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J Anderson

Publications and source records attributed to J Anderson.

At least 145 records · Page 8Linked to original sources
PubMed2000

Recombinant rinderpest vaccines expressing membrane-anchored proteins as genetic markers: evidence of exclusion of marker protein from the virus envelope.

Rinderpest virus (RPV) causes a severe disease of cattle resulting in serious economic losses in parts of the developing world. Effective control and elimination of this disease require a genetically marked rinderpest vaccine that allows serological differentiation between animals that have been vaccinated against rinderpest and those which have recovered from natural infection. We have constructed two modified cDNA clones of the vaccine strain RNA genome of the virus, with the coding sequence of either a receptor site mutant form of the influenza virus hemagglutinin (HA) gene or a membrane-anchored form of the green fluorescent protein (GFP) gene (ANC-GFP), inserted as a potential genetic marker. Infectious recombinant virus was rescued in cell culture from both constructs. The RPVINS-HA and RPVANC-GFP viruses were designed to express either the HA or ANC-GFP protein on the surface of virus-infected cells with the aim of stimulating a strong humoral antibody response to the marker protein. In vitro studies showed that the marker proteins were expressed on the surface of virus-infected cells, although to different extents, but neither was incorporated into the envelope of the virus particles. RPVINS-HA- or RPVANC-GFP-vaccinated cattle produced normal levels of humoral anti-RPV antibodies and significant levels of anti-HA or anti-GFP antibodies, respectively. Both viruses were effective in stimulating protective immunity against RPV and antibody responses to the marker protein in all animals when tested in a cattle vaccination trial.

Animals↗
PubMed2000

Defects in tRNA processing and nuclear export induce GCN4 translation independently of phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2.

Induction of GCN4 translation in amino acid-starved cells involves the inhibition of initiator tRNA(Met) binding to eukaryotic translation initiation factor 2 (eIF2) in response to eIF2 phosphorylation by protein kinase GCN2. It was shown previously that GCN4 translation could be induced independently of GCN2 by overexpressing a mutant tRNA(AAC)(Val) (tRNA(Val*)) or the RNA component of RNase MRP encoded by NME1. Here we show that overexpression of the tRNA pseudouridine 55 synthase encoded by PUS4 also leads to translational derepression of GCN4 (Gcd(-) phenotype) independently of eIF2 phosphorylation. Surprisingly, the Gcd(-) phenotype of high-copy-number PUS4 (hcPUS4) did not require PUS4 enzymatic activity, and several lines of evidence indicate that PUS4 overexpression did not diminish functional initiator tRNA(Met) levels. The presence of hcPUS4 or hcNME1 led to the accumulation of certain tRNA precursors, and their Gcd(-) phenotypes were reversed by overexpressing the RNA component of RNase P (RPR1), responsible for 5'-end processing of all tRNAs. Consistently, overexpression of a mutant pre-tRNA(Tyr) that cannot be processed by RNase P had a Gcd(-) phenotype. Interestingly, the Gcd(-) phenotype of hcPUS4 also was reversed by overexpressing LOS1, required for efficient nuclear export of tRNA, and los1Delta cells have a Gcd(-) phenotype. Overproduced PUS4 appears to impede 5'-end processing or export of certain tRNAs in the nucleus in a manner remedied by increased expression of RNase P or LOS1, respectively. The mutant tRNA(Val*) showed nuclear accumulation in otherwise wild-type cells, suggesting a defect in export to the cytoplasm. We propose that yeast contains a nuclear surveillance system that perceives defects in processing or export of tRNA and evokes a reduction in translation initiation at the step of initiator tRNA(Met) binding to the ribosome.

Alcohol Oxidoreductases↗
PubMed2000

"Virtual" experiment for understanding the electrocardiogram and the mean electrical axis.

