Risk factors for MACE and bleeding in atrial fibrillation patients undergoing surgery: Insights from the bridge trial.

INTRODUCTION: Patients with atrial fibrillation (AF) undergoing elective procedures are at risk for Major Adverse Cardiovascular Events (MACE) and symptomatic bleeding. We aimed to identify risk factors to guide perioperative risk stratification. METHODS: We conducted a post-hoc analysis of the "Bridging Anticoagulation in Patients who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery" randomized trial. The primary outcomes were MACE and symptomatic bleeding. Our statistical approach encompassed standard univariate analysis, logistic stepwise regression, and Cox regression models. Additional interaction analyses evaluated the interplay between low-molecular-weight heparin bridge therapy and other identified risk factors. RESULTS: Among a total of 1,813 participants (mean age 71.6 ± 8.8, 73.3 % male), MACE occurred in 25 (1.4 %) individuals, with pre-procedure clopidogrel use (adjusted hazard ratio [aHR] 7.73, 95 % CI 2.63-22.72, p < 0.001) and CHA2DS2-VASc score ≥ 5 (aHR 2.89, 95 % CI 1.26-6.63, p = 0.012) identified as risk factors. Symptomatic bleeding occurred in 57 (3.1 %) individuals, with bridge therapy (aHR 1.84, 95 % CI 1.07-3.19, p = 0.029), renal disease (aHR 2.50, 95 % CI 1.34-4.67, p = 0.004), post-procedure aspirin use (aHR 2.86, 95 % CI 1.66-4.91, p < 0.001), post-procedure nonsteroidal anti-inflammatory drug use excluding aspirin (aHR 3.40, 95 % CI 1.22-9.43, p = 0.019), and major surgery (aHR 3.94, 95 % CI 2.26-6.85, p < 0.001) identified as risk factors. The interactions between risk factors and bridging therapy on MACE and symptomatic bleeding outcomes were not significant (p > 0.05). CONCLUSION: We identified predictors for MACE and symptomatic bleeding in AF patients undergoing elective procedures. These insights may help guide perioperative decisions to reduce the risk of adverse outcomes.

FLAIR signal intensity ratio predicts small subcortical infarct early neurologic deterioration: a cross-sectional study.

PURPOSE: Prior studies have used the fluid-attenuated inversion recovery sequence signal intensity ratio (FLAIR-SIR) to predict those with an incomplete infarct that may safely receive acute thrombolytics. Clinical early neurologic deterioration (END) of small subcortical infarcts (SSIs) is suspected to occur due to delayed infarct completion. We aimed to understand if a lower FLAIR-SIR, suggestive of an incomplete infarct, would have a higher likelihood of SSI-related END. METHODS: A cross-sectional retrospective study was performed of those with an acute SSI (anterior or posterior circulation) without significant parent vessel steno-occlusive disease. END was defined as a new or worsened disabling neurologic deficit during the index hospitalization. Standard-of-care brain MRIs were reviewed from the hospitalization, and a FLAIR-SIR cutoff of ≤ 1.15 was used based on prior studies. Adjusted logistic regression models were used for analysis. RESULTS: We identified 252 patients meeting inclusion criteria: median (IQR) age 68 (12) years, 38.5% (97/252) female, and 11% (28/252) with END. Tobacco use was more common in those without END (32%) compared with END (55%, p = 0.03). In adjusted analyses, a FLAIR-SIR cutoff of ≤ 1.15 yielded an odds ratio of 2.8 (95% CI 1.23-6.13, p = 0.012) of early neurological deterioration. CONCLUSION: Those with a FLAIR-SIR ≤ 1.15 are nearly threefold more likely to develop SSI-related END.

Novel grading system for CADASIL severity: A multicenter cross-sectional study.

Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited progressive cerebral microangiopathy with considerable phenotypic variability. The purpose of this study was to describe the generalizability of a recently proposed grading system of CADASIL across multiple centers in the United States. Methods: Electronic medical records (EMR) of an initial neurological assessment of adult patients with confirmed CADASIL were reviewed across 5 tertiary referral medical centers with expertise in CADASIL. Demographic, vascular risk factors, and neuroimaging data were abstracted from EMR. Patients were categorized into groups according to the proposed CADASIL grading system: Grade 0 (asymptomatic), Grade 1 (migraine only), Grade 2 (stroke, TIA, or MCI), Grade 3 (gait assistance or dementia), and Grade 4 (bedbound or end-stage). Inter-rater reliability (IRR) of grading was tested in a subset of cases. Results: We identified 138 patients with a mean age of 50.9 ± 13.1 years, and 57.2% were female. The IRR was acceptable over 33 cases (κ=0.855, SD 0.078, p<0.001) with 81.8% being concordant. There were 15 patients (10.9%) with Grade 0, 50 (36.2%) with Grade 1, 61 (44.2%) with Grade 2, 12 (8.7%) with Grade 3, and none with Grade 4. Patients with a lower severity grade (grade 0 vs 3) tended to be younger (49.5 vs. 61.9 years) and had a lower prevalence of hypertension (50% vs. 20%, p = 0.027) and diabetes mellitus (0% vs. 25%, p = 0.018). A higher severity grade was associated with an increased number of vascular risk factors (p = 0.02) and independently associated with hypertension and diabetes (p<0.05). Comparing Grade 0 vs. 3, cortical thickness tended to be greater (2.06 vs. 1.87 mm; p = 0.06) and white matter hyperintensity volume tended to be lower (54.7 vs. 72.5 ml; p = 0.73), but the differences did not reach significance. Conclusion: The CADASIL severity grading system is a pragmatic, reliable system for characterizing CADASIL phenotype that does not require testing beyond that done in standard clinical practice. Higher severity grades tended to have a higher vascular risk factor burden. This system offers a simple method of categorizing CADASIL patients which may help to describe populations in observational and interventional studies.

Perioperative Acute Ischemic Stroke in Patients with Atrial Fibrillation.

OBJECTIVE: Anticoagulation therapy is commonly interrupted in patients with atrial fibrillation (AF) for elective procedures. However, the risk factors of acute ischemic stroke (AIS) during the periprocedural period remain uncertain. We performed a nationwide analysis to evaluate AIS risk factors in patients with AF undergoing elective surgical procedures. METHODS: Using the Nationwide Readmission Database, we included electively admitted adult patients with AF and procedural Diagnosis-Related Group codes from 2016 to 2019. Diagnoses were identified based on International Classification of Disease, 9th revision-Clinical Modification (ICD-10 CM) codes. We constructed a logistic regression model to identify risk factors and developed a new scoring system incorporating CHA2 DS2 VASc to estimate periprocedural AIS risk. RESULTS: Of the 1,045,293 patients with AF admitted for an elective procedure, the mean age was 71.5 years, 39.2% were women, and 0.70% had a perioperative AIS during the index admission or within 30 days of discharge. Active cancer (adjusted OR [aOR] = 1.58, 95% confidence interval [CI] = 1.42-1.76), renal failure (aOR = 1.14, 95% CI = 1.04-1.24), neurological surgery (aOR = 4.51, 95% CI = 3.84-5.30), cardiovascular surgery (aOR = 2.74, 95% CI = 2.52-2.97), and higher CHA2 DS2 VASc scores (aOR 1.25 per point, 95% CI 1.22-1.29) were significant risk factors for periprocedural AIS. The new scoring system (area under the receiver operating characteristic curve [AUC] = 0.68, 95% CI = 0.67 to 0.79) incorporating surgical type and cancer outperformed CHA2 DS2 VASc (AUC = 0.60, 95% CI = 0.60 to 0.61). INTERPRETATION: In patients with AF, periprocedural AIS risk increases with the CHA2 DS2 VASc score, active cancer, and cardiovascular or neurological surgeries. Studies are needed to devise better strategies to mitigate perioperative AIS risk in these patients. ANN NEUROL 2023;94:321-329.

Recurrence risk in symptomatic intracranial stenosis treated medically in the real world.

