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Biomedical subjects

H Harris

Publications and source records attributed to H Harris.

At least 109 records · Page 6Linked to original sources
PubMed1986

Radiation damage in patients treated by total-body irradiation, bone marrow grafting, and cyclosporin.

The bone marrow (BM) and peripheral blood (PB) from 63 patients were assessed for the presence of chromosomal aberrations after bone marrow transplantation (BMT) following total body irradiation (TBI) for leukemia. Forty-one patients showed no abnormalities in either BM or PB, and 22 had aberrations in either BM or PB or both. Only stable aberrations were found in the BM, but both stable and unstable abnormalities were present in the PB, the majority showing only unstable aberrations. Among the 25 patients who had a leukemic relapse, clonal chromosomal abnormalities were found in the BM of 12 out of the 16 cases for whom marrow was studied at the time of the relapse. A statistically significant negative correlation between leukemic relapse and graft versus host disease (GvHD) was found, but the relationships between chromosome damage and leukemic relapse, GvHD, and the pretransplant radiation dose and between the radiation dose and both leukemic relapse and GvHD were not significant.

Adolescent↗
PubMed1986

Cataracts in patients heterozygous for galactokinase deficiency.

The role of heterozygous galactokinase deficiency in the development of presenile cataracts is presently undetermined. Erythrocyte galactokinase activity was measured from 95 normal Caucasian subjects and from 39 Caucasian patients who had developed idiopathic bilateral cataracts between ages 20 and 55. The diagnosis of heterozygous galactokinase deficiency was based on the following criteria: galactokinase activity more than 2.0 SD below the control population mean; when available, familial evidence for heterozygous galactokinase activity was used as additional evidence. Three of 39 patients (1/13) with cataracts were found to be carriers of the galactokinase deficiency allele (P less than 0.001). Two heterozygotes had high dietary galactose intake suggesting a possible relationship between a high galactose diet and cataract formation. Dietary information was unavailable for the third heterozygote. We conclude that there is a high prevalence of heterozygous galactokinase deficiency existing in patients less than 55 yr of age with cataracts, and recommend that adults at risk restrict their consumption of dairy products.

Adolescent↗
PubMed1985

Purification of human galactokinase and evidence for its existence as a monomer form.

A procedure for preparing a highly purified galactokinase (ATP:D-galactose 1-phosphotransferase, EC 2.7.1.6) from human erythrocytes and placenta is described, involving DEAE-Sephacel, ammonium sulfate fractionation, gel-filtration and a subsequent chromatography step on Blue Sepharose CL-6B. The final chromatography step yields a homogeneous preparation of high specific activity. The subunit molecular weight was determined to be 38 000 for both placental and erythrocyte galactokinases. Both active preparations of the native enzyme eluted from a gel filtration column gave a molecular weight of 37 000-38 000, thus suggesting the enzyme to be present in monomeric form. The isoelectric points for both crude and their respective purified enzymes was determined to be at pH 5.7. This method for purifying human galactokinase from placenta and erythrocytes represents a significant improvement over that previously reported and contradicts past evidence for the enzyme existing as a dimer.

Chromatography, Gel↗
PubMed1985

Ca2 and Ca3. New monoclonal antibodies evaluated as tumor markers in serous effusions.

Ca2 and Ca3 are new monoclonal antibodies of IgG1 class, directed against the Ca antigen, a mucus-type glycoprotein expressed on the surface of a wide range of malignant human cells and certain specialized normal epithelia. These antibodies were produced by immunization with purified preparations of the Ca antigen. They were tested to assess their value in the diagnosis of malignant effusions. Immuno-alkaline-phosphatase staining was used. Smears of pleural and peritoneal effusions were chosen to show: undoubted malignant cells of various types; and mesothelial cells in effusions from cases in which cancer was not in question. The Ca2 antibody, at 1 in 20 dilution of the culture supernatant, was the most specific, giving no reactions with benign mesothelial cells from any of the 35 cases tested. Malignant cells were clearly stained in 35 of 40 cases of carcinoma or mesothelioma. The staining was negative in two cases of oat cell bronchial carcinoma, and in three of four cases of carcinoma of the colon. Ca3 gave similar, but somewhat stronger, reactions with carcinoma cells, but was less specific, reacting weakly with mesothelial cells in 8 of 35 benign effusions. Because the false-negative reactions given by the Ca series of antibodies are to some extent complementary to those given by monoclonal antibodies directed against the carcinoembryonic antigen (CEA), a combination of Ca2 and anti-CEA is recommended as a most useful addition to the normal cytologic examination of effusions.

