Development of the Physiology Professional Skills Curriculum Mapping Tool (PS-MAP).

During the course of undergraduate studies, physiology (and related STEM) majors should acquire a both broad and in-depth foundation in physiological knowledge along with a distinct range of transferable (professional) skills (e.g., critical thinking, communication skills, data analysis). Previously, through a consultative and iterative process with physiology educators, the Professional Skills Committee of the Physiology Majors Interest Group (PMIG) defined and refined a consensus list of professional skills that physiology majors should acquire during their program of study. Here we describe the development and beta testing of a convenient tool to enable physiology and physiology-related program educators to map these professional skills across their curricula. The tool, referred to as PS-MAP, uses the Qualtrics platform and allows programs to collect and organize data about whether students are provided the opportunity to learn and develop the defined professional skills during their undergraduate experience. The authors have made the PS-MAP tool freely available to educators and provide practical tips for its implementation. Use of the PS-MAP tool and the data collected can help programs identify curricular strengths and gaps as well as facilitate curricular discussions among educators within the program.NEW & NOTEWORTHY In addition to foundational physiology knowledge, undergraduate physiology and related STEM majors should develop a range of transferable professional skills. However, evidence of this curricular goal has been lacking. Therefore, the Professional Skills Committee of the Physiology Majors Interest Group (PMIG) developed the freely available and convenient Physiology Professional Skills Curriculum Mapping Tool (PS-MAP) to assist educators in mapping these professional skills throughout their programs.

Effects of long-term inhaled corticosteroid treatment on fragility fractures in older women: the Manitoba BMD registry study.

The effects of inhaled corticosteroids (ICS) on fracture risk in older women with chronic respiratory diseases are not well established. Our results indicate long-term ICS use in this population does not increase the risk of major osteoporotic fracture. This finding further elucidates the long-term safety of ICS in older women. INTRODUCTION: Inhaled corticosteroids (ICS) are frequently used in older women with chronic respiratory diseases. There is insufficient evidence regarding the association between long-term ICS use and the risk of fragility fractures in this population. METHODS: We used linked Manitoba health administrative databases and the provincial bone mineral density (BMD) registry (1996-2013) to identify women ≥ 40 years of age with asthma and/or chronic obstructive pulmonary disease (COPD) within 3 years preceding the baseline BMD test. We followed them until the first major osteoporotic fracture or end of study, whichever came first. ICS use, stratified by exposure tertiles, was measured within the 12-month period following the baseline BMD test (by total days and quantity, primary outcome), and over the entire follow-up period (by medication possession ratio (MPR) and average annual dose, secondary outcome). The hazard ratio of fracture with ICS use was estimated using a Cox proportional hazards model, controlling for baseline determinants of fracture. RESULTS: Of 6880 older women with asthma (38%) or COPD (62%), 810 (12%) experienced a major osteoporotic fracture over a mean follow-up of 7.7 years (SD = 3.9). ICS use at any tertile was not associated with an increased risk of fracture (dispensed days, p = 0.90; dispensed quantity, p = 0.67). Similarly, ICS use at any tertile during the entire follow-up period was not associated with an increased risk of fracture (MPR, p = 0.62; average annual dose, p = 0.58). CONCLUSION: Our findings do not support an increased risk of major osteoporotic fracture in older women with chronic respiratory diseases due to long-term ICS use.

Decreased rotational flow and circumferential wall shear stress as early markers of descending aorta dilation in Marfan syndrome: a 4D flow CMR study.

