401
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Abstract
The crystal structures of the flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) containing isoforms of NADH oxidase from Thermus thermophilus have been determined by isomorphous and molecular replacement and refined to 2.3 A and 1.6 A resolution with R-values of 18.5% and 18.6% respectively. The structure of the homodimeric enzyme consists of a central 4-stranded antiparallel beta-sheet covered by helices, a more flexible domain formed by two helices, and a C-terminal excursion connecting the subunits. The active sites are located in a deep cleft between the subunits. The binding site of the flavin cofactor lacks the common nucleotide binding fold and is different from the FMN binding site found in flavodoxins.
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402
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A trace component of ginseng that inhibits Ca2+ channels through a pertussis toxin-sensitive G protein. Proc Natl Acad Sci U S A 1995; 92:8739-43. [PMID: 7568008 PMCID: PMC41042 DOI: 10.1073/pnas.92.19.8739] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A crude extract from ginseng root inhibits high-threshold, voltage-dependent Ca2+ channels through an unknown receptor linked to a pertussis toxin-sensitive G protein. We now have found the particular compound that seems responsible for the effect: it is a saponin, called ginsenoside Rf (Rf), that is present in only trace amounts within ginseng. At saturating concentrations, Rf rapidly and reversibly inhibits N-type, and other high-threshold, Ca2+ channels in rat sensory neurons to the same degree as a maximal dose of opioids. The effect is dose-dependent (half-maximal inhibition: 40 microM) and it is virtually eliminated by pretreatment of the neurons with pertussis toxin, an inhibitor of G(o) and Gi GTP-binding proteins. Other ginseng saponins--ginsenosides Rb1, Rc, Re, and Rg1--caused relatively little inhibition of Ca2+ channels, and lipophilic components of ginseng root had no effect. Antagonists of a variety of neurotransmitter receptors that inhibit Ca2+ channels fail to alter the effect of Rf, raising the possibility that Rf acts through another G protein-linked receptor. Rf also inhibits Ca2+ channels in the hybrid F-11 cell line, which might, therefore, be useful for molecular characterization of the putative receptor for Rf. Because it is not a peptide and it shares important cellular and molecular targets with opioids, Rf might be useful in itself or as a template for designing additional modulators of neuronal Ca2+ channels.
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403
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Dysphagia due to mediastinal tuberculous lymphadenitis presenting as an esophageal submucosal tumor: a case report. Yonsei Med J 1995; 36:386-91. [PMID: 7483683 DOI: 10.3349/ymj.1995.36.4.386] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Mediastinal tuberculous lymphadenitis is rare in adults, and it is even rarer for dysphagia to be the presenting symptom of mediastinal tuberculous lymphadenitis. Mediastinal tuberculous lymphadenitis with esophageal symptoms has been presented as esophageal ulceration, mucosal or submucosal mass with ulceration, fistula or sinus formation, extrinsic compression, or displacement of the esophagus. An exaggerated form of extrinsic compression may be presented as a submucosal tumor, radiologically or endoscopically. A barium esophagography of a 34 year-old woman with painful dysphagia revealed a large submucosal tumor-like mass on the mid-esophagus. The symptom was spontaneously improved over a 3-week period together with reduction of the mass size. A computed tomography of the chest disclosed an enlarged subcarinal lymph node and histologic examination of the specimen obtained by thoracoscopic biopsy brought about a diagnosis of tuberculosis. We herein report a case of mediastinal tuberculosis with unusual manifestations.
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404
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Abstract
Sixteen children of uncontrollable fecal incontinence have been treated with Pickrell's gracilis muscle transposition since 1983: 12 had an imperforate anuses with multiple corrective operative procedures and 4 had traumatic destructions of anal sphincters. We report a series of 11 cases whom we followed-up over a period of 0.8 to 10.5 years (mean; 5.6 years). Seven patients were evaluated by anorectal manometry. All patients except one who had left hemipelvectomy and permanent colostomy showed nearly normal continence during the follow-up period. There was no evidence of fibrosis in the transposed muscles and the tensions of the transposed muscles were well maintained. The voluntary contractions of the transposed muscles were well maintained and efficient in all cases. The general manometric parameters did not correlate well with the functional results; however, there was a strong correlation in the S/R ratio (maximum squeeze pressure/resting pressure) with the functional results. We believe that the good functional outcome of this procedure need not only the meticulous surgical technique but also the personal motivation and the compliance with physiotherapy. In conclusion, although the gracilis muscle transposition never results in normal continence, acceptable continence can be achieved in the selected patients.
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405
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Abstract
Abdominal cocoon is a rare disease of the peritoneum and almost invariably presents as an acute or subacute intestinal obstruction with or without a mass. The etiology of this disease is largely unknown and abdominal cocoon of unknown etiology has been limited to the tropical and subtropical zones and primarily affects young adolescent females. In the temperate zone, only one case has been reported from the United Kingdom, but the patient was also born in Pakistan. No case of abdominal cocoon purely developed in the temperate zone has been reported. Recently, we experienced a case of abdominal cocoon in a 34-year-old female patient(Korean) who had never been abroad. The diagnosis was made postoperatively by reviewing the literature. We herein report this rare condition developed in an unusual geographical location with a brief review of the literature.
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406
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Abstract
The effect of topical application of interleukin 2 (IL-2) on afferent sensory transmission to the neurones in the primary somatosensory (SI) cortex was determined quantitatively in anaesthetized rats. IL-2 (0.1, 1.0, 5.0 units) significantly suppressed afferent sensory transmission in SI cortical neurones (n = 19) in a dose-dependent manner. IL-2-induced suppression fully recovered by 60 min after drug. In control experiments, saline solution containing 0.2% bovine serum albumin, used as a vehicle, did not affect afferent sensory transmission. Our results suggest that IL-2 and its receptor present in the SI cortex may be involved in the processing of afferent sensory information.
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407
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Abstract
PURPOSE This study was designed to investigate neural and muscular features of the colonic wall in patients with severe idiopathic constipation. METHODS By using quantitative immunohistochemistry, resected specimens from 14 patients with idiopathic chronic constipation and 17 nonobstructed cancer controls were studied. RESULTS Routine histology revealed no significant histologic abnormality throughout the colon apart from four cases of melanosis coli. Ratio of the thickness of circular to longitudinal muscle was significantly lower in the left colon in constipated subjects. The myenteric plexus appeared morphologically normal in all subjects. S-100 protein, which stains neuronal supporting tissues, demonstrated an increase in the proportion of neural tissue in the myenteric plexus. There was an increased number of PGP-9.5 immunoreactive nerve fibers in the muscularis propria in constipated patients, and this was significantly higher in the ascending and descending colon. CONCLUSION Intractably constipated patients have alterations in the neural composition of the colonic myenteric plexus and innervation of the circular muscle.
