A249 RETROSPECTIVE CHART REVIEW OF PATIENTS WITH MALNUTRITION REQUIRING ADVANCED NUTRITIONAL SUPPORT POST BARIATRIC SURGERY

Background

Obesity is a global pandemic with a steady increase in global BMI since 1975. Bariatric surgery is an effective treatment for patients with severe obesity in order to sustain long-term weight loss and reduce comorbidity burden and mortality associated with obesity. However, post-bariatric surgery patients face nutritional complications ranging from micronutrient deficiencies to intestinal failure requiring total parenteral nutrition (TPN). From our institution of home TPN patients, 6.4% of patients had bariatric surgery. Intestinal failure is a burdensome diagnosis for patients, and there is a paucity of literature characterizing patients post-bariatric surgery who develop intestinal failure.

Aims

We aim to identify the patient characteristics, surgical details, and nutritional traits that predisposed patients to developing intestinal failure requiring advanced nutritional support.

Methods

This is a retrospective chart review of 48 patient admitted to the Royal Alexandra Hospital post-bariatric surgery for nutritional support and followed by the TPN program dieticians and nurses.

Results

Our results show the mean BMI was 49.94 kg/m2 pre-bariatric surgery. Interestingly, the mean BMI at time of hospitalization for bariatric-surgery related complications was 33.210 kg/m2 which is classified as overweight but most of patients were severely malnourished with SGA C (43.8%), SGA B (29.17%), and 8.3% were SGA A. Patients requiring parenteral nutrition post-bariatric surgery are mostly female, developed barriers to oral intake, 15% engaged in medical tourism, 58.3% had an underlying mental health diagnosis, and only 18.8% were on a multivitamin even though it is standard of post-bariatric surgery care. The time between initial bariatric surgery to hospital admission was 11.2 years, and most required ≥1 revisional surgery. The mean age at bariatric surgery was 33.2-years old and the average age at initial hospitalization was 48.9-years old. Patients requiring ≥2 admissions had vertical band gastroplasty or sleeve gastrectomy (both 36.8%) while 21.1% had Roux-en-Y gastric bypass. Of these patients, 39.6% of patients required ≥2 hospital admissions and the mean total days spent in hospital was 57.15 days. While these complications are uncommon, these patients result in multiple prolonged hospitalizations and can be difficult to manage.

Conclusions

Overall, the results of our study will allow the multidisciplinary teams that care for post-bariatric surgery patients to identify patients at risk of intestinal failure and potentially intervene with early enrollment into home nutrition program. With increasing awareness, patients at higher risk can be closely monitored in order to prevent micronutrient deficiencies before they progress to intestinal failure and require lifetime parenteral nutrition.

Funding Agencies

None

A226 INCIDENTAL FINDING OF A LARGE GASTRIC VARIX ASSOCIATED WITH NEONATAL UMBILICAL VEIN CANALIZATION

Results

A 41-year old Asian male, who immigrated to Canada many years ago, and who had previously been successfully treated for Helicobacter pylori infection underwent gastroscopy for investigation of dyspepsia. His gastroscopy was normal except for a large subepithelial abnormality that was noted close to the gastroesophageal junction. Routine gastric biopsies from the antrum and body were normal. Subsequent endoscopic ultrasound revealed flow through the anechoic tortuous lesion and confirmed it was a very large isolated gastric varix type 1.

Abdominal CT scan revealed chronic occlusion of the portal vein, splenic vein, and the portal confluence with extensive collateralization in the upper abdomen. There was complete cavernous transformation of the portal vein. Of the numerous varices in the upper abdomen, a very large varix drained into the left renal vein and indented into the posterior wall of the fundus of the stomach which accounted for the endoscopic finding. Multiple mesenteric veins were identified that connected to varices adjacent to the inferior aspect of the pancreas and duodenum. Notably, there was no evidence of cirrhosis or chronic pancreatitis. Liver enzymes, albumin, and INR were normal.

Further collateral history revealed that he was hospitalized as a neonate for pneumonia with catheterization of the umbilical vein, which is known to be associated with thrombosis of the portal vein.

Conclusions

Detection of congenital absence of the portal vein (CAPV) is recognized more often due to advances in diagnostic imaging. Radiologically, the absence of the portal vein in CAPV is distinguished from portal vein thrombosis by the lack of venous collaterals or sequalae of portal hypertension, such as ascites or splenomegaly. A more gradual thrombosis of the portal vein may permit collaterals to develop without acute changes and is not equivalent to portal vein aplasia or agenesis as intrahepatic bile ducts are normal.

The gold standard for diagnosis of CAPV is histologic absence of the portal vein in the liver on catheter angiography. CAPV is associated with abnormal embryologic development of the portal vein and frequently presents with complications of portal hypertension or portosystemic encephalopathy or the sequalae of venous shunts, hepatic or cardiac abnormalities found on imaging.

