Alzheimer's disease: early alterations in brain DNA methylation at ANK1, BIN1, RHBDF2 and other loci

We used a collection of 708 prospectively collected autopsied brains to assess the methylation state of the brain's DNA in relation to Alzheimer's disease (AD). We found that the level of methylation at 71 of the 415,848 interrogated CpGs was significantly associated with the burden of AD pathology, including CpGs in the ABCA7 and BIN1 regions, which harbor known AD susceptibility variants. We validated 11 of the differentially methylated regions in an independent set of 117 subjects. Furthermore, we functionally validated these CpG associations and identified the nearby genes whose RNA expression was altered in AD: ANK1, CDH23, DIP2A, RHBDF2, RPL13, SERPINF1 and SERPINF2. Our analyses suggest that these DNA methylation changes may have a role in the onset of AD given that we observed them in presymptomatic subjects and that six of the validated genes connect to a known AD susceptibility gene network.

Requirement for T-cell apoptosis in the induction of peripheral transplantation tolerance

The mechanisms of allograft tolerance have been classified as deletion, anergy, ignorance and suppression/regulation. Deletion has been implicated in central tolerance, whereas peripheral tolerance has generally been ascribed to clonal anergy and/or active immunoregulatory states. Here, we used two distinct systems to assess the requirement for T-cell deletion in peripheral tolerance induction. In mice transgenic for Bcl-xL, T cells were resistant to passive cell death through cytokine withdrawal, whereas T cells from interleukin-2-deficient mice did not undergo activation-induced cell death. Using either agents that block co-stimulatory pathways or the immunosuppressive drug rapamycin, which we have shown here blocks the proliferative component of interleukin-2 signaling but does not inhibit priming for activation-induced cell death, we found that mice with defective passive or active T-cell apoptotic pathways were resistant to induction of transplantation tolerance. Thus, deletion of activated T cells through activation-induced cell death or growth factor withdrawal seems necessary to achieve peripheral tolerance across major histocompatibility complex barriers.

Electrophysiologic testing to identify patients with coronary artery disease who are at risk for sudden death. Multicenter Unsustained Tachycardia Trial Investigators

BACKGROUND

The mortality rate among patients with coronary artery disease, abnormal ventricular function, and unsustained ventricular tachycardia is high. The usefulness of electrophysiologic testing for risk stratification in these patients is unclear.

METHODS

We performed electrophysiologic testing in patients who had coronary artery disease, a left ventricular ejection fraction of 40 percent or less, and asymptomatic, unsustained ventricular tachycardia. Patients in whom sustained ventricular tachyarrhythmias could be induced were randomly assigned to receive either antiarrhythmic therapy guided by electrophysiologic testing or no antiarrhythmic therapy. The primary end point was cardiac arrest or death from arrhythmia. Patients without inducible tachyarrhythmias were followed in a registry. We compared the outcomes of 1397 patients in the registry with those of 353 patients with inducible tachyarrhythmias who were randomly assigned to receive no antiarrhythmic therapy in order to assess the prognostic value of electrophysiologic testing.

RESULTS

Patients were followed for a median of 39 months. In a Kaplan-Meier analysis, two-year and five-year rates of cardiac arrest or death due to arrhythmia were 12 and 24 percent, respectively, among the patients in the registry, as compared with 18 and 32 percent among the patients with inducible tachyarrhythmias who were assigned to no antiarrhythmic therapy (adjusted P<0.001). Overall mortality after five years was 48 percent among the patients with inducible tachyarrhythmias, as compared with 44 percent among the patients in the registry (adjusted P=0.005). Deaths among patients without inducible tachyarrhythmias were less likely to be classified as due to arrhythmia than those among patients with inducible tachyarrhythmias (45 and 54 percent, respectively; P=0.06).

CONCLUSIONS

Patients with coronary artery disease, left ventricular dysfunction, and asymptomatic, unsustained ventricular tachycardia in whom sustained ventricular tachyarrhythmias cannot be induced have a significantly lower risk of sudden death or cardiac arrest and lower overall mortality than similar patients with inducible sustained tachyarrhythmias.

