Feasibility and Safety of Tethered Capsule Endomicroscopy in Patients With Barrett's Esophagus in a Multi-Center Study

BACKGROUND & AIMS

Tethered capsule endomicroscopy (TCE) involves swallowing a small tethered pill that implements optical coherence tomography (OCT) imaging, procuring high resolution images of the whole esophagus. Here, we demonstrate and evaluate the feasibility and safety of TCE and a portable OCT imaging system in patients with Barrett's esophagus (BE) in a multi-center (5-site) clinical study.

METHODS

Untreated patients with BE as per endoscopic biopsy diagnosis were eligible to participate in the study. TCE procedures were performed in unsedated patients by either doctors or nurses. After the capsule was swallowed, the device continuously obtained 10-μm-resolution cross-sectional images as it traversed the esophagus. Following imaging, the device was withdrawn through mouth, and disinfected for subsequent reuse. BE lengths were compared to endoscopy findings when available. OCT-TCE images were compared to volumetric laser endomicroscopy (VLE) images from a patient who had undergone VLE on the same day as TCE.

RESULTS

147 patients with BE were enrolled across all sites. 116 swallowed the capsule (79%), 95/114 (83.3%) men and 21/33 (63.6%) women (P = .01). High-quality OCT images were obtained in 104/111 swallowers (93.7%) who completed the procedure. The average imaging duration was 5.55 ± 1.92 minutes. The mean length of esophagus imaged per patient was 21.69 ± 5.90 cm. A blinded comparison of maximum extent of BE measured by OCT-TCE and EGD showed a strong correlation (r = 0.77-0.79). OCT-TCE images were of similar quality to those obtained by OCT-VLE.

CONCLUSIONS

The capabilities of TCE to be used across multiple sites, be administered to unsedated patients by either physicians or nurses who are not expert in OCT-TCE, and to rapidly and safely evaluate the microscopic structure of the esophagus make it an emerging tool for screening and surveillance of BE patients. Clinical trial registry website and trial number: NCT02994693 and NCT03459339.

Alterations in cardiac adrenergic signaling and calcium cycling differentially affect the progression of cardiomyopathy

The medical treatment of chronic heart failure has undergone a dramatic transition in the past decade. Short-term approaches for altering hemodynamics have given way to long-term, reparative strategies, including beta-adrenergic receptor (betaAR) blockade. This was once viewed as counterintuitive, because acute administration causes myocardial depression. Cardiac myocytes from failing hearts show changes in betaAR signaling and excitation-contraction coupling that can impair cardiac contractility, but the role of these abnormalities in the progression of heart failure is controversial. We therefore tested the impact of different manipulations that increase contractility on the progression of cardiac dysfunction in a mouse model of hypertrophic cardiomyopathy. High-level overexpression of the beta(2)AR caused rapidly progressive cardiac failure in this model. In contrast, phospholamban ablation prevented systolic dysfunction and exercise intolerance, but not hypertrophy, in hypertrophic cardiomyopathy mice. Cardiac expression of a peptide inhibitor of the betaAR kinase 1 not only prevented systolic dysfunction and exercise intolerance but also decreased cardiac remodeling and hypertrophic gene expression. These three manipulations of cardiac contractility had distinct effects on disease progression, suggesting that selective modulation of particular aspects of betaAR signaling or excitation-contraction coupling can provide therapeutic benefit.

Immunologic response to a single dose of tetanus toxoid in older people

OBJECTIVES

Several studies have demonstrated that a large percentage of older people are inadequately immunized against tetanus. The aim of this study was to assess the immunity against tetanus in a group of individuals aged 69 and older and to examine the immune response to a single dose of tetanus toxoid.

DESIGN

A convenience sample of 115 residents of a large retirement home, aged 69 and older, was studied. After a blood sample for anti-tetanus antibody titer, a single dose of tetanus toxoid vaccine was administered. Repeat titers were obtained 6 weeks after the vaccination and analyzed by ELISA assay. Antibody levels equal to or greater than 0.1 IU/mL were considered protective.

RESULTS

Sixty-seven of 115 (58.3%) individuals had adequate antibody titers. Those individuals who reported having been vaccinated with tetanus toxoid in the past were more likely to be immunized adequately compared with those who reported having never been vaccinated (66.7% vs 39.3%, P = .02). After vaccination, 34 of 46 (73.9%) individuals with inadequate antibody titers became seropositive. Those who remained seronegative had mean prevaccination antibody titers significantly lower than those who seroconverted. Sixteen of 17 (94.1%) persons who reported having been vaccinated in the past and were found to be seronegative developed adequate antibody titers following vaccination, compared with only nine of 16 (56.2%) who reported never having been vaccinated (P = .04). There was no association between seroconversion rate and age, sex, underlying diseases, and army service.

