Association between proactive esophageal cooling and increased lab throughput

INTRODUCTION

Proactive esophageal cooling has been FDA cleared to reduce the likelihood of ablation-related esophageal injury resulting from radiofrequency (RF) cardiac ablation procedures. Data suggest that procedure times for RF pulmonary vein isolation (PVI) also decrease when proactive esophageal cooling is employed instead of luminal esophageal temperature (LET) monitoring. Reduced procedure times may allow increased electrophysiology (EP) lab throughput. We aimed to quantify the change in EP lab throughput of PVI cases after the introduction of proactive esophageal cooling.

METHODS

EP lab throughput data were obtained from three EP groups. We then compared EP lab throughput over equal time frames at each site before (pre-adoption) and after (post-adoption) the adoption of proactive esophageal cooling.

RESULTS

Over the time frame of the study, a total of 2498 PVIs were performed over a combined 74 months, with cooling adopted in September 2021, November 2021, and March 2022 at each respective site. In the pre-adoption time frame, 1026 PVIs were performed using a combination of LET monitoring with the addition of esophageal deviation when deemed necessary by the operator. In the post-adoption time frame, 1472 PVIs were performed using exclusively proactive esophageal cooling, representing a mean 43% increase in throughput (p < .0001), despite the loss of two operators during the post-adoption time frame.

CONCLUSION

Adoption of proactive esophageal cooling during PVI ablation procedures is associated with a significant increase in EP lab throughput, even after a reduction in total number of operating physicians in the post-adoption group.

Atrioesophageal Fistula Rates Before and After Adoption of Active Esophageal Cooling During Atrial Fibrillation Ablation

BACKGROUND

Active esophageal cooling reduces the incidence of endoscopically identified severe esophageal lesions during radiofrequency (RF) catheter ablation of the left atrium for the treatment of atrial fibrillation. A formal analysis of the atrioesophageal fistula (AEF) rate with active esophageal cooling has not previously been performed.

OBJECTIVES

The authors aimed to compare AEF rates before and after the adoption of active esophageal cooling.

METHODS

This institutional review board (IRB)-approved study was a prospective analysis of retrospective data, designed before collecting and analyzing the real-world data. The number of AEFs occurring in equivalent time frames before and after adoption of cooling using a dedicated esophageal cooling device (ensoETM, Attune Medical) were quantified across 25 prespecified hospital systems. AEF rates were then compared using generalized estimating equations robust to cluster correlation.

RESULTS

A total of 14,224 patients received active esophageal cooling during RF ablation across the 25 hospital systems, which included a total of 30 separate hospitals. In the time frames before adoption of active cooling, a total of 10,962 patients received primarily luminal esophageal temperature (LET) monitoring during their RF ablations. In the preadoption cohort, a total of 16 AEFs occurred, for an AEF rate of 0.146%, in line with other published estimates for procedures using LET monitoring. In the postadoption cohort, no AEFs were found in the prespecified sites, yielding an AEF rate of 0% (P < 0.0001).

CONCLUSIONS

Adoption of active esophageal cooling during RF ablation of the left atrium for the treatment of atrial fibrillation was associated with a significant reduction in AEF rate.

64 HIGH-DOSE STEROIDS IN HAEMATOLOGICAL MALIGNANCY: A RED FLAG FOR BONE HEALTH

Background

Bone-protective treatment should always be considered when commencing glucocorticoid therapy in individuals at high risk of fracture, as outlined in recent guidelines (National Osteoporosis Guideline Group, July 2018). Despite this, many patients receive high dose glucocorticoids (&gt;7.5mg/kg/day or equivalent for &gt;3 months) during treatment of haematological malignancy without formal assessment of bone health.

Methods

Twenty-five patients with Non-Hodgkin’s Lymphoma (NHL) on high dose steroid chemotherapy protocols were retrospectively assessed. The inclusion criterion was defined as any patient commenced on a cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP) containing protocol from 1/8/2020 to 1/8/21. Data was collected from electronic and written patient records. Information regarding patient age, diagnosis, steroid preparation and dose, presence of risk factors for osteoporosis and calcium and vitamin D prescriptions were collected. Radiological imaging was reviewed to assess for the occurrence of fragility fractures. Each patient had a FRAX® score calculated to assess fracture risk.

Results

The mean age of patients studied was 67 years and equally distributed between males and females. All patients had NHL. 32% (n=25) of patients were identified to be at high risk for fracture (FRAX® score &gt;20% ten-year probability of major osteoporotic fracture). 16% had already established fragility fractures prior to commencing steroid treatment. 28% of patients were females over the age of 70 years. Only 12% of patients received vitamin D and calcium supplementation. No patient commenced bone protection therapy.

