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Biomedical subjects

R W Wilson

Publications and source records attributed to R W Wilson.

At least 55 records · Page 3Linked to original sources
PubMed1996

Calcifying fibrous pseudotumor of pleura. A report of three cases of a newly described entity involving the pleura.

A newly recognized distinctive fibrous soft tissue lesion called "calcifying fibrous pseudotumor" (CFPT) was recently described in the soft tissues of the extremities, trunk, scrotum, groin, neck, or axilla. To date, CFPT has not been described in the pleura. The authors reviewed the clinical, radiologic, and pathologic features of three cases. A 23-year old woman and 34-year old man who presented with chest pain, and a 28-year old woman without chest symptoms were found to have a pleural mass on chest radiographs. Computed tomography (CT) scans of each patient revealed pleural-based nodular masses with central areas of increased attenuation due to calcifications. Each lesions consisted of circumscribed, but unencapsulated masses of hyalinized collagenous fibrotic tissue interspersed with lymphoplasmacytic infiltrates and calcifications, many of which had psammomatous features. The lesions were limited to the pleura and did not involve the underlying lung parenchyma. Electron microscopy in one case showed fibroblasts scattered in dense collagenous tissue. Calcifying fibrous pseudotumor is distinct from other pleural lesions such as fibrous tumor of pleura, calcified granulomas, calcified pleural plaques, and chronic fibrous pleuritis as well as intrapulmonary lesions such as hyalinizing granuloma, inflammatory pseudotumor, and amyloid. As in the soft tissues, local excision appears adequate therapy for CFPT of the pleura. If these lesions behave in a similar fashion to CFPT of soft tissues, one might expect a low frequency of local recurrence.

Adult↗
PubMed1996

Functional performance following an ice immersion to the lower extremity.

Cryotherapy is a widely accepted component of treatment for acute injuries. It has recently re-entered the later stages of rehabilitation as a contributing modality. Cryotherapy's depressive effects on the body's physiological systems have generated concern among many health care practitioners about its effect on motor activity. This study examined the effects of an ice immersion on three functional performance tests: the shuttle run, the 6-m hop test, and the single-leg vertical jump. Twenty volunteers from Division III soccer and football teams who had not sustained an injury to the lower extremity within the past 6 months were randomly assigned to either an experimental or control group. Subjects in the experimental group performed three trials of each functional performance test before and after the application of a 20-minute ice immersion (13 degrees C) to the lower leg. Subjects in the comparison group followed the same procedure except that a 20-minute resting period replaced the cold treatment. A mixed design analysis of variance was used to analyze the data. Vertical jump scores decreased in the experimental group (41.4 +/- 6.8 cm to 39.3 +/- 6.1 cm) but not in the control group (45.2 +/- 5.5 cm to 45.7 +/- 5.9 cm) as a result of the treatment. Shuttle run times decreased in the experimental group (6.5 +/- 0.3 seconds to 6.7 +/- 0.4 seconds) but not in the control group (6.8 +/- 0.4 seconds to 6.8 +/- 0.4 seconds). Six-meter hop test values were not affected. We suggest that clinicians should carefully consider the immediate effects, potentially, of cold on motor activity.

Journal Article↗
PubMed1996

Surveillance of HIV knowledge, attitudes, beliefs, and behaviors in the general population.

This article discusses methods and elements of three major national health survey systems, particularly as they relate to HIV infection and AIDS. The National Health Interview Survey and the Behavioral Risk Factor Surveillance System provide information about health-related knowledge, attitudes, beliefs, and behaviors of adults in the United States. The Youth Risk Behavior Surveillance System measure health-related behaviors of American youth. Questions and survey designs differ among the three surveys, but all three surveys utilize probability sampling. The National Health Interview Survey's AIDS Knowledge and Attitudes Supplement is administered to a subsample of approximately 20,000 people annually. The Behavioral Risk Factor Surveillance System consists of telephone surveys providing data for all 50 states and the District of Columbia, with an average annual sample size of approximately 2,000 per state. The Youth Risk Behavior Surveillance System samples approximately 12,000 youth for its national school-based survey, 2,000 (average) for each of its state and local school-based surveys, 10,000 for its national household-based survey, and 6,000 (projected) for its national college-based survey. This article is meant to assist researchers, students, health educators, public health officials and others in utilizing survey data bases to address policy, program, research, and evaluation needs. All three surveys can help guide prevention efforts by providing information about the general population and by identifying national, local, or state-wide trends. More detailed studies and targeted studies of specific high-risk populations are also needed in light of the complexity of the determinants of HIV risk behavior.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Estimated potassium reflection coefficient in perfused proximal convoluted tubules of the anaesthetized rat in vivo.

