Difference in behavior between responses to forskolin and general odorants in turtle vomeronasal organ

To elucidate the signal transduction mechanisms in the turtle vomeronasal receptor neurons, the effects of forskolin, changes in mucosal Ca2+ concentrations and ruthenium red on the responses of the accessory olfactory bulb to general odorants were examined. Forskolin elicited a large response, suggesting that there are cAMP-gated channels in the vomeronasal neurons. On the other hand, the dependence of the responses to general odorants on Ca2+ concentrations was different from that of the response to forskolin. A large response to an odorant (n-amyl acetate) appeared after the cAMP-mediated pathway was fully desensitized by application of 50 microM forskolin. These results suggest that the cAMP-mediated pathway does not contribute significantly to generation of the response to general odorants. A concentration of 50 microM ruthenium red significantly reduced the responses to n-amyl acetate alone and after 50 microM forskolin desensitization, suggesting that the inositol triphosphate-mediated pathway contributes partly to generation of the responses to general odorants in the vomeronasal neurons.

V alpha 14+ NK T cells: a novel lymphoid cell lineage with regulatory function

A novel lymphoid lineage, NK T cells, was recently found. The NK T cells are the major population in the periphery comprising 5% of splenic T cells and 40% of bone marrow T cells. They express a unique TCR composed of invariant V alpha 14J alpha 281 and V beta 8.2 together with NK receptor (NKRPI). Surprisingly, the invariant V alpha 14+ TCR is exclusively expressed on NK T cells but not on conventional T cells. As the selective decrease in V alpha 14+ NK T cell population in the periphery is tightly correlated with autoimmune disease development, V alpha 14+ NK T cells control development of autoimmune diseases. We also found that V alpha 14 TCR gene rearrangement and transcripts were detected at an early embryogenesis (d9.5) before the thymus formation. Therefore NK T cells are in the distinct category from conventional T cells. The target of NK T cells is found to be CD1 (class 1b, monomorphic class I MHC-like molecule) present on bone marrow-derived cells and is killed by Fas-FasL interaction or perforin-mediated mechanisms. These results indicate that NK T cells consist of an immunoregulatory system different from defense system in terms of homogeneous repertoire, extrathymic development in early stage of gestation, and their regulatory functional role.

Temperature-dependent enhancement of proteolysis in C2C12 myotubes in association with the activation of 26S proteasome

The effect of temperature on protein metabolism of C2C12 myotubes was investigated in order to estimate the potential effect of fever on muscle catabolism. The half-life of long-lived proteins in C2C12 myotubes was significantly (13%) shorter when incubated at 40 degrees C than at 37 degrees. The activities of cathepsins B and L were not significantly different at 37 and 40 degrees C, nor were the levels of the protein and mRNA of the two cathepsins. In contrast, the chymotrypsin-like activity of 26S proteasome was elevated by 53% at 40 degrees C, compared to that at 37 degrees C, although it was not associated with an increase in the levels of the protein and mRNA of proteasome subunits. mRNA levels of calpain and ubiquitin were not affected by temperature. It is concluded that temperature-dependent enhancement of proteolysis in C2C12 myotubes is associated with an increase in 26S proteasome activity.

Identification of low molecular weight probes on perforin- and Fas-based killing mediated by cytotoxic T lymphocytes

Perforin- and Fas-based killing pathways are two major mechanisms of cytotoxic T lymphocytes (CTL)-mediated cytotoxicity. In this paper, we have reported the identification of low molecular weight probes on CTL-mediated cytolysis. In addition to inhibitors of acidification so far reported, three other groups of compounds have been identified to block perforin-based cytolysis by the CD8+ CTL clone: (1) an inhibitor of actin polymerization (cytochalasin D), (2) respiratory inhibitors (antimycin A and oligomycin A), and (3) protein kinase inhibitors (calphostin C, herbimycin A, K252a, and staurosporine). Since Fas-based cytolysis by CD4+ CTL clone was inhibitable or rather increased by these agents, only vacuolar type H(+)-ATPase inhibitors such as concanamycin A have been shown to be highly specific probes to block perforin-based CTL-mediated cytotoxicity.

