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Biomedical subjects

S Casey

Publications and source records attributed to S Casey.

13 recordsLinked to original sources
PubMed1996

Worldwide patterns of mitochondrial DNA differentiation in the harbor seal (Phoca vitulina).

The harbor seal (Phoca vitulina) has one of the broadest geographic distributions of any pinniped, stretching from the east Baltic, west across the Atlantic and Pacific Oceans to southern Japan. Although individuals may travel several hundred kilometers on annual feeding migrations, harbor seals are generally believed to be philopatric, returning to the same areas each year to breed. Consequently, seals from different areas are likely to be genetically differentiated, with levels of genetic divergence increasing with distance. Differentiation may also be caused by long-standing topographic barriers such as the polar sea ice. We analyzed samples of 227 harbor seals from 24 localities and defined 34 genotypes based on 435 bp of control region sequence. Phylogenetic analysis and analysis of molecular variance showed that populations in the Atlantic and Pacific Oceans and east and west coast populations of these oceans are significantly differentiated. Within these four regions, populations that are geographically farthest apart generally are the most differentiated and often do not share genotypes or differ in genotype frequency. The average corrected sequence divergence between populations in the Atlantic and Pacific Oceans is 3.28% +/- 0.38% and those among populations within each of these oceans are 0.75% +/- 0.69% and 1.19% +/- 0.65%, respectively. Our results suggest that harbor seals are regionally philopatric, on the scale of several hundred kilometers. However, genetic discontinuities may exist, even between neighboring populations such as those on the Scottish and east English coasts or the east and west Baltic. The mitochondrial data are consistent with an ancient isolation of populations in both oceans, due to the development of polar sea ice. In the Atlantic and Pacific, populations appear to have been colonized from west to east with the European populations showing the most recent common ancestry. We suggest the recent ancestry of European seal populations may reflect recolonization from Ice Age refugia after the last glaciation.

Animals↗
PubMed1995

Randomized trial of chemoendocrine therapy started before or after surgery for treatment of primary breast cancer.

PURPOSE: To evaluate in a randomized clinical trial systemic chemoendocrine therapy used as primary (neo-adjuvant) treatment before surgery in women with primary operable breast cancer. PATIENTS AND METHODS: Patients aged less than 70 years with clinically palpable, primary operable breast cancer diagnostically confirmed by fine-needle aspiration cytology (FNAC) and suitable for treatment with surgery, radiotherapy, cytotoxic chemotherapy, and tamoxifen were considered eligible. Patients randomized to neoadjuvant treatment received four cycles of chemo-therapy for 3 months before surgery followed by another four cycles after surgery, and were compared with patients randomized to adjuvant therapy who received eight cycles of chemotherapy over 6 months after surgery. RESULTS: Of 212 patients who were randomized to receive either adjuvant (n = 107) or neoadjuvant (n = 105) chemoendocrine therapy, 200 are now assessable for response. The two groups are comparable for age, menopausal status, disease stage, and surgical requirements. The overall clinical response rate was 85%, with a complete histologic response rate of 10%. There was a significant reduction in the requirement for mastectomy in patients who received neoadjuvant treatment (13%) as compared with those who received adjuvant therapy (28%) (P < .005). Symptomatic and hematologic acute toxicity was low and similar for adjuvant and neoadjuvant therapy. The median follow-up period for patients in this trial is 28 months, during which time four patients have relapsed locally and 20, including one of the local relapses, have developed metastatic disease, 19 of whom have died. The follow-up period is too brief to evaluate relapse rate or survival duration. CONCLUSION: This trial confirms previous reports of a high rate of response to neoadjuvant therapy, but is the first to include small primary cancers and to show, in the context of a randomized trial, a reduction in the requirement for mastectomy. Until disease-free and overall survival data are available from the larger National Surgical Adjuvant Breast and Bowel Project (NSABP)-18 trial, such neoadjuvant treatment cannot be recommended outside of a clinical trial.

Adult↗
PubMed1995

Reducing escape behavior and increasing task completion with functional communication training, extinction, and response chaining.

The effects of functional communication training, extinction, and response chaining on 3 subjects' escape-maintained aberrant behavior were evaluated using a multielement design. Functional communication training consisted of teaching subjects a verbal response that was functionally equivalent to their aberrant behavior. Subjects initially were allowed to escape from a task contingent on the trained verbal response. In subsequent treatment phases, escape was contingent on the trained verbal response plus the completion of the specified number of steps in the task (response chaining). The number of steps was increased until a subject completed the task to obtain a break. Results showed that the treatment reduced rates of aberrant behavior and that the chaining procedure was effective in decreasing the availability of escape.

Adolescent↗
PubMed1995

Evaluation of the circle of Willis with three-dimensional CT angiography in patients with suspected intracranial aneurysms.

