Analysis of the fecal metagenome in long-term survivors of pancreas cancer.

BACKGROUND: The 5-year overall survival of pancreas adenocarcinoma (PCa) remains less than 10%. Clinical and tumor genomic characteristics have not differentiated PCa long-term survivors (LTSs) from unselected patients. Preclinical studies using fecal transplant experiments from LTSs of PCa have revealed delayed tumor growth through unknown mechanisms involving the fecal microbiota. However, features of the fecal microbiome in patients with long-term survival are not well described. METHODS: In this cross-sectional study, comprehensive shotgun metagenomics was performed on stool from PCa patients with long-term survival (n = 16). LTS was defined as >4 years from pancreatectomy and all therapy without recurrence. LTSs were compared to control patients with PCa who completed pancreatectomy and chemotherapy (n = 8). Stool was sequenced using an Illumina NextSeq500. Statistical analyses were performed in R with MicrobiomeSeq and Phyloseq for comparison of LTSs and controls. RESULTS: All patients underwent pancreatectomy and chemotherapy before sample donation. The median time from pancreatectomy of 6 years (4-14 years) for LTSs without evidence of disease compared to a median disease-free survival of 1.8 years from pancreatectomy in the control group. No differences were observed in overall microbial diversity for LTSs and controls using Shannon/Simpson indexes. Significant enrichment of species relative abundance was observed in LTSs for the Ruminococacceae family specifically Faecalibacterium prausnitzii species as well as Akkermansia muciniphila species. CONCLUSIONS: Stool from patients cured from PCa has more relative abundance of Faecalibacterium prausnitzii and Akkermansia muciniphila. Additional studies are needed to explore potential mechanisms by which the fecal microbiota may influence survival in PCa. PLAIN LANGUAGE SUMMARY: Although pancreatic cancer treatments have improved, the number of long-term survivors has remained stagnant with a 5-year overall survival estimate of 9%. Emerging evidence suggests that microbes within the gastrointestinal tract can influence cancer response through activation of the immune system. In this study, we profiled the stool microbiome in long-term survivors of pancreas cancer and controls. Several enriched species previously associated with enhanced tumor immune response were observed including Faecalibacterium prausnitzii and Akkermansia muciniphila. These findings warrant additional study assessing mechanisms by which the fecal microbiota may enhance pancreatic cancer immune response.

Isolated cerebral Mucormycosis and Aspergillosis coinfection in an immunocompromised adult.

Opportunistic fungal infections are a major cause of mortality in immunosuppressed patients, with mucormycosis and aspergillosis as two of the most commonly identified fungal organisms. Coinfection with mucormycosis and aspergillosis is rare, but cases have been reported in literature, most commonly presenting as disseminated invasive fungal infection with cerebrorhino-orbital involvement in an immunocompromised patient. Infections are most commonly caused by direct implantation of spores with localised angioinvasion. Haematogenous spread is rare, with most cases secondary to haematological malignancies or intravenous drug use. Coinfection with mucormycosis and aspergillosis portends a poor prognosis, with a high mortality rate. Thus, prompt recognition and intervention are crucial to prevent poor outcomes. In this unique case report, we describe a case of isolated cerebral mucormycosis and aspergillosis coinfection, not previously reported in literature.

The association of sleep duration with adolescents' fat and carbohydrate consumption.

STUDY OBJECTIVES: To investigate the relation between sleep duration and energy consumption in an adolescent cohort. DESIGN: Cross-sectional. SETTING: Free-living environment. PARTICIPANTS: Two hundred forty adolescents (mean age 17.7 +/- 0.4 years). MEASUREMENTS AND RESULTS: Daily 24-hour food-recall questionnaires and wrist-actigraphy measurements of sleep duration were employed to test the hypothesis that shorter weekday sleep duration (< 8 h) is associated with altered nutrient intake. Nutrition parameters included total calories, calories from meals and snacks, and proportions of caloric intake from fat and carbohydrates. Compared with adolescents sleeping 8 or more hours on average on weekdays, those sleeping less than 8 hours consumed a higher proportion of calories from fats (35.9% +/- 6.7% vs 33.2% +/- 6.9%; mean +/- SD; P = 0.004) and a lower proportion of calories from carbohydrates (49.6% +/- 8.2% vs 53.3% +/- 8.3%; P = 0.001). After adjusting for potential confounders, shorter sleep duration was significantly associated with an average daily increase of calories consumed from fat of 2.2 percentage points and an average daily decrease in percentage of calories from carbohydrates of 3.0 percentage points. In unadjusted analyses, shorter sleep duration was also associated with a 2.1-fold increased odds (95% confidence interval: 1.03, 4.44) of daily consuming 475 or more kcal from snacks. CONCLUSION: Quantitative measures of macronutrient intake in adolescents were associated with objectively measured sleep duration. Short sleep duration may increase obesity risk by causing small changes in eating patterns that cumulatively alter energy balance.

