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Biomedical subjects

T Seidl

Publications and source records attributed to T Seidl.

16 recordsLinked to original sources
PubMed2003

[Chronic recurrent multifocal osteomyelitis].

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare, inflammatory, skeletal disease of unknown origin, which mainly affects children and adolescents in terms of cleido-spondylo-metaphysal skeletal inflammation. Only 10% of the patients are older than 20 years. To date, only about 200 cases have been reported in the literature. In the course of the disease, the initial radiological signs are osteolysis followed by sclerosis and hyperostosis in the end stage. The histological investigations reveal chronic inflammatory infiltrates with lymphocytes and hyperostosis. Although the prognosis of CRMO, to our current understanding, is self limiting, serious complications have been reported such as pathological fractures and compression fractures of the spine. A recently recommended therapy scheme is based on the administration of azithromycin combined with calcitonin. We present the case of a 25 year old female patient who has suffered from CRMO for 1.5 years with the cervical spine and the manubrium sterni being affected. The current state of diagnosis, therapy, and prognostic outlook of this rare disease are discussed.

Adult↗
PubMed2003

Adhesion measurements on the attachment devices of the jumping spider Evarcha arcuata.

The feet of the jumping spider Evarcha arcuata attach to rough substrates using tarsal claws. On smooth surfaces, however, attachment is achieved by means of a claw tuft, the scopula. All eight feet bear a tarsal scopula, which is equipped with setae, these again being covered by numerous setules. In E. arcuata, an estimated 624,000 setules, with a mean contact area of 1.7 x 10(5) nm(2), are present. The spider's entire contact area thus totals 1.06 x 10(11) nm(2). Adhesion to the substrate does not depend on the secretion of an adhesive fluid. Analysis via atomic force microscopy (AFM) shows that a single setule can produce an adhesive force (F(a)) of 38.12 nN perpendicular to a surface. Consequently, at a total F(a) of 2.38 x 10(-2) N and a mean body mass of 15.1 mg, a safety factor (SF; F(a)/F(m), where F(m) is weight) of 160 is achieved. Tenacity (tau(n); F(a)/A, where A is area of contact) amounts to 2.24 x 10(5) N m(-2).

Adhesiveness↗
PubMed2001

The VpreB protein of the surrogate light-chain can pair with some mu heavy-chains in the absence of the lambda 5 protein.

Nineteen different mu heavy-chains, seven of them not capable of forming a pre B cell receptor were expressed in Drosophila melanogaster Schneider cells together with either VpreB1, VpreB2, lambda5, or the complete surrogate light-chain to study their interactions in the formation of the pre B cell receptor. The lambda5 protein alone was unable to bind properly to any of the mu heavy-chains, while the VpreB proteins alone formed complexes with five of the mu heavy-chains. All mu heavy-chains incapable of forming a pre B cell receptor with surrogate light-chain were also incapable of complex formation with VpreB. The possible role of the VpreB/mu heavy-chain in allelic exclusion of the heavy-chain locus during B cell development is discussed.

Animals↗
PubMed2001

Mouse pre-immunocytes as non-proliferating multipotent precursors of macrophages, interferon-producing cells, CD8alpha(+) and CD8alpha(-) dendritic cells.

In this study we characterize in mouse bone marrow and peripheral blood a homogeneous cell subset expressing Ly6C, CD31 and CD11c, that can give rise to multiple cell types involved in the immune response. Under the aegis of M-CSF or GM-CSF these cells rapidly differentiate without division to either macrophages or immature dendritic cells, which can be further induced to mature by LPS stimulation. In fetal thymic organ cultures the same cells generate both CD8alpha(+) and CD8alpha(-) dendritic cells in comparable proportion as found in normal thymus. The Ly6C(+), CD31(+) and CD11c(+) cells express not only TLR2 and TLR4, which are characteristic of myeloid dendritic cells, but also TLR7 and TLR9, which conversely are characteristic of human interferon-producing cells. Moreover, following stimulation with influenza virus, they rapidly express high levels of IFN-alpha mRNA. Finally these precursors are increased in bone marrow and peripheral blood during systemic inflammation. These cells are defined as "pre-immunocytes" to underline the fact that they serve in a flexible fashion multiple, and often divergent, functions required for the immune response to pathogens.

