2,236 research outputs found
Stability of Glutamate-Aspartate Cardioplegia Additive Solution in Polyolefin IV Bags
Objective: Glutamate-aspartate cardioplegia additive solution (GACAS) is used to enhance myocardial preservation and left ventricular function during some cardiac surgeries. This study was designed to evaluate the stability of compounded GACAS stored in sterile polyolefin intravenous (IV) bags. The goal is to extend the default USP beyond-use date (BUD) and reduce unnecessary inventory waste.
Methods: GACAS was compounded and packaged in sterile polyolefin 250 mL IV bags. The concentration was 232 mM for each amino acid. The samples were stored under refrigeration (2°C-8°C) and analyzed at 0, 1, and 2 months. At each time point, the samples were evaluated by pH measurement and visual inspection for color, clarity, and particulates. The samples were also analyzed by high-performance liquid chromatography (HPLC) for potency and degradation products. Due to the lack of ultraviolet (UV) chromophores of glutamate and aspartate, the samples were derivatized by ortho-phthalaldehyde prior to HPLC analysis.
Results: The time zero samples of GACAS passed the physical, chemical, and microbiological tests. Over 2 months of storage, there was no significant change in pH or visual appearance for any of the stability samples. The HPLC results also indicated that the samples retained 101% to 103% of the label claim strengths for both amino acids.
Conclusion: The physical and chemical stability of extemporaneously prepared GACAS has been confirmed for up to 2 months in polyolefin IV bags stored under refrigeration. With proper sterile compounding practice and microbiology testing, the BUD of this product can be extended to 2 months
Fallout from U.S. atmospheric nuclear tests in New Mexico and Nevada (1945-1962)
One hundred and one atmospheric nuclear weapon tests were conducted between
1945 and 1962 in the United States, resulting in widespread dispersion of
radioactive fallout, and leading to environmental contamination and population
exposures. Accurate assessment of the extent of fallout from nuclear weapon
tests has been challenging in the United States and elsewhere, due to limited
monitoring and data accessibility. Here we address this deficit by combining
U.S. government data, high-resolution reanalyzed historical weather fields, and
atmospheric transport modeling to reconstruct radionuclide deposition across
the contiguous United States, with 10-kilometer spatial and one-hour temporal
resolution for five days following detonation, from all 94 atmospheric tests
detonated in New Mexico and Nevada with fission yields sufficient to generate
mushroom clouds. Our analysis also includes deposition estimates for 10 days
following the detonation of Trinity, the first ever nuclear weapon test, on
July 16, 1945. We identify locations where radionuclide deposition
significantly exceeded levels in areas covered by the U.S. Radiation Exposure
Compensation Act (RECA). These findings include deposition in all 48 contiguous
U.S. states. They provide an opportunity for re-evaluating the public health
and environmental implications from atmospheric nuclear testing. Finally, our
findings also speak to debates about marking the beginning of the Anthropocene
with nuclear weapons fallout. Our deposition estimates indicate that direct
fallout from Trinity, a plutonium device, reached Crawford Lake in Canada, the
proposed "golden spike" site marking the beginning of the Anthropocene epoch,
starting on July 20, 1945.Comment: 19 pages, 4 figures, 1 supplementary table, 3 supplementary figure
Evidence for cooperative interactions between the two motor domains of cytoplasmic dynein
AbstractCytoplasmic dynein is a force-transducing ATPase that powers the movement of cellular cargoes along microtubules. Two identical heavy chain polypeptides (> 500 kDa) of the cytoplasmic dynein complex contain motor domains that possess the ATPase and microtubule-binding activities required for force production [1]. It is of great interest to determine whether both heavy chains (DHCs) in the dynein complex are required for progression of the mechanochemical cycle and motility, as observed for other dimeric motors. We have used transgenic constructs to investigate cooperative interactions between the two motor domains of the Drosophila cytoplasmic dynein complex. We show that 138 kDa and 180 kDa amino-terminal fragments of DHC can assemble with full-length DHC to form heterodimeric complexes containing only a single motor domain. The single-headed dynein complexes can bind and hydrolyze ATP, yet do not show the ATP-induced detachment from microtubules that is characteristic of wild-type homodimeric dynein. These results suggest that cooperative interactions between the monomeric units of the dimer are required for efficient ATP-induced detachment of dynein and unidirectional movement along the microtubule
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Lack of Awareness of Partner STD Risk Among Heterosexual Couples
CONTEXT: Individualsâ accurate assessment of their exposure to the risk of HIV and other STDs requires awareness of their sexual partnersâ risk behaviors and disease status.
METHODS: In a sample of 217 couples enrolled in a risk intervention trial in 1997â2002, both partners reported on their own risk behaviors and their perceptions of their partner's behavior; concordance of partnersâ reports was examined using kappa statistics. Individual and relationship characteristics predicting lack of awareness of a partner's risk behavior were explored using multivariate logistic regression.
