assuming no difference in proportional discharge status (i.e. patients not treated with r-tPA are discharged in the same manner as r-tPA patients), the estimated life years gained are approximately 35,000 and QALYS gained are approximately 90,000.

CONCLUSIONS

r-tPA for AIS has resulted in estimated gains in quality-adjusted life years due to reduction in disability and improvement in functioning since its introduction in 1998.

Refining the definition of clinically important mineral and bone disorder in hemodialysis patients

BACKGROUND

It is important to identify an easily defined subset of patients at increased risk of adverse clinical outcomes associated with mineral and bone disorder (MBD) biomarkers (parathyroid hormone, calcium and phosphate).

METHODS

Observational cohort study of 26 221 prevalent hemodialysis patients in Davita clinics as of 31 August 2005 and followed up until 31 December 2006 (16 months). Predictors were 12 possible definitions of 'clinically important' MBD based on all 3 biomarkers, and 18 alternative definitions based on only 1 or 2 biomarkers. Events were death alone and a composite of cardiovascular hospitalization or death. Excess events were calculated based on a multivariate Cox model using 5224 patients in target for all MBD biomarkers and applied to 20 997 patients out of target for at least one biomarker. Excess events attributable to MBD were estimated by subtracting the multivariate model-derived predicted number from the actual number. Outcomes were the proportion of excess events attributable to MBD captured by each definition (threshold ≥70%) and the reduction in the population size considered to have clinically important MBD (threshold ≥30%). The excess fraction was excess events divided by actual events.

RESULTS

Patients with more biochemical markers out of target tended to be younger, black and have longer times since starting dialysis. The excess fraction associated with MBD ranged from ∼10 to 26% depending on the clinical endpoint and definition. The only definition to meet the thresholds required at least two of the three MBD biomarkers to be out of target (high or low). It captured 82% of excess composite endpoints and 74% of excess deaths and reduced the at-risk population by 46%.

CONCLUSIONS

Patients with at least two of three MBD biomarkers out of target represent a subgroup of patients at elevated risk of adverse clinical events.

Abstract P1-16-01: Skeletal-related events (SRE) prevented in breast cancer patients with bone metastases in the United States (US)

Background: SREs are potentially debilitating consequences of bone metastases in advanced stage cancers. Bone-targeting agents (BTAs), including denosumab and intravenous zoledronic acid (ZA) are approved to prevent SREs. The purpose of this study was to estimate the annual number of SREs that might occur in US women with breast cancer without intervention, and to estimate the SREs that could be prevented with denosumab or with ZA.

Methods: A model was developed using US prevalence estimates (Li, et al. 2011), combined with 2012 Census projections to estimate the number of SREs in women with bone metastases from breast cancer in 2012. SREs were defined as fracture, radiation to bone, surgery to bone, or spinal cord compression. The SRE rate in untreated patients was estimated by pooling rates from 8 treatment groups in 4 trials (Lipton 2000; Rosen 2003; Kohno 2005; Stopeck 2010), applying the appropriate relative hazard (RH) of first and subsequent SRE from a network meta-analysis (NMA;Ford 2012), and weighting by the sample size. The denosumab and ZA SRE rates were derived from the pooled rate and the RH estimates from the NMA. Ineligibility was defined as one of the following: all uninsured patients (US Census) and patients discontinuing due to adverse events or non-compliance (ZA 4.6%, denosumab 3.7%; Stopeck 2010). Patients with kidney clearance &lt; 30 ml/min (1.3%; Launay-Vacher 2007) were considered ineligible to receive ZA. Using Monte Carlo sampling, we derived mean estimates and 95% simulation intervals (SI) based on 1,000 samples.

Results: Overall, we estimated 96,598 women with breast cancer had bone metastases at any given time in 2012. We estimated 164,673 (95% SI 110,153 to 220,770) SREs would have occurred in 2012 if no women were treated. Assuming all women eligible to receive ZA were treated with ZA (n = 83,870), the number of SREs would have been 108,233 (decline of 56,440, 95% SI 13,744 to 100,098); assuming all women eligible to received denosumab were treated with denosumab (n = 85,780), the number of SREs would have been 86,992 (decline of 77,681, 95% SI 38,327 to 120,521). The incremental difference between denosumab and ZA was 21,242 (95% SI 9,312 to 36,674).

