SARS-CoV-2 Vaccine-Elicited Immunity after B Cell Depletion in Multiple Sclerosis

The impact of B cell deficiency on the humoral and cellular responses to SARS-CoV2 mRNA vaccination remains a challenging and significant clinical management question. We evaluated vaccine-elicited serological and cellular responses in 1) healthy individuals who were pre-exposed to SARS-CoV-2 (n = 21), 2) healthy individuals who received a homologous booster (mRNA, n = 19; or Novavax, n = 19), and 3) persons with multiple sclerosis on B cell depletion therapy (MS-αCD20) receiving mRNA homologous boosting (n = 36). Pre-exposure increased humoral and CD4 T cellular responses in immunocompetent individuals. Novavax homologous boosting induced a significantly more robust serological response than mRNA boosting. MS-α CD20 had an intact IgA mucosal response and an enhanced CD8 T cell response to mRNA boosting compared with immunocompetent individuals. This enhanced cellular response was characterized by the expansion of only effector, not memory, T cells. The enhancement of CD8 T cells in the setting of B cell depletion suggests a regulatory mechanism between B and CD8 T cell vaccine responses.

Sub-Kelvin cooling for two kilopixel bolometer arrays in the PIPER receiver

The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne telescope mission to search for inflationary gravitational waves from the early universe. PIPER employs two 32 × 40 arrays of superconducting transition-edge sensors, which operate at 100 mK. An open bucket Dewar of liquid helium maintains the receiver and telescope optics at 1.7 K. We describe the thermal design of the receiver and sub-Kelvin cooling with a continuous adiabatic demagnetization refrigerator (CADR). The CADR operates between 70 and 130 mK and provides ≈10 μW cooling power at 100 mK, nearly five times the loading of the two detector assemblies. We describe electronics and software to robustly control the CADR, overall CADR performance in flightlike integrated receiver testing, and practical considerations for implementation in the balloon float environment.

Tau positron emission tomography imaging in C9orf72 repeat expansion carriers

BACKGROUND AND PURPOSE

AV-1451 (18 F-AV-1451, flortaucipir) positron emission tomography was performed in C9orf72 expansion carriers to assess tau accumulation and disease manifestation.

METHODS

Nine clinically characterized C9orf72 expansion carriers and 18 age- and gender- matched cognitively normal individuals were psychometrically evaluated and underwent tau positron emission tomography imaging. The regional AV-1451 standard uptake value ratios from multiple brain regions were analyzed. Spearman correlation was performed to relate the AV-1451 standard uptake value ratio to clinical, psychometric and cerebrospinal fluid measures.

RESULTS

C9orf72 expansion carriers had increased AV-1451 binding in the entorhinal cortex compared to controls. Primary age-related tauopathy was observed postmortem in one patient. AV-1451 uptake did not correlate with clinical severity, disease duration, psychometric performance or cerebrospinal fluid markers.

CONCLUSION

C9orf72 expansion carriers exhibited increased AV-1451 uptake in entorhinal cortex compared to cognitively normal controls, suggesting a propensity for primary age-related tauopathy. However, AV-1451 accumulation was not associated with psychometric performance in our cohort.

C9orf72 is required for proper macrophage and microglial function in mice

Expansions of a hexanucleotide repeat (GGGGCC) in the noncoding region of the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Decreased expression of C9orf72 is seen in expansion carriers, suggesting that loss of function may play a role in disease. We found that two independent mouse lines lacking the C9orf72 ortholog (3110043O21Rik) in all tissues developed normally and aged without motor neuron disease. Instead, C9orf72 null mice developed progressive splenomegaly and lymphadenopathy with accumulation of engorged macrophage-like cells. C9orf72 expression was highest in myeloid cells, and the loss of C9orf72 led to lysosomal accumulation and altered immune responses in macrophages and microglia, with age-related neuroinflammation similar to C9orf72 ALS but not sporadic ALS human patient tissue. Thus, C9orf72 is required for the normal function of myeloid cells, and altered microglial function may contribute to neurodegeneration in C9orf72 expansion carriers.

Contamination and bioaccumulation of benzotriazole ultraviolet stabilizers in fish from Manila Bay, the Philippines using an ultra-fast liquid chromatography-tandem mass spectrometry

Benzotriazole ultraviolet stabilizers (BUVSs) used in plastic products, building materials and personal hygiene products were analyzed in fishes collected from Manila Bay, the Philippines. BUVSs were detected at ng g⁻¹ level in all the fish samples, indicating their ubiquitous contamination in coastal waters. Among the targeted eight BUVSs, UV-328 was predominantly found with a mean concentration of 34.2 ng g⁻¹ lipid weight, implying large scale production and use of this compound in the Philippines. High concentrations of ∑BUVSs were found in bumpnose trevally (Carangoides hedlandensis), bluetail mullet (adult) (Valamugil buchanani), common ponyfish (Leiognathus equulus) and coral grouper (adult) (Epinephelus corallicola) indicating their active uptake and/or lower metabolic capacity to eliminate BUVSs. Among BUVSs, UV-P showed significant positive relationship (p<0.05) between concentration and fish length (r=0.29) and fish weight (r=0.31). Levels of UV-P in demersal species had positive correlation with δ¹⁵N, indicating that possibile sink of UV-P is bottom sediment in the bay, and ultimately accumulate through benthic food web rather than pelagic food web. To our knowledge, this is the first study on BUVSs distribution in fish from developing countries.

