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J Warren

Publications and source records attributed to J Warren.

At least 73 records · Page 4Linked to original sources
PubMed1996

Mapping of the epitope recognized by non-specific cytotoxic cells: determination of the fine specificity using synthetic peptides.

NCC recognize a conserved target cell antigen (NKTag) expressed on protozoan parasites and on transformed tumour cells. In the present study, synthetic peptides corresponding to N-terminal, C-terminal and internal NKTag(deduced) amino acid sequences were tested for binding and inhibition of NCC lysis of sensitive target cells. A 20-mer peptide equivalent to amino acids (aa) nos. 55-74 specifically inhibited NCC lysis of human EBV transformed target cells (IM-9). Inhibitory effects were nonreversible and concentration dependent, and 30 min pre-incubation produced optimum inhibition. The inhibitory 20-mer peptide was truncated into 17, 14, 10, 9 and 6-mer peptides and tested for inhibition of cytotoxicity. All produced almost complete inhibition except the 6-mer which had no activity. The NKTag sequence required for NCC binding (minimally) consisted of seven amino acids [aa nos 68-74 (ARG-ASN-LEU-THR-PHE-ILE-LEU-)]. The specificity of inhibition and the distribution of target cells expressing NKTag was determined. A 14-mer peptide composed of aa nos 61-74 inhibited lysis of HL-60, IM-9, DAUDI, YAC-1, U937 and NC-37 target cells. Flanking peptides (aa nos 35-54 and 75-94) were negative. Biotinylated aa nos 61-74 bound to NCC effector cells. The recognition requirements for aa sequence versus aa content were determined. Randomization of the aa in the cognate 9-mer obliterated the inhibitory effects. The 17-mer (cognate) synthetic peptide inhibited conjugate formation between NCC and IM-9 targets. These data demonstrate that NCC recognize a conserved antigen determinant on susceptible target cells consisting of a minimum of 7-9 amino acids in the N-terminal region of NKTag.

Amino Acid Sequence↗
PubMed1996

Effect of land-based and water-based fitness programs on the cardiovascular fitness, strength and flexibility of women aged 65-75 years.

The purpose of this study was to determine the effectiveness of a generalized water-based exercise program (WBE) compared to a land-based exercise program (LBE) on improving cardiorespiratory fitness, body composition, forward trunk flexion and strength measurements of elderly women aged 70 +/- 3.2 years (mean +/- SD). Forty-one healthy, sedentary women were selected to participate in the study and were randomly assigned to the LBE or WBE. The 2 groups exercised for 12 weeks, 3 times/week for 45 min. Fitness testing was done before, during and after training, and included measurements of peak aerobic power (VO2 peak), forward trunk flexion, sum of skinfolds, grip strength, curl-ups and push-ups. Between the tests performed before and after training, there were significant improvements in VO2 peak in both groups (p < 0.05) with no significant differences between the groups (p > 0.05). The LBE group also showed a significant improvement in the total number of curl-ups performed (p < 0.05). There were no significant differences in trunk forward flexion, total (right plus left) grip strength, push-ups, waist to hip ratio, sum of skinfolds or body mass index between the tests performed before and after training over time within groups or between groups (p > 0.05). The results show that general exercise interventions resulted in improvements in cardiovascular fitness (for both groups) and abdominal endurance (in the LBE only), but the two exercise programs used were not specific enough or long enough to cause improvements in muscular strength, flexibility or body composition. Furthermore, except for changes in abdominal endurance, the type of exercise venue (land vs. water) did not have a significant effect on the results obtained.

Aged↗
PubMed1996

Bladder dose estimation during intracavitary brachytherapy for carcinoma of the cervix using a single line source system.

