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Biomedical subjects

J Shapiro

Publications and source records attributed to J Shapiro.

At least 235 records · Page 13Linked to original sources

Keratitis and endophthalmitis caused by Petriellidium boydii.

A 26-year-old man sustained burns of the left eye and eyelids from molten aluminum. Antimicrobial and anti-inflammatory therapy was instituted. Cultures of conjunctival material collected 14 days after the burn grew abundant colonies of Petriellidium boydii. Because of severe pain and impending corneal perforation, the eye was enucleated.

Adult↗

Calcitonin therapy of children with osteogenesis imperfecta.

Two children, ages 13 2/12 and 6 6/12 years, with osteogenesis imperfecta were treated with salmon calcitonin. During the course of therapy the older child developed calcitonin dose-related hypomagnesemia on two occasions. The younger child, coincident with otitis media and vomiting, developed hypomagnesemia, hypophosphatemia, hyponatremia, and hypokalemia. Since rib biopsies obtained before and after one year of treatment with salmon calcitonin failed to demonstrate any histologic changes, therapy was discontinued because of the induced metabolic consequences of calcitonin therapy.

Adolescent↗

Transposition of a beta-lactamase locus from RP1 into Pseudomonas putida degradative plasmids.

The beta-lactamase gene from the RP1 plasmid transposes into at least two Pseudomonas putida degradative plasmids. Donor strains that carry RP1 (bla+ tet+ aphA+) and a degradative plasmid yield transconjugants that have only the bla+ marker of RP1. This occurs in up to 80% of all bla+ transconjugants. Segregation of the bla+ marker requires the presence of a degradative plasmid in the donor and is only observed in transconjugants that have received degradative markers. The bla+ tet aphA transconjugants show 100% linkage of bla+ to degradative markers in conjugation,transduction, and transformation crosses. A transduction cross of an (RP1), (SAL) donor shows that 8% of all SAL plasmids also carry the transposed bla+ marker. Tn401 is the name we assign to the bla+ transposon from RP1 observed in Pseudomonas. Its identity with the RP1 bla+ transposon observed in Escherichia coli is not known. In four cases, Tn401 has inserted into the camphor genes of the CAM-OCT plasmid.

Alkanes↗

Fractionation of inducible alkane hydroxylase activity in Pseudomonas putida and characterization of hydroxylase-negative plasmid mutations.

The plasmid-determined inducible alkane hydroxylase of Pseudomonas putida resolved into particulate and soluble fractions. Spinach reductase and spinach ferredoxin could replace the soluble hydroxylase component. Two alkane hydroxylase mutants show in vitro complementation (S. Benson and J. Shapiro, J. Bacteriol., 123: 759-760, 1975): one, alk-7, lacks an active soluble component and the other, alk-181, lacks an active particulate component. Together with previous results on a particulate alcohol dehydrogenase enzyme (Benson and Shapiro, J. Bacteriol., 126: 794-798, 1976), these results allowed us to assay three plasmid-determined inducible activities: soluble alkane hydroxylase (alkA+), particulate alkane hydroxylase (alkB+), and particulate alcohol dehydrogenase (alkC+). Growth tests and in vitro complementation assays revealed three groups of plasmid mutations that block expression of alkane hydroxylase activity: alkA, which so far includes only the alk-7 mutation; alkB, which includes alk-181 and 11 other mutations; and a pleiotropic-negative class, which includes nine mutations that lead to loss of alkA+, alkB+, and alkC+ activities. Thus, the alk+ gene cluster found on IncP-2 plasmids contains at least four cistrons. We believe it is significant that two of these determined the presence of membrane proteins. The accompanying paper shows that these loci are part of a single regulon.

Alkanes↗

Regulatory mutations of the Pseudomonas plasmid alk regulon.

Pseudomonas putida strains with plasmids carrying pleiotropic alk mutations gave rise to alkane-positive "revertants," which differ from wild type. Some had restricted ability to utilize alkane and primary alcohol growth substrates, and others could grow on undecane and dodecanol, which are not utilized by alk+ strains. These revertants showed altered responses to normal inducers of alkA+, alkB+, and alkC+ activities. Some revertants were constitutive for these activities. Constitutive mutants could also be isolated directly from wild type, but they appeared spontaneously at a frequency of less than 2 X 10(-8). Regulatory mutations of all three types, pleiotropic negative, altered inducer specificity, and constitutive, were tightly linked in transduction crosses with a polar alkB mutation. These results demonstrate that the IncP-2 plasmid alk gene cluster constitutes a regulon. They also permit the identification of at least one cistron whose gene product participates in inducer recognition and suggest that the alkABC regulon is not under simple repressor control.

Alcohol Oxidoreductases↗

Lipotoma of the breast diagnosed by film and xeromammography.

