A cohort study of toner-handling workers on inflammatory, allergic, and oxidative stress markers: cross-sectional and longitudinal analyses from 2003 to 2008.

OBJECTIVES: This study examines the relationship between toner exposure and its health effects in terms of biomarkers which are known to assess the damages to humans caused by toxic material exposure. METHODS: The subjects were 1504 male workers aged below 50 in 2003 in a Japanese toner and photocopier manufacturing company. Personal exposure measurements, pulmonary function tests, chest X-ray examinations, biomarker measurement, and a questionnaire about respiratory symptoms were conducted. We will report about biomarker measurement in this study. Cross-sectional survey studies and a longitudinal study from 2003 to 2008 were conducted. RESULTS: Few significant findings were associated with the toner exposure in both the cross-sectional and the longitudinal studies. The higher toner exposure concentrations did not induce effects on increasing biomarkers. CONCLUSION: There was no evidence of excessive inflammatory, allergic, or oxidative stress reaction in toner-handling workers as compared to non-handling workers, despite some sporadically significant findings. There are no other reports of a longitudinal epidemiological study with regard to toner exposure; this report significantly contributes to toner exposure literature. Although in the current well-controlled working environment, the toner exposure concentrations are quite low; further studies are needed to completely understand the health effects toner may have, however small they may be.

A cohort study using pulmonary function tests and x-ray examination in toner-handling workers: cross-sectional and longitudinal analyses from 2003 to 2008.

OBJECTIVES: This study uses pulmonary function tests and chest x-ray examinations to examine the relationship between toner-handling work and its health effects. METHODS: The subjects were 1504 male workers in a Japanese toner and photocopier manufacturing company, in the age range from 19 to 50 years in 2003. Personal exposure measurements, pulmonary function tests, chest x-ray examinations, biomarker measurements, and a questionnaire about respiratory symptoms were conducted. The present study reports the results of pulmonary function tests and chest x-ray examinations conducted in the subjects, which includes a cross-sectional study on the toner handling and non-handling workers and a longitudinal study from 2003 to 2008. RESULTS: Few significant findings were suspected to be caused by toner exposure found in pulmonary function indices in both the cross-sectional and longitudinal studies. Any obvious fibrotic findings in chest x-ray findings related to the toner exposure could not be found out. CONCLUSION: No evidence of adverse effects on pulmonary function indices and chest x-rays was present in the toner-handling workers as compared to the nonspecifically exposed workers. Although the toner exposure concentration is quite low in the current well-controlled working environment, even among the toner-handling workers, we would like to continue this study in the future to verify the toner exposure health effects.

Alcohol and aldehyde dehydrogenase polymorphisms in Japanese patients with alcohol-induced chronic pancreatitis.

In order to clarify the genetic factors in alcohol-related chronic pancreatitis among Japanese, we determined the genotype of two major alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). The restriction fragment-length polymorphisms of the ADH2 and the ALDH2 genes were analyzed in 47 normal subjects and 31 patients with alcoholic pancreatitis. No significant difference between the patient and control groups was found in the ADH2 genotypes. A significant genetic difference between the two groups was found in the ALDH2 locus. The frequency of the ALDH2*1 allele was found to be 0.681 and that of the ALDH2*2 allele was 0.319 in the controls, while these values were 0.935 and 0.065 in the patients, respectively. Most of the patients (27 of 31) were ALDH2*1/2*1, only four were ALDH2*1/2*2, and none of the patients were ALDH2*2/2*2. These results indicate that genetic polymorphism of the ALDH2 gene influences the risk of developing alcoholic pancreatitis in Japanese.

[Arterial oxygenation during one lung ventilation in obese patients].

To test the hypothesis that arterial oxygenation during one lung ventilation (OLV) is impaired more in obese patients than in non-obese control patients, we performed consecutive measurements of arterial oxygen tension (PaO2) during OLV in 48 patients scheduled for pulmonary lobectomy. Minimum value of PaO2 during OLV was significantly less in 16 obese patients [body mass index (BMI) > 25] compared to 32 control patients (BMI < 25). Moreover, PaO2 value of left lung ventilation was significantly less than the value of right lung ventilation in obese patients while the difference was not statistically significant in the control group.

cDNA Subtractive Cloning of Genes Expressed during Early Stage of Appressorium Formation by Magnaporthe grisea.

