Expression of pulmonary vasoactive factors after sevoflurane anaesthesia in rats: a quantitative real-time polymerase chain reaction study.

BACKGROUND: Sevoflurane is a fluorinated volatile anaesthetic agent that lowers arterial pressure, in part by vasodilation. We previously showed, in rat lungs, that sevoflurane affected the expression of endothelin-1 (ET-1), a potent vasoconstrictor peptide. Therefore, we hypothesized that the vasodilation induced by sevoflurane involved vasodilatory and vasoconstrictor components. METHODS: Rats were anaesthetized with sevoflurane 4% for 0, 2, and 6 h (n=9 each group) before death. In addition, a further group (n=9) were anaesthetized for 6 h then awoken for 2 h before death (n=9). We measured expression of mRNA encoding ET-1, nitric oxide synthase-1, 2, 3 (NOS1, 2, 3), haeme oxygenase-1, 2 (HO-1, 2), adrenomedullin (ADM), calcitonin gene-related peptide, vasoactive intestinal peptide, and prostacyclin synthase in whole lung using real-time reverse transcriptase-polymerase chain reaction. RESULTS: Expressions of ET-1 and ADM were significantly increased by inhalation of sevoflurane for 2 and 6 h (P<0.05). Expression of NOS3 was significantly increased at 6 h (P<0.05). After awaking from anaesthesia, the expressions of NOS3, ET-1, and ADM returned to baseline levels. CONCLUSIONS: Sevoflurane increased the expressions of ET-1, NOS3, and ADM. Our results suggest that the increased expressions of NOS3 and ADM may counteract that of ET-1 and so regulate pulmonary circulation under sevoflurane anaesthesia.

Role of angiotensin II type 1 receptor in the leucocytes and endothelial cells of brain microvessels in the pathogenesis of hypertensive cerebral injury.

OBJECTIVES: To elucidate the mechanisms of activation of polymorphonuclear neutrophils (PMNs) and their adhesion to endothelial cells in hypertensive cerebral injury, and to determine the effects of angiotensin II type 1 (AT1) receptor antagonism on PMNs and endothelial cells. DESIGN: We examined expression of AT1 receptor in PMNs in relation to that in endothelial cells of brain microvessels, using mature stroke-prone spontaneously hypertensive rats (SHRSP). METHODS: To investigate the expression of AT1 receptor, we used 23-week-old male spSHRs and age-matched Wistar-Kyoto (WKY) rats. For the effects of AT1 receptor blockade, the AT1 receptor antagonist, TCV-116, was orally administered at a dosage of 0.5 mg/kg per day for 4 weeks in rats from age 19 weeks. A PMN-rich fraction was obtained by density gradient using Ficol-hypaque. AT1 receptor expression in PMNs was investigated by immunohistochemistry (avidin-biotinylated peroxidase complex method) and reverse transcriptase-polymerase chain reaction (RT-PCR). Expression of macrophage-1 (Mac-1) in PMNs was examined by flow cytometry. Expression of intercellular adhesion molecule-1, glucose transporter-1 and fibrinogen in the cerebral cortex (occipital region) was investigated by immunohistochemistry. RESULTS: AT1 receptor was identified in PMNs by both immunohistochemistry and RT-PCR. It was also detected in the cerebral cortex. Expression in both types of cells was much more intense in spSHRs than in WKY rats. AT1 receptor antagonism ameliorated the enhanced expression of Mac-1 in PMNs. In addition, it was confirmed that enhanced expression of adhesion molecules and increased permeability of brain microvessels were decreased by AT1 receptor antagonism. CONCLUSIONS: The results indicate that both PMNs and brain microvessel endothelial cells possess AT1 receptor, that AT1 receptor antagonism ameliorates endothelial injury via inhibition of PMNs and endothelial cell adhesion, and that angiotensin II must be a key factor in hypertensive endothelial injury.

Effects of the AT1 receptor antagonist on adhesion molecule expression in leukocytes and brain microvessels of stroke-prone spontaneously hypertensive rats.

