Rumen volatile fatty acid molar proportions, rumen epithelial gene expression, and blood metabolite concentration responses to ruminally degradable starch and fiber supplies

The objective of this work was to characterize rumen volatile fatty acid (VFA) concentrations, rumen epithelial gene expression, and blood metabolite responses to diets with different starch and fiber sources. Six ruminally cannulated yearling Holstein heifers (body weight = 330 ± 11.3 kg) were arranged in a partially replicated Latin square experiment with 4 treatments consisting of different starch [barley (BAR) or corn (CRN)] and fiber [timothy hay (TH) or beet pulp (BP)] sources. Treatments were arranged as a 2 × 2 factorial. Beet pulp and TH were used to create relative changes in apparent ruminal fiber disappearance, whereas CRN and BAR were used to create relative changes in apparent ruminal starch disappearance. Each period consisted of 3 d of diet adaptation and 15 d of dietary treatment. In situ disappearance of fiber and starch were estimated from bags incubated in the rumen from d 10 to 14. From d 15 to 17, rumen fluid was collected every hour from 0500 to 2300 h. Rumen fluid samples were pooled by animal/period and analyzed for pH and VFA concentrations. On d 18, 60 to 80 papillae were biopsied from the epithelium and preserved for gene expression analysis. On d 18, one blood sample per heifer was collected from the coccygeal vessel. In situ ruminal starch disappearance rate (7.30 to 8.72%/h for BAR vs. 7.61 to 10.5%/h for CRN) and the extent of fiber disappearance (22.2 to 33.4% of DM for TH vs. 34.4 to 38.7% of DM for BP) were affected by starch and fiber source, respectively. Analysis of VFA molar proportions showed a shift from propionate to acetate, and valerate to isovalerate on TH diets compared with BP. Corn diets favored propionate over butyrate in comparison to BAR diets. Corn diets also had higher molar proportions of valerate. Expression of 1 gene (SLC9A3) were increased in BP diets and 2 genes (BDH1 and SLC16A4) tended to be increased in TH diets. Plasma acetate demonstrated a tendency for a starch by fiber interaction with BAR-BP diets having the highest plasma acetate, but other metabolites measured were not significant. These results suggest that TH has the greatest effect on shifts in VFA molar proportions and epithelial transporters, but does not demonstrate shifts in blood metabolite concentrations.

Mammary transcriptome reveals cell maintenance and protein turnover support milk synthesis in early-lactation cows

A more complete understanding of the molecular mechanisms that support milk synthesis is needed to develop strategies to efficiently and sustainably meet the growing global demand for dairy products. With the postulate that coding gene transcript abundance reflects relative importance in supporting milk synthesis, we analyzed the global transcriptome of early lactation cows across magnitudes of normalized RNA-Seq read counts. Total RNA was isolated from milk samples collected from early-lactation cows (n = 6) following two treatment periods of postruminal lysine infusion of 0 or 63 g/day. Twelve libraries were prepared and sequenced on an Illumina NovaSeq6000 platform using paired end reads. Normalized read counts were averaged across both treatments, because EBseq analysis found no significant effect of lysine infusion. Approximately 10% of the total reads corresponded to 12,730 protein coding transcripts with a normalized read count mean ≥5. For functional annotation analysis, the protein coding transcripts were divided into nine categories by magnitude of reads. The 13 most abundant transcripts (≥50K reads) accounted for 67% of the 23M coding reads and included casein and whey proteins, regulators of fat synthesis and secretion, a ubiquitinating protein, and a tRNA transporter. Mammalian target of rapamycin, JAK/STAT, peroxisome proliferator-activated receptor alpha, and ubiquitin proteasome pathways were enriched with normalized reads ≥100 counts. Genes with ≤100 reads regulated tissue homeostasis and immune response. Enrichment in ontologies that reflect maintenance of translation, protein turnover, and amino acid recycling indicated that proteostatic mechanisms are central to supporting mammary function and primary milk component synthesis.

