Improvement in gait velocity variability after cerebrospinal fluid elimination and its relationship to clinical symptoms in patients with idiopathic normal pressure hydrocephalus.

AIM: This study aimed to investigate the improvement in gait velocity variability after cerebrospinal fluid (CSF) elimination, and the association between gait velocity variability and gait and cognitive impairment in patients with idiopathic normal pressure hydrocephalus. METHODS: The gait velocity of 44 patients with idiopathic normal pressure hydrocephalus was measured using the Timed Up and Go Test (TUG) for a total of 10 times over 3 days each before and after CSF elimination. The coefficient of variation (CV) in the time required for the sequence of actions in TUG (TUG-CV) was calculated using 10 TUG data, and used for measuring intraindividual gait velocity variability. Gait quality was evaluated with the Gait Status Scale Revised (GSSR), and cognitive function was evaluated with the Mini-Mental State Examination and the Frontal Assessment Battery. RESULTS: The TUG, TUG-CV, GSSR and Frontal Assessment Battery results improved significantly after CSF elimination. The analyses using pre-CSF elimination results showed that the TUG-CV significantly and positively correlated with the TUG and GSSR results, and negatively with Mini-Mental State Examination results, but not with age and the Frontal Assessment Battery results. The stepwise multiple regression analysis indicates that the TUG, GSSR and Mini-Mental State Examination results were significant predictors of the TUG-CV. The analysis using data of change after CSF elimination showed that ΔTUG and ΔGSSR were significant predictors of ΔTUG-CV. CONCLUSIONS: Gait velocity variability improved after CSF elimination, and gait velocity variability was associated with gait disturbances and cognitive impairment in patients with idiopathic normal pressure hydrocephalus. Geriatr Gerontol Int 2024; 24: 693-699.

Effects of neostigmine on bronchoconstriction with continuous electrical stimulation in rats.

PURPOSE: When neostigmine is used to reverse muscle relaxants in patients with asthma without signs of airway inflammation, asthma attack is occasionally encountered. It is likely that abnormally increased electrical impulses traveling from the brain through cholinergic nerves to airway smooth muscles may be one of the pathogeneses of asthma attack. We applied continuous electrical field stimulation (c-EFS) or continuous electrical stimulation (c-ES) of low frequency to the vagal nerve of the rat in vitro and in vivo to determine the role of cholinergic nerve activation in inducing airway constriction. METHODS: Fifty-seven male Wistar rats were used. In an in vitro study we examined whether tetrodotoxin (TTX), an Na(+)-channel blocker, 4-DAMP, a muscarinic M(3) receptor antagonist, or neostigmine could affect c-EFS-induced contraction of the tracheal ring. In an in vivo study, we examined whether c-ES of the vagal nerve could increase maximum airway pressure (P (max)) and whether neostigmine could potentiate c-ES-induced P (max). RESULTS: TTX and 4-DAMP completely inhibited c-EFS-induced contraction whereas neostigmine potentiated c-EFS-induced contraction dose-dependently. P (max) was not increased by neostigmine. P (max) was not increased by 2-Hz c-ES, but was increased by the addition of neostigmine. P (max) was increased by 5-Hz c-ES, and further increased by the addition of neostigmine. CONCLUSION: The contractile response of the tracheal ring to c-EFS is potentiated by neostigmine. P (max) is increased by c-ES of the vagal nerve, and is potentiated by neostigmine. These data suggest that increased activity of the cholinergic nerve could be involved in asthma attack.

Association of right precuneus compression with apathy in idiopathic normal pressure hydrocephalus: a pilot study.

Apathy is frequently observed in idiopathic normal pressure hydrocephalus (iNPH) and worsens cognitive impairment and gait disturbance. In this study, we evaluated the regions associated with apathy in iNPH using statistical imaging analysis on the whole brain, both in terms of cerebral blood flow and gray matter volume. Twenty-seven patients with iNPH were assigned to two groups based on their scores on the neuropsychiatric inventory items related to apathy; 18 patients were assigned to the group with apathy (iNPH + APA) and 9 to the group without apathy (iNPH - APA). The magnetic resonance images and cerebral blood flow single-photon emission computed tomography data of the two groups were compared using statistical parametric mapping 12. The regional gray matter volume of the right precuneus was significantly larger in the iNPH + APA group than in the iNPH - APA group, but the regional cerebral blood flow in any region of the brain was not significantly different between the two groups. These results suggested that the larger gray matter volume, which is thought to reflect gray matter compression, in the precuneus might be involved in apathy in iNPH.

Differing growth responses of major phylogenetic groups of marine bacteria to natural phytoplankton blooms in the western North Pacific Ocean.

