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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
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↗
PubMed1979

Counterion-induced condesation of deoxyribonucleic acid. a light-scattering study.

The addition of the trivalent or tetravalent cations spermidine or spermine to a solution of T7 DNA in aqueous solution causes an alteration of the DNA from its extended coil form to a condensed form. If performed at low DNA concentration and at low ionic strengths, this transformation results in a monomolecular collapse to form a particle with a hydrodynamic radius of about 500 A. We have monitored this change using quasielastic and total intensity light scattering. In a solution of 50% methanol in water, the divalent cations Mg2+ and putrescine also can cause the condensation of DNA. Using Manning's (1978) counterion condensation theory, we calculate a striking unity among these disparate ions: the collapse occurs in each case when from 89 to 90% of the DNA phosphate charges are neutralized by condensed counterions.

Chemical Phenomena↗
PubMed1977

Are "medically underserved areas" medically underserved?

A comparison of medically underserved areas (MUAs) and adequately served areas (ASAs) is presented. Nonmetropolitan areas represented in the Health Interview Survey (HIS) are classified as MUAs or ASAs by the official criterion of their scores on the Index of Medical Underservice (IMU), and HIS data from the two types of areas are examined for differences. Standard metropolitan statistical areas are also compared with the nonmetropolitan MUAs and ASAs. Results show no difference between MUA and ASA residents in number of physician visits per year or proportion with at least one visit in the past year, although MUA residents reported poorer health status, used some preventive services less, and used nonsurgical hospitalization more than did ASA residents. In gereral, most MUA-ASA differences tend to be similar in size to differences between ASAs and SMSAs. An alternative to the IMU, using HIS data to identify underserved areas, is discussed.

Adolescent↗