Technical note: A muscle biopsy technique for stratifying cattle by skeletal muscle metabolic activity

Tissue biopsy metabolic activity, assessed using the oxidation-reduction indicator resazurin, may serve as a proxy to assess energy expenditure associated with maintenance in nongrowing animals or growth rate in growing animals. Herein, we evaluate the repeatability, practicality, and sensitivity of a resazurin-based assay for ranking bovine skeletal muscle biopsies based on metabolic activity. Six yearling Holstein heifers (body weight = 330 ± 11.3 kg) were fed 4 dietary treatments consisting of high or low rumen-degradable starch and fiber arranged factorially in a partially replicated Latin square design. Periods were 18 d, consisting of 3 d for diet transition, 14 d for diet adaptation, and 1 d for sample collection. Semitendinosus biopsies were collected into ice-cold Dulbecco's modified Eagle medium (Fisher Scientific, Hampton, NH) from each heifer during each period. Analysis was initiated within an hour of sample collection. To assess tissue metabolic rate, biopsies were transferred to Dulbecco's modified Eagle medium with resazurin and incubated at 37°C. Fluorescence of each sample was read at time 0 and at 15-min intervals for 2 h. Change in fluorescence was representative of skeletal muscle reducing equivalent production. Fluorescent signal strength increased with time and relative rank of treatments did not change with time; accordingly, future studies may compare fluorescence at a single time point. Change in fluorescence at 120 min was used for analysis of the fixed effects of fiber, starch, and animal when accounting for a random effect of period. Samples collected when animals were on a high-ruminally degradable starch diet were more metabolically active than samples collected from animals on low-starch diets. Significant differences in metabolic activity among individual animals were also identified. Average relative fluorescence was correlated with dry matter intake, average daily gain, and feed-to-gain ratio. The relative fluorescence tended to correlate with average daily gain (r = 0.749) and feed-to-gain ratio (r = -0.783); change in fluorescence did not correlate with dry matter intake. Although evaluated on a small sample size, this technique shows promise as a potential means of ranking animals by growth or feed efficiency. Further work on a larger experimental population is needed to confirm the usefulness of this assay as a consistent and reliable predictor of these important phenotypic parameters.

Propionate Affects Insulin Signaling and Progesterone Profiles in Dairy Heifers

Emerging data highlighting gut microbiome influences on health support evaluation of how microbial fermentation end-products influence postabsorptive systems. This study aimed to investigate the effect of increased propionate status on progesterone profiles and insulin sensitivity in dairy heifers. Eleven Holstein heifers, synchronized in estrus, were assigned to one of two continuous, 5-day IV treatments: sodium propionate (PRO; n = 5) or saline (CON; n = 6). These infusions culminated in a hyperglycemic clamp with daily blood samples for an additional 7 days. Plasma propionate concentrations increased over the first 9 h in PRO heifers, then decreased until day 3 when they matched CON heifers. Maximum plasma progesterone concentrations tended to be greater in PRO heifers than CON heifers (4.19 vs 3.73 ng/mL; P = 0.087). Plateau insulin concentrations in CON animals were significantly greater than those in PRO animals (249.4 ± 25.1 vs 123.9 ± 35.8; P = 0.008) with a trend for an increased insulin sensitivity index in PRO heifers compared to CON heifers (P = 0.06). These changes in plasma propionate clearance leading to increased progesterone response and changes in insulin sensitivity suggest a role for SCFA metabolism in reproductive hormone regulation.

The contributions of MRI-based measures of gray matter, white matter hyperintensity, and white matter integrity to late-life cognition

BACKGROUND AND PURPOSE

GM volume, WMH volume, and FA are each associated with cognition; however, few studies have detected whether these 3 different types of MR imaging measurements exert independent or additive effects on cognitive performance. To detect their extent of contribution to cognitive performance, we explored the independent and additive contributions of GM atrophy, white matter injury, and white matter integrity to cognition in elderly patients.

MATERIALS AND METHODS

Two hundred and 9 elderly patients participated in the study: 97 were CN adults, 65 had MCI, and 47 had dementia. We measured GM on T1-weighted MR imaging, WMH on FLAIR, and FA on DTI, along with psychometrically matched measures of 4 domains of cognitive performance, including semantic memory, episodic memory, executive function, and spatial abilities.