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408
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Central projection of the peripheral cochlear nerve from each turn to the cochlear nuclei in the Mongolian gerbil. Yonsei Med J 1995; 36:111-5. [PMID: 7618358 DOI: 10.3349/ymj.1995.36.2.111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The central projections of the peripheral cochlear nerve fiber from each turn to the cochlear nuclei (CN) in the mongolian gerbil were investigated using retrograde transportation of horseradish peroxidase (HRP). The organ of Corti and the osseous spiral lamina were scratched with an electrolytically-sharpened fine needle via a small hole at each turn of the cochlea. The cochlea was filled with a 30% horseradish peroxidase (HRP) solution. After 48 hours, 50 microns transverse serial sections of the brainstem were made with a vibratome. The tissue was processed with the diaminobenzidine procedure of the cobalt-glucose method. Our experiment revealed that the fibers from the basal turn terminated at the dorsomedial portion of anteroventral cochlear nuclei (AVCN), but those from the apical turn were distributed among the ventrolateral portion of the AVCN. In the posteroventral cochlear nuclei (PVCN) and dorsal cochlear nuclei (DCN), the fibers from basal to apical turns extend from the dorsal to the ventral portion of each nuclei. A distinct tonotopic arrangement could be found between the origin of cochlear fibers of each turn and their termination in the regions of the cochlear nuclei (CN). Also, the results suggested that the scratch method combined with retrograde transportation of horseradish peroxidase was useful in investigating the tonotopic arrangement of the peripheral auditory nerve in the CN.
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409
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Abstract
To investigate a possible role of the central serotonergic system in the central control of pancreatic exocrine secretion, the median raphe nucleus of the anesthetized rat was electrically stimulated. The parameters of the biphasic square wave stimulus were 2 V, 2 ms, and 40 Hz. Electrical stimulation of the median raphe nucleus for 10 min resulted in large increases in pancreatic volume flow and protein output. The pancreatic responses were completely abolished by spinal cord transection at the level between C4 and C5. Cervical vagotomy or adrenalectomy failed to attenuate the pancreatic responses. The median raphe stimulation evoked a remarkable elevation of the blood pressure of the carotid artery as well as the plasma concentrations of noradrenaline and adrenaline. The responses were also completely inhibited by spinal cord transection but unaffected by cervical vagotomy. Adrenalectomy blocked the elevation of the plasma concentration of adrenaline only. Noradrenaline, given intravenously, stimulated the pancreatic volume flow and protein output. The actions of noradrenaline were antagonized by propranolol but not by phentolamine. It is, therefore, concluded from the present study that the median raphe nucleus may play a stimulatory role in pancreatic exocrine secretion of anesthetized rats and that the stimulatory role is mediated via the sympathetic nervous system acting on beta-adrenoceptors.
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410
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A large common bile duct stone migrated from the gallbladder through a cholecystohepaticodochal fistula: an unusual complication of Mirizzi syndrome type II. Yonsei Med J 1995; 36:206-13. [PMID: 7618367 DOI: 10.3349/ymj.1995.36.2.206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Mirizzi syndrome with a biliobiliary fistula (Mirizzi syndrome type II) is a rare complication of a long-standing gallbladder stone disease. It is even rarer for a gallbladder stone to migrate through a biliobiliary fistula into the common duct. We encountered this interesting complication of Mirizzi syndrome type II in an 86 year-old female patient. A large gallbladder stone migrated into, and impacted into the distal common bile duct through a cholecystohepaticodochal fistula. The stone was resistant to mechanical lithotripsy and was treated with biliary endoprosthesis and oral bile acids.
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411
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Identification of immunodominant epitopes in the core and non-structural region of hepatitis C virus by enzyme immunoassay using synthetic peptides. JOURNAL OF IMMUNOASSAY 1995; 16:167-81. [PMID: 7543117 DOI: 10.1080/15321819508013556] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Thirty-two synthetic peptides, components of the core and non-structural protein of Hepatitis C virus (HCV), were tested for their reactivities against antibodies in sera of healthy, HCV antibody positive of chronic liver disease patients. Among them, 8 of the core peptides, 4 of the NS4 peptides and 3 of the NS5 peptides reacted with the HCV infected sera. In particular, C22 (core peptide) and NS4-1924 (NS4 peptide) were most reactive with the serum samples giving a positive signal with commercially available enzyme-linked immunosorbent assay (ELISA) kit. Our results indicate that the immunodominant regions of the HCV-derived proteins are located at three regions in the core protein, three regions in the NS4 protein, and one region in the NS5 protein. These results indicate that the selected peptides are useful antigens in detecting antibodies in the sera from individuals infected with HCV.
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412
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Redistribution of facial nerve motor neurons after recovery from nerve crushing injury in the gerbil. Acta Otolaryngol 1995; 115:273-5. [PMID: 7610820 DOI: 10.3109/00016489509139307] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We investigated the redistribution of facial motor neurons after recovery from a crush injury of the facial nerve in the mongolian gerbil, with the retrograde transportation of horseradish peroxidase (HRP) technique. The facial nerve at the vertical segment was crushed unilaterally for 10 s with forceps. After 1 month, movement of the vibrissae and blinking reflex were observed. Three months after nerve injury, we obtained the brainstems to investigate the distribution of the facial nerve motor neurons. On the normal side, motor neurons of the ophthalmic branch of the facial nerve were organized at the dorsomedial and dorsolateral subdivisions of the facial nucleus, and those of the superior buccal branch were distributed at intermediate and ventrolateral subdivisions of the facial nucleus in the brainstem. On the experimental side, instead of somatotopical organization, we found widespread irregular distribution of the motor neurons of both branches in the entire facial nucleus of the brainstem.
