Aggressive endoscopic mucosal resection in the upper GI tract - Hook knife EMR method

We have developed a new EMR method, the 'Hook knife' method, for the en-bloc resection of larger lesions. First, we placed marks around the lesion with a coagulation tip. Next, 10% glycerol diluted epinephrine solution was injected into the submucosal layer to separate the mucosa from the muscular layer proper. Then, we cut the mucosa around the lesion with a needle knife. Finally, we cut the submucosal fibers and vessels using a hook-type knife and resected the lesions. A large en-bloc resection, ≥70 mm in size, was possible with this new EMR method. Because of this, the histological examination for both the range of lateral spreading and the depth of invasion can be made more precisely. Aggressive endoscopic mucosal resection is established by this new EMR method.

Periostin is expressed in pericryptal fibroblasts and cancer-associated fibroblasts in the colon

Periostin is a unique extracellular matrix protein, deposition of which is enhanced by mechanical stress and the tissue repair process. Its significance in normal and neoplastic colon has not been fully clarified yet. Using immunohistochemistry and immunoelectron microscopy with a highly specific monoclonal antibody, periostin deposition was observed in close proximity to pericryptal fibroblasts of colonic crypts. The pericryptal pattern of periostin deposition was decreased in adenoma and adenocarcinoma, preceding the decrease of the number of pericryptal fibroblasts. Periostin immunoreactivity appeared again at the invasive front of the carcinoma and increased along the appearance of cancer-associated fibroblasts. ISH showed periostin signals in cancer-associated fibroblasts but not in cancer cells. Ki-67-positive epithelial cells were significantly decreased in the colonic crypts of periostin-/- mice (approximately 0.6-fold) compared with periostin+/+ mice. In three-dimensional co-culture within type I collagen gel, both colony size and number of human colon cancer cell line HCT116 cells were significantly larger ( approximately 1.5-fold) when cultured with fibroblasts derived from periostin+/+ mice or periostin-transfected NIH3T3 cells than with those from periostin-/- mice or periostin-non-producing NIH3T3 cells, respectively. Periostin is secreted by pericryptal and cancer-associated fibroblasts in the colon, both of which support the growth of epithelial components.

Optically accessible microchannels formed in a single-crystal silicon substrate for studies of blood rheology

An attempt to use microgrooves as blood flow channels in single-crystal silicon is described. Grooves were formed in the (100) crystalline surface by means of photolithography and orientation-dependent etching. This substrate surface was tightly covered with an optically flat glass plate to prevent leakage. This structure was used to microscopically observe flow behavior of blood cells. As a first design of such a cell-flow apparatus, many parallel same-size channels of relatively short length (equivalent diameter 6 microns, length 14.4 microns, number 2600) have been produced to simultaneously measure the total volume flow rate of blood under constant suction. Despite differences in cross-sectional shape and length, the ratio of blood flow velocity to pressure gradient in the channels was comparable with estimates for capillary vessels in vivo. Activated white blood cells blocked the channels, while aggregations of red blood cells showed unexpectedly small resistance to channel transit.

ICH-harmonised guidances on genotoxicity testing of pharmaceuticals: evolution, reasoning and impact

The International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) has convened an expert working group which consisted of the authors of this paper and their respective committees, consulting groups and task forces. Two ICH guidances regarding genotoxicity testing have been issued: S2A, 'Guidance on Specific Aspects of Regulatory Genotoxicity Tests' and S2B, 'Genotoxicity: A Standard Battery for Genotoxicity Testing of Pharmaceuticals.' Together, these guidance documents now form the regulatory backbone for genotoxicity testing and assessment of pharmaceuticals in the European Union, Japan, and the USA. These guidances do not constitute a revolutionary new approach to genotoxicity testing and assessment, instead they are an evolution from preexisting regional guidelines, guidances and technical approaches. Both guidances describe a number of specific criteria as well as a general test philosophy in genotoxicity testing. Although these guidances were previously released within the participating regions in their respective regulatory communiqués, to ensure their wider distribution and better understanding, the texts of the guidances are reproduced here in their entirety (see Appendix A) and the background for the recommendations are described. The establishment of a standard battery for genotoxicity testing of pharmaceuticals was one of the most important issues of the harmonisation effort. This battery currently consists of: (i) a test for gene mutation in bacteria, (ii) an in vitro test with cytogenetic evaluation of chromosomal damage with mammalian cells or an in vitro mouse lymphoma tk assay, (iii) an in vivo test for chromosomal damage using rodent hematopoietic cells. A major change in testing philosophy is the acceptance of the interchangeability of testing for chromosomal aberrations in mammalian cells and the mouse lymphoma tk assay. This agreement was reached on the basis of the extensive review of databases and newly generated experimental data which are in part described in this publication. The authors are fully aware of the fact that some of the recommendations given in these ICH guidances are transient in nature and that the dynamic qualities and ongoing evolution of genetic toxicology makes necessary a continuous maintenance process that would serve to update the guidance as necessary.

