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1.
J Mech Behav Biomed Mater ; 153: 106469, 2024 May.
Article in English | MEDLINE | ID: mdl-38402693

ABSTRACT

Intracranial aneurysm is a critical pathology related to the arterial wall deterioration. This work is an essential aspect of a large scale project aimed at providing clinicians with a non-invasive patient-specific decision support tool regarding the rupture risk assessment. A machine learning algorithm links the aneurysm shape observed and a database of UIA clinical images associated with in vivo wall mechanical properties and rupture characterisation. The database constitution is derived from a device prototype coupled with medical imaging. It provides the mechanical characterisation of the aneurysm from the wall deformation obtained by inverse analysis based on the variation of luminal volume. Before performing in vivo tests of the device on small animals, a numerical model was built to quantify the device's impact on the aneurysm wall under natural blood flow conditions. As the clinician will never be able to precisely situate the device, several locations were considered. In preparation for the inverse analysis procedure, artery material laws of increasing complexity were studied (linear elastic, hyper elastic Fung-like). Considering all the device locations and material laws, the device induced relative displacements to the Systole peak (worst case scenario with the highest mechanical stimulus linked to the blood flow) ranging from 375 µm to 1.28 mm. The variation of luminal volume associated with the displacements was between 0.95 % and 4.3 % compared to the initial Systole volume of the aneurysm. Significant increase of the relative displacements and volume variations were found with the study of different cardiac cycle moments between the blood flow alone and the device application. For forthcoming animal model studies, Spectral Photon CT Counting, with a minimum spatial resolution of 250 µm, was selected as the clinical imaging technique. Based on this preliminary study, the displacements and associated volume variations (baseline for inverse analyse), should be observable and exploitable.


Subject(s)
Aneurysm, Ruptured , Intracranial Aneurysm , Humans , Intracranial Aneurysm/diagnostic imaging , Hemodynamics , Risk Assessment , Rupture , Aneurysm, Ruptured/pathology
2.
Histochem Cell Biol ; 156(4): 301-313, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34185148

ABSTRACT

The adenohypophysis is composed of the anterior and intermediate lobes (AL and IL), and secretes important hormones for growth, sexual development, metabolism, and reproduction. In the marginal cell layer (MCL) facing Rathke's cleft between the IL and AL, cluster of differentiation (CD) 9-, CD81-, S100ß-, and SOX2-quadruple positive (CD9/CD81/S100ß/SOX2-positive) cells in the adult IL are settled as tissue-resident stem/progenitor cells supplying hormone-producing cells to the AL. However, it is unclear how CD9/CD81/S100ß/SOX2-positive cells in the IL-side MCL migrate into the AL across Rathke's cleft. In the present study, we performed chimeric pituitary tissue culture using S100ß/GFP-transgenic rats and Wistar rats, and traced the footprint of S100ß/GFP-expressing cells. We detected IL-side S100ß/GFP-expressing cells in the AL tissue, demonstrating that these cells migrate from the IL to the AL. However, the cells failed to migrate in the opposite direction. Consistently, scanning electron microscopic analysis revealed well-developed cytoplasmic protrusions in the IL-side MCL, but not in the AL-side MCL, suggesting that IL-side CD9/CD81/S100ß/SOX2-positive cells had higher migratory activity. We also searched for a specific marker for IL-side CD9/CD81/S100ß/SOX2-positive cells and identified tetraspanin 1 (TSPAN1) from microarray analysis. Downregulation of Tspan1 by specific siRNA impaired cell migration and significantly reduced expression of snail family transcriptional repressor 2 (Slug), a marker of epithelial-mesenchymal transition (EMT). Therefore, CD9/CD81/S100ß/SOX2-positive cells in the IL-side MCL can be stem/progenitor cells that provide stem/progenitor cells to the AL-side MCL via SLUG-mediated EMT and cell migration.


