Biennial Endoscopic Surveillance of Gastrointestinal Metaplasia and Its Subtypes Reduces Gastric Cancer Mortality and Is Cost-Effective in a Markov State Transition Model

OBJECTIVES

Gastric cancer in the United States has a low survival rate mainly because of the late stage of diagnosis. Furthermore, there are no well-established guidelines concerning screening and surveillance even for higher risk patients such as those with nondysplastic noncardia gastrointestinal metaplasia (GIM), and thus they are not routinely performed. This study was designed to provide new evidence-based data that can be used to support the implementation of biennial surveillance guidelines in individuals with nondysplastic noncardia GIM. This practice can help detect early malignant lesions, thereby decreasing morbidity and mortality. We evaluated the cost-effectiveness of surveillance endoscopies for noncardia gastric cancer in populations with two different pathological diagnoses: mixed GIM and incomplete GIM (iGIM).

METHODS

Markov state transition models were developed using a cohort simulation of 1000 hypothetical patients. Analysis was conducted for both mixed and iGIM. Quality-adjusted life-years and transition probabilities were derived from the published medical literature. Costs associated with endoscopy, cancer care, and surgery were based on Medicare reimbursement. A willingness-to-pay threshold of $100,000 per quality-adjusted life-year was used to determine cost-effectiveness.

RESULTS

Our study determined that it is significantly cost-effective to perform biennial endoscopy surveillance in patients who have been incidentally found to have noncardia mixed GIM, with a cost savings of $5783.84 per person, and in those with iGIM, with a cost savings of $8093.08 per person.

CONCLUSIONS

Biennial endoscopy surveillance should be considered in all individuals found to have mixed or incomplete noncardia GIM on endoscopy. Furthermore, screening specifically for iGIM after differentiating between the two groups can lead to further cost savings. As such, we recommend that pathologists routinely differentiate between the two and recommend robust routine surveillance of iGIM.

The Epithelial-Stromal Microenvironment in Early Colonic Neoplasia

Stromal cells play a central role in promoting the progression of colorectal cancer. Here, we analyze molecular changes within the epithelial and stromal compartments of dysplastic aberrant crypt foci (ACF) formed in the ascending colon, where rapidly developing interval cancers occur. We found strong activation of numerous neutrophil/monocyte chemokines, consistent with localized inflammation. The data also indicated a decrease in interferon signaling and cell-based immunity. The immune checkpoint and T-cell exhaustion gene PDCD1 was one of the most significantly upregulated genes, which was accompanied by a decrease in cytotoxic T-cell effector gene expression. In addition, CDKN2A expression was strongly upregulated in the stroma and downregulated in the epithelium, consistent with diverse changes in senescence-associated signaling on the two tissue compartments. IMPLICATIONS: Decreased CD8 T-cell infiltration within proximal colon ACF occurs within the context of a robust inflammatory response and potential stromal cell senescence, thus providing new insight into potential promotional drivers for tumors in the proximal colon.

A Review of Hepatitis B Virus and Hepatitis C Virus Immunopathogenesis

Despite the advances in therapy, hepatitis B virus (HBV) and hepatitis C virus (HCV) still represent a significant global health burden, both as major causes of cirrhosis, hepatocellular carcinoma, and death worldwide. HBV is capable of incorporating its covalently closed circular DNA into the host cell's hepatocyte genome, making it rather difficult to eradicate its chronic stage. Successful viral clearance depends on the complex interactions between the virus and host's innate and adaptive immune response. One encouraging fact on hepatitis B is the development and effective distribution of the HBV vaccine. This has significantly reduced the spread of this virus. HCV is a RNA virus with high mutagenic capacity, thus enabling it to evade the immune system and have a high rate of chronic progression. High levels of HCV heterogeneity and its mutagenic capacity have made it difficult to create an effective vaccine. The recent advent of direct acting antivirals has ushered in a new era in hepatitis C therapy. Sustained virologic response is achieved with DAAs in 85-99% of cases. However, this still leads to a large population of treatment failures, so further advances in therapy are still needed. This article reviews the immunopathogenesis of HBV and HCV, their properties contributing to host immune system avoidance, chronic disease progression, vaccine efficacy and limitations, as well as treatment options and common pitfalls of said therapy.

