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Biomedical subjects

N Kotani

Publications and source records attributed to N Kotani.

At least 19 recordsLinked to original sources
PubMed2005

Isoflurane increases norepinephrine release in the rat preoptic area and the posterior hypothalamus in vivo and in vitro: Relevance to thermoregulation during anesthesia.

General anesthetics modulate autonomic nervous system function including thermoregulatory control, which resides in the preoptic area of the anterior hypothalamus. However, the mechanism by which anesthetics modulate hypothalamic function remains unknown. We hypothesized that isoflurane increases norepinephrine release in the preoptic area and in the posterior hypothalamus causing hypothermia during anesthesia. To test this hypothesis, we performed a series of in vivo and in vitro studies in rats. In vivo studies: 1) Norepinephrine release was measured by microdialysis in the preoptic area or the posterior hypothalamus (n=9 each) before, during (30 min), and after (50 min) rats were anesthetized with 2% isoflurane. 2) In five rats, blood gases and arterial pressure were measured. 3) Body temperature changes (n=6 each) were measured after prazosin (0, 0.05, 0.5 microg), norepinephrine (0, 0.1, 1.0 microg), or 0.5 microg prazosin with 1.0 microg norepinephrine injection into the preoptic area. In vitro study: Norepinephrine release was measured from anterior or posterior hypothalamic slices (n=10 each) incubated with 0, 1, 2, or 4% isoflurane in Ca2+-containing buffer or with 4% isoflurane (n=10) in Ca2+-free buffer. Data were analyzed with repeated measures or factorial ANOVA and Student-Newman-Keuls tests. P<0.05 was significant. During anesthesia, norepinephrine release in the preoptic area was increased approximately 270%, whereas the release in the posterior hypothalamus remained unchanged. During emergence, posterior hypothalamic norepinephrine release increased by approximately 250% (P<0.05). Rectal temperature changes correlated with norepinephrine release from the preoptic area. Norepinephrine in the preoptic area enhanced isoflurane-induced hypothermia, while prazosin reversed it. Norepinephrine release from anterior hypothalamic slices increased at all isoflurane concentrations, but only at the highest concentration in posterior hypothalamic slices. Under Ca2+-free conditions, 4% isoflurane increased norepinephrine from both regions. These results suggest that augmentation of norepinephrine release in the preoptic area is responsible for hypothermia during general anesthesia.

Anesthesia↗
PubMed2001

Knockout of mouse beta 1,4-galactosyltransferase-1 gene results in a dramatic shift of outer chain moieties of N-glycans from type 2 to type 1 chains in hepatic membrane and plasma glycoproteins.

To understand the contribution of beta 1,4-galactosyltransferase (beta 4Gal-T)-1 to galactosylation in vivo, N-glycans of hepatic membrane glycoproteins and plasma glycoproteins from beta 4Gal-T1 wild-type (beta 4Gal-T1(+/+)) and beta 4Gal-T1 knockout mice were compared. Unexpectedly, glycoproteins from the knockout mice were found to express considerable amounts of sialylated, galactosylated N-glycans. A striking contrast was that galactose residues were largely beta 1,4-linked to GlcNAc residues in the beta 4Gal-T1(+/+) mouse glycans but beta 1,3-linked in the knockout mouse glycans, thus resulting in the shift of the backbone structure from type 2 chain (Gal beta 1-->4GlcNAc) to type 1 chain (Gal beta 1-->3GlcNAc). Detailed analysis of plasma glycoproteins revealed that the expression of sialyl linkage in N-glycans was shifted from the Sia alpha 2-->6Gal to the Sia alpha 2-->3Gal, and oversialylated type 1 chains were, remarkably, found in the knockout mouse glycans. Thus beta 4Gal-T1 deficiency was primarily compensated for by beta1,3-galactosyltransferases, which resulted in different sialyl linkages being formed on the outer chains and altered backbone structures, depending on the acceptor specificities of sialyltransferases. These results suggest that beta 4Gal-T1 in mouse liver plays a central role in the synthesis of type 2 chain and is also involved in the regulation of sialylation of N-glycans. The knockout mice may prove useful in investigation of the mechanism which regulates the tissue-dependent terminal glycosylation.

