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Biomedical subjects

B Anderson

Publications and source records attributed to B Anderson.

At least 145 records · Page 8Linked to original sources
PubMed1996

Analgesic efficacy of paracetamol in children using tonsillectomy as a pain model.

The analgesic efficacy of paracetamol was assessed in a prospective, randomized, double-blinded study of 100 children undergoing tonsillectomy with or without adenoidectomy. Fifty children were given paracetamol elixir 40 mg/kg 40 minutes preoperatively (Group A); the remaining 50 children were given an oral placebo 40 minutes preoperatively and paracetamol suppositories 40 mg/kg after induction of anaesthesia (Group B). Paracetamol was the only analgesic given and was given either orally or rectally in order to produce high variations in plasma paracetamol concentrations postoperatively. At 30 minutes after the end of surgery a pain score (0-10) was obtained and a venous blood sample was taken for serum paracetamol concentration analysis. Children given paracetamol elixir had a higher mean paracetamol concentration (0.15 [SD 0.06] mmol/l vs 0.05 [SD 0.03] mmol/l, P < 0.001) and a lower median pain score (5 vs 7, P < 0.02) than those who were given suppositories. The use of rescue morphine was higher (10 vs 23, P < 0.001) in the latter group. The incidence of nausea and vomiting was the same in both groups (20%) during the 24 hour postoperative period. Plasma paracetamol concentrations of 0.066-0.132 mmol/l are known to reduce temperature; plasma paracetamol concentrations which provide analgesia are unknown. Children with plasma paracetamol concentrations above 0.07 mmol/l had superior analgesia to those with concentrations below this level (P < 0.05).

Acetaminophen↗
PubMed1996

Substance-use and psychiatric disorders among American Indian veterans.

Native American (NA) veterans have rarely been the focus of investigational efforts. We review studies relevant to an assessment of NA substance-use disorders, and discuss findings of the Drug Abuse Treatment Services Evaluation Project pertaining specifically to NA veterans. A larger proportion of NA veterans discharged from VA inpatient care in FY93 were diagnosed with a substance-use disorder compared to the total population of veterans discharged that year. Substance-dependent NAs were more likely to be diagnosed with alcohol-use disorders and posttraumatic stress disorder, and less likely to be diagnosed with drug-use disorders and other psychiatric disorders than substance-dependent veterans generally.

Adult↗
PubMed1996

Caring for children with special needs in HMOs: the consumer's perspective.

HMOs should design and include in their services case management systems and health plan policies that meet the special needs of children with chronic illness and their families. Information provided by the plan on case management support and access to specialty care services is critical in helping families choose HMOs that can best serve their child. A child advocate illustrates certain steps, including partnership roles, that health plans can take to assist families with children with special needs.

Case Management↗
PubMed1996

Treatment outcome of squamous cell carcinoma of the oral tongue.

Treatment outcome was retrospectively assessed in 106 patients with squamous cell carcinoma of the oral tongue registered in the population-based Manitoba Cancer Registry between January 1979 and December 1992. Twenty-six percent were diagnosed with stage I lesions, while 33%, 16%, and 24% were stage II, III, and IV, respectively. Most patients with stage I and II disease were treated with either surgery alone (57%) or in combination with radiotherapy (29%). Advanced lesions were generally treated with radiotherapy alone (37%) or in combination with surgery (35%). Actuarial survival at 5 years was 44% for all patients, and 64%, 46%, 42%, and 16% for stages I to IV, respectively. Over 90% of the 35 treatment failures occurred within 24 months. The initial sites of recurrence were the neck in 22 patients, the primary site in 16 patients, and distant metastases in 5 patients. At the time of death, disease was present above the clavicles in 62%, and metastases were identified in 22%. Locoregional control remains a significant problem in oral cancer. Elective treatment of the neck, resection of the primary with negative surgical margins, and the use of combined modality treatment in advanced stages of disease may help reduce treatment failure.

Adult↗
PubMed1996

Cat scratch disease: detection of Bartonella henselae DNA in archival biopsies from patients with clinically, serologically, and histologically defined disease.