Subject(s)
Endocrine Cells/metabolism , Pituitary Gland, Anterior/metabolism , Tetraspanin 29/metabolism , Animals , Cell Movement , Male , Rats , Rats, Wistar
3.
Appl Microbiol Biotechnol ; 98(4): 1853-61, 2014 Feb.
Article in English | MEDLINE | ID: mdl-23912114

ABSTRACT

Oil souring has important implications with respect to energy resources. Understanding the physiology of the microorganisms that play a role and the biological mechanisms are both important for the maintenance of infrastructure and mitigation of corrosion processes. The objective of this study was to identify crude-oil components and microorganisms in oil-field water that contribute to crude-oil souring. To identify the crude-oil components and microorganisms that are responsible for anaerobic souring in oil reservoirs, biological conversion of crude-oil components under anaerobic conditions was investigated. Microorganisms in oil field water in Akita, Japan degraded alkanes and aromatics to volatile fatty acids (VFAs) under anaerobic conditions, and fermenting bacteria such as Fusibacter sp. were involved in VFA production. Aromatics such as toluene and ethylbenzene were degraded by sulfate-reducing bacteria (Desulfotignum sp.) via the fumarate-addition pathway and not only degradation of VFA but also degradation of aromatics by sulfate-reducing bacteria was the cause of souring. Naphthenic acid and 2,4-xylenol were not converted.


Subject(s)
Petroleum/microbiology , Anaerobiosis , Bacteria/metabolism , Biodegradation, Environmental , Fatty Acids, Volatile/metabolism , Oil and Gas Fields
4.
Pharmacogenomics J ; 13(1): 60-9, 2013 Feb.
Article in English | MEDLINE | ID: mdl-21912425

ABSTRACT

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are severe, cutaneous adverse drug reactions that are rare but life threatening. Genetic biomarkers for allopurinol-related SJS/TEN in Japanese were examined in a genome-wide association study in which Japanese patients (n=14) were compared with ethnically matched healthy controls (n=991). Associations between 890 321 single nucleotide polymorphisms and allopurinol-related SJS/TEN were analyzed by the Fisher's exact test (dominant genotype mode). A total of 21 polymorphisms on chromosome 6 were significantly associated with allopurinol-related SJS/TEN. The strongest association was found at rs2734583 in BAT1, rs3094011 in HCP5 and GA005234 in MICC (P=2.44 × 10(-8); odds ratio=66.8; 95% confidence interval, 19.8-225.0). rs9263726 in PSORS1C1, also significantly associated with allopurinol-related SJS/TEN, is in absolute linkage disequilibrium with human leukocyte antigen-B*5801, which is in strong association with allopurinol-induced SJS/TEN. The ease of typing rs9263726 makes it a useful biomarker for allopurinol-related SJS/TEN in Japanese.


Subject(s)
Allopurinol/adverse effects , Stevens-Johnson Syndrome/genetics , Aged , Aged, 80 and over , Allopurinol/therapeutic use , Asian People/genetics , Biomarkers/metabolism , Chromosomes, Human, Pair 6/drug effects , Chromosomes, Human, Pair 6/genetics , Drug-Related Side Effects and Adverse Reactions , Female , Genome-Wide Association Study/methods , HLA Antigens/genetics , HLA Antigens/metabolism , Humans , Linkage Disequilibrium , Male , Middle Aged , Polymorphism, Single Nucleotide , Skin/drug effects , Skin/metabolism , Skin/pathology , Stevens-Johnson Syndrome/chemically induced , Stevens-Johnson Syndrome/etiology , Stevens-Johnson Syndrome/metabolism
5.
Anaesth Intensive Care ; 39(6): 1111-9, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22165367