Animals↗
PubMed2001

A new beta-1,2-N-acetylglucosaminyltransferase that may play a role in the biosynthesis of mammalian O-mannosyl glycans.

Recent studies have shown that O-mannosyl glycans are present in several mammalian glycoproteins. Although knowledge on the functional roles of these glycans is accumulating, their biosynthetic pathways are poorly understood. Here we report the identification and initial characterization of a novel enzyme capable of forming GlcNAc beta 1-2Man linkage, namely UDP-N-acetylglucosamine: O-linked mannose beta-1,2-N-acetylglucosaminyltransferase in the microsome fraction of newborn rat brains. The enzyme transfers GlcNAc to beta-linked mannose residues, and the formed linkage was confirmed to be beta 1-2 on the basis of diplococcal beta-N-acetylhexosaminidase susceptibility and by high-pH anion-exchange chromatography. Its activity is linearly dependent on time, protein concentration, and substrate concentration and is enhanced in the presence of manganese ion. Its activity is not due to UDP-N-acetylglucosamine: alpha-3-D-mannoside beta-1,2-N-acetylglucosaminyltransferase I (GnT-I) or UDP-N-acetylglucosamine: alpha-6-D-mannoside beta-1,2-D-acetylglucosaminyltransferase II (GnT-II), which acts on the early steps of N-glycan biosynthesis, because GnT-I or GnT-II expressed in yeast cells did not show any GlcNAc transfer activity against a synthetic mannosyl peptide. Taken together, the results suggest that the GlcNAc transferase activity described here is relevant to the O-mannosyl glycan pathway in mammals.

Animals↗
PubMed2001

Recovery of intraoperative microbicidal and inflammatory functions of alveolar immune cells after a tobacco smoke-free period.

BACKGROUND: Tobacco smoking inhibits alveolar macrophage function, but cessation of smoking markedly reduces the risk of postoperative pulmonary complications. The authors therefore evaluated the effect of nonsmoking duration on both antimicrobial and inflammatory functions of alveolar macrophages during anesthesia and surgery. METHODS: The authors studied 15 patients who had never smoked, 15 current smokers, and 41 former smokers, all of whom underwent general anesthesia. Former smokers were further allocated to one of three groups depending on their smoke-free periods: 2 months (n = 13), 3-5 months (n = 13), and 6-12 months (n = 15). Alveolar immune cells were collected by bronchoalveolar lavage immediately after induction of anesthesia, at 2 and 4 h after induction of anesthesia, and at the end of surgery. Opsonized and nonopsonized phagocytosis were measured. Microbicidal activity was determined as the ability of the macrophages to kill Listeria monocytogenes directly. Finally, we determined the expression of proinflammatory cytokines, including interleukin 1beta, interleukin 8, interferon gamma, and tumor necrosis factor alpha, and of antiinflammatory cytokines (interleukin 4 and 10) by semiquantitative polymerase chain reaction. RESULTS: Nonopsonized and opsonized phagocytosis and microbicidal activity of alveolar macrophages (antimicrobial functions) decreased 20-50%, and the expression of genes for all proinflammatory and antiinflammatory cytokines increased 3-30-fold over time in all groups. Starting 4 h after induction of anesthesia, the decreases in antimicrobial functions were 1.5-3 times greater in current and former smokers (2 months' abstinence) than in patients who had never smoked. Starting 4 h after anesthesia, the increase in expression of all cytokines, except interleukin 8, was twofold to fivefold less in current and former smokers (2-6 months' abstinence) than in patients who had never smoked. CONCLUSION: Our data suggest that former smokers may have a limited ability to mount effective pulmonary immune defenses for long as 6 months after stopping cigarette use.

Adult↗
PubMed2001

Preoperative intradermal acupuncture reduces postoperative pain, nausea and vomiting, analgesic requirement, and sympathoadrenal responses.

