An unusual case of Salmonella Enteritidis causing pneumonia, septic shock and multiple organ failure in an immunocompetent patient.

Salmonella species are facultative intracellular pathogens that most frequently cause self-limiting gastrointestinal disease, often acquired through the ingestion of contaminated food. We report the case of a 33-year-old otherwise healthy, not overtly immunosuppressed, man who was transferred to our facility with the chief complaint of respiratory failure and septic shock. Computed tomography of the chest revealed multifocal pneumonia in both lungs. A bronchial alveolar lavage was performed in the right middle lobe and cultures predominantly grew Salmonella enterica serovar Enteritidis. The patient received a prolonged course of antimicrobials, ultimately changing to oral levofloxacin. The etiology of the salmonella infection likely occurred through an aspiration event. Salmonella species are not a typical respiratory pathogen in immunocompetent hosts; however, clinicians should be aware of the possibility that salmonella species may be a pathogenic source of infection in the lungs; a prolonged course of antimicrobials may be warranted.

Genetic diversity of Cheju horses (Equus caballus) determined by using mitochondrial DNA D-loop polymorphism.

We used sequence polymorphism of the mitochondrial DNA D-loop (968 bp excluding the tandem repeat region) to determine genetic diversity of horses inhabiting Cheju (a southern island of Korea). Seventeen haplotypes with frequencies from 1.5 to 21.5% were found among 65 Cheju horse samples. Genetic diversity (h) of the 17 haplotypes was calculated to be 0.91, indicating that the extant Cheju horse population consists of diverse genetic groups in their maternal lineage. Phylogenetic analysis showed that 17 types of Cheju (D-loop sequences determined), 5 Mongolian, 6 Arabian, 3 Belgian, 2 Tsushima, 2 Yunnan, 1 Przewalskii, and 3 Thoroughbred horses (published sequences for the latter seven breeds) showed that Cheju horses were distributed into many different clusters in the tree. Four Mongolian horses clustered with separate Cheju horse groups, showing that some Cheju horses are clearly of Mongolian origin. The analysis of partial sequences (284 bp) of the D-loop of 109 horses showed that Thoroughbred, Mongolian, Lipizzan, and Arabian breeds are as diverse as Cheju horses. Our data together with others suggest that most horse breeds tested with reasonably sufficient numbers of samples are diverse in their maternal lineages and also are not uniquely different from each other.

Pump-regulated cerebrospinal fluid drainage.

The drainage of cerebrospinal fluid (CSF) from the lumbar subarachnoid space is an effective technique for the treatment of CSF fistula and control of intracranial pressure in children and adults. The use of the lumbar drain poses unique challenges, however, in the pediatric population. We present a safe and effective method of pump-controlled lumbar subarachnoid drainage. This technique allows accurate titration of CSF removal while providing a closed system which is not sensitive to position changes or patient activity. Four case histories are reviewed.

Mapping studies on a pericentric inversion (18) (p11.31 q21.1) in a family with both schizophrenia and learning disability.

Chromosomal abnormalities that co-occur with psychiatric disorders can be useful direct pointers to the locus of susceptibility genes. Two families with pericentric inversions of chromosome 18, inv 18(p11.3 q21.1) and psychiatric illness have previously been described. We have fine mapped the chromosomal breakpoints of the rearrangement in a clinically well, inversion carrier from one of these families where other inversion carriers suffered from chronic schizophrenia or severe learning disability. Yeast artificial chromosomes (YACs) from the Whitehead/MIT physical maps of human chromosome 18 have been positioned relative to the chromosomal breakpoints and a number of YACs that span these breakpoints have been identified. Linkage and association studies have previously suggested these regions of chromosome 18q and 18p as candidate loci harbouring genes involved in bipolar disorder and schizophrenia.

Pediatric neurosurgery work force: a pilot study.

