Racial Disparities in Eligibility for Preemptive Waitlisting for Kidney Transplantation and Modification of eGFR Thresholds to Equalize Waitlist Time

BackgroundPatients may accrue wait time for kidney transplantation when their eGFR is ≤20 ml/min. However, Black patients have faster progression of their kidney disease compared with White patients, which may lead to disparities in accruable time on the kidney transplant waitlist before dialysis initiation.MethodsWe compared differences in accruable wait time and transplant preparation by CKD-EPI estimating equations in Chronic Renal Insufficiency Cohort participants, on the basis of estimates of kidney function by creatinine (eGFR_cr), cystatin C (eGFR_cys), or both (eGFR_cr-cys). We used Weibull accelerated failure time models to determine the association between race (non-Hispanic Black or non-Hispanic White) and time to ESKD from an eGFR of ≤20 ml/min per 1.73 m². We then estimated how much higher the eGFR threshold for waitlisting would be required to achieve equity in accruable preemptive wait time for the two groups.ResultsBy eGFR_cr, 444 CRIC participants were eligible for waitlist registration, but the potential time between eGFR ≤20 ml/min per 1.73 m² and ESKD was 32% shorter for Blacks versus Whites. By eGFR_cys, 435 participants were eligible, and Blacks had 35% shorter potential wait time compared with Whites. By the eGFR_cr-cys equation, 461 participants were eligible, and Blacks had a 31% shorter potential wait time than Whites. We estimated that registering Blacks on the waitlist as early as an eGFR of 24–25 ml/min per 1.73 m² might improve racial equity in accruable wait time before ESKD onset.ConclusionsPolicies allowing for waitlist registration at higher GFR levels for Black patients compared with White patients could theoretically attenuate disparities in accruable wait time and improve racial equity in transplant access.     

The association between social isolation and musculoskeletal health in older community-dwelling adults: findings from the Hertfordshire Cohort Study

Quality of Life Research - Social isolation has been associated with both physical and psychological adverse outcomes and is prevalent in older adults. We investigated the impact of social...     

Specific cerebellar reductions in children with chromosome 22q11.2 deletion syndrome

Children with chromosome 22q11.2 deletion syndrome commonly are found to have morphological brain changes, cognitive impairments, and elevated rates of psychopathology. One of the most commonly and consistently reported brain changes is reduced cerebellar volume. Here, we demonstrate that, in addition to the global cerebellum reductions previously reported, volumetric reductions of the anterior lobule and the vermal region of the neo-cerebellum in the mid-sagittal plane best differentiate children with the deletion from typically developing children. These results suggest that the morphological changes of specific portions of the cerebellum may be an important underlying substrate of cognitive impairments and increased incidence of psychopathology in this group.     

Viral myocarditis: Changing concepts in pathogenesis and implications in diagnosis and treatment

Viral myocarditis is an important potential precursor to idiopathic dilated cardiomyopathy. An understanding of its pathogenesis has evolved with the recent clarification of the role of immune mechanisms, which appears to have both protective and autodestructive effects. In animal models immune modulation has led to paradoxical worsening of the disease, and clinical trials of immunosuppression have not shown any beneficial effects. Through the use of molecular diagnostic techniques, a possible direct role for the virus itself is now increasingly recognized in human disease. This is supported by animal models demonstrating viral cytopathic effects and chronic persistence of virus within the myocardium. A novel contribution from microvascular ischemia has also recently been demonstrated; this may play a particularly important role in the evaluation and treatment of dilated cardiomyopathy. These changing concepts in pathogenesis will have an impact on diagnosis; myocardial biopsy will be used for molecular diagnosis of viral infection, in addition to providing important histological information. Therapy for viral myocarditis will also evolve in parallel to include trials of antiviral agents, targeted immune modulators, and anti-ischemic or vasodilator therapy. With new tools of molecular diagnosis in myocarditis complementing the traditional morphological and immunological assessments, we now have avenues of opportunity to explore in depth the pathogenesis, epidemiology, and prognosis of this challenging disease.     

Phase I clinical study of LL-D49194α1 with retrospective pharmacokinetic investigations in mice and humans

Summary LL-D491941 is a new cytotoxic antibiotic selected for clinical phase I study because of its impressive pre-clinical anti-tumour activity and its low toxicity profile in experimental animals. A total of 15 patients were treated in centres in Glasgow and Amsterdam at doses ranging from 0.25 to 4 mg/m². One minor response was noted in a patient with colonic carcinoma. The study was suspended following the discovery of unexpected cardiotoxicity. As this toxicity was not consistent with the standard (EORTC) European Organisation for Research and Treatment of Cancer toxicology profile, we chose to investigate the pharmacokinetics of LL-D491941 in mice and humans in more detail to try to explain this phenomenon. A major difference in plasma protein binding was discovered between mice and patients, with a suggestion of non-linear kinetics being noted at higher doses in humans. It is likely that these differences in drug handling account for the unexpected and serious toxicity encountered in this trial.     

