The effect of ephedrine and phenylephrine on BIS values during propofol anaesthesia

BACKGROUND

The purpose of this study was to evaluate the effect of ephedrine and phenylephrine on propofol concentrations and bispectral index during propofol anesthesia.

METHODS

General anaesthesia was induced with propofol and was maintained with propofol (4 mg kg-1 h-1) and fentanyl. Vecuronium was used to facilitate the artificial ventilation of the lungs. Patients with systolic blood pressure > 90 mmHg were defined as the control group (n = 16). Patients who had to be treated for larger decreases in arterial blood pressure (systolic blood pressure 60, whereas no patient in the control or phenylephrine groups had bispectral index >60. There were no significant differences in propofol concentrations or cardiac output relative to baseline at 3 or 10 min after the administration of ephedrine or phenylephrine.

CONCLUSIONS

Ephedrine increases bispectral index values without decreasing propofol concentrations during general anesthesia.

Slow rewarming improves jugular venous oxygen saturation during rewarming

BACKGROUND

There have been many studies regarding the etiology of postoperative cognitive dysfunction after coronary artery bypass graft (CABG) surgery. Although its etiology remains unresolved, one possible factor related to postoperative cognitive dysfunction is a reduced internal jugular venous oxygen hemoglobin saturation (SjvO2) during the rewarming period. The purpose of this study was to examine the effect of rewarming rates on SjvO2 during rewarming.

METHODS

One-hundred patients scheduled for elective CABG surgery were randomly divided into two groups; control group (0.48 +/- 0.09 degrees C, n = 50), slow rewarming group (0.24 +/- 0.09 degrees C, n = 50). After the induction of anesthesia, a fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to monitor SjvO2 continuously. Hemodynamic parameters, arterial and jugular venous blood gases were measured at nine time-points.

RESULTS

Cerebral desaturation (defined as a SjvO2 value below 50%) during rewarming was more frequent in the control group than in the slow group. Cerebral desaturation time (duration when SjvO2 was less than 50%) and the ratio of the cerebral desaturation time to the total CPB time in the control group differed significantly from those in the slow group (control group: 17 +/- 11 min, 12 +/- 4%, slow group: 10 +/- 8 min, 7 +/- 4%, respectively, P < 0.05). There was no significant difference in mini-mental state examination on the day before the operation nor at 1 month after the surgery among four values (the day before the operation: control group; 48 +/- 8, slow group; 48 +/- 7, at one month after the surgery: control group; 46 +/- 7, slow group; 45 +/- 9).

CONCLUSIONS

A slow rewarming rate could reduce the chance of a decrease in SjvO2 during rewarming.

Inhibition by docosahexaenoic acid of receptor-mediated Ca(2+) influx in rat vascular smooth muscle cells stimulated with 5-hydroxytryptamine

The effect of docosahexaenoic acid treatment on intracellular Ca(2+) dynamics in rat vascular smooth muscle cells stimulated with 5-hydroxytryptamine (5-HT) has been investigated in order to elucidate one of the mechanisms for its beneficial effect on cardiovascular disorders. The treatment of cells with 30 microM docosahexaenoic acid for 2 days inhibited an increase in intracellular Ca(2+) concentration induced by 5-HT (10 microM) and a depolarizing concentration of KCl (80 mM). Docosahexaenoic acid treatment significantly inhibited divalent cation influx stimulated by 5-HT and KCl, as measured by Mn(2+) quenching method, whereas had no effect on 5-HT-induced Ca(2+) release from the internal stores. Docosahexaenoic acid treatment also significantly inhibited 5-HT receptor-mediated Ca(2+) influx through Ni(2+)-insensitive channels that were distinct from store-operated channels. These results suggest that the specific inhibition of intracellular Ca(2+) dynamics in vascular smooth muscle cells may contribute to the beneficial properties of docosahexaenoic acid on cardiovascular disorders.

Left ventricular aneurysm without coronary artery disease, incidence and clinical features: clinical analysis of 11 cases

OBJECTIVE

To examine the incidence, underlying disease and clinical features of left ventricular aneurysm (LVA) not related to coronary artery occlusion.

METHODS

Retrospective review of consecutive patients who underwent both left ventriculography and coronary angiography.

PATIENTS

LVA was confirmed in 11 of 2,348 consecutive patients (0.47%).