BACKGROUND: Diseases of the descending aorta have emerged as a clinical issue in Marfan syndrome following improvements in proximal aorta surgical treatment and the consequent increase in life expectancy. Although a role for hemodynamic alterations in the etiology of descending aorta disease in Marfan patients has been suggested, whether flow characteristics may be useful as early markers remains to be determined. METHODS: Seventy-five Marfan patients and 48 healthy subjects were prospectively enrolled. In- and through-plane vortexes were computed by 4D flow cardiovascular magnetic resonance (CMR) in the thoracic aorta through the quantification of in-plane rotational flow and systolic flow reversal ratio, respectively. Regional pulse wave velocity and axial and circumferential wall shear stress maps were also computed. RESULTS: In-plane rotational flow and circumferential wall shear stress were reduced in Marfan patients in the distal ascending aorta and in proximal descending aorta, even in the 20 patients free of aortic dilation. Multivariate analysis showed reduced in-plane rotational flow to be independently related to descending aorta pulse wave velocity. Conversely, systolic flow reversal ratio and axial wall shear stress were altered in unselected Marfan patients but not in the subgroup without dilation. In multivariate regression analysis proximal descending aorta axial (p = 0.014) and circumferential (p = 0.034) wall shear stress were independently related to local diameter. CONCLUSIONS: Reduced rotational flow is present in the aorta of Marfan patients even in the absence of dilation, is related to aortic stiffness and drives abnormal circumferential wall shear stress. Axial and circumferential wall shear stress are independently related to proximal descending aorta dilation beyond clinical factors. In-plane rotational flow and circumferential wall shear stress may be considered as an early marker of descending aorta dilation in Marfan patients.

Synergistic Effects of Temperature and Salinity on the Gene Expression and Physiology of Crassostrea virginica.

The eastern oyster, Crassostrea virginica, forms reefs that provide critical services to the surrounding ecosystem. These reefs are at risk from climate change, in part because altered rainfall patterns may amplify local fluctuations in salinity, impacting oyster recruitment, survival, and growth. As in other marine organisms, warming water temperatures might interact with these changes in salinity to synergistically influence oyster physiology. In this study, we used comparative transcriptomics, measurements of physiology, and a field assessment to investigate what phenotypic changes C. virginica uses to cope with combined temperature and salinity stress in the Gulf of Mexico. Oysters from a historically low salinity site (Sister Lake, LA) were exposed to fully crossed temperature (20°C and 30°C) and salinity (25, 15, and 7 PSU) treatments. Using comparative transcriptomics on oyster gill tissue, we identified a greater number of genes that were differentially expressed (DE) in response to low salinity at warmer temperatures. Functional enrichment analysis showed low overlap between genes DE in response to thermal stress compared with hypoosmotic stress and identified enrichment for gene ontologies associated with cell adhesion, transmembrane transport, and microtubule-based process. Experiments also showed that oysters changed their physiology at elevated temperatures and lowered salinity, with significantly increased respiration rates between 20°C and 30°C. However, despite the higher energetic demands, oysters did not increase their feeding rate. To investigate transcriptional differences between populations in situ, we collected gill tissue from three locations and two time points across the Louisiana Gulf coast and used quantitative PCR to measure the expression levels of seven target genes. We found an upregulation of genes that function in osmolyte transport, oxidative stress mediation, apoptosis, and protein synthesis at our low salinity site and sampling time point. In summary, oysters altered their phenotype more in response to low salinity at higher temperatures as evidenced by a higher number of DE genes during laboratory exposure, increased respiration (higher energetic demands), and in situ differential expression by season and location. These synergistic effects of hypoosmotic stress and increased temperature suggest that climate change will exacerbate the negative effects of low salinity exposure on eastern oysters.

Demographic consequences of invasion by a native, controphic competitor to an insular bird population.

Species invasions and range shifts can lead to novel competitive interactions between historically resident and colonizing species, but the demographic consequences of such interactions remain controversial. We present results from field experiments and 45 years of demographic monitoring to test the hypothesis that the colonization of Mandarte Is., BC, Canada, by fox sparrows (Passerella iliaca) caused the long-term decline of the resident population of song sparrows (Melospiza melodia). Several lines of evidence indicate that competition with fox sparrows for winter food reduced over-winter survival in juvenile song sparrows by 48% from 1960 to 2015, enforcing population decline despite an increase in annual reproductive rate in song sparrows over the same period. Preference for locally abundant seeds presented at experimental arenas suggested complete overlap in diet in song and fox sparrows, and observations at arenas baited with commercial seed showed that fox sparrows displaced song sparrows in 91-100% of interactions in two periods during winter. In contrast, we found no evidence of interspecific competition for resources during the breeding season. Our results indicate that in the absence of marked shifts in niche dimension, range expansions by dominant competitors have the potential to cause the extirpation of historically resident species when competitive interactions between them are strong and resources not equitably partitioned.