The estimation of maximum bladder doses from orthogonal radiographs is unreliable when triple source systems are used for intracavitary brachytherapy (BT) for gynaecological cancers. For single line source systems, the estimation of maximum bladder doses from radiographs should be more reliable due to the radial symmetry of the isodose distribution. A pilot study has been carried out to compare the estimated maximum bladder doses from standard radiographs with data obtained from CT for single line source BT treatments. 12 patients undergoing treatment for carcinoma of the cervix were selected for CT assessment of their bladder doses. For each patient, the dose rates at the International Commission of Radiation Units and Measurements (ICRU) bladder reference point B1 and a second reference point B2 2.5 cm cranially were computed from orthogonal radiographs and were compared with the maximum bladder dose rate as determined by CT scanning. Dose rates were computed for two different source loading patterns: (1) a 6 cm line source with uniformly distributed linear activity along its length; (2) a 6 cm line source with increased activity in the central 2 cm segment. The mean ratio of the maximum CT bladder dose rate to the dose rate at the ICRU reference point B1 on orthogonal radiographs for the line source with uniform linear activity was 1.32 (range 0.62-2.43, SD = 0.54). When the dose rates at both reference points B1 and B2 were considered, the mean ratio of the maximum CT dose rate to the maximum dose rate from radiographs was only 1.05 (range 0.72-1.72, SD = 0.24). For the line source with increased activity in the central segment, the mean ratio of the maximum CT bladder dose rate to the dose rate at B1 was 1.38 (range 0.60-2.63, SD = 0.64). When both B1 and B2 were considered, the variation in the ratio of the maximum CT dose rate to the maximum dose rate from radiographs was considerably smaller (mean ratio = 1.07, range 0.69-1.76, SD = 0.26). For single line source systems, single point dose estimation using the ICRU reference point on orthogonal radiographs will underestimate the maximum bladder dose although the discrepancy is less than for triple source systems. If the ICRU reference point is used in conjunction with a second reference point 2.5 cm cranially, then underestimation of the maximum bladder dose is unlikely to occur as at least one of the points is likely to be a reasonable estimate of the maximum bladder dose.

Brachytherapy↗
PubMed1996

Is there an observer bias with random-zero blood pressure machines?.

BACKGROUND: Random Zero (R-Z) sphygmomanometers are used in many epidemiological studies and clinical trials. A recent study reported that blood pressure measured with an R-Z sphygmomanometer was significantly correlated with R-Z values. In addition, the investigators showed that such blood pressure measurements were on average a few mmHg lower than those obtained with standard mercury column devices. It was suggested that a major part of this discrepancy could be explained by incorrect operation of the R-Z machine. DESIGN: This was an observational study based on 5021 blood pressure measurements that had been collected with an electronic machine that permits positive and negative random-zero values. METHOD: The association between corrected blood pressure and random-zero values was calculated separately for positive and negative offset values. RESULTS: The relationship between corrected blood pressure and random-zero values measured with the electronic device was similar to that observed when the R-Z machine was used correctly. However, we found that this correlation occurred primarily for high random-zero values. CONCLUSION: We attribute our findings to observer reluctance to accept high blood pressure values at the first Korotkoff sound and suggest that indirect blood pressure measurements with high values are on average biased towards lower values, regardless of the instrument used. The effect may, however, be more pronounced with R-Z machines because they display higher blood pressure values. The magnitude of the bias of 2-3 mmHg, which appears to be limited to high blood pressure values measured at high random-zero values, may not be large enough to outweigh the advantages of R-Z devices, especially in clinical trials and epidemiological studies.

Journal Article↗
PubMed1995

Circumcision.

Explore the source record for details and available documents.

Analgesia↗
PubMed1995

Practice parameters for intravenous analgesia and sedation for adult patients in the intensive care unit: an executive summary. Society of Critical Care Medicine.

