Late preterm birth has direct and indirect effects on infant gut microbiota development during the first six months of life.

AIM: Preterm infants display aberrant gut microbial colonisation. We investigated whether the differences in gut microbiota between late preterm and full-term infants results from prematurity or external exposures. METHODS: This study comprised 43 late preterm infants (340/7 -366/7 ) and 75 full-term infants based on faecal samples collected following birth and at two to four weeks and six months of age. We assessed clinically relevant bacteria using quantitative polymerase chain reaction. Logistic regression analyses were performed to determine whether the observed differences in gut microbiota were attributable to prematurity or perinatal exposure. RESULTS: The prevalence of bifidobacteria differed in the intestinal microbiota of the full-term and late preterm neonates. Differences in the presence of specific species were detected at the age of six months, although the microbiota alterations were most prominent following delivery. As well as prematurity, the mode of birth, intrapartum and neonatal antibiotic exposure, and the duration of breastfeeding had an additional impact on gut microbiota development. CONCLUSION: The gut microbiota composition was significantly different between late preterm and full-term infants at least six months after birth. Antibiotic exposure was common in late preterm infants and modulated gut colonisation, but preterm birth also affected gut microbiota development independently.

Incidence and pathogenesis of clinical relapse after herpes simplex encephalitis in adults.

OBJECTIVES: To study the occurrence of relapse of herpes simplex encephalitis (HSE) and to find out whether soluble activity markers in cerebrospinal fluid (CSF) indicate direct viral or immune- mediated events. METHODS: A consecutive series of 32 adult survivors of HSE were followed to determine the incidence of clinical relapse of HSE. Four patients had neurological deterioration interpreted as relapsing HSE. Four non-relapsing HSE cases were selected as matched controls. Fifty nine batched, paired CSF and serum samples from the eight HSE patients were analysed for soluble activity markers, predominantly cytokines and mediators (interferon-gamma, soluble CD8, tumour necrosis factor-alpha, and interleukin-10), amount of HSV-DNA and markers of glial and neuronal destruction (neurofilament protein, glial fibrillary acidic protein, S-100-beta, and neuron specific enolase). RESULTS: Relapse of HSE was diagnosed in 3 of 26 (12 %) acyclovir-treated patients (5 episodes during 6.1 years of followup) and in 1 of 6 vidarabine-recipients. All relapses occurred from 1 to 4 months after acute HSE, except for a second relapse after 3.3 years in one patient. Computer tomography at relapses revealed few abnormalities apart from those found during the primary disease. Intravenous acyclovir and corticosteroids were given for 7-21 days in all the relapse patients. All relapse patients seemed to recover to the pre-relapse condition. HSV-DNA was demonstrated in CSF in all patients during the acute stage but not in any of 13 CSF samples taken during relapse phases. The HSV viral load during the acute stage of HSE was not higher or of longer duration in the relapsing patients than in the non-relapsing HSE controls. The levels of sCD8 were increased in nearly all CSF samples tested with peaks of sCD8 at one month of acute HSE. In all episodes of relapse, sCD8 peaks were detected during the first week at high levels. CSF levels of neuron-specific enolase, S-100 and glial fibrillary acidic protein were markedly lower at relapse than at the acute stage of HSV-1 encephalitis. CONCLUSION: The lack of demonstrable HSV DNA in CSF, the lack of acute CSF signs and the lack of signs of neural and glia cells destruction indicate that a direct viral cytotoxicity is not the major pathogenic mechanism in relapse. Instead, the pronounced CSF proinflammatory immunological response and the relative lack of CSF anti-inflammatory cytokine IL-10 response suggest immunologically-mediated pathogenicity.

Maternal enteroviral infection during pregnancy as a risk factor for childhood IDDM. A population-based case-control study.

