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T Kitajima

Publications and source records attributed to T Kitajima.

At least 127 records · Page 7Linked to original sources
PubMed1996

UVB radiation interrupts cytokine-mediated support of an epidermal-derived dendritic cell line (XS52) by a dual mechanism.

We have established long-term dendritic cell lines from the epidermis of newborn mice. These cell lines (XS series) proliferate maximally in response to granulocyte/macrophage-colony stimulating factor, as well as to CSF-1, which is produced by skin-derived NS fibroblast lines and by keratinocytes (albeit in smaller amounts). The purpose of this study was to examine the impact of UVB radiation on CSF-1-mediated interaction of dendritic cells with fibroblasts and keratinocytes. Exposure of NS cells to UVB radiation (unfiltered FS20 sunlamp) decreased CSF-1 production at mRNA and protein levels. Both changes occurred in a dose-dependent fashion, with 50 J/m2 causing a significant reduction. UVB radiation also downregulated CSF-1 mRNA expression by Pam 212 keratinocytes. UVB exposure of XS cells diminished the surface expression of CSF-1 receptors, with 50 J/m2 causing a significant reduction. Thus, UVB radiation interrupts CSF-1-mediated cell-cell interaction by a dual mechanism: downregulating CSF-1 production and abrogating CSF-1 receptor expression. Importantly, granulocyte/macrophage-colony stimulating factor receptor expression by XS cells was also inhibited by UVB radiation, once again, with 50 J/m2 producing significant inhibition. We propose that the resulting CSF-1 deficiency in epidermal microenvironment and unresponsiveness by dendritic cells to relevant growth factors may contribute to UVB-mediated loss of resident epidermal dendritic cells (i.e., Langerhans cells) in skin.

Animals↗
PubMed1996

Assessment of neuromuscular block at the thumb and great toe using accelography in infants.

We assessed neuromuscular block at the thumb and great toe using accelography after the administration of vecuronium in infants. Train-of-four stimuli were simultaneously applied to the ulnar and tibial nerves using cutaneous electrodes. Anaesthesia was maintained with nitrous oxide (66%) in oxygen and sevoflurane (1%). Vecuronium 0.1 mg.kg-1 was used for paralysis and reversed with intravenous neostigmine 0.04 mg.kg-1 with atropine 0.02 mg.kg-1 when the train-of-four ratio on the right great toe returned to 25%. The mean (SD) times from initial administration of vecuronium to completion of maximal block on the thumb and great toe were 78 (21.1) s and 75 (14.3) s, respectively (p > 0.05). The times from maximal block to 25% recovery of twitch height at the thumb and great toe were 46 (9.1) min and 45 (9.0) min, respectively. The reversal time from 25% to 75% of the train-of-four ratio after the administration of neostigmine was 136 (49.1) s. We conclude that neuromuscular monitoring of the great toe in infants may be a suitable alternative when the thumb is inaccessible.

Anesthesia, General↗
PubMed1996

Spontaneous perforated pyometra presenting as pneumoperitoneum.

BACKGROUND: Spontaneous perforated pyometra presenting as pneumoperitoneum is extremely rare. CASE REPORT: An 80-year-old Japanese female with spontaneous perforating pyometra presenting as pneumoperitoneum is reported. The patient came to our institute with severe abdominal pain. Routine abdominal examination showed muscular defense, and plain chest roentgenograms revealed infradiaphragmatic free gas. Subsequent computed tomography also demonstrated pneumoperitoneum. Laparotomy was performed on the basis of a tentative diagnosis of perforation of the gastrointestinal tract but revealed a perforated pyometra. A simple hysterectomy was performed. The histological diagnosis of the surgical specimen was acute endometritis without neoplasm. The present report is the third case of spontaneous perforated pyometra with pneumoperitoneum to date. CONCLUSION: Although uterine disease presenting as pneumoperitoneum is rare in elderly patients with an acute abdomen, the possibility of a perforated pyometra should be considered in the differential diagnosis.

Aged↗
PubMed1996

[Use of a laryngeal mask airway for anesthesia in a patient with bronchomalacia].

