Neuronal spiking responses to direct electrical microstimulation in the human cortex

Microstimulation can modulate the activity of individual neurons in order to affect behavior, but the effects of stimulation on neuronal spiking are complex and remain poorly understood. This is especially challenging in the human brain where the response properties of individual neurons are sparse and heterogenous. Here we use micro- electrode array (MEAs) in the human anterior temporal lobe in six participants (3 female) to examine the spiking responses of individual neurons to microstimulation delivered through multiple distinct stimulation sites. We demonstrate that individual neurons can be driven with excitation or inhibition using different stimulation sites, which suggests an approach for providing direct control of spiking activity at the single neuron level. Spiking responses are inhibitory in neurons that are close to the site of stimulation, while excitatory responses are more spatially distributed. Together, our data demonstrate that spiking responses of individual neurons can be reliably identified and manipulated in the human cortex.SIGNIFICANCE STATEMENT:One of the major limitations in our ability to interface directly with the human brain is that the effects of stimulation on the activity of individual neurons remains poorly understood. Here, Youssef et al. examine the spiking responses of neurons in the human temporal cortex in response to pulses of microstimulation. They find that individual neurons can either be excited or inhibited depending on the site of stimulation. These data suggest an approach for modulating the spiking activity of individual neurons in the human brain.

Multicenter review of a tadalafil suspension formulation in infants and children with pulmonary hypertension: a north american experience

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary arterial hypertension (PAH) is a disease characterised by an increase in pulmonary vascular resistance and pulmonary artery pressure. Phosphodiesterase type 5 (PDE5) inhibitors, with sildenafil the earliest among them, are widely used in the management of pediatric PAH. There has more recently been a transition to once-daily tadalafil suspensions. Herein, we present a multicenter experience detailing safety, tolerability and haemodynamic data utilizing tadalafil suspension alone or in combination for the management of pediatric PAH.

Methods and materials

We performed a retrospective review of all infants and children at two North American paediatric PH centres between December 2013 and April 2022. We included all patients less than 9 years of age who were treated with a tadalafil suspension after an initial treatment with sildenafil. Demographic, clinical, imaging, and laboratory data were collected.

Results

Over the study period, 158 children were treated with tadalafil therapy: 41 (25.9%) had group 1 PAH, 81 (51.3%) had group 3 PH, and 33 (20.9%) had group 5 PH. The median initial dose of tadalafil was 1.0 mg/kg once daily with a median time to maximum dose of 1 day. The majority of patients required the suspension formulation due to an inability to take oral tablets or the need for nasogastric or nasojejunal feeding. We observed improvements in median echocardiographic parameters in the six months following initiation, namely, in RVFAC from 34.7% (Q1 = 31.0%, Q3 = 42.0%) to 37.0% (Q1 = 31.0%, Q3 = 44.0%) and in TAPSE from 1.0 (Q1 = 0.8, Q3 = 1.7) cm to 1.3 (Q1 = 1.0, Q3 = 1.7) cm. We observed median decreases in RVSp from 51.0 (Q1 = 35.0, Q3 = 69.0) mmHg to 37.0 (Q1 = 30.0, Q3 = 50.0) mmHg and in NT pro BNP levels from 439.0 (Q1 = 217.0, Q3 = 2051.0) ng/L to 313.0 (Q1 = 193.0, Q3 = 1110.0) ng/L. Tadalafil therapy was well tolerated over the six-month period: at baseline, only four patients (2.5%) reported gastrointestinal side effects, two (1.3%) reported adverse skin adverse effects (i.e., rash and flushing), and one (0.6%) reported adverse neurological effects. At six months, 150 patients (94.9%) reported no adverse effects.

Conclusion

Tadalafil, a long-acting PDE5 inhibitor, when administered in a suspension formulation, has a safe and tolerable adverse effect profile once patients are established on sildenafil therapy. Following 6 months of once daily tadalafil suspension, alone or in combination, showed a trend towards improvement in clinical parameters, echocardiographic measurements, and laboratory results for pediatric PAH. All patient adverse effects were managed with non pharmacological measures and there was good patient compliance.

