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PubMedDate not supplied

Virtual anatomical three-dimensional fit trial for intra-thoracically implanted medical devices.

Our purpose is to develop a system that converts computed tomography (CT) scans into an interactive three-dimensional (3-D) model of the thoracic cavity. This study will allow for the preoperative determination of optimal anatomical fit of intra-thoracically implanted medical equipment such as circulatory support devices. From the radiology data bank, we consecutively selected 34 cardiac and 42 noncardiac patients who had CT scans of the chest. Anatomical structures of the electronic CT scans were manually extracted using software. These structures included the thoracic cage, lungs, heart, and the great vessels. The information was converted into a 3-D surface mesh model, which was imported into a 3-D viewer to acquire direct anatomical measurements. The thoracic cage and intra-thoracic organs were measured for data analysis. A methodology was successfully developed to convert a patient's thoracic CT scans into interactive 3-D models, permitting the collection of key anatomical measurements to assess intra-thoracic device fit feasibility. Extensive measurements of the reconstructed thoracic cavity were recorded in a database format and analyzed. This study demonstrated the feasibility of implementing a rapid preoperative screening method based on anatomical fit for the selection or rejection of patients who are candidates for an intra-thoracic mechanical device. This new method will allow for the virtual preoperative implantation of such devices within a patient's chest cavity.

Aged↗
PubMed2005

Using the gastroscope for incomplete colonoscopy.

PURPOSE: Reports of virtual colonoscopy demonstrate sensitivity similar to that of conventional colonoscopy for polyps 5 mm or larger, suggesting the validity of its use for colorectal cancer screening. Critical to the success of either procedure is the ability to evaluate the entire colon. Cecal intubation rates during diagnostic or screening colonoscopies vary from 53 to 99 percent. We describe the added value of using a gastroscope to perform a colonoscopic examination that would otherwise result in an incomplete colonoscopy. METHODS: From January 1, 2002 to December 31, 2002 a total of 1,979 colonoscopies were performed. A gastroscope was used in 1.3 percent (n = 26) of these colonoscopies in an effort to complete the index examination initially started with a standard or pediatric colonoscope. The success rate was defined as intubating proximal to the initial area of impasse and entering the cecum. RESULTS: Cecal intubation was achieved in 62 percent of patients. CONCLUSIONS: In patients with incomplete conventional colonoscopy, the gastroscope can usually advance through the initial area of impasse with a cecal intubation rate of 62 percent.

Aged↗
PubMed2003

Management of Patients at High Risk for Pancreatic Cancer.

Because pancreatic cancer patients seldom exhibit disease-specific symptoms until the cancer is at an advanced stage, its diagnosis is a virtual death sentence. Therefore, to make a significant impact on long-term survival for subjects with pancreatic cancer, asymptomatic individuals would have to be screened for premalignant precursors of pancreatic cancer or for asymptomatic pancreatic cancer. A number of formidable obstacles limit the ability of healthcare providers to screen for early neoplastic changes and to make a very early and specific diagnosis of pancreatic cancer. These include lack of a high-risk population for sporadic pancreatic cancer and lack of a simple, noninvasive test sensitive enough to detect small cancers. However, progress is being made in defining various high-risk groups for pancreatic cancer, and improvements in imaging modalities make detection of premalignant lesions and small cancers possible in such individuals. The protocols currently being studied, including use of endoscopic ultrasound and endoscopic retrograde cholangiopancreatography to detect precancerous lesions and small pancreatic cancer in high-risk patients, are still in the research arena and not yet ready for clinical practice.

Journal Article↗
PubMed1985

Identification of a specific epitope of Haemophilus influenzae on a 16,600-dalton outer membrane protein.

A mouse monoclonal antibody that recognizes an epitope on a 16,600-dalton outer membrane protein was developed to nontypable Haemophilus influenzae. This epitope was present on all 115 isolates of H. influenzae tested, including typable and nontypable strains. Screening of 89 strains of other bacteria demonstrated that this epitope is a highly specific marker for H. influenzae because the epitope was absent in virtually all other bacterial species tested. Western blot assays were performed with two normal human serum samples and convalescent-phase serum from an adult with bacteremia due to nontypable H. influenzae. Antibody to the 16,600-dalton outer membrane protein was present in all three human serum samples.