The conidial germ tube of the fungus Magnaporthe grisea differentiates an infection-specific structure, an appressorium, for penetration into the host plant. Formation of the appressorium is also observed on synthetic solid substrata such as polycarbonate. We found that a plant lectin, concanavalin A, specifically suppressed the appressorium formation without affecting the germling adhesion if it was applied within 2-3 hours after germination. Standing on the result, we constructed a cDNA library that represents the early stage of germ tube development and/or appressorium formation from the 2.5-hour-old germ tubes using a cDNA subtraction strategy by the combination of the biotin labeled driver method and adapter-primed PCR method. Out of 686 colonies of the library, 158 distinct clones' nucleotide sequences were partially analyzed. Some clones' expression patterns were detected by RT-PCR and from those results, our library seemed to well represent the objective developmental stage of M. grisea.

Gene cloning and characterization of recombinant RNase HII from a hyperthermophilic archaeon.

We have cloned the gene encoding RNase HII (RNase HIIPk) from the hyperthermophilic archaeon Pyrococcus kodakaraensis KOD1 by screening of a library for clones that suppressed the temperature-sensitive growth phenotype of an rnh mutant strain of Escherichia coli. This gene was expressed in an rnh mutant strain of E. coli, the recombinant enzyme was purified, and its biochemical properties were compared with those of E. coli RNases HI and HII. RNase HIIPk is composed of 228 amino acid residues (molecular weight, 25,799) and acts as a monomer. Its amino acid sequence showed little similarity to those of enzymes that are members of the RNase HI family of proteins but showed 40, 31, and 25% identities to those of Methanococcus jannaschii, Saccharomyces cerevisiae, and E. coli RNase HII proteins, respectively. The enzymatic activity was determined at 30 degreesC and pH 8.0 by use of an M13 DNA-RNA hybrid as a substrate. Under these conditions, the most preferred metal ions were Co2+ for RNase HIIPk, Mn2+ for E. coli RNase HII, and Mg2+ for E. coli RNase HI. The specific activity of RNase HIIPk determined in the presence of the most preferred metal ion was 6. 8-fold higher than that of E. coli RNase HII and 4.5-fold lower than that of E. coli RNase HI. Like E. coli RNase HI, RNase HIIPk and E. coli RNase HII cleave the RNA strand of an RNA-DNA hybrid endonucleolytically at the P-O3' bond. In addition, these enzymes cleave oligomeric substrates in a similar manner. These results suggest that RNase HIIPk and E. coli RNases HI and HII are structurally and functionally related to one another.

[A case of mitral valve prolapse diagnosed by transesophageal echocardiography during emergency laparotomy].

We described a case of severe mitral valve prolapse diagnosed and successfully managed with transesophageal echocardiography (TEE) during emergency laparotomy for obstructive ileus. As the nature of the surgical procedure and the condition of the patient did not allow us to spend time to perform full cardiac examination preoperatively, we decided to use intraoperative TEE for the determination of cardiac pathology and for the monitoring of ventricular function. We discussed the indication of TEE during noncardiac surgery in patients having cardiac complications. The anesthesiologists should be able to utilize TEE to make correct decision in the hemodynamic management, especially when the preoperative cardiac evaluation is insufficient or lacking.

[The risk of palliative operation for bone metastasis].

Palliative operations for various bone metastases are being performed more frequently than before with the improvement of surgical technique and the development of new instruments. However, anesthesia in advanced cancer patients who are under palliative care accompanies inherent risks which are uncommon in general orthopaedic populations. Thus, we made a retrospective analysis of the medical records of 59 patients scheduled for palliative operation against metastatic bone lesions during the last 4 years. The survey revealed 5 cases of perioperative lethal events. Two of them died preoperatively from the hepatic failure and unexpected cerebral tumor embolism. An intraoperative cardiac arrest secondary to pulmonary embolism occurred in a patient during intramedullary nailing. There was a patient who developed disseminated intravascular coagulation and acute renal failure after posterior fixation of the lumbar vertebrae. The remaining one patient with superior vena cava syndrome developed life-threatening airway obstruction during general anesthesia with endotracheal intubation. We conclude that the exact evaluation of the patient's condition and the careful management of vital organ functions are mandatory during the perioperative period. In this regard, the anesthesiologists should be involved not only in the intraoperative anesthetic management but also in the perioperative care of the patients with bone metastasis.

[Intraoperative continuous epidural block influences postoperative changes in breathing pattern and thoracoabdominal movement associated with upper abdominal surgery].