A Canadian, retrospective, multicenter experience with selexipag for a heterogeneous group of pediatric pulmonary hypertension patients

Introduction

Selexipag, an oral nonprostanoid prostaglandin receptor agonist, has led to reduced morbidity and mortality in adults with pulmonary arterial hypertension (PAH). While the adult literature has been extrapolated to suggest selexipag as an oral treatment for severe pediatric pulmonary hypertension (PH), longitudinal, multicenter data on the benefits of selexipag in this population are lacking. The purpose of this study is to present a longitudinal, multicentre experience with selexipag in a relatively large cohort of pediatric PH patients and add to the existing selexipag literature.

Materials and methods

We performed a retrospective, multicenter review describing the clinical outcomes of pediatric PH patients receiving selexipag in addition to standard oral pulmonary vasodilator therapy across three Canadian centers between January 2005 and June 2021.

Results

Twenty-four pediatric patients (fifteen female) with a mean age of 9.7 (range 2.0-15.5) years were included. Of this cohort, eighteen (75.0%) were in group 1, one (4.2%) was in group 2, four (16.7%) were in group 3, and one (4.2%) was in group 4. Twenty-two (91.7%) patients were on dual PH therapy after six months. Dosing was targeted to achieve 20-30 mcg/kg/dose orally every twelve hours. Median dose after twelve months was 30 mcg/kg/dose. Twelve months following selexipag initiation, median decreases of 0.2 cm in tricuspid annular plane systolic excursion, 3.5 mmHg in right-ventricular systolic pressure, and 6.1 mmHg in mean pulmonary arterial pressure were observed; none of these changes were statistically significant. Three patients died, one clinically deteriorated and required admission to a pediatric intensive care unit, ten had gastrointestinal symptoms, and three had flushing.

Conclusion

Selexipag appears to be a safe and effective adjunctive therapy for pediatric PH patients and has a tolerable adverse effect profile aside from gastrointestinal disturbances. Additional prospective studies of changes in hemodynamics and functional classification over a longer period and with a larger sample are needed. Future research should aim to identify subgroups that stand to benefit from the addition of selexipag as well as optimal timing and dosing for the pediatric population.

Integrating Health Belief model to determine factors associated with COVID-19 Vaccine Acceptance in Lebanon: Differences between health care workers and non-healthcare workers

Purpose

Vaccine acceptance is critical to the success of immunization programs, especially for emerging infectious diseases. This study aims to assess the willingness to receive the COVID-19 vaccine, and the factors associated with this willingness among healthcare workers (HCWs) and non-healthcare workers in Lebanon.

Methods & Materials

A web-based cross-sectional survey was conducted among Lebanese adults aged 18 years and above during November 2020 among Lebanese adults from all Lebanese provinces using a snowball sampling technique. Data were collected using an anonymous Arabic questionnaire that included sociodemographic, health-related variables, intention to receive COVID-19 vaccine, and the Health Belief Model covariates. Multivariable logistic regression analyses were performed to identify the factors associated with the COVID-19 vaccine acceptance among the 2 groups.

Results

A total number of 2802 participants completed the survey. The overall intention to receive a COVID-19 vaccine among the Lebanese adult population was 51.5%. HCWs expressed a higher willingness of getting vaccinated against COVID-19 than non HCWs (65.8% vs. 47%, p< 0.001). The factors that are positively associated with the willingness to vaccinate among the general population, non HCWs and HCWs were: older age, being married, living in urban areas, receiving influenza vaccine for this season, higher perception of susceptibility and benefits, concerns related to availability and accessibility of vaccines and recommendation of vaccine from health authorities. However, the previous refusal of any vaccine, concerns about vaccine safety, and side effects impacted negatively this intention. Female gender, importance accounted to religiosity, and concerns about the reliability of the manufacturer were negatively associated with vaccine acceptance among non HCWs. Conversely, good knowledge, vaccine intake by the public, and self-motivation were positively associated with this willingness. Of note, these factors were not significantly associated with such willingness among HCWs.

Conclusion

To control COVID-19 effectively, efforts targeting modifiable factors driving COVID-19 vaccine acceptance are required to increase the acceptance rate among the Lebanese population.

