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Biomedical subjects

R W Wilson

Publications and source records attributed to R W Wilson.

At least 19 recordsLinked to original sources
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

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↗
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↗
PubMed1992

Molecular cloning and analysis of in vivo expression of murine P-selectin.

P-selectin (CD62) is a rapidly inducible cell surface adhesion molecule that is expressed on platelets and endothelial cells and mediates their interaction with leukocytes. In vitro studies have suggested that this receptor may play an important role in hemostasis and in inflammatory response to tissue injury. We report the molecular cloning and sequencing of murine cDNA for P-selectin. The lectin, epidermal growth factor (EGF)-like, transmembrane, and cytoplasmic domains are highly conserved between mouse and human, with an overall amino acid identity of 79%. To further investigate the biology of this adhesion molecule in vivo, we analyzed mRNA levels for P-selectin in mice after injection with endotoxin. Northern blot data indicate that the cellular response in vivo includes a rapid increase in the level of mRNA, presumably for new synthesis of P-selectin. The increase in mRNA is maximal at 4 hours, and turnover is relatively rapid, with levels of RNA having decreased substantially by 6 hours following stimulation with endotoxin. After administration of endotoxin, the highest levels of mRNA expression were detected in liver, lung, kidney, and heart.

3T3 Cells↗
PubMed1992

Life expectancy in patients attending multiple sclerosis clinics.

One multiple sclerosis (MS) is diagnosed, important considerations often include life expectancy and the availability of life insurance. We designed a study specifically to examine life expectancy among MS clinic patients and analyzed the data using standard actuarial methods, both including and excluding suicides. The data show that severe MS disability, as measured by an Expanded Disability Status Score (EDSS) of greater than or equal to 7.5, is a major risk factor for death with case fatality ratios for this group of patients approaching 4 times the rate for controls. Conversely, excluding deaths by suicide, case fatality ratios for those with mild and moderate disability (EDSS less than or equal to 7.0) approach 1.4 times and 1.6 times for age- and sex-matched comparison groups. Life tables indicate that the overall life expectancy for MS is only about 6 to 7 years less than that for the "insured" population without MS.

Adolescent↗
PubMed1992

Transbranchial ammonia gradients and acid-base responses to high external ammonia concentration in rainbow trout (Oncorhynchus mykiss) acclimated to different salinities.

Transbranchial ammonia gradients and blood acid-base status have been examined in rainbow trout acclimated to fresh water (FW), 33% sea water (33% SW) and sea water (SW) and exposed to 1.0 mmol l-1 total ammonia (TAmm) at pH 7.9 for 24 h. At all three salinities trout maintained large negative (inwardly directed) NH3 and NH4+ gradients throughout the exposure, presumably by active excretion of NH4+ to counteract the passive inward diffusion of ammonia. Analysis of blood non-respiratory acid-base status (delta H+m) revealed an acid load in FW trout and a base load in SW trout following 24 h of exposure. This indicates that active NH4+/H+ exchange predominates in FW whereas NH4+/Na+ is the principal exchange utilised in SW under these experimental conditions. The plasma TAmm load incurred during ammonia exposure increased with salinity. Compared to FW trout, plasma TAmm values were 34 and 73% higher in the 33% SW and SW trout, respectively, after 24 h. This cannot be explained by differences in the prevailing transbranchial PNH3 gradient because ambient PNH3 was substantially lower at the higher salinities (due to higher pK' and solubility values). We interpret the difference between FW and SW trout as an increased permeability to NH4+ in fish acclimated to the higher-salinity environments. Transbranchial diffusion of NH4+ is, therefore, probably more important as a route for ammonia excretion in SW than in FW trout, especially considering the favourable transepithelial potentials normally found in SW teleosts. In addition, increased NH4+ permeability implies that the toxicity of ammonia will be greater in seawater than in freshwater teleosts and should not simply be measured as a function of the unionised ammonia concentration when considering seawater-adapted species.

Acclimatization↗
PubMed1991

Serotonin immunoreactivity in pancreatic endocrine neoplasms (carcinoid tumors).