BACKGROUND: The risk of early recurrence in medically treated patients with intracranial atherosclerotic stenosis (ICAS) may differ in clinical trials versus real-world settings. Delayed enrollment may contribute to lower event rates in ICAS trials. We aim to determine the 30-day recurrence risk in a real-world setting of symptomatic ICAS. METHODS: We used a comprehensive stroke center stroke registry to identify hospitalized patients with acute ischemic stroke or TIA due to symptomatic 50-99% ICAS. The outcome was recurrent stroke within 30 days. We used adjusted Cox regression models to identify factors associated with increased recurrence risk. We also performed a comparison of 30-day recurrent stroke rates in real world cohorts and clinical trials. RESULTS: Among 131 hospitalizations with symptomatic 50-99% ICAS over 3 years, 80 hospitalizations of 74 patients (mean age 71.6 years, 55.41% men) met the inclusion criteria. Over 30 days, 20.6 % had recurrent stroke; 61.5% (8/13) occurred within first 7 days. The risk was higher in patients not receiving dual antiplatelet therapy (HR 3.92 95% CI 1.30-11.84, p = 0.015) and hypoperfusion mismatch volume >3.5 mL at a T max>6 s threshold (HR 6.55 95% CI 1.60-26.88, p < 0.001). The recurrence risk was similar to another real world ICAD cohort (20.2%), and higher than that seen in clinical trials (2.2%-5.7%), even in those treated with maximal medical treatment or meeting inclusion criteria for trials. CONCLUSIONS: In patients with symptomatic ICAS, the real-world recurrence of ischemic events is higher than that seen in clinical trials, even in subgroups receiving the same pharmacological treatment strategies.

Trends in Venous Thromboembolism Readmission Rates after Ischemic Stroke and Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: Venous thromboembolism (VTE) is a life-threatening complication of stroke. We evaluated nationwide rates and risk factors for hospital readmissions with VTE after an intracerebral hemorrhage (ICH) or acute ischemic stroke (AIS) hospitalization. METHODS: Using the Healthcare Cost and Utilization Project (HCUP) Nationwide Readmission Database, we included patients with a principal discharge diagnosis of ICH or AIS from 2016 to 2019. Patients who had VTE diagnosis or history of VTE during the index admission were excluded. We performed Cox regression models to determine factors associated with VTE readmission, compared rates between AIS and ICH and developed post-stroke VTE risk score. We estimated VTE readmission rates per day over a 90-day time window post-discharge using linear splines. RESULTS: Of the total 1,459,865 patients with stroke, readmission with VTE as the principal diagnosis within 90 days occurred in 0.26% (3,407/1,330,584) AIS and 0.65% (843/129,281) ICH patients. The rate of VTE readmission decreased within first 4-6 weeks (P<0.001). In AIS, cancer, obesity, higher National Institutes of Health Stroke Scale (NIHSS) score, longer hospital stay, home or rehabilitation disposition, and absence of atrial fibrillation were associated with VTE readmission. In ICH, longer hospital stay and rehabilitation disposition were associated with VTE readmission. The VTE rate was higher in ICH compared to AIS (adjusted hazard ratio 2.86, 95% confidence interval 1.93-4.25, P<0.001). CONCLUSIONS: After stroke, VTE readmission risk is highest within the first 4-6 weeks and nearly three-fold higher after ICH vs. AIS. VTE risk is linked to decreased mobility and hypercoagulability. Studies are needed to test short-term VTE prophylaxis beyond hospitalization in high-risk patients.

Mutation of breast cancer susceptibility genes increases cerebral microbleeds: A pilot study.