RESULTS

As expected, patients with dementia performed significantly more poorly in all 4 cognitive domains, whereas patients with MCI performed generally less poorly than dementia patients, though considerable overlap in performance was present across groups. GM, FA, and WMH each differed significantly between diagnostic groups and were associated with cognitive measures. In multivariate models that included all 3 MR imaging measures (GM, WMH, and FA), GM volume was the strongest determinant of cognitive performance.

CONCLUSIONS

These results strongly suggest that MR imaging measures of GM are more closely associated with cognitive function than WM measures across a broad range of cognitive and functional impairment.

The relative efficiency of time-to-threshold and rate of change in longitudinal data

Randomized, placebo-controlled trials often use time-to-event as the primary endpoint, even when a continuous measure of disease severity is available. We compare the power to detect a treatment effect using either rate of change, as estimated by linear models of longitudinal continuous data, or time-to-event estimated by Cox proportional hazards models. We propose an analytic inflation factor for comparing the two types of analyses assuming that the time-to-event can be expressed as a time-to-threshold of the continuous measure. We conduct simulations based on a publicly available Alzheimer's disease data set in which the time-to-event is algorithmically defined based on a battery of assessments. A Cox proportional hazards model of the time-to-event endpoint is compared to a linear model of a single assessment from the battery. The simulations also explore the impact of baseline covariates in either analysis.

Encouraging activity of bicalutamide and everolimus in castration-resistant prostate cancer (CRPC): Early results from a phase II clinical trial

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Background: Multiple signaling pathways are involved in the development of CRPC. We previously showed that the mTOR pathway is activated in CRPC cell lines while inhibition of this pathway results in upregulation of androgen receptor (AR) signaling (Wang et al, Oncogene. 2008). Simultaneous blockade of the mTOR and AR pathways synergize in inducing PCa cell death and delaying tumor formation in mouse models. We hypothesize that simultaneous blockade of the AR and mTOR pathways in CRPC patients with bicalutamide and everolimus will result in improved efficacy compared to bicalutamide alone.

Methods: A phase II clinical trial with a lead-in safety phase was designed to determine the efficacy and tolerability of the bicalutamide and everolimus combination in CRPC patients compared with bicalutamide alone. Patients must have histologically confirmed disease and demonstrated disease progression (either by PSA or radiographically) while on androgen deprivation therapy. At the lead-in phase, all patients receive both agents. At the phase II stage, patients are randomized to bicalutamide +/− everolimus. The primary endpoint is PSA response. The second endpoints include progression-free survival, time-to-treatment failure, overall survival and toxicity. Here, we report the results of the lead-in phase.

Results: Eight patients were recruited at the lead-in phase. The bicalutamide/everolimus combination was well tolerated with no unexpected toxicities. Six of 8 patients have had PSA response after at least 8 weeks of therapy and the remaining two patients had stable PSA response. The median time to disease progression was 6.8 months. Nine patients have been recruited at the phase II stage so far. This clinical trial is being subcontracting to the other sites of the California Cancer Consortium. Tumor and blood specimens are being collected for molecular correlative studies of mTOR pathway markers.

Conclusions: The rational combination of bicalutamide and everolimus appears to have promising anti-tumor activity and an acceptable toxicity profile. The randomized phase of the clinical trial is currently ongoing and will be reported. Supported by Novartis.

[Table: see text]

Subtypes based on cerebrospinal fluid and magnetic resonance imaging markers in normal elderly predict cognitive decline

Cerebrospinal fluid (CSF) and structural magnetic resonance imaging (MRI) show patterns of change in Alzheimer's disease (AD) that precede dementia. The Alzheimer's Disease Neuroimaging Initiative (ADNI) studied normal controls (NC), subjects with mild cognitive impairment (MCI), and subjects with AD to identify patterns of biomarkers to aid in early diagnosis and effective treatment of AD. Two hundred twenty-two NC underwent baseline MRI and clinical examination at baseline and at least one follow-up. One hundred twelve also provided CSF at baseline. Unsupervised clustering based on initial CSF and MRI measures was used to identify clusters of participants with similar profiles. Repeated measures regression modeling assessed the relationship of individual measures, and of cluster membership, to cognitive change over 3 years. Most individuals showed little cognitive change. Individual biomarkers had limited predictive value for cognitive decline, but membership in the cluster with the most extreme profile was associated with more rapid decline in ADAS-cog. Subtypes among NC based on multiple biomarkers may represent the earliest stages of subclinical cognitive decline and AD.

