HEALTH-RELATED QUALITY OF LIFE AND CARDIOVASCULAR DISEASE IN ASIAN AMERICAN AND PACIFIC ISLANDER OLDER ADULTS

Cardiovascular disease (CVD) is the leading cause of death for Asian American (AA), Native Hawaiian, and Pacific Islander (NHPI) older adults, and AAs/NHPIs have not enjoyed decreases in CVD mortality rates, as have non-Hispanic whites (NHWs). Heterogeneity exists in the prevalence of traditional CVD risk factors for AAs/NHPIs. Health-related quality of life (HRQOL) reflect physical and mental burdens beyond clinical burdens, which may help explain discrepant CVD rates and risk factors in AAs/NHPIs. We examined HRQOL among NHW and AA/NHPI Medicare Advantage enrollees with and without a CVD (i.e., coronary artery disease, congestive heart failure, myocardial infarction, and stroke) using the Medicare Health Outcomes Survey. The sample included 655,914 older adults who were 65 years or older, self-reported as AA/NHPI or NHW, and were enrolled in Medicare Advantage plans in 2011-2015. HRQOL was measured using the Veterans RAND 12-item survey and is composed of a physical component score (PCS) and mental component score (MCS), where higher scores reflect better physical and mental health, respectively. Multivariable linear regression was used to explore HRQOL and CVD prevalence. Asian Indian, Filipino, Vietnamese, Other Asian, and NHPI subgroups had lower overall PCS, and all AA/NHPI subgroups had lower overall MCS, compared to NHWs. Among those reporting having any CVD, PCS varied by CVD outcomes and subgroups, whereas MCS was lower for all CVD outcomes and for all but one AA/NHPI subgroups (Japanese), compared to NHWs. Attention to mental health for AA/NHPI older adults could be important for the equitable realization of healthy aging.

PREDICTORS OF MORTALITY RISK AMONG MEDICARE ADVANTAGE ENROLLEES

Overall all-cause mortality rates have declined significantly in past decades among individuals aged 65 and above in every racial and ethnic group. We explored demographic, overall health, and disability development as predictors of mortality in Medicare beneficiaries enrolled in Medicare Advantage plans. We used data from the 2014-2018 Medicare Health Outcomes Survey, a nationally representative panel survey with a two-year follow-up, administered by the Centers for Medicare and Medicaid Services. Our sample consisted of 1,273,494 community-dwelling adults aged 65 and older (Mage = 74.5 years, age range: 65-109 years) enrolled in Medicare Advantage plans. Mortality was assessed over a 2-year follow-up period. We used Cox proportional hazards regression analysis to predict risk of all-cause mortality by demographics, self-rated health, chronic health conditions, smoking status, and activities of daily living (ADLs). Among all participants, the mortality rate was 7.0% (n = 88,058) at 2-year follow-up. Advanced age and being male were significantly associated with greater risk of mortality, while higher levels of education and income were inversely associated with mortality. Controlling for other factors, white adults had higher mortality risk than black or African American, Hispanic, and Asian older adults. Individuals who were unmarried, had lower self-rated health, had more chronic health conditions, smoked, and had more ADL limitations had higher mortality risk. Our findings suggest that sustained health and better functional capacity are important elements in decreasing the risk of mortality in older adults.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Engineered cartilage heals skull defects

INTRODUCTION

The purposes of this study were to differentiate embryonic limb bud cells into cartilage, characterize the nodules produced, and determine their ability to heal a mouse skull defect.

METHODS

Aggregated mouse limb bud cells (E12-E12.5), cultured in a bioreactor for 3 weeks, were analyzed by histology or implanted in 6 skull defects. Six controls had no implants. The mice were scanned with microcomputed tomography weekly. At 2 and 4 weeks, a mouse from each group was killed, and the defect region was prepared for histology.

RESULTS

Chondrocytes in nodules were mainly hypertrophic. About 90% of the nodules mineralized. BrdU staining showed dividing cells in the perichondrium. Microcomputed tomography scans showed increasing minerals in implanted nodules that completely filled the defect by 6 weeks; defects in the control mice were not healed by then. At 2 and 4 weeks, the control skull sections showed only a thin bony layer over the defect. At 2 weeks, bone and cartilage filled the defects with implants, and the implants were well integrated with the adjacent cortical bone. At 4 weeks, the implant had turned almost entirely into bone.

CONCLUSIONS

Cartilage differentiated in the bioreactor and facilitated healing when implanted into a defect. Engineering cartilage to replace bone is an alternative to current methods of bone grafting.