Conclusions: The use of BTAs to reduce SRE risk, including denosumab, could result in reductions in the number of adverse skeletal complications in the US.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-16-01.

Lifetime cost-effectiveness of denosumab versus zoledronic for prevention of skeletal-related events (SREs) in patients (pts) with castrate-resistant prostate cancer (CRPC) and bone metastases (BM): United States managed care perspective

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Background: Denosumab (Dmab) is superior to zoledronic acid (ZA) for prevention of SREs in pts with CRPC and BM. As Dmab is not cleared renally, it can be used in pts regardless of renal status or concomitant use of nephrotoxic drugs. Previous economic analyses were limited as the analyses were based on short duration-trial based perspectives and/or did not account for disutility associated with IV vs SC administration of ZA and Dmab, respectively. These analyses assess the lifetime cost-effectiveness of Dmab vs ZA in pts with CRPC and BM from a US managed care perspective, with extensive scenario and sensitivity analyses. Methods: A lifetime Markov model was developed, with efficacy of Dmab vs ZA in SRE prevention from a head-to-head phase 3 trial; clinical practice SRE rate in ZA pts from a large commercial claims database analysis; SRE and mode of administration (IV vs SC) quality adjusted life-year (QALY) decrements estimated using the time trade-off method; and SRE costs estimated from a nationally representative commercial claims database. Drug, drug administration, and renal monitoring costs were also included. Costs and QALYs were discounted at 3% per year. Scenario analyses (including adverse events, drug discontinuation, etc), one-way and multivariate probabilistic sensitivity analyses were conducted. Results: Dmab reduced the number of SREs and increased pts’ QALY vs ZA. In the base case and the scenario analyses, cost per QALY gained was below $50,000, which is commonly considered good value. Cost per SRE avoided was below $9,000. In one-way sensitivity analyses, drug costs and SRE rate were the most influential variables. Probabilistic sensitivity analyses showed the probabilities of Dmab being cost-effective vs ZA were 0.83, 0.94, and 0.98 with willingness-to-pay of $100,000, $150,000 and $200,000 per QALY gained, respectively. Conclusions: Dmab is a cost-effective treatment option in preventing SREs in pts with CRPC and BM compared with ZA from a US managed care perspective. The overall value of Denosumab is based on superior efficacy and more efficient administration.

Cost-effectiveness of denosumab (Dmab) versus zoledronic acid (ZA) for prevention of skeletal-related events (SREs) in patients (pts) with castrate-resistant prostate cancer (CRPC) and bone metastases (BM)

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Background: It has become more important to understand the incremental cost/benefit of new medicines as healthcare costs rise. Subcutaneous Dmab is superior to intravenous ZA for prevention of SREs in pts with CRPC and BM (Fizazi, 2011). In addition, a lower proportion of pts receiving Dmab progressed to moderate/severe pain than those receiving ZA (Brown, 2011). Dmab can be used in pts regardless of renal status or concomitant use of nephrotoxic drugs. These analyses assess the lifetime, real world cost-effectiveness of Dmab vs ZA in pts with CRPC and BM from a US managed care perspective.

Methods: A lifetime Markov model was developed to estimate SREs, quality adjusted life-years (QALYs), and costs. The relative rate reduction in SREs for Dmab vs ZA was based on a large head-to-head phase 3 trial (N=1,901). The real world SRE rate in ZA pts was derived from a large commercial claims database analysis (Hatoum, 2008). SRE QALY decrements were estimated using the time trade-off method (Matza, 2011). SRE costs were estimated from a nationally representative commercial claims database (Barlev, 2010). Wholesale acquisition drug cost (Analysource, 2011), drug administration, and renal monitoring costs (National Fee Analyzer, 2011) were included. Compliance and mortality were assumed to be the same in both groups. Costs and QALYs were discounted at 3% annually.

Results: With a median pt survival of 1.7 years, Dmab reduced the number of SREs and increased pts’ QALY vs ZA. The lifetime cost/pt on Dmab was $7,430 higher than ZA. Cost/QALY gained was $65,134, commonly considered good value based on oncologists’ implied threshold in the US (Nadler, 2006). Cost/SRE avoided was $9,212.

Conclusions: Dmab is cost-effective in preventing SREs in pts with CRPC and BM compared with ZA in the US. The overall value of Dmab is based on superior efficacy and more efficient administration.