Circumspinal decompression for thoracic myelopathy due to combined ossification of the posterior longitudinal ligament and ligamentum flavum

Ossification of the posterior longitudinal ligament (OPLL) combined with ossification of the ligamentum flavum (OLF) in the thoracic spine can result in serious myelopathy, leading to circumferential compression of the spinal cord in advanced stages of the disease. The authors performed circumspinal decompression (circumferential decompression of the spinal cord) on these patients. This operation consists of two steps: posterior and lateral decompression of the spinal cord by removal of the OLF (first step) and anterior removal of the OPLL for anterior decompression (second step), followed by interbody fusion. In the first step, two deep parallel gutters, covering the extent of the OPLL to be removed anteriorly, are drilled down from the rear into the vertebral body along both sides of the dura to easily and safely remove the OPLL anteriorly at the second step. In the second step, the surgical approach varies according to the affected level; costotransversectomy in the upper thoracic spine and standard thoracotomy in the middle or lower thoracic spine. According to the authors, circumspinal decompression is not an easy procedure, but from their results in 10 patients, they identify it as a radical and promising surgical procedure.

Delayed re-epithelialization in periostin-deficient mice during cutaneous wound healing

Background

Matricellular proteins, including periostin, are important for tissue regeneration.

Methods and Findings

Presently we investigated the function of periostin in cutaneous wound healing by using periostin-deficient (−/−) mice. Periostin mRNA was expressed in both the epidermis and hair follicles, and periostin protein was located at the basement membrane in the hair follicles together with fibronectin and laminin γ2. Periostin was associated with laminin γ2, and this association enhanced the proteolytic cleavage of the laminin γ2 long form to produce its short form. To address the role of periostin in wound healing, we employed a wound healing model using WT and periostin−/− mice and the scratch wound assay in vitro. We found that the wound closure was delayed in the periostin−/− mice coupled with a delay in re-epithelialization and with reduced proliferation of keratinocytes. Furthermore, keratinocyte proliferation was enhanced in periostin-overexpressing HaCaT cells along with up-regulation of phosphorylated NF-κB.

Conclusion

These results indicate that periostin was essential for keratinocyte proliferation for re-epithelialization during cutaneous wound healing.

Nitric oxide as a retrograde messenger in the nucleus tractus solitarii of rats during hypoxia

1. We examined the role of nitric oxide (NO) in respiratory regulation in the nucleus tractus solitarii (NTS), where L-glutamate release associated with peripheral chemoreceptor activation modulates the hypoxic ventilatory response. 2. Experiments were performed in unanaesthetized freely moving rats. First, the effects on the hypoxic ventilatory response of sodium nitroprusside (SNP, a NO donor) or NG-monomethyl-L-arginine (L-NMMA, a NO synthase inhibitor), microinjected into the NTS, were investigated. Second, using in vivo microdialysis, changes in extracellular L-glutamate during hypoxia were examined in the presence of L-NMMA. Third, the effect of L-NMMA on ventilatory augmentation by exogenous L-glutamate was examined. Furthermore, we measured extracellular L-citrulline concentration changes during hypoxia in the NTS to assess NO formation indirectly and also examined the effect of MK-801 (an NMDA receptor antagonist) on L-citrulline levels during hypoxia. 3. SNP increased ventilation during both normoxia and hypoxia. L-NMMA did not alter ventilation or L-glutamate levels during normoxia but significantly attenuated the hypoxic ventilatory response and the increase in L-glutamate during hypoxia. The inhibition by L-NMMA was blocked by L-arginine. The ventilatory augmentation by exogenous L-glutamate was attenuated by L-NMMA. L-Citrulline increased during hypoxia, and this increase was inhibited by MK-801. 4. We provide the first in vivo evidence that, in the NTS, NO works as a retrograde messenger in an L-glutamate-releasing positive feedback system contributing to the augmentation of ventilation during hypoxia.

