Disparities in stroke incidence contributing to disparities in stroke mortality

OBJECTIVE

While black-white and regional disparities in U.S. stroke mortality rates are well documented, the contribution of disparities in stroke incidence is unknown. We provide national estimates of stroke incidence by race and region, contrasting these to publicly available stroke mortality data.

METHODS

This analysis included 27,744 men and women without prevalent stroke (40.4% black), aged ≥45 years from the REasons for Geographic And Racial Differences in Stroke (REGARDS) national cohort study, enrolled 2003-2007. Incident stroke was defined as first occurrence of stroke over 4.4 years of follow-up. Age-sex-adjusted stroke mortality rates were calculated using data from the Centers for Disease Control and Prevention (CDC) Wide-Ranging Online Data for Epidemiological Research (WONDER) System.

RESULTS

There were 460 incident strokes over 113,469 person-years of follow-up. Relative to the rest of the United States, incidence rate ratios (IRRs) of stroke in the southeastern stroke belt and stroke buckle were 1.06 (95% confidence interval [CI], 0.87-1.29) and 1.19 (95% CI, 0.96-1.47), respectively. The age-sex-adjusted black/white IRR(black) was 1.51 (95% CI, 1.26-1.81), but for ages 45-54 years the IRR(black) was 4.02 (95% CI, 1.23-13.11) while for ages 85+ it was 0.86 (95% CI, 0.33-2.20). Generally, the IRRs(black) were less than the mortality rate ratios (MRRs) across age groups; however, only in ages 55-64 years and 65-74 years did the 95% CIs of IRRs(black) not include the MRR(black) . The MRRs for regions were within 95% CIs for IRRs.

INTERPRETATION

National patterns of black-white and regional differences in stroke incidence are similar to those for stroke mortality; however, the magnitude of differences in incidence appear smaller.

Transdermal nicotine for active ulcerative colitis

BACKGROUND

Ulcerative colitis is largely a disease of nonsmokers. Because anecdotal reports suggest that smoking and nicotine may improve the symptoms of the disease, we examined the effect of nicotine as a supplemental treatment for ulcerative colitis.

METHODS

We treated 72 patients with active ulcerative colitis with either transdermal nicotine patches or placebo patches for six weeks in a randomized, double-blind study. Incremental doses of nicotine were given; most patients tolerated doses of 15 to 25 mg per 24 hours. All the patients had been taking mesalamine, and 12 were receiving low doses of glucocorticoids; these medications were continued without change during the study. Clinical, sigmoidoscopic, and histologic assessments were made at base line and at the end of the study; symptoms were recorded daily on a diary card, and the clinician made a global assessment. Side effects and plasma nicotine and cotinine concentrations were monitored throughout the study.

RESULTS

Seventeen of the 35 patients in the nicotine group had complete remissions, as compared with 9 of the 37 patients in the placebo group (P = 0.03). The patients in the nicotine group had greater improvement in the global clinical grade of colitis (P < 0.001) and the histologic grade (P = 0.03), lower stool frequency (a difference of 1.6 stools daily; P = 0.008), less abdominal pain (P = 0.05), and less fecal urgency (P = 0.009). More patients in the nicotine group had side effects (23, vs. 11 in the placebo group; P = 0.002), the most common of which were nausea, lightheadedness, headache, and sleep disturbance. Withdrawals due to ineffective therapy were more common in the placebo group (3 vs. 8, P = 0.12).

CONCLUSIONS

The addition of transdermal nicotine to conventional maintenance therapy improves symptoms in patients with ulcerative colitis.

