Biomedical subjects

L Ellsworth

Publications and source records attributed to L Ellsworth.

6 recordsLinked to original sources

PubMed1999

Diagnostic accuracy and image quality using a digital camera for teledermatology.

OBJECTIVE: The study was designed to evaluate the effectiveness of digital photography for dermatologic diagnoses and compare it with in-person diagnoses. MATERIALS AND METHODS: Patients referred for specialty consultations (n = 308) were recruited from a university dermatology clinic. Patients were examined in-person by one of three board-certified dermatologists who provided clinical diagnoses. Digital photos were obtained on all patients and were evaluated as computer images by a panel of dermatologists. RESULTS: There was 83% concordance between in-person versus digital photo diagnoses. Intradermatologist concordance averaged 84%, and interdermatologist concordance averaged 81%. Decision confidence was rated as "very definite" to "definite" 62% of the time. Concordance with biopsy results was achieved in 76% of the cases. Image sharpness and color quality were rated "good" to "excellent" 83% and 93% of the time, respectively. CONCLUSION: Digital photography for store-and-forward teledermatology produces high-quality images and diagnostic concordance rates that compare favorably with in-person clinical diagnoses.

Arizona↗

PubMed1997

Sulindac sulfone inhibits azoxymethane-induced colon carcinogenesis in rats without reducing prostaglandin levels.

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as sulindac, have cancer chemopreventive properties by a mechanism that has been suggested to involve cyclooxygenase inhibition and reduction of prostaglandin (PGE2) levels in the target tissue. To test this hypothesis, we studied the effect of dietary sulindac sulfone (500-2000 ppm), a metabolite of sulindac reported to lack cyclooxygenase inhibitory activity, on tumor formation and PGE2 levels in the azoxymethane model of colon carcinogenesis. Rats treated with sulindac at 400 ppm and piroxicam at 150 ppm were used as positive controls. Rats received two s.c. injections of azoxymethane (15 mg/kg) for 2 weeks and were fed either experimental or control diets until necropsy. After 31 weeks of sulfone treatment, a dose-related increase in sulfone levels in both serum and cecal contents was measured; there was no evidence of metabolic conversion to sulindac or other metabolites. Rats treated with sulfone at 1000 and 2000 ppm, sulindac, and piroxicam had significantly fewer colonic adenomas and carcinomas compared with rats fed control diet as measured by tumor incidence, multiplicity, and tumor burden. Sulfone-treated rats also showed a dose-response relationship for inhibiting all tumor parameters. Colons from rats treated with sulindac or piroxicam contained PGE2 levels that ranged from approximately 16-49% of control levels. PGE2 levels in rats treated with sulfone up to 2000 ppm ranged from 78-118% of control levels. Moreover, the effects of sulindac sulfone on various enzymes responsible for regulating prostaglandin levels were evaluated. No significant inhibitory effects were observed for cyclooxygenase, lipoxygenase, or phospholipase A2. These results suggest that reduction of prostaglandin levels in the target tissue may not be necessary for the chemopreventive properties of sulindac.

Animals↗

PubMed1995

Cardiotoxicity in the SCID mouse following administration of doxorubicin and cyclosporin A.

Multiple myeloma is a plasma cell malignancy which is generally incurable in spite of a high initial response to chemotherapy. Relapsing disease commonly heralds an increase in the incidence of drug resistance which is often mediated by the product of the MDR-1 gene, P-glycoprotein (Pgp). One approach to modulating drug resistance due to Pgp overexpression has involved the use of agents known as chemomodulators which inhibit its function. We have developed a human xenograft model of multiple myeloma using the SCID mouse to evaluate the efficacy and toxicities of new MDR-1 chemomodulators. Cyclosporin A (CsA) is a widely used immunosuppressant which has been demonstrated to be a potent inhibitor of Pgp in vitro at concentrations which are clinically achievable. Preliminary studies revealed an acute toxicity in our SCID model which was associated with the combination of CsA and doxorubicin, and which was not observed with either drug alone, nor with cremaphor, the vehicle for CsA. In the current study, non-tumor bearing SCID mice were dosed with doxorubicin or the combination of doxorubicin with cremaphor, verapamil or CsA. Animals were sacrificed and tissues harvested for morphologic examination and for HPLC analysis of doxorubicin levels. In all tissues examined, there was a marked increase in tissue levels of doxorubicin when combined with CsA. Results also revealed a higher incidence and severity of myocardial damage in those animals receiving the combination of doxorubicin and CsA than in those receiving other combinations. The elevations in tissue levels observed with doxorubicin and CsA may contribute to the acute toxicities observed in the SCID mouse model.

