Quantitative Analyses of Hepatic OATP-Mediated Interactions Between Statins and Inhibitors Using PBPK Modeling With a Parameter Optimization Method.

This study aimed to construct a widely applicable method for quantitative analyses of drug-drug interactions (DDIs) caused by the inhibition of hepatic organic anion transporting polypeptides (OATPs) using physiologically based pharmacokinetic (PBPK) modeling. Models were constructed for pitavastatin, fluvastatin, and pravastatin as substrates and cyclosporin A (CsA) and rifampicin (RIF) as inhibitors, where enterohepatic circulations (EHC) of statins were incorporated. By fitting to clinical data, parameters that described absorption, hepatic elimination, and EHC processes were optimized, and the extent of these DDIs was explained satisfactorily. Similar in vivo inhibition constant (Ki ) values of each inhibitor against OATPs were obtained, regardless of the substrates. Estimated Ki values of CsA were comparable to reported in vitro values with the preincubation of CsA, while those of RIF were smaller than reported in vitro values (coincubation). In conclusion, this study proposes a method to optimize in vivo PBPK parameters in hepatic uptake transporter-mediated DDIs.

Effects of halothane on GABAergic and glutamatergic transmission in isolated hippocampal nerve-synapse preparations.

We evaluated the effects of halothane on synaptic and extrasynaptic GABA(A) and glutamate receptor responses using mechanically dissociated rat hippocampal CA3 neurons in which the well isolated neurons retain functional native nerve endings (the 'synaptic bouton' preparation). The preparation allows the simultaneous comparison of extrasynaptic GABA(A) and glutamate receptors, activated by bath applied GABA and glutamate, respectively, to the synaptic receptors measured as spontaneous and evoked postsynaptic currents. Paired-pulse synaptic responses evoked by focal electrical stimulation were also measured to evaluate any presynaptic effects. Halothane enhanced the extrasynaptic GABA(A)-receptor mediated postsynaptic responses in a concentration dependent fashion. At clinically relevant concentrations, halothane significantly increased both the amplitude and frequency of spontaneous postsynaptic inhibitory currents (sIPSCs) mediated by synaptic GABA(A) receptors. The relative amplitude of evoked IPSCs (eIPSCs) was also increased, concurrent with a decrease in failure rate and a significantly decreased eIPSC paired-pulse ratio. Halothane concentration dependently decreased the extrasynaptic glutamate-receptor induced postsynaptic responses but had no effects on spontaneous or evoked excitatory postsynaptic currents. These results suggest that halothane acts predominantly at presynaptic sites at GABAergic synapses to enhance inhibitory transmission at CA3 synapses, although it also increases extra-synaptic GABA responses. At excitatory synapses on to CA3 neurons, halothane has no presynaptic action-effecting only extrasynaptic receptors. Our results have clarified the locus of effects of the volatile anesthetic halothane at excitatory and inhibitory synapses, drawing somewhat different conclusions from those deduced from slices and culture systems.

Overexpression of GalNAc-transferase GalNAc-T3 promotes pancreatic cancer cell growth.

O-linked glycans of secreted and membrane-bound proteins have an important role in the pathogenesis of pancreatic cancer by modulating immune responses, inflammation and tumorigenesis. A critical aspect of O-glycosylation, the position at which proteins are glycosylated with N-acetyl-galactosamine on serine and threonine residues, is regulated by the substrate specificity of UDP-GalNAc:polypeptide N-acetylgalactosaminyl-transferases (GalNAc-Ts). Thus, GalNAc-Ts regulate the first committed step in O-glycosylated protein biosynthesis, determine sites of O-glycosylation on proteins and are important for understanding normal and carcinoma-associated O-glycosylation. We have found that one of these enzymes, GalNAc-T3, is overexpressed in human pancreatic cancer tissues and suppression of GalNAc-T3 significantly attenuates the growth of pancreatic cancer cells in vitro and in vivo. In addition, suppression of GalNAc-T3 induces apoptosis of pancreatic cancer cells. Our results indicate that GalNAc-T3 is likely involved in pancreatic carcinogenesis. Modification of cellular glycosylation occurs in nearly all types of cancer as a result of alterations in the expression levels of glycosyltransferases. We report guanine the nucleotide-binding protein, α-transducing activity polypeptide-1 (GNAT1) as a possible substrate protein of GalNAc-T3. GalNAc-T3 is associated with O-glycosylation of GNAT1 and affects the subcellular distribution of GNAT1. Knocking down endogenous GNAT1 significantly suppresses the growth/survival of PDAC cells. Our results imply that GalNAc-T3 contributes to the function of O-glycosylated proteins and thereby affects the growth and survival of pancreatic cancer cells. Thus, substrate proteins of GalNAc-T3 should serve as important therapeutic targets for pancreatic cancers.

Volatile anesthetic effects on isolated GABA synapses and extrasynaptic receptors.

