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J W Scott

Publications and source records attributed to J W Scott.

At least 73 records · Page 4Linked to original sources
PubMed1985

Synthesis of thymosin alpha 1 by fragment condensation using tert.-butyl side chain protection.

A novel synthesis of thymosin alpha 1 by classical methods using seven tert.-butyl side chain protected fragments is described. Optimum conditions were found for the final DCC/HOBt coupling of the two key intermediates; decapeptide and octadecapeptide. Thymosin alpha 1 was purified by two stages of preparative HPLC (partial purification with C8 and final purification with C18 reverse phase silica gel) to give a 30% overall yield for the final four stages of synthesis (including catalytic hydrogenation of octadecapeptide, coupling, deprotection and purification). The product was shown to be homogeneous by thin-layer and paper high voltage electrophoresis, isoelectric focusing analysis, thin-layer chromatography and high performance liquid chromatography. Amino acid analysis, optical rotation, 1H-n.m.r. spectroscopy, FAB mass spectroscopy and peptide mapping after tryptic digestion confirmed the structure of thymosin alpha 1. Three minor stereoisomer contaminants were isolated by HPLC and characterized as [D-Lys14]-thymosin alpha 1, [D-Lys17]-thymosin alpha 1 and [D-Ala3]-thymosin alpha 1 resulting from racemization at Lys14, Lys17 and Ala3 during the coupling of the fragments. A final contaminant, isolated by HPLC, was characterized as N alpha-isobutyloxycarbonyl-thymosin alpha 1 (15-28), which results from "wrong way opening" of an activated mixed anhydride.

Amino Acid Sequence↗
PubMed1985

Reversal of phorbol ester-mediated reduction of cloned T lymphocyte cytolysis by interleukin 2.

During previous studies on the regulation of cloned T lymphocyte function, we observed that murine cytotoxic T lymphocyte (CTL) clones progressively lose the ability to lyse appropriate target cells during prolonged (24 to 48 hr) incubation with the tumor promoter phorbol myristic acetate (PMA). We further observed that the cytolytic function of PMA-treated CTL clones can be restored by incubation with secondary MLC supernatant (2 degrees MLC SN), a potent source of cytokines. We now report our observations on the nature of the cytokine(s) responsible for recovery of CTL activity. Like 2 degrees MLC SN, the lectin-induced SN from a cloned helper T cell and the lectin-induced SN from a T cell hybridoma can restore cytolytic activity to cloned CTL treated with PMA. In contrast, supernatants from L929 cells, WEHI-3 cells, and P388D1 cells fail to restore cytolytic activity to similarly treated cloned CTL. These data suggest that IL 2 and/or gamma-IFN, but not CSF-1, CSF-GM, IL 3, or IL 1, can influence expression of cytolysis by cloned CTL. Furthermore, highly purified IL 2 can restore cytolytic activity, even when cytosine arabinoside is present to inhibit clonal expansion. Our studies indicate that cytolysis is a reversible function of cloned CTL, and that cytolysis may not necessarily represent an end-stage feature of CTL maturation. Our studies further show that IL 2 is both necessary and sufficient for resumption of cytolytic function by "deactivated" CTL. As such, these observations suggest that IL 2 can regulate not only T cell proliferation but also the expression of cytolysis by some cytolytic T cell populations.

Animals↗
PubMed1985

Phorbol ester-inactivation of cloned cytotoxic T lymphocytes: restoration of lytic activity by interleukin 2 and induction of interferon production are separable events.

We have examined the interrelationship between Interleukin 2 (IL 2) and Interferon gamma (IFN gamma) for the induction of cytolytic activity from inactivated cloned cytotoxic T lymphocytes (CTL). In previous work we showed that treatment of cloned CTL with phorbol myristate acetate (PMA) inactivated their cytolytic function and that these inactivated cells provided an experimental approach to define the cytokines necessary for the induction of cytolysis. We further showed that IL 2 could provide a sufficient signal to restore cytolytic activity to inactivated cells by a process that was independent of cellular proliferation. Here we report that reactivation of the lytic response by IL 2 did not correlate with IFN production. IL 2 had the ability to restore lytic activity to PMA-treated cells but did not induce IFN gamma production. Similarly, IL 2 augmented the preexisting lytic response of non-PMA-treated cloned cells without stimulating IFN gamma production. However, PMA-treated and untreated cells had the capacity to produce IFN gamma when cultured with mitogen. These results suggest that IL 2 mediated reactivation of the cytolytic response and IFN gamma production by a cloned CTL appear to be regulated independently.