Does donating blood for the first time during a national emergency create a better commitment to donating again?

BACKGROUND AND OBJECTIVES

Emergency situations often elicit a generous response from the public. This occurred after attacks on the US on September 11, 2001 when many new blood donors lined up to donate. This study was performed to compare return rates for first time donors (FTD) after September 11th, 2001 to FTD during a comparable period in 2000.

MATERIALS AND METHODS

A total of 3315 allogeneic whole blood donations from FTD at a regional blood centre were collected between September 11th and 30th, 2001. Subsequent donations by the FTD before March 31, 2002 were reviewed. This (test) group was compared to 1279 FTD (control group) donating during the same time period in September 2000 and to their return rate in the subsequent 6 months.

RESULTS

Following September 11, 2001, 1087/3315 (32.8%) FTD returned by March 31, 2002. This return rate was similar to the control group [427/1279 (33.4%)]. The deferral rate during the donor screening process for the control group was significantly higher than the deferral rate for the September 11-30, 2001 group (P < 0.01). The odds of an individual FTD returning increased with age, and the chance of a female donor returning was 1.13 times higher than a male (P = 0.06). There was a carryover effect after September 11, 2001 too.

CONCLUSION

A national emergency, September 11, 2001, inspired people to donate blood for the first time. However, the proportion of return donations amongst them was not increased. Females and males in certain age groups were more likely to become repeat donors due to the residual effect of September 11, 2001. Additional efforts are needed to retain eligible FTD in donor pools.

Dual epidermal growth factor receptor (EGFR) inhibition: Phase I study combining cetuximab (C225) and erlotinib (E) in advanced solid tumors

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Background: The EGFR pathway is implicated in lung tumorigenesis by aberrantly regulating cell proliferation, apoptosis, and invasion. Maximal blockade of the EGFR can be achieved by dually inhibiting the extracellular and intracellular domain with the monoclonal antibody C225 and the tyrosine kinase inhibitor, E. Given preclinical synergy of C225 and E, we hypothesized this combination would be feasible and result in improved therapeutic benefit. Methods: Patients (pts) with advanced solid tumors were enrolled using a standard phase I dose escalation design. C225 was administered IV weekly, with no loading dose, and E given orally daily on a 28-day cycle. Four dose levels were studied: C225 150 mg/m2, E 100 mg; C225 200 mg/m2, E 100 mg; C225 250 mg/m2, E 100 mg; and C225 250 mg/m2, E 150 mg. Dose limiting toxicity (DLT) was defined as: grade (Gr) 4 platelets, Gr 3 platelets with bleeding, febrile neutropenia, ≥ Gr 3 ANC with documented infection, or clinically significant > Gr 3 non-hematologic toxicity. Gr 3 rash based solely on pain or Gr 3 hypersensitivity infusion reactions were not considered DLTs. Results: 18 pts were treated: 13 NSCLC, 3 H&N, 1 pancreas, and 1 invasive thymoma. Characteristics: Age range 41–80, median 62.5; Gender: 7 M; ECOG PS ≤1 = 17; Prior chemo ≤1 = 10. Planned dose escalation was completed without reaching the MTD. The highest dose level was expanded to 6 pts. A single DLT for Gr 3 diarrhea was observed at the second dose level (C225 200 mg/m2, E 100 mg). Gr 3/4 toxicities were: lymphopenia (3), acneiform rash (3), nausea/vomiting (3), pruritis (1), fatigue (1), diarrhea (1), confusion (1), hypomagnesemia (1), hypocalcemia (1), hyponatremia (1), hyperkalemia (1), and anemia (1). Of 13 evaluable pts, 1 PR (NSCLC) and 4 with SD (2 NSCLC, 2 H&N). Median cycles: 2 (1–14) with one NSCLC pt on therapy for 8 cycles and one H&N pt receiving 14 cycles. Biomarker analysis of EGFR polymorphisms, gene copy number via FISH, and protein expression will be presented, along with the mutation status of EGFR and KRAS. Conclusions: 1) Dual EGFR inhibition with C225 250 mg/m2 weekly and E 150 mg daily is feasible, well tolerated, and the recommended phase II dose. 2) Efficacy of this combination in NSCLC is being evaluated in a phase II trial.