A multicentre survey of paediatric out-of-hospital cardiac arrest incidence, aetiology, and survival in New South Wales over an 11-year period

Funding Acknowledgements

Type of funding sources: None.

Introduction

Out-of-hospital cardiac arrest (OOHCA) is commonly associated with pulseless ventricular tachycardia and ventricular fibrillation (VT/VF) and cardiac aetiologies. One New South Wales (NSW) ambulance registry reported(1) cardiac aetiologies with a prevalence of 31% among OOHCA cases. Multicentre OOHCA data and NSW’s well-developed services for cardiac genetic predisposition screening motivate us to consider the following study of paediatric OOHCA in this state.

Purpose

We present a multicentre, retrospective study summarizing the demographics, clinical characteristics, incidence, presenting rhythm, and survival-to-discharge status of paediatric OOHCA cases in NSW over an 11-year period. We also present and categorize diagnostic outcomes for patients presenting with VT/VF.

Methods

A retrospective case series of 298 patients admitted to one of three NSW PICUs (two in Sydney and one in Newcastle) under 18 years of age and presenting with OOHCA between January 2009 and December 2019.

Results

Out of 296 paediatric OOHCA patients that survived until PICU admission, 187 (63.2%) were male and 160 (54.1%) survived until hospital discharge. Of those surviving to discharge, 105 (65.6%) were male. Presenting rhythm was asystole or pulseless electrical activity in 240 patients (84.8%, aged 0–17 years, median age 2 years), VT/VF in 41 patients (14.5%, aged 0–16 years, median age 9 years), and complete heart block in 2 patients (0.7%, aged 4–4 years, median age 4 years). Survival was higher in the VT/VF group (82.9%) relative to the asystole and pulseless electrical activity group (50.0%). Of the 41 patients presenting with VT/VF, 13 (31.7%) had a predisposing cardiac condition (2 truncus arteriosus, 1 arrhythmogenic right ventricular cardiomyopathy, 1 double outlet right ventricle, 1 hypoplastic right ventricle, 1 left ventricular non-compaction, 2 asystolic syncope, 2 left ventricular intramyocardial fibroma, 1 familial dilated cardiomyopathy, and 2 undetermined cardiac conditions) and 20 (48.8%) had a genetic condition (9 catecholaminergic polymorphic ventricular tachycardia, 4 hypertrophic cardiomyopathies, 1 Nkx-2.5 mutation, 2 Long QT syndrome, 2 PPA2 mutation, 1 TANGO2 mutation, 1 supraventricular tachycardia). Toxins or trauma were involved in 4 (9.8%) cases, while no cause was determined in 4 (9.8%) other cases.

Conclusions

Overall, 54.1% of paediatric OOHCA patients admitted to PICU survived until hospital discharge, rising to 82.9% among those with VT/VF. Genetic conditions (48.8%), predominated by CPVT, were present in over one-third of VT/VF cases: this figure confirms the continued need for detailed cardiac/genetic assessment for paediatric OOHCA cases.

Correlation of ventricular septal defect height and outcomes after complete atrioventricular septal defect repair

 

OBJECTIVES

There are limited data available on the height of the ventricular component of the septal deficiency (VSD) in patients undergoing complete atrioventricular septal defect (CAVSD) repair. VSD height may influence optimal choice of repair strategy with potential consequences for long-term outcomes. We aimed to measure VSD height using 2-dimensional echocardiography and review its association with postoperative outcomes.

METHODS

We retrospectively reviewed the preoperative echocardiograms of 45 consecutive patients who underwent CAVSD repair between May 2010 and December 2015 at a single centre. VSD height and left ventricular length on the four-chamber view were measured. Demographic details and early and late outcomes including reoperation and long-term survival were studied.

RESULTS

Twenty patients underwent modified single-patch repair and 25 patients underwent double-patch repair of CAVSD. VSD height in the modified single-patch group ranged from 4.2 to 11.7 mm and in the double-patch group ranged from 5.1 to 14.9 mm. Nine patients had a deep ‘scoop’ with a VSD height of >10 mm, (7 double patch, 2 modified single patch). VSD height did not correlate with a specific Rastelli classification. There was no significant difference in the VSD height (P = 0.51) or the VSD height-to-left ventricular length ratio (P = 0.43) between the 2 repair groups. There was no 30-day mortality. Eight patients required reoperation; however, VSD height was not a significant predictor of reoperation (hazard ratio 0.95, 95% confidence interval 0.69–1.33; P = 0.08).