Animals↗
PubMed1984

Dendritic and axonal organization of mitral and tufted cells in the rat olfactory bulb.

The output cells of the main olfactory bulb, the mitral and tufted cells, can be categorized into subclasses on the basis of their intrabulbar dendritic and axonal characteristics. Their form was studied in rats following labeling by iontophoretic injection of horseradish peroxidase into the external plexiform layer (EPL). The fact that these extracellular injections labeled small numbers of neurons permitted reconstruction of individual cells. The injection depth within the EPL determined the type of cells labeled. Secondary dendrites of each cell type lay in one of three partially overlapping zones in the EPL. The deepest zone contained the secondary dendrites of one group of mitral cells (Type I), which had the deepest and longest dendrites of the output cells. An intermediate zone of the EPL contained the secondary dendrites of middle tufted and a second class of mitral cells (Type II). The superficial zone, adjacent to the glomerular layer, contained the relatively short, asymmetric dendritic fields of external tufted cells. The few labeled internal tufted cells had secondary dendrites in either the intermediate or deep zones. Every cell type, except the Type I mitral cells, had axon collaterals in the internal plexiform and upper granule cell layers. No cell types had axons re-entering the EPL. These results for output cells combined with our previous observations on granule cells point to a functional sublaminar organization of the EPL that has not previously been proposed.

Animals↗
PubMed1983

Different granule cell populations innervate superficial and deep regions of the external plexiform layer in rat olfactory bulb.

Studies on the morphological organization of the main olfactory bulb have indicated that there are subpopulations of granule cells with different dendritic patterns in the external plexiform layer (EPL). Small, extracellular injections of horseradish peroxidase (HRP) were made iontophoretically into superficial and deep parts of the EPL and the granule cell layer (GCL) in adult rats. Superficial EPL injections principally labeled superficial granule cell somata, whereas deep EPL injections labeled both superficial and deep granule cell somata. Injections in the superficial GCL labeled granule cell dendritic processes extending across the entire EPL. However, deep GCL injections labeled few granule cell dendrites in the superficial EPL, but labeled many such processes in the deep EPL. These results were the same in material processed with the Hanker-Yates procedure, where the morphology of individual neurons could be studied, and in the more sensitive tetramethyl benzidine procedure. Serial reconstructions of individual granule cells were made from both HRP and Golgi-Kopsch material. The distal dendrites of deep granule cells reached only as far as the deep EPL, where they branched extensively and had many dendritic spines. The dendrites of superficial granule cells, however, reached the most superficial part of the EPL where they ramified most extensively. The superficial granule cells typically had a higher spine density in the superficial part of the EPL than in the deep part. On the basis of these results, we conclude that the superficial granule cells predominantly innervate the superficial EPL and that the deep granule cells exclusively influences on the bulbar output neurons, the mitral and tufted cells, through reciprocal dendrodendritic synapses. Since the secondary dendrites of the tufted cells ramify in the superficial EPL and the dentrites of most mitral cells ramify in deep EPL, the superficial and deep granule cells may preferentially modulate the responses of tufted and mitral cells, respectively.

Animals↗
PubMed1983

Unusual scintigraphic appearance of perforation of the common bile duct.

This report deals with the diagnosis of perforation of the common bile duct into the lesser sac by HIDA cholescintigraphy. The first hour images after injection were suggestive of biliary obstruction. Subsequent images demonstrated unusual accumulations of the activity into the lesser sac and retroperitoneal potential spaces. Careful correlation between scintigraphic and surgical findings were undertaken. The case is reported to demonstrate the scintigraphic findings in choledochal perforation and to stress the importance of carrying out late images when the initial ones are abnormal.

Aged↗
PubMed1983

Analysis of amoxapine, 8-hydroxyamoxapine, and maprotiline by high-pressure liquid chromatography.

