Magnesium sulphate and perinatal mortality and morbidity in very-low-birthweight infants born between 24 and 32 weeks of gestation in Japan.

OBJECTIVE: Maternal exposure to magnesium sulphate has a neuroprotective effect in premature infants. This study aimed to examine this neuroprotective effect and the dose-response relationship in very-low-birthweight infants born between 24 and 32 weeks of gestation. STUDY DESIGN: A retrospective cohort study compared the rates of mortality and brain damage between three groups: no magnesium sulphate, low-dose (<50g) magnesium sulphate and high-dose (≥50g) magnesium sulphate. RESULTS: Japanese maternal and neonatal databases were linked using six key parameters from 2003 to 2007. Of 298,514 deliveries, 9101 were very-low-birthweight infants. Among these, full matching was possible for 5562 infants. Of the fully-matched infants, 3763 were born between 24 and 32 weeks of gestation, and 1813 (48%) were followed-up beyond 18 months. A multivariate analysis of the data, including gestational age, sex, fetal growth restriction, antenatal steroids and low pH (<7.1), showed that the low-dose group had no beneficial effects in terms of a reduction in mortality or incidence of brain damage (cerebral palsy or mental retardation). The high-dose group showed a significantly higher mortality rate [odds ratio (OR) 1.9, 95% confidence interval (CI) 1.2-2.9]. A stratified subgroup analysis of infants born between 28 and 32 weeks of gestation showed that survivors in the low-dose group had significantly lower rates of cerebral palsy (OR 0.4, 95% CI 0.2-0.98) and brain damage (OR 0.2, 95% CI 0.1-0.9), while the high-dose group did not show any significant changes. CONCLUSION: This study found that antepartum exposure to magnesium sulphate did not reduce the infant mortality rate or influence neurological outcomes. However, among infants born between 28 and 32 weeks of gestation, rates of cerebral palsy and brain damage were found to be significantly lower among survivors in the low-dose group.

Evaluation of cellular adhesions on silicone and poly(methyl methacrylate) intraocular lenses in monkey eyes: an electron microscopic study.

PURPOSE: To assess the biocompatibility of intraocular lens (IOL) material by studying the number of cells adhering to IOLs in monkey eyes. SETTING: Department of Ophthalmology, Kyushu University, Fukuoka, Japan. METHODS: Silicone or poly(methyl methacrylate) (PMMA) IOL implantation was performed in 21 monkeys. One eye of each animal had surgery. The IOL-implanted eyes were enucleated 1, 2, 3, 5, and 7 days and 1, 3, 4, 5, and 9 months after the procedure. One eye was studied at each time. Cells on the anterior IOL surface were photographed using a scanning electron microscope, counted and assessed with NEC, Graphtec, and Nikon equipment, and then observed using a transmission electron microscope. RESULTS: Leukocytes, macrophages, and giant cells were found on the anterior IOL surface. Numerous cells were observed on the PMMA IOLs in the early postoperative period; they gradually decreased. Few cells were seen on the silicone IOLs during the course of the study. The giant cells became larger during the postoperative period. CONCLUSION: The foreign-body reaction to silicone IOLs in monkey eyes was less than that to PMMA IOLs.

Gene transfer by adenovirus in rabbit iris sphincter muscle.

The effect of insertion of an exogenous gene on smooth muscle function in rabbit iris sphincter muscle was investigated. An adenoviral vector encoding the bacterial LacZ gene (AdLacZ, 10(7) pfu) and viscoelastics were injected into the posterior chamber of eyes of albino rabbits. Three days after injection, the effects of acetylcholine (Ach), carbachol (Carb), substance P (SP) and electrical field stimuli on isolated iris sphincter were investigated using isometric tension-recording methods. X-Gal histostaining showed that iris sphincter smooth muscle cells were transfected in 7 of 11 muscle strips. Contraction-response curves for Ach, Carb or SP were not different from control. We conclude that the iris sphincter muscle can be gene-transfected by posterior chamber infusion of an adenoviral vector with viscoelastics. Adenovirus-mediated gene transfer per se had no measurable effect on tension development.

NF-kappaB activation in peripheral blood monocytes/macrophages and T cells during acute Kawasaki disease.

