Novel T cell antigen 4-1BB associates with the protein tyrosine kinase p56lck1

4-1BB is a 30-kDa inducible T cell Ag, and is expressed predominantly as a 55-kDa dimer on both CD4+ and CD8+ T lymphocytes. The cytoplasmic tail of 4-1BB contains the sequence Cys-Arg-Cys-Pro, which is similar to the sequence Cys-X-Cys-Pro, which mediates the binding of the CD4 and CD8 molecules to the protein tyrosine kinase p56lck. An anti-4-1BB mAb, 53A2, was used to determine whether 4-1BB may associate with p56lck. The 53A2 mAb specifically recognized 4-1BB on a CD8+ T cell line, CTLL-2, and coimmunoprecipitated a 56-kDa protein along with 4-1BB. Peptide mapping indicated that the 56-kDa phosphoprotein was identical to p56lck. The coimmunoprecipitation of p56lck with 4-1BB also occurred in nonlymphoid cells such as insect (Sf-21) and HeLa cells when the two recombinant proteins were coexpressed. Analysis of mutant p56lck recombinant proteins showed that two cysteine residues critical for p56lck-CD4 (or -CD8) complex formation are also required for the p56lck-4-1BB interaction. These studies establish that 4-1BB physically associates with p56lck.

Magnetic resonance imaging in the evaluation of the lumbar herniated intervertebral disc

Two hundred and eleven patients with lumbar disc herniation at 242 levels were divided into 5 groups by their appearances on magnetic resonance imaging (MRI), and the findings at operation were compared to assess the accuracy of the MRI classification. There were no negative explorations. There was 92% sensitivity, 91% specificity and 92% accuracy for MRI in distinguishing protruded discs from other forms of lumbar disc herniation. For sequestrated discs there was 92% sensitivity, 99% specificity and 97% accuracy. In the extruded subligamentous type there was 71% sensitivity, 82% specificity and 79% accuracy, and 52% sensitivity, 92% specificity and 81% accuracy in the extruded transligamentous type. The overall accuracy of MRI predicting the types of herniated lumbar intervertebral disc was 85%. High resolution MRI is sensitive in detecting disc disease and specific in characterizing various subgroups of disc herniation, especially those which are sequestrated.

Residue lookup table processor using an optical phase conjugation correlator

Described is a new optical residue lookup table (LUT) processor that is based on the residue LUT from an optical phase-conjugated correlation output of spatial position-encoded input vector patterns in a photorefractive BaTiO(3) correlator and a holographic mapping unit to group the same residue numbers. Some preliminary experimental results of these proposed techniques are presented and discussed.

IDDM patients' sera recognize a novel 30-kD pancreatic autoantigen related to chymotrypsinogen

We have examined, by western immunoblot analysis, the sera of 16 insulin-dependent diabetes mellitus patients (IDDM) for the presence of autoantibodies against proteins extracted from islet-cell enriched preparations of normal human pancreata. A novel putative autoantigen recognized by late stage IDDM patients sera was identified, and its amino acid sequence was partially determined. Islets of Langerhans were partially purified by a modified collagenase digestion procedure, and subsequent protein extracts were fractionated by one-dimensional or two-dimensional polyacrylamide gel electrophoresis (1-D or 2-D SDS-PAGE). Immunoblot analysis revealed a 30-kD species which was recognized by 4 of 16 IDDM patients sera, but none of 16 normal sera. The 30-kD protein, appeared as a single band on 1-D SDS-PAGE, but was resolved on 2-D gel electrophoresis as several distinct protein species with different isoelectric points (pI's), ranging from 7 to 9. The amino terminal sequence of one such species was partially determined by microsequencing, and the second through the fourteenth amino acids were found to be identical to the corresponding sequence in human chymotrypsinogen. The fifteenth through the eighteenth amino acids were different from the known chymotrypsinogen sequence. This region corresponds with the site that is cleaved to activate chymotrypsinogen. Based on the size and sequence homology, this antigen appears to be related to chymotrypsinogen. We conclude that this 30-kD species may be an autoantigen in some late stage IDDM patients.