Conclusion

Omission of bone health assessment prior to high dose glucocorticoid treatment is prevalent in haematological malignancy and places patients at risk of significant morbidity. Patients are not routinely considered for protective measures including calcium and vitamin D supplementation and bone protection therapy. A simple risk-assessment tool and education to staff and patients prior to glucocorticoid therapy could significantly improve practice in this area. It is now planned to introduce routine risk assessment for this cohort of patients, with re-audit following implementation.

Genetics of prostate cancer and its utility in treatment and screening

Prostate cancer heritability is attributed to a combination of rare, moderate to highly penetrant genetic variants as well as commonly occurring variants conferring modest risks [single nucleotide polymorphisms (SNPs)]. Some of the former type of variants (e.g., BRCA2 mutations) predispose particularly to aggressive prostate cancer and confer poorer prognoses compared to men who do not carry mutations. Molecularly targeted treatments such as PARP inhibitors have improved outcomes in men carrying somatic and/or germline DNA repair gene mutations. Ongoing clinical trials are exploring other molecular targeted approaches based on prostate cancer somatic alterations. Genome wide association studies have identified >250 loci that associate with prostate cancer risk. Multi-ancestry analyses have identified shared as well as population specific risk SNPs. Prostate cancer risk SNPs can be used to estimate a polygenic risk score (PRS) to determine an individual's genetic risk of prostate cancer. The odds ratio of prostate cancer development in men whose PRS lies in the top 1% of the risk profile ranges from 9 to 11. Ongoing studies are investigating the utility of a prostate cancer PRS to target population screening to those at highest risk. With the advent of personalized medicine and development of DNA sequencing technologies, access to clinical genetic testing is increasing, and oncology guidelines from bodies such as NCCN and ESMO have been updated to provide criteria for germline testing of "at risk" healthy men as well as those with prostate cancer. Both germline and somatic prostate cancer research have significantly evolved in the past decade and will lead to further development of precision medicine approaches to prostate cancer treatment as well as potentially developing precision population screening models.

Cardiac Sarcoidosis With Prominent Epsilon Waves: A Perfect Phenocopy of ARVC

Cardiac sarcoidosis (CS) overlaps in clinical presentation with arrhythmogenic right ventricular cardiomyopathy and shares phenotypic classification, including the presence of epsilon waves. The presence of conduction disease is seen exclusively in CS, as an important phenotypic difference. We present a case of ventricular tachycardia and epsilon waves due to CS, without conduction disease. (Level of Difficulty: Intermediate.).

Periaortic Ventricular Tachycardias in Nonischemic Cardiomyopathy: Substrate and Electrocardiographic Correlations

BACKGROUND

Periaortic fibrotic ventricular tachycardia (VT) substrate is common in nonischemic cardiomyopathy (NICM), often intramural, and difficult to ablate. We sought to better characterize normal and abnormal periaortic voltage map parameters and NICM periaortic VTs.

METHODS

In 15 patients without heart disease, the 5th percentile of endocardial voltage for increasing distance from the aortic valve ring was determined. In 53 consecutive patients with NICM (64±11 years; left ventricular ejection fraction 31±10%) undergoing ablation of recurrent VT, periaortic electrogram voltage and VT characteristics were analyzed.

RESULTS

In healthy patients, the fifth percentile of the bipolar voltage increased proportional to the distance from the aortic valve ring, from 1.0 mV at 1 cm to 1.5 mV at 1.5 cm; the corresponding unipolar voltage cutoffs were 5.0 and 7.5 mV. A total of 160 VTs were induced in 53 patients with NICM, of which 28 VTs in 20 patients had periaortic origins. Periaortic VTs were associated with similar periaortic bipolar voltage, but lower UVs consistent with intramural fibrosis as an important substrate. Periaortic VTs could be divided into left and right bundle branch block forms with mapping showing right septal and lateral exits. Left bundle branch block VTs were more often acutely abolished with ablation (100% versus 69%; P=0.034), but with a 23% incidence of heart block. Greater extent of low voltage was associated with more induced VTs and worse acute outcome.

CONCLUSIONS

Adjusting voltage parameters based on distance from the aortic valve may improve definition of left ventricular outflow tract arrhythmia substrate. Periaortic VTs are common in NICM, often associated with intramural substrate and can be divided into left bundle branch block and right bundle branch block types associated with different ablation outcomes and risks.

