Adenocarcinima in the columnar epithelial lined lower (Barret) oesophagus

Hawe, A., Payne, W. S., Weiland, L. H., and Fontana, R. S. (1973).Thorax, 28, 511-514. Adenocarcinoma in the columnar epithelial lined lower (Barrett) oesophagus. At the Mayo Clinic, five patients with Barrett oesophagus developed adenocarcinoma of the oesophagus at sites cephalad from the anatomic cardia but separated from it by a definite segment of columnar lined oesophagus. Twelve similar cases have been reported in the literature, including one from this institution. Of 85 Mayo Clinic patients in whom a clinical diagnosis of benign Barrett oesophagus was made in the 20-year period 1950-69, two subsequently developed oesophageal cancer. Since its description in 1950 by Barrett, the columnar epithelial lined lower oesophagus has been encountered with increasing frequency. The full clinical implications of this unusual condition are only partially appreciated at this time, and the present report, as well as previous ones, suggest that the condition may be premalignant.

Capillary electrophoresis-mass spectrometry using noncovalently coated capillaries for the analysis of biopharmaceuticals

In this work, the usefulness of capillary electrophoresis-electrospray ionization time-of-flight-mass spectrometry for the analysis of biopharmaceuticals was studied. Noncovalently bound capillary coatings consisting of Polybrene-poly(vinyl sulfonic acid) or Polybrene-dextran sulfate-Polybrene were used to minimize protein and peptide adsorption, and achieve good separation efficiencies. The potential of the capillary electrophoresis-mass spectrometry (CE-MS) system to characterize degradation products was investigated by analyzing samples of the drugs, recombinant human growth hormone (rhGH) and oxytocin, which had been subjected to prolonged storage, heat exposure, and/or different pH values. Modifications could be assigned based on accurate masses as obtained with time-of-flight-mass spectrometry (TOF-MS) and migration times with respect to the parent compound. For heat-exposed rhGH, oxidations, sulfonate formation, and deamidations were observed. Oxytocin showed strong deamidation (up to 40%) upon heat exposure at low pH, whereas at medium and high pH, mainly dimer (>10%) and trisulfide formation (6-7%) occurred. Recombinant human interferon-β-1a (rhIFN-β) was used to evaluate the capability of the CE-MS method to assess glycan heterogeneity of pharmaceutical proteins. Analysis of this N-glycosylated protein revealed a cluster of resolved peaks which appeared to be caused by at least ten glycoforms differing merely in sialic acid and hexose N-acetylhexosamine composition. Based on the relative peak area (assuming an equimolar response per glycoform), a quantitative profile could be derived with the disialytated biantennary glycoform as most abundant (52%). Such a profile may be useful for in-process and quality control of rhIFN-β batches. It is concluded that the separation power provided by combined capillary electrophoresis and TOF-MS allows discrimination of highly related protein species.

Pulmonary atresia or severe stenosis and coronary artery-to-pulmonary artery fistula

Five patients have had the common features of pulmonary atresia or severe stenosis associated with a septal defect and a coronary artery-to-pulmonary artery (CA-PA) fistula. Four had pulmonary valvular atresia, and one had severe pulmonary stenosis. In all five, the CA-PA fistula contributed the principal component of the pulmonary blood flow. Cyanosis, continuous murmur, right ventricular hypertrophy, and decreased or normal pulmonary vascularity were frequent clinical manifestations, but angiocardiography was required to establish the diagnosis. The fistula was a side-to-side communication between the left coronary artery and the main pulmonary artery in each of the five patients. The dilated proximal coronary artery connecting the aortic root with the pulmonary artery gave a unique angiocardiographic appearance distinguishing it from truncus arteriosus or aorticopulmonary window. It is suggested that this unique angiocardiographic appearance be called an "aorticopulmonary tunnel." The surgical repair of this anomaly is closely related to that for severe tetralogy of Fallot and should involve a comparable risk and achieve a comparable result.