The physician work force of tomorrow is influenced by the number of physicians and specialists trained today. Little information exists about the need for pediatric neurosurgeons in the next 10 years or about the activity of pediatric neurosurgeons currently in practice. The objective of this study was to obtain preliminary data about pediatric neurosurgeons and current work loads. A questionnaire was distributed to physicians attending the Pediatric Section Meeting of the American Association of Neurological Surgeons, 1997, 93 questionnaires were returned. A majority of the respondents were between 35 and 55 years of age. The largest group geographically was from the northeast. Fifty-five respondents described their practice as academic and of that group, 48% reported that their practice was either exclusively or at least 95% pediatric neurosurgery. Self-described work load varied with geographic location. In the northeast, only 26% of practitioners felt they were not busy enough, whereas in the southwest, 60% reported not being busy enough. Academic practitioners were more likely than other respondents to describe their practice as too busy or appropriately busy. Thirty-six respondents indicated plans to either expand their practice or retire within the next 10 years. This pilot study demonstrates the potential for future growth in pediatric neurosurgery as well as providing information about the current self-reported work load and its distribution over practice types and geographic locations. This study provides guidance for development of future studies to improve the sensitivity and usefulness of acquired data.

Chromosomal localization of the human diadenosine 5',5"'-P1,P4-tetraphosphate pyrophosphohydrolase (Ap4A hydrolase) gene (APAH1) to 9p13.

Diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A) hydrolase is the enzyme responsible for maintaining the intracellular level of the dinucleotide Ap4A, the function of which has yet to be established. The APAH1 gene encoding this Ap4A hydrolase has been mapped by fluorescence in situ hybridization and PCR to human chromosome 9p13. Radiation hybrid panel mapping further located APAH1 between the IL11RA and the GALT genes, thus excluding it as a candidate gene for cartilage-hair hypoplasia, which maps proximal to GALT. Several tumor suppressor genes have previously been mapped within the 9p13-p21 region. Given that the FHIT gene at 3p14.2, which encodes a diadenosine 5',5"'-P1,P3-triphosphate (AP3A) hydrolase, is a candidate tumor suppressor, APAH1 should also be considered a potential tumor suppressor.

Correlation of the exon/intron organization to the secondary structures of the protease domain of mouse meprin alpha subunit.

Metalloendopeptidases of the astacin family contain a homologous protease domain of about 200 amino acids. We now report the genomic structure corresponding to the protease domain for one member of this family, the mouse meprin alpha subunit. This is the first such description for the mammalian meprin subunits. It consists of four small exons (76 to 222 base pairs) and three large introns (2.9 to 4.2 kilobases). The exon/intron organization correlates well with the secondary structure elements of the domain as predicted by computer modeling. Exon Ep1 contains beta strand I, and Ep2 consists of helix A and beta strands II-III. Ep3 corresponds to beta strands IV-V and helix B. Ep4 correlates with helices C and D. Introns Ip1 and Ip2 are present at the beginning of helix A and beta strand IV, respectively, and Ip3 is between helices B and C. Similar analyses of sequences previously published by others, have extended this correlation to other astacin family members from different organisms. The relationship between gene and protein structures within the astacin family provide novel information on the evolution of this family in relation to other gene families.

Lymphangiolipoma of the thoracic spine in a pediatric patient with Proteus syndrome.

Proteus syndrome is a rare hamartomatous disorder involving macrodactyly, hemihypertrophy, and subcutaneous lymphangiomas; fewer than 25 cases have been reported worldwide. We report a case of a thoracic epidural lymphangiolipoma in a 5-year-old boy with Proteus syndrome. Computerized axial tomography (CT) of the thoracic spine revealed a left posterior mediastinal mass that extended into the spinal canal through adjacent neural foramina. No sign of spinal cord compression was observed despite the extensive volume of tumor within the spinal canal. Surgical debulking utilizing a T3-10 laminectomy resulted in gross total resection of the tumor. Microscopic examination of the surgical specimen revealed a lymphangiolipoma. No previous report of spinal cord involvement has been reported in this syndrome. A detailed discussion of the phenotypic features and probable mode of genetic transmission is included.

A candidate gene for mild mental handicap at the FRAXE fragile site.