A 56-year-old woman with bronchomalacia underwent three consecutive operations for bronchoscopy, cautery YAG-laser, and the insertion of a stent under general anesthesia using a laryngeal mask airway (LMA). For the first operation, anesthesia was induced with ketamine 20 mg, diazepam 5 mg and pentazocine 20 mg. The patient was ventilated with N2O-O2-sevoflurane with a face mask. Then vecuronium 6 mg was administered intravenously and LMA was inserted blindly. Anesthesia was maintained with N2O-O2-sevoflurane during bronchoscopy. Immediately after the operation, the patient coughed and experienced dyspnea. The symptoms were alleviated using theophyllin, hydrocortisone and droperidol. For the second and third operations, anesthesia was induced with droperidol and fentanyl with N2O-O2. After administration of vecuronium, LMA was inserted. The patient was stable during the second and third operations compared with the first operation. It was concluded that LMA may be useful for anesthetic management of a patient with bronchomalacia.

Anesthesia, General↗
PubMed1996

Cerebral oxygen metabolism measured by near-infrared laser spectroscopy during laparoscopic cholecystectomy with CO2 insufflation.

To clarify the influence of carbon dioxide (CO2) on cerebral oxygen metabolism and blood volume during laparoscopy with CO2 insufflation in 12 patients who underwent laparoscopic cholecystectomy, changes in the concentrations of cerebral oxyhemoglobin (HbO2), reduced hemoglobin (HbR), total hemoglobin (total Hb), and oxidized cytochrome aa3 (Cyt aa3) were measured using near-infrared laser spectroscopy. Anesthesia was maintained with nitrous oxide (66%)-oxygen-sevoflurane. Pneumoperitoneum was maintained at an endoabdominal pressure of 10 to 12 mm Hg using CO2. Minute ventilation was constant before and after CO2 insufflation. End-tidal CO2 tension (PETCO2) increased significantly, from 33.9 +/- 1.3 to 52.8 +/- 3.3 mm Hg, after CO2 insufflation. The concentration of HbO2 increased significantly, from 0 to 7.3 +/- 2.8 mumol/L, after CO2 insufflation. The concentration of HbR increased significantly, from 0 to 2.2 +/- 1.2 mumol/L, after CO2 insufflation. Therefore, the concentration of total Hb increased significantly, from 0 to 8.8 +/- 3.3 mumol/L after CO2 insufflation. The concentration of Cyt aa3, however, did not change significantly during pneumoperitoneum. These results suggest that cellular respiration remained intact despite a concomitant increase in PETCO2 and cerebral blood volume during laparoscopy with CO2 insufflation.

Adult↗
PubMed1996

[Cerebral blood volume, cerebral hemoglobin and cytochrome AA3 during hypotension induced by prostaglandin E1 or epidural anesthesia under general anesthesia].

The effect of hypotension induced by PGE1 or epidural anesthesia under general anesthesia on cerebral blood volume (CBV), cerebral tissue hemoglobin, cytochrome AA3 was studied using a near infrared spectrophotometry in 20 patients undergoing abdominal operation. In PGE1 group (n = 10), CBV, cerebral oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) were unchanged during hypotension. However, cerebral HbO2 decreased and Hb increased slightly in a case of severe hypotension more than 40 percent of control, but CBV did not show any significant change. On the other hand, in epidural anesthesia group, HbO2 decreased significantly along with MAP reduction (r = 0.84) and Hb increased slightly. Cytochrome AA3 did not show any significant changes in both groups. From these results, we concluded that PGE1 drip infusion was better than epidural anesthesia to sustain the cerebral blood volume during hypotension.

Adult↗
PubMed1996

[Imbalance of blood flow induced by sympathetic block was corrected by prostaglandin E1].