Myelopoiesis in the zebrafish, Danio rerio

Genome-wide chemical mutagenesis screens in the zebrafish (Danio rerio) have led to the identification of novel genes affecting vertebrate erythropoiesis. In determining if this approach could also be used to clarify the molecular genetics of myelopoiesis, it was found that the developmental hierarchy of myeloid precursors in the zebrafish kidney is similar to that in human bone marrow. Zebrafish neutrophils resembled human neutrophils, possessing segmented nuclei and myeloperoxidase-positive cytoplasmic granules. The zebrafish homologue of the human myeloperoxidase (MPO) gene, which is specific to cells of the neutrophil lineage, was cloned and used to synthesize antisense RNA probes for in situ hybridization analyses of zebrafish embryos. Granulocytic cells expressing zebrafish mpo were first evident at 18 hours after fertilization (hpf) in the posterior intermediate cell mass (ICM) and on the anterior yolk sac by 20 hpf. By 24 hpf, mpo-expressing cells were observed along the ICM and within the developing vascular system. Thus, the mpo gene should provide a useful molecular probe for identifying zebrafish mutants with defects in granulopoiesis. The expression of zebrafish homologues was also examined in 2 other mammalian hematopoietic genes, Pu.1, which appears to initiate a commitment step in normal mammalian myeloid development, and L-Plastin, a gene expressed by human monocytes and macrophages. The results demonstrate a high level of conservation of the spatio-temporal expression patterns of these genes between zebrafish and mammals. The morphologic and molecular genetic evidence presented here supports the zebrafish as an informative model system for the study of normal and aberrant human myelopoiesis. (Blood. 2001;98:643-651)

Thickness of adherent mucus gel on colonic mucosa in humans and its relevance to colitis

The thickness of adherent mucus gel on the surface of colonic mucosa was measured in surgically resected specimens from 46 'control' patients most of whom had carcinoma of the colon; 12 were from right colon, 17 left colon, and 21 from rectum. In addition specimens were examined from 17 patients with ulcerative colitis and 15 patients with Crohn's disease. In controls a continuous layer of mucus was readily seen on specially prepared sections viewed by phase contrast illumination. Mean values for right and left colon and rectum were 107 (48), 134 (68), and 155 (54) microns respectively with a significant difference between right colon and rectum (p = 0.015). Values in ulcerative colitis showed greater variation and in those areas with acute inflammation mucosa was denuded of the mucus layer. In contrast, values for Crohn's disease were normal or greater than normal in thickness--right colon 190 (83) microns compared with 107 48 microns, p = 0.0093. A series of validation experiments are described for the method used to measure mucus thickness. The possible role of mucus in the pathogenesis of inflammatory bowel disease is discussed.

Osteoporosis in patients with inflammatory bowel disease

Bone mineral content in spinal trabecular and peripheral cortical bone was measured in 75 unselected patients with small and/or large intestinal inflammatory bowel disease. Osteoporosis, defined as a bone mineral content greater than 2 SD below the age and sex matched normal mean value was present in 23 patients (30.6%). Three amenorrhoeic females aged 34, 38, and 42 years had severe clinical osteoporosis and a further three patients had one or more vertebral crush fractures. Eighteen of the 23 patients with osteoporosis had small intestinal disease with one or more resections and the mean lifetime steroid dose in those with osteoporosis was significantly higher than in those with normal bone mineral content. Bone mineral content in spinal trabecular bone showed significant negative correlations with lifetime steroid dose and serum alkaline phosphatase and a significant positive correlation with serum albumin. Peripheral cortical bone mineral content was positively correlated with body weight, height and body mass index. We conclude that the prevalence of osteoporosis is increased in patients with inflammatory bowel disease, severe clinical osteoporosis developing in some relatively young patients. The pathogenesis of this bone loss is probably multifactorial; steroid therapy is likely to be an important contributory factor.

Traditional risk factors as the underlying cause of racial disparities in stroke: lessons from the half-full (empty?) glass

BACKGROUND AND PURPOSE

Black/white disparities in stroke incidence are well documented, but few studies have assessed the contributions to the disparity. Here we assess the contribution of "traditional" risk factors.

METHODS

A total of 25 714 black and white men and women, aged≥45 years and stroke-free at baseline, were followed for an average of 4.4 years to detect stroke. Mediation analysis using proportional hazards analysis assessed the contribution of traditional risk factors to racial disparities.

RESULTS

At age 45 years, incident stroke risk was 2.90 (95% CI: 1.72-4.89) times more likely in blacks than in whites and 1.66 (95% CI: 1.34-2.07) times at age 65 years. Adjustment for risk factors attenuated these excesses by 40% and 45%, respectively, resulting in relative risks of 2.14 (95% CI: 1.25-3.67) and 1.35 (95% CI: 1.08-1.71). Approximately one half of this mediation is attributable to systolic blood pressure. Further adjustment for socioeconomic factors resulted in total mediation of 47% and 53% to relative risks of 2.01 (95% CI: 1.16-3.47) and 1.30 (1.03-1.65), respectively.

