Biomedical subjects

M R Wilson

Publications and source records attributed to M R Wilson.

At least 127 records · Page 7Linked to original sources

PubMed1994

Organ site-dependent expression of basic fibroblast growth factor in human renal cell carcinoma cells.

We investigated the influence of organ microenvironment on the angiogenic phenotype in human renal cell carcinoma (HRCC) cells. HRCC line SN12C was established in vitro from a surgical specimen, and metastatic line SN12PM6 was isolated from a lung metastasis produced by parental cells implanted into the kidney of nude mice. SN12C (low metastasis) and SN12PM6 (high metastasis) cells were injected into the kidney or subcutis of nude mice. The kidney tumors were highly vascularized (as revealed by immunohistochemistry using antibodies against factor VIII), and metastatic, whereas the subcutaneous tumors were not. The expression of mRNA for basic fibroblast growth factor (bFGF) in kidney tumors was 10 to 20 times that found in subcutaneous tumors. Similar data were obtained at the protein level by using fluorescence activated cell sorting, immunohistochemistry, and enzyme-linked immunosorbent assay. bFGF was detected in the urine of mice with tumors in the kidney but not subcutaneous tumors. The level of bFGF in the serum of mice with kidney tumors was two to three times that in mice with subcutaneous tumors. The changes in bFGF expression in the tumors was transient. Collectively, these data indicate that the organ microenvironment can influence the expression level of bFGF in HRCC.

Animals↗

PubMed1993

Reproducibility of postural changes in intraocular pressure with the Tono-Pen and Pulsair tonometers.

Reproducibility of measurements of postural changes in intraocular pressure was determined by using the Tono-Pen (Mentor O & O, Inc., Norwell, Massachusetts) and Pulsair (Keeler Instruments, Inc., Broomhall, Pennsylvania) tonometers. Thirty subjects had three repeated sitting and reclining measurements performed on three separate visit days. Reproducibility coefficients of 3.3% for the Tono-Pen and 6.3% for the Pulsair were obtained for the within-visit postural change measurements. Across-visit reproducibility coefficients were 7.9% and 26.2% for the Tono-Pen and Pulsair, respectively. The estimated standard deviations for both the within-visit and across-visit postural change measurements were high for both instruments. These results indicate poor reproducibility of measurements of postural changes in intraocular pressure.

Adult↗

PubMed1993

Enzyme complex amplification--a signal amplification method for use in enzyme immunoassays.

An amplification system for enzyme immunoassays, in which complexes of streptavidin, biotinylated horseradish peroxidase, antibody are used to detect biotinylated target molecules was developed. In enzyme-linked immunosorbent assay (ELISA) experiments this enzyme complex enhancement (ECA) system gave up to a better than two orders of magnitude increase in sensitivity, compared to a horseradish peroxidase-conjugated streptavidin detection system. The ECA system was shown to be applicable to direct detection of biotinylated antigens, as well as in ELISA employing biotinylated antibodies and in sandwich ELISA. The ECA system was also applicable to immunoblots, giving a sensitivity comparable to that obtained using a radiochemical detection system.

Bacterial Proteins↗

PubMed1993

Composite PAGE: an alternate method for increased separation of amplified short tandem repeat alleles.

Genetic typing of short tandem repeat (STR) loci may require electrophoretic separation techniques which, depending on the locus, can resolve alleles differing in size by only 2, 3 or 4 base pairs (bps). Many such loci can be separated by horizontal, discontinuous polyacrylamide gel electrophoresis (hd-PAGE). However, some loci present particular separation challenges. A composite (or step) gel system consisting of 2 zones, anodal and cathodal, which differ by pore size and ionic strength, has been developed to augment resolution of DNA fragments without a need for additional electrophoretic equipment. Depending on pore size, as well as ionic strength, initial migration can be increased or decreased to effect resolution. When compared with hd-PAGE, this composite gel electrophoretic system can result in enhanced resolution of PCR amplified STR alleles.

Actins↗

PubMed1993

Expression of a mouse-channel catfish chimeric IgM molecule in a mouse myeloma cell.