Our case is an incidentally discovered absence of the portal venous system due to chronic thrombosis with extensive collateralization and an enlarged gastric varix protruding into the proximal stomach. It is well documented that canalization of the umbilical vein in infancy is associated with portal vein thrombosis, with incidences up to 68%. This case highlights the importance of eliciting a childhood hospitalization history in cases of non-cirrhotic portal hypertension.

Funding Agencies

None

A master protocol to investigate a novel therapy acetyl-L-leucine for three ultra-rare neurodegenerative diseases: Niemann-Pick type C, the GM2 gangliosidoses, and ataxia telangiectasia

BACKGROUND

The lack of approved treatments for the majority of rare diseases is reflective of the unique challenges of orphan drug development. Novel methodologies, including new functionally relevant endpoints, are needed to render the development process more feasible and appropriate for these rare populations and thereby expedite the approval of promising treatments to address patients' high unmet medical need. Here, we describe the development of an innovative master protocol and primary outcome assessment to investigate the modified amino acid N-acetyl-L-leucine (Sponsor Code: IB1001) in three separate, multinational, phase II trials for three ultra-rare, autosomal-recessive, neurodegenerative disorders: Niemann-Pick disease type C (NPC), GM2 gangliosidoses (Tay-Sachs and Sandhoff disease; "GM2"), and ataxia telangiectasia (A-T).

METHODS/DESIGN

The innovative IB1001 master protocol and novel CI-CS primary endpoints were developed through a close collaboration between the Industry Sponsor, Key Opinion Leaders, representatives of the Patient Communities, and National Regulatory Authorities. As a result, the open-label, rater-blinded study design is considerate of the practical limitations of recruitment and retention of subjects in these ultra-orphan populations. The novel primary endpoint, the Clinical Impression of Change in Severity© (CI-CS), accommodates the heterogenous clinical presentation of NPC, GM2, and A-T: at screening, the principal investigator appoints for each patient a primary anchor test (either the 8-m walk test (8MWT) or 9-hole peg test of the dominant hand (9HPT-D)) based on his/her unique clinical symptoms. The anchor tests are videoed in a standardized manner at each visit to capture all aspects related to the patient's functional performance. The CI-CS assessment is ultimately performed by independent, blinded raters who compare videos of the primary anchor test from three periods: baseline, the end of treatment, and the end of a post-treatment washout. Blinded to the time point of each video, the raters make an objective comparison scored on a 7-point Likert scale of the change in the severity of the patient's neurological signs and symptoms from video A to video B. To investigate both the symptomatic and disease-modifying effects of treatment, N-acetyl-L-leucine is assessed during two treatment sequences: a 6-week parent study and 1-year extension phase.

DISCUSSION

The novel CI-CS assessment, developed through a collaboration of all stakeholders, is advantageous in that it better ensures the primary endpoint is functionally relevant for each patient, is able to capture small but meaningful clinical changes critical to the patients' quality of life (fine-motor skills; gait), and blinds the primary outcome assessment. The results of these three trials will inform whether N-acetyl-L-leucine is an effective treatment for NPC, GM2, and A-T and can also serve as a new therapeutic paradigm for the development of future treatments for other orphan diseases.

TRIAL REGISTRATION

The three trials (IB1001-201 for Niemann-Pick disease type C (NPC), IB1001-202 for GM2 gangliosidoses (Tay-Sachs and Sandhoff), IB1001-203 for ataxia telangiectasia (A-T)) have been registered at www.clinicaltrials.gov (NCT03759639; NCT03759665; NCT03759678), www.clinicaltrialsregister.eu (EudraCT: 2018-004331-71; 2018-004406-25; 2018-004407-39), and https://www.germanctr.de (DR KS-ID: DRKS00016567; DRKS00017539; DRKS00020511).

Efficient calculation of electron diffraction for the structural determination of nanomaterials

A critical advance in the technique of low-energy electron diffraction is presented and shown to enable determining detailed structures of nanomaterials, based on experimental methods that already exist or have been proposed. Our new cluster approach speeds up the computation to scale as n logn, rather than the current n3 or n2, with n the number of atoms, for example. Applications are illustrated for C60 molecules adsorbed on a Cu(111) surface, with and without coadsorbed metal atoms, exhibiting sensitivity to important structural features such as buckyball size and deformation.

Distribution and elimination of tobramycin administered in single or multiple daily doses in adult patients with cystic fibrosis

Aminoglycosides are often prescribed as part of the treatment regimen for acute pulmonary exacerbations due to their potent activity and low potential for development of resistance. Preliminary evidence from randomized controlled trials in patients with cystic fibrosis (CF) suggests that once-daily administration of aminoglycosides results in similar efficacy and a low risk for toxicity compared with traditional dosing. The pharmacokinetics of aminoglycosides administered once daily in CF patients are currently not well described. In this study we compare the distribution and elimination patterns of traditional dosing (3.3 mg/kg q8h) versus once-daily dosing (10 mg/kg q24h) of tobramycin in six adult patients with CF. The pharmacokinetics of tobramycin administered either once daily or every 8 h were best described by a two-compartment model. No statistically significant differences in any of the pharmacokinetic parameter values between regimens were noted. The distribution phase half-lives of 32 and 24 min following the q8h and q24h regimens were longer than expected. The use of a one-compartment model requires clinical peak levels to be drawn 2 h after initiation of either a 30 min infusion for multiple daily dosing or a 60 min infusion with once-daily dosing, to ensure completion of the distribution phase. Our data indicate that a dose of 10 mg/kg/day provides post-distributional phase peak concentrations that achieve the desired goal for susceptible organisms (>20 mg/L) and AUC(24) values at the upper end of the desired range (70-100 mg.h/L).