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413
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Abstract
Bombesin was intracisternally administered to determine the effects on the neuronal activities of the dorsal column nuclei (DCN) of anesthetized rats. Although averaged afferent somatosensory transmission through 22 DCN neurons did not appear to be altered by bombesin (-1.11 +/- 3.5%), 12 of them were actually augmented (+17.15 +/- 2.7%) and 10 of them were suppressed (-26.15 +/- 4.9%) during 40 min after bombesin (0.01 microgram) administration. Pretreatment of a bombesin antagonist ([Leu13,Psi(CH2NH)Leu14]bombesin, 0.1 microgram) blocked the effects of bombesin. Lower dose (0.001 microgram) of bombesin did not exert any influences. These results suggest that bombesin may heterogeneously influence afferent somatosensory information in the brain stem of the rat.
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414
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Quantitative analysis of changes of automated perimetric thresholds after pupillary dilation and induced myopia in normal subjects. KOREAN JOURNAL OF OPHTHALMOLOGY 1994; 8:53-60. [PMID: 7853732 DOI: 10.3341/kjo.1994.8.2.53] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We quantitatively analyzed the changes of the (retinal) threshold sensitivities between normal status and dilated emmetropic status, and between dilated emmetropic status and -1.0D induced myopic status. Three consecutive visual field examinations by Humphrey Field Analyzer C-30-2 threshold test and STATPAC program were performed in 36 eyes of 21 normal subjects who ranged in age from 23 to 40 years. The results were as follows: 1) There was a statistically significant decrease (0.87 +/- 0.91dB)in the mean threshold sensitivity within the central 30 degrees at the dilated emmetropic status (27.90dB) as compared with the normal status (28.77dB)(p = 0.0001). 2) There was a statistically significant decrease(0.99 +/- 0.61dB) at -1.0D induced myopic status(26.91dB) as compared with the dilated emmetropic status(27.90dB)(p = 0.0001). 3) After dilation, the mean threshold sensitivity between 20 and 30 degrees of field showed statistically significant decrease as compared with those within the central 20 degrees of visual field(p < 0.05). In case of -1.0D induced myopia, there were uniform decreases in the mean threshold sensitivities within the central 30 degrees of visual field (p > 0.05). Therefore, we emphasize the importance of consistent pupillary size and correct refractive state in performing the serial automated visual field tests.
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415
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Abstract
Compound action potentials (CAPs) of A- and C-fibres were recorded from isolated sciatic nerves of the rat to determine whether lidocaine-induced phasic impulse block was affected by low doses of capsaicin. Preceding impulse activity produced phasic reductions of the amplitudes of both A- (5.7 +/- 1.3%) and C-CAPs (20.7 +/- 7.0%) in drug-free solution. Capsaicin alone (50 microM) did not change the activity-induced reductions of the heights of both CAPs (A-CAP: 6.2 +/- 1.7%, C-CAP: 22.3 +/- 8.0%). Lidocaine (100 microM) caused differential phasic blocks between the A-CAP (20.1 +/- 3.7%; n = 7) and the C-CAP (33.8 +/- 4.9% n = 7). Lidocaine's phasic impulse block was potentiated after 30 min of subsequent capsaicin administration (A-CAP: 40.6 +/- 4.7%, n = 7; C-CAP: 48.8 +/- 5.5% n = 9). Capsaicin's phasic potentiating effects were reversed after 30 min of washing. These results suggest that capsaicin may be a useful agent for the reversible potentiation of phasic impulse blockade by lidocaine.
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416
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Abstract
Compound action potentials (CAPs) of A- and C-fibers were recorded from isolated sciatic nerves of the rat to determine whether tonic block of impulse conduction induced by lidocaine was affected by low doses of capsaicin. Capsaicin alone (50 microM) did not change the CAPs of either A- or C-fibers. Although the lower concentrations of capsaicin (5-30 microM) caused no change of the tonic blocking action of lidocaine, 30 min of 50 microM capsaicin administration did induce a significant potentiation of tonic block. Capsaicin's potentiating effects were partially reversed after 30 min of wash. These results suggest that capsaicin may be a useful agent for the potentiation of impulse blockade by lidocaine.
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417
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Abstract
We report three cases of solitary rectal ulcer syndrome (SRUS). The diagnosis was established according to histopathologic criteria. But, the initial clinical diagnosis was carcinoma, non-specific ulcer and localized proctitis respectively. SRUS is considered as one of functional disorder in pelvic floor which might go underdiagnosed due to unfamiliar concept in Korea. So we should consider SRUS to be one of the differential diagnosis in cases of complaining anorectal symptoms.
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418
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Abstract
Changes in the conduction velocity and subsequent conduction block were characterized following impulse activity in single C fibers of rat sciatic nerves. C fibers which had the same resting conduction velocities often exhibited quite different profiles of the activity-dependent latency change and/or conduction block following impulses. The results imply underlying variation among C fibers in the activity-dependent excitability changes, especially in the build-up and recovery of the hypoexcitable phases.
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419
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Differential phasic modulation of short and long latency afferent sensory transmission to single neurons in the primary somatosensory cortex in behaving rats. Neurosci Res 1994; 19:419-25. [PMID: 8090371 DOI: 10.1016/0168-0102(94)90083-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Single neurons were recorded in the forepaw area of the primary somatosensory (SI) cortex of awake rats during rest and running behavior. Locomotor step cycle dependent changes of the transmission of the short (4.5 +/- 0.1-10.5 +/- 0.1 ms, SEURs) and the long (10.6 +/- 0.6-28.5 +/- 2.3 ms, LEURs) latency evoked unit responses were tested by generating post-stimulus time histograms of these neurons' responses to stimulation through electrodes chronically implanted under the skin of the forepaw. Times of footfall were determined by way of frame-by-frame analyses of video recordings, and peri-footfall histograms were generated to differentiate a total of 55 SI cortical neurons into two types: footfall responsive (n = 37) and footfall unresponsive (n = 18) neurons. Peri-footfall gating patterns were determined for both types of cells. The SEURs and the LEURs showed significantly different phasic sensory modulation patterns. A major difference in sensory modulations between footfall responsive and footfall unresponsive cells was noted during the swing phase of the locomotor step cycle. In footfall responsive cells, the SEURs were suppressed most strongly just after footfall, while the LEURs were phasically suppressed following both footfall and footoff. The SEURs were disinhibited during the swing phase. In footfall unresponsive cells, the SEURs were tonically suppressed during the whole locomotor step cycle phases. However, the LEURs were phasically facilitated during the early swing phase.(ABSTRACT TRUNCATED AT 250 WORDS)
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420
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Expression cloning of the nox, mdh and ldh genes from Thermus species encoding NADH oxidase, malate dehydrogenase and lactate dehydrogenase. Appl Microbiol Biotechnol 1994; 40:676-81. [PMID: 7508721 DOI: 10.1007/bf00173328] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The Thermus thermophilus HB8 mdh and ldh genes and the T. aquaticus EP00276 nox and mdh genes encoding the biotechnologically important enzymes NADH oxidase (EC 1.6.99.3), malate dehydrogenase (EC 1.1.1.37) and lactate dehydrogenase (EC 1.1.1.27) were cloned on the basis of known sequences from related species using the polymerase chain reaction. The nox and mdh genes were directly placed under the control of regulatory expression elements from Escherichia coli. When the 5'-portions of the re-cloned nox gene and the mdh gene of T. thermophilus HB8 were simultaneously altered, enzyme yields of 18-42% of the total soluble cellular protein were obtained as compared to 2-6% obtained from the unchanged genes. The high overproduction level upon the alterations can be explained by the occurrence of additional potential base pairs between nucleotides in the mRNA downstream of the start codon ('downstream box') and the 16S rRNA. An 'universal translation initiation sequence' providing such strong interactions may be of general use for high overproduction levels.