On the relation between the activation energy for electron attachment reactions and the size of their thermal rate coefficients

Rate coefficients k(T) for dissociative electron attachment (DEA) to molecules in many cases exhibit a more or less strong rise with increasing temperature T (the electron temperature T(e) and the molecular temperature T(G) are assumed to be in thermal equilibrium, i.e., T = T(e) = T(G)). This rise is frequently modeled by the Arrhenius equation k(T) = k(A) exp[-E(a)∕(k(B)T)], and an activation energy E(a) is deduced from fits to the experimental data k(T). This behavior reflects the presence of an energy barrier for the anion on its path to the dissociated products. In a recent paper [J. Kopyra, J. Wnorowska, M. Foryś, and I. Szamrej, Int. J. Mass Spectrom. 268, 60 (2007)] it was suggested that the size of the rate coefficients for DEA reactions at room temperature exhibits an exponential dependence on the activation energy, i.e., k(E(a); T ≈ 300 K) = k(1) exp[-E(a)∕E(0)]. More recent experimental data for molecules with high barriers [T. M. Miller, J. F. Friedman, L. C. Schaffer, and A. A. Viggiano, J. Chem. Phys. 131, 084302 (2009)] are compatible with such a correlation. We investigate the validity and the possible origin of this dependence by analyzing the results of R-matrix calculations for temperature-dependent rate coefficients of exothermic DEA processes with intermediate barrier toward dissociation. These include results for model systems with systematically varied barrier height as well as results of molecule-specific calculations for CH(3)Cl, CH(3)Br, CF(3)Cl, and CH(2)Cl(2) (activation energies above 0.2 eV) involving appropriate molecular parameters. A comparison of the experimental and theoretical results for the considered class of molecules (halogenated alkanes) supports the idea that the exponential dependence of k(T = 300 K) on the activation energy reflects a general phenomenon associated with Franck-Condon factors for getting from the initial neutral vibrational levels to the dissociating final anion state in a direct DEA process. Cases are discussed for which the proposed relation does not apply.

[Composition and levels of phospholipids in plasma from patients with exacerbation of chronic gastritis]

Blood plasma phospholipids from 45 patients with chronic gastritis and 20 healthy volunteers have been investigated. Chronic gastritis exacerbation is accompanied by essential change in the spectrum and concentration of the phospholipids. The absolute concentrations of the phospholipids and such fractions as phosphatidylcholine, phosphatidylserine, lysophosphatidylcholine, lysophosphatidylethanolamine and sphingomyelin significally increased while concentrations of phosphatidilinositol and lysophosphatidylserine decreased. The period of the remission of the disease was accompanied by a certain normalization of the level and spectrum phospholipids and literature data suggest that phospholipids and their particular fractions are involved into pathogenesis of the inflammatory process in gastric mucosa and in the process of reparative regeneration aswell.

Correlating phenotype and genotype in the periodic paralyses

BACKGROUND

Periodic paralyses and paramyotonia congenita are rare disorders causing disabling weakness and myotonia. Mutations in sodium, calcium, and potassium channels have been recognized as causing disease.

OBJECTIVE

To analyze the clinical phenotype of patients with and without discernible genotype and to identify other mutations in ion channel genes associated with disease.

METHODS

The authors have reviewed clinical data in patients with a diagnosis of hypokalemic periodic paralysis (56 kindreds, 71 patients), hyperkalemic periodic paralysis (47 kindreds, 99 patients), and paramyotonia congenita (24 kindreds, 56 patients). For those patients without one of the classically known mutations, the authors analyzed the entire coding region of the SCN4A, KCNE3, and KCNJ2 genes and portions of the coding region of the CACNA1S gene in order to identify new mutations.

RESULTS

Mutations were identified in approximately two thirds of kindreds with periodic paralysis or paramyotonia congenita. The authors found differences between the disorders and between those with and without identified mutations in terms of age at onset, frequency of attacks, duration of attacks, fixed proximal weakness, precipitants of attacks, myotonia, electrophysiologic studies, serum potassium levels, muscle biopsy, response to potassium administration, and response to treatment with acetazolamide.

CONCLUSIONS

Hypokalemic periodic paralysis, hyperkalemic periodic paralysis, and paramyotonia congenita may be distinguished based on clinical data. This series of 226 patients (127 kindreds) confirms some clinical features of this disorder with notable exceptions: In this series, patients without mutations had a less typical clinical presentation including an older age at onset, no changes in diet as a precipitant, and absence of vacuolar myopathy on muscle biopsy.