CONCLUSIONS

Between ages 45 to 65 years, approximately half of the racial disparity in stroke risk is attributable to traditional risk factors (primarily systolic blood pressure) and socioeconomic factors, suggesting a critical need to understand the disparity in the development of these traditional risk factors. Because half of the excess stroke risk in blacks is not attributable to traditional risk factors and socioeconomic factors, differential impact of risk factors, residual confounding, or nontraditional risk factors may also play a role.

Transcriptional regulation of beta-defensin gene expression in tracheal epithelial cells

Innate immunity provides an ever-present or rapidly inducible initial defense against microbial infection. Among the effector molecules of this defense in many species are broad-spectrum antimicrobial peptides. Tracheal antimicrobial peptide (TAP) was the first discovered member of the beta-defensin family of mammalian antimicrobial peptides. TAP is expressed in the ciliated epithelium of the bovine trachea, and its mRNA levels are dramatically increased upon stimulation with bacteria or bacterial lipopolysaccharide (LPS). We report here that this induction by LPS is regulated at the level of transcription. Furthermore, the transfection of reporter gene constructs into tracheal epithelial cells indicates that DNA sequences in the 5' flanking region of the TAP gene, within 324 nucleotides of the transcription start site, are responsible in part for mediating gene induction. This region includes consensus binding sites for NF-kappaB and nuclear factor interleukin-6 (NF IL-6) transcription factors. Gel mobility shift assays indicate that LPS induces NF-kappaB binding activity in the nuclei of these cells, while NF IL-6 binding activity is constitutively present. The gene encoding human beta-defensin 2, a human homologue of TAP with similar inducible expression patterns in the airway, was cloned and found to have conserved NF-kappaB and NF IL-6 consensus binding sites in its 5' flanking region. Previous studies of antimicrobial peptides from insects indicated that their induction by infectious microbes and microbial products also occurs via activation of NF-kappaB-like and NF IL-6-like transcription factors. Together, these observations indicate that a strategy for the induction of peptide-based antimicrobial innate immunity is conserved among evolutionarily diverse organisms.

An oral preparation to release drugs in the human colon

1 A colonic delivery system is described to deliver orally ingested drugs to the colon and release them at that site by coating with an acrylic based resin (Eudragit S). The technique is validated using X-ray evidence and serum levels of a convenient marker, sulphapyridine. 2 This colonic delivery system is particularly suitable for drugs such as 5-amino salicylic acid or steroids in the management of patients with colitis.

Expression of a protein tyrosine phosphatase in normal and v-src-transformed mouse 3T3 fibroblasts

A rat cDNA encoding a 51-kD protein tyrosine phosphatase (PTP1) was cloned into a mammalian expression vector and transfected into normal and v-src-transformed mouse NIH 3T3 fibroblasts. In the stable subclones isolated, PTP1 expression at the mRNA level was elevated twofold to 25-fold. The highest constitutive level of phosphotyrosine- specific dephosphorylating activity observed without cytotoxic effects or significant clonal instability was approximately 10-fold over the endogenous activity. The expressed PTP1 was found to be associated with the particulate fraction of the fibroblasts. Subcellular fractionation and immunofluorescent microscopic examination of PTP1-overexpressing cells has shown the phosphatase to be localized to the reticular network of the ER. PTP1 was readily solubilized by detergents, but not by high salt. Limited proteolysis of membrane-associated PTP1 resulted in the release of lower molecular mass (48 and 37 kD) forms of the enzyme to the cytosol. Thermal phase partitioning of isolated membranes with Triton X-114 indicated that the full-length PTP1 was strongly integrated into the membrane in contrast to the proteolytically derived fragments of PTP1. Overexpression of PTP1 caused little apparent change in the rate of cell proliferation, but did induce changes in fibroblast morphology. A substantial increase in the proportion of bi- and multinucleate cells in PTP1-expressing cell populations was observed, and, in the case of the v-src-transformed cells, cell flattening and loss of refractibility occurred. Although no apparent difference in the tyrosine phosphorylation of pp60v-src was noted in v-src-transformed control and PTP1-overexpressing fibroblasts, the phosphotyrosine content of a 70-kD polypeptide was decreased in PTP1-overexpressing cells.

