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Biomedical subjects

L Green

Publications and source records attributed to L Green.

At least 19 recordsLinked to original sources
PubMed1992

Prognostic significance of DNA ploidy in male breast carcinoma. A retrospective analysis of 32 cases.

BACKGROUND: DNA aneuploidy has been prognostically significant in female breast carcinoma of low stage, but its value in male breast carcinoma remains undetermined. METHODS: Flow cytometric DNA analyses were performed retrospectively on paraffin-embedded tissue from 32 men with breast carcinoma (mean follow-up time, 5.97 years [standard deviation +/- 4.63]; range, 1 to 18 years). RESULTS: Multivariate discriminant function analysis showed only tumor size less than 2 cm to be independently predictive of better disease-free survival (P less than 0.05). DNA ploidy (aneuploid, 25 patients; diploid, 7 patients) and lymph node status (positive, 22 patients; negative, 10 patients) were not predictive of survival, regardless of tumor size. CONCLUSIONS: The authors concluded that DNA ploidy may not significantly predict survival in male breast carcinoma.

Adult↗
PubMed1992

Attributions and relapse in opiate addicts.

This study investigated whether attributions of opiate addicts would predict both their ability to abstain from future use and their reactions to abstinence violations. Measures of generalized beliefs about responsibility for positive and negative outcomes and specific attributions about relapse episodes were elicited from 80 addicts at the time of admission for inpatient detoxification and treatment. Addicts who at admission attributed to themselves greater responsibility for negative outcomes and who attributed relapse episodes to more personally controllable factors were subsequently (at 6-month follow-up) more likely either to be completely abstinent or to contain the effects of temporary lapses into opiate use.

Adaptation, Psychological↗
PubMed1992

Translation initiation in Escherichia coli: sequences within the ribosome-binding site.

The translational roles of the Shine-Dalgarno sequence, the initiation codon, the space between them, and the second codon have been studied. The Shine-Dalgarno sequence UAAGGAGG initiated translation roughly four times more efficiently than did the shorter AAGGA sequence. Each Shine-Dalgarno sequence required a minimum distance to the initiation codon in order to drive translation; spacing, however, could be rather long. Initiation at AUG was more efficient than at GUG or UUG at each spacing examined; initiation at GUG was only slightly better than UUG. Translation was also affected by residues 3' to the initiation codon. The second codon can influence the rate of initiation, with the magnitude depending on the initiation codon. The data are consistent with a simple kinetic model in which a variety of rate constants contribute to the process of translation initiation.

Base Sequence↗
PubMed1991

Detection of Escherichia coli ribosome binding at translation initiation sites in the absence of tRNA.

Binary complexes between messenger RNA and E. coli ribosomes were examined. A ribosome-mRNA binary complex on T4 gene 32 mRNA withstood inhibition by antibodies against ribosomal protein S1. Anti-S1 blocks ternary complex formation, as measured by "extension inhibition" or "toeprinting" analysis, only when preincubated with ribosomes prior to mRNA addition and not when anti-S1 was added after preincubation of ribosomes and mRNA. The ribosome was directly localized in a binary complex on two translation initiation sites by toeprinting analysis. In the absence of tRNA the ribosome halted cDNA synthesis by reverse transcriptase close to the Shine and Dalgarno sequence. Binary complex formation was inhibited by an oligodeoxynucleotide competitor of the Shine and Dalgarno sequence.

Base Sequence↗
PubMed1991

The bedside assessment of splenic enlargement.

STUDY OBJECTIVE: To evaluate the clinical assessment of splenic enlargement using specific bedside maneuvers including Traube's space percussion, the splenic percussion sign, Middleton's maneuver, supine palpation, and right lateral decubitus palpation. DESIGN: Quasi-experimental prospective study of cases and controls selected according to the results of abdominal ultrasonographic examinations. SETTING: Selected inpatients of a tertiary care hospital. MAIN RESULTS: Comparing the areas under the receiver operating characteristic curves for each bedside maneuver demonstrated that Traube's space percussion and palpation were significant discriminators (p less than 0.001) of splenic enlargement with respective areas of 0.70 +/- 0.04 and 0.76 +/- 0.04. No one palpation maneuver was superior to another, and right lateral decubitus palpation was not useful when performed after supine palpation. The splenic percussion sign (sensitivity 79%, specificity 46%) was no better than Traube's space percussion (sensitivity 62% and specificity 72%) in assessing splenic enlargement. The palpation maneuvers appeared more sensitive and more specific than Traube's space percussion. Palpation was a significant clinical discriminator when performed on patients who exhibited percussion dullness of Traube's space (area = 0.87 +/- 0.04, p less than 0.0001) but was of little value among those without percussion dullness (area = 0.55 +/- 0.08). Also, palpation was significantly more accurate when performed on lean patients versus obese patients (areas = 0.83 +/- 0.04 versus 0.65 +/- 0.08, p less than 0.05). When a positive bedside examination was defined as positive palpation and positive percussion (concordant-positive), the combined test sensitivity and specificity were 46% and 97% respectively. CONCLUSIONS: The optimal clinical assessment of splenic enlargement includes the percussion of Traube's space. If Traube's space is dull, palpation of the spleen is warranted. This assessment is most accurate in lean patients.

