Factors Associated with Health Care Utilization at the End of Life for Patients with Acute Myeloid Leukemia.

Background: Patients (≥60 years) with acute myeloid leukemia (AML) often receive intense health care utilization at the end of life (EOL). However, factors associated with their health care use at the EOL are unknown. Methods: We conducted a secondary analysis of 168 deceased patients with AML within the United States. We assessed quality of life (QOL) (Functional-Assessment-Cancer-Therapy-Leukemia), and psychological distress (Hospital-Anxiety-and-Depression Scale [HADS]; Patient-Health-Questionnaire-9 [PHQ-9]) at diagnosis. We used multivariable logistic regression models to examine the association between patient-reported factors and the following outcomes: (1) hospitalizations in the last 7 days of life, (2) receipt of chemotherapy in the last 30 days of life, and (3) hospice utilization. Results: About 66.7% (110/165) were hospitalized in the last 7 days of life, 51.8% (71/137) received chemotherapy in the last 30 days of life, and 40.7% (70/168) utilized hospice. In multivariable models, higher education (odds ratio [OR] = 1.54, p = 0.006) and elevated baseline depression symptoms (PHQ-9: OR = 1.09, p = 0.028) were associated with higher odds of hospitalization in the last seven days of life, while higher baseline QOL (OR = 0.98, p = 0.009) was associated with lower odds of hospitalization at the EOL. Higher baseline depression symptoms were associated with receipt of chemotherapy at the EOL (HADS-Depression: OR = 1.10, p = 0.042). Higher education was associated with lower hospice utilization (OR = 0.356, p = 0.024). Conclusions: Patients with AML who are more educated, with higher baseline depression symptoms and lower QOL, were more likely to experience high health care utilization at the EOL. These populations may benefit from interventions to optimize the quality of their EOL care.

Association of Social Support With Overall Survival and Healthcare Utilization in Patients With Aggressive Hematologic Malignancies.

BACKGROUND: Social support plays a crucial role for patients with aggressive hematologic malignancies as they navigate their illness course. The aim of this study was to examine associations of social support with overall survival (OS) and healthcare utilization in this population. METHODS: A cross-sectional secondary analysis was conducted using data from a prospective longitudinal cohort study of 251 hospitalized patients with aggressive hematologic malignancies at Massachusetts General Hospital from 2014 through 2017. Natural Language Processing (NLP) was used to identify the extent of patients' social support (limited vs adequate as defined by NLP-aided chart review of the electronic health record). Multivariable regression models were used to examine associations of social support with (1) OS, (2) death or readmission within 90 days of discharge from index hospitalization, (3) time to readmission within 90 days, and (4) index hospitalization length of stay. RESULTS: Patients had a median age of 64 years (range, 19-93 years), and most were White (89.6%), male (68.9%), and married (65.3%). A plurality of patients had leukemia (42.2%) followed by lymphoma (37.9%) and myelodysplastic syndrome/myeloproliferative neoplasm (19.9%). Using NLP, we identified that 8.8% (n=22) of patients had limited social support. In multivariable analyses, limited social support was associated with worse OS (hazard ratio, 2.00; P=.042) and a higher likelihood of death or readmission within 90 days of discharge (odds ratio, 3.11; P=.043), but not with time to readmission within 90 days or with index hospitalization length of stay. CONCLUSIONS: In this cohort of hospitalized patients with aggressive hematologic malignancies, we found associations of limited social support with lower OS and a higher likelihood of death or readmission within 90 days of hospital discharge. These findings underscore the utility of NLP for evaluating the extent of social support and the need for larger studies evaluating social support in patients with aggressive hematologic malignancies.

Distress in a Pandemic: Association of the Coronavirus Disease-2019 Pandemic with Distress and Quality of Life in Hematopoietic Stem Cell Transplantation.