HETC radiation transport code development for cosmic ray shielding applications in space

In order to facilitate three-dimensional analyses of space radiation shielding scenarios for future space missions, the Monte Carlo radiation transport code HETC is being extended to include transport of energetic heavy ions, such as are found in the galactic cosmic ray spectrum in space. Recently, an event generator capable of providing nuclear interaction data for use in HETC was developed and incorporated into the code. The event generator predicts the interaction product yields and production angles and energies using nuclear models and Monte Carlo techniques. Testing and validation of the extended transport code has begun. In this work, the current status of code modifications, which enable energetic heavy ions and their nuclear reaction products to be transported through thick shielding, are described. Also, initial results of code testing against available laboratory beam data for energetic heavy ions interacting in thick targets are presented.

First observation of four-body breakup in electron recombination: C2D+5

We report the first observation of four-body breakup in electron dissociative recombination of a molecular ion: C2D+5. In an ion storage ring experiment, the branching ratio for the process C2D+5 + e(-)-->C2D2 + D + D + D was determined to be 13%. This means that three covalent chemical bonds are broken as a result of the action of a single electron. This is the first time a four-body breakup of chemical bonds has been observed in a low-energy binary reaction.

Double-differential heavy-ion production cross sections

Current computational tools used for space or accelerator shielding studies transport energetic heavy ions either using a one-dimensional straight-ahead approximation or by dissociating the nuclei into protons and neutrons and then performing neutron and proton transport using Monte Carlo techniques. Although the heavy secondary particles generally travel close to the beam direction, a proper treatment of the light ions produced in these reactions requires that double-differential cross sections should be utilised. Unfortunately, no fundamental nuclear model capable of serving as an event generator to provide these cross sections for all ions and energies of interest exists currently. Herein, we present a model for producing double-differential heavy-ion production cross sections that uses heavy-ion fragmentation yields produced by the NUCFRG2 fragmentation code coupled with a model of energy degradation in nucleus-nucleus collisions and systematics of momentum distributions to provide energy and angular dependences of the heavy-ion production.

Double-differential light-ion production cross sections

Codes used for space radiation shielding studies typically transport light-ions from the incident cosmic ray spectrum using either a one-dimensional straight-ahead approximation or in three dimensions, often without accounting for their breakup. Light-ions are also produced by breakup of energetic heavy ions in target materials. Herein, we present cross section models that can be used to predict double-differential light-ion production cross sections. Deuteron breakup is based on a parameterization of the total reaction cross sections. Alpha fragmentation utilizes a parameterization based on an abrasion-ablation model that has been augmented by experimental data. Neutron and proton production is modelled with a quantum mechanical abrasion-ablation-coalescence model. This same model is also used to predict cross sections for triton and 3He breakup. Finally, energies and emission angles for particles other than nucleons are specified using a model of energy degradation in nucleus-nucleus collisions and systematics of momentum distributions.

Particle Formation by Ion Nucleation in the Upper Troposphere and Lower Stratosphere

Unexpectedly high concentrations of ultrafine particles were observed over a wide range of latitudes in the upper troposphere and lower stratosphere. Particle number concentrations and size distributions simulated by a numerical model of ion-induced nucleation, constrained by measured thermodynamic data and observed atmospheric key species, were consistent with the observations. These findings indicate that, at typical upper troposphere and lower stratosphere conditions, particles are formed by this nucleation process and grow to measurable sizes with sufficient sun exposure and low preexisting aerosol surface area. Ion-induced nucleation is thus a globally important source of aerosol particles, potentially affecting cloud formation and radiative transfer.

Effectiveness of Agency for Health Care Policy and Research clinical practice guideline and patient education methods for pregnant smokers in medicaid maternity care

OBJECTIVE

The purposes of this study were (1) to determine the extent to which tobacco exposure assessment and new patient education methods, derived from a meta-analysis and the Agency for Health Care Policy and Research guideline recommendations, could be provided routinely by trained Medicaid maternity care staff members and (2) to document the behavioral impact of these interventions among pregnant smokers.

STUDY DESIGN

After 265 pregnant smokers were assigned at their first visit to an experimental group (n = 139) or a control group (n = 126), they received standardized risk information and were advised to quit smoking. The experimental group also received evidence-based patient education methods, including the videocassette Commit to Quit During and After Pregnancy, the publication A Pregnant Woman's Guide to Quit Smoking, and a brief counseling session. Self-report and saliva cotinine assessments of tobacco exposure were performed at baseline and at the end of pregnancy.

RESULTS

A significantly higher percentage of patients quit smoking in the experimental group (17.3%) than in the control group (8.8%).

CONCLUSIONS

The application of principles of organizational development and quality improvement at the management and clinical practice levels and the delivery of evidence-based health education methods by trained prenatal care providers significantly increased smoking cessation rates among pregnant Medicaid recipients.

Enhancement of clinicians' diagnostic reasoning by computer-based consultation: a multisite study of 2 systems

CONTEXT

Computer-based diagnostic decision support systems (DSSs) were developed to improve health care quality by providing accurate, useful, and timely diagnostic information to clinicians. However, most studies have emphasized the accuracy of the computer system alone, without placing clinicians in the role of direct users.