Growth and productivity of phytoplankton substantially change organic matter characteristics, which affect bacterial abundance, productivity, and community structure in aquatic ecosystems. We analyzed bacterial community structures and measured activities inside and outside phytoplankton blooms in the western North Pacific Ocean by using bromodeoxyuridine immunocytochemistry and fluorescence in situ hybridization (BIC-FISH). Roseobacter/Rhodobacter, SAR11, Betaproteobacteria, Alteromonas, SAR86, and Bacteroidetes responded differently to changes in organic matter supply. Roseobacter/Rhodobacter bacteria remained widespread, active, and proliferating despite large fluctuations in organic matter and chlorophyll a (Chl-a) concentrations. The relative contribution of Bacteroidetes to total bacterial production was consistently high. Furthermore, we documented the unexpectedly large contribution of Alteromonas to total bacterial production in the bloom. Bacterial abundance, productivity, and growth potential (the proportion of growing cells in a population) were significantly correlated with Chl-a and particulate organic carbon concentrations. Canonical correspondence analysis showed that organic matter supply was critical for determining bacterial community structures. The growth potential of each bacterial group as a function of Chl-a concentration showed a bell-shaped distribution, indicating an optimal organic matter concentration to promote growth. The growth of Alteromonas and Betaproteobacteria was especially strongly correlated with organic matter supply. These data elucidate the distinctive ecological role of major bacterial taxa in organic matter cycling during open ocean phytoplankton blooms.

The decline and fate of an iron-induced subarctic phytoplankton bloom.

Iron supply has a key role in stimulating phytoplankton blooms in high-nitrate low-chlorophyll oceanic waters. However, the fate of the carbon fixed by these blooms, and how efficiently it is exported into the ocean's interior, remains largely unknown. Here we report on the decline and fate of an iron-stimulated diatom bloom in the Gulf of Alaska. The bloom terminated on day 18, following the depletion of iron and then silicic acid, after which mixed-layer particulate organic carbon (POC) concentrations declined over six days. Increased particulate silica export via sinking diatoms was recorded in sediment traps at depths between 50 and 125 m from day 21, yet increased POC export was not evident until day 24. Only a small proportion of the mixed-layer POC was intercepted by the traps, with more than half of the mixed-layer POC deficit attributable to bacterial remineralization and mesozooplankton grazing. The depletion of silicic acid and the inefficient transfer of iron-increased POC below the permanent thermocline have major implications both for the biogeochemical interpretation of times of greater iron supply in the geological past, and also for proposed geo-engineering schemes to increase oceanic carbon sequestration.

Large-scale metabarcoding analysis of epipelagic and mesopelagic copepods in the Pacific.

A clear insight into the large-scale community structure of planktonic copepods is critical to understanding the mechanisms controlling diversity and biogeography of marine taxa in terms of their high abundance, ubiquity, and sensitivity to environmental changes. Here, we applied a 28S metabarcoding approach to large-scale communities of epipelagic and mesopelagic copepods at 70 stations across the Pacific Ocean and three stations in the Arctic Ocean. Major patterns of community structure and diversity, influenced by water mass structures, agreed with results from previous morphology-based studies. However, a large-scale metabarcoding approach could detect community changes even under stable environmental conditions, including changes in the north/south subtropical gyres and east/west areas within each subtropical gyre. There were strong effects of the epipelagic environment on mesopelagic communities, and community subdivisions were observed in the environmentally stable mesopelagic layer. In each sampling station, higher operational taxonomic unit (OTU) numbers and lower phylogenetic diversity were observed in the mesopelagic layer than in the epipelagic layer, indicating a recent rapid increase in species numbers in the mesopelagic layer. The phylogenetic analysis utilizing representative sequences of OTUs revealed trends of recent emergence of cold-water OTUs, which are mainly distributed at high latitudes with low water temperatures. Conversely, the high diversity of copepods at low latitudes was suggested to have been formed through long evolution under high water temperature conditions. The metabarcoding results suggest that evolutionary processes have strong impacts on current patterns of copepod diversity, and support the "out of the tropics" theory explaining latitudinal diversity gradients of copepods. Diversity patterns in both epipelagic and mesopelagic copepods was highly correlated to sea surface temperature; thus, predicted global warming may have a significant impact on copepod diversity in both layers.

Effects of amitriptyline, a tricyclic antidepressant, on smooth muscle reactivity in isolated rat trachea.