CONCLUSIONS

There was no correlation between VSD height and risk of reoperation after CAVSD repair. A deep ventricular scoop is uncommon in CAVSD patients.

Small bowel intussusception and Enterobius vermicularis infestation in a 20-year-old woman

A 20-year-old woman presented with abdominal pain and MRI findings of intussusception of the distal small bowel with no identifiable lead point and no visualisation of the appendix. A diagnostic laparoscopy succeeded in manually reducing the intussusception but was unable to find any candidate lead point. Intraoperatively, hyperperistalsis was observed throughout the small bowel which seemed prone to transient intussusception. Incidental appendectomy revealed an uninflamed appendix with Enterobius vermicularis (pinworm) infestation, the most common parasite present in appendectomy specimens worldwide. Although intussusception in young adults is an uncommon occurrence, the unique nature of this case is amplified by the concurrent finding of E. vermicularis infection of the appendix in an adolescent in western Canada, a phenomenon normally observed in paediatric populations with higher incidence in tropical areas. Although the mechanism of intussusception in this patient remains unclear, it is hypothesised that E. vermicularis colonisation acted as an irritant stimulating intestinal hypercontractility with resulting intussusception. Successful medical eradication of the pinworm in this individual may prevent future recurrence.

Assessing the clinical significance of echocardiograms in determining treatment of patent ductus arteriosus in neonates

BACKGROUND

To evaluate the utility of echocardiogram (ECHO) in detection and treatment of patent ductus arteriosus (PDA) and hemodynamically significant PDA (hsPDA) in preterm neonates.

METHODS

This was a retrospective case-control study of all preterm infants born or admitted to the level III Neonatal Intensive Care Unit in McMaster Children's Hospital from January 2009 to January 2013. These cases were further classified into the following sub-groups: group A) hsPDA confirmed on ECHO; and the control, group B) PDA (but not hemodynamically significant) confirmed on ECHO. Patients without an ECHO were excluded from all analyses. The primary outcome was incidence of treatment for PDA.

RESULTS

PDA treatment was administered in 83.3% and 11.2% of patients in groups A and B respectively (P < 0.05). Among patients with a hsPDA within group A, 17% did not receive treatment, while 11% of patients with non-hemodynamically significant PDA received treatment for the PDA. Within the cohort of patients who received treatment for a hsPDA, gestational age below 35 weeks as well as murmurs heard on auscultation were both found to be predictors of treatment.

CONCLUSION

While the ECHO remains the gold standard for detecting pathological PDA, there is evidence that other traditional clinical measures continue to guide clinical practice and treatment decisions. Further research is required to gain an understanding of how clinical measures and ECHO may be used in conjunction to optimize resource utilization.

Evaluation of personalized right ventricle to pulmonary artery conduits using in silico design and computational analysis of flow

Objectives

Right ventricle to pulmonary artery (RV-PA) conduits are required for the surgical management of pulmonary atresia with ventricular septal defect and truncus arteriosus. Bioengineered RV-PA connections may address some of the shortcomings of homografts and xenografts, such as lack of growth potential and structural deterioration and may be manufactured to accommodate patient-specific anatomy. The aim of this study was to develop a methodology for in silico patient-specific design and analysis of RV-PA conduits.

Methods

Cross-sectional imaging was obtained from patients with truncus arteriosus (n = 5) and pulmonary atresia with ventricular septal defect (n = 5) who underwent complete repair with a RV-PA conduit. Three-dimensional models of the heart were constructed by segmentation of the right ventricle, existing conduit, branch pulmonary arteries, and surrounding structures. A customized conduit design for each patient was proposed. Computational fluid dynamics analysis was performed and outputs, including wall shear stress and energy loss, were used to compare the performance of the existing conduits and the customized geometries.