Educators have placed an emphasis on the development of laboratory materials that supplement the traditional lecture format. The laboratory materials should encourage active learning, small group discussion, and problem-solving skills. To this end, we developed a virtual experiment designed to introduce students to the theory and application of the electrocardiogram (ECG) and the mean electrical axis (MEA). After reviewing background material, the students will analyze ECG recordings from two individuals who underwent a series of experimental procedures. The students are challenged to reduce and analyze the data, calculate and plot the MEA, and answer questions related to the theory and application of the ECG. In conducting the virtual experiment, students are introduced to inquiry-based learning through experimentation.

Computer Simulation↗
PubMed2000

Rotavirus alters paracellular permeability and energy metabolism in Caco-2 cells.

Rotaviruses infect epithelial cells of the small intestine, but the pathophysiology of the resulting severe diarrhea is incompletely understood. Histological damage to intestinal epithelium is not a consistent feature, and in vitro studies showed that intestinal cells did not undergo rapid death and lysis during viral replication. We show that rotavirus infection of Caco-2 cells caused disruption of tight junctions and loss of transepithelial resistance (TER) in the absence of cell death. TER declined from 300 to 22 Omega. cm(2) between 8 and 24 h after infection and was accompanied by increased transepithelial permeability to macromolecules of 478 and 4,000 Da. Distribution of tight junction proteins claudin-1, occludin, and ZO-1 was significantly altered during infection. Claudin-1 redistribution was notably apparent at the onset of the decline in TER. Infection was associated with increased production of lactate, decreased mitochondrial oxygen consumption, and reduced cellular ATP (60% of control at 24 h after infection), conditions known to reduce the integrity of epithelial tight junctions. In conclusion, these data show that rotavirus infection of Caco-2 intestinal cells altered tight junction structure and function, which may be a response to metabolic dysfunction.

Animals↗
PubMed2000

Enzyme inhibitory antibody to pyruvate dehydrogenase: diagnostic utility in primary biliary cirrhosis.

In primary biliary cirrhosis, autoantibodies are produced to the family of 2-oxoacid dehydrogenase complexes. These 'anti-mitochondrial' antibodies are traditionally detected by immunofluorescence but this method of detection is subjective and labour-intensive. We assessed an enzymatic mitochondrial antibody (EMA) assay based on antibody inhibition of enzymatic activity of pyruvate dehydrogenase complex in wells of microtitre plates with a colorimetric read-out. We tested 48 Australian and 1947 Japanese patients with primary biliary cirrhosis, 306 normal subjects and 691 patients with various hepatic and non-hepatic diseases. The overall sensitivity of the EMA for the diagnosis of primary biliary cirrhosis, 82%, was slightly lower than that of immunofluorescence, 90% The advantages of the EMA test include high specificity, >99%, and semi-automated features facilitating objectivity, rapidity, simplicity and economy. The EMA test could be particularly applicable to population screening for early primary biliary cirrhosis.

Autoantibodies↗
PubMed2000

Bicalutamide treatment for locally advanced prostate cancer.

In men with locally advanced prostate cancer, bicalutamide 150 mg monotherapy provides a similar disease outcome to medical or surgical castration. However, castration is associated with loss of sexual interest and function, decreased energy and an increased risk of osteoporotic fractures. Bicalutamide 150 mg monotherapy has less impact on sexual interest and physical capacity than castration.

Androgen Antagonists↗
PubMed2000

Molecular epidemiology of EBNA-1 substrains of Epstein-Barr virus in posttransplant lymphoproliferative disorders which have infrequent p53 mutations.