1. As yet there is no definitive description of the mechanism and route by which K+ reabsorption is achieved in the proximal convoluted tubule (PCT). We have assessed the contribution of convective K+ transport to net potassium ion flux (JK) by estimating the reflection coefficient of K+ (sigma K) in the proximal tubule of anaesthetized rats previously prepared for in vivo microperfusion. 2. Alterations in the luminal concentration of the impermeant solute raffinose in single-perfused (lumen only) and double-perfused (lumen and capillaries) PCTs were found to change fluid reabsorption in a predictable fashion. 3. Net potassium ion flux (JK) in single- and double-perfused tubules was significantly correlated with net fluid flux (Jv), suggesting that convective K+ transport may be a significant factor in overall K+ transport by the PCT. 4. Estimates of sigma K in single- and double-perfused tubules were very similar (0.14 +/- 0.06 and 0.13 +/- 0.05, respectively), even though K+ diffusion was not strictly controlled in the former group. The maximum effect of 'pseudo-solvent' drag in double-perfused tubules was estimated to give a sigma K of 0.40. This low value for sigma K suggests that true convection/solvent drag may be an important driving force for the reabsorption of K+ from the PCT of the rat.

Anesthesia↗
PubMed1995

PCR amplification and restriction endonuclease analysis of a 65-kilodalton heat shock protein gene sequence for taxonomic separation of rapidly growing mycobacteria.

A total of 129 reference and clinical strains of rapidly growing mycobacteria (RGM) belonging to 10 taxonomic groups were studied for restriction fragment length polymorphism patterns from a PCR-amplified 439-bp segment of the 65-kDa heat shock protein (HSP) gene. Of 24 endonucleases evaluated, restriction fragment length polymorphism patterns produced by HaeIII and BstEII and then by AciI and CfoI gave the best separation. Sixty percent of all RGM taxa studied were differentiated by HaeIII digests alone. Single unique patterns were observed with HaeIII and/or BstEII for Mycobacterium fortuitum (100%), M. chelonae (94%), M. abscessus (96%), M. smegmatis (100%), M. mucogenicum (formerly the M. chelonae-like organism) (100%), and the sorbitol-negative third biovariant of M. fortuitum (100%). Evidence is presented in support of two subgroups within M. peregrinum, M. smegmatis, and the unnamed third biovariant of M. fortuitum (sorbitol positive and sorbitol negative). PCR-based technology provides a rapid, accurate system for the identification of clinically important species of RGM which should be particularly useful for reference laboratories.

Bacterial Proteins↗
PubMed1995

DNA amplification and restriction endonuclease analysis for differentiation of 12 species and taxa of Nocardia, including recognition of four new taxa within the Nocardia asteroides complex.

Nineteen reference and 156 clinical strains of the genus Nocardia belonging to 12 taxonomic groups were studied for restriction fragment length polymorphism (RFLP) by using an amplified 439-bp segment of the 65-kDa heat shock protein gene. Of 30 restriction endonucleases, digestion with MspI and then digestion with BsaHI produced RFLP band patterns which separated all 12 groups except N. asteroides type IV from 6 of 12 N. transvalensis isolates and N. carnea from the N. asteroides type VI isolates. Commonly encountered species such as N. nova, N. farcinica, N. brasiliensis sensu stricto, and N. otitidiscaviarum were easily separated. Each taxon resulted in a single RFLP band pattern that included > or = 96% of all biochemically grouped isolates for 9 of 12 taxa with MspI and for 8 of 12 taxa with BsaHI. With the use of both patterns, only 6 of 175 (3.4%) isolates failed to fit the biochemically defined group patterns. These studies provide the first evidence for the separate identities of four antibiogram-defined (but currently unnamed) groups within the N. asteroides complex (types I, II, IV, and VI) and the presence of two subgroups within N. transvalensis. They also provide genotypic evidence for the separate identities of N. nova and N. farcinica. The lack of BstEII recognition sites in amplicons obtained from nocardiae provides a simple and rapid method for the differentiation of nocardiae from mycobacteria. DNA amplification with RFLP analysis is the first rapid method that distinguishes all clinically significant taxa and recognized species within the genus Nocardia.

