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Biomedical subjects

T Schultz

Publications and source records attributed to T Schultz.

At least 19 recordsLinked to original sources
PubMed2001

Integrating digital educational content created and stored within disparate software environments: an extensible markup language (XML) solution in real-world use.

OBJECTIVE: To provide a standardized and scaleable mechanism for exchanging digital radiologic educational content between software systems that use disparate authoring, storage, and presentation technologies. MATERIALS/METHODS: Our institution uses two distinct software systems for creating educational content for radiology. Each system is used to create in-house educational content as well as commercial educational products. One system is an authoring and viewing application that facilitates the input and storage of hierarchical knowledge and associated imagery, and is capable of supporting a variety of entity relationships. This system is primarily used for the production and subsequent viewing of educational CD-ROMS. Another software system is primarily used for radiologic education on the world wide web. This system facilitates input and storage of interactive knowledge and associated imagery, delivering this content over the internet in a Socratic manner simulating in-person interaction with an expert. A subset of knowledge entities common to both systems was derived. An additional subset of knowledge entities that could be bidirectionally mapped via algorithmic transforms was also derived. An extensible markup language (XML) object model and associated lexicon were then created to represent these knowledge entities and their interactive behaviors. Forward-looking attention was exercised in the creation of the object model in order to facilitate straightforward future integration of other sources of educational content. XML generators and interpreters were written for both systems. RESULTS: Deriving the XML object model and lexicon was the most critical and time-consuming aspect of the project. The coding of the XML generators and interpreters required only a few hours for each environment. Subsequently, the transfer of hundreds of educational cases and thematic presentations between the systems can now be accomplished in a matter of minutes. The use of algorithmic transforms results in nearly 100% transfer of context as well as content, thus providing "presentation-ready" outcomes. CONCLUSION: The automation of knowledge exchange between dissimilar digital teaching environments magnifies the efforts of educators and enriches the learning experience for participants. XML is a powerful and useful mechanism for transfering educational content, as well as the context and interactive behaviors of such content, between disparate systems.

Computer Storage Devices↗
PubMed2001

Integrating digital teaching-file systems with off-the-shelf presentation software to facilitate speaker-led conferences.

OBJECTIVE: Develop methods for automated transfer of images and associated text from a teaching-file repository into presentation material for speaker-led conferences. MATERIALS/METHODS: Our institution uses a Microsoft Windows (Microsoft Corp, Redmond, WA) software application to maintain a digital teaching-file database that can store and retrieve content in a case-centric fashion. Virtually any number of images can be stored with any given case. Cases and their associated images can be retrieved via a module that supports searches by American College of Radiology (ACR) code and by free-text Boolean queries on the history, findings, diagnosis, and discussion components of a case. In addition to the software system serving directly as an interactive teaching tool, the digital teaching file itself serves as an image repository and resource for attending radiologists who create their own presentations and lectures. To better support this use, software modules were developed for interprocess communication and automated creation of Powerpoint slides. These modules are fully integrated with the teaching-file software application. A single image or a set of selected images can be automatically made into individual slides with two mouse clicks. Images are automatically centered and optimally sized. A slide title is automatically rendered from the user's preference of the case history or diagnosis (stored with the case), or via the entry of freeform text. We describe the programming techniques that are used, as well as how several features of the operating system and Powerpoint itself can be integrated with a customized software application to facilitate this objective. RESULTS: The creation of presentation-ready Powerpoint slides is fully automated from within our teaching-file application, and the time required to create a presentation compared to the conventional method of manually seeking and inserting files from within Powerpoint itself, on a per-slide basis, is drastically reduced. The benefits are magnified by having all imagery stored within an organized and searchable database system so that desired images can be easily located. CONCLUSION: A digital teaching-file system can serve as a useful image repository for purposes ancillary to direct computerized instruction. Software that supports these uses, such as the automated creation of presentation material for speaker-led conferences, facilitates the radiologist's role as an educator.

Computer-Assisted Instruction↗
PubMed2000

Mitochondrial FtsZ in a chromophyte alga.

A homolog of the bacterial cell division gene ftsZ was isolated from the alga Mallomonas splendens. The nuclear-encoded protein (MsFtsZ-mt) was closely related to FtsZs of the alpha-proteobacteria, possessed a mitochondrial targeting signal, and localized in a pattern consistent with a role in mitochondrial division. Although FtsZs are known to act in the division of chloroplasts, MsFtsZ-mt appears to be a mitochondrial FtsZ and may represent a mitochondrial division protein.

