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Biomedical subjects

H M Taylor

Publications and source records attributed to H M Taylor.

At least 19 recordsLinked to original sources
PubMed2001

Plasmodium falciparum homologue of the genes for Plasmodium vivax and Plasmodium yoelii adhesive proteins, which is transcribed but not translated.

The 235-kDa family of rhoptry proteins in Plasmodium yoelii and the two reticulocyte binding proteins of P. vivax comprise a family of proteins involved in host cell selection and erythrocyte invasion. Here we described a member of the gene family found in P. falciparum (PfRH3) that is transcribed in its entirety, under stage-specific control, with correct splicing of the intron, but appears not to be translated, probably due to two reading frameshifts at the 5' end of the gene.

Amino Acid Sequence↗
PubMed2000

A study of var gene transcription in vitro using universal var gene primers.

The polymorphic multigene family, var, encodes the variant antigen, Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), present on the surface of erythrocytes infected with the human malaria parasite, P. falciparum. PfEMP1 has been implicated in the pathology of malaria through its ability to bind to host endothelial receptors and uninfected erythrocytes. Understanding the relationship between host pathology, immune response and parasite variation is crucial, but requires a method of reliably detecting and differentiating all possible var genes. Several primer pairs used to date are biased and limited in their detection capacity. Here we describe a set of PCR primers that amplify the majority of var genes in the laboratory isolates 3D7 and A4, and appear to work equally well on all isolates tested. We use these universal primers to examine the relationship between var gene transcription as assessed by reverse transcriptase-PCR (RT-PCR) with that measured by Northern analysis of parasite RNA. Phenotypically selected young parasites have multiple transcripts detected by RT-PCR, but the full-length transcript appears to be homogeneous. In addition, we demonstrate that the choice of primers used for RT-PCR is crucial in data interpretation.

Amino Acid Sequence↗
PubMed1998

Hepatic imaging. An overview.

Recent advances in ultrasound, CT scan, MR imaging, and scintigraphy permit characterization of a variety of focal and diffuse liver diseases. Accurate clinical information, however, is of vital importance in selecting the optimal imaging modality and interpreting the study accurately. Using a combination of radiologic findings and clinical information, a correct diagnosis may be achieved noninvasively.

Contrast Media↗
PubMed1998

Significance of radiographic cardiomegaly in orthotopic heart transplant recipients.

OBJECTIVE: The purpose of this study is to evaluate the clinical significance of radiographic cardiomegaly in orthotopic heart transplant recipients and to identify causative anatomic and physiologic parameters. MATERIALS AND METHODS: We retrospectively compared the cardiothoracic ratio (CTR) measured using standard posteroanterior chest radiography with left ventricular end-diastolic diameter and left ventricular ejection fraction measured on two-dimensional echocardiography; right ventricular systolic pressure; and systolic, diastolic, and mean blood pressure measured at biopsy in 46 heart transplant recipients. RESULTS: Twenty-eight (61%) of the 46 patients had radiographic cardiomegaly. When we compared heart transplant recipients who had a CTR greater than 0.5 with recipients who had a CTR less than or equal to 0.5, we found no significant difference between their respective left ventricular end-diastolic diameters, left ventricular ejection fractions, right ventricular systolic pressures, systolic blood pressures, or mean blood pressures. A statistically significant difference existed between the mean values of diastolic blood pressure for transplant recipients with and without radiographic cardiomegaly. We found no significant correlation between CTR and left ventricular end-diastolic diameter, left ventricular ejection fraction, systolic blood pressure, diastolic blood pressure, or mean blood pressure. CONCLUSION: The statistically significant difference between the mean values of diastolic blood pressure of transplant recipients with and without radiographic cardiomegaly is clinically insignificant and unlikely to account for the finding of radiographic cardiomegaly. We conclude that radiographic cardiomegaly, which occurs frequently in heart transplant recipients, does not correlate with anatomic or physiologic parameters obtained under the same conditions. Radiographic cardiomegaly in heart transplant recipients does not connote allograft dysfunction or heart failure.

Adult↗
PubMed1997

The use of prophylactic antibiotics in ultrasound-guided transrectal prostate biopsy.

The use of antibiotic prophylaxis for transrectal prostate biopsy significantly reduces the incidence of infective complications, but no recommendations exist as to the most appropriate antibiotic regimen. This study was designed to find out which antibiotics were used in different departments and the financial cost of each regimen. A postal survey of 144 hospitals in the UK and Ireland was undertaken. Respondents were asked the name(s), dose(s), route(s) of administration and timing of antibiotics given pre and post biopsy. The response rate was 73.6%. Thirteen different antibiotics were used in 48 different regimens. The most commonly used antibiotic was metronidazole (orally or rectally) in 55% of regimens followed by oral ciprofloxacin in 48% and intravenous gentamicin in 48%. Most regimens (89.7%) contained an oral antibiotic and 58.6% contained an intravenous antibiotic. The cheapest regimen cost 38.7p/patient and the most expensive pounds sterling 21.36/patient, calculated according to prices quoted in the British National Formulary, March 1996. We conclude that there is a lack of standardization in antibiotic prophylaxis for ultrasound-guided transrectal prostate biopsy with widely differing costs for the different regimens. A review of the literature shows that oral antibiotics are inexpensive, well tolerated and effective at reducing the incidence of urinary tract infection and fever following transrectal prostate biopsy. A regimen is proposed including ciprofloxacin or norfloxacin. The addition of oral metronidazole is a subject for further study.