[Table: see text]

Cost-effectiveness of denosumab vs zoledronic acid for prevention of skeletal-related events in patients with solid tumors and bone metastases in the United States

OBJECTIVE

With increasing healthcare resource constraints, it has become important to understand the incremental cost-effectiveness of new medicines. Subcutaneous denosumab is superior to intravenous zoledronic acid (ZA) for the prevention of skeletal-related events (SREs) in patients with advanced solid tumors and bone metastases. This study sought to determine the lifetime cost-effectiveness of denosumab vs ZA in this setting, from a US managed-care perspective.

METHODS

A lifetime Markov model was developed, with relative rate reductions in SREs for denosumab vs ZA derived from three pivotal Phase 3 trials involving patients with castration-resistant prostate cancer (CRPC), breast cancer, and non-small-cell lung cancer (NSCLC), and bone metastases. The real-world SRE rates in ZA-treated patients were derived from a large commercial database. SRE and treatment administration quality-adjusted life year (QALY) decrements were estimated with time-trade-off studies. SRE costs were estimated from a nationally representative commercial claims database. Drug, drug administration, and renal monitoring costs were included. Costs and QALYs were discounted at 3% annually. One-way and probabilistic sensitivity analyses were conducted.

RESULTS

Across tumor types, denosumab was associated with a reduced number of SREs, increased QALYs, and increased lifetime total costs vs ZA. The costs per QALY gained for denosumab vs ZA in CRPC, breast cancer, and NSCLC were $49,405, $78,915, and $67,931, respectively, commonly considered good value in the US. Costs per SRE avoided were $8567, $13,557, and $10,513, respectively. Results were sensitive to drug costs and SRE rates.

LIMITATIONS

Differences in pain severity and analgesic use favoring denosumab over ZA were not captured. Mortality was extrapolated from fitted generalized gamma function beyond the trial duration.

CONCLUSION

Denosumab is a cost-effective treatment option for the prevention of SREs in patients with advanced solid tumors and bone metastases compared to ZA. The overall value of denosumab is based on superior efficacy, favorable safety, and more efficient administration.

Deregulated expression of homeobox-containing genes, HOXB6, B8, C8, C9, and Cdx-1, in human colon cancer cell lines

Previously we have demonstrated a reciprocal deregulation of various homeobox genes (HOXB6, B8, C8 and C9 vs Cdx-1) in human colorectal cancer (CRC). In the present study, using RT-PCR, we have investigated the expression pattern of these homeobox genes in various human colon cell lines, representing various stages of colon cancer progression and differentiation. Thus, we have tested polyposis coli Pc/AA adenoma cells, Caco-2, HT-29 and LS174T adenocarcinoma cell lines. All cell lines, except LS174T, demonstrated a pattern of deregulated homeobox gene expression which resembled that of CRC. In contrast, the pattern of expression of these genes in the highly oncogenic LS174T cells, as well as in Caco-2 cells transfected with activated Ha-ras or Polyoma middle T oncogene, resembled that of the normal mucosa. The reciprocal deregulation of HOX and Cdx-1 genes in CRC and in CRC-derived cell lines suggests a possible role in human CRC development.

Acute necrotizing pancreatitis, lactic acidosis and prolonged hypoglycemia in a hemodialysed patient--a logical but unfortunately fatal combination

A hemodialysed patient with abdominal pain, severe lactic acidosis and prolonged hypoglycemia is described. The diagnosis of acute necrotizing pancreatitis was delayed and the patient died from both systemic and peripancreatic complications of the acute pancreatitis. The article deals with the problem of diagnosing acute pancreatitis in an end-stage renal failure (ESRF) patient; on the possible surgical options open to the physician in the management of acute pancreatitis and on a pathophysiological explanation behind both the lactic acidosis and hypoglycemia in this patient.

Can a severe degree of ketoacidosis develop overnight?

Insulin-dependent diabetes mellitus in poor control, alcohol intake associated with extracellular fluid volume contraction, or hypoglycemia may each lead to an increased rate of production of ketoacids. Generally, several days of illness are required before ketoacidosis becomes severe. Two clinical examples are presented to suggest that a severe degree of ketoacidosis may develop over a short period of time, literally overnight. In both examples, there was the ingestion of a modest amount of ethanol. From a quantitative analysis of factors that may influence the rate of production and removal of ketoacids, the following were deduced. Contributing factors to the very rapid development of maximal ketoacidosis could include the absence of a lag period for the conversion of ethanol to acetyl-coenzyme A in the liver and an impaired ability of the brain and kidneys to oxidize ketoacids, especially if these ketoacids are produced very rapidly and/or if less metabolic work is performed by these organs. In special settings, ketoacidosis may develop more rapidly than is generally appreciated.