The purpose of this study was to investigate the effect of prostaglandin E2 (PGE1) on imbalance of blood flow induced by sympathetic block. Seven mongrel dogs were anesthetized with intravenous pentazocine 0.5 mg. kg-1, diazepam 0.1 mg. kg-1 and pancuronium 0.1 mg. kg-1. Bilateral brachial arterial blood flows were measured using an ultrasonic transit time flowmeter (Transonic T201, Advance). After a thoracotomy, left stellate ganglion block (SGB) with 0.5% mepivacaine was performed for sympathetic block. Left brachial arterial blood flow increased significantly by 80% 15 min after SGB, and statistically significant decrease (13%) in right brachial arterial blood flow occurred 15 min after left SGB. After intravenous infusion of PGE1 at a rate of 150 ng. kg-1. min-1 for 10 min, left brachial arterial blood flow increased (127%) still, and right brachial arterial blood flow returned to the pre-value. As to peripheral circulation, a combination of SGB and intravenous infusion of PGE1 was more effective than SGB alone. Moreover, the administration of PGE1 may improve imbalance of blood flow induced by sympathetic block.

Alprostadil↗
PubMed1996

[Influence of stellate ganglion block and electrical stimulation of the stellate ganglion on bilateral brachial arterial blood flow--is stellate ganglion block effective either unilaterally or bilaterally?].

The purpose of this study was to investigate the influence of the stellate ganglion block (SGB), stellate ganglion electrical stimulation (SGES) and stellate ganglionectomy on bilateral arterial blood flows (BAF). Sixteen mongrel dogs were divided into two groups; a SGB group (n = 8) and a SGES group (n = 8). Anesthesia was induced with pentobarbital 25 mg.kg-1 and the animals were mechanically ventilated to maintain proper PaO2 (90-100 mmHg) and PaCO2 (35-40 mmHg). After a thoracotomy, the SGB with 0.5% mepivacaine 1.0 ml was performed in the SGB group. SGES was performed at a strength of 12 volts, and at a frequency of 50 Hz, applied for 15 minutes and then 15 minutes after the SGES, stellate ganglionectomy was performed in SGES group. In the SGB group, BAF in the blocked side increased significantly but BAF in the contralateral side decreased significantly after SGB. In the SGES group, bilateral BAF decreased significantly (Lt > Rt) and after the stellate ganglionectomy, bilateral BAF increased more than after SGES. These results suggest that the SGB may not be effective on the contralateral side under normal conditions, but under the conditions of sympathetic stimulation, the SGB may be effective on the contralateral side.

Animals↗
PubMed1995

Biosynthesis of recombinant human pro-alpha 1(III) chains in a baculovirus expression system: production of disulphide-bonded and non-disulphide-bonded species containing full-length triple helices.

We have investigated the expression of human procollagen III by insect cells infected with a recombinant baculovirus carrying cDNA for the pro-alpha1(III) chain of type-III collagen. A high level of expression was obtained, and a small proportion of the heterologously expressed pro-alpha1(III) chains formed normally disulphide-bonded procollagen III, which was secreted into the culture medium. This species displayed a melting temperature (Tm) of approx. 38 degrees C as assessed by its resistance to digestion by a mixture of trypsin and chymotrypsin, slightly lower than that of 39.5 degrees C for procollagen III synthesized by cultured human dermal fibroblasts, and reflected a slight degree of under-hydroxylation of prolyl residues. This is possibly a consequence of the lower incubation temperature of insect cells, or of an insufficiency of prolyl hydroxylase activity within them. A significant proportion of the expressed chains formed trimeric molecules of similar thermal stability containing an apparently full-length triple-helical region, but were not disulphide-bonded and not secreted. In addition to providing a source of recombinant human procollagen III, the system promises to be useful in the study of procollagen chain association and subsequent folding.

Amino Acids↗
PubMed1995

T cell-dependent loss of proliferative responsiveness to colony-stimulating factor-1 by a murine epidermal-derived dendritic cell line, XS52.

