Impaired opsonophagocytosis of serotypes Ib and II of group B streptococci as compared with serotypes Ia and III: role of the alternative pathway of complement in opsonisation of serotype III of group B streptococci.

Using the technique of phagocytic chemiluminescence, we have shown that serotypes Ib and II of group B streptococci are resistant to opsonophagocytosis. The resistant strains became susceptible to opsonophagocytosis by trypsin treatment, but neuraminidase had no effect. Several studies have failed to define a significant role for the alternative pathway of complement in opsonisation of group B streptococci. By simple chelation and heat inactivation studies, we have shown that the alternative pathway of complement is activated by serotype III of group B streptococci.

Sequential study of C reactive protein in neonatal septicaemia using a latex agglutination test.

The usefulness of serial study of C reactive protein in the early detection of neonatal septicaemia was evaluated in a neonatal unit using a commercially available latex agglutination slide test as a rapid screening method and electroimmunoassay as a reference method for C reactive protein determination. A positive latex test was obtained in 11 infants with verified septicaemia (positive blood culture), two infants with clinically evident infection but without bacteriological confirmation, one infant with recurrent chest infection due to Pseudomonas aeruginosa, and one infant who showed signs of birth asphyxia with meconium aspiration, but was not infected. Positive latex test results correlated with raised concentrations of C reactive protein, measured by immunoassay. In some instances, however, concentrations of C reactive protein in excess of 12 mg/100 ml gave weaker agglutination results in the slide test, which could be interpreted as negative results. In a sequential study of the infected infants, 6.3% of the values recorded on a slide test were false negatives. In contrast, false positive values were observed on a slide test in 1.9% of 27 non-infected infants. The higher percentage of false negative values may be due to the presence of excess antigen in the sera of some infected children. It is suggested that the latex test should be carried out on suitable dilutions of serum. Although the slide test may reliably indicate infection at an early stage in neonates, the C reactive protein response is non-specific, as seen in a non-infected infant who showed signs of birth asphyxia with meconium aspiration. Provided the non-specific nature of the C reactive protein response is recognised, the latex test may be a useful serum measurement for early diagnosis of neonatal septicaemia of the newborn. The test has the advantage of being performed easily, quickly, and cheaply.

Serum C-reactive protein in normal and infected neonates.

Serum C-reactive protein determinations were performed on well and sick neonates, in order to gain information about normal values and its value in the diagnosis of neonatal septicaemia. The median value in 48 cord sera was 200 micrograms/l (range 15 to greater than 6,000 micrograms/L); there was no correlation between paired maternal and cord serum CRP levels (12 pairs). Thirty-six children were followed from birth for a mean of 20 days. There were 21 episodes of confirmed infection in 16 children, each associated with a sustained rise in C-reactive protein, often commencing before there was clinical evidence of infection. In four patients with raised levels, infection was suspected, but no firm evidence was obtained. In the remaining 16 children there were no values above 10 mg/l, and the 95th centile was about 6 mg/l, with no difference between values obtained in the first three days of life and those found subsequently. Hyaline membrane disease and jaundice were not associated with a rise. Raised serum C-reactive proteins is a good indicator of the presence of infection in the neonatal period.

The use of cryopreserved lymphocytes in assessing inter-individual radiosensitivity with the micronucleus assay.

