Tumor necrosis factor receptor-associated factor (TRAF)2 represses the T helper cell type 2 response through interaction with NFAT-interacting protein (NIP45).

Recently we have identified a novel protein NIP45 (nuclear factor of activated T cells [NFAT]-interacting protein) which substantially augments interleukin (IL)-4 gene transcription. The provision of NIP45 together with NFAT and the T helper cell type 2 (Th2)-specific transcription factor c-Maf to cells normally refractory to IL-4 production, such as B cells or Th1 clones, results in substantial IL-4 secretion to levels that approximate those produced by primary Th2 cells. In studies designed to further our understanding of NIP45 activity, we have uncovered a novel facet of IL-4 gene regulation. We present evidence that members of the tumor necrosis factor receptor-associated factor (TRAF) family of proteins, generally known to function as adapter proteins that transduce signals from the tumor necrosis factor receptor superfamily, contribute to the repression of IL-4 gene transcription and that this effect is mediated through their interaction with NIP45.

An isotype-specific activator of major histocompatibility complex (MHC) class II genes that is independent of class II transactivator.

Patients with one type of major histocompatibility complex class II combined immunodeficiency have mutations in a gene termed class II transactivator (CIITA), which coordinately controls the transcription of the three major human class II genes, HLA-DR, -DQ, and -DP. However, the experimentally derived B-lymphoblastoid cell line, clone 13, expresses high levels of HLADQ in the absence of HLA-DR and HLA-DP, despite its mapping by complementation analysis to this group. It was possible that one of the clone 13 CIITA alleles bore a mutation that allowed HLA-DQ, but not HLA-DR or -DP transcription. Alternatively, another factor, distinct from CIITA, might control HLA-DQ expression. We report here that ectopic expression of CIITA cDNAs derived by reverse transcriptase polymerase chain reaction from clone 13 do not restore expression of HLA-DQ in another CIITA-deficient cell line, RJ2.2.5. In addition, no CIITA protein is detectable in clone 13 nuclear extracts. In contrast, somatic cell fusion between clone 13 and RJ2.2.5 restored expression of the HLA-DQ haplotype encoded by the RJ2.2.5 DQB gene. Taken together, these data demonstrate the existence of an HLA-DQ isotype-specific trans-acting factor, which functions independently of CIITA.

NF-AT-Driven interleukin-4 transcription potentiated by NIP45.

The induction of cytokine gene transcription is mediated in part by the nuclear factor of activated T cells (NF-AT). Factors involved in the mechanisms of NF-AT-mediated transcription are not well understood. A nuclear factor that interacted with the Rel homology domain (RHD) of NF-ATp was identified with the use of a two-hybrid interaction trap. Designated NIP45 (NF-AT interacting protein), it has minimal similarity to any known genes. Transcripts encoding this factor were enriched in lymphoid tissues and testes. NIP45 synergized with NF-ATp and the proto-oncogene c-Maf to activate the interleukin-4 (IL-4) cytokine promoter; transient overexpression of NIP45 with NF-ATp and c-maf in B lymphoma cells induced measurable endogenous IL-4 protein production. The identification of NIP45 advances our understanding of gene activation of cytokines, critical mediators of the immune response.

Immunoglobulin gene transcription ceases upon deletion of a distant enhancer.

The tissue-specific E mu enhancer within the immunoglobulin heavy chain (IgH) locus has recently been shown to be essential for efficient V region gene assembly in early B lineage cells. However, we and others have shown that late stage, Ig-secreting cells can produce IgH in the absence of E mu. In the present study we have explored the notion that another enhancer found in the far 3' region of the IgH locus (3' alpha E) takes on an important regulatory role in cells that have reached this terminal stage in B cell development. The technique of homologous recombination was used to disrupt the 3' alpha E region in an E mu-deficient, Ig gamma 2a-secreting cell line. Loss of 3' alpha E completely abolished Ig heavy chain gene expression, demonstrating that transcription of this gene was dependent upon sequences that reside over 70 kb downstream. The ability of these sequences to function efficiently in the absence of E mu may also provide an explanation for deregulated c-myc expression in many Ig-secreting tumors.

An enhancer at the 3' end of the mouse immunoglobulin heavy chain locus.

A tissue-specific enhancer (E mu) lies between the joining (JH) and mu constant region (C mu) gene segments of the immunoglobulin heavy chain (IgH) locus. Since mouse endogenous IgH genes are efficiently transcribed in its absence, the normal function of this enhancer remains ill-defined. Recently, another lymphoid-specific enhancer of equal strength has been identified 3' of the rat IgH locus. We have isolated an analogous sequence from mouse and have mapped it 12.5 kb 3' of the 3'-most constant region gene (C alpha-membrane) of the BALB/c mouse locus. The mouse and rat sequences are 82% homologous and share with other enhancers several DNA sequence motifs capable of binding protein. However, in transient transfection assays, the mouse sequence behaves as a weaker enhancer. The role of this distant element in the expression of endogenous IgH genes, both in E mu-deficient, Ig-producing cell lines and during normal B cell development, is discussed.

Hangman's fracture or primary spondylolysis: a patient and a brief review.

Recognizing cervical fractures in the younger patient is often difficult. Potential fractures may look like congenital lesions or normal uncalcified synchondroses. We report a three month old infant with a subtle hangman's fracture which might have been confused with primary spondylolysis. The traumatic nature of the defect was confirmed by serial plain films and CT. In addition to showing the value of serial studies, we believe that this is the youngest confirmed case of hangman's fracture reported to date. The literature is reviewed.