Results

In this study, a methodology for patient-specific analysis of RV-PA conduit in silico was developed. The results of simulations for 10 patients showed between 23% and 56% decrease in the average wall shear stress and between 24% and 87% reduction in average power requirements in customized designs compared with the stenosed conduits, translating into better hemodynamic performance.

Conclusions

Creation of an optimal conduit for an individual patient can be achieved using surgeon-guided design and computational fluid dynamics analysis. Manufacture of personalized RV-PA conduits may obviate the need for surgical customization to accommodate existing materials and provide superior long-term outcomes.

Cytomegalovirus duodenitis associated with life-threatening duodenal hemorrhage in an immunocompetent patient: A case report

INTRODUCTION

Cytomegalovirus (CMV) is known to be opportunistic in immunocompromised patients. However, there have been emerging cases of severe CMV infections found in immunocompetent patients. Gastrointestinal (GI) CMV disease is the most common manifestation affecting immunocompetent patients, with duodenal involvement being exceedingly rare. Presented is a case of an immunocompetent patient with life-threatening bleeding caused by CMV duodenitis, requiring surgical intervention.

PRESENTATION OF CASE

A 60-year-old male with history of disseminated Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia and aortic valve infective endocarditis, presented with life-threatening upper GI hemorrhage. Endoscopy revealed ulcerations, with associated generalized mucosal bleeding in the duodenum. After repeated endoscopic therapies and failed interventional-radiology arterial embolization, the patient required a duodenectomy and associated total pancreatectomy, to control the duodenal hemorrhage. Pathologic review of the surgical specimen demonstrated CMV duodenitis. Systemic ganciclovir was utilized postoperatively.

DISCUSSION

GI CMV infections should be on the differential diagnosis of immunocompetent patients presenting with uncontrollable GI bleeding, especially in critically ill patients due to transiently suppressed immunity. Endoscopic and histopathological examinations are often required for diagnosis. Ganciclovir is first-line treatment. Surgical intervention may be considered if there is recurrent bleeding and CMV duodenitis is suspected because of high potential for bleeding-associated mortality.

CONCLUSION

Presented is a rare case of life-threatening GI hemorrhage caused by CMV duodenitis in an immunocompetent patient. The patient failed endoscopic and interventional-radiology treatment options, and ultimately stabilized after surgical intervention.

Efficacy and safety of sodium-glucose co-transporter-2 inhibitors in type 2 diabetes mellitus: systematic review and network meta-analysis

AIM

To assess the comparative efficacy and safety of sodium-glucose co-transporter-2 (SGLT2) inhibitors in adults with type 2 diabetes.

METHODS

We electronically searched randomized controlled trials (≥24 weeks) including canagliflozin, dapagliflozin or empagliflozin that were published up to 3 November 2015. Data were collected on cardiometabolic and safety outcomes and synthesized using network meta-analyses.

RESULTS

A total of 38 trials (23 997 participants) were included. Compared with placebo, all SGLT2 inhibitors reduced glycated haemoglobin (HbA1c), fasting plasma glucose (FPG), body weight and blood pressure, and slightly increased HDL cholesterol. Canagliflozin 300 mg reduced HbA1c, FPG and systolic blood pressure and increased LDL cholesterol to a greater extent compared with other inhibitors at any dose. At their highest doses, canagliflozin 300 mg reduced: HbA1c by 0.2% [95% confidence interval (CI) 0.1-0.3] versus both dapagliflozin 10 mg and empagliflozin 25 mg; FPG by 0.6 mmol/l (95% CI 0.3-0.9) and 0.5 mmol/l (95% CI 0.1-0.8) versus dapagliflozin and empagliflozin, respectively; and systolic blood pressure by 2 mmHg (95% CI 1.0-3.0) versus dapagliflozin; and increased LDL cholesterol by 0.13 mmol/l (95% CI 0.03-0.23) and 0.15 mmol/l (95% CI 0.06-0.23) versus dapagliflozin and empagliflozin, respectively. The highest doses of inhibitors had similar effects on body weight reduction. Canagliflozin 300 and 100 mg increased the risk of hypoglycaemia versus placebo, dapagliflozin 10 mg and empagliflozin 10 mg [odds ratios (ORs) 1.4-1.6]. Dapagliflozin 10 mg increased the risk of urinary tract infection versus placebo and empagliflozin 25 mg (ORs 1.4). All inhibitors similarly increased the risk of genital infection (ORs 4-6 versus placebo).