Animals↗
PubMed2000

Repertoire selection by pre-B-cell receptors and B-cell receptors, and genetic control of B-cell development from immature to mature B cells.

During B-cell development the surrogate light (SL) chain is selectively expressed in progenitor and precursor B cells during the developmental stages of D(H) to J(H) and V(H) to D(H)J(H) rearrangements. Approximately half of all muH chains produced by these rearrangements cannot pair with SL chains and cannot form a pre-B-cell receptor (pre-BCR). A spectrum of affinities between VpreB and individual V(H) domains generates preB cells with pre-BCR of different fitness which, in turn, determines the extent of the pre-B II-cell proliferation and the fidelity of allelic exclusion of the H chain locus. Once pre-BCR is expressed, SL chain expression is turned off. As pre-B II cells proliferate, SL is diluted out, thus limiting pre-BCR formation. As a consequence, pre-B II cells stop proliferating, become small and resting and begin to rearrange the L chain loci. Multiple rearrangements of the kappaL chain alleles are often detected in wild-type small pre-B II cells. Around 20% of the muH chain-expressing small pre-B II cells also express L chains but do not display the Ig on the surface. Hence, it is likely that not all L chains originally generated in resting pre-B II cells can pair with the muH chain previously present in that cell. The best fitting ones are selected preferentially to generate sIg+ B cells. Furthermore, the transition of immature B cells from the bone marrow to spleen and their development to mature cells appear as two separate steps controlled by different genes.

Alleles↗
PubMed1999

Nearest neighbor classification in 3D protein databases.

In molecular databases, structural classification is a basic task that can be successfully approached by nearest neighbor methods. The underlying similarity models consider spatial properties such as shape and extension as well as thematic attributes. We introduce 3D shape histograms as an intuitive and powerful approach to model similarity for solid objects such as molecules. Errors of measurement, sampling, and numerical rounding may result in small displacements of atomic coordinates. These effects may be handled by using quadratic form distance functions. An efficient processing of similarity queries based on quadratic forms is supported by a filter-refinement architecture. Experiments on our 3D protein database demonstrate the high classification accuracy of more than 90% and the good performance of the technique.

Algorithms↗
PubMed1998

Activated murine B lymphocytes and dendritic cells produce a novel CC chemokine which acts selectively on activated T cells.

Genes were isolated using the suppression subtractive hybridization method by stimulation of pro/pre B cells with anti-CD40 and interleukin (IL)-4 to mature S mu-Sepsilon-switched cells. One of the strongly upregulated genes encodes a novel murine CC chemokine we have named ABCD-1. The ABCD-1 gene has three exons separated by 1. 2- and 2.7-kb introns. It gives rise to a 2.2-kb transcript containing an open reading frame of 276 nucleotides. Two polyadenylation sites are used, giving rise to cDNAs with either 1550 or 1850 bp of 3' untranslated regions. The open reading frame encodes a 24 amino acid-long leader peptide and a 68 amino acid-long mature protein with a predicted molecular mass of 7.8 kD. ABCD-1 mRNA is found in highest quantities in activated splenic B lymphocytes and dendritic cells. Little chemokine mRNA is present in lung, in unstimulated splenic cells, in thymocytes, and in lymph node cells. No ABCD-1 mRNA is detected in bone marrow, liver, kidney, or brain, in peritoneal exudate cells as well as in the majority of all unstimulated B lineage cells tested. It is also undetectable in Concanavalin A-activated/IL-2-restimulated splenic T cells, and in bone marrow-derived IL-2-induced natural killer cells and IL-3-activated macrophages. Recombinant ABCD-1 revealed a concentration-dependent and specific migration of activated splenic T lymphoblasts in chemotaxis assays. FACS(R) analyses of migrated cells showed no preferential difference in migration of CD4(+) versus CD8(+) T cell blasts. Murine as well as human T cells responded to ABCD-1. Freshly isolated cells from bone marrow, thymus, spleen, and lymph node, IL-2-activated NK cells, and LPS-stimulated splenic cells, all did not show any chemotactic response. Thus, ABCD-1 is the first chemokine produced in large amounts by activated B cells and acting selectively on activated T lymphocytes. Therefore, ABCD-1 is expected to play an important role in the collaboration of dendritic cells and B lymphocytes with T cells in immune responses.

