Adaptive Language Mapping Paradigms for Presurgical Language Mapping.

BACKGROUND AND PURPOSE: Functional MR imaging is widely used for preoperative language assessment in candidates for resective neurosurgery. Language mapping paradigms that are adaptive to participant performance have the potential to engage the language network more robustly and consistently, resulting in more accurate functional maps. The aim of the current study was to compare two adaptive paradigms with the recommended language mapping paradigms that constitute the current standard of care. MATERIALS AND METHODS: Seventy-three patients undergoing fMRI for language lateralization and/or localization completed an adaptive semantic matching paradigm, an adaptive phonological judgment paradigm, and two standard paradigms: sentence completion and word generation. The paradigms were compared in terms of the degree to which they yielded lateralized language maps and the extent of activation in frontal, temporal, and parietal language regions. RESULTS: The adaptive semantic paradigm resulted in the most strongly lateralized activation maps, the greatest extent of frontal and temporal activations, and the greatest proportion of overall satisfactory language maps. The adaptive phonological paradigm identified anterior inferior parietal phonological encoding regions in most patients, unlike any of the other paradigms. CONCLUSIONS: The adaptive language mapping paradigms investigated have several psychometric advantages compared with currently recommended paradigms. Adoption of these paradigms could increase the likelihood of obtaining satisfactory language maps in each individual patient.

Restitution of the NHS breast reconstruction service during the recovery phase of the Covid 19 pandemic.

During the recovery restitution phase of the coronavirus pandemic, breast reconstruction teams have faced particular challenges to restarting this essential service. This is due to the length and complexity of the surgery, along with the demands on healthcare staff. The Royal College of Surgeons have classified immediate breast reconstruction as priority 2 and the National Institute for Health and Care Excellence have provided a pre-operative pathway for resumption of elective procedures. We therefore describe our experience in restarting our service for providing a breast reconstruction service from the 29th June 2020.

Patch clamp studies of human sperm under physiological ionic conditions reveal three functionally and pharmacologically distinct cation channels.

Whilst fertilizing capacity depends upon a K(+) conductance (GK) that allows the spermatozoon membrane potential (Vm) to be held at a negative value, the characteristics of this conductance in human sperm are virtually unknown. We therefore studied the biophysical/pharmacological properties of the K(+) conductance in spermatozoa from normal donors held under voltage/current clamp in the whole cell recording configuration. Our standard recording conditions were designed to maintain quasi-physiological, Na(+), K(+) and Cl(-) gradients. Experiments that explored the effects of ionic substitution/ion channel blockers upon membrane current/potential showed that resting Vm was dependent upon a hyperpolarizing K(+) current that flowed via channels that displayed only weak voltage dependence and limited (∼7-fold) K(+) versus Na(+) selectivity. This conductance was blocked by quinidine (0.3 mM), bupivacaine (3 mM) and clofilium (50 µM), NNC55-0396 (2 µM) and mibefradil (30 µM), but not by 4-aminopyridine (2 mM, 4-AP). Progesterone had no effect upon the hyperpolarizing K(+) current. Repolarization after a test depolarization consistently evoked a transient inward 'tail current' (ITail) that flowed via a second population of ion channels with poor (∼3-fold) K(+) versus Na(+) selectivity. The activity of these channels was increased by quinidine, 4-AP and progesterone. Vm in human sperm is therefore dependent upon a hyperpolarizing K(+) current that flows via channels that most closely resemble those encoded by Slo3. Although 0.5 µM progesterone had no effect upon these channels, this hormone did activate the pharmacologically distinct channels that mediate ITail. In conclusion, this study reveals three functionally and pharmacologically distinct cation channels: Ik, ITail, ICatSper.

Low cardiac and aerobic scope in a coastal population of sockeye salmon Oncorhynchus nerka with a short upriver migration.

