Study of hematopoietic progenitor cells, hematological values and lymphocyte subsets in cord blood: application for cord blood transplantation.

Hematological values, lymphocyte subsets and hematopoietic progenitor cells from normal term cord blood samples were studied, compared with normal adult blood, and analysed to determine whether a single collection of cord blood is sufficient for transplantation in adults. The parameters were assayed by automatic cells counter, flow cytometry and semisolid cell culture. All of the hematological values except RBC and MCHC were higher than in normal adult blood. Sex had an influence on RBC, Hb, Hct, Plt and reticulocyte counts. For lymphocyte subsets, all of the absolute CD3+, CD4+, CD8+ counts and T helper: suppressor ratio were higher than those of adult blood. All of the hematopoietic progenitor cells in cord blood were also higher than in adult blood. The mean volume of cord blood for each collection was 80.75 +/- 4.81 ml and the mean numbers of nucleated cells, CFU-GM and CD34+ were 13.51 +/- 0.38 x 10(8) cells, 4.33 +/- 0.66 x 10(5) colonies and 42.65 +/- 7.00 x 10(5) cells respectively. This 80 ml of cord blood would contain sufficient marrow repopulating cells for a recipient weighing about 20 kg. Recently developed technology, including ex vivo expansion may even permit transplants in adults.

Intradermal hepatitis B virus immunization: immunogenicity and reactogenicity.

Mass immunization of hepatitis B virus (HBV) vaccine in adults is frequently demanded. However the high cost of conventional immunization is an obstacle to the provision of this vaccine. We investigated the serological response and adverse reactions following administration of a low-dose (1 or 2 micrograms of yeast-derived HBV vaccine (HB-VAX II, Merck, Sharp and Dohme) intradermally in young adults. Each 1 ml dose of the vaccine contained 10 micrograms of HBsAg protein. The study population included 58 female volunteers, aged 20-33 years, who were serologically-negative for HBV. They were alternately allocated to 1 microgram or 2 micrograms intradermal dose given by 2 experienced nurses as one or two 0.1 ml injections. Doses were given at 0, 1, and 6 months. Anti-HBs concentration was tested by enzyme-immunoassay on their sera obtained at 1, 6, and 7 months after the first dose. Positive seroconversion (anti-HBs greater than 10 IU/1) at 7 months was found in 90% (95% CL 79%, 100%) of the 1 microgram group and 96% (95% CL 89%, 100%) of the 2 micrograms group. Local reaction, a transient pigmented macule with an underlying nodule, was found in most volunteers but did not bother them. Intradermal HBV immunization could be an alternative strategy for mass immunization in young adults.

HBsAg carrier rate among institutionalised children from Phyathai Institute.

To identify the evidence supporting the horizontal transmission of hepatitis B virus, HBsAg carrier rate among institutionalised children is determined and compared to children of the same age-group from the well baby clinic, Ramathibodi hospital. The results of this study show that HBsAg is detected four times more frequently in institutionalised children than in children from a well baby clinic. The chance of becoming an HBsAg carrier increases with age and duration of stay in the institution. Repeated study one year later shows that the HBsAg carrier rate among the same group of institutionalised children had increased by 35 per cent. The evidence supports the hypothesis that hepatitis B virus can be transmitted nonparenterally. To prevent this mode of transmission in both institutions and the community, hepatitis B vaccine should be given to these children.

The value of an indirect hemagglutination test for streptococcal antibodies in children with acute rheumatic fever.

This study was made to evaluate the value of the IHA test for streptococcal antibodies in children with acute rheumatic fever in comparison with the conventional ASO titer. The upper limit titers of ASO and IHA in control group were 170 and 640 respectively. All sera from 37 patients with rheumatic fever had IHA titers over 640. In contrast, the level of ASO titer above upper normal limits was found in only 62% of these cases. This report present data which favours the use of IHA test. Its sensitivity is very similar to that of the commercial Anti Streptozyme test. In addition, the test is simple and could be performed economically. More studies are needed to evaluate the test further. If the results proved as favourable as this report a negative test would be of a considerable value in excluding the diagnosis of acute, rheumatic fever especially in questionable cases.