BACKGROUND: In a controlled and double-blind study, the authors tested the hypothesis that preoperative insertion of intradermal needles at acupoints 2.5 cm from the spinal vertebrae (bladder meridian) provide satisfactory postoperative analgesia. METHODS: The authors enrolled patients scheduled for elective upper and lower abdominal surgery. Before anesthesia, patients undergoing each type of surgery were randomly assigned to one of two groups: acupuncture (n = 50 and n = 39 for upper and lower abdominal surgery, respectively) or control (n = 48 and n = 38 for upper and lower abdominal surgery, respectively). In the acupuncture group, intradermal needles were inserted to the left and right of bladder meridian 18-24 and 20-26 in upper and lower abdominal surgery before induction of anesthesia, respectively. Postoperative analgesia was maintained with epidural morphine and bolus doses of intravenous morphine. Consumption of intravenous morphine was recorded. Incisional pain at rest and during coughing and deep visceral pain were recorded during recovery and for 4 days thereafter on a four-point verbal rating scale. We also evaluated time-dependent changes in plasma concentrations of cortisol and catecholamines. RESULTS: Starting from the recovery room, intradermal acupuncture increased the fraction of patients with good pain relief as compared with the control (P < 0.05). Consumption of supplemental intravenous morphine was reduced 50%, and the incidence of postoperative nausea was reduced 20-30% in the acupuncture patients who had undergone either upper or lower abdominal surgery (P < 0.01). Plasma cortisol and epinephrine concentrations were reduced 30-50% in the acupuncture group during recovery and on the first postoperative day (P < 0.01). CONCLUSION: Preoperative insertion of intradermal needles reduces postoperative pain, the analgesic requirement, and opioid-related side effects after both upper and lower abdominal surgery. Acupuncture analgesia also reduces the activation of the sympathoadrenal system that normally accompanies surgery.

Abdomen↗
PubMed2001

Intraoperative prostaglandin E1 improves antimicrobial and inflammatory responses in alveolar immune cells.

OBJECTIVE: Anesthesia and surgery decrease antimicrobial and increase proinflammatory functions of alveolar immune cells. Thus, anti-inflammatory agents that do not further suppress antimicrobial functions are required. We tested the hypothesis that intraoperative prostaglandin E1 (PGE1) suppresses proinflammatory responses and prevents the reduction in antimicrobial responses of alveolar immune cells. DESIGN: Prospective, randomized, controlled, double-blind study. SETTING: University hospital. PATIENTS: A total of 40 patients undergoing elective orthopedic surgery under propofol/fentanyl anesthesia. INTERVENTION: In double-blind fashion, the patients received PGE1 from the beginning to the end of surgery (PGE1 group, n = 20) or nothing (control group, n = 20). METHODS AND MAIN RESULTS: Alveolar immune cells were harvested by bronchoalveolar lavage immediately after induction of anesthesia; 2, 4, and 6 hrs after induction of anesthesia; and at the end of surgery. We measured opsonized and nonopsonized phagocytosis. Microbicidal activity was evaluated to directly kill Listeria monocytogenes in alveolar macrophages. Finally, we determined the expression of proinflammatory cytokines including interleukin (IL)-1beta, IL-8, interferon-gamma, and tumor necrosis factor-alpha, and that of anti-inflammatory cytokines (IL-4 and IL-10) by semiquantitative polymerase chain reaction. Nonopsonized and opsonized phagocytosis and microbicidal activity of alveolar macrophages decreased and the expression of genes for all pro- and anti-inflammatory cytokines increased significantly over time in both groups. Starting 2-4 hrs after induction of anesthesia, the increases in gene expression of proinflammatory cytokines were 1.5-3 times smaller in the PGE1 than in the control group. Starting 6 hrs after anesthesia, the increase in gene expression of IL-10 was 1.5-3 times greater in the PGE1 than in the control group. Intraoperative decreases in phagocytic and microbial activities were the same in the two groups. CONCLUSION: Intraoperative PGE1 not only suppressed proinflammatory responses, but also protected antimicrobial functions of alveolar macrophages, possibly because PGE1 is mostly inactivated in the pulmonary intravascular space. Our results suggest that intraoperative PGE1 protects the pulmonary immune defense in alveolar immune cells.

Adult↗
PubMed2001

A family with von Hippel-Lindau disease revealed by pheochromocytoma.