To elucidate the possible involvement of angiotensin II (AII) in the pathogenesis of microvascular changes in severe hypertension, we investigated the effects of angiotensin II type 1 (AT1) receptor antagonist and angiotensin-converting enzyme inhibitor (ACEI) on the expression of adhesion molecules of leukocytes and brain microvessels. Male stroke-prone spontaneously hypertensive rats (SHRSP) at 19 weeks of age were divided into three groups and age-matched Wistar-Kyoto rats (WKY) were used as the control group. AT1 receptor antagonist (TCV-116, 0.5 mg/kg/day) and ACEI (captopril, 20 mg/kg/day) were administered to SHRSP for 4 weeks. Mac-1 expression in leukocytes was investigated by flow cytometric analysis. For endothelial cells, we examined the expression of intercellular adhesion molecule-1 (ICAM-1), the AT1 receptor, and glucose transporter-1 (GLUT-1, a marker of the blood-brain barrier) using reverse transcription-polymerase chain reaction (RT-PCR). The blood pressure of AT1 receptor antagonist and ACEI-treated groups was slightly lower than that of the control, but was still greater than 220 mm Hg. Mac-1 expression, as well as ICAM-1 expression, was higher in control SHRSP than in WKY. Such enhanced expression of adhesion molecules in SHRSP was ameliorated by the administration of AT1 receptor antagonist or ACEI, the former being more effective. AT1 receptor expression was higher in control SHRSP than in WKY, and was lower in the AT1 receptor antagonist group, whereas no difference was found in the ACEI group. No significant differences were found in GLUT-1 expression among all groups. In the case of hypertensive cerebral injuries in SHRSP, leukocytes may have an important role for initiation via adhesion to endothelial cells. AT1 receptor antagonist showed a beneficial effect for the amelioration of enhanced expression of adhesion molecule in both leukocytes and endothelial cells. Thus, AII seems to be an important mediator for the hypertensive microvascular injuries.

The order of ward rounds influences nosocomial infection. A 2-year study in gastroenterologic surgery patients.

We studied the effect of the order of ward rounds on nosocomial infection in gastroenterologic surgery patients. The subjects were patients with gastrointestinal diseases admitted between September 1992 and August 1994. During the 1st year, the round proceeded indiscriminately among recovery rooms and rooms with stable patients and isolated patients with methicillin-resistant Staphylococcus aureus (MRSA). In the subsequent year, the round started in the recovery rooms and moved into the general rooms with stable patients and finally into the isolation rooms. Against the time course, piecewise linear regression analyses were made with the number of culture-positive patients and the quantities of antibiotics and disinfectants used. Of a total of 1894 strains from 264 patients, isolates of MRSA (n = 200) decreased from 150 in the 1st year to 50 in the 2nd year. The number of MRSA-positive patients showed the point of inflexion in the analysis at the change of round order, with a later decrease. The trend was similar for Candida (n = 99) and Enterococcal (n = 225) species. The amount of antibiotics was unchanged while the amount of disinfectants used decreased in the 2nd year. Thus, the round re-ordering appeared to help prevent nosocomial infection. Ward rounds for patients who have had gastroenterologic surgery should proceed from compromised hosts to stable patients, and then isolated patients.

A newly established strain of spontaneously hypertensive rat with a defect of ascorbic acid biosynthesis.

To investigate the effects of ascorbic acid deficiency on the pathogenesis of hypertension and/or its complications, we established a rat strain with both genetic hypertension and a defect of ascorbic acid biosynthesis. The od gene (L-gulono-gamma-lactone oxidase gene) of the ODS (Osteogenic Disorder Shionogi) rat, which is a rat mutant unable to synthesize ascorbic acid, was introduced into spontaneously hypertensive rats (SHR), and a novel congenic strain, SHR-od, was established. SHR-od showed scurvy when fed an ascorbic acid-free diet. Systolic blood pressure of male SHR-od began to increase at 9 weeks of age and reached 190-200 mmHg at 20 weeks of age. In 25-week-old SHR-od, ascorbic acid deficiency when fed an ascorbic acid-free diet for 6 weeks caused a remarkable reduction of blood pressure to lower than 110 mmHg. The wall to lumen ratio of the testicular artery in ascorbic acid-deficient SHR-od was lower than that of the control rats. When rats were fed a diet supplemented with ascorbic acid (300 mg/kg), ascorbic acid concentration in SHR-od was lower in the serum and liver than that in ODS rats. These results indicate that ascorbic acid could be closely related to the development of hypertension in SHR-od. We believe that SHR-od will be a useful model for experimental studies on hypertension and its complications, since all of them suffer from hypertension spontaneously and the level of ascorbic acid deficiency in these rats could be controlled at will both in concentration and duration.

Effects of inducible nitric oxide synthase inhibition on cerebral edema in severe hypertension.

