Biomedical subjects
Ben A Semmekrot
Publications and source records attributed to Ben A Semmekrot.
Congenital cytomegalovirus infection after recurrent infection: case reports and review of the literature.
Cytomegalovirus (CMV) is one of the most common causes of congenital infections in developed countries with reported incidences varying between 0.15% and 2.0%. The effects of congenital CMV infection may vary from a congenital syndrome to an asymptomatic course. Infants that are asymptomatic at birth may still present handicaps at a later age. It is generally accepted that symptoms of congenitally infected children are more severe after primary infection than after recurrent infection. In this article, we present two case reports which demonstrate that the outcome of recurrent maternal CMV infection may be severe. In the first case, early pregnancy serology showed positive IgG and IgM, but negative IgA, whereas at the time of diagnosed fetal death, 5 weeks later, there was only positive IgG. The second case showed positive IgG and negative IgM and IgA both in early pregnancy and after delivery. Since in both cases CMV was isolated from several organs, these findings are compatible with recurrent rather than primary CMV infection. In the reported patients, fetal death and necrotising enterocolitis occurred after a congenital CMV infection, with mothers having pre-existing immunity to CMV. In conclusion, these case reports and review of the literature emphasise that the outcome of recurrent maternal CMV infection may be severe and that congenital CMV infection should be considered in cases of pregnancy loss and necrotising enterocolitis with recurrent maternal CMV infection.
A novel splice site mutation in neonatal carnitine palmitoyl transferase II deficiency.
Mitochondrial beta-oxidation of long-chain fatty acids requires the concerted action of three tightly integrated membrane-bound enzymes (carnitine palmitoyltransferase I and II and carnitine/acylcarnitine translocase) that transport them into mitochondria. Neonatal onset of carnitine palmitoyltransferase II (CPT II) deficiency is an autosomal recessive, often lethal disorder of this transport. We describe a novel splice-site mutation in the CPT II gene, found in a Moroccan family, of which four out of five children have died from the neonatal form of CPT II deficiency. Mutation detection studies at the mRNA level in the CPT II gene implied that the affected children were homozygous for the previously reported 534T insertion followed by a 25-bp deletion (encompassing bases 534-558). Studies of genomic DNA, however, revealed all patients to be compound heterozygous for this 534T ins/del 25 mutation, and for a new g-->a splice-site mutation in the splice-acceptor site of intron 2. Because of these findings, prenatal diagnosis was performed in chorionic villi of three new pregnancies. This did not reveal new compound heterozygous genotypes, and, after uneventful pregnancies, all children appeared to be healthy. The new mutation is the first splice-site mutation ever identified in CPT II deficiency. The fact that it was not discovered in the patient's cDNA makes this study another example of the incompleteness of mutation detection at the mRNA level in cases where a mutation leads to aberrant splicing or nonsense-mediated messenger decay.
Congenital cytomegalovirus infection: review of the epidemiology and outcome.
UNLABELLED: Cytomegalovirus (CMV) is one of the most common viral causes of congenital infection. A future decision to lower its incidence by vaccination will depend on epidemiological conditions within a country and on the safety of the vaccine to be used, because a life vaccine may cause latency and subsequent reactivation that still may harm the fetus. The aim was to review the epidemiological studies published so far, with respect to factors that affect the incidence of congenital CMV infection, and factors that may influence its outcome, such as preexisting maternal immunity. The study included the data of 19 studies that were retrieved from a MEDLINE search during the period 1977 to 1997. The incidence of congenital CMV infection varied between 0.15% and 2.0% and seemed to correlate with the level of preexisting immunity in the population. Although preexisting maternal immunity was reported to strongly reduce transmission, the severity of congenital CMV infection (symptoms at birth and or sequelae later in life) was not significantly greater after virus transmission due to a primary infection of the mother as compared with recurrence or reinfection. The data indicate that preexisting immunity of the mother does not significantly mitigate the outcome of congenital infection. Moreover, life vaccines may bear a serious risk when transmittable to the fetus. TARGET AUDIENCE: Obstetricians and Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to describe the natural course of a CMV infection, to list the potential sequelae of a congenital CMV infection, to outline potential strategies to prevent transmission of CMV, and to summarize the diagnostic work up of a patient with a potential CMV infection.
Seroprevalences of herpes simplex virus type 1 and type 2 among pregnant women in the Netherlands.
BACKGROUND: In the Netherlands 73% of cases of neonatal herpes are caused by herpes simplex virus type 1 (HSV-1), whereas in the United States a majority are caused by HSV type 2 (HSV-2). GOAL To understand this difference we undertook a seroepidemiological study on the prevalence of HSV-1 and HSV-2 among pregnant women. STUDY DESIGN: Type-specific antibodies to HSV-1 and HSV-2 were detected by enzyme-linked immunosorbent assay (ELISA) in serum samples from 1,507 pregnant women in Amsterdam, Rotterdam, and Nijmegen. RESULTS: The prevalence of HSV-1 was 61% in Nijmegen, 73% in Amsterdam, and 75% in Rotterdam. The prevalence of HSV-2 was 11% in Nijmegen, 35% in Amsterdam, and 27% in Rotterdam. CONCLUSION: The seroprevalence of HSV-1 and HSV-2 antibodies among pregnant women in the Netherlands shows significant geographical differences, which were attributed to ethnical variation. However, the epidemiologic differences did not correlate with the incidence of neonatal herpes in the Netherlands.
Serial plasma concentrations of atrial natriuretic peptide, plasma renin activity, aldosterone, and antidiuretic hormone in neonates on extracorporeal membrane oxygenation.
To obtain information on water and salt regulating hormones and volume homeostasis during neonatal extracorporeal membrane oxygenation (ECMO), serial determinations of atrial natriuretic peptide (ANP), plasma renin activity (PRA), aldosterone (Aldo), antidiuretic hormone (ADH), colloid-osmotic pressure (COP), osmolality (Osmol), and central venous pressure (CVP) before, during, and after neonatal ECMO in 10 neonates with meconium aspiration syndrome (MAS) were carried out. Mean gestational ages and birth weights were 41(+3) weeks (39(+6) - 42(+4)) and 4,063 gm (3,500-4700), respectively; mean age at start and duration of ECMO 29.3 (14-69) and 152.6 hr (92-267), respectively. Plasma ANP (mean +/- SD) was 67.8+/-69.1 pmol/L before, decreased to 33.3+/-22.1 (not significant) pmol/L during, and significantly increased to 274.6+/-131.8 pmol/L after ECMO (p < 0.05). ANP correlated positively with CVP (r = 0.63; p < 0.001). Pre-ECMO PRA, Aldo, and ADH were comparable to those described earlier in normal neonates, decreased during (p < 0.001 for Aldo; p < 0.05 for PRA and ADH) and either remained elevated (PRA, p < 0.001; Aldo, p < 0.05) or decreased (ADH) after ECMO. COP and Osmol remained unchanged. Neonatal ECMO for MAS is characterized by circulatory and osmotic equilibrium. It is suggested that circulating volume contracts during and expands after neonatal ECMO for MAS.