Metabolism and urinary excretion of 5-amino salicylic acid in healthy volunteers when given intravenously or released for absorption at different sites in the gastrointestinal tract

In six healthy subjects serum concentrations of 5 amino salicylic acid (5ASA) and acetyl 5ASA were measured for up to 24 hours, and urinary excretion over 48 hours. After an intravenous injection of 3.26 mmol 5ASA serum concentrations fell rapidly with a distribution half-life of 17 +/- 2 min and an elimination half-life of 42 +/- 5 min. After 45 minutes acetyl 5ASA became the dominant compound and after seven hours serum concentrations of both components were almost unrecordable. Orally ingested 5ASA in three preparations to ensure its release in the stomach, small intestine and ileocaecal region respectively gave lower serum concentrations and urinary excretion than those obtained after an intravenous infusion. Bioavailabilities which ranged from 19% for ileocaecal release to 75% for release in the upper gastrointestinal tract, were calculated from areas under the serum concentration curves. Urinary excretion of 5ASA and its acetyl metabolite over 48 hours was 78%, 52%, 55%, and 21% respectively of the dose given intravenously and orally for gastric, small intestinal and ileocaecal release.

Stroke after carotid stenting and endarterectomy in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST)

BACKGROUND

Stroke occurs more commonly after carotid artery stenting than after carotid endarterectomy. Details regarding stroke type, severity, and characteristics have not been reported previously. We describe the strokes that have occurred in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST).

METHODS AND RESULTS

CREST is a randomized, open-allocation, controlled trial with blinded end-point adjudication. Stroke was a component of the primary composite outcome. Patients who received their assigned treatment within 30 days of randomization were included. Stroke was adjudicated by a panel of board-certified vascular neurologists with secondary central review of clinically obtained brain images. Stroke type, laterality, timing, and outcome were reported. A periprocedural stroke occurred among 81 of the 2502 patients randomized and among 69 of the 2272 in the present analysis. Strokes were predominantly minor (81%, n=56), ischemic (90%, n=62), in the anterior circulation (94%, n=65), and ipsilateral to the treated artery (88%, n=61). There were 7 hemorrhages, which occurred 3 to 21 days after the procedure, and 5 were fatal. Major stroke occurred in 13 (0.6%) of the 2272 patients. The estimated 4-year mortality after stroke was 21.1% compared with 11.6% for those without stroke. The adjusted risk of death at 4 years was higher after periprocedural stroke (hazard ratio, 2.78; 95% confidence interval, 1.63-4.76).

CONCLUSIONS

Stroke, particularly severe stroke, was uncommon after carotid intervention in CREST, but stroke was associated with significant morbidity and was independently associated with a nearly 3-fold increased future mortality. The delayed timing of major and hemorrhagic stroke after revascularization suggests that these strokes may be preventable.

Controlled trial of azathioprine in Crohn's disease

The effect of azathioprine in patients with active Crohn's disease has been evaluated in a double-blind cross-over trial. Fifteen patients were treated with both azathioprine and placebo: only two improved while on azathioprine, six got worse, and in seven there was no change. The drug seemed to be the cause of deterioration in two of the patients. Although the drug may be of some value in a few patients, it should be used with caution and only when other measures have failed.

Transdermal nicotine as maintenance therapy for ulcerative colitis

BACKGROUND

Ulcerative colitis is largely a disease of nonsmokers. Having found previously that treatment with transdermal nicotine patches and mesalamine (5-aminosalicylic acid) has a beneficial effect on active colitis, we examined the value of transdermal nicotine for the maintenance of remission.

METHODS

We treated 80 patients with ulcerative colitis in remission with either transdermal nicotine or placebo patches for six months in a randomized, double-blind study. Incremental doses of nicotine were given for the first three weeks to achieve a maintenance dose; most patients tolerated 15 mg for 16 hours daily. All patients were taking mesalamine preparations as maintenance treatment at entry into the study; this treatment was stopped once the maintenance dose of nicotine was achieved. Clinical, sigmoidoscopic, and histologic assessments were made at the beginning and the end of the study, or at relapse. Side effects and serum nicotine and cotinine concentrations were monitored throughout the study.

