ABSTRACT
N-acetyl-beta-glucosaminidase activity was determined in peripheral blood lymphocytes by means of Hayashi's cytochemical method in 50 premature infants born between the 21st and 37th weeks of gestation. The lymphocytes exhibited three types of enzymatic cytochemical reaction, i.e. granular, diffuse and mixed (both granular and diffuse). The total count of enzyme-positive lymphocytes was significantly lower in the group of premature infants born between the 21st and 28th weeks of gestation as compared with those born later. This difference was due to the smaller numbers of enzyme-positive lymphocytes with granular reaction type in the group of more immature infants. The formation of enzyme-positive lysosomal granules within the lymphocyte cytoplasm during the last months of fetal development has been suggested and the relationship between the enzymatic equipment of lymphocyte lysosomes and immune response discussed.
Subject(s)
Acetylglucosaminidase/blood , Fetus/enzymology , Hexosaminidases/blood , Infant, Premature , Lymphocytes/enzymology , Lysosomes/enzymology , Humans , Infant, NewbornABSTRACT
Activity of acid phosphatase, beta-glucuronidase, and beta-glucosaminidase was determined in peripheral blood lymphocytes of 29 premature and 20 term infants with the use of cytochemical methods. The results were expressed semiquantitatively and included the total count of enzyme-positive and the enzyme-negative lymphocytes as well as the intracellular content of enzyme-positive and enzyme-negative lysosomal granules. The premature infant exhibited significantly lower activity of all the studied enzymes than the term infants. It thus argues in favour of the opinion that the lysosomal apparatus in lymphocytes undergoes development in the course of fetal maturation of the immune system. Evaluation of the activity of lysosomal enzymes in lymphocytes can serve as an indicator of fetal maturity and immunological status.
Subject(s)
Lymphocytes/enzymology , Lysosomes/enzymology , Acid Phosphatase/metabolism , Female , Gestational Age , Glucuronidase/metabolism , Hexosaminidases/metabolism , Histocytochemistry , Humans , Infant, Newborn , Infant, Premature , Male , PregnancyABSTRACT
Scanning electron microscopic studies of peripheral blood lymphocytes showed that percentage of T cells was lower in four cases of premature infants born between 30th and 34th week of gestation when compared with that in four cases of term infants (18.6% and 39.9% counted from 956 and 1,379 lymphocytes, respectively). The occurence of lymphocytes with intermediate patterns of surface morphology (I cells) was noted in both groups studied. Percentages of B and I cells were higher in the premature than in the term infant (26.3% and 55.1% and 20.0% and 39.1%, respectively). Analogous tendency in the T cell occurence in the premature and the term infant was demonstrated with acid phosphatase as T cell marker.
Subject(s)
B-Lymphocytes/ultrastructure , T-Lymphocytes/ultrastructure , Acid Phosphatase , Humans , Infant, Newborn , Infant, Premature , Microscopy, Electron, ScanningSubject(s)
Acid Phosphatase/blood , Infant, Premature , Lymphocytes/enzymology , Female , Glucuronidase/blood , Hexosaminidases/blood , Histocytochemistry , Humans , Infant, Newborn , MaleABSTRACT
Activity of beta-glucuronidase (GR) was determined cytochemically by the Hayashi et al. method on peripheral blood lymphocytes of 50 premature infants, born between 21st and 37th week gestation. The subjects studied were subtyped into group I (21st to 28th week), group II (29th to 33rd week), and group III (34th to 37th week). Absolute count of enzyme-positive lymphocytes was lower in group I, when compared with group II and III as a whole. Absolute count of GR-positive lymphocytes exhibiting granular reaction type was significantly lower in group I, when compared with other groups. Absolute counts of GR-positive cells, with both granular and diffuse, or diffuse enzymatic reaction did not differ in groups I, II and III. The results obtained indicate ontogenetic development of lysosomal granules containing GR in the lymphocyte cytoplasm in premature infants related to their fetal age.
Subject(s)
Glucuronidase/metabolism , Lymphocytes/enzymology , Female , Gestational Age , Humans , Infant, Newborn , Infant, Premature , Lysosomes , Pregnancy , Pregnancy Trimester, Second , Pregnancy Trimester, ThirdABSTRACT
The activity of some lymphocyte lysosomal enzymes such as: acid phosphatase, beta-glucuronidase and beta-glucosaminidase was studied comparatively in 29 prematures, 20 term infants and 20 adults. The activity of lysosomal enzymes was found to increase gradually in the course of fetal maturation and later on after birth. The percentage of lymphocytes exhibiting strong intracellular acid phosphatase and beta-glucuronidase activity was highest in adults. Differences between lymphocyte beta-glucuronidase activity in the term infants and that in adults were less evident. The results of the study seem to confirm the previous assumption of certain authors that B lymphocytes, generally characterized by a low activity of lysosomal enzymes, are more numerous in the premature and term infants than in the adults.