Animals↗
PubMed2004

When to look for Von Hippel-Lindau disease in gastroenteropancreatic neuroendocrine tumors?

Von Hippel-Lindau (VHL) disease is a progressive autosomal dominant multisystem disorder that is associated with a germ line mutation of the VHL gene on the short arm of chromosome 3. A variety of benign and malignant diseases, including eye and CNS hemangioblastomas, renal cell carcinoma and pheochromocytoma are the major components. Gastroenteropancreatic neuroendocrine tumors are also listed among the typical complications, although these occur seldom. Virtually all such tumors are pancreatic islet cell tumors. VHL-associated islet cell tumors are mostly hormone-inactive. They can be detected during screening investigations according to the multidisciplinary disorder or by workup of space-occupying lesions. There are no specific predictors for malignancy in VHL-associated islet cell neoplasias, but tumors smaller than 3 cm in diameter are believed to be always benign. Gadolinium-enhanced MRI is currently the imaging method of choice, but contrast-enhanced CT is also a diagnostic option. The spectrum of manifestations is illustrated by selected cases.

Adenoma, Islet Cell↗
PubMed2006

Linking cDNA-AFLP-based gene expression patterns and ESTs.

Massive amounts of DNA sequence data, generated from expressed sequence tag (EST) and genome sequencing projects, require efficient methods to link sequence databases with temporal and spatial expression profiles. To meet this need, we have developed a powerful computer program (GenEST), which links cDNA sequence data (including EST sequences) with transcript profiles revealed by cDNA-amplified fragment length polymorphism (AFLP). cDNA-AFLP is a highly reproducible differential display method based on restriction enzyme digests and selective amplification under high stringency conditions. GenEST predicts the sizes of virtual transcript derived fragments (TDFs) from cDNA sequences digested in silico. The resulting virtual TDFs could be traced back among the thousands of TDFs displayed on cDNA-AFLP gels. As a consequence, cDNA sequence databases can be screened very efficiently to identify genes with relevant expression profiles. Vice versa, using the restriction enzyme recognition sites, the primer extensions and the estimated TDF size as identifiers, the DNA sequence(s) corresponding to a TDF with an interesting expression pattern can be identified.

Automation↗
PubMed1999

Cortical visuomotor integration during eye pursuit and eye-finger pursuit.

To elucidate cortical mechanisms of visuomotor integration, we recorded whole-scalp neuromagnetic signals from six normal volunteers while they were viewing a black dot moving linearly at the speed of 4 degrees /sec within a virtual rectangle. The dot changed its direction randomly once every 0.3-2 sec. The subject either (1) fixated a cross in the center of the screen (eye fixation task), (2) followed the moving dot with the eyes (eye pursuit task), or (3) followed the dot with both the eyes and the right index finger (eye-finger pursuit task). Prominent magnetic signals, triggered by the changes of the direction of the dot, were seen in all conditions, but they were clearly enhanced by the tasks and were strongest during the eye-finger pursuit task and over the anterior inferior parietal lobule (aIPL). Source modeling indicated activation of aIPL [Brodmann's area (BA) 40], the posterosuperior parietal lobule (SPL; BA 7), the dorsolateral frontal cortex (DLF; BA 6), and the occipital cortex (BA 18/19). The activation first peaked in the occipital areas, then in the aIPL and DLF, and some 50 msec later in the SPL. Our results suggest that all these areas are involved in visuomotor transformation, with aIPL playing a crucial role in this process.

Adult↗
PubMed1989

The hepatitis B immunization programme in Singapore.

