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Biomedical subjects

J M Shaw

Publications and source records attributed to J M Shaw.

At least 73 records · Page 4Linked to original sources
PubMed1996

Fresh and cryopreserved ovarian tissue samples from donors with lymphoma transmit the cancer to graft recipients.

Girls and young women who require ovariectomy or cancer therapy may consider having their own eggs, embryos or ovarian tissue stored (cryopreserved) for their own future use. Ovarian tissue is simple to collect and contains large numbers of germ cells. Transplantation of fresh and frozen-thawed ovarian tissue in healthy sheep and mice has resulted in normal live young. Similar techniques may be effective in the human but it is unclear whether ovarian tissue cryopreservation and grafting is suitable for ovaries from individuals with cancer or infections. If cancer cells were present in an ovary at the time of collection and survived cryopreservation and grafting they could establish cancer in the recipient. We therefore performed ovarian cryopreservation and transplantation trials using a mouse lymphoma model. This established that the lymphoma was transmitted by grafts of both fresh and frozen ovarian tissue. The normal healthy recipient mice died 9-43 days after receiving a small piece (1 mm3) of ovarian tissue from a donor with lymphoma. We conclude that ovarian tissue which is collected, cryopreserved and grafted while it contains cancer cells has the potential to spread the cancer to the graft recipient.

Aging↗
PubMed1995

Evaluation of propanediol, ethylene glycol, sucrose and antifreeze proteins on the survival of slow-cooled mouse pronuclear and 4-cell embryos.

Mouse pronuclear and 4-cell embryos were cryopreserved by slow cooling to -33 degrees C in 1.5 M 1,2-propanediol or 1.5 M ethylene glycol, with or without 0.1 M sucrose. Straws were thawed by immersion into a 37 degrees C water bath, immediately after their removal from liquid nitrogen (protocol 1), or after being held in air for 15 (protocol 2) or 30 s (protocol 3). Others were held in air until the ice melted (protocol 4). Embryos which formed blastocysts that hatched and attached to the Petri dish in vitro (plated) were considered viable. The thawing protocol did not significantly influence the viability of embryos frozen in propanediol with 0.1 M sucrose (52-72% of pronuclear and 69-97% of 4-cell embryos plated). In the other solutions tested, propanediol without sucrose and ethylene glycol with/without sucrose, only protocol 2 resulted in uniformly high development of both pronuclear (45-65% plating) and 4-cell embryos (70-97% plating). Thawing protocol 4 significantly reduced development, in particular for embryos frozen in ethylene glycol (0% 1-cell; 0-25% 4-cell plating). The difference between thawing protocols 2 and 4 was reduced by continuing slow cooling of ethylene glycol solutions to lower temperatures (-41 degrees C). Adding antifreeze proteins type I or III did not improve survival or development. Thus, although mouse pronuclear and 4-cell embryos can be frozen-thawed in either ethylene glycol or propanediol without significant loss of viability, an appropriate thawing protocol is essential for embryos frozen in ethylene glycol or propanediol-sucrose.

Animals↗
PubMed1994

Influence of growth rate on the relative activities of free and bound dextranase and dextranase inhibitor in continuous cultures of Streptococcus sobrinus.

The rate of growth of Streptococcus sobrinus was a major factor governing the activity of free dextranase and free dextranase inhibitor in continuous culture filtrates. Depending on the growth conditions, a variable proportion of dextranase and dextranase inhibitor was combined in a tightly bound enzyme-inhibitor (EI) complex. Dissociation of the EI complexes revealed that the total productivity (free + bound) of both the enzyme and the inhibitor increased with growth rate, and that the activities of the enzyme and inhibitor released from the EI complex greatly exceeded their free activities, when the dilution rate (D) was high (D, 0.45 h-1). At low growth rate (D, 0.05 h-1), all the enzyme was bound to the inhibitor, and no free dextranase could be determined in culture filtrates; by contrast, at high growth rate (D, 0.45 h-1), all the inhibitor was bound to dextranase in the active EI complex, leaving active dextranase but no free inhibitor.

Bacterial Proteins↗
PubMed1993

Preparation and characterization of basolateral membrane vesicles from pig and human colonocytes: the mechanism of glucose transport.

Membrane vesicles were isolated from the basolateral domains of pig and normal human colonocytes. The activity of the ouabain-sensitive K(+)-activated phosphatase, the basolateral membrane marker, was enriched 13-fold in these membrane vesicles over the original homogenate. The membranes displayed cross-reactions with antibodies to the (Na+/K+)ATPase and the RLA class I major histocompatibility antigen, both known indicators of the basolateral membrane. There was negligible contamination by other organelles and the luminal membrane, as revealed by marker-enzyme analysis and Western blotting, using an antibody to villin. The vesicles transported D-glucose in a cytochalasin B-inhibitable Na(+)-independent manner, with a Km of 28.1 +/- 0.8 mM and Vmax. of 3.1 +/- 0.4 nmol/s per mg of protein. The transport was inhibited by 2-deoxy-D-glucose and 3-O-methyl-D-glucose, but not by L-glucose or methyl-alpha-D-glucose. Probing the colonocyte basolateral membranes with an antibody against the C-terminus of the human liver GLUT 2 produced a cross-reaction at 52 kDa. These properties indicate the presence of a GLUT 2 isoform on the basolateral membranes of human and pig colonocytes.