The cytogenetic expression of the folate sensitive fragile site, FRAXE, is due to the expansion of a GCC repeat in proximal Xq28 of the human X chromosome and is associated with a mild form of mental handicap. Normal individuals have 6-35 copies of the repeat whereas cytogenetically positive, developmentally delayed males have > 200 copies and show methylation of the associated CpG island. Through the use of conserved sequences adjacent to the FRAXE GCC repeat, we have isolated a 1495 bp cDNA which begins 331 bp distal to the FRAXE site and extends to a region > 170 kb distal in Xq28. The cDNA sequence possesses both a putative start of translation and a poly-A tail. The predicted protein has amino acid motifs which share significant homologies with the human AF-4 gene which encodes a putative transcription factor. On northern analysis, the cDNA detects a 9.5 kb transcript in human brain, placenta and lung. This transcript is present in multiple human brain tissues, but is more abundant in the hippocampus and the amygdala, thus providing possible functional insights. RT-PCR of normal adult brain RNA provides evidence for the existence of the 1495 bp transcript represented by the isolated cDNA.

Two new cases of FMR1 deletion associated with mental impairment.

Screening of families clinically ascertained for the fragile X syndrome phenotype revealed two mentally impaired males who were cytogenetically negative for the fragile X chromosome. In both cases, screening for the FMR1 trinucleotide expansion mutation revealed a rearrangement within the FMR1 gene. In the first case, a 660-bp deletion is present in 40% of peripheral lymphocytes. PCR and sequence analysis revealed it to include the CpG island and the CGG trinucleotide repeat, thus removing the FMR1 promoter region and putative mRNA start site. In the second case, PCR analysis demonstrated that a deletion extended from a point proximal to FMR1 to 25 kb into the gene, removing all the region 5' to exon 11. The distal breakpoint was confirmed by Southern blot analysis and localized to a 600-bp region, and FMR1-mRNA analysis in a cell line established from this individual confirmed the lack of a transcript. These deletion patients provide further confirmatory evidence that loss of FMR1 gene expression is indeed responsible for mental retardation. Additionally, these cases highlight the need for the careful examination of the FMR1 gene, even in the absence of cytogenetic expression, particularly when several fragile X-like clinical features are present.

Triplet repeat expansion at the FRAXE locus and X-linked mild mental handicap.

We have recently shown that the expression of the FRAXE fragile site in Xq28 is associated with the expansion of a GCC trinucleotide repeat. In the families studied, FRAXE expression is also associated with mild mental handicap. Here we present data on families that previously had been diagnosed as having the fragile X syndrome but that later were found to be negative for trinucleotide repeat expansion at the FRAXA locus. In these families we demonstrate the presence of a GCC trinucleotide repeat expansion at the FRAXE locus. Studies of the FRAXE locus of normal individuals show that they have 6-25 copies of the repeat, whereas affected individuals have > 200 copies. As in the fragile X syndrome, the amplified CpG residues are methylated in affected males.

Trinucleotide repeat amplification and hypermethylation of a CpG island in FRAXE mental retardation.

We have cloned the fragile site FRAXE and demonstrate that individuals with this fragile site possess amplifications of a GCC repeat adjacent to a CpG island in Xq28 of the human X chromosome. Normal individuals have 6-25 copies of the GCC repeat, whereas mentally retarded, FRAXE-positive individuals have > 200 copies and also have methylation at the CpG island. This situation is similar to that seen at the FRAXA locus and is another example in which a trinucleotide repeat expansion is associated with a human genetic disorder. In contrast with the fragile X syndrome, the GCC repeat can expand or contract and is equally unstable when passed through the male or female line. These results also have implications for the understanding of chromosome fragility.

Identification of the FRAXE fragile site in two families ascertained for X linked mental retardation.

Chromosome fragility in two families not exhibiting amplification of the CGG trinucleotide associated with the fragile X site has been examined. Fluorescence in situ hybridisation with cosmid DNA from loci immediately flanking FRAXA and other distal loci have confirmed that cytogenetic fragility in these subjects is the result of expression of a new folate sensitive fragile X site, FRAXE.

Posttraumatic pseudoaneurysm of the posterior meningeal artery associated with intraventricular hemorrhage.

A 22-year-old man sustained a severe head injury and had a torn posterior meningeal artery that caused massive intraventricular hemorrhage. Traumatic pseudoaneurysm of the posterior meningeal artery should be considered in cases where intraventricular hemorrhage occurs in the presence of occipital bone fracture and contiguous epidural hematoma; vertebral angiography is of value in this regard.

