The breath print represents a novel biomarker of malnutrition in pulmonary arterial hypertension: A proof of concept study.

BACKGROUND: The breath print is a quantitative measurement of molecules in exhaled breath and represents a new frontier for biomarker identification. It is unknown whether this state-of-the-art, noninvasive method can detect malnutrition. We hypothesize that individuals with malnutrition will present with a distinguishable breath print. METHODS: We conducted a retrospective chart review on patients with previously analyzed breath samples to identify malnutrition. Breath was analyzed by selected-ion flow-tube mass spectrometry. Registered dietitians conducted a retrospective chart review to collect malnutrition diagnoses and nutrition status indicators. Patients were categorized into one of four groups: pulmonary arterial hypertension (PAH), PAH with malnutrition (PAH-Mal), control, and control with malnutrition (Control-Mal), based on the malnutrition diagnosis present in the patient's chart. Principle component analysis was conducted to characterize the breath print. A logistic regression model with forward selection was used to detect the best breath predictor combination of malnutrition. RESULTS: A total of 74 patients met inclusion criteria (PAH: 52; PAH-Mal: 10; control: 10; Control-Mal: 2). Levels of 1-octene (PAH-Mal, 5.1 ± 1.2; PAH, 12.5 ± 11.2; P = 0.005) and ammonia (PAH-Mal, 14.6 ± 15.8; PAH, 56.2 ± 64.2; P = 0.013) were reduced in PAH-Mal compared with PAH. The combination of 1-octene (P = 0.010) and 3-methylhexane (P = 0.045) distinguished malnutrition in PAH (receiver operating characteristic area under the curve: 0.8549). CONCLUSIONS: This proof of concept study provides the first evidence that the breath print is altered in malnutrition. Larger prospective studies are needed to validate these results and establish whether breath analysis may be a useful tool to screen for malnutrition in the clinical setting.

Dietitians' Evaluation of Clearing Luminal Occlusions of Gunk (DECLOG): A Pilot Feasibility Study.

BACKGROUND: Tube clogging is the most frequent mechanical complication associated with enteral nutrition. The objective of this study was to assess the efficacy of a protocol incorporating prophylactic use of a declogging system with enhanced patient education and monitoring to proactively reduce the incidence of tube occlusions in the home care setting. METHODS: A convenient sample of patients discharged from hospital to home enteral nutrition (HEN) was screened for eligibility and randomized to control group (standard care) or study group (standard care with prophylactic protocol and monitoring). Study patients received 4 enzyme declogging kits before discharge and were instructed to administer them every 7 days for 4 weeks. RESULTS: Seventeen of 49 (35%) patients reported tube occlusions. The incidence of tube occlusion in the control group was not statistically different than in the study group (29% vs 39%, P = 0.44). There was no difference between the 2 groups for negative tube outcomes, such as tube occlusion (P = 0.44), emergency department visit (P = 0.24), tube replacement (P = 0.99), or hospital readmission (P = 0.33). Continuous feeding method (P = 0.037), small-bowel feeding tubes (P = 0.016), and tube diameter <14 French (P = 0.069) were associated with tube occlusions. CONCLUSION: A prophylactic protocol using an enzyme declogging system did not lessen the likelihood of tube occlusions when compared with standard care. Multiple factors are associated with tube occlusion. More research investigating the use of a declogging system to prevent clogging incidence in patients receiving HEN is warranted.

Near-infrared spectroscopy: applications in neonates.

Near-infrared spectroscopy (NIRS) offers non-invasive, in-vivo, real-time monitoring of tissue oxygenation. Changes in regional tissue oxygenation as detected by NIRS may reflect the delicate balance between oxygen delivery and consumption. Originally used predominantly to assess cerebral oxygenation and perfusion perioperatively during cardiac and neurosurgery, and following head trauma, NIRS has gained widespread popularity in many clinical settings in all age groups including neonates. However, more studies are required to establish the ability of NIRS monitoring to improve patient outcomes, especially in neonates. This review provides a comprehensive description of the use of NIRS in neonates.

Optimization of a glycoengineered Pichia pastoris cultivation process for commercial antibody production.

Glycoengineering enabled the production of proteins with human N-linked glycans by Pichia pastoris. This study used a glycoengineered P. pastoris strain which is capable of producing humanized glycoprotein with terminal galactose for monoclonal antibody production. A design of experiments approach was used to optimize the process parameters. Followed by further optimization of the specific methanol feed rate, induction duration, and the initial induction biomass, the resulting process yielded up to 1.6 g/L of monoclonal antibody. This process was also scaled-up to 1,200-L scale, and the process profiles, productivity, and product quality were comparable with 30-L scale. The successful scale-up demonstrated that this glycoengineered P. pastoris fermentation process is a robust and commercially viable process.

A case report of reappearance of spinal anesthesia.

OBJECTIVE: We present a case of reappearance of spinal anesthesia despite the use of plain (isobaric) lidocaine and without an associated cough or Valsalva maneuver. CASE REPORT: A 66-year-old man had spinal anesthesia for knee arthroscopy. Two hours after the induction of spinal anesthesia and after the patient's motor strength had returned to the lower extremities, his head was elevated to 30 degrees. His legs became weak and he became hypotensive. Within 1 hour, his strength returned and he was discharged uneventfully. CONCLUSIONS: The reappearance of spinal anesthesia may be secondary to remixing of the cerebrospinal fluid with the pooled local anesthetic or transfer of the local anesthetic from the subdural to the subarachnoid space with movement of the patient.

Stereoselective synthesis of a potent thrombin inhibitor by a novel P2-P3 lactone ring opening.

The concise synthesis of a potent thrombin inhibitor was accomplished by a mild lactone aminolysis between an orthogonally protected bis-benzylic amine and a diastereomerically pure lactone. The lactone was synthesized by the condensation of l-proline methyl ester with an enantiomerically pure hydroxy acid, which in turn was synthesized by a highly stereoselective (>500:1 er) and productive (100,000:1, S/C) enzymatic reduction of an alpha-ketoester. In addition, a second route to the enantiomerically pure lactone was accomplished by a diastereoselective ketoamide reduction.