Publications by authors named "Sewell W"

End-user searching of National Library of Medicine (NLM) online data bases during eleven years has been investigated through transaction logs, questionnaires, and follow-up interviews. From 1976 through 1984, pathologists and pharmacists performed 8,313 searches. Highlights of our studies are compared with a review of other end-user research.

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Cell mediated immunity (CMI) to hepatitis B viral antigens was studied in BALB/mice after immunization with purified hepatitis B surface antigen (HBsAg), or core antigen (HBcAg), with adjuvants. The two in vitro assays for cell-mediated immunity (CMI), utilizing lymph node cells, were release of interferon after exposure to antigen, and blast transformation of lymphocytes, and the in vivo assay was ear swelling at 24 h after local injection of antigen. Immunization with HBsAg or HBcAg with adjuvants induced antigen-specific cutaneous reactivity; if no adjuvants were given, immunization with HBcAg, but not HBsAg, induced cutaneous reactivity.

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We have studied the effects on interferon-gamma (IFN-gamma) production of pertussigen, a protein toxin from Bordetella pertussis that augments and prolongs delayed-type hypersensitivity (DTH) reactions. Lymphoid cell suspensions from immunized mice were incubated with antigen or mitogen, and the culture supernatants were assayed for IFN-gamma. The production of IFN-gamma on exposure to specific antigen or concanavalin A was greatly enhanced if mice were given pertussigen at the time of immunization.

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In recent years studies on isolated hair cells have suggested that there is an inherent tuning of hair cells determined by their mechanical and electrical properties. However, tuning for mammalian cochleas appears to be much more complicated since there are typically two types of receptor cells (inner and outer hair cells) imbedded in a highly organized framework of supporting cells, membranes and fluids. The major neural output of the cochlea can be monitored by recording the activity of myelinated axons of spiral ganglion cells, not only under normal conditions, but also when the discharge patterns are altered by ototoxic drugs, acoustic trauma or olivocochlear bundle stimulation.

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The ability of magnetic resonance imaging (MR) to demonstrate breast carcinoma depends upon significantly different relaxation times in benign and malignant tissues. The authors conducted an in vitro study of transverse relaxation times (T2) of 393 breast tissue samples in order to establish a range of values for normal tissue, benign lesions, and carcinoma. All T2 values were multiexponential.

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The potentiation of delayed-type hypersensitivity (DTH) reactions by pertussigen, a protein toxin from Bordetella pertussis, has been studied in adoptive transfer assays. Lymph node or spleen cells from mice treated with or without pertussigen at the time of immunization with protein antigens were transferred to naive, syngeneic recipients that were challenged with antigen. Cells from donors treated with pertussigen had the capacity to transfer vigorous, antigen-specific DTH reactions.

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Furosemide, an ototoxic diuretic, was administered intravenously while rate- and phase-level functions of auditory nerve fibers were measured in the cat. Normal level functions can demonstrate two components distinguished by an abrupt shift in the phase of the response as the sound level is increased. Furosemide, administered at doses that decrease the endocochlear potential, selectively reduces the discharge rate in response to tones at sound levels below that of the abrupt phase shift.

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Pertussigen, one of the toxins from Bordetella pertussis, greatly increased the inflammatory response produced by complete Freund adjuvant in the footpads of mice. This effect was not produced by pertussigen when the emulsion was made with saline and incomplete Freund adjuvant, but if an antigen was included in incomplete Freund adjuvant, the strong potentiating effect was again demonstrated. As little as 100 ng of pertussigen given intravenously was effective, but 400 ng proved better, and this latter dose was used routinely.

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Furosemide was injected intravenously in anesthetized cats while the endocochlear potential (EP) and tuning curves from fibers of the auditory nerve were simultaneously monitored in the same ear. The characteristic frequencies (CF's) of the fibers studied ranged from 0.25 to 28 kHz.

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The relation between the endocochlear potential and spontaneous discharge rate in auditory nerve fibres was determined following intravenous injections of furosemide in anaesthetized cats. Following furosemide administration, both the endocochlear potential and the spontaneous discharge rates of auditory nerve fibres decreased synchronously. The logarithm of the spontaneous discharge rate was proportional to the endocochlear potential.

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The purpose of this study was to show the similarities and differences in like-sex and unlike-sex parent-adolescent modeling. Minnesota Multiphasic Personality Inventories were administered to male and female adolescents and their mothers upon admission of the adolescents to the St. Joseph Hospital Children and Youth Center.

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Highly purified mouse colony-stimulating factors (CSF) were tested for their effect on neutrophil cytotoxic function in a homologous antibody-dependent cell-mediated cytotoxicity (ADCC) assay in which TNP-coupled mouse thymoma cells coated with mouse anti-TNP antibodies were used as targets, and purified normal mouse bone marrow neutrophils or induced peritoneal neutrophils were used as effector cells. Biochemically pure granulocyte-macrophage (GM)- and granulocyte (G)-CSF enhanced the cytotoxic activity of neutrophils obtained from both sources, allowing them to kill target cells at low antibody concentrations. Furthermore, GM- and G-CSF showed an additive effect, suggesting either the presence of separate receptors for GM- and G-CSF or of separate subsets of neutrophils.

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Pertussigen, a purified protein from Bordetella pertussis, was shown to increase delayed-type hypersensitivity (DTH) to protein antigens in mice. First, it caused an approximately twofold enhancement of the magnitude of 24-h DTH reactions. Second, the peak magnitude of DTH was delayed to 4-7 d after challenge, at which time it was five times more intense than in mice not receiving pertussigen.

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The genetic control of eosinophilia has been studied in congenic strains of mice. Eosinophilia was induced with cyclophosphamide followed by keyhole limpet hemocyanin in complete Freund's adjuvant. After this treatment, BALB/c mice developed a high eosinophil response, whereas CBA, C57BL and A/J mice developed a low one.

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A substance or substances capable of increasing the firing rate of primary auditory fibers is detectable in the perilymph of frogs and guinea pigs subjected to sound stimulation. The increase in firing rate occurs in single units of the frog auditory nerve after perilymph obtained from frogs or guinea pigs during sound stimulation is infused into the frog perilymphatic sac. Perilymph collected from animals maintained in silence failed to cause an increase in firing rate of primary auditory fibers of the frog.

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Cholecystokinin (CCK) is a major stimulant for enzyme secretion by pancreatic acinar cells. In most animals this enzyme secretion is accompanied by a small volume of chloride-rich "carrier" fluid in which the enzymes are dissolved. In order to determine whether this carrier fluid is secreted independently of the pancreatic digestive enzymes, and how its composition is altered by interaction with them, we have studied CCK-evoked juice collected from anaesthetized rats before and after administration of cycloheximide, a powerful inhibitor of protein synthesis.

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Pathologists and pharmacists have used terminals in their departmental areas successfully to perform searches on MEDLINE and TOXLINE, during the period from fall 1974 through August 1975; MEDLINE has been used more than TOXLINE. In the Department of Pathology at the University of Maryland Health Sciences Center, the annual rate of combined mediated and nonmediated use of MEDLINE increased from 142 search sessions to 432, over half of the identified use being by three individuals. About half of the total potential users from each group tried MEDLINE or TOXLINE at least once.

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The use of one end-to-side anastomosis with side-to-side technique for all additional vein-coronary anastomoses has given continually good results and has been used in 227 of 411 patients undergoing vein graft operations, including all multiple graftings done since April, 1972. The operative mortality was 4.6%.

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1. HCO-3, Na+ and K+ concentrations were measured in bile-free pancreatic juice collected from fasted and fed anaesthetized rats. 2.

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