RESULTS: Three percent of women and 14% of men were unaware that their partner had recently had a concurrent partner. Eleven percent and 12%, respectively, were unaware that their partner had ever injected drugs; 10% and 12% were unaware that their partner had recently received an STD diagnosis; and 2% and 4% were unaware that their partner was HIVâpositive. Women's lack of awareness of partner risk was associated with increasing age (odds ratio, 1.1), being of a race or ethnicity other than black or Latina (15.8) and having a Latino partner (3.7); it was positively associated with a man's report that he was married (4.4) and with relationship satisfaction as reported by both the woman and her partner (1.2 for each). Among men, lack of awareness was positively associated with partner's age (1.1) and with having a partner who was formerly married (8.2).
CONCLUSIONS: Coupleâbased interventions that assess each partner's awareness of the other's risk behavior may help programs better target couplesâ STD prevention needs
Intimate Partner Violence and HIV Among Drug-Involved Women: Contexts Linking These Two EpidemicsâChallenges and Implications for Prevention and Treatment
Intimate partner violence (IPV) and HIV are two serious overlapping public health epidemics that disproportionately affect drug-involved women. This article reviews research that has identified a number of contexts that may explain the links between IPV and HIV transmission risks. These contexts include sexual coercion, fear of violence, negotiation of condom use, extra dyadic relationships, disclosure of sexually transmitted infections or HIV seropositivity to intimate partners, drug involvement of women and their male partners, low social status of drug-involved women, relationship dependencies, and sex ratio imbalances. The article focuses on how the bidirectional relationship between IPV and HIV risks may be mediated by a history of childhood sexual abuse and post-traumatic stress disorder. Also addressed are the challenges that substance user treatment programs face in dealing with female clients who experience IPV and the implications for HIV prevention
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Predictors of Discordant Reports of Sexual and HIV/Sexually Transmitted Infection Risk Behaviors Among Heterosexual Couples
Objectives: Assessments undertaken as part of couple-based HIV/sexually transmitted infection (STI) prevention intervention studies offer opportunities to expand our understanding of couple reporting of sexual and HIV/STI risk behavior. Increases in heterosexual transmission of HIV worldwide support more attention on the quality and use of couple-level sexual risk assessment.
Study Design: This study examined interpartner concordance of self-reported sexual behaviors and HIV/STI risk behaviors among 217 women and their main male sexual partners at high risk for HIV/STI transmission and further explored specific individual and relationship characteristics by partner gender associated with discordant reporting of sexual and HIV/STI risk behaviors.
Results: Consistent with prior studies, findings suggest fair to substantial agreement between partners on reports of most sexual and HIV/STI risk behavior, but only poor to fair agreement on reports of concurrent sexual behaviors and drug or alcohol use. Factors significantly associated with discordant reporting of sexual behaviors included length of couple relationship, level of relationship satisfaction, female partnerâs marital status, and male partnerâs HIV status, ethnicity, and age.
Conclusions: Individual- and relationship-level factors predicting discordant partner reports of sexual and sexual risk behaviors highlight an opportunity to improve couple assessment by anticipating such discrepancies and developing effective mechanisms of quality assurance to avoid, address, or better explain such discordance in couple data sets
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Enrollment of minority women and their main sexual partners in an HIV/STI prevention trial
There is a paucity of empirical reports that quantitatively assess the success of recruitment strategies in randomized clinical trials (RCTs) using sampling units other than the individual. As innovations in HIV and sexually transmitted infection (STI) preventive intervention protocols and targets of change evolve, there is a need to examine the efficacy of attendant adaptations to recruitment protocols and strategies in the enrollment of study participants. This article examines factors related to enrollment of women and their main, male sexual partners in an RCT of a relationshipâbased HIV/STI preventive intervention conducted from 1997 to 2001. Among eligible participants (N = 388), findings indicate that race/ethnicity, employment status, marital status, and language preference were significantly associated with enrollment among eligible, potential participants. Additionally, being HIVâpositive and having a past or current STI were significantly associated with enrollment. These findings underscore the need to ensure sufficient representation of all risk groups in RCTs, especially those testing innovative HIV/STI preventive intervention approaches or using novel enrollment strategies
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Promoting Female Condom Use to Heterosexual Couples: Findings from a Randomized Clinical Trial
CONTEXT: The female condom remains the only femaleâinitiated method for preventing pregnancy and STDs, including HIV. Innovative methods for promoting its use, and for involving male partners in its use, are needed.
METHODS: A sample of 217 women and their main male sexual partners were randomly assigned to one of three study conditions: a sixâsession relationshipâbased STD prevention intervention provided to the couple together, the same intervention provided to the woman only or a singleâsession education control provided to the woman only. Assessments were conducted at baseline and three months postintervention. Contrast coding was used to examine whether the effects of the two active interventions differed from those of the control intervention, and whether the effects of the two active interventions differed from each other. Regression analyses were used to estimate treatment effects.
RESULTS: During followâup, participants in either active intervention were more likely to use a female condom with their study partner and with all partners, and used female condoms at a higher rate with all partners, than individuals assigned to the control intervention; at the end of three months, they were more likely to intend to use the condom in the next 90 days. No significant differences in outcomes were found between the active intervention groups.
CONCLUSIONS: Focusing on both a woman and her main male sexual partner is efficacious in increasing female condom use and intention to use among heterosexual couples at risk for HIV and other STDs
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