PURPOSE: This study was designed to investigate the action of amitriptyline, a tricyclic antidepressant, on airway smooth muscle reactivity and its underlying mechanisms. METHODS: In isolated rat trachea, isometric force was recorded to examine the effects of amitriptyline on the contractile response to acetylcholine (ACh), electrical field stimulation (EFS), calyculin A (a myosin light chain phosphatase inhibitor), and sphingosylphosphorylcholine (SPC; a Rhokinase activator). In addition, inositol monophosphate (IP1) accumulation was measured to examine its effects on inositol 1, 4, 5-trisphosphate (IP(3)) production during stimulation with ACh. RESULTS: Amitriptyline inhibited the contractile responses to ACh, EFS, calyculin A, and SPC, with the concentrations of amitriptyline (mean +/- SD) required to exert 50% inhibition (IC(50)) being 4.3 +/- 1.3 microM, 3.2 +/- 1.6 microM, 256.4 +/- 106.4 microM, and 98.2 +/- 21.8 microM, respectively. In addition, amitriptyline (10 microM) eliminated the ACh (10 microM)-induced IP(1) accumulation. CONCLUSION: The results suggest that amitriptyline does not influence tracheal smooth muscle reactivity at clinical concentrations (<1 microM), but attenuates the reactivity at supraclinical concentrations (> or =1 microM). The attenuated response to ACh brought about by amitriptyline is presumably due, at least in part, to the inhibition of phosphatidylinositol (PI) metabolism. The ability of amitriptyline to inhibit the calyculin Ainduced contraction suggests that amitriptyline also inhibits the Ca(2+)-calmodulin-myosin light chain pathway independently of the inhibition of PI metabolism. Finally, the difference between the IC(50) values for SPC-induced contraction and those for calyculin A-induced contraction suggests that amitriptyline may also inhibit the Rho-kinase pathway.

Recent comparability of oceanographic nutrients data: results of a 2003 intercomparison exercise using reference materials.

An intercomparison exercise was conducted using the recently developed Reference Material for Nutrients in Seawater (RMNS). Discrepancies of reported values among laboratories were greater than the homogeneity of RMNS samples and the reported analytical precision of nutrients. The variability of in-house standards of the participating laboratories might be the most likely source of interlaboratory discrepancies. Therefore, the use of common reference materials, i.e. certified RM, is essential to establish and improve the comparability of nutrient data of the world's oceans.

[Anesthetic management of a neonate with laryngotracheoesophageal cleft and tracheoesophageal fistula].

Laryngotracheoesophageal cleft (LTEC) is an extremely rare congenital anomaly characterized by an absence of all or a part of the tracheoesophageal septum producing an abnormal communication between the trachea and esophagus, and is often difficult to be diagnosed. A 2-day-old male baby was tentatively diagnosed as tracheoesophageal fistula type Gross C, and underwent gastrostomy. The trachea was intubated before anesthetic induction. When a balloon of gastrostomy catheter was inflated, the lung could not be ventilated. After extubation of endotracheal tube and removal of gastrostomy catheter, the lung could be ventilated with mask. When endotracheal tube was intubated again, the lung could not be ventilated at all. Thus the surgery was performed under mask ventilation. Endoscopic examination performed 2 weeks later gave diagnosis of LTEC type 3. It is likely that the endotracheal tube might have been advanced into the end of the esophagus due to absence of the tracheoesophageal septum. In spite of a rare disease, LTEC should be considered as an extreme case of transesophageal fistula with a high risk of difficult airway.

[Anesthetic management of a pregnant patient with congenitally corrected transposition of the great arteries for emergency cesarean delivery].

A 30-year-old woman at 35 weeks' gestation with congenitally corrected transposition of the great arteries (CCTGA), whose associated anomalies were VSD, ASD and pulmonary stenosis, underwent emergency cesarean delivery under general anesthesia. She had hypoxemia due to right-to-left shunt. We discussed with obstetricians and pediatric cardiologists about her at 25 weeks' gestation. Discussed points included: 1) delivery after 30 weeks' gestation, 2) her cardiac function and anomalies, 3) cesarean delivery under general anesthesia in case of emergency, 4) management of a sleeping baby after cesarean delivery by pediatricians. Cyanosis and heart failure were noted worsening during pregnancy. General anesthesia was induced by midazolam and fentanyl following cannulation of radial artery and right internal jugular vein for blood pressure and CVP monitoring. Anesthesia was maintained with sevoflurane and fentnyl. Dopamine and dobutamine were used to support blood pressure and cardiac function. After delivery, because of decreased CVP, lactated Ringer's solution was administrated. After operation, the patient was hemodynamically stable and trachea was extubated. Anesthetic management of the patient depends on the anatomical defects of CCTGA and associated conditions. Anesthesiologist should obtain information about a pregnant woman with CCTGA from cardiologists and obstetricians in early gestation to manage patient successfully.

Dissimilarity of species and forms of planktonic Neocalanus copepods using mitochondrial COI, 12S, nuclear ITS, and 28S gene sequences.

