Infection and labor. III. Interleukin-1: a signal for the onset of parturition

The regulatory signals responsible for the increased biosynthesis of prostaglandins during parturition have not been established. Because interleukin-1 is capable of stimulating prostaglandin production by intrauterine tissues and is an inflammatory mediator, we propose that interleukin-1 may act as a signal for the onset of human labor in the setting of intrauterine infection. The purpose of these studies was to determine interleukin-1 activity in amniotic fluid and to establish its relationship with the onset of term and preterm labor. Amniotic fluid from 182 patients was assayed for interleukin-1 activity. Cell-associated interleukin-1 activity was detected in fluid obtained in the third trimester but not in fluid obtained in the second trimester of pregnancy, suggesting a maturational event in interleukin-1 production. The factor responsible for interleukin-1 activity had biochemical characteristics of interleukin-1 alpha (estimated molecular weight of 14 kilodaltons, isoelectric point = 4.9), and its activity was blocked with an anti-interleukin-1 alpha antisera. Women in spontaneous labor at term were likely to have fluid phase interleukin-1 activity in amniotic fluid than women who were not in labor at term. Preterm labor in the setting of intraamniotic infections was associated with significant interleukin-1 activity in amniotic fluid. This bioactivity was predominantly attributable to interleukin-1 beta. A strong correlation between interleukin-1 and amniotic fluid concentrations of prostaglandin E2 and prostaglandin F2 alpha was found in women in preterm labor. These findings support the hypothesis that interleukin-1 may play a role in the initiation of preterm labor associated with intraamniotic infection.

Retained placenta and leucocytic activity

In a study of 262 cows, the relationship between the activity of peripheral leucocytes and the expulsion of the placenta was investigated, bearing in mind that the post- partal placenta may be considered as a foreign tissue. The activity of the leucocytes against the cotyledon was examined by determining the presence of chemotaxis in a Boyden Chamber, and by estimating the number of leucocytes in the cotyledon at the time of parturition. It was shown that in the absence of leucocytic activity, retained placenta occurred in 100 per cent of cases. When chemotaxis is used as the sole criterion, positive chemotaxis resulted in an incidence of 2.6 per cent retained placenta and negative chemotaxis in 35.6 per cent.

Pre-partum leucocytic activity and retained placenta

An investigation concerning the association of the leucocytecotyledon reaction and the expulsion of the placenta is described. The in vitro reaction does not appear to be individual-specific. It is thus possible to determine the activity of the leucocytes against a cotyledon before parturition. The leucocytes of cows which will develop a retained placenta have lowered activity against the chemotactic stimulus of a cotyledon; this reduced activity of the leucocytes can be observed some days before parturition.

Perinatal characteristics and obstetric complications as risk factors for asthma, allergy and eczema at the age of 6 years

BACKGROUND

Considerable effort has been put into identifying early determinants for atopic disorders. Many studies have evaluated the role of fetal development and obstetric complications. However, the results are not unequivocal.

STUDY OBJECTIVE

To assess the relationship between perinatal characteristics and obstetric complications, and the presence of reported current asthma, allergy and eczema at the age of 6 years in the framework of a previously conducted study.

METHOD

Seven hundred families in the Netherlands with index children born in 1988-1990 were retrospectively selected. Data were extracted from the Municipal Health Service's records of health examinations of these children and their siblings. These examinations were carried out at the age of 6 years. The records contained data on reported atopic disorders and perinatal characteristics.

RESULTS

Gestational age was inversely related to the risk of asthma (P for trend: 0.03). Children with low birth weight tended to have a lower risk of any allergy, albeit not significant (P=0.07). However, no link was found between neonatal head circumference and atopic disorders. The ratio of neonatal head circumference to birth weight was positively associated with the risk of atopic disorders, especially with the risk of asthma (odds ratio (OR)=1.87; 95% confidence interval (CI(95%))=[1.11, 3.15]). Vacuum extraction was a risk factor for allergy (OR=1.84, CI(95%)=[1.03, 3.28]), but not for asthma. Induced labour was positively associated with the risk of inhalant allergy (OR=2.22, CI(95%)=[1.09, 4.51]) and, to a lesser extent, asthma (OR=1.72, CI(95%)=[0.95, 3.10]). For caesarean section and forcipal extraction there were no such relationships.