Primary serotonin secreting pancreatic endocrine neoplasms (carcinoid tumors) are extremely rare and may be associated with manifestations of the carcinoid syndrome. Two cases of primary carcinoid tumor of the pancreas with liver metastases showed clinical and biochemical features of the carcinoid syndrome. Both cases demonstrated strong positive immunoreactivity for serotonin within the tumor cells. In an attempt to determine the relationship between pancreatic carcinoid tumors and other pancreatic endocrine neoplasms, immunostains for serotonin were performed on 11 additional islet cell tumors and on non-neoplastic pancreatic tissues. These cases showed serotonin immunoreactivity within islet cell tumors (36%). In addition, focal staining for serotonin was present in non-neoplastic ducts and ductules (88%), acini (22%), and islets of Langerhans (33%). Based on these observations, specific criteria are suggested for the diagnosis of primary pancreatic carcinoid tumor.

Adult↗
PubMed1990

Longitudinal study of human papillomavirus infection of the female urogenital tract by in situ hybridization.

The recurrence and/or persistence of human papillomavirus (HPV)-associated lesions constitute a well-recognized clinical problem; yet, few studies have demonstrated and typed the HPV within these recurrence lesions. A patient with a 17-year history of anogenital condylomata presented with an unusual bladder tumor that had histologic features of HPV infection. This prompted a longitudinal analysis of HPV DNA in archival material from these urogenital lesions. Colorimetric in situ hybridization was used to assay for HPV types 6, 11, 16, and 18. Human papillomavirus types 6 and 11 were present throughout the period of follow-up in all the condylomatous lesions, including those identified in the bladder, suggesting a common source of infection and spread. By contrast, HPV type 16 was associated only with the vaginal intraepithelial neoplasia that was identified midway through the period of follow-up, and it was apparently cured by excision of the lesion.

Adult↗
PubMed1990

Granular cell tumors of the vulva.

Granular cell tumor (GCT), although nearly ubiquitous, is seen infrequently in the vulva. A review of the surgical pathology files from Grady Memorial Hospital, Atlanta, Georgia, from 1983 through 1987 identified eight cases of vulvar GCT. Five of the eight patients had more than one skin and soft tissue lesion. Two of the five had biopsy-proven multicentric GCT with a unique clinical course. One of the patients was a 32-year-old woman with multiple vulvar, lingual, laryngeal, bronchial and pulmonary GCT, necessitating multiple excisions and ultimately pneumonectomy. The second patient had multiple GCTs in the vulva and inguinal area and finally in both lungs, resulting in her death at age 39. No dependable microscopic features could be identified to distinguish benign GCT from its more aggressive variant. However, Feulgen DNA histomorphometry demonstrated aneuploidy in the patient with apparent lung metastases, whereas the tumors from patients with a benign course as well as from the patient with multiorgan involvement were diploid. In three of five patients who could be interviewed there was a history of soft tissue tumors in members of the family. The multifocal nature and possible familial component of GCT need to be explored further.

Adult↗
PubMed1989

Tetracycline and erythromycin resistance among clinical isolates of Branhamella catarrhalis.

We reviewed tetracycline and erythromycin disk diffusion susceptibility of 457 isolates of Branhamella catarrhalis. Four isolates were resistant to tetracycline, with MICs for two available isolates of 16 micrograms/ml. Sixteen isolates were in the moderately susceptible range for erythromycin, with an MIC for one available isolate being greater than 8 micrograms/ml. These are the first tetracycline- and (by MIC) erythromycin-resistant B. catarrhalis isolates reported from the United States.

Drug Resistance, Microbial↗
PubMed1989

Services for maintaining independence.

Providing a range of health-related services may be necessary for some elderly to remain in independent living environments. Wellness Centers can identify those at risk for disease, promote self-care techniques, and assess the need for other health services. Entrepreneural nurses have the opportunity to seek out congregate housing sites with large aging populations to create ways of promoting healthy lifestyles and a higher quality of life for older persons. A holistic approach to health care helps the elderly to manage chronic disease, maintain high levels of functioning, and promote self-responsibility.

Adult↗
PubMed1988

Monoclonal antibody-based immunoenzymetric assays for quantification of human IgG and its four subclasses.