Esophageal Cancer: An Updated Review

The incidence of esophageal cancer (EC) is on the rise. With the distinct subtypes of adenocarcinoma and squamous cell carcinoma comes specific risk factors, and as a result, people of certain regions of the world can be more prone to a subtype. For example, squamous cell carcinoma of the esophagus has the highest incidence in eastern Africa and eastern Asia, with smoking being a major risk factor, whereas adenocarcinoma is more prevalent in North America and western Europe, with gastroesophageal reflux disease being a leading risk factor. With that being said, adenocarcinoma and squamous cell carcinoma have similar and unfortunately poor survival rates, partly because EC is prone to early metastasis given that the esophagus does not have a serosa, as well as the superficial nature of its lymphatics compared with the rest of the gastrointestinal tract. This makes early detection of the utmost importance, and certain patients have been shown to have the benefit of screening/surveillance endoscopies, including those with Barrett's esophagus, lye-induced/caustic strictures, tylosis, and Peutz-Jeghers syndrome. Until treatments significantly improve, identifying EC at the earliest stage will have the best success for patient outcomes, and further elucidation of its pathogenesis and risk factors may lead to identifying other high-risk groups that should be screened.

Is the anesthesiologist necessary in the endoscopy suite? A review of patients, payers and safety

The use of propofol for sedation during endoscopy has been increasing, particularly given its association with superior patient satisfaction. Propofol sedation may also allow for higher quality endoscopy exams, increased efficiency of endoscopy suites and most particularly, permit better patient compliance with colonoscopy for colorectal cancer screening. However, propofol is typically provided by anesthesia specialists via monitored anesthesia care, and is associated with significant economic burden. Given the increasing use of monitored anesthesia care, which adds significant costs to endoscopy, payers are likely to react with changes in payer policies. One alternative to monitored anesthesia care is non-anesthesiologist administered propofol, which due to safety concerns and a lack of reimbursement has not been widely adopted in the US.

The potential utility of serum CA 72-4 as a marker for stage IV esophageal adenocarcinoma

BACKGROUND

Adenocarcinoma of the esophagus has one of the fastest growing incidence rates of all cancers. The treatment and the prognosis of these patients depend mainly on the clinical stage of their disease. The purpose of this study was to see if CA72-4 can potentially be used as a marker for staging advanced esophageal adenocarcinoma.

METHODS

We enrolled a consecutive sample of 21 patients with biopsy-proven esophageal adenocarcinoma. Serum CA72-4 was then obtained from all patients and compared to the clinical stage of these patients.

RESULTS

CA 72-4 at cut-off value of > or = 7 U/ml has a high diagnostic performance in detecting stage IV esophageal adenocarcinoma: sensitivity (86%), specificity (93%), NPV(0.93), PPV(0.86), LR+ (12), LR- (0.15), and AUC of 8.5 (CI; 0.62-1.0).

CONCLUSION

Clinicians may use serum CA72-41 levels as a predictor of stage IV disease. It may also have utility in reassessing the likelihood of metastatic disease.

Pancreatic cancer: an endoscopic perspective

Pancreatic cancer continues to be a diagnostic and therapeutic challenge. The advent of endoscopic ultrasound-guided interventions have brought about a paradigm shift in the endoscopic approach to diagnosis, treatment and palliation of this common malignancy. The last decade has witnessed significant advances in techniques of endoscopic biliary drainage, endoluminal stenting, celiac plexus neurolysis and image-guided radiation therapy, which have transformed the scope of palliation in pancreatic cancer. Moreover, endoscopic ultrasound-aided intratumoral delivery of fiducials, radioisotopes and chemotherapeutic agents have shown promising results and warrant further investigation. This review summarizes the recent advances in endoscopic applications for the management of pancreatic neoplasms.