Pressure Mapping and Hemodynamic Assessment of Intracranial Dural Sinuses and Dural Arteriovenous Fistulas with 4D Flow MRI.

The feasibility of 4D flow MR imaging to visualize flow patterns and generate relative pressure maps in the dural venous sinus in healthy subjects (n = 60) and patients with dural arteriovenous fistulas (n = 7) was investigated. Dural venous drainage was classified based on torcular Herophili anatomy by using 4D flow MR imaging-derived angiograms and magnitude images. Subjects were scanned in a 3T clinical MR imaging system. 4D flow MR imaging enabled noninvasive characterization of dural sinus anatomy and mapping of relative pressure differences.

Comparison of radial 4D Flow-MRI with perivascular ultrasound to quantify blood flow in the abdomen and introduction of a porcine model of pre-hepatic portal hypertension.

OBJECTIVES: Objectives of this study were to compare radial time-resolved phase contrast magnetic resonance imaging (4D Flow-MRI) with perivascular ultrasound (pvUS) and to explore a porcine model of acute pre-hepatic portal hypertension (PHTN). METHODS: Abdominal 4D Flow-MRI and pvUS in portal and splenic vein, hepatic and both renal arteries were performed in 13 pigs of approximately 60 kg. In six pigs, measurements were repeated after partial portal vein (PV) ligature. Inter- and intra-reader comparisons and statistical analysis including Bland-Altman (BA) comparison, paired Student's t tests and linear regression were performed. RESULTS: PvUS and 4D Flow-MRI measurements agreed well; flow before partial PV ligature was 322 ± 30 ml/min in pvUS and 297 ± 27 ml/min in MRI (p = 0.294), and average BA difference was 25 ml/min [-322; 372]. Inter- and intra-reader results differed very little, revealed excellent correlation (R 2 = 0.98 and 0.99, respectively) and resulted in BA differences of -5 ml/min [-161; 150] and -2 ml/min [-28; 25], respectively. After PV ligature, PV flow decreased from 356 ± 50 to 298 ± 61 ml/min (p = 0.02), and hepatic arterial flow increased from 277 ± 36 to 331 ± 65 ml/min (p = n.s.). CONCLUSION: The successful in vivo comparison of radial 4D Flow-MRI to perivascular ultrasound revealed good agreement of abdominal blood flow although with considerable spread of results. A model of pre-hepatic PHTN was successfully introduced and acute responses monitored. KEY POINTS: • Radial 4D Flow-MRI in the abdomen was successfully compared to perivascular ultrasound. • Inter- and intra-reader testing demonstrated excellent reproducibility of upper abdominal 4D Flow-MRI. • A porcine model of acute pre-hepatic portal hypertension was successfully introduced. • 4D Flow-MRI successfully monitored acute changes in a model of portal hypertension.

Inflammatory cytokine receptor blockade in a rodent model of mild traumatic brain injury.

In rodent models of traumatic brain injury (TBI), both Interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNFα) levels increase early after injury to return later to basal levels. We have developed and characterized a rat mild fluid percussion model of TBI (mLFP injury) that results in righting reflex response times (RRRTs) that are less than those characteristic of moderate to severe LFP injury and yet increase IL-1α/ß and TNFα levels. Here we report that blockade of IL-1α/ß and TNFα binding to IL-1R and TNFR1, respectively, reduced neuropathology in parietal cortex, hippocampus, and thalamus and improved outcome. IL-1ß binding to the type I IL-1 receptor (IL-1R1) can be blocked by a recombinant form of the endogenous IL-1R antagonist IL-1Ra (Kineret). TNFα binding to the TNF receptor (TNFR) can be blocked by the recombinant fusion protein etanercept, made up of a TNFR2 peptide fused to an Fc portion of human IgG1. There was no benefit from the combined blockades compared with individual blockades or after repeated treatments for 11 days after injury compared with one treatment at 1 hr after injury, when measured at 6 hr or 18 days, based on changes in neuropathology. There was also no further enhancement of blockade benefits after 18 days. Given that both Kineret and etanercept given singly or in combination showed similar beneficial effects and that TNFα also has a gliotransmitter role regulating AMPA receptor traffic, thus confounding effects of a TNFα blockade, we chose to focus on a single treatment with Kineret.

A rodent model of mild traumatic brain blast injury.