[Epidural anesthesia for patients with bronchial asthma]

The choice of epidural anesthesia for patients with bronchial asthma is controversial. We used epidural anesthesia during surgery in 16 cases of asthma. Epidural anesthesia produced by 1% or 2% lidocaine or mepivacaine without epinephrine did not induce asthmatic attack in any patients. After epidural block, general anesthesia was induced with midazolam and vecuronium and endotracheal tube was inserted in 9 patients. Asthmatic attack occurred in two patients. In one patient it occurred by the endotracheal intubation and in another patient during thyroidectomy under nitrous oxide - oxygen - sevoflurane anesthesia, although no attack was observed in 7 patients. Two patients were considered to be in severe state of bronchial asthma and they had been on steroid drug and inhalation therapy before surgery. Both patients recovered soon with antiasthmatic therapy. These results suggest that epidural anesthesia has little or no relevance to asthmatic attack.

Essential requirement of an invariant V alpha 14 T cell antigen receptor expression in the development of natural killer T cells

NK1.1+ T [natural killer (NK) T] cells express an invariant T cell antigen receptor alpha chain (TCR alpha) encoded by V alpha 14 and J alpha 281 segments in association with a limited number of V betas, predominantly V beta 8.2. Expression of the invariant V alpha 14/J alpha 281, but not V alpha 1, TCR in transgenic mice lacking endogenous TCR alpha expression blocks the development of conventional T alpha beta cells and leads to the preferential development of V alpha 14 NK T cells, suggesting a prerequisite role of invariant V alpha 14 TCR in NK T cell development. In V beta 8.2 but not B beta 3 transgenic mice, two NK T cells with different CD3 epsilon expressions, CD3 epsilon(dim) and CD3 epsilon(high), can be identified. CD3 epsilon(high) NK T cells express surface V alpha 14/V beta 8 TCR, indicating a mature cell type, whereas CD3 epsilon(dim) NK T cells express V beta 8 without V alpha 14 TCR and no significant CD3 epsilon expression (CD3 epsilon(dim)) on the cell surface. However, the latter are positive for recombination activating gene (RAG-1 and RAG-2) mRNA, which are only expressed in the precursor or immature T cell lineage, and also possess CD3 epsilon mRNA in their cytoplasm, suggesting that CD3 epsilon(dim) NK T cells are the precursor of V alpha 14 NK T cells.

[A case of middle cranial fossa meningioma extending into the infratemporal fossa: an approach to the pterygoid extension of the sphenoid sinus via the infratemporal fossa]

A case of middle cranial fossa meningioma extending into infratemporal fossa and the pterygoid process is presented. The patient had a sphenoid sinus extending inferolaterally into the pterygoid process, which is known as pterygoid extension of the sphenoid sinus. This type of variation of the sphenoid sinus allowed a safe and well-oriented approach to the pterygoid process via the infratemporal fossa. The tumor extending into the pterygoid process was removed successfully without damaging any surrounding structures, e.g. maxillary nerve or Vidian nerve. However, pterygoid extension of the sinus is seen in only 40% of cases. Therefore, close preoperative examination with bone window CT scan is mandatory before employing this approach.

UK-2A, B, C and D, novel antifungal antibiotics from Streptomyces sp. 517-02. I. Fermentation, isolation, and biological properties

Novel antifungal antibiotics, UK-2A, B and a mixture of C and D, were obtained from the mycelial cake of Streptomyces sp. 517-02. All of the UK-2 compounds were similar in structure to antimycin A. The antifungal activities of UK-2 compounds were as strong as that of antimycin A. However, the UK-2 compounds demonstrated weak cytotoxicity compared to antimycin A.