Posttransplant lymphoproliferative disorders (PTLDs), which are highly associated with Epstein-Barr virus infection, have a low frequency of molecular genetic abnormalities. Recently it has been suggested certain EBV substrains may be associated with specific lymphoma subtypes. The goals of our study were two fold: 1) to determine the prevalence of EBNA-1 substrains and prognostic utility in PTLD and 2) to determine the incidence of p53 gene mutations and p53 protein overexpression in 32 EBV-positive PTLD cases. Tumor DNA was sequenced to identify EBNA-1 substrains at codon 487 and p53 gene mutations in exons 5-8. The PTLD samples contained the following EBNA-1 substrains: P-thr in 17/32 (53%), P-ala in 11/32 (34%), and V-leu in 4/32 (13%). More heterogeneity within major subtypes was seen in the PTLD cases than in the referral group. A second group of 25 referral (non-PTLD) samples including infectious mononucleosis (6) and sequential EBV positive virology samples (19) contained P-thr in 17/25 (68%); P-ala in 2/25 (8%); and V-leu in 6/25 (24%). In the 29 B-cell PTLD the time to presentation was an average of 13.3 months in the P-ala group, 16.6 months in the P-thr group, and 40.6 months in the V-leu group: (p>0.05). There was no difference in survival in patients (median overall--60 months) between the three different substrains of EBNA-1 (Log rank test, p=0.39). One of 31 (4.1%) cases (a diffuse large cell B-cell) had a p53 mutation. Seven of 31 (23%) cases (all B-cell), including the p53 mutated case, had over-expression of p53 protein. We conclude EBNA-1 substrains vary in PTLD and suggest the pattern reflects the geographical incidence of substrains in the region. We also conclude p53 mutations are not a significant molecular genetic abnormality in PTLD.

Epstein-Barr Virus Infections↗
PubMed2000

Improved patient positioning for percutaneous nephroscopic procedures using a surgical saddle.

PURPOSE: We describe modified patient positioning on the Cloward surgical saddle for use during percutaneous nephroscopic procedures. MATERIALS AND METHODS: The Cloward surgical saddle, which was designed for prone patient positioning, has been used primarily for lumbar surgery. We evaluated the use of the surgical saddle for ease of patient positioning during percutaneous nephroscopic procedures. RESULTS: We have used the surgical saddle in 10 patients to date, including 1 who was 5 feet 8 inches (173 cm.) tall and who weighed 370 pounds (168 kg.). In all cases pulmonary airway pressure was maintained at less than 30 cm. water. We have observed no incidence of pressure injury or other complications associated with position. CONCLUSIONS: Patient positioning during percutaneous nephroscopic surgery is important for preventing pressure injury and allowing adequate pulmonary ventilation. The surgical saddle is an excellent aid for secure patient positioning during percutaneous nephroscopic procedures that helps to minimize the risk of pressure injury and pulmonary compromise.

Beds↗
PubMed2000

On variability of effects for a metaanalysis of rheumatoid arthritis radiographic progression.

Variance of an outcome that is the topic of a metaanalysis may be estimated in a variety of ways. Variances are also not used in the same way in every metaanalysis. The metaanalysis may be of a single measure expressed in its original units, or of several such measures simultaneously, or it may be done using unitless effect sizes. We present some observations and practical recommendations on the estimation and use of variances relating to these several approaches to metaanalysis, as they may apply in a metaanalysis of radiographic progression in rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed2000

Clinical practice guidelines. Review of the recommendations for colorectal screening.

Data suggest that vigilant screening and polyp removal can help reduce mortality caused by colorectal cancer (CRC), the incidence of which increases with age. Although several screening methods are available, wide variation exists among them in accuracy, effectiveness of identifying cancerous lesions, potential complications, costs, ease of administration, and patient compliance. Moreover, a lack of direct evidence demonstrating the long-term benefits (compared with the costs and risks) of the individual screening methods complicates the decision of when and whether to screen. In 1994, an expert, multidisciplinary panel was convened to review the evidence and produce recommendations to help guide clinicians and patients with regard to CRC screening and surveillance. The resulting clinical practice guidelines, released in 1997, are examined.

Age Factors↗
PubMed2000

A novel and consistent amplicon at 13q31 associated with alveolar rhabdomyosarcoma.