Demonstration of highly efficient photon echoes

Highly efficient two-pulse and stimulated photon echoes are experimentally demonstrated in an absorbing medium. Recall efficiencies of 235% and 150% with excellent signal contrast are measured for two-pulse and stimulated photon echoes, respectively, in a Tm:YAG crystal with an absorption length of 3.8. The reported efficiencies do not include any correction for decay or beam profile. We believe that this is the first demonstration of an uncorrected echo efficiency greater than 100% with good signal fidelity in an optically thick medium.

Scattering of electromagnetic waves from dense distributions of spheroidal particles based on Monte Carlo simulations

In a dense discrete random medium, the propagation and scattering of waves are affected not only by the individual properties of the particles such as size, shape, and permittivity, but also by group properties such as the statistics of relative particle positions and relative orientations. We use Monte Carlo simulations to investigate the interactions of electromagnetic waves with a dense medium consisting of spheroidal particles for cases of random orientation and for cases of aligned orientation. A shuffling process is used to generate the positions of densely packed spheroids. Multiple-scattering equations are formulated by means of the volume integral equation and are solved numerically. The scattering results are averaged over realizations. Numerical results are presented for the extinction rates and the phase matrices. Salient features of the numerical results indicate that (1) the extinction rates of densely packed small spheroids are smaller than those of independent scattering; (2) for aligned spheroids, the extinction rates are polarization dependent; and (3) the co-polarized part of the phase matrix for densely packed spheroids is smaller than that of independent scatering, while the cross-polarized part is larger than that for independent scattering. This means that the ratio of cross-polarization to co-polarization is significantly higher than that of independent scattering.

Quantitative determination of glucose in blood plasma and in fruit juices by combined WATR-CPMG 1H NMR spectroscopy

The quantitative analysis of pure glucose solution < or = 225 mM (< or = 40.8 mg/mL) in 90/10 H2O/D2O was successfully completed in dilute aqueous solution by the WATR-CPMG method whereby the T2 of the water resonance is manipulated by the WATR method followed by elimination of the water peak by the CPMG pulse sequence. The method was applied to the quantitative analysis of total glucose in blood plasma from human subjects undergoing the oral glucose tolerance test in the teaching hospital, and the results were compared to those obtained using a standard glucose oxidase method in a hospital chemical pathology laboratory. The accuracy of the results obtained using the WATR-CPMG method were generally within 5% of the glucose oxidase method. The coefficient of variation was determined to be better than 4% using plasma samples of diabetic subjects. Application to the quantitative analysis of orange and guava juice was also successfully demonstrated.

Particle-size distribution determination using optical sensing and neural networks

We present an inverse technique to determine particle-size distributions by training a layered perception neural network with optical backscattering measurements at three wavelengths. An advantage of this approach is that, even though the training may take a long time, once the neural network is trained the inverse problem of obtaining size distributions can be solved speedily and efficiently.

CHEMOSENSORY RESPONSES TO AMINO ACIDS AND CERTAIN AMINES BY THE CILIATE TETRAHYMENA: A FLAT CAPILLARY ASSAY

An assay for chemosensory responses by the ciliate Tetrahymena thermophila is described that uses glass capillaries with a rectangular cross-section (inner dimensions, 20 x 2 x 0.2 mm). These have optical and geometrical properties permitting convenient observation of cell behavior within the capillaries. Washed cells, starved for 12 h, accumulated preferentially in capillaries containing L-methionine, L-leucine, L-cysteine, L-histidine, L-histamine, cimetidine, agmatine, and berenil at concentrations of 10^-3 M or less. They avoided capillaries containing tripelennamine, diphenhydramine, and pentamidine at these concentrations. It is argued that the actual response thresholds are much lower than the concentrations put into the capillaries, since cells respond to the gradient of the diffusing chemical. L-Isoleucine, itself inert, blocked the response to L-leucine but not to L-methionine, L-cysteine, or L-histidine. L-Ethionine and 1-homocysteine caused accumulation but not L-cysteine or DL-cystathionine. L-Cystine did not block the response to L-cysteine. Cells accelerated when entering a capillary where accumulation occurred. On reaching the interior they swam more slowly and uniformly, and with fewer turns or stops than in control capillaries lacking the chemical signal, or when outside of the capillaries. Cells were inhibited from leaving both control and test capillaries, possibly because of accumulated wastes or secretions in the surrounding medium.