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Biomedical subjects

A Coda

Publications and source records attributed to A Coda.

67 records · Page 4Linked to original sources
PubMed1989

Aplysia limacina myoglobin. Crystallographic analysis at 1.6 A resolution.

The crystal structure of the ferric form of myoglobin from the mollusc Aplysia limacina has been refined at 1.6 A resolution, by restrained crystallographic refinement methods. The crystallographic R-factor is 0.19. The tertiary structure of the molecule conforms to the common globin fold, consisting of eight alpha-helices. The N-terminal helix A and helix G deviate significantly from linearity. The distal residue is recognized as Val63 (E7), which, however, does not contact the heme directly. Moreover the sixth (distal) co-ordination position of heme iron is not occupied by a water molecule at neutrality, i.e. below the acid-alkaline transition point of A. limacina myoglobin. The heme group sits in its crevice in the conventional orientation and no signs of heme isomerism are evident. The iron atom is 0.26 A out of the porphyrin plane, with a mean Fe-N (porphyrin) distance of 2.01 A. The co-ordination bond to the proximal histidine has a length of 2.05 A, and forms an angle of 4 degrees with the heme normal. A plane containing the imidazole ring of the proximal His intersects the heme at an angle of 29 degrees with the (porphyrin) 4N-2N direction. Inspection of the structure of pH 9.0 indicates that a hydroxyl ion is bound to the Fe sixth co-ordination position.

Animals↗
PubMed1989

[Intramural infiltration of gastric cancer].

The relationship between the degree of intramural infiltration and the aspect and macroscopic dimensions of stomach cancer is investigated in the light of personal experience and reports in the literature. Statistics in the literature suggest that the choice between total and subtotal gastrectomy is only available in antropyloric cancers.

Duodenal Neoplasms↗
PubMed1985

Crystallization of an odorant-binding protein from cow nasal mucosa.

The first odorant-binding protein isolated from mammalian nasal mucosa is a dimer of subunits of identical molecular weight (19,000) that specifically binds bell pepper odorants, "green" smelling compounds. The protein can be purified in milligram quantities from tissue extractions by sequential use of a silica based anion exchange column and Mono-P chromatofocussing column. In the presence of the binding compound 2-isobutyl-3-methoxypyrazine and of the organic solvent 2-methyl-2,4-pentanediol (17%, v/v), the protein crystallizes in the monoclinic space group P2(1), with unit cell constants a = 54.3 A, b = 66.7 A, c = 41.5 A, beta = 97.2 degrees. From consideration of the crystal packing densities compatible with its unit cell, it can be concluded that two subunits of 19,000 Mr each are present in the asymmetric unit. The diffraction pattern on still photographs of this crystal form of the protein extends to 2.5 A resolution and allows for a detailed crystallographic investigation.

Animals↗
PubMed1985

Crystal structure of ferric Aplysia limacina myoglobin at 2 X 0 A resolution.

The three-dimensional structure of ferric myoglobin from the mollusc Aplysia limacina has been refined at 2 X 0 A resolution. The crystallographic R factor, calculated at this stage, is 0 X 194. Despite its high content of apolar residues (both aromatic and aliphatic), Aplysia limacina myoglobin, which contains only one histidine residue (at the proximal position), has a structure that conforms to the common eight-helices globin fold observed in other phyla.

Amino Acid Sequence↗
PubMed1984

Crystallization of hen egg-white avidin in a tetragonal form.

Hen egg-white avidin has been crystallized at pH 5.7 from ammonium sulfate solutions. The crystals belong to the tetragonal space group P4(2)2(1)2, with unit cell edges a = b = 79.6 A, c = 84.3 A. Assuming a molecular weight of 15,600 per avidin monomer, this crystal form is compatible with the presence of a dimer in the asymmetric unit, and is suitable for a crystallographic structural investigation at high resolution.

Animals↗
PubMed1983

A new crystalline modification of the copper enzyme ascorbate oxidase.

The copper enzyme ascorbate oxidase, purified from green zucchini squash, has been crystallized at pH 5.4 employing the organic solvent 2-methyl-2,4-pentanediol. The crystals obtained are larger than one millimetre and belong to the space group P2(1)2(1)2, with unit cell parameters; a = 106.7 A, b = 105.1 A, c = 113.5 A. The crystallographic asymmetric unit contains two subunits of the enzyme (Mr = 140,000) and the solvent content of the crystals is 46% (v/v). The diffraction pattern extends to 2.5 A resolution; this crystal form is suitable for a X-ray structural investigation.

Ascorbate Oxidase↗
PubMedDate not supplied

[The long-term results of mechanical anal sphincteroclasis].

BACKGROUND: The long-term results of 36 patients operated of manual dilatation of the anus are presented. Chronic anal fissure or benign anal stricture have been treated by this procedure in the years '80s. METHODS: Patients have been in part clinically examined and the other called up by phone interview. Average follow-up is 78 months. RESULTS: Nobody has been re-operated for the same cause, but 2 patients underwent sphincter sparing operation for rectal cancer. Twenty-five patients (72%) completely recovered, 5 (12.5%) complain sometimes from sudden anal pain and 3 (8%) report minor incontinence problems. CONCLUSIONS: These long-term results do not confirm disastrous conclusions reported by other authors in the literature, even if the incidence of continence disorders is higher than in anal sphincterotomies.

Adult↗
PubMedDate not supplied

[Possible cost reduction and better surgical results using EEA stapler in tumors of the upper rectum].

The aim of this work was to compare the relative costs and outcome of the anterior resection of the rectum for upper rectal cancer mechanically or manually performed. Therefore, the last two manual sutures and the first two cases operated using mechanical sutures were taken into account. Patients were homogenous for age, general conditions and cancer stage. Upper rectal location was choosen for the comparison considering the use of stapler not essential in this site. Analysis of the course showed no complications, shorter hospitalization, reduced drug therapy, and fewer diagnostic procedures needed in patients operated on with staplers. Although these data have no statistical rank, better surgical results and remarkable saving in social costs were observed with the use of stapling devices.

Adenocarcinoma↗