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Mechanical hyperventilation may produce hypo-capnic apnoea below the carbon dioxide off-switch threshold whereas an increase in arterial PCO2after 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 P'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 P'CO2(P< 0.01) but the on-switch threshold was significantly greater than resting P'CO2(P< 0.01). During surgical stimulation, resting P'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 PÉCO2, 2 (P< 0.01), there were no significant differences between resting P'CO2and on-switch threshold. These results indicate that surgical stimulation does not affect equally the carbon dioxide on- and off-switch thresholds.

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, PaCO2and mean SpO2values 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.

AbstractA series of cyclopenteno annelated bis-fused TTF derivatives (CP-TTP 1a-d) have been synthesized. The present donors have produced many molecular complexes showing high conductivity. In particular, several cation radical salts based on the bis(methylthio)- (CPTM-TTP 1c) and ethylenedithio (CPET-TTP, 1d) derivatives are metallic down to liquid helium temperature, though resistivity of CPTM-TTP salts increases a little at low temperature. Among metallic salts, (CPTM-TTP)4X (X = PF6−, AsF6−and SbF6−) are isostructural and have two-dimensional “β-type” arrangement of donor molecules. The band calculations of these salts indicate they have eclipsed Fermi surfaces characteristic of two-dimensional metals.

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].

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 Spo2attained 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.

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.

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.

The determination of serum enzyme levels has been increasingly used in diagnosis of children's diseases. However, urinary enzymes have been little studied and many problems remain to be elucidated.

The origin of urinary enzymes is obscure. We therefore determined the levels of urinary, serum and kidney enzymes (lysozyme, amylase, alkaline phosphatase, glutamate transaminase, lactic dehydrogenase, leucine aminopeptidase and ß-glucuronidase) and isozymes (alkaline phosphatase, glutamate transaminase, leucine aminopeptidase and ß-glucuronidase) in Wistar rats with nephrotoxin nephritis or aminonucleoside nephrosis.

The present study aimed to estimate cumulative incidence of overweight and obesity and describe 5‐year longitudinal changes in body mass index (BMI) in a large occupational cohort in Japan. Participants were 55 229 Japanese employees, who were aged 20‐59 years and attended at all subsequent annual health check‐ups between 2009 and 2014. Mixed model analysis was performed to examine the effects of age and cohort by gender on BMI change, with age as a random variable. Cumulative incidence of overweight (23.0≤ BMI <27.5 kg/m2) and obesity (BMI ≥27.5 kg/m2) was calculated. Logistic regression analysis was used to estimate odds ratios for the incidence of overweight and obesity according to age group. The incidence of overweight and obesity was approximately double in men (28.3% and 6.7%, respectively) compared to women (14.3% and 3.9%, respectively).The incidence of obesity decreased with age in men, but did not differ according to age in women (Pfor trend: .02 and .89, respectively). Among overweight participants, the incidence of obesity was higher in women (18.9%) than men (14.5%) and decreased with advancing age (Pfor trend: <.001 in men and .003 in women). Mean BMI was higher in men than women in all age groups throughout the period. Younger cohorts tended to have a higher BMI change compared with older cohorts. In this Japanese occupational cohort, transition from overweight to obesity is higher in women than men, and the more recent cohorts had a higher change in mean BMI than the older cohorts.

Several derivatives of 2,2′-ethanediylidenebis(1,3-dithiole) fused with 1,3-dithiol-2-ylidenes (DT-EBDTs) have been prepared. Their cyclic voltammograms consist of three single-electron redox waves. The first redox potential of MeDT-EBDT (+0.37 V vs. SCE in PhCN) is lower by 0.08 V than those of the corresponding TTF, MeDT-TTF. On the other hand, the E2-E1 value (0.13 V) is smaller by 0.18 V than that of MeDT-TTF. The present donors afford semiconducting AsF6− salts, TCNQF4 and DDQ complexes (σrt = 10−5=10−1 S cm−1, Ea = 0.03–0.19 eV).