RESULTS

There was no significant difference in the number of relapses between the groups. Twenty-two patients in the nicotine group were prematurely withdrawn from the study, 14 because of relapse and 8 for other reasons, including side effects and protocol violations. In the placebo group, 20 patients were withdrawn prematurely, 17 because of relapse and 3 for other reasons. Among patients using 15-mg nicotine patches, serum nicotine and cotinine concentrations were lower than expected and may reflect poor compliance. Side effects were reported by 35 patients--21 in the nicotine group and 14 in the placebo group--the most common of which were nausea, lightheadedness, and itching.

CONCLUSIONS

Transdermal nicotine alone was no better than placebo in the maintenance of remission of ulcerative colitis, and premature withdrawal due to side effects was more common in the nicotine group.

Evaluation of Racial Disparities in Hospice Use and End-of-Life Treatment Intensity in the REGARDS Cohort

Importance

Although hospice use is increasing and patients in the US are increasingly dying at home, racial disparities in treatment intensity at the end of life, including hospice use, remain.

Objective

To examine differences between Black and White patients in end-of-life care in a population sample with well-characterized causes of death.

Design, Setting, and Participants

This study used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, an ongoing population-based cohort study with enrollment between January 25, 2003, and October 3, 2007, with linkage to Medicare claims data. Multivariable logistic regression models were used to examine racial and regional differences in end-of-life outcomes and in stroke mortality among 1212 participants with fee-for-service Medicare who died between January 1, 2013, and December 31, 2015, owing to natural causes and excluding sudden death, with oversampling of Black individuals and residents of Southeastern states in the United States. Initial analyses were conducted in March 2019, and final primary analyses were conducted in February 2020.

Main Outcomes and Measures

The primary outcomes of interest were hospice use of 3 or more days in the last 6 months of life derived from Medicare claims files. Other outcomes included multiple hospitalizations, emergency department visits, and use of intensive procedures in the last 6 months of life. Cause of death was adjudicated by an expert panel of clinicians using death certificates, proxy interviews, autopsy reports, and medical records.

Results

The sample consisted of 1212 participants (630 men [52.0%]; 378 Black individuals [31.2%]; mean [SD] age at death, 81.0 [8.6] years) of 2542 total deaths. Black decedents were less likely than White decedents to use hospice for 3 or more days (132 of 378 [34.9%] vs 385 of 834 [46.2%]; P < .001). After stratification by cause of death, substantial racial differences in treatment intensity and service use were found among persons who died of cardiovascular disease but not among patients who died of cancer. In analyses adjusted for cause of death (dementia, cancer, cardiovascular disease, and other) and clinical and demographic variables, Black decedents were significantly less likely to use 3 or more days of hospice (odds ratio [OR], 0.72; 95% CI, 0.54-0.96) and were more likely to have multiple emergency department visits (OR, 1.35; 95% CI, 1.01-1.80) and hospitalizations (OR, 1.39; 95% CI, 1.02-1.89) and undergo intensive treatment (OR, 1.94; 95% CI, 1.40-2.70) in the last 6 months of life compared with White decedents.

Conclusions and Relevance

Despite the increase in the use of hospice care in recent decades, racial disparities in the use of hospice remain, especially for noncancer deaths. More research is required to better understand racial disparities in access to and quality of end-of-life care.

Validity of claims-based stroke algorithms in contemporary Medicare data: reasons for geographic and racial differences in stroke (REGARDS) study linked with medicare claims

BACKGROUND

The accuracy of stroke diagnosis in administrative claims for a contemporary population of Medicare enrollees has not been studied. We assessed the validity of diagnostic coding algorithms for identifying stroke in the Medicare population by linking data from the REasons for Geographic And Racial Differences in Stroke (REGARDS) Study to Medicare claims.

METHODS AND RESULTS

The REGARDS Study enrolled 30 239 participants ≥45 years in the United States between 2003 and 2007. Stroke experts adjudicated suspected strokes, using retrieved medical records. We linked data for participants enrolled in fee-for-service Medicare to claims files from 2003 through 2009. Using adjudicated strokes as the gold standard, we calculated accuracy measures for algorithms to identify incident and recurrent strokes. We linked data for 15 089 participants, among whom 422 participants had adjudicated strokes during follow-up. An algorithm using primary discharge diagnosis codes for acute ischemic or hemorrhagic stroke (International Classification of Diseases, Ninth Revision, Clinical Modification codes: 430, 431, 433.x1, 434.x1, 436) had a positive predictive value of 92.6% (95% confidence interval, 88.8%-96.4%), a specificity of 99.8% (99.6%-99.9%), and a sensitivity of 59.5% (53.8%-65.1%). An algorithm using only acute ischemic stroke codes (433.x1, 434.x1, 436) had a positive predictive value of 91.1% (95% confidence interval, 86.6%-95.5%), a specificity of 99.8% (99.7%-99.9%), and a sensitivity of 58.6% (52.4%-64.7%).