Two high-pressure liquid chromatography procedures are presented for the routine analysis of two new antidepressant drugs, amoxapine (Asendin) as well as its active metabolite and maprotiline (Ludiomil). Recovery rates were excellent with both methods of extraction. Method 1, for amoxapine and its metabolites, was linear up to 1,000 ng/ml. Sensitivity for the parent drug was 10 ng/ml and, for the active metabolite, 25 ng/ml. Within-run coefficients of variation (CV) were 4.57% for 8-hydroxyamoxapine and 3.84% for amoxapine. Method 2, for maprotiline, was linear from 10 to 1,000 ng/ml. Intraassay CV was 3.2%. Reliable, yet simple, methods for monitoring these drugs are needed in order to establish firmly the pharmacological data important to appropriate patient therapy.

Amoxapine↗
PubMed1983

The sentiments of love and aspirations for marriage and their association with teenage sexual activity and pregnancy.

This study questions the findings of most research claiming that teenage pregnancies are generally unwanted, unplanned and unintended. It starts with the question of why most sexually active teenagers put themselves at risk of becoming pregnant if they do not desire it. The hypothesis is that sentiments of "love" and "aspirations for marriage" are related to starting sexual activity and subsequent pregnancy. The sample is 123 school-age mothers. It was found that sentiments of "love" were associated with becoming pregnant more than with starting sexual activity. Most of the respondents who were "in love" at the onset of pregnancy were hoping to marry their sex partners and, in fact, many thought that marriage would occur in the very near future following the outcome of pregnancy. These findings suggest that more research needs to be directed at the development of affective bonds with and the aspirations for marriage to the sex partners. Such research may explain why these teenagers put themselves at risk.

Adolescent↗
PubMed1981

Comprehensive renal scintillation procedures in spinal cord injury: comparison with excretory urography.

A 131iodine orthoiodohippurate comprehensive renal scintillation procedure was performed and compared to results of excretory urography in 200 spinal cord injury patients. No severe urographic abnormalities were undetected by the comprehensive renal scintillation procedure. Only 1.4 per cent of renal units had greater than minimal pyelocaliectasis or ureterectasis in the presence of a normal radionuclide examination. A relatively large number of abnormalities were detected on the renal scintillation procedure when the excretory urogram was normal. Serial followup will be required to determine the significance of these findings but present data suggest that a comprehensive renal scintillation procedure and a plain film of the kidneys, ureters and bladder may be used for screening upper urinary tract abnormalities in lieu of an excretory urogram. This is particularly advantageous for the spinal cord injury population, since there have been no toxic or allergic reactions reported, no bowel preparation or dehydration is required and there is relatively low radiation exposure.

Humans↗
PubMed1981

CTL helper factor(s) produced by peritoneal cells of mice immunized to Listeria monocytogenes: relationship to interferon.

We have studied the relationship of interferons (IFN) to soluble helper factor(s) produced in vitro by activated peritoneal exudate cells of mice immunized to Listeria monocytogenes. This helper factor(s) can assist the generation of cytotoxic lymphocytes (CTLs) in response to allogeneic thymocytes that have been heat-treated to remove functional antigens that would normally stimulate CTLs in the absence of added exogenous help. In addition to IFN and CTL helper activity, a thymocyte proliferative activity also was detected. There appeared to be collaboration between activated nonadherent T cells and macrophages (MO) in the production of all three activities. The IFN produced appeared to be primarily IFN-gamma, however, some IFN-alpha/beta probably was present as well. Although CTL helper activity and IFN were both contained in fractions comprising the major peak of thymocyte proliferative activity when supernatant fluids containing all three were chromatographed, functional IFN could be deleted with pH-2 and anti-IFN treatment without appreciably altering the other two activities. Furthermore, when fluids containing helper activity, but depleted of functional IFN, were added to cultures of responder lymphocytes and heat-treated thymocytes, IFN was produced during the course of the five day culture as were CTLs. In parallel cultures to which fluids containing helper factor(s) were not added, no IFN was produced, and no CTLs were generated. Thus, although fluids having activities required for the generation of CTLs may be depleted of IFN at the time they are added to cultures, a role for IFN in some phase of CTL development cannot be excluded.

Animals↗