Insulin analogs for the treatment of diabetes mellitus: therapeutic applications of protein engineering.

The engineering of insulin analogs represents a triumph of structure-based protein design. A framework has been provided by structures of insulin hexamers. Containing a zinc-coordinated trimer of dimers, such structures represent a storage form of the active insulin monomer. Initial studies focused on destabilization of subunit interfaces. Because disassembly facilitates capillary absorption, such targeted destabilization enabled development of rapid-acting insulin analogs. Converse efforts were undertaken to stabilize the insulin hexamer and promote higher-order self-assembly within the subcutaneous depot toward the goal of enhanced basal glycemic control with reduced risk of hypoglycemia. Current products either operate through isoelectric precipitation (insulin glargine, the active component of Lantus(®); Sanofi-Aventis) or employ an albumin-binding acyl tether (insulin detemir, the active component of Levemir(®); Novo-Nordisk). To further improve pharmacokinetic properties, modified approaches are presently under investigation. Novel strategies have recently been proposed based on subcutaneous supramolecular assembly coupled to (a) large-scale allosteric reorganization of the insulin hexamer (the TR transition), (b) pH-dependent binding of zinc ions to engineered His-X(3)-His sites at hexamer surfaces, or (c) the long-range vision of glucose-responsive polymers for regulated hormone release. Such designs share with wild-type insulin and current insulin products a susceptibility to degradation above room temperature, and so their delivery, storage, and use require the infrastructure of an affluent society. Given the global dimensions of the therapeutic supply chain, we envisage that concurrent engineering of ultra-stable protein analog formulations would benefit underprivileged patients in the developing world.

Rapid histochemistry using slow off-rate modified aptamers with anionic competition.

Immunohistochemistry is used in both research and clinical settings to identify proteins in tissue samples. Despite the power and versatility of immunohistochemistry, limitations are imposed by the slow diffusion of antibodies through tissue and the need for secondary staining or signal amplification. Aptamers can circumvent these limitations, but their application has been hindered by nonspecific binding to cellular components, particularly in the nucleus. Here we describe unique slow off-rate modified aptamers that facilitate rapid and selective binding to target proteins in tissue. Specifically, we have developed a fluorescent aptamer that binds to the human epidermal growth factor receptor 2 (HER2) in breast carcinomas quickly and specifically, and we have shown that the slow off-rate of the aptamer from the HER2 protein contributes to its selectivity. These findings open the door to aptamer histochemistry applications in both research and clinical settings, including intraoperative diagnostics in which speed and accuracy are paramount.

Validity of activity-based devices to estimate sleep.

STUDY OBJECTIVES: The aim of this study was to examine the feasibility of sleep estimation using a device designed and marketed to measure core physical activity. METHODS: Thirty adolescent participants in an epidemiological research study wore 3 actigraphy devices on the wrist over a single night concurrent with polysomnography (PSG). Devices used include Actical actigraph, designed and marketed for placement around the trunk to measure physical activity, in addition to 2 standard actigraphy devices used to assess sleep-wake states: Sleepwatch actigraph and Actiwatch actigraph. Sleep-wake behaviors, including total sleep time (TST) and sleep efficiency (SE), were estimated from each wrist-device and PSG. Agreements between each device were calculated using Pearson product movement correlation and Bland-Altman plots. RESULTS: Statistical analyses of TST revealed strong correlations between each wrist device and PSG (r = 0.822, 0.836, and 0.722 for Sleepwatch, Actiwatch, and Actical, respectively). TST measured using the Actical correlated strongly with Sleepwatch (r = 0.796), and even stronger still with Actiwatch (r = 0.955). In analyses of SE, Actical correlated strongly with Actiwatch (r = 0.820; p < 0.0001), but not with Sleepwatch (0.405; p = 0.0266). SE determined by PSG correlated somewhat strongly with SE estimated from the Sleepwatch and Actiwatch (r = 0.619 and 0.651, respectively), but only weakly with SE estimated from the Actical (r = 0.348; p = 0.0598). CONCLUSIONS: The results from this study suggest that a device designed for assessment of physical activity and truncal placement can be used to measure sleep duration as reliably as devices designed for wrist use and sleep wake inference.

Photoaptamer arrays applied to multiplexed proteomic analysis.

Multiplexed photoaptamer-based arrays that allow for the simultaneous measurement of multiple proteins of interest in serum samples are described. Since photoaptamers covalently bind to their target analytes before fluorescent signal detection, the arrays can be vigorously washed to remove background proteins, providing the potential for superior signal-to-noise ratios and lower limits of quantification in biological matrices. Data are presented here for a 17-plex photoaptamer array exhibiting limits of detection below 10 fM for several analytes including interleukin-16, vascular endothelial growth factor, and endostatin and able to measure proteins in 10% serum samples. The assays are simple, scalable, and reproducible. Affinity of the capture reagent is shown to be directly correlated to the limit of detection for the analyte on the array.