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421
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Alkylation of guanine and cytosine in DNA by bizelesin. Evidence for a covalent immobilization leading to a proximity-driven alkylation of normally unreactive bases by a (+)-CC-1065 cross-linking compound. Chem Res Toxicol 1993; 6:889-94. [PMID: 8117929 DOI: 10.1021/tx00036a020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Bizelesin, an intrahelical DNA-DNA interstrand cross-linker related to (+)-CC-1065, has been shown to alkylate DNA through guanine in restriction enzyme sequences in which there is a suitably positioned adenine contained in a highly reactive monoalkylation sequence on the opposite strand. Oligomers containing the sequence 5'-TTTTTN*, in which "N" was either G, C, or T, were synthesized to evaluate the cross-linking potential of bizelesin at nonadenine bases. Kinetic analysis of monoalkylation and cross-linking events demonstrates that it is the reaction at "N" (guanine or cytosine) that results in the cross-link which is the slow step. On the basis of this analysis and the normal unreactivity of guanine and cytosine to alkylation by the cyclopropapyrroloindole alkylating moiety of (+)-CC-1065, we propose that the molecular mechanism for this type of cross-linking reaction most likely involves a covalent immobilization of the second alkylating arm, resulting in a "proximity-driven" reaction.
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422
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Differential phasic modulation of short and long latency afferent sensory transmission to single neurons in the ventroposterolateral thalamus in behaving rats. Neurosci Res 1993; 17:117-25. [PMID: 8233117 DOI: 10.1016/0168-0102(93)90089-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Single neurons were recorded in the forepaw area of the ventroposterolateral (VPL) thalamus of awake rats during rest and running behaviors. Locomotor step cycle dependent changes of the transmission of the short (4.0 +/- 0.1-10.1 +/- 0.3 ms, SEURs) and the long (10.2 +/- 0.2-26.0 +/- 2.1 ms, LEURs) latency somatic sensory responses were tested by generating post-stimulus time histograms of these neurons' responses to stimulation through electrodes chronically implanted under the skin of the forepaw. The magnitudes of firing during these responses were measured and normalized as percent increases over background firing. Times of footfall were determined through frame-by-frame analyses of video recordings and peri-footfall histograms were generated to differentiate a total of 40 VPL thalamic neurons into two types, footfall responsive (n = 21) and unresponsive (n = 19) neurons. Perifootfall gating patterns were determined for both types of cells. The SEURs and the LEURs showed significantly different phasic sensory modulation patterns across the locomotor step cycle. Major difference of the sensory modulations between footfall responsive and footfall unresponsive cells was noted during swing phase of the locomotor step cycle. In footfall responsive cells, the SEURs were suppressed most strongly just after footfall, while the LEURs were tonically suppressed during late stance and swing phases. The SEURs were disinhibited during the swing phase, while the LEURs were disinhibited during the middle stance phase. In footfall unresponsive cells, the LEURs were suppressed more strongly around footfall event than the SEURs were.(ABSTRACT TRUNCATED AT 250 WORDS)
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423
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Crystallization and preliminary X-ray diffraction studies of a NADH oxidase from Thermus thermophilus HB8. J Mol Biol 1993; 230:1086-8. [PMID: 8478921 DOI: 10.1006/jmbi.1993.1222] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The thermophile NADH oxidase from Thermus thermophilus, cloned and expressed in Escherichia coli, has been purified to homogeneity and crystallized. Three different crystal forms were found to be suitable for X-ray diffraction analysis. Crystals of the tetragonal form, grown in the presence of 25% polyethylene glycol 4000 and 0.25 M-NaCl at pH 6.6, were chosen for further analysis. These crystals belong to the space group P4(1)(3)2(1)2 with refined lattice constants of a = 94.8 A and c = 49.0 A, indicating a cell content of one monomer per asymmetric unit of the crystal. The crystals diffract to a resolution of 2.2 A.
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424
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Abstract
1. Effects of pancreatic polypeptide (PP) on insulin action in pancreatic exocrine secretion was investigated by using an isolated rat pancreas that was perfused with Krebs-Henseleit solution containing 2.5 mM glucose, 0.1% bovine serum albumin and 3% Dextran T-70 at a vascular flow rate of 1.2 ml min-1. 2. Cholecystokinin-8 (CCK-8) at a concentration of 14 pM stimulated basal flow rate and amylase output of the isolated pancreas. Twenty-five millimolar glucose not only increased the basal flow rate and amylase output but also potentiated the CCK-stimulated flow rate and amylase output. 3. Porcine insulin, administered intra-arterially at a concentration of 100 nM, also increased the basal flow rate and amylase output, and also potentiated the CCK-stimulated flow rate and amylase output. 4. Rat PP, given intra-arterially at a concentration of 10 pM, completely abolished the potentiation effects of both the 25 mM glucose and the exogenous insulin on the CCK-stimulated flow rate and amylase output. Rat PP also inhibited the flow rate and amylase output increased by either 25 mM glucose alone or exogenous insulin alone. However, rat PP did not change the flow rate and amylase output stimulated by CCK-8 alone. 5. These results indicate that insulin is an important stimulatory hormone of pancreatic exocrine secretion, and that PP exerts the inhibitory role in pancreatic exocrine secretion by modulating the insulin action.