ABSTRACT

High frequency oscillatory ventilation has been shown to improve oxygenation of patients with severe respiratory failure. This prospective study examined the potential benefits and risks of the latest generation high frequency oscillatory ventilator (R100, Metran, Saitama, Japan), initiated when the target oxygenation could not be achieved by conventional mechanical ventilation in adult patients with severe hypoxaemic respiratory failure. Thirty-six patients with severe respiratory failure treated with the R100 high frequency oscillatory ventilator were considered. Pneumonia and exacerbation of interstitial pneumonia were the main causes of respiratory failure. The median time on conventional mechanical ventilation or airway pressure release ventilation prior to high frequency oscillatory ventilation was 9.3 hours (interquartile range 4.8 to 25). PaO2/FiO2 at 24 hours after initiation of high frequency oscillatory ventilation was significantly better than the PaO2/FiO2 at baseline (151.2 +/- 61.2 vs. 99.5 +/- 50.0, P = 0.0001). Refractory hypoxaemia within 24 hours was associated with a high risk of mortality (P = 0.0092) and 23 patients (64%), including 11 patients with exacerbation of interstitial pneumonia, died by 30 days. Of the 36 patients included in the study (including one who had developed pneumothorax before high frequency oscillatory ventilation), 12 (33%) developed barotrauma during the course of their intensive care unit stay. In the multivariate analysis, only exacerbation of interstitial pneumonia was a significant risk factor for barotrauma. In summary, the latest generation high frequency oscillatory ventilator could improve oxygenation in adult patients with life-threatening hypoxaemic respiratory failure but the incidence of barotrauma was substantial.


Subject(s)
High-Frequency Ventilation/instrumentation , Hypoxia/therapy , Respiratory Insufficiency/therapy , APACHE , Aged , Barotrauma/epidemiology , Barotrauma/etiology , Blood Gas Analysis , Blood Pressure/physiology , Central Venous Pressure/physiology , Data Interpretation, Statistical , Female , Heart Rate/physiology , High-Frequency Ventilation/adverse effects , Hospital Mortality , Humans , Hypoxia/mortality , Kaplan-Meier Estimate , Male , Middle Aged , Prospective Studies , Respiration, Artificial , Respiratory Insufficiency/mortality , Risk Assessment , Survival Analysis , Treatment Outcome
6.
Br J Cancer ; 100(6): 870-3, 2009 Mar 24.
Article in English | MEDLINE | ID: mdl-19293806

ABSTRACT

Among 242 Japanese pancreatic cancer patients, three patients (1.2%) encountered life-threatening toxicities, including myelosuppression, after gemcitabine-based chemotherapies. Two of them carried homozygous CDA*3 (CDA208G>A [Ala70Thr]), and showed extremely low plasma cytidine deaminase activity and gemcitabine clearance. Our results suggest that homozygous *3 is a major factor causing gemcitabine-mediated severe adverse reactions among the Japanese population.


Subject(s)
Antimetabolites, Antineoplastic/adverse effects , Asian People/genetics , Cytidine Deaminase/genetics , Deoxycytidine/analogs & derivatives , Pancreatic Neoplasms/drug therapy , Polymorphism, Single Nucleotide , Aged , Area Under Curve , Deoxycytidine/adverse effects , Deoxycytidine/pharmacokinetics , Female , Humans , Male , Middle Aged , Gemcitabine
7.
Neurogastroenterol Motil ; 20(10): 1147-56, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18761632

ABSTRACT

Gastroenteritis is one of the risk factors for developing irritable bowel syndrome (IBS). However, the precise mechanism of postinfectious IBS is still unknown. We tested the hypothesis that a combination of previous inflammation and repetitive colorectal distention (CRD) makes the colon hypersensitive and that treatment with a corticotropin-releasing hormone receptor 1 (CRH-R1) antagonist blocks this colonic hypersensitivity. Rats were pretreated with vehicle or 2,4,6-trinitrobenzene sulphonic acid (TNBS) 6 weeks before CRD. For the CRD experiment, the colorectum was distended once a day for six consecutive days. The CRH-R1 antagonist (CP-154,526, 20 mg kg(-1)) or vehicle was injected subcutaneously 30 min before CRD. Visceral perception was quantified as visceromotor response (VMR) using an electromyograph. For histological examination, the rats were killed on the last day of CRD experiment, and haematoxylin and eosin-staining of colon segments was performed. Although from the first to the third day of CRD, VMRs increased in both the vehicle-treated rats and TNBS-treated rats, they were significantly higher in TNBS-treated rats than those in vehicle-treated controls. On the fifth day of CRD, however, VMRs in the vehicle-treated rats were significantly greater than those in TNBS-treated rats. Pretreatment of rats with CP-154,526 significantly attenuated the increase in VMR induced by repetitive CRD with previous inflammation. Finally, we found that repetitive CRD and repetitive CRD after colitis induced visceral inflammation. These results indicate that a combination of previous inflammation and repetitive CRD induces visceral hypersensitivity and that a CRH-R1 antagonist attenuates this response in rats.


