Serum-Mediated Resistance Induced with Immunogenic Preparations of Salmonella typhimurium

Serum obtained from animals immunized with attenuated Salmonella typhimurium strain RIA, heat-killed bacterial suspensions, or immunogenic ribosomal preparations was capable of passively conferring protection on normal recipient mice to challenge infection with virulent S. typhimurium strain SR-11. Protection was measured by the ability of a recipient animal to reduce the total number of challenge organisms significantly below that found in challenged control mice. Intraperitoneal administration of 0.1 ml of pooled sera was more effective than 0.05 ml in transferring resistance. The transfer of equivalent amounts of immune serum subcutaneously did not result in demonstrable resistance. In all cases in which serum transfer was effective, resistance was maximal at 5 days, greatly diminished by 10 days, and gone by 15 days post-transfer. Pooled serum obtained from normal donor mice or 0.2 ml of serum from mice hyperimmunized with immunogenic ribonucleic acid preparations did not possess the capacity to confer demonstrable resistance on normal recipients.     

Inconsistent effects of all-trans retinoic acid on different clones of chemically transformed rat liver epithelial cells

The effects of all-trans retinoic acid (RA) on the growth andbiochemical properties of five clonal strains of neoplasticallytransformed rat liver epithelial cells were studied. These cellstrains were derived clonally from a single line of normal diploidrat liver epithelial cells that had been transformed by treatmentwith N-methyl-N'-nitro-N-nitrosoguanidine. The results showthat RA induces inconsistent alterations in selected phenotypicproperties of these five different cell strains. Retinoic acideither depressed, enhanced or produced no effect on the colony-formingability in soft agar, on the activity of -glutamyl transpeptidase,on the amount of cell-associated fibronectin, and on the bindingcapacity of ¹²⁵I-epidermal growth factor (EGF). The only consistentcorrelation observed among cell strains was between the cellularability to grow in soft agar and the amount of cell-associatedfibronectin. Enhancement of anchorage-independent growth byretinoic acid was not mediated through changes in the numberof EGF receptors. Our data demonstrate that the responses toretinoic acid of clonal subpopulations of chemically transformedrat liver epithelial cells are inconsistent, even when the clonalsubpopulations are derived from a common precursor.     

High-altitude pulmonary edema

Lay summary: High Altitude Pulmonary Edema (HAPE) is a potentially fatal disease of altitude, in which the lungs can become filled with fluid. In this article we explore the mechanisms causing this condition and how it can be viewed as a condition of a mismatch between current environment and evolutionary experience.     

The Frequency and Context of Snacking among Children: An Objective Analysis Using Wearable Cameras

Snacking is a common eating behaviour, but there is little objective data about children’s snacking. We aimed to determine the frequency and context of children’s snacking (n = 158; mean age = 12.6 years) by ethnicity, gender, socioeconomic deprivation and body mass index (BMI) children. Participants wore wearable cameras that passively captured images of their surroundings every seven seconds. Images (n = 739,162) were coded for snacking episodes, defined as eating occasions in between main meals. Contextual factors analysed included: snacking location, food source, timing, social contact and screen use. Rates of total, discretionary (not recommended for consumption) and healthful (recommended for consumption) snacking were calculated using negative binomial regression. On average, children consumed 8.2 (95%CI 7.4, 9.1) snacks per day, of which 5.2 (95%CI 4.6, 5.9) were discretionary foods/beverages. Children consumed more discretionary snacks than healthful snacks in each setting and at all times, including 15.0× more discretionary snacks in public spaces and 2.4× more discretionary snacks in schools. Most snacks (68.9%) were sourced from home. Girls consumed more total, discretionary and healthful snacks than boys, and Māori and Pacific consumed fewer healthful snacks than New Zealand (NZ) Europeans. Results show that children snack frequently, and that most snacking involves discretionary food items. Our findings suggest targeting home buying behaviour and environmental changes to support healthy snacking choices.     

Decomposing Racial and Ethnic Disparities in Nursing Home Influenza Vaccination

ObjectivesQuantify how observable characteristics contribute to influenza vaccination disparities among White, Black, and Hispanic nursing home (NH) residents.DesignRetrospective cohort.Setting and ParticipantsShort- and long-stay U.S. NH residents aged ≥65 years.MethodsWe linked Minimum Data Set (MDS) and Medicare data to LTCFocUS and other facility data. We included residents with 6-month continuous enrollment in Medicare and an MDS assessment between October 1, 2013, and March 31, 2014. Residents were classified as short-stay (<100 days in NH) or long-stay (≥100 days in NH). We fit multivariable logistic regression models to assess the relationships between 27 resident and NH-level characteristics and receipt of influenza vaccination. Using nonlinear Oaxaca-Blinder decomposition, we decomposed the disparity in influenza vaccination between White versus Black and White versus Hispanic NH residents. Analyses were repeated separately for short- and long-stay residents.ResultsOur study included 630,373 short-stay and 1,029,593 long-stay residents. Proportions vaccinated against influenza included 67.2% of White, 55.1% of Black, and 54.5% of Hispanic individuals among short-stay residents and 84.2%, 76.7%, and 80.8%, respectively among long-stay residents. Across 4 comparisons, the crude disparity in influenza vaccination ranged from 3.4 to 12.7 percentage points. By equalizing 27 prespecified characteristics, these disparities could be reduced 37.7% to 59.2%. Living in a predominantly White facility and proxies for NH quality were important contributors across all analyses. Characteristics unmeasured in our data (eg, NH staff attitudes and beliefs) may have also contributed significantly to the disparity.Conclusions and ImplicationsThe racial/ethnic disparity in influenza vaccination was most dramatic among short-stay residents. Intervening on factors associated with NH quality would likely reduce these disparities; however, future qualitative research is essential to explore potential contributors that were unmeasured in our data and to understand the degree to which these factors contribute to the overall disparity in influenza vaccination.     