Conduction Recovery After Cavotricuspid Isthmus Ablation When Performed With or Without Concomitant Atrial Fibrillation Ablation

OBJECTIVES

This study sought to define the association between conduction recovery across the cavotricuspid isthmus (CTI) and typical atrial flutter (AFL) recurrence when CTI ablation is performed with pulmonary vein isolation (PVI) compared with a stand-alone procedure.

BACKGROUND

CTI ablation is commonly performed at the same time as PVI to treat AFL or as an empiric therapy. Conduction recovery is a recognized problem after linear ablation in the left atrium (e.g., mitral isthmus ablation) and is proarrhythmic. Less is known about conduction recovery after CTI ablation and possible differences in outcomes when performed at the time of PVI compared with at the time of a stand-alone procedure.

METHODS

Eligible participants who underwent stand-alone CTI ablation were compared with those who underwent a combined (CTI+PVI) procedure. CTI conduction recovery was assessed at the time of a second ablation. Conduction recovery across the CTI (primary outcome) and recurrence of typical AFL (secondary outcome) were studied using multivariable logistic regression.

RESULTS

Among 295 eligible participants (median age: 64 years [interquartile range: 55 to 69 years]; 33% women), recovery was assessed in 232 and was more common after combined versus stand-alone CTI ablation (52% [72 of 139] vs. 13% [12 of 93]; p < 0.001). In multivariable analysis, CTI ablation performed as a combined procedure increased odds of CTI conduction recovery 7.8-fold (odds ratio: 7.8; 95% confidence interval: 3.3 to 18.3; p < 0.001) and clinical AFL recurrence 4.1-fold (odds ratio: 4.1; 95% confidence interval: 1.0 to 16.9; p = 0.049).

CONCLUSIONS

CTI ablation performed at the time of atrial fibrillation ablation is associated with higher rates of conduction recovery and typical flutter recurrence.

RNA binding proteins as regulators of immune cell biology

Sequence-specific RNA binding proteins (RBP) are important regulators of the immune response. RBP modulate gene expression by regulating splicing, polyadenylation, localization, translation and decay of target mRNAs. Increasing evidence suggests that RBP play critical roles in the development, activation and function of lymphocyte populations in the immune system. This review will discuss the post-transcriptional regulation of gene expression by RBP during lymphocyte development, with particular focus on the Tristetraprolin family of RBP.

Haematological considerations in urology: A systematic review

Deep venous thrombosis (DVT) remains a serious and common complication of surgical procedures and is therefore an issue of importance for all urologists. In the UK, pulmonary embolism (PE) following DVT in hospitalised patients causes 32,000 deaths each year. DVT and PE represent the outcome of venous thromboembolism (VTE). The total cost for management of VTE in 2005 was approximately ₤640 million. Early risk assessment and optimising modifiable risks are paramount in order to reduce the incidence of VTE. In this article we review common risk factors for VTE and emphasise specific risk factors for urological procedures. The perioperative management of urological patients who are chronically anticoagulated is discussed. We review the literature regarding anticoagulation and its relevance to all urological procedures and mention the problems associated with new anticoagulant agents. All urologists should be familiar with the new range of anticoagulant agents due to the increasing number of patients taking them.

Evaluation of CD44 variant expression in oral, head and neck squamous cell carcinomas using a triple approach and its clinical significance

Cancer stem cells possess the qualities of self-renewal, tumorigenesis and the ability to recapitulate a heterogeneous tumor. Our group was the first to isolate head and neck squamous cell carcinoma (HNSCC) stem cells using the cell surface marker CD44. CD44 is a trans-membrane glycoprotein with a multitude of key-functions that regulate cancer cell proliferation and metastasis. The variety of CD44 functions is due to tissue-specific patterns of glycosylation of the extracellular portion, and to the multiple protein isoforms (CD44 variants, CD44v) generated by alternative splicing. This study investigates the expression pattern of CD44 variants in HNSCC. Ten cell lines from the most common HNSCC locations and representative of various clinical outcomes were assayed by quantitative realtime PCR, flow cytometry and immunofluorescence comparatively with normal oral keratinocytes. The CD44 v4 and v6 were exclusively abundant in HNSCC while the isoform v1,2 was expressed in normal oral keratinocytes. Of interest, the highest level of CD44v6 expression was detected in advanced metastatic HNSCC, suggesting a link between CD44v6 expression and HNSCC metastasis, while the highest CD44v4 was detected in a stage IV HNSCC refractory to chemotherapy which developed recurrence. Oral-derived HNSCC expressed the highest CD44v4 and v6, and levels corresponded with staging, showing also an increasing tendency with recurrence and metastasis. CD44v were detected predominantly in smaller cells (a characteristic that has been associated with stem cell properties) or cells with mesenchymal morphology (a characteristic that has been associated with the migratory and invasive potential of epithelial tumor cells), suggesting that CD44v differential expression in HNSCC may be representative of the morphological changes inherent during tumor progression towards a more aggressive potential, and thus contributing to the individual tumor biology. The mechanism of CD44 variant involvement in HNSCC progression and metastasis is under investigation.