CONCLUSIONS

Although they increase the risk of genital infection, SGLT2 inhibitors are effective in improving cardiometabolic markers in type 2 diabetes, with canagliflozin 300 mg performing better in this respect than other inhibitors. Further studies will clarify whether these differences are likely to translate into differing long-term outcomes.

Multicenter assessment of neoadjuvant chemotherapy for muscle-invasive bladder cancer

BACKGROUND

The efficacy of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (BCa) was established primarily with methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC), with complete response rates (pT0) as high as 38%. However, because of the comparable efficacy with better tolerability of gemcitabine and cisplatin (GC) in patients with metastatic disease, GC has become the most commonly used regimen in the neoadjuvant setting.

OBJECTIVE

We aimed to assess real-world pathologic response rates to NAC with different regimens in a large, multicenter cohort.

DESIGN, SETTING, AND PARTICIPANTS

Data were collected retrospectively at 19 centers on patients with clinical cT2-4aN0M0 urothelial carcinoma of the bladder who received at least three cycles of NAC, followed by radical cystectomy (RC), between 2000 and 2013.

INTERVENTION

NAC and RC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was pathologic stage at cystectomy. Univariable and multivariable analyses were used to determine factors predictive of pT0N0 and ≤pT1N0 stages.

RESULTS AND LIMITATIONS

Data were collected on 935 patients who met inclusion criteria. GC was used in the majority of the patients (n=602; 64.4%), followed by MVAC (n=183; 19.6%) and other regimens (n=144; 15.4%). The rates of pT0N0 and ≤pT1N0 pathologic response were 22.7% and 40.8%, respectively. The rate of pT0N0 disease for patients receiving GC was 23.9%, compared with 24.5% for MVAC (p=0.2). There was no difference between MVAC and GC in pT0N0 on multivariable analysis (odds ratio: 0.89 [95% confidence interval, 0.61-1.34]; p=0.6).

CONCLUSIONS

Response rates to NAC were lower than those reported in prospective randomized trials, and we did not discern a difference between MVAC and GC. Without any evidence from randomized prospective trials, the best NAC regimen for invasive BCa remains to be determined.

PATIENT SUMMARY

There was no apparent difference in the response rates to the two most common presurgical chemotherapy regimens for patients with bladder cancer.

Cystic intratesticular lesions in pediatric patients

BACKGROUND/PURPOSE

Intratesticular cysts are a rare clinical entity in the pediatric population. Recently, testes sparing surgery has been recommended. We share our experience with the management of pediatric testicular cysts.

METHODS

A retrospective review of all pediatric patients referred for intratesticular cysts was conducted at a single pediatric institution from 2002 to 2010. Charts were evaluated for patient demographics, diagnosis, and management.

RESULTS

Seven patients were identified and included in this series. After partial orchiectomy, the final diagnosis in three patients was epidermoid cyst. Three further patients were diagnosed as mature cystic teratoma, with two of these demonstrating adjacent intra-tubular germ cell neoplasia (ITGCN). One cyst in the series underwent spontaneous resolution after eight months.

CONCLUSION

All of the cystic lesions in our case series were benign with one undergoing complete resolution. The remainder became smaller and developed a solid component prompting surgery. The pre-pubertal findings of ITGCN in two patients raise a dilemma regarding the optimal long-term management for these patients. Initial conservative observation is an option for the majority of pre-pubertal cystic testicular lesions until such time that testis sparing surgery is deemed technically feasible. Testes sparing surgery should be advocated in those patients undergoing surgical management.