PURPOSE: The feasibility of using cryopreserved lymphocytes to detect inter-individual differences in chromosomal radiosensitivity was investigated. Typically, such studies are conducted with fresh blood samples but, in a clinical setting, when availability of samples is unpredictable, this is not always convenient. The sensitivity of 23 normal healthy donors, 11 breast cancer patients who had shown severe acute skin reactions to radiotherapy and seven ataxia telangiectasia (A-T) heterozygotes was determined. MATERIALS AND METHODS: Thawed lymphocytes were exposed to high (HDR) or low dose rate (LDR) gamma irradiation (3.5 Gy) in Go, stimulated with PHA, treated with cytochalasin-B 24 h later and then harvested at 90 h for the determination of micronucleus (MN) yields in binucleate cells. RESULTS: Each normal donor was tested one to three times. Mean MN yields were 76.1 +/- 9.3/100 cells at HDR and 44.5 +/- 5.3 at LDR, giving an LDR sparing effect of 39.6 +/- 9.3%. A relatively high proportion of tests failed to yield sufficient binucleate cells for analysis. Inter-experimental variability was also high and it was not possible to demonstrate inter-individual differences in sensitivity in spite of the use of an internal control sample from a single normal donor in each experiment. There was a small but significant increase in radiation-induced MN in the breast cancer patients compared with the normals at LDR (but not at HDR), but a complete overlap with the normal range. There was no increase in sensitivity in the A-T heterozygotes at HDR. The LDR samples failed because the LDR protocol reduced proliferation rates, and radiation-induced mitotic inhibition in this group was higher than in normals. CONCLUSIONS: In comparison with previous experience with fresh blood samples, the use of frozen lymphocytes is not as satisfactory because: (1) experimental failures are higher; (2) inter-experiment variability is higher: (3) dose-rate sparing is lower, suggesting poorer repair; and (4) the ability to discriminate between breast cancer cases and normals is probably lower.

Histamine release from human leucocytes by IgG4 subclass in the sera of allergic children.

Our studies on histamine release from normal washed leucocytes sensitised with sera of children allergic to various inhaled and ingested allergens show that besides IgE, IgG4 present in these sera was capable of sensitising leucocytes of normal donors, and these leucocytes released histamine on challenge with anti-IgG4. By contrast, antisera of other subclasses of IgG released very small amounts of histamine from sensitised leucocytes. A discordant correlation between skin tests and RAST IgE was observed in some children. Significantly greater amounts of histamine were released from normal leucocytes sensitised with serum from these children when challenged with anti-IgG4 compared to anti-IgE. These studies indicate that IgG4 merits further study as a reaginic marker in atopic diseases of the children with possible prognostic significance.

Assessment of neutrophil chemotaxis and random migration in children and adults. Comparison between filter and agarose techniques.

Polymorphonuclear leucocyte migration was studied in 16 children and 11 normal adults, both by a filter technique and under agarose. Assays were carried out in parallel. There were no significant differences (p greater than 0.5) between adult controls and children's mean neutrophil migration coefficients within methods, but highly significant differences were found between methods (p less than 0.001) both in adult and children's samples. The observed intermethod differences are shown to be the result of increased random migration under agarose in both age groups.

The placental transfer of IgG subclasses in human pregnancy.

Total IgG concentrations and the concentrations of the four subclasses of IgG were estimated in thirty-four pairs of maternal and foetal sera from pregnancies of various gestations ranging from 28 to 42 weeks using the method of radial immunodiffusion. It was found that: (1) all subclasses of IgG cross the human placenta freely, (2) foetal levels of IgG and each subclass of IgG exceed maternal levels in full-term pregnancies and (3) there was a close linear relationship between gestational age and the placental transfer of IgG and each of its subclasses.

Traveller's diarrhoea with a vengeance in children of UK immigrants visiting their parental homeland.

Six healthy children, born in the UK, travelled to their parental homeland and developed a severe form of traveller's diarrhoea. This was characterised by rapid loss of weight and chronic diarrhoea. On return to this country, investigation in 5 of them showed an abnormal, small intestinal mucosa. There was a high incidence of pathogens and potential pathogens found in stools and duodenal juice. Immunodeficiency was found in 2 of them. Small intestinal mucosal damage related to gut infection in previously well children appears to be of cardinal importance in the interaction between chronic diarrhoea and malnutrition. This observation may point the way to future research into the primary role of gut infection in the initiation of the cycle of malnutrition and chronic diarrhoea in developing communities.

Serial study of C reactive protein in neonatal septicaemia.