The circadian clock in oral health and diseases

Most physiological processes in mammals display circadian rhythms that are driven by the endogenous circadian clock. This clock is comprised of a central component located in the hypothalamic suprachiasmatic nucleus and subordinate clocks in peripheral tissues. Circadian rhythms sustain 24-hour oscillations of a large number of master genes controlling the correct timing and synchronization of diverse physiological and metabolic processes within our bodies. This complex regulatory network provides an important communication link between our brain and several peripheral organs and tissues. At the molecular level, circadian oscillations of gene expression are regulated by a family of transcription factors called "clock genes". Dysregulation of clock gene expression results in diverse human pathological conditions, including autoimmune diseases and cancer. There is increasing evidence that the circadian clock affects tooth development, salivary gland and oral epithelium homeostasis, and saliva production. This review summarizes current knowledge of the roles of clock genes in the formation and maintenance of oral tissues, and discusses potential links between "oral clocks" and diseases such as head and neck cancer and Sjögren's syndrome.

Clock genes show circadian rhythms in salivary glands

Circadian rhythms are endogenous self-sustained oscillations with 24-hour periods that regulate diverse physiological and metabolic processes through complex gene regulation by "clock" transcription factors. The oral cavity is bathed by saliva, and its amount and content are modified within regular daily intervals. The clock mechanisms that control salivary production remain unclear. Our objective was to evaluate the expression and periodicity of clock genes in salivary glands. Real-time quantitative RT-PCR, in situ hybridization, and immunohistochemistry were performed to show circadian mRNA and protein expression and localization of key clock genes (Bmal1, Clock, Per1, and Per2), ion and aqua channel genes (Ae2a, Car2, and Aqp5), and salivary gland markers. Clock gene mRNAs and clock proteins were found differentially expressed in the serous acini and duct cells of all major salivary glands. The expression levels of clock genes and Aqp5 showed regular oscillatory patterns under both light/dark and complete-dark conditions. Bmla1 overexpression resulted in increased Aqp5 expression levels. Analysis of our data suggests that salivary glands have a peripheral clock mechanism that functions both in normal light/dark conditions and in the absence of light. This finding may increase our understanding of the control mechanisms of salivary content and flow.

Portal osmopressor mechanism linked to transient receptor potential vanilloid 4 and blood pressure control

Human subjects with impaired baroreflex function cannot buffer rises or falls in blood pressure (BP), thus allowing BP effects of endogenous or environmental stimuli that previously escaped detection to emerge dramatically. Studies in these patients led us to discover that water ingestion induced a robust increase in BP and vascular resistance. Here, using a mouse model of baroreflex impairment, we show that the increase in blood pressure after water ingestion is mediated through sympathetic nervous system activation and that the osmosensitive transient receptor potential vanilloid 4 channel (Trpv4) is an essential component of the response. Although portal osmolality decreases after water ingestion in both wild-type and Trpv4(-/-) mice, only the wild-type animals show a pressor response. The same volume of physiological saline does not elicit an increase in BP, suggesting osmolality as the stimulus. The osmopressor response to water, and Trpv4 thus represent new factors now implicated in the physiology of BP regulation.

Accuracy of whole-body low-dose multidetector CT (WBLDCT) versus skeletal survey in the detection of myelomatous lesions, and correlation of disease distribution with whole-body MRI (WBMRI)

AIM

The aim of the study is to assess the feasibility of whole-body low-dose computed tomography (WBLDCT) in the diagnosis and staging of multiple myeloma and compare to skeletal survey (SS), using bone marrow biopsy and whole-body magnetic resonance imaging (WBMRI; where available) as gold standard.