Alphaproteobacteria↗
PubMed2000

Time- and frequency-resolved photoionisation of the allyl radical

We report picosecond time-resolved pump-probe photoelectron spectra of the allyl radical, C3H5, and the fully deuterated allyl, C3D5, carried out in order to elucidate the primary photophysical processes upon UV excitation. It is shown that the UV bands of allyl decay in a two-step process: the first step is an internal conversion to the lower-lying A-state within 20 ps or less, while the second step is a very fast decay from the A-state to the electronic ground state through a conical intersection. In addition we report the first zero kinetic energy (ZEKE) photoelectron spectrum of allyl, yielding an ionisation energy of 65762 cm-1.

Journal Article↗
PubMed1998

The primary interpretation workstation: information beyond image data.

With the advent of picture archival and communication systems (PACS), the importance of design surrounding primary review workstations has become apparent. To help acceptance of filmless medical imaging, workstations must be developed that serve the needs of both radiologists and referring clinicians. This report will discuss integral requirements of workstation design, including information creation, medical management, medical knowledge, and enabling technologies.

Data Display↗
PubMed1998

The effects of linear acceleration on distortion product otoacoustic emissions in human ears.

BACKGROUND: The effect of high levels of linear acceleration (G) on the cochlea has never been studied prospectively. HYPOTHESIS: Linear acceleration at high levels has no effect on the human cochlea as demonstrated by a comparison of pre- and post-exposure measurements. METHODS: There were 22 healthy volunteers who underwent exposure to up to 9 G in a military aviation training centrifuge. Prior to exposure they were screened for cochleovestibular disorders and underwent tympanometry, audiometry and distortion product otoacoustic emissions testing (DPOAE). Immediately after exposure, they underwent serial testing of each of these parameters until they returned to baseline. RESULTS: There was no significant change in tympanometry in any subject. Audiometry revealed a temporary threshold shift of 30 db at 6 kHz in one ear of a single subject. This was accompanied by a complete loss of DPOAE at the same frequency. DPOAE did not return to baseline at 2 weeks even though the audiogram had reverted to baseline by 8 d. Four other ears displayed significant losses of emissions at single frequencies without an accompanying change on the audiogram. CONCLUSIONS: This study demonstrates that accelerative stress may cause transient injury to the cochlea. The mechanism of injury due to acceleration is probably ischemia, although a purely mechanical effect on the outer hair cells cannot be precluded. These data also reinforce a growing body of evidence that demonstrates the greater sensitivity of DPOAE over psychoacoustic testing in detecting early or subclinical cochlear damage.

Acceleration↗
PubMed1997

Evaluation of a pocket-sized turbine spirometer for clinical use with children.

The results of pulmonary function testing with a turbine spirometer (TS) and a bell spirometer (BS) of a randomized group of 275 patients aged 4-18 years were compared. In the TS, an inexpensive device without graphical display was used. The difference BS minus TS (d) for forced expiratory volume in 1 s (FEV1) was calculated. The results indicate that the FEV1 might be overestimated by the TS, and that the difference of the readings of FEV1 between the spirometers increases with airway obstruction. The TS should be used with caution in young patients with asthma.

Adolescent↗
PubMed1995

Bilateral renal oncocytoma: case report and implications in renal tumour management.

Renal oncocytomas are uncommon benign tumours that have recently been recognized as a unique pathological entity. These lesions may attain considerable size; however, most present as an asymptomatic incidental finding. Although usually solitary, these tumours are occasionally multicentric or bilateral at presentation. Retrospective studies suggest that oncocytoma may account for up to 5% of tumours previously classified as well-differentiated renal cell carcinoma. At present, conservative management is hampered by difficulty in establishing a confident pre-operative or intra-operative diagnosis. A case of bilateral asymptomatic renal oncocytoma is presented, and the implications of this lesion for the management of renal tumours is discussed.

Adenoma, Oxyphilic↗
PubMed1994

The sympathetic and parasympathetic nature of neuropeptide Y-immunoreactive nerve fibres in the major salivary glands of the rat.

