Hepatic encephalopathy associated with hemochromatosis in a toco toucan.
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Animals↗
Biomedical subjects
M G Brown
Publications and source records attributed to M G Brown.
De novo partial duplication of 17p [dup(17)(p12----p11.2)]: clinical report.
Duplication of band p11.2 and a small proximal portion of band p12 of chromosome 17 was noted in an infant with unusual facial appearance and left calcaneovalgus deformity. Developmental delay was documented over time. Only one other similar case has been found in the literature, but deletion of the same region is known in nine recently described cases [Smith et al, 1986]. This suggests that abnormalities of this small region of 17p are relatively common and only recently detectable with modern high-resolution techniques.
Calcaneus↗
Tandem duplication of proximal 22q: a cause of cat-eye syndrome.
A boy with bilateral colobomas, preauricular pits, and developmental delay had a 46,XY,22q+ karyotype. His parents had normal chromosomes. The abnormality of 22q was interpreted as a de novo tandem duplication of 22q11.1----q11.2. Although no anal abnormality was identified, his manifestations are otherwise consistent with those of the cat-eye syndrome. Blood marker results and the levels of galactosidase-2, galactosidase-B and arylsulfatase-A, which are known to be coded on 22q, are normal.
Abnormalities, Multiple↗
Fluoride exposure from hydrofluoric acid in a motor gasoline alkylation unit.
To assess the possible health risks associated with occupational exposure to gaseous fluoride, air and biological monitoring surveys were carried out at a motor gasoline alkylation unit within an oil refinery. Pre- and post-shift urinary fluoride measurements were obtained from 27 male operators and maintenance workers attached to the plant; personal fluoride-in-air monitoring was carried out simultaneously for 23 of these men. All readings were below NIOSH recommendations and Australian exposure standards. Significant exposure identified by changes in urine level during the shift could be demonstrated only in sub-groups of workers whose jobs involved higher routine exposures. No significant correlation between air levels and changes in urinary fluoride during the shift could be demonstrated. This survey indicates that the workers in this plant are not at risk of chronic fluorosis.
Air Pollutants, Occupational↗
Immunofixation of complement component C3 phenotypes in bloodstains after cellulose acetate electrophoresis.
The determination of the polymorphic C3 phenotypes was accomplished by electrophoresis on cellulose acetate followed by immunofixation. The three common phenotypes resulting from the two common codominant alleles C3S and C3F were clearly distinguishable in blood and bloodstain samples. Storage and degradation of C3 in blood samples as well as the stability of C3 in dried bloodstains is discussed.
Blood Stains↗
Turner syndrome resulting from partial deletion of Y chromosome short arm: localization of male determinants.
Chromosome studies performed because of the possibility of Turner syndrome in an infant girl with pedal edema and mild neck webbing revealed an XY karyotype. Subsequent exploratory laparotomy showed dysplastic ovaries with nests of germ cells with the morphologic features of gonadoblastoma. Repeat chromosome studies from peripheral blood using high-resolution techniques, and also from skin and ovarian fibroblasts, showed an XY karyotype but with a partial deletion of the Y short arm, which was not detected with standard techniques. These findings indicate that testis determining factors are located in this deleted region of the Y chromosome but that other gene(s) remain that induce gonadoblastoma.
Chromosome Deletion↗
Characterization of nonfimbrial mannose-resistant protein hemagglutinins of two Escherichia coli strains isolated from infants with enteritis.
Escherichia coli strains 444-3 and 469-3, isolated from patients with severe infantile enteritis, are able to adhere to and penetrate human epithelial cells in culture. In addition to type 1 fimbriae and glycocalyces , both strains elaborate mannose-resistant nonfimbrial protein hemagglutinins specific for human erythrocytes. Purified agglutinins are aggregates (greater than 4 X 10(6) daltons) of a single protein subunit of apparent Mr 14,000 (469-3) to 14,500 (444-3). The optimal temperature for expression of the agglutinins is 37 degrees C. Bacteria grown at 22 degrees C, which show 1% or less of maximal activity, and mutants deficient in the ability to agglutinate human erythrocytes do not synthesize detectable levels of these surface proteins and, moreover, do not adhere to cultured epithelial cells. Coupled with the observation that purified agglutinins competitively inhibit bacterial adherence to cultured cells, these data indicate that the nonfimbrial surface proteins expressed by strains 444-3 and 469-3 are essential for adherence both to erythrocytes and to cultured epithelial cells.