Mutational analysis of the feedback sites of phenylalanine-sensitive 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase of Escherichia coli

In Escherichia coli, aroF, aroG, and aroH encode 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase isozymes that are feedback inhibited by tyrosine, phenylalanine, and tryptophan, respectively. In vitro chemical mutagenesis of the cloned aroG gene was used to identify residues and regions of the polypeptide essential for phenylalanine feedback inhibition.

Effects of submental electrical stimulation during sleep on upper airway patency in patients with obstructive sleep apnea

We examined the effects of percutaneous electrical stimulation of the genioglossus in six patients with obstructive sleep apnea syndrome (OSAS) during sleep and investigated the possible applicability of this procedure as a treatment of OSAS. Six patients with OSAS were polysomnographically studied in the supine position during all-night sessions with and without electrical stimulation of the genioglossus. Using an apnea demand-type stimulator that we developed, electrical pulses of 0.5 ms (repetition rate, 50 Hz) and 15 to 40 V were delivered through bipolar electrodes (10 mm in diameter) attached to the skin of the submental region when apnea lasted more than 5 s, and was stopped immediately after breathing resumed or after 10 s at the longest. With submental stimulation, the apnea index, apnea time/total sleep time, longest apnea duration, and the number of times per hour that oxygen saturation dropped below 85% decreased significantly compared with those on control nights. The lowest arterial oxygen saturation and the duration of sleep stages III and IV increased significantly. The stimulation employed did not cause arousal, and it did not affect blood pressure or heart rate significantly. These findings show that submental stimulation decreases the incidence of apnea episodes and promotes deeper sleep without accompanying serious side effects, suggesting that the apnea demand-type stimulator may be a noninvasive and effective treatment for OSAS.

Intracavernous injection of prostaglandin E1 for the treatment of erectile impotence

We administered intracavernous injections of 20 micrograms. prostaglandin E1 to 135 patients with impotence, and evaluated the effects and side effects. Among 135 patients who underwent intracavernous injection of prostaglandin E1 complete erection was observed in 83 (62 per cent), while incomplete erection was noted in 33 (24 per cent). In both groups the erection was sufficient for sexual intercourse. Tumescence without rigidity was noted in 12 patients and no response was obtained in 7. Poor response was seen frequently in patients with disorders of the vascular system and/or damage to the cavernous body of the penis. Priapism after the injection was not observed. Moreover, we never observed any other severe side effects. Intracavernous injection of prostaglandin E1 could be applicable to the therapy of impotence, especially that due to neurogenic disturbance. Since prostaglandin E1 acts quickly and loses its validity rapidly it is considered to be a more suitable agent than other vasoactive drugs.

Selective hypercontraction caused by ergonovine in the canine coronary artery under conditions of induced atherosclerosis