The distribution and origin of neuropeptide Y in the major salivary glands of the rat was studied by indirect immunofluorescence technique. Numerous nerve fibres immunoreactive for the peptide were seen in the parotid and sublingual glands. Most of the fibres were located around blood vessels and salivary acini. In the submandibular gland the number of immunoreactive nerve fibres around the acini was lower in comparison with that in the parotid and sublingual glands. Some immunoreactive nerve fibres were also found around or along intra- and interlobular ducts in all major salivary glands. A large number of the neuropeptide-containing neuronal cell bodies and nerve fibres were detected in the sympathetic superior cervical ganglion. Sympathetic postganglionic nerve trunks of this ganglion contained numerous immunoreactive nerve fibres as well. A subpopulation of the neuronal cell bodies in the submandibular ganglion were immunoreactive to neuropeptide Y. Both uni- and bilateral superior cervical ganglionectomies caused a significant decrease in the number of immunoreactive nerve fibres around the blood vessels in all the major salivary glands. However, these denervations did not affect the density of nerve fibres around the acini and ducts. On the contrary, unilateral parasympathetic denervation by sectioning the auriculotemporal nerve reduced the fibres around the secretory acini in the parotid gland remarkably, while only a minor reduction in the density of immunoreactive fibres associated with the blood vessels of the gland was detected. Unilateral electrocoagulation of the trigeminal nerve branches caused no detectable change in the density of immunoreactive nerve fibres in any of the major salivary glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Relationship of plasma epinephrine and circulating eosinophils to nocturnal asthma.

The mechanisms of nighttime airway obstruction are not fully established, but include circadian fluctuations in epinephrine and cortisol. To evaluate the relationship of circadian patterns in epinephrine and cortisol to nighttime airflow obstruction, 10 young adult asthma patients (ages 19 to 25 yr) were admitted to a hospital clinical research unit for a 3-day study during which plasma concentrations of epinephrine, cortisol, and histamine were determined along with white blood cell and eosinophil counts every 6 h (1600, 2200, 0400, and 1000 h). Six of the 10 patients experienced at least one episode of nocturnal asthma (defined by more than a 15% decrease in antemeridian (A.M.) to postmeridian (P.M.) FEV1 values). Plasma epinephrine levels (pg/ml) showed a circadian pattern, and the concentration at 2200 h was significantly (p = 0.039) different for the nocturnal and non-nocturnal asthma groups. Circulating eosinophil numbers were greater in subjects who had more frequent episodes of nocturnal asthma, and correlated with the frequency of nocturnal asthma (r = 0.732, p = 0.02, Spearman rank correlation) and average percent decrease in FEV1 (r = 0.667, p = 0.035). Plasma cortisol concentrations also showed circadian patterns, but no direct association with nocturnal asthma; plasma histamine concentrations showed no circadian patterns and no association with nocturnal asthma. Our findings indicate that changes in plasma epinephrine precede the development of nocturnal airway obstruction and contribute to the likelihood of nighttime airflow obstruction.

Adult↗
PubMed1991

Tyrosine phosphatase CD45 is required for T-cell antigen receptor and CD2-mediated activation of a protein tyrosine kinase and interleukin 2 production.

CD45, a hematopoietic cell-specific surface antigen, has recently been shown to be a protein tyrosine phosphatase. Expression of CD45 is essential for the T-cell antigen receptor to couple with the phosphatidylinositol second messenger pathway and for antigen-mediated proliferation of T lymphocytes. In this report we describe a CD45-deficient mutant of the human T-cell leukemia line Jurkat. CD45 expression is required for the activation of a T-cell receptor-associated tyrosine kinase as well as the phosphatidylinositol pathway. Additionally, stimulation of T lymphocytes by way of the accessory molecule CD2 requires the expression of CD45. The mutation in the CD45-deficient cell specifically impairs signal transduction by the T-cell receptor and CD2 because activation events by way of another accessory molecule, CD28, are unimpaired.

Antibodies, Monoclonal↗
PubMed1991

Neurokinin A in the parotid and submandibular glands of the rat: immunohistochemical localization and effect on protein and peroxidase secretion.