3-O-Methylglucose↗
PubMed1993

A new macrophage differentiation antigen which is a member of the scavenger receptor superfamily.

The antibodies Ki-M8, Ber-Mac3, GHI/61 and SM4 define a human macrophage-associated antigen with a relative molecular mass of 130,000 which we designate M130. The protein was purified by immunoaffinity chromatography and an N-terminal and three internal amino acid sequences were obtained. A cDNA fragment was initially obtained by polymerase chain reaction (PCR) using reverse-translated primers. Several variant cDNA clones, derived from alternative spliced messages, were obtained from a lipopolysaccharide-stimulated human monocyte library and were sequenced. The relative abundance of these variants was evaluated by a series of overlapping PCR reactions. The size of the most representative cDNA is 3.7 kb and closely agrees with the mRNA size of 3.8 kb determined by Northern blot analysis. The membrane protein encoded contains a leader peptide of 40 residues, a putative extracellular domain of 1003 residues, followed by a hydrophobic segment of 24 residues and a cytoplasmic domain of 49 residues. The extracellular domain was found to contain nine repeating elements, of about 110 residues, which are similar to those of the scavenger receptor superfamily.

Amino Acid Sequence↗
PubMed1993

Dissociation and electrophoretic separation of dextranase and dextranase inhibitor from a tightly bound enzyme-inhibitor complex of Streptococcus sobrinus.

Endodextranase was separated from dextranase inhibitor in culture filtrates of Streptococcus sobrinus by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) in gel slabs containing blue dextran. Sample preparation included dissociation of the enzyme from its inhibitor by boiling for 1 min in SDS. During subsequent incubation of the gel, dextranase was located as clear bands on a blue background, and dextranase inhibitor appeared as blue zones on a clear background following incubation in dextranase solution. The enzyme and the inhibitor existed in multiple forms, and the range of molecular masses for dextranase (223-132 kDa) permitted an excellent separation from dextranase inhibitor (49-25 kDa). Although dextranase-negative mutants, and wild type strains grown at low dilution rate in the chemostat, were devoid of free dextranase activity, the enzyme was easily located by analytical SDS-PAGE. Likewise, analysis of filtrates from wild type strains, which contained no free inhibitor activity when growth occurred at high dilution rate, revealed dextranase inhibitor activity on the gels. The total production (free + combined) of dextranase and inhibitor by S. sobrinus was determined by dissociation of enzyme-inhibitor complexes in concentrated cell-free filtrates, their separation by preparative SDS-PAGE and electroelution from the gels, followed by renaturation of protein activity. From a comparison of activity tests of free dextranase and free inhibitor in untreated filtrates with the results of similar tests on renatured electroeluates, the proportion of each constituent bound into a complex under each growth condition could be deduced.

Dextranase↗
PubMed1993

Granulocytic sarcoma is associated with the 8;21 translocation in acute myeloid leukemia.

PURPOSE: Since the only three cases of granulocytic sarcoma among patients with acute myeloid leukemia (AML) seen at our institution during the last 12 years were each associated with the 8;21 translocation [t(8;21)], we sought to determine if this association is specific and more frequent than previously recognized. PATIENTS AND METHODS: We report three patients with AML and t(8;21) who developed granulocytic sarcomas, and review the world literature. RESULTS: Between 1980 and 1992, 53 cases of AML French-American-British (FAB) M2 were identified at our institution. Eight (15%) patients had t(8;21). Three of these eight patients (38%) developed granulocytic sarcoma. All three of our patients received conventional intensive antileukemic chemotherapy yet had short relapse-free survival durations. Several series of patients with t(8;21) report that granulocytic sarcomas occur in approximately 18% of this population, which is four times the expected incidence in AML. Thirty-seven cases have been previously reported. Although karyotype analyses were not reported in many cases of granulocytic sarcoma in the literature, the vast majority of abnormal karyotypes in patients with AML involved t(8;21). Recent work with a cell line derived from a patient with t(8;21) indicates that such cells are unusually adherent to culture bottles and are aggregable CONCLUSION: Our data suggest that this association is more common than generally recognized and may be specific. Patients with t(8;21) should be observed closely for signs and symptoms of granulocytic sarcoma. These patients may have a less favorable prognosis than other patients with t(8;21). Cooperative oncology groups should retrospectively identify patients with AML and t(8;21) who had a poor outcome to determine if they had a disproportionate incidence of granulocytic sarcoma. If so, aggressive therapy such as bone marrow transplantation may be warranted early in the therapeutic strategy.

Acute Disease↗
PubMed1991

vac2: a yeast mutant which distinguishes vacuole segregation from Golgi-to-vacuole protein targeting.