OBJECTIVE

To explore the extent to which consultations with DSSs improve clinicians' diagnostic hypotheses in a set of diagnostically challenging cases.

DESIGN

Partially randomized controlled trial conducted in a laboratory setting, using a prospective balanced experimental design in 1995-1998.

SETTING

Three academic medical centers, none of which were involved in the development of the DSSs.

PARTICIPANTS

A total of 216 physicians: 72 at each site, including 24 internal medicine faculty members, 24 senior residents, and 24 fourth-year medical students. One physician's data were lost to analysis.

INTERVENTION

Two DSSs, ILIAD (version 4.2) and Quick Medical Reference (QMR; version 3.7.1), were used by participants for diagnostic evaluation of a total of 36 cases based on actual patients. After training, each subject evaluated 9 of the 36 cases, first without and then using a DSS, and suggested an ordered list of diagnostic hypotheses after each evaluation.

MAIN OUTCOME MEASURE

Diagnostic accuracy, measured as the presence of the correct diagnosis on the hypothesis list and also using a derived diagnostic quality score, before and after consultation with the DSSs.

RESULTS

Correct diagnoses appeared in subjects' hypothesis lists for 39.5% of cases prior to consultation and 45.4% of cases after consultation. Subjects' mean diagnostic quality scores increased from 5.7 (95% confidence interval [CI], 5.5-5.9) to 6.1 (95% CI, 5.9-6.3) (effect size: Cohen d = 0.32; 95% CI, 0.23-0.41; P<.001). Larger increases (P = .048) were observed for students than for residents and faculty. Effect size varied significantly (P<.02) by DSS (Cohen d = 0.20; 95% CI, 0.08-0.32 for ILIAD vs Cohen d = 0.45; 95% CI, 0.31-0.59 for QMR).

CONCLUSIONS

Our study supports the idea that "hands-on" use of diagnostic DSSs can influence diagnostic reasoning of clinicians. The larger effect for students suggests a possible educational role for these systems.

The effect of professional education on the knowledge and attitudes of physical therapist and occupational therapist students about acquired immunodeficiency syndrome

BACKGROUND AND PURPOSE

Anxiety and fear about caring for people with acquired immunodeficiency syndrome (AIDS) are concerns expressed by students in health care professions. This study was designed to evaluate the influence of education offered to physical therapist (PT) and occupational therapist (OT) students on their knowledge, attitudes, and willingness to provide services to people with AIDS.

SUBJECTS AND METHODS

Twenty-six undergraduate PT students and 23 undergraduate OT students completed a questionnaire at the beginning of their professional education program, following a 5-hour AIDS education seminar, and shortly before their graduation. The questionnaire consisted of 3 subscales designed to evaluate the respondents' knowledge, attitudes, and willingness to treat people with AIDS.

RESULTS

At the time of graduation, the students in both disciplines showed improvement in knowledge about AIDS (14.3% for PT students and 13.8% for OT students) and more positive attitudes toward people with AIDS (7.4% for PT students and 5% for OT students). In both disciplines, the students' willingness to provide services for people with AIDS remained unchanged following the AIDS education seminar and at the end of the professional education program.

CONCLUSION AND DISCUSSION

The professional education offered to the cohort of students in this study appeared to be beneficial in improving their knowledge and attitudes toward people with AIDS, but it did not affect their willingness to work with this patient group.

Bax deletion further orders the cell death pathway in cerebellar granule cells and suggests a caspase-independent pathway to cell death

Dissociated cerebellar granule cells maintained in medium containing 25 mM potassium undergo an apoptotic death when switched to medium with 5 mM potassium. Granule cells from mice in which Bax, a proapoptotic Bcl-2 family member, had been deleted, did not undergo apoptosis in 5 mM potassium, yet did undergo an excitotoxic cell death in response to stimulation with 30 or 100 microM NMDA. Within 2 h after switching to 5 mM K+, both wild-type and Bax-deficient granule cells decreased glucose uptake to <20% of control. Protein synthesis also decreased rapidly in both wild-type and Bax-deficient granule cells to 50% of control within 12 h after switching to 5 mM potassium. Both wild-type and Bax -/- neurons increased mRNA levels of c-jun, and caspase 3 (CPP32) and increased phosphorylation of the transactivation domain of c-Jun after K+ deprivation. Wild-type granule cells in 5 mM K+ increased cleavage of DEVD-aminomethylcoumarin (DEVD-AMC), a fluorogenic substrate for caspases 2, 3, and 7; in contrast, Bax-deficient granule cells did not cleave DEVD-AMC. These results place BAX downstream of metabolic changes, changes in mRNA levels, and increased phosphorylation of c-Jun, yet upstream of the activation of caspases and indicate that BAX is required for apoptotic, but not excitotoxic, cell death. In wild-type cells, Boc-Asp-FMK and ZVAD-FMK, general inhibitors of caspases, blocked cleavage of DEVD-AMC and blocked the increase in TdT-mediated dUTP nick end labeling (TUNEL) positivity. However, these inhibitors had only a marginal effect on preventing cell death, suggesting a caspase-independent death pathway downstream of BAX in cerebellar granule cells.