The volatile anesthetics enhance GABAergic inhibitory transmission at synaptic and extrasynaptic sites at central neurons. In the present study, we investigated the effects of three volatile anesthetics (isoflurane, enflurane and sevoflurane) on synaptic and extrasynaptic GABA(A) receptor responses using mechanically dissociated rat hippocampal CA1 neurons in which functional native nerve endings (boutons) were retained. The extrasynaptic GABA(A) receptors were activated by exogenous GABA application while synaptic ones were assessed by miniature and evoked inhibitory postsynaptic currents (mIPSCs and eIPSCs, respectively). All volatile anesthetics concentration-dependently enhanced the exogenous GABA-induced postsynaptic responses. The structural isomers, isoflurane and enflurane, increased mIPSC frequency while sevoflurane had no effect. None of these anesthetics altered mIPSC amplitudes at their clinically relevant concentrations. Sevoflurane prolonged event kinetics by increasing decay time of mIPSCs and eIPSCs at clinically relevant concentration. On the other hand, both isoflurane and enflurane only prolonged the kinetics of these events at 1 mM of high concentration. For GABAergic eIPSCs, both isoflurane and enflurane decreased the evoked response amplitude and increased the failure rate (Rf), while sevoflurane decreased the amplitude without affecting Rf. These results suggest that isoflurane and enflurane at the clinically relevant concentrations predominantly act on GABAergic presynaptic nerve endings to decrease action potential dependent GABA release. It was concluded that these anesthetics have heterogeneous effects on mIPSCs and eIPSCs with different modulation of synaptic and extrasynaptic GABA(A) receptors.

Multi-nucleated giant cell formation from human cord blood monocytes in vitro, in comparison with adult peripheral blood monocytes.

Multi-nucleated giant cells (MGCs; Langhans-type cell), formed from macrophage fusion, are recognized as a hallmark histological feature in chronic inflammation. However, their precise pathological role is still poorly understood, especially for microorganism pathogens in the neonatal immune system, which are capable of surviving intracellularly in phagocytes. To conduct a partial evaluation of the monocyte function of neonates, we investigated the ability of human cord blood monocytes to form MGCs in vitro by stimulating various cytokines and comparing them with adult peripheral blood monocytes. Monocytes from cord blood and adult peripheral blood were isolated and cultured for 14 days with cytokines known to induce MGC in vitro. The fusion index in experiments with a combination of interleukin (IL)-4 and macrophage colony-stimulating factor (M-CSF) and a combination of IL-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly lower in cord blood than in adult blood monocytes (P = 0.0018 and P = 0.0141, respectively). The number of nuclei per MGC was significantly lower in cord blood than in adult blood monocytes in experiments with IL-4 alone, the combination of IL-4 and M-CSF, and the combination of IL-4 and GM-CSF (P < 0.0001). These results suggest the possibility that the susceptibility of newborns to mycobacterium infection is due partly to impaired MGC formation.

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.

Insertion of intradermal needles into painful points provides analgesia for intractable abdominal scar pain.

BACKGROUND AND OBJECTIVES: Conventional treatments are often ineffective for patients having painful abdominal scars. There are painful points in and around scar tissue. We tested the hypothesis that insertion of intradermal needles into these painful points reduces scar pain. METHODS: Patients with abdominal scar pain with painful points that is not relieved by conventional treatments were allocated to a treatment group (n = 23), a sham-treatment group (n = 23), or a control group (n = 24). In the treatment group, intradermal needles were inserted into painful points detected by a pressure threshold meter (pain < or = 2.5 kg/cm(2)). In the sham-treatment group, the same needles were inserted into nonpainful points. The needles were kept in place for 24 hours. This process was repeated 20 times over a 4-week period. Responses were evaluated before and at the end of treatment, and 4 and 26 weeks after the treatment. Continuous and lancinating pain was evaluated on a 10-cm visual analog scale. We measured the area of pain and the pressure required to initiate painful-point pain. All patients took diclofenac as needed and completed a diary of daily diclofenac consumption. RESULTS: Patients in the treatment group showed a marked reduction in all pain parameters (>70%). In contrast, analgesia was minimal in the other groups. The decreases in the pain threshold pressure correlated with the decreases in continuous and lancinating pain (r =.57 and r =.63, respectively). CONCLUSION: Our data suggest that insertion of intradermal needles into painful points is a remarkably effective treatment for intractable abdominal scar pain. Analgesia presumably results from inactivation of painful points, through a yet to be elucidated mechanism.

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.

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.

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.

Rebound perioperative hyperkalemia in six patients after cessation of ritodrine for premature labor.

IMPLICATIONS: This report describes six patients who had marked hyperkalemia 60-150 min after cessation of intravenous ritodrine, which had been administered for management of preterm labor. Abnormal electrocardiographic findings are very important clues for a prompt diagnosis of hyperkalemia.

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.

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.

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.

[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.

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.

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.

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.

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.