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425
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Molecular cloning and nucleotide sequence of the gene encoding a H2O2-forming NADH oxidase from the extreme thermophilic Thermus thermophilus HB8 and its expression in Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 211:909. [PMID: 8436145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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426
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GM3 affects carboxyl methylation in the human erythrocyte membrane. BIOCHEMISTRY INTERNATIONAL 1992; 28:393-9. [PMID: 1482383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Effects of gangliosides in human erythrocyte membrane using carboxyl methyltransferase have been investigated. As GM3 concentration increased, methylatability for membrane was increased. But bovine brain ganglioside mixture did not alter methylatability even at a higher concentration. When 30 microM of GM3 was used in erythrocyte membrane, methylatability was increased by 32%. When purified-glucose transporters were reconstituted into egg phosphatidylcholine-liposome with GM3, methylatability was increased by 37%. Thus conformational difference of membrane according to localization of GM3 in intact human erythrocyte membrane or liposome possibly increases the methylatability and activity of glucose transporter itself.
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427
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Abstract
BACKGROUND A variety of methods were used to establish objective diagnostic criteria of Raynaud's phenomenon. We intended to introduce another method, using radionuclide (Tc-99m methylene diphosphonate) scintigraphy, which is more objective, simple and economical than the past methods. METHODS The finger blood flow with radionuclide scintigraphy was evaluated in 10 patients of Raynaud's syndrome, 12 patients of connective disease without Raynaud's symptoms, and 20 normal persons. After immersing one hand in ice water (4 degrees C) for 30 seconds, the hand was exposed to 22 degrees C room air for 15 minutes, and then the patients received the intravenous (IV) bolus of 20 microCi of Tc-99m methylene diphosphonate (MDP). At the same time, scintigraphic image of both hands started with the region of interest, including the second, third, fourth and fifth fingers distal to the metacarpophalangeal (MCP) joints. Computer recording of the counts in the region of interest every 2 seconds for 310 seconds was started on IV bolus injection. RESULTS The 310 seconds cumulative digital blood flow ratio of cold exposed hand to room air exposed hand was significantly lower in Raynaud's group (p < 0.001), and the ratio of initial slope of activity curve was also lower in the Raynaud's group (p < 0.001). Of the 8 patients showing Raynaud's syndrome, 4 patients of scleroderma and 1 patient of multiple myeloma showed no improvement of finger blood flow in the cold exposed hand after 2 weeks of pharmacological therapy, but 1 patient of mixed connective tissue disease, 1 patient of Behcet's syndrome and 1 patient of SLE showed much improved finger blood flow after combined administration of vasodilator, calcium channel blockers and antiplatelet drugs. CONCLUSIONS The evaluation of finger blood flow with 99mTc-MDP could be considered to be one of the simple, economical and new methods that can be used in the follow-up, objective assessment of therapeutic effect, and giving an aid in the study of the pathophysiology of the Raynaud's phenomenon.
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428
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Molecular cloning and nucleotide sequence of the gene encoding a H2O2-forming NADH oxidase from the extreme thermophilic Thermus thermophilus HB8 and its expression in Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 205:875-9. [PMID: 1577004 DOI: 10.1111/j.1432-1033.1992.tb16852.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The sequence of the 32 N-terminal amino acids of the NADH oxidase from the extreme thermophile, Thermus thermophilus HB8, was used to synthesize oligonucleotides to probe for the respective gene in a genomic library of T. thermophilus HB8. The gene encoding the NADH oxidase, designated nox, was cloned, its nucleotide sequence was determined and found to be colinear with the N-terminal sequence of the enzyme. The molecular mass of 26835 Da, as deduced from the nox gene, agrees with that of the purified NADH oxidase from T. thermophilus HB8 (25,000 Da), as estimated by polyacrylamide gel electrophoresis under denaturing conditions. The nox gene was overexpressed in Escherichia coli and a protocol for the rapid purification of the enzyme was developed. The E. coli-borne T. thermophilus HB8 NADH oxidase has properties identical to those of the authentic T. thermophilus HB8 enzyme and possesses a high thermal stability.
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429
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Purification and characterization of a NADH oxidase from the thermophile Thermus thermophilus HB8. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 205:881-5. [PMID: 1577005 DOI: 10.1111/j.1432-1033.1992.tb16853.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A NADH oxidase has been purified from the extreme thermophile Thermus thermophilus HB8 by several chromatographic steps. The purified enzyme was essentially homogeneous as judged by gel electrophoresis under denaturing conditions and by determination of the N-terminal amino acids sequence. It is a monomeric flavin-adenine-dinucleotide-containing flavoprotein with an apparent molecular mass of 25 kDa and an 1:1 ratio of FAD to the polypeptide chain. The purified enzyme catalyzes the oxidation of reduced NADH or NADPH with the formation of H2O2. The apparent Km values for NADH and NADPH are 4.14 microM and 14.0 microM (pH 7.2 at room temperature), respectively, with a sixfold greater kcat/Km values for NADH compared to NADPH. The enzyme uses O2 as an electron acceptor in the presence of either FAD, riboflavin 5'-phosphate or riboflavin as cofactor. In addition, the enzyme is able to catalyze electron transfer from NADH to various other electron acceptors (methylene blue, cytochrome c, p-nitroblue tetrazolium, 2,6-dichloroindophenol and potassium ferricyanide), even in the absence of flavin shuttles. No significant inhibition of the NADH oxidoreductase activity by superoxide dismutase was observed with these artificial electron acceptors, indicating that electron transfer occurs mainly from NADH directly to the electron acceptors, not via O2- as an intermediate. The purified NADH oxidase exhibits highest activity at pH 5.0 and is stable at elevated temperatures of up to 80 degrees C.
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430
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Abstract
Blood lipid levels in rats with high fat-fed hyperlipemia were determined after intraperitoneal administration of a methanolic extract of Prunus davidiana Fr. stems. Administration of the methanolic extract for 6 days produced a significant decrease of blood triglyceride and total cholesterol, and the atherogenic index was also improved. In addition to the hypolipemic effect, the methanolic extract was also shown to be effective in reducing an elevated level of glucose in rats with hyperlipemia resulting from high-fat feeding. On the other hand, blood triglyceride and total cholesterol in rats fed with stock diet were not affected by administration of the methanolic extract even if there was a tendency to decrease. No significant change was also found in the level of glucose. Thus, it is suggested that this methanolic extract probably may increase the metabolic utilization only when fed with excess fat.