OBJECTIVES: Growing evidence suggests breast cancer susceptibility gene (BRCA) mutations may augment cerebrovascular risk factors. With this influence in mind, we aimed to identify if BRCA mutations increased the prevalence of cerebral small vessel disease (CSVD). METHODS AND MATERIALS: We performed a retrospective cross-sectional analysis of adults undergoing malignancy evaluation with confirmed BRCA mutations compared to BRCA wildtype individuals. A standard-of-care brain MRI was reviewed. Chi-squared or Fisher's, Wilcoxon rank-sum and the Student's t-test analyses were used when appropriate. Adjusted logistic regression models were fit to calculate odds ratio. Multicollinearity was tested by variance inflation factor calculation and for goodness-of-fit via the Hosmer-Lemeshow test. RESULTS: Of 116 individuals, 44.8% (52/116) carried a BRCA mutation. Demographic and cerebrovascular risk factors did not differ. Cerebral microbleeds were more common in those with BRCA mutation: [32.7% (17/52) vs. 17.2% (11/64), p = 0.05] with an adjusted odds ratio of 2.8 (95%CI 1.08-6.89, p = 0.03). Other markers of CSVD were similar amongst the cohort. CONCLUSIONS: We identified a nearly 3-fold increase in identified cerebral microbleed in those with BRCA mutations compared with BRCA wildtype individuals suggestive of an interaction between the BRCA gene and cerebral microbleed formation. Further studies are needed to confirm our findings and to understand clinical implications.

Branch Retinal Vein Occlusion and Venous Abnormalities in CADASIL.

INTRODUCTION: Individuals with the inherited progressive microangiopathy Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts (CADASIL) most classically develop migraine with aura and recurrent subcortical ischemic infarcts with progressive cognitive decline, gait dysfunction, psychiatric disturbances culminating in early death. However, clinically important venous pathologies may not be anticipated by treating neurologists such as branch retinal vein occlusions (BRVOs). Herein we describe a case of CADASIL with a BRVO and a brief review of venous pathology in CADASIL. CASE REPORT: A 66-year-old man with CADASIL and clinical symptoms of chronic migraine with aura, episodic "CADASIL coma," recurrent subcortical ischemic infarcts and normal cognition presented with an asymptomatic superior BRVO. Retinal analysis by wide-field fluorescein angiography revealed dye extravasation and optical coherence tomography identified macular edema prompting a monthly regimen of intravitreal bevacizumab. Systemic investigations for provoking etiologies was unfruitful tentatively attributing the BRVO to his underlying CADASIL. CONCLUSIONS: Within CADASIL, the venous circulation undergoes similar pathologic changes as compared with the arterial circulation. The retinal veins of CADASIL exhibit increased venous compliance, vessel wall diameter and wall thickness which may represent a structurally causative factor for retinal venous disease. However, these findings are not isolated to the retina as lower extremity varicose veins have associated with a family pedigree of CADASIL. Although presently it is uncertain whether those with CADASIL should undergo routine retinal screening, neurologists, and ophthalmologists, need to be cognizant of the extra-arterial manifestations of CADASIL to provide comprehensive clinical care.

Brain tumor related-epilepsy.

INTRODUCTION: Gliomas are commonly associated with the development of epilepsy; in some cases the two conditions share common pathogenic mechanisms and may influence each other. Brain tumor related-epilepsy (BTRE) complicates the clinical management of gliomas and can substantially affect daily life. STATE OF THE ART: The incidence of seizures is high in patients with slow growing tumors located in the frontotemporal regions. However, recent studies suggest that epileptogenesis may be more associated with tumor molecular genetic markers than tumor grade or location. Although the exact mechanism of epileptogenesis in glioma is incompletely understood, glutamate-induced excitotoxicity and disruption of intracellular communication have garnered the most attention. CLINICAL MANAGEMENT: Management of BTRE requires a multidisciplinary approach involving the use of antiepileptic drugs (AEDs), surgery aided by electrocorticography, and adjuvant chemoradiation. FUTURE DIRECTIONS: Insight into the mechanisms of glioma growth and epileptogenesis is essential to identify new treatment targets and to develop effective treatment for both conditions. Selecting AEDs tailored to act against known tumor molecular markers involved in the epileptogenesis could enhance treatment value and help inform individualized medicine in BRTE.

Cost of care for subjective tinnitus in relation to patient satisfaction.

