Biomedical subjects
Publications and source records attributed to H C Clarke.
This report describes the use of the Clarke ligator (knot-pusher) and lists its recent applications. Laparoscopic suturing is simplified by the use of a new technique allowing any size curved needle to be inserted through a 5-mm puncture site.
Tips of synthetic and natural condoms were filled with serum samples containing either hepatitis B virus, herpes simplex virus, or cytomegalovirus, then fit over an 8-in. mechanical vibrator and inserted vibrating into sterile bath solutions for 30 min. Phosphorus 32-labeled hepatitis B and cytomegalovirus molecular probes and viral culture techniques for herpes simplex and cytomegalovirus were used to determine whether leakage of virus had occurred into the surrounding bath solutions. Natural condoms allowed leakage of hepatitis B virus but not herpes simplex virus or cytomegalovirus, whereas synthetic condoms prevented leakage of all viruses. These results suggest that natural condoms might not be effective in preventing sexually transmitted hepatitis B virus infection.
The photodecomposition fluorimetric method has been modified for determination of small quantities of whole blood, erythrocytes, leucocytes, platelets and plasma. The method is accurate in each constituent and contains a test of specificity in each determination. Automation of the method is described. In 13 normal subjects riboflavin in whole blood was range 14.5-24.2, mean 17.7 +/- 2.7 microgram %, in corresponding erythrocytes was range 21.0-44.0, mean 33.7 +/- 6.6 microgram%.
The reliability of the photodecomposition method for riboflavin in various constituents of blood is demonstrated by recovery tests in vivo. In normal subjects no significant rise in whole blood, erythrocyte or plasma riboflavin is detected 2 hours after oral treatment. With intervenous therapy a rise occurs in plasma riboflavin and not in erythrocytes. In kidney disease after oral riboflavin unusually high sustained plasma levels are recorded with no change in erythrocyte levels. Correspondingly higher erythrocyte riboflavin concentration in cord blood as compared to that of maternal blood may indicate greater avidity of new fetal cells for riboflavin.
Riboflavin deficiency is endemic in Trinidad. A syndrome is observed peculiar to pregnancy. It occurs in the second trimester in women with low blood riboflavin levels. Treatment with riboflavin gives clinical improvement in mothers and raises fetal blood levels. Early biochemical diagnosis and treatment of subclinical deficiency is of value to the Trinidadian mother but protection to the fetus is doubtful. This is because of the effect of multiple limiting factors in which the mother is deficient.