Adult↗
PubMed1991

Psychosocial adjustment and physical growth in children with imperforate anus or abdominal wall defects.

Pediatric surgeons have the unique responsibility of performing surgical procedures that will enable their patients to function normally throughout a lifetime. Good anatomic results may not ensure that this goal will be achieved. Using a battery of psychological testing instruments, we evaluated the academic achievement and psychosocial status of 56 children (mean age, 10.6 years) with imperforate anus (IA) and abdominal wall defects (AWDs). Physical growth was assessed by measurement of standard anthropometric parameters, and a parent questionnaire was used to define clinical status. As a group, the children presented with average intellectual ability. Achievement in both reading and math was in the normal range. In 12.5% of the children a reading learning disability was noted and 10.7% had a disability in math. On the basis of parental assessments, 25% of the children demonstrated externalizing behavior disorders (eg, conduct problems) and 29% displayed internalizing symptomatology (eg. withdrawal, anxiety). Social competency deficits were described in 23% of the children. Data obtained from the teachers were consistent with the parental assessments. No major differences between the IA and AWD patients in academic achievement, psychosocial status, or physical growth were discovered. Routine screening of these children for learning disabilities and behavior problems is recommended.

Abdominal Muscles↗
PubMed1991

A case report of giant cell arteritis of the uterus and adnexa.

Giant cell arteritis of the uterus and adnexa is a rare disorder, which is generally asymptomatic and occasionally associated with temporal arteritis. The true clinical significance of this dramatic microscopic finding remains obscure, but arteritis of the uterus and adnexa may be associated with later development of giant cell arteritis elsewhere in the body.

Adnexal Diseases↗
PubMed1991

Congenital gastrointestinal anomalies: psychosocial functioning of children with imperforate anus, gastroschisis, and omphalocele.

This study assessed the psychosocial status of 56 children aged 6-16 years with imperforate anus, gastroschisis, or omphalocele. Results indicate that (a) children were of average intellectual ability; (b) approximately 9% of the sample had learning disabilities; (c) although the mean maternal ratings of behavioral adjustment did not differ from those reported for children without anomalies, approximately 18% of the children had deviant adjustment scores; (d) a multivariate risk and resistance model accounted for a significant amount of the variance in children's adjustment; and (e) child, maternal, and family utilitarian and psychological risk and resistance resources contributed independently to children's overall behavioral adjustment.

Abdominal Muscles↗
PubMed1991

Recombination in Escherichia coli and the definition of biological species.

The DNA sequence of part of the gnd (6-phosphogluconate dehydrogenase) gene was determined for eight wild strains of Escherichia coli and for Salmonella typhimurium. Since a region of the trp (tryptophan) operon and the phoA (alkaline phosphatase) gene have been sequenced from the same strains, the gene trees for these three regions were determined and compared. Gene trees are different from species or strain trees in that a gene tree is derived from a particular segment of DNA, whereas a species or strain tree should be derived from many such segments and is the tree that best represents the phylogenetic relationship of the species or strains. If there were no recombination in E. coli, the gene trees for different genes would not be statistically different from the strain tree or from each other. But, if the gene trees are significantly different, there must have been recombination. Methods are proposed that show these gene trees to be statistically different. Since the gene trees are different, we conclude that recombination is important in natural populations of E. coli. Finally, we suggest that gene trees can be used to create an operational means of defining bacterial species by using the biological species definition.

Alleles↗
PubMed1991

Isolation and characterization of a sulfur-regulated gene encoding a periplasmically localized protein with sequence similarity to rhodanese.

During sulfur-limited growth, the cyanobacterium Synechococcus sp. strain PCC 7942 loses most of its photosynthetic pigments and develops an increased capacity to acquire sulfate. Sulfur deprivation also triggers the synthesis of several soluble polypeptides. We have isolated a prominent polypeptide of 33 kDa that accumulates specifically under sulfur-limiting conditions. This polypeptide was localized to the periplasmic space. The gene for this protein (designated rhdA) was isolated and discovered to lie within a region of the Synechococcus sp. strain PCC 7942 genome that encodes components of the sulfate permease system. The mRNA for the 33-kDa protein accumulates to high levels within an hour after the cells are deprived of sulfur and drops rapidly when sulfur is added back to the cultures. The amino acid sequence of the protein has similarity to bovine liver rhodanese, an enzyme that transfers the thiol group of thiosulfate to a thiophilic acceptor molecule, and a rhodaneselike protein of Saccharopolyspora erythraea. A strain in which rhdA was interrupted by a drug resistance marker exhibited marginally lower levels of rhodanese activity but was still capable of efficiently utilizing a variety of inorganic sulfur sources. The possible role of this protein in the transport of specific sulfur compounds is discussed.

Amino Acid Sequence↗
PubMed1991

Economic substitutability of electrical brain stimulation, food, and water.