Adenocarcinoma at ureterosigmoidostomy junction in a renal transplant recipient 15 years after conversion to ileal conduit

In recent years, adenocarcinoma of the colon mucosa has become a recognized complication of ureterosigmoidostomy and in most cases the tumor arises at the site of ureterocolonic anastomosis. We report a case of a 29-year-old renal transplant recipient who developed two colonic carcinomas at the site of ureterosigmoidostomy 25 years after the urinary diversion and 15 years after conversion to an ileal conduit. This case emphasizes the need for a careful life-long follow-up of all patients who undergo ureterosigmoidostomy.

Chronic myelomonocytic leukemia associated with primary amyloidosis

A case of chronic myelomonocytic leukemia (CMML) associated with primary amyloidosis (AL) is presented. Hepatosplenomegaly, macroglossia, and xanthelasma were the major physical findings. Laboratory tests showed macrocytic anemia, thrombocytopenia, monocytosis and a bi-clonal gammopathy. Early monocytes and monoblasts were noted in the bone marrow aspiration biopsy. Cytogenetic evaluation showed a clonal deletion of chromosome 21 long arm (21q-). Amyloid was present in the liver, tongue and xanthelasma. In addition, the patient was noted to have osteosclerosis of the lower extremities. Treatment with prednisone and colchicine resulted in a subjective response. The unusual association of CMML, and primary amyloidosis is discussed.

Organ transplants from living donors

I. Survey of Transplant Techniques

The kidney is one of the few organs which today can be successfully transplanted from a living donor to an ailing recipient. A healthy donor can function satisfactorily with a single kidney; therefore the removal of one kidney for transplantation does not significantly endanger the donor's life. However, removal, or even partial removal, of other organs, such as the heart, lungs, or pancreas, will present a serious risk to the health and life of the donor.

In addition to organs, skin, bone marrow, blood and other body parts can be transplanted from living donors.

A. Kidney Transplants

The kidneys function to regulate the body's electrolyte and water balance and eliminate various wastes. Severe kidney dysfunction endangers the patient's life, and requires treatment by dialysis or kidney transplant. Up until a decade ago, the life expectancy of patients treated by dialysis exceeded that of patients who underwent kidney transplants. Over the past decade, the life expectancy of patients who have undergone kidney transplants from deceased donors has increased to a point where it is now comparable with the life expectancy of patients on dialysis.

Chronic lactic acidosis in a patient with acquired immunodeficiency syndrome and mitochondrial myopathy: biochemical studies

A 30-yr-old man with acquired immunodeficiency syndrome treated with zidovudine developed biopsy-proven mitochondrial myopathy. Chronic lactic acidosis (lactate, 10 +/- 1 mmol/L) persisted for more than 5 wk. Liver function tests were normal, but the concentration of lactose rose to 16.1 mmol/L when 500 mmol of ethanol was infused. The concentration of lactose rose by only 1.5 mmol/L with maximally tolerated exercise. If this mitochondrial lesion compromised flux through the electron transport system, increased turnover of ATP with exercise should have exacerbated the degree of lactic acidosis because of increased need to regenerate ATP via glycolysis. Two possible explanations will be discussed: first, there was both a rapid rate of production of lactic acid in affected muscles in conjunction and an equally rapid rate of removal by uninvolved organs. Second, there was a low net rate of production of lactic acid in involved muscles despite the exercise.

Can oxygen consumption in blood in vitro be detected by a change in PCO2?