Adhesion of epidermal Langerhans cells to keratinocytes mediated by E-cadherin

Langerhans cells (LC) are the principal accessory cells present in epidermis. Because LC have limited capacity for self-renewal, epidermis is continually repopulated by as-yet uncharacterized bone marrow-derived LC progenitors. In addition, although LC persist in epidermis for extended periods, LC are induced to migrate from skin to regional lymph nodes after antigen exposure. To begin to elucidate mechanisms involved in LC trafficking, we characterized LC-keratinocyte (KC) interactions. Here we report that fresh murine LC express cadherins, and that LC adhere to KC in vitro through E-cadherin. Cultured LC (which may bear a phenotypic and functional relationship to LC that have migrated to lymph nodes) express lower levels of E-cadherin and exhibit decreased affinity for KC. These results suggest that expression of E-cadherin by LC promotes persistence of these cells in epidermis, and that cadherins may play important and unanticipated roles in interactions between leukocytes and epithelia.

Randomized trial of allopurinol in the prevention of calcium oxalate calculi

In a double-blind study, we examined the efficacy of allopurinol in the prevention of recurrent calcium oxalate calculi of the kidney. Sixty patients with hyperuricosuria and normocalciuria who had a history of calculi were randomly assigned to receive either allopurinol (100 mg three times daily) or a placebo. After the study, the placebo group had 63.4 percent fewer calculi (P less than 0.001), whereas the allopurinol group had 81.2 percent fewer calculi (P less than 0.001). During the study period, the mean rate of calculous events was 0.26 per patient per year in the placebo group and 0.12 in the allopurinol group. When the treatment groups were compared by actuarial analysis, the allopurinol group was found to have a significantly longer time before recurrence of calculi (P less than 0.02). We conclude that allopurinol is effective in the prevention of calcium oxalate stones in patients with hyperuricosuria. The large reduction in the frequency of calculi in the placebo group underscores the positive treatment bias that regularly occurs in trials of prophylaxis against renal calculi when historical controls are used.

E-cadherin is the major mediator of human melanocyte adhesion to keratinocytes in vitro

E- and P-cadherin are calcium (Ca2+)-dependent cell adhesion molecules important in the morphogenesis and maintenance of skin structure. By use of flow cytometry and specific antibodies, we now show that cultured human melanocytes express E- and P-cadherin on their surfaces, and that these molecules have the same characteristics as reported for other cell types. Specifically, melanocyte cadherins are sensitive to trypsin digestion in the absence of Ca2+ and are protected from trypsin degradation by Ca2+, and are functional at 37 degrees C but not at 4 degrees C. We further show that melanocytes contain mRNA transcripts encoding both E- and P-cadherin. Adhesion of cultured melanocytes to keratinocyte monolayers is abolished by pre-treatment of the melanocytes with trypsin/EDTA, which degrades E- and P-cadherins, is greatly reduced by anti-E-cadherin antibodies and is slightly reduced by antibodies to P-cadherin, alpha 2, alpha 3 and beta 1 integrins. In contrast to normal melanocytes, eight of nine melanoma cell lines lacked E-cadherin (or expressed markedly reduced levels) and five were negative for P-cadherin. Melanoma cells also failed to adhere to keratinocyte monolayers. These results demonstrate that normal human melanocytes express functional E- and P-cadherin and that E-cadherin is primarily responsible for adhesion of human melanocytes to keratinocytes in vitro. In addition, transformed melanocytes express markedly reduced levels of E- and P-cadherin, and exhibit decreased affinity for normal keratinocytes in vitro, suggesting that loss of cadherins may play a role in melanoma metastasis.

Discriminatory sonographic criteria for the diagnosis of carpal tunnel syndrome

OBJECTIVE

Sonographic examination of the median nerve has been suggested as a useful alternative to electrophysiologic study in the diagnosis of carpal tunnel syndrome. To determine its usefulness and the best diagnostic criterion, sonograms of patients with the disease were compared with sonograms of healthy subjects in a case-control study.