This study showed that a coastal population (Harrison) of Fraser River sockeye salmon Oncorhynchus nerka had a lower aerobic and cardiac scope compared with interior populations with more challenging upriver spawning migrations, providing additional support to the idea that Fraser River O. nerka populations have adapted physiologically to their local migratory environment.

Accurately costing unilateral delayed DIEP flap breast reconstruction.

INTRODUCTION: Free tissue transfer for breast reconstruction is widely practiced in the UK and its availability forms part of the NICE guidelines in treating breast cancer. Free flap reconstruction scores highly on patient reported outcome measures for both immediate and delayed procedures. However there are significant resource implications and a concern that the financial burden is not adequately met by the fixed price tariff system (Payment by Results). This study aims to compare the cost of treatment with both local financial estimates and reimbursement. METHOD: We conducted a prospective costing analysis for 10 consecutive delayed unilateral DIEP breast reconstructions from August 2011 by a single surgeon in Frenchay Hospital, Bristol. Comparison was made to both the hospital's costing estimates and the Health Resource Group (HRG) tariffs received for 27 similar cases performed by the same surgeon in the 2010-11 financial year. RESULTS: The mean treatment cost for performing a delayed unilateral DIEP procedure was £7628 (±£754 Standard Deviation). This compared to an estimate from the financial department of £8072±(£1683 SD). These values were not significantly different (p=0.27). The HRG tariff was £8792 (±£423 SD). There was an average net income of £720 per case. Personnel in theatre represented the largest cost area at an average of 73% of total cost. CONCLUSIONS: This study highlights that the costs of this procedure have been estimated accurately by the financial department and that the current HRG code provides adequate reimbursement. The new HRG code for 2012-13, HRG JA14z, provides significantly less reimbursement at £7012 and measures need to be taken to address this. This study has identified that personnel costs are the greatest contributor to overall cost and allowed us to recognise and implement changes to improve efficiency.

Calibrating acoustic acceleration transmitters for estimating energy use by wild adult Pacific salmon.

This study is the first to calibrate acceleration transmitters with energy expenditure using a vertebrate model species. We quantified the relationship between acoustic accelerometer output and oxygen consumption across a range of swim speeds and water temperatures for Harrison River adult sockeye salmon (Oncorhynchus nerka). First, we verified that acceleration transmitters with a sampling frequency of 10 Hz could be used as a proxy for movement in sockeye salmon. Using a mixed effects model, we determined that tailbeat frequency and acceleration were positively correlated (p<0.0001), independent of tag ID. Acceleration (p<0.0001) was positively related to swim speed while fork length (p=0.051) was negatively related to swim speed. Oxygen consumption and accelerometer output (p<0.0001) had a positive linear relationship and were temperature dependent (p<0.0001). There were no differences in swim performance (F(2,12)=1.023, p=0.820) or oxygen consumption (F(1,12)=0.054, p=0.332) between tagged and untagged individuals. Five tagged fish were released into the Fraser River estuary and manually tracked. Of the five fish, three were successfully tracked for 1h. The above relationships were used to determine that the average swim speed was 1.25±0.03 body lengths s(-1) and cost of transport was 3.39±0.17 mg O(2) kg(-1)min(-1), averaged across the three detected fish. Acceleration transmitters can be effectively used to remotely evaluate fine-scale behavior and estimate energy consumption of adult Pacific salmon throughout their homeward spawning migration.

Prevention of posttraumatic axon sprouting by blocking collapsin response mediator protein 2-mediated neurite outgrowth and tubulin polymerization.