One of the criteria defining mild traumatic brain injury (mTBI) in humans is a loss of consciousness lasting for less than 30 min. mTBI can result in long-term impairment of cognition and behavior. In rats, the length of time it takes a rat to right itself after injury is considered to be an analog for human return to consciousness. This study characterized a rat mild brain blast injury (mBBI) model defined by a righting response reflex time (RRRT) of more than 4 min but less than 10 min. Assessments of motor coordination relying on beam-balance and foot-fault assays and reference memory showed significant impairment in animals exposed to mBBI. This study's hypothesis is that there are inflammatory outcomes to mTBI over time that cause its deleterious effects. For example, mBBI significantly increased brain levels of interleukin (IL)-1ß and tumor necrosis factor-α (TNFα) protein. There were significant inflammatory responses in the cortex, hippocampus, thalamus, and amygdala 6 hr after mBBI, as evidenced by increased levels of the inflammatory markers associated with activation of microglia and macrophages, ionized calcium binding adaptor 1 (IBA1), impairment of the blood-brain barrier, and significant neuronal losses. There were significant increases in phosphorylated Tau (p-Tau) levels, a putative precursor to the development of neuroencephalopathy, as early as 6 hr after mBBI in the cortex and the hippocampus but not in the thalamus or the amygdala. There was an apparent correlation between RRRTs and p-Tau protein levels but not IBA1. These results suggest potential therapies for mild blast injuries via blockade of the IL-1ß and TNFα receptors.

Reproducibility of cerebrospinal venous blood flow and vessel anatomy with the use of phase contrast-vastly undersampled isotropic projection reconstruction and contrast-enhanced MRA.

BACKGROUND AND PURPOSE: The chronic cerebrospinal venous insufficiency hypothesis raises interest in cerebrospinal venous blood flow imaging, which is more complex and less established than in arteries. For accurate assessment of venous flow in chronic cerebrospinal venous insufficiency diagnosis and research, we must account for physiologic changes in flow patterns. This study examines day-to-day flow variability in cerebrospinal veins by use of 4D MR flow and contrast-enhanced MRA under typical, uncontrolled conditions in healthy individuals. MATERIALS AND METHODS: Ten healthy volunteers were scanned in a test-retest fashion by use of a 4D flow MR imaging technique and contrast-enhanced MRA. Flow parameters obtained from phase contrast-vastly undersampled isotropic projection reconstruction and contrast-enhanced MRA scoring measurements in the head, neck, and chest veins were analyzed for internal consistency and interscan reproducibility. RESULTS: Internal consistency was satisfied at the torcular herophili, with an input-output difference of 2.2%. Percentages of variations in flow were 20.3%, internal jugular vein; 20.4%, azygos vein; 6.8%, transverse sinus; and 5.1%, common carotid artery. Retrograde flow was found in the lower internal jugular vein (4.8%) and azygos vein (7.2%). Contrast-enhanced MRA interscan κ values for the internal jugular vein (left: 0.474, right: 0.366) and azygos vein (-0.053) showed poor interscan agreement. CONCLUSIONS: Phase contrast-vastly undersampled isotropic projection reconstruction blood flow measurements are reliable and highly reproducible in intracranial veins and in the common carotid artery but not in veins of the neck (internal jugular vein) and chest (azygos vein) because of normal physiologic variation. Retrograde flow normally may be observed in the lower internal jugular vein and azygos vein. Low interrater agreement in contrast-enhanced MRA scans was observed. These findings have important implications for imaging diagnosis and experimental research of chronic cerebrospinal venous insufficiency.

Measuring pulsatile flow in cerebral arteries using 4D phase-contrast MR imaging.

