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Biomedical subjects

B King

Publications and source records attributed to B King.

At least 55 records · Page 3Linked to original sources

Caprine mucopolysaccharidosis IIID: a preliminary trial of enzyme replacement therapy.

Mucopolysaccharidosis type IIID (MPS IIID) is a lysosomal storage disorder resulting from lack of activity of the lysosomal hydrolase N-acetylglucosamine 6-sulfatase (6S) (EC 3.1.6.14). The syndrome is associated with systemic and central nervous system (CNS) heparan sulfate glycosaminoglycan (HS-GAG) accumulation, secondary storage of lipids, and severe, progressive dementia. In this investigation, caprine MPS IIID, established as a large animal model for the human disease, was used to evaluate the efficacy of enzyme replacement therapy (ERT). Recombinant caprine 6S (rc6S) (1 mg/kg/dose) was administered intravenously to one MPS IIID goat kid at 2, 3, and 4 wks of age. Five days after the last dose, the uronic acid (UA) content and the composition of uncatabolized HS-GAG fractions in the brain of the ERT-treated MPS IIID kid were similar to those from a control, untreated MPS IIID animal. However, hepatic uronic acid levels in the treated MPS IIID kid were approximately 90% lower than those in the untreated MPS IIID control; whereas the composition of the residual hepatic HS-GAG was identical to that in the untreated animal. Marked reduction of lysosomal storage vacuoles in hepatic cells of the treated MPS IIID kid was observed, but ERT had no effect on CNS lesions. No residual 6S activity was detected in brain or liver. This preliminary investigation indicates that other treatment regimens will be necessary to ameliorate MPS III-related CNS lesions.

Animals↗

Telephone therapy for patients with breast cancer.

PURPOSE/OBJECTIVES: To test the value of telephone-administered cognitive-behavioral therapy in a study of patients with breast cancer. DESIGN: Women were assigned randomly to a therapy group or an assessment-only control group. SETTING: A tertiary cancer treatment center serving rural areas of North Dakota and Minnesota. SAMPLE: Women were recruited within three to four months of stage I (n = 27) or stage II (n = 26) breast cancer diagnosis. Age ranged from 30-82 (mean = 51.5 years). Most participants (n = 35) underwent a modified radical mastectomy; 17 underwent a lumpectomy. METHODS: Therapy involved 10 30-minute (or less) telephone sessions. Data that were collected from mailed questionnaires included psychological distress (Profile of Mood States), perceived stress, coping (Coping Response Indices-Revised), quality of life (Medical Outcome Scale), and satisfaction with therapy. Measures were completed at baseline and at 4- and 10-month follow-up intervals. MAIN RESEARCH VARIABLES: Telephone therapy, stress, coping, and quality of life. FINDINGS: With time, women in the therapy and control groups reported reduced stress and improved quality of life. However, significant reductions in some kinds of distress (anxiety, anger, depression, and confusion) were not observed. Most therapy participants liked the telephone treatment sessions but showed only modest improvement (less anxiety and confusion) compared with women in the control group. CONCLUSIONS: Most patients reported being comfortable with the telephone therapy and said that they felt better as a result of it. However, the outcome data showed that telephone therapy--as carried out in this study--produced only modest benefits. Researchers need to consider who is best for delivering such therapy. IMPLICATIONS FOR NURSING PRACTICE: Providing telephone therapy to patients with breast cancer has potential benefits, and nurses may be the appropriate professionals to administer the therapy.

Adaptation, Psychological↗

Imaging of lung cancer with fluorine-18 fluorodeoxyglucose: comparison of a dual-head gamma camera in coincidence mode with a full-ring positron emission tomography system.