MATERIALS AND METHODS

Patients referred over an 18-month period for investigation of suspected multiple myeloma or restaging of myeloma were randomized to undergo one of two WBLDCT protocols using high kVp, low mAs technique (140 kVp, 14 mAs; or 140 kVp, 25 mAs). Recent WBMRI scans were reviewed in 23 cases. Each imaging modality was assessed by two radiologists in consensus and scored from 0-3 (0 = normal, 1 = 1-4 lesions, 2 = 5-20 lesions, 3 >or= 20 lesions/diffuse disease) in ten anatomical areas. Overall stage of disease, image quality score, and the degree of confidence of diagnosis were recorded. Diagnostic accuracy of skeletal survey and WBLDCT were determined using a gold standard of bone marrow biopsy and distribution of disease was compared to WBMRI.

RESULTS

Thirty-nine patients were evaluated. WBLDCT identified more osteolytic lesions than skeletal survey with a greater degree of diagnostic confidence and led to restaging in 18 instances (16 upstaged, two downstaged). In those with recent WBMRI, distribution of disease on WBLDCT showed superior correlation with WBMRI when compared with SS. Overall reader impression of stage on WBLDCT showed significant correlation with WBMRI (kappa = 0.454, p < 0.05). WBLDCT provided complementary information to WBMRI in nine patients with normal marrow signal following treatment response, but which were shown to have diffuse residual cortical abnormalities on CT.

CONCLUSION

WBLDCT at effective doses lower than previously reported, is superior to SS at detecting osteolytic lesions and at determining overall stage of multiple myeloma, and provides complementary information to WBMRI.

Screening for ocular surface disease in the intensive care unit

PURPOSE

Ventilated patients in the intensive care unit (ICU) often develop exposure keratopathy. This predisposes to the development of bacterial keratitis, which in ICU is often bilateral, with a high risk of perforation. As regular examinations of all ventilated patients by ophthalmologists would be impractical, the purpose of this study was to assess whether ICU staff can screen reliably for keratopathy.

METHODS

A prospective study was performed in a general adult ICU. Twice each week, two junior ICU doctors examined the lid position and ocular surface of all patients who had been continuously sedated for more than 24 h, using fluorescein and a pen torch with a blue filter. An ophthalmologist performed similar examinations using a portable slit lamp.

RESULTS

A total of 48 ocular examinations were performed in 18 patients. Exposure keratopathy was found by the ophthalmologist in 37.5% of examinations and by ICU doctors in 31.3% of examinations. ICU doctors had a sensitivity of 77.8% and a specificity of 96.7% in detecting keratopathy, when compared with the findings of the ophthalmologist. All cases missed by ICU doctors had punctate erosions of less than 5% of the corneal surface. Keratopathy was significantly commoner in patients with incomplete lid closure than in patients with closed lids (70.0 vs 28.9%; two-tailed Fisher's exact test P=0.027).

CONCLUSIONS

ICU staff can perform screening examinations for exposure keratopathy with reasonable sensitivity and specificity. Regular screening by ICU staff would facilitate appropriate treatment of exposure keratopathy and promote earlier identification of cases of keratitis.

Vaccinia virus entry, exit, and interaction with differentiated human airway epithelia

Variola virus, the causative agent of smallpox, enters and exits the host via the respiratory route. To better understand the pathogenesis of poxvirus infection and its interaction with respiratory epithelia, we used vaccinia virus and examined its interaction with primary cultures of well-differentiated human airway epithelia. We found that vaccinia virus preferentially infected the epithelia through the basolateral membrane and released viral progeny across the apical membrane. Despite infection and virus production, epithelia retained tight junctions, transepithelial electrical conductance, and a steep transepithelial concentration gradient of virus, indicating integrity of the epithelial barrier. In fact, during the first four days of infection, epithelial height and cell number increased. These morphological changes and maintenance of epithelial integrity required vaccinia virus growth factor, which was released basolaterally, where it activated epidermal growth factor 1 receptors. These data suggest a complex interaction between the virus and differentiated airway epithelia; the virus preferentially enters the cells basolaterally, exits apically, and maintains epithelial integrity by stimulating growth factor receptors.

Human neural progenitors deliver glial cell line-derived neurotrophic factor to parkinsonian rodents and aged primates

Glial cell line-derived neurotrophic factor (GDNF) has been shown to increase the survival and functioning of dopamine neurons in a variety of animal models and some recent human trials. However, delivery of any protein to the brain remains a challenge due to the blood/brain barrier. Here we show that human neural progenitor cells (hNPC) can be genetically modified to release glycosylated GDNF in vitro under an inducible promoter system. hNPC-GDNF were transplanted into the striatum of rats 10 days following a partial lesion of the dopamine system. At 2 weeks following transplantation, the cells had migrated within the striatum and were releasing physiologically relevant levels of GDNF. This was sufficient to increase host dopamine neuron survival and fiber outgrowth. At 5 weeks following grafting there was a strong trend towards functional improvement in transplanted animals and at 8 weeks the cells had migrated to fill most of the striatum and continued to release GDNF with transport to the substantia nigra. These cells could also survive and release GDNF 3 months following transplantation into the aged monkey brain. No tumors were found in any animal. hNPC can be genetically modified, and thereby represent a safe and powerful option for delivering growth factors to specific targets within the central nervous system for diseases such as Parkinson's.