Polymerization of murine macrophage inflammatory protein 1 alpha inactivates its myelosuppressive effects in vitro: the active form is a monomer

Macrophage inflammatory protein (MIP) 1 alpha has myelosuppressive and myeloprotective activity. That MIP-1 alpha polymerizes is known; this phenomenon was evaluated in terms of myelosuppression by assessing the effects of recombinant murine MIP-1 alpha on colony formation of murine and human myeloid progenitor cells in vitro. The following results are reported: (i) Polymerization is diluent- and concentration-dependent. (ii) Monomeric MIP-1 alpha is the active suppressive form for myeloid progenitor cells in vitro. (iii) Polymerized MIP-1 alpha is inactive and does not interfere with suppression by monomeric MIP-1 alpha. (iv) MIP-1 alpha has approximately 1000-fold higher specific activity than has been reported, but its effects are still specific for immature subsets of myeloid progenitors. (v) Suppression is initiated during the DNA-synthesis phase of the cell cycle. We conclude that polymerization of MIP-1 alpha might be a control mechanism that limits the myelosuppressive effects of monomeric MIP-1 alpha.

The Drosophila gene rbp9 encodes a protein that is a member of a conserved group of putative RNA binding proteins that are nervous system-specific in both flies and humans

The rbp9 gene of Drosophila melanogaster has been molecularly characterized and shown to be expressed solely in the CNS, where it encodes proteins with three RNA recognition motifs (RRMs). Sequencing of genomic and cDNA clones of rbp9 revealed a complex gene with three alternative promoters as well as alternative patterns of splicing. The deduced amino acid sequence of the RBP9 proteins is highly similar to those of three other nervous system-specific genes, human HuC and HuD and Drosophila elav, which also encode proteins with three RRMs. Developmental Northern analysis revealed that rbp9 is expressed from the late third instar larva through adult stages. The RBP9 protein was detected specifically in nuclei of the nervous system after morphogenesis of the adult CNS in the mid-pupal stage. Thus, the RBP9 protein does not appear until substantially later than rbp9 transcripts are detected. The adult nervous system nuclear-limited expression pattern, the presence of RRMs, and the high similarity to a group of nervous system-specific proteins in flies and humans suggest that rbp9 belongs to a nervous system-specific RRM protein gene subfamily that may participate in the processing of RNAs involved in the development of the CNS.

Identification of tubular cell nephron segment origin in renal fine-needle aspirates

Currently there are no definitive criteria for identification of the nephron segment origin of tubular cells in renal fine-needle aspirates. This information would be useful for determining the cortical or medullary location of aspirate specimens. To establish morphologic criteria for identifying tubular cell origin, we evaluated 60 allograft and four native kidney aspirates with immunocytochemistry (IC) and May-Grünwald-Giemsa (MGG) stains. IC markers included URO-3 and Tetragonolobus purpuras for proximal cells, URO-5 and Arachis hypogaea for distal cells, and URO-5, Arachis hypogaea, and anti-cytokeratin antibody for collecting duct cells. Cell and nuclear areas were measured morphometrically, and cell grouping and MGG staining characteristics were assessed. Proximal tubular cells have an area of 335 +/- 112 microns2 (IC strains) and 350 +/- 107 microns2 (MGG stain) with a nuclear:cytoplasm (N:C) ratio of 1:4. The cells occur singly or in small clusters of four to seven cells with abundant pale cytoplasm. Distal tubular cells measure 224 +/- 66 microns2 (IC stains) and 171 +/- 38 microns2 (MGG stain) with an N:C ratio of 1:2. They often form honeycomb aggregates of 10 to 20 cells with moderately dense cytoplasm. Cells of collecting ducts have areas of 96 +/- 32 microns2 (IC stains) and 99 +/- 35 microns2 (MGG stain) with an N:C ratio of 2:3. These cells are found in glandular clusters of two to seven cells with dense cytoplasm. All tubular cell size and staining characteristics were the same in allograft and native kidney samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of temperature and oxygen on cell growth and recombinant protein production in insect cell cultures

The effect of temperature and O2 saturation on the production of recombinant proteins beta-galactosidase and human glucocerebrosidase by Spodoptera frugiperda cells (Sf9) infected with recombinant Autographa californica nuclear polyhedrosis virus was investigated. The rates of cell growth, glucose consumption, O2 consumption and product expression were measured at temperatures between 22 degrees C and 35 degrees C. The results indicated that possible O2 limitation may be alleviated without compromising the maximum cell yield by lowering the incubation temperature from 27 degrees C to 25 degrees C. The expression level of the recombinant proteins at 27 degrees C was similar to that obtained at 22 degrees C and 25 degrees C; lower protein yields were obtained at 30 degrees C. An increase in temperature from 22 degrees C to 27 degrees C led to earlier production of the proteins and to an increase in the proportion of the product released outside the cells.