Inhibition of phosphatidylinositol 3-kinase activity blocks depolarization- and insulin-like growth factor I-mediated survival of cerebellar granule cells

Depolarizing concentrations of potassium promote the survival of many neuronal cell types including cerebellar granule cells. To begin to understand the intracellular mediators of neuronal survival, we have tested whether the survival-promoting effect of potassium depolarization on cerebellar granule cells is dependent on either mitogen-activated protein (MAP) kinase or phosphatidylinositol 3-kinase (PI-3-K) activity. In 7-day cerebellar granule cell cultures, potassium depolarization activated both MAP kinase and PI-3-K. Preventing the activation of MAP kinase with the MEK1 inhibitor PD98059 did not affect potassium saving. In contrast, the survival-promoting effect of 25 mM potassium was negated by the addition of 30 microM LY 294002 or 1 microM wortmannin, two distinct inhibitors of PI-3-K. The cell death induced by PI-3-K inhibition was indistinguishable from the cell death caused by potassium deprivation; LY 294002-induced death included nuclear condensation, was blocked by cycloheximide, and had the same time course as potassium deprivation-induced cell death. Cerebellar granule cells can also be maintained in serum-free medium containing either 100 ng/ml insulin-like growth factor I (IGF-I) or 800 microM cAMP. PI-3-K inhibition completely blocked the survival-promoting activity of IGF-I, but had no effect on cAMP-mediated survival. These data indicate that the survival-promoting effects of depolarization and IGF-I, but not cAMP, require PI-3-K activity.

Metabolic and genetic analyses of apoptosis in potassium/serum-deprived rat cerebellar granule cells

Cerebellar granule cells maintained in medium containing serum and 25 mM potassium undergo an apoptotic death within 96 hr when switched to serum-free medium with 5 mM potassium. Because large numbers of apparently homogeneous neurons can be obtained, this represents a potentially useful model of neuronal programmed cell death (PCD). Analysis of the time course and extent of death after removal of either serum or K+ alone demonstrated that a fast-dying (T(1/2) = 4 hr) population (20%) responded to serum deprivation, whereas a slow-dying (T(1/2) = 25 hr) population (80%) died in response to K+ deprivation. Taking advantage of the complete death after removing both K+ and serum, changes in metabolic events and mRNA levels were analyzed in this model. Glucose uptake, protein synthesis, and RNA synthesis fell to <35% of control by 9 hr after potassium/serum deprivation, a time when 85% of the cells were still viable. The pattern of the fall in these metabolic parameters was similar to that reported for trophic factor-deprived sympathetic neurons. Most mRNAs decreased markedly after K+/serum deprivation. Levels of c-jun mRNA increased fivefold in potassium/serum-deprived granule cells; c-jun is required for cell death of sympathetic neurons. mRNA levels of cyclin D1, c-myb, collagenase, and transin remained relatively constant in potassium/serum-deprived granule cells. These data demonstrate the existence of two populations of granule cells with respect to cell death and define common metabolic and genetic events involved in neuronal PCD.

Collaborative needs assessment and systems development in Alabama: Process and products

This article describes the implementation of a collaborative project and its results, involving a department of maternal and child health (DMCH) in a school of public health and a state department of public health. The state received a federal grant to enhance systems development for women and children. Adequate information regarding the existing system of health care was lacking. The state contracted with the DMCH for assistance in designing and conducting a needs assessment, whose purpose was to (1) identify strengths and weaknesses in the state system of care, (2) provide baseline information for targeting resources and measuring change, and (3) initiate an on-going process of assessment and evaluation of need. The DMCH collected data about financial and nonfinancial barriers to care from state-level health agency and organization experts, county-level service personnel, and consumers. The contributions to understanding the needs of the state offered by the information garnered in the three surveys helped the state in setting immediate and long-range objectives. The presence of the school of public health and the focus of its particular DMCH on assisting state agencies provided an atmosphere in which the state could ask for assistance and the university could respond in a way that was useful and relevant to the state's needs. Medical Subject Headings (MeSH): assessment, health planning, health priorities, interprofessional relations, program planning, public health.

Design and Application of Electron-Transporting Organic Materials

Operating lifetime is the main problem that complicates the use of polymeric light-emitting diodes (LEDs). A class of electron transport (ET) polymers [poly(aryl acrylate) and poly(aryl ether)s] is reported in which moieties with high electron affinities are covalently attached to stable polymer backbones. Devices based on poly(p-phenylenevinylene) (PPV) prepared with these materials exhibited a 30-fold improvement in stability and, in one case, dramatically lower (10 volts versus about 30 volts) operating voltage relative to those having conventional ET layers. The current-carrying capacity of indium tin oxide-PPV-polymeric ET layer-aluminum LEDs was also increased by a factor of 30. These improvements lead to an enhancement in power efficiency of nearly an order of magnitude. Choosing polymers with high glass transition temperatures increases device lifetime.