Subject(s)
Colon/drug effects , Colon/immunology , Dilatation, Pathologic/physiopathology , Inflammation/physiopathology , Pyrimidines/pharmacology , Pyrroles/pharmacology , Receptors, Corticotropin-Releasing Hormone/antagonists & inhibitors , Animals , Colitis/chemically induced , Colitis/physiopathology , Colon/pathology , Electromyography , Humans , Irritable Bowel Syndrome/physiopathology , Male , Rats , Rats, Wistar , Trinitrobenzenesulfonic Acid/pharmacology
8.
J Clin Pharm Ther ; 32(2): 177-85, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17381668

ABSTRACT

BACKGROUND AND OBJECTIVE: As pharmacokinetic drug interactions frequently cause adverse events, it is important that the relevant information is given in package inserts (PIs). We previously analysed the provision of PIs for HMG-CoA reductase inhibitors and Ca antagonists, for which metabolism by cytochrome P450 could be a major interaction mechanism. In this article, we focus on interactions involving glucuronoconjugates because many drugs and their metabolites undergo this conjugation. METHODS: We reviewed clinical drug interactions related to glucuronoconjugates, focusing on reports of adverse events. Then, we picked out three important drugs (zidovudine, valproic acid and lamotrigine), and examined how the literature information is reflected in the relevant PIs in Japan, UK and USA. RESULTS AND DISCUSSION: Pharmacokinetic interactions related to glucuronoconjugates were found with 33 drug combinations. Of these, five combinations induced clear adverse events: (i) severe anaemia due to zidovudine and caused by interaction with valproic acid, (ii) recurrence/increased frequency of seizure or increased manic states from a reduction in therapeutic effects of valproic acid caused by panipenem, (iii) meropenem or (iv) ritonavir and (v) of lamotrigine caused by oral contraceptives. Analysis of PIs showed a lack of description of the interaction of zidovudine with valproic acid in the Japanese PI. The UK PI mentioned this interaction without quantitative data, whereas full information was given in the US PI. A lack of description was also present on the interaction between valproic acid with ritonavir, reported in 2006, in the PIs of all three countries. For the interactions involving valproic acid and panipenem or meropenem, even though marked reduction of blood valproic acid level has been reported, no quantitative data were provided in any of the PIs. CONCLUSION: Five combinations were identified to cause severe adverse events because of interactions related to glucuronoconjugates. This information, including quantitative data, is not always properly provided in the relevant PIs in Japan, UK or USA. PIs should be improved to better inform healthcare providers and thereby help them and their patients.


Subject(s)
Drug Interactions , Drug Labeling/standards , Glucuronates/adverse effects , Triazines/adverse effects , Valproic Acid/adverse effects , Zidovudine/adverse effects , Area Under Curve , Communication , Disclosure/standards , Drug Combinations , Drug-Related Side Effects and Adverse Reactions , Glucuronates/metabolism , Glucuronates/pharmacokinetics , Half-Life , Humans , Japan , Lamotrigine , Triazines/metabolism , Triazines/pharmacokinetics , United Kingdom , United States , Valproic Acid/metabolism , Valproic Acid/pharmacokinetics , Zidovudine/metabolism , Zidovudine/pharmacokinetics
9.
Regul Toxicol Pharmacol ; 47(3): 296-307, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17157422