Risk factors and outcomes of cardiovascular disease readmission within the first year after dialysis in peritoneal dialysis patients

BackgroundIn the first year of dialysis, patients are vulnerable to cardiovascular disease (CVD) hospitalization, but knowledge regarding the risk factors and long-term outcomes of cardiovascular readmission within the first year after dialysis in incident continuous ambulatory peritoneal dialysis (CAPD) patients is limited.MethodsThis retrospective cohort study was conducted in incident CAPD patients. The demographic characteristics, laboratory parameters, and CVD readmission were collected and analyzed. The primary outcome was all-cause mortality, and the secondary outcomes included CVD mortality, infection-related mortality and technique failure. A logistic regression was used to identify the risk factors associated with CVD readmission within the first year after dialysis. Cox proportional hazards models were used to evaluate the association between CVD readmission and the outcomes.ResultsIn total, 1589 peritoneal dialysis (PD) patients were included in this study, of whom 120 (7.6%) patients had at least one episode of CVD readmission within the first year after dialysis initiation. Advanced age, CVD history, and a lower level of serum albumin were independently associated with CVD readmission. CVD readmission within the first year after dialysis was significantly associated with all-cause (HR 2.66, 95%CI 1.91–3.70, p < 0.001) and CVD (HR 3.42, 95%CI 2.20–5.31, p < 0.001) mortality, but not infection-related mortality or technique failure, after adjusting for confounders.ConclusionsOur findings suggest that an advanced age, a history of CVD, and a lower level of serum albumin were independently associated with CVD readmission. Moreover, CVD readmission was associated with all-cause and cardiovascular mortality in incident CAPD patients.     

Cognitive Behavioral Therapy of Minor Depressive Symptoms in Elderly Chinese Americans: A Pilot Study

There is a high prevalence of suicide amongelderly Chinese, and particularly among elderly Chinesewomen in Mainland China with a prevalence of 19.6 perhundred thousand. Since Chinese individuals may much more highly value education, acognitive-behavioral package originated by RicardoMunoz, Ph.D. was adapted for Chinese American subjects.The material was videotaped in eight sessions,approximately 25 minutes in length, to be shown to communitysubjects who were at least 40 years and over. Inaddition, a videotape of muscular relaxation techniqueswas made. A manual written in Chinese about the content of each class, was given to each subject whenhe/she attended. The experimental group showedsignificant improvement in the scores in the HamiltonDepression Scale, including the Somatic Subscale in the Hamilton Anxiety Scale. There was nosignificant improvement in the control group on any ofthe measures. Thus the study suggests the efficacy ofpsychoeducational classes in reducing symptoms ofdepression in non-patient community elderly. Other studiesare being conducted among Korean Americans and JapaneseAmericans in the United States, and also in the Orientamong Japanese elderly.     

cAMP potentiates beta-amyloid-induced nitric oxide release from microglia

The beta-amyloid peptide (Abeta) has been known to activate microglia and to induce release of nitric oxide (NO). In this study, we examined the effect of cAMP on Abeta-induced microglial activation using cultured rat brain microglia. Dibutyryl-cAMP (dbcAMP) and 3-isobutyl-1-methylxanthine (IBMX) significantly potentiated Abeta(25-35)- or Abeta(1-42)-induced NO release in a dose-dependent manner. The increase in NO release was due to the increased expression of inducible nitric oxide synthase (iNOS). However, forskolin, an adenylate cyclase activator, weakly increased NO release at 10-50 microM but caused a decrease at 100 microM. These results suggest that increase in intracellular cAMP could potentiate microglial activation induced by Abeta.     

Distribution of bratton-marshall-positive material in mice following intravenous injections of nitrosoureas

Summary As determined by a colorimetric assay measuring parent compounds plus ether-extractable, nitroso-containing metabolites, N,N-bis(2-chloroethyl)-N-nitrosourea (BCNU) disappeared more rapidly than N-(2-chloroethyl)-N cyclohexyl-N-nitrosourea (CCNU) and N-(2-chloroethyl)-N-(4-transmethylcyclohexyl)-N-nitrosourea (MeCCNU) and their products from the tissues of mice injected IV. Assay of selected samples by high-pressure liquid chromatography revealed that the colorimetric assay for BCNU was specific in that the two assays gave equivalent results. Following IV-injections of CCNU and MeCCNU, however, levels of the parent compounds decreased much more rapidly than the total, color-producing material.Of seven tissues, the largest Cxt values for BCNU, as determined by the colorimetric assay, were noted for blood (442 g-min/ml) and large intestine (285 g-min/g). Liver (29 g-min/g) had the lowest Cxt value, reflecting rapid metabolism of the compound by this organ. Color-producing material related to CCNU disappeared from the solid tissues of mice in a manner generally parallel to that for blood. Of the Cxt values for this compound and its products, those for lung (1753 g-equivalents-min/g), kidney (1633 g-equivalents-min/g), and small intestine (1557 g-equivalents-min/g) were highest. Consistent with its slower rate of metabolism, MeCCNU and its color-producing metabolites remained in most tissues of mice for 12 h following injection. Except for brain (1434 g-equivalents-min/g), Cxt values for this nitrosourea and its metabolites in tissues were higher than those of blood (5485 g-equivalents-min/ml), with kidney (15,324 g-equivalents-min/g), liver (12,921 g-equivalents-min/g), and large intestine (11,501 g-equivalents-min/g) being highest. For each nitrosourea, a fair correlation was observed between the Cxt values for tissues and the toxic and/or antitumor effects at those sites.