The relationship between the hypercontractile response of the regional coronary artery to ergonovine and induced vascular change after endothelial denudation and a high-cholesterol diet was examined in dogs by arteriographic (in situ) and mechanographic (in vitro) methods. In 15 mongrel dogs, selective endothelial denudation of either the left circumflex coronary artery (LCX) or left anterior descending coronary artery (LAD) was repeated twice 1 month apart by means of coronary arterial catheterization. A high-cholesterol diet (20 g/day) was given thereafter for 3 (n = 15) and 6 (n = 8) months. Although there was no difference in the extent of coronary vasoconstriction between the LAD and LCX before or immediately after endothelial denudation, after intravenous administration of ergonovine a significant augmentation of coronary constriction along the denuded portion was noted arteriographically in the long-term phase (1 to 6 months). At the end of the study in vivo, isometric tension of the strips of the denuded and contralateral intact coronary arteries was measured during the cumulative addition of ergonovine, serotonin, or phenylephrine to the organ bath; agonist responses were standardized by the response to 35 mM KCl. Although the concentration-response relations for phenylephrine (10(-9) M to 10(-5) M) were not significantly different between intact and denuded arteries, responses of the denuded portion to cumulative addition of ergonovine (10(-10) M) or serotonin 10(-9) M to 10(-5) M) exhibited markedly depressed threshold concentrations along with a significantly lowered negative logarithm (pD2) of the dose producing 50% of the maximum effect. The tension developed in the denuded portion was also enhanced over that noted in the contralateral coronary artery during the cumulative addition of ergonovine but not during application of phenylephrine. Thus enhanced constriction documented arteriographically may be derived from the localized hypersensitivity to ergonovine. Microscopically, the endothelial denudation and a long-term high-cholesterol diet resulted in a regional intimal thickening with fibrous proliferation but little lipid deposition. Therefore smooth muscle in atherosclerotic arteries may be hypersensitive to specific agonists such as ergonovine and serotonin in a canine preparation. These results suggest that coronary spasm induced by ergonovine in humans is relevant to the presence of atherosclerotic changes in the vascular wall.

Caspase activation accompanying cytochrome c release from mitochondria is possibly involved in nitric oxide-induced neuronal apoptosis in SH-SY5Y cells

It is well known that caspases are produced as proforms, which are proteolytically cleaved and activated during apoptosis or programmed cell death. We report here that caspases are activated during apoptosis by treatment with NOC18, a nitric oxide (NO) donor. Our present experiments have examined the way in which NO induces neuronal cell death, using a new type of NO donor that spontaneously releases only NO without enzymatic metabolism. NOC18 induced apoptosis in human neuroblastoma SH-SY5Y cells in a concentration- and time-dependent manner as estimated by DNA fragmentation assay, FACScan analysis, and nuclear morphology. Oxyhemoglobin, an NO trapper, suppressed NOC18-triggered DNA fragmentation, indicating that NO from NOC18 is a real activator in this study. Upon the induction of apoptosis, an increase in caspase-3-like protease activity, but not caspase-1, was observed. Procaspase-2 protein, an inactive form of caspase-2, decreased dramatically. In addition, NOC18 also resulted in poly (ADP-ribose) polymerase (PARP) cleavage, yielding an 85-kDa fragment typical of caspase activity. Oxyhemoglobin blocked the decrease of procaspase-2 and the cleavage of PARP by NOC18 in a concentration-dependent manner. Moreover, NO elicited the release of cytochrome c into the cytosol during apoptosis. These results suggest that both stimulation of caspase activity and cytochrome c release are partly involved in NO-induced neuronal apoptosis.

A novel factor required for the SUMO1/Smt3 conjugation of yeast septins

SUMO1/Smt3, a ubiquitin-like protein modifier, is known to be conjugated to other proteins and modulate their functions in various important processes. Similar to the ubiquitin system, SUMO1/Smt3 is activated in an ATP-dependent reaction by thioester bond formation with E1 (activating enzyme), transferred to E2 (conjugating enzyme), and passed to a substrate lysine. It remained unknown, however, whether any SUMO1/Smt3 ligases (E3s) are involved in the final transfer of this modifier. Here we report a novel factor Siz1 (YDR409w) required for septin-sumoylation of budding yeast, possibly acting as E3. Siz1 is a member of a new family (Miz1, PIAS3, etc.) containing a conserved domain with a similarity to a zinc-binding RING-domain, often found in ubiquitin ligases. In the siz1 mutant septin-sumoylation was completely abolished. A conserved cysteine residue in the domain was essential for this conjugation. Furthermore, Siz1 was localized at the mother-bud neck in the M-phase and physically bound to both E2 and the target proteins.

Prognostic Factors of Stage IV Epithelial Ovarian Cancer: A Multicenter Retrospective Study

OBJECTIVE

In the present study, we conducted a multicenter retrospective analysis to elucidate the prognostic factors of stage IV epithelial ovarian cancer.