ABSTRACT

We comprehensively re-analyzed the toxicity data for 18 industrial chemicals from repeated oral exposures in newborn and young rats, which were previously published. Two new toxicity endpoints specific to this comparative analysis were identified, the first, the presumed no observed adverse effect level (pNOAEL) was estimated based on results of both main and dose-finding studies, and the second, the presumed unequivocally toxic level (pUETL) was defined as a clear toxic dose giving similar severity in both newborn and young rats. Based on the analyses of both pNOAEL and pUETL ratios between the different ages, newborn rats demonstrated greater susceptibility (at most 8-fold) to nearly two thirds of these 18 chemicals (mostly phenolic substances), and less or nearly equal sensitivity to the other chemicals. Exceptionally one chemical only showed toxicity in newborn rats. In addition, Benchmark Dose Lower Bound (BMDL) estimates were calculated as an alternative endpoint. Most BMDLs were comparable to their corresponding pNOAELs and the overall correlation coefficient was 0.904. We discussed how our results can be incorporated into chemical risk assessment approaches to protect pediatric health from direct oral exposure to chemicals.


Subject(s)
Environmental Exposure/adverse effects , Environmental Pollutants/toxicity , Age Factors , Animals , Animals, Newborn , Benzene Derivatives/toxicity , Humans , No-Observed-Adverse-Effect Level , Phenols/toxicity , Rats , Rats, Sprague-Dawley , Risk Assessment , Trityl Compounds/toxicity
11.
J Clin Pharm Ther ; 30(1): 21-37, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15659001

ABSTRACT

BACKGROUND AND OBJECTIVES: Statins (HMG-CoA reductase inhibitors) are one of the most widely prescribed classes of drugs throughout the world, because of their excellent cholesterol-lowering effect and overall safety profile except for rare but fatal rhabdomyolysis arising either directly or indirectly by pharmacokinetic interactions with certain other drugs. As package inserts in pharmaceuticals are the primary source of information for health care providers, we carried out a literature search to examine how crucial information was provided in package inserts of five statins approved in Japan (simvastatin, atorvastatin, fluvastatin, pravastatin and pitavastatin). METHODS: A MEDLINE search from 1996 to June 2004 was carried out to identify studies on clinical pharmacokinetic drug interactions for the five statins. We mainly collected information on area under plasma concentration (AUC) following co-administration of statins with other drugs. The current package inserts used in Japan were obtained from the website of the Pharmaceutical and Medical Device Agency whereas USA package inserts were obtained from the Food and Drug Administration website. RESULTS: The majority of package inserts listed the drugs that interacted with statins with most describing the risk of rhabdomyolysis because of the possibility of increases in blood concentration. However, quantitative information such as change in AUC was provided in only a few cases. Instructions for dosage adjustment are seldom provided in the Japanese package inserts. USA package inserts list almost identical drug interactions as the Japanese package inserts, although they contain more quantitative data, especially for typical cytochrome P450 (CYP) inhibitors. CONCLUSION: All pharmacokinetic drug interactions including relevant quantitative data for potential effectors and details on mechanisms of interaction need to be given in package inserts as soon as the information becomes available, to ensure safe and proper use of the drugs concerned. Including such information in the package insert will be an extremely valuable aid for health care providers.