Several derivatives of 2,2′-ethanediylidenebis(1,3-dithiole) fused with 1,3-dithiol-2-ylidenes (DT-EBDTs) have been prepared. Their cyclic voltammograms consist of three single-electron redox waves. The first redox potential of MeDT-EBDT (+0.37 V vs. SCE in PhCN) is lower by 0.08 V than those of the corresponding TTF, MeDT-TTF. On the other hand, the E2-E1value (0.13 V) is smaller by 0.18 V than that of MeDT-TTF. The present donors afford semiconducting AsF6−salts, TCNQF4and DDQ complexes (σrt= 10−5=10−1S cm−1, Ea= 0.03–0.19 eV).

The AsF6− salts based on TTP and its selenium analogues ST-TTP and BDS-TTP are isostructural with each other, in which the donor are arranged in the so-called β-type packing.

The AsF6−salts based on TTP and its selenium analogues ST-TTP and BDS-TTP are isostructural with each other, in which the donor are arranged in the so-called β-type packing.

We have investigated, in six healthy male volunteers, the effect of high thoracic extradural anaesthesia on the ventilatory pattern and hypercapnic ventilatory response. Ventilatory variables were determined using a respiratory inductive plethysmograph. Duration of inspiration, rib cage excursion and its contribution to tidal volume decreased significantly following extradural anaesthesia, while mean inspiratory flow rate and minute ventilation increased. End-tidal PCO2 and the tidal excursion of the abdomen were unchanged. Hypercapnic ventilatory response decreased significantly following extradural anaesthesia, principally because of the rib cage component. The slope of the abdominal component did not change significantly. The results indicate that mechanical impairment of rib cage movement can produce decreased ventilatory response to carbon dioxide. The ventilatory impairment and the changes in breathing pattern induced by the high thoracic extradural anaesthesia probably reflect blockade of the efferent or afferent pathway (or both) of the intercostal nerve roots.

A novel film formation technology using a free‐jet molecular flow expanding into UHV as a source gas supply system, is presented.

We have studied the effect of halothane on diaphragmatic contractile function by measuring transdiaphragmatic pressure (Pdi) and electromyogram of the diaphragm (Edi) during various stimulation frequencies in 15 pentobarbitone anaesthetized dogs undergoing mechanical ventilation. We have examined also the effect of halothane on the fatigued diaphragm by repeating the measurements 5, 10, 15, 30, 60 and 90 min after 30 min of tetanic stimulation applied to the phrenic nerves. Administration of 1–2 MAC of halothane did not affect Pdi at any given stimulation frequency. Changes in the depth of halothane anaesthesia (0, 1 and 2 MAC) did not alter the force-frequency relationship of the diaphragm during recovery from fatigue. Edi was unaffected by halothane, except for a small decline during 100-Hz stimulation with 2 MAC. In contrast with the changes in Pdi, Edi during recovery from fatigue was the same as that determined before fatigue. It is concluded that halothane, in clinical concentrations, did not depress the contractile function of fresh or fatigued diaphragm in vivo.

We have examined the sensitivity of the geniohyoid, an upper airway dilating muscle, to vecuronium in 12 anaesthetized dogs undergoing mechanical ventilation of the lungs and compared it with that of the diaphragm. Dogs were allocated randomly to two groups: pentobarbitone alone (group 1, n = 7); pentobarbitone combined with 0.2 MAC (0.44%) of enflurane anaesthesia (group 2, n = 5). Supramaximal single twitch stimulations (0.1 Hz) were applied to the phrenic nerves in the upper thorax and the geniohyoid branches of the hy-poglossal nerves at the neck. The evoked responses were assessed by the transdiaphragmatic pressure (Pdi) and the isometric force of the geniohyoid muscles (Tgh) until complete recovery of these variables after i.v. administration of vecuronium 0.02 mg kg−1. In both groups, the magnitude of the depression of twitch response was greater and time required to reach control amplitude was longer in the geniohyoid than the diaphragm. The depression of Tgh. was significantly greater in group 2 than in group 1, whereas no change was observed in Pdi between the two groups. We conclude that the geniohyoid is more sensitive to vecuronium than the diaphragm and the differential effects of vecuronium are facilitated by a low concentration of enflurane.