The global coronavirus disease 2019 (COVID-19) pandemic has drastically disrupted cancer care, potentially exacerbating patients' distress levels. Patients undergoing hematopoietic stem cell transplantation (HSCT) may be especially vulnerable to this pandemic stress. However, the associations of the COVID-19 pandemic with distress, fatigue, and quality of life (QoL) are not well understood in this population. In a cross-sectional analysis of data from 205 patients undergoing HSCT enrolled in a supportive care trial, we compared baseline pre-HSCT distress symptoms (depression, anxiety, and posttraumatic stress disorder [PTSD]), fatigue, and QoL between enrollees before (ie, March 2019-January 2020) and during (ie, March 2020-January 2021) the COVID-19 pandemic. We used linear regression models adjusting for sociodemographics and cancer diagnosis to examine the associations between enrollment period and patient-reported outcomes. We used semistructured qualitative interviews in 20 allogeneic HSCT recipients who were ≥3-months post-HSCT to understand the impact of the COVID-19 pandemic on their recovery post-HSCT. One hundred twenty-four participants enrolled before COVID-19, and 81 participants enrolled during the pandemic. The 2 cohorts had similar baseline demographics and disease risk factors. In multivariate regression models, enrollment during COVID-19 was not associated with pre-HSCT symptoms of depression, anxiety, PTSD, fatigue, or QoL impairment. COVID-19-era participants reported themes of negative (eg, increased isolation) and positive (eg, engagement with meaningful activities) implications of the pandemic on HSCT recovery. We found no differences in pre-HSCT distress, fatigue, or QoL in patients undergoing HSCT before or during the COVID-19 pandemic; however, patients in early recovery post-HSCT report both negative and positive implications of the COVID-19 pandemic in their lives.

Association Between Baseline Patient-Reported Outcomes and Complications of Hematopoietic Stem Cell Transplantation.

Hematopoietic cell transplantation (HCT) is a potentially curative therapy for hematologic malignancies, but it often results in significant toxicities and impaired quality of life (QOL). Although the value of patient-reported outcomes (PROs) is increasingly recognized in HCT, data are limited regarding the relationship between PROs and HCT complications. We conducted a secondary data analysis of 250 patients who were hospitalized for autologous or allogeneic HCT at Massachusetts General Hospital from 2011 through 2016. We assessed QOL (Functional Assessment of Cancer Therapy-General), mood (Hospital Anxiety and Depression Scale), and fatigue (FACT-Fatigue) at baseline. We abstracted from the Electronic Health Record (1) hospitalization during the first 100 days after HCT, (2) days alive and out of the hospital in the first 100 days after HCT, and (3) cumulative incidence of acute graft-versus-host disease (GVHD) among allogeneic HCT recipients. We assessed the association of baseline PROs with HCT complications using multivariable models adjusting for patient and transplant characteristics. Overall, 44.4% (111/250) of patients underwent an autologous HCT, 25.2% (63/250) received a myeloablative allogeneic HCT, and 30.4% (76/250) underwent a reduced-intensity allogeneic HCT. In multivariable logistic regression, higher anxiety (odds ratio [OR] = 1.14, P = .004) was associated with higher likelihood of rehospitalization within 100 days after HCT. In multivariable Poisson regression, lower fatigue (ß = 0.003, P = .015) was associated with increased days alive and out of the hospital in the first 100 days post-HCT. In multivariable logistic regression, lower baseline QOL (OR = 0.97, P = .034), higher fatigue (OR = 0.95, P = .004), and higher depression (OR = 1.15, P = .020) were associated with increased likelihood of acute GVHD. Baseline PROs are associated with health care utilization after HCT and risk of acute GVHD in allogeneic HCT recipients. These findings underscore the potential utility of pretransplantation PROs as important prognostic factors for HCT.

Post-Traumatic Stress Symptoms in Hematopoietic Stem Cell Transplant Recipients.