Radiation therapy and mechanical dilation of endobronchial obstruction secondary to Wegener's granulomatosis

A patient with Wegener's granulomatosis, which was otherwise well controlled with steroids and cyclophosphamide, had persistent total obstruction of an inflamed left mainstem bronchus. The inflammation resolved, and the lung expanded following radiation therapy. However, intermittent atelectasis and pneumonia occurred distal to a residual short stricture. Repeated dilation endoscopically with Plummer bougies has proven effective in maintaining good ventilation and preventing recurrence of the atelectasis and pneumonia in the left lung for 18 months.

Embolic complications following repair of atrial septal defects

Postoperative embolism occurred in 35 of 546 patients traced for 2 to 15 years after surgical repair of uncomplicated ASD. A total of 58 embolic episodes occurred, resulting in the death of 11 of these 35 patients. The incidence of embolism was not significantly related to the technique used for surgical repair. Six of the nine patients who had had a preoperative embolism also had an embolism in the postoperative period. The most significant factors associated with an increased risk of postoperative embolism were increased age of the patient, atrial fibrillation, and pulmonary hypertension, all of which are interrelated: seventy-seven per cent (27/35) of patients having a postoperative embolism had either atrial fibrillation or pulmonary hypertension, and 77% (27/35) of patients with postoperative embolism were more than 40 years old at the time of the first embolism. Because actuarial analysis suggests that 30% of patients more than 40 years of age who have atrial fibrillation after repair of ASD may have an embolism within 10 years postoperatively, continuation of anticoagulation therapy indefinitely in these patients is suggested. The highest risk of embolism occurs in the early postoperative period, suggesting the advisability of anticoagulation therapy for all adult patients during convalescence.

Forced degradation of cell-based medicinal products guided by flow imaging microscopy: Explorative studies with Jurkat cells

Cell-based medicinal products (CBMPs) offer ground-breaking opportunities to treat diseases with limited or no therapeutic options. However, the intrinsic complexity of CBMPs results in great challenges with respect to analytical characterization and stability assessment. In our study, we submitted Jurkat cell suspensions to forced degradation studies mimicking conditions to which CBMPs might be exposed from procurement of cells to administration of the product. Flow imaging microscopy assisted by machine learning was applied for determination of cell viability and concentration, and quantification of debris particles. Additionally, orthogonal cell characterization techniques were used. Thawing of cells at 5 °C was detrimental to cell viability and resulted in high numbers of debris particles, in contrast to thawing at 37 °C or 20 °C which resulted in better stability. After freezing of cell suspensions at -18 °C in presence of dimethyl sulfoxide (DMSO), a DMSO concentration of 2.5% (v/v) showed low stabilizing properties, whereas 5% or 10% was protective. Horizontal shaking of cell suspensions did not affect cell viability, but led to a reduction in cell concentration. Fetal bovine serum (10% [v/v]) protected the cells during shaking. In conclusion, forced degradation studies with application of orthogonal analytical characterization methods allow for CBMP stability assessment and formulation screening.

Imaging Flow Cytometry for Sizing and Counting of Subvisible Particles in Biotherapeutics

Imaging flow cytometry (IFC), a technique originally designed for cellular imaging, is featured by the parallel acquisition in brightfield (BF), fluorescence (FL), and side scattering channels. Introduced to the field of subvisible particle analysis in biopharmaceuticals roughly ten years ago, it has the potential to yield additional information, e.g., on particle origin. Here, we present an extensive, systematic development of masks for IFC image analysis to optimize the accuracy of size determination of polystyrene beads and pharmaceutically relevant particles (protein, silicone oil) in BF and FL channels. Based on the developed masks, particle sizing and counting by IFC are compared to flow imaging microscopy (FIM). Mask verification based on fluorescent polystyrene particles revealed good agreement between sizes obtained from IFC and FIM. In the evaluation of counting accuracy, IFC reported lower concentrations for polystyrene particle standards than FIM. For the analysis of fluorescently stained silicone oil and protein particles however, IFC FL imaging reported higher particle concentrations in the low micrometer size range. Overall, we identified IFC as suitable tool to generate supportive data for particle characterization purposes or trouble shooting activities, but not as routine quantitative technique, e.g., for subvisible particle analysis during drug product development or quality control.