Concurrent variable-ratio schedules of electrical brain stimulation, food, and water were paired in various combinations as reinforcement of rats' lever presses. Relative prices of the concurrent reinforcers were varied by changing the ratio of the response requirements on the two levers. Economic substitutability, measured by the sensitivity of response ratio to changes in relative price, was highest with brain stimulation reinforcement of presses on both levers and lowest with food reinforcement of presses on one lever and water reinforcement of presses on the other. Substitutability with brain stimulation reinforcement of presses on one lever and either food or water reinforcement for presses on the other was about as high as with brain stimulation for presses on both levers. Electrical brain stimulation for rats may thus serve as an economic substitute for two reinforcers, neither of which is substitutable for the other.

Animals↗
PubMed1991

Adverse reaction reporting of interaction between warfarin and fluoroquinolones.

Reports to the Food and Drug Administration's Adverse Drug Reaction Reporting System of prolonged prothrombin time due to a suspected interaction between warfarin sodium and a fluoroquinolone were reviewed. Five reports of patients who experienced this adverse reaction 2 to 16 days after the addition of a fluoroquinolone to their treatment regimen are described. Possible mechanisms of action that are discussed include inhibition of warfarin metabolism by the anti-infective agent and displacement of warfarin's binding to protein. Physicians need to be aware of this interaction and closely monitor prothrombin time in patients concurrently receiving warfarin and a fluoroquinolone.

Adult↗
PubMed1991

Pregnancy and cystic fibrosis.

Despite reduced fertility, pregnancy is likely to occur with increasing frequency in cystic fibrosis in proportion to the number of patients reaching childbearing age. Thirty-eight pregnancies in 25 patients with cystic fibrosis are presented. Twelve of the 25 mothers were pancreatic-sufficient. Despite previous reports of the hazards of pregnancy in cystic fibrosis, we found that pregnancy was well tolerated by the vast majority of our patients and had little effect on their pulmonary and nutritional status. Therapeutic abortion for medical indications was required in two pregnancies. The incidence of prematurity and the neonatal mortality rate were low, and no congenital abnormalities occurred. We conclude that pregnancy can be tolerated by the majority of cystic fibrosis patients, particularly those who are pancreatic-sufficient.

Adolescent↗
PubMed1990

Binding of the bacteriophage T4 regA protein to mRNA targets: an initiator AUG is required.

Bacteriophage T4 regA protein translationally represses the synthesis of a subset of early phage-induced proteins. The protein binds to the translation initiation site of at least two mRNAs and prevents formation of the initiation complex. We show here that the protein binds to the translation initiation sites of other regA-sensitive mRNAs. Analysis of mRNA binding by filtration and nuclease protection assays shows that AUG is necessary but not sufficient for specific binding of regA protein to its mRNA targets. Anticipating the need for large quantities of regA protein for structural studies to further define the regA protein-RNA ligand interaction, we also report cloning the regA gene into a T4 overexpression system. The expression of regA protein in uninfected E. coli is lethal, so in our system regA driven by a strong T7 promoter is sequestered in a T4 phage until 'induction' by phage infection is desired. We have replaced the regA sensitive wild-type ribosome binding site with a strong insensitive ribosome binding site at an optimal distance from the regA initiation codon for maximizing expression. We have obtained large amounts of regA protein.

Base Sequence↗
PubMed1990

Diagnosis and antibiotic treatment of acute otitis media: report from International Primary Care Network.

STUDY OBJECTIVE: The relation between a history of disorders suggestive of acute otitis media, symptoms, and findings of an examination of the tympanic membrane and doctors' certainty of diagnosis. Also, to examine differences in prescribing habits for acute otitis media among doctors from different countries. DESIGN: Questionnaires were completed by participating doctors for a maximum of 15 consecutive patients presenting with presumed acute otitis media. SETTING: General practices in Australia, Belgium, Great Britain, Israel, The Netherlands, New Zealand, Canada, Switzerland, and the United States. PATIENTS: 3660 Children divided into the three age groups 0-12 months, 13-30 months, and greater than or equal to 31 months. MAIN OUTCOME MEASURES: General practitioners' responses to questions on their diagnostic certainty and resolution of patients' symptoms after two months. RESULTS: The diagnostic certainty in patients aged 0-12 months was 58.0%. This increased to 66.0% in those aged 13-30 months and 73.3% in those aged greater than or equal to 31 months. In all age groups diagnostic certainty was positively associated with the finding of a tympanic membrane that was discharging pus or bulging. Redness of the membrane and pain were also associated with certainty in patients aged 13-30 months, and a history of decreased hearing or recent upper respiratory infection was positively associated in patients aged greater than or equal to 31 months. The proportion of patients prescribed antibiotics varied greatly among the countries, from 31.2% in The Netherlands to 98.2% in both Australia and New Zealand, as did the duration of treatment. Patients who did not take antibiotics had a higher rate of recovery than those who did; the rate of recovery did not differ between different types of antibiotic. CONCLUSIONS: Doctors' certainty of diagnosis of acute otitis media was linked to patient's age. Improved criteria or techniques for diagnosing acute otitis media, especially in very young children, need to be developed. Antibiotic treatment did not improve the rate of recovery of patients in this study.

Acute Disease↗