A voluntary immunization programme to prevent perinatal transmission of hepatitis B virus (HBV) infection in Singapore was implemented on 1 October 1985 as an integral component of the national childhood immunization programme. Up to April 1988, a total of 68,845 mothers who attended government maternal and child health clinics were screened for the disease. Of these, 2432 (3.5%) were positive for hepatitis B surface antigen (HBsAg) and 904 (1.3%) for hepatitis B e antigen (HBeAg). Virtually all the babies born to carrier mothers completed the full immunization schedule; and in addition, those of HBeAg-positive mothers were given a dose of hepatitis B immunoglobulin at birth. The hepatitis B immunization programme was extended on 1 September 1987 to cover all newborns. About 90% of the 15,943 babies delivered in government institutions from September 1987 to April 1988 were immunized at birth, with the subsequent doses being administered at maternal and child health clinics at 4-6 weeks and 5 months later. More than 85% of the children given the full course of plasma-derived and yeast-derived hepatitis B vaccine from birth continued to have protective antibody to HBV two years after immunization. The programme is being closely monitored to assess the duration of immunity and the need for booster doses, while seronegative adults are also being encouraged to be vaccinated.

Adolescent↗
PubMed1983

Secretion of acid proteinases by different species of the genus Candida.

Strains of several Candida species that are isolated from humans aside of C. albicans have been screened for secretion of acid proteinases. A third of the strains of C. tropicalis was strongly proteolytic, other strains of this species were moderately or virtually nonproteolytic; the variety of activities resembled pattern found among strains of C. albicans (32). Strains of C. parapsilosis produced 24% of the proteolytic activity of strongly proteolytic strains of C. tropicalis. The proteolytic activity of C. pseudotropicalis, C. krusei, and C. glabrata accounted for 7.5, 2.0, and 0.8% respectively. Four strains of C. guilliermondii developed strain-specific proteolysis after prolonged cultivation only. Five proteinases from strains of C. tropicalis cross reacted immunologically as did five proteinases from C. albicans. Interspecific cross reaction, though, was not observed when certain sera from rabbits were employed.

Aspartic Acid Endopeptidases↗
PubMed2004

Simulation of patient encounters using a virtual patient in periodontology instruction of dental students: design, usability, and learning effect in history-taking skills.

Simulations are important educational tools in the development of health care competence. This study describes a virtual learning environment (VLE) for diagnosis and treatment planning in oral health care. The VLE is a web-based, database application where the learner uses free text communication on the screen to interact with patient data. The VLE contains forms for history taking, clinical images, clinical data and X-rays. After reviewing the patient information, the student proposes therapy and makes prognostic evaluations of the case in free text. A usability test of the application was performed with seven dental students. The usability test showed that the software responded with correct answers to the majority of the free text questions. The application is generic in its basic functions and can be adapted to other dental or medical subject areas. A randomised controlled trial was carried out with 39 students who attended instruction in history taking with problem-based learning cases, lectures and seminars. In addition, 16 of the 39 students were randomly chosen to practise history taking using the virtual patient prior to their first patient encounter. The performance of each student was recorded on video during the patient sessions. The type and order of the questions asked by the student and the degree of empathy displayed towards the patient were analysed systematically on the videos. The data indicate that students who also undertook history taking with a virtual patient asked more relevant questions, spent more time on patient issues, and performed a more complete history interview compared with students who had only undergone standard teaching. The students who had worked with the virtual patient also seemed to have more empathy for the patients than the students who had not. The practising of history taking with a virtual patient appears to improve the capability of dental students to take a relevant oral health history.

Clinical Competence↗
PubMed1991

Laboratory quality control issues related to screening newborns for cystic fibrosis using immunoreactive trypsin.