RESULTS

The location of LVA was mainly in the apical region (81.8%). In five of the 11 patients (45.5%), the underlying heart disease was hypertrophic cardiomyopathy (HCM), including 4 patients of dilated phase and one patient of midventricular type. The serial ECG changes from left ventricular hypertrophy to abnormal Q wave and endomyocardial biopsy were useful for the differential diagnosis of these cases against myocardial infarction. The underlying disease of the remaining patients was: myocarditis (2 patients), arrhythmogenic right ventricular dysplasia (1 patient), Chagas' disease (1 patient), glycogen storage disease (1 patient), and sarcoidosis (1 patient). Ventricular tachycardia appeared in 9 of 11 cases (81.8%) including 2 patients with sustained ventricular tachycardia.

CONCLUSION

LVA formation without coronary artery disease was a rare phenomenon. The underlying disease was varied but the incidence of hypertrophic cardiomyopathy in the dilated phase was comparatively high. Ventricular tachycardia was a significant complication in these patients.

Jugular venous bulb oxygen saturation in patients with preexisting diabetes mellitus or stroke during normothermic cardiopulmonary bypass

BACKGROUND

The authors hypothesized that patients with cerebrovascular abnormalities or metabolic disorders may experience abnormality in cerebral circulation more frequently than patients without these risks. The current study attempted to assess jugular venous bulb oxygen saturation (SjvO2) in patients with preexisting diabetes mellitus or stroke undergoing normothermic cardiopulmonary bypass.

METHODS

Thirty-nine patients undergoing elective coronary artery bypass graft surgery were studied, including 19 age-matched control patients, 10 diabetic patients, and 9 patients with preexisting stroke A 4.0-French fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to continuously monitor internal SjvO2. Hemodynamic parameters and arterial and jugular venous blood gases were measured at seven time points: (1) after the induction of anesthesia and before the start of surgery, (2) just after the beginning of cardiopulmonary bypass, (3) 20 min after the beginning of bypass, (4) 40 min after the beginning of bypass, (5) 60 min after the beginning of bypass, (6) just after the cessation of bypass, and (7) at the end of the operation.

RESULTS

No significant differences were seen in mean arterial pressure, arterial carbon dioxide tension (PaCO2), or hemoglobin concentration among the three groups during the study. The SjvO2 value did not differ among the three groups after anesthesia induction and before surgery, just after the beginning of cardiopulmonary bypass, 60 min after the beginning of bypass, just after the end of bypass, or at the end of the operation. Significant differences between the control group and the diabetic and stroke groups were observed, however, at 20 min and 40 min after the beginning of bypass (at 20 min: control group 62.2 +/- 6.8%, diabetes group 48.4 +/- 5.1%, stroke group 45.9 +/- 6.3%; at 40 min: control group 62.6 +/- 5.2%, diabetes group 47.1 +/- 5.2%, stroke group 48.8 +/- 4.1% [values expressed as the mean +/- SD]; P < 0.05). Also, values in the diabetes and stroke groups were decreased at 20 min and 40 min after the beginning of bypass compared with before the start of surgery.

CONCLUSIONS

A reduced SjvO2 value was observed more frequently in patients with preexisting diabetes mellitus or stroke during normothermic cardiopulmonary bypass. It is possible that cerebral circulation during normothermic bypass is altered in patients with risk factors for cerebrovascular disorder.

[Malfunctioning of cerebral function monitors in three cases of carotid endarterectomy]

In three patients, EEG, jugular venous oxygen saturation (Sjvo2) and near infrared spectroscopy (NIRS) were monitored to detect cerebral ischemia during carotid endarterectomy. In all cases, no changes in Sjvo2 and NIRS were observed during carotid artery occlusion, but in two patients EEG showed changes when carotid artery was clamped. It is important to know the precise mechanism of cerebral monitors to assess the cerebral ischemia in patients with preexisting neurological disorder during carotid endarterectomy.

Activation of matrix metalloproteinase-2 in human breast cancer cells overexpressing cyclooxygenase-1 or -2

Human breast cancer cell line Hs578T was stably transfected with cDNA for cyclooxygenase-1 or -2. When the cells overexpressing cyclooxygenase-1 or -2 were stimulated with concanavalin A, the processing of matrix metalloproteinase-2 was observed with the aid of gelatin zymography. This processing was not seen in mock-transfected and original cells which did not express detectable cyclooxygenase activity. Furthermore, Northern blotting showed 8-13 fold induction of membrane-type 1 matrix metalloproteinase which processed matrix metalloproteinase-2 in the cells expressing cyclooxygenases. These findings suggest that both isoforms of cyclooxygenase mediate the processing of matrix metalloproteinase-2 through induction of membrane-type I metalloproteinase in breast cancer cells.

Adjuvant chemotherapy with a combination of mitoxantrone, methotrexate, 5-fluorouracil for node-positive breast cancer: phase II pilot study

A phase II pilot study was carried out on 30 patients to ascertain the toxicity and efficacy of combination chemotherapy with mitoxantrone, methotrexate, 5-fluorouracil (NMF) in the adjuvant setting for axillary lymph node-positive breast cancer. The NMF regimen was mitoxantrone 10 mg/m2, methotrexate 40 mg/m2, and 5-fluorouracil 600 mg/m2 administered i.v. on day 1, repeated every 3-4 weeks for 6 cycles. The median nadir WBC count was 2,000/microl; grade 4 leukocytopenia occurred only in 1 patient. Nausea and vomiting appeared as grade 0 and 1 severity in 26/30 patients. Alopecia was extremely mild, appeared as grade 0 and 1 in 29/30 patients. The overall and relapse-free survival rates were 67.8% and 68.4% at the 82-month follow-up, respectively. The overall survival rate in premenopausal patients was significantly better than that in postmenopausal patients (P<0.05). NMF is a well-tolerated combination regimen, suitable as adjuvant chemotherapy for node-positive breast cancer.

5-hydroxytryptamine induces transient Ca2+ influx through Ni2+-insensitive Ca2+ channels in rat vascular smooth muscle cells

The effects of Ni2+, a non-selective cation channel inhibitor, on 5-hydroxytryptamine (5-HT)- and angiotensin II (Ang II)-induced intracellular Ca2+ dynamics in rat aortic smooth muscle cells were investigated. Ni2+ (1 mM) significantly inhibited the transient increase in intracellular Ca2+ concentration ([Ca2+]i) induced by Ang II (100 nM) in aortic smooth muscle cells, as measured using fura-2. However, Ni2+ did not suppress the transient increase in Ca2+ influx induced by 5-HT (10 microM), while significantly suppressed the sustained increase. Ca2+ influx evoked by high KCl (80 mM), thapsigargin (TG) (1 microM) or depletion of intracellular Ca2+ store was almost completely suppressed by Ni2+. Ni2+ had no effect on 5-HT-induced inositol triphosphate production and Ca2+ release from the intracellular store(s). These results suggest that 5-HT, but not Ang II, induces transient Ca2+ influx through Ni2+-insensitive Ca2+ channels, which are distinguishable from the voltage-dependent or store-operated Ca2+ channels.

Balloon pump-induced pulsatile perfusion during cardiopulmonary bypass does not improve brain oxygenation

BACKGROUND

Whether pulsatile flow offers substantial advantages for brain protection during cardiopulmonary bypass is controversial. The purpose of this study is to determine whether differences exist between pulsatile and nonpulsatile bypass concerning the effects on internal jugular venous saturation and on the state of regional cerebral oxygenation during normothermia.

METHODS

Twenty-two patients undergoing elective coronary artery bypass grafting were randomly divided into 2 groups: group 1 (n = 11) received nonpulsatile perfusion during cardiopulmonary bypass and group 2 (n = 11) received pulsatile perfusion during bypass. We used an intra-aortic balloon pump to generate pulsatility. A spectrophotometric probe (INVOS 3100R, Somanetics, Troy, Mich) was used to assess the state of regional cerebral oxygenation. A 4F fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to monitor jugular venous oxygen saturation. Hemodynamic variables, arterial and jugular venous blood gases, and regional cerebral oxygenation were measured at 7 times points.

RESULTS

In both groups, jugular venous oxygen saturation decreased at the early stage of the cardiopulmonary bypass (P =.03). Five patients in group 1 and 6 in group 2 had a jugular venous oxygen saturation of less than 50%. In both groups, the regional cerebral oxygenation value decreased during cardiopulmonary bypass (P =.04).

CONCLUSIONS

The present results showed that pulsatility generated through the use of intra-aortic balloon pumping did not produce any beneficial effects on jugular venous oxygen saturation and regional cerebral oxygenation at normothermia.

Effects of hypothermic and normothermic cardiopulmonary bypass on brain oxygenation

BACKGROUND

In this study, we assessed the effects of normothermia and hypothermia during cardiopulmonary bypass (CPB) both on internal jugular venous oxygen saturation (SjvO2) and the regional cerebral oxygenation state (rSO2) estimated by near infrared spectroscopy (NIRS).

METHODS

Thirty patients scheduled for elective coronary artery bypass graft surgery (CABG) were randomly divided into two groups. Group 1 (n = 15) underwent surgery for normothermic (> 35 degrees C) CPB, and group 2 (n = 15) underwent surgery for hypothermic (30 degrees C) CPB, and alpha-stat regulation was applied. A 4.0-French fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to continuously monitor the SjvO2 value. To estimate the rSO2 state, a spectrophotometer probe was attached to the mid-forehead. SjvO2 and rSO2 values were then collected simultaneously using a computer.

RESULTS

Neither the cerebral desaturation time (duration during SjvO2 value below 50%), nor the ratio of the cerebral desaturation time to the total CPB time significantly differed (normothermic group: 18+/-6 min, 15+/-6%; hypothermic group: 17+/-6 min, 13+/-6%, respectively). The rSO2 value in the normothermic group decreased during the CPB period compared with the pre-CPB period. The rSO2 value in the hypothermic group did not change throughout the perioperative period.

CONCLUSIONS

These findings suggest that near infrared spectroscopy might be sensitive enough to detect subtle changes in regional cerebral oxygenation.

Chronic Chagas' heart disease in a Japanese-Brazilian traveler. A case report

A 57-year-old Japanese-Brazilian man, visiting Japan for only 9 days, was admitted to our hospital due to syncope and frequent ventricular premature beats. He grew up in a rural area of Brazil and moved to Sao Paulo in 1959 when he was 20 years old. We suspected chronic Chagas' heart disease, i.e., dilated cardiomyopathy with apical ventricular aneurysm, right bundle branch block with left anterior fascicular block, and various arrhythmias including supraventricular premature beats, ventricular premature beats and non-sustained ventricular tachycardia because he showed typical echo- and electrocardiographic features of the disease. Coronary arteriograms were normal, and left ventriculogram confirmed the existence of apical ventricular aneurysm. A left ventricle biopsy specimen showed hypertrophic cardiac muscle with mild fibrosis. The diagnosis of chronic Chagas' disease was finally confirmed by the demonstration of Trypanosoma cruzi itself in the blood as well as Trypanosoma cruzi antibodies.

Sentinel lymphadenectomy in breast cancer: identification of sentinel lymph node and detection of metastases

Sentinel lymphadenectomy is a useful way of assessing axillary status and obviating axillary dissection in patients with node-negative breast cancer. However, controversies remain concerning the optimal method to identify the sentinel lymph node (SLN) and detect micrometastases in this lymph node. We reviewed the literature concerning sentinel lymphadenectomy in breast cancer and reached the following conclusions: (a) A combination of preoperative lymphoscintigraphy with intraoperative dye-guided and gamma probe-guided methods achieves a higher rate of identification of SLN than any of these techniques alone. (b) Immediate and reliable intraoperative assessment of sentinel node status is vital to the technique's success. However, the reliability of sentinel node diagnosis using frozen sections is questionable, because micrometastatic foci cannot always be identified. (c) Hematoxylin and eosin (H&E) staining and/or immunohistochemistry on permanent sections are useful for the detection of micrometastases in the sentinel node. Although a reverse transcriptase-polymerase chain reaction (RT-PCR) method is more sensitive than H&E staining and immunohistochemistry, it would not distinguish benign from malignant epithelial cells in the SLN. Therefore, further study is required before sentinel lymphadenectomy gains general acceptance for patients with primary breast cancer.

Influence of mild to moderate obesity on left ventricular stress filling pattern in hypertension

In resting condition, obese subjects are described as having impaired diastolic filling. To examine the effect of mild to moderate obesity on left ventricular diastolic performance during stress in hypertension, we determined the filling responses to dynamic submaximal exercise in 19 obese hypertensive patients (body mass index, 26 to 30 kg/m2) with a normal left ventricular structure, 19 age- and sex-matched, non-obese hypertensive patients, and 19 age- and sex-matched, non-obese normotensive controls (mean age, 55+/-3 yr). Doppler echocardiographic studies were performed at baseline and 1 min after exercise on a supine ergometer bicycle. At rest, systolic function and filling indices, peak velocities of early (E) and late (A) filling, and their ratio (E/A), were similar in the two hypertensive groups, while normotensive controls had higher peak velocities of E and E/A. At a maximum workload of 75 W, blood pressure and heart rate increased similarly in the two hypertensive groups. Peak velocities of E and A increased significantly after exercise. The percentage change in the peak velocity of E was greater in obese hypertensive patients than in non-obese hypertensive patients and normotensive controls (23+/-4 vs. 12+/-3 and 14+/-3%, p < 0.05). Percentage changes in A and E/A were similar in the three groups. Our study suggests that mild to moderate obesity does not further worsen left ventricular diastolic filling at rest and mitigates diastolic filling abnormalities after exercise in hypertensive patients.

Dye-Guided Sentinel Lymphadenectomy in Clinically Node-Negative and Node-Positive Breast Cancer Patients

BACKGROUND: Sentinel lymphadenectomy has been used to assess the axillary nodal status in patients with breast cancer in an attempt to avoid unnecessary axillary dissection. Most studies have examined the utility of this procedure in clinically node-negative patients. However, the clinical evaluation of axillary nodes is often inaccurate for both clinically node-negative and clinically node-positive patients. METHODS: We performed dye-guided sentinel lymphadenectomy in both clinically node-negative and clinically node-positive patients with breast cancer. All patients also underwent a formal axillary dissection. The results of imprint cytology, frozen sections, and permanent sections of the sentinel lymph node (SLN) werecompared with each other and with histologic findings of the nonsentinel nodes. RESULTS: The SLN was identified in 30 (79%) of 38 patients with clinically negative nodes, and in 11 (92%) of 12 patients with clinically positive nodes. Forclinically node-negative patients, SLN evaluation yielded a diagnostic accuracyof 90%, a sensitivitiy of 72%, and a specificity of 100%. For clinically node-positive patients, these values were 100%, 100% and 100%, respectively. These values were not significantly different for the two groups of patients. CONCLUSION: Sentinel lymphadenectomy may be useful in assessing the axillarynodal status of both clinically node-positive and clinically node-negative breast cancer patients.

Effect of docosahexaenoic acid on intracellular calcium dynamics in vascular smooth muscle cells from normotensive and genetically hypertensive rats

The effects of DHA treatment on intracellular Ca2+ dynamics in aortic smooth muscle cells isolated from young stroke-prone spontaneously hypertensive rats (SHRSP) and age-matched normotensive Wistar Kyoto rats (WKY) were investigated. The resting intracellular Ca2+ concentration ([Ca2+]i) before stimulation and the peak [Ca2+]i induced by 5-HT, angiotensin II and depolarizing concentration of KC1 were higher in SHRSP than in WKY. When added to the culture medium for 2 days, DHA at a concentration of 30 microM significantly suppressed the peak [Ca2+]i induced by these stimulants in aortic smooth muscle cells isolated from WKY, whereas smooth muscle cells of SHRSP were refractory to the suppression. DHA had no suppressive effect on the 5-HT-induced increase in the inositol triphosphate production. The present study indicates that DHA can suppress receptor-mediated Ca2+ influx, at least, through the voltage-dependent channel, in vascular smooth muscle cells. Since the intracellular Ca2+ plays an important role in regulating vascular tone, the suppressive effect of DHA on [Ca2+]i in vascular smooth muscle cells may be contributed to the beneficial properties of DHA on cardiovascular disorders. The precise mechanisms of action remain to be elucidated.

Cerebral oxygenation during prostaglandin E1 induced hypotension

PURPOSE

To evaluate the cerebral oxygenation effects of hypotension induced by prostaglandin E1 (PGE1) during fentanyl-oxygen anaesthesia.

METHODS

Ten patients who underwent elective cardiac surgery received infusion of PGE1. After measuring the baseline arterial, mixed venous and internal jugular vein blood gases, systemic haemodynamics, and regional cerebral oxygen saturation (rSO2) estimated by INVOS 3100R, PGE1 was continuously infused at 0.25-0.65 microgram.kg-1.min-1 (mean dosage: 410 +/- 41.4 mg.kg-1.min-1) intravenously. Ten, 20 and 30 minutes after the start of drug infusions, blood gases described above were obtained simultaneously with the measurement of systemic haemodynamics and rSO2. Thirty minutes from the start of drug infusions, administration of PGE1 was stopped. The same parameters were measured again 10, 30 minutes after the stop of drug infusion.

RESULTS

PGE1 decreased mean arterial pressure (MAP) to approximately 70% of the baseline value (P < 0.05). PGE1 increased mixed venous saturation, but in contrast did not affect internal jugular pressure, internal jugular oxygen saturation and rSO2.

CONCLUSIONS

These results suggest that PGE1 is a suitable drug for induced hypotension because flow/metabolism coupling of brain and regional