Study of the murine allantois by allantoic explants

The murine allantois will become the umbilical artery and vein of the chorioallantoic placenta. In previous studies, growth and differentiation of the allantois had been elucidated in whole embryos. In this study, the extent to which explanted allantoises grow and differentiate outside of the conceptus was investigated. The explant model was then used to elucidate cell and growth factor requirements in allantoic development. Early headfold-stage murine allantoises were explanted directly onto tissue culture plastic or suspended in test tubes. Explanted allantoises vascularized with distal-to-proximal polarity, they exhibited many of the same signaling factors used by the vitelline and cardiovascular systems, and they contained at least three cell types whose identity, gene expression profiles, topographical associations, and behavior resembled those of intact allantoises. DiI labeling further revealed that isolated allantoises grew and vascularized in the absence of significant cell mingling, thereby supporting a model of mesodermal differentiation in the allantois that is position- and possibly age-dependent. Manipulation of allantoic explants by varying growth media demonstrated that the allantoic endothelial cell lineage, like that of other embryonic vasculatures, is responsive to VEGF(164). Although VEGF(164) was required for both survival and proliferation of allantoic angioblasts, it was not sufficient to induce appropriate epithelialization of these cells. Rather, other VEGF isoforms and/or the outer sheath of mesothelium, whose maintenance did not appear to be dependent upon endothelium, may also play important roles. On the basis of these findings, we propose murine allantoic explants as a new tool for shedding light not only on allantoic development, but for elucidating universal mechanisms of blood vessel formation, including vascular supporting cells, either in the intact organism or in existing in vitro systems.

Cyclosporine has a direct effect on the differentiation of a mucin-secreting cell line

Cyclosporine is a potent immunosuppressant used in the treatment of ulcerative colitis and keratoconjunctivitis sicca. Neither the etiologies of these diseases nor the mechanism by which cyclosporine exerts its therapeutic effect is well understood. Since both diseases are linked by a common decrease in mucin-filled goblet cells, this study tests a hypothesis that cyclosporine acts directly on goblet cells to promote their differentiation and production of secretory mucins. The HT29-18N2 human colon adenocarcinoma cell line, which is capable of forming monolayers of well-differentiated goblet cells, was used as a model system. Cyclosporine induced a dose-dependent increase in intracellular mucin stores. A 2-week exposure to 1 microM cyclosporine resulted in an average increase in mucin volume of 94%. This increase resulted from both a higher percentage of cells with mucin stores and an increased volume of mucin per cell. PSC-833, a nonimmunosuppressive analog of cyclosporine, also increased mucin production. The intracellular accumulation of mucin was not a result of reduced secretion, since the time required for the release of pulse-radiolabeled glycoproteins was similar for both control and cyclosporine-treated monolayers. The effect of cyclosporine was not mediated by the drug's previously documented abilities to decrease cellular proliferation rates, inhibit calmodulin, antagonize prolactin receptor binding, or modulate prostaglandin production.

The Labour Party and the Parliamentary campaign to abolish the military death penalty, 1919-1930

This is a study of a successful parliamentary campaign led throughout the 1920s by a small group of backbench Labour MPs aimed at abolishing the military death penalty for the offences of cowardice and desertion. It was sustained in the face of opposition from the military establishment, the Conservatives, and finally the House of Lords. The campaigners used the opportunity afforded by the requirement on government to pass, annually, an Army Bill, to challenge the military establishment's insistence that a capital penalty was essential to the maintenance of army discipline. Despite the unwillingness of the 1924 Labour government to confront the military on this issue, the reformers persevered, securing some minor, incremental reform before the coming of the second Labour government in 1929. The new government was prevailed upon by backbench pressure to authorize a free vote in the Commons which approved the abolition of the capital penalty for cowardice and desertion in the Army Act of 1930.