CORRELATION BETWEEN MICRO-CT SECTIONS AND HISTOLOGICAL SECTIONS OF MOUSE SKULL DEFECTS IMPLANTED WITH ENGINEERED CARTILAGE

One advantage of using cartilage to replace/repair bone is that the implant disappears as bone is formed by endochondral ossification. Previously, we showed that cartilage spheroids, grown in a rotating bioreactor (Synthecon, Inc.) and implanted into a 2 mm skull defect, contributed to healing of the defect. Skulls with or without implants were subjected to microCT scans. Mineralized regions from microCT sections correlated with regions of bone in histological sections of the defect region of demineralized skulls. Recently, sections from microCT scans of live mice were compared to histological sections from the same mice. The area of the defect staining for bone in histological sections of demineralized skulls was the same region shown as mineralized in microCT sections. Defects without implants were not healed. This study demonstrates that microCT scans are an important corollary to histological studies evaluating the use of implants in healing of bony defects.

Older immigrants: language competencies and mental health

Later-life immigration and a lack of dominant language competency present many challenges to mental health for older adults. English as a Second Language (ESL) classes for seniors, often regarded as the sole domain of ESL teachers, offer mental health professionals opportunities for mental health promotion and education. This paper examines some of the mental health issues that emerged from stories written by older adults in an ESL for Seniors program. The program is presented as an example of best practices in an ESL for Seniors program because of its specific development to meet the needs of ESL older persons.

New insights on the mechanisms of the pH-independent reactions of benzo[a]pyrenes 7,8-diol 9,10-epoxides

The rates and products of the reactions of (+/-)-7beta,8alpha-dihydroxy-9beta,10beta-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (1) and (+/-)-7beta,8alpha-dihydroxy-9alpha,10alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (2) in water and dioxane-water mixtures have been determined over a pH range wider than that of earlier studies. This study provides additional insight on the mechanisms of the pH-independent reactions of 1 and 2. The rate profile for reaction of 1 shows acid-catalyzed hydrolysis at pH <5, a rate plateau at pH 5-9.5, a negative inflection at pH 10-11.5, and a rate increase at pH >11.5. The rate decrease between pH 10 and pH 11.5 is accompanied by a decrease in the yield of tetrols from 60% (pH 8) to 29% (pH 11.2) and is interpreted to be the result of a partial change in mechanism brought about by attack of hydroxide ion acting as a base to deprotonate a carbocation intermediate and regenerate 1 at pH >10, thus reducing the contribution of the pathway for tetrol formation in which water attacks the carbocation. The rate profile for the reaction of 2 exhibits only a single rate plateau at intermediate pH, along with increases in rate at low and high pH because of second-order reactions of 2 with H+ and HO-, respectively. The lack of a rate depression at pH >10 and the product studies for the reaction of 2 in dilute sodium azide solutions suggest that the tetrol-forming reactions of the pH-independent reaction of 2 are concerted or near-concerted.

Stereotaxic percutaneous core biopsy versus surgical biopsy of nonpalpable breast lesions using a standard mammographic table with an add-on device

OBJECTIVE

To determine the accuracy of using a regular mammographic table with an add-on device for biopsy of nonpalpable breast lesions in women in a community hospital setting.

PATIENTS AND METHODS

During a 3-year period, 70 consenting women (39-80 years of age) with a nonpalpable mammographically suspicious lesion on routine screening mammography underwent 14-gauge automated percutaneous core biopsies, immediate needle localization and lumpectomy. The needle and surgical biopsy results were independently classified into 1 of 5 categories: cancer, fibroadenoma, fibrocystic change, normal or other.

RESULTS

The procedure was well tolerated, and all core specimens yielded adequate tissue for pathologic evaluation. There were 3 episodes of vasovagal reaction. There was complete agreement in histologic findings in 64 cases (91%), including 22 of 24 cancers (92%). The overall agreement for categorizing lesions was 91% (kappa = 0.88), and there was 97% agreement (kappa = 0.94) for the classification of cancer versus benign lesion.

CONCLUSION

The results are similar to those of studies performed with dedicated prone equipment. Stereotaxic core biopsies can be done safely and accurately in a community hospital setting with relatively inexpensive nondedicated mammographic equipment.

