Factors influencing blood viscosity: adult and newborn blood analysis.

Our finding of a decrease in blood viscosity in newborn infants compared with adults leads to analysis of this change by measuring blood viscosity, plasma fibrinogen concentration, plasma viscosity and mean corpuscular volume (MCV) of 24 adults and 16 newborn infants. Plasma proteins in newborn infants are synthesized to a lesser extent than in adults, therefore plasma fibrinogen concentration of newborn infants is less than that of adults. This causes decreased blood viscosity in newborn infants compared with adults. Secondly plasma viscosity of newborn infants is also less than that of adults. In the same situation this causes a decrease in blood viscosity in newborn. Thirdly. MCV of newborn infants is greater than that of adults because of young red cells. There is a negative correlation between blood viscosity and MCV. High MCV in newborns leads to low blood viscosity in newborn infants, compared with adults.

Acetylcholinesterase activities in cerebrospinal fluid of patients with Plasmodium falciparum cerebral malaria.

Serum cholinesterase (CHE) and acetylcholinesterase (ACHE) in cerebrospinal fluid (CSF) were determined simultaneously in 30 patients with P. falciparum cerebral malaria. Nineteen patients (63%) had low serum CHE and mean value of this serum enzyme in 30 patients was significantly lower than that of non-infected group. CSF ACHE levels were found to be significantly lower than those of normal subjects reported earlier. Post-treatment in the hospital for one week, both serum CHE and CSF ACHE levels in 9 convalescent subjects increased significantly. These findings indicated that both serum CHE and CSF ACHE levels were depressed in patients with cerebral malaria and increased on recovery.

Serum cholinesterase activity in patients with malaria infection.

Serum cholinesterase activities were determined in 87 patients of both sexes with P. falciparum malaria in comparison to those of 80 blood donors. Patients with acute P. falciparum malaria had significantly lower serum cholinesterase activity than those of the control group. After treatment, their serum cholinesterase levels returned to the normal level. Serum albumin concentration also showed the same pattern and had a direct relationship to those of serum cholinesterase levels. These findings indicated that malarial parasites had some effect on the liver cells which resulted in impaired hepatic synthesis of serum cholinesterase and albumin concentrations. This result therefore add new information that there was a disturbance of enzyme cholinesterase among many liver enzymes that have been shown to be altered during an acute malarial attack.

Serum vitamin B12, serum and red cell folates, vitamin B12 and folic acid binding proteins in women taking oral contraceptives.

Serum and red cell folate, FABP, serum vitamin B12 and vitamin B12 binding proteins were determined in 20 women taking oral contraceptives continuously for at least one year. Studies were also performed on 50 apparently healthy women with history of never taken or not taking oral contraceptives for at least one year as a control group. Serum vitamin B12 level, UBBC and TBBC in women taking oral contraceptives were slightly but not significantly lower than those of the control group. TCI and TCIII increased with a decreased TCII, so that UBBC was within the normal limit. Serum folate was non-significantly lower while red cell folate was significantly lower in the oral contraceptive group than those of the control group. However, all cases of the former showed red cell folate over 200 ng/ml. A highly significant increased serum FABP was demonstrated in the women taking oral contraceptives. This was probably due to the increased synthesis of the FABP in order to bind more folate from the low serum folate and the hormonally induced stimulation.