CONCLUSIONS

Claims-based algorithms to identify stroke in a contemporary Medicare cohort had high positive predictive value and specificity, supporting their use as outcomes for etiologic and comparative effectiveness studies in similar populations. These inpatient algorithms are unsuitable for estimating stroke incidence because of low sensitivity.

Phagocytosis of Histoplasma capsulatum yeasts and microconidia by human cultured macrophages and alveolar macrophages. Cellular cytoskeleton requirement for attachment and ingestion

Phagocytosis of Histoplasma capsulatum (Hc) yeasts and microconidia by human macrophages (M phi) was quantified by a fluorescence quenching technique. Phagocytosis of unopsonized Hc yeasts by monocyte-derived M phi and human alveolar M phi (AM) was rapid. After 60 min, 79% of cultured M phi and 59% of AM had ingested an average of 9.8 and 11 yeasts/M phi, respectively. In contrast, only 26% of monocytes ingested 4.5 yeasts/cell after 60 min. Phagocytosis of unopsonized microconidia by cultured M phi and by AM was equivalent. Monoclonal antibodies specific for the alpha-chains and beta-chain of the CD18 family of adhesion receptors inhibited the binding of Hc yeasts and microconidia to cultured M phi and AM. Thus, the M phi CD18 complex mediates recognition of both phases of this dimorphic fungus. Disruption of actin microfilaments with cytochalasin D inhibited both attachment and ingestion of yeasts by M phi. In contrast, nocodazole, which prevents polymerization of microtubules, did not inhibit binding or ingestion. Both drugs inhibited ingestion, but neither drug inhibited binding of C3b- and C3bi-coated sheep erythrocytes to complement receptors type one (CR1) or type three (CR3), respectively. Therefore, different signal transducing mechanisms for phagocytosis appear to be triggered by the binding of Hc yeasts to CD18, and by the binding of EC3bi to CD11b/CD18, respectively.

Cardiff Crohn's disease jubilee: the incidence over 50 years

The incidence of Crohn's disease in Cardiff between 1931 and 1985 has been examined using hospital diagnostic indices supplemented in recent years by records from clinicians, and the departments of pathology and radiology. Four hundred and seven new patients were confirmed after all notes had been reviewed. There has been a large increase from 0.18 cases/10(5) of the population per year in the 1930s to current values of 8.3/10(5)/year. The incidence continues to rise and shows an increasing proportion of patients with colorectal disease. Peak age specific incidences occur in the third and eighth decades of life.

Maintenance of remission in ulcerative colitis with oral preparation of 5-aminosalicylic acid

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Vitamin D status in Crohn's disease: association with nutrition and disease activity

Forty patients with Crohn's disease were divided into undernourished (18) and well nourished (22) groups depending on whether their midarm circumference was below or above 90% of the ideal standard. Plasma 25-(OH)D3 and the dihydroxylated metabolites, 24,25-(OH)2D3 and 1,25-(OH)2D3 were measured in the summer. Results were related to clinical and biochemical parameters and also compared with results from patients with ulcerative colitis and healthy subjects who served as controls. Plasma 25-(OH)D3 was reduced in the undernourished Crohn's group compared with the well nourished Crohn's group, who did not differ from the controls. Over 50% of the undernourished Crohn's group had evidence of secondary hyperparathyroidism and raised alkaline phosphatase concentrations, although concentrations of 1,25-(OH)2D3 were normal. The low 25-(OH)D3 concentrations related to disease activity. It is suggested that undernourished Crohn's patients who have high levels of disease activity are at risk of vitamin D deficiency, and attempts should be made to improve their vitamin D nutrition.