METHODS

Patients with carpal tunnel syndrome and asymptomatic controls who were matched for age and sex were enrolled and underwent sonography of the wrists. Eight separate sonographic criteria were analyzed in each wrist. Data from the patient group and the control group were compared to establish optimal diagnostic criteria for carpal tunnel syndrome, using receiver operating characteristic analytic techniques.

RESULTS

Thirty-five patients with carpal tunnel syndrome and 35 asymptomatic controls were examined. Increased cross-sectional area of the median nerve was found to be the most predictive measure of carpal tunnel syndrome, proximal to the tunnel inlet, at the tunnel inlet, and at the tunnel outlet, with significant differences between patients and controls. Using a receiver operating characteristic curve, a cut-off value >0.098 cm(2) at the tunnel inlet provided a diagnostic sensitivity of 89% and a specificity of 83%.

CONCLUSION

Sonographic measurement of the median nerve cross-sectional area is both sensitive and specific for the diagnosis of carpal tunnel syndrome.

Abnormal force--EMG relations in paretic limbs of hemiparetic human subjects

The relations between surface EMG and isometric force generated by elbow flexor muscles were compared in normal and paretic limbs of 17 hemiparetic human subjects. Similar analyses were performed on both arms of 11 normal subjects. In almost half of the hemiparetic subjects examined (8/17), the slope of the relation between elbow flexion force and surface EMG, measured over the biceps-brachialis and brachioradialis muscle groups was increased in the paretic limb. A mechanism based on anomalous reductions in mean motor unit discharge rate in paretic muscles is advanced as the most likely cause of the findings.

High resolution sonographic detection of axillary lymph node metastases in breast cancer

Axillary lymph node status is crucial in the evaluation of prognosis and in treatment planning of breast cancer. High-resolution real-time sonographic scans of the breast and both axillae were performed on 114 patients with breast carcinoma, all of whom had axillary lymph node dissection and histologic assessment. The sensitivity of high-resolution ultrasonography in the detection of axillary nodal metastases was 84.1%, with a specificity of 97.1%, accuracy of 92.1%, positive predictive value of 94.9%, and negative predictive value 90.7%. Ultrasonography of the axilla provides good information on anatomy and pathology and may have a potential role in the prognostic work-up of patients who are not surgical candidates.

Meta-analysis of randomised controlled trials of the effectiveness of antiarrhythmic agents at promoting sinus rhythm in patients with atrial fibrillation

OBJECTIVE

To conduct a meta-analysis of randomised controlled trials to estimate the effectiveness of antiarrhythmic drugs at promoting sinus rhythm in patients with atrial fibrillation.

DESIGN

Articles were identified by using a comprehensive search of English language papers indexed in Medline from 1966 to August 2001. For the outcomes of sinus rhythm and death, a random effects model was used to model repeated assessments within a study at different time points.

SETTING

Emergency departments and ambulatory clinics.

PATIENTS

Patients with atrial fibrillation.

INTERVENTIONS

Antiarrhythmic agents grouped according to their Vaughan-Williams class.

MAIN OUTCOME MEASURES

Sinus rhythm and mortality.

RESULTS

91 articles met a priori criteria for inclusion in the analysis. Median duration of follow up was one day (range 0.04-1096, mean (SD) 46 (136) days). The median proportion of patients in sinus rhythm at follow up was 55% (range 0-100%) and 32% (range 0-90%) receiving active treatment and placebo, respectively. Median survival was 99% (range 55-100%) and 99% (range 55-100%). Compared with placebo, the following drug classes were associated with increased sinus rhythm at follow up: IA (treatment difference 21.5%, 95% confidence interval (CI) 16.3% to 26.8%); IC (treatment difference 33.1%, 95% CI 23.3% to 42.9%); and III (treatment difference 17.4%, 95% CI 11.5% to 23.3%). Class IC drugs were associated with increased sinus rhythm at follow up compared with class IV drugs (treatment difference 43.2%, 95% CI 11.5% to 75.0%). There was no significant difference in mortality between any drug classes.

CONCLUSIONS

Class IA, IC, and III drugs are associated with increased sinus rhythm at follow up compared with placebo. It is unclear whether any antiarrhythmic drug class is associated with increased or decreased mortality.