Kawasaki disease (KD) is a febrile disease of childhood characterized by systemic vasculitis, and the levels of many proinflammatory cytokines are elevated in the serum at the acute stage. We investigated the activation of transcription factor NF-kappaB for genes that encode the proinflammatory cytokines in CD14+ monocytes/macrophages and CD3+ T cells in peripheral blood by means of Western blot and flow cytometric analyses. Western blot analysis demonstrated that NF-kappaB activation was more increased in CD14+ monocytes/macrophages than in CD3+ T cells in all children during the acute stage. Flow cytometric analysis revealed that NF-kappaB activation in CD14+ monocytes/macrophages was significantly higher than in CD3+ T cells at the acute stage (30.0 +/- 16.0% vs 11.4 +/- 5.0%, P < 0.01, Wilcoxon test). NF-kappaB activation in CD14+ monocytes/macrophages was significantly decreased after high-dose intravenous immunoglobulin therapy (P < 0.05). The present findings suggest that CD14+ monocytes/macrophages play an important role in cytokine production during acute KD.

[Presynaptic effects of botulinum toxin type A on the neuronally evoked response of albino and pigmented rabbit iris sphincter and dilator muscles].

PURPOSE: To investigate the effects of botulinum toxin type A(botulinum A toxin) on the autonomic and other non-adrenergic, non-cholinergic nerve terminals. METHODS: The effects of neurotoxin on twitch contractions evoked by electrical field stimulation (EFS) were studied in isolated rabbit iris sphincter and dilator muscles using isometric tension recording. RESULTS: Botulinum A toxin(150 nM) inhibited the fast cholinergic and slow substance P-ergic component of contraction evoked by EFS in the rabbit iris sphincter muscle without affecting the response to carbachol and substance P. Botulinum A toxin(150 nM) did not affect the twitch contraction evoked by EFS in the rabbit iris dilator muscle. CONCLUSION: These data indicated that botulinum A toxin may inhibit not only the acetylcholine release in the cholinergic nerve terminals, but also substance P release from the trigeminal nerve terminals of the rabbit iris sphincter muscle. However, neurotoxin has little effect on the adrenergic nerve terminals of the rabbit iris dilator muscle.

Clarithromycin inhibits NF-kappaB activation in human peripheral blood mononuclear cells and pulmonary epithelial cells.

Macrolide antibiotics modulate the production of proinflammatory cytokines in vivo and in vitro. Transcription of the genes for these proinflammatory cytokines is regulated by nuclear factor kappaB (NF-kappaB). We examined whether or not clarithromycin inhibits the activation of NF-kappaB induced by tumor necrosis factor alpha (TNF-alpha) or staphylococcal enterotoxin A (SEA) in human monocytic U-937 cells, a T-cell line (Jurkat), a pulmonary epithelial cell line (A549), and peripheral blood mononuclear cells (PBMC). Flow cytometry revealed that clarithromycin suppresses NF-kappaB activation induced by TNF-alpha in U-937 and Jurkat cells in a concentration-related manner. Western blot analysis also demonstrated that clarithromycin inhibits NF-kappaB activation induced by TNF-alpha in U-937, Jurkat, and A549 cells and PBMC and by SEA in PBMC. Western blot analysis of cytoplasmic extracts of A549 cells revealed that this inhibition is not linked to preservation of expression of the IkappaBalpha protein. The chloramphenicol acetyltransferase assay indicated that NF-kappaB-dependent reporter gene expression is suppressed in U-937 cells pretreated with clarithromycin. These findings are consistent with the idea that clarithromycin suppresses the production of proinflammatory cytokines via inhibition of NF-kappaB activation.

Circadian change of adenylate cyclase activity in rabbit ciliary processes.

PURPOSE: To characterize in vivo changes of adenylate cyclase activity in rabbit ciliary processes during the circadian cycle. METHODS: After removal of vitreous, lens, retina and choroid from freshly enucleated rabbit eyes, the anterior segment and attached sclera was chilled in cold buffer containing the non-selective phosphodiesterase (PDE) inhibitor, 3-isobutyl-1-methylxanthine (IBMX). Then ciliary processes were excised and homogenized in ice cold trichloro-acetic acid (TCA) 2.5 min after IBMX treatment. Increased cyclic AMP in response to PDE inhibition was measured in ciliary processes at six times during the circadian cycle, after preganglionic section of the cervical sympathetic trunk (decentralization, DX), and after topical instillation of hydroxyamphetamine, timolol, brimonidine, rauwolscine or a soluble derivative of forskolin. RESULTS: The increase of rabbit ciliary process cyclic AMP levels in response to PDE inhibition with IBMX was enhanced at night. Much of the enhanced nocturnal increase persisted in constant dark and was blunted by DX. Topical instillation of hydroxyamphetamine enhanced the increase during the day; whereas, timolol, a beta-adrenergic antagonist, or brimonidine, an alpha2-adrenergic agonist, blunted the IBMX induced increase. Neither instillation of rauwolscine, an alpha2-adrenergic antagonist, nor the soluble forskolin derivative enhanced the increase of cyclic AMP after IBMX. CONCLUSIONS: The technique reported here can be used to estimate ciliary process adenylate cyclase activity in vivo. There is a circadian rhythm of adenylate cyclase activity in rabbit ciliary processes that is driven in part by ocular sympathetic input and stimulation of beta-adrenergic receptors.