Nitric oxide and regulation of vascular tone: pharmacological and physiological considerations

The endothelial cells of the vascular system are responsible for many biological activities that maintain vascular homeostasis. Responding to a variety of chemical and physical stimuli, the endothelium elaborates a host of vasoactive agents. One of these agents, endothelium-derived relaxing factor, now accepted as nitric oxide, influences both cellular constituents of the blood and vascular smooth muscle. A principal intracellular target for nitric oxide is guanylate cyclase, which, when activated, increases the intracellular concentration of cyclic guanosine monophosphate, which in turn activates protein kinase G. Acting by this pathway, nitric oxide induces relaxation of vascular smooth muscle and inhibits platelet activation and aggregation. Derangements in endothelial production of nitric oxide are implicated as both cause and consequence of vascular diseases, including hypertension, atherosclerosis, and coronary artery disease.

Nitric oxide and regulation of vascular tone: pharmacological and physiological considerations

The endothelial cells of the vascular system are responsible for many biological activities that maintain vascular homeostasis. Responding to a variety of chemical and physical stimuli, the endothelium elaborates a host of vasoactive agents. One of these agents, endothelium-derived relaxing factor, now accepted as nitric oxide, influences both cellular constituents of the blood and vascular smooth muscle. A principal intracellular target for nitric oxide is guanylate cyclase, which, when activated, increases the intracellular concentration of cyclic guanosine monophosphate, which in turn activates protein kinase G. Acting by this pathway, nitric oxide induces relaxation of vascular smooth muscle and inhibits platelet activation and aggregation. Derangements in endothelial production of nitric oxide are implicated as both cause and consequence of vascular diseases, including hypertension, atherosclerosis, and coronary artery disease.

DNA-binding antibodies from viable motheaten mutant mice: implications for B cell tolerance

C57BL/6 me(v)/me(v) (viable motheaten) mice have defective hemopoietic cell protein-tyrosine phosphatase (HCP, SHP-1) and are a model in which to study the role of this phosphatase in immune regulation and hemopoietic development. Immune defects in these mice include hypergammaglobulinemia, production of multiple autoantibodies, and glomerular nephritis. The presence of self-reactive Abs in these mice is an enigma, since it has been demonstrated that they have increased negative selection against self-reactive transgenic Abs. It was of interest to examine autoantibodies from these mice to identify reactivity or structural features that might account for their persistence and expansion in the repertoire. Abs to DNA were selected for investigation, since they have been characterized extensively from normal and autoimmune strains of mice. Viable motheaten mice had high titers of IgM, anti-dsDNA Abs, and all 12 anti-DNA hybridomas generated were also IgM. They had high avidity for dsDNA, also bound to ssDNA, but were not polyreactive. They used V(H) and V(L) gene families found in anti-DNA Abs from other strains, which reinforces evidence that there is preferential use of a restricted number of germline elements in anti-DNA Abs. The results indicate that Hcph-mutant mice do not delete DNA-reactive B cells, nor are they able to maintain these B cells in a state of anergy. Evidence for positive selection and clonal expansion after V-D-J rearrangement was also seen, in that several Abs expressed the same heavy chain in combination with different light chains, which is also a hallmark of the autoimmune anti-DNA response.

DNA-binding antibodies from viable motheaten mutant mice: implications for B cell tolerance

C57BL/6 me(v)/me(v) (viable motheaten) mice have defective hemopoietic cell protein-tyrosine phosphatase (HCP, SHP-1) and are a model in which to study the role of this phosphatase in immune regulation and hemopoietic development. Immune defects in these mice include hypergammaglobulinemia, production of multiple autoantibodies, and glomerular nephritis. The presence of self-reactive Abs in these mice is an enigma, since it has been demonstrated that they have increased negative selection against self-reactive transgenic Abs. It was of interest to examine autoantibodies from these mice to identify reactivity or structural features that might account for their persistence and expansion in the repertoire. Abs to DNA were selected for investigation, since they have been characterized extensively from normal and autoimmune strains of mice. Viable motheaten mice had high titers of IgM, anti-dsDNA Abs, and all 12 anti-DNA hybridomas generated were also IgM. They had high avidity for dsDNA, also bound to ssDNA, but were not polyreactive. They used V(H) and V(L) gene families found in anti-DNA Abs from other strains, which reinforces evidence that there is preferential use of a restricted number of germline elements in anti-DNA Abs. The results indicate that Hcph-mutant mice do not delete DNA-reactive B cells, nor are they able to maintain these B cells in a state of anergy. Evidence for positive selection and clonal expansion after V-D-J rearrangement was also seen, in that several Abs expressed the same heavy chain in combination with different light chains, which is also a hallmark of the autoimmune anti-DNA response.