METHODS

In November 1999, 24 Japanese institutions received questionnaires regarding stage IV epithelial ovarian cancer patients. Eligibility criteria included all patients with stage IV epithelial ovarian cancer who were surgically confirmed and initially treated in each institution between January 1990 and December 1997. Data were collected regarding age, performance status, tumor histologic subtype, site of metastasis, preoperative CA125, cytoreductive surgery, residual disease after cytoreductive surgery, and response to primary chemotherapy. Survival analysis and comparisons were performed by univariate and multivariate methods.

RESULTS

Two hundred twenty-five patients with stage IV ovarian cancer were identified. The median age of the patients was 54 years. The most common site of extraperitoneal disease was malignant pleural effusion (39.6%). Of the 225 patients who underwent an attempt at surgical debulking, 70 (31.1%) were optimally cytoreduced. Most patients received platinum-based combination chemotherapy for primary chemotherapy. In multivariate analysis, performance status, histology, and residual disease after cytoreductive surgery were independent prognostic predictors of outcome. The overall median survival for optimally debulked patients was 32 months compared to 16 months for suboptimally debulked patients (P < 0.0001, hazard ratio: 0.415).

CONCLUSION

Optimal surgical debulking, performance status, and histology appear to be important prognostic factors of survival in patients with stage IV epithelial ovarian cancer.

Bul1, a new protein that binds to the Rsp5 ubiquitin ligase in Saccharomyces cerevisiae

We characterized a temperature-sensitive mutant of Saccharomyces cerevisiae in which a mini-chromosome was unstable at a high temperature and cloned a new gene which encodes a basic and hydrophilic protein (110 kDa). The disruption of this gene caused the same temperature-sensitive growth as the original mutation. By using the two-hybrid system, we further isolated RSP5 (reverses Spt- phenotype), which encodes a hect (homologous to E6-AP C terminus) domain, as a gene encoding a ubiquitin ligase. Thus, we named our gene BUL1 (for a protein that binds to the ubiquitin ligase). BUL1 seems to be involved in the ubiquitination pathway, since a high dose of UBI1, encoding a ubiquitin, partially suppressed the temperature sensitivity of the bul1 disruptant as well as that of a rsp5 mutant. Coexpression of RSP5 and BUL1 on a multicopy plasmid was toxic for mitotic growth of the wild-type cells. Pulse-chase experiments revealed that Bul1 in the wild-type cells remained stable, while the bands of Bul1 in the rsp5 cells were hardly detected. Since the steady-state levels of the protein were the same in the two strains as determined by immunoblotting analysis, Bul1 might be easily degraded during immunoprecipitation in the absence of intact Rsp5. Furthermore, both Bul1 and Rsp5 appeared to be associated with large complexes which were separated through a sucrose gradient centrifugation, and Rsp5 was coimmunoprecipitated with Bul1. We discuss the possibility that Bul1 functions together with Rsp5 in protein ubiquitination.

Interleukin 5, a T-cell-derived B-cell differentiation factor also induces cytotoxic T lymphocytes

We describe an interleukin, termed interleukin 5, that is the recombinant product previously referred to as T-cell-replacing factor (TRF), B-cell growth factor II (BCGF II), or killer-helper factor (KHF). TRF has been defined as a T-cell-derived lymphokine that acts on activated B cells as a B-cell differentiation factor. We have previously demonstrated that TRF is identical to BCGF II and induces expression of receptors for interleukin 2 (IL-2) on activated B cells. We also have reported that KHF can induce not only expression of IL-2 receptors on peanut agglutinin-binding (PNA+) thymocytes but also generation of cytotoxic T lymphocytes (CTL) in PNA+ thymocytes in the presence of IL-2. We show here that culture supernatants of T-cell hybridomas that produce TRF as well as TRF purified by high-pressure liquid chromatography (HPLC-TRF) have KHF activity and generate CTL in PNA+ thymocytes in the presence of stimulator cells and IL-2. Moreover, translation products (recombinant TRF) of Xenopus oocytes injected with cDNA encoding for murine TRF (BCGF II) also exert KHF activity. A rat monoclonal anti-TRF antibody TB13 can block generation of CTL by HPLC-TRF or recombinant TRF. These results indicate that TRF acts not only on B cells as BCGF II but also on PNA+ thymocytes as KHF. In view of the diverse activities and targets of TRF, we propose that TRF refers to a different interleukin, interleukin 5.