OBJECTIVE: The development of practice parameters for intravenous analgesia and sedation for adult patients in the intensive care unit (ICU) setting for the purpose of guiding clinical practice. PARTICIPANTS: A task force of more than 40 experts in disciplines related to the use of analgesic and sedative agents in the ICU was convened from the membership of the American College of Critical Care Medicine (ACCM) and the Society of Critical Care Medicine (SCCM). EVIDENCE: The task force members provided the personal experience and determined the published literature (MEDLINE articles, textbooks, pharmacopeias, etc.) from which consensus would be sought. Published literature was reviewed and classified into one of four predetermined categories, according to study design and scientific value. CONSENSUS PROCESS: The task force met several times as a whole, and numerous times in smaller groups by teleconference, over a 1-yr period to identify the pertinent literature and arrive at consensus recommendations for the whole task force to discuss. Consideration was given to the relationship between the weight of scientific information and the experts' viewpoints. Over the next year, draft documents were composed by a task force steering committee and debated by the task force members until consensus was reached by nominal group process. The task force draft was then reviewed, assessed, and edited by the Board of Regents of the ACCM. After steering committee approval, the draft document was reviewed and approved by the SCCM Council. DATA SYNTHESIS: To facilitate rapid communication of the six recommendations contained within the complete and unabridged practice parameter document, an executive summary was prepared for publication by the ACCM Board of Regents, and this executive summary was approved by the task force steering committee and the SCCM Executive Council. CONCLUSIONS: A consensus of experts provided six recommendations with supporting data for intravenous analgesia and sedation in the ICU setting: a) morphine sulfate is the preferred analgesic agent for critically ill patients; b) fentanyl is the preferred analgesic agent for critically ill patients with hemodynamic instability, for patients manifesting symptoms of histamine release with morphine, or morphine allergy; c) hydromorphone can serve as an acceptable alternative to morphine; d) midazolam or propofol are the preferred agents only for the short-term (< 24 hrs) treatment of anxiety in the critically ill adult; e) lorazepam is the preferred agent for the prolonged treatment of anxiety in the critically ill adult; f) haloperidol is the preferred agent for the treatment of delirium in the critically ill adult. This executive summary selectively presents supporting information and is not intended as a substitute for the complete document.

Adult↗
PubMed1995

Practice parameters for sustained neuromuscular blockade in the adult critically ill patient: an executive summary. Society of Critical Care Medicine.

OBJECTIVE: The development of practice parameters for achieving sustained neuromuscular blockade in the adult critically ill patient for the purpose of guiding clinical practice. PARTICIPANTS: A task force of more than 40 experts in disciplines related to the use of neuromuscular blocking agents in the intensive care unit was convened from the membership of the American College of Critical Care Medicine (ACCM) and the Society of Critical Care Medicine (SCCM). EVIDENCE: The task force members provided the personal experience and determined the published literature (MEDLINE articles, textbooks, pharmacopeias, etc.) from which consensus would be sought. Published literature was reviewed and classified into one of four predetermined categories, according to study design and scientific value. CONSENSUS PROCESS: The task force met several times as a whole, and numerous times in smaller groups by teleconference, over a 1-yr period to identify the pertinent literature and arrive at consensus recommendations for the whole task force to discuss. Consideration was given to the relationship between the weight of scientific information and the experts' viewpoints. Over the next year, draft documents were composed by a task force steering committee and debated by the task force members until consensus was reached by nominal group process. The task force draft was then reviewed, assessed, and edited by the Board of Regents of the ACCM. After steering committee approval, the draft document was reviewed and approved by the SCCM Council. DATA SYNTHESIS: To facilitate rapid communication of the three recommendations contained within the complete and unabridged practice parameter document, an executive summary was prepared for publication by the ACCM Board of Regents, and this executive summary was approved by the task force steering committee and the SCCM Executive Council. CONCLUSIONS: A consensus of experts provided three recommendations with supporting data for achieving sustained neuromuscular blockade in critically ill patients: a) pancuronium is the preferred neuromuscular blocking agent for most critically ill patients; b) vecuronium is the preferred neuromuscular blocking agent for those patients with cardiac disease or hemodynamic instability in whom tachycardia may be deleterious; c) patients receiving neuromuscular blocking agents should be appropriately assessed for the degree of blockade that is being sustained. This executive summary selectively presents supporting information and is not intended as a substitute for the complete document.

Adult↗
PubMed1995

Comparison of a fungal (family I) and bacterial (family II) cellulose-binding domain.

