Biomedical subjects
S Crawford
Publications and source records attributed to S Crawford.
Changing trends in marrow transplantation for aplastic anemia.
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A novel 110-kDa maternal CAAX box-containing protein from Xenopus is palmitoylated and isoprenylated when expressed in baculovirus.
We describe a unique 110-kDa protein, xlcaax-1, that is a member of a group of membrane-associated proteins such as the ras and ras-related proteins and nuclear lamins. Many of these proteins are involved in signal transduction or cell signaling, possess a C-terminal CAAX box, and undergo fatty acid acylation (Glomset, J. A., Gelb, M. H., and Farnsworth, C. C. (1990) Trends Biochem. Sci. 15, 139-142). The ras and ras-related proteins bind GTP and in most cases are both isoprenylated and palmitoylated. The xlcaax-1 protein possesses a C-terminal CAAX sequence that is identical to the N-ras protein. In addition to the CAAX box, xlcaax-1 contains a series of basic amino acids upstream of the CAAX sequence similar to several nonpalmitoylated forms of the ras-related proteins. When the xlcaax-1 cDNA is expressed in a baculovirus expression system, the product undergoes isoprenylation and palmitoylation utilizing a mechanism similar to that of the ras proteins. In addition, the xlcaax-1 protein is isoprenylated, and a minor fraction is palmitoylated in Xenopus XTC tissue culture cells. We have also demonstrated that the protein is associated with membrane fractions in full-grown Xenopus oocytes and in Xenopus XTC tissue culture cells and that membrane association is isoprenylation-dependent. The presence of maternal molecules possessing signal transduction potential is an attractive mechanism for modulating the effects of growth factors and other signal molecules during development.
Comparison of heterotypic protection against influenza A/Taiwan/86 (H1N1) by attenuated and inactivated vaccines to A/Chile/83-like viruses.
Children (n = 192) aged 3-19 years from 98 families completed this double-blind, placebo-controlled study comparing the efficacy of a bivalent attenuated (CR) vaccine with trivalent inactivated (TI) vaccine. Both vaccines contained A/Chile/83 (H1N1)-like antigens. After vaccination the geometric mean titer to A/Taiwan/86 (H1N1) was 1:36 in the CR group, 1:92 in the TI group, and 1:5 in the placebo group. During the influenza A/Taiwan/86 (H1N1) epidemic, 21.4% of CR recipients, 16.7% of TI recipients, and 43.9% of placebo recipients were infected with influenza A/Taiwan. TI vaccine provided better heterotypic protection than did CR vaccine for children aged 10-18 years (infection rate, 0 vs. 24%, respectively; P less than .025); in contrast, in the younger children (3-9 years), CR vaccine tended to be more protective (19% vs. 26% for TI).
The effect of student residence on food choice.
This study assessed the effect of student residence on food choices and dietary practices of students enrolled in an undergraduate nutrition class at Washington State University. We compared food consumption patterns of students living on campus, off campus, and in Greek housing. We also identified differences between men and women in food consumption and dietary practices. The results suggested that students' residence and sex may influence food choice and dietary practices. Significant differences in food choice related to students' residence were found for 8 of the 27 variables included on a food frequency list. Differences in the consumption of fresh fruits and vegetables, beer, fish, unsweetened cereal, white bread, and cookies were identified. In addition, students who lived in Greek housing were found to skip meals less frequently than other students, and men were found to consume significantly more beer, sugar-sweetened soft drinks, meat, and white bread than women students. Men were also more accurate in their perception of their body weight.
The palindromic series I repeats in the simian cytomegalovirus major immediate-early promoter behave as both strong basal enhancers and cyclic AMP response elements.
A 600-base-pair (bp) enhancer region upstream from the major IE94 gene of simian cytomegalovirus (SCMV) produces very strong basal expression of associated gene products. This domain consists of multiple sets of interspersed repetitive elements, including 11 copies of a conserved 16-bp palindromic sequence with the consensus CCATTGACGTCAATGG. These series I repeats contain an 8-bp core TGACGTCA that resembles the cyclic AMP (cAMP) response element (CRE) of cellular genes. In transient chloramphenicol acetyltransferase assays in K562 human erythroleukemia cells, a set of deleted variants of the IE94 promoter all responded up to 15-fold to induction by cAMP. However, successive removal of most of the SCMV 16-bp motifs reduced basal expression over 20-fold. The cAMP stimulation was also manifested at the steady-state RNA level after SCMV infection of K562 cells and was detectable within 1.5 h after treatment of DNA-transfected cells. Addition of a single 30-bp oligonucleotide encompassing the 16-bp palindrome conveyed up to 10-fold cAMP responsiveness onto a heterologous weak promoter but had no effect on basal expression. In contrast, two or more adjacent copies produced 20- to 40-fold increases in basal expression and provided greater than 200-fold activation in the presence of cAMP. Similar effects were obtained when the oligonucleotides were placed in a downstream location relative to the reporter gene. Studies with mutant oligonucleotides revealed that both the core CRE and the flanking sequence portions of the 16-bp elements were essential for enhancer function. Both components were also important for maximum cAMP responsiveness. Band shift assays with fractionated nuclear extracts from Raji lymphocytes revealed multiple competable complexes with cellular DNA-binding factors that recognized the series I elements. Three distinct CREB-like factors were detected that required only the core 8-bp elements for binding. We conclude that the 16-bp series I repeats provide a major contribution to the constitutive enhancer properties of the IE94 promoter and also act as functional CREs. The cAMP response properties appear likely to play a key role in reactivation of the virus from a latent state in appropriately differentiating cell types.