We have examined the changes in breathing pattern and thoracoabdominal movement associated with upper abdominal surgery in order to evaluate the possible influences of nociceptive input on respiration. Sixteen patients scheduled for gastrectomy were studied. Continuous epidural block was instituted prior to the induction of anesthesia and maintained throughout the surgery in 8 of 16 patients (Group 1) while it was instituted upon the peritoneal closure and maintained thereafter in the remaining 8 patients (Group 2). Breathing pattern and thoracoabdominal motion were determined before and after surgery while the patients awake by respiratory inductance plethysmography (Respisomnography, Chest MI). Breathing frequency and minute ventilation increased significantly while tidal volume was unchanged after the operation regardless of the intraoperative epidural block. Furthermore, there were identical shortening of inspiratory time and prolongation of duty ratio (inspiratory time/duration of a breath) in the two groups. Contribution of rib cage movement on tidal volume increased significantly postoperatively in all the patients. However, the changes were significantly smaller in patients receiving intraoperative epidural block. These results indicate that the causes of tachypnea and increased minute ventilation are different from the mechanism responsible for the alteration of thoracoabdominal partitioning of ventilation after upper abdominal surgery. The former may be related to the metabolic changes and, conceivably, unaffected by continuous epidural block. While the latter may be the consequence of the reflex inhibition of the diaphragmatic function that can be, at least partially, modified by continuous epidural block.

Changes in respiratory pattern during induction of anaesthesia with sevoflurane: comparison of nasal and the oral breathing.

In order to test the hypothesis that the effects on ventilation of nasal inhalation of sevoflurane during induction of anaesthesia differ from those of oral inhalation, 20 patients underwent inhalation induction of anaesthesia with sevoflurane 5% either through the nasal route or the oral route. In 10 patients who breathed through the nose (N-group), there was an immediate decrease in tidal volume with no change in respiratory duration whereas no similar change was observed in the 10 patients who breathed through the mouth (O-group). The time from the start of sevoflurane inhalation to the onset of sleep was significantly shorter in the O-group compared with the N-group [86.2 +/- 4.4 (mean +/- SE) vs. 115.0 +/- 8.4 sec, P < 0.01].

Differences in respiratory reflex responses from the larynx, trachea, and bronchi in anesthetized female subjects.

BACKGROUND: Animal studies show that airway receptors responsible for eliciting respiratory protective reflexes are not uniformly distributed in the airways. Based on this information, it is possible that the protective reflex responses to airway irritation in humans may vary, depending on the site of stimulation. The purpose of this study is to examine whether the protective reflex responses evoked from the larynx are different from those evoked from the lower airways and to see how change in depth of anesthesia modifies the protective reflex responses evoked from individual sites. METHODS: The airway mucosa of the larynx, tracheal carina, and bronchi were stimulated by injection of distilled water (0.5 ml) at two different depths of sevoflurane anesthesia (1.2 and 1.8 MAC) in 11 female subjects breathing spontaneously through the laryngeal mask airway. The respiratory responses were monitored by measuring ventilatory flow and airway pressure. RESULTS: At 1.2 MAC of sevoflurane anesthesia, both laryngeal and tracheal stimulation caused protective responses, such as forceful expiratory efforts, apnea, and spasmodic panting, whereas bronchial stimulation caused little or no such responses. There was no significant difference in the incidence of different types of reflex responses between the larynx and the trachea. At 1.8 MAC of sevoflurane, the nature of the elicited responses was very similar to that observed at 1.2 MAC of sevoflurane, showing little dose-dependence of anesthetic effect. CONCLUSIONS: The respiratory reflex responses evoked by injection of water vary, depending on the site of stimulation. The incidence of various reflex responses was not affected by the changing depth of anesthesia. The sensitivity to airway irritation seems to be greater at the larynx and trachea than at the more peripheral airways.

Distribution of diaphragm blood flow during sevoflurane anaesthesia in dogs.

PURPOSE: The purpose of this study was to determine the effect of increasing the concentrations of sevoflurane anaesthesia on the distribution of diaphragm blood flow (Qdi) in ten dogs during mechanical ventilation. METHODS: Animals were divided into two groups, sevoflurane (n = 6) and time control (n = 4) groups. Blood flow to the crural and the costal diaphragm (Qcru, Qcost) was determined by the hydrogen clearance technique at 0, 0.5, 1.0 and 1.5 minimum alveolar concentration (MAC) of sevoflurane after a 30 min period of steady-state conditions. Cardiac output (CO) and the mean arterial blood pressure (MBP) were also measured. RESULTS: Sevoflurane anaesthesia caused a reduction in CO (L.min-1) from a control value of 1.51 +/- 0.21 to 1.38 +/- 0.1 (0.5 MAC), 1.09 +/- 0.15 (1.0 MAC) and 0.98 +/- 0.12 (1.5 MAC) (Mean +/- SD). Mean blood pressure, Qcru and Qcost also decreased with increasing depth of anaesthesia. In addition, the decrease of Qcru was greater than that of Qcost at all levels of MBP and CO. No change occurred in these variables in the time control group. CONCLUSION: Sevoflurane anaesthesia changes the distribution of Qdi with a greater reduction occurring in Qcru than in Qcost.