Adhesiveness↗
Urine desmosine is unrelated to cigarette smoking or to spirometric function.
We measured urine desmosine by radioimmunoassay in 157 subjects. Desmosine excretion (expressed as desmosine/creatinine ratio) did not correlate with ventilatory function (assessed by spirometry) or with current smoking status or total lifetime cigarette consumption. We conclude that measurement of urine desmosine may not be useful as an indirect measurement of elastolysis in cigarette smokers.
Adult↗
Distal 19q duplication.
Two brothers with a distal 19q duplication due to a maternal balanced reciprocal translocation were observed. Clinical features included intrauterine and postnatal growth retardation, microcephaly, and mental retardation with seizures. Dysmorphic facies consisted of coarse hair with a high frontal hairline, short philtrum and nose, flat nasal root, and a broad mouth with downturned commissures. Both routine G-banded and high-resolution prometaphase chromosome studies were employed in evaluation of the family. The dysmorphic features and karyotypes of the affected brothers are compared with those of the two previously reported families with 19q duplication, and a common distal-19q phenotype is suggested.
Adult↗
Resolution of breakpoints in a complex rearrangement by use of multiple staining techniques: confirmation of suspected 12p12.3 intraband by deletion dosage effect of LDHB.
A complex de novo translocation was found in leukocytes and fibroblasts from a boy with mental retardation and minor abnormalities. The 45,XY chromosome constitution found in all cells was initially interpreted from routine G- and Q-banding techniques as a balanced translocation of part of the short arm of 12 to the short arm of 15 and of the long arm of 21 to the short arm of 12. With additional staining techniques and use of prometaphase chromosome preparations, it was determined that the distal portion of band 12.3 of the short arm of chromosome 12 was missing from the 12/15 and the 12/21 translocation chromosomes. This interpretation was confirmed by a decreased concentration of the LDH-B subunit in lactate dehydrogenase isozymes of the patient's fibroblasts, consistent with his being hemizygous for the LDHB locus.
Abnormalities, Multiple↗
The role of plasmids in adherence of invasive Escherichia coli to mammalian cells.
Strains of Escherichia coli isolated from persons with dysentery-like diarrheal disease were demonstrated to adhere to the surface of cultured HEp-2 (human epithelial) cells under conditions that removed nonpathogenic control bacteria and to cause hemagglutination of human red blood cells. The plasmid content of 13 stains surveyed was found to be variable with respect to resistance to antibiotics and the presence of small cryptic plasmids. Conjugal transfer to resistance plasmids from two of the clinical isolates to a number of nonpathogenic laboratory and field isolates of E. coli was not accompanied by transfer of the capacity either for specific interaction with cultured HEp-2 cells or for hemagglutination of human red blood cells. Furthermore, cured derivatives of the enteroinvasive strains retained positive reactions in the assay systems.
Diarrhea↗
Transformation of Escherichia coli with plasmid deoxyribonucleic acid: calcium-induced binding of deoxyribonucleic acid to whole cells and to isolated membrane fractions.
Plasmid deoxyribonucleic acid (DNA) was tightly bound to cells of Escherichia coli at 0 degrees C in the presence of divalent cations. During incubation at 42 degrees C, 0.1 to 1% of this DNA became resistant to deoxyribonuclease. Deoxyribonuclease-resistant DNA binding and the ability to produce transformants became saturated when transformation mixtures contained 1 to 2 micrograms of plasmid NTP16 DNA and about 5 X 10(8) viable cells. Under optimum conditions, between 1 and 2 molecule equivalents of 3H-labeled NTP16 DNA per viable cell became deoxyribonuclease resistant. Despite this, only 0.1 to 1% of viable cells became transformed by saturating amounts of the plasmid. The results suggest that transport of DNA across the inner membrane is a limiting step in transformation. After transformation the bulk of labeled plasmid DNA remained associated with outer membranes. However, in vitro assays indicated that plasmid DNA would bind equally well to preparations of inner or outer membranes provided divalent cations were present to preparations of inner or outer membranes provided divalent cations were present. Divalent cations promoted differing levels of binding to isolated inner and outer membranes in the order Ca2+ much greater than Ba2+ greater than Sr2+ greater than Mg2+. This parallels their relative efficiencies in promoting transformation. Binding of plasmid DNA was greatly reduced when outer membranes were treated with trypsin; this suggests that protein components may be required for the binding or transport of DNA (or both) during transformation.