Prevalence of asymptomatic intracranial atherosclerosis in high-risk patients

We used transcranial Doppler to screen 3,057 patients who had at least one vascular risk factor of hypertension, diabetes, or hyperlipidemia and found 385 (12.6%) had middle cerebral artery stenosis. Elderly, hypertension, diabetes, and hyperlipidemia were associated factors. The prevalence escalated quadratically with increasing number of associated factors: from 7.2% for one, to 29.6% for four associated factors. Asymptomatic middle cerebral artery stenosis is common in patients with vascular risk factors.

A door-to-door survey of intracranial atherosclerosis in Liangbei County, China

We studied 590 asymptomatic villagers aged > or =40 years in Liangbei County in central rural China and found 41 subjects (prevalence 6.9%) with intracranial atherosclerosis. In a multivariate analysis, the significant risk factors for intracranial stenosis were hypertension (OR 2.53; 95% CI 1.12 to 5.72), glycosuria (OR 3; 1.19 to 7.97), heart disease (OR 4; 1.39 to 11.6), and family history of stroke (OR 5.2; 1.38 to 20). Intracranial atherosclerosis is not uncommon among asymptomatic Chinese subjects.

Quality of life is predictive of survival in patients with unresectable hepatocellular carcinoma

BACKGROUND

Patients with unresectable hepatocellular carcinoma (HCC) have a dismal prognosis. The objective of this study was to evaluate whether patient-reported baseline quality of life (QoL) measured by the EORTC QLQ-C30 instrument is predictive of survival for these patients.

MATERIALS AND METHODS

Two hundred and thirty-three patients with unresectable HCC (mainly hepatitis B-associated) who were recruited into two separate randomized phase III clinical studies, based on palliative chemotherapy and palliative hormonal therapy, respectively, gave consent and received pretreatment QoL assessment. EORTC QLQ-C30 scores and clinical variables at the time of study entry were analyzed to identify factors that influenced survival by applying multivariate analysis. Independent prognostic factors for survival were studied by Cox regression analysis.

RESULTS

Median survival of the 233 patients was 5.5 months (95% CI 4.2-6.5 months). Significant independent predictors of shorter survival were advanced Okuda staging (P = 0.0030; HR = 2.058), high baseline total bilirubin (P = 0.0008; HR = 1.013) and worse QoL score in the appetite score domain (P = 0.0028; HR for 10 point increase = 1.070). Patients who were entered into the chemotherapy trial (P = 0.0002; HR = 0.503), those who scored better in the physical functioning domain (P = 0.0034; HR for 10 point decrease = 0.911) and the role functioning domain (P = 0.0383; HR for 10 point decrease = 0.944) of the QoL questionnaire, were associated with longer survival.

CONCLUSIONS

In the studied HCC population, patient-reported baseline QoL provides additional prognostic information that supplements traditional clinical factors, and is a new prognostic marker for survival for patients with unresectable HCC.

Improvement in diabetes control with a monitoring system based on a hand-held, touch-screen electronic diary

We conducted a six-month prospective interventional crossover study examining a computerized diabetes monitoring system (DMS) that conveyed dietary information. The objectives were to compare glycaemic control between intervention and control periods, and to assess patients' acceptance of the DMS. Nineteen patients were randomized into two groups, each using the DMS for three months and serving as the control group for another three months. The patients recorded information about their meal portions and blood glucose readings in a hand-held electronic diary. After transmitting the data to the DMS through a telephone modem, the patients received immediate feedback about the carbohydrate, protein and fat content of the meal, as well as the calorie content. A significant improvement in glycaemic control was achieved during intervention compared with control periods (mean HbA1C reduction of 0.825%). The DMS was also highly acceptable: 95% patients found it easy to operate while 63% found it useful. The DMS was thus a feasible model of telemedicine in diabetes care and a larger study is warranted to examine its cost-effectiveness.

The changing epidemiology of spinal trauma: a 13-year review from a Level I trauma centre

INTRODUCTION

Spinal injuries secondary to trauma are a major cause of patient morbidity and a source of significant health care expenditure. Increases in traffic safety standards and improved health care resources may have changed the characteristics and incidence of spinal injury. The purpose of this study was to review a single metropolitan Level I trauma centre's experience to assess the changing characteristics and incidence of traumatic spinal injuries and spinal cord injuries (SCI) over a 13-year period.