RNA and DNA hydrolysis are catalyzed by the influenza virus endonuclease

The influenza virus polymerase complex contains a metal ion-dependent endonuclease activity, which generates short capped RNA primer molecules from capped RNA precursors. Previous studies have provided evidence for a two-metal ion mechanism of RNA cleavage, and the data are consistent with a direct interaction of a divalent metal ion with the catalytic water molecule. To refine the model of this active site, we have generated a series of DNA, RNA, and DNA-RNA chimeric molecules to study the role of the 2'-hydroxy groups on nucleic acid substrates of the endonuclease. We could observe specific cleavage of nucleic acid substrates devoid of any 2'-hydroxy groups if they contained a cap structure (m7GpppG) at the 5'-end. The capped DNA endonuclease products were functional as primers for transcription initiation by the influenza virus polymerase. The apparent cleavage rates were about 5 times lower with capped DNA substrates as compared with capped RNA substrates. Cleavage rates with DNA substrates could be increased to RNA levels by substituting the deoxyribosyl moieties immediately 5' and 3' of the cleavage site with ribosyl moieties. Similarly, cleavage rates of RNA substrates could be lowered to DNA levels by exchanging the same two ribosyl groups with deoxyribosyl groups at the cleavage site. These results demonstrate that the 2'-hydroxy groups are not essential for binding and cleavage of nucleic acids by the influenza virus endonuclease, but small differences of the nucleic acid conformation in the endonuclease active site can influence the overall rate of hydrolysis. The observed relative cleavage rates with DNA and RNA substrates argue against a direct interaction of a catalytic metal ion with a 2'-hydroxy group in the endonuclease active site.

Metal ion catalysis of RNA cleavage by the influenza virus endonuclease

The influenza virus RNA-dependent RNA polymerase protein complex contains an associated RNA endonuclease activity, which cleaves host mRNA precursors in the cell nucleus at defined positions 9-15 nucleotides downstream of the cap structure. This reaction provides capped oligoribonucleotides, which function as primers for the initiation of viral mRNA synthesis. The endonuclease reaction is dependent on the presence of divalent metal ions. We have used a number of divalent and trivalent metal ions alone and in combination to probe the mechanism of RNA cleavage by the influenza virus endonuclease. Virus-specific cleavage was observed with various metal ions, and maximum cleavage activity was obtained with 100 microM Mn2+ or 100 microM Co2+. This activity was about 2-fold higher than that observed with Mg2+ at the optimal concentration of 1 mM. Activity dependence on metal ion concentration was cooperative with Hill coefficients close to or larger than 2. Synergistic activation of cleavage activity was observed with combinations of different metal ions at varying concentrations. These results support a two-metal ion mechanism of RNA cleavage for the influenza virus cap-dependent endonuclease. The findings are also consistent with a structural model of the polymerase, in which the specific endonuclease active site is spatially separated from the nucleotidyl transferase active site of the polymerase module.

Halide effects in the hydrolysis reactions of (+/-)-7beta, 8alpha-dihydroxy-9alpha,10alpha-epoxy-7,8,9,10-tetrahydrobenzo- [a]pyrene

Rates of reaction of (+/-)-7beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (DE-2) have been determined in 1:9 dioxane-water solutions containing 1.0 M KCl, 0.5 M KBr, and 0.1 M NaI over the pH range 4-13. These pH-rate profiles are more complicated than those for reaction of DE-2 in 0.2 M NaClO4 solutions and are interpreted in part by mechanisms in which halide ion attacks the diol epoxide as a nucleophile at intermediate pH, resulting in the formation of a trans-halohydrin. Reaction of DE-2 in these halide solutions at pH < ca. 5 occurs by rate-limiting carbocation formation, followed by capture of the intermediate carbocation by halide ion. The relative magnitudes of the rate constants for reaction of the intermediate carbocation with halide ions are estimated from product studies. The halohydrins are unstable intermediates and react quickly in subsequent reactions to yield tetrols in a ratio different than that formed from reaction of the carbocation with solvent. Nucleophilic attacks of 1.0 M Cl-, 0.5 M Br-, and 0.1 M I- on DE-2 are the principal reactions in the pH range ca. 6-9, leading to intermediate trans-halohydrins that hydrolyze to tetrols. At pH ca. 9-11, halohydrin formed from attack of halide ion on DE-2 reverts back to epoxide, leading to a negative break in the pH-rate profile. The main product-forming reaction of DE-2 at pH 11.3 is the spontaneous reaction. At pH > 12, the rate of reaction of DE-2 increases due to a second-order reaction of HO- with DE-2.