Partial rescue of in vivo insulin signalling in skeletal muscle by impaired insulin clearance in heterozygous carriers of a mutation in the insulin receptor gene

AIMS/HYPOTHESIS

Recently we reported the coexistence of postprandial hypoglycaemia and moderate insulin resistance in heterozygous carriers of the Arg1174Gln mutation in the insulin receptor gene (INSR). Controlled studies of in vivo insulin signalling in humans with mutant INSR are unavailable, and therefore the cellular mechanisms underlying insulin resistance in Arg1174Gln carriers remain to be clarified.

SUBJECTS, MATERIALS AND METHODS

We studied glucose metabolism and insulin signalling in skeletal muscle from six Arg1174Gln carriers and matched control subjects during a euglycaemic-hyperinsulinaemic clamp.

RESULTS

Impaired clearance of exogenous insulin caused four-fold higher clamp insulin levels in Arg1174Gln carriers compared with control subjects (p<0.05). In Arg1174Gln carriers insulin increased glucose disposal and non-oxidative glucose metabolism (p<0.05), but to a lower extent than in controls (p<0.05). Insulin increased Akt phosphorylation at Ser473 and Thr308, inhibited glycogen synthase kinase-3alpha activity, reduced phosphorylation of glycogen synthase at sites 3a+3b, and increased glycogen synthase activity in Arg1174Gln carriers (all p<0.05). In the insulin-stimulated state, Akt phosphorylation at Thr308 and glycogen synthase activity were reduced in Arg1174Gln carriers compared with controls (p<0.05), whereas glycogen synthase kinase-3alpha activity and phosphorylation of glycogen synthase at sites 3a+3b were similar in the two groups.

CONCLUSIONS/INTERPRETATION

In vivo insulin signalling in skeletal muscle of patients harbouring the Arg1174Gln mutation is surprisingly intact, with modest impairments in insulin-stimulated activity of Akt and glycogen synthase explaining the moderate degree of insulin resistance. Our data suggest that impaired insulin clearance in part rescues in vivo insulin signalling in muscle in these carriers of a mutant INSR, probably by increasing insulin action on the non-mutated insulin receptors.

Toward more user-friendly electronic endoscopy information systems: role of accessories

The needs placed on today's physician to improve efficiency in the endoscopy unit are nowhere more apparent than in transcribing endoscopy reports. In spite of the constant progress made in currently available electronic endoscopy information systems, the systems lack efficiency and ease of use. Both of these problems could be addressed through the linkage of electronic endoscopy information systems to currently available accessory systems. W review how the linkage of tablet personal computers, voice recognition systems, and web connectivity software, which facilitates communication with electronic-based medical records, can be helpful. The final answer, however, will have to await clinical trials.

Phosphorylation-dependent proline isomerization catalyzed by Pin1 is essential for tumor cell survival and entry into mitosis

Pin1, a member of the parvulin family of peptidyl-prolyl cis-trans isomerases (PPIases) has been implicated in the G2-M transition of the mammalian cell cycle. Pin1 interacts with a series of mitotic phosphoproteins, including Polo-like kinase-1, Cdc25C, and Cdc27, and is thought to act as a phosphorylation-dependent PPIase for these target molecules. Pin1 recognizes phosphorylated serine-proline or threonine-proline peptide-bonds in test substrates up to 1300-fold better than in the respective unphosphorylated peptides. To test directly whether Pin1 regulates the G2-M transition and/or progression through mitosis by catalyzing phosphorylation-dependent prolyl isomerization of essential mitotic targets, we examined the consequences of Pin1 depletion, achieved by (a) overexpression of Pin1 antisense RNA, (b) overexpression of dominant-negative Pin1, and (c) by a known small-molecule Pin1-PPIase inhibitor, juglone. The results of all of the three lines of investigation show that the catalytic activity of Pin1 is essential for tumor cell survival and entry into mitosis.

Rational herbicide design by inhibition of tryptophan biosynthesis

Compounds designed to mimic the tryptophan synthase alpha subunit reactive intermediate were found to be potent inhibitors of the enzyme. These compounds are herbicidal and the herbicidal mode of action was demonstrated to be due to disruption of tryptophan biosynthesis.