PATIENTS AND METHODS

A retrospective review of patients admitted to a Level I trauma centre between 1996 and 2008 was performed. Patients with spinal fractures and SCI were identified. Demographics, mechanism of injury, level of spinal injury and Injury Severity Score (ISS) were extracted. The outcomes assessed were the incidence rate of SCI and in-hospital mortality.

RESULTS

Over the 13-year period, 5.8% of all trauma patients suffered spinal fractures, with 21.7% of patients with spinal injuries having SCI. Motor vehicle accidents (MVAs) were responsible for the majority of spinal injuries (32.6%). The mortality rate due to spinal injury decreased significantly over the study period despite a constant mean ISS. The incidence rate of SCI also decreased over the years, which was paralleled by a significant reduction in MVA associated SCI (from 23.5% in 1996 to 14.3% in 2001 to 6.7% in 2008). With increasing age there was an increase in spinal injuries; frequency of blunt SCI; and injuries at multiple spinal levels.

CONCLUSION

This study demonstrated a reduction in mortality attributable to spinal injury. There has been a marked reduction in SCI due to MVAs, which may be related to improvements in motor vehicle safety and traffic regulations. The elderly population was more likely to suffer SCI, especially by blunt injury, and at multiple levels. Underlying reasons may be anatomical, physiological or mechanism related.

Regulation of keratinocyte growth factor gene expression in human skin fibroblasts

Human keratinocyte growth factor (KGF) is a recently identified mitogen for epithelial cells produced by normal stromal fibroblasts. KGF has been shown to stimulate keratinocyte migration and promote re-epithelialization of skin suggesting a critical role for KGF in wound healing. To understand how KGF might be regulated during wound healing, we examined the ability of the pro-inflammatory cytokines interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta) interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) transforming growth factor-beta 1 (TGF-beta 1) and interferon-gamma (IFN-gamma) to modulate KGF gene expression in cultured human fibroblasts, using northern blot analysis. Exposure to IL-1 alpha (20 units/ml) or IL-1 beta (100 units/ml) for 24 h increased KGF mRNA expression by 352% and 504%, respectively, with early induction seen at 2 h and maximal induction seen at 8 h. TNF-alpha (30 ng/ml) increased KGF mRNA expression by 535% at 24 h, with induction first seen at 8 h. The maximal induction of KGF mRNA was observed when IL-1 alpha, IL-1 beta and TNF-alpha were used at 100 units/ml, and 3 ng/ml, respectively, although concentrations 100-500-fold lower (IL-1 alpha, 0.02 units/ml; IL-beta, 0.02 units/ml; and TNF-alpha, 0.03 ng/ml) were nearly as stimulatory, increasing KGF mRNA expression by 175%, 254% and 322%, respectively. IL-6 (200 units/ml), TGF-beta 1 (5 ng/ml) and IFN-gamma (200 units/ml) did not change the level of KGF mRNA at 24 h in human fibroblasts under the same conditions. The protein synthesis inhibitor cycloheximide abrogated the effects of IL-1 alpha, IL-1 beta and TNF-alpha on KGF gene induction, indicating that new protein synthesis is required in the process. Dexamethasone (10(-7) M), known to inhibit inflammatory reactions and retard wound healing, also inhibited the induction of KGF mRNA expression by IL-1 alpha, IL-1 beta and TNF-alpha. Individual variation in KGF mRNA expression was see when fibroblasts from different aged donors were analysed, but no consistent age-associated change was observed. These results suggest that IL-1 alpha, IL-1 beta and TNF-alpha up-regulate KGF gene expression in fibroblasts and might be responsible for its induction following skin wounding or other injury.

Immunogenicity and protective efficacy of DNA vaccines encoding secreted and non-secreted forms of Mycobacterium tuberculosis Ag85A

OBJECTIVE

To determine the efficacy of Ag85A-DNA against challenge with a highly virulent human clinical isolate of Mycobacterium tuberculosis (CSU37) and to compare the potencies of two types of Ag85A-DNA vaccines; those expressing secreted and non-secreted forms of the protein.