BACKGROUND AND PURPOSE: 4D PCMRI can be used to quantify pulsatile hemodynamics in multiple cerebral arteries. The aim of this study was to compare 4D PCMRI and 2D PCMRI for assessments of pulsatile hemodynamics in major cerebral arteries. MATERIALS AND METHODS: We scanned the internal carotid artery, the anterior cerebral artery, the basilar artery, and the middle cerebral artery in 10 subjects with a single 4D and multiple 2D PCMRI acquisitions by use of a 3T system and a 32-channel head coil. We assessed the agreement regarding net flow and the volume of arterial pulsatility (ΔV) for all vessels. RESULTS: 2D and 4D PCMRI produced highly correlated results, with r = 0.86 and r = 0.95 for ΔV and net flow, respectively (n = 69 vessels). These values increased to r = 0.93 and r = 0.97, respectively, during investigation of a subset of measurements with <5% variation in heart rate between the 4D and 2D acquisition (n = 31 vessels). Significant differences were found for ICA and MCA net flow (P = .004 and P < .001, respectively) and MCA ΔV (P = .006). However, these differences were attenuated and no longer significant when the subset with stable heart rate (n = 31 vessels) was analyzed. CONCLUSIONS: 4D PCMRI provides a powerful methodology to measure pulsatility of the larger cerebral arteries from a single acquisition. A large part of differences between measurements was attributed to physiologic variations. The results were consistent with 2D PCMRI.

Hemodynamic changes in patients with arteriovenous malformations assessed using high-resolution 3D radial phase-contrast MR angiography.

BACKGROUND AND PURPOSE: Arteriovenous malformations have a high lifetime risk of hemorrhage; however, treatment carries a significant risk of morbidity and mortality, including permanent neurologic sequelae. WSS and other hemodynamic parameters are altered in patients with symptomatic AVMs, and analysis of hemodynamics may have value in stratifying patients into different risk groups. In this study, we examined hemodynamic data from patients with stable symptoms and those who presented with acute symptoms to identify trends which may help in risk stratification. MATERIALS AND METHODS: Phase-contrast MRA using a radial readout (PC-VIPR) is a fast, high-resolution technique that can acquire whole-brain velocity-encoded angiograms with scan times of approximately 5 minutes. Ten patients with AVMs were scanned using PC-VIPR; velocity, area, flow, and WSS in vessels feeding the AVMs and normal contralateral vessels were calculated using velocity data from the phase-contrast acquisition. RESULTS: Patients with an asymptomatic presentation or mild symptoms (n = 4) had no significant difference in WSS in feeding vessels compared with normal contralateral vessels, whereas patients presenting with hemorrhage, severe headaches/seizures, or focal neurologic deficits (n = 6) had significantly higher WSS in feeding vessels compared with contralateral vessels. CONCLUSIONS: In this study, we demonstrate that estimates of WSS and other hemodynamic parameters can be obtained noninvasively in patients with AVMs in clinically useful imaging times. Variation in WSS between feeders and normal vessels appears to relate to the clinical presentation of the patient. Further analysis of hemodynamic changes may improve characterization and staging of AVM patients, when combined with existing risk factors.

Four-dimensional velocity mapping of the hepatic and splanchnic vasculature with radial sampling at 3 tesla: a feasibility study in portal hypertension.

PURPOSE: To demonstrate the feasibility of PC-VIPR (Phase Contrast Vastly undersampled Imaging with Projection Reconstruction) for the depiction and hemodynamic analysis of hepatic and splanchnic vessels in patients with portal hypertension. MATERIALS AND METHODS: Twenty-four cirrhotic patients (55.9 ± 10.4 years) were scanned using 5-point PC-VIPR for high spatial resolution imaging with large volume coverage at 3 Tesla (T) using a 32-channel body coil. Vessel segmentation and hemodynamic visualization included color-coded three-dimensional (3D) streamlines and particle traces. Segmentation quality was compared with contrast-enhanced multi-phase liver imaging. Flow pattern analysis was performed in consensus of three readers. The MELD score was calculated to estimate disease severity and was correlated to image quality. RESULTS: Good to excellent visualization quality was achieved in 23/24 cases. All arterial vessels and 144/168 vessels of the portal venous (PV) circulation were unambiguously identified. No correlation with the MELD score was found. Eight of 148 vessels of the PV circulation demonstrated reverse (hepatofugal) flow. Hepatofugal flow in small tributaries to PV flow were present in three cases despite hepatopetal flow in the PV. CONCLUSION: This feasibility study demonstrates the feasibility of PC-VIPR for simultaneous morphological and hemodynamic assessment of the hepatic and splanchnic vasculature in cirrhosis and portal hypertension. Future studies with quantitative analyses are warranted.