Development of Valpha4+ NK T cells in the early stages of embryogenesis

The majority of T lymphocytes start to develop at around day 15 of gestation (d15)-d17 in the thymus and comprise the peripheral repertoire characterized by the expression of polymorphic T-cell antigen receptors (TCRs). Contrary to these conventional T cells, a subset of T cells, called natural killer (NK) T cells (most of them expressing an invariant TCR encoded by the Valpha14Jalpha281 gene with a 1-nt N-region), preferentially differentiates extrathymically and dominates the peripheral T-cell population at a high frequency (5% in splenic T cells and 40% in bone marrow T cells). Here, we investigated the development of NK T cells and found that the invariant Valpha14+ TCR transcripts and the circular DNA created by Valpha14 and Jalpha281 gene rearrangements can be detected in the embryo body at d9.5 of gestation and in the yolk sac and the fetal liver at d11.5-d13.5 of gestation, but not in the thymus, whereas T cells with Valpha1+ TCR expression, a major population in the thymus, were not observed at these early stages of gestation. Fluorescence-activated cell sorter analysis also demonstrated that there exist CD3+ alpha beta+ T cells, almost all of which are Valpha14/Vbeta8+ NK+ T cells, during early embryogenesis. To our knowledge, this demonstrates for the first time that a T lymphocyte subset develops in extrathymic tissues during the early stages of embryogenesis.

Selective reduction of V alpha 14+ NK T cells associated with disease development in autoimmune-prone mice

A novel peripheral T cell subset characterized by the expression of a NK marker and invariant TCR encoded by V alpha 14 J alpha 281 gene segments with a 1-base N-region was investigated in relation to autoimmune disease development. First, we observed that invariant V alpha 14+ NK T cells are specifically reduced with aging in C57BL/6 lpr/lpr or MRL lpr/lpr mice, whereas no change was observed in age-matched control C57BL/6 or MRL +/+ mice as determined by FACS analysis and RNase protection assay. This reduction precedes the disease development and could also be detected in other autoimmune disease-prone mice, such as C3H gld/gld and (NZB x NZW)F1 mice. These results suggest that the specific decrease in invariant V alpha 14+ NK T cells correlates strongly with the development of autoimmunity. Second, injection of MRL lpr/lpr mice with anti-V alpha 14 mAb resulted in the early onset and exacerbation of lymphosplenomegaly due to the accumulation of abnormal CD3+ B220+ CD4-CD8- T cells as well as an increase in the titers of anti-dsDNA autoantibodies. These results indicate that V alpha 14+ NK T cells regulate autoimmune responses and play a crucial role in controlling the development of autoimmune diseases.

Selective reduction of V alpha 14+ NK T cells associated with disease development in autoimmune-prone mice

A novel peripheral T cell subset characterized by the expression of a NK marker and invariant TCR encoded by V alpha 14 J alpha 281 gene segments with a 1-base N-region was investigated in relation to autoimmune disease development. First, we observed that invariant V alpha 14+ NK T cells are specifically reduced with aging in C57BL/6 lpr/lpr or MRL lpr/lpr mice, whereas no change was observed in age-matched control C57BL/6 or MRL +/+ mice as determined by FACS analysis and RNase protection assay. This reduction precedes the disease development and could also be detected in other autoimmune disease-prone mice, such as C3H gld/gld and (NZB x NZW)F1 mice. These results suggest that the specific decrease in invariant V alpha 14+ NK T cells correlates strongly with the development of autoimmunity. Second, injection of MRL lpr/lpr mice with anti-V alpha 14 mAb resulted in the early onset and exacerbation of lymphosplenomegaly due to the accumulation of abnormal CD3+ B220+ CD4-CD8- T cells as well as an increase in the titers of anti-dsDNA autoantibodies. These results indicate that V alpha 14+ NK T cells regulate autoimmune responses and play a crucial role in controlling the development of autoimmune diseases.