Amino Acid Sequence↗
PubMed1997

Specific labelling of cell wall proteins by biotinylation. Identification of four covalently linked O-mannosylated proteins of Saccharomyces cerevisiae.

Intact Saccharomyces cerevisiae cells were biotinylated with the non-permeable sulfosuccinimidyl-6-(biotinamido) hexanoate reagent. Twenty specifically labelled cell wall proteins would be extracted and visualized on SDS gels via streptavidin/horseradish peroxidase. Nine cell wall proteins were released by SDS extraction under reducing conditions and were designated Scw1-9p for (soluble cell wall proteins); five proteins were released from SDS-extracted cell walls by laminarinase (Ccw1-5p for covalently linked cell wall proteins) and six with mild (30 mM-NaOH, 4 degrees C, 14 h) alkali treatment (Ccw6-11p). N-terminal sequences of the Ccw proteins 6, 7, 8 and 11 showed that these cell wall proteins are members of the PIR gene family (predicted proteins with internal repeats), CCW6 being identical to PIR1 and CCW8 to PIR3. Single gene disruptions of all four genes did not yield a phenotype. In the CCW11 disruption the Ccw11p as well as the laminarinase-extracted Ccw5 protein was missing. The new cell wall proteins are O-mannosylated, contain a Kex2 processing site, but no C-terminal GPI anchor sequence.

Amino Acid Sequence↗
PubMed1997

Pediatric injury resulting from family violence.

OBJECTIVE: Children who live in violent households are at risk for emotional and physical injury. Although recent research has addressed the emotional impact of witnessing family violence, no study has addressed the inadvertent physical injuries that result to children who witness family violence. The objective of this study was to describe the causes, types, and patterns of pediatric injuries resulting from family violence. METHODS: We reviewed the medical records of 139 children who presented to the emergency department with injuries resulting from domestic violence for demographic information, mechanism of injury, type, location, and severity of injury, treatment, and disposition. RESULTS: Children who were injured during domestic violence ranged in age from 2 weeks to 17 years. Although the mean age of the children identified was 5 years, 48% of the children were younger than 2 years. Although the most common dyad involved in the fight was the mother and father (57% of cases), extended family members and nonrelated adults were involved in almost one third of the cases. The most common mechanism of injury was a direct hit (36%). Of the injured children who were younger than 2 years, 59% were injured while being held by parents. Thirty-nine percent of the children were injured during attempts to intervene in fights. The majority of injuries were to the head (25%), face (19%), and eyes (18%). Young children sustained more head and facial injuries than older children, who had disproportionately more extremity trauma. Medical intervention was indicated in 43% of patients, of which 9% required hospital admission and 2% required surgical or intensive care intervention. Of the 91% of children discharged from the emergency department, 73% returned home, and 27% went to alternative homes. CONCLUSIONS: Children sustain a wide range of physical injuries from family violence. Because the majority of injuries are minor, specific inquiry into the causes of all pediatric injuries may help further identify children living among family violence.

Adolescent↗
PubMed1996

Long-term outcome in infants with the shaking-impact syndrome.

Nonaccidental injury accounts for nearly one quarter of all hospital admissions for head injury in infancy, and is associated with significant morbidity and mortality. Long-term outcome in survivors, however, has been incompletely studied. In this series, 84 infants 2 years of age and younger with the shaking-impact syndrome consecutively admitted to a single hospital between 1978 and 1988 were identified. A questionnaire detailing current medical, developmental, and behavioral status was developed, and attempts were made to locate the 62 children surviving the acute injury. Family instability and strict confidentiality restrictions precluded locating the majority of children, but 14 children with demographic and injury characteristics similar to those of the overall group were contacted at an average of 9 years after injury. Seven children were severely disabled or vegetative, 2 were moderately disabled, and 5 had a good outcome. Of the latter group, 3 had repeated grades and/or required tutoring. Acute factors associated with poor outcome included unresponsiveness on admission, need for intubation, age less than 6 months, and bilateral or unilateral diffuse hypodensity on CT scan. All children with bilateral diffuse hypodensity and loss of gray-white differentiation on CT scan remained blind, retarded, nonverbal, and nonambulatory in spite of aggressive medical and surgical management. This study suggests that the majority of children surviving the shaking-impact syndrome suffer major permanent morbidity, and that acute factors predicting long-term outcome may help guide aggressiveness of care.