Mechanism of tolerance development to 2,5-dimethoxy-4-iodoamphetamine in rats: down-regulation of the 5-HT2A, but not 5-HT2C, receptor

  Rationale: Defining the mechanism of tolerance development to hallucinogenic drugs will help to explain their mechanism of action. Objectives: The present study was conducted to determine first, if tolerance develops to the discriminative stimulus (DS) properties of the hallucinogen, 2,5 dimethoxy-4-iodo-amphetamine (DOI) and second, the mechanism mediating tolerance. Methods: Rats were trained to discriminate 0.75 mg/kg DOI from saline on a concurrent VI-30-min schedule of reinforcement with a 15-min time-out for incorrect responses. To evaluate tolerance development, rats were assigned to one of four groups and treated with either chronic saline or chronic DOI. Prior to chronic treatment, two groups were tested for choice behavior following vehicle administration while the remaining two groups were tested following the administration of 0.375 mg/kg DOI. One group from each pre-test condition was injected with either saline or DOI (1 mg/kg) for 8 days. Twenty-four hours after the last chronic injection the pre-test treatments were replicated. Using receptor autoradiography, the density of 5-HT_2A and 5-HT_2C receptors was measured in independent groups of rats that had received identical treatment conditions. Results: Animals receiving chronic DOI showed a 60% decrease in DOI lever responding (from 100% to 40%) when tested on 0.375 mg/kg DOI, while animals receiving chronic saline showed no change in percent choice (100%) on the DOI lever. Significant changes in binding were observed in 5-HT_2A receptors but not 5-HT_2C receptors. The results of tests with antagonists were consistent with the changes in binding. Conclusions: These results suggest that behavioral tolerance to DOI reflects neuroadaptive changes in 5-HT_2A receptors. Received: 17 July 1998 / Final version: 19 January 1999     

Combined finasteride and flutamide therapy in men with advanced prostate cancer

Objectives

To evaluate the efficacy of combined finasteride and flutamide therapy in men with advanced prostate cancer by determining (1 ) the short-term tolerability of finasteride monotherapy and its effect on serum prostate-specific antigen (PSA) and hormone (testosterone, dihydrotestosterone) levels, and (2) the effects of the addition of flutamide on tolerability and on serum PSA and hormone levels.

Methods

Thirteen hormone-naive men with advanced prostate cancer (4 with Stage D2, 1 with Stage D1, 1 with Stage DO, 7 with rising PSA levels after radical prostatectomy [n = 2]or definitive radiation therapy [n = 5]) were initially treated with 5 mg finasteride daily. Flutamide (250 mg three times a day) was added after serum PSA levels stabilized.

Results

Finasteride alone (median 5 weeks) had no significant effect on serum PSA levels (P>0.05). Combined finasteride and flutamide resulted in a mean 91% reduction in serum PSA levels, with 85% of men achieving a nadir serum PSA level of less than 4.0 ng/mL and 46% achieving undetectable levels (0.2 ng/mL or less). Finasteride alone had no significant effect on serum testosterone levels (P>0.05) but did result in a mean 74% reduction in serum dihydrotestosterone levels. Combined finasteride and flutamide resulted in a mean 56% increase in serum testosterone levels but had no additional effect on serum dihydrotestosterone levels (P>0.05). Side effects occurred in 85% (gynecomastia or breast tenderness in 62% [8 of 13]and diarrhea in 23% [3 of 13]) of men on combined therapy. Potency was preserved in 66%. Combined finasteride and flutamide therapy was withdrawn from 15% (2 of 13) because of flutamide-induced diarrhea and from 23% (3 of 13) because of disease progression. All remaining patients (8 of 13) have serum PSA levels below 4.0 ng/mL and 4 of these 8 have undetectable levels. These men have received combined finasteride and flutamide for a median 11 months (range 6 to 19).

Conclusions

Finasteride monotherapy is inadequate therapy for advanced prostate cancer, but combined finasteride and flutamide may be a reasonable alternative for men with advanced prostate cancer who refuse conventional hormone therapy.