Tear mucus crystallization in children with cystic fibrosis

Cystic fibrosis is characterized by an abnormally high electrolyte concentration in exocrine secretions. The authors performed the tear mucus ferning test in 26 eyes of children with cystic fibrosis and compared the results to those in an equal number of age-matched normals. The results suggest that the increased electrolyte concentration could be responsible for the increased hyperviscosity of mucus. The tear mucus ferning test appears to be a suitable diagnostic test for the assessment of cystic fibrosis.     

Genetics: Genetic analysis prior to selective fetal reduction in multiple pregnancy: technical aspects and clinical outcome

Multiple pregnancies resulting from ovarian stimulation areat a higher risk of carrying at least one fetus affected byMendelian or chromosomal anomalies, the incidence of which isdirectly related to the order of multiples. Genetic analysisbefore fetal reduction was offered to both high-and low-riskpregnant women carrying two or more fetuses after ovulationinduction. Chorionic villus sampling (CVS) and fetal reductionwere achieved by transabdominal needling. The use of short-termculture, the polymerase chain reaction and fresh tissue enzymaticanalyses have made it possible for genetic diagnosis to be availablein a few days. A total of 100 patients had multifetal pregnancyreduction performed by a single operator; all of them completedpregnancy and none was lost at follow-up. The total fetal lossbefore 24 weeks was 7% and no statistically significant relationshipwas found with the final number of fetuses and CVS. Perinatallosses (3.9%) were only present in the series with a final numberof two fetuses. Pregnancy duration and birthweight were significantlyhigher in singletons than in twins, but were not related toCVS. The rate of chromosomal disorders was higher (7.2%) inthe study series than in singleton pregnancies not undergoingfetal reduction. Diagnostic error due to incorrect samplingwas reported in 1.5% of cases. These data support fetal reductionas a valuable strategy to improve the outcome of multiple pregnancy.The outcome of pregnancies reduced to singletons was significantlybetter than of those reduced to twins, and was not related toCVS. Therefore, prenatal genetic diagnosis should become anintegral part of counselling on multiple pregnancy, and is stronglyrecommended when reduction to singleton pregnancy is requested.     

Brain-derived neurotrophic factor in cerebrospinal fluid of patients with chronic daily headache: relationship with nerve growth factor and glutamate levels

Little has been done to investigate the biochemical basis of chronic daily headache (CDH). Our group has recently demonstrated an increase in the cerebrospinal fluid (CSF) levels of nerve growth factor (NGF) in CDH patients, supporting the involvement of this growth factor in the abnormal processing of head pain in this pathological condition. Other members of the neurotrophin family, especially brain-derived neurotrophic factor (BDNF), have been hypothesized as being involved in the development of chronic head pain in patients affected by CDH, but so far no data are available on this subject. BDNF, NGF and glutamate levels were determined in the CSF of 25 patients affected by CDH with a previous history of migraine. These levels were compared with those of a group of 20 control subjects, for whom the CSF examination and other instrumental investigations excluded diseases of the central and peripheral nervous systems. Significantly higher levels of BDNF, NGF and glutamate were found in CDH patients compared with control subjects (p<0.0001, p<0.0002 and p<0.001, respectively). A significant positive correlation emerged between CSF values of BDNF and those of NGF (r=0.61, p<0.001) and glutamate (r=0.44, p<0.025) in CDH patients. No significant differences were detected in BDNF, NGF and glutamate levels between CDH patients with analgesic overuse and those without. These results support the involvement of BDNF in CDH through the potentiation of glutamatergic transmission involved in the processing of head pain. The significant correlation between BDNF and NGF levels suggests that NGF-mediated up-regulation of BDNF in central sites involved in long-term sensitization plays a key role in persistent head pain in CDH patients. Correspondence to P. Sarchielli     

Identification and disruption of the gene encoding the third member of the low-molecular-mass rhoptry complex in Plasmodium falciparum

The low-molecular-mass rhoptry complex of Plasmodium falciparum consists of three proteins, rhoptry-associated protein 1 (RAP1), RAP2, and RAP3. The genes encoding RAP1 and RAP2 are known; however, the RAP3 gene has not been identified. In this study we identify the RAP3 gene from the P. falciparum genome database and show that this protein is part of the low-molecular-mass rhoptry complex. Disruption of RAP3 demonstrated that it is not essential for merozoite invasion, probably because RAP2 can complement the loss of RAP3. RAP3 has homology with RAP2, and the genes are encoded on chromosome 5 in a head-to-tail fashion. Analysis of the genome databases has identified homologous genes in all Plasmodium spp., suggesting that this protein plays a role in merozoite invasion. The region surrounding the RAP3 homologue in the Plasmodium yoelii genome is syntenic with the same region in P. falciparum; however, there is a single gene. Phylogenetic comparison of the RAP2/3 protein family from Plasmodium spp. suggests that the RAP2/3 duplication occurred after divergence of these parasite species.     

The purification of a gs antigen of the murine mammary tumor virus and its quantitation by radioimmunoassay.

A method using Concanavalin (ConA) affinity chromatography has been developed for the purification of the mouse mammary tumor virus (MuMTV) gs antigens (gp52) and (p27). The procedure combines ConA chromatography and DEAE cellulose fractionation to yield the gs antigens in both high yield and sufficient purity for use in radioimmunoassay (RIA). The gp52 obtained has been iodinated with the [¹²⁵I]Bolton-Hunter reagent, chromatographed on Sephadex G-100, and utilized in the development of a blocking radio immunoassay (RIA). The sensitivity of this assay (0.5–1.0 ng) is superior to that achieved with whole particle assays. The procedures used for the isolation and iodination of the gp52 avoid the technical problem of incomplete displacement of [¹²⁵I]gp52 by native viral antigen. The resulting RIA provides a sensitive, reliable tool for studying the expression of the gp52 antigen and its relationship to the onset and progression of murine breast cancer.     

