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Biomedical subjects

I Wood

Publications and source records attributed to I Wood.

18 recordsLinked to original sources
PubMed1991

Functionally important regions of glucose-6-phosphate dehydrogenase defined by the Saccharomyces cerevisiae enzyme and its differences from the mammalian and insect forms.

The primary structure of Saccharomyces cerevisiae glucose-6-phosphate dehydrogenase has been determined. It consists of 503 amino acid residues, with an acetyl-blocked N-terminus. The structure shows equally extensive differences from the corresponding mammalian and fruit fly enzymes (52% residues non-identical). Residues conserved in all the forms constitute about 40% of the structures and include two histidines. One of these (His200 in the numbering of the rat enzyme) occurs in a 10-residue conserved segment, including the reactive Lys204, probably related to substrate binding. Two segments with conserved Gly-Xaa-Xaa-Gly-Xaa-Xaa-Gly/Ala pattern constitute possibilities for the coenzyme-binding site. One is N-terminally located (positions 37-43) with two conserved arginine residues nearby (positions 56 and 71), of interest for phosphate binding. The other (positions 241-247) is in a middle region, with many residue identities, containing the conserved residues Arg256 and His264.

Amino Acid Sequence↗
PubMed1991

Eukaryotic glucose-6-phosphate dehydrogenases: structural screening of related proteins.

Rapid assessment of structural relationships between yeast glucose-6-phosphate dehydrogenases and other eukaryotic types of this enzyme is described. Separation and size estimation of large fragments by sodium dodecylsulfate/polyacrylamide gel electrophoresis, electroblotting onto disks, and sequencer analysis provide data that permit alignment of the segments thus characterized with the related proteins, and utilize existing structural knowledge to assess new enzyme structures. Affinity labeling allows further correlations. The results establish the overall structural arrangements of the new proteins, including the location of the active-site lysine residue, even though the yeast enzyme structures are found to differ markedly from the few previously characterized glucose-6-phosphate dehydrogenases.

Amino Acid Sequence↗
PubMed1989

Glucose-6-phosphate dehydrogenase. Characteristics revealed by the rat liver enzyme structure.

The primary structure of glucose-6-phosphate dehydrogenase from rat liver has been determined, showing the mature polypeptide to consist of 513 amino acid residues, with an acyl-blocked N-terminus. This structure is homologous to those of both other eutherian and marsupial mammals (human and opossum), thus characterizing a mammalian type enzyme to which the human form, notwithstanding its large number of genetic variants, conforms. The mammalian type differs from the fruit fly enzyme by about 50%. Known mutant forms exhibit further differences, widely distributed along the polypeptide chain. Structural patterns show glucose-6-phosphate dehydrogenases to consist of a few variable regions intermixed with relatively constant segments.

Amino Acid Sequence↗
PubMed1989

Glucose-6-phosphate dehydrogenase. Characterization of a reactive lysine residue in the Pichia jadinii enzyme reveals a limited structural variation in a functionally significant segment.

Glucose-6-phosphate dehydrogenase from the yeast Pichia jadinii has a reactive lysine residue in a segment of amino acid sequence Ile-Asp-His-Tyr-Leu-Gly-Lys*-Glu-Met-Val-Lys. This structure differs from that of other characterized glucose-6-phosphate dehydrogenases, but outside yeasts the segment is invariant in known mammalian, insect and bacterial forms. Thus, limited structural variation is now defined within yeasts for a part of the protein otherwise strictly conserved, and for which stringent structural requirements probably relate to enzymic mechanisms.

Amino Acid Sequence↗
PubMed1979

Terminal course of nerve supply to Müller's muscle in the rhesus monkey and its clinical significance.

Electron microscopic, histochemical fluorescence, and pharmacologic evidence suggested that, in the rhesus monkey, Müller's muscle was not totally denervated either by cutting the levator palpebrae superioris muscle or by a Fasanella-Servat procedure. We examined the terminal course of the sympathetic nerve supply and the potential for preserving Müller's muscle in blepharoptosis surgery.

Adrenergic Fibers↗
PubMed1978

Experimental and clinical data on the insertion of the levator palpebrae superioris muscle.

Radiographic and electron microscopic evidence showed that the upper eyelid skin crease is formed by the insertion of the levator palpebrae superioris muscle into the septa between the orbicularis muscle into the septa between the orbicularis muscle bundles and not into the skin itself. Experiments on monkeys showed that the insertions of the aponeurosis and of Müller's muscle both contribute to normal eyelid elevation. No histologic evidence was found for a disinsertion of Müller's muscle in 20 cases of blepharoptosis. This, with other evidence discussed, supports the functional importance of the human aponeurotic insertions in eyelid elevation.

