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J Maxwell

Publications and source records attributed to J Maxwell.

At least 37 records · Page 2Linked to original sources
PubMed1986

Commercializing university research. Lessons from the experience of the Wisconsin Alumni Research Foundation.

Universities that are now seeking ways to capture the financial rewards of advances made in biotechnology and other fields on their campuses have been encouraged by the apparent success of previous efforts to benefit from the commercial application of research findings by obtaining patents and granting licenses. Notable among these efforts is the Wisconsin Alumni Research Foundation (WARF). A close examination of the experience of this foundation reveals that, with good fortune and good management, a patenting and licensing organization can enjoy financial success. It also indicates, however, that the success experienced by WARF would be difficult to achieve today and that such efforts may yield lower financial returns than university administrators expect. Universities should be aware that such ventures entail financial risks and pose potential threats to traditional university values.

Academic Medical Centers↗
PubMed1984

Mg2+- or Mn2+-dependent p-nitrophenylphosphatase activity is present in Ehrlich ascites tumor cells.

The presence of a soluble, Mg2+- or Mn2+-dependent p-nitrophenylphosphatase activity in Ehrlich ascites tumor cell homogenates is reported. The crude homogenate was fractionated over Sephadex G-150 gel-filtration and DEAE-Sephacel anion-exchange columns, and two p-nitrophenylphosphatase activities were resolved. The most active fraction, Peak I, was characterized and found to be similar to phosphotyrosyl-protein phosphatases characterized elsewhere in that it has optimal activity at neutral pH; it is inhibited by phosphate, Zn2+, and vanadate; and it is not inhibited by levamisole. However, Peak I differs from phosphotyrosyl-protein phosphatases in that Mg2+ or Mn2+ is required for activity, fluoride is an inhibitor, and pyrophosphate is not inhibitory. Inhibition by the phosphorylated compounds phosphotyrosine, phosphoserine, phosphothreonine, ATP, CTP, GTP, ITP, NADP, fructose 6-phosphate, glucose 1-phosphate, galactose 1-phosphate, 2-phosphogluconic acid, and 6-phosphogluconic acid was also observed. Ehrlich ascites tumor cell p-nitrophenylphosphatase is shown to be sensitive to inactivation by trypsin, N-ethylmaleimide, or heat treatments.

4-Nitrophenylphosphatase↗
PubMed1984

Amplified KpnL repetitive DNA sequences in homogeneously staining regions of a human melanoma cell line.

The human melanoma cell line MeWo was found to contain two populations of cells, one containing 83 chromosomes (hypotetraploid) and the other containing 43 chromosomes (hypodiploid). All of the hypodiploid cells, but none of the hypotetraploid cells, contained chromosomes with long homogeneously staining regions (HSR's) when examined with quinacrine fluorescence. These long HSR's on an X-chromosome and derivative chromosome 15, produced characteristic patterns of positive- and negative-staining areas along the HSR's with both conventional Giemsa (G) staining and C-banding. The C- and G-positive regions stained with distamycin A-DAPI, which is specific for the centromeric heterochromatin of chromosomes 1, 9, 15p, 16, and Y. DNA extracted from MeWo cells and digested with the restriction enzymes KpnL or Sau3A exhibited marked amplification of a 1.8-kilobase fragment. The amplified Sau3A fragment (D15Z1) was cloned, mapped, and partially sequenced. The sequenced region contained a five-base-pair repeat unit (adenine-adenine-thymine-guanine-guanine) that has undergone considerable divergence. Estimates of the size of the HSR's and the amount of amplified DNA suggested that each HSR contained at least 30,000 copies of the 1.8-kb KpnL fragment, representing about 50% of each HSR. The amplified sequence was identified as one member of the previously described KpnL family of repeated sequences. In situ hybridization of D15Z1 to MeWo metaphase chromosomes resulted in heavy labeling over both HSR's. These data suggested that centromeric heterochromatin and neighboring sequences on chromosome 15 have been amplified and some of this material translocated to the X-chromosome.

DNA Restriction Enzymes↗
PubMed1982

Antigenic polypeptide fragments of a receptor related to the Fab fragment of human immunoglobulin from thymus-derived lymphocytes.

Certain thymus-derived lymphocytes of man and other primates express surface components related to the variable region of immunoglobulin heavy chains but lack constant region determinants defining any known immunoglobulin class. To obtain structural information on this molecule that can be used for comparison with known immunoglobulins and other surface molecules, we isolated the T cell-derived molecule by affinity chromatography using an antiserum raised against the monomeric Fab fragment of a human Waldenström macroglobulin and subjected the isolated molecule to either proteolysis using enzymes or cleavage with cyanogen bromide, followed by isolation of polypeptides which bore the Fab- or heavy chain variable region (VH)-related antigenic markers. The intact T cell molecule had an apparent mass of 68,000 daltons and no evidence was found for covalent or noncovalent association with polypeptides resembling light chains in apparent mass. The pattern of fragments obtained by cleavage of the T cell heavy chain suggests that the molecule is comprised of domains of approximate mass 12,000 daltons. Isolation of fragments from the digests that bear Fab-related serological markers shows that the molecule can be degraded into fragments resembling the Fd and VH of standard immunoglobulin heavy chains. A procedure was developed enabling the isolation of milligram quantities of VH-related T cell products. These results support the concept of a sharing of combining site determinants between T cell receptors and immunoglobulin heavy chains and show a general formal similarity between the two classes of molecules, even though they lack shared constant region determinants. The susceptibility of the T cell molecule to be cleaved into discrete antigenic fragments by controlled proteolysis might help to explain the plethora of sizes observed for antigen-specific T cell factors.

Animals↗
PubMed1979

Gas-liquid chromatographic analysis of urinary steroids.

A method for gas-liquid chromatographic separation and quantitation of urinary steroid metabolites is described. A normal reference range has been established and classic examples of urinary steroid profiles of the major steroid disorders are given.

17-Ketosteroids↗
PubMed1979

Isolation of influenza virus from muscle in myoglobinuric polymyositis.

We report the first isolation of influenza virus from muscle in a man with myoglobinuria and acute polymyositis. Influenza virus was isolated from cultures of Madin Darby bovine kidney and primary rhesus monkey kidney cells inoculated with muscle homogenates in the presence of trypsin; the virus was identified by neutralization and hemagglutination inhibition studies using influenza B/Lee antiserum. Viral plaque assay was performed with Madin Darby canine cells. Viral antigen was also detected by specific immunofluorescence in muscle, and myxovirus-like particles were seen in subsarcolemmal vacuoles by electronmicroscopy. The pathologic findings were similar to those of childhood dermatomyositis, except for a large proportion of necrotic muscle fibers. The evidence suggests that the pathogenesis of influenzal polymyositis in this patient involved direct viral infection of muscle.

Acute Disease↗