ATP stimulation of Ca2+ -dependent plasminogen release from cultured microglia

1. ATP (10-100 microM), but not glutamate (100 microM), stimulated the release of plasminogen from microglia in a concentration-dependent manner during a 10 min stimulation. However, neither ATP (100 microM) nor glutamate (100 microM) stimulated the release of NO. A one hour pretreatment with BAPTA-AM (200 microM), which is metabolized in the cytosol to BAPTA (an intracellular Ca2+ chelator), completely inhibited the plasminogen release evoked by ATP (100 microM). The Ca2+ ionophore A23187 induced plasminogen release in a concentration-dependent manner (0.3 microM to 10 microM). 2. ATP induced a transient increase in the intracellular calcium concentration ([Ca2+]i) in a concentration-dependent manner which was very similar to the ATP-evoked plasminogen release, whereas glutamate (100 microM) had no effect on [Ca2+]i (70 out of 70 cells) in microglial cells. A second application of ATP (100 microM) stimulated an increase in [Ca2+]i similar to that of the first application (21 out of 21 cells). 3. The ATP-evoked increase in [Ca2+]i was totally dependent on extracellular Ca2+, 2-Methylthio ATP was active (7 out of 7 cells), but alpha,beta-methylene ATP was inactive (7 out of 7 cells) at inducing an increase in [Ca2+]i. Suramin (100 microM) was shown not to inhibit the ATP-evoked increase in [Ca2+]i (20 out of 20 cells). 2'- and 3'-O-(4-Benzoylbenzoyl)-adenosine 5'-triphosphate (BzATP), a selective agonist of P2X7 receptors, evoked a long-lasting increase in [Ca2+]i even at 1 microM, a concentration at which ATP did not evoke the increase. One hour pretreatment with adenosine 5'-triphosphate-2', 3'-dialdehyde (oxidized ATP, 100 microM), a selective antagonist of P2X7 receptors, blocked the increase in [Ca2+]i induced by ATP (10 and 100 microM). 4. These data suggest that ATP may transit information from neurones to microglia, resulting in an increase in [Ca2+]i via the ionotropic P2X7 receptor which stimulates the release of plasminogen from the microglia.

Ssd1p of Saccharomyces cerevisiae associates with RNA

The SSD1 gene has been isolated as a single copy suppressor of many mutants, such as sit4, slk1/bck1, pde2, and rpc31, in the yeast Saccharomyces cerevisiae. Ssd1p has domains showing weak but significant homology with RNase II-related proteins, Cyt4p, Dss1p, VacB, and RNase II, which are involved in the modification of RNA. We found that Ssd1p had the ability to bind RNA, preferably poly(rA), as well as single-stranded DNA. Interestingly, the most conserved domain among the RNase II-related proteins was not necessary for interaction with RNA. Indirect immunofluorescence staining with anti-Ssd1p antibody revealed that Ssd1p was detected mainly in the cytoplasm. Furthermore, sucrose gradient sedimentation analysis demonstrated that Ssd1p was not cofractionated with polyribosomes, suggesting that Ssd1p is not particularly bound to a translationally active subpopulation of mRNA in the cytoplasm.

Association of tumor necrosis factor receptor type II polymorphism 196R with Systemic lupus erythematosus in the Japanese: molecular and functional analysis

OBJECTIVE

To investigate whether a polymorphism(s) or mutation(s) in the tumor necrosis factor receptor II (TNFRII) gene is involved in the pathogenesis of systemic lupus erythematosus (SLE).

METHODS

All 10 exons of the TNFRII gene were analyzed by exon-specific polymerase chain reaction-single-strand conformation polymorphism, followed by nucleotide sequencing of exons that displayed aberrant bands. To analyze the function of the TNFRII polymorphisms, the full-length TNFRII complementary DNA of each allele was transfected in HeLa cells and then studied for specific binding of 125I-TNFalpha, as well as interleukin-6 (IL-6) production and cytotoxic activity after treatment with recombinant human TNFalpha.