Ventilatory responses to inspiratory resistive loading before and after gastrectomy during isoflurane anesthesia.

We tested the hypothesis that steady-state responses to inspiratory-flow-resistive loading would be preserved immediately after upper abdominal surgery in anesthetized patients. Twenty patients were studied immediately before and after gastrectomy under 1 minimum alveolar anesthetic concentration (MAC) of isoflurane anesthesia. Ventilation, airway occlusion pressure, and Paco2 were measured before and during inspiratory-flow-resistive breathing lasting from 6 to 7 min. Ten of 20 subjects were tested with resistance of 51.8 cm H2O.L-1.s-1 (Load 1) and the remaining 10 subjects were tested with resistance of 83.3 cm H2O.L-1.s-1 (Load 2). Ventilatory variables obtained immediately before and after surgery were compared in each group. Baseline ventilation increased postoperatively with greater frequency of breathing and comparable tidal volume (VT). Immediately after the application of resistive load, minute ventilation (VI) significantly decreased both pre- and postoperatively, due primarily to the decrease of VT. During sustained loading, VI gradually increased and reached steady state in 2-3 min. After 5 min of loading, Paco2 returned to the control level with Load 1 whereas with Load 2, it was higher than the control value. The magnitude and time course of reduced ventilation in response to resistive load were identical between pre- and postoperative conditions. We conclude that the ability of maintaining ventilation to imposed inspiratory-flow-resistive loading is well preserved during 1 MAC of isoflurane anesthesia before and after gastrectomy.

Effects of surgical stimulation on the apnoeic thresholds for carbon dioxide during anaesthesia with sevoflurane.

Mechanical hyperventilation may produce hypocapnic apnoea below the carbon dioxide off-switch threshold whereas an increase in arterial PCO2 after post-hyperventilation apnoea causes reappearance of respiratory effort above the carbon dioxide on-switch threshold. To study the effects of surgical stimulation on these two thresholds, we have measured end-tidal PCO2 (PE'CO2) at the two thresholds, before and during surgical stimulation, in 14 patients undergoing mastectomy, anaesthetized with sevoflurane (1.2 MAC). Based on the reproducibility of the results, data from 11 patients were analysed and data from the three other patients were discarded. Before surgical stimulation, mean resting PE'CO2' off-switch threshold and on-switch threshold were 5.7 (SEM 0.2), 5.2 (0.2) and 6.1 (0.2) kPa, respectively. The off-switch threshold was significantly less than resting PE'CO2 (P < 0.01) but the on-switch threshold was significantly greater than resting PE'CO2 (P < 0.01). During surgical stimulation, resting PE'CO2' off-switch threshold and on-switch threshold were 4.8 (0.2), 4.1 (0.2) and 4.7 (0.2) kPa, respectively. Although the off-switch threshold was significantly less than resting PE'CO2 (P < 0.01), there were no significant differences between resting PE'CO2 and on-switch threshold. These results indicate that surgical stimulation does not affect equally the carbon dioxide on- and off-switch thresholds.

Breathing route and ventilatory responses to inspiratory resistive loading in humans.

In response to ventilatory loading, a number of compensatory mechanisms can serve to maintain ventilation at or near control levels. To test the hypothesis that respiratory compensation for inspiratory flow-resistive load during nasal breathing may be different from that during oral breathing, we investigated the ventilatory responses to four different magnitudes of inspiratory flow-resistive loads ("control," "light," "moderate," and "severe" loads: 3.5, 15.0, 51.8, 83.3 cm H2O/L/s at a flow rate of 30 L/min, respectively) during nasal breathing and during oral breathing in 11 conscious subjects. With the control, light, and moderate loads, there were no significant differences in tidal volume (VT), respiratory frequency (f), minute ventilation (VI), and end-tidal (partial) carbon dioxide pressure (PETCO2) between nasal and oral breathing. With the severe load, however, VI and f were significantly lower and PETCO2 was significantly higher during nasal breathing than during oral breathing. Occlusion pressure (P0.1) progressively increased during both nasal and oral breathing with increasing magnitudes of loading. However, the value of P0.1 during oral breathing at the severe loading was significantly higher than that during nasal breathing. Our results indicate that ventilatory compensation for the inspiratory flow-resistive load is better during oral breathing than during nasal breathing.