Antibiotic Prophylaxis↗
PubMed1997

Progressive facial hemiatrophy: MRI appearances.

The cranial CT and MRI appearances of a 14-year-old girl with Parry-Romberg syndrome and epilepsy are described. The findings are compared with the two published descriptions of MRI and CT in such patients. MRI appearances in our patient differ from those published and may be consistent with a vascular malformation. The one published report on the intracranial histopathology of a patient with Parry-Romberg syndrome and epilepsy states that a microscopic vascular malformation was found. We discuss the relationship between radiological and pathological findings. The possible aetiologies of Parry-Romberg syndrome (vascular malformation, immunological, trauma, sympathetic innervation, hereditary, slow virus) are discussed. We suggest that Parry-Romberg syndrome could be regarded as a neurocutaneous syndrome, a component of which includes intracerebral vascular dysplasia. In this and the other three cases of Parry-Romberg syndrome with epilepsy, the sensitivity of MRI in detecting intracranial lesions is demonstrated. Recommendations for imaging these patients are proposed.

Brain Diseases↗
PubMed1990

Estrogen synthetase inhibitors. 2. Comparison of the in vitro aromatase inhibitory activity for a variety of nitrogen heterocycles substituted with diarylmethane or diarylmethanol groups.

The preparation and in vitro aromatase inhibitory activity of a wide variety of heterocyclic (4,4'-dichlorodiphenyl)methanes and -methanols are described. The choice of the two diaryl-bearing moieties as a vehicle for the evaluation of the heterocycles was made by the comparison of series of imidazole and pyridine-derived compounds with similar pyrimidine compounds reported previously. A structural model for the most active compounds is also presented. The activity of a related series of the compounds which contain two heterocyclic moieties was found to be consistent with the model. Many of the compounds evaluated, including representatives of the pyridine, imidazole, pyrimidine, pyrazole, triazole, thiazole, and isothiazole classes, exhibit EC50 potencies for aromatase inhibition at low nanomolar levels. These compounds are at least as potent as other nonsteroidal aromatase inhibitors reported previously.

Androstenedione↗
PubMed1989

Myelodysplastic syndrome: prospective evaluation of fifty-one patients using the Dutcher scoring system.

Fifty-one patients with primary myelodysplastic syndrome were prospectively evaluated using a scoring system based on the presentation blood and bone marrow findings. Twenty-four patients (47%) evolved to acute nonlymphocytic leukemia. Stepwise regression model showed that the scoring system was the only significant variable for predicting transformation to acute leukemia (p = 0.0007, sensitivity 70.8%, specificity 77.8%). Seventy-six percent of patients with a score of 14 or greater developed acute leukemia compared to 19% with a score of 13 or less. Median survival of the entire group was 10 months. The most important prognostic factor for predicting survival was the scoring system (p = 0.0001). Survival correlated inversely with the score. This scoring system may be useful in the management of patients with myelodysplasia.

Acute Disease↗
PubMed1987

Aromatase inhibition by 5-substituted pyrimidines and dihydropyrimidines.

The inhibition of estrogen biosynthesis has been suggested to be an effective treatment of hormone-dependent diseases, particularly breast cancer. Several series of 5-substituted pyrimidine derivatives have been synthesized and tested for their ability to inhibit the enzyme aromatase (estrogen synthetase). Compounds were evaluated in an in vitro assay that measured the inhibition of rat ovarian microsomal aromatase activity. Greatest inhibitory activity was achieved in the cases of diarylpyrimidinemethanols and diarylpyrimidinyl methanes which were substituted in the 4- and 4'-positions with electron-withdrawing substituents, particularly Cl.

Animals↗
PubMed1987

Fluorescence intensity as a quality control parameter in clinical flow cytometry.

The fluorescence intensity (FI) and percentage of immunostained peripheral blood lymphocytes (PBLs) were tested as parameters for monitoring quality control of monoclonal antibodies (MoAbs) and the staining procedure. Several potential variables were addressed, including optimal dilutions of MoAbs, standardization of instrument functions with fluorescent microspheres, stability of day-to-day fluorescence detection with fluorescent fixed cells, and effects of separation method and storage conditions on FI and PBL antigens. Although some small (but statistically significant) changes were found in certain tests, in general the FI and percentages of MoAB-positive human PBLs provided information useful in a standardized flow cytometry quality control program. This type of standardization and quality control facilities early discovery of methodologic and reagent problems in the clinical laboratory, as well as the ability to routinely evaluate disease states associated with abnormal antigen density.

Adult↗
PubMed1987

Reference values for peripheral blood lymphocytes from Aotus lemurinus ssp. griseimembra (owl monkey).

The reactivities of several monoclonal antibodies that define human lymphocyte cell-surface antigens have been tested with peripheral blood lymphocytes of Aotus lemurinus ssp. griseimembra. Based on reactivity patterns in humans, reactive MoAb were identified that mark pan-T, helper/inducer, suppressor/cytotoxic, pan-B, and natural killer cells. Reference values of these subsets in Aotus are presented. These MoAb should provide a useful tool for further phenotypic and functional dissection of the immune system in this simian model of human disease.

Animals↗