Fast whole-brain 4D contrast-enhanced MR angiography with velocity encoding using undersampled radial acquisition and highly constrained projection reconstruction: image-quality assessment in volunteer subjects.

We report on the image quality obtained by using fast contrast-enhanced whole-brain 4D radial MRA with 0.75-second temporal resolution, isotropic submillimeter spatial resolution, and velocity encoding (HYPRFlow). Images generated by HYPR-LR by using the velocity-encoded data as the constraining image were of diagnostic quality. In addition, we demonstrate that measurements of shear stress within the middle cerebral artery can be derived from the high-resolution 3D velocity data.

Velocity measurements in the middle cerebral arteries of healthy volunteers using 3D radial phase-contrast HYPRFlow: comparison with transcranial Doppler sonography and 2D phase-contrast MR imaging.

BACKGROUND AND PURPOSE: We have developed PC HYPRFlow, a comprehensive MRA technique that includes a whole-brain CE dynamic series followed by PC velocity-encoding, yielding a time series of high-resolution morphologic angiograms with associated velocity information. In this study, we present velocity data acquired by using the PC component of PC HYPRFlow (PC-VIPR). MATERIALS AND METHODS: Ten healthy volunteers (6 women, 4 men) were scanned by using PC HYPRFlow and 2D-PC imaging, immediately followed by velocity measurements by using TCD. Velocity measurements were made in the M1 segments of the MCAs from the PC-VIPR, 2D-PC, and TCD examinations. RESULTS: PC-VIPR showed approximately 30% lower mean velocity compared with TCD, consistent with other comparisons of TCD with PC-MRA. The correlation with TCD was r = 0.793, and the correlation of PC-VIPR with 2D-PC was r = 0.723. CONCLUSIONS: PC-VIPR is a technique capable of acquiring high-resolution MRA of diagnostic quality with velocity data comparable with TCD and 2D-PC. The combination of velocity information and fast high-resolution whole-brain morphologic angiograms makes PC HYPRFlow an attractive alternative to current MRA methods.

Hippocampal neurogenesis in food-storing red squirrels: the impact of age and spatial behavior.

The adaptive significance of adult hippocampal neurogenesis remains unknown. In the laboratory, it is influenced by a variety of environmental and physiological stimuli. In the wild, it may be influenced by the reliance on spatial memory and by environmental stressors. The one common denominator in both settings is that neurogenesis declines markedly with age. Red squirrels are long-lived rodents that store food (thousands of tree cones) to permit survival under harsh winter conditions. We compared a population from the eastern North America that stores its cones singly or in small clusters with one from the west that stores its cones in large stockpiles. The reliance on spatial memory should be much greater in the east than the west, and should not decline with age, as cone storage and recovery is a yearly necessity. We found no difference between the populations in the density of young neurons and both populations showed the same decline with age. Thus, we reject the spatial memory hypothesis for adult neurogenesis in mammals in its original form. Instead, our evidence is consistent with the neurogenic reserve hypothesis in which neuronal cell production early in life leads to enhanced hippocampal function later in life according to environmental demand but without requirement for ongoing cell production as a function of site- and species-specific needs. A more general interpretation of the data leads us to consider a possible role of neurogenesis in novel, flexible episodic memories.

Guidelines for the development of social marketing programmes for sun protection among adolescents and young adults.

OBJECTIVES: To formulate 'best practice' guidelines for social marketing programmes for adolescents' and young adults' sun protection. STUDY DESIGN: A Delphi consensus process. METHODS: Eleven experts in sun protection and social marketing participated in a Delphi consensus process, where they were asked to provide up to 10 key points, based on their knowledge and practical experience, which they felt were most important in developing social marketing interventions for the primary prevention of skin cancer among adolescents and young adults. After reaching consensus, the evidence base for each guideline was determined and graded via the Scottish Intercollegiate Guideline Network grading system. Participants were then asked to indicate how strongly they rated the finalized 15 recommendations based on all aspects relating to their knowledge and practical opinion, as well as the research evidence, on a visual analogue scale. RESULTS: The resultant 15 guidelines offer general principles for sun protection interventions utilizing a social marketing approach. CONCLUSIONS: This method of guideline development brought the expertise of practitioners to the forefront of guideline development, whilst still utilizing established methods of evidence confirmation. It thus offers a useful method for guideline development in a public health context.