Adolescent↗
PubMed1995

Ten-year review of pediatric bathtub near-drownings: evaluation for child abuse and neglect.

STUDY OBJECTIVE: To evaluate the risk factors associated with bathtub submersion injury and their relationship to child abuse and neglect. DESIGN: Retrospective chart review. SETTING: An urban children's hospital. PARTICIPANTS: Any child sustaining a bathtub near-drowning over the 10-year period from 1982 to 1992. INTERVENTIONS: None. RESULTS: Twenty-one patients were treated for bathtub near-drownings during the 10-year period, accounting for 24% of all submersion injuries. A significant number (67%) had historic and/or physical findings suspicious for abuse or neglect, including incompatible history for the injury, other physical injuries, previous child abuse reports, psychiatric history of the caretaker, and/or psychosocial concerns noted in the chart. The mortality rate of 42% was significant. No demographic characteristics identified the children at risk. CONCLUSION: Many children who are injured in the bathtub suffer from abuse or neglect. Medical evaluation should include social work consultation and a search for other accompanying injuries.

Child↗
PubMed1995

Solvent accessible surface representation in a database system for protein docking.

Protein docking is a new and challenging application for query processing in database systems. Our architecture for an efficient support of docking queries is based on the multistep query processing paradigm, a technique well-known from spatial database system. Along with physicochemical parameters, the geometry of the molecules plays a fundamental role for docking retrieval. Thus, 3D structures and 3D surfaces of molecules are basic objects in molecular databases. We specify a molecular surface representation based on topology, define a class of neighborhood queries, and sketch some applications with respect to the docking problem. We suggest a patch-based data structure called the TriEdge structure, first, to efficiently support topological query processing, and second, to save space in comparison to common planar graph representations such as the quad-edge structure. In analogy to the quad-edge structure, the TriEdge structure has an algebraic interface and is implemented via complex pointers. However, we achieve a reduction of the space requirement by a factor of four. Finally, we investigate the time performance of our prototype.

Computer Graphics↗
PubMed1988

Major blunt abdominal trauma due to child abuse.

We reviewed 15 years' experience with childhood trauma at two hospitals in different cities, one a city hospital, the other a children's hospital, to learn the extent, circumstances, presentations, and consequences of major blunt abdominal trauma due to child abuse. Some 10,000 children admitted to these hospitals for treatment of injuries from 1972 through 1986 provided the basis for the study; the incidence and severity of pediatric trauma at the two hospitals was similar, in that 13% of the visits to both hospitals' emergency rooms were for trauma, of which 5% resulted in admission. Major blunt abdominal trauma due to child abuse accounted for 22 of these cases, six at the former, 16 at the latter, and represented less than 0.50% of all abused children seen at both institutions. The average age was 24 mo; 14 were boys and eight were girls. In only two instances was the family unit intact; in both, the child was abused by the babysitter. Otherwise, the father, or the mother's "boyfriend," was responsible. Overall mortality was 45%, and was related both to type of injury and presenting signs. Of one who presented with an epigastric mass due to a pancreatic hematoma, none died; the pseudocyst which subsequently developed resolved on bowel rest and TPN. Of three who presented with bilious vomiting due to duodenal hematoma, none died; one required operative evacuation. Of five who presented with peritonitis due to duodenojejunal rupture, one died; this child presented greater than 24 hr following injury in profound septic shock. Of three who presented with hypovolemia due to moderate hemorrhage, none died; the former two were managed conservatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