Subject(s)
Databases, Bibliographic , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacokinetics , Product Labeling/standards , Area Under Curve , Atorvastatin , Biomedical Research/methods , Drug Interactions , Fatty Acids, Monounsaturated/adverse effects , Fatty Acids, Monounsaturated/metabolism , Fatty Acids, Monounsaturated/pharmacokinetics , Fluvastatin , Heptanoic Acids/adverse effects , Heptanoic Acids/metabolism , Heptanoic Acids/pharmacokinetics , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Hydroxymethylglutaryl-CoA Reductase Inhibitors/metabolism , Hyperlipidemias/drug therapy , Indoles/adverse effects , Indoles/metabolism , Indoles/pharmacokinetics , Japan , Pharmacology, Clinical/methods , Pravastatin/adverse effects , Pravastatin/metabolism , Pravastatin/pharmacokinetics , Product Labeling/methods , Pyrroles/adverse effects , Pyrroles/metabolism , Pyrroles/pharmacokinetics , Quinolines/adverse effects , Quinolines/metabolism , Quinolines/pharmacokinetics , Simvastatin/adverse effects , Simvastatin/metabolism , Simvastatin/pharmacokinetics , United States , United States Food and Drug Administration/standards
12.
Anaesth Intensive Care ; 31(4): 371-5, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12973959

ABSTRACT

In the intubated patient, the presence of an endotracheal tube increases the work of breathing during spontaneous breathing. The tube compensation technique was developed as a new ventilator mode that can compensate for that additional the work of breathing. We investigated the respiratory parameters during the pressure support ventilation 0, 5, 10 cmH2O and tube compensation 100% modes of the Puritan Bennett 840 ventilator in ten postoperative patients who had undergone radical surgery for oesophageal cancer. Measurements were performed just before extubation. The tidal volume, respiratory rate and other respiratory parameters were measured with a Ventrak respiratory monitor, and the duty ratio, mean inspiratory flow, and rapid shallow breathing index were calculated. In particular, we performed a comparison between pressure support ventilation 5 cmH2O and tube compensation 100%, because pressure support ventilation 5 cmH2O is the usual ventilating mode before the extubation in our intensive care unit. The tidal volume of pressure support ventilation 10 cmH2O was significantly larger and the respiratory rate was significantly lower than the other three modes. There was no significant difference in the minute volume, tidal volume, and respiratory rate between pressure support ventilation 5 cmH2O and tube compensation 100%. The duty ratio of pressure support ventilation 10 cmH2O was significantly smaller than the other three modes. There was no significant difference in the duty ratio and rapid shallow breathing index between pressure support ventilation 5 cmH2O and tube compensation 100%. It was concluded that the assist levels of pressure support ventilation 5 cmH2O and tube compensation 100% were almost equal for clinical purposes.


Subject(s)
Intubation, Intratracheal , Respiration, Artificial/methods , Respiration , Aged , Female , Humans , Male , Middle Aged , Postoperative Period
13.
Masui ; 50(9): 1012-5, 2001 Sep.
Article in Japanese | MEDLINE | ID: mdl-11593712

ABSTRACT

A 67-year-old man with von Willebrand's disease, was referred to our hospital for operation of the lung cancer. He underwent right upper lobectomy of the lung and mediastinal lymph node dissection under general anesthesia. Three days before surgery, 1-desamino-8-D-arginine-vasopressin (DDAVP) was infused with good response of bleeding time shortening from 6 minutes to 3 minutes. Therefore, immediately before operation, DDAVP was infused. During the operation bleeding tendency was observed. Heat-treated factor VIII concentration and fresh frozen plasma were administered. Bleeding tendency was controlled. Total blood loss was 613 ml. During intraoperative and postoperative period, factor VIII activity and von Willebrand factor (vWF) activity were kept at adequate levels (factor VIII: 105-150%; vWF: 65-225%). The postoperative course was uneventful and he was discharged 18 days after the operation.


Subject(s)
Anesthesia, General/methods , Pneumonectomy , von Willebrand Diseases/complications , Aged , Deamino Arginine Vasopressin/administration & dosage , Factor VIII/administration & dosage , Humans , Lung Neoplasms/surgery , Lymph Node Excision , Male , Perioperative Care
14.
Cancer Lett ; 173(2): 163-74, 2001 Nov 28.
Article in English | MEDLINE | ID: mdl-11597791

ABSTRACT

Pentachlorophenol (PCP), a promoter of murine hepatocarcinogenesis, inhibits gap junctional intercellular communication (GJIC) in rat liver epithelial cells in vitro. To test the hypothesis that both inhibition of GJIC and apoptosis contribute to tumor promotion, we investigated the effect of PCP on both GJIC and serum deprivation-induced apoptosis in v-myc-transfected rat liver epithelial cells. The results showed that PCP inhibited apoptosis, as measured by the TUNEL assay and DNA ladder formation. Inhibition of apoptosis was associated with a decrease in GJIC. The study demonstrated that PCP has a potential for inhibiting apoptosis and GJIC, supporting the hypothesis.


