PubMed Health⌕ Search

Biomedical subjects

S Chow

Publications and source records attributed to S Chow.

62 records · Page 4Linked to original sources
PubMed1981

North American blastomycosis in an immunosuppressed patient.

A 49-year-old man with sarcoidosis presented with a large nonhealing verrucous and eroded lesion (of two years' duration) over the left flank. Biopsy of the lesion revealed granulomatous infiltration, and special fungal stains showed the typical broad-necked budding structure of Bastomyces dermatitidis. The patient underwent en masse surgical removal of the lesion followed by systemic administration of amphotericin B. This report emphasizes the need for skin biopsy for nonhealing ulcers of unknown etiology, reviews the natural history of North American blastomycosis, and speculates on its relationship to immunosuppression.

Blastomycosis↗
PubMed1979

Coexisting malignant lymphoma and adenocarcinoma of the stomach.

The fourth case of malignant lymphoma coexisting with an adenocarcinoma in the stomach is presented. Although an increased incidence of systemic malignant lymphoma in association with gastrointestinal tumors has recently been emphasized, primary gastric lymphoma and adenocarcinoma coexisting in the same stomach is still rare.

Adenocarcinoma↗
PubMedDate not supplied

Imaging features of avulsion injuries.

Avulsion injuries are common among participants in organized sports, especially among adolescent participants. Imaging features of both acute and chronic avulsion injuries of the pelvis, knee, ankle and foot, shoulder, and elbow were evaluated to help distinguish these injuries from more serious disease processes such as neoplasm and infection. At radiography, acute injuries (ie, those resulting from extreme, unbalanced, often eccentric muscular contractions) may be associated with avulsed bone fragments, whereas subacute injuries have an aggressive appearance that may include areas of mixed lysis and sclerosis. Chronic injuries (ie, those resulting from repetitive microtrauma or overuse) or old inactive injuries may be associated with a protuberant mass of bone and may bear a striking resemblance to a neoplastic or infectious process. Although not usually required, computed tomography is helpful in the diagnosis if radiographic findings are equivocal or if the injury is not in the acute phase. MR imaging is best suited for the evaluation of injuries to muscles, tendons, and ligaments. Recognition of characteristic imaging features and familiarity with musculotendinous anatomy will aid in accurate diagnosis of avulsion injuries.

Acute Disease↗
PubMedDate not supplied

The Functional Pain Scale: reliability, validity, and responsiveness in an elderly population.

OBJECTIVES: Because of difficulty experienced in assessing pain in frail older patients and the lack of pain assessment tools with standardization in the elderly, the Functional Pain Scale (FPS), an instrument incorporating both subjective and objective components to assess pain, was developed and evaluated. DESIGN, SETTING, PARTICIPANTS, AND MEASURES: One hundred subjects more than 65 years old participated in the validity, reliability, and responsiveness (the clinical sensitivity of the instrument to change) testing of the Functional Pain Scale. Subjects were recruited from a geriatrics inpatient setting, a geriatrics outpatient setting, and a local hospice (residing in their homes). Ninety-four of the subjects completed all phases of testing. Reliability was tested using a test-retest format and a correlation matrix. Criterion-related validity was established as compared with the Visual Analog Scale (VAS), the Present Pain Intensity (PPI), the McGill Short Form Questionnaire (MPQ-SF), and the Numeric Pain Scale (NPS) instruments. Responsiveness for the FPS, the VAS, the PPI, the MPQ-SF, and the NPS instruments was determined using five previously described techniques: effect size, standardized response means, relative efficiency, direct comparison of t test scores, and direct comparison of P values. A cumulative index was developed to rank each scale. Cumulative responsiveness index scores were based on individual scale performance for each separate responsiveness test. The lowest score in the cumulative responsiveness index indicated the most responsive scale. RESULTS: Interrater reliability for instruments tested exceeded 0.95 for all instruments tested. Validity testing showed high correlations as well (r = 0.62, r = 0.85, r = 0.80, r = 0.90 for the VAS, the PPI, the MPQ-SF, and the NPS respectively). Responsiveness evaluated overall by the responsiveness index was best for the Functional Pain Scale (7) followed by the Visual Analog Scale (12), the Present Pain Intensity (13), the McGill Pain Questionnaire-Short Form (19), and the Numerical Pain Questionnaire (24). CONCLUSIONS: The Functional Pain Scale was determined to be reliable, valid, and responsive. The responsiveness of the Functional Pain Scale was superior to the other instruments tested. The Functional Pain Scale is an acceptable instrument for assessing pain in older adults and may reflect changes in pain better than other instruments tested. Further testing in other populations is warranted.

Journal Article↗
PubMedDate not supplied

The cell biology of ras-induced transformation: insights from studies utilizing an inducible hybrid oncogene system.

The c-Ha-ras oncogene has been implicated as a causative agent in the development of tumors in humans as well as mice. The molecular nature of the ras-induced tumorigenic process remains unclear, however. To address this question directly we have constructed a cell line which carries a zinc-inducible metallothionein-ras hybrid oncogene, transformant 212. Upon exposure to zinc for 24-48 hr, 212 cells assume a highly transformed morphology, concomitant with the induction of ras-expression. Natural killer cells constitute a subpopulation of lymphoid effector cells which have for a long time been hypothesized to be involved in the earliest stages of antitumor surveillance. Central to this hypothesis is the prediction that NK sensitivity arises during cellular transformation. By carrying out cytotoxicity assays against the 212 transformant, we showed that, indeed, increased sensitivity to NK-mediated lysis correlated with expression of the ras oncogene, which is consistent with the above hypothesis. We then addressed the question of the biochemical mechanism of ras-induced transformation. Owing to their similarity to G proteins, regulatory elements interposed between cell-surface receptors and their effector enzymes, it has been postulated that p21, the ras oncogene protein, mediates its transforming effects by constitutive activation of proliferative signal transduction pathways. We studied the effect of ras expression on the regulation of adenylate cyclase (A.C.), key enzyme of one such major pathway. We found that ras expression correlated with a dampening of responsiveness of A.C. to several stimuli, including hormones such as isoproterenol and other agents such as GMP-PNP, forskolin and fluoride-ion. Accumulation of cAMP as measured by RIA in intact cells, as basal or in response to stimulation of A.C. activity with forskolin, was also decreased (approximately 10-fold) with ras expression. Because the regulation of calcium, another important second messenger is dependent, in part, upon cAMP and GTP-binding proteins, we investigated the possible influence of ras expression on the intracellular concentration of calcium. Steady-state intracellular free Ca2+ concentration, as measured by fluorimetry, was indeed increased by approximately 50-125% in association with ras expression. Finally, we studied the possible influence of p21ras on protein kinase C (PKC), which is a key enzyme in the important signal transduction pathway of phosphatidylinositol lipid turnover. We assessed PKC activity directly, in a cell-free system, by measuring the ability of the enzyme to transfer radiolabelled phosphate from gamma-32P-ATP to histone, and exogenous substrate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenylyl Cyclases↗