Maturational asynchrony between oocyte cumulus-coronal morphology and nuclear maturity in gonadotropin-releasing hormone agonist stimulations

OBJECTIVE

To determine oocyte meiotic maturity and asynchrony between cumulus-coronal morphology and nuclear maturity after gonadotropin-releasing hormone agonist (GnRH-a) and norethindrone-programmed stimulations.

DESIGN

Oocyte meiotic maturity was evaluated at follicular aspiration in 4,961 oocytes after GnRH-a/follicle-stimulating hormone (FSH)/human menopausal gonadotropin stimulations (hMG) for in vitro fertilization patients and 299 oocytes after norethindrone-programmed clomiphene citrate (CC)/hMG in oocyte donors. Maturational asynchrony between the oocyte's cumulus-coronal morphology and nuclear maturity was evaluated in 2,336 oocytes.

SETTING

In vitro fertilization program at the University of Iowa Hospitals and Clinics; academic tertiary care center.

INTERVENTIONS

After evaluating oocyte cumulus-coronal maturity, cumulus masses were spread to determine oocyte nuclear maturity.

RESULTS

Fourteen percent, 17%, 50%, 17%, and 2% of oocytes were prophase I, metaphase I, metaphase II, postmature metaphase II, and atretic, respectively. Asynchrony was noted in 28% of prophase I, 71% of metaphase I, 11% of metaphase II, 45% of postmature metaphase II, 32% of atretic, and 28% of all oocytes. Significant differences were not found between GnRH-a and norethindrone-programmed stimulations in asynchrony between cumulus-coronal morphology and nuclear maturity or percentage of prophase I, metaphase I, metaphase II, postmature metaphase II, or atretic oocytes. Sixty-seven percent of oocytes possessed a polar body at retrieval. The rate of fertilization was significantly higher for metaphase II oocytes than postmature metaphase II and metaphase I oocytes > prophase I oocytes. Parthenogenetic activation tended to be highest for postmature metaphase II oocytes. Embryo cleavage was significantly higher for postmature metaphase II, metaphase II, and metaphase I oocytes than for prophase I oocytes.

CONCLUSIONS

This is the first report of asynchrony between cumulus-coronal morphology and nuclear maturity at follicular aspiration in GnRH-a and norethindrone-programmed stimulations. Asynchrony was observed in 28% of oocytes. A higher percentage of oocytes possessed a polar body at egg retrieval with these stimulation regimens compared with rates reported previously for FSH, FSH/hMG, and CC/hMG stimulations.

Prediction of nuclear maturity from cumulus-coronal morphology: influence of embryologist experience

PURPOSE

A majority of in vitro fertilization (IVF) programs continues to evaluate oocyte maturity on the basis of cumulus-coronal morphology (CCM) even though marked asynchrony has been reported between CCM and nuclear maturity. This study was designed to examine changes in embryologists' ability to correctly predict nuclear maturity from CCM as a function of increasing experience. Nuclear maturity was assessed by inverted microscopy with a modified spreading technique at follicular aspiration. A second objective was to determine the percentage of oocytes which displayed asynchrony between CCM and nuclear maturity as assessed by embryologists with extensive experience in oocyte maturity evaluation.

RESULTS

The three participating embryologists had directly evaluated 1304, 75, and 0 oocytes for nuclear maturity and CCM at study initiation and correctly predicted nuclear maturity from CCM in 74, 64, and 47% of oocytes, respectively. Embryologist 1 did not significantly change in predictive ability during the 17-month study period. Embryologist 2 significantly improved in predictive ability during the first 9 months of the study (841 oocytes evaluated) and plateaued thereafter, at a similar percentage of correct predictions as embryologist 1. Embryologist 3 continued to improve in predictive ability throughout the study period, reaching 61% correct predictions at the close of the study after evaluating 223 oocytes. Once embryologists had plateaued in their predictive ability, 72% of oocytes evaluated received the correct nuclear maturity classification based on CCM. Significantly fewer oocytes (54%; 375/690) evaluated by embryologists who had not plateaued in their predictive ability received the correct nuclear maturity classification based on CCM.

CONCLUSIONS

These results indicate that embryologists' ability to predict oocyte nuclear maturity correctly from CCM continues to change over several months even when pretraining video recordings are used before beginning direct evaluations. After embryologists plateaued in their predictive ability, nuclear maturity still could not be correctly predicted from CCM in 28% of oocytes due to asynchrony between nuclear and CCM maturity. Based upon this, circumstances in which the spreading technique should be used for direct assessment of nuclear maturity as opposed to assessment of CCM only are discussed.

Identification and characterization of an actin-binding site of CapZ

A mAb (1E5) that binds the COOH-terminal region of the beta subunit of chicken CapZ inhibits the ability of CapZ to bind the barbed ends of actin filaments and nucleate actin polymerization. CapZ prepared as fusion proteins in bacteria or nonfusion proteins by in vitro translation has activity similar to that of CapZ purified from muscle. Deletion of the COOH-terminus of the beta subunit of CapZ leads to a loss of CapZ's ability to bind the barbed ends of actin filaments. A peptide corresponding to the COOH-terminal region of CapZ beta, expressed as a fusion protein, binds actin monomers. The mAb 1E5 also inhibits the binding of this peptide to actin. These results suggest that the COOH-terminal region of the beta subunit of CapZ is an actin- binding site. The primary structure of this region is not similar to that of potential actin-binding sites identified in other proteins. In addition, the primary structure of this region is not conserved across species.