Increased peripheral blood interferon gamma-producing T cells in acute disseminated encephalomyelitis.

There have been few reports on immunological studies in patients with acute disseminated encephalomyelitis (ADEM). We investigated the immunological features of ADEM using flow cytometry to examine interferon gamma (IFN-gamma)-and interleukin 4 (IL-4)-producing peripheral blood CD3+T cells from four patients with ADEM, three other neurological disorders (Fisher syndrome, epilepsy and aseptic meningitis) and 10 healthy children. IFN-gamma-producing CD3+T cells were increased in ADEM during the acute stage. In a relapsing case of ADEM, the percentages of IFN-gamma-producing CD3+T cells correlated with disease activity. There were no significant changes of IL-4-producing CD3+T cells in ADEM during the acute and convalescent stages. In conclusion, peripheral blood IFN-gamma-producing T cells are related to the pathogenesis at the early phase of the acute ADEM.

Mononuclear cells and cytokines in the cerebrospinal fluid of echovirus 30 meningitis patients.

The local immune response to echovirus 30 meningitis in children was investigated in 2 ways: using flow cytometry to examine the mononuclear cell and lymphocyte subsets and enzyme-linked immunosorbent assays to examine the cerebrospinal fluid (CSF) levels of cytokines, including monocyte chemoattractant protein-1 (MCP-1), interferon gamma (IFN-gamma) and interleukin-12 (IL-12). The numbers of macrophages in the CSF were increased, in particular during the early part of the acute stage. The levels of MCP-1, which is responsible for the accumulation of macrophages, as well as those of IFN-gamma and IL-12, which play important roles in the activation of macrophages and T helper (Th) 1 cells, respectively, were increased in the CSF of patients compared with the levels found in the controls. Likewise, numbers of activated CD4 + and CD8 + T lymphocytes were increased in the CSF. Since the ratio of CD4/CD8 correlated with the age of the patients, CD8 + T lymphocytes in the CSF might play a more important role in younger children.

Abnormalities of brain perfusion in echovirus type 30 meningitis.

From May to August 1998 an epidemic of aseptic meningitis (AM) due to echovirus type 30 (E30) occurred in Yamaguchi prefecture, Japan. We performed single-photon emission-computed tomography (SPECT) to evaluate cerebral perfusion during the acute stage in 27 patients with AM due to E30. Moreover, we measured the cerebrospinal fluid (CSF) concentrations of soluble tumor necrosis factor receptor (sTNF-R) and interleukin-1 beta (IL-1beta) in all 27 patients, and the serum concentration of soluble E-selectin (sE-selectin) in 19 of the 27 patients, which is responsible for vasculitis, by means of a sandwich enzyme-linked immunosorbent assay. In 20 of the 27 (74.1%) children, SPECT imaging revealed localized cerebral hypoperfusion without abnormal focal neurological findings or symptoms. Follow-up SPECT after about 1 month revealed no abnormalities. The CSF concentrations of sTNF-R and IL-1beta, and the serum concentration of sE-selectin in the group with abnormal findings on SPECT were significantly higher than those in the group without abnormal findings on SPECT and the control subjects. Our results indicate that transient reduced regional blood flow is a frequent finding in children with AM due to E30 infection and that this abnormal finding may be induced by cerebral vasculitis.

Elevated cerebrospinal fluid level of ciliary neurotrophic factor in acute disseminated encephalomyelitis.

We investigated the concentrations of ciliary neurotrophic factor (CNTF) in cerebrospinal fluid (CSF) from children with inflammatory diseases of the central nervous system. We studied 6 children with acute disseminated encephalomyelitis (ADEM), 14 with acute encephalitis/encephalopathy, 17 with bacterial meningitis, and 24 with aseptic meningitis. We found that CNTF was undetectable in the CSF of all children with acute encephalitis/encephalopathy during the acute and convalescent stages, those with aseptic meningitis, and the 25 control subjects. In children with ADEM, CNTF was undetectable during the acute stage, but its concentration was elevated in all six at the convalescent stage. In children with bacterial meningitis, the CNTF concentration was slightly elevated in two of the 17 during the acute stage and another two at the convalescent stage. Our results suggest that CNTF is part of the regulatory system for oligodendrocyte functions, such as remyelination, in ADEM.