Dual-head gamma cameras operated in coincidence mode are a new approach for tumour imaging using fluorine-18 fluorodeoxyglucose (FDG). The aim of this study was to assess the diagnostic accuracy of such a camera system in comparison with a full-ring positron emission tomography (PET) system in patients with lung cancer. Twenty-seven patients (1 female, 26 males, age 62+/-9 years) with lung cancer or indeterminate pulmonary nodules were studied on the same day with a full-ring PET scanner (Siemens ECAT EXACT) and a coincidence gamma camera system (ADAC Vertex MCD). Sixty minutes after injection of 185-370 MBq FDG, a scan of the chest was performed with the full-ring system. Approximately 2 h p.i., the coincidence camera study was performed. Coincidence gamma camera (CGC) and PET images with (PETac) and without attenuation correction (PETnac) were analysed independently by two blinded observers. In addition, FDG uptake in primary tumours and involved lymph nodes was quantified relative to normal contralateral lung (T/L ratios). All primary tumours were histologically proven. The lymph node status was histologically determined in 23 patients. In four patients, no lymph node sampling was performed because of extensive disease or concurrent illnesses. In the 27 patients, 25 primary lung cancers and two metastatic lesions were histologically diagnosed. The number of coincidences per centimetre axial field of view was 3.33+/-0. 93x10(5) for the CGC and 1.09+/-0.36x10(6) for the dedicated PET system. All primary tumours (size: 4.6+/-2.6 cm) were correctly identified in the CGC and dedicated PET studies. T/L ratios were 4. 7+/-2.5 for CGC and 6.9+/-2.8 for PETnac (P <0.001). Histopathological evaluation revealed lymph node metastases in 11 of 88 sampled lymph node stations (size: 2.3+/-1.0 cm). All lymph node metastases were identified in the PETac studies, while PETnac detected 10/11 and CGC 8/11. For positive lymph nodes that were visible in CGC and PETnac studies, T/L ratios were 3.7+/-2.3 for CGC and 6.6+/-3.1 for PETnac (P=0.02). The diameters of false-negative lymph nodes in the CGC studies were 0.75, 1.5 and 2 cm. False-positive FDG uptake in lymph nodes was found in two patients with all three imaging methods. For all lesions combined, T/L ratios in CGC relative to PETnac studies decreased significantly with decreasing lesion size (r=0.62; P<0.001). In conclusion, compared with a full-ring PET system the sensitivity of CGC imaging for detection of lung cancer is limited by a lower image contrast which deteriorates with decreasing lesion size. Nevertheless, the ability of CGC imaging to detect pulmonary lesions with a diameter of at least 2 cm appears to be similar to that of a full-ring system. Both systems provide a similar specificity for the evaluation of lymph node involvement.

Aged↗

Evidence of large particle allergen inhalation from contact with surfaces.

BACKGROUND: To establish a more accurate relationship between dust mite allergen on surfaces such as bedding with respiratory uptake, an exposure method is needed which correlates exposure of allergen on surfaces with respiratory dose. OBJECTIVES: Assess if aerodynamically large allergen particles (> 10 microm), similar in nature to dust mite allergen, is inhaled into the nose from direct head-and-hand contact with allergen contaminated surfaces. METHODS: Short ragweed pollen (20-microm diameter) was used as a surrogate for dust mite allergen exposure because of its similar aerodynamic and physiologic properties. Pillows and a section of linoleum (followed by a hand press) were embedded with 99MTechnetium labeled pollen. Particles on the linoleum were transferred to the sampler after a hand press to the surface. Simulated human exposure was performed by surface-sampling particles, at a capture velocity of the nose, onto a filter. Human evaluation of hand transfer to the nose or direct inhalation from a pillow was performed with three subjects. Percentage respiratory uptake and deposition location was determined by gamma camera imaging. RESULTS: Simulated respiratory uptake of pollen by hand-to-nose transfer and directly off pillows was 20% and 1.4%, respectively. Human subject respiratory uptake by hand-to-nose transfer and directly off pillows was 6.6% and 1.5%, respectively. Most of the regional activity was found immediately in the nasal vestibule with 13% to 39% of the total activity localized in the pharyngeal region. CONCLUSIONS: Aerodynamically large allergen particles (pollen) are inhaled and deposited into the anterior nose and pharyngeal areas of the respiratory tract from direct contact with allergen-containing surfaces.