Using the nationwide childhood-onset diabetes register in Sweden, we were able to trace children who contracted diabetes before the age of 15 years and who were born at a specific hospital in Sweden where maternal sera from delivery had been stored during the years 1969-1989. Sera obtained at delivery from 57 mothers of diabetic children were compared with sera from 203 mothers of control subjects who were delivered at the same hospital during the same time period. The sera were analyzed blindly using a group-specific enzyme-linked immunosorbent assay for enteroviral IgG and IgM antibodies before and after urea wash as an avidity test. On the same plates, IgG antibodies to herpes, mumps, and toxoplasmosis were analyzed. The mean absorbance values of enteroviral IgG antibodies against enteroviral antigens (echo30, coxsackie B5, and echo9) were significantly higher among mothers whose children later developed diabetes (P = 0.002, P = 0.02, and P = 0.04, respectively). When reduction in activity after urea wash, indicating recently formed antibodies, was compared, the differences were even more pronounced (P < 0.001 for all three antigens). No significant differences were found for antibodies against herpes (all types), herpes type 2, mumps, or toxoplasmosis. When IgM activity and/or a significant decrease in avidity index, an indication of recent enterovirus infection, was used as a risk exposure, the odds ratio standardized for year of birth (95% confidence interval) was 3.19 (1.39-7.30). We conclude that the results of this study indicate that enteroviral infection during pregnancy is a risk factor for childhood-onset diabetes in the offspring.(ABSTRACT TRUNCATED AT 250 WORDS)

Association between intrathecal anti-HIV-1 immunoglobulin G synthesis and occurrence of HIV-1 in cerebrospinal fluid.

The levels of antibodies to HIV-1 and the occurrence of HIV-1 were determined in the cerebrospinal fluid (CSF) and the blood of 60 people in various stages of HIV-1 infection. Intrathecal synthesis of anti-HIV-1 immunoglobulin (Ig) G was detectable at a low frequency in individuals with normal immunological parameters, and in the majority of patients with various degrees of immunodeficiency. The intrathecal production of antibodies to HIV-1 was strongly associated with the recovery of the virus from CSF. A relationship between high anti-HIV-1 IgG levels and occurrence of HIV-1 was also found in blood. Patients without overt neurological symptoms exhibited intrathecal synthesis of anti-HIV-1 IgG as often as those with such symptoms. These findings suggest that intrathecal synthesis of antibodies to HIV-1 is related to a persistent HIV-1 antigenic stimulation in the central nervous system (CNS). HIV-1 often seems to elicit a humoral immune response in the CNS, without concomitant overt neurological symptoms.

Detection of immunoglobulin M antibody in primary human immunodeficiency virus infection.

Consecutive serum samples obtained from 20 homosexual men during symptomatic primary HIV infection were examined by a variety of IgG and IgM antibody assays. All sera obtained 2-5 weeks after onset of disease contained IgM anti-HIV as demonstrated by an IgM antibody capture assay. The IgM antibodies appeared during the 2 first weeks of illness, reached peak titres at 2-5 weeks and declined thereafter to undetectable levels at 2-3 months after the onset of disease. By contrast, IgG anti-HIV appeared later, during the second week after the onset of symptoms, and did not reach maximal levels until the IgM response had waned. The first IgM antibodies to appear were directed against gag proteins. IgM antibodies against env antigens were found less frequently and later in the course of the disease. These results suggest that IgM antibody determination may be helpful in the diagnosis of early HIV infection as a possible addition to the combined use of antigen detection and a second generation ELISA, which, in the present study, was found to be highly reliable for diagnostic purposes.

Molecular cloning and characterization of a full-length cDNA clone for human plasminogen.

A human liver cDNA library enriched for full-length clones was screened for plasminogen cDNA using a synthetic 24-nucleotide probe derived from a reported partial cDNA sequence. 12 positive clones were identified and one of these was characterized in detail. The 2.7 kb insert contains the complete coding region. At 5 positions, it gives residues different from those reported in a previous amino acid sequence analysis of the protein. The present results show an extra Ile at position 65, Gln instead of Glu at positions 53 and 342, Asn at position 88 instead of Asp, and Asp at position 453 rather than Asn. In the 3'-non-coding region an extension of 29 bases is found which does not contain any structure compatible with a known polyadenylation signal. Instead, the consensus signal AATAAA is placed at a distance of 46 bases upstream of the poly(A)-tail.

Regional cerebral blood flow scintigraphy in tick-borne encephalitis and other aseptic meningoencephalitis.