Hematopoietic stem cell transplantation (HCT) is an intensive and potentially curative therapy for patients with hematologic malignancies. Patients admitted for HCT experience a prolonged, isolating hospitalization and endure substantial physical and psychological symptoms. However, there is a paucity of research on the impact of HCT on post-traumatic stress disorder (PTSD) symptoms in transplant recipients. This secondary analysis of 250 patients who underwent autologous and allogeneic HCT examined PTSD using the PTSD Checklist-Civilian measured at 6 months after HCT. We used the Functional Assessment of Cancer Therapy-Bone Marrow Transplant, and the Hospital Anxiety and Depression Scale to assess quality of life (QOL) and depression and anxiety symptoms at the time of admission for HCT, week 2 during hospitalization, and 6 months after HCT. We used multivariate regression models to assess factors associated with PTSD symptoms. Given collinearity between QOL, depression, and anxiety symptoms, we modeled these separately. The rate of clinically significant PTSD symptoms at 6 months after HCT was 18.9% (39/206). Participants with clinically significant PTSD symptoms experienced hypervigilance (92.3%), avoidance (92.3%), and intrusion (76.9%) symptoms. Among patients without clinically significant PTSD symptoms, 24.5% had clinically significant hypervigilance symptoms and 13.7% had clinically significant avoidance symptoms. Lower QOL at time of HCT admission (B = -0.04, P = .004) and being single (B = -3.35, P = .027) were associated with higher PTSD symptoms at 6 months after HCT. Higher anxiety at time of HCT admission (B = 1.34, P <.001), change in anxiety during HCT hospitalization (B = 0.59, P =.006), and being single (B = -3.50, P = .017) were associated with higher PTSD symptoms at 6 months. In a separate model using depression, younger age (B = -0.13, P = .017), being single (B = -3.58, P = .018), and higher baseline depression symptoms were also associated with higher PTSD symptoms at 6 months (B = 0.97, P < .001). Approximately one fifth of patients undergoing HCT experience clinically significant PTSD symptoms at 6 months after transplantation. The prevalence of hypervigilance and avoidance symptoms are notable even among patients who do not have clinically significant PTSD symptoms. Interventions to prevent and treat PTSD symptoms in HCT recipients are clearly warranted.

Healthcare Utilization and End-of-Life Outcomes in Patients Receiving CAR T-Cell Therapy.

BACKGROUND: CAR T-cell therapy has revolutionized the treatment of patients with hematologic malignancies, but it can result in prolonged hospitalizations and serious toxicities. However, data on the impact of CAR T-cell therapy on healthcare utilization and end-of-life (EoL) outcomes are lacking. METHODS: We conducted a retrospective analysis of 236 patients who received CAR T-cell therapy at 2 tertiary care centers from February 2016 through December 2019. We abstracted healthcare utilization and EoL outcomes from the electronic health record, including hospitalizations, receipt of ICU care, hospitalization and receipt of systemic therapy in the last 30 days of life, palliative care, and hospice referrals. RESULTS: Most patients (81.4%; n=192) received axicabtagene ciloleucel. Overall, 28.1% of patients experienced a hospital readmission and 15.5% required admission to the ICU within 3 months of CAR T-cell therapy. Among the deceased cohort, 58.3% (49/84) were hospitalized and 32.5% (26/80) received systemic therapy in the last 30 days of life. Rates of palliative care and hospice referrals were 47.6% and 30.9%, respectively. In multivariable logistic regression, receipt of bridging therapy (odds ratio [OR], 3.15; P=.041), index CAR-T hospitalization length of stay >14 days (OR, 4.76; P=.009), hospital admission within 3 months of CAR T-cell infusion (OR, 4.29; P=.013), and indolent lymphoma transformed to diffuse large B-cell lymphoma (OR, 9.83; P=.012) were associated with likelihood of hospitalization in the last 30 days of life. CONCLUSIONS: A substantial minority of patients receiving CAR T-cell therapy experienced hospital readmission or ICU utilization in the first 3 months after CAR T-cell therapy, and most deceased recipients of CAR T-cell therapy received intensive EoL care. These findings underscore the need for interventions to optimize healthcare delivery and EoL care for this population.

Sharing and caring: The impact of social support on quality of life and health outcomes in hematopoietic stem cell transplantation.