Epileptogenesis following traumatic brain injury (TBI) is likely due to a combination of increased excitability, disinhibition, and increased excitatory connectivity via aberrant axon sprouting. Targeting these pathways could be beneficial in the prevention and treatment of posttraumatic epilepsy. Here, we tested this possibility using the novel anticonvulsant (R)-N-benzyl 2-acetamido-3-methoxypropionamide ((R)-lacosamide [LCM]), which acts on both voltage-gated sodium channels and collapsin response mediator protein 2 (CRMP2), an axonal growth/guidance protein. LCM inhibited CRMP2-mediated neurite outgrowth, an effect phenocopied by CRMP2 knockdown. Mutation of LCM-binding sites in CRMP2 reduced the neurite inhibitory effect of LCM by ∼8-fold. LCM also reduced CRMP2-mediated tubulin polymerization. Thus, LCM selectively impairs CRMP2-mediated microtubule polymerization, which underlies its neurite outgrowth and branching. To determine whether LCM inhibits axon sprouting in vivo, LCM was injected into rats subjected to partial cortical isolation, an animal model of posttraumatic epileptogenesis that exhibits axon sprouting in cortical pyramidal neurons. Two weeks following injury, excitatory synaptic connectivity of cortical layer V pyramidal neurons was mapped using patch clamp recordings and laser scanning photostimulation of caged glutamate. In comparison with injured control animals, there was a significant decrease in the map size of excitatory synaptic connectivity in LCM-treated rats, suggesting that LCM treatment prevented enhanced excitatory synaptic connectivity due to posttraumatic axon sprouting. These findings suggest, for the first time, that LCM's mode of action involves interactions with CRMP2 to inhibit posttraumatic axon sprouting.

Prevalência de esteatose hepática e consumo de álcool em participantes do Projeto Atividade Física na Vila / Prevalence of nonalcoholic fatty liver disease and alcoholism in the participants of the Physical Activity in Community Project / Prevalencia de esteatosis hepática y consumo de alcohol en participantes del Projeycto Actividad Física en la Vila

A esteatose hepática é um achado cada vez mais frequente em exames de rastreamento por estudo de imagem. Tem sido descrita associação entre esteatose, obesidade, resistência à insulina e síndrome metabólica (SM). Também parece existir sinergismo entre esteatose hepática, álcool e fibrose hepática. O objetivo foi descrever a prevalência de esteatose e de etilismo nos participantes do Projeto "Atividade Física na Vila" e avaliar sua associação com a presença de obesidade e obesidade visceral. Foi realizada ultrassonografia abdominal em 69 participantes, 53,02±1,26 anos, sendo avaliados a presença e o grau de esteatose e as medidas da gordura subcutânea e visceral (GV). Foram excluídos os pacientes com hepatite viral e com etilismo significativo na anamnese ou após teste AUDIT. Após análise inicial, 60 pacientes foram avaliados quanto aos dados antropométricos e divididos em 2 grupos: com e sem esteatose. A prevalência de etilismo foi de 8,7%. A esteatose hepática foi observada em 37% dos pacientes sendo a maioria classificada como leve e moderada (91%). O grupo com esteatose apresentou aumento significativo de IMC (34,±8,7 versus 29,8±6,5kg/m2), cintura abdominal (102,6±12,7 versus 95,3±12,3cm), peso (85,8±18,7 versus 74,5±17,7kg) e GV (47,9±10,5 versus 36,0±12,7mm). A esteatose hepática é comum em obesos, especialmente naqueles com obesidade visceral. Sabemos que o álcool e a obesidade visceral podem estar envolvidos em seu mecanismo fisiopatológico. Por isso, os pacientes com esteatose hepática e consumo excessivo de álcool podem apresentar maior chance de evoluir desfavoravelmente para a cirrose e insuficiência hepática.