A family II cellulose-binding domain (CBD) of an exoglucanase/xylanase (Cex) from the bacterium Cellulomonas fimi was replaced with the family I CBD of cellobiohydrolase I (CbhI) from the fungus Trichoderma reesei. Expression of the hybrid gene in Escherichia coli yielded up to 50 mg of the hybrid protein, CexCBDCbhI, per liter of culture supernatant. The hybrid was purified to homogeneity by affinity chromatography on cellulose. The relative association constants (Kr) for the binding of Cex, CexCBDCbhI, the catalytic domain of Cex (p33), and CbhI to bacterial microcrystalline cellulose (BMCC) were 14.9, 7.8, 0.8, and 10.6 liters g-1, respectively. Cex and CexCBDCbhI had similar substrate specificities and similar activities on crystalline and amorphous cellulose. Both released predominantly cellobiose and cellotriose from amorphous cellulose. CexCBDCbhI was two to three times less active than Cex on BMCC, but significantly more active than Cex on soluble cellulose and on xylan. Unlike Cex, the hybrid protein neither bound to alpha-chitin nor released small particles from dewaxed cotton fibers.

Amino Acid Sequence↗
PubMed1994

A culture system for the development of the preimplantation rat embryo.

We describe a system for the culture of 1-cell rat embryos through to the blastocyst stage, using co-culture on specific feeder cell layers and particular defined media. We show that the use of rat uterine epithelial cells as a feeder layer, together with either M16M, CZB or HECM-1 media at 38.5 degrees C can improve the in vitro development of cultured rat embryos. There was considerable variation in the culture conditions, which were optimal for each strain of rat tested. We show that the 4 to 8-cell embryos are viable after reimplantation and that the second 4 to 8-cell block in the rat can be overcome using HECM-1 in a co-culture system, thus enabling the in vitro culture of rat embryos up to the blastocyst stage.

Journal Article↗
PubMed1994

The use of third-party information in forensic assessments: a two-state comparison.

There is virtually no research on the normative characteristics of forensic mental health assessment, despite the significant increase in conceptual and empirical attention devoted to such assessment within the last 10 years. The present study addressed this deficit by examining the use of third-party information, a crucial component of forensic mental health assessment, by forensic clinicians in two states: Florida (a total of 277 evaluations on the issues of competency to stand trial and sanity at the time of the offense) and Virginia (316 evaluations addressing the same legal issues). Evaluations in each state were performed in either a community or a hospital setting. Basic information about the offense, records of prior mental health evaluation or treatment, and specific statements by victims or witnesses were the variables examined comprising "third-party information" in this study. More than three fourths of all evaluations across states and settings incorporated this information. There was less consistency in the use of mental health records and victim/witness statements, with significant differences observed across settings and states. Results are discussed in light of potential influences of state, setting, and study methodology.

Expert Testimony↗
PubMed1993

International Commission for Protection Against Environmental Mutagens and Carcinogens. Power frequency electric and magnetic fields: a review of genetic toxicology.

Epidemiologic studies have reported a modestly increased risk of childhood leukemia associated with certain electric power wire configurations. Since cancer likely involves DNA damage, this review discusses the evidence of direct and indirect genetic toxicity effects for both electric and magnetic fields at 50- and 60-Hz and miscellaneous pulsed exposures. Exposure conditions vary greatly among different end points measured, making comparisons and conclusions among experiments difficult. Although most of the available evidence does not suggest that electric and/or magnetic fields cause DNA damage, the existence of some positive findings and limitations in the set of studies carried out suggest a need for additional work.

Animals↗
PubMed1993

A bifunctional affinity linker to couple antibodies to cellulose.

We have constructed a fusion protein between the staphylococcal A protein and the cellulose binding domain of an exoglucanase (Cex) from Cellulomonas fimi that can be directly immobilized on cellulose while retaining its capacity to bind immunoglobulin G molecules. The cellulose domain provides binding that does not interfere with the biological activity of the fusion partner, does not involve hazardous chemicals and the matrix does not need to be chemically activated which reduces its cost. We have tested some of the possible applications of the fusion protein and show that it can be used in immunoassays, affinity chromatography and immunoprecipitations.

Antibodies↗