We have reported previously that XS52 cells, a long-term dendritic cell (DC) line established from mouse epidermis, proliferate maximally in response to CSF-1, and that XS52 cells expanded in this manner induce brisk proliferation of HDK-1 T cells (KLH-specific Th1 clone) and 5S8 T cells (DNBS-specific Th0 clone) in the presence of Ag. Our purpose was to determine whether CSF-1-dependent mitotic potential of XS52 cells might be affected upon Ag-dependent interaction with these T cell clones. Both surface CSF-1R expression and mitotic responsiveness to CSF-1 became undetectable within 24 h after incubation with each T cell clone in the presence of relevant Ag. By contrast, incubation with T cells alone or Ag alone had minimal effect, indicating a requirement for both T cells and Ag. Exposure of fresh XS52 cells to the supernatant collected from complete XS52/HDK-1/KLH or XS52/5S8/DNBS coculture was sufficient to abrogate both CSF-1R expression and CSF-1 responsiveness. Importantly, both were restored by mAb against IFN-gamma, and both were diminished by rIFN-gamma in the absence of T cells or Ag. Thus, IFN-gamma, which was detected in relatively large amounts in the above supernatants, serves as a major mediator. rIFN-gamma reduced the number of CSF-1 binding sites on XS52 cell surface, without affecting CSF-1R mRNA expression. Thus, it appears that IFN-gamma down-regulates CSF-1R by a post-transcriptional mechanism. We interpret these results to document a novel, bi-directional signaling event in which Ag-dependent DC-T cell interaction promotes the growth of T cells, but inhibits the growth of DC.

Animals↗
PubMed1995

T cell-dependent secretion of IL-1 beta by a dendritic cell line (XS52) derived from murine epidermis.

IL-1 beta has been reported to play an essential role in the induction of T cell-mediated immune responses in skin, and Langerhans cells are considered to be the primary source of IL-1 beta in epidermis. We have established recently a long-term dendritic cell line (XS52) from mouse epidermis. This line resembles resident epidermal Langerhans cells in many respects, including the potent capacity to present a protein Ag (KLH) to a CD4+ Th1 clone (HDK-1) and the expression of IL-1 beta mRNA. We sought to determine whether XS52 cells secrete IL-1 beta upon Ag-dependent interaction with T cells and, if so, to elucidate the mechanism. Despite constitutive expression of mRNA for both IL-1 beta and the IL-1 beta-converting enzyme (ICE), XS52 cells secreted no detectable IL-1 beta spontaneously. When they were cultured with HDK-1 T cells and KLH, relatively large amounts of IL-1 beta (17.5-kDa form) were detected in the culture supernatant. IL-1 beta was secreted by LPS-stimulated XS52 cells, but not by LPS- or Con A-stimulated HDK-1 cells, suggesting that IL-1 beta is secreted primarily by XS52 cells in the coculture system. Incubation with HDK-1 cells alone or with KLH alone caused no IL-1 beta secretion, indicating the requirement for both T cells and Ag. IL-1 beta secretion was associated with a striking up-regulation of IL-1 beta mRNA and a modest up-regulation of ICE mRNA and enzymatic activity. IL-1 beta secretion was blocked by Ac-YVAD-CHO (a peptide inhibitor of ICE), CTLA4-Ig fusion protein, or anti-Ia mAb. IL-1 beta secretion was triggered in a T cell-independent manner by either CTLA4-Ig or anti-Ia mAb in immobilized forms. Thus, the XS52 dendritic cell line secretes, by an ICE-dependent mechanism, biologically relevant amounts of IL-1 beta upon Ag-dependent interaction with T cells, with both Ia molecules and B7-related molecules playing essential roles.

Animals↗
PubMed1995

Colony-stimulating factor-1 secreted by fibroblasts promotes the growth of dendritic cell lines (XS series) derived from murine epidermis.