OBJECTIVE: A consistent management algorithm for subjective tinnitus remains to be elucidated. Chronic tinnitus yields approximately US$2110 in annual health care costs per patient. However, it is unclear whether spending more in the management of tinnitus equates with greater patient satisfaction. Thus, the aim of this study is to correlate patient satisfaction with patient demographics, provider recommendations, and total health care-related expenditures. STUDY DESIGN: A retrospective chart review and a patient satisfaction questionnaire. SETTING: All data were collected from a large Midwestern hospital. SUBJECTS AND METHODS: Patients were included who presented to the tinnitus clinic during the year 2011 and were between the ages of 18 and 89 years. They were excluded with diagnoses of Ménière's disease, pulsatile tinnitus, acoustic neuromas, or autoimmune inner ear diseases. The retrospective data and satisfaction surveys were entered by 3 of the authors. Responses were based on Likert scales. RESULTS: Of the 692 patients included, 230 completed and returned the satisfaction questionnaire (33.2% response rate), yielding an overall mean of $662.60 charges. The frequency of intervention recommendations per patients ranged from 0 to 13, with a median of 4. Spearman's correlations did not result in significant correlations between patient satisfaction and number of clinic visits (P=.499) or associated charges (P=.453). CONCLUSION: Given that the variability among provider recommendations, the high overall mean of tinnitus-related charges, and patient satisfaction was not related to costs, further research is needed examining patient preference in the treatment of tinnitus.

Head and neck cancer screenings and human papillomavirus knowledge across diverse suburban and urban populations.

BACKGROUND: Minimal research has explored community dwelling adults' knowledge of the human papillomavirus (HPV) in relation to head and neck cancer (HNC). The purpose of this study was to report on community dwelling adults' knowledge of HPV in relation to infection, symptoms, and the development of HNC. METHODS: Cross-sectional assessment of community-dwelling adults on history of behavioral risk factors for HNC, health literacy, and knowledge regarding HPV in relation to HNC. RESULTS: Of those who completed the measure of health literacy, 17.1% read at or below an 8th grade level. Participants reported a range of history of behaviors putting them at increased risk for HPV and HNC. Respondents answered an average of 67.2% of HPV questions correctly, only one person answered all 15 questions correctly. There were no differences in knowledge of HPV in relation to HNC based upon demographics, suburban versus urban location, health literacy, or cancer history. CONCLUSIONS: Adults reported a range of behaviors associated with an increased risk of HPV transmission but also displayed large gaps in knowledge regarding HPV in relation to HNC.

Pathway to dry skin prevention and treatment.

BACKGROUND: This article presents an evidence-supported clinical pathway for dry skin prevention and treatment. OBJECTIVE: The development of the pathway involved the following: a literature review was conducted and demonstrated that literature on dry skin is scarce. To compensate for the gap in the available literature, a modified Delphi method was used to collect information on prevention and treatment practice through a panel, which included 10 selected dermatologists who currently provide medical care for dermatology patients in Ontario. An advisor experienced in this therapeutic area guided the process, including a central meeting. Panel members completed a questionnaire regarding their individual practice in caring for these patients and responded to questions on assessment of dry skin etiology, frequency of skin care visits for consultation and follow-up, assessment, and referral to other specialties. The panel members reviewed a summary of all responses and reached a consensus. The result was presented as a clinical pathway. CONCLUSION: The panel concluded that our current awareness of dry skin and therefore prevention and effective treatment is limited; that identifying dry skin and its clinical issues requires tools such as clinical pathways, which may improve patient outcomes; and that additional research on dry skin etiology, prevention, and treatment is necessary.

Thermodynamics of peptide and non-peptide interactions with the human 5HT1a receptor.