In order to clarify the causative role of cytotoxic nitric oxide (NO) in hypertensive cerebral injury, the effects of inducible nitric oxide synthase (iNOS) inhibition on leukocytes and endothelial function were examined using stroke-prone spontaneously hypertensive rats (SHRSP). For the iNOS inhibition, S-methylisothiourea (SMT) was administered to 12-week-old male SHRSP for 3 weeks. Immunohistochemical examination were carried out for the expression of intercellular adhesion molecule-1 (ICAM-1), glucose transporter-1 (GLUT-1), fibrinogen and glial fibrillary acidic protein (GFAP) in cerebral cortex. The effects of iNOS inhibition was also examined for Mac-1 expression by flow cytometric analysis. Plasma NO metabolites level was significantly lower in the SMT group than in the control group. Mac-1 expression was inhibited by SMT. In the SMT group, brain weight was significantly lower than in the control. By SMT administration, ICAM-1 expression was suppressed, GLUT-1 was enhanced, fibrinogen was decreased and GFAP was decreased as compared to those in control group. In hypertensive cerebral injury in SHRSP, iNOS-derived NO, mainly in activated leukocytes, could be an important causative factor for endothelial injury.

AT1 receptor antagonist prevents brain edema without lowering blood pressure.

In order to investigate the role of Angiotensin II (AII) for the vasogenic cerebral edema, the AT1 receptor antagonist (TCV-116) was administered to 19-week-old stroke-prone spontaneously hypertensive rats (SHRSP) for 2 weeks at a dosage which did not decrease the blood pressure. Although no remarkable changes were found in blood pressure after treatment, the average brain weight of the treated group was relatively lower as compared to that of control SHRSP and no edematous changes were found in any brains. The immunohistochemical expression of intercellular adhesion molecule-1 (ICAM-1) was less and the glucose transporter-1 (GLUT-1) expression was much more intense in the endothelial cells of the micro vessels in the cerebral cortex of the treated group. Fibrinogen expression around micro-vessels was also remarkably reduced in the treated group. A decreased expression of ICAM-1 in the treated group was confirmed by RT-PCR analysis. These results indicate that the AT1 receptor blockade ameliorates hypertensive cerebral injury in a blood pressure-independent manner and suggest that AII may have an important role for endothelial injury in severe hypertension.

Serum lactic dehydrogenase and its isoenzymes in patients with ovarian dysgerminoma.

Lactic dehydrogenase (LDH) is a glycolytic enzyme that may be elevated in the serum of patients with gonadal and extragonadal germinomas. In this report, a case of unilateral ovarian pure dysgerminoma with remarkably elevated levels of serum LDH is presented. After complete excision of the tumor, serum LDH levels promptly returned to normal levels. Although an electrophoretic pattern of serum LDH isoenzymes was within normal limits pre-operatively, an increase in LDH-1 and 2 was found 1 week after operation. Seventeen additional examples of ovarian dysgerminomas with elevated serum LDH levels have been reported in the English literature including five cases who had high levels of two fast fractions of LDH. These data suggest that serum LDH levels and its isoenzymes pattern are useful tumor markers for diagnosis and post-therapy surveillance in patients with ovarian dysgerminomas.

[A case of acquired immunodeficiency syndrome (AIDS) with histoplasmosis].

Fungal infection is a major opportunistic infection in AIDS. Histoplasmosis is often seen in American AIDS, but only one case has been reported in Japan. We report a AIDS case of with histoplasmosis in Japan. The patient was a forty year old male living in the U.S from 1987 to 1990. He was diagnosed as candidial esophagitis in July, 1994, and human immunodeficiency virus type 1 (HIV) antibody positive led to a diagnosis of AIDS. He was admitted to our hospital with fever and lymphadenopathy (neck, abdomen) in August. The therapy for candidial esophagitis was successful and he was recovering, but he was newly diagnosed as atypical mycobacteriosis and Kaposi's sarcoma. Though the fever was slight, it persisted. He was discharged from our hospital in October. He was readmitted for a high fever and dehydration in December, but died after a week from disseminated intravascular coagulation (DIC). Histoplasma capsulatum was found by blood and ascites cultures on second admission. Many yeast like histoplasma cells in granuloma of the liver were found at autopsy. For moderate or severe histoplasmosis, amphotericin B is generally used as the first induction therapy. Fluconazole (FLCZ) is used as a maintenance therapy. We did not use amphotericin B, but used FLCZ because we did not diagnose histoplasmosis before death, and his general condition became worse. The effect of FLCZ therapy was unclear in our case because he had other infections. We expect that AIDS with histoplasimosis will increase in Japan through HIV infected patients infected in the U.S.A.