We have isolated four yeast mutants that are unable to partition maternal vacuoles into growing buds. Three of these vacuole segregation (vac) mutants also mislocalize the vacuolar protease carboxypeptidase Y (CPY) to the cell surface, a phenotype previously reported for vac strains. A fourth mutant, vac2-1, exhibits a temperature-sensitive defect in vacuole segregation but does not show a defect in protein targeting from the Golgi apparatus to the vacuole. Haploid vac2-1 cells grown at the non-permissive temperature do not secrete CPY or a second vacuolar protease, proteinase A (PrA). Furthermore, newly synthesized precursors of CPY are converted to mature forms with similar kinetics in both vac2-1 and wild-type cells. In addition, invertase is secreted normally from vac2-1 cells, indicating that post-Golgi steps in the secretory pathway are not blocked in this mutant. These results suggest that VAC2 function is necessary for vacuole division and segregation in yeast but is not involved in vacuole protein sorting events at the Golgi apparatus.

Aspartic Acid Endopeptidases↗
PubMed1991

A simple rapid 4.5 M dimethyl-sulfoxide freezing technique for the cryopreservation of one-cell to blastocyst stage preimplantation mouse embryos.

This study applies a 4.5 M dimethyl-sulfoxide freezing procedure, developed for 2-cell mouse embryos, to pronuclear to hatched blastocyst stage mouse embryos. The embryos were plunged into liquid nitrogen after 3 min equilibration at room temperature, or 3-60 min equilibration at 0 degrees C. Equilibration at 0 degrees C gave survival rates as high as or higher than rates after equilibration at room temperature. Optimal blastocyst formation, or re-expansion, rates for embryos frozen after equilibration at 0 degrees C were 76% for pronuclear stage embryos and 96-100% for 2-cell to mid-blastocyst stage embryos. The optimal rates of fetus formation, per embryo frozen, ranged from 62 to 88% for pronuclear to mid-blastocyst stage embryos. These results compared favourably with non-frozen control embryos (80-100% blastocyst formation, and 67-78% fetus formation).

Analysis of Variance↗
PubMed1991

Cold exposure during military operations: effects on anaerobic performance.

This study examined the effects of military field operations (MFO) under different environmental conditions on anaerobic performance. US Marines were tested in the field under the following conditions: 1) noncold environment (NC; n = 30, 10-32 degrees C) and 2) cold environment (CO; n = 32, -2 to -22 degrees C). Subjects performed 30-s Wingate tests (WIN) pre- and immediately post-MFO to assess anaerobic performance. The MFO consisted of approximately 4.5 days of combat training maneuvers while carrying field equipment (packs and weapon, approximately 25 kg). WIN measures obtained were absolute and relative mean power (MP), 5-s peak power (PP), and fatigue index (% decline). Significant main effects (P less than 0.01) were observed for time (pre-post MFO). Reductions occurred in absolute MP [651.8 +/- 30.3 to 616.4 +/- 28.5 (SE) W] and PP (897.8 +/- 41.6 to 857.0 +/- 39.1 W); however, no effect on fatigue index was seen. Significant interaction effects (P less than 0.05) were observed in relative measures. Reductions (pre-post) in MP (NC = 8.64 +/- 0.16 to 8.37 +/- 0.14 W/kg; CO = 8.91 +/- 0.26 to 8.04 +/- 0.15 W/kg) and PP (NC = 11.80 +/- 0.24 to 11.61 +/- 0.33 W/kg; CO = 12.23 +/- 0.35 to 11.20 +/- 0.19 W/kg) were greater under CO than NC conditions. These changes were found despite significant (P less than 0.05) but comparable pre-post weight reductions in both CO and NC conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

An association between chromosomal abnormalities in rapidly frozen 2-cell mouse embryos and the ice-forming properties of the cryoprotective solution.

This paper investigates the effect of straw handling on the viability of 2-cell mouse embryos rapidly frozen in dimethyl sulphoxide (DMSO) solutions. During the brief (3 min) equilibration step, straws were either rotated periodically to keep the embryos in suspension, or kept still to allow the embryos to settle onto the the inner surface of the straw. The effects of these straw movements were tested with cryoprotectant solutions containing 1.5, 3.0 or 4.5 M-DMSO. Rapidly cooled straws containing 4.5 M-DMSO vitrify throughout on cooling, but ice forms on warming. The survival and normality of embryos frozen in 4.5 M-DMSO was not influenced by straw handling as 91-92% formed blastocysts in vitro, 77-78% formed normal fetuses, and no chromosomal rearrangements were observed. In solutions containing less than 4.5 M-DMSO ice formation occurred throughout (1.5 M-DMSO), or in parts (3.0 M-DMSO) of the cryoprotectant during cooling. The viability of embryos frozen in 3.0 or 1.5 M-DMSO solutions was reduced both in vitro and in vivo and structural chromosome aberrations, predominantly tri- and quadri-radial rearrangements, were observed. The reduction in embryo viability, and the chromosomal damage was particularly pronounced in embryos frozen in 3.0 M-DMSO in straws which were rotated during the equilibration step (47% blastocysts, 15% fetuses, 77% chromosome rearrangements). The results indicate that rapid freezing of 2-cell mouse embryos in 4.5 M-DMSO is safe and efficient, whereas freezing at lower DMSO concentrations is associated with severe chromosome damage, and reduced viability in vitro and in vivo.

Animals↗