Antibodies, Monoclonal↗
PubMed1985

Genetic variability of alkaline phosphatase expression in inbred mouse tissues.

Quantitative alkaline phosphatase (ALP; EC 3.1.3.1) expression varies among various tissues and among inbred mouse strains. There is about a 20-fold difference in ALP activity in lungs from CBA/J and C57L/J inbred strains and this difference is inherited additively with a heritability of 0.84. Studies of thermostability at 56 and 65 degrees C and sensitivity toward inhibitors (L-phenylalanine, L-homoarginine, L-phenylalanylglycylglycine, and levamisole) do not demonstrate differences in the ALP from lungs or liver of the CBA/J and C57L/J strains. The ALP activity in intestine expressed by the intestinal locus varies over 100-fold between A/J and DBA/1J strains. Further studies of the mechanisms resulting in this difference in ALP activity should help elucidate the mechanisms for aberrant expression of ALP in malignancy and for manipulation of low ALP activity in hypophosphatasia.

Alkaline Phosphatase↗
PubMed1985

Long-term effects of chemotherapy on lymphocyte chromosomes from patients treated for gestational trophoblastic tumours.

A cytogenetic follow-up study of patients treated with chemotherapy for gestational trophoblastic tumours was undertaken. In some cases, high levels of chromosome damage were found to persist in lymphocytes for several years after completion of therapy. These results are compared with those found in similar studies of non-malignant and other malignant diseases. The relevance of these findings to the risk of subsequent chemotherapy-induced malignancy is discussed.

Adult↗
PubMed1985

Purification of neutral lens endopeptidase: close similarity to a neutral proteinase in pituitary.

A neutral endopeptidase (EC 3.4.24.5) that degrades alpha- and beta-crystallins occurs in mammalian lens. A procedure for purification of this enzyme from bovine lens is described. The enzyme appears to have a high molecular weight (Mr approximately equal to 700,000) and under denaturing conditions dissociates into at least eight polypeptide subunits with Mrs ranging from 24,000 to 32,000. A neutral proteinase in bovine pituitary has been reported previously to have similar structural characteristics. We have found that this enzyme purified from bovine pituitary is indistinguishable in molecular weight and in subunit composition from bovine lens endopeptidase. In addition, antiserum raised in rabbit against the purified lens enzyme crossreacts with bovine pituitary enzyme. When examined side by side in Ouchterlony double-diffusion tests, the two enzymes give a continuous precipitin line with no spurring. It is concluded that lens neutral endopeptidase and pituitary neutral proteinase are structurally closely similar, if not identical. This is a surprising result because it had been thought previously that the lens endopeptidase was unique to lens, where its crystallin substrates comprise a large proportion of the total tissue protein. In other tissues, crystallin is either absent or occurs, at most, in trace amounts.

Animals↗
PubMed1985

Long-term cytogenetic follow-up study of patients with uveitis treated with chlorambucil.

We have studied the long-term effects of chlorambucil treatment on the chromosomes of peripheral blood lymphocytes from patients with uveitis. Amounts of chromosome damage (breaks and rearrangements) were found to vary between individuals, but tended to increase with the cumulative dose. Some patients were found to have persistently high levels of chromosome damage many years after treatment had been completed.

Chlorambucil↗
PubMed1985

Subdural collection of intravenous fat emulsion in a neonate. Complication of central venous catheterization for total parenteral nutrition.

An infected subdural collection of intravenous fat emulsion (Intralipid) was diagnosed in a 5-week-old premature infant who was receiving total parental nutrition (TPN) through a facial vein cutdown. This fluid was successfully drained and the infection, due to Staphylococcus epidermidis, was treated with vancomycin. We postulate that the subdural collection occurred as a result of septic thrombosis of the internal jugular vein with subsequent retrograde flow and infiltration of Intralipid from the bridging veins into the subdural space. This complication of central TPN has not been reported previously.