Chronic encapsulated expanding hematoma in association with gamma knife stereotactic radiosurgery for a cerebral arteriovenous malformation. Case report

The authors report a rare case of a patient with a chronic encapsulated expanding hematoma and progressive neurological deterioration who presented 2 years after gamma knife radiosurgery for a cerebral arteriovenous malformation (AVM). A tough capsule containing multiple layers of organized hematoma resulting from previous bleeding was confirmed surgically. Histological examination revealed that the capsule consisted of a dense collagenous outer layer and a granulomatous newly vascularized inner layer with marked fibrosis. Hemosiderin deposits were frequently observed in the inner layer, which suggested recurrent minor bleeding from fragile vessels in this layer. An AVM was found in the hematoma, which had degenerated as the result of radiosurgery. A cross-section of the abnormal vessels showed various stages of obliteration due to intimal hypertrophy. The clinical course, radiological features, and histological findings in this case were compatible with those of previously reported chronic encapsulated hematomas. A possible mechanism of hematoma formation and its expansion are discussed.

Somatosensory evoked potential phase reversal and direct motor cortex stimulation during surgery in and around the central region

In 99 patients with mass lesions in and around the central region, the central sulcus was intraoperatively localized with the use of somatosensory evoked potential (SEP) phase reversal. In 33 of these patients, the motor cortex was directly stimulated and electromyographic responses were recorded from the forearm flexor, thenar, and hypothenar muscles. An additional 25 patients, with subcortical lesions or lesions directly located at the pyramidal tract, were continuously monitored during surgery by motor evoked potentials (MEPs). An exact determination of the central sulcus and tumor localization was possible in all patients; a phase reversal was obtained in 90.8% of the patients, and localization was possible as a result of anatomic structures and the loss of N20 or P20 of SEPs in the other 9.2%. MEPs were obtained in 32 of 33 patients and also in all 25 patients who underwent MEP monitoring at the beginning of tumor removal. From this study, it can be concluded that the combination of SEP phase reversal and modified electrical cortex stimulation is compatible with general anesthesia, although anesthesia was not systematically controlled according to a protocol. Although this study demonstrates that the combined SEP/MEP technique was feasible, it is not yet possible to demonstrate benefit in improving the outcome of patients. Concerning the safety of stimulation, the exact localization of the central sulcus by the noninvasive SEP method, compared with direct electrical stimulation, offered more safety for the patient. The modified technique of direct motor cortex stimulation needed much less charge density than did the common technique. The recording of electromyographic responses instead of movements made objective documentation possible, and the analysis of amplitudes and latencies will supply quantitative information about the motor system.

Possible involvement of an environmental agent in the development of acute eosinophilic pneumonia

BACKGROUND

Although the pathogenesis of acute eosinophilic pneumonia remains largely unknown, it has been suggested that it may include a hypersensitivity phenomenon induced by inhaled environmental antigens.

METHODS

To investigate this possibility, we studied the effect of environmental challenges in three patients with acute eosinophilic pneumonia. Symptoms and laboratory findings were evaluated before and after the challenge tests in the patient's homes and their places of work.

RESULTS

After the provocation challenges to their homes, all three patients developed fever, cough, and fatigue and two of them presented with dyspnea. Inspiratory crackles became audible in all cases, and there was a decreased Pao2 level in two. Similar challenges at their workplaces were negative. After moving out of their homes, the patients engaged in their usual work but had no recurrent episodes.

CONCLUSIONS

These results suggest that environmental factors in the home can be the cause of acute eosinophilic pneumonia. In order to elucidate the pathogenesis of the disease, it is important to further investigate environmental factors.

A role for mel-18, a Polycomb group-related vertebrate gene, during theanteroposterior specification of the axial skeleton

Segment identity in both invertebrates and vertebrates is conferred by spatially restricted distribution of homeotic gene products. In Drosophila, the expression of Homeobox genes during embryogenesis is initially induced by segmentation gene products and then maintained by Polycomb group and Trithorax group gene products. Polycomb group gene homologs are conserved in vertebrates. Murine mel-18 and closely related bmi-1 are homologous to posterior sex combs and suppressor two of zeste. Mel-18 protein mediates a transcriptional repression via direct binding to specific DNA sequences. To gain further insight into the function of Mel-18, we have inactivated the mel-18 locus by homologous recombination. Mice lacking mel-18 survive to birth and die around 4 weeks after birth after exhibiting strong growth retardation. Similar to the Drosophila posterior sex combs mutant, posterior transformations of the axial skeleton were reproducibly observed in mel-18 mutants. The homeotic transformations were correlated with ectopic expression of Homeobox cluster genes along the anteroposterior axis in the developing paraxial mesoderm. Surprisingly, mel-18-deficient phenotypes are reminiscent of bmi-1 mutants. These results indicate that the vertebrate Polycomb group genes mel-18 and bmi-1, like Drosophila Polycomb group gene products, might play a crucial role in maintaining the silent state of Homeobox gene expression during paraxial mesoderm development.