Von Hippel-Lindau (VHL) disease is an inherited neoplastic disease characterized by a predisposition to develop retinal angiomas, central nervous system hemangioblastomas, renal cell carcinomas, pancreatic cysts and pheochromocytomas. Recently, we encountered three members of the same family who each had both VHL disease and pheochromocytoma. As in all three patients we suspected pheochromocytoma, the diagnosis of VHL disease should be considered. The possible presence of VHL disease was initially investigated in all three patients based on the presence of pheochromocytoma. A mutational analysis of the VHL gene revealed the presence of a missense mutation, consisting of a G to A transversion, at nucleotide 713 in all three patients. This germline point mutation in the VHL gene is often detected in type 2 VHL disease with pheochromocytoma. Genetic analysis seems to be useful for early detection of VHL disease, even when the formal criteria for diagnosis of this disease are lacking.

Adrenal Gland Neoplasms↗
PubMed2001

[A case of long-term respiratory management following resection of a huge facial hemangioma].

A 49 year-old-woman was scheduled for resection of a huge hemangioma of the face and neck region. After the resection, severe edema developed on the tongue, larynx, and pharynx even leaving no space between the tracheal tube and these tissues. Prolonged respiratory management with endotracheal tube intubation was needed to maintain the upper airway for more than three weeks. Tracheostomy was performed 27 days after the operation. Two weeks later, the edema of the upper airway subsided. Thereafter her clinical course was uneventful, and she was discharged 22 days after the tracheostomy. Resection of a huge facial and neck hemangioma should be carefully managed as it can be followed by unexpected severe postoperative upper airway edema leading to suffocation.

Edema↗
PubMed2000

Intrathecal methylprednisolone for intractable postherpetic neuralgia.

BACKGROUND: There is no effective treatment for intractable postherpetic neuralgia. Because there is evidence that postherpetic neuralgia has an inflammatory component, we assessed treatment with intrathecally administered methylprednisolone to reduce pain in patients with this disorder. METHODS: We enrolled 277 patients who had had intractable postherpetic neuralgia for at least one year, 270 of whom were followed for two years. The patients were randomly assigned to receive intrathecal methylprednisolone and lidocaine (3 ml of 3 percent lidocaine with 60 mg of methylprednisolone acetate, 89 patients), lidocaine alone (3 ml of 3 percent lidocaine, 91 patients), or no treatment (90 patients) once per week for up to four weeks. Each weekly dose was injected into the lumbar intrathecal space. Pain was evaluated before randomization, at the end of the treatment period, and then four weeks, one year, and two years later. Samples of cerebrospinal fluid were obtained for measurement of interleukin-8 before and at the end of the treatment period. RESULTS: There was minimal change in the degree of pain in the lidocaine-only and control groups during and after the treatment period. In the methylprednisolone-lidocaine group, the intensity and area of pain decreased, and the use of the nonsteroidal antiinflammatory drug diclofenac declined by more than 70 percent four weeks after the end of treatment. No complications related to intrathecal methylprednisolone were observed. Before treatment, the concentrations of interleukin-8 in the cerebrospinal fluid were inversely related to the duration of neuralgia in all the patients (r=-0.49, P<0.001). In the patients who received methylprednisolone, interleukin-8 concentrations decreased by 50 percent, and this decrease correlated with the duration of neuralgia and with the extent of global pain relief (P<0.001 for both comparisons). CONCLUSIONS: The results of this trial indicate that the intrathecal administration of methylprednisolone is an effective treatment for postherpetic neuralgia.

Aged↗
PubMed2000

Cardiopulmonary bypass produces greater pulmonary than systemic proinflammatory cytokines.

Cardiopulmonary bypass (CPB) impairs pulmonary endothelial injury in part by increasing expression of adhesion molecules that results in neutrophil influx. Although numerous proinflammatory cytokines up-regulate these responses, the extent to which systemic and pulmonary proinflammatory cytokines increase remains unknown. We therefore examined systemic and pulmonary gene expression and production of proinflammatory cytokines during CPB. Bronchoalveolar lavage and peripheral blood sampling were performed just after the induction of anesthesia and at the end of surgery in 80 patients undergoing CPB. RNA was extracted from harvested cells and cDNA was synthesized by reverse transcription. The expression of interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) was measured by semiquantitative polymerase chain reaction using beta-actin as an internal standard. We also measured these cytokines in cultured alveolar macrophages and plasma monocytes in standard medium alone, or in the presence of lipopolysaccharide. We found 2- to 20-fold increases in gene expression for these cytokines in both plasma and alveolar leukocytes at the end of surgery. However, the increases were 4-8 times greater in alveolar than plasma leukocytes. Alveolar macrophages obtained at the end of surgery produced 1.5-3 times more IL-6, IL-8, and TNF-alpha than those obtained at the beginning (P < 0.0001). Although plasma monocytes produced more IL-8 at the end of surgery (P < 0.001), TNF-alpha and IL-6 did not increase. The production of all cytokines was 1.5-3 times greater in alveolar macrophages obtained at the end of surgery than in plasma monocytes obtained simultaneously (P < 0.005). Our data thus suggest that CPB provokes a greater pulmonary than systemic inflammatory response.