BACKGROUND: A total of six Neocalanus species inhabit the oceans of the world. Of these, three species plus form variants (N. cristatus, N. plumchrus, N. flemingeri large form, and N. flemingeri small form), which constitute a monophyletic group among Neocalanus copepods, occur in the Northwestern Pacific off Japan. In the present study, we have tried to discriminate the three species plus form variants of Neocalanus copepods based on sequences of four DNA marker regions. METHODOLOGY/PRINCIPAL FINDINGS: Discrimination was performed based on the DNA sequence information from four genetic markers, including the mitochondrial COI, 12S, nuclear ITS, and 28S gene regions. Sequence dissimilarity was compared using both distance- and character-based approaches. As a result, all three species were confirmed to be distinct based on the four genetic marker regions. On the contrary, distinction of the form variants was only confirmed based on DNA sequence of the mitochondrial COI gene region. CONCLUSIONS/SIGNIFICANCE: Although discrimination was not successful for the form variants based on the mitochondrial 12S, nuclear ITS, and 28S genes, diagnostic nucleotide sequence characters were observed in their mitochondrial COI gene sequences. Therefore, these form variants are considered to be an important unit of evolution below the species level, and constitute a part of the Neocalanus biodiversity.

Effects of ATP-sensitive potassium channel openers on the contractile and phosphatidylinositol responses of the rat trachea.

PURPOSE: Although ATP-sensitive potassium channel openers suppress airway smooth muscle contraction, their potencies are different and the mechanisms involved are not fully understood. We examined the effects of cromakalim and Y-26763, a novel ATP-sensitive potassium channel opener, on the contractile and phosphatidylinositol responses of the rat trachea. METHODS: Thirty-six male Wistar rats, weighing 250-350 g, were used. In the experiment on contractile response, active contraction was induced with 0.55 microM carbachol in the presence or absence of cromakalim or Y-26763. In the experiment on phosphatidylinositol response, the tracheal slices were incubated with [(3)H] myo-inositol, 0.55 microM carbachol, and cromakalim or Y-26763, and the formation of [(3)H]inositol monophosphate (IP(1)), a degradation product of phosphatidylinositol response, was measured with a liquid scintillation counter. Statistical significance ( P < 0.05) was determined by analysis of variance (ANOVA). RESULTS: Carbachol-induced tension was attenuated by both cromakalim and Y-26763, the latter displaying significantly greater potency. Carbachol-induced IP(1) accumulation was influenced neither by cromakalim nor by Y-26763. CONCLUSION: Both cromakalim and Y-26763 have effects on airway smooth muscle relaxation. Carbachol-induced IP(1) accumulation was influenced neither by cromakalim nor by Y-26763, suggesting that phosphatidylinositol response may not be a common pathway for the effect of ATP-sensitive potassium channel openers.

The vasodilatory effects of hydralazine, nicardipine, nitroglycerin, and fenoldopam in the human umbilical artery.

We studied the effects of hydralazine, nicardipine, nitroglycerin, and fenoldopam (a dopamine D1-agonist) on isolated human umbilical arteries (HUA) from patients classified as normotensive and with pregnancy-induced hypertension (PIH). Umbilical artery rings were contracted with the thromboxane A(2) analog (U46619; 10(-8) M) and then exposed to cumulative concentrations of fenoldopam, hydralazine, nicardipine, and nitroglycerin. Second, rings were preexposed to prazosin (10(-5) M), phenoxybenzamine (10(-5) M), or none, and the constriction responses to increasing doses of fenoldopam or dopamine were recorded. Nitroglycerin, hydralazine, and nicardipine produced concentration-dependent relaxation of U46619-preconstricted HUA segments from normotensive and PIH patients. Fenoldopam and dopamine induced umbilical artery constriction in both normal and PIH rings at concentrations > or = 10(-5) M and > or = 10(-3) M, respectively. Phenoxybenzamine, but not prazosin, pretreatment irreversibly abolished fenoldopam-induced contraction. In this in vitro study, nitroglycerin was the most potent vasodilator of the HUA constricted with U46619, followed by nicardipine and hydralazine. However, fenoldopam constricted HUA rings only at supratherapeutic concentrations. No significant differences of vascular responses to fenoldopam (P = 0.3534), nitroglycerin (P = 0.7416), nicardipine (P = 0.0615), and hydralazine (P = 0.5514) between rings from normotensive or hypertensive pregnant patients were shown.

A mesoscale iron enrichment in the western subarctic Pacific induces a large centric diatom bloom.

We have performed an in situ test of the iron limitation hypothesis in the subarctic North Pacific Ocean. A single enrichment of dissolved iron caused a large increase in phytoplankton standing stock and decreases in macronutrients and dissolved carbon dioxide. The dominant phytoplankton species shifted after the iron addition from pennate diatoms to a centric diatom, Chaetoceros debilis, that showed a very high growth rate, 2.6 doublings per day. We conclude that the bioavailability of iron regulates the magnitude of the phytoplankton biomass and the key phytoplankton species that determine the biogeochemical sensitivity to iron supply of high-nitrate, low-chlorophyll waters.