Administration, Inhalation↗

A soiling system for evaluation of house dust, allergens, and lead retention on carpets and other surfaces.

Artificial soiling of carpeted or other floor surfaces has several important applications in human exposure assessment and textile research including evaluation of textile properties, sampling devices, and cleaning regimens. A method was developed and validated to deposit uniform and reproducible known quantities of house dust, allergens, and leaded dust on carpets. The soiling apparatus consisted of a 100 cm x 60 cm inclined steel track and a plastic cylinder, with a series of staggered holes, that contains a known volume of reference house dust. After deposition, the dust is embedded by dragging a steel rod over the carpet surface. Deposition tests were performed with bulk house dust, sodium chloride, and house dust with reference quantities of dust mite allergen and lead. The apparatus deposited equivalent (arithmetic mean) amounts of dust, sodium chloride, and dust mite allergen on the front and back halves of test carpets. The introduction of inert fumed silica to the reference sample aided in dispersal of dust over test surfaces. Little to no variation in mean deposition was found within or between 4 days of testing. Using a grid containing weighing boats under the apparatus, spatial deposition was found to vary across a 92 x 46 cm surface by 13 percent. The apparatus deposited reproducible mean quantities of bulk dust on test surfaces from 7 g/m2 to 28 g/m2 with a coefficient of variation ranging from 4-6 percent. The apparatus could be altered to deliver smaller or larger amounts of dust.

Allergens↗

Treatment costs of directly observed therapy and traditional therapy for Mycobacterium tuberculosis: a comparative analysis.

OBJECTIVE: Treatment of tuberculosis is a time-consuming and expensive process, often complicated by patient non-adherence. Directly observed therapy (DOT), an out-patient management strategy designed to ensure adherence, is not widely used because it is perceived to be too expensive. This study compared costs of tuberculosis treatment in DOT to the same factors in traditional therapy. DESIGN: A retrospective economic evaluation of 659 tuberculosis cases was reported to a major metropolitan county public health department between 1980 and 1994. Out-patient costs, in-patient costs and the cost impact of relapse and acquired resistance were estimated in 1995 dollars. RESULTS: Treatment costs were lower with DOT: $15,670 per case for in-patient care and $700 per case for out-patient care (P < 0.001). These cost differences resulted from shorter therapy duration (334 vs 550 days), fewer patient hospitalizations (58 vs 75%) and shorter hospital stays (26 vs 55 days per hospitalized patient). Relapse or acquired resistance occurred in 10.9% of patients and accounted for 35.7% of cost with traditional therapy, as compared to 1.2% of patients and 6.0% of cost with observed therapy. CONCLUSIONS: Directly observed therapy is less costly than traditional therapy.

Adolescent↗

Local treatment of prosthetic vascular graft infection with multivesicular liposome-encapsulated amikacin.

BACKGROUND: Contaminated surgical fields limit the use of prosthetic vascular grafts. We studied the efficacy of sustained-release amikacin applied locally to contaminated grafts in the prevention of infectious complications. MATERIALS AND METHODS: Thirty-one New Zealand white rabbits underwent placement of a polytetrafluoroethylene (PTFE) interposition graft in a 1-cm segment of the descending aorta. The surgical field was infected with application of 10(5) to 10(8) Staphylococcus aureus organisms suspended in normal saline solution. Nineteen rabbits underwent contaminated aortic graft placement without treatment. Twelve rabbits were treated with local application of 2.5 ml of amikacin encapsulated in lipid particle-based sustained-release dosage form. Rabbits were observed for 2 weeks and then evaluated for the presence of graft infection. RESULTS: Seventy-five percent of the treated rabbits survived without evidence of graft infection or systemic sepsis versus 37% in the untreated group (P < 0.04). Cultures verified the absence of organisms in all surviving rabbits without clinical infection. CONCLUSIONS: Sustained-release lipid particle-encapsulated amikacin applied to contaminated PTFE grafts increased survival and decreased postoperative graft infections. Adjunctive use of local, delayed-release antibiotics in contaminated vascular beds may allow wider clinical use of prosthetic grafts.

