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Biomedical subjects

J T Taylor

Publications and source records attributed to J T Taylor.

13 recordsLinked to original sources
PubMed2001

AVP (4-8) improves concept learning in PFC-damaged but not hippocampal-damaged rats.

A position reversal task was used to test the memory-enhancing effects of the arginine vasopressin analog [pGlu4, Cyt6] AVP (4-8) at a dose of 1.5 microg/kg. Rats received either sham operations (SHM), medial prefrontal cortex lesions (PFC), or hippocampal lesions (HIP). The peptide was administered daily, via s.c. injection, 30 min prior to training to half of the animals in each group. As expected, all animals performed equally well on the initial position habit and the first reversal. Overall, it was found that AVP (4-8)-treated animals performed significantly better across trials than saline (SAL)-treated animals. Further analysis showed that PFC animals that received AVP (4-8) (PFC+AVP) performed significantly better (at the level of controls) across trials than saline-treated PFC (PFC+SAL) animals. Sham animals that received the AVP (4-8) analog (SHM+AVP) only showed significant improvement on the last two reversals when compared to the sham saline-treated animals (SHM+SAL), which was likely due to a ceiling effect as performance reached high levels early in the reversal task. Trial 2 analysis across reversals revealed enhanced cognitive abilities in both sham groups (SHM+SAL, SHM+AVP) and the PFC+AVP group, but not in the PFC+SAL, HIP+AVP or the HIP+SAL groups. Hippocampal lesioned animals performed poorly on the task and injections of AVP (4-8) did not improve their performance. It is thus concluded that AVP (4-8) enhanced the acquisition of concept learning (win-stay/loose-shift) in this paradigm in PFC-damaged animals and ameliorated the perseverance habit that is often seen in PFC animals on this task. It is suggested that AVP (4-8) might have an enhancing effect on general cognitive abilities that is not limited to memory processes.

Animals↗
PubMed1995

Cloning of a receptor for amphibian [Phe13]bombesin distinct from the receptor for gastrin-releasing peptide: identification of a fourth bombesin receptor subtype (BB4).

Bombesin is a tetradecapeptide originally isolated from frog skin and demonstrated to have a wide range of actions in mammals. Based on structural homology and similar biological activities, gastrin-releasing peptide (GRP) has been considered the mammalian equivalent of bombesin. We previously reported that frogs have both GRP and bombesin, which therefore are distinct peptides. We now report the cloning of a bombesin receptor subtype (BB4) that has higher affinity for bombesin than GRP. PCR was used to amplify cDNAs related to the known bombesin receptors from frog brain. Sequence analysis of the amplified cDNAs revealed 3 classes of receptor subtypes. Based on amino acid homology, two classes were clearly the amphibian homologs of the GRP and neuromedin B receptors. The third class was unusual and a full-length clone was isolated from a Bombina orientalis brain cDNA library. Expression of the receptor in Xenopus oocytes demonstrated that the receptor responded to picomolar concentrations of [Phe13]-bombesin, the form of bombesin most prevalent in frog brain. The relative rank potency of bombesin-like peptides for this receptor was [Phe13]bombesin > [Leu13]bombesin > GRP > neuromedin B. In contrast, the rank potency for the GRP receptor is GRP > [Leu13]bombesin > [Phe13]bombesin > neuromedin B. Transient expression in CHOP cells gave a Ki for [Phe13]bombesin of 0.2 nM versus a Ki of 2.1 nM for GRP. Distribution analysis showed that this receptor was expressed only in brain, consistent with the distribution of [Phe13]-bombesin. Thus, based on distribution and affinity, this bombesin receptor is the receptor for [Phe13]bombesin. Phylogenetic analysis suggests that this receptor separated prior to separation of the GRP and neuromedin B receptors; thus, BB4 receptors and their cognate ligands may also exist in mammals.

Amino Acid Sequence↗
PubMed1993

A 5' portion of the ICAM-1 gene confers tissue-specific differential expression levels and cytokine responsiveness.