[Sinus bradyarrhythmia during administration of all-trans retinoic acid in a patient with acute promyelocytic leukemia]

A case of acute promyelocytic leukemia (APL) complicated by sinus bradyarrhythmia during the course of all-trans retinoic acid (ATRA) administration is reported. A 3-year-old boy was admitted for evaluation of petechiae and APL was diagnosed. He was initially treated with 45 mg/m2 of ATRA without success, and a complete remission was achieved when the dose was increased to 135 mg/m2. Sinus bradyarrhythmia was first recognized 3 days after the induction therapy with ATRA. It did not disappear even when the patient stopped taking the medication. However, the arrhythmia tended to be augmented whenever he received ATRA again. Close observation of his cardiac condition was mandatory to continue ATRA as an integral part of the therapy for APL, combined with multidrug chemotherapy including anthracyclines, which themselves are potentially toxic to myocardium. In conclusion, the present case revealed the possibility that ATRA therapy induces sinus node arrhythmia, or that it can potentiate preexisting node dysfunctions.

Intravenous trimethaphan during epidural plus general anesthesia decreases the direct radial artery pressure lower than the brachial artery pressure

STUDY OBJECTIVE

To determine whether vasodilators such as sodium nitroprusside (SNP) and trimethaphan (TMP) produce a pressure difference between the radial artery and the brachial artery during epidural plus general anesthesia or simple general anesthesia.

DESIGN

Randomized study and prospective study.

SETTING

Operating rooms of two hospitals.

PATIENTS

36 and 6 adult patients in the first and second studies, respectively, who received spherical acetabular osteotomy with induced hypotensive anesthesia.

INTERVENTIONS

In the first study, 18 patients received epidural plus general anesthesia (epidural group) and 18 patients received general anesthesia alone (general group). All patients received the hypotensive drugs for more than 50 minutes each. In the second study, 6 patients received TMP-induced hypotension for 20 minutes under epidural plus general anesthesia.

MEASUREMENTS AND MAIN RESULTS

In the first study, radial intra-arterial blood pressure (RIBP) and tonometric blood pressure (TBP) calibrated with oscillometric blood pressure of the arm were compared. In the second study, RIBP and the brachial intra-arterial blood pressure (BIBP) were compared. In the first study, the bias between RIBP and TBP for systolic, mean and diastolic blood pressure were significantly less during TMP-induced hypotension in the epidural group (-11.5 +/- 2.5 (mean +/- SD), -6.0 +/- 3.1, and -2.8 +/- 3.7 mmHg, respectively] than during SNP-induced hypotension in the epidural group and SNP- and TMP-induced hypotension in the general group (p < 0.01). The precision of systolic and mean pressures were significantly greater during TMP-induced hypotension in the epidural group (11.8 +/- 2.3 and 7.1 +/- 1.9 mmHg, respectively) than the other three hypotension groups (p < 0.01). In the second study, the bias between RIBP and BIBP for systolic, mean, and diastolic pressures were significantly less (p < 0.01), and precision was significantly greater during hypotension than during normotension (p < 0.01).

CONCLUSIONS

Our results demonstrate that TMP decreases the direct radial artery systolic and mean pressures to levels below the brachial artery systolic and mean pressures in patients who received epidural plus general anesthesia.