CONCLUSIONS

Prematurity is a risk factor for asthma reported at 6 years. A high ratio of head circumference to birth weight is a risk factor for any atopic disorder. Vacuum extraction was associated with a higher risk of allergy, and induced labour is a risk factor for inhalant allergy. All results should be viewed with the possibility of residual confounding.

Post-partum leucocytic activity and its relationship to caesarian section and retained placenta

The activity of the leucocytes of 30 cows during 10 days after parturition is described. A comparison is made between the activity of leucocytes of 10 cows after normal parturition, 10 cows after caesarian section and 10 cows with retained placenta. When compared with normal parturition, caesarian section does not have a negative influence on the activity of the leucocytes during the puerperal period, during which time however the activity of leucocytes of cows with retained placenta is strongly decreased.

Significance of raised immunoglobulin M levels in cord blood of small-for-gestational-age infants

Cord IgM values were determined in small-for-gestational-age infants born at Hammersmith Hospital during a 5 1/2-year period. 121 (12.5%) infants had levels more than 0.2 g/l; in 92 these were between 0.21 and 0.3 g/l. In only 18 (14.8%) was a level of 0.4 g/l exceeded, and 5 proved cases of intrauterine infection--rubella (2), syphilis (2), and toxoplasmosis (1)--were in this group. The factor most often associated with cord IgM more than 0.4 g/l was prolonged rupture of the membranes. There was an increased incidence of blood group B among the mothers, probably reflecting the greater number of nonCaucasian women giving birth to small-for-gestational-age infants. Determination of cord IgM did not help significantly indiagnosis.

Influence of dilution on the chemotactic properties of cotyledon suspensions

In this study the influence of dilution of cotyledon suspensions on the chemotactic stimulus was investigated. When the concentration of the chemotactic stimulus is reduced, the activity of the leucocytes is reduced as well. Dilutions of retained placenta cotyledon suspensions showed an increase in leucocyte activity. This may indicate the existence of a leucocyte inhibition factor in the retained placenta cotyledon.

Prolonged gestation does not extend survival of uterine natural killer lymphocytes in mice deleted in the receptor for prostaglandin F2alpha

During decidualization in mice and women, expansion of the Natural Killer (NK) cell lineage occurs within the uterus. In rodents, peak numbers of uterine (u)NK cells are reached at mid-gestation. The population then declines and residual cells are shed with the placenta. Decidualization, but not a fetus, is required to induce division and maturation of uNK cells. Mechanisms regulating the decline in uNK cells are unknown. To determine if the conceptus or its products have regulatory roles on uNK cell survival during normal gestation, a histological time course study was undertaken of implantation sites in mice ablated in the gene for the Prostaglandin F2alpha receptor (PGF2alphaR). These females experience normal gestation but fail to initiate labour and delivery. Their pregnancies extend a further 4-7 days before onset of maternal compromise. Large numbers of uNK cells were present in PGF2alphaR null mice by gestational day (gd) 10 and numbers had begun to decline at gd 14. By gd 18, very few uNK cells remained and no uNK cells were found at day 22 of extended gestation. Thus, the population history of uNK cells in PGF2alphaR null mice resembles that of uNK cells in normal mice, suggesting that the placenta, its products, the fetus and PGF2alpha are not factors that influence the rate of uNK cell decline in late gestation.