Serial C reactive protein concentrations were assayed by electroimmunoassay in 41 infants. Values in most of the non-infected infants were below 0.3 mg/dl, the lower limit of detection of C reactive protein by electroimmunoassay. Eleven of 12 infants with proved sepsis (positive blood cultures) had significantly raised concentrations and one infant with recurrent pseudomonas chest infection had a raised C reactive protein concentration. High C reactive protein concentrations were also found in infants with suspected infection. Successful treatment was followed by a decrease in the C reactive protein concentration. Total white blood cell count was not as appropriate as C reactive protein determination in the early identification of bacterial infection in the newborn.

Acute phase proteins in chronic inflammatory bowel disease in childhood.

The serum levels of five acute phase proteins (APP) were measured in 18 children with Crohn's Disease (CD) or ulcerative colitis (UC) and in two control groups. The levels of C-reactive protein, alpha 1-acid glycoprotein, alpha 1-antitrypsin, C9, and Factor B were significantly raised in patients with CD and UC with good separation from controls, but they were not entirely reliable used as screening tests unless used in combination. The levels of APP were monitored for periods varying from 18 to 28 months in each patient and found to reflect the disease activity in both CD and UC. On seven occasions the APP levels did not match the clinically assessed disease activity, but when the serum levels were related to outcome of the disease, C-reactive protein was found to be elevated--whether or not there were symptoms of the disease--in all patients who later had a relapse, while normal values were found in those who had a long remission. These results suggest that the estimation of Creative protein is of prognostic value and that its measurement is particularly useful in children with mild symptoms in whom disease activity and prognosis are difficult to assess.

Suppressor cells in asthmatic children.

Peripheral blood mononuclear cells (PBMC) from thirteen asthmatic children, and from normal control subjects, were pre-incubated with and without concanavalin A (con A), washed, and cultured with fresh allogenic PBMC from healthy donors. The con A pre-treated cells from fifteen of seventeen normal controls clearly suppressed the blast transformation response to con A by normal allogeneic PBMC. However, con A-generated suppressor activity was found in only seven of the asthmatic patients studied, most of whom could be classified as "short-term' asthmatics. It is thus possible that either dysfunction or a reduction of the (con A)-inducible, T-suppressor cell subpopulation in peripheral blood is frequent among "long-term' asthmatic patients. This may suggest that a different pathogenesis may be operating in early-onset, long-continued asthma, when compared with those investigated early in the course of asthma which has begun later in childhood.

In vitro effect of Panax ginseng on phytohaemagglutinin-induced lymphocyte transformation.

The effect of hydrocortisone or Panax ginseng, and/or a combination of hydrocortisone and Panax ginseng on phytohaemagglutinin (PHA-P)-induced transformation of peripheral blood lymphocytes were studied in 4 normal healthy adult volunteers. Increasing concentrations of Panax ginseng 0.16-1.60 micrograms X ml-1 caused a dose-related inhibition of PHA-P transformation of lymphocytes. A combination of 500 micrograms X ml-1 hydrocortisone and 0.80 micrograms X ml-1 Panax ginseng produced a greater suppression of PHA-P stimulation than either drug used alone. This suggests that Panax ginseng has a steroid-like effect in vitro, and may have a potentiating effect with hydrocortisone on T-cell-mediated immunity.

Flat small intestinal mucosa and autoantibodies against the gut epithelium.

A male infant, aged 1 year 3 months, was admitted to the hospital with protracted diarrhoea, vomiting, and weight loss. The diarrhoea and vomiting coincided with an outbreak of acute diarrhoea and vomiting affecting other family members. Biopsy showed a flat small intestinal mucosa which did not respond to a diet free of gluten, cow's milk, and eggs, or during 8 weeks of intravenous alimentation. Steroids were given, and courses of nalcrom and later cimetidine, but these did not produce any significant improvement. A rare IgG autoantibody specific for gut epithelium was found, which, when present, was associated with a cytological abnormality of crypt enteroblasts. The autoantibody disappeared after treatment with cyclophosphamide, and the cytological abnormality subsequently diminished. However, the mucosa remained severely abnormal and has been so for 23 months. It is possible that an autoimmune reaction against the patient's small intestinal mucosa has led to persistence of the enteropathy.