Treatment of severe male-factor infertility with high concentrations of motile sperm by microinsemination in embryo cryopreservation straws

A microinsemination technique was evaluated for treating our program's most severe cases of male-factor infertility. Oocytes were inseminated with high concentrations of motile sperm (1 to 9 x 10(6)/ml) in 10 to 150 microliters within embryo cryopreservation straws. Fertilization was obtained in 20 of 29 (69%) couples treated by this technique. In the 15 patients in which only embryos generated from the straw technique were transferred, 7 clinical pregnancies resulted (46.7% per transfer). The implantation rate for couples receiving embryos from the straw technique only (12/58; 20.7%) compared favorably to that observed for other cases treated during this same time period with regular insemination techniques (111/766; 14.5%). Clinical pregnancy rates per transfer for IVF-ET, TET, and PROST were 33.0% (1/3), 0% (0/2), and 60.0% (6/10), respectively. The percentage of polyploidic embryos was significantly lower (P less than 0.0001) for male-factor patients treated by the straw technique with high sperm concentrations than for non-male-factor patients treated during this same time period with standard sperm concentrations. Normal births have resulted from straw inseminations with 3.4 x 10(6) and ongoing pregnancies with 5.0 x 10(6) motile sperm/ml. The results of this study suggest that some cases of male-factor infertility can be successfully treated by insemination with high concentrations of motile sperm in embryo cryopreservation straws. A technique of centrifuging sperm in straws was also developed to concentrate the entire fraction of washed sperm into 10 microliters. Further development of this technique may allow treatment of more severe cases of oligo/asthenospermia by microinsemination with high concentrations of motile sperm than is presently possible with standard washing techniques.

Human alpha- and gamma-thrombin specificity with tripeptide p-nitroanalide substrates under physiologically relevant conditions

Kinetic parameters [the Michaelis-Menten (Km), catalytic (kcat), and specificity (kcat/Km) constants] were determined for human alpha- and gamma-thrombins with the chromogenic substrate S-2238 (H-D-Phe-Pip-Arg-p-nitroanilide), Chromozym-TH (Tos-Gly-Pro-Arg-p-nitroanilide), and Spectrozyme-TH (H-D-HHT-Ala-Arg-p-nitroanilide) under physiologically relevant conditions (0.15 M NaCl buffered with 10 mM HEPES and 10 mM Tris-HCL, pH 7.4 at 37 degrees C). No major differences were found between alpha-thrombin with high fibrinogen clotting activities (greater than 3,500 killo clotting units/g) and gamma-thrombin with essentially no clotting activities (less than 10 kCU/g), although the Km values and in most cases kcat values for alpha-thrombin were slightly lower than for the gamma-thrombin. At 37 degrees C, relative to 23 degrees C, Km values increased 2-fold for S-2238, approximately 1.5-fold for Chromozym-TH, and remained essentially the same for Spectrozyme-TH (e.g., reciprocal substrate binding), whereas the kcat values increased for all 3 substrates (e.g., enzyme turnover). This caused kcat/Km values to decrease slightly for S-2238, remain the same for Chromozym-TH, and increase for Spectrozyme-TH (e.g., enzyme efficiency). Since spontaneous hydrolysis was not limiting at 37 degrees C, assays employing these substrates may be satisfactorily performed under physiologically relevant conditions. Under these conditions, kcat/Km ratios for the 3 substrates are similar to that for the A alpha cleavage in fibrinogen by alpha-thrombin.

The effect of pulse-modulated thermal radiation on the time-intensity relationship for dermal pain

A simple experimental model was used to examine the relationship between modulation and hazard for thermal bioelectromagnetic effects. The inner forearms of 11 human volunteers were exposed to continuous and pulse-modulated thermal radiation from an incandescent light source. The time of irradiation required to produce threshold pain sensation was measured as a function of the average power density (450-2500 m W cm-2), pulse repetition frequency (continuous, 0.4 Hz, 8.0 Hz) and duty cycle (continuous, 0.33, 0.50). The resulting 32 sets of data could be described by a single power function expression which relates time and power density through a regression slope. The slope was found to depend on the modulation of the radiation, but not on the age of the subject or wet bulb globe temperature (WBGT). The minimum average power density which could elicit pain within 200 sec (an effective threshold intensity) was determined to be independent of modulation, regression slope, subject age and WBGT.

Evidence for two physiologically distinct gap junctions expressed by the chick lens epithelial cell

Lens epithelial cells communicate with two different cell types. They communicate with other epithelial cells via gap junctions on their lateral membranes, and with fiber cells via junctions on their apices. We tested independently these two routes of cell-cell communication to determine if treatment with a 90% CO2-equilibrated medium caused a decrease in junctional permeability; the transfer of fluorescent dye was used as the assay. We found that the high-CO2 treatment blocked intraepithelial dye transfer but not fiber-to-epithelium dye transfer. The lens epithelial cell thus forms at least two physiologically distinct classes of gap junctions.

