MRI intensity inhomogeneity correction by combining intensity and spatial information

We propose a novel fully automated method for retrospective correction of intensity inhomogeneity, which is an undesired phenomenon in many automatic image analysis tasks, especially if quantitative analysis is the final goal. Besides most commonly used intensity features, additional spatial image features are incorporated to improve inhomogeneity correction and to make it more dynamic, so that local intensity variations can be corrected more efficiently. The proposed method is a four-step iterative procedure in which a non-parametric inhomogeneity correction is conducted. First, the probability distribution of image intensities and corresponding second derivatives is obtained. Second, intensity correction forces, condensing the probability distribution along the intensity feature, are computed for each voxel. Third, the inhomogeneity correction field is estimated by regularization of all voxel forces, and fourth, the corresponding partial inhomogeneity correction is performed. The degree of inhomogeneity correction dynamics is determined by the size of regularization kernel. The method was qualitatively and quantitatively evaluated on simulated and real MR brain images. The obtained results show that the proposed method does not corrupt inhomogeneity-free images and successfully corrects intensity inhomogeneity artefacts even if these are more dynamic.     

Very fast analysis of impurities in immunoglobulin concentrates using conjoint liquid chromatography on short monolithic disks

Transferrin and albumin are often present in immunoglobulin G (IgG) concentrates and are considered as impurities. Therefore, it is important to determine their concentration in order to obtain a well-characterized biological product. Here, we describe their determination based on conjoint liquid chromatography (CLC). The established method combines two different chromatographic modes in one step: affinity and ion-exchange chromatography (IEC) combined in one column. Therefore, two CIM Protein G and one CIM quaternary amine (QA) monolithic disks were placed in series in one housing forming a CLC monolithic column. Binding conditions were optimized in a way that immunoglobulins were captured on the CIM Protein G disks, while transferrin and albumin were bound on the CIM QA disks. Subsequently, transferrin and albumin were eluted separately by a stepwise gradient with sodium chloride, whereas immunoglobulins were released from the Protein G ligands by applying low pH. A complete separation of all three proteins was achieved in less than 5 min. The method permits the quantification of albumin and transferrin in IgG concentrates and has been successfully validated.     

Biliary and pancreatic secretions influence experimental duodenal ulcer without affecting gastric secretion in the rat

The effect of the absence of biliary and/or pancreatic secretions in the duodenum or the enhanced presence of bile at the proximal duodenum on the incidence, severity, number, and location of cysteamine-induced duodenal ulcers was investigated in the rat. Cysteamine produced ulcers on the anterior wall of the duodenum in 75% and on the posterior wall (kissing ulcers) in 50% of the animals. Diversion of biliary and/or pancreatic secretions from the duodenum increased both the severity and the incidence of the posterior duodenal ulcers. Diversion of bile to the proximal duodenum, on the other hand, decreased the severity as well as the incidence of the anterior duodenal ulcers. Mortality in rats receiving cysteamine correlated with the severity of ulcers. Taurocholic acid at nontoxic doses given subcutaneously or orally to nonoperated rats and rats which had bile diverted to the proximal duodenum aggravated the cysteamine-caused duodenal ulcers. Neither proximal nor distal diversion of bile had a major effect on gastric secretion of acid and pepsin in normal or cysteamine-treated rats. We conclude that both bile and pancreatic secretions may directly influence the development of cysteamine-induced duodenal ulcers in the rat.These studies were supported in part by a grant (AM25229) and Research Career Development Award (AM00600) to S. Szabo from NIH and U.S. Public Health Service.     

Effect of von Willebrand Factor and its proteolytic fragments on kinetics of interaction between the light and heavy chains of human factor VIII

It was previously shown that vWF increases the rate of divalent cation-mediated fVIII reconstitution from isolated light chain (LCh) and heavy chain (HCh) subunits. We examined the effect of vWF on kinetic parameters for interaction between LCh and HCh in the presence of Ca2+ and Mn2+ ions, the most effective mediators of fVIII reconstitution from isolated subunits, and determined the minimal structural portion of vWF able to enhance fVIII formation. We found that affinity (Kd) for LCh/HCh binding mediated by Ca2+ and Mn2+ was 91 and 34.9 nM in the absence of vWF and 15.5 and 5.6 nM in its presence. This decrease of Kd resulted from a sixfold increase of the association rate constant (k(on)) for this interaction. The value of the dissociation rate constant (k(off)) for LCh/HCh complex was lower in the presence of Mn2+ (k(off) 4.6x 10(-6) s(-1)) than Ca2+ (k(off) 8.4 x 10(-6) s(-1)) but in both cases vWF had no effect on k(off). This indicates that at physiological concentration of 1 nM the rate of fVIII inactivation via dissociation to subunits would be entirely determined by the k(off) value, and it should not depend on the presence of vWF. Indeed, our experiments demonstrated that vWF did not have any effect on the rate of fVIII inactivation resulting from its dissociation to subunits at the physiological concentrations of the fVIII and vWF proteins. We identified the minimal portion of the vWF molecule, able to enhance reconstitution of fVIII from isolated subunits. Only vWF large proteolytic N-terminal homodimeric fragment SPIII (vWF residues 1-1365), but not small monomeric N-terminal fragment SPIII-T4 (1-272), both of which are known to contain a major fVIII binding site, was able to support reconstitution of fVIII activity from isolated LCh and HCh subunits in the presence of Mn2+ or Ca2+. The effect of SPIII on the LCh/HCh association was similar to that of vWF, because both proteins identically increased of the value of k(on) and did not alter the k(off) value.     