Fusion genes encoding a murine VH domain and the constant region domains of the mu chain from the channel catfish, Ictalurus punctatus, were stably expressed in the lambda light chain producing mouse myeloma cell line J558L. Although the pathways of pre-mRNA processing for expression of membrane (micron and secreted (microsecond) forms of the mu chain differ between mammals and teleosts, mRNAs encoding both catfish micron and microsecond were correctly expressed in the mouse myeloma cells. The mouse-channel catfish chimeric mu chain polypeptide was able to associate covalently with the mouse lambda light chain and assemble, intracellularly, into polymers of covalent structure (microL)2-8 which resembled those seen with native catfish IgM. In contrast to native catfish IgM, the mouse-catfish chimeric IgM showed the property of binding strongly to protein A of Staphylococcus aureus. The mouse-channel catfish chimeric IgM was core-glycosylated, but did not contain terminal sialic acid. Secretion rates for the chimeric IgM were low, and the possibility could not be excluded that extracellular chimeric IgM was released from dead or dying cells. The reason(s) for the intracellular retention of the chimeric IgM (probably in the endoplasmic reticulum) are not known, but those mechanisms involving retention via cysteine residues were excluded.

Animals↗

PubMed1993

Aqueous and vitreous concentration of mitomycin C by topical administration after glaucoma filtration surgery in rabbits.

PURPOSE: The authors investigated the aqueous and vitreous pharmacokinetics of mitomycin after postoperative topical administration in rabbits. METHODS: Filtration surgery was performed in one eye of each rabbit. On the first postoperative day, mitomycin solution (0.4 mg/ml) was administered by either topical drop or cellulose sponge in both eyes of each rabbit. Aqueous and vitreous paracenteses were performed at 0.25, 0.5, 1, 2, 3, and 4 hours thereafter. Three rabbits were tested at each time interval for each type of administration. RESULTS: After topical drop administration, the peak aqueous concentration was 0.03 +/- 0.02 microgram/ml (mean +/- standard error) in surgical eyes and 0.06 +/- 0.03 microgram/ml in control eyes. After sponge administration, the peak aqueous concentration was 0.10 +/- 0.03 microgram/ml in surgical eyes and 0.08 +/- 0.04 microgram/ml in control eyes. Peak aqueous concentrations from drop and sponge applications were achieved at 1 to 2 hours after administration. Vitreous levels were well below the concentration known to cause retinal toxicity at all time intervals tested. CONCLUSION: Postoperative topical administration of mitomycin was successful in delivering mitomycin into the aqueous humor of rabbit eyes. Alternative methods of mitomycin application from the currently popular intraoperative administration may be beneficial in situations in which mitomycin delivery across intact conjunctiva may be desirable.

Administration, Topical↗

PubMed1993

Effects of family and marital psychotherapies: a meta-analysis.

This meta-analysis of 163 randomized trials (including 59 dissertations) examines a number of questions not studied in previous syntheses. These include differences in outcome associated with different theoretical orientations, differences between marital and family therapies versus individual therapies, the clinical significance of therapy outcome, differences between marital versus family therapies in both outcomes and problems treated, and the effects of various substantive and methodological moderators of therapy outcome. The review concludes with some observations about the methodological status of this literature.

Clinical Trials as Topic↗

PubMed1993

Levobunolol compared to dipivefrin in African American patients with open angle glaucoma.

The prevalence of open angle glaucoma is disproportionately high in the African American population. Information about the effectiveness of anti-glaucoma medications in an exclusively African American population is lacking. We treated both eyes of 38 African American patients who have stable open angle glaucoma with either levobunolol b.i.d. or dipivefrin b.i.d. to evaluate the effectiveness of each drug in lowering intraocular pressure. Patients were treated for six weeks following a two week washout period. We measured intraocular pressure levels after one, three, and six weeks. Each medication produced a statistically significant decrease in intraocular pressure by week one. The mean pre-treatment pressure of 24.4 mmHg in the levobunolol was reduced to 17.0 mmHg by week six. The mean pre-treatment pressure of 25.4 mmHg in the dipivefrin treated group was reduced to 18.2 mmHg by week six. There was not a statistically significant difference in the pre-treatment or the final pressure between the two groups. Both levobunolol and dipivefrin produce a statistically significant decrease in intraocular pressure in African American patients with open angle glaucoma.

Adult↗

PubMed1993

Posterior sacroiliac fixation using a sacral pedicle targeting device: an anatomical study.

