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Biomedical subjects

R C Taylor

Publications and source records attributed to R C Taylor.

At least 19 recordsLinked to original sources

Role of laparoscopic salpingostomy in the treatment of hydrosalpinx.

OBJECTIVE: To determine pregnancy rates after laparoscopic salpingostomy in occlusive distal tubal disease. To evaluate the relative impact of various historical, physical, and operative factors on pregnancy outcome using a multivariate statistical analysis. DESIGN: Prospective cohort. SETTING: University-affiliated tertiary care infertility clinic. PATIENT(S): One hundred thirty-nine infertile women with occlusive distal tube disease. INTERVENTION(S): Laparoscopic salpingostomy. MAIN OUTCOME MEASURE(S): The occurrence of intrauterine (IUP) and ectopic pregnancy (EP). RESULT(S): The overall IUP and EP rates were 24.5% and 16.5%, respectively. Analysis of historical variables, assessed independently, demonstrated a significantly higher IUP rate with a positive history of gonorrhea and a significantly higher EP rate with a positive history of pelvic inflammatory disease, lack of history of intrauterine device (IUD) usage, or the performance of a bilateral procedure. The logistic regression model to predict intrauterine pregnancy had an overall predictive value of 77.5% and included the following significant variables: secondary infertility, positive history of gonorrhea, and the operative finding of moderate periadnexal adhesions. The logistic regression model to predict ectopic pregnancy had an overall predictive value of 89.0% and included the following significant variables: previous ectopic pregnancy, negative history of IUD use, positive history of PID, a bilateral procedure, and perihepatic adhesions. CONCLUSION(S): Operative laparoscopy may be effective for the correction of hydrosalpinges in selected patients. The probability of achieving an intrauterine or an ectopic pregnancy can be predicted based on combinations of significant variables.

Adult↗

GEST: a gene expression search tool based on a novel Bayesian similarity metric.

Gene expression array technology has made possible the assay of expression levels of tens of thousands of genes at a time; large databases of such measurements are currently under construction. One important use of such databases is the ability to search for experiments that have similar gene expression levels as a query, potentially identifying previously unsuspected relationships among cellular states. Such searches depend crucially on the metric used to assess the similarity between pairs of experiments. The complex joint distribution of gene expression levels, particularly their correlational structure and non-normality, make simple similarity metrics such as Euclidean distance or correlational similarity scores suboptimal for use in this application. We present a similarity metric for gene expression array experiments that takes into account the complex joint distribution of expression values. We provide a computationally tractable approximation to this measure, and have implemented a database search tool based on it. We discuss implementation issues and efficiency, and we compare our new metric to other standard metrics.

Bayes Theorem↗

Efficacy of granular deltamethrin against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidade) nymphs.

A single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of Ixodes scapularis Say nymphs. The application also suppressed the population of Amblyomma americanum (L.) nymphs, which recently became established in the study area. The efficacy of deltamethrin is compared with other commonly used acaricides.

Animals↗

High-resolution solid state 13C nuclear magnetic resonance spectra of 3,4-methylenedioxyamphetamine hydrochloride and related compounds and their mixtures with lactose.

Differences between solution and solid state 13C nuclear magnetic resonance spectra of some amphetamines namely, 3,4-methylenedioxyamphetamine HCI, (R.S)-MDA HCI, the methyl derivative 3,4-methylenedioxy-N-methylamphetamine x HCI, (R,S)-MDMA x HCI, the ethyl derivative, (R,S)-MDEA x HCI, and the analogues (R,S)-methamphetamine HCI, (-)-ephedrine x HCI (the 3R,2S enantiomer as numbered here), and (+)-pseudo-ephedrine x HCI (the 3S,2S enantiomer as numbered here) have been studied and related to their crystal structure. For (R,S)-MDMA x HCI, an interesting new finding is that the observed solid state chemical shifts changed when lactose monohydrate was added as a dry powder and thoroughly mixed at room temperature. This experiment mimicked the illicit production of "Ecstasy" tablets. The mixing phenomena with lactose observed for (R.S)-MDMA x HCI was not seen for the other compounds studied. The results are discussed in terms of hydrogen bonding and possible polymorphs. It appears that lactose affects crystal packing by reducing conformational rigidity so that the molecule more closely resembles that in solution.

3,4-Methylenedioxyamphetamine↗

Tobacco craving: intensity-related effects of imagery scripts in drug abusers.

Two experiments were conducted to determine whether active imagery would elicit tobacco craving in smokers with histories of drug abuse who were not interested in quitting smoking. In Experiment 1, the authors used scripts that contained positive, negative, or neutral affective content with and without descriptions of smoking urge. Scripts with urge content and negative affect scripts increased subjective reports of tobacco craving. An interaction between affective manipulation and urge content was observed on self-reported mood. In Experiment 2, positive affect scripts that varied in amount of urge content produced an orderly increase in tobacco craving as a function of urge intensity, suggesting that changes were specific to the imagery manipulation. In both experiments, increases in tobacco craving were positively correlated with craving for drug of choice, suggesting that stimuli that engender smoking urges may occasion craving for other drugs of abuse.