Inducible T cell antigen 4-1BB. Analysis of expression and function

4-1BB is an inducible receptor-like protein expressed in both cytolytic and Th cells. Optimal induction of 4-1BB mRNA in T cells required both PMA and ionomycin stimulation, indicating that protein kinase C activation and increases in intracellular Ca2+ were required for its expression. 4-1BB was categorized as an early activation gene since the protein synthesis inhibitor, cycloheximide, blocked the induction of 4-1BB mRNA. A rat mAb, 53A2, was generated against recombinant soluble 4-1BB and was used to characterize this molecule. 4-1BB is a 30-kDa glycoprotein and appears to exist as both a monomer and a 55-kDa dimer on the cell surface of a T cell clone. The 4-1BB protein may be post-translationally modified since its predicted backbone is 25 kDa. FACS analysis indicated that 4-1BB was inducible and expressed on the cell surface of activated splenic T cells and thymocytes. Cross-linking of 4-1BB on anti-CD3-stimulated T cells with 53A2 resulted in a dramatic enhancement of T cell proliferation. This suggests that 4-1BB may function as an accessory signaling molecule during T cell activation.

Inducible T cell antigen 4-1BB. Analysis of expression and function

4-1BB is an inducible receptor-like protein expressed in both cytolytic and Th cells. Optimal induction of 4-1BB mRNA in T cells required both PMA and ionomycin stimulation, indicating that protein kinase C activation and increases in intracellular Ca2+ were required for its expression. 4-1BB was categorized as an early activation gene since the protein synthesis inhibitor, cycloheximide, blocked the induction of 4-1BB mRNA. A rat mAb, 53A2, was generated against recombinant soluble 4-1BB and was used to characterize this molecule. 4-1BB is a 30-kDa glycoprotein and appears to exist as both a monomer and a 55-kDa dimer on the cell surface of a T cell clone. The 4-1BB protein may be post-translationally modified since its predicted backbone is 25 kDa. FACS analysis indicated that 4-1BB was inducible and expressed on the cell surface of activated splenic T cells and thymocytes. Cross-linking of 4-1BB on anti-CD3-stimulated T cells with 53A2 resulted in a dramatic enhancement of T cell proliferation. This suggests that 4-1BB may function as an accessory signaling molecule during T cell activation.

On the intrinsic force of convergence to stability

"Observed populations differ greatly in the speed with which they approach the stable form, but what determines rates of convergence is not fully understood.... Here we examine the trajectory to stability, derive a mathematical expression for the force of convergence, and provide an approximate relationship in terms of the mean and variance of the stable net maternity function." Trajectories for Japan, Togo, and the United States are used as illustrations. (SUMMARY IN FRE)

Blood flow to respiratory muscles and major organs during inspiratory flow resistive loads

To determine whether diaphragmatic fatigue in the intact animal subjected to loaded breathing is associated with a decrease in diaphragmatic blood flow, seven unanesthetized sheep were subjected to severe inspiratory flow resistive (IFR) loads that led to a decrease in transdiaphragmatic pressure (Pdi) and a rise in arterial PCO2 (PaCO2). Blood flow to the diaphragm, other respiratory muscles, limb muscles, and major organs was measured using the radionuclide-labeled microsphere method. With these loads blood flow increased to the diaphragm (621 +/- 242%) and all the other inspiratory and expiratory diaphragm (621 +/- 242%) and all the other inspiratory and expiratory muscles; there was no statistically significant change in blood flow to these muscles at the time when Pdi decreased and PaCO2 rose. Blood flow also increased to the heart (103 +/- 34%), brain (212 +/- 39%), and adrenals (76 +/- 9%), whereas pancreatic flow decreased (-66 +/- 14%). Limb muscle blood flow remained unchanged. We conclude that in unanesthetized sheep subjected to IFR loads 1) we did not demonstrate a decrease in respiratory muscle blood flow associated with diaphragmatic fatigue and ventilatory failure, and 2) there is a redistribution of blood flow among major organs.