DESIGN

Ag85A-DNA vaccinated mice were challenged with a highly virulent clinical isolate of M. tuberculosis (CSU37) in order to compare the efficacy of these vaccines. In vitro studies were also performed.

RESULTS

Enhanced humoral and cellular responses were induced in mice vaccinated with the secreted Ag85A-DNA compared to the non-secreted Ag85A-DNA. In addition, secreted Ag85A-DNA conferred protective immunity against infection with M. tuberculosis (CSU37).

CONCLUSIONS

DNA vaccines encoding M. tuberculosis Ag85A have been shown to induce potent humoral and cellular immune responses leading to protection from M. tuberculosis (Erdman) challenge in mouse models. In this study we demonstrate that Ag85A can confer protection in a rigorous challenge model using a highly virulent human clinical isolate of M. tuberculosis (CSU37). This challenge model appears able to discriminate between DNA vaccines of differing potencies, as the more immunogenic DNA construct encoding a secreted form of Ag85A was protective, whereas the less immunogenic DNA construct encoding a non-secreted form of Ag85A was not.

Intravenous bolus somatostatin after diagnostic cholangiopancreatography reduces the incidence of pancreatitis associated with therapeutic endoscopic retrograde cholangiopancreatography procedures: a randomised controlled trial

BACKGROUND

Previous studies suggested that somatostatin given before endoscopic retrograde cholangiopancreatography (ERCP) may reduce the incidence of post-ERCP pancreatitis. However, the routine use of somatostatin in all patients undergoing ERCP is not likely to be cost effective. This study evaluated whether intravenous bolus somatostatin given after diagnostic cholangiopancreatography could reduce the incidence of pancreatitis in a group of patients undergoing therapeutic ERCP procedures.

METHODS

In a randomised, double blind, controlled trial, the effect of intravenous bolus somatostatin 250 microg given immediately after diagnostic cholangiopancreatography was compared with that of placebo in patients who required endoscopic sphincterotomy or other therapeutic procedures. The primary end point was the incidence of post-ERCP clinical pancreatitis, and a secondary end point was the incidence of hyperamylasemia.

RESULTS

A total of 270 patients were randomised. The somatostatin group (n=135) and the placebo group (n=135) were comparable in age, sex, indications for treatment, and types of procedure. The frequencies of clinical pancreatitis (4.4% v 13.3%; p=0.010) and hyperamylasemia (26.0% v 38.5%; p=0.036) were both significantly lower in the somatostatin group compared with the placebo group.

CONCLUSIONS

A single dose of intravenous bolus somatostatin, given immediately after diagnostic cholangiopancreatography, is effective in reducing the incidence of pancreatitis after therapeutic ERCP. This novel approach of administering prophylactic somatostatin may offer a cost effective prophylaxis for post-ERCP pancreatitis.

Sequence of the spacer in the recombination signal sequence affects V(D)J rearrangement frequency and correlates with nonrandom Vkappa usage in vivo

Functional variable (V), diversity (D), and joining (J) gene segments contribute unequally to the primary repertoire. One factor contributing to this nonrandom usage is the relative frequency with which the different gene segments rearrange. Variation from the consensus sequence in the heptamer and nonamer of the recombination signal sequence (RSS) is therefore considered a major factor affecting the relative representation of gene segments in the primary repertoire. In this study, we show that the sequence of the spacer is also a determinant factor contributing to the frequency of rearrangement. Moreover, the effect of the spacer on recombination rates of various human Vkappa gene segments in vitro correlates with their frequency of rearrangement in vivo in pre-B cells and with their representation in the peripheral repertoire.

Aspirin-associated intracerebral hemorrhage: clinical and radiologic features

OBJECTIVE

To identify the clinical and radiologic features of intracerebral hemorrhage (ICH) in aspirin users.

BACKGROUND

Although the benefits of aspirin outweigh its hemorrhagic risks for patients at high risk of vascular diseases, prolonged use of aspirin is associated with an increased risk of ICH.

