Evaluation of noninvasive monitoring of preoxygenation

Administration of 100% oxygen before a "rapid-sequence" induction of anesthesia is recommended to prevent hypoxemia during induction. In the present study, we used a laser scattering analyzer to study the effectiveness of nitrogen washout from the lungs with oxygen wash into the lungs under two different preoxygenation regimens; 4 times of maximal breathing of 100% oxygen in one minute and normal tidal breathing of 100% oxygen for 3 minutes. The volunteers were healthy, ASA physical status 1, 22 to 33 years of age (26 +/- 3), 167 +/- 5 cm tall, and weighing 60 +/- 5 kg. Arterial blood saturation measured by a pulse oximeter was 97 while breathing 21% oxygen, and 99% while breathing 100% oxygen. Arterial oxygen tensions were 98 mmHg while breathing 21% oxygen, and over 480 mmHg while breathing 100% oxygen. Arterial carbon dioxide and end tidal carbon dioxide concentrations indicated that 4 time of maximal breathing in a minute leads to hyperventilation. The end-tidal oxygen concentration was not significantly different between before and after oxygen administration in two different regimens. End-tidal nitrogen concentration after tidal volume ventilation was lower than that of 4 breath in a minute. These results indicate that end-tidal nitrogen and oxygen could reflect arterial nitrogen and oxygen tensions during preoxygenation.     

The effects of inhalation of nebulized nitroglycerin on dogs with experimental pulmonary hypertension induced by U46619

Ｔｏｆｉｎｄａｓａｆｅ,ｓｉｍｐｌｅ,ｅｆｆｅｃｔｉｖｅａｎｄｓｅｌｅｃｔｉｖｅｐｕｌｍｏｎａｒｙｖａｓｏｄｉｌａｔｏｒ,ｗｅｔｅｓｔｅｄｔｈｅｅｆｆｅｃｔｉｖｅｎｅｓｓａｎｄｓａｆｅｔｙｏｆｉｎｈａｌｅｄｎｅｂｕｌｉｚｅｄｎｉｔｒｏｇｌｙｃｅｒｉｎ(ＮｅｂＮＴＧ)ｉｎｄｏｇｓｗｉｔｈｅｘｐｅｒｉｍｅｎｔａｌｐｕｌｍｏｎａｒｙｈｙｐｅｒｔｅｎｓｉｏｎ(ＰＨ)ｉｎｄｕｃｅｄｂｙｃｏｎｔｉｎｕｏｕｓｉｎｆｕｓｉｏｎｏｆａｔｈｒｏｍｂｏｘａｎｅａｎａｌｏｇｕｅ(Ｕ46619)ＴｈｅｕｓｅｏｆｉｎｔｒａｖｅｎｏｕｓＮ…     

Interaction of cyclosporin derivatives with the ATPase activity of human P-glycoprotein

1. P-glycoprotein, a 170–180 kDa membrane glycoprotein that mediates multidrug resistance, hydrolyses ATP to efflux a broad spectrum of hydrophobic agents. In this study, we analysed the effects of three MDR reversing agents, verapamil, cyclosporin A and [3′-keto-Bmt]-[Val^*]-cyclosporin (PSC 833), on the adenosine triphosphatase (ATPase) activity of human P-glycoprotein.
2. P-glycoprotein was immunoprecipitated with a monoclonal antibody (MRK-16) and the P-glycoprotein-MRK-16-Protein A-Sepharose complexes obtained were subjected to a coupled enzyme ATPase assay.
3. While verapamil activated the ATPase, the cyclosporin derivatives inhibited both the substrate-stimulated and the basal P-glycoprotein ATPase. No significant difference was observed between PSC 833 and cyclosporin A on the inhibition of basal P-glycoprotein ATPase activity. PSC 833 was more potent than cyclosporin A for the substrate-stimulated activity.
4. Kinetic analysis indicated a competitive inhibition of verapamil-stimulated ATPase by PSC 833.
5. The binding of 8-azido-[α-³²P]-ATP to P-glycoprotein was not altered by the cyclosporin derivatives, verapamil, vinblastine and doxorubicin, suggesting that the modulation by these agents of P-glycoprotein ATPase cannot be attributed to an effect on ATP binding to P-glycoprotein.
6. The interaction of the cyclosporin derivatives with ATPase of P-glycoprotein might present an alternative and/or additional mechanism of action for the modulation of P-glycoprotein function.