Intercellular adhesion molecule-1 (ICAM-1), a cell-adhesion molecule critically involved in leukocyte trafficking and adherence, displays tissue-specific and cytokine-specific expression profiles. Although human dermal microvascular endothelial cells (HDMEC) constitutively express ICAM-1, keratinocytes (HK) do not. Interleukin-1 (IL-1) upregulates ICAM-1 expression in HDMEC, but fails to do so in either HK or A431, a human squamous carcinoma cell line, even though both have IL-1 receptors and express ICAM-1 on exposure to other cytokines. We have previously characterized a human ICAM-1 genomic clone that contains the 5' flanking transcriptional regulatory region. To test the hypothesis that tissue- and cytokine-specific ICAM-1 gene expression results from the interaction of constitutive and inducible tissue-specific trans-acting factors with distinct cis-elements of the ICAM-1 gene, various ICAM-1-based reporter gene (CAT) plasmids were constructed. Transcriptional activity of these various constructs was assessed after transient transfection into HDMEC and A431. A critical ICAM-1 region was identified that conferred enhanced expression of CAT in HDMEC and suppressed expression of CAT in A431. This same region further enhanced CAT expression in transfected HDMEC treated with IL-1 alpha, yet no such enhancement was seen with IL-1 treatment of identically transfected A431. However, treatment of A431 transfectants with IFN gamma did result in enhanced CAT expression, demonstrating reversal of A431 cell context suppression of the ICAM-1-based reporter gene construct. These data implicate the existence of both tissue- and cytokine-specific responsive elements in the 5' flanking region of the ICAM-1 gene and demonstrate that regulatory effects directed by such elements are dependent upon their cellular context. Moreover, they provide the basis for identification of specific cis-acting genetic elements, the trans-acting factors with which they interact, and the molecular mechanisms by which they regulate transcription of the ICAM-1 gene.

Base Sequence↗
PubMed1991

Documentation of cost savings from decentralized clinical pharmacy services at a community hospital.

A pilot program designed to justify the costs of clinical pharmacy services through the use of workload documentation cards is described. At this community hospital, defining a philosophy of care was the first step in developing and implementing decentralized services. A patient-specific care model was chosen, and principles of patient-oriented service were outlined. Daily workload documentation cards were designed for recording pharmacist activities; distribution functions were noted on one side, clinical activities on the other. Direct cost savings that could be attributed to the clinical pharmacists' drug therapy recommendations were quantified and recorded on a second form. Sixty-three beds in four hospital units were chosen as sites of the pilot effort. At the end of the six-month study, an analysis of the cost-savings forms documented that clinical pharmacist activities produced an average savings of $1.49 per patient day. The break-even point at which pharmacist salary expenses would equal direct cost savings was determined to be one clinical pharmacist per 80 patient beds. A request to expand clinical services at the hospital was granted. By documenting clinical and distributive activities on a simple form and quantifying the savings associated with clinical interventions, this pilot program demonstrated the cost-effectiveness of clinical pharmacy services.

Centralized Hospital Services↗
PubMed1981

Liquid chromatography at 3-methoxy-4-hydroxyphenylethylene glycol in urine with fluorescence detection.

We describe a liquid-chromatographic procedure for determining low concentrations of 3-methoxy-4-hydroxyphenylethylene glycol in urine. After liquid-liquid extraction and cleanup of the sample, an aliquot of the extract is injected onto a reversed-phase chromatographic column, with isocratic elution with an acetonitrile/acetate buffer mobile phase. An on-line fluorescence detector is used for measuring the natural fluorescence of the compound. The method gives a relatively clean extract, which is suitable for measuring the less-than-normal concentrations associated with mentally depressed patients. Although a liquid-chromatographic technique has been recently described for measuring this compound in urine, the method involves electrochemical detection, which may not be available in many clinical laboratories, and, because of its nonspecificity, the method is only suitable for detecting the increased amounts of 3-methoxy-4-hydroxyphenylethylene glycol excreted by patients with pheochromocytoma.

Chromatography, Liquid↗
PubMed1980

Determination of urinary placental estriol by reversed-phase liquid chromatography with fluorescence detection.

Ww describe a liquid-chromatographic procedure for determining urinary estriol concentrations. The urine sample, after enzymatic hydrolysis to free the conjugated estrogen, is extracted with ether, and an aliquot of the resulting extraction residue is injected into the liquid chromatograph. Sample components are separated with a reversed-phase C18 column and isocratic elution with an acetonitrile/water mobile phase. Using a far-ultraviolet excitation wavelength, we measure the natural fluorescence of the eluted estrogen with a fluorescence detector. The procedure provides excellent sensitivity for determing near-term pregnancy concentrations of urinary estriol. The selectivity of the method limits the effect of potentially interfering compounds.

Chromatography, Gas↗