Monoclonality of B-cell lineage in primary pulmonary lymphoma demonstrated by immunoglobulin heavy chain gene sequence analysis of histologically non-definitive transbronchial biopsy specimens

Immunoglobulin heavy chain (IgH) gene rearrangements were amplified in transbronchial lung biopsy (TBLB) specimens taken from five patients with primary lymphoma of the lung in whom the diagnosis was established by surgical specimens. By histopathological analysis of TBLB specimens, only two of the five cases were diagnosed as lymphoma, the other three cases being classified as equivocal due mainly to low levels of cellular atypia and to artefactual distortion. All five TBLB specimens, as well as the subsequent surgical specimens, showed a sharp monoclonal band of IgH gene rearrangement on electrophoresis of polymerase chain reaction (PCR) products. By contrast, three surgical biopsy specimens from cases of lymphoid interstitial pneumonia (LIP) showed smear polyclonal bands. No clonal rearrangements were detected in six non-neoplastic controls, including five cases of chronic bronchitis and one of sarcoidosis. The PCR products of three of the lymphoma cases were sequenced from both TBLB and surgical specimens. In all three cases, there was dominant expression of a particular rearrangement, assumed to be tumour-derived. In each case, the major clones derived from the TBLB and the surgical specimen were identical. In both lymphoma and LIP cases, more frequent usages of JH4 and JH6 were evident. The diagnosis of lymphoma can be confirmed on TBLB specimens by use of this technique.

Third complementarity determining region sequence analysis of low-grade bronchus-associated lymphoid tissue lymphoma: genotypic analysis reveals heterogeneity in maturation

It has recently been suggested that autoimmunity may play a role in the pathogenesis of low-grade mucosa-associated lymphoid tissue lymphomas, but precise genotypic analysis of antigen binding sites of low-grade bronchus-associated lymphoid tissue (BALT) lymphomas has not been reported. We analyzed the third complementarity determining region (CDR3) in eight cases of low-grade BALT lymphoma by 2-step PCR and sequencing analysis. All cases showed a distinct monoclonal band (about 100 base pairs) on electrophoresis. In seven cases, a single major CDR3 sequence was identified with five to nine clones among 10 vector clones being identical; and in the remaining case, two major sequences were obtained, with four clones among nine vector clones being identical. Findings suggestive of the autoimmunity of low-grade BALT lymphoma were obtained: (1) VHDJH rearrangements in seven of the eight lymphoma cell clones were potentially functional; (2) genotypically, two lymphoma cell clones showed 60 to 74% homology with G6 positive lymphocyte clones; and (3) five lymphoma cell clones showed 61 to 71 % homology with lymphocyte clones derived from fetal liver or cord blood. In one case, the N-D-N length of the neoplastic clone was very short and lacked N nucleotides at the D-JH junction. Therefore, our study demonstrates genotypic heterogeneity in maturation in low-grade BALT lymphoma.

Cloning and characterization of two transcripts generated from the mel-13 gene positioned adjacent to the mammalian Polycomb group-related gene mel-18

We previously isolated the mel-18 gene, a mammalian Polycomb group (PcG)-related gene with homology to bmi-1 oncogene. We show in this paper the existence of a new gene, mel-13, which overlapped with the mel-18 anti-oncogene. We discuss the relationships between mel-13 and the mel-18, bup, and Su(z)2 genes.

A clinical study of minocycline-induced pneumonitis

We studied the clinical features of minocycline-induced pneumonitis in seven patients. Acute symptoms included fever, dry cough and dyspnea, indicating acute respiratory failure. Diffuse ground glass shadows with Kerley's B lines, bronchial wall thickening, swelling of vascular bundles and pleural effusion were visible on radiography. Bronchoalveolar lavage or transbronchial lung biopsy confirmed pulmonary eosinophilia. Cessation of minocycline led to rapid remission with no treatment or only short-term steroid therapy. The lymphocyte stimulation test for minocycline with peripheral blood lymphocytes was not found to be useful for diagnosis.

Production of monoclonal antibodies against quail Pax-1

Monoclonal antibodies (MAbs) against quail Pax-1 were generated using a fusion protein of the C-terminal part of Pax-1 and glutathione S-transferase. The MAbs generated could detect quail Pax-1 protein by Western blotting and immunoprecipitate it from whole cell extracts of quail embryos, indicating their usefulness for biochemical analyses of Pax-1 protein function in development or oncogenesis.