Rhabdomyosarcomas are the most common soft-tissue sarcoma found in children. The alveolar subtype is clinically more aggressive than the embryonal subtype. In addition to the presence of specific chromosome translocations and associated fusion gene products in a high proportion of the alveolar subtype, we previously showed that tumors with this histology frequently show evidence of genomic amplification. Here, we substantially extended the number of alveolar rhabdomyosarcoma samples examined by comparative genomic hybridization analysis. Regions of loss were noted, including the smallest overlapping regions corresponding to 16q, 17/17p, and 9q32-34, in 16%, 10%, and 10% of cases, respectively (44 primary samples/6 cell lines). Amplification or gain at 12q13-15 in the region of the MDM2/GLI1/SAS/CDK4 loci and 2p24 at the MYCN locus was found in 28% and 32% of cases, respectively. Single amplicons were found at locations that in other samples showed consistent gain, including the regions 5q15-23, 7q21-31, 11p11-14, 17q23-24, and 20q13, and amplification was found in two cases at 15q24-26. However, most striking was a novel region of amplification or gain at 13q31 in 19% of cases (51 primary samples/6 cell lines). This indicates that a gene or genes at 13q31 are significant in the development or progression of alveolar rhabdomyosarcoma.

Adolescent↗
PubMed2000

H pylori infection. Review of the guideline for diagnosis and treatment.

Helicobacter pylori infection is prevalent among persons over age 60, is strongly associated with peptic and duodenal ulcer, and is caused by a microbe classified as a carcinogen. These factors combine to make the primary care physician key to proper diagnosis and treatment of H pylori infection. In 1998, the American College of Gastroenterology published an evidence-based guideline for the management of this infection. The guideline produced several fundamental recommendations that help clarify the management process: asymptomatic persons should not undergo testing, but testing should be performed on certain persons, testing should only be done if the intention is to treat; the choice of test is governed by the need for endoscopy; and several triple-therapy regimens are effective for eradication.

Aged↗
PubMed2000

Isolated directional preponderance of caloric nystagmus: I. Clinical significance.

OBJECTIVES: To determine the clinical significance of an isolated directional preponderance (DP) on bithermal caloric testing. An isolated caloric DP was defined as a DP, calculated according to the standard Jongkees formula, of > or = 40%, with a spontaneous nystagmus (SN) in darkness of < or = 2 degrees/s and a canal paresis (unilateral weakness) of < or = 25%. STUDY DESIGN: A retrospective analysis of all 15,542 bithermal caloric tests performed in the authors' department in the previous 10 years to identify all tests with an isolated DP of > or = 40%. This was followed by a review of the clinical data on the 144 patients identified with such a result and then by a telephone or postal follow-up study of these patients. The study group eventually comprised 114 patients; these were patients in whom a clinical diagnosis could be made at the time the caloric test was done, or who responded to requests for follow-up information. The 34 patients in whom a clinical diagnosis could not be made at the time of the caloric test, and who did not respond to requests for follow-up information, were excluded. STUDY SETTING: A balance disorders clinic in a tertiary referral hospital. INTERVENTION: All patients underwent standard bithermal caloric testing. Some of the patients also underwent rotational testing. OUTCOME MEASURES: A clinical diagnosis for the cause of the isolated DP, made either at the time of the caloric test or on the basis of information supplied at follow-up by the patient or by the referring physician. RESULTS: Of 114 patients, 39 had benign paroxysmal positioning vertigo, 14 had Ménière's disease, and 5 had migrainous vertigo. Five patients had central nervous system (CNS) disorders, and this was clinically apparent at the time of the caloric test in 4, so that only 1 patient with an isolated DP developed evidence of a CNS disorder after the caloric test was done. In the other 54 patients, no definite diagnosis could be made, but 41 of these 54 were either completely well or much better at follow-up. CONCLUSIONS: An isolated DP on caloric testing is usually a transient, benign disorder. About half the patients with an isolated DP have either Ménière's disease or benign paroxysmal positioning vertigo; in most of the other half, no definite diagnosis is made but most of these patients will do well. Only approximately 5% have a CNS lesion and in almost all this is apparent at the time the caloric test is done. In a relapsing-remitting peripheral vestibular disorder such as benign paroxysmal positioning vertigo or Ménière's disease, the mechanism of an isolated DP could be enhanced dynamic gain of ipsilesional medial vestibular nucleus neurons, perhaps as a result of intermittent hyperfunction of primary semicircular canal vestibular afferents. The authors postulate that an isolated DP reflects a gain asymmetry between neurons in the medial vestibular nucleus on either side, caused either by increased sensitivity on one side or by reduced sensitivity on the other, perhaps as an adaptive change in response to abnormal input. In an accompanying article, the authors implement a realistic neural network model in which it is possible to simulate an isolated DP by adjusting the dynamic sensitivity of type 1 medial vestibular nucleus neurons on one side or of type 2 medial vestibular nucleus neurons on the other.