Hepatic copper concentrations in purebred and mixed-breed dogs.
Histomorphologic, histochemical, and atomic absorption analysis studies were performed on liver tissue from 623 clinically normal purebred and mixed-breed dogs to assess the range of hepatic copper concentrations, the histologic distribution of copper, and the histomorphologic changes associated with the various copper concentrations that were found. Atomic absorption analysis revealed a continuous numerical spectrum ranging from less than 100 parts per million on a dry weight basis (ppm dw) to more than 2,000. No decisive numerical criterion was found that could be used to separate normal from abnormal copper concentrations because of this continuous array. The threshold for histochemical demonstration of copper-containing granules using rhodanine or rubeanic acid staining was 400 ppm dw. At this concentration the copper-containing granules were located in the centrilobular hepatocytes (zone 3 of Rappaport). Copper-containing granules were found in the midzonal and periportal hepatocytes (zones 2 and 1 of Rappaport) in livers with 1,000 ppm dw and higher copper concentrations. The majority of the 623 livers were normal histomorphologically. Multifocal hepatitis characterized by mixed inflammatory cell accumulation and centrilobular distribution was found to be associated with copper concentrations in the range of 2,000 ppm dw or higher. An appropriate upper limit for normal hepatic copper concentration in the dog was not determined based on the present study.
Fungal infection with non-Hodgkin's lymphoma.
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Spinal cord ischemia after resection of thoracoabdominal aortic aneurysms: MR findings in 24 patients.
MR images of the thoracic spinal cord were made in 24 patients who developed signs and symptoms of spinal cord ischemia or infarction following surgery for a thoracoabdominal aortic aneurysm. Findings consisted primarily of four different patterns of signal abnormalities in the distribution of the anterior spinal artery. These abnormalities were identified as types A-D, depending on the degree of involvement of the gray matter and surrounding white matter. We found good correlation between the distribution of the signal abnormalities in the cord, the severity of the neurologic deficits, and the clinical outcome. MR is the imaging method of choice for diagnosing spinal cord ischemia or infarction. A thorough knowledge of the spinal cord arterial territories is crucial for characterizing ischemic MR signal abnormalities and for differentiating them from other causes of myelopathy.
The effect of end-user searching on reference services: experience with MEDLINE and current contents.
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Planning a new library in an age of transition: the Washington University School of Medicine Library and Biomedical Communications Center.
In an era of great technological and socioeconomic changes, the Washington University School of Medicine conceptualized and built its first Library and Biomedical Communications Center in seventy-eight years. The planning process, evolution of the electronic library, and translation of functions into operating spaces are discussed. Since 1983, when the project was approved, a whole range of information technologies and services have emerged. The authors consider the kind of library that would operate in a setting where people can do their own searches, order data and materials through an electronic network, analyze and manage information, and use software to create their own publications.
Medical school libraries in the United States: evolution to information management.
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Family functioning and stress as predictors of influenza B infection.
A prospective cohort study was designed to study the effects of family functioning and stress on the incidence of influenza infection. Families from the clinic roster, containing two adults and at least one child between the ages of 1 and 18 years, were asked to participate. Baseline (pre-influenza) data included a serum determination for influenza A and B antibodies, family functioning as measured by the Family Adaptability and Cohesion Evaluation Scales (FACES) II and the Family APGAR, and parental stress as measured by the social readjustment rating scale (SRRS). During the study all family members of patients with upper respiratory tract infection symptoms or fever were seen, and throat swabs were obtained for viral culture. Approximately 2 weeks after the influenza epidemic ended (March 1984), sera for antibodies were again collected on all family members. Chi-square analysis showed that infection (defined as a fourfold titer rise or a positive viral throat culture) was significantly associated with both cohesion and adaptability as measured by FACES II. Neither the Family APGAR nor the SRRS was associated with influenza B infection. It was concluded that family functioning affects the frequency of influenza B infection within families. This finding raises the possibility that family dysfunction may lead to altered immune responses, which increases susceptibility to infection.
Increased cytotoxicity against cytomegalovirus-infected target cells by bronchoalveolar lavage cells from bone marrow transplant recipients with cytomegalovirus pneumonia.
Cytotoxic activity of bronchoalveolar lavage (BAL) cells from 23 bone marrow transplant recipients against CMV-infected fibroblast target cells was evaluated to determine if responses differed between patients with and without CMV pneumonia. Responses of BAL cells were also compared with responses of peripheral blood lymphocytes (PBLs). BAL cells from patients with CMV pneumonia had greater cytotoxicity than BAL cells from patients with non-CMV pneumonia (P = .008). Cytotoxicity of BAL cells was also increased, as compared with PBLs, from patients with CMV pneumonia (P = .008). Lymphocytes, not alveolar macrophages, were found to be the cytotoxic effector cells in studies using purified BAL populations. Depletion studies using Leu 11b and complement suggested that natural killer cells were responsible for the cytotoxic activity. These studies demonstrate that BAL cells from patients with CMV pneumonia after bone marrow transplant have increased cytotoxicity against CMV-infected target cells.
Disorders of migration and sulcation.
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Peer review and the evaluation of manuscripts.
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Myths and more myths about insulin injection.
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Beyond the online catalog: developing an academic information system in the sciences.
The online public access catalog consists essentially of a machine-readable database with network capabilities. Like other computer-based information systems, it may be continuously enhanced by the addition of new capabilities and databases. It may also become a gateway to other information networks. This paper reports the evolution of the Bibliographic Access and Control System (BACS) of Washington University in end-user searching, current awareness services, information management, and administrative functions. Ongoing research and development and the future of the online catalog are also discussed.