Biological Transport↗
An inhalation exposure chamber designed for animal handling.
A whole-body inhalation exposure chamber was designed and constructed that provided for uniform distribution of aerosols within the chamber and facilitated animal care. Animals were permanently housed in the chamber while on experiment. The entire chamber (including cage units) was sanitized in our cagewashing unit. Animals and their feed were easily observed since cages were mounted in pull-out drawers. The chamber accommodated 360 mice, 196 rats (depending on size), 312 hamsters, 60 guinea pigs, or 30 rabbits (the latter for exposure only). A special feature of the design was that cages and their associated excreta pans were equally spaced from chamber walls and arranged in vertical columns which were offset. This arrangement prevented excreta from dropping on animals in lower tiers.
Animals↗
Simultaneous transformation of Escherichia coli by pairs of compatible and incompatible plasmid DNA molecules.
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DNA↗
Immediate chromosome diagnosis on bone marrow cells: an aid to management of the malformed newborn infant.
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Bone Marrow↗
Inverted tandem ("mirror") duplications in human chromosomes: -nv dup 8p, 4q, 22q.
We have studied 4 patients with inverted tandem duplications of parts of chromosomes, a hitherto rarely identified form of a structural rearrangement involving a single chromosome in man. In patients 1 and 2, the duplication involved parts of the short arm of chromosome 8 (regions 8p12 leads to 8p23 and 8p21 leads to 8p23, respectively). Both patients manifested certain characteristics of the mosaic trisomy 8 syndrome. Elevated levels of glutathione reductase (GSR) in their erythrocytes supported the interpretation of a partial duplication of chromosome 8 and indicated a regional localization for the GSR gene locus. In Partient 3, the distal half of the long arm of chromosome 4 was duplicated (region 4q23 leads to 4q35). Clinical evidence supported this interpretation, as Patient 3 resembled phenotypically the 13 reported cases with duplication of the distal 4q. The cytogenetic findings in Patient 4 suggested a possibly inverted duplication of 22q. The clinical correlation was less convincing due to the lack of a well-defined phenotype for trisomy 22. These chromosome aberrations had occurred de novo in all 4 cases. Although they involved different chromosomal regions, they might well have arisen by the same mechanism. Possible modes of origin that are discussed in detail include unequal exchange between homologous chromosomes, between chromatids of 1 chromosome or between strands of 1 DNA duplex.
Adolescent↗
Gene dose effect: intraband mapping of the LDH A locus using cells from four individuals with different interstitial deletions of 11p.
The quantitative expression of LDH A was studied in hemolysates from four patients with different but overlapping interstitial deletions of the short arm of chromosome 11. Deficiency of LDH A was demonstrated in one patient, and the LDH A locus has been assigned to that segment of 11p for which this patient alone was deficient, i.e., to band 11p12 (region 11p1203 leads to 11p1208).
Abnormalities, Multiple↗
Partial trisomy 20p derived from a t(18;20) translocation.
Two sibs show a strikingly concordant syndrome of congenital anomalies and G-banding reveals that each has partial trisomy 20p resulting from a t(18;20) translocation. They resemble other cases of partial trisomy 20p in some respects but also differ in some ways. Their normal sib, mother, and half-aunt are balanced heterozygotes for the t(18;20) translocation. The segregation of the balanced translocation in this family is associated with an extremely poor reproductive record. The segregation pattern closely parallels that of a t(13;20) translocation in a family described by Carrel et al. (1971) and Francke (1972). The similarity of segregation patterns is predictable on the basis of probable pachytene configurations, but the dissimilarity of phenotypes between families is not readily explained.
Adolescent↗