Error analysis of surface normals determined by radiometry

Surface normals can be computed from three images of a workpiece taken under three distinct lighting conditions without requiring surface continuity. Radiometric methods are susceptible to systematic errors such as: errors in the measurement of light source orientations; mismatched light source irradiance; detector nonlinearity; the presence of specular reflection or shadows; the spatial and spectral distribution of incident light; surface size, material, and microstructure; and the length and properties of the light source to target path. Typically, a 1° error in surface orientation of a Lambertian workpiece is caused by a 1 percent change in image intensity due to variations in incident light intensity or a 1° change in orientation of a collimated light source. Tests on a white nylon sphere indicate that by using modest error prevention and calibration schemes, surface angles off the camera axis can be computed within 5°, except at edge pixels. Equations for the sensitivity of surface normals to major error sources have been derived. Results of surface normal estimation and edge extraction experiments on various non-Lambertian and textured workpieces are also presented.

Bicuculline blocks diazepam-induced feeding in Syrian hamsters

Bicuculline antagonizes diazepam induced feeding in Syrian hamsters in a dose dependent manner using doses which do not affect running wheel activity. These results suggest that diazepam-induced feeding can be completely and specifically blocked by antagonizing GABA.

A new application of LBNP to measure orthostatic tolerance before and after 0-g simulation (water immersion)

Lower body negative pressure (LBNP) remains an important device for the generation of orthostatic stress in the space flight environment as well as a tool to measure inflight and postflight changes in orthostatic response. These applied levels of LBNP have typically not exceeded 50-60 mm Hg negative pressure. Information is incomplete as to the levels of absolute LBNP orthostatic tolerance, and the factors responsible for their variance. A better definition of the tolerance limits for males and females could be expected to aid the evaluation of lower levels of LBNP. An LBNP device was built to study absolute orthostatic tolerance; additionally, another LBNP device was constructed to permit orthostatic tolerance testing directly after a controlled water immersion period. Absolute LBNP orthostatic tolerance patterns are analyzed for a group of males and females (series I). A preliminary statement on the variations of LBNP orthostatic tolerance after limited periods of water immersion and bed rest is also provided (series II).

Image feature extraction using diameter-limited gradient direction histograms

Features extracted by operators which examine diameter-limited gradient direction histograms are important because they describe images of industrial workpieces efficiently and have the potential for rapid computation via special purpose hardware. When such operators are passed over an image in raster fashion, features such as the following are detected: a strong peak in the direction histogram indicating the presence of a relatively straight edge, a second strong direction indicating a corner, a wide direction group indicating a curved edge, and a uniform distribution of directions over the histogram indicating small holes. Diameter-limited optimization can be used to substantially reduce the number of pixels which have been given feature labels by such operators without losing descriptive power. Feature labels for direction histograms having a second strong direction, a wide direction group, or a uniform distribution might be retained only if all other pixels within a circular aperture have a lower bin value. Pixels with a strong direction label might be retained only if all other pixels within a circular aperture and along the gradient direction have a smaller bin value. Tracking can then be applied to the remaining strong direction pixels in the direction perpendicular to the gradient to achieve representation of edges by endpoints. Experimental results indicate that descriptions which are compatible with human interpretation can be achieved.

Thyroid function in term newborn infants with congenital goiter

Eighty-four term newborn infants without goiter and 45 newborn infants with congenital goiter were studied with regard to thyroid function. The radiologic development of the femoral and tibial epiphyses was evaluated in those with goiter. Fifty-eight percent of the patients had retarded bone age, markedly elevated TSH levels, elevated TBI, decreased total T4I, and decreased PBI values. Forty-two percent of newborn infants with congenital goiter had a normal bone age, normal values for TSH, PBI, and total T4I, and elevated values for TBI. It is concluded that the 58% of the newborn infants with congenital goiter had subtle hypothyroidism. They require substitution therapy with thyroid hormones in order to avoid possible retardation of normal brain development. Patients with congenital goiter who have no biochemical evidence of hypothyroidism should also be treated with thyroid hormones to achieve rapid regression of goiter.