BACKGROUND: Social support is crucial for successful recovery after hematopoietic stem cell transplantation (HSCT) and has the potential to affect patient quality of life (QOL) and health outcomes. However, there are limited data on the relationship between a patient's perception of his or her social support and these outcomes. METHODS: The authors conducted a secondary analysis of 250 autologous and allogeneic HSCT recipients enrolled in 2 supportive care trials at Massachusetts General Hospital from April 2011 through February 2016. They assessed social support as a patient's perception of his or her social well-being via the social well-being subscale of the Functional Assessment of Cancer Therapy. The authors used multivariate regression analyses to examine the relationship between pretransplant social well-being and QOL (Functional Assessment of Cancer Therapy-Treatment Outcome Index), psychological distress (Hospital Anxiety and Depression Scale), posttraumatic stress disorder [PTSD] symptoms (PTSD Checklist), fatigue (Functional Assessment of Cancer Therapy-Fatigue), and health care utilization (hospitalizations and days alive and out of the hospital) 6 months after HSCT. RESULTS: Participants were on average 56.4 years old (SD, 13.3 years); 44% (n = 110) and 56% (n = 140) received autologous and allogeneic HSCT, respectively. Greater pre-HSCT social well-being was associated with higher QOL (B = 0.10; 95% CI, 0.06-0.13; P < .001), lower psychological distress (B = -0.21; 95% CI, -0.29 to -0.12; P < .001), and lower PTSD symptoms (B = -0.12; 95% CI, -0.19 to -0.06; P < .001). Pre-HSCT social well-being was not significantly associated with fatigue or health care utilization 6 months after HSCT. CONCLUSIONS: Patients with higher pre-HSCT perceptions of their social support reported better QOL and lower psychological distress 6 months after HSCT. These findings underscore the potential for social support as a modifiable target for future supportive care interventions to improve the QOL and care of HSCT recipients.

Psychological Distress in Bereaved Caregivers of Patients With Advanced Cancer.

CONTEXT: Individuals caring for patients with advanced cancer (caregivers) experience psychological distress during the patient's illness course. However, data on the prevalence of bereaved caregivers' psychological distress and its relationship with the quality of patient's end of life (EOL) care are limited. OBJECTIVES: To describe rates of depression and anxiety symptoms in bereaved caregivers of patients with advanced cancer and to understand the relationship between these outcomes and patient distress at the EOL. METHODS: We conducted a secondary analysis of 168 caregivers enrolled in a supportive care trial for patients with incurable lung and gastrointestinal cancers and their caregivers. We used the Hospital Anxiety and Depression Scale to assess caregivers' depression and anxiety symptoms at three months after the patient's death. Caregivers also rated the patient's physical and psychological distress in the last week of life on a 10-point scale three months after the patient death. We used linear regression adjusting for caregiver age, sex, randomization, and cancer type to explore the relationship between bereaved caregivers' depression and anxiety symptoms and their ratings of physical and psychological distress in patients at the EOL. RESULTS: Of the 168 bereaved caregivers, 30.4% (n = 51) and 43.4% (n = 73) reported clinically significant depression and anxiety symptoms, respectively. Caregiver ratings of worse physical (B = 0.32; P = 0.009) and psychological (B = 0.50; P < 0.001) distress experienced by the patient at the EOL were associated with worse depression symptoms in bereaved caregivers. Only caregiver rating of worse psychological distress experienced by the patient at the EOL (B = 0.42; P < 0.001) was associated with worse bereaved caregivers' anxiety symptoms. CONCLUSION: Many bereaved caregivers of patients with advanced cancer experience symptoms of depression and anxiety, which are associated with their perceptions of distress in their loved ones at the EOL.

In situ measurement of cesium-137 contamination in fruits from the northern Marshall Islands.

Radioactive contamination of fruits in the northern Marshall Islands, resulting from the US nuclear weapons testing program in the 1940s and 1950s, is still a human health concern, in particular pertaining to island population resettlement and the economic benefit from farming. Over 200 fruits, primarily coconuts and pandanus, were collected on 11 islands from four atolls in the northern Marshall Islands in 2017. The energy spectra from nuclear gamma decays were measured on a research vessel for each fruit in situ. From these recordings, the level of cesium-137 (137Cs) contamination was determined for individual fruits. Comparisons of the results are made to past studies and international food safety standards. There is a broad distribution of values, ranging from below detectable radiation levels to relatively high levels; safety concerns are largest for Bikini Island. A noticeable fraction of fruits from Bikini have significantly higher levels of 137Cs contamination compared with those from all other measured islands.

Canadian survey of clinical status at dialysis initiation 1998-1999: a multicenter prospective survey.