Gap junction structures after experimental alteration of junctional channel conductance

Gap junctions are known to present a variety of different morphologies in electron micrographs and x-ray diffraction patterns. This variation in structure is not only seen between gap junctions in different tissues and organisms, but also within a given tissue. In an attempt to understand the physiological meaning of some aspects of this variability, gap junction structure was studied following experimental manipulation of junctional channel conductance. Both physiological and morphological experiments were performed on gap junctions joining stage 20-23 chick embryo lens epithelial cells. Channel conductance was experimentally altered by using five different experimental manipulations, and assayed for conductance changes by observing the intercellular diffusion of Lucifer Yellow CH. All structural measurements were made on electron micrographs of freeze-fracture replicas after quick-freezing of specimens from the living state; for comparison, aldehyde-fixed specimens were measured as well. Analysis of the data generated as a result of this study revealed no common statistically significant changes in the intrajunctional packing of connexons in the membrane plane as a result of experimental alteration of junctional channel conductance, although some of the experimental manipulations used to alter junctional conductance did produce significant structural changes. Aldehyde fixation caused a dramatic condensation of connexon packing, a result not observed with any of the five experimental uncoupling conditions over the 40-min time course of the experiments.

Oxygen deficiency hazards associated with liquefied gas systems: derivation of a program of controls

The use of liquefied gases in industry and research has become commonplace. Release into the atmosphere of these gases will result in a displacement of air and a reduction in the oxygen concentration. Exposure to reduced levels of oxygen may cause reduced abilities, unconsciousness or death. This paper describes the derivation of a novel program of controls for oxygen deficiency hazards. The key to this approach is a quantitative assessment of risk for each planned operation and the application of control measures to reduce that risk to an acceptable level. Five risk levels evolve which are based on the probability of fatality. Controls such as training, oxygen monitoring equipment, self-rescue respirators and medical surveillance are required when the probability of fatality exceeds 10(-7) per hour. The quantitative nature of this program ensures an appropriate level of control without undue burden or expense.

Endocytosis of synaptic vesicle membrane at the frog neuromuscular junction

Frog nerve-muscle preparations were quick-frozen at various times after a single electrical stimulus in the presence of 4-aminopyridine (4-AP), after which motor nerve terminals were visualized by freeze-fracture. Previous studies have shown that such stimulation causes prompt discharge of 3,000-6,000 synaptic vesicles from each nerve terminal and, as a result, adds a large amount of synaptic vesicle membrane to its plasmalemma. In the current experiments, we sought to visualize the endocytic retrieval of this vesicle membrane back into the terminal, during the interval between 1 s and 2 min after stimulation. Two distinct types of endocytosis were observed. The first appeared to be rapid and nonselective. Within the first few seconds after stimulation, relatively large vacuoles (approximately 0.1 micron) pinched off from the plasma membrane, both near to and far away from the active zones. Previous thin-section studies have shown that such vacuoles are not coated with clathrin at any stage during their formation. The second endocytic process was slower and appeared to be selective, because it internalized large intramembrane particles. This process was manifest first by the formation of relatively small (approximately 0.05 micron) indentations in the plasma membrane, which occurred everywhere except at the active zones. These indentations first appeared at 1 s, reached a peak abundance of 5.5/micron2 by 30 s after the stimulus, and disappeared almost completely by 90 s. Previous thin-section studies indicate that these indentations correspond to clathrin-coated pits. Their total abundance is comparable with the number of vesicles that were discharged initially. These endocytic structures could be classified into four intermediate forms, whose relative abundance over time suggests that, at this type of nerve terminal, endocytosis of coated vesicles has the following characteristics: (a) the single endocytotic event is short lived relative to the time scale of two minutes; (b) earlier forms last longer than later forms; and (c) a single event spends a smaller portion of its lifetime in the flat configuration soon after the stimulus than it does later on.

An empirical time-intensity relationship for thermal bioelectromagnetic effects

Published experimental data for three thermal/harmful bioelectromagnetic effects (lethality, cataractogenesis, and threshold pain sensation) are examined in an effort to develop a generally consistent empirical expression relating the time of irradiation necessary to induce an effect to the intensity of the radiation. A critical organ is assigned to each effect and the SAR's in these organs are estimated, when necessary, from the incident power density. It is found that all the data can be satisfactorily described by a single power function expression which gives the exposure duration as a function of the SAR in the critical organ and an experiment-specific constant.

Survey on body image, weight, and diet of college students

In this study, college students visiting a university health service were categorized according to various anthropometric measurements and completed a questionnaire. Fifty-five per cent of the men were realistic in their self-perception of body size, but 63 per cent of the women perceived themselves to be one category of weight higher than they actually were. Fifty-six per cent of the students sampled (but only 60 per cent of those who were dissatisfied with their body images) said they were modifying their eating practices. The majority of students were realistic in their goals for weight loss, but 46 per cent of the women wanted to be underweight or slightly underweight.