Isolation of RRM-type RNA-binding protein genes and the analysis of their relatedness by using a numerical approach

Proteins with RNA recognition motifs (RRMs) have important roles in a great many aspects of RNA metabolism. However, this family has yet to be systematically studied in any single organism. In order to investigate the size of the RRM gene family in Drosophila melanogaster and to clone members of this family, we used a polymerase chain reaction (PCR) with highly degenerate oligonucleotides to amplify DNA fragments between the RNP-1 and RNP-2 consensus sequences of the RRM proteins. Cloning and sequencing of 124 PCR products revealed 12 different RRM sequences (RRM1 to RRM12). When PCR products were used as probes in genomic Southern and Northern (RNA) analyses, 16 restriction fragments and 25 transcripts, respectively, were detected. Since the combinations of nucleotide sequences represented in the PCR primers correspond to only 4% of the RRM sequences inferred to be possible from known RRM sequences, we estimate the size of the RRM gene family in the order of three hundred genes in flies. In order to gain insight into the possible functions of the genes encoding the RRMs, we analyzed the sequence similarities between the 12 RRMs and 62 RRM sequences of known proteins. This analysis showed that the RRMs of functionally related proteins have similar sequences and are clustered together in the RRM gene tree. On the basis of this observation, the RRMs can be divided into three groups: a heterogeneous nuclear ribonucleoprotein type, a splicing regulator type, and a development-specific factor type. This result suggests that we have isolated good candidates for both housekeeping and developmentally important genes involved in RNA metabolism.

Crossovers that link populations with the same vital rates

"In this paper, we consider crossovers of demographic density distributions from...populations that have the same fertility and mortality rates. We focus on observed populations and their associated stationary and stable models, and on proportional distributions of persons, births, deaths and reproductive values.... Three different populations were selected to represent a range of demographic behavior. Those populations are Japan 1963, a low mortality, low fertility population; Togo 1961, a high mortality, high fertility population; and the United States 1919-1921, a population whose fertility and mortality are intermediate."

Development of an index of maternal transport

The authors used a decision-analytic approach to develop a Maternal Transport Index (MTI) from ACOG guidelines for maternal transport. Data were obtained from three questionnaires administered to five perinatologists, practicing in facilities with various casemixes. Each questionnaire was based on a given level of hospital and contained scenarios describing indications for maternal transport. The MTIs, ratios of the logs of the proportions with given outcomes in Level III hospitals relative to Level I (or II) hospitals, ranged from 1.0 to 26.3 for newborn outcomes. They were greater for Level I hospitals (than Level II) and when newborn outcomes included severe disability as well as death. Within gestational age categories, the MTI was generally greatest for active preterm labor and, within complication categories, for 24-26 or 27-31 weeks' gestation. It was large for maternal outcomes only for two rare acute medical conditions. The MTI has potential use in setting priorities for maternal transport.

The Drosophila RNA-binding protein RBP1 is localized to transcriptionally active sites of chromosomes and shows a functional similarity to human splicing factor ASF/SF2

An RNA-binding protein gene (rbp1) from Drosophila melanogaster, encoding an RNA recognition motif and an Arg-Ser rich (RS) domain, has been characterized. The predicted amino acid sequence of rbp1 is similar to those of the human splicing factor ASF/SF2, the Drosophila nuclear phosphoprotein SRp55, and the Drosophila puff-associated protein B52. Northern and immunohistochemical analyses showed that rbp1 is expressed at all stages in all tissues and that the RBP1 protein is localized to the nucleus. Consistent with a role in mRNA metabolism, indirect immunofluorescence reveals that the RBP1 protein colocalizes with RNA polymerase II on larval salivary gland polytene chromosomes. RBP1 protein made in Escherichia coli was tested for splicing activity using human cell extracts in which ASF has been shown previously both to activate splicing and to affect the choice of splice sites in alternatively spliced pre-mRNAs. In these assays, RBP1 protein, like ASF, is capable of both activating splicing and switching splice site selection. However, in each case, clear differences in the behavior of the two proteins were detected, suggesting that they have related but not identical functions. The general nuclear expression pattern, colocalization on chromosomes with RNA polymerase II, the similarity to ASF/SF2, SRp55, and B52, along with the effect on alternative splicing shown in vitro, suggest that rbp1 is involved in the processing of precursor mRNAs.