Subject(s)
Apoptosis , Down-Regulation , Epithelial Cells/pathology , Liver/cytology , Oncogene Protein p55(v-myc)/metabolism , Pentachlorophenol/pharmacology , Animals , Blotting, Western , Cell Communication , Cell Line , Cell Nucleus/metabolism , Culture Media, Serum-Free , DNA/metabolism , Gap Junctions , In Situ Nick-End Labeling , Mice , Microscopy, Fluorescence , Proto-Oncogene Proteins c-bcl-2/metabolism , Rats , Reverse Transcriptase Polymerase Chain Reaction , Time Factors , Transfection , Tumor Suppressor Protein p53/metabolism
15.
Tohoku J Exp Med ; 194(1): 45-54, 2001 May.
Article in English | MEDLINE | ID: mdl-11556733

ABSTRACT

The extubation criteria of pressure support ventilation (PSV) in infants and children were not yet established. We studied the differences in respiratory parameters during continuous positive airway pressure (CPAP) using a constant flow type ventilator and PSV using a demand valve type ventilator. Nineteen children (1.9+/-2.9 years old) who were ready to extubate were studied. All patients had recovered from their respiratory failure and had finished the weaning process of the ventilatory support. They were scheduled for extubation on the next day when their ventilatory mode had attained to a PSV of 3 cmH2O with a positive end-expiratory pressure (PEEP) of 3 cmH2O. On the extubation day, tidal volume (TV) and respiratory frequency (RR) were measured with a respiratory monitor at two modes (CPAP of 3 cmH2O and PSV), and the duty ratio (DR) and mean inspiratory flow (MF) were calculated. The sequence of the ventilatory mode was random. No case required reintubation. TV was 61.6+/-54.9 during CPAP and 67.7+/-61.4 ml during PSV, and RR was 38.5+/-10.6 and 37.1+/-8.8 beats/min., respectively. DR was 0.382+/-0.067 and 0.359+/-0.085, and MF was 96.6+/-78.3 and 101.0+/-69.0 ml/sec., respectively. The measured parameters and calculated values showed no significant difference between CPAP and PSV. It was found that the respiratory parameters were almost the same with CPAP and PSV immediately before the extubation, and the previous extubation criteria of CPAP can be used.


Subject(s)
Positive-Pressure Respiration/methods , Blood Gas Analysis , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Positive-Pressure Respiration/instrumentation , Respiratory Function Tests
16.
Psychiatry Clin Neurosci ; 55(3): 203-4, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11422842

ABSTRACT

Four of the 708 snorers (0.56%), referred to our sleep breathing disorders clinic for the past 2 years were diagnosed as having narcolepsy-cataplexy. Detecting HLA DRB1*1501/DQB1*0602 positive was informative for differentiating genuine narcolepsy from non-sleep apnea syndrome (non-SAS) hypersomnia in our clinic. A non-SAS obese boy, diagnosed as having essential hypersomnia syndrome, was found to be HLA DRB1*1502/DQB1*0601 positive. His hypocretin concentration was 206 pg/mL in the cerebrospinal fluid.