[Table: see text]

Pharmacodynamic separation of erlotinib and docetaxel (DOC) in advanced non-small cell lung cancer (NSCLC): Overcoming hypothesized antagonism

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Background: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) given concurrently with chemotherapy do not improve patient (pt) outcomes compared with chemotherapy alone in advanced NSCLC. Based on our preclinical data, we hypothesized that G1 cell cycle arrest from EGFR-TKI antagonizes the cytotoxicity of concurrent chemotherapy, and that pharmacodynamic separation (PDS) by intermittent delivery of EGFR-TKIs with chemotherapy would increase efficacy (Gumerlock, ASCO 2003, Davies, ASCO 2005). To test this concept, we conducted a phase I-II study of intermittent erlotinib combined with DOC. Methods: 37 previously treated IIIB (pleural effusion) or IV NSCLC pts received DOC 70–75 mg/m2 IV on day 1 every 21 days and erlotinib orally days 2–16 (150–200 mg). Patients without progression after 6 cycles continued erlotinib alone. Primary endpoint was response rate. Results: Pt characteristics: Age: median/range 57/35–80; Sex: 14 M; KPS ≥90=13; smoker/non-smoker/unknown 20/13/4, Median cycles: 5. Adenoca: 18. Prior chemotherapy regimens: 1 - 26; >1 - 11. In 34 evaluable pts: 1 CR, 11 PR (35% response rate), 16 stable disease. Median time to progression (TTP) was 5.6 months (95% CI: 3.7 - 7.9). MST: not reached. Treatment was generally well tolerated. Most common grade (Gr) 3/4 toxicities included: neutropenia (60%), diarrhea (16%), infection (11%), febrile neutropenia (8%). Gr 1/2 acneform rash: 88%. PK analysis showed that PDS was achieved in nadir levels of erlotinib in 4 pts tested. Correlative studies examining biomarkers for response with EGFR TKIs are ongoing. Conclusions: 1) DOC every 3 weeks plus intermittent dosing of erlotinib (2 weeks on, 1 week off) achieved PDS in limited PK sampling. 2) This combination resulted in a favorable response rate and TTP in previously treated NSCLC, with MST not yet reached. 3) Febrile neutropenia necessitated the prophylactic use of G-CSF. 4). Further clinical study of this concept is warranted, and trials are currently ongoing.

[Table: see text]

Proteasome inhibition with bortezomib (BORT) in combination with topotecan : A phase I solid tumor trial

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Background: Topoisomerase-I (Topo-I) down-regulation via the ubiquitin/26S proteasome pathway has been associated with drug resistance. We hypothesize that proteasome inhibition by BORT would enhance topotecan sensitivity by preventing down-regulation of topo-I. This phase I trial examined the safety and feasibility of combining weekly BORT with topotecan in patients (pts) with advanced solid tumors. Methods: Pts on 1 of 4 dose levels were treated with topotecan (3–4 mg/m2) IV and BORT (1–1.6 mg/m2) IV on days 1, 8, and 15. BORT was given 3 hours after topotecan based on preclinical studies (Flannery, 2003). Cycles were repeated q28 days. After 6 cycles, pts without progression could remain on BORT alone. Dose limiting toxicity (DLT) was defined as: grade (Gr) 4 platelets (plts) (<25K), Gr3 plts (<50K) with bleeding, febrile neutropenia, neutropenia with infection, Gr3 neuropathy, or any=Gr3 non-heme toxicity. Results: 15 pts were accrued. Pt characteristics: Median age 58 years (range 25–73); Male sex:7; Performance status =80%:13. Two DLTs were seen at dose level 4 (Topotecan 4 mg/m2 and BORT 1.6mg/m2): Gr 4 plts (1) and Gr 3 neutropenia with infection (1). Few other toxicities > Gr3 were seen past cycle 1. Of 11 evaluable pts, 1 had a partial response (small cell bladder). 4 had stable disease (lung, brain, adenoid cystic and prostate). Conclusions: Weekly BORT and topotecan is feasible and well tolerated. The recommended phase II dose is topotecan 3mg/m2 and BORT 1.6mg/m2 IV weekly (3 of 4). An expanded cohort at this dose will examine efficacy of this combination in pts with small cell cancers. Correlative studies evaluating serum markers for proteasome inhibition and topo-1 activity are ongoing.