Lumbar epidural block reduces cough strength in healthy young subjects.

Effects of lumbar epidural block on maximum expiratory strength were studied in 12 healthy volunteers. Subjects performed maximum expiratory effort against occluded airway at functional residual capacity (FRC) and total lung capacity (TLC) while measuring airway pressure and electromyogram of the abdominal muscles (EMGab). Cough strength was assessed by maximum expiratory pressure (PEmax) and peak EMGab (peak-EMGab). Following injection of 2% lidocaine 17.8±1.1 ml into the lumbar epidural space (L2.3±0.4), upper levels of analgesia ranged from T11 to T4 (T7.8±1.3). Peak-EMGab and PEmax were significantly reduced by lumbar epidural block at both lung volumes. Compared with severe reduction in peak-EMGab, PEmax was well maintained at TLC, but changes in PEmax were identical to those in peak-EMGab at FRC. When analgesia spread to higher than T6, PEmax at TLC decreased considerably. We conclude that lumbar epidural block producing analgesia above T6 paralyzes the abdominal muscles and severely impairs the ability of effective cough in healthy young men.

Effects of sedation produced by thiopentone on responses to nasal occlusion in female adults.

To test the hypothesis that full wakefulness is an important factor in the control of the route of breathing in adult humans, we have studied the responses to nasal occlusion before and during sedation with thiopentone in 14 female subjects. A tightly fitting partitioned face mask separated the nasal and oral breathing routes. Nasal and oral breathing were identified from changes in carbon dioxide concentration and airway pressure in the different compartments of the face mask. Arterial oxygen saturation (SpO2) was monitored simultaneously. Eleven of 14 subjects breathed only through the nose (nasal breathers) both before and during sedation. In these subjects, the time required to initiate oral breathing in response to nasal occlusion during sedation was significantly longer than that before sedation (mean 37.7 (SD 15.5) s vs 3.2 (1.3) s (P < 0.01)). Also, there was a significant difference (P < 0.01) in the smallest values of SpO2 attained during nasal occlusion before (98.0 (0.8)%) and after (89.3 (4.3)%) sedation. In adult humans the ability to maintain adequate ventilation by switching from the nasal to the oral route in response to nasal occlusion is greatly impaired during sedation, probably because of the impairment of conscious influence on the control of the palatal muscles.

Thoracic epidural anesthesia causes rib cage distortion in anesthetized, spontaneously breathing dogs.

The effects of thoracic epidural anesthesia on the performance of the parasternal intercostal muscles were investigated by measuring electromyographic activity and length changes of the parasternals (EMG activities and length, respectively, of the parasternals) in seven pentobarbital anesthetized, spontaneously breathing dogs. Epidural injection of 0.1 mL/kg of 2% lidocaine decreased tidal volume and minute ventilation during unstimulated breathing. These changes were accompanied by complete abolishment of EMG activities of the parasternals and passive elongation of the parasternals during inspiration. At equivalent end-tidal PCO2 values (70 and 80 mm Hg) during CO2 rebreathing, tidal volume and minute ventilation were lower after epidural block compared to the corresponding values before the block. Thoracic epidural anesthesia impaired contraction of the parasternals and conceivably other respiratory muscles in the rib cage as well and could induce a distortion of the rib cage. The authors conclude that respiratory muscles in the rib cage contribute considerably to the maintenance of ventilation in anesthetized dogs.

Apnoea and oximetric desaturation in patients receiving epidural morphine after gastrectomy: a comparison of intermittent bolus and patient controlled administration.

The number of apnoeic episodes and arterial oxygen desaturations were measured preoperatively and for sixty hours postoperatively in twenty ASA status 1-2 patients scheduled for elective gastrectomy. Monitoring included continuous pulse oximetry, respiratory inductive plethysmography and repeated arterial blood gas analysis. The number and magnitude of apnoeas and desaturation episodes were compared between two postoperative analgesic regimens of epidural morphine; intermittent bolus injection (Group B, n = 10), and patient controlled administration with continuous infusion (Group P, n = 10). Morphine dose, P(a)CO2 and mean SpO2 values were similar between the two groups. Although the number of central apnoeas with SpO2 < 90% was greater in Group B, other episodes of apnoea or desaturation were similarly seen preoperatively. In the postoperative period, central apnoeas with SpO2 < 90% were significantly increased in Group B, while no change was seen in Group P. Apnoeas with SpO2 < 80% were only seen in Group B. We conclude from these results that postoperative apnoeas and episodic desaturations are greatly influenced by the different modes of opioid administration.