Subject(s)
Disorders of Excessive Somnolence/complications , Disorders of Excessive Somnolence/epidemiology , Intracellular Signaling Peptides and Proteins , Narcolepsy/complications , Narcolepsy/epidemiology , Sleep Apnea Syndromes/complications , Adolescent , Adult , Aged , Ambulatory Care Facilities , Carrier Proteins/cerebrospinal fluid , Disorders of Excessive Somnolence/immunology , Female , HLA-DQ Antigens/immunology , HLA-DQ beta-Chains , HLA-DR Antigens/immunology , HLA-DRB1 Chains , Humans , Male , Middle Aged , Narcolepsy/immunology , Neuropeptides/cerebrospinal fluid , Orexins
17.
Psychiatry Clin Neurosci ; 55(3): 257-8, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11422865

ABSTRACT

In six patients with chronic bradydysrhythmias, polysomnographies were performed before cardiac pacemaker implantation and over the week following implantation. A patient with third-degree atrioventricular block (AVB) and two patients with sinus node dysfunction (SND) were associated with sleep-disordered breathing (SDB). Their cardiac pacemaker therapies, with the increase in the average heart rate, led to a reduction of apnea-hypopnea index and/or an improvement of Cheyne-Stokes breathing. It seems that chronic bradydysrhythmia is one of the causative factors leading to SDB.


Subject(s)
Bradycardia/complications , Pacemaker, Artificial , Sleep Apnea Syndromes/complications , Sleep Apnea Syndromes/diagnosis , Aged , Aged, 80 and over , Cheyne-Stokes Respiration , Chronic Disease , Female , Heart Block/complications , Heart Block/therapy , Heart Rate/physiology , Humans , Male , Middle Aged , Polysomnography , Postoperative Period , Preoperative Care , Severity of Illness Index , Treatment Outcome
18.
Anesth Analg ; 93(1): 96-7, TOC, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11429347

ABSTRACT

IMPLICATIONS: We describe the successful management of thoracoscopic thoracic duct ligation in a 2.5-kg compromised infant by using selective lobar-bronchial blockade. The technique reduces the risk of intraprocedural physiologic impairment, allowing the benefits of otherwise minimally invasive thoracoscopic procedures, even when the conditions of children are severely compromised.


Subject(s)
Chylothorax/surgery , Respiration, Artificial , Thoracic Duct/surgery , Thoracic Surgical Procedures , Female , Fiber Optic Technology , Heart Defects, Congenital/complications , Humans , Infant, Newborn , Ligation
19.
Tohoku J Exp Med ; 195(2): 65-72, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11846210

ABSTRACT

Respiratory care patients frequently require intubation with an endotracheal tube (ETT). Unfortunately, the ETT introduces a pressure drop (deltaPETT) that depends on the respiratory flow rate, thus increasing the work of breathing (WOB). Pressure support ventilation (PSV) cannot adequately compensate for this added WOB, because the degree of inspiratory assistance by PSV is fixed. Therefore, a technique called tube compensation (TC) has been developed to address deltaPETT. We examined the performance of TC and compared it with PSV of 5 cm H2O. The experimental system was constructed from a simulator, a test-lung, flow sensors, and a Bennett 840, and the respiratory parameters were studied. ETTs with IDs 6.5 and 8.0 mm were used. The quadratic approximation obtained for deltaPETT in the 6.5-mm ETT was 2.316 x flow + 7.910 x flow2, while that for the 8.0-mm ETT was 1.881 x flow + 3.353 x flow2. The maximum inspiratory flow (MIF) increased significantly with increasing TC, but tidal volume and inspiratory time did not show marked changes. The MIF for TC of 100% was larger than that for PSV of 5 cm H2O, when the 6.5-mm ID was used, but there was no significant difference between these modes when an ID of 8.0 mm was used. For both the 6.5 and 8.0-mm IDs, the PV loop corresponding to 100% TC was larger than that for PSV of 5 cm H2O. TC only compensated for the WOB caused by the ETT, whereas PSV compensated for the WOB caused by the ETT and the demand valve system. In clinical use, the differences between TC and PSV will demand attention.


Subject(s)
Lung/physiopathology , Pulmonary Ventilation/physiology , Ventilators, Mechanical , Humans , Maximal Expiratory Flow Rate , Tidal Volume , Work of Breathing
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