Immunological detection of degradation intermediates of skeletal-muscle glycogen phosphorylase in vitro and in vivo.

Over 95% of the pyridoxal phosphate (PLP) in skeletal is bound to one protein, glycogen phosphorylase. This, and the fact that phosphorylase constitutes approx. 5% of the soluble protein in skeletal muscle, introduce the possibility that PLP might be used as a specific label to identify degradation intermediates of the enzyme. In this investigation, we have developed immunological methods, using a monoclonal antibody to PLP and polyclonal antibodies to phosphorylase, to detect degradation intermediates in vitro and in vivo. We have identified a family of degradation intermediates of glycogen phosphorylase in the high-speed-supernatant fraction of mouse skeletal muscle. These peptides react with both types of antibodies and are in the size and concentration range expected for degradation intermediates in a model in which the committed step is followed by rapid clearance of the products. Changes in amounts of degradation intermediates are examined in physiological or pathological conditions in which the rate of degradation of phosphorylase is altered.

Turnover of glycogen phosphorylase in the pectoralis muscle of broiler and layer chickens.

Glycogen phosphorylase is a major sarcoplasmic protein in chicken pectoralis muscle, constituting approx. 4% of the total protein complement. In slow-growing layer chicks phosphorylase accumulated in parallel with muscle accretion, but in fast-growing broiler chicks the concentration of phosphorylase in the muscle increased (from 5 to 8 mg/g wet wt.) with time. In a 5-week period, the total amount of phosphorylase in the pectoralis muscles increased 18-fold in broiler chicks (from approx. 75 to 1400 mg total), but only 3-fold (from approx. 100 to 270 mg total) in layers. Pyridoxal phosphate, the cofactor of the enzyme glycogen phosphorylase, was used as a specific label to measure the rate of degradation of the enzyme in the pectoralis muscle of growing broiler and layer chickens in vivo. In young animals, the fractional rate of phosphorylase synthesis was similar in broiler and layer chickens (approx. 15%/day), but the rate of degradation in layers (5%/day) was 5-fold higher than in broilers (1%/day). As the animals aged, the rate of synthesis decreased, but more so in layers than in broilers. The rate of degradation of phosphorylase also decreased in layers, but in broilers it remained at the low level seen in young animals. The dramatically higher rate of phosphorylase accretion in the pectoralis muscles of the broilers is therefore achieved by an initial lower rate of degradation combined with a sustained difference between rates of synthesis and degradation.

The alpha subunit of meprin A. Molecular cloning and sequencing, differential expression in inbred mouse strains, and evidence for divergent evolution of the alpha and beta subunits.

Meprin A, a membrane-bound oligomeric metalloendopeptidase, contains two different subunits, alpha and beta. We report here the cloning and sequencing of the alpha subunit cDNA. The translated polypeptide consists of 760 amino acids, including a preprosequence (77 amino acids) that precedes the NH2 terminus of the purified enzyme. The next 198 amino acids constitute the "astacin family" protease domain, which includes the astacin family signature sequence, HE(L,I)XHXXGFXHE(Q,H)XRXDRDX(Y,H)(V,I)X(I,V). An immunoglobulin/major histocompatibility complex protein signature was found at the end of the protease domain. At the COOH terminus of the alpha subunit, there is an epidermal growth factor-like domain, followed by a transmembrane domain, and six additional amino acids. Ten potential glycosylation sites have been identified, and at least three of those sites are glycosylated. Northern blot analyses of kidney tissue from C57BL/6 and C3H/He mice indicate that variations in meprin A activity in these strains reflect differences in the levels of the alpha subunit mRNA. Several internal peptide sequences obtained from the beta subunit indicate that it is approximately 50% identical to the alpha subunit. Furthermore, NH2-terminal sequence analyses (39 residues) indicate that rat and mouse alpha are 79% identical, rat and mouse beta are 74% identical, and that alpha and beta subunits for both species are 47% identical. These data indicate that alpha and beta are closely related products of divergent evolution.