Activation of MAP kinases in airway smooth muscle

To test the hypothesis that mitogen-activated protein (MAP) kinases are activated by contractile agonists in intact nonproliferating airway smooth muscle, kinase activities were compared in resting and stimulated canine tracheal smooth muscle. Kinase activities in sodium dodecyl sulfate extracts were assayed by a gel renaturation method. Myelin basic protein kinase activities corresponding to ERK1 and ERK2 immunoreactive proteins were activated twofold above the basal level within 5 min by 1 microM carbachol. MAP kinase activity assayed in crude homogenates using a synthetic peptide substrate (APRTPGGRR) also increased twofold above basal in muscles stimulated with 1 microM carbachol. Two protein kinases separated by Mono-Q chromatography were identified on Western blots as ERK1 and ERK2 MAP kinases. Carbachol stimulation increased caldesmon phosphorylation in intact muscle, and purified caldesmon was a substrate for activated murine ERK2 MAP kinase. Activated ERK2 MAP kinase added to Triton X-100-permeabilized fibers potentiated Ca2+-induced contraction. The results show that ERK MAP kinases are activated after stimulation of muscarinic receptors in airway smooth muscle, which is consistent with coupling of MAP kinases to phosphorylation of caldesmon in vivo.

Mandatory Continuing Education Relevancy for Nurses With Advanced Preparation

This descriptive study reports a survey of states on their regulations mandating continuing education for relicensure of professional nurses. The findings reveal that mandates are useful for a minority of unmotivated nurses, but problematic for nurses in advanced practice, education, and research.

Irreversible inhibition of sodium current and batrachotoxin binding by a photoaffinity-derivatized local anesthetic

We have synthesized a model local anesthetic (LA), N-(2-di-N-butyl-aminoethyl)-4-azidobenzamide (DNB-AB), containing the photoactivatable aryl azido moiety, which is known to form a covalent bond to adjacent molecules when exposed to UV light (Fleet, G.W., J.R. Knowles, and R.R. Porter. 1972. Biochemical Journal. 128:499-508. Ji, T.H. 1979. Biochimica et Biophysica Acta. 559:39-69). We studied the effects of DNB-AB on the sodium current (INa) under whole-cell voltage clamp in clonal mammalian GH3 cells and on 3[H]-BTX-B binding to sheep brain synaptoneurosomes. In the absence of UV illumination, DNB-AB behaved similarly to known LAs, producing both reversible block of peak INa (IC50 = 26 microM, 20 degrees C) and reversible inhibition of 3[H]-BTX-B (50 nM in the presence of 0.12 microgram/liter Leiurus quinquestriatus scorpion venom) binding (IC50 = 3.3 microM, 37 degrees C), implying a noncovalent association between DNB-AB and its receptor(s). After exposure to UV light, both block of INa and inhibition of 3[H]-BTX-B binding were only partially reversible (INa = 42% of control; 3[H]-BTX-B binding = 23% of control) showing evidence of a light-dependent, covalent association between DNB-AB and its receptor(s). In the absence of drug, UV light had less effect on INa (post exposure INa = 96% of control) or on 3[H]-BTX-B binding (post exposure binding = 70% of control). The irreversible block of INa was partially protected by coincubation of DNB-AB with 1 mM bupivacaine (IC50 = 45 microM, for INa inhibition at 20 degrees C, Wang, G.K., and S.Y. Wang. 1992. Journal of General Physiology. 100:1003-1020), (post exposure INa = 73% of control). The irreversible inhibition of 3[H]-BTX-B binding also was partially protected by coincubation with bupivacaine (500 microM, 37 degrees C) (post exposure binding = 51% of control), suggesting that the site of irreversible inhibition of both INa and 3[H]-BTX-B binding is shared with the clinical LA bupivacaine.

A double blind clinical trial to assess the value of aprotinin in third molar surgery

The bovine derived polypeptide, aprotinin, inhibits the activation of certain chemical mediators of acute inflammation. These mediators are responsible for causing pain and swelling in traumatised tissue. The properties of aprotinin were assessed in patients requiring surgical removal of third molars, a procedure which often results in considerable postoperative pain and swelling. A double blind clinical trial compared the effects of local infiltration of 1 ml of saline on one side of the mouth and aprotinin (10,000 international units) on the other, in patients requiring extraction of both mandibular third molars. Pain scores were assessed with a visual analogue scale, and swelling was subjectively assessed. The results, when analysed statistically, showed that aprotinin significantly reduced postoperative pain and swelling on the side of the mouth on which it was used, as compared to the control side (0.01% significance).