[Multi-center evaluation to discriminate between the strains of methicillin-resistant Staphylococcus aureus (MRSA) and those susceptible (MSSA) by Showa oxacillin and methicillin disk susceptibility tests].

The Showa disk susceptibility test using two penicillinase-resistant penicillins, oxacillin and methicillin, was evaluated to discriminate between the strains of Staphylococcus aureus resistant to methicillin (MRSA) and those susceptible (MSSA) in the multi-center trials. The study included 651 clinical isolates of S. aureus, comprising of 329 MRSA and 322 MSSA isolates. The inhibitory zone diameters by Showa disks to oxacillin and methicillin highly correlated with minimum inhibitory concentrations (MICs) determined by standard agar dilutions with 0.961 and 0.930 correlation coefficients, respectively. Of 651 duplicate MIC determinations, 79.9% (oxacillin) and 80.3% (methicillin) were within +/- 1 log2 dilutions with each other. When Showa oxacillin and methicillin disks were incubated at 35 degrees C, sensitivity and specificity of oxacillin to detect MRSA were 95.4% and 98.1%, and those of methicillin were 94.8% and 95.2%. When tested on agar plates supplemented with 5% NaCl, sensitivity and specificity markedly improved to > 97%. Also, when incubated at 30 degrees C, sensitivity and specificity became to nearly 100%. Of 329 MRSA isolates, the interpretive criteria combined with incubation at 30 degrees C and testing onto 5% NaCl supplemented agar plates could correctly identify 324 (98.5%) and 329 (100%) isolates, respectively. In conclusion, when the Showa oxacillin and methicillin disk susceptibility tests were employed exactly according to the manufacturer's instruction, the test performances to detect MRSA were enough reliable to screen MRSA isolates in clinical microbiology laboratories.

[Multi-center evaluation of Showa ceftizoxime disk susceptibility test to discriminate between the strains of methicillin-resistant Staphylococcus aureus (MRSA) and those susceptible (MSSA)].

An increasing prevalence of methicillin-resistant Staphylococcus (S.) aureus (MRSA) has a serious therapeutic problem, and accurate methods to detect such strains are needed. We studied the antimicrobial susceptibility of S. aureus to ceftizoxime, in comparison with those to four other cephems (cefazolin, cefoxitin, latamoxef and cefmenoxime), by broth microdilutions and disk susceptibility tests, and also evaluated whether the reagents, in replace of penicillinase-resistant penicillins (PRPs), could discriminate between the strains of MRSA and those susceptible to PRPs (MSSA). A total of 651 clinical isolates of S. aureus were collected from six geographically different hospitals. All the strains collected were first classified into either MRSA (n = 329) or MSSA (n = 322) according to the interpretations of MRSA screening agar, minimum inhibitory concentrations (MICs) to oxacillin and methicillin (NCCLS M7-A2), and the presence or absence of mecA gene by polymerase chain reaction. In broth microdilution tests, the MICs of MRSA to ceftizoxime ranged > or = 64 micrograms/ml, whereas all the MSSA were at the concentration of < or = 16 micrograms/ml. The results of Showa disk diffusion tests highly correlated with those of MIC determinations. The distribution of inhibitory zone diameters to ceftizoxime were clearly divided into two groups; 99.2% (sensitivity) of MRSA had inhibitory zones of < or = 20 mm and 98.9% (specificity) of MSSA produced > or = 21 mm. It was concluded that the Showa ceftizoxime disk susceptibility test was useful and enough reliable to screen MRSA isolates in clinical laboratories.

Clinical features of patients suffering from Streptococcus milleri infections--a retrospective analysis.

We examined the clinical records of patients from whom S. milleri was isolated at Kyushu University Hospital from January 1987 through December 1988. Sixty-one patients were treated in 64 episodes with drainage or antibiotics. Oral and nasopharyngeal infections were observed in 27 cases, intrathoracic infections in 13, urogenital infections in 8, intraabdominal infections in 6 and skin and subcutaneous infections in 6. Except for acute bronchitis and urogenital infections, all of them were suppurative. As to underlying diseases, 21 patients had malignancies and 6 had diabetes mellitus. Leukocytopenia was not observed in any of the patients. S. milleri can be eradicated by treatment but it is sometimes replaced by other organisms. However, considering its tendency to cause suppurative infections, its pathogenic significance should be taken into account and patients should undergo surgical drainage combined with antibiotic therapy.