Amikacin↗

An explanatory model of the dental care utilization of low-income children.

OBJECTIVES: Factors related to the utilization of dental care by 5- to 11-year-old children from low-income households were investigated using a comprehensive multivariate model that assessed the contribution of structure, history, cognition, and expectations. The influence of dentist-patient interactions, psychosocial and health beliefs, particularly fear of the dentist, on utilization were investigated. METHODS: Children were chosen randomly from public schools, and 895 mothers were surveyed and their children were interviewed in the home. Utilization was studied during the 1991-1992 school year, including a 6-month follow-up period after the interview. RESULTS: The overall utilization rate was 63.2%, and the rate for nonemergent (preventive) visits was 59.9%. Utilization was unrelated to actual oral health status. Race and years the guardian lived in the United States were predictive of an episode of care. Preventive medical visits and perceived need were strong predictors of a visit to the dentist, as were beliefs in the efficacy of dental care. Mothers who were satisfied with their own care and oral health and whose children were covered by insurance were more likely to utilize children's dental care. In contrast, child dental fear and absences from school for family problems were associated with lower rates of utilization. CONCLUSIONS: Mutable factors that govern the use of care in this population were identified. These findings have implications for the design of dental care delivery systems for children and their families.

Adult↗

Proton MR spectroscopy in Lesch-Nyhan disease.

In vivo proton spectra for four patients with Lesch-Nyhan disease and four control subjects matched for age and sex were acquired from voxels (1.5 x 1.5 x 1.5 cm3) placed in the prefrontal cortex and striatum. The patients with Lesch-Nyhan disease had decreased metabolites, especially N-acetylaspartate and glutamate/glutamine, only in the prefrontal cortex as compared with the control group. These findings suggest axonal loss in the prefrontal area of this population. The cortical glutamate/glutamine peak decrement does not confirm cytopathologic studies of Lesch-Nyhan disease and deserves further investigation.

Adolescent↗

A role for calcineurin in the desensitization of the P2X3 receptor.

The sensory neurone-specific ATP-gated cation channel P2X3, when expressed in Xenopus oocytes, desensitizes rapidly. Complete removal of extracellular calcium abolishes desensitization. Pretreatment of oocytes with cyclosporin also abolishes P2X3 desensitization. When the calcineurin auto-inhibitory peptide (CaN A457-481) was injected into oocytes, the rate of desensitization of P2X3 decreased on consecutive applications of ATP, suggesting a role for calcineurin in the regulation of desensitization. Truncated P2X3 clones initiating at Met-75 lack the N-terminal intracellular region, but express functional channels in oocytes that do not desensitize. Taken together, these data suggest that P2X3 desensitizes through a calcium-dependent calcineurin-mediated dephosphorylation involving N-terminal residues that are phosphorylated in functional channels.

Animals↗

Assessment of intraaxial and extraaxial brain lesions with digitized computed tomographic images versus film: ROC analysis.

RATIONALE AND OBJECTIVES: The authors evaluated the diagnostic accuracy of viewing computed tomographic (CT) scans as film versus soft-copy images at a workstation. METHODS: Receiver operating characteristic analysis of the interpretation of 202 CT scans (103 were normal, 99 were abnormal) by five neuroradiologists was performed. Abnormal images contained high- or low-attenuation intraaxial lesions or extraaxial fluid (subdural, subarachnoid, or epidural hemorrhage). Hard copies were read on a standard light box, and digital images were examined at a 1,024 x 1,250 workstation. Lesion location and type and confidence ratings were recorded on a worksheet. RESULTS: There were no statistically significant differences in diagnostic accuracy between the two display modes. Reader performance was slightly better with the workstation in the assessment of low-attenuation lesions. CONCLUSION: Diagnostic accuracy is similar for CT scans displayed at a workstation and those displayed as hard copy in the assessment of subtle intra- and extraaxial brain lesions.

Brain↗