Decompression of lumbar spinal stenosis and stabilization with Knodt rods in the elderly patient.

We present a series of 25 elderly patients who exhibited signs and symptoms of neurogenic claudication and who were found to have one or two levels of spinal stenosis. At the time of decompressive surgery, excessive movement was found at the stenotic levels, so a simple stabilization procedure was performed using Knodt rods and a facet fusion. The expectation was that spine fixation would decrease the amount of postoperative back pain, which can be a result of continued abnormal mobility. All of the patients have been followed for 2 or more years. This elderly group of individuals tolerated surgery well, and long-term results were good.

Immunoglobulin heavy-chain enhancer is required to maintain transfected gamma 2A gene expression in a pre-B-cell line.

The immunoglobulin heavy-chain (IgH) enhancer serves to activate efficient and accurate transcription of cloned IgH genes when introduced into B lymphomas or myelomas. The role of this enhancer after gene activation, however, is unclear. The endogenous IgH genes in several cell lines, for example, have lost the IgH enhancer by deletion and yet continue to be expressed. This might be explained if the role of the enhancer were to establish high-level gene transcription but not to maintain it. Alternatively, other enhancers might lie adjacent to endogenous IgH genes, substituting their activity for that of the lost IgH enhancer. To address both of these alternatives, we searched for enhancer activity within the flanking regions of one of these IgH enhancer-independent genes and designed an experiment that allowed us to consider separately the establishment and maintenance of expression of a transfected gene. For the latter experiment we generated numerous pre-B cell lines stably transformed with a gamma 2a gene. In this gene, the IgH enhancer lay at a site outside the heavy-chain transcription unit, between DH and JH gene segments. After expression of the transfected gene was established, selective conditions were chosen for the outgrowth of subclones that had undergone D-J joining and thus IgH enhancer deletion. Measurements of gamma 2a expression before and after enhancer deletion revealed that the enhancer was required for maintenance of expression of the transfected gene. The implication of this finding for models of enhancer function in endogenous genes is discussed.

Hyperglycemia decreases acute neuronal ischemic changes after middle cerebral artery occlusion in cats.

Hyperglycemia has been reported to worsen the tolerance of the brain to ischemia, and it has therefore been recommended that patients undergoing neurosurgical procedures not receive glucose-containing solutions. However, whereas most animal studies have used global ischemia models, most neurosurgical procedures are associated with risks of focal rather than global ischemia. We therefore studied the effects of glucose administration in an animal model of focal cerebral ischemia. We anesthetized 20 cats with halothane (0.85% end tidal in oxygen), and a focal cerebral ischemic lesion was produced by clip ligation of the left middle cerebral artery using a transorbital approach. Hyperglycemia (10 cats, mean +/- SEM plasma glucose concentration 561 +/- 36 mg/dl) was established before ligation by infusion of 50% glucose in 0.45% saline; the control group (10 cats, mean +/- SEM plasma glucose concentration 209 +/- 28 mg/dl) received 0.45% saline only. Total fluid administered, mean arterial blood pressure, body temperature, and arterial blood gas values did not differ between the two groups 0, 2, and 6 hours after ligation. The cats were killed 6 hours after ligation, and the area of severe ischemic neuronal damage was determined by microscopic examination of a coronal section at the level of the optic chiasm. The mean +/- SEM area of left cortical severe ischemic neuronal damage was 12 +/- 2% of the left cortex in the hyperglycemic group compared with 28 +/- 5% in the control group (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal anti-DNA IgM kappa in neuropathy binds to myelin and to a conformational epitope formed by phosphatidic acid and gangliosides.

Anti-DNA antibodies that cross-react with phosphorylated epitopes of other cellular constituents may be involved in the pathogenesis of autoimmune disease. An IgM monoclonal antibody from a patient with chronic lymphocytic leukemia (CLL) and neuropathy bound to denatured DNA and immunostained myelin in peripheral nerve and spinal cord. The monoclonal IgM bound to ELISA microwells coated with a mixture of phosphatidic acid and gangliosides at serum dilutions of up to 1/100,000, but binding to phosphatidic acid alone was observed at dilutions of less than 1/100 only, and there was no binding to gangliosides alone. Incubation with micelles containing phosphatidic acid and gangliosides selectively absorbed the monoclonal IgM and inhibited its binding to denatured DNA and to myelin. These observations suggest that autoantibodies may bind to conformational epitopes formed by two separate molecules, and that autoantibodies that cross-react with phosphorylated epitopes in DNA and neural tissue could be involved in autoimmune neurologic diseases.

A computerized system for the elastic matching of deformed radiographic images to idealized atlas images.

A system of computer programs is described which, for the first time, is able to use computerized tomographic data to automatically locate, measure, and describe anatomical structures of interest with accuracy and consistency. Input to the system consists of any digitized radiographic data. Computer assisted tomographic (CAT) scans of the head were used in this first implementation. Using these data and a predefined atlas picture representing an idealized view of the average normal image, an individualized atlas was created. From the individualized atlas, structure size, density, location displacement, and distortion may be calculated. The individualized atlas created using high resolution data, such as the CAT scan, may then be directly superimposed on pictures obtained using lower resolution modalities, such as positron emission tomographic scan images. This allows the precise location of structures poorly visualized by the secondary imaging modality. This system is capable of using either two- or three-dimensional data.