Adult↗

Smoking after nicotine deprivation enhances cognitive performance and decreases tobacco craving in drug abusers.

This study investigated the effects of nicotine deprivation and smoking on cognitive abilities and tobacco craving. Twenty smokers with histories of drug abuse completed the Questionnaire on Smoking Urges (QSU) and two cognitive tests before and after smoking two cigarettes during two 90-min sessions. After two cigarettes were smoked at Session 1, subjects were tobacco abstinent for 18 h until Session 2 the next morning. Response time on a logical reasoning test was unchanged by tobacco deprivation and was faster after smoking on Session 2. Deprivation slowed responding on a letter search test, which was reversed by smoking to pre-deprivation baseline. Tobacco deprivation increased scores on the QSU; smoking after deprivation reduced craving scores to smoking baseline levels. These results confirmed the utility of the QSU to measure changes in craving induced by tobacco deprivation and smoking. Further, the data suggest that deprivation-induced deficits and smoking-induced enhancements in performance may be specific to certain cognitive domains.

Adult↗

Identification of putative programmed -1 ribosomal frameshift signals in large DNA databases.

The cis-acting elements that promote efficient ribosomal frameshifting in the -1 (5') direction have been well characterized in several viral systems. Results from many studies have convincingly demonstrated that the basic molecular mechanisms governing programmed -1 ribosomal frameshifting are almost identical from yeast to humans. We are interested in testing the hypothesis that programmed -1 ribosomal frameshifting can be used to control cellular gene expression. Toward this end, a computer program was designed to search large DNA databases for consensus -1 ribosomal frameshift signals. The results demonstrated that consensus programmed -1 ribosomal frameshift signals can be identified in a substantial number of chromosomally encoded mRNAs and that they occur with frequencies from two- to sixfold greater than random in all of the databases searched. A preliminary survey of the databases resulting from the computer searches found that consensus frameshift signals are present in at least 21 homologous genes from different species, 2 of which are nearly identical, suggesting evolutionary conservation of function. We show that four previously described missense alleles of genes that are linked to human diseases would disrupt putative programmed -1 ribosomal frameshift signals, suggesting that the frameshift signal may be involved in the normal expression of these genes. We also demonstrate that signals found in the yeast RAS1 and the human CCR5 genes were able to promote significant levels of programmed -1 ribosomal frameshifting. The significance of these frameshifting signals in controlling gene expression is not known, however.

Amino Acid Sequence↗

Nucleic acid sequences coding for internal antisense peptides: are there implications for protein folding and evolution?

We have asked whether coding segments of nucleic acids generate amino acid sequences which have an antisense relationship to other amino acid sequences in the same chain (i.e. 'Internal Antisense'), and if so, could the internal antisense content be related to the structure of the encoded protein? Computer searches were conducted with the coding sequences for 132 proteins. The result for each search of a specific sequence was compared to the mean result obtained from 1000 randomly assembled nucleic acid chains whose length and base composition were identical to that of the native sequences. The study was conducted in all three reading frames. The normal reading frame (frame one) was found to be contain lower amounts of internal antisense than the randomly assembled chains, whereas the frame two results were much higher. The internal antisense content in frame three was not significantly different from that in the random chains. The amount of internal antisense in frames two and three was correlated with the GC content at the center position of the codons in that frame, but this correlation was absent in frame one. No correlation with chain length was found. Qualitatively similar results were obtained when the random model was limited to retain the same purine/pyrimidine ratio as the native chains at each position in the codons, but in this case the internal antisense in frame three was also significantly greater than the computer-generated sequences. The results suggest that the internal antisense content in the correct reading frame has a qualitatively different origin from that in the other two frames. The high amount in frames two and three is apparently an artifact resulting from the asymmetric distribution of G and C in the codons, while the low amount in frame one may suggest evolutionary selection against internal antisense. Thus, the results do not support a relationship between internal antisense and protein structure.

Amino Acid Sequence↗

Taxol and cisplatin inhibit proliferation of T47D human breast cancer cells.

We have examined the influence of taxol and cisplatin on the rate and extent of proliferation of T47D cells grown in the presence of 5% fetal bovine serum (FBS). An 8-day exposure of the cells to taxol inhibited the growth completely maintaining the number of cells to the level seen at initial plating. The taxol effect was evident at 10 nM-1 microM concentration and the half maximum inhibition was calculated to be 20 nM taxol. While the cells in the control group taxol-treated group remained at the initial number. Similar observations were made regarding the influence of cisplatin, which caused 80-90% inhibition in the number of the cells. When combined, taxol and cisplatin caused a further inhibition in the proliferation of T47D cells. The results of our studies demonstrate that both taxol and cisplatin, the known antineoplastic agents, block the proliferation of T47D human breast cancer cells effectively and are potentially useful chemotherapeutic agents for the management of breast cancer.