The PO2 measured in a sample of blood can be misleadingly low, owing to consumption of oxygen in vitro in patients with leukemia. The purpose of this study was to determine whether a rise in PCO2 in such blood could be a useful indication of consumption of oxygen in vitro. Because of the non-bocarbonate buffer capacity of blood and the carriage of CO2, mainly as bicarbonate, we reasoned that the rise in PCO2 would be too small to be helpful. Hence the quantitative relationship between the consumption of oxygen and the production of CO2 in blood was determined. Other reactions yielding CO2 (the titration of lactic acid) were monitored. Consumption of oxygen was stimulated in blood of normals in vitro by adding methylene blue (100 mumol/L); in addition, blood from four patients with leukemia was studied without additions. The rate of consumption of oxygen at 22 degrees C was linear over 60 min; the respiratory quotient was close to unity. The rise in PCO2 was small even when the fall in PO2 was 60 mmHg. We conclude that a rise in PCO2 is not a reliable way to diagnose consumption of oxygen in blood in vitro as patients may hyperventilate, making it very difficult to recognize a small rise in PCO2.

Moloney murine leukemia virus IN protein from disrupted virions binds and specifically cleaves its target sequence in vitro

The integration of retroviral DNA plays an essential role in the viral life cycle. Previous studies of the Moloney murine leukemia virus (M-MuLV) have shown that viral integration is mediated by the integrase (IN) protein acting on the 13-bp inverted repeats that flank the linear viral DNA produced during reverse transcription. Prior studies have also shown that when the M-MuLV IN protein is produced in Escherichia coli it retains an ability to specifically associate with the viral inverted repeats (Krogstad and Champoux, 1990). In this study we present evidence that the IN protein present in detergent-disrupted virions is capable of specifically interacting with double-stranded oligonucleotides that correspond to the viral inverted repeats, and that this interaction may change after integration-related processing of the viral att sites. We further present evidence that, in vitro, detergent-disrupted virions are capable of specifically cleaving ds-IR oligonucleotides in an IN-dependent reaction that mimics the trimming step that precedes integration.

Early methodological developments for clinical trials at the National Heart, Lung and Blood Institute

The National Heart Institute, now known as the National Heart, Lung and Blood Institute (NHLBI), initiated its first multicentre randomized clinical trials of rheumatic fever and rheumatic heart disease in 1951. The modern era of multicentre trials began, however, when the Coronary Drug Project was initiated in the 1960s. This trial and subsequent NHLBI trials stimulated a wide variety of research on clinical trial methodology. This paper reviews early methodologic developments in four areas. First, an organizational structure for multicentre clinical trials was developed and codified in the 'Greenberg Report' in 1967. Second, design considerations related to patient risk, non-compliance, a lag in treatment effect, and changing risk were explored. The 'intention-to-treat' principle was implicit in these investigations. Thirdly, the concept of periodic review of accumulating data, recommended in the Greenberg report, stimulated research on methods for sequential analysis. Three statistical approaches were developed and investigation of their statistical properties continues today. These approaches are usually described as group sequential, stochastic curtailment, and Bayesian methods. Finally, comparison of treatments in longitudinal studies has been an increasing part of NHLBI research and methods have been developed for design and analysis of longitudinal studies.

Enzyme-linked immunosorbent assay for distinguishing serological responses of lepromatous and tuberculoid leprosies to the 29/33-kilodalton doublet and 64-kilodalton antigens of Mycobacterium tuberculosis

Immunoblot assays for the antibodies to Mycobacterium tuberculosis sonic extracts showed that all serum specimens of 40 lepromatous and of 28 tuberculoid leprosy patients reacted in a significant manner to 29/33-kilodalton (kDa) doublet and 64-kDa antigens, respectively. By using an enzyme-linked immunosorbent assay, we observed a significantly high immunoglobulin G antibody titer to the purified M. tuberculosis 29/33-kDa doublet and 64-kDa antigens in lepromatous and tuberculoid leprosy patients, respectively, as compared with normal subjects and tuberculosis patients. This enzyme-linked immunosorbent assay serology may be useful for distinguishing two polar types of leprosy and for diagnosing leprosy in general.

Distribution-free confidence intervals for a parameter of Wilcoxon-Mann-Whitney type for ordered categories and progressive censoring

Halperin, Gilbert, and Lachin (1987, Biometrics 43, 71-80) obtain confidence intervals for Pr(X less than Y) based on the two-sample Wilcoxon statistic for continuous data. Their approach is applied here to ordered categorical data and right-censored continuous data, using the generalization zeta = Pr(X less than Y) + 1/2Pr(X = Y) to account for ties. Deviations from nominal coverage probability for various sample sizes and values of zeta are obtained via simulation of either three or six ordered categories based on underlying Poisson or exponential distributions. The simulation results indicate that the proposed method performs quite well, and it is apparently superior to the approach of Hochberg (1981, Communications in Statistics--Theory and Methods A10, 1719-1732) for values of zeta far from 1/2.