Young motherhood and infant hospitalization during the first year of life

We studied the relationship of young maternal age with infant hospitalization using data from the National Longitudinal Survey of Youth for 3,130 infants born between 1979 and 1983 to mothers aged 14-25 years. Data on the mothers were first collected in 1979 and yearly thereafter. Data on their children were collected starting in 1982. Logistic regressions of infant hospitalization rates were estimated for first and second and higher births. The odds of infant hospitalization during the first year of life increased with decreasing maternal age, even with adjustment for sociodemographic characteristics, preventive health-care practices, and newborn health status, factors hypothesized to explain the maternal age effect. The maternal age relationship with hospitalization differed by birth order; among second and higher births, the odds of hospitalization was increased only for infants of mothers aged 20-22 years. Male infants, infants with a first well-baby visit after the first month of life, with birth weights between 1501 and 2500 g, and with nursery stays longer than 1 week also had increased odds of hospitalization. Ethnicity, grandmother's education, poverty status, mother's school enrollment, and family composition were not related to the odds of hospitalization, nor was smoking during pregnancy when adjustment was made for birth weight and length of nursery stay.

Impact of a primary reader's opinion on the detection of rib fractures

RATIONALE AND OBJECTIVES

The authors assessed the influence of a prior reader's opinion on the detectability of rib fractures.

METHODS

Six pairs of observers read the chest PA radiographs of 92 subjects with rib fracture(s) and 28 normal subjects to detect rib fracture(s) according to a five-point rating of confidence with three methods. In method A, each reader read films as a primary reader. In method B, each reader read films after knowing his or her partner's opinion. In method C, each reader initially observed films and then made the final decision after knowing his or her partner's opinion.

RESULTS

Methods B and C were superior to method A in sensitivity. There was no difference in performance between methods B and C. Method C required a significantly longer time than the other methods.

CONCLUSION

Detection of rib fractures is improved by seeking the opinion of other observers.

Recombinant human interleukin-9 induces protein tyrosine phosphorylation and synergizes with steel factor to stimulate proliferation of the human factor-dependent cell line, M07e

Human interleukin-9 (IL-9) was originally identified and cloned based on its stimulatory effect on proliferation of human myeloid cell line, M07e. IL-9 synergized with Steel factor, the ligand for the c-kit product, to stimulate M07e cell proliferation. To investigate potential mechanisms for this, IL-9 was assessed for effects on protein tyrosine kinase activities in M07e cells by immunoblotting with anti-phosphotyrosine monoclonal antibody; results were compared with those of Steel factor alone and in combination with IL-9, and those of 12-0-tetradecanoyl phorbol-13-acetate (TPA). Recombinant human IL-9 (10 ng/mL) rapidly and transiently induced or enhanced at least four tyrosine phosphorylated protein bands with molecular weights of 105, 97, 85, and 81 Kd. This tyrosine phosphorylation pattern was different from that generated by recombinant murine Steel factor or TPA stimulation and the combination of IL-9 and Steel factor did not change the IL-9-induced pattern. IL-9-induced tyrosine phosphorylated bands were completely blocked by treatment of IL-9 with anti-IL-9 antibody under conditions that also neutralized the synergistic effect of IL-9 with Steel factor on M07e cell proliferation. Genistein, a tyrosine kinase inhibitor, blocked phosphorylation of IL-9 and Steel factor-induced bands. Unlike Steel factor or TPA, IL-9 did not appear to stimulate phosphorylation of 42-Kd mitogen-activated protein (MAP) kinase or Raf-1, or enhance MAP kinase activity. MAP kinase and Raf-1 are serine/threonine kinases that are phosphorylated and activated by many growth factors and by agonists for protein kinase C. While the combination of IL-9 plus SLF did not appear to induce phosphorylation of new bands not already seen with either IL-9 or SLF alone, or enhance the phosphorylation of those bands seen with either cytokine alone, the results suggest that IL-9 activates specific and unique signal transduction pathways.