[Markers of hepatitis-viral infection in children born of mothers with hepatitis B]

Sixty-two women suffering from hepatitis B (HB) and their newborn babies were examined by a highly sensitive radioimmunoassay (RIA). The fluorescent antibody technique was also used to examine autopsy specimens of livers of 7 fetuses, 1 stillborn, and 3 babies dying in the first days of life whose mothers during pregnancy or delivery had experienced HB. Frequent infection of babies (77.8%) was observed at high concentrations of HBsAg in mothers in labor with subsequent development of persisting HBs-antigenemia, and in half of the babies of chronic hepatitis. HBsAg was detected in the first days of life not only in the blood serum, but also in the liver tissue which may be explained by intrauterine infection. At low concentrations of HBsAg in mothers the babies were infected less frequently (26.1%) and half of them were shown to have anti-HBs in the umbilical blood and blood serum in the first days and months of life. Anti-HBc transmission from mothers was also demonstrated. In babies born to convalescents after HB in the absence of HBsAg, anti-HBs in combination with anti-HBc were determined.

IgG, IgM and IgA umbilical blood concentrations in normal singleton vaginal deliveries with stinking amniotic fluid or intrapartal maternal febrility > or = 38 degrees C or duration of delivery > 12 hours

Total of 321 preterm/term newborns delivered in normal singleton vaginal deliveries was studied. Babies were divided into two groups. The first one includes 62 newborns with single, isolated clinical sign: stinking amniotic fluid or intrapartal maternal febrility > or = 38 degrees C or duration of delivery > 12 hours. The second one (control group) contained 259 newborns with no such a sign. In both groups the umbilical cord blood IgG, IgM and IgA concentration (g/L) were quantified by a radial immunodiffusion method. The obtained values were classified into the groups according to 500-grams-birth-weight-ranges. The differences of the mean IgG, IgM and IgA concentrations between the each 500-grams-birth-weight-range subgroup separately in both control and experimental group so as between the same subgroup of the control and experimental group were tested by the means of the Student's t-test. Obtained results did not express the significant differences in the mean IgG, IgM and IgA umbilical cord blood concentrations between the experimental and control group of the newborns.

[The pathogenesis of generalized suppurative-septic complications in patients with eclampsia and massive blood loss of obstetrical origin]

Changes in immune status, central hemodynamics, oxygen regimen and endogenous intoxication indexes have been compared in patients with eclampsia combined with blood loss and in patients with isolated blood loss. It has been established that severe septic processes were 1.5 times and lethality was 4 times more frequent in the first group of patients than in patients with isolated blood loss. Generalized septic processes accompany marked secondary immune defects. The main reasons for the immune system damage are circulatory hypoxia and severe endogenous intoxication.

Anaphylaxis to cefazolin during labor secondary to prophylaxis for group B Streptococcus: a case report

BACKGROUND

Anaphylaxis is an uncommon event during pregnancy, but if it does arise, it can lead to serious fetal consequences even if there are no serious long-term maternal complications.

CASE

A parturient developed anaphylaxis in the labor unit shortly after intravenous cefazolin chemoprophylaxis had begun for perinatal group B streptococcal disease. Prompt treatment for anaphylaxis commenced, involving the administration of epinephrine and glucocorticoids, and an emergency cesarean section spared the mother serious morbidity, with a favorable perinatal outcome for the fetus.

CONCLUSION

To the best of our knowledge, this case is the first reported one of anaphylaxis to cefazolin in pregnancy secondary to prophylaxis against for B Streptococcus. The case demonstrates that a life-threatening anaphylactic reaction can occur at any time during pregnancy and that all staff in a maternal unit should be familiar with the management of perinatal anaphylaxis.

[Hentaxan as an immunoregulator in purulent wounds in parturient women]

Hentaxan, a new silicon sorbent, is a complex drug preparation containing hentamycin sulfate and zinc-tryptophan, endowed with antioxidant and immunomodulating activities. We used it for treating suppurating wounds in those women in labour. As many as 65 parturient women were examined. The conclusion drawn from the obtained results is that the immunomodulating potential of hentaxan is not very high, for which reason we recommend that hentaxan be combined with laferon which effects the T-link of immunity. The proposed method is at present under study.

