Epidemiology of group-B streptococcal carriage in pregnant women and newborn infants.

In a population of pregnant women, the prevalence of group-B streptococcal carriage was relatively low. During the 3rd trimester of pregnancy 5-6% of women haboured group-B streptococci and 8-3% were positive at the onset of labour. Some 42% of women who gave positive cultures in labour had given negative cultures during the 3rd trimester and 19% of women who were positive during late pregnancy were culture-negative in labour. The conversion of culture status observed in these women suggests that carriage may be intermittent or that new acquisition of genital-tract streptococci may occur in late pregnancy. The unpredictability of conversion diminishes the reliability of a single culture taken during the 3rd trimester of pregnancy.     

Vitamin D nutrition in pregnant Nigerian women at term and their newborn infants.

In view of the high incidence of rickets in infants of women practising purdah (the use of veils) in northern Nigeria we conducted a study on plasma calcium, phosphate, and serum 25-hydroxyvitamin D (25 OHD) concentrations in pregnant Nigerian women and in cord blood obtained from the newborns. Plasma calcium, phosphate, and serum 25 OHD concentrations were lower in practising women and their newborns than those not practising purdah and their infants, respectively. The concentrations of 25 OHD in all Nigerian women were greater than those observed in caucasian women in the United Kingdom. These data emphasise the role of exposure to sunshine in regulating serum 25 OHD concentrations and the adverse effect of deliberate exclusion of sunshine and are consistent with previous data indicating hypovitaminosis D in purdah clad women and their newborns in Saudi Arabia. These data do not, however, provide an explanation for the pathogenesis of the high incidence of neonatal rickets and tetany in infants born of purdah clad women as these women have 25 OHD concentrations greater than those in caucasian women in the United Kingdom.     

Colonization of pregnant women and their newborn infants with group-B streptococci

As group B streptococci (GBS) prevalence varies from place to place and this organism is responsible for serious infections in newborns such as septicaemia and meningitis, the present study was carried out to find the prevalence of GBS in pregnant women and their neonates. From June 1998 to April 1999 a total of 317 pregnant women and their neonates were examined for GBS. GBS colonization rate was 2.52% and 1.26% in pregnant women and their neonates respectively. Four sites - viz. throat, external ears, external nares and stump of umbilicus from neonates were found to be equally colonized by GBS immediately after birth and at the time of discharge from hospital, except the umbilicus which was not swabbed at the time of discharge. None of the neonates developed GBS related sepsis. Selective broth medium (SBM) was found to be a superior transport method over Stuart transport medium and filter paper method. All the isolates were sensitive to Ampicillin, Erythromycin, Penicillin followed by Chloramphenicol 66.6% (12/18). All the strains were resistant to Gentamicin, followed by Tetracycline 94.4% (17/18) and Kanamycin 88.8% (16/18).     

Immunoblot analysis of antibody responses to Sporothrix schenckii

The serologic response to Sporothrix schenckii was investigated in patients with sporotrichosis by solid-phase enzyme-linked immunosorbent assays (ELISAs) and Western immunoblot techniques. A soluble antigen preparation derived from an S. schenckii isolate contained 15 protein staining components ranging in molecular size from 22 to 70 kilodaltons (kDa) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Sera from 40 patients with sporotrichosis demonstrated Sporothrix immunoglobulin G antibody by ELISA with titers between 128 and 65,200. No sera from 300 healthy individuals or 100 patients with various systemic mycoses other than sporotrichosis had ELISA titers greater than 64. By Western immunoblotting of the antigens separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, sera from 10 patients with cutaneous sporotrichosis reacted with 8 to 10 antigen components (range, 40 to 70 kDa), while sera from 15 patients with extracutaneous sporotrichosis reacted with a greater number of antigen components (15 to 20 bands) over a wider range of molecular sizes (22 to 70 kDa). Antibody to 40- and 70-kDa antigen components was detected by immunoblots in all sera tested from patients with sporotrichosis. Antibody to 22- to 36-kDa antigen components was present in sera from 13 of 15 patients with extracutaneous sporotrichosis, but these lower-molecular-weight components were not detected by sera from patients with cutaneous sporotrichosis. Antibody to these components was not detected by Western blotting in sera from 19 of 20 patients with other fungal diseases or from 30 healthy individuals. Purification of these specific antigen fractions could provide the basis of a sensitive and specific serodiagnostic test to indicate the presence and activity of extracutaneous sporotrichosis.     