Stochastic curtailing for comparison of slopes in longitudinal studies

In some clinical trials, rate of change of a physiological function is used as a surrogate for a more serious outcome. We assume an expected change linear in time for each study participant with variation in slopes and intercepts from individual to individual and repeated measures over time for each individual. We also assume that deviations of response for an individual from expected response have zero mean, constant variance, and are uncorrelated. Under these assumptions we describe ways in which stochastic curtailing as defined by Lan, Simon, and Halperin (Commun Stat Seq Anal 1:207-219, 1982) can be implemented in a two-treatment trial for one-sided comparison of slopes in the two groups. Staggered entry is taken into account, as is the possibility that some of an individual's responses are not available; this is assumed to be random. The analysis assumes the number of participants in each group is large and that most individuals have at least two measurements (including baseline value). The possibility that rate of change is not constant and its consequences are discussed.

Interleukin 1 inhibitory activity secreted by a human myelomonocytic cell line (M20)

Culture supernatants from a myelomonocytic cell line (M20) were found to inhibit interleukin 1 (IL 1) activity in vitro. The factor, isolated from these supernatants, inhibited augmentation of phytohemagglutinin response of mouse thymus cells induced by IL 1 derived from several established cell lines. Various IL 1-dependent activities such as lymphocyte and fibroblast proliferation in vitro were also inhibited by the factor. The factor did not inhibit IL 2-induced or other proliferative responses not related to IL 1. Preliminary biochemical characterization of the factor indicated that the activity resides in a protein with a molecular mass of 52 kDa.

The orthogonal electrocardiogram as risk indicator for the prediction of myocardial infarction and/or cardiac death

In a prospective study on Coronary Heart Disease (CHD) orthogonal electrocardiograms (Frank) were recorded annually for ten years from 1,444 asymptomatic, middle-aged males with a mean age of 57.4 +/- 10.6 years. Cases with overt or suspected CHD were excluded. The purpose of the study was to identify risk indicators in electrocardiograms and to compare them with other known risk factors used for prediction of acute CHD events such as myocardial infarction (MI) and/or cardiac death (CD). Such acute events occurred in 88 cases. Pre-event ECGs of these acute events were compared with all others without events, using logistic regression analysis. Identified ECG risk indicators were then compared with other known risk factors such as smoking, blood pressure, cholesterol, age, weight, etc. The predictive power of the ECG, derived mainly from the ST-T complex, exceeded all others by a wide margin. The amplitude of the first 1/8 of the ST-T complex in lead x (similar to V5-V6) together with relative body weight proved best when one pre-event record was available. Prediction improved when ECG changes between two pre-event recordings were included. Precision of measurements by computer appeared essential for improvements in CHD prediction.

Detection of different interleukin-1 activities in human monocytes and monocytic cell lines

Culture supernatants from normal human monocytes, monocyte hybrid cell lines, and myelomonoblastic cell lines were tested for human interleukin-1 (IL-1) activity. In the present study, we report the detection of IL-1 secreted by several cell lines of monocyte origin and compare their biological and biochemical characteristics. IL-1 activity was tested by the regular assay of phytohemagglutinin (PHA) response of mouse thymus cells. IL-1 was found to be constitutively secreted by U937 and the M20 cell lines, as well as by three of the monocyte hybrid cell lines. The activity was always augmented following dialysis and did not require the presence of serum for its secretion. We compared the IL-1 activity of the myelomonoblastic M20 and hybrid 1C4 cell lines to that of normal monocytes. We found differences in the kinetics of IL-1 secretion, the pattern of activity following dilution of concentrated supernatants, and augmentation of activity by various inducers. The differences described may be explained by concomitant secretion of IL-1 inhibitory factors, as well as the secretion of activities other than IL-1. Preliminary biochemical analysis showed that all three cell sources tested shared some species of molecules characterized by gel filtration and ion-exchange chromatography. However, some species of molecules expressing IL-1 activity were unique to the cell lines and were not found in normal monocytes.