Bacterial Typing Techniques↗
PubMed1995

Effect of barium on potassium diffusion across the proximal convoluted tubule of the anesthetized rat.

The role of diffusion in transepithelial potassium flux and the importance of potassium channels in the luminal cell membrane to this process were examined by applying a luminal microperfusion technique to surface tubules in kidneys of anesthetized rats. Potassium concentration gradients were applied by altering the concentration of KCl in perfusates. To some perfusates, 2 mmol/l BaCl2 was added to block potassium channels in the luminal cell membrane. The mean applied potassium concentration gradient was highly predictive of net potassium transport in the absence of any change in fluid reabsorption, with an apparent potassium permeability of 22 x 10(-5) cm/s. Thus potassium transport in the proximal tubule may have an important diffusive component. Luminal barium significantly reduced the concentration of potassium in collected fluid under conditions of net potassium secretion, although a substantial barium-insensitive potassium permeability was also observed. However, the site of action of luminally applied barium is uncertain in proximal tubule, since barium was reabsorbed by the tubule at a rate of 13.6 pmol.mm-1.min-1. We conclude that diffusion is a significant driving force for potassium reabsorption in proximal tubule and that most diffusive potassium transport occurs via a barium-insensitive route, possibly the paracellular pathway.

Animals↗
PubMed1994

Effects of zinc on the kinetics of branchial calcium uptake in freshwater rainbow trout during adaptation to waterborne zinc.

The effects of sublethal waterborne Zn2+ (150 micrograms l-1 = 2.3 mumol-1) on the kinetics of unidirectional Ca2+ influx were studied in juvenile freshwater rainbow trout during chronic exposure (60 days) at a water [Ca2+] of 1.0 mmol l-1. An unexposed group held under identical conditions served as control. The presence of Zn2+ in the water increased the apparent Km for Ca2+ influx by up to 300% with only a small inhibitory effect (35% at most) on the maximum rate of uptake (Jmax). These results, in combination with earlier data showing that Ca2+ competitively inhibits Zn2+ uptake, suggest that Zn2+ and Ca2+ compete for the same uptake sites. Acute withdrawal of Zn2+ after 3h of exposure resulted in a 23-fold reduction in Km for Ca2+, but a persistent small depression of Jmax. During prolonged exposure to Zn2+, the apparent Km for Ca2+ remained greatly elevated and Jmax remained slightly depressed. The actual Ca2+ influx in hard water ([Ca2+] = 1.0 mmol l-1) decreased marginally and paralleled the small changes in Jmax. The increases in apparent Km had a negligible influence on the actual Ca2+ influx because Km values (38-230 mumol l-1), even when elevated by Zn2+, remained below the water [Ca2+] (1000 mumol l-1). Rainbow trout exposed to Zn2+ exhibited a slower rate of protein synthesis in the gills (measured on day 23) and an increased tolerance to Zn2+ challenge (measured on both days 27 and 50). Unidirectional Zn2+ influx, measured at the end of the exposure period, was significantly reduced in the Zn2+-exposed fish. There were no changes in hepatic or branchial Zn2+, Cu2+ or metallothionein concentrations. We hypothesize that, during exposure to sublethal [Zn2+] in hard water, the fish may change the Km for a mutual Ca2+/Zn2+ carrier so as to reduce markedly Zn2+ influx without greatly altering Ca2+ influx. This reduced Zn2+ influx, rather than metallothionein induction, may be the basis of adaptation to elevated concentrations of waterborne Zn2+.

Adaptation, Physiological↗
PubMed1994

Orthopedic prostheses.

This article discusses the complications of total joint arthroplasties, and intramedullary, internal, and external fixation devices. It emphasizes the emergency physician's role in emergency department management, especially with deep infections, thromboembolic events, and compartment syndromes.

Emergencies↗
PubMed1993

Gene targeting yields a CD18-mutant mouse for study of inflammation.

CD18 is the common beta subunit for the heterodimeric leukocyte integrins that mediate many inflammatory cell adhesion responses including binding to intercellular adhesion molecules 1 and 2. CD18 deficiency in humans causes a severe granulocyte disorder with susceptibility to bacterial infections and high morbidity and mortality. Gene targeting was used to prepare an insertion mutation in the murine CD18 gene. The insertion mutation resulted in a hypomorphic rather than a null allele due to low expression from a cryptic promoter in the plasmid construct. Homozygous mutant mice are viable and fertile, demonstrate a mild granulocytosis, and have 2 or 16% of normal CD18 expression on granulocytes in the resting or activated state, respectively. Mutant mice show an impaired inflammatory response to a chemical peritonitis and delayed rejection of cardiac transplants. These CD18-mutant mice provide a model of the moderate form of the human disease and should be extremely valuable for in vivo analysis of the role of leukocyte integrin-dependent adhesion in inflammatory disease models.