CONCLUSIONS

Most individuals will develop an adequate anti-tetanus antibody titer following administration of a single dose of tetanus vaccine. A history of past immunization is a good predictor of becoming adequately immunized. It is important that physicians follow the current recommendations for adult immunization and initiate campaigns to ensure that the older population is protected against tetanus.

Hypopituitarism in Two Brothers Born by Breech Delivery

OBJECTIVE

To describe two brothers with hypopituitarism who had been born by breech delivery and to discuss whether this condition corresponds to a familial form or to a pituitary stalk section as a result of the breech delivery.

METHODS

We present the clinical, biochemical, and magnetic resonance imaging (MRI) characteristics of two Mexican brothers, 19 and 21 years old, with hypopituitarism and a history of breech delivery.

RESULTS

Physical examination of both patients showed short stature with normal body proportions, an obviously younger appearance than that expected for their chronologic age, high-pitched voice, irregularly positioned teeth, no axillary or pubic hair, and prepubertal genitalia. Biochemical testing showed low thyroxine and free thyroxine values with inadequate or normal thyrotropin, low basal testosterone, and mildly increased serum prolactin levels. Stimulation tests showed a normal and a delayed thyrotropin response to thyrotropin-releasing hormone, subnormal serum cortisol, considerably blunted growth hormone (GH) response to insulin-induced hypoglycemia, and absence of GH response to GH-releasing hormone in both cases. MRI showed an ectopic neuropituitary gland. In case 1, a caudal portion of a very thin pituitary stalk was observed, suggesting the preservation of a vascular component of the stalk. Because both parents of these brothers shared the major histocompatibility complex haplotype HLA-A*2301, B*3501, DRB1*0407, DQA1*03, DQB1*0201, consanguinity was suggested.

CONCLUSION

The phenotype of these patients differs from that described in families with POU1F1 (Pit-1) and PROP1 mutations. These cases are most likely related to an autosomal recessive gene mutation that warrants further research. To our knowledge, this is the first report of hypopituitarism in two brothers born by breech delivery.

Diabetes knowledge and its determinants in a Mexican population

PURPOSE

The purpose of this study was to measure the level of diabetes knowledge in a representative group of Mexican individuals with diabetes and to identify the factors that influence it.

METHODS

A validated questionnaire was administered to 570 outpatients; 11.2% had Type 1 diabetes, 36.4% had Type 2 diabetes treated with insulin, and 52.2% had Type 2 diabetes treated with oral agents. Samples for HbA1c determination also were obtained.

RESULTS

The percentage of correct answers in each section of the questionnaire was low. Type 1 patients had the highest scores, followed by the insulin-treated Type 2 patients; those with chronic complications also had high scores. Educational background, attendance at diabetes courses, age, and HbA1c concentration were the main predictors of knowledge. Attendance at courses was influenced by the severity of the disease.

CONCLUSIONS

The amount of patient knowledge about diabetes-related issues was low in this representative Mexican population. The educational efforts were focused on those with the worst metabolic control and/or with diabetes complications.

Mechanism of tumorigenesis of renal carcinomas associated with the constitutional chromosome 3;8 translocation

PURPOSE

Members of a family carrying a constitutional balanced translocation [t(3;8) (p14;q24)] have a high risk of developing multiple, bilateral clear-cell renal carcinomas. Two genetic mechanisms of carcinogenesis for this malignancy have been proposed: (1) disruption of a gene at the translocation breakpoint and (2) mutation of the von Hippel-Lindau tumor-suppressor gene at 3p25. This study further evaluates the role of the von Hippel-Lindau gene in the etiology and pathogenesis of t(3;8)-associated renal carcinomas.

METHODS

Two new t(3;8)-associated renal carcinomas were tested for mutations in the von Hippel-Lindau gene by single-stranded conformational polymorphism analysis followed by direct DNA sequencing, for loss of alleles on chromosomes 3p and 8, and for methylation abnormalities in the first cloned exon of the von Hippel-Lindau gene.

RESULTS

A missense mutation in the von Hippel-Lindau gene was found in one of the two t(3;8)-associated renal carcinomas. This mutation would produce a stop codon and a truncated protein. Both tumors showed a loss of alleles on the derivative 8 chromosome. When these results were combined with the results of our previous studies, two of the four t(3;8)-associated renal carcinomas, which were examined for molecular genetic changes, showed different von Hippel-Lindau somatic mutations. All renal tumors from the 3;8 translocation family showed loss of the translocated portion of chromosome 3.

CONCLUSIONS

These results support a mechanism of tumorigenesis in the chromosome (3;8) translocation family that involves the loss of both copies of the von Hippel-Lindau gene.