No significant financial relationships to disclose.

Longitudinal volumetric MRI change and rate of cognitive decline

OBJECTIVE

To examine how baseline and change of volumetric MRI relate to cognitive decline in older individuals.

BACKGROUND

Memory is associated with hippocampal integrity, whereas executive function has been linked to impaired frontal lobe function. Previous studies have shown that hippocampal and cortical atrophy are more strongly related to cognition than are measures of subcortical cerebrovascular disease (CVD). The authors hypothesized that memory (MEM) decline would be related to change in hippocampal volume (HC), whereas decline in executive function (EXEC) would be related to change of cortical gray matter volume (CGM) and measures of subcortical CVD.

METHODS

Subjects from a multicenter study (n = 103) included cognitively normal, mildly impaired, and demented cases with and without subcortical lacunes. All had longitudinal cognitive evaluation (mean = 4.8 years) and two or more MRI scans at least one year apart (mean = 3.4 years). MRI measures included HC, CGM, total lacune volume (LAC), and white matter hyperintensity volume (WMH). Random effects modeling of longitudinal data assessed effects of MRI baseline and MRI change on baseline and change of psychometrically matched measures of MEM and EXEC.

RESULTS

Change in MEM was related to HC baseline and HC change. Change in EXEC was related to baseline CGM and to change in CGM, HC, and LAC. Results were unchanged when demented cases were excluded. WMH was not associated with change in MEM or EXEC independent of HC, CGM, and LAC.

CONCLUSION

Hippocampal volume was the primary determinant of memory decline, whereas executive function (EXEC) decline was related to multiple brain components. Results support a hypothesis that MEM decline is strongly influenced by Alzheimer disease (AD), whereas EXEC decline may be complexly determined by cerebrovascular disease and AD.

Incidence, mechanism and prognostic value of activated AKT in pancreas cancer

When activated, the serine/threonine kinase AKT mediates an antiapoptotic signal implicated in chemoresistance of various cancers. The mechanism(s) of AKT activation are unknown, though overexpression of HER-2/neu has been implicated in breast cancer. Therefore, we determined the incidence of activated AKT in human pancreatic cancer, whether HER-2/neu is involved in AKT activation, and if AKT activation is associated with biologic behaviour. HER-2/neu expression and AKT activation were examined in seven pancreatic cancer cell lines by Western blotting. The in vitro effect of HER-2/neu inhibition on AKT activation was similarly determined. Finally, 78 pancreatic cancer specimens were examined for AKT activation and HER-2/neu overexpression, and correlated with the clinical prognostic variable of histologic grade. HER-2/neu was overexpressed in two of seven cell lines; these two cell lines demonstrated the highest level of AKT activation. Inhibition of HER-2/neu reduced AKT activation in vitro. AKT was activated in 46 out of 78 (59%) of the pancreatic cancers; HER-2/neu overexpression correlated with AKT activation (P=0.015). Furthermore, AKT activation was correlated with higher histologic tumour grade (P=0.047). Thus, it is concluded that AKT is frequently activated in pancreatic cancer; this antiapoptotic signal may be mediated by HER-2/neu overexpression. AKT activation is associated with tumour grade, an important prognostic factor.