Serological and epidemiological studies suggest that Bartonella henselae is the etiological agent of cat scratch disease. We designed a study to detect B. henselae in archival biopsies by polymerase chain reaction amplification of the 16S rRNA gene followed by Southern blot hybridization. Forty-two histologically defined cat scratch disease biopsies and eighteen controls were selected for blinded analysis. After testing, charts were reviewed for clinical, immunological, and microbial evidence of infection. Results were correlated with duration of illness and antimicrobial therapy. B. henselae DNA was identified in 27 of 42 (64%) histologically defined patients and 23 of 34 (68%) patients defined both clinically and histologically. There were no false positives (0 of 18). A small subset (n = 14) had cat scratch disease serological tests performed. B. henselae was identified in 8 of 10 serologically positive patients. Polymerase chain reaction detected 50% of our DNA-positive cases (most of these early in the clinical course). Southern blotting of amplicons both doubled sensitivity (detecting patients > 4 weeks into illness) and confirmed B. henselae as the causative species. Our study strongly associates B. henselae with cat scratch disease, suggesting that it may be the most likely etiological agent in the majority of patients with cat scratch disease.

Adolescent↗
PubMed1996

Anti-free radical mechanisms in captopril protection against reperfusion injury in isolated rat hearts.

OBJECTIVE: Captopril, an angiotensin-converting enzyme (ACE) inhibitor, is known to modulate ischemia-reperfusion injury in the isolated hearts. This study was designed to examine the involvement of anti-free radical mechanisms in this protection. METHODS: Isolated perfused rat hearts were subjected to 60 mins of global ischemia and 30 mins of reperfusion with or without captopril (100 mumol/L). Myocardial resting tension and contractile force were recorded. At the end of reperfusion, hearts were analyzed for the activities of antioxidant enzymes, superoxide dismutase, glutathione peroxidase and catalase, as well as for the extent of lipid peroxidation. Another potent ACE inhibitor, enalapril (100 mumol/L) was used for comparison. RESULTS: Captopril significantly improved the recovery of contractile function as well as attenuated the rise in resting tension in the ischemic-reperfused hearts as compared to the control. Captopril-exposed ischemic-reperfused hearts showed an increase in the activity of superoxide dismutase with no change in glutathione peroxidase and catalase enzyme activities. Lipid peroxidation at the end of reperfusion was significantly attenuated in the captopril-exposed hearts compared to the control. Enalapril had no protective effect against ischemia-reperfusion induced contractile failure or rise in resting force. CONCLUSIONS: These results suggest that cardioprotection by captopril, against ischemia-reperfusion injury, may involve an anti-free radical mechanism independent of its ACE inhibition property.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

Kinetic characterization and cross-resistance patterns of HIV-1 protease mutants selected under drug pressure.

Eleven different recombinant, drug-resistant HIV-1 protease (HIV PR) mutants--R8Q, V32I, M46I, V82A, V82F, V82I, I84V, V32I/I84V, M46I/V82F, M46I/I84V, and V32I/K45I/F53L/A71V/I84V/L89M--were generated on the basis of results of in vitro selection experiments using the inhibitors A-77003, A-84538, and KNI-272. Kinetic parameters of mutant and wild-type (WT) enzymes were measured along with inhibition constants (Ki) toward the inhibitors A-77003, A-84538, KNI-272, L-735,524, and Ro31-8959. The catalytic efficiency, kcat/Km, for the mutants decreased relative to WT by a factor of 1.2-14.8 and was mainly due to the elevation of Km. The effects of specific mutations on Ki values were unique with respect to both inhibitor and mutant enzyme. A new property, termed vitality, defined as the ratio (Kikcat/Km)mutant/(Kikcat/Km)WT was introduced to compare the selective advantage of different mutants in the presence of a given inhibitor. High vitality values were generally observed with mutations that emerged during in vitro selection studies. The kinetic model along with the panel of mutants described here should be useful for evaluating and predicting patterns of resistance for HIV PR inhibitors and may aid in the selection of inhibitor combinations to combat drug resistance.