In vitro differentiation and establishment of cell lines derived from human myelomonocytic leukemia cells

Primary cultures of cells derived from 13 patients with acute myelomonocytic leukemia (AMML) were studied with particular emphasis on in vitro proliferation, cell differentiation and the mode for establishment of cell lines. Using irradiated human macrophage monolayers to assist cell growth, we obtained four new cell lines of myelomonocytic origin. All the cell lines were characterized for cytochemical markers and response to phorbol esters (TPA), a differentiation inducing agent. In the absence of any inducing agent, spontaneous differentiation of blast cells into mature macrophages-like cells occurred in 8 out of the 13 primary cultures. Thus, maturation induction by agents such as TPA is not always required in order to obtain leukemic cell differentiation in vitro. The regulation of cell proliferation and differentiation by cellular interactions and by extrinsic soluble products is discussed in detail, in the light of these findings.

Regulation of glutamine metabolism in dog kidney in vivo

In summary, we propose: that renal ammoniagenesis is regulated both by factors dependent and independent of the acid-base status, the net effect of the ammoniagenic process on the proton balance being directly related to the rate of urinary ammonium excretion; that the renal metabolism of glutamine should not be examined independently of the metabolism of other substrate physiologically taken up by the kidney; that different pathways for glutamine metabolism will change during acid-base disorders of organic or nonorganic origin; that, among the main glutamine utilizing pathways, only the GLDH pathway is influenced directly by the acid-base status; the ammoniagenic transamination pathways is regulated by substrate availability in the kidney; that the lowest ammoniagenic flux in the kidney coincides with the rate of alanine production since alanine appears to derive directly from glutamine. When this pathway is stimulated without concomitant acidosis, most of the ammonia produced is not excreted in urine but released in the renal venous blood: thus, no significant effect on the acid-base balance is produced; that glutamine is metabolized by proximal kidney tubules of acidotic dogs probably through net oxidation; that the quantitative analysis of the metabolic consequence of this process indicates that the rate of ATP turnover at this site may effectively place an upper limit to the rate of glutamine oxidation, and ammonia production by the kidney, and that this limit is nearly reached in chronically acidotic animals.

Inhibition of natural killer cell-mediated cytotoxicity by lipids extracted from Mycobacterium bovis BCG

Several studies have demonstrated an augmentation of natural killer (NK) cell-mediated cytotoxicity by various adjuvants including BCG. Inhibitory effects of BCG have also been reported, particularly for relatively high doses. Because the cell wall of Mycobacterium bovis BCG contains a high proportion of lipids, the possibility was considered that these lipids may modulate NK activity. A total lipid fraction was extracted from Mycobacterium bovis BCG and used for the lipid modulation of NK effector and target cells. Treatment of effector or target cells resulted in decreased membrane fluidity and decreased NK cell-mediated cytotoxicity in both cases. Pretreatment of target cells did not affect the binding between target and effector cells, as shown in the single cell assay, whereas pretreatment of effectors resulted in inhibition of conjugation. It was further demonstrated that treatment of target cells which were first programmed for lysis protected these cells from subsequent lysis during the killer cell independent lysis stage. The results of this study suggest that adverse effects of BCG treatment on immune functions may be mediated by BCG derived lipids.

Studies on the "labile-bound" glucose compartment in erythrocytes: studies on Psammomys obesus (sand rat) and preliminary studies on human erythrocytes

Enzymatic (glucose oxidase) measurement of glucose concentration in the fluid compartment of Psammomys erythrocytes (Gfe) and of its concentration in the fluid compartment of blood plasma (Gfp) gives the ratio (mean +/- SD): Gfe/Gfp = 1.50 +/- 0.43 (n = 12, 23 degrees C). However, when we added 3H-labeled glucose (G*) in vitro to the whole blood, the ratio after 2 min was G*fe/G*fp = 0.90 (SD 0.11) and after 5 min G*fe/G*fp = 0.97 (SD 0.12). These calculations were based on previous determination of the fractional volumes of the fluid and non-fluid compartments in Psammomys blood. The results suggest that there is more than one compartment of measurable glucose in Psammomys erythrocytes. Glucose undergoes a fast free transfer between the plasma and the erythrocyte fluids, and a much slower transmission to another measurable compartment in the erythrocyte, where it is loosely bound to other molecules. This loosely bound glucose does not participate in the fast kinetic transmission across the erythrocyte membrane, but it is measurable by the glucose-oxidase-based method. Preliminary studies on human erythrocytes lead to similar conclusions.