This study compares the accuracy of posterior sacroiliac (SI) screw placement using a "free-hand" method, without the use of fluoroscopy, versus a specially developed targeting device. Posterior SI screws were inserted after exposing the iliac wing in five cadavers on one side, and inserted percutaneously with a unique targeting device on the opposite side. Fluoroscopy was not used for screw or pedicle placement on either side. Computed tomography and dissection results were then used to grade screw placement for both sides. A statistically significant difference between the sides was found. More importantly, three screws on the free-hand side violated major neurovascular structures. The regional anatomy was defined: structures most at risk are the iliac vein ventrally and the sacral canal dorsally. A highly variable "safe zone" (mean arc 43 degrees at the S1 level and 30 degrees at the S2 level) was established. Inclination of the SI joint was also defined (mean 29 degrees at the S1 level and 17 degrees at the S2 level). SI screw placement using the specially developed targeting device is technically less demanding, requires less soft tissue dissection, allows variable placement, and poses minimal risk to major neurovascular structures. Our limited clinical experience with the device is encouraging. The potential application of this technique to unstable vertical shear fractures is appealing.

Bone Screws↗

PubMed1993

Serum endotoxin, tumor necrosis factor, and interleukin-6 response to total hip arthroplasty.

The purpose of this study was to determine if endotoxin, tumor necrosis factor (TNF), and interleukin 6 (IL-6) increased in patients during or after total hip arthroplasty. Endotoxin is absorbed from the gut lumen and stimulates macrophages to make TNF. TNF is one of the stimuli for the increased production of IL-6. All three entities cause fever. If an increase takes place in any of the three, it could contribute to the commonly observed postop fever in total hip patients. Five serum samples were obtained from 12 patients: preoperatively; after the acetabular component was seated intraoperatively; in the recovery room; day 1 postoperatively; and day 3 postoperatively. IL-6 and TNF were measured using monoclonal antibody tests and endotoxin was measured with a chromogenic limulus amoebocyte lysate assay. A statistically significant increase in all three parameters was demonstrated. Endotoxin peaked intraoperatively or in the recovery room, TNF tended to peak in the recovery room, and the peak in IL-6 was more variable. Ten patients had a concomitant postoperative fever.

Adult↗

PubMed1993

Diabetes-related eye disorders.

Ocular complications from diabetes represent a significant public health problem. Diabetic retinopathy alone represents a leading cause of new blindness each year in the United States. Neovascular glaucoma from diabetes, although not nearly as common, inflicts devastating consequences on vision. Together with the more frequent occurrence of other ocular disorders that cause visual impairment, the visual toll of diabetes is staggering. Much of this blindness is preventable with early detection and timely treatment.

Blindness↗

PubMed1992

Clusterin binds by a multivalent mechanism to the Fc and Fab regions of IgG.

Clusterin was purified from human serum by IgG and monoclonal antibody affinity chromatography. SDS-PAGE and immunoblotting revealed no major differences between clusterin prepared in these two ways. An ELISA method for measuring the binding of clusterin to immunoglobulins was developed. Clusterin purified by IgG affinity chromatography bound to pooled human IgG with a similar affinity (S0.5 5.9 +/- 0.4 micrograms/ml) as clusterin purified by monoclonal antibody chromatography (S0.5 6.1 +/- 0.2 micrograms/ml). The apparent affinity of clusterin for IgG immobilised on ELISA plates increased with increasing concentrations of IgG in the coating solution. Aggregated IgG in solution was a more potent inhibitor of the binding of clusterin to immobilised IgG than was monomer IgG. Clusterin bound to all of the isotypes of human IgG, and to human IgA and IgM, with apparent affinities in the order IgG3 > IgG4 > IgM > IgG1 > IgG2, IgA. Clusterin bound to both the Fab and Fc fragments of human IgG. The clusterin binding site(s) on the Fc do not overlap with those for protein A and Clq.

Antibodies, Monoclonal↗

PubMed1992

Structural relationship between the two IgY of the duck, Anas platyrhynchos: molecular genetic evidence.

cDNA clones encoding the H chains of the 7.8S and 5.7S IgY of the White Pekin duck have been isolated and sequenced. The H chain of the 7.8S IgY possesses four C region domains and thus resembles the H chain of chicken IgY with which it shows, in the C region, 54% inferred amino acid sequence identity, and complete conservation of the C region cysteine and tryptophan residues. The H chain of the 5.7S IgY possesses only two C region domains, that are virtually identical to CH1 and CH2 of the 7.8S IgY H chain. Although Southern blot genomic analysis did not resolve whether the two transcripts encoding the H chains of the 7.8S and 5.7S IgY are derived from one or two H chain-encoding genes, the CH 1, 2, 3, and 4 exons are apparently colinear, and no evidence was found for a separate locus in which CH1 and 2 exons were present and CH3 and 4 exons were lacking. The VH domain-encoding sequences of the cDNA for the two IgY H chains showed high similarity in the inferred VH gene (93% nucleotide and 91% inferred amino acid identity) and in the inferred JH segment (89% nucleotide and 93% inferred amino acid identity) but low similarity in the D region (26% nucleotide and 7% inferred amino acid identity). Genomic Southern blot hybridization analysis showed multiple VH-hybridizing sequences represented on up to 20 restriction fragments.

