Some cellular immune reactions in infants. MIF, E-rosette formation and changes in nucleolar morphology.

The cellular immune response (MIF, E-rosette formation and changes in nucleolar morphology of lymphocytes) was followed as related to age and antigenic stimulation. MIF in healthy infants increased from the 2nd to the 12th week of life as compared with the first week, probably due to BCG vaccination. The total and active E-rosette formation did not change during the whole period of investigation. Ring-shaped nucleoli increased gradually from the second week of life. Active nucleoli increased up to the 4th week, i.e. after BCG vaccination and then slowly decreased. Micronucleoli being high in the first week, decreased during 24 weeks of life. After artificial colonization of the intestine the production of MIF was slightly lower in colonized infants than in controls from the 2nd to the 12th week. The other parameters followed were not influenced by colonization.

Pregnancy-induced morphologic changes in lymphocytes; an experimental study on materno-fetal tolerance in the rat.

Morphological changes in lymphocyte nucleoli were examined in the course of pregnancy in rats. Small amounts of lymphocytes became activated, most of them producing micronucleoli. These findings show the same changes as found in the course of pregnancy in women. Subcutaneous administration of human placental eluate to non-pregnant rats induced a low degree of activation and high micronucleoli formation, dependent on the dose of placental antigen. Repeated administration of increasing doses of placental eluate revealed almost the same morphological changes in lymphocyte nucleoli as seen in normal pregnancy. This is considered an experimental verification that the morphological changes in lymphocyte nucleoli during pregnancy are due to permanent and gradually increasing doses of foreign antigen.

Skin-window study on the migration of leukocytes of newborns and infants.

Migration of leukocytes of newborns and of infants up to the age of 6 months was studied using the in vivo skin-window technique according to Rebuck. Using the non-specific stimulation (abrasion of the skin only) a slight age-dependent physiological increase of migration of cells was observed within the observation period; after a strong local irritation with diphtheria-tetanus-pertussis vaccine (Alditepera) there was a vigorous migratory response of cells in the skin lesion. Both quantitatively and qualitatively, the migration pattern (i.e. shift from PMN leukocyte to mononuclear cells in the exudate within a 1 d period after abrasion) was not influenced by immunization of infants with Alditepera, suggesting thus the nonspecific nature of this cellular response. The "normal" values of the chemotactic response of leukocytes of newborns and infants are given as a basis for evaluation of defects of this functional activity of leukocytes.

Antibody production by the mammary gland in mothers after artificial oral colonisation of their infants with a non-pathogenic strain E. coli 083.

Twenty five breast-fed and 25 formula-fed infants were colonised by oral administration of a living suspension of E. coli 083. Twenty breast-fed and 13 formula-fed infants were followed as controls. Specific antibody titres in serum, stool filtrates and milk, and secretory IgA levels in stool filtrates and milk were determined in samples taken fortnightly from birth until 20 weeks of age. The haemagglutinating antibody in serum and milk increased in the colonised groups, but in stool filtrates an inhibitory effect of breast-milk was demonstrated. Secretory IgA levels in stool filtrates were significantly higher in colonised infants and breast-fed controls than in bottle-fed infants during the period of breast feeding. Then levels in the colonised groups remained high, but in breast-fed controls they decreased to values found in bottle-fed controls. Artificial colonisation evoked local antibody and secretory IgA responses in the intestine, as well as an antibody response in the mother's mammary gland. The possible protective effect of those responses is discussed.

Influence of oral lysozyme administration on serum immunoglobulin and intestinal secretory IgA levels in infants.

The influence of lysozyme feeding on the production of serum immunoglobulins and intestinal secretory IgA was studied in full-term and premature infants, from birth up to the age six months. Serum immunoglobulins were not influenced by lysozyme administration. An increase in secretory IgA was found in stool filtrates of full-term lysozyme-fed infants; no secretory IgA was detected in controls. In this way lysozyme feeding partly substituted for passive transfer of secretory IgA from maternal milk.

A contemporary review of incidence and detection of enterotoxigenic E. coli strains in human diarrheal diseases.

Methodical possibilities for detection of enterotoxic strains of E. coli and the frequency of appearence of these strains in infants and adults suffering from diarrheal diseases are reviewed. Our own study, using the ligated rabbit intestinal loop, revealed 6.8% incidence of enterotoxin producing strains among the classical enteropathogenic serotypes of E. coli, isolated from stools of infants with mild diarrhoea. The model of mice intestinal loop was not found to be suitable for detection of enterotoxin of E. coli strains. The most sensitive model seems to be the intestine of precolostral piglet; however this model is not suitable for routine tests.

Feto-maternal relationship in normal pregnancy in mixed lymphocyte cultures.

In eight wife-husband pairs during the whole pregnancy the reactivity of lymphocytes to PHA, to lymphocytes of unrelated donor and to lymphocytes of husband was studied. No statistically significant differences were found in reactivity of wife's and husband's lymphocytes. In eleven women at delivery a statistically significant decline of MLC reaction to lymphocytes of own and unrelated newborn was found, while the reactivity to PHA and to lymphocytes of unrelated adult donor remained unchanged. Similarly, the lymphocytes of eleven newborn infants reacted statistical significantly less to lymphocytes of own mother and unrelated mother, while the reaction to PHA and to lymphocytes of unrelated donor was well expressed.

Morphological changes in maternal lymphocytes in pregnancy.

By use of staining with toluidine blue, the changes in the nucleoli of lymphocytes in 150 healthy women were studied. The patients were divided into five groups: non-pregnant women; women in the first, second and third trimesters of pregnancy; and women who were five days post partum. A progressive and statistically significant rise in the number of lymphocytes with micronucleoli was found during pregnancy and there was a fall after delivery. This increase was associated with a decrease in the incidence of ring-shaped nucleoli. There were no significant changes in the absolute number of lymphocytes and in "active" lymphocytes during pregnancy.