Amino Acid Sequence↗
PubMed1995

Evaluation of hyperbaric oxygen as a chemosensitizer in the treatment of epithelial ovarian cancer in xenografts in mice.

BACKGROUND: Resistance to chemotherapy is common in bulky hypoxic tumors such as epithelial ovarian cancer. Hyperbaric oxygen (HBO) oxygenates hypoxic tissues and promotes neovascularization. These unique properties of HBO may help overcome chemotherapy resistance by increasing both tumor perfusion and cellular sensitivity. This study was undertaken to determine if HBO increases the response of epithelial ovarian cancer to cisplatin chemotherapy. METHODS: In Phase I, 64 nu/nu mice were divided into four groups and subcutaneously inoculated with cells from the A2780 human epithelial ovarian cancer cell line. Group 1 served as controls. Group 2 received weekly intraperitoneal cisplatin (3.15 mg/kg). Group 3 was exposed to HBO (dives) at 2.4 atmospheres absolute pressure for 90 minutes, 7 days a week. Group 4 received both cisplatin and HBO. In Phase II, 72 mice were divided into two groups and similarly inoculated. Both groups received weekly intraperitoneal cisplatin (2.5 mg/kg). Group 1 was not exposed to HBO. Group 2 was exposed to HBO for 5 days a week. RESULTS: Dramatic tumor neovascularization was found in tumors of mice exposed to HBO (P = 0.0001). There was significant (P = 0.014) tumor growth retardation in Phase I for mice receiving both cisplatin and HBO compared with those treated with cisplatin alone. This significance was noted after just two doses of cisplatin but subsequently lost due to reduced numbers of mice. In Phase II, neovascularization was detectable after 10 HBO treatments (2 weeks) and was maximal after 15 treatments (3 weeks). CONCLUSIONS: Hyperbaric oxygen increases vascularity in bulky tumors such as epithelial ovarian cancer. There appears to be a relationship between increased vascularity and enhanced response to chemotherapy that merits further investigation.

Animals↗
PubMed1995

Prevalence and geographic genetic variation of hantaviruses of New World harvest mice (Reithrodontomys): identification of a divergent genotype from a Costa Rican Reithrodontomys mexicanus.

We recently described a novel hantavirus (HMV-1) of the western harvest mouse Reithrodontomys megalotis. Screening of 181 additional specimens of Reithrodontomys from the United States and Mexico, including samples of R. mexicanus, R. sumichrasti, and R. gracilis of Costa Rica, for antibodies to hantavirus nucleocapsid protein revealed a widespread enzootic of hantavirus infection. Genetic analyses of 7 S genomes of Reithrodontomys-associated hantaviruses demonstrated that the enzootic of HMV-1 extends from central Mexico into the southwestern United States. A presumed deer mouse hantavirus was found in an R. megalotis animal in Mexico. A highly divergent HMV-1-like virus, tentatively called HMV-2, was identified in a Costa Rican R. mexicanus. These data suggest a longstanding radiation of hantaviruses among New World harvest mice. We identify possible opportunities for genetic exchange among hantaviruses of related rodent hosts.

Animals↗
PubMed1995

Does recruitment method make a difference? Effects on protocol retention and treatment outcome in elderly depressed patients.

The specific aim of this study was to contrast effects of recruitment method (solicited, referred) on demographic, psychosocial, medical, and treatment outcome measures in an ongoing clinical trial of maintenance therapies in late-life depression. Data from 125 elderly patients (56 solicited via media campaign, 69 clinically referred) with recurrent, unipolar major depression were available for analysis. Several statistical contrast procedures, including group t tests, chi 2 tests, survival analysis, and logistic regression, were used to assess differences in patient profiles related to method of recruitment. Referred patients included a higher proportion of African Americans and had a lower level of education, fewer economic resources, and higher chronic medical burden. Solicited patients had been in the index episode longer than the referred patients at the time of protocol entry and were 3.4 times more likely to have experienced a "provoking agent" (severe life event or chronic difficulty) during the 6 months that preceded the onset of depressive symptoms. In contrast to these demographic and illness history differences, there were no differences in treatment response rates or time to response related to recruitment method. Solicited patients had an overall treatment response rate of 71% versus 62% in the referred group. Median time to response was 14.3 weeks in the solicited group and 13.6 weeks in the referred group. These results suggest that the inclusion of solicited patients in geriatric depression clinical trials does not bias short-term treatment outcome.