Studies on the "labile-bound" glucose compartment in erythrocytes: studies on Psammomys obesus (sand rat) and preliminary studies on human erythrocytes

Enzymatic (glucose oxidase) measurement of glucose concentration in the fluid compartment of Psammomys erythrocytes (Gfe) and of its concentration in the fluid compartment of blood plasma (Gfp) gives the ratio (mean +/- SD): Gfe/Gfp = 1.50 +/- 0.43 (n = 12, 23 degrees C). However, when we added 3H-labeled glucose (G*) in vitro to the whole blood, the ratio after 2 min was G*fe/G*fp = 0.90 (SD 0.11) and after 5 min G*fe/G*fp = 0.97 (SD 0.12). These calculations were based on previous determination of the fractional volumes of the fluid and non-fluid compartments in Psammomys blood. The results suggest that there is more than one compartment of measurable glucose in Psammomys erythrocytes. Glucose undergoes a fast free transfer between the plasma and the erythrocyte fluids, and a much slower transmission to another measurable compartment in the erythrocyte, where it is loosely bound to other molecules. This loosely bound glucose does not participate in the fast kinetic transmission across the erythrocyte membrane, but it is measurable by the glucose-oxidase-based method. Preliminary studies on human erythrocytes lead to similar conclusions.

A new myelomonoblastic cell line (M20): analysis of properties, differentiation, and comparison with other established lines of similar origin

A new myelomonoblastic cell line (M20) was established from the peripheral blood of a ten-year-old child with acute myeloblastic leukemia, using an improved method for supporting the initial stages of cell proliferation. The addition of irradiated macrophage monolayers to the proliferating cells appeared to overcome the deterioration of the primary cultures and enable them to continue proliferating until they became independent of this environment. The cell line that developed consisted of myeloblasts and promyelocytes characterized by light and scanning electron microscopy, cytochemistry, and enzymatic activities. The cells expressed Fc receptors and WT1 antigens but did not exhibit HLA-DR, HMA1, Epstein-Barr virus nuclear antigen, and surface Ig. The M20 cells produced colonies when cultured in semisolid medium and secreted lysozyme, prostaglandin E2, and interleukin 1. An attempt was also made to analyse the position of the M20 cells in the scheme of differentiation of the myelomonocytic lineage using different approaches. Treatment of the cells with 12-O-tetradecanoyl phorbol 13-acetate induced their adherence to plastic surfaces and partial maturation to macrophages as judged by morphological criteria, cytochemistry, and enzyme activities. However, comparison of the M20 cells to other well-established myelomonoblastic cell lines did not reveal any pattern suggesting a possible relationship between surface markers, cell function, and differentiation pathway of the various cell lines tested. Establishment of additional cell lines and identification of new markers may assist in defining the mechanisms involved in normal differentiation and malignant transformation of this cell lineage. In addition, such cell lines may also provide a tool for the quantitative recovery of a variety of monokines.

On the use of the logistic model in prospective studies

We describe the usual statistical concepts and consequent appropriate simulations of a prospective study for the simple case of a single risk variable and an assumed logistic model. We examine the simulations of Lilienfeld and Pyne, and show that they are seriously flawed. Contrary to those authors' claims, the estimates of parameters by the Walker-Duncan technique are both accurate and reliable.

Mode of delivery in the low birth weight fetus. Delivery by cesarean section independent of fetal lie versus vaginal delivery in vertex presentation. A study with long-term follow-up

In a paired controlled multicenter study of patients in preterm labor of unknown etiology without additional maternal or fetal complications, 59 low birth weight infants in vertex presentation born vaginally were compared with 59 infants delivered by cesarean section. In the early postpartum period, hypothermia and acidosis occurred more often in the vaginal delivery group. The rate of respiratory disorders and need for assisted ventilation did not differ between the groups. Persistent ductus arteriosus occurred in 19% in the vaginal delivery group and in 7% in the abdominal delivery group. At follow-up until 18-24 months of age the rate of cerebral palsy did not differ between the groups, whereas the rate of psychomotor retardation was significantly higher in the vaginal delivery group (p less than 0.05). The difference in percentage of total outcome, i.e. sum of mortality and neurodevelopmental sequelae, being 20.3% in the vaginal delivery group versus 8.5% in the cesarean section group, fails to reach a statistical significance, but the results suggest that for the low birth weight infants, vaginal delivery may be more hazardous than abdominal delivery.