AIMS: The current growth in end-stage kidney disease populations has led to increased efforts to understand the impact of status at dialysis initiation on long-term outcomes. Our main objective was to improve the understanding of current Canadian nephrology practice between October 1998 and December 1999. METHODS: Fifteen nephrology centers in 7 provinces participated in a prospective data collection survey. The main outcome of interest was the clinical status at dialysis initiation determined by: residual kidney function, preparedness for chronic dialysis as measured by presence or absence of permanent peritoneal or hemodialysis access, hemoglobin and serum albumin. Uremic symptoms at dialysis initiation were also recorded, however, in some cases these symptom data were obtained retrospectively. RESULTS: Data on 251 patients during 1-month periods were collected. Patients commenced dialysis at mean calculated creatinine clearance levels of approximately 10 ml/min, with an average of 3 symptoms. 35% of patients starting dialysis had been known to nephrologists for less than 3 months. These patients are more likely to commence without permanent access and with lower hemoglobin and albumin levels. Even of those known to nephrologists, only 66% had permanent access in place. CONCLUSIONS: Patients commencing dialysis in Canada appear to be doing so in relative concordance with published guidelines with respect to timing of initiation. Despite an increased awareness of kidney disease, a substantial number of patients continues to commence dialysis without previous care by a nephrologist. Of those who are seen by nephrologists, clinical and laboratory parameters are suboptimal according to current guidelines. This survey serves as an important baseline for future comparisons after the implementation of educational strategies for referring physicians and nephrologists.

Cardiovascular disease in patients with chronic kidney disease: getting to the heart of the matter.

The high prevalence of cardiovascular disease (CVD) in patients with kidney disease is well described. This Canadian, multicenter, observational cohort study reports the prevalence and risk factors of CVD associated with kidney disease, in a cohort of patients with established chronic kidney disease (CKD), who are followed-up by nephrologists. This analysis sought to answer 2 questions: (1) in patients with established CKD, are the prevalence and progression of CVD accounted for by conventional or uremia-related risk factors, and (2) to what extent can progression to renal replacement therapy (RRT) be explained by CVD versus traditional risk factors for kidney disease? This study population consists of 313 patients (predominantly men) who had a mean age of 56 years and a mean creatinine clearance of 36 mL/min. Thirty percent were diabetic. The overall prevalence of CVD was 46%, and was independent of severity of kidney dysfunction (P = 0.700). The median follow-up time was 23 months, for a total of 462 patient years. We note the overall incidence of CVD events (new CVD or worsening of CVD) was 47/244 (20%). The best predictors of new CVD events among those without preexisting CVD were diabetes (odds ratio [OR] = 5.35, P = 0.018) and age (OR = 1.26, P = 0.08). In those with preexisting CVD, low diastolic pressure (DP) (OR =.72, P = 0.004) and high triglycerides (OR = 1.48, P = 0.019) at baseline were independent predictors of progression of CVD. We could not determine an independent impact of kidney function on CVD in the overall cohort. Furthermore, we determined that the presence of CVD itself confers an increased risk for progression to RRT (relative risk [RR] = 1.58, P = 0.047), adjusted for kidney function. This is the first in-depth analysis of CVD in a cohort of patients with established chronic kidney disease who are not on dialysis. The question regarding the impact of the altered biology of uremia in contributing to CVD progression remains unanswered, and clearly needs further study. However, the findings do raise the issue of whether aggressive treatment of CVD and risk factors might, in fact, reduce progression to RRT. Further large-scale, observational studies as well as interventional studies are needed to more clearly understand the complex biology of cardiovascular and kidney disease progression.

Enhancing hepatocyte adhesion by pulsed plasma deposition and polyethylene glycol coupling.

Decreased hepatocyte adhesion to polymeric constructs limits the function of tissue engineered hepatic assist devices. We grafted adhesion peptides (RGD and YIGSR) to polycaprolactone (PCL) and poly-L-lactic acid (PLLA) in order to mimic the in vivo extracellular matrix and thus enhance hepatocyte adhesion. Peptide grafting was done by a novel technique in which polyethylene glycol (PEG)-adhesion peptide was linked to allyl-amine coated on the surface of PCL and PLLA by pulsed plasma deposition (PPD). Peptide grafting density, quantified by radio-iodinated tyrosine in YIGSR, was 158 fmol/cm(2) on PLLA and 425 fmol/cm(2) on PCL surfaces. The adhesion of hepatocytes was determined by plating 250,000 hepatocytes/well (test substrates were coated on 12 well plates) and quantifying the percentage of adhered cells after 6 h by MTT assay. Adhesion on PCL surfaces was significantly enhanced (p < 0.05) by both YIGSR (percentage of adhered cells = 53 +/- 7%) and RGD (53 +/- 12%) when compared to control surfaces (31 +/- 8%). Hepatocyte adhesion on PLLA was significantly (p < 0.05) enhanced on PLLA-PEG-RGD surfaces (76 +/- 14%) compared to control surfaces (42 +/- 19%) and more (68 +/- 25%) but not statistically significant (p = 0.15) on PLLA-PEG-YIGSR surfaces compared to control surfaces. These results indicate that hepatocyte adhesion to PCL and PLLA based polymeric surfaces can be enhanced by a novel adhesion peptide grafting technique using pulsed plasma deposition and PEG cross-linking.