RESULTS

We identified 4 polymorphisms, at codons 56, 181, 196, and 232. The latter 2 had amino acid substitutions M196R and E232K, respectively. Only the 196R allele was significantly associated with SLE in our 105 Japanese SLE patients, with an allele frequency of 20.5%, compared with 12.6% in 99 healthy controls (P = 0.0335). More importantly, using TNFRII-transfected HeLa cells, we demonstrated significantly increased IL-6 production by 196R TNFRII compared with 196M TNFRII. The cytotoxic activity induced by 196R TNFRII was also increased compared with that of 196M TNFRII. This increase was achieved without affecting the binding affinity of TNFalpha to TNF-RII, as demonstrated by the finding that specific TNFalpha binding to the HeLa transfectants of 196R and 196M TNFRII was similar, with Kd values of 3.12 x 10(-10)M and 4.34 x 10(-10)M, respectively.

CONCLUSION

These results suggest that 196R TNFRII, which transduces the signals of TNFalpha more effectively than does 196M TNFRII, is involved in the pathogenesis of SLE.

The primary gustatory area in human cerebral cortex studied by magnetoencephalography

Magnetic fields (MFs) from gustatory stimulation with 1 M NaCl and 3 mM saccharin were recorded from the human brain by using a whole-cortex SQUID system. The averaged onset latency of MFs was 93 ms for NaCl and 172 ms for saccharin and no response was obtained for water. A high correlation coefficient was noted between the difference of onset MFs latencies in two tastants and that of behavioral reaction times, and responses to saccharin were delayed or abolished after treatment of a subject's tongue with a sweet-suppressing agent. This finding indicates that the MFs obtained were caused by gustatory stimulation. By plotting the estimated current dipole on the magnetic resonance image, we could locate the primary gustatory area at the transition area between the operculum and insula, as reported in macaque monkeys.

Neurotrophins regulate the function of cultured microglia

Although the physiological role of neurotrophins in neuronal development and survival has been extensively investigated, their role in glial cell physiology remains to be elucidated. In the present study, we investigated the effects of neurotrophins on cultured microglia from newborn rat brain. All of the neurotrophins tested nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4), increased the secretion of plasminogen and urokinase type-plasminogen activator and specific activity of acid phosphatase, but suppressed the release of constitutively-produced and lipopolysaccharide-stimulated nitric oxide (NO) from microglia. The reverse transcription-polymerase chain reaction, immunocytochemical staining, and Western blotting revealed that cultured microglia express Trk A, B, and C, and low-affinity NGF receptor, LNGFRp75. Neurotrophin was found to phosphorylate Trk A and B, and the neurotrophin-induced enhancement of plasminogen-secretion was suppressed by protein kinase inhibitor, K252a. Furthermore, neurotrophins caused an activation of transcription factor, NF-kappaB. These results indicate that the neurotrophin family regulate the function of microglia through Trk and/or LNGFRp75-mediated signal transduction.

Interaction of int protein with specific sites on lambda att DNA

We have studied the interaction of highly purified Int protein with DNA restriction fragments from the lambda phage attachment site (attP) region. Two different DNA sequences are protected by bound Int protein against partial digestion by either pancreatic DNAase or neocarzinostatin. One Int binding site includes the 15 bp common core sequence (the crossover region for site-specific recombination) plus several bases of sequence adjoining the core in both the P and P' arms. The second Int-protected site occurs 70 bp to the right of the common core in the P' arm, just at the distal end of the sequence encoding Int protein. The two Int binding sites are of comparable size, 30-35 bp, but do not share any extensive sequence homology. The interaction of Int with the two sites is distinctly different, as defined by the observation that only the site in the P' arm and not the site at the common core region is protected by Int in the face of challenge by the polyanion heparin. Restriction fragments containing DNA from the bacterial attachment site (attB) region exhibit a different pattern of interaction with Int. In the absence of heparin, a smaller (15 bp) sequence, which includes the left half of the common core region and the common core-B arm juncture, is protected against nuclease digestion by Int protein. No sequences from this region are protected by Int in the presence of heparin.