Animals↗
PubMed1993

Expression of human CD18 in murine granulocytes and improved efficiency for infection of deficient human lymphoblasts.

The CD18 gene encodes the beta 2-subunit of leukocyte integrins, and mutations in this gene cause extreme host susceptibility to bacterial and fungal infection. Because expression of CD18 is restricted to bone marrow-derived cells, this disorder is considered an excellent candidate for somatic gene therapy utilizing ex vivo infection of bone marrow stem cells. We have constructed a retroviral vector expressing CD18 with the Moloney murine leukemia virus (Mo-MLV) long terminal repeat (LTR) as the promoter, and high-titer ecotropic and amphotropic producer cell lines were isolated using the GP+E-86 and GP+envAM12 safe packaging cell lines. Infection of CD18-deficient lymphoblasts resulted both in expression of immunodetectable CD18 at 35-40% of normal levels on 55-60% of cells and in functional restoration of CD18-dependent aggregation. All of 16 mice transplanted with syngeneic bone marrow infected with the CD18 retrovirus expressed human CD18 on 17-36% of granulocytes at 2 weeks after transplantation, and expression was appropriately up-regulated in response to stimulation with zymosan-activated serum. This recombinant retrovirus should prove useful for further studies of somatic gene therapy for CD18 deficiency.

3T3 Cells↗
PubMed1993

Retroviral mediated expression of CD18 in normal and deficient human bone marrow progenitor cells.

The CD18 gene encodes the beta subunit of leukocyte integrins, and autosomal recessive deficiency of CD18 in humans causes a life-threatening abnormality of granulocyte migration. A high titer amphotropic retrovirus encoding CD18 was used to infect bone marrow cells from normal and CD18-deficient human donors. Infected cells were maintained in a long-term culture system and analyzed (1) using PCR to detect the provirus in granulocyte or macrophage colonies (CFU-GMs) derived from the culture, (2) using reverse transcription-PCR (RT-PCR) to detect transcripts in the floating cells in the culture, and (3) using immunostaining of the floating cells to analyze expression of human CD18. By both cocultivation and supernatant infection, a significant fraction (10-82%) of the CFU-GMs were positive for the provirus after five weeks in long-term culture, and as high as 10-15% of the floating cells were positive by immunostaining after nine weeks in the long-term culture. In all cases, cocultivation showed higher infection efficiency than supernatant infection. This is the first report of the introduction of human CD18 cDNA into the bone marrow progenitor cells of patients with leukocyte adhesion deficiency.

3T3 Cells↗
PubMed1993

Amyloid precursor protein (APP) in the striatum in Alzheimer's disease: an immunohistochemical study.

Increasing recognition of diffuse plaques has raised questions about the differences between diffuse and neuritic plaques, particularly in regard to the role of amyloid precursor protein (APP) processing in their formation. To address this issue, corpus striatum (containing almost exclusively diffuse plaques) and cerebral cortex (containing an admixture of plaque types) from patients with Alzheimer's disease (AD) were examined immunohistochemically with antibodies to domain-specific sites of APP (N-terminal, C-terminal, beta A4-related, isoform-specific, and other epitopes). Striatal plaques labeled strongly with beta A4 antibodies as did cortical plaques in AD and the occasional diffuse plaques in cortex from nondemented elderly controls. Weak labeling of some cortical neuritic plaques but not diffuse plaques was observed with antibodies directed against other APP epitopes. Electron microscopy of diffuse plaque-rich striatum in AD cases revealed only rare degenerating neurites without apparent fibrillar amyloid; no changes were noted in the plaque-free striatum of controls. These results suggest that antibodies to beta A4 recognize not only fibrillar amyloid of neuritic plaques but also antigenic determinants of diffuse plaques which lack fibrillar amyloid. Furthermore, the finding that antibodies to non-A4 domains of APP labeled only cortical but not striatal plaques suggests that APP processing mechanisms in cortical and striatal tissues may differ.

Aged↗