Behavioral risk factors for injury among rural adolescents

This 3-year, longitudinal, prospective study examined behavioral risk factors for medically attended injuries among a cohort of 758 rural students from Maryland's Eastern Shore region who were 12-14 years of age in 1987. Students were surveyed annually in the eighth, ninth, and tenth grades with a self-administered questionnaire. Information was obtained on the number of injuries experienced, risk-taking behaviors, delinquency, alcohol and drug use, physical exercise and sports, parental supervision, and work experience. Information on the parents' education was obtained from a parental interview. Slightly more than half (53.5%) of the students reported having experienced one or more injuries in the eighth grade as compared with one-third of the students in ninth grade, and 38% of those in the tenth grade. Poisson regression analyses were conducted to examine the association of eighth grade variables with ninth grade injuries and ninth grade variables with tenth grade injuries. Results from these analyses indicated that, in addition to sex and race, a high degree of risk taking, frequent cruising, and having high and low parental supervision in the eighth grade significantly increased the number of injuries in ninth grade. In the tenth grade, risk taking continued to be associated with injuries. In addition, students who reported disciplinary problems in school, working 1-10 hours per week, drinking on 1-2 days during the past month, lifetime use of marijuana equal to 1-5 occasions, and involvement in sports experienced greater numbers of injuries in the tenth grade.

Influence of recombinant human interleukin (IL)-7 on disease progression in mice infected with Friend virus complex

Recombinant human (rhu) IL-7 was evaluated for its influence on disease progression in mice infected with the polycythemia-inducing strain of the Friend virus complex (FVC). DBA/2 mice were injected i.v. with FVC, and then treated s.c. with rhuIL-7. IL-7 significantly prolonged survival time and decreased spleen focus-forming virus (SFFV) levels, expression of SFFV mRNA and SFFV protein production in FVC-infected mice. IL-7 did not appear to directly inactivate SFFV. Although both splenic weight and cellularity in FVC-infected mice treated with IL-7 were higher than those of normal mice, they were respectively 58% and 66% lower than those of the untreated FVC-infected mice. NK-cell activity was substantially lower in FVC-infected mice than in normal mice, while IL-7 restored NK-cell activity to normal levels. IL-6 and IFN-gamma levels were markedly reduced in FVC-infected mice compared to normal mice, but treatment of FVC-infected mice with IL-7 restored these cytokine levels. While the actual mechanisms of these effects are not yet known, the results suggest the potential therapeutic efficacy of IL-7 for certain hematopoietic and viral disorders, possibly mediated through an action on accessory cells and cytokine production.

Baseline frequency of sister-chromatid exchanges in 142 persons of the general Korean population

Baseline frequencies of sister-chromatid exchange (SCE) were measured in lymphocytes of 142 healthy Koreans ranging in age from newborn infants to the fifties. The overall mean frequency of SCE was 8.78 +/- 0.24/cell. However, highly significant differences were found between individuals. The mean SCE values of the newborn babies and small children less than 10 years old were significantly lower than those of other age groups. No age effect was, however, observed in adolescent and adult subjects. Females had statistically higher SCE levels than males. The mean SCE frequencies of smokers, measured in male subjects more than 10 years old, were slightly, but statistically significantly, higher than those of non-smokers.

Avascular necrosis after fracture-separation of the distal end of the humerus in children

Fracture-separation of the distal end of the humerus in children has been reported infrequently, and may be misdiagnosed as a fracture of the condyle or a traumatic dislocation of the elbow. We discuss eight cases of a seldom reported complication following fracture-separation of the distal end of the humerus. This complication consists of dissolution of the trochlea within three to six weeks postinjury and a defect of the medial or central part of the condyle that develops later. The fractures were severely displaced fracture-separation of the distal end of the humerus with large medial or lateral metaphyseal fragment, but initially misdiagnosed as a fracture of the medial, lateral condyle or a traumatic dislocation of the elbow in six of eight cases. We performed open reduction in six cases because of initial misdiagnosis or because of difficulty in satisfactory closed reduction. We speculated that this complication is due to avascular necrosis of the distal end of the humerus, and that fracture-separation of the distal end of the humerus is more common than reported.