Actins↗
PubMed2000

Neutrophil number and interleukin-8 and elastase concentrations in bronchoalveolar lavage fluid correlate with decreased arterial oxygenation after cardiopulmonary bypass.

Atelectasis is a major cause of decreased arterial oxygenation after cardiopulmonary bypass (CPB). There is a close relationship between atelectasis and inflammatory responses. We therefore tested the hypothesis that neutrophil number and the concentrations of proinflammatory cytokines and elastase in plasma and bronchoalveolar lavage fluid correlate with changes in arterial oxygenation. Bronchoalveolar lavage was performed just after the induction of anesthesia and at the end of surgery in 80 patients undergoing CPB. Peripheral blood was sampled simultaneously. Arterial oxygenation was quantified by PaO(2)/fraction of inspired oxygen (FIO(2)) and intrapulmonary shunt (Q(s)/Q(t)). PaO(2)/FIO(2) and Q(s)/Q(t) decreased significantly at the end of surgery, whereas neutrophil number, interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, and elastase concentrations in the lavage fluid increased significantly. The increase in neutrophil count from the lavage fluid correlated significantly with the increases in IL-8 and elastase concentrations. The increase in neutrophil number and IL-8 and elastase concentrations in the lavage fluid correlated significantly with PaO(2)/FIO(2) and Q(s)/Q(t) at the end of surgery. In contrast, none of the plasma values correlated with these variables. Significant correlation between immune mediators and decreased arterial oxygenation suggests that inflammatory responses in the distal airway are strongly related to a decrease in arterial oxygenation after CPB.

Bronchoalveolar Lavage Fluid↗
PubMed2000

Smoking decreases alveolar macrophage function during anesthesia and surgery.

BACKGROUND: Smoking changes numerous alveolar macrophage functions and is one of the most important risk factors for postoperative pulmonary complications. The current study tested the hypothesis that smoking impairs antimicrobial and proinflammatory responses in alveolar macrophages during anesthesia and surgery. METHOD: The authors studied 30 smoking and 30 nonsmoking patients during propofol-fentanyl general anesthesia. Alveolar immune cells were harvested by bronchoalveolar lavage immediately and 2, 4, and 6 h after induction of anesthesia and at the end of surgery. The types of alveolar immune cell and macrophage aggregation were determined. The authors measured opsonized and unopsonized phagocytosis. Microbicidal activity was determined as the ability of the macrophages to kill Listeriamonocytogenes directly. Finally, RNA was extracted from harvested cells and cDNA was synthesized by reverse transcription. The expression of interleukin 1beta, 6, and 8, interferon gamma, and tumor necrosis factor alpha were measured by semiquantitative polymerase chain reaction using beta-actin as an internal standard. RESULTS: The fraction of aggregated macrophages increased significantly over time in both groups, whereas phagocytosis of opsonized and nonopsonized particles and microbicidal activity of alveolar macrophages decreased significantly. The changes, though, were nearly twice as great as in patients who smoked. Gene expression of all proinflammatory cytokines in alveolar immune cells except interleukin 6 increased 2- to 20-fold over time in both groups. The expression of interleukin 1beta, interferon gamma, and tumor necrosis factor alpha, however, increased only half as much in smokers as in nonsmokers. CONCLUSION: Smoking was associated with macrophage aggregation but markedly reduced phagocytic and microbicidal activity-possibly because expression of proinflammatory cytokines was reduced in these patients. Our data thus suggest that smokers may have a limited ability to mount an effective pulmonary immune defense after anesthesia and surgery.