Screening image studies have shown that the frequency of hepatic steatosis findings has been progressivly increasing. The risk of developing NAFLD has been described and associated with obesity, insulin resistance and metabolic syndrome. There seems to be a correlation between NAFLD, alcohol e hepatic fibrosis. Our objective was to describe the prevalence of NAFLD and alcoholism in the participants of the of the Physical Activity in Community Project and to evaluate the associations between hepatic steatosis and presence of obesity and visceral obesity. Abdominal ultrasound was performed in 69 patients, 53.02±1.26 years old, looking for the presence and for the degree of fatty liver as well as subcutaneous and visceral fat. Patients with viral hepatitis and significant alcoholism were excluded after the AUDIT test. After this analysis, 60 patients were evaluated according to their anthropometrics data and were allocated into two groups: with and without fatty liver disease. The prevalence of alcoholism was 8.7%. Thirty seven percent of the patients showed up with NAFLD and were considered low to moderate risk (91%). The NAFLD showed a significant rise in the body mass index (34.1±8.7 versus 29.8±6.5kg/m2), waist circumference (102,6±12,7 versus 95.3±12.3cm), overall weight, (85,8±18,7 versus 74,5± 17.7kg), and visceral fat (47.9±10.5 versus 36.0±12.7mm). Hepatic steatosis is common in obese, especially in those with visceral obesity. We know that alcohol and visceral obesity are involved in the physiopathologic process of hepatic steatosis. For this reason, patients with Hepatic steatosis and excessive alcohol consumption may be at greater risk for Cirrhossis and hepatic insufficiency.

La esteatosis hepática es un descubrimiento cada vez más frecuente en exámenes de rastreamento por estudio de imágenes. Ha sido descripta asociación entre esteatosis, obesidad, resistencia a la insulina y síndrome metabólica (SM) .También parece existir sinergismo entre esteatosis hepática, alcohol y fibrosis hepática. El objetivo ha sido de describir la prevalencia de esteatosis hepática y de etilismo en los participantes del Proyecto Actividad Física en Vila y evaluar su asociación con la presencia de obesidad y obesidad visceral. Ha sido realizada ultrasonido abdominal en 69 participantes, 53,02±1,26 años, siendo evaluado la presencia y el grado de esteatosis y las medidas de grasa subcutánea y visceral (GV). Han sido excluidos los pacientes con la hepatitis viral y con etilismo significativo en las anamnesis o después del teste AUDIT. Después del análisis inicial, 60 pacientes se evaluaron cuanto a los datos antropométricos y divididos en 2 grupos: con y sin esteatosis. La prevalencia de etilismo ha sido de 8,7%.La esteatosis hepática ha sido observada en 37% de los pacientes siendo la mayoría clasificada como leve y moderada (91%). El grupo con esteatosis ha presentado aumento significativo de IMC (34,±8,7 x 29,8±6,5Kg/m2), cintura abdominal (102,6±12,7 x 95,3±12,3cm) peso (85,8±18,7 x 74,5±17,7 Kg) e GV (47,9±10,5 x 36,0±12,7 mm). La esteatosis hepática es común en obesos, especialmente en aquellos con obesidad visceral. Sabemos que el alcohol y la obesidad visceral pueden estar envueltos en su mecanismo fisiopatológico. Por eso, los pacientes con esteatosis hepática y consumo excesivo de alcohol pueden presentar mayor chance de evolucionar desfavorablemente para la cirrosis y insuficiencia hepáticas.

Semantic dementia and persisting Wernicke's aphasia: linguistic and anatomical profiles.

Few studies have directly compared the clinical and anatomical characteristics of patients with progressive aphasia to those of patients with aphasia caused by stroke. In the current study we examined fluent forms of aphasia in these two groups, specifically semantic dementia (SD) and persisting Wernicke's aphasia (WA) due to stroke. We compared 10 patients with SD to 10 age- and education-matched patients with WA in three language domains: language comprehension (single words and sentences), spontaneous speech and visual semantics. Neuroanatomical involvement was analyzed using disease-specific image analysis techniques: voxel-based morphometry (VBM) for patients with SD and overlays of lesion digitized lesion reconstructions in patients with WA. Patients with SD and WA were both impaired on tasks that involved visual semantics, but patients with SD were less impaired in spontaneous speech and sentence comprehension. The anatomical findings showed that different regions were most affected in the two disorders: the left anterior temporal lobe in SD and the left posterior middle temporal gyrus in chronic WA. This study highlights that the two syndromes classically associated with language comprehension deficits in aphasia due to stroke and neurodegenerative disease are clinically distinct, most likely due to distinct distributions of damage in the temporal lobe.