UNLABELLED: In a prospective study, regional cerebral blood flow (rCBF) was studied in patients with aseptic meningoencephalitis at 6 wk and 1 yr after onset of disease. METHODS: Patients with tick-borne encephalitis ([TBE] n = 73) and meningoencephalitis of other etiology ([non-TBE] n = 56) were investigated with rCBF-scintigraphy (SPECT). SPECT images in the acute phase of disease and at long-term follow-up were analyzed for blood-flow disturbances and their localization in the central nervous system and were correlated to clinical course and outcome. RESULTS: Decreased rCBF was seen in 50% of patients after 6 wk (TBE 49%, non-TBE 50%) and in 46% (TBE 47%, non-TBE 46%) after 1 yr. The decrease in rCBF was moderate in 18% and 11% at 6 wk and in 8% and 9% at the 1-yr follow-up of TBE and non-TBE patients, respectively. Reduced rCBF was significantly more common among patients with encephalitis than among those with meningitis, and more common in males. The distribution of cerebral flow changes was predominantly patchy or multifocal. At long-term follow-up, improvement in rCBF was seen in 28 of 109 patients (26%), but worsening of decreased rCBF was demonstrated in 19 of 109 (17%). In TBE patients, remaining neurological symptoms at 6 wk of disease were associated with worsening of decreased rCBF at the 1-yr follow-up. CONCLUSION: With SPECT, rCBF changes, mostly slight and patchy or multifocal, were detected in patients with aseptic meningoencephalitis. Decreased rCBF was more frequent in patients with moderate-to-severe encephalitis, although the clinical use in predicting long-term outcomes in aseptic meningoencephalitis (e.g., TBE) seems limited.

Respiratory syncytial virus infection in hospitalized patients and healthy children in El Salvador.

Nasopharyngeal specimens from 42 children less than one-year old hospitalized with bronchiolitis or pneumonia in El Salvador were analyzed for the presence of subgroup-specific respiratory syncytial virus (RSV) antigens by the indirect immunofluorescence technique. The antigen RSV-A was demonstrated in 28 children, RSV-B in three, and in one child subgroup, specificity could not be determined. The male:female ratio in the RSV-infected children was 1.9:1. The most severe disease, requiring intensive care, was observed in two infants with RSV-B infection. Determination of serum IgG, IgA, and IgM antibodies in acute and convalescent sera showed that none of the tests alone had sufficient sensitivity for routine diagnostic purposes, although, in combination, they provided a correct diagnosis in 86% of the RSV-infected children. A seroprevalence study of IgG, IgA, and IgM antibodies in 206 healthy children showed that a primary RSV infection is usually acquired during the first year of life in El Salvador. These results also indicated that reinfections with RSV frequently occur during the first 3-4 years of life and suggest that the occurrence of serum RSV IgA antibodies may be a marker of reinfection.

Comparison between a commercial ELISA, Rubazyme, and hemolysis-in-gel test for determination of rubella antibodies.

A commercial enzyme-linked immunosorbent assay, Rubazyme, was compared with the hemolysis-in-gel (HIG) test for antibodies to rubella in 826 sera. The results were in agreement for 99.4% of the 725 sera tested for immunity. However, the Rubazyme assay was no more efficient that either the hemagglutination-inhibition or HIG test in discriminating between sera with low levels of antibody and negative sera. Thus, it was concluded that the HIG test is the method of choice for immunity testing because of the low cost and simplicity. Rubazyme may be of value to confirm equivocal HIG results.

Tick-bone encephalitis in Sweden in relation to aseptic meningo-encephalitis of other etiology: a prospective study of clinical course and outcome.

A total of 149 patients with clinical symptoms of acute viral meningo-encephalitis were enrolled in this study from June 1991 to December 1993. Tick-borne encephalitis (TBE) was diagnosed in 85 of the 149 patients (males 54%, median age 42 years (range 15-78)). The initial clinical appearance of TBE was classified as mild (mainly meningeal; (n = 47), moderate (n = 31) or severe (n = 7), more or less encephalitic. The most common acute symptoms of encephalitis were ataxia (26%), altered consciousness (20%), decreased concentration or memory (9%), irritable response to light and sound (28%), tremor (9%) and dysphasia (9%). Spinal nerve paralysis (11%) occurred in all three clinical stages and did not correlate with the severity or duration of encephalitis. The duration of hospitalisation, the time on the sick-list and the time to recovery were significantly longer in TBE patients. All patients survived, but many patients with TBE suffered an extended period of neurological dysfunction. Of patients with TBE 80% (68/85) showed persisting symptoms of CNS dysfunction on follow-up at week 6, compared with 55% (35/64) of the patients with aseptic meningitis of other aetiology. The corresponding figures after 1 year were 40% (33/83) and 20% (13/64). One year after TBE 13 (28%) patients with initially mild, meningeal symptoms had decreased memory and decreased concentration capacity, dysphasia or ataxia. Spinal nerve paralysis persisted after 1 year in 5 of 9 patients with TBE. In conclusion, TBE in Sweden is associated with a significant morbidity and a post-TBE syndrome existed after 1 year in more than one third of the patients.