Left ventricular mass index increase in early renal disease: impact of decline in hemoglobin.

Cardiovascular disease occurs in patients with progressive renal disease both before and after the initiation of dialysis. Left ventricular hypertrophy (LVH) is an independent predictor of morbidity and mortality in dialysis populations and is common in the renal insufficiency population. LVH is associated with numerous modifiable risk factors, but little is known about LV growth (LVG) in mild-to-moderate renal insufficiency. This prospective multicenter Canadian cohort study identifies factors associated with LVG, measured using two-dimensional-targeted M-mode echocardiography. Eight centers enrolled 446 patients, 318 of whom had protocol-mandated clinical, laboratory, and echocardiographic measurements recorded. We report 246 patients with assessable echocardiograms at both baseline and 12 months with an overall prevalence of LVH of 36%. LV mass index (LVMI) increased significantly (>20% of baseline or >20 g/m2) from baseline to 12 months in 25% of the population. Other than baseline LVMI, no differences in baseline variables were noted between patients with and without LVG. However, there were significant differences in decline of Hgb level (-0.854 v -0.108 g/dL; P = 0.0001) and change in systolic blood pressure (+6.50 v -1.09 mm Hg; P = 0.03) between the groups with and without LVG. Multivariate analysis showed the independent contribution of decrease in Hgb level (odds ratio [OR], 1.32 for each 0.5-g/dL decrease; P = 0.004), increase in systolic blood pressure (OR, 1.11 for each 5-mm Hg increase; P = 0.01), and lower baseline LVMI (OR, 0.85 for each 10-g/m2; P = 0.011) in predicting LVG. Thus, after adjusting for baseline LVMI, Hgb level and systolic blood pressure remain independently important predictors of LVG. We defined the important modifiable risk factors. There remains a critical need to establish optimal therapeutic strategies and targets to improve clinical outcomes.

Improved bioresorbable microporous intravascular stents for gene therapy.

Drug imbibing microporous stents are under development at a number of centers to enhance healing of the arterial wall after balloon coronary angioplasty procedures. The authors improved the mechanical strength and reservoir properties of a biodegradable microporous stent reported to this Society in 1994. A combined tubular/helical coil stent is readily fabricated by flotation/precipitation and casting/ winding techniques. A two stage solvent swelling technique allows precise adjustment of the surface hydrophilic/hydrophobic balance. These developments permit seven-fold improvement in drug capacity without significantly altering mechanical properties. Stents modified in this manner retain tensile and compressive strength and are suitable for remote deployment. Elution kinetics of these modified stents suggest they are suitable for gene delivery. Successful gene transfer and transmural expression have been demonstrated after implantation of stents impregnated with a recombinant adenovirus carrying a nuclear localizing beta-galactosidase reporter gene into rabbit carotid arteries. These studies suggest that surface modified, bioresorbable polymer stents ultimately may be useful adjunctive devices for gene transfer during percutaneous transluminal revascularization.

Structural organization of the human gene (PKR) encoding an interferon-inducible RNA-dependent protein kinase (PKR) and differences from its mouse homolog.