Mediastinal hibernoma: a case report

Hibernomas are rare benign tumours that arise most often in adults from the remnants of fetal brown adipose tissue. They usually affect muscle and subcutaneous tissue and are asymptomatic and slow growing. The distribution of this tumour follows the sites of persistence of brown fat. Out of more then 100 cases described in the word literature only three hybernomas were mediastinal. A recent clinicopathological study of 170 cases from the Armed Forces Institute of Pathology confirmed the exceptionality of the intrathoracic location. This report describes a very rare case of mediastinal hibernoma in a young man.     

Identification, characterization and biological activity of oxytocin receptor in the developing human penis

Although abnormalities of the male external genitalia (MEG) are a relatively common problem, little is known concerning the molecular mechanisms that finely regulate penile development. We report here the expression of the oxytocin receptor (OTR) gene by real-time RT-PCR in human fetal tissues (11th-12th week of gestation), including the MEG. The developing penis expressed a very high level of OTR mRNA, only a half log(10) unit lower than fetal central nervous system, used as a positive control. The OTR protein is also highly expressed (western, immunohistochemistry and binding studies) and immunolocalized both in the mesenchymal body and in the surrounding blood capillaries, which will later constitute penile trabeculae and sinusoids. Binding studies using [125I]oxytocin antagonist ([125I]OTA) in cultured human fetal penile smooth muscle cells (hfPSMC) revealed the presence of specific OTR with a high capacity and affinity for oxytocin (OT) and for OTA. Increasing concentrations of OT dose-dependently induced intracellular Ca2+ mobilization. Furthermore, OTR mediated an increase in the proliferation and the migration of hfPSMC. In conclusion, we demonstrate that in the developing human MEG, OTR is highly expressed and might be involved in coordinating timely and appropriate proliferation and migration of the penile cells. Thus, OTR might represent an additional target for investigating human fetal MEG organogenesis.     

Occurrence and Potential Diagnostic Applications of Serological Cross-Reactivities between Brucella and Other Alpha-Proteobacteria

Agrobacterium, Sinorhizobium, and Ochrobactrum are genera closely related to Brucella but, in contrast to the latter, are not pathogenic for humans and animals. We studied by an indirect enzyme-linked immunosorbent assay (ELISA) the reactivities of brucellosis sera against cytosolic (CYT) and membrane (MA) antigens from these nonpathogenic bacteria, and we evaluated the potential usefulness of these cross-reactions for the diagnosis of brucellosis in humans, sheep, cows, and dogs. Canine infection by Brucella canis was detected with high specificity by CYT antigen-based ELISAs (96% for Agrobacterium, 96% for Sinorhizobium, and 91% for Ochrobactrum), while sensitivity was variable (58% for Agrobacterium, 88% for Sinorhizobium, and 84% for Ochrobactrum). In addition, it was possible to diagnose canine disease shortly after exposure to the pathogen (15 days). Similar results for canine brucellosis were obtained with MA antigens. In contrast, normal sera from humans, sheep, and cattle reacted strongly with all the antigens (CYT and MA antigens from the three bacteria), producing high cutoff values and, consequently, low sensitivities. While for some host species the reactivity patterns of normal sera by Western blotting were similar to those produced with sera from infected individuals, the reactivity pattern of bovine sera against Sinorhizobium meliloti antigens exhibited some differential bands for the two groups of sera. These results show that crude fractions from nonpathogenic alpha-proteobacteria can be used to diagnose canine brucellosis but may need to be further separated into simpler fractions to have diagnostic usefulness in ovine, bovine, or human infection. By reducing the biosafety requirements, the use of antigens derived from these nonpathogenic bacteria would simplify the production of diagnostic kits for brucellosis, especially in settings where biosafety level-3 facilities are scarce or absent.     

Lack of association between serotonin transporter gene promoter variants and autistic disorder in two ethnically distinct samples

Family-based studies performed to date provide conflicting evidence of linkage/association between autistic disorder and either the "short" [Cook et al., 1997: Mol Psychiatry 2:247-250] or the "long" [Klauck et al., 1997: Hum Mol Genet 6:2233-2238] allele of a polymorphic repeat located in the serotonin transporter (5-HTT) gene promoter region, affecting 5-HTT gene expression [Lesch et al., 1996: Science 274:1527-1531]. The present study was designed to assess linkage and linkage disequilibrium in two new ethnically distinct samples of families with primary autistic probands. The 5-HTT promoter repeat was genotyped in 54 singleton families collected in Italy and in 32 singleton and 5 multiplex families collected in the U.S.A., yielding a total sample of 98 trios. Linkage/association between 5-HTT gene promoter alleles and autistic disorder was assessed using the transmission/disequilibrium test (TDT) and the haplotype-based haplotype relative risk (HHRR). Both the Italian and the American samples, either singly or combined, displayed no evidence of linkage/association between 5-HTT gene promoter alleles and autistic disorder. Our findings do not support prominent contributions of 5-HTT gene variants to the pathogenesis of idiopathic infantile autism. Heterogeneity in pathogenetic mechanisms underlying the disease may require that linkage/association studies be targeted toward patient subgroups isolated on the basis of specific biochemical markers, such as serotonin (5-HT) blood levels. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:123-127, 2000.