Anti-I antibody in normal human newborn infants

A cold agglutinin with anti-I specificity is present in a high percentage of cord sera. Evidence is produced that this antibody, like the `naturally-occurring' anti-I present in adult serum, is not a γG-globulin; thus the antibody, both in cord serum and in adult serum, is inactivated by treatment with 2-mercaptoethanol, is not eluted with γG-globulin using DEAE-cellulose chromatography and is recovered in the fast sedimenting fractions after ultracentrifugation. Furthermore, the antibody does not disappear from the circulation of newborn infants as do γG antibodies which cross the human placenta.

These findings indicate that the antibody in cord serum is a γM-globulin and that its production often begins before birth.

     

孕妇解脲支原体、沙眼衣原体感染的诊断与药物干预

目的探讨妊娠期孕妇解脲支原体（UU）、沙眼衣原体（CT）感染的发病率及其对感染者的治疗效果。方法对108例妊娠妇女采用核酸杂交的方法检测宫颈分泌物,对标本UU、CT-DNA进行DNA扩增、核酸杂交检测。结果 108例妊娠早中期孕妇宫颈分泌物UU、CT的阳性率分别是33.33%,7.41%,口服阿奇霉素治疗后检测UU、CT阳性率分别是17.59%,1.85%。两组间有显著性差异（P=0.001或P=0.002）。结论解脲支原体、沙眼衣原体是妊娠期妇女感染的常见病原体,临床治疗效果显著值得推广应用。     

Serotypes of Ureaplasma urealyticum isolated from normal pregnant women and patients with pregnancy complications.

To compare the distribution of Ureaplasma urealyticum serotypes 1 to 10 in different patient populations, the serotypes of 240 U. urealyticum strains from 207 patients were determined by the indirect immunofluorescence test by using U. urealyticum antisera 1 to 10. Strains were obtained from the following four patient groups: group 1, 24 couples in which the women had a history of recurrent spontaneous abortion; group 2, 25 patients who had their first spontaneous abortion; group 3, 14 pregnant patients with pregnancy complications (premature delivery, intrauterine death); and group 4, 138 patients with uneventful pregnancies. The serotypes most often found in these 207 patients were as follows: serotype 3, 52.2%; serotype 6, 30.3%; serotype 10, 11.4%; serotype 1, 9.5%; serotype 4, 6.5%; serotype 8, 6.5%. Serotypes 2, 5, 7, and 9 were found in less than 1% of the patients. More than one serotype was found in 16.9% of the patients. The overall distribution of the 10 serotypes in the different groups was similar, except for that of serotype 4. Serotype 4 was isolated from 20.8% of the patients in group 1 and from 5.1% of the patients in group 4 (P less than 0.01). Results of this study indicate that U. urealyticum serotype 4 can be isolated more frequently from patients with a history of recurrent miscarriages than from normal pregnant women.     

Neutralizing antibody response to cytomegalovirus in seropositive pregnant women.

The neutralizing (NT) antibody response to human cytomegalovirus (HCMV) in seropositive pregnant women was evaluated to establish the role of protective humoral immunity in HCMV infections (reactivation) during pregnancy. Complement fixation (CF) antibody titers increased significantly in 54 (0.62%) of 8,663 seropositive cases tested during gestation. However, titers of NT antibody, when tested in the presence of complement (C'), increased as gestation progressed and exceeded 1:500 in most of the cases in whom the CF antibody titer had shown earlier an insignificant increase. When NT antibodies were tested in the absence of C', insignificant increase in titers were found. The results suggest that the presence of high titer of NT antibody may play an important role in protective humoral immunity against reactivation of HCMV in pregnant women, and may also be effective in preventing intrauterine infection and modulating the severity of perinatal infection in offspring borne of HCMV carrier mothers.     

Immunoblot analysis of antibody response in mice infected with Coxiella burnetii phase I.

Mouse sera collected from day 4 to day 133 postinfection (p.i.) with phase I Coxiella burnetii strain Nine Mile were analysed by immunoblotting with phase I C. burnetii cell lysate. Antibodies of IgG class protein antigens were revealed already on day 10 p.i. (60, 49 and 27 kD proteins), followed by those to 77 kD protein from day 18 p.i. and to further 7 (from 42 to 70 kD) proteins from day 28 p.i. IgG antibody reaction was observed also with 5 antigens in 14-20 kD region corresponding to lipopolysaccharides from day 22 p.i. Surprisingly, antibodies of IgM type appeared later (from day 22 p.i.) and were directed only to protein antigens, most markedly to 60 and 77 kD proteins. Differences in immunoblot patterns observed with the serum collected on day 72 p.i. before and after absorption to phase I and phase II C. burnetii cells, and to phase I cells treated by trichloroacetic acid (TCA) or KIO4, indicate the surface localization of protein phase I antigenic epitopes, which can be destroyed partly by TCA and almost completely by KIO4 treatment.     