The human serotonin 1a receptor (H5HT1aR) is a highly studied member of the 7 transmembrane G protein-coupled receptors. This model receptor, negatively coupled to adenylyl cyclase via Gi, is linked to physiological processes such as cognition and mood regulation and to associated disorders like anxiety and depression. Gibb's free energies, enthalpies, and entropies were calculated for the agonist [(3)H]8-OH-DPAT in the presence of synthetic peptides derived from sequences of intracellular loops 2 and 3 of the H5HT1aR. For comparative purposes, the thermodynamic parameters were also determined in the presence of a limited number of ligand-binding site substances (the partial agonist dipropyltryptamine [DPT], and the full agonist [(3)H]8-OH-DPAT alone). All of these thermodynamic measurements were based on binding data accumulated over a range of temperatures (0-35 degrees C). Representative examples of binding constant experiments and van't Hoff plots are shown to establish the thermodynamic variables. Although differences exist between the peptides themselves and the non-peptide agonists, in all situations the binding events are highly entropy driven. Differences between this information and published data for rat 5HT1aR are discussed, as are relationships to other receptor systems. Overall, the conclusions should be useful in further defining a comprehensive model of 5HT1aR, and for future development of binding-site and non-binding-site directed agents for the receptor.

Granulomatous enterocolitis associated with Hermansky-Pudlak syndrome.

BACKGROUND: Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder. It consists of a triad of tyrosinase-positive oculocutaneous albinism (Ty-pos OCA), bleeding diathesis resulting from platelet dysfunction, and systemic complications associated with accumulation of ceroid lipofuscin. Many patients are from a small area in northwestern Puerto Rico. HPS has been associated with granulomatous enterocolitis in up to 20% of affected patients. It is not known whether this granulomatous colitis is a part of the syndrome, or represents an independent but associated process, such as Crohn's disease. This colitis can be severe, and has been reported to be poorly responsive to medical therapies including sulfasalazine, mesalamine, steroids, and metronidazole. CASE REPORT: We report a series of four patients with refractory enterocolitis in the setting of HPS who were treated at Mount Sinai Hospital between 1998 and 2005. A trial of infliximab was attempted in all four, and produced a complete response in two. CONCLUSIONS: Many phenotypic and pathologic similarities exist between granulomatous enterocolitis in HPS and Crohn's disease. However, it is unclear whether the granulomatous enterocolitis in HPS is because of ceroid deposition or reflects the coexistence of Crohn's disease and HPS. The occurrence of ileal involvement and perianal fistulization in our cases suggests that in at least some instances, HPS and Crohn's disease are truly associated.

Studying the S-nitrosylation of model peptides and eNOS protein by mass spectrometry.

Oxidative addition of a nitric oxide (NO) molecule to the thiol group of cysteine residues is a physiologically important post-translational modification that has been implicated in several metabolic and pathophysiological events. Our previous studies have indicated that S-nitrosylation can result in the disruption of the endothelial NO synthase (eNOS) dimer. It has been suggested that for S-nitrosylation to occur, the cysteine residue must be flanked by hydrophilic residues either in the primary structure or in the spatial proximity through appropriate conformation. However, this hypothesis has not been confirmed. Thus, the objective of this study was to determine if the nature of the amino acid residues that flank the cysteine in the primary structure has a significant effect on the rate and/or specificity of S-nitrosylation. To accomplish this, we utilized several model peptides based on the eNOS protein sequence. Some of these peptides contained point mutations to allow for different combinations of amino acid properties (acidic, basic, and hydrophobic) around the cysteine residue. To ensure that the results obtained were not dependent on the nitrosylation procedure, several common S-nitrosylation techniques were used and S-nitrosylation followed by mass spectrometric detection. Our data indicated that all peptides independent of the amino acids surrounding the cysteine residue underwent rapid S-nitrosylation. Thus, there does not appear to be a profound effect of the primary sequence of adjacent amino acid residues on the rate of cysteine S-nitrosylation at least at the peptide levels. Finally, our studies using recombinant human eNOS confirm that Cys98 undergoes S-nitrosylation. Thus, our data validate the importance of Cys98 in regulating eNOS dimerization and activity, and the utility of mass spectroscopy to identify cysteine residues susceptible to S-nitrosoylation.

Is perianal Crohn's disease associated with intestinal fistulization?