Five cases of the relatively uncommon intramammary lipoma and 4 cases of the rare adenolipoma were found in more than 5,000 patients who underwent mammography. The mammographic features of the intramammary and paramammary lipomata are given and the characteristic xeroradiographic appearance of adenolipomata is described. The 4 adenolipomata were only visualised by xeroradiography. The reason for these neoplasms being visible on xerograms and not on film mammograms is not clear, but we surmise that it is owing to the 'edge enhancement' phenomenon inherent in the xeroradiographic process. The question whether adenolipomata of the breast are true invasive tumours or mixed neoplasms is discussed.

Breast↗

Plasmid-determined alcohol dehydrogenase activity in alkane-utilizing strains of Pseudomonas putida.

We have identified an alcohol dehydrogenase activity in Pseudomonas putida strains carrying the CAM-OCT degradative plasmid that were grown on octane. The activity is nicotinamide adenine dinucleotide independent, sediments at 48,000 x g, and shows 20-fold greater activity with octanol rather than butanol as substrate. The enzyme is inducible by unoxidized alkane and is present only in strains that have the OCT plasmid genes for alkane degradation with a wild-type alcO locus. No analogous chromosomal dehydrogenase could be detected. Wild-type and actanol-negative mutants (alcA-) without plasmids both contain a constitutive nicotinamide adenine dinucleotide-linked soluble alcohol dehydrogenase activity. This means that alcA- mutants are cryptic for octanol oxidation and suggests that the particulate plasmid-coded alcohol dehydrogenase activity is active on surface- or membrane-bound substrate.

Alcohol Oxidoreductases↗

Absent mesosternum in congenital heart disease.

The association of developmental abnormalities of the sternum with congenital heart disease is well known. These abnormalities include hypoplasia, multiple centers, and premature fusion. The absence of the sternal bodies in patients with congenital heart disease unrelated to a specific syndrome complex has not been previously described. Possible association with congenital pulmonary vascular disease was noted.

Child↗

Physiological function of the Pseudomonas putida PpG6 (Pseudomonas oleovorans) alkane hydroxylase: monoterminal oxidation of alkanes and fatty acids.

Pseudomonas putida PpG6 is able to utilize purified n-alkanes of six to ten carbon atoms for growth. It can also grow on the primary terminal oxidation products of these alkanes and on 1-dodecanol but not on the corresponding 2-ketones or 1,6-hexanediol, adipic acid, or pimelic acid. Revertible point mutants can be isolated which have simultaneously lost the ability to grow on all five n-alkane growth substrates but which can still grow on octanol or nonanol. An acetate-negative mutant defective in isocitrate lysase activity is unable to grow on even-numbered alkanes and fatty acids. Analysis of double mutants defective in acetate and propionate or in acetate and glutarate metabolism shows that alkane carbon is assimilated only via acetyl-coenzyme A and propionyl-coenzyme A. These results support the following conclusions: (i) The n-alkane growth specificity of P. putida PpG6 is due to the substrate specificity of whole-cell alkane hydroxylation; (ii) there is a single alkane hydroxylase enzyme complex; (iii) the physiological role of this complex is to initiate the monoterminal oxidation of alkane chains; and (iv) straight-chain fatty acids from butyric through nonanoic are degraded exclusively by beta-oxidation from the carboxyl end of the molecule.

Alkanes↗

Regulation of alkane oxidation in Pseudomonas putida.

We have studied the appearance of whole-cell oxidizing activity for n-alkanes and their oxidation products in strains of Pseudomonas putida carrying the OCT plasmid. Our results indicate that the OCT plasmid codes for inducible alkane-hydroxylating and primary alcohol-dehydrogenating activities and that the chromosome codes for constitutive oxidizing activities for primary alcohols, aliphatic aldehydes, and fatty acids. Mutant isolation confirms the presence of an alcohol dehydrogenase locus on the OCT plasmid and indicated the presence of multiple alcohol and aldehyde dehydrogenase loci on the P. putida chromosome. Induction tests with various compounds indicate that inducer recognition has specificity for chain length and can be affected by the degree of oxidation of the carbon chain. Some inducers are neither growth nor respiration substrates. Growth tests with and without a gratuitous inducer indicate that undecane is not a growth substrate because it does not induce alkane hydroxylase activity. Using a growth test for determining induction of the plasmid alcohol dehydrogenase it is possible to show that heptane induces this activity in hydroxylase-negative mutants. This suggests that unoxidized alkane molecules are the physiological inducers of both plasmid activities.

Alcohol Oxidoreductases↗

Blue-green algae: why they become dominant.

The injection of carbon dioxide and the addition of nitrogen and phosphorus to a lake population dominated by blue-green algae results in a rapid shift to dominance by green algae. The basis for the change and its implications are discussed.

Carbon Dioxide↗