Therapeutic potentiation of the immune system by costimulatory Schiff-base-forming drugs

Immune responses are orchestrated by CD4 T lymphocytes, which receive a cognitive signal when clonally distributed receptors are occupied by major histocompatibility complex (MHC) class II-bound peptides on antigen-presenting cells (APCs). The APCs provide costimulatory signals, through macromolecules such as CD80, that regulate outcomes in terms of T-cell activation or anergy. We have studied essential complementary chemical events in the form of Schiff base formation between carbonyls and amines that are constitutively expressed on presenting cell and T-cell surfaces and provide a new target for manipulation of immune responses. Here we show that small Schiff base-forming molecules can substitute for the physiological donor of carbonyl groups and provide a costimulatory signal to CD4 Th-cells through a mechanism that activates clofilium-sensitive K+ and Na+ transport. One such molecule, tucaresol, enhances CD4 Th-cell responses, selectively favouring a Th1-type profile of cytokine production. In vivo tucaresol potently enhances CD4 Th-cell priming and CD8 cytotoxic T-cell priming to viral antigens, and has substantial therapeutic activity in murine models of disease.

Sex and Race Differences in the Association of Incident Ischemic Stroke With Risk Factors

Importance

Race-specific and sex-specific stroke risk varies across the lifespan, yet few reports describe sex differences in stroke risk separately in black individuals and white individuals.

Objective

To examine incidence and risk factors for ischemic stroke by sex for black and white individuals.

Design, Setting, and Participants

This prospective cohort study included participants 45 years and older who were stroke-free from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, enrolled from the continental United States 2003 through 2007 with follow-up through October 2016. Data were analyzed from March 2018 to September 2018.

Exposures

Sex and race.

Main Outcomes and Measures

Physician-adjudicated incident ischemic stroke, self-reported race/ethnicity, and measured and self-reported risk factors.

Results

A total of 25 789 participants (14 170 women [54.9%]; 10 301 black individuals [39.9%]) were included. Over 222 120 person-years of follow-up, 939 ischemic strokes occurred: 159 (16.9%) in black men, 326 in white men (34.7%), 217 in black women (23.1%), and 237 in white women (25.2%). Between 45 and 64 years of age, white women had 32% lower stroke risk than white men (incidence rate ratio [IRR], 0.68 [95% CI, 0.49-0.94]), and black women had a 28% lower risk than black men (IRR, 0.72 [95% CI, 0.52-0.99]). Lower stroke risk in women than men persisted at age 65 through 74 years in white individuals (IRR, 0.71 [95% CI, 0.55-0.94]) but not in black individuals (IRR, 0.94 [95% CI, 0.68-1.30]); however, the race-sex interaction was not significant. At 75 years and older, there was no sex difference in stroke risk for either race. For white individuals, associations of systolic blood pressure (women: hazard ratio [HR], 1.13 [95% CI, 1.05-1.22]; men: 1.04 [95% CI, 0.97-1.11]; P = .099), diabetes (women: HR, 1.84 [95% CI, 1.35-2.52]; men: 1.13 [95% CI, 0.86-1.49]; P = .02), and heart disease (women: HR, 1.76 [95% CI, 1.30-2.39]; men, 1.26 [95% CI, 0.99-1.60]; P = .09) with stroke risk were larger for women than men, while antihypertensive medication use had a smaller association in women than men (women: HR, 1.17 [95% CI, 0.89-1.54]; men: 1.61 [95% CI, 1.29-2.03]; P = .08). In black individuals, there was no evidence of a sex difference for any risk factors.

Conclusions and Relevance

For both races, at age 45 through 64 years, women were at lower stroke risk than men, and there was no sex difference at 75 years or older; however, the sex difference pattern may differ by race from age 65 through 74 years. The association of risk factors on stroke risk differed by race-sex groups. While the need for primordial prevention, optimal management, and control of risk factors is universal across all age, racial/ethnic, and sex groups, some demographic subgroups may require earlier and more aggressive strategies.

Colonic release of 5-amino salicylic acid from an oral preparation in active ulcerative colitis

5-amino salicylic acid coated with acrylic based resin was given orally to eight patients with active ulcerative colitis. Abdominal X-rays confirmed that the preparation released its contents in the terminal ileum and proximal colon. Differences between individuals were marked; the plasma 'concentration-time profile' reflected variations in the time taken for tablets to reach the terminal ileum.

Maintenance of remission in ulcerative colitis with 5-amino salicylic acid in high doses by mouth

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