METHODS

The authors enrolled consecutive patients with acute stroke who were admitted to a regional hospital from 1993 to 1998 into a stroke registry. From this registry, they identified all stroke patients who had ICH confirmed by CT scan and then selected those taking regular aspirin before ICH as the study group. For each study patient, they selected the immediate next two patients with ICH but not taking aspirin as controls.

RESULTS

The authors identified 58 aspirin users and 1193 nonusers among all patients hospitalized for ICH. From the group of nonusers, they selected 116 patients as controls. The locations of the hematoma were different (p = 0.002), with more lobar hematoma in the aspirin group (32.8%) than in the control group (10.3%). Prior cerebrovascular disease was the reason for taking aspirin in 37 (64%) patients but five patients had prior ICH.

CONCLUSIONS

The propensity for lobar hematoma in aspirin-associated ICH suggests its pathology may be somewhat different from spontaneous ICH among nonaspirin users. Further research to examine the risks and benefits of aspirin use in certain subgroups at risk of both thrombotic and hemorrhagic events is needed.

Phase I/II trial of palbociclib, pembrolizumab and letrozole in patients with hormone receptor-positive metastatic breast cancer

BACKGROUND

CDK4/6 inhibitors modulate immune response in breast cancer. This phase I/II trial was designed to test the safety and efficacy of palbociclib, pembrolizumab and letrozole in women with hormone receptor positive (HR⁺) human epidermal growth factor receptor 2 negative (HER2^-) metastatic breast cancer (MBC).

PATIENTS AND METHODS

Women with stage IV HR⁺ HER2^- MBC were enrolled and treated with palbociclib, pembrolizumab and letrozole. Primary end-points were safety, tolerability and efficacy.

RESULTS

Between November 2016 and July 2020, 23 patients were enrolled with 20 evaluable for response, including 4 patients in cohort 1 and 16 patients in cohort 2. Cohort 1 median age was 48 years (33-70) and cohort 2 median age was 55 (37-75). Cohort 1 closed early due to limited accrual. Grade III-IV adverse events were neutropenia (83%), leucopaenia (65%), thrombocytopenia (17%) and elevated liver enzymes (17%). In cohort 1, 50% achieved a partial response (PR) and 50% had stable disease (SD). In cohort 2, 31% achieved complete response (CR), 25% had PR and 31% had SD by Response Evaluation Criteria in Solid Tumours version 1.1. Median progression-free survival was 25.2 months (95% confidence interval [CI] 5.3, not reached) and median overall survival was 36.9 months (95% CI 36.9, not reached) in cohort 2 with a median follow-up of 24.8 months (95% CI 17.1, not reached). A correlative immune biomarker analysis was published separately.

CONCLUSION

The combination of palbociclib, pembrolizumab and letrozole is well tolerated, and a complete response rate of 31% was identified in HR⁺ MBC patients who received this combination as front-line therapy. Confirmatory trials are required to better understand the immune-priming effects of CDK4/6 inhibitors.

