溶液粘度影响聚合物角膜滞留时间的体外评价

目的比较水溶性聚合物的角膜滞留能力,评价溶液粘度对其角膜滞留时间的影响,为眼用液体制剂的处方设计提供参考。方法用束缚泡技术,以接触角的连续变化为指征,在模拟生理条件下考察聚合物从离体眼球表面解吸附的动力学过程。结果卡波姆、透明质酸钠(HA)、羟丙基甲基纤维素、聚乙烯醇和羧甲基纤维素钠(CMC-Na)的角膜滞留能力有显著差异,其中卡波姆和HA吸附于离体眼球表面达15 min以上,显示出较好的生物粘附性。溶液粘度由12 mPa·s增大至50 mPa·s,卡波姆和HA的角膜滞留时间分别延长10 min和7 min,而CMC-Na的角膜滞留时间未受影响。结论体外实验结果表明,适当提高溶液粘度能够延长生物粘附性聚合物在角膜表面的滞留时间。     

The Bilayer Floating Capsule: A Stomach-Directed Drug Delivery System for Misoprostol

A bilayer floating dosage unit is proposed to achieve local delivery of misoprostol, a prostaglandin E₁ analogue, at the gastric mucosa level. The system is a capsule consisting of a floating layer maintaining the dosage unit buoyant upon the gastric content and a drug layer formulated to act as a sustained-delivery system. The differential design of the two layers allows the optimization of both floating capability and drug release profile. The layers are both composed of a hydrophilic matrix based upon hydroxypropylmethyl cellulose (HPMC). Parameters influencing the release profiles are described. The use of a large capsule increases the gastric residence time (GRT), as it impedes passage through the pylorus opening. -Scintigraphic studies were performed to visualize cohesion of the two layers in vivo and to determine GRT as a function of meal regimen. The average GRTs were 199 ± 69 min after a single meal (breakfast) and 618 ± 208 min after a succession of meals.     

Does social isolation,social support or loneliness influence health or well-being after a cardiovascular disease event? A narrative thematic systematic review

Identification of factors which influence health after a cardiovascular disease (CVD) event will assist with reducing the high health and economic burden of CVD. We undertook a systematic review to investigate the association between social health (lower social isolation, higher social support and lower loneliness) and health and well-being after a CVD event among people living in Australia and New Zealand. Four electronic databases were systematically searched until June 2020. Two reviewers undertook title/abstract screen. One reviewer undertook full-text screen and data extraction. A second author either independently extracted or checked data. Narrative thematic analysis was undertaken. Of the 752 unique records retrieved, 39 papers from 29 studies met our inclusion criteria. Included studies recruited between 10 and 1,455 participants, aged 12–96 years, and the majority were male. Greater social health was consistently associated with better mental health outcomes (lower depressive symptoms, anxiety symptoms and psychological distress). Lower social isolation and higher social support were associated with the extent to which patient needs were being met. Living situation was not associated with mental health outcomes, and being married or living with someone was associated with greater medication adherence. Our systematic review demonstrates that greater social health is associated with better mental health outcomes and met patient needs among cardiac patients. As partner status and living status did not align with social isolation and social support findings in this review, we recommend they not be used as social health proxies when assessing health outcomes among CVD patients. Our review highlights the need for more research focused on women and the importance of gender-disaggregated reporting. Further assessment is required to evaluate whether loneliness is associated with health and well-being outcomes after a CVD event.     

基于停留时间分布的气流床气化炉通用网络模型

气流床气化炉的数学模型是气化装置设计和操作优化的基础,气固停留时间分布是影响气流床气化炉出口组成和碳转化率的关键因素。以气固停留时间分布为依据,结合反应动力学建立气流床气化炉的通用网络模型,模拟值与工业值吻合。对于神府煤,考察了氧煤比改变对气化结果的影响,结果表明：最佳氧煤比（氧气体积与煤（干基）质量之比）期望值约为0.655 Nm3/kg,生产中为保证液态排渣,氧煤比应控制在0.663 Nm3/kg左右。该通用网络模型计算速度快,适用于建立气化炉的动态模型。     

BO-0742, a derivative of AHMA and N-mustard,has selective toxicity to drug sensitive and drug resistant leukemia cells and solid tumors

This is a preclinical study of BO-0742, a derivative of 3-(9-acridinylamino)-5-hydroxymethyl-aniline (AHMA) and N-mustard, as an anti-cancer agent. MTS assays revealed a broad spectrum of anti-cancer activities in vitro, with the greatest cytotoxicity against leukemia and neuroblastoma including those with drug resistant characteristics, and a good therapeutic index with leukemia being 10–40 times more sensitive to BO-0742 than hematopoietic progenitors. Administration of BO-0742 at an optimal dose schedule based on its pharmacokinetics significantly suppressed the growth of xenografts of human breast and ovarian cancers in mice. Thus, BO-0742 is a potent anti-cancer agent worthy of further clinical development.     

Associations between neighbourhood characteristics and community mobility in older adults with chronic health conditions

Purpose: To explore associations between perceptions of neighbourhood built and social characteristics and satisfaction with community mobility in older adults with chronic health conditions. Method: Two hundred and thirty-seven community-dwelling adults aged 60 years or more with one or more of arthritis (osteoarthritis or rheumatoid arthritis), chronic obstructive pulmonary disease, diabetes or heart disease completed a cross-sectional, mailed survey. The survey addressed community mobility and 11 neighbourhood characteristics: amenities (three types), problems (six), social cohesion and safety. Analysis involved logistic regression modeling for each neighbourhood characteristic. Results: Satisfaction with community mobility was associated with perception of no traffic problems (OR?=?3.0, 95% CI?=?1.4–6.2, p?≤?0.05) and neighbourhood safety (OR?=?3.4, 95% CI?=?1.2–9.8, p?≤?0.05), adjusted for age, ability to walk several blocks and depressive symptoms.