     

Anaesthetic management of a neonate with prenatally diagnosed cervical tumour and upper airway obstruction

We report the anaesthetic management of a mother, and airway management of a neonate with a prenatal diagnosis of cervical cystic hygroma causing upper airway obstruction. The mortality of such neonates due to upper airway obstruction is reported to exceed 20% following deliveries. Elective Caesarean section was performed under general anaesthesia, and in utero tracheal intubation of the neonate was accomplished under uninterrupted maternal-fetal circulation. By utilizing isoflurane and ritodrine, the heart rate of the neonate remained between 120 to 150 bpm for four minutes following uterine incision. We believe that it is important that a multidisciplinary approach be initiated for planning of airway management of the neonate soon after the diagnosis is made. Laryngoscopy blades larger than normal for neonates, and a portable Doppler to monitor the viability of the neonate were found to be useful in the management of the neonate during in utero tracheal intubation. Although estimated blood loss was not increased, nor did uterine atony occur postoperatively despite the use of ritodrine during Caesarean section, the efficacy and safety of ritodrine to delay placental detachment have not been proved.     

MR detection of cytoplasmic fat in clear cell renal cell carcinoma utilizing chemical shift gradient-echo imaging

We attempted to determine whether cytoplasmic fat in clear cell renal cell carcinoma (RCC) can be identified by chemical shift gradient-echo magnetic resonance imaging (CSI). CSI was performed for 22 clear cell RCCs and 30 other renal tumors (including 16 non-clear cell RCCs), all of which were surgically proven. Signal reduction in out-of-phase images of these tumors was retrospectively evaluated and compared. The signal loss ratio (SLR) was defined and calculated. Fat staining of specimens from 16 tumors was performed and correlated with SLR. SLR was significantly higher in clear cell RCCs than in non-clear cell RCCs (P < 0.001). There was a significant correlation between degree of fat staining positivity of the specimens and SLR (P < 0.01). When signal reduction in out-of-phase images suggested the diagnosis of clear cell RCC, correct diagnosis of this entity was made in resected renal tumors with sensitivity, specificity, and accuracy of 82%, 90%, and 87%, respectively. CSI can demonstrate cytoplasmic fat in clear cell RCCs, which helps to differentiate this entity from other RCCs.     

Neurological prognosis correlated with variations over time in the number of subependymal nodules in tuberous sclerosis

In tuberous sclerosis (TS), brain CT reveals subependymal nodules, cortical tubers and white matter lesions. This study is a retrospective analysis of the relationship between the variations over time in the number of subependymal nodules and the clinical course in cases of tuberous sclerosis. Twenty-four children with tuberous sclerosis, who attended the National Children's Hospital as outpatients, were followed by means of brain CT examinations for 7 years and 1 month on average. Cranial MRI was also performed in 22 cases. Brain CT disclosed subependymal nodules already in early infancy. In almost all cases, the number of subependymal nodules gradually increased with age, especially around the frontal horn of the lateral ventricle. The increase stopped at around age 10. The cases with five or more subependymal nodules at the initial or subsequent CT examination (17 patients; Group A) exhibited a significantly greater number of cortical tubers than those with less than five (five patients; Group B) and had white matter lesions unlike Group B. In addition, the number of cases with either infantile spasms or mental retardation was significantly higher in Group A than Group B (P<0.005). In conclusion, the number of ventricular subependymal nodules may allow prediction of the severity of the cerebral dysfunction in TS. Our results suggest that its variation may reflect the degree of the embryologic disorder when neuronal cells grow in the early gestational period.     

The antigen 85 complex vaccine against experimental Mycobacterium leprae infection in mice

The proteins in culture filtrate derived from Bacillus Calmette-Guérin (BCG) were examined for protection against infection by Mycobacterium leprae. Immunization with the major secreted proteins, antigen 85 complex (Ag 85) A, B and C, induced effective protective immunity against multiplication of M. leprae in the foot pads of mice. The most effective protection was observed when mice were immunized with Ag 85A. A single immunization with Ag 85 could induce antigen-specific interferon gamma (IFNgamma) synthesis and more effective protection than live BCG vaccine. This study demonstrates that Ag 85 is an important immunoprotective molecule against leprosy infection.     

Factors relate to participation in medical checkups in a rural community an analysis including social network scores]

Since 1969, community-based stroke prevention programs have been conducted in N town, Kochi prefecture. To clarify factors related to participation in medical checkups including social networks, a cross-sectional questionnaire survey was performed on 6,704 residents aged 40 and over in N town in 1996. 1. Location of the workplace, types of medical insurance and interest in health were significantly associated with participation in medical checkups. 2. Participation in medical examinations provided at the workplace was significantly, inversely related with participation rates in community checkups in the group aged 40 to 59 years. 3. Low independence level in daily activities was inversely associated with participation rates for medical checkups in groups aged 60 years and older. 4. Visiting medical facilities was inversely associated with the participation rate for medical checkups in female groups. 5. The group with the highest social networks score (5 points) had the highest participation rate for medical checkups. After adjusting for other participation related factors, social networks scores had a significantly positive association with the participation rate for medical checkups provided by the Health Services for the Elderly Act.