An indirect immunofluorescence technique was used to study the distribution of neurokinin A immunoreactive (NKA-IR) nerve fibres in submandibular and parotid glands of the rat. The functional role of neurokinin A on protein and peroxidase secretion in these glands was evaluated by using in vitro methods. In the parotid gland neurokinin A immunoreactive fibres were mainly distributed around the secretory acini, but some were also in evidence around the stromal blood vessels and ducts. The number of the neurokinin A immunoreactive nerve fibres was lower in the submandibular gland than in the parotid gland. They were mainly distributed around the secretory acini and stromal blood vessels and ducts. In vitro, neurokinin A significantly stimulated the release of total amount of released proteins and peroxidase from parotid gland fragments, while in the submandibular gland only the release of peroxidase was increased. By using SDS polyacrylamide gel electrophoresis (SDS-PAGE) specific changes were found in the release of proteins after neurokinin A stimulation. The results of the present study demonstrate that neurokinin A immunoreactive nerve fibres are present in the rat parotid and submandibular glands. Their localization around the secretory elements of the glands and the effect of neurokinin A in vitro experiments indicates that neurokinin A might have a significant role in the regulation of salivary secretion.

Animals↗
PubMed1991

Polar axis fixation in Fucus zygotes: components of the cytoskeleton and extracellular matrix.

Polar axis formation and polar axis stabilization (or fixation) can be separated and analyzed in synchronously developing zygotes of the brown alga Fucus. Extensive experimental evidence points to a role for both the cytoskeleton and the extracellular matrix (ECM) in the process of axis fixation in Fucus. A structural complex composed of the cytoskeleton and the ECM has been postulated to stabilize membrane asymmetries generated as a result of axis-forming vectors. This axis stabilizing complex (ASC) may take the form of transmembrane connections between the cytoskeleton on the cytoplasmic face and the ECM on the external side of the plasma membrane, similar to focal contacts in animal cells. At present we know of two components in the proposed ASC of Fucus: an adhesive sulfated glycoprotein which is localized in the ECM, and an actin network which is localized on the adjoining cytoplasmic face. This preliminary report describes evidence for the presence of molecules in two-celled Fucus embryos that are similar to those found in focal contacts in animal cells, i.e. vinculin, integrin and vitronectin. However, their localization and interaction with each other relative to the polar axis has yet to be determined. These initial observations will provide the basis to pursue further an analysis of these components in the process of polar axis fixation.

Cell Polarity↗
PubMed1989

Function of a heterologous muscarinic receptor in T cell antigen receptor signal transduction mutants.

Previously we have described a system of somatic cell genetics (J.CaM1 and J.CaM2) for analyzing signal transduction via the T cell antigen receptor complex (CD3/Ti). Here we describe a third mutant, J.CaM3, which also expresses high levels of receptors that are functionally impaired. Like J.CaM1, J.CaM3 demonstrates partial signal transduction via CD3/Ti to only certain stimuli. J.CaM1, J.CaM2, and J.CaM3 define three non-Ti complementation groups involved in receptor function. To evaluate the mutations further we have introduced a heterologous receptor, the human muscarinic receptor 1 (HM1), into the parental Jurkat and mutant cell lines. This receptor demonstrates signal transduction competence in all these hosts, indicating that 1) T cells express the necessary apparatus for the coupling of HM1 to second messenger generation and 2) the mutations in the J.CaM family all affect molecules that are specific to CD3/Ti, and not HM1, function. Finally, the HM1 receptor exhibits partial sensitivity to cholera toxin in Jurkat cells, in contrast to the virtually complete sensitivity of CD3/Ti to cholera toxin.

Antibodies, Monoclonal↗
PubMed1989

Crystal methamphetamine-induced acute pulmonary edema: a case report.

"Crystal methamphetamine" is a crystalline form of amphetamine, the abuse of which is growing rapidly in popularity in Japan, Hawaii and the West Coast. Drug experts and law enforcement officials say that the use of crystal meth is spreading east from California. It may produce permanent addiction and can produce violent schizophrenic behavior. Introduced along the Leeward Coast of Hawaii about 3 years ago, it is now being used throughout Oahu and is starting to rival cocaine as the illicit drug of choice in Hawaii. It is also the major drug problem in Japan, where the powder form is called "shabu." The smoking of crystal ("ice") in a glass pipe is more common in Hawaii, whereas other routes of administration, such as snorting or intravenous use, are more common on the West Coast. We present the case of a young woman who was admitted to Kaiser Moanalua Medical Center with near fatal acute pulmonary edema consequent to the use of crystal meth.

Acute Disease↗