A randomized, placebo-controlled study of the immunogenicity of human immunodeficiency virus (HIV) rgp160 vaccine in HIV-infected subjects with > or = 400/mm3 CD4 T lymphocytes (AIDS Clinical Trials Group Protocol 137)

Immune responses provoked by human immunodeficiency virus (HIV) infection ultimately are insufficient to control the disease and do not include strong lymphocyte-proliferative responses to HIV antigens or antibodies to many viral epitopes. A randomized double-blind, placebo-controlled trial evaluated the immunogenicity of recombinant HIV envelope vaccine (rgp160) in HIV-infected subjects with > or = 400/mm3 CD4 T cells. Controls received hepatitis B vaccine. Of subjects receiving rgp160, 98% developed lymphocyte-proliferative responses to the immunogen, 33% to a different envelope protein, and 56% and 60% to p24 and p66, respectively. All doses of vaccine (20, 80, 320, 1280 microgram) induced new responses. New antibodies to epitopes on rgp160 developed only in recipients of higher doses of rgp160. CD4 T cell percentages declined less rapidly in recipients of rgp160 than in controls. Vaccination of HIV-infected subjects with rgp160 results in cellular and humoral immune responses to HIV that infection itself had not stimulated.

Ex vivo expansion of HIV type 1-specific cytolytic T cells from HIV type 1-seropositive subjects

Cytotoxic T lymphocytes that specifically lyse HIV-1-infected cells occur at uncommonly high frequency in the blood of infected individuals. The CTL response is dominated by the recognition of a small number of peptides encoded by HIV-1 structural and regulatory genes. These two facts have enabled us to develop potent HIV-specific CTL lines from the blood of infected patients without AIDS opportunistic infections by ex vivo culture of nonspecifically stimulated T cell lines with autologous antigen-presenting cells (APCs) preincubated with immunodominant HIV-1 peptides. After one selection, HIV-specific cytotoxicity is enhanced 1.4- to sixfold. Frequency analysis of the T cell line from 1 patient revealed that after exposure to peptide-incubated autologous B-LCLs, the frequency of CTLs specific for the gp160-expressing APCs was enhanced 6-fold and, after a second exposure, 11-fold compared to the nonselected T cell line. Because the APCs used for the frequency analysis were EBV-transformed B-LCLs, some of the specific CTLs in the culture recognized the EBV-expressing APCs. HIV-specific cytotoxicity is enhanced without augmentation of EBV-specific cytotoxicity when PBMCs are used as APCs. Because T cell lines enhanced for HIV-1 specificity are highly cytotoxic and can be expanded to approximately 10(9)-10(10) cells/ml of blood, they may be useful for laboratory research or for immunotherapy.

Comparison of neurologic changes in 'successfully aging' persons vs the total aging population

OBJECTIVE

To determine age-related changes in neurologic function in the general population.

DESIGN

To administer a neurologic examination to participants in such a way that it is possible to calculate the proportion of elderly persons in the population with each abnormal finding and the proportion of persons with each finding but without evidence of the medical and neurologic diseases likely to produce neurologic abnormalities (eg, stroke and diabetes).

SETTING

Individuals were selected from a community-dwelling population.

PARTICIPANTS

A stratified random sample of 467 persons aged 65 years and older were evaluated.

RESULTS

Many neurologic abnormalities are increasingly common with advancing age and are present in a substantial portion of the elderly population. The prevalence of abnormal neurologic findings not attributable to disease, however, is substantially lower, typically one half to one third the total prevalence. Moreover, the increase with age in the prevalence of abnormal neurologic findings not attributable to major disease varies substantially among the different measures.

CONCLUSIONS

Primitive reflexes and measures of gait show statistically significant increases with age in multiple measurement domains, suggesting a selective age-related vulnerability.