Effects of isopropyl unoprostone on rabbit ciliary artery.

PURPOSE: Isopropyl unoprostone (unoprostone), a prostaglandin F(2 alpha) (PG F(2 alpha))-related compound, is widely used for treatment of glaucoma in Japan and is reported to have effects on ocular circulation. To investigate the action of this drug, we have studied the effect of unoprostone on the isolated rabbit ciliary artery. METHODS: Under microscopic observation, ciliary arteries were prepared from rabbit eyes and mounted in a myograph system. The effects of unoprostone on the isolated rabbit ciliary artery were investigated in vitro using isometric tension recordings. RESULTS: Exogenously applied PG F(2 alpha) but not unoprostone evoked contraction in the rabbit ciliary artery. After precontraction with excess-[K](o) solution, unoprostone evoked dose-dependent relaxation. The relaxation was not blocked by 10 microM/L N(G)-nitro-L-arginine methylester (L-NAME), 1 microM/L 8-37 calcitonin gene-related peptide (8-37 CGRP) or 10 microM/L indomethacin. Moreover, unoprostone could induce relaxation even in preparations without endothelium. The relaxation induced by diltiazem was greater in muscle precontracted in excess-[K](o) solution than that precontracted by 10 microM/L histamine. On the other hand, unoprostone induced a similar amplitude of relaxation in muscles precontracted by either drug. CONCLUSIONS: These results indicate that unoprostone acts directly to relax rabbit ciliary artery. The relaxation was not dependent on the endothelium and was not caused by intrinsic prostoglandins CGRP, or nitric oxide. Moreover, the relaxation was different from that caused by a Ca(2)+ antagonist. The mechanism for this relaxation is not yet determined.

Pharmacological effects of pilocarpine on rabbit ciliary artery.

PURPOSE: A disturbance in ocular blood flow is an important factor in the pathogenesis of visual damage caused by glaucoma. We investigated the innervation of the ciliary artery, important to blood flow in the optic nerve head, and the effects of pilocarpine thereon. METHODS: Ciliary arteries were prepared from rabbit eyes and mounted in a myograph system. The effects of electrical nerve stimulation and pilocarpine on the isolated rabbit ciliary artery were investigated using isometric tension recording methods. RESULTS: Electrical field stimulation evoked contraction of the ciliary artery, which was inhibited by pretreatment with 10 microM bunazosin. Electrical field stimulation also evoked relaxation when the ciliary artery was pre-contracted by 10 microM histamine in the presence or absence of endothelium. This relaxation was inhibited by pretreatment with 10 microM N(G)-nitro-L-arginine methylester (L-NAME). Pilocarpine administration produced a dose-dependent muscle relaxation that was abolished by treatment with L-NAME, 1 aeM atropine, or denudation of the endothelium. CONCLUSIONS: Results indicate that the rabbit ciliary artery is innervated by at least two different types of nerves, adrenergic nerves, which evoke contraction and nerve fibers that cause an endothelium-independent release of nitric oxide (NO). Pilocarpine relaxation of this muscle was dependent on the endothelium and NO synthesis.

Presynaptic effects of botulinum toxin type A on the neuronally evoked response of albino and pigmented rabbit iris sphincter and dilator muscles.

PURPOSE: To investigate the effects of botulinum toxin type A (botulinum A toxin) on the autonomic and other nonadrenergic, noncholinergic nerve terminals. METHODS: The effects of botulinum A toxin on twitch contractions evoked by electrical field stimulation (EFS) were studied in isolated albino and pigmented rabbit iris sphincter and dilator muscles using the isometric tension recording method. RESULTS: Botulinum A toxin inhibited the fast cholinergic and slow substance P-ergic component of the contraction evoked by EFS in the rabbit iris sphincter muscle without affecting the response to carbachol and substance P. These inhibitory effects were more marked in the albino rabbit than in the pigmented rabbit. Botulinum A toxin (150 nmol/L) did not affect the twitch contraction evoked by EFS in the rabbit iris dilator muscle. CONCLUSIONS: These data indicated that botulinum A toxin may inhibit not only the acetylcholine release in the cholinergic nerve terminals, but also substance P release from the trigeminal nerve terminals of the rabbit iris sphincter muscle. However, the neurotoxin has little effect on the adrenergic nerve terminals of the rabbit iris dilator muscle. Furthermore, the botulinum A toxin binding to the pigment melanin appears to influence the response quantitatively in the two types of irides.