Adjustment Disorders↗
PubMed1995

Stage I squamous cell cervical carcinoma in pregnancy: planned delay in therapy awaiting fetal maturity.

PURPOSE: It is not known whether intentional delay to allow fetal maturity in patients with Stage I cervical carcinoma diagnosed during pregnancy will affect the survival of these patients. The purpose of this study is to report our experience with invasive squamous cervical carcinoma after planned delay in therapy for fetal indications, to assess maternal morbidity due to treatment delay, and to report maternal and fetal survival. METHODS: Between 1989 and 1994, eight pregnant women with Stage I squamous cervical carcinoma, who declined immediate therapy in order to improve fetal outcome, were prospectively followed until the late third trimester. Serial MRIs were used to follow the lesion in two patients. RESULTS: Stage IB cervical cancer was diagnosed in seven pregnant women. All lesions were less than 2.5 cm. The mean diagnosis-to-treatment interval was 109 days (range, 21-201; median, 112). One woman conceived in the cycle after diagnosis and had a diagnosis-to-treatment interval of 282 days. All were delivered by cesarean section-radical hysterectomy late in the third trimester. There was no clinical progression of disease detected during any of the pregnancies. Serial MRI examination confirmed stable disease in one patient and suggested an increase in tumor volume in one patient that was not pathologically confirmed. All are alive and disease free after a mean follow-up of 37 months (range, 13-68; median, 33). Neonatal morbidity was encountered in one infant (spontaneous pneumothorax). CONCLUSIONS: With a median follow-up of 33 months, patient-requested delays in therapy between 3 and 40 weeks (mean, 19) did not affect progression.

Adult↗
PubMed1995

Isolation and preliminary characterization of an ovarian carcinoma cell line from a patient with familial ovarian cancer.

An epithelial ovarian cancer cell line is established from a patient with recurrent familial ovarian cancer. Two of the patient's sisters and her mother have also had ovarian cancer. The histological resemblance of the cell line to the patient's Stage IV, Grade 3 papillary serous ovarian primary cancer is striking. The cell line does not secrete CA125 and is estrogen and progesterone receptor negative. Overexpression of the p53 tumor suppressor gene but not the HER-2/neu oncogene was detected by immunohistochemical analysis. An unusual chemosensitivity to cisplatin, doxorubicin, etoposide, and taxol is demonstrated, suggesting that a chemosensitivity mechanism might explain prolonged survival of some patients with familial ovarian cancers. This truly unique cell line should prove invaluable in the further evaluation of molecular genetic changes associated with familial ovarian cancers.

Antineoplastic Agents↗
PubMed1995

Steroid hormone receptor content and lymph node status in endometrial cancer.

The purpose of this study was to correlate the steroid hormone receptor status in endometrial adenocarcinoma with tumor metastasis to the pelvic and para-aortic lymph nodes, and with other known prognostic variables which influence survival. Tumor samples from 85 patients with endometrioid adenocarcinoma, or adenocarcinoma with squamous differentiation of the endometrium who underwent complete surgical staging, were assayed for cytoplasmic steroid hormone receptors using a dextran-coated charcoal technique. Steroid hormone receptor content was correlated to lymph node status, along with other prognostic variables, such as patient's age, depth of myometrial invasion, tumor grade, and pelvic cytology. By univariate analysis, the likelihood of nodal involvement was associated with younger age and poorly differentiated tumors. Multivariate analysis revealed that age, tumor grade, and myometrial involvement added significant independent prognostic information. Estrogen or progesterone receptor content did not add independent prognostic information concerning lymph node status once other factors were controlled. Knowledge of estrogen and progesterone receptor binding status in adenocarcinoma of the uterus does not replace the prognostic information imparted by careful sampling of lymph nodes.

Adenocarcinoma↗