Conclusion: Satisfaction with community mobility is associated with neighbourhood safety and no traffic problems among older adults with chronic conditions. While further research is needed to explore these neighbourhood characteristics in more detail and to examine causation, addressing these neighbourhood characteristics in health services or community initiatives may help promote community mobility in this population.

• Implications for Rehabilitation

• Community mobility, or the ability to move about one’s community, is a key aspect of participation that enables other aspects of community participation.

• Good community mobility is associated with perception of no traffic problems and neighbourhood safety among older adults.

• Considering and addressing a broad range of environmental influences has the potential to improve community mobility in older adults, beyond traditional approaches.

• Health professionals can work with clients to develop strategies to avoid traffic and safety problems and can work with communities to develop safe spaces within neighbourhoods, to improve community mobility in older adults.

     

Racial disparities in the use of hospice services according to geographic residence and socioeconomic status in an elderly cohort with nonsmall cell lung cancer

BACKGROUND:

The authors investigated whether there were racial disparities in the receipt of hospice services within geographic residence and socioeconomic status (SES) levels.

METHODS:

In total, 117,894 patients aged ≥66 years with nonsmall cell lung cancer (NSCLC) were identified from the Surveillance, Epidemiology, and End Results‐Medicare linked database who had received hospice services in the last 6 months before death and who died between January 1, 1991 and December 31, 2005. Multivariate odds ratios (ORs) with 95% confidence intervals (CIs) using mixed‐effects logistic regression models were used to describe relations.

RESULTS:

In urban areas, there were significant disparity trends in age/sex‐adjusted rates for blacks and Asians/Pacific Islanders compared with whites (P = .003 and P = .036, respectively). Blacks (OR, 0.79; 95% CI, 0.75‐0.82), Asians/Pacific Islanders (OR, 0.42; 95% CI, 0.39‐0.46), and Hispanics (OR, 0.81; 95% CI, 0.73‐0.91) were less likely to receive hospice services. In rural areas, blacks were 21% less likely to receive hospice services (OR, 0.79; 95% CI, 0.63‐0.98). Patients in the poorest socioeconomic status (SES) quartile were 7% less likely to receive hospice services (OR, 0.93; 95% CI, 0.86‐1.00). Moreover, within stratified SES quartiles, blacks and Asians/Pacific Islanders had lower receipt of hospice services, and Asians/Pacific Islanders were the least likely to receive hospice services, particularly those in the poorest SES quartile. In general, older patients and women were more likely to receive hospice services.

CONCLUSIONS:

There were substantial disparities in the receipt of hospice services among ethnic minorities within urban and rural areas and within SES levels. The results indicated that efforts are needed to identify barriers, enhance support, and educate patients on the benefits of hospice services. Cancer 2010. © 2010 American Cancer Society.     

Needle Sharing Among Puerto Rican Injection Drug Users in Puerto Rico and Massachusetts: Place of Birth and Residence Matter

This study explored whether place of birth and residence was associated with needle sharing for Puerto Rican injection drug users (IDUs) (N = 348). In-person interviews were conducted in Puerto Rico and Massachusetts during 2005–2007. Multivariate regression analyses revealed IDUs born and living in Puerto Rico were four times more likely to have shared needles compared to those residing in Massachusetts. Respondents residing in Massachusetts were 76% less likely to have ever shared needles with an HIV-positive individual, controlling for covariates. Findings highlight the increased HIV-risk of Puerto Rican IDUs born and residing in Puerto Rico. Prevention and treatment needs are discussed.     

Stomach-Specific Anti-H. pylori Therapy. II. Gastric Residence Studies of Tetracycline-Loaded Chitosan Microspheres in Gerbils

This study examines the gastric residence of chitosan microspheres and the local tetracycline concentrations following oral administration in gerbils. Chitosan microspheres were prepared by ionic cross-linking and precipitation with sodium sulfate. Gastric retention studies were performed by administering radioiodinated [¹²⁵I] chitosan microsphere suspension in the nonacid-suppressed and acid-suppressed states. At different time points, animals were sacrificed, and the radioactivity in tissues and fluids was measured with a gamma counter. Local tetracycline concentrations were measured using chitosan microspheres loaded with tritiated-[³H]-tetracycline. The radioactivity, measured with a liquid scintillation analyzer, was used to determine the μg of drug per gram of tissues or fluids under nonacid-suppressed and acid-suppressed states. Microspheres with a spherical shape and an average diameter of 2.0–3.0 μm were formed. After 2 hr in the fasted stomach, approximately 10% of the administered dose remained. The microspheres were predominantly found in the colon after 6 hr of administration. There was no detectable radioactivity in the small intestine, plasma, urine, liver, and kidneys. Additionally, acid suppression with ranitidine did not influence the gastric residence time of chitosan microspheres. To our disappointment, tetracycline concentration profile in the stomach from microsphere formulation was similar to the aqueous solution. Also, there was no significant difference between the stomach tetracycline concentrations in the nonacid-suppressed and acid-suppressed states. The drug was predominantly found in the colon and urine samples after 6 hr. Tetracycline could not be detected in the plasma, small intestine, liver, or kidneys. Results of this study show that chitosan microspheres prepared by ionic cross-linking do not provide a longer residence time in the fasted gerbil stomach. The tetracycline concentration profile in the stomach, following administration in microsphere formulation, was similar to that of aqueous solution. Lastly, acid suppression did not influence the gastric residence time of chitosan microspheres or tetracycline concentration profiles.