Individual Mycobacterium tuberculosis universal stress protein homologues are dispensable in vitro.

Mycobacterium tuberculosis has 10 universal stress proteins, whose function is unknown. However, proteomic and transcriptomic analyses have shown that a number of usp genes are significantly upregulated under hypoxic conditions and in response to nitric oxide and carbon monoxide, as well as during M. tuberculosis infection of macrophage cell lines. Six of these USPs are part of the DosR regulon and this, along with their expression pattern and the phenotypes of usp mutants in other bacterial species, suggests a potential role in the persistence and/or intracellular survival of Mtb. Knock-out mutants of individual usp genes encoding the USPs Rv1996, Rv2005c, Rv2026c and Rv2028c were generated and their growth and survival under hypoxic and other stress conditions examined. Although the majority of usp genes are highly induced in hypoxic conditions, mutation did not affect the long term survival of Mtb under these conditions, or in response to a range of stress conditions chosen to represent the environmental onslaughts experienced by the bacillus during an infection, nor during infection of mouse and human - derived macrophage cell lines. The possibility remains that these USPs are functionally redundant in Mtb.

Cation currents in human airway epithelial cells induced by infection with influenza A virus.

Influenza A viruses cause lung disease via an incompletely understood mechanism that involves the accumulation of liquid within the lungs. The accumulation of lung liquid is normally prevented by epithelial Na(+) absorption, a transport process regulated via several pathways including phosphoinositide-3-kinase (PI3K). Since the influenza A virus encodes a non-structural protein (NS1) that can activate this kinase, we now explore the effects of NS1 upon the biophysical properties of human airway epithelial cells. Transient expression of NS1 depolarized electrically isolated cells maintained in glucocorticoid-free medium by activating a cation conductance identical to the glucocorticoid-induced conductance seen in single cells. This response involved PI3K-independent and PI3K-dependent mechanisms. Infecting glucocorticoid-deprived cells with influenza A virus disrupted the normal electrical coupling between neighbouring cells, but also activated a conductance identical to that induced by NS1. This response to virus infection was only partially dependent upon NS1-mediated activation of PI3K. The presence of NS1 allows influenza A to modify the biophysical properties of infected cells by activating a Na(+)-permeable conductance. Whilst the activation of Na(+)-permeable channels may be expected to increase the rate of Na(+) absorption and thus reduce the volume of liquid in the lung, liquid does normally accumulate in influenza A-infected lungs. The overall effect of influenza A on lung liquid volume may therefore reflect a balance between the activation and inhibition of Na(+)-permeable channels.

SGK1 activity in Na+ absorbing airway epithelial cells monitored by assaying NDRG1-Thr346/356/366 phosphorylation.

Studies of HeLa cells and serum- and glucocorticoid-regulated kinase 1 (SGK1) knockout mice identified threonine residues in the n-myc downstream-regulated gene 1 protein (NDRG1-Thr(346/356/366)) that are phosphorylated by SGK1 but not by related kinases (Murray et al., Biochem J 385:1-12, 2005). We have, therefore, monitored the phosphorylation of NDRG1-Thr(346/356/366) in order to explore the changes in SGK1 activity associated with the induction and regulation of the glucocorticoid-dependent Na(+) conductance (G (Na)) in human airway epithelial cells. Transient expression of active (SGK1-S422D) and inactive (SGK1-K127A) SGK1 mutants confirmed that activating SGK1 stimulates NDRG1-Thr(346/356/366) phosphorylation. Although G (Na) is negligible in hormone-deprived cells, these cells displayed basal SGK1 activity that was sensitive to LY294002, an inhibitor of 3-phosphatidylinositol phosphate kinase (PI3K). Dexamethasone (0.2 muM) acutely activated SGK1 and the peak of this response (2-3 h) coincided with the induction of G (Na), and both responses were PI3K-dependent. While these data suggest that SGK1 might mediate the rise in G (Na), transient expression of the inactive SGK1-K127A mutant did not affect the hormonal induction of G (Na) but did suppress the activation of SGK1. Dexamethasone-treated cells grown on permeable supports formed confluent epithelial sheets that generated short circuit current due to electrogenic Na(+) absorption. Forskolin and insulin both stimulated this current and the response to insulin, but not forskolin, was LY294002-sensitive and associated with the activation of SGK1. While these data suggest that SGK1 is involved in the control of G (Na), its role may be minor, which could explain why sgk1 knockout has different effects upon different tissues.

