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Biomedical subjects

K Chin

Publications and source records attributed to K Chin.

177 records · Page 10Linked to original sources
PubMedDate not supplied

Optimized scanning conditions of high resolution CT in the follow-up of pulmonary emphysema.

PURPOSE: To address the optimal scanning condition of high resolution computerized tomography from the perspective of minimizing exposed dose. METHOD: The influence of the electric current, the slice number, and the slice thickness on precise percent ratio of the low attenuation area to whole lung field (LAA%) of chronic obstructive pulmonary disease patients was examined. The standard conditions were 250 mA, 3 slices, 2 mm slice thickness, and a varied parameter. RESULTS: In cases showing an LAA% less than 30, LAA% obtained by < or =150 mA were significantly larger than those by 250 mA. The mean LAA% with 3 and 10 slices were well correlated and the correlation with lung function was similar. The correlation of LAA% with lung function was approximately the same between the 2 and 5 mm slice thicknesses. CONCLUSION: The electrical current must be > or =200 mA, and 3 slices and 2 mm slice thickness are appropriate.

Electricity↗
PubMedDate not supplied

Relation between increase in length of hip axis in older women between 1950s and 1990s and increase in age specific rates of hip fracture.

OBJECTIVE: To determine whether length of hip axis in elderly women has increased over the past 40 years and, if so, whether the increase may have contributed to the increase in the age adjusted rate of hip fractures during those years. DESIGN: Retrospective assessment of anteroposterior x ray films of the pelvis. SETTING: Radiology department of a rheumatology hospital, New Zealand. PATIENTS: Two cohorts of women aged > 60 (mean 70) who were x rayed on the same apparatus in either the 1950s or the 1990s. MAIN OUTCOME: Length of hip axis (distance from the medial aspect of the pelvis to the lateral aspect of the femur along the axis of the femoral neck), length of femoral neck (length of hip axis excluding the femoral head and more medial structures), and width of femoral neck (see figure). RESULTS: Both the mean length of the hip axis and the mean length of the femoral neck were significantly greater in the women whose x ray films were taken in the 1990s than in those in the 1950s (124.0 mm (SE 1) v 130.5 (1), P = 0.0002; 79.4 (1) v 84.9 (1), P < 0.0001, respectively). The width of the femoral neck did not change, and the lengths expressed as ratios to width were greater in the more recent x ray films, indicating that these findings are not due to an unrecognised change in radiographic technique. CONCLUSIONS: An increase in the length of the hip axis in elderly women in New Zealand during the past 40 years has occurred which is large enough to account for the increase in the age adjusted rate of hip fractures during those years.

Aged↗
PubMedDate not supplied

Central neurogenic hyperventilation with primary cerebral lymphoma: a case report.

We report a case of a bright, alert patient with central neurogenic hyperventilation (CNH) associated with cerebral malignant lymphoma. CNH is a syndrome comprising normal or elevated arterial oxygen tension, decreased arterial carbon dioxide tension, and respiratory alkalosis in the absence of cardiac or pulmonary disease that stimulates a compensatory hyperpnea. A-72-year-old man with recurrent central nervous system lymphoma presented with hyperpnea. showing a respiratory rate over 30 per minute. He was fully awake and conscious. Routine laboratory studies and chest X-ray were normal, but arterial blood gas examination on room air showed respiratory alkalosis, regardless of wakefulness or sleep. Pulmonary infarction was denied by pulmonary flow scintigram. Rebreathing from a paper bag, intravenous administration of diazepam, and oxygen inhalation failed to alter the respiratory pattern. Brain MRI demonstrated two mildly enhanced lesions within the left side of the medulla oblongata and right side of the pons. CNH is rare in patients with normal consciousness. It seems to be caused by brainstem injury that includes the respiratory center.

Aged↗
PubMedDate not supplied

Lack of response to recombinant hepatitis B vaccine in nonresponders to the plasma vaccine.

Yeast recombinant hepatitis B vaccine was administered to 25 nonresponders to the plasma-derived hepatitis B vaccine. After three 10-micrograms doses, nine subjects (36%) produced levels of antibodies to hepatitis B surface antigen (anti-HBs) of less than 2.1 sample ratio units (SRU) (nonresponders), and five (20%) developed anti-HBs of 2.1 to 9.9 SRU (hyporesponders); anti-HBs levels of 10 SRU or greater were detected at least once in 11 vaccinees (44%), but by the sixth and 12th months after the last vaccination, only three and one of these "responders," respectively, still maintained anti-HBs values of 10 SRU or greater. In these 25 subjects HLA subtyping showed a high prevalence of DR7, B8, and the combinations of DR3 and DR7 and DR4 and DR7. Our findings indicate that the yeast recombinant hepatitis B vaccine was not effective in eliciting a sustained anti-HBs response in nonresponders to the plasma hepatitis B vaccine.

Adult↗