Long-term persistence of intrathecal virus-specific antibody responses after herpes simplex virus encephalitis.

Paired sera and cerebrospinal fluids (CSF) from nine surviving patients were collected 4.5 to 8 years after acute herpes simplex (HS) virus encephalitis. Oligoclonal bands of IgG were detected in the CSF of all, and seven patients had an elevated CSF IgG index. Antibodies to HS, varicella-zoster (VZ), measles, and cytomegalo viruses were analysed by enzyme-linked immunosorbent assay (ELISA) and by imprint immunofixation (IIF) of specimens separated by electrophoresis and by thin-layer electrofocusing. Intrathecal synthesis of HS and VZ IgG antibodies was demonstrated in all and of measles IgG antibodies in one patient by both methods. Intrathecal synthesis of HS IgA antibodies was demonstrated by ELISA in three and by IIF in seven patients; the latter method also disclosed intrathecal synthesis of VZ IgA antibodies in two. No patient had intrathecal synthesis of viral IgM antibodies. The intrathecally synthesized antibodies demonstrated by IIF displayed oligoclonal characteristics. The IIF analyses as well as virus absorption tests indicated that the intrathecally synthesized VZ IgG and IgA antibodies could be explained as HS antibodies cross-reacting with VZV. The results indicate that a long-term persistence of intrathecal antibody responses to HS virus is a common feature after acute HS encephalitis. The intrathecal production of measles IgG antibodies in one case may reflect a similar persistence of non-specific immune responses induced during the acute infection.

Late ophthalmologic manifestations of neonatal herpes simplex virus infection.

We examined 32 children one to 15 years after virologically verified neonatal herpes simplex virus infection. Sixteen of 17 (94%) neurologically impaired children had ocular abnormalities compared to three of 15 (20%) neurologically healthy children. Disturbed oculomotor control occurred in 14 children (44%), most of whom were among those with severe handicap. Ocular morbidity was present in 13 (40%) of 32 children: one had cataracts, two had corneal scars, seven had optic atrophy, and nine had chorioretinal scars. The clinically silent chorioretinal lesions were manifest as coarse hyperpigmented areas between the equator and ora serrata. One child had suffered from acute fulminant retinitis. Twelve of 13 (93%) severely handicapped children had impaired vision, mainly because of cortical blindness. Less affected children had normal vision unless corneal scars were present. Long-term observation of patients with neonatal herpes infections is essential because ocular manifestations are not rare, and recurrences may be more common than previously reported.

Intrathecal antibody production against viruses of the herpesvirus family in acute retinal necrosis syndrome.

Viruses of the herpesvirus family cause acute retinal necrosis syndrome, a devastating necrotic retinitis in immunocompetent individuals. Direct proof of the viral origin of this disease may be obtained by demonstration of the virus, viral antigens, or viral DNA in biopsy specimens of retinas. In search of alternative diagnostic methods, we analyzed cerebrospinal fluid and serum with enzyme-linked immunosorbent assays for virus-specific antibody activity. Intrathecally produced viral antibodies were found in three consecutive patients with acute retinal necrosis syndrome: herpes simplex type 2 in a 30-year-old woman with a history of suspected neonatal herpes encephalitis, herpes simplex type 1 in a 35-year-old man, and varicella-zoster virus activity in a 62-year-old woman. None of the patients had clinical signs indicating an acute disorder in the central nervous system. This serologic approach seems to be of value for the diagnosis of an associated intracerebral viral infection in cases of acute retinal necrosis syndrome.

Influence of adjuvant radiation therapy in breast cancer on PWM induced Ig-secretion by blood lymphocytes in vitro.

The capacity of PWM (poke-weed mitogen) to stimulate Ig-secretion by blood lymphocytes was examined before and at various times after local radiation therapy (46.0 Gy) for breast cancer. It was observed that the secretion of IgM, IgA and IgG were significantly reduced at completion of radiation therapy. Secretion of IgM was reduced to the highest relative extent (approximately 10% of the pretreatment value). Thereafter there was a recovery of the Ig-secreting capacity which, however, remained below the pretreatment level, 12-18 months after completion of radiation therapy. The capacity of PWM-stimulated blood lymphocytes to secrete specific antibodies against morbilli and herpes simplex virus was also significantly impaired after radiation therapy. The reduction of Ig-synthesis in vitro was not correlated with the increase in the ratio between numbers of monocytes and lymphocytes in peripheral blood after radiation therapy. Possible explanations for these results are discussed.

