PubMed Health⌕ Search

Biomedical subjects

P J Kirk

Publications and source records attributed to P J Kirk.

6 recordsLinked to original sources
PubMed1977

Twice weekly prophylactic therapy in haemophilia A.

Factor VIII-containing materials were administered to four severely affected haemophiliacs twice weekly in doses calculated to raise the factor VIII level to either 15% or 30% of average normal. The pooled results from those patients with statistically similar baseline bleeding frequencies showed a significant reduction in bleeding frequency on both doses in the first 48 hours. The 30% dose produced a more significant reduction than the 15% dose in the first 24 hours, but there was no significant difference between the two doses in the second 24 hours. It appears that to reduce the bleeding frequency of severely affected haemophiliacs by 60% would require a two-and-a-half-fold increase in therapeutic materials. A 90% reduction would need nine times the amount of material currently in use.

Child↗
PubMed1977

Cardiovascular responses of men and women to lower body negative pressure.

Changes in blood flow and blood redistribution were measured by impedance plethysmography in the pelvic and leg regions of six male and four female subjects during three 5-min exposures to -20, -40, and -60 mm Hg lower body negative pressure (LBNP). Female subjects demonstrated significantly higher mean heart rate and lower leg blood flow indices than the male subjects during the recumbent control periods. Men had slightly higher mean resting systolic and diastolic blood pressures and higher mean control pelvic blood flow indices. Women demonstrated significantly less blood pooling in the legs and slightly less in the pelvic region than the men. All of the 18 tests with male subjects at -60 mm Hg were completed without initial signs of syncope, while only two of the tests with women were completed successfully without the subject exhibiting presyncopal conditions. The results of this study indicate that impedance plethysmography can be used to measure segmental cardiovascular responses during LBNP and that females may be less tolerant to -60 mm Hg LBNP than males.

Atmospheric Pressure↗
PubMed1976

Prophylaxis in haemophilia: a double-blind controlled trial.

A double-blind controlled trial of prophylactic factor VIII therapy has been carried out on nine severe haemophiliacs at the Lord Mayor Treloar College. Infusions were given once weekly and calculated to give a post-infusion plasma concentration of at least 0.25 I.U./ml of factor VIII. This regime reduced the overall bleeding frequency by 15%. The bleeding frequency in the first 3 days post-infusion was reduced by 66%. A moderate overall reduction in morbidity was also achieved. It is calculated that to reduce the incidence of bleeding in severe haemophiliacs by 15% would require a 73% increased usage of therapeutic materials. More than twice this amount of material is likely to be needed to reduce the bleeding frequency of the same group by 66%.

Adolescent↗