Immunoglobulin M antibodies detected by enzyme-linked immunosorbent assay and radioimmunoassay in the diagnosis of cytomegalovirus infections in pregnant women and newborn infants.

Immunoglobulin M (IgM) antibodies were detected by a commercially available enzyme-Linked Immunosorbent Assay (ELISA) in 36 of 49 (73%) pregnant women with primary cytomegalovirus (CMV) infection. A positive ELISA-IgM result occurred in 10 of 13 patients (77%) assessed within 8 weeks of seroconversion. The sensitivity of the radioimmunoassay (RIA) to identify primary infection in pregnant women was comparable, 78% in general and 86% for women tested within 16 weeks of seroconversion. Of the 36 women with primary infection who had detectable IgM antibodies by ELISA, 25 (69%) were delivered of congenitally infected infants, whereas of the 13 with undetectable IgM antibodies, 7 (54%) transmitted the infection in utero. IgM antibodies were detected by ELISA in only 5 of 43 (11%) women who experienced a recurrence of CMV which either did or did not result in congenital infection. RIA was less likely to measure CMV-specific IgM in recurrent infection, inasmuch as 1 of 19 (5.2%) women with proven recurrent infection had detectable IgM antibody, giving RIA a better specificity for primary infection. Specific IgM antibodies were detected by ELISA in 42 of 61 (69%) babies congenitally infected with CMV and in 4 of 70 (5.7%) uninfected control newborn infants. The RIA was superior for diagnosis of congenital CMV infection, with a sensitivity of 89% and a specificity of 100%. The lower sensitivity of the ELISA-IgM occurred in the category of congenitally infected infants born to mothers with recurrent infection (43%), a group that is at the lowest risk of disease or to develop sequelae. This commercially available ELISA-IgM could be used in combination with a CMV-specific IgG test for monitoring women during pregnancy for primary infection.     

Interleukin-1 receptor antagonist in newborn babies and pregnant women

We have used patch-clamp techniques to study the effect of the sulfhydryl group oxidizing agents mercury and thimerosal on calcium-activated nonselective cation channels from brown adipose tissue. 100 nmol/l mercury and 50 mol/l thimerosal induced a complete block. Blockade could be reversed by reduction of the mercaptide by dithiotreitol (DTT). Mercury was found to be the most potent blocker (IC₅₀-value 21×10^–9 mol/l), whereas thimerosal (IC₅₀-value 1.5×10^–6 mol/l) was as effective as 3,5-dichlorodiphenylamine-2-carboxylic acid (DCDPC). The DCDPC effect, however, could not be reversed by DTT, indicating different blocking mechanisms. It is concluded that SH-groups are involved in gating of the calcium-activated nonselective channel.     

Hyperoxia potentiates Ureaplasma urealyticum pneumonia in newborn mice.

The effect of continuous exposure to 80% oxygen on newborn mice with Ureaplasma urealyticum pneumonia was determined. Mice were inoculated intranasally with either U. urealyticum or sterile broth and then housed in either 80% oxygen or room air (21% oxygen). The mice were sacrificed at either 7 or 14 days after inoculation. Significantly more mice in the U. urealyticum group housed in 80% O2 than in the room air-exposed group were culture positive 14 days after inoculation (P = 0.042), but no difference was found at 7 days. The presence of alveolar macrophages, neutrophils, and lymphocytes and alveolar wall thickness were determined. Overall, the group housed in 80% O2 and inoculated with U. urealyticum had severe pulmonary lesions at both time points, while the lesion severity in the room air-exposed group inoculated with U. urealyticum and the group housed in 80% O2 and inoculated with sterile broth was dependent on the time point. Mortality was significantly higher in the group housed in 80% O2 and inoculated with U. urealyticum than it was in all other groups (P less than 0.001). Our results indicate that hyperoxia causes the persistence of U. urealyticum in the lungs of newborn mice, acutely potentiates the inflammatory response, and turns an otherwise self-limited pneumonia into a lethal disease.     