Breast Neoplasms↗

Suppression of Ixodes scapularis (Acari: Ixodidae) nymphs in a large residential community.

To determine the feasibility of suppressing Ixodes scapularis Say populations in a large, hyperendemic residential community, several rates of granular carbaryl were applied by ground and air to the shrub layer and wooded buffers of a forested residential community during the peak activity period of nymphs. Granular carbaryl significantly reduced the abundance of I. scapularis nymphs on Peromyscus leucopus Raphinesque. Control nymphal ticks ranged between 70.0 and 90.3%. The use of properly timed acaricide applications to I. scapularis habitat within residential communities can provide an effective means of reducing exposure to I. scapularis nymphs, which are chiefly responsible for transmitting Borrelia burgdorferi to humans.

Animals↗

Sweet's syndrome in children.

Acute febrile neutrophilic dermatosis (Sweet's syndrome) is a rare inflammatory disease of unknown cause characterized by painful, erythematous plaques and a dermal infiltrate of mature neutrophils. Associated systemic disease is a common finding in patients with Sweet's syndrome, and in fact determines the prognosis; therefore, the diagnosis of Sweet's syndrome warrants a thorough medical evaluation. We found only 17 reported cases of Sweet's syndrome in children. Two cases of Sweet's syndrome in children are presented; these cases are typical, except for the tibial pain in the first patient and the marked leukocytosis in the second patient. Both patients responded promptly to systemic corticosteroid therapy, although both had relapse.

Child, Preschool↗

DNA correlations.

Explore the source record for details and available documents.

Base Sequence↗

Lyme disease: a proposed ecological index to assess areas of risk in the northeastern United States.

BACKGROUND: Recent public awareness has resulted in a demand for information about ways to reduce the risk of acquiring Lyme disease. METHODS: Twenty-two school properties and recreational areas within a Lyme disease endemic area of central Monmouth County, New Jersey were evaluated for risk of transmission using an ecological index on the suitability, amount, and access to Ixodes dammini habitat by target human populations and the abundance of infected adult ticks. RESULTS: The characterization of tick habitat accurately predicted the elimination of 11 sites from concern. Of the remaining 11 sites, six were classified high risk and five as moderate risk. On-site tick surveys identified infected I. dammini adults at only four sites (three risk; one moderate risk). CONCLUSIONS: These results indicate that the use of selected ecological parameters provides a cost-effective method to rapidly identify areas at risk for Lyme disease transmission.

Animals↗

Identification of transforming growth factor beta family members present in bone-inductive protein purified from bovine bone.

Characterization of the polypeptides present in bone-inductive protein extracts from bovine bone has led to the cloning of seven regulatory molecules, six of which are distantly related to transforming growth factor beta. The three human bone morphogenetic proteins (BMPs) we describe herein, BMP-5, BMP-6, and BMP-7, show extensive sequence similarity to BMP-2, a molecule that by itself is sufficient to induce de novo bone formation in vivo. The additive or synergistic contribution of these BMP-2-related molecules to the osteogenic activity associated with demineralized bone is strongly implicated by the presence of these growth factors in the most active fractions of highly purified bone extract.

Amino Acid Sequence↗

A computer-assisted, interactive radiology learning program.

A computer-assisted adjunct to traditional radiology teaching files is described. The student is presented with an image and questions with multiple choice answers. The student's choice leads to additional presentations that reinforce correct responses and provide a critique of incorrect answers. The process is under the control of a teaching script. Requirements for the system included the ability to present high-resolution radiology images along with text; high capacity for storing teaching scripts and images; ease of use by students and authors of teaching scripts; and reasonable cost. A prototype program was written in C-language and run on an IBM PS/2 (IBM Corp., Armonk, NY) with DOS. The hardware also included a 30 megabyte disk drive, an IBM Image Adapter/A and a 14 inch IBM 8514 monitor operating at a 1024 X 768 X 8 bit resolution. Image acquisition was accomplished with a high resolution Pulnix video camera (Pulnix Corp., Tokyo, Japan), with an Imaging Technology (Imaging Technology Corp., Weston, MA) frame grabber, attached to an IBM PC/AT. All hardware is available commercially. A sample teaching file was constructed using a case of ischemic colon after a cecal volvulus. Students used the system and provided a critique. Results indicate that computer-assisted teaching programs can be a valuable addition to traditional teaching methods in radiology.

Computer-Assisted Instruction↗