We have incorporated the IRT assay for CF to our newborn screening program, relying heavily on electronic data processing to optimize the test results in order to provide the most reliable data possible from the specimen at hand. We have established an internal cut-off of 100 ng/mL and an external referral of 180 ng/mL; this virtually eliminates the possibility that analytical imprecision will result in misidentifying a positive patient specimen. The relationship between IRT levels and various mutant forms of CF are not well established, and it is possible that various forms of CF may exhibit different levels of IRT in the first few days of life. We believe that IRT screening for CF could be a useful procedure for early identification of potential CF. However, by comparison with other newborn screening tests, its sensitivity, 90%, presents a concern. The expectation for PKU, hypothyroidism, MSUD, and galactosemia screening is 100% sensitivity. A false-negative usually results in litigation. The use of IRT in routine newborn screening will require considerable education of the general public and physicians receiving test results. Our program, along with many others, is anxiously watching the developments in the area of gene testing. We feel the relatively inexpensive IRT, used for mass screening can be successfully coupled with the more definitive (and expensive) gene test on a selected population to identify CF at the earliest possible age in a more effective manner. It is possible that in the near future gene probe tests will be applied in a cost effective manner to the initial filter paper specimen.

Cystic Fibrosis↗
PubMedDate not supplied

Report on the Belgian consensus meeting on colorectal cancer screening.

Screening and prevention of colorectal cancer must be a public health priority. It is the most frequent malignancy in Europe, the second leading cause of cancer death, including Belgium where more than 6000 new cases occur per year. Various screening modalities, from non invasive to invasive are available and currently in use and they are all cost-effective in comparison with no screening. The decision as to which screening test to use should be made by the patient and clinician. Consensus documents prepared by the Belgian scientific community appear in this issue of Acta Gastroenterologica Belgica, summarizing the scientific evidence in favour as well as the limitations of fecal occult blood tests, flexible sigmoidoscopy, videocolonoscopy and virtual colonoscopy.

Belgium↗
PubMedDate not supplied

Medullary carcinoma of the thyroid: current diagnosis and management.

Medullary thyroid carcinoma (MTC) accounts for 5-10% of thyroid malignancies and occurs in either a sporadic or a familial form. The familial form is inherited in an autosomal dominant pattern, and expressed clinically as multiple endocrine neoplasia (MEN), types IIa and IIb, or as familial MTC alone. This neoplasm is derived from the parafollicular or C-cells, and has the ability to secrete a variety of polypeptide hormones including calcitonin, which serves as a tumor marker for the presence of MTC. The development of a calcitonin radioimmunoassay and the screening of patients at risk for the familial forms of MTC allows the diagnosis of the neoplasm in an occult stage when total thyroidectomy results in virtually 100% cure. We will present our experience with the diagnosis, treatment, and postoperative follow-up of our patients with this interesting neoplasm.

Carcinoma↗
PubMed1987

Rigidity in cinema seen from the front row, side aisle.

Pictures and cinema seen at a slant present the optics of virtual objects that are distorted and inconsistent with their real counterparts. In particular, it should not be possible for moving objects on slanted film and television screens to be seen as rigid, at least according to rules of linear perspective. Previous approaches to this problem have suggested that some process (perhaps cognitive) rectifies the optics of objects in slanted pictures to derive true shape and preserve shape constancy. The means for this rectification is usually thought to be based on recovery of true screen slant. In three experiments I show that this account is unnecessary and insufficient to explain the perception of rotating, rectangular objects in slanted cinema. I present data in favor of an alternate view, one in which the information is sufficient for perceivers to determine rigidity in an object on slanted screens, at least for parallel projections. In the human visual system, local measurements of objects are apparently made according to projective geometry; in those measurements, small amounts of certain distortions in projection are tolerated. Stimuli that appear nonrigid are ones that violate certain local principles, known as Perkins's laws, of projections of rectangular solids.

Humans↗
PubMed1995

Requirement for Drosophila cytoplasmic tropomyosin in oskar mRNA localization.

The localization of oskar (osk) RNA to the posterior pole of the developing fruit fly (Drosophila) oocyte induces the assembly of pole plasm, causing development of the abdomen and germ line. Failure to localize oskar RNA results in embryos that lack abdomen and germ cells. Conversely, mis-targeting of oskar RNA to the anterior of the oocyte causes formation of ectopic abdomen and germ cells at the anterior pole. Maternal mutants that have reduced pole plasm activity produce sterile adults with normal abdominal development, suggesting that germ cells are more sensitive than abdomen to defects in pole plasm assembly. Thus mutations in genes that reduce oskar RNA localization or activity can be recovered as viable sterile adults. In a screen for mutants defective in germ cell formation, we isolated nine alleles of the tropomyosin II gene. Here we show that mutations in tropomyosin II (TmII) virtually abolish oskar RNA localization to the posterior pole, suggesting an involvement of the actin network in oskar RNA localization.