Anesthesia, General↗
PubMed2000

Supplemental intraoperative oxygen augments antimicrobial and proinflammatory responses of alveolar macrophages.

BACKGROUND: The first goal was to test the hypothesis that 100% inspired oxygen maintained for approximately 8 h intraoperatively is not associated with impaired pulmonary oxygenation. The authors also tested the hypothesis that intraoperative inhalation of 100% oxygen augments proinflammatory and antimicrobial responses of alveolar macrophages during anesthesia and surgery. METHODS: The authors studied patients administered 100% oxygen (n = 30) and 30% oxygen (n = 30) during propofol-fentanyl general anesthesia. Alveolar macrophages were harvested by bronchoalveolar lavage immediately, 2, 4, and 6 h after induction of anesthesia, and at the end of surgery. The authors measured "opsonized" and "unopsonized" phagocytosis and microbicidal activity. RNA was extracted from harvested cells and cDNA was synthesized. The expression of interleukin(IL)-1beta, IL-6, IL-8, interferon-gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) was measured by semiquantitative polymerase chain reaction. RESULTS: Gene expression of all proinflammatory cytokines except IL-6 increased fourfold to 20-fold over time in both groups. However, expression of TNF-alpha and IL-8, IFN-gamma, and IL-6 and IL-1beta was 2-20 times greater in patients administered 100% than in those administered 30% oxygen. Unopsonized and opsonized phagocytosis and microbicidal activity decreased progressively, with the decreases being nearly twice as great during inhalation of 30% oxygen versus 100% oxygen. CONCLUSION: Inhalation of 100% oxygen improved intraoperative decreases in phagocytic and microbicidal activity possibly because expression of proinflammatory cytokines was augmented. These data therefore suggest that intraoperative inhalation of 100% oxygen augments antimicrobial and proinflammatory responses in alveolar macrophages during anesthesia and surgery.

Anesthesia, Intravenous↗
PubMed2000

Forced hyperphasia and environmental dependency syndrome.

A distinctive, language related fragment of the environmental dependency syndrome is described: compulsive, involuntary, environmentally dependent speaking. Because this syndrome represents the observe of aphasia, it is named forced hyperphasia. An 84 year old woman with acute left frontal infarction was admitted to hospital with gait disturbance, forced grasp reflex, and striking imitation behaviour. After 2 weeks her imitation behaviour disappeared, but an equally striking new behaviour emerged. In the presence of others she would call out the names of objects in the room, and also call out the actions and gestures of people in the room, even though she was not asked to do so, and even though she was asked to stop. For example, if the doctor scratched his nose, she said, "The doctor is scratching his nose." Brain CT, MRI, and SPECT showed cerebral atrophy and a left superior frontal subcortical infarct. It is suggested that "forced hyperphasia" is a clinical fragment of the environmental dependency syndrome and that her compulsive, impulsive, involuntary release of spoken language resulted from the release of frontal inhibition of the complex reflex linking environmental cues to the set of motor, limbic, spatial, and linguistic associations underlying spoken language.

Aged↗
PubMed2000

Contribution of cardiovascular hypersensitivity to orthostatic hypertension and the extreme dipper phenomenon.

We report the case of a 68-yr-old woman who, upon standing, experienced dizziness in association with increased blood pressure (BP) and heart rate (HR). We made a diagnosis of orthostatic hypertension and examined the BP response to postural change using the head-up tilt test. Positional change resulted in a 20-mmHg increase in systolic BP and a 15-bpm increase in HR. A 24-h ambulatory BP recording showed daytime hypertension that decreased at night, along with a nocturnal decrease in HR. Based on these post-diagnostic results, the patient was rediagnosed as an extreme dipper with silent lacunar infarction as the only complication of orthostatic hypertension. We suggest that, in our patient, the mechanism of orthostatic hypertension was hypersensitivity of cardiovascular responsiveness to endogenous vasoconstrictors. This was evidenced by increased pressure sensitivity to isoproterenol as well as phenylephrine. We thus selected carvedilol, a beta-blocker with slight alpha-blocking action, and were more effective in abolishing the hypertension.

Adrenergic alpha-Agonists↗