Prevalence of hepatitis B virus markers and exposure to occupational risks likely to be associated with acquisition of hepatitis B virus among health care workers in Stockholm.

The prevalence of hepatitis B virus (HBV) markers and exposure to risks possibly associated with HBV transmission were investigated in 797 health care workers (HCW) from Stockholm. Altogether, 31/797 (3.9%) persons were positive for at least one HBV marker, 8.0, 7.9 and 6.4% respectively of children's nurses, laboratory assistants and psychiatric assistant nurses. A history of exposure to needle-stick injuries from any patient, was more often obtained from HCW with HBV markers than from HCW without such markers. The prevalence of HBV markers increased with age and duration of occupation in health care. Most HCW had been exposed to at least one occupational risk for HBV transmission early in their professional careers. Although the risk of acquiring HBV at present is low, the virus constitutes a potential occupational hazard for non-vaccinated HCW in Stockholm, a risk which may increase in the future since the number of chronic HBsAg carriers is increasing in Sweden.

Neonatal herpes simplex virus infections: HSV DNA in cerebrospinal fluid and serum.

AIM: To investigate the diagnostic potential of herpes simplex virus (HSV) DNA in cerebrospinal fluid and serum; to correlate the findings with outcome in the child and with type of maternal infection. METHODS: Cerebrospinal fluid and serum specimens from 36 children with verified neonatal HSV infections, diagnosed between 1973 and 1996, were examined using the polymerase chain reaction technique (PCR). RESULTS: In 21 children for whom both cerebrospinal fluid and sera were available, HSV DNA was found in one or both specimens in 19 (90%). Overall, HSV DNA was found in the cerebrospinal fluid of 74% of 27 children, and in the sera of 20 out of 30 children (67%). In two children HSV DNA was not demonstrable in either serum or cerebrospinal fluid. In sequential specimens from four children, the persistence of HSV DNA after the end of intravenous treatment was associated with a poor prognosis. CONCLUSIONS: These findings indicate that HSV DNA detection in CSF and serum is highly sensitive for the diagnosis of neonatal HSV infections but does not replace the detection of virus in other locations using virus isolation and antigen detection.

Cytomegalovirus DNA detection on Guthrie cards in patients with neonatal cholestasis.

AIM: To time the onset of cytomegalovirus (CMV) infection in patients (n = 39) with CMV associated neonatal cholestasis by analysing CMV DNA on Guthrie cards sampled at 3 days of age. METHODS: CMV infection was diagnosed by serology/urine isolation or by CMV DNA detection (polymerase chain reaction) in liver biopsy specimens. In order to time the infection dry blood filter paper discs were punched out from stored Guthrie cards. After phenol-choloroform extraction CMV DNA was detected by nested polymerase chain reaction. RESULTS: All cards from control children (n = 8) with congenital CMV tested positive; none of the negative controls (n = 4) did so. Two of 39 cholestatic infants were CMV DNA positive; their mothers had serological signs compatible with infection during the second half of the pregnancy. All other cholestatic infants tested negative. CONCLUSIONS: CMV DNA was not detected in most of the children using Guthrie cards, suggesting that infection developed at or soon after birth.

Prevalence of antibodies to herpes simplex virus in pregnant women in Stockholm in 1969, 1983 and 1989: implications for STD epidemiology.

Prevalence of antibody to herpes simplex virus types 1 and 2 was assessed in consecutive serum samples from a total of 3700 women pregnant in 1969, 1983, or 1989 from the same catchment area in Stockholm. There was little change in seroprevalence of antibody to herpes simplex type 1 in the 3 groups, but age-adjusted herpes simplex virus type 2 antibody prevalence was 19, 33, and 33% respectively. Increase in type 2 seropositivity with age was slight and similar in 1969 and 1989, but steep in 1983, indicating a shift in sexual behaviour. However, rising prevalence in women will be mirrored by rising prevalence in their male partners. The increase from 1969 to 1989 will thus partly be due to higher risk of infection per partner, and cannot be taken as direct evidence of increased rate of partner change during this 20-year period.