The left-sided predominance of asbestos-related pleural disease

In a series of 406 subjects with a diagnosis of asbestos-related pleural disease (ARPD), the left-right symmetry of radiographically diagnosed ARPD was assessed using the International Labour Organization (ILO) system for classifying radiographic abnormalities and three different statistical models for testing the degree of symmetry. The extent of chest disease was found to be greater on the left than on the right for a number of parameters of pleural disease, including the width and extent of localized pleural thickening, the extent of enface pleural thickening, and the extent of diaphragmatic and chest wall calcification. Current cigarette smoking significantly enhanced the observed asymmetry, with the most pronounced effect being in diaphragmatic calcification. Using a composite scale for each subject's pleural disease, the left side had 1.6 times more localized disease than did the right (p < 0.001). Asymmetry in one parameter was associated with asymmetry in another for a number of pairs. The most significant of these associations was between enface pleural thickening and chest wall calcification (Kendall's tau B = 0.42). The pathophysiologic mechanisms that explain these findings remain elusive and need further investigation.

Acute delirium and functional decline in the hospitalized elderly patient

BACKGROUND

Delirium is often considered a transient cognitive syndrome. Its effect on long-term physical function, however, has not been well defined.

METHODS

In a prospective study of 325 hospitalized community and nursing home elderly, we analyzed the effect of in-hospital delirium on subsequent physical function. ADL performance was assessed prior to admission, and at 3 and 6 months after hospital discharge.

RESULTS

There was a strong univariate (unadjusted) association between incident delirium and functional decline (p < .02). Delirious subjects lost a mean of almost one ADL, as measured 3 months after hospital discharge. Using multivariate linear regression analysis, with adjusted change in function as the dependent variable, delirium persisted as the sole predictor of loss of function (p = .009) at 3 months after discharge. The functional decline persisted at 6 months after hospital discharge.

CONCLUSION

This finding of a nontransient, perhaps permanent consequence of delirium invites reexamination of the definition of delirium from that of an acute, reversible syndrome to one of acute onset with long-term sequelae.

Serial analysis of plasma lipids and lipoproteins from individuals 9-21 y of age

Total cholesterol (TC) and low-density- (LDL-C) and high-density-lipoprotein cholesterol (HDL-C) concentrations were recorded annually from 9 to 21 y of age to study tracking and predictive values for adulthood lipid concentrations associated with cardiovascular disease. The tracking coefficients for TC and LDL-C were congruent to 0.7 for 4-, 6-, and 12-y intervals, indicating good predictive value at ages 9-11 y for risk of elevated concentrations at ages 19-21 y. Tracking of HDL-C was less marked but the patterns were similar. The risk ratios for high concentrations at 19-21 y were 3.8 for TC, 2.6 for LDL-C, and 4 for HDL-C for 9-y-olds with values of 5.17 mmol/L for TC, 3.36 mmol/L for LDL-C, and 0.90 mmol/L for HDL-C, relative to 9-y-olds with values of 4.65 mmol/L for TC, 2.84 mmol/L for LDL-C, and 1.29 mmol/L for HDL-C.

Serum levels of soluble CD8, neopterin, beta 2-microglobulin and p24 antigen as indicators of disease progression in children with AIDS on zidovudine therapy

OBJECTIVE

To test the hypothesis that serum levels of soluble markers in children change after initiation of zidovudine therapy and that the extent and pattern of these longitudinal changes correlates with clinical outcome.

PATIENTS AND METHODS

We measured serum levels of soluble CD8, neopterin, beta 2-microglobulin (beta 2M), and p24 antigen, and CD4 cell counts, before the initiation of zidovudine therapy and at 12, 24 and 48 weeks of treatment in 24 HIV-1-infected children (Centers for Disease Control classification P2) and 15 controls.

RESULTS

Soluble CD8 levels were elevated before therapy in 70% of the infected children; subsequent decreases were associated with lower risk of disease progression. The mean serum neopterin level before treatment was elevated in infected children; decreases in neopterin levels marginally reflected improved or stable clinical status. Serum beta 2M levels and CD4+ cell counts were not associated with clinical outcome. Only 10 out of the 24 patients had detectable levels of serum p24 antigen before treatment; again, the amount of decline after initiation of therapy did not predict clinical outcome.

CONCLUSION

Decreasing levels of soluble CD8 and neopterin in HIV-1-infected children receiving zidovudine therapy might reflect a good response to treatment and a slowing of disease progression.

Canadian doctors may want to take this Popcorn with a grain of salt

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