Plastic and Reconstructive Body Contouring in the Post-vertical Banded Gastroplasty Patient: a retrospective review

Class IV obesity (body mass index > 40) is associated with an increased risk of a variety of health problems, many of them potentially life-threatening or life-shortening. Vertical banded gastroplasty (VBG) is currently the most frequently performed surgical procedure used to restrict food intake and assist with weight loss. After massive weight loss, however, redundant abdominal and breast tissue can result in physiological and psychological problems related to an unusual body habitus. Patients complain of difficulties with daily activities, choice of clothing, social acceptance, etc. Body contouring has proven to be an important part of the rehabilitation of the morbidly obese patient, and we have therefore reviewed the records of 55 patients who experienced massive weight loss following VBG and then underwent abdominoplasty with or without mammoplasty/mastopexy, in order to assess the parameters which will be seen more frequently in the future by plastic surgeons as bariatric surgery becomes more widely accepted and performed.     

Cancer Incidence in Kentucky, Pennsylvania, and West Virginia: Disparities in Appalachia

CONTEXT: Composed of all or a portion of 13 states, Appalachia is a heterogeneous, economically disadvantaged region of the eastern United States. While mortality from cancer in Appalachia has previously been reported to be elevated, rates of cancer incidence in Appalachia remain unreported. PURPOSE: To estimate Appalachian cancer incidence by stage and site and to determine if incidence was greater than that in the United States. METHODS: Using 1994--1998 data from the central registries of Kentucky, Pennsylvania, and West Virginia, age-adjusted incidence rates were calculated for the rural and nonrural regions of Appalachia. These state rates were compared to rates from the Surveillance, Epidemiology, and End Results (SEER) program for the same years by calculating the adjusted rate ratio (RR) and a 95% confidence interval (CI). FINDINGS: Both the entire and rural Appalachian regions had an adjusted incidence rate for all cancer sites similar to the SEER rate (RR = 1.00 [95% CI, 1.00-1.01] and RR = 0.99 [95% CI, 0.99-1.00], respectively). However, incidence of cancer of the lung/ bronchus, colon, rectum, and cervix in Appalachia was significantly elevated (RR = 1.22 [95% CI, 1.20-1.23], 1.13 [95% CI, 1.11-1.14], 1.19 [95% CI, 1.16-1.22], and 1.12 [95% CI, 1.07-1.17], respectively). Incidence of cancer of the lung/bronchus and cervix in rural Appalachia was even more elevated (RR = 1.34 [95% CI, 1.31-1.36] and 1.29 [95% CI, 1.21-1.38], respectively). Incidence of unstaged disease for all cancer sites in Appalachia (RR = 1.06 [95% CI, 1.05-1.08]), particularly rural Appalachia (RR = 1.28 [95%CI, 1.25-1.301), was elevated. CONCLUSIONS: Cancer incidence in Appalachia was not found to be elevated. However, incidence of cancer of the lung/bronchus, colon, rectum, and cervix was elevated in Appalachia. The rates of unstaged cancer of every examined site were elevated in rural Appalachia, suggesting a lack of access to cancer health care.     

Temporomandibular disorder in a patient with pseudoxanthoma elasticum: a case report and review

Pseudoxanthoma elasticum (PXE) is a disorder characterized by progressive degeneration of elastic fibers and ectopic mineralization. Cutaneous manifestations are a hallmark of this disease and organs that may be affected by the disease process include cardiovascular, central nervous system, ocular and gastrointestinal systems. Oral manifestations of PXE have been previously reported as intramucosal nodules observed on various intraoral surfaces. We present a case of a 46‐year‐old female with PXE diagnosed with temporomandibular disorder (TMD). To our knowledge, this is the first report of a patient with TMD coexisting with PXE in the scientific literature.