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431
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Interaction of recombinant human tumor necrosis factor and etoposide in human lung cancer cell lines. MOLECULAR BIOTHERAPY 1990; 2:169-74. [PMID: 2171561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Studies have suggested that recombinant tumor necrosis factor-alpha (TNF-alpha) may potentiate the killing of murine tumor cells by drugs targeted at DNA topoisomerase II. We have examined the combined cytotoxic effects of the topoisomerase-targeted drug etoposide and TNF in small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) cell lines using clonogenic assays and a novel flow cytometry technique relying on differential uptake of fluorescein diacetate (FDA) and propidium iodide (PI) by viable and nonviable cells. Good correlation of IC50 determinations for etoposide were noted between clonogenic assays and the FDA/PI technique for both classic and variant SCLC cell lines. The effects of etoposide on the classic SCLC line H209 were potentiated by TNF with a decrease in the IC50 from 3.3 microM to 1.0 microM as determined by FDA/PI. Tumor necrosis factor alone had little effect on the growth or cloning efficiency of H209 cells. Tumor necrosis factor alone stimulated the growth and cloning of variant SCLC line N417, but the cytotoxicity of etoposide was not potentiated by TNF in N417 cells. Tumor necrosis factor alone inhibited the growth and cloning of the NSCLC line H125 but exerted a marked protective effect against higher concentrations of etoposide. It appears that the interaction of TNF with etoposide varies between cell lines and between subclasses of human lung cancer.
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432
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Detection of early visual field change in ocular hypertension using STATPAC. KOREAN JOURNAL OF OPHTHALMOLOGY 1990; 4:16-22. [PMID: 2214246 DOI: 10.3341/kjo.1990.4.1.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Perimetric tests were performed on 32 ocular hypertensive eyes (17 patients) with the C-30-2 threshold program of the Humphrey Visual Field Analyzer. The global indices of 32 ocular hypertensive eyes were compared with those of 34 normal eyes (17 controls). None of the 34 normal eyes had visual field sensitivity loss. However, three out of 32 ocular hypertensive eyes, which is 0.4%, had visual field sensitivity loss. Of these three eyes, two eyes showed generalized depression (MD, P less than 5%) and one eye showed paracentral scotoma.
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433
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Loading of quin2 into the oat protoplast and measurement of cytosolic calcium ion concentration changes by phytochrome action. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1051:115-22. [PMID: 2310765 DOI: 10.1016/0167-4889(90)90182-d] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The loading of quin2 into oat protoplasts was carried out in an incubation medium (0.6 M sorbitol, 1 mM CaCl2, 5 mM Mes, 5 mM Tris, 0.05% BSA, 1 mM KCl, 1 mM MgSO4 (pH 6.8)), in which we found the best viability of the protoplast and the highest membrane permeability of quin2/AM, compared with the results obtained from any other incubation medium we had tried to use. 50 microns of quin2/AM was added in the suspension medium containing 5 x 10(5)/ml of oat protoplasts, and incubation at 4 degrees C was performed for 24 h. From atomic absorption data, we confirmed that quin2 loading was 1.78 mmol per liter of cells. Red-light (660 nm) irradiation for 5 min caused an increase of the cytosolic Ca2+ concentration from 30 to 193 nM. On the other hand, a subsequent irradiation with far-red light (730 nm) for 5 min decreased it by about 48 nM. Even when the extracellular Ca2+ was completely chelated with 1 mM EDTA, red light increased the cytosolic Ca2+ concentration by about 51 nM and far-red light decreased it to 3 nM. These results imply that the Pfr form of phytochrome functions not only in the process of influx of Ca2+, but also in the mobilization process of Ca2+ from the intracellular Ca2+ pools. The fact that the Pr form of phytochrome lowers the cytosolic Ca2+ concentration is also presented in this report.
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434
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Induction and inhibition of meiotic maturation of amphibian (Rana dybowskii) follicular oocytes by forskolin and cAMP in vitro. Mol Reprod Dev 1990; 25:147-54. [PMID: 2155627 DOI: 10.1002/mrd.1080250207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Previous studies have demonstrated that direct or indirect elevation of cAMP levels in cultured amphibian ovarian follicles simultaneously stimulated production of oocyte maturation-inducing steroid (progesterone) by the follicles and inhibited oocyte maturation induced by endogenous or exogenous hormone. The duration of cAMP stimulation influenced arrest and reinitiation of oocyte meiotic maturation in ovarian follicles of Rana dybowskii. Addition of forskolin (adenylate cyclase stimulator) to cultured follicles inhibited both progesterone- and frog pituitary homogenate (FPH)-induced oocyte maturation. Similar inhibitory results were obtained when hormone-treated follicles were cultured in the continual presence of cAMP. Oocyte maturation increasingly occurred in follicular oocytes when cAMP or forskolin addition was delayed following treatment with FPH or progesterone. Transient exposure (6-8 hr) of ovarian follicles to forskolin or cAMP markedly stimulated oocyte maturation as well as accumulation of progesterone as measured by radioimmunoassay within the ovarian follicles. Forskolin was more effective than cAMP, at the dose tested, in stimulating progesterone production and accumulation by the follicles. The data demonstrate that transient manipulation (elevation) of cAMP levels in cultured follicles, without added FPH or steroid, was sufficient to initiate oocyte maturation. Results suggest that, with transient exposure to forskolin or exogenous cAMP, there is a sequential increase and decrease in endogenous cAMP levels in the somatic cells and germ cell components of the ovarian follicle. These changes appear to mediate production of maturation-inducing steroid and secondarily allow its effects on the oocyte to be expressed.
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435
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Differentiation of human variant small cell lung cancer cell lines to a classic morphology by retinoic acid. Cancer Res 1989; 49:6745-51. [PMID: 2555051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Variant small cell lung cancer (SCLC) is distinguished from the classic histology by changes in growth characteristics and morphology, c-myc amplification, a loss of some biochemical markers, and relative chemo- and radioresistance. Three variant SCLC lines were incubated in 1 microM all-trans retinoic acid. After 8-10 days, a marked change in morphology was noted in all three lines, with tight cell aggregation and central necrosis of large floating spheroids similar to classic SCLC. The retinoid-treated cells demonstrated decreases in growth rate and cloning efficiency to levels comparable with classic SCLC cell lines. Retinoic acid incubation caused a reproducible decrease in c-myc expression in variant SCLC cells, but was not noted to increase L-dopa decarboxylase, an enzyme which biochemically distinguishes classic from variant SCLC cell lines. Retinoid exposure led to an increase in HLA and Leu-7 antigens, but a reduction of antibody binding to 3-fucosyllactosamine, a dominant SCLC glycolipid antigen. Clonogenic assays revealed that the variant cells, after incubation in retinoic acid, became more sensitive to etoposide, but more resistant to Adriamycin. We conclude that exposure of variant SCLC cells to retinoic acid can lead to a morphologic phenotype similar to classic SCLC, but with substantial differences in cell biology. ?