[Effect of levamisole on the course of chronic cytomegalovirus infection in women]

The therapeutic effect of orally given levamisole in the treatment of women with chronic cytomegalovirus infection was studied. The patients were examined serologically, cytologically, virologically; the factors of cell-mediated immunity were also studied. Oral therapy with levamisole resulted in a definite increase of the cell-mediated immunity with a trend for decrease in antibody titres and reduced virus excretion. Evaluation of the clinical effect of levamisole therapy, however, revealed no distinct difference in the outcomes of pregnancy in the groups of women treated or not treated with levamisole.

Peripheral lymphocyte subpopulations changes during labor

Peripheral circulating E-rosette-forming cells subpopulations (high affinity and low affinity E--RFC) were studied in pregnant women. In prelabor the high affinity/low affinity E--RFC ratio was found to decrease as compared with the controls by the decrease of the high affinity E--RFC (mean +/- SD, 33.4 +/- 15.9%, p less than 0.01) and the increase of the low affinity E--RFC percentage (mean +/- SD, 37.0 +/- 11.8%, p less than 0.001). As compared with prelabor the low affinity E--RFC subpopulation decreased during normal labor (mean +/- SD, 14.1 +/- 6.2%, p less than 0.001) and not in abnormal labor. These changes might be implicated in the final "fetal allograft rejection" and are probably due to some serum factors in pregnancy.

Pathophysiology of the periparturient egg rise in sheep: the role of prolactin

The involvement of prolactin in the periparturient rise in the faecal nematode egg count in sheep was investigated. Ostertagia circumcincta larvae (5000 third stage larvae three times weekly) were administered to adult immune ewes from three weeks before parturition to three weeks afterwards. Ten ewes were injected twice daily with 2-bromo-alpha-ergocryptine (bromocriptine), an antagonist of prolactin secretion, for two weeks starting two days after lambing while 10 ewes remained untreated. Bromocriptine treatment was initiated approximately two weeks pre partum in three other ewes. Plasma pepsinogen concentrations rose significantly by one week after the start of O circumcincta larval challenge in all the ewes but faecal egg counts remained negative until approximately one week post partum. Plasma prolactin concentration was reduced to a very low level in all bromocriptine treated ewes but this did not alter the dynamics of the periparturient rise in faecal egg counts. Neither cell-mediated nor humoral immunity of the ewes, as assessed by their sensitivity to BCG inoculation and by antibody titre raised against horse red blood cells, respectively, were impaired during the rise in faecal egg count, nor were these parameters altered by manipulation of plasma prolactin concentration. Lamb growth rate was not retarded by low plasma prolactin concentration in the bromocriptine treated ewes. These results are not consistent with the generally held hypothesis that elevated plasma prolactin concentration is directly associated with the periparturient rise.

[Is there a relation between an increase in IgM in the newborn infant and the course of pregnancy and labor?]

In order to check the significance of the serum IgM concentration in newborns the IgM levels in the placental blood of 263 randomly selected neonates were determined; in 105 of these children the IgM concentration was again determined on the 6th day of life. The maternal IgM concentrations were also determined for the purpose of comparison. All of the newborns were allocated to infection risk categories on the basis of history and clinical data. The findings were evaluated on the basis of the mean values with simple standard deviation, single-case analysis and arrangement of the medium values in sequence. Significantly elevated IgM concentrations were found in newborns with the risk factor asphyxia on the 6th day of life. There was a certain tendency to elevated IgM concentrations - established on the basis of the mean values and the median value grouping - in the groups with maternal infection, premature rupture, frequent vaginal examination, and post-term birth of the child. The investigation shows that the majority of elevated IgM concentrations in neonates in whom no infection can be found are not closely correlated to a certain risk factor. An elevated IgM concentration in a newborn appears to be a factor of low specificity with regard to infection. However, in the diagnosis of neonatal infections it provides additional information in the overall context of the clinical examination.