Animals↗

PubMed1992

Factors associated with intestinal amyloidosis in pigtailed macaques (Macaca nemestrina).

Factors associated with intestinal amyloidosis in pigtailed macaques (Macaca nemestrina) were studied in 74 cases at the Washington Regional Primate Research Center. The medical records of monkeys during the 5-year period from 1983 to 1988 were analyzed to determine the age at death, age at first episode of diarrhea, number of episodes of diarrhea, episode and cumulative duration of diarrhea, and etiologies of diarrhea. Univariate analysis, using one control for each case, indicated that only episode duration was related to intestinal amyloidosis. Affected monkeys had significantly longer mean episode durations of diarrhea. None of the etiologies examined--bacteria, protozoa, fungi, and simian retrovirus--were significant risk factors for amyloid deposition in the intestinal tract.

Age Factors↗

PubMed1987

The role of gonadal steroids in feedback regulation of gonadotropin secretion at different stages of primate development.

The serum gonadotropin response to castration was assessed in 8 foetal, 2 neonatal, 30 juvenile, and 2 adult rhesus monkeys (M. mulatta). In the 30 castrated juvenile monkeys and 8 sham-operated controls, concentrations of oestrone, oestradiol, androstenedione, dihydrotestosterone, testosterone and 17OH-progesterone were measured in 10 ml serum pools before, one month after, and one year after the surgical procedure. Castration during foetal life (83-137 days gestation) was followed within 48-72 h by a significant rise in serum FSH levels in males, but had no effect on the already high levels in females. Similarly, castration of males during the first post-natal month raised serum FSH and LH into the adult castrate range; however, after 3 months of age serum gonadotropin levels again declined to the normal juvenile range in spite of the open feedback loop. Orchiectomy of prepubertal juvenile monkeys (age 3 month-2 8/12 years) had no immediate effect on serum gonadotropins, but was followed by a delayed rise in FSH (at age 2 3/12-4 3/12 years) and LH (at age 2 7/12-4 4/12 years) to adult castrate levels. Orchiectomy of older prepubertal (by serum testosterone) or adult males resulted within a few days in a progressive and sustained rise in serum FSH and a more gradual rise in LH. Prepubertal gonadotropin regulation appeared to be sexually dimorphic, since ovariectomy in juvenile females (age 3 months-1 5/12 years) was followed by generally elevated, if somewhat erratic, serum FSH values, with a secondary rise in both FSH and LH levels at 2-2 1/12 years. In both sexes, prepubertal castration caused a significant and sustained decline in serum concentrations of oestradiol; castrated males also showed a decline in serum testosterone levels. Although prepubertal castration also caused in both sexes a slight decline in serum oestrone, and ovariectomy a decline in serum androstenedione and dihydrotestosterone, these effects were not sustained one year later, and values were not significantly different from sham-operated controls. Taken together, these data lend support to a model of primate sexual maturation in which the primary regulator of gonadotropin secretion in both sexes during the prolonged juvenile phase is central inhibition of the hypothalamic GnRH regulator. However, during foetal and neonatal life, and again following the onset of puberty, the major modulator of gonadotropin secretion becomes sex steroid-mediated feedback inhibition.

Age Factors↗

PubMedDate not supplied

Lymphomatoid granulomatosis in a 4-year-old boy.

Lymphomatoid granulomatosis is a necrotizing angiocentric and angiodestructive infiltrative process involving primarily the lung, skin, central nervous system, and kidney. The incidence is highest in middle-aged men and is rare in children. We report a case of lymphomatoid granulomatosis involving both skin and lung in a 4-year-old boy. The disease progressed to peripheral T-cell lymphoma, which was unusual in light of recent evidence suggesting a B-cell origin in the majority of cases.

Biopsy↗