Adolescent↗
PubMed1977

Pigment epithelial ensheathment and phagocytosis of extrafoveal cones in human retina.

The association between extrafoveal cone outer segments and pigment epithelial cells was studied by transmission electron microscopy in three human retinas; ages 5,45 and 60. The pigment epithelial apical surface from a fourth human retina, age 38,was viewed in the scanning electron microscope. Multiple villous-like apical processes protrude from the pigment epithelium into the space above each cone. Sometimes one or more of these processes is sheet-like in form and contains a wealth of intracellular organelles, including mitochondria. One or more of the villous-like procesess reaches the cone and expands to ensheath the upper one-third of the outer segment. Llike vertebrate rods, extrafoveal human cones shed their terminal disks in packets and these packets are phagocytosed by the ensheathing apical processes. The phagosomes then ascend in the processes toward the pigment epithelia soma. Digestion of phagosomes appears to begin in the apical processes.

Adult↗
PubMed1977

Climatic droplet keratopathy in a 16-year-old boy.

Primary climatic droplet degeneration of the cornea that consisted of bandshaped keratopathy and superficial spheroidal golden opacities occurred in a 16-year-old boy. Light microscopy showed proteinaceous deposits in the superficial corneal stroma. Electron microscopy confirmed the colloidal nature of this material.

Adolescent↗
PubMed1975

Salzmann's nodular degeneration of the cornea.

Eleven corneal specimens from nine patients with Salzmann's nodular degeneration of the cornea, together with all available clinical information, were collected for this study. The specimens were examined by light and electron microscopy. An antecedent keratitis was diagnosed by history and microscopic findings in every case. The corneal epithelium showed degenerative changes, its thickness varied, and in nodular areas it often consisted of only a single layer of flattened epithelial cells by light microscopy. Bowman's membrane was missing over the nodules, and in this zone there was excessive secretion of a basement membrane-like material. Hyaline degeneration of collagen, cellular debris, and electron-dense hyaline deposits were seen in the collagen of the nodules. The number of fibrocytes in the nodules varied from many that were active to a few that were degenerating. External irritation because of poor epithelial protection was interpreted as a causative factor, although other tissue repair mechanisms may also have played a role.

Basement Membrane↗
PubMed1975

Lens changes in a galactosemic fetus.

The first child of a Spanish-American couple died presumbably from galactosemia. Early in the mother's fourth pregnancy, the parents' red blood cell levels of galactose 1-phosphate uridyl transferase were measured and both parents were found to be heterozygous (carriers) for transferase deficiency. A prenatal diagnosis of galactosemia in the fetus was made with the aid of amniocentesis and tissue culture. Abortion was induced when the fetus was 5 months old. Biochemical studies of lung and liver tissues confirmed the diagnosis of galactosemia. Cataractous changes were found by electron microscopy in both fetal eyes. Lens epithelial cells showed degenerative changes and a tendency to proliferate into two cell layers. Edema, liquefaction, and a variation in density characterized the lens cells.

Abortion, Induced↗
PubMed1975

Observation of Kolmer's crystalloid outside the retina. Presence in the corneal endothelium in various conditions.

A structure similar to Kolmer's crystalloid, an organelle found in the horizontal cells of the retina, was observed in endothelial cells of the cornea from four patients (one case of hyperparathyroidism and three cases of corneal dystrophy). Based on a morphological analysis it is concluded that the structures in the present cases are identical with the cytoplasmic structure of the horizontal cell, and that the membranous tubes probably constitute a special form of rough surfaced endoplasmic reticulum, eventually involved in transport and/or a specialized protein synthesis.

Cell Membrane↗
PubMedDate not supplied

The use of vacuum-molded polyvinyl acetate-polyethylene copolymer (PVAC.PE) for a handicapped patient.

This paper provides a survey of recent literature on the use of mouth sticks for patients who have little or no use of their limbs. Criteria for mouth stick design, types of appliances, and the fabrication of such devices are described. Details are given of a case of a young child with arthrogryposis multiplex congenita, in whom a novel approach was used to allow the safe intra-oral retention of writing implements.

Arthrogryposis↗
PubMedDate not supplied

Smart moves in Zagreb.

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Emergency Nursing↗
PubMedDate not supplied

Assessing trauma.

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Blood Pressure↗