[Perioperative evaluation of cerebral hemodynamics by transcranial Doppler ultrasonography in patient with hemolytic uremic syndrome].

Major central nervous system (CNS) complications such as seizures and coma, occur in about 30% of children with hemolytic uremic syndrome (HUS). Serious CNS involvement is associated with an increased mortality. The purpose of this study was to evaluate intracranial hemodynamics in HUS encephalopathy. We measured mean blood flow velocity and pulsatility index (PI) of the middle cerebral artery (MCA) with transcranial Doppler (TCD) in a two year-old girl with acute encephalopathy, and compared them to those in a one year-old girl with febrile convulsion incidentally complicating HUS (a disease control). In the patient with HUS encephalopathy TCD demonstrated abnormally low PI of 0.58, while the magnetic resonance imaging (MRI) and single-photon emission-computed tomography (SPECT) reveal no abnormal findings in the acute stage. The abnormal TCD findings disappeared with her recovery. In the HUS patient with febrile convulsion alone, TCD demonstrated normal maximal flow velocity and PI. Thus TCD may be useful in evaluating intracranial hemodynamics in HUS encephalopathy in the absence of MRI and SPECT abnormalities at the early stage of illness.

Effects of beta antagonists on mechanical properties in rabbit ciliary artery.

BACKGROUND: We set out to clarify the mechanisms involved in the effectiveness of beta-adrenergic receptor antagonists on the ocular circulation. METHODS: The effects of three beta antagonists, timolol, betaxolol and carteolol, on the isolated rabbit ciliary artery were investigated in vitro using isometric tension recording methods. RESULTS: Phenylephrine dose-dependently contracted ciliary artery smooth muscle, and bunazosin (1 microM) shifted this dose-response curve to the right. Isoproterenol, on the other hand, had no effect up to the concentration of 1 mM. Betaxolol and timolol had no effect on the ciliary artery. However, carteolol dose-dependently contracted this muscle from a concentration of 1 microM. After precontraction by excess-[K]0 solutions, application of betaxolol or timolol dose-dependently provoked relaxation; the minimum concentration of betaxolol or timolol required to generate the relaxation was 100 microM and 300 microM, respectively. Carteolol did not generate relaxation at concentrations up to 1 mM. After pretreatment with L-NAME (300 microM), the amplitude of relaxation induced by 10 microM carbachol was reduced to 33.0+/-20.2%, while betaxolol- or timolol-induced relaxation was unchanged. Diltiazem (10 microM) induced relaxation which was not inhibited by pretreatment with L-NAME. CONCLUSION: Betaxolol and timolol could directly relax rabbit ciliary artery in vitro at relatively high concentrations, and relaxation was not due to NO released from the preparation. Presumably, this relaxation occurs through action similar to Ca antagonists. However, the clinical importance of this effect is not yet clear. Carteolol had no relaxant effect in vitro.

Does the Murphy eye reduce the reliability of chest auscultation in detecting endobronchial intubation?

UNLABELLED: Bilateral breath sounds are routinely auscultated after endotracheal intubation to verify that the endotracheal tube (ETT) tip is properly positioned. We conducted the present study to ascertain whether the eye of the Murphy tube has an influence on the reliability of auscultation of breath sounds in detecting endobronchial intubation. Twenty patients undergoing scheduled oral and maxillofacial surgery participated in this study. After the induction of general anesthesia, either the Magill tube or the Murphy tube was inserted through the nose into the trachea. The fiberoptic bronchoscope was inserted through the ETT, and the distance from the nares to the carina of the trachea was measured. When breath sounds from the left side of the chest changed and disappeared while the ETT was being advanced, the distance from the nares to the ETT tip was measured. Unilateral auscultatory change was not observed until the ETT tip was advanced beyond the carina and inserted 1.5+/-0.4 cm into the right mainstem bronchus when the Magill tube was used and 2.0+/-0.4 cm when the Murphy tube was used (P < 0.01). Breath sounds disappeared when the ETT tip was further advanced up to 3.2+/-0.3 cm from the carina. We demonstrated that the eye of the Murphy tube reduces the reliability of chest auscultation in detecting endobronchial intubation. IMPLICATIONS: The Murphy eye was designed to allow ventilation of the lung when the bevel of the endotracheal tube is occluded. We demonstrated that the eye of the Murphy tube reduces the reliability of chest auscultation in detecting endobronchial intubation.