Differential effects of Usp14 and Uch-L1 on the ubiquitin proteasome system and synaptic activity.

The ubiquitin proteasome pathway has been implicated in the pathogenesis of many neurodegenerative diseases, and alterations in two different deubiquitinating enzymes, Uch-L1 and Usp14, result in neurological phenotypes in mice. We identified a new mutation in Uch-L1 and compared the roles of Uch-L1 and Usp14 in the ubiquitin proteasome system. Deficiencies in either Uch-L1 or Usp14 result in decreased levels of ubiquitin, suggesting that they both regulate ubiquitin stability in the nervous system. However, the effect of ubiquitin depletion on viability and onset of symptoms is more severe in the Usp14-deficient mice, and changes in hippocampal synaptic transmission were only observed in Usp14-deficient mice. In addition, while Usp14 appears to function at the proteasome, Uch-L1 deficiency resulted in up-regulation of lysosomal components, indicating that Uch-L1 and Usp14 may differentially affect the ubiquitin proteasome system and synaptic activity by regulating different pools of ubiquitin in the cell.

Abductor pollicis longus "hammock" ligamentoplasty for treatment of first carpometacarpal arthritis.

The association of trapeziectomy with ligamentoplasty is a simple treatment for osteoarthritis at the base of the thumb. Here we present the long-term results of a technique that creates a "hammock" under the first metacarpal bone using the Abductor Pollicis Longus tendon. This paper reports the results of treatment by this operation of 60 thumbs in 50 patients, including 13 men and 37 women of average age 60 (46-75) years. Thirty thumbs presented with severe pain and 30 with moderate pain. At final follow-up, 47 thumbs (78%) had experienced dramatic relief of pain following the procedure, 12 (20%) thumbs still had mild pain and one (2%) thumb had severe pain. No patients needed revision.

[Bilateral congenital fusion of the scaphoid and the trapezium. A case report]. / Synostose scaphotrapézienne congénitale bilatérale.

Congenital synostosis has been described between nearly all of the carpal bones. It can occur in an isolated form or most commonly in relation between the lunatum and the triquetrum. It can also occur in a multiple form and be associated with other malformations. We report a rare case of scaphoid-trapezium fusion observed bilaterally in a nearly asymptomatic 63-year-old patient.

A longitudinal fMRI study of the paced auditory serial addition task.

The paced auditory serial addition task (PASAT) is a test of working memory and attention that is frequently abnormal in MS and is used serially to assess cognitive dysfunction as part of the MS Functional Composite in clinical trials. Previous studies using functional MRI (fMRI) during PASAT performance have shown significant differences in activation patterns between healthy controls and MS patients matched for performance, but serial fMRI measures have not been reported. A confound is that learning effects are common with repeated PASAT testing, diminishing over successive trials. After measuring PASAT performance weekly for four weeks in 10 healthy controls to eliminate practice effects, we assessed brain activity using fMRI at baseline and after six months to determine the reproducibility of activation patterns in healthy controls during PASAT performance. Results showed that scores improved during the first three testing trials and stabilized subsequently. Brain activation during PASAT performance was seen in left frontal and parietal regions consistent with previous reports. After a six-month interval, PASAT performance and fMRI activity were stable, suggesting that serial fMRI during PASAT performance could be used as an outcome measure in trials assessing cognitive decline in clinical populations once practice effects are eliminated.

Microvascular free tissue transfer in reconstruction of the lower limb.