PURPOSE: To determine the usefulness of CT angiography in the setting of suspected acute subarachnoid hemorrhage or intracranial aneurysm. METHODS: We prospectively studied 68 patients suspected of having subarachnoid hemorrhage or an intracranial aneurysm with noncontrast CT of the head followed immediately by contrast-enhanced helical CT of the circle of Willis with three-dimensional reconstruction. Twenty-seven patients with CT findings positive for subarachnoid hemorrhage or intracranial aneurysm were evaluated with digital subtraction angiography or MR angiography within 12 hours of CT angiography. Patients with negative CT/CT angiography findings were followed up with lumbar puncture. RESULTS: CT angiography showed 23 of 24 aneurysms and 2 of 2 arteriovenous malformations (sensitivity, 96%; specificity, 100%). Aneurysm size ranged from 2 to 40 mm (mean, 7.9 mm). Interobserver variability was 10%. In the 23 cases of subarachnoid hemorrhage, cisternal blood did not limit the three-dimensional reconstruction. Two patients with aneurysms on CT angiography had normal noncontrast scans. CONCLUSIONS: CT angiography of the circle of Willis is a useful technique for evaluation of suspected acute subarachnoid hemorrhage and intracranial aneurysm. It provides anatomic display of intracranial aneurysms, allowing for planning of conventional angiography and surgical approach. In selected cases, CT angiography may eliminate the need for preoperative conventional angiography.

Adolescent↗
PubMed1994

Oral absorption of omega-3 fatty acids in patients with cystic fibrosis who have pancreatic insufficiency and in healthy control subjects.

Dietary supplementation with fish oils high in the omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, may have an antiinflammatory effect. We determined whether patients with cystic fibrosis (CF) could incorporate omega-3 fatty acids into their plasma and cell membrane phospholipids without adverse effects. In this double-blind study, 12 patients with pancreatic insufficiency who have CF (mean age, 12.2 +/- 5.4 (SD) years) and 13 subjects without CF (mean age, 13.4 +/- 6.3 (SD) years) were randomly assigned to ingest 8 gm daily of either encapsulated fish oil (3.2 gm of eicosapentaenoic acid and 2.2 gm of docosahexaenoic acid daily) or olive oil ethyl esters for 6 weeks. Two of seven and two of five patients with CF who received fish and olive oils, respectively, and one of eight and none of five subjects without CF discontinued taking the capsules before 6 weeks because of eructation or diarrhea. Significant incorporation of omega-3 fatty acids into plasma and erythrocyte membrane phospholipids was observed in subjects with and those without CF randomly assigned to the fish oil treatment. For example, in subjects randomly assigned to receive fish oil, the eicosapentaenoic acid/arachidonic acid ratio in plasma increased 9.8-fold, from 0.04 +/- 0.02 (mean +/- SEM) to 0.39 +/- 0.11 (p = 0.02), in the patients with CF (n = 7) and 23.0-fold, from 0.04 +/- 0.01 to 0.92 +/- 0.17 (p = 0.001), in the subjects without CF (n = 8) who received fish oil (p = 0.02, patients with CF vs subjects without CF at 6 weeks). No clinically or statistically significant changes from baseline were observed in platelet aggregation or levels of vitamin E or A in subjects who received fish oil. Future studies are indicated to determine whether omega-3 fatty acid enrichment provides a clinically beneficial antiinflammatory effect in patients with CF.

Adolescent↗
PubMed1988

Lethal osteogenesis imperfecta associated with 46,XY,inv(7)(p13q22) karyotype.

An infant who died of complications of osteogenesis imperfecta (OI) at 22 days of age had a 46,XY,inv(7)(p13q22) karyotype. His mother carried the same inversion. One breakpoint of the inversion was within the region of the gene for alpha 2(I) procollagen. The product of this gene is a component of type I collagen, the principal collagen synthesised by osteoblasts. Karyotypic abnormalities involving type I collagen gene sites have not previously been reported in association with OI.

Chromosome Aberrations↗
PubMed1982

The latex agglutination test versus counterimmunoelectrophoresis for rapid diagnosis of bacterial meningitis.

A modified latex agglutination (LA) test was compared with Gram-staining and counterimmunoelectrophoresis (CIE) for the rapid detection in the cerebrospinal fluid (CSF) of antigen to Haemophilus influenzae type b, Neisseria meningitidis groups A, B and C, Escherichia coli K1, Streptococcus pneumoniae and group B streptococci, seven frequent causes of bacterial meningitis in children. Of 50 CSF samples from patients with culture-proven bacterial meningitis 90% were correctly shown by the LA test to contain antigen of the responsible organism. Gram-staining revealed organisms in 80% of 45 of these samples. In 75% of the 40 samples that were of sufficient volume for CIE, positive results for the appropriate antigen were obtained. The concentration of antigen detected in the CSF by the LA test varied from undetectable to 800 000 ng/ml. Patients with a high concentration (more than 2000 ng/ml or a positive result at dilutions of CSF over 1/8) were significantly more likely to have a poor response to therapy (two died and two had persistent pleocytosis or bacteria in the CSF) than patients with a lower concentration (4/16 v. 0/18, P < 0.05). After appropriate therapy was begun the concentration of antigen fell dramatically, but measurable amounts of antigen persisted in the CSF for up to 6 days. The LA test detected bacterial antigen at concentrations 2 to 70 times below the lower limit detected by CIE. In seven additional patients who had received antibiotics before lumbar puncture was performed the LA test detected antigen from meningitis-causing bacteria even though cultures of the CSF were sterile. In another 145 patients who did not have meningitis the results of the LA test were negative. The LA test, done as described in this article, is easier to perform than CIE and should be a useful addition to the diagnostic tests carried out on the CSF of any patient suspected of having meningitis.

Antigens, Bacterial↗