Differential role of N-methyl-D-aspartate receptor subunits 2A and 2B in mediating phencyclidine-induced perinatal neuronal apoptosis and behavioral deficits.

The mechanism underlying phencyclidine (PCP)-induced apoptosis in perinatal rats and the development of schizophrenia-like behaviors is incompletely understood. We used antagonists for N-methyl-D-aspartate (NMDA) receptor subunit NR2A- and NR2B-containing NMDA receptor to test the hypothesis that the behavioral and apoptotic effects of PCP are mediated by blockade of NR1/NR2A-containing receptors, rather than NR1/NR2B-containing receptors. Sprague-Dawley rats were treated on PN7, PN9, and PN11 with PCP (10 mg/kg), PEAQX (NR2A-preferring antagonist; 10, 20, or 40 mg/kg), or ifenprodil (selective NR2B antagonist; 1, 5, or 10 mg/kg) and sacrificed for measurement of caspase-3 activity (an index of apoptosis) or allowed to age and tested for locomotor sensitization to PCP challenge on PN28-PN35. PCP or PEAQX on PN7, PN9, and PN11 markedly elevated caspase-3 activity in the cortex; ifenprodil showed no effect. Striatal apoptosis was evident only after subchronic treatment with a high dose of PEAQX (20 mg/kg). Animals treated with PCP or PEAQX on PN7, PN9, and PN11 showed a sensitized locomotor response to PCP challenge on PN28-PN35. Ifenprodil treatment had no effect on either measure. Therefore, PCP blockade of cortical NR1/NR2A, rather than NR1/NR2B, appears to be responsible for PCP-induced apoptosis and the development of long-lasting behavioral deficits.

The effects of blastomere biopsy and oxygen tension on bovine embryo development, rate of apoptosis and interferon-tau secretion.

A series of experiments was performed to examine the effects of blastomere biopsies on subsequent development of IVF-derived bovine embryos. The first experiment was designed to assess the optimal time for blastomere removal. One blastomere was removed either 48 or 72 h after IVF. Biopsy at 48 h resulted in 17.2% of embryos proceeding to the blastocyst stage, which was lower than when biopsies were performed at 72 h (37.5%, p < 0.05). In the second experiment, embryos were cultured either under atmospheric or 5% O(2) following blastomere removal. Biopsies had no effect on rate of blastocyst formation with 36% of controls and 33.7% of biopsied embryos proceeding to that stage. However, culture under 5% O(2) significantly increased the number of blastocysts from 29.9% to 40.3% (p < 0.05). This effect was significant in both biopsied and control embryos. In the final experiment, biopsied embryos were again cultured under different oxygen tension. Blastocysts were collected and cultured individually for 48 h in medium droplets in their respective O(2) concentration after which time the medium was assayed for concentration of interferon-tau (IFN-tau). Reduced O(2) concentration again significantly increased blastocyst formation from 24.9% to 41.9% (p < 0.05). IFN-tau secretion was not affected by biopsies, but culture under atmospheric O(2) resulted in significantly increased IFN-tau concentration in medium droplets (12274.0 +/- 2825.9 pM vs 5046.5 +/- 2562.2 pM; p < 0.05).

Intraocular use of rituximab.

PURPOSE: To evaluate the toxicity of 1 mg of intraocular rituximab and to present a small case-series of patients treated with intravitreal rituximab. METHODS: Rituximab (1 mg/0.1 ml) was injected in the vitreous of one eye of three Dutch-belted rabbits. Two animals were injected with balanced salt solution as controls. At 1 month the rabbits were killed and the eyes examined by light microscopy. Three patients (five eyes) with intraocular lymphoma were also treated with a 1 mg injection of rituximab. RESULTS: The treated rabbit eyes and the control eyes showed no light microscopic evidence of ocular toxicity at 1 month following injection. The five human eyes of three patients have shown no evidence of intraocular toxicity with a median follow-up time of 3.6 months (range 2.0-6.4 months). One patient received a total of four injections in the right eye and three injections in the left eye. CONCLUSION: Intravitreal rituximab at a dose of 1 mg does not appear to cause toxicity in rabbit eyes and in the five eyes of three patients.