Amino Acid Sequence↗

PubMed1992

Alternate splicing pathways of the immunoglobulin heavy chain transcript of a teleost fish, Ictalurus punctatus.

Previously we sequenced a partial cDNA clone encoding the 3' region of the message for the membrane receptor form of the heavy (mu) chain of the channel catfish which indicated that the first transmembrane (TM1) exon is spliced directly to the C mu 3 exon and not into a cryptic site within the CH4 exon, as occurs in other vertebrates. Studies utilizing polymerase chain reaction analysis of mRNA and further analysis of cDNA clones now confirm that the only detectable splicing pattern used in micron production by the channel catfish utilizes this C mu 3----TM1 pathway of pre-mRNA splicing.

Animals↗

PubMed1992

Use of phenylpropanolamine to reduce nicotine cessation induced weight gain in rats.

The present study was conducted to determine if phenylpropanolamine (PPA) administered during the first week of nicotine termination could reduce or eliminate the body weight rebound which accompanies nicotine cessation. Sprague-Dawley rats were administered nicotine for 2 weeks after which they received either PPA or saline for 1 week. Control animals received saline during both drug periods. Body weight, food consumption, and water consumption were measured daily before drug, during nicotine and PPA administration, and for 14 days after PPA administration. In contrast to animals receiving saline upon termination of nicotine, animals receiving PPA did not gain weight at an accelerated rate. Termination of PPA did not result in a body weight rebound. To the extent that these results generalize to humans, they suggest that PPA could be used to reduce or eliminate postcessation weight gain in smokers who stop smoking.

Animals↗

PubMed1992

RHP is antigenically related to factor H and binds to the globular heads of C1q.

RHP was purified from normal serum by sequential euglobin precipitation, ion exchange chromatography on DEAE-Sephacel and gel filtration using Sephacryl S-300. RHP reacted with anti-Factor H antibodies in ELISA assays and in Western blots, suggesting that it is antigenically related to Factor H. It bound to intact C1q but not to the collagen-like N-terminal half of the molecule. C1q-specific monoclonal antibody BUS-1, which blocks the binding of C1q to immune complexes, did not block the binding of RHP to C1q. This implies that the binding sites on C1q for IgG and RHP do not overlap.

Binding Sites↗

PubMed1992

Sequential therapy with chemotherapeutic drugs and liposome-encapsulated muramyl tripeptide: determination of potential interactions between these agents.

Three syngeneic murine tumor models were used to determine potential interactions between chemotherapeutic drugs and the synthetic liposome-encapsulated macrophage activator, muramyl tripeptide phosphatidylethanolamine (MLV-19835). Experiments were designed to maximize any additive toxicity of the simultaneous administration of MLV-19835 on the known myelosuppressive effects of doxorubicin, ifosfamide, and cisplatin. Treatment with these drugs resulted in diminished blood leukocyte counts, altered leukocyte differentials, and decreased hematocrits, but the systemic administration of MLV-19835 produced no additional deleterious effects. Myelosuppression normally observed at 2 weeks following treatment of mice with doxorubicin was prevented by combination treatment with MLV-19835. In addition, there was no interference of the antitumor activity of ifosfamide or doxorubicin against subcutaneous, kidney, and spleen tumors. These studies and the recent demonstration of the biological activity of MLV-19835 in phase II trials of osteosarcoma recommend clinical testing of these combined modalities.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed1991

Clusterin enhances the formation of insoluble immune complexes.

Clusterin was purified from human serum by sequential affinity chromatography over IgG-, protein A- and Con A-Sepharose. The protein was approximately 70 kDa by SDS/PAGE under nonreducing conditions and was resolved into approximately 35 kDa bands under reducing conditions. The protein reacted with clusterin-specific Mabs in ELISA and in Western blots. Its N-terminal sequences agreed with those published for clusterin. An antiserum specific for clusterin made by the above method detected it in complement membrane attack complexes on rabbit erythrocyte membranes. The interaction of clusterin with IgG was physiologically relevant because it was found to increase the rate of formation of insoluble immune complexes.

Amino Acid Sequence↗