We have established recently from mouse epidermis long-term dendritic cell lines (XS series) that resemble epidermal Langerhans cells (LC) by their surface phenotype, Ag-presenting profile and cytokine mRNA profile. The growth of XS lines was promoted maximally by granulocyte-macrophage-CSF or by a factor secreted by NS lines, which are fibroblastic cell lines established from dispase-separated specimens of mouse epidermis. The purpose of this study was to determine the identity of XS cell growth factor secreted by NS cells. We report the following: 1) NS cells express constitutively mRNA for CSF-1; 2) XS cells express the CSF-1R at mRNA and protein levels; 3) rCSF-1 mimics NS culture supernatant in its ability to promote XS cell growth; 4) NS supernatant-dependent XS cell growth is blocked completely by each of two Abs against the CSF-1R. We conclude that CSF-1 is responsible for the XS growth-promoting activity secreted by NS lines. We also report the following: 5) LC freshly isolated from skin express CSF-1R mRNA; and 6) fibroblasts derived from specimens of dermis also express mRNA and secrete large amounts (50-100 ng/ml) of CSF-1. These observations give rise to a new concept that dermal fibroblasts may support the survival and growth of LC (and their precursors) through the paracrine effect of elaborated CSF-1.

Animals↗
PubMed1995

Interleukin-1 beta converting enzyme in murine Langerhans cells and epidermal-derived dendritic cell lines.

Interleukin (IL)-1 beta plays an essential role in the induction of T cell-mediated immune responses in skin. Langerhans cells (LC), which constitutively express IL-1 beta mRNA, have been assumed to be the primary source of IL-1 beta in murine epidermis. The purpose of this study was to determine whether LC express mRNA for the IL-1 beta converting enzyme (ICE), a protease that is required for processing pro-IL-1 beta into an active form. Here, we report that both IL-1 beta and ICE mRNA are expressed by the Ia+ population (i.e. LC) in murine epidermis. Moreover, murine epidermal-derived DC lines (XS series) also express both IL-1 beta and ICE mRNA, and they secrete relatively large amounts of IL-1 beta following lipopolysaccharide (LPS) stimulation. Finally, LPS-triggered IL-1 beta secretion by XS cells is blocked almost completely by the ICE inhibitor acetyl-Tyr-Val-Ala-Asp-CH2OC(O)-[2,6-(CF3)2]Ph. These results demonstrate that LC are the primary source of IL-1 beta within the epidermis, and suggest that the proinflammatory role of IL-1 beta may be regulated pharmacologically by ICE inhibitors in vivo.

Animals↗
PubMed1995

Differential effects of vecuronium on the thumb and great toe as measured by accelography and electromyography.

We evaluated possible differential effects of vecuronium on the thumb and great toe using two types of neuromuscular transmission monitor. Train-of-four stimuli were simultaneously applied to the ulnar nerve and tibial nerves using cutaneous electrodes. The responses were quantified with accelographs (thumb and left great toe) and an electromyograph (right great toe). Twenty ASA 1 or 2 patients received, by random allocation, one of two types of anaesthesia: neuroleptanaesthesia or sevoflurane-based anaesthesia. With both techniques, the shortest time to maximum block after vecuronium 0.1 mg.kg-1 occurred in the thumb as measured by accelography. The average (SD) values with neuroleptanaesthesia were: 173(23) s for thumb using accelography; 220(16) s for great toe using accelography; 205(44) s for great toe using electromyography. The average (SD) value(s) with sevoflurane-based anaesthesia were: 137(15) for thumb using accelography; 179(21) for great toe using accelography; 153(23) for great toe using electromyography. The differences between the thumb and great toe were statistically significant during both types of anaesthesia when measured with the accelograph (p < 0.01). The time from completion of maximal block to 25% recovery of twitch height in the thumb was significantly longer than that of the great toe as measured by accelography during both types of anaesthesia (p < 0.05). In contrast, there were no statistically significant differences between time to maximum block and 25% recovery of twitch height of the thumb as measured by accelography compared to the values measured for the great toe using electromyography during either anaesthetic technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Edrophonium as an antagonist of vecuronium-induced neuromuscular block in the elderly.