Role of integrins in melanocyte attachment and dendricity

Integrins are a family of proteins known to mediate attachment of cells to extracellular matrix materials. The substratum specificity and cation dependence of specific integrin heterodimers have been extensively characterized, and to a lesser degree specialized roles in cell attachment versus dendricity have been defined in some cell types. In the past decade, melanocyte attachment rate and morphology have been found to have strong substratum dependence, suggesting a major role for integrins in these processes. In order to investigate this aspect of pigment cell biology, human newborn melanocytes were subjected to flow cytometry analysis and plated on a variety of substrata under conditions known to promote or block the binding of specific integrin pairs. Melanocyte attachment to laminin and type IV collagen was promoted by Mg2+ and Mn2+ but not by Ca2+, in the range of concentrations examined. However, dendrite outgrowth from melanocytes already attached on laminin or type IV collagen was promoted by Ca2+ to a far greater degree than by Mg2+, and Mn2+ had no effect on dendrite outgrowth. Flow cytometry analysis revealed that melanocytes expressed beta 1, alpha 2, alpha 3, alpha 5, alpha 6 and alpha v integrin subunits as well as the alpha v beta 3 heterodimer. The influence of substratum on the profile of integrin expression was minimal, but alpha 6 and beta 1 integrins were observed by confocal microscopy to be expressed over the entire cell surface, while alpha 2, alpha 5 and alpha v beta 3 integrins localized along dendritic processes or at their tips. In accordance with the implications of these distribution patterns, anti-beta 1 and anti-alpha 6 integrin monoclonal antibodies blocked melanocyte attachment to laminin, while anti-alpha 2, anti-alpha 5 and anti-alpha v beta 3 inhibited dendrite outgrowth but did not block substratum attachment on either laminin or type IV collagen. On the basis of these data and the known characteristics of integrin molecules, we conclude that melanocyte attachment to laminin is mediated primarily by alpha 6 beta 1 integrin in a Ca(2+)-independent, Mg(2+)- and/or Mn(2+)-dependent manner, while dendrite outgrowth on laminin and type IV collagen requires extracellular Ca2+ and is mediated by alpha v beta 3 as well as alpha 2 and alpha 5 integrins.

Human dTMP kinase: gene expression and enzymatic activity coinciding with cell cycle progression and cell growth

dTMP kinase (E.C.2.7.4.9.) catalyzes the phosphorylation of dTMP to the corresponding diphosphate. This enzyme is essential for DNA synthesis in vivo and is an important intermediate enzyme in the pathway of many pyrimidine analog drugs. In this report, we describe the isolation of the human dTMP kinase gene by functional complementation of a Saccharomyces cerevisiae cell cycle mutant, cdc8. The cDNA sequence revealed an open reading frame that encodes a protein with the molecular weight of 23,806. The deduced protein sequence was compared to known dTMP kinase sequences from different organisms. Although functionally complementary and structurally conserved, expressed human dTMP kinase in yeast shows little enzymatic activity. In contrast, active human dTMP kinase can be expressed from the gene cloned into the baculovirus expression system, as evidenced by increased enzymatic activity by four- to five-fold. Unlike yeast dTMP kinase, human dTMP kinase does not contain a cysteine residue after the conserved glycine-rich loop, but its enzymatic activity is still affected by the sulfhydryl inhibitor, 5,5'-dithio-bis(2-nitrobenzoic acid) (DTNB). The levels of dTMP kinase mRNA and its enzymatic activity fluctuate during the cell cycle, peaking at the S phase. Thus, like Saccharomyces cerevisiae CDC8 (encoding dTMP kinase), the human homolog mRNA and enzymatic activity are also cell cycle regulated. We have also examined four neuroblastoma cell lines for dTMP kinase mRNA levels and its kinase activities, which appear to vary according to cell growth rate. Our results suggest that the expression of the dTMP kinase gene and its activity coincide with various stages of cell growth. The identification of the human dTMP kinase gene and expression of its product in the baculovirus expression system should facilitate study of the mechanism of gene regulation and its role in pyrimidine metabolism.

Neonatal novelty exposure modulates hippocampal volumetric asymmetry in the rat

Early life environmental manipulations have been shown to affect hippocampal-dependent learning, hippocampal volume and cerebral lateralization. In this study, we investigated the effects of neonatal stimulation on hippocampal volumetric asymmetry. Long-Evans hooded rats were exposed to a novel non-home environment 3 min daily for the first 3 weeks of life. Histological measures of the left and right hippocampus were made at 8 months of age. We found that neonatal novelty exposure resulted in a long-lasting change in hippocampal volumetric asymmetry. Specifically, this brief and transient early life stimulation increased the right hippocampal volumetric dominance at mid-adulthood.

Local vs systemic corticosteroids in the treatment of carpal tunnel syndrome

The authors compared the effectiveness of low-dose, short-term oral prednisolone vs local methylprednisolone injection in a prospective, double-blinded, parallel treatment study of carpal tunnel syndrome (CTS). A single injection of 15 mg methylprednisolone resulted in significant improvement in global symptom scores over a 12-week period. This study demonstrated the superiority of local steroid injection to oral steroid in the treatment of CTS.