Catheterization↗
PubMed1985

Studies on the endogenous galactose-binding lectin during early development of the embryo of Xenopus laevis.

Embryos of the frog Xenopus laevis at cleavage, blastula, gastrula and neurula stages contain a galactose-specific lectin. Extracts of gastrula embryos show the highest specific activity for this lectin compared to the other stages. Haemagglutinating activity of crude extracts is inhibited by lactose, alpha-galactose, beta-galactose, alpha Gal(1----4) beta Gal, beta Gal(1----3) alpha GalNAc, beta Gal(1----3) beta GlcNAc, beta Gal (1----4) beta GlcNAc, and most effectively by the disaccharide alpha Gal(1----3) beta Gal. Lectin from all stages was purified by absorption to galactose-linked immunoadsorbent or by affinity chromatography on a column of p-aminophenyl-beta-D-lactoside coupled to Sepharose 4B. In order to identify a single lectin band under reducing conditions in sodium dodecyl sulphate/polyacrylamide electrophoresis SDS/PAGE, it was necessary to treat aqueous suspensions of the purified lectin with chloroform/methanol (2:1, v/v). The lectin remained in the aqueous layer and gave rise on SDS/PAGE to a distinct band of 65 500 +/- 2780 molecular weight. Aqueous suspensions of the purified lectin that were not subjected to extraction with chloroform/methanol gave rise to several bands. Isoelectric focussing of the purified lectin resulted in two bands that separated at pI 4.3 and 4.5. In aqueous solution in the presence of lactose the chloroform/methanol-treated lectin appears to be an aggregate of apparent molecular weight of 375 000; the non-treated lectin under the same conditions has an apparent molecular weight of 490 000.

Animals↗
PubMed1985

Suppression of malignancy in hybrid cells: the mechanism.

When malignant cells, defined by their ability to grow progressively in genetically compatible hosts, are fused with diploid fibroblasts of the same species, the resulting hybrid cells, so long as they retain certain specific chromosomes donated by the diploid parent cell, are non-malignant. When these particular chromosomes are eliminated from the hybrid, the malignant phenotype reappears, and the segregant cell is again able to grow progressively in vivo. In the present experiments the histological character of the lesions produced by the inoculation of crosses between malignant and non-malignant cells was examined. It was found, in a wide range of material, and without exception, that where one or other of the parent cells in the cross was of fibroblastic lineage, malignancy was suppressed when the hybrid cells produced a collagenous extracellular matrix in vivo; and it reappeared when genetic segregants were produced that had lost the ability to produce this matrix. These results are interpreted in terms of a general model in which it is proposed that the progressive multiplication of malignant cells in vivo is a secondary consequence of a genetically stable impairment of terminal differentiation.

Animals↗
PubMed1985

Quantitative analysis of alkaline phosphatases in serum and amniotic fluid: comparison of biochemical and immunologic assays.

An immunoprecipitation method using monoclonal antibodies specific for the three categories of alkaline phosphatases, liver/bone/kidney, placental, and intestinal, is described and compared with the heat denaturation-chemical inhibition method for quantitating the contributions of the various isoenzymes to the total activity in biologic fluids. Activity values for the three categories of isoenzymes present in normal and pregnancy sera as well as in early gestation amniotic fluids were determined by both methods. There is very close correlation between the values obtained by both methods. Thus, two independent procedures are now available for quantitating the contributions of the various alkaline phosphatase isoenzymes in biologic fluids.

Alkaline Phosphatase↗
PubMed1984

Purification of monoclonal antibodies to human alkaline phosphatases by antigen-immunoaffinity chromatography: comparisons of their molar binding values.

Antigen-immunoaffinity chromatography has been used to purify monoclonal antibodies to human alkaline phosphatases. The binding of the purified antibodies to various alkaline phosphatases was tested utilizing an electrophoretic titration assay. The results indicate that binding differences among the various ALPs seen with several of the antibodies are due to antigenic differences in the molecular structure of the enzymes. We define a molar binding value as the minimum molar concentration of antibody necessary to complex all of the ALP in a standard reaction mixture. These values varied widely, indicating marked differences in the avidities of the different antibodies.

Alkaline Phosphatase↗