The gene encoding the interferon-inducible, RNA-dependent protein kinase (PKR) was isolated as lambda phage and P1 phage clones from human genomic DNA libraries and characterized by Southern blot and nucleotide sequence analyses. Southern blot analyses were consistent with a single PKR gene, and genomic clones colocalized by fluorescence in situ hybridization to human chromosome 2p. Sequence analysis demonstrated that the human PKR gene consists of 17 exons and spans about 50 kb. The AUG translation initiation site for the 551-amino-acid PKR protein was located in exon 3; exon 17 was the largest exon and included the UAG translation termination site, AUUAAA polyadenylation signal, and putative C(A) 3' cleavage site. Two RNA-binding motifs, RI and RII, were present in exons 4 and 6, respectively, and the codon phasing of these exon junctions was conserved between them. The organization of the regulatory and catalytic subdomains of the PKR protein was remarkably preserved between the human and the mouse PKR genes; the amino acid junction positions for 13 of the 15 protein coding exons were exactly conserved.

Metaanalysis of the relative nephrotoxicity of high- and low-osmolality iodinated contrast media.

To determine whether low-osmolality contrast media (LOCM) are less nephrotoxic than high-osmolality contrast media (HOCM), the authors searched MEDLINE and EMBASE databases and other sources to find randomized trials with data collected on changes in glomerular filtration rate or serum creatinine (SCr) level with LOCM and HOCM. Forty-five trials were found. Data were unavailable from 14 trials. When the P values from the other 31 trials were pooled, an overall P value of .02 was found. Among 24 trials with available data, the mean change in SCr was 0.2-6.2 mumol/L less with LOCM than HOCM. Among 25 trials with available data, the pooled odds of a rise in SCr level of more than 44 mumol/L with LOCM was 0.61 (95% confidence interval [CI], 0.48-0.77) times that after HOCM. For patients with existing renal failure, this odds ratio was 0.5 (CI, 0.36-0.68), while it was 0.75 (CI, 0.52-1.1) in patients without prior renal failure. Greater changes in SCr level occurred only in those with existing renal failure and were less common with LOCM (odds ratio, 0.44; CI, 0.26-0.73). Use of LOCM may be beneficial in patients with existing renal failure.

Binaural auditory processing in multiple sclerosis subjects.

In order to relate human auditory processing to physiological and anatomical experimental animal data, we have examined the interrelationships between behavioral, electrophysiological and anatomical data obtained from human subjects with focal brainstem lesions. Thirty-eight subjects with multiple sclerosis were studied with tests of interaural time and level discrimination (just noticeable differences or jnds), brainstem auditory evoked potentials and magnetic resonance (MR) imaging. Interaural testing used two types of stimuli, high-pass (> 4000 Hz) and low-pass (< 1000 Hz) noise bursts. Abnormal time jnds (Tjnd) were far more common than abnormal level jnds (70% vs 11%); especially for the high-pass (Hp) noise (70% abnormal vs 40% abnormal for low-pass (Lp) noise). The HpTjnd could be abnormal with no other abnormalities; however, whenever the BAEPs, LpTjnd and/or level jnds were abnormal HpTjnd was always abnormal. Abnormal wave III amplitude was associated with abnormalities in both time jnds, but abnormal wave III latency with only abnormal HpTjnds. Abnormal wave V amplitude, when unilateral, was associated with a major HpTjnd abnormality, and, when bilateral, with both HpTjnd and LpTjnd major abnormalities. Sixteen of the subjects had their MR scans obtained with a uniform protocol and could be analyzed with objective criteria. In all four subjects with lesions involving the pontine auditory pathway, the BAEPs and both time jnds were abnormal. Of the twelve subjects with no lesions involving the pontine auditory pathway, all had normal BAEPs and level jnds, ten had normal LpTjnds, but only five had normal HpTjnds. We conclude that interaural time discrimination is closely related to the BAEPs and is dependent upon the stimulus spectrum. Redundant encoding of low-frequency sounds in the discharge patterns of auditory neurons, may explain why the HpTjnd is a better indicator of neural desynchrony than the LpTjnd. Encroachment of MS lesions upon the pontine auditory pathway always is associated with abnormal BAEPs and abnormal interaural time discrimination but may have normal interaural level discrimination. Our data provide one of the most direct demonstrations in humans of relationships among auditory performance, evoked potentials and anatomy. We present a model showing that many of these interrelationships can be readily interpreted using ideas developed from work on animals, even though these relationships could not have been predicted with confidence beforehand. This work provides a clear advance in our understanding of human auditory processing and should serve as a basis for future studies.