Reconstruction of the lower extremity using microvascular free tissue transfer has been adopted as a routine procedure since the 1980s. Success rates in overall free tissue transfer are now as high as 98%. In the lower limb, however, the failure rate has been reported to be as high as 15 to 20%. A review of 50 consecutive microvascular free flaps to the lower extremity was carried out in the Ulster Hospital Belfast. The indication for surgery, the flap type, the recipient vessel, re-exploration rate, complication rate, success rate and the changing pattern in management during the first six years of a single consultant's practice was assessed. Six patients (12%) were re-explored for anastomotic complications or haematoma. Thrombosis of the arterial anastomosis was noted in one case, venous thrombosis in two and haematoma under the flap in the remaining three cases. Salvage was successful in four cases, thus producing an overall success rate of 96%.

Developmental regulation of lumenal lung fluid and electrolyte transport.

In the fetus, there is a net secretion of liquid (LL) by the lung as a result of active transport of chloride ions. The rate of secretion and the resulting volume of LL are vital for normal lung growth but how volume is sensed and how secretion may be regulated are still unknown. Towards term under the influence of thyroid and adrenocorticoid hormones, the epithelial sodium channel (ENaC) is increasingly expressed in the pulmonary epithelium. Adrenaline released by the fetus during labour activates ENaC and produces rapid absorption of liquid in preparation for air breathing; absence of ENaC is incompatible with survival. There may be other mechanisms involved in aiding liquid clearance including changes in epithelial permeability, an effect of oxygen on both ENaC and Na/K ATPase and perhaps the influence of additional hormones on ENaC activity. Some time after birth there are further developmental changes with the appearance of other cation channels (CNG1 and perhaps NSCC) which contribute to the liquid absorptive side of the balance existing across the epithelium between secretion and absorption to produce essentially almost no net liquid movement in the postnatal lung. The evidence for these processes is discussed and areas of uncertainty indicated.

Role of InsP3 and ryanodine receptors in the activation of capacitative Ca2+ entry by store depletion or hypoxia in canine pulmonary arterial smooth muscle cells.

BACKGROUND AND PURPOSE: Experiments were performed to determine if capacitative Ca(2+) entry (CCE) in canine pulmonary arterial smooth muscle cells (PASMCs) is dependent on InsP(3) receptors or ryanodine receptors as induction of CCE is dependent on simultaneous depletion of the functionally separate InsP(3)- and ryanodine-sensitive sarcoplasmic reticulum (SR) Ca(2+) stores in these cells. EXPERIMENTAL APPROACH: Myocytes were isolated from canine pulmonary arteries using enzymatic procedures and were used within 8 h of preparation. Measurements of cytosolic Ca(2+) were made by imaging fura-2 loaded individual myocytes that were perfused with physiological buffered saline solution with or without Ca(2+). KEY RESULTS: Treating myocytes with 10 microM cyclopiazonic acid (CPA), removing extracellular Ca(2+), and briefly applying 10 mM caffeine and 10 microM 5-hydroxytryptamine (5-HT) depleted SR Ca(2+) stores. Extracellular Ca(2+) reintroduction caused cytosolic [Ca(2+)] to elevate above baseline signifying CCE. The InsP(3) receptor inhibitors 2-aminobiphenylborate (50-75 microM; 2-APB) and xestospongin-C (20 microM; XeC) abolished CCE. Yet, CCE was unaffected by 10 microM or 300 microM ryanodine or 10 microM dantrolene, which modify ryanodine receptor activity. Higher dantrolene concentrations (50 microM), however, can inhibit both ryanodine receptors and InsP(3) receptors, did reduce CCE. In contrast, CCE activated by hypoxia was unaffected by XeC (20 microM). CONCLUSIONS AND IMPLICATIONS: The results provide evidence that CCE activated by depletion of both InsP(3) and ryanodine SR Ca(2+) stores in canine PASMCs is dependent on functional InsP(3) receptors, whereas the activation of CCE by hypoxia appears to be independent of functional InsP(3) receptors.