A panel of 5 immunoenzymetric assays (IEMAs) has been developed for quantification of the total and four subclasses of immunoglobulin G (IgG) in human serum using IUIS/WHO documented monoclonal antibodies (MoAb). Human IgG specific MoAb was adsorbed to microtiter plates and used to capture IgG from serum. Peroxidase conjugated forms of polyclonal mouse anti-human IgG Fc or a mixture of 4 MoAb (anti-kappa, anti-lambda, anti-IgG Fc PAN and anti-IgG Fd PAN) were used as detection antibodies. Use of monoclonal antibody in chromatographically purified form was required for acceptable assay sensitivity (S) and working ranges (WR). All 5 IEMAs displayed good precision (intra-assay %CV less than 5%, inter-assay %CV less than 12%) and parallelism (inter-dilutional CV less than 20%). Both HP6069 or HP6070 (anti-IgG1 Fc) worked well alone or together as capture antibodies in the IgG1 IEMA: WR = 20-1250 ng/ml, S = 15 ng/ml. HP6002 (anti-gG2 Fc) alone or in combination with HP6014 (anti-IgG2 Fd) produced an IgG2 IEMA with a WR of 5-200 ng/ml and S of 5 ng/ml. HP6047 (anti-IgG3 hinge) alone generated a sensitive IgG3 IEMA with a narrow working range: WR = 2-50 ng/ml, S = 1.6 ng/ml. Both HP6025 and HP6023 (anti-IgG4 Fc) worked equally well alone and together to produce a useful IgG4 IEMA: WR = 8-250 ng/ml, S = 7.8 ng/ml. HP6017 (anti-IgG PAN Fc) was combined in an equal molar ratio with HP6046 (anti-IgG PAN Fd) to produce a total IgG PAN IEMA with a WR of 5-530 ng/ml and a sensitivity of 5 ng/ml. All 5 IEMAs fulfilled requirements for robust clinical immunoassays that permit the quantitation of human IgG and its 4 subclasses.

Animals↗
PubMed1988

Ampicillin, tetracycline, and chloramphenicol resistant Haemophilus influenzae in adults with chronic lung disease. Relationship of resistance to prior antimicrobial therapy.

Antibiotic resistance in 1,003 sputum isolates of Haemophilus influenzae from adults with chronic lung disease was assessed from January 1983 through June 1986. The incidence of resistance was 3.2% for tetracycline, 0.6% for chloramphenicol, and 12.5% for ampicillin. Resistance to ampicillin or tetracycline usually occurred alone, while 100% of chloramphenicol resistant isolates were co-resistant to tetracycline or ampicillin. More than 90% of antibiotic resistant isolates were nontypable and belonged to biotypes II, III, or V. Chart reviews of 331 patients revealed that patients with ampicillin resistant isolates were more likely than control subjects to have received ampicillin in the prior 6 wk (33% versus 6%, p less than 0.0001), whereas patients with isolates resistant to tetracycline or chloramphenicol plus tetracycline were more likely to have received tetracycline than control subjects (24% and 50%, respectively, versus 5%, p less than 0.005). The incidence of ampicillin resistance and the reluctance of physicians caring for adults to use chloramphenicol suggests that a newer cephalosporin such as cefotaxime may be the initial therapy of choice for severe H. influenzae disease in our patient population.

Adult↗
PubMed1987

National trends in the morbidity and mortality of asthma in the US. Prevalence, hospitalization and death from asthma over two decades: 1965-1984.

National population-based data systems of the National Center for Health Statistics (NCHS) were used to study the epidemiology of asthma in the United States over the last 20 years. Asthma is more prevalent among males, those living below the poverty level, persons living in the South and West, and blacks; however, this difference did not attain statistical significance. Death rates from asthma among the older age groups probably increased between 1968 and 1982, with a substantial increase since 1979. For children, the evidence is less clear, but the death rate has increased for children over five years of age during the period from 1979 to 1982. Between 1964 and 1980, asthma has become more prevalent in children under 17 years of age, but this does not reflect an increase in the severity of asthma over this same time period. Hospitalization rates for asthma between 1965 and 1983 increased by 50 percent in adults and by over 200 percent in children. Rates for black patients are 50 percent higher in adults and 150 percent greater in children. It is concluded that there has been a marked increase in hospitalization rates for asthma, a moderate increase in death rates from asthma and a smaller increase in overall prevalence of the disease in the United States.

Activities of Daily Living↗