Immunoblot analysis of the humoral immune response to cytomegalovirus in non-pregnant and pregnant guinea pigs

Summary The temporal appearance of antibodies to guinea pig cytomegalovirus (CMV) proteins was examined in pregnant and non-pregnant guinea pigs by immunoblotting. Antibodies to 12 guinea pig CMV proteins appeared in a defined time course during primary infection and were detected at a later time and in lower concentrations in pregnant than in non-pregnant guinea pigs.     

Immunoblot analysis of IgG subclass antibody response against Coxiella burnetii in Balb/c mice.

Balb/c mice were inoculated with live or inactivated organisms of Coxiella burnetii, strain Nine Mile, phase I. Sera collected after different time intervals were subjected to immunoblot analysis and results compared with ELISA values. Immunoblots were performed with different horseradish peroxidase labelled conjugates (goat anti-mouse IgG1, IgG2a, IgG2b, IgG3) and results monitored and analysed by laser densitometry. ELISA analysis was performed using the same peroxidase labelled goat anti-mouse subclass antibody conjugates. In addition, goat anti-mouse IgG(H+L), IgG(H), IgM, and IgA conjugates were used for ELISA tests.     

1627例新生儿红细胞抗体筛查和鉴定试验的分析

目的红细胞血型抗体（即不规则抗体）筛查和鉴定试验在新生儿溶血病中的意义。方法采用微柱凝胶技术对1627例新生儿进行ABO、Rh血型定型、直接抗人球白试验、游离抗体测定、放散试验,红细胞血型抗体筛查试验,检测出6例有ABO以外的抗体,进一步用盐水、聚凝胺法、抗球蛋白试验进行抗体鉴定。结果6例红细胞血型抗体筛查阳性,进一步抗体鉴定,检测出抗-D4例,抗-E1例,抗-c1例。结论根据红细胞血型抗体的特性,可为患儿选择无相应抗原的血液进行换血和治疗。     

High-resolution cry analysis in preterm newborn infants

Infant monitoring is a common procedure in clinical practice in neonatal critical care units. A number of vital functions are monitored, such as heart beat, breathing, blood flow, etc. Specifically, preterm and/or low-birth-weight infants often present respiratory problems that require monitoring. These may range from insufficient ventilation to apnoea. One of the most common events that may affect the respiratory flow is crying, a physiological action made by the infant to communicate and draw attention, but, for a preterm infant, this action requires great effort, which may cause distress and even may have an adverse impact on blood oxygenation. Acoustic analysis of newborn infant cry is thus of importance, since it is related to other basic neuro-physiological parameters. Being easy to perform, cheap and completely non-invasive, it can be successfully applied in many circumstances.The newborn infant cry is characterised by very high fundamental frequency (F₀) and resonance frequency (RFs) values, with abrupt changes and voiced/unvoiced features of very short duration in a single utterance. To deal with such signals, a new user-friendly software tool has been developed, that allows robust tracking of main acoustic parameters on very short and time-varying signal frames. The software developed provides the user with a high-resolution picture of the cry signal characteristics.     

Immunoblot analysis of the antibody response to antigens of Leishmania donovani in Indian kala-azar

When infected with Leishmania donovani, patients develop specific antibodies that constitute the basis of serodiagnosis. Using immunoblot analysis, we examined the antibody response to antigens of L. donovani in 35 kala-azar (KA) patients and 67 controls. Sera from KA patients recognised numerous antigens with molecular weights ranging from 14-110 kDa. Antigens of 40 kDa, 55 kDa, 65 kDa, 70 kDa and 82 kDa were recognised most frequently. All KA patients produce an antibody response to one or more of these antigens. The majority (83%) of KA cases recognised at least four of these five parasite antigens. The 70 kDa antigen showed the greatest sensitivity for Indian KA, and produced a positive reaction in 94% of patients. This antigen gave 10% false-positive reactions in controls comprising patients with related diseases (i.e. tuberculosis, leprosy and malaria) and in healthy controls. Data indicated that the 70 kDa antigen may include a member of the heat shock protein 70 family. Studies with four clinical isolates of L. donovani showed that the 70 kDa component was expressed in all the strains examined. Immunoblot assay (Western blotting) provided a sensitive diagnostic test for KA patients, and identified the 70 kDa parasite antigen that is promising as a potential target antigen for the development of less complex serodiagnostic assays for KA.