Caloric Tests↗
PubMed2000

High-dose therapy with 90Yttrium-labeled monoclonal antibody CC49: a phase I trial.

A Phase I trial of increasing administered activities of 90yttrium (90Y)-labeled monoclonal antibody (MAb) CC49 was conducted to determine whether extrahematopoietic toxicity occurred with this radioimmunoconjugate. Twelve patients with various gastrointestinal tract cancers were administered a tracer dose of 111In-labeled MAb CC49 for biodistribution and pharmacokinetic studies. Patients then underwent a single treatment with increasing administered activities of 90Y-labeled MAb CC49 (0.3, 0.4, and 0.5 mCi/kg). Biodistribution studies, using 111In-labeled MAb CC49 as a surrogate, were determined using planar and single photon emission computed tomography imaging. Pharmacokinetic studies were performed by measuring radioactivity in blood samples taken at intervals after radioimmunoconjugate infusions. Tissue biopsies of tumor metastases and related normal tissues (liver and bone marrow) were obtained for radioactivity measurements. Radiation dosimetry estimates were calculated using these data. Toxicity was evaluated using the National Cancer Institute Common Toxicity Criteria. No dose limiting extrahematopoietic toxicity was identified in the range of administered activities used in this study. Radioimmunolocalization based on planar and single photon emission computed tomography images 111In-labeled MAb CC49 showed heterogeneous (nonspecific) liver and splenic uptake. Liver metastases were usually photopenic, and extrahepatic metastases showed faint to moderate uptake. The alpha and beta half-lives of 111In-labeled MAb CC49 and 90Y-labeled MAb CC49 in the blood were similar. Absorbed radiation dose estimates in metastatic tumor sites ranged from 180 to 3000 cGy. The percentage of injected dose/kg of tumor ranged from 1.12 to 18.14; however, tumor:normal liver ratios were consistently <1. No objective responses were observed. Doses of up to 0.5 mCi/kg could be administered with reversible grade IV myelotoxicity. Absorbed radiation dose in tumor was suboptimal, even at the highest administered activity level. Deposition of 90Y in liver was high, and estimates of absorbed dose in liver equaled or exceeded that which could be achieved in metastatic tumor sites. Strategies to enhance access of radioimmunoconjugates in tumor and diminish deposition in the liver need to be developed for effective treatment using MAb CC49 with chelated radiometals.

Adenocarcinoma↗
PubMed2000

Basaloid squamous cell carcinoma of the vagina metastasizing to the lung. A case report.

BACKGROUND: While observed on the vulva, basaloid squamous cell carcinoma (BC) of the vagina is extremely rare, with no reported cases. CASE: A 54-year-old, African American woman presented with carcinoma metastatic to both lungs, morphologically similar to her BC of the vagina four years previously. She was treated initially in 1995 with local excision. Reexcision and radiation therapy were given for a recurrence in 1996. CONCLUSION: BC of the vagina is an extremely rare and aggressive tumor, which can recur and metastasize.