Healthcare costs of methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa infections in veterans: role of vitamin D deficiency

Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) infections are frequently associated with hospitalization and increased healthcare costs. Vitamin D deficiency may contribute to increased costs for patients with these infections and there is evidence that vitamin D may have an antimicrobial role. To evaluate the role of vitamin D deficiency in the costs incurred with these infections, we studied the relationship of serum 25(OH)D levels to healthcare costs in veterans in the southeastern United States. Patients with both infections were vitamin D deficient to a similar extent and so were combined for further analysis. Vitamin D deficient patients had higher costs and service utilization than those who were not vitamin D deficient. Those with vitamin D deficiency had higher inpatient costs compared to the non-deficient group, and this difference was across most categories except for the number of inpatient hospitalizations or total number of days as an inpatient. Vitamin D deficiency was not significantly related to outpatient cost or service utilization parameters. We conclude that vitamin D deficiency is intimately linked to adverse healthcare costs in veterans with MRSA and P. aeruginosa infections. Vitamin D status should be assayed in patients with these infections.

Alkaline phosphatase-positive colony formation is a sensitive, specific, and quantitative indicator of undifferentiated human embryonic stem cells

Human embryonic stem cells (hESCs) can be maintained in vitro as immortal pluripotent cells but remain responsive to many differentiation-inducing signals. Investigation of the initial critical events involved in differentiation induction would be greatly facilitated if a specific, robust, and quantitative assay for pluripotent hESCs with self-renewal potential were available. Here we describe the results of a series of experiments to determine whether the formation of adherent alkaline phosphatase-positive (AP(+)) colonies under conditions optimized for propagating undifferentiated hESCs would meet this need. The findings can be summarized as follows. (a) Most colonies obtained under these conditions consist of >or=30 AP(+) cells that coexpress OCT4, NANOG, SSEA3, SSEA4, TRA-1-60, and TRA-1-81. (b) Most such colonies are derived from SSEA3(+) cells. (c) Primary colonies contain cells that produce secondary colonies of the same composition, including cells that initiate multilineage differentiation in embryoid bodies (EBs). (d) Colony formation is independent of plating density or the colony-forming cell (CFC) content of the test population over a wide range of cell concentrations. (e) CFC frequencies decrease when differentiation is induced by exposure either to retinoic acid or to conditions that stimulate EB formation. Interestingly, this loss of AP(+) clonogenic potential also occurs more rapidly than the loss of SSEA3 or OCT4 expression. The CFC assay thus provides a simple, reliable, broadly applicable, and highly specific functional assay for quantifying undifferentiated hESCs with self-renewal potential. Its use under standardized assay conditions should enhance future elucidation of the mechanisms that regulate hESC propagation and their early differentiation.

Constituents of the Egyptian Centaurea scoparia. III. Phenolic constituents of the aerial parts

The ethanolic extract of the aerial parts of Centaurea scoparia Sieb. (Asteraceae) afforded five polyoxygenated flavones apigenin, luteolin, salvigenin, cirsimaritin, and hispidulin, the two lignans (-)-matairesinol and (-)-arctigenin together with omega-hydroxypropioguaiacone and vanillin. The structure elucidations of the isolated compounds are based on spectroscopic methods including 1D- and 2D-NMR spectra. Some proton and carbon signals are revised or newly reported.

Constituents of the Egyptian Centaurea scoparia; Part II. Guaianolides of the Aerial Parts

Aerial parts of CENTAUREA SCOPARIA Sieb. afforded a new chlorinated guaianolide with an unusual isobutyl structural feature, diain ( 1), together with three known guaianolides, janerin ( 2), cynaropicrin ( 3), and deacylcynaropicrin ( 4). Structural assignments of the isolated compounds are based on spectroscopic methods including 1D- and 2D-NMR spectroscopy as well as mass spectroscopy. New and revised (1)H- and (13)C-NMR data are reported.

Constituents of the Egyptian Centaurea scoparia; Chlorinated Guaianolides of the Aerial Parts

A new chlorine-containing guaianolide, chloroscoparin, was isolated from the ethanol extract of the aerial parts of CENTAUREA SCOPARIA Sieb. together with three known chlorine-containing guaianolides. The structures of the isolated compounds were elucidated by spectroscopic methods including (1)H-NMR-, 2D (1)H- (1)H COSY-, (13)C-NMR-, APT-, DEPT-, HETCOR-, long-range-HETCOR-, 2D INADEQUATE-, and mass spectra. The relative configuration was determined by 2D-NOESY studies. New NMR data for the known compounds are reported.