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436
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437
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Abstract
Adult T-cell leukemia/lymphoma is a relatively uncommon disease, most often found in Japan, the Caribbean, the southeastern United States, and South America. To date there have been few reports of its skeletal manifestations. A case is reported in a 44-year-old man in which a short history of swelling of the hands and feet and painful motion in the fingers was followed by the rapid development of severe acroosteolysis.
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438
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Radiation trapping in sodium-noble-gas mixtures. PHYSICAL REVIEW. A, GENERAL PHYSICS 1987; 35:2892-2901. [PMID: 9898489 DOI: 10.1103/physreva.35.2892] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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439
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Differential hydrolysis of phospholipid molecular species during activation of human platelets with thrombin and collagen. J Biol Chem 1987; 262:2262-9. [PMID: 3102469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Mass changes in the various molecular species of phospholipids were determined after stimulation of human platelets with thrombin and collagen. Upon stimulation, every molecular species of phosphatidylinositol and phosphatidylserine was equally hydrolyzed, whereas the molecular species of phosphatidylcholine and diacyl- and alkenylacylphosphatidylethanolamine containing arachidonic acid were selectively hydrolyzed. At low Ca2+ concentrations, which result from mobilization of intracellular Ca2+ stores, phosphatidylinositol, phosphatidylcholine, and diacylphosphatidylethanolamine were hydrolyzed after stimulation with thrombin, whereas only phosphatidylinositol was hydrolyzed with production of thromboxane B2 after stimulation with collagen. At high Ca2+ concentrations, phosphatidylcholine and diacylphosphatidylethanolamine were hydrolyzed after stimulation with collagen, and phosphatidylserine and alkenylacylphosphatidylethanolamine were degraded after stimulation with both thrombin and collagen. [1-14C]Arachidonic acid was heterogeneously incorporated into the individual molecular species of the various phospholipid classes, indicating that the determination of mass is essential for an accurate picture of phospholipid hydrolysis. The data reported here indicate that the Ca2+ concentration affects the differential degradation of phospholipid molecular species in activated human platelets.
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440
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Abstract
Several shorter-term alternatives for whole-day ambulatory monitoring of blood pressure using Pressurometer III or conventional sphygmomanometer were evaluated in 12 male patients with mild hypertension. Averages of BP reading at 8 AM once, 3 consecutive-readings either with Pressurometer or manually, serial readings for 2-hour intervals from 8-10 AM and 2-4 PM were compared with that of 24-hour ambulatory, non-invasive BP readings by Pressurometer. Both systolic and diastolic 2-hour BP averages in the morning (8 to 10 o'clock) correlated more strongly with 24-hour averages (r = 0.91 and 0.91) than the 3 consecutive (r = 0.88 and 0.66) or single (r = 0.49 and -0.35) reading alternatives did. In conclusion, the average of serial readings obtained during 2-hour monitoring period from 8 to 10 AM is a reliable predictor of 24-hour ambulatory BP and represents it more closely than the conventional single or multiple BP readings.
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441
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Dissociation of Ca2+ mobilization from breakdown of phosphatidylinositol 4,5-bisphosphate in activated human platelets. J Biochem 1986; 99:1277-80. [PMID: 3011769 DOI: 10.1093/oxfordjournals.jbchem.a135592] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The early breakdown of phosphatidylinositol 4,5-bisphosphate in human platelets stimulated by a threshold concentration of either collagen or thrombin was inhibited by 5 mM NaF through its inhibition of phospholipase C activity. However, 5 mM NaF did not inhibit Ca2+ mobilization due to the stimuli from internal stores, but it did inhibit the influx of extracellular Ca2+ through its suppression of thromboxane A2 formation.
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442
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Insufficient mobilization of calcium by early breakdown of phosphatidylinositol 4,5-bisphosphate for aggregation of human platelets by collagen. J Biochem 1985; 98:1063-8. [PMID: 3001036 DOI: 10.1093/oxfordjournals.jbchem.a135353] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
When human platelets (5 X 10(8)/ml) were stimulated by a threshold concentration of collagen (2 micrograms/ml), a lag period of about 60 s was seen before the initiation of release reaction and aggregation. Breakdown of [32P]phosphatidylinositol 4,5-bisphosphate was seen within 10 s after the addition of collagen. The concentration of intracellular free Ca2+ (monitored by Quin II) rose from 80 nM to 145 nM within 10 s after stimulation by collagen. However, a lag period of about 50 s remained. The rise was not blocked by indomethacin. It was supposed that the initial Ca2+ mobilization by myo-inositol 1,4,5-trisphosphate was too small to cause aggregation. Thromboxane A2 was gradually accumulated during the lag period and then abruptly increased in parallel with aggregation. These events were completely inhibited by 10 microM indomethacin. Thus, aggregation appeared to be dependent on the generation of thromboxane A2. Addition of 25 nM A23187 at 10 s after stimulation by collagen shortened the lag period before initiation of the abrupt thromboxane A2 generation, secretion and aggregation, whereas 25 nM A23187 could not cause these reactions in the absence of collagen. Accordingly, the lag period is assumed to be required for accumulation of free Ca2+ to the threshold for aggregation of platelets. It is considered that thromboxane A2 plays a central role in Ca2+ mobilization during stimulation of human platelets by collagen.