Train-of-four stimuli were applied to the ulnar nerve using an accelograph in 10 elderly patients (aged 70-82 years) and 10 younger patients (aged 27-54 years). Anaesthesia was induced with thiopentone 5 mg.kg-1 and was maintained with nitrous oxide (66%) oxygen and sevoflurane (1 MAC). Vecuronium 0.1 mg.kg-1 was used for paralysis, and reversed with intravenous edrophonium 0.75 mg.kg-1 and atropine 0.015 mg.kg-1 when the train-of-four ratio returned to 25%. The times from initial administration of vecuronium to completion of maximal block were 211.5 (SD 66.9) s and 154.0 (SD 39.7) s in the elderly and younger patients, respectively (p < 0.05). The times from maximal block to 25% recovery of train-of-four ratio were 64.8 (SD 36.3) min and 61.8 (SD 36.3) min in the elderly and younger patients, respectively. There was no statistically significant difference between them. The reversal times from 25% to 75% of the train-of-four ratio after the administration of edrophonium were 210.0 (SD 136.7) s and 177.0 (SD 100.4) s in the elderly and younger patients, respectively. There was no statistically significant difference between them. The authors were unable to show that healthy elderly patients differ significantly from younger patients in the neuromuscular blocking effect of vecuronium and the reversal effect of edrophonium.

Adult↗
PubMed1995

Effect of parent genetic background on latency and antigenicity of UV-induced tumors originating in F1 hybrids.

Wide variations in susceptibility to skin tumor development by chronic ultraviolet light (UV) exposure and antigenicity of induced tumors which is estimated by tumor rejection in syngeneic recipients have been recognized among various murine strains. To examine the effect of parent genetic background on latency and antigenicity of UV-induced tumors originating in F1 hybrids, we induced skin tumors in three mouse strains: BALB/c, C57BL/6, (B6), and C3H/HeMs (C3H/He), and their F1 hybrids: (BALB/c x C3H/He)F1 (CC3F1), (BALB/c x B6)F1 (CB6F1) and (C3H/HexB6)F1 (C3B6F1) by exposing mice to UV radiation (0.44 mW/cm2 for 1 h) three times a week, and analyzed whether the UV-induced tumors originating in F1 hybrids possess the similar property in latency or antigenicity as seen in the UV-induced tumors derived from the parent strains. The latency of tumor induction by chronic UV exposure in C3H/He, BALB/c and their F1 hybrid CC3F1 was relatively short whereas that of B6 was relatively long, and that of F1 hybrids with B6 (CB6F1 and C3B6F1) was intermediate. On the other hand, the low antigenicity as progressive growth behavior of UV-induced tumors in syngeneic recipients was observed not only in tumors derived from C3H/He but also in those from F1 hybrids with C3H/He (C3B6F1 and CC3F1) whereas most tumors derived from B6, BALB/c and their F1 hybrid CB6F1 were highly antigenic as to be rejected in syngeneic recipients. These findings suggest that the parent genetic quality regulating the susceptibility to tumor induction by chronic UV exposure is co-dominantly inherited into F1 hybrids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Role of endogenous endothelin in gastric mucosal injury induced by hemorrhagic shock in rats.

We examined the role of endogenous endothelin in the pathogenesis of hemorrhagic shock-induced gastric mucosal injury in rats. Animals were bled to induce hypotension (20-30 mm Hg) for 20 min and the shed blood was retransfused. Rats were sacrificed at the end of hypotension, 20 min, and 60 min after retransfusion, respectively. Gastric erosions were induced with this experimental protocol. The total area of erosions was minimal only at the end of hypotension, and increased time-dependently after blood retransfusion. Plasma endothelin concentration significantly increased at the end of hypotension and persistently increased after retransfusion, whereas in gastric endothelin concentration a significant increase was observed at 60 min after retransfusion. The gastric mucosal hemodynamics as assessed by continuous measurement with reflectance spectrophotometry showed ischemia associated with congestion after retransfusion. Treatment with a monoclonal antibody against endothelin (0.2 mg/100 g BW/h) prevented these hemodynamic disturbances, rendering a significant decrease in the total area of erosions at 20 and 60 min after retransfusion. These results strongly suggest an important role of circulating endothelin in the pathogenesis of hemorrhagic shock-induced gastric mucosal injury through mucosal microcirculatory perturbation.

Animals↗