Actins↗
PubMed1998

A novel family of ubiquitin-specific proteases in chick skeletal muscle with distinct N- and C-terminal extensions.

We have recently identified a cDNA for a ubiquitin-specific protease (UBP), UBP41, that encodes the smallest functional UBP identified to date, using an Escherichia coli-based in vivo screening method. In the present study we isolated highly related cDNAs encoding a new family of UBP enzymes, named UBP46, UBP52 and UBP66. These UBPs have virtually identical catalytic domains spanning the sequence of UBP41 between the active-site Cys and the His box (95% identity). However, they possess distinct N- and/or C-terminal extensions. Moreover, they are more closely related to each other than to any other members of the UBP family. Thus these chick UBPs must define a novel family of de-ubiquitinating enzymes and should represent the first example among the UBP family enzymes, whose multiplicity is achieved by variation in their N- and C-terminal extensions. The chick UBPs were expressed in E. coli, and purified from the cells to apparent homogeneity using 125I-labelled ubiquitin-alphaNH-MHISPPEPESEEEEEHYC as a substrate. Each of the purified UBP46, UBP52 and UBP66 enzymes behaved as proteins of similar sizes under both denaturing and non-denaturing conditions, suggesting that all of them consist of a single polypeptide chain. The UBP enzymes cleaved the C-terminus of the ubiquitin moiety in natural and engineered fusions irrespective of their sizes and thus are active against ubiquitin-beta-galactosidase as well as a ubiquitin C-terminal extension protein of 80 amino acids. All UBPs except UBP66 released free ubiquitin from poly-His-tagged di-ubiquitin. However, the isopeptidase activity for hydrolysing polyubiquitinated lysozyme conjugates was not detected from these UBPs, which makes these UBPs distinct from UBP41. These results suggest that the chick UBPs may play an important role in production of free ubiquitin from linear polyubiquitin chains and of certain ribosomal proteins from ubiquitin fusion proteins.

Amino Acid Sequence↗
PubMed1992

Cancer prevention education in United States medical schools. Cancer Education Survey II: cancer education in United States medical schools.

The Cancer Education Survey collected data from 126 of 128 US Medical Schools on the current status of cancer-related educational activities for undergraduate medical students. The study was conducted by a Supervisory Committee of the American Association for Cancer Education, with funding from the American Cancer Society. The survey obtained data concerning institutional characteristics in support of undergraduate medical student cancer education, ie, administrative structures, current cancer-related curricula, sources of financial support, and anticipated changes in these characteristics. Institutions were also queried on specific topics of cancer prevention, detection, and diagnosis that might be taught as identifiable areas of instruction for medical students. Three-fourths of the institutions had a lecture on the principles of cancer screening, and, among those, nearly three-fourths classified it as a part of a required course or rotation. Detection of common cancers is taught in virtually all institutions. The least likely cancer prevention lecture topics are related to prevention and cessation of smoking, a well-verified cancer risk. Also, no consistent pattern emerges that might indicate that association with a cancer center imparts to a medical school a greater emphasis on delivery of cancer prevention topics.

American Cancer Society↗
PubMed1976

A cross-national epidemiological study of mania.

An epidemiological study of the first admission rate for mania was carried out in London and Aarhus. The case registers in these two centres were used to conduct a retrospective study of case notes covering several years, and a screening procedure was used for the prospective collection of new cases over the course of one year. The annual incidence of mania was found to be virtually identical in both centres. The retrospective study gave a figure of 2-6 per 100,000 population in both Aarhus and London. But the London sample was found to contain 45 per cent of immigrants in contrast to the Aarhus sample in which only a negligible proportion were born outside Denmark. Male West Indians, in particular, were over-represented in the London sample.

Adolescent↗