BACKGROUND: When cases of Crohn's disease (CD) are described as "fistulizing," distinctions are often not drawn between perianal and intestinal fistulization. The question, therefore, remains open as to whether or not there is truly an association between perianal fistulization and intraabdominal intestinal fistulization in CD. AIMS: We have sought to determine the association between perianal and intestinal fistulization by analyzing the cases of CD recorded in databases from six international centers. PATIENTS: Six databases provided information on 5491 cases of CD in the United States, France, Italy, and The Netherlands. Of these cases, 1686 had isolated ileal disease and 1655 had Crohn's colitis. METHODS: An association between perianal disease and internal fistulae was sought by calculating relative risks for the chance of internal fistulae among patients with perianal fistulae relative to those without. Statistical significance was calculated by the Mantel-Haenszel procedure, stratifying on the separate centers. All statistical tests and estimates were implemented using SAS for the PC. RESULTS: Among the 1686 cases with isolated ileal disease, the evidence of an association between perianal disease and internal fistulization was not consistent across centers, with relative risks ranging from 0.8 to 2.2. For patients with Crohn's colitis (n = 1655), the association was much stronger and more consistent, with an estimated common relative risk of 3.4, 95% confidence interval (2.6-4.6, p < 0.0001). CONCLUSIONS: We have found a statistically significant association between perianal CD and intestinal fistulization, much stronger and more consistent in cases of Crohn's colitis than in cases limited to the small bowel.

Binding properties of dipropyltryptamine at the human 5-HT1a receptor.

Dipropyltryptamine (DPT) is a synthetic indolealkylamine first characterized in the 1960s. Largely forgotten since the discovery of multiple serotonin receptor subtypes, some of the properties of DPT at the cloned human 5-HT1a receptor are described here. When [3H]8-OH-DPAT is bound to the receptor, DPT inhibits the interaction with an IC50 of 0.1 micromol/l. This interaction is shown to be competitive when double-reciprocal plots of the DPT/agonist interaction are analyzed. DPT's effects in the signal transduction system are complex. While DPT alone (0.1-1,000 micromol/l) activates Gi when both cAMP and gamma-S-GTP incorporation are measured, in the presence of 5-HT (0.1-10 micromol/l), DPT blocks the agonist effect. In combination, the findings suggest that DPT is a moderate affinity partial agonist at the human 5-HT1a receptor. These results provide evidence that DPT has potential as a versatile experimental tool at 5-HT1a receptors.

6-Mercaptopurine is effective in Crohn's disease without concomitant steroids.

BACKGROUND: 6-Mercaptopurine (6-MP) has shown efficacy in the treatment of Crohn's disease when used in conjunction with corticosteroids. Sparse literature to date suggests that 6-MP is effective when used without steroids. We therefore studied the efficacy of 6-MP in corticosteroid-naive Crohn's patients. METHODS: We conducted a retrospective chart review of 24 patients who were treated with 6-MP but had never received any form of steroid treatment at any time. 6-MP efficacy was assessed with serial modified Harvey-Bradshaw scores. In addition to overall response, data were also analyzed according to the indication for treating with 6-MP (disease activity, fistulae, or both). The time to relapse and the treatments required were also analyzed. RESULTS: Overall, remission or significant improvement was seen in 20 patients (83% of original group). Seven patients (29%) achieved complete remission; another 13 patients (54%) demonstrated significant clinical improvement. By indication, 89% of patients treated for activity, 50% of patients treated for activity and fistula, and 100% of patients treated for fistula alone showed response. Drug effect required a median of 5.7 months to occur (for all patients: range, 1.7-37.9 months). Thirteen of the twenty patients who improved or remitted on 6-MP eventually relapsed, usually due to stopping 6-MP, at a median of 13.8 months (range, 0.9-57.8). Relapse was less frequent if patients continued 6-MP. Treatment of relapses required only antibiotics, and/or restarting 6-MP (or increasing the dose) in most patients. CONCLUSIONS: 6-MP is an effective medication for use in steroid-naive patients and is likely to be effective in patients who have received steroids in the past but are not currently receiving them. Relapses occur despite continued therapy, but are often easily treated, and do not require initiating steroids.