Carcinoma, Basosquamous↗
PubMed2000

Routine, single-item screening to identify abusive relationships in women.

BACKGROUND: Abusive relationships are associated with several demographic factors and many clinical problems in women. However, practices often do not screen for abuse. METHODS: This is a descriptive study of 1526 women aged 19 to 69 years who completed a health survey in 31 office practices. The 53-item survey included a question designed to screen for an abusive relationship. Our analysis compared self-reported measures of symptoms (N = 13) and functional limitations (n = 6) of women who had abusive relationships with those who did not. We also examined the utility of using a constellation of clinical problems to identify risk for abuse. RESULTS: Women in abusive relationships were more likely to be poor (37% vs 14%; P < .001) and young (87% were younger than 51 years versus 69% of those who were not in such relationships; P < .001). They had twice as many bothersome symptoms (3.1 vs 1.7; P < .001) and functional problems (1.6 vs 0.8; P < .001). Approximately 40% (36/89) of low-income women with emotional problems were at risk for abuse versus only 6% (64/1025) of women with adequate financial resources and no emotional problems. However, because so many women were at low risk, almost twice as many in this group (n = 64) reported abusive relationships than in the high-risk group (n = 36). CONCLUSIONS: Women in abusive relationships have many symptoms and functional limitations. However, symptoms and clinical problems provide insufficient clues for abuse. It is better just to ask. A single-item screening question appears adequate for this purpose.

Adult↗
PubMed1999

Reduction in vascular lesion formation by hirudin secreted from retrovirus-transduced confluent endothelial cells on vascular grafts in baboons.

BACKGROUND: The hypothesis that thrombin mediates the formation of neointimal vascular lesions at sites of mechanical vascular injury has been tested in baboons by measurement of the effects of hirudin delivered by retrovirus-transduced hirudin-secreting vascular endothelial cells (ECs) lining surgically implanted arterial vascular grafts (AVGs). METHODS AND RESULTS: The antithrombotic efficacy of baboon ECs transduced with cDNA encoding hirudin was assessed in vitro and in vivo on thrombogenic segments in chronically exteriorized femoral arteriovenous (AV) shunts. Bilateral brachial AVGs lined with hirudin-transduced versus nonhirudin control ECs at confluent density were surgically implanted, and vascular lesion formations at distal graft-vessel anastomoses were compared after 30 days. Hirudin-transduced ECs secreted 20+/-6 ng x 10(6) cells(-1) x 24 h(-1) (range, 14 to 24 ng x 10(6) cells(-1) x 24 h(-1)) hirudin in supernatants of static cultures. Hirudin-secreting ECs on segments of collagen-coated graft interposed in chronic AV shunts decreased the accumulation of (111)In-labeled platelets to 0.52+/-0.34 x 10(9) platelets, compared with 0.82+/-0.49 x 10(9) platelets in controls (P = 0.03) and reduced platelet deposition in propagated thrombotic tails extending downstream from segments of vascular graft from 1.38+/-0.41 x 10(9) platelets in controls to 0.59+/-0.22 x 10(9) platelets (P = 0.04). ECs recovered from 30-day AVG implants generated 17+/-9 ng x 10(6) cells(-1) x 24 h(-1) (range, 9 to 25 ng x 10(6) cells(-1) x 24 h(-1)) hirudin. Hirudin-secreting ECs reduced neointimal lesion formation at distal graft-vessel anastomoses, ie, 1.02 mm(2) (range, 0.88 to 1.95 mm(2)) versus 1.82 mm(2) (range, 0.88 to 2.56 mm(2)) in contralateral AVGs bearing nonhirudin control ECs (P<0.01). CONCLUSIONS: Viral vector-directed secretion of hirudin from ECs lining implanted AVGs significantly reduces the formation of thrombus and neointimal vascular lesions.

Animals↗