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443
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Phosphoinositide breakdown as an indirect link between stimulation and aggregation of rat platelets by thrombin and collagen. J Biochem 1985; 97:765-72. [PMID: 2991207 DOI: 10.1093/oxfordjournals.jbchem.a135116] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
When washed rat platelets (1.5 x 10(9)/ml) were stimulated by a threshold concentration of thrombin (0.3 unit/ml) or collagen (10 micrograms/ml), a lag period of about 10 or 30 s, respectively, was seen before the start of aggregation. During the lag period, [32P]phosphatidylinositol 4,5-bisphosphate was degraded as the earliest event within 5-10 s of addition of the stimulus. However, though the extent of phosphatidylinositol 4,5-bisphosphate degradation within 10 s of addition of collagen was greater than that within 20 s of addition of thrombin (0.3 unit/ml), a lag of about 20 s remained before the initiation of aggregation by collagen. This casts doubt on the hypothesis that the stimulus-dependent phosphatidylinositol 4,5-bisphosphate breakdown induces the aggregation of platelets. Phosphatidylinositol labeled with 32Pi or [1-14C]arachidonic acid was scarcely degraded during the lag period. As aggregation proceeded, [14C-arachidonic acid]phosphatidylinositol was degraded with generation of diacylglycerol, phosphatidic acid, arachidonic acid and its metabolites. The maximum aggregation by collagen of rat platelets in which arachidonic acid of phospholipids was replaced in vivo with eicosapentaenoic acid was reduced, but that by thrombin was not, though reduction of thromboxane A2 generation was caused by both stimuli. Indomethacin also fully inhibited the aggregation induced by collagen, but not that induced by thrombin. Hence, thromboxane A2 is required for full aggregation by collagen, but not that by thrombin. These results indicate that thrombin-induced phosphoinositide metabolism may proceed independently of aggregation.
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444
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Studies on mechanism of retching and vomiting in dogs. Effect of peripheral dopamine blocker on myoelectric changes in antrum and upper small intestine. Dig Dis Sci 1985; 30:22-8. [PMID: 3965272 DOI: 10.1007/bf01318366] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In five conscious dogs prepared with a gastric cannula and platinum monopolar electrodes in the antrum, duodenum, and jejunum, the effect of dopamine or copper sulfate on the myoelectric activity was studied. During phase I of interdigestive myoelectric activity, retching, and/or vomiting occurred in 1.6 +/- 0.2 (mean +/- SE) min after intravenous bolus injection of dopamine (50 micrograms/kg) or in 8.7 +/- 1.8 min after intragastric administration of copper sulfate (2%, 50 mg). Immediately prior to the retching and/or vomiting act, a group of disordered myoelectric activities occurred, including retrograde-moving trains of spike activity starting from the jejunum and the subsequent tachyarrhythmia in the antrum. These motility changes also occurred in the two anesthetized dogs so studied. Both the retching and/or vomiting act and the abnormal myoelectric activity which were induced by dopamine and by copper sulfate were prevented by intravenous administration of a peripheral dopamine blocker, domperidone, 5 mg, in 100% and 70%, respectively. Although domperidone could not prevent the retching and/or vomiting induced by copper sulfate in three of 10 experiments, it delayed the onset of vomiting from 8.7 +/- 1.8 to 14.5 +/- 5.3 min. A possible role of peripheral dopamine receptor on the motility disorders associated with retching and/or vomiting has been suggested.
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445
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Abstract
In 18 patients with hypersecretion of acid, severe ulcer diathesis, and pancreatic islet cell tumor or hyperplasia, 14 had hypergastrinemia and 4 had normal plasma gastrin concentration. The neoplasms contained several gut peptides beside gastrin. The immunoreactive gastrin in the tumor extracts measured less than 7 ng/g, less than the amount previously reported. The extracts of each patient's tumor also contained a secretogogue other than gastrin that stimulated gastric acid secretion in rats. In addition, the plasma extracts of 2 patients also contained a secretogogue that stimulated acid secretion. After surgical resection of a recurrent metastatic tumor in 1 patient, basal acid secretion decreased from 13.9 to less than 1 meq/h, and the bioactivity of the plasma disappeared. These observations suggest the existence of a secretogogue that appears to be a protein in the pancreatic tumors of some patients with severe ulcer diathesis and hypersecretion.
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446
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Abstract
Using immunohistocytochemical techniques, secretin cells are again demonstrated in the antral mucosae of both dogs and rats. Secretin-like immunoreactivity was found in the crude extracts of antral mucosae in 15 dogs [1.18 +/- 0.48 (+/- SE) ng/g wet wt of mucosae], and a similar amount of SLI was also found in 82 rat antral mucosae. Upon ion exchange chromatography, the extracts of dog antral mucosae exhibited a predominant species eluted by the same salt concentration as porcine secretin. The rat antral mucosal extract also produced a chromatogram exhibiting the same predominant species on the ion exchanger. The main immunoreactive secretin peak, when gel filtrated on a Sephadex G-50 (superfine) column, produced an elution profile identical to that of standard natural porcine secretin. These results indicated that antral mucosae of both animal species contain an immunoreactive secretin-like material of the same charge and size as natural porcine secretin. Intravenous injection of a preparation of partially purified secretin from the extracts of canine antral mucosae resulted in a significant increase in the pancreatic flow in anesthetized rats. We conclude that a small number of secretin cells are, therefore, present in the antral mucosae of dog and rat, and this observation is supported by the presence of an immunologically and biologically active secretin-like molecule with charge and size similar to those of porcine secretin in the canine mucosal extracts.
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447
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Abstract
In conscious dogs with gastric fistula and platinum electrodes on the antrum, duodenum and jejunum, IV atropine 100 micrograms/kg/hr and hexamethonium 10 mg/kg/hr, blocked cyclic increases in fasting plasma motilin concentration (PMC) and spontaneous migrating myoelectric complexes (MMCs) of both antrum and duodenum. The two drugs also blocked occurrence of premature MMCs produced by synthetic porcine motilin. In anesthetized dogs, electrical stimulation of cervical vagi with stimulation parameters: 9 V, 10 c/s, 5 msec, caused a significant increase in both portal and femoral venous PMC which was blocked by atropine. Fractionations of vagus nerve extracts by gel filtration using Sephadex G-50 superfine column revealed most of motilin-like immunoreactivity (MLI) with the same mobility as pure porcine motilin. Studies suggest that cholinergic influence plays a significant role on release of motilin.
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448
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449
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[Keynote address: health and social welfare. The nurse as a protector of health rights]. TAEHAN KANHO. THE KOREAN NURSE 1977; 16:29-32. [PMID: 267211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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450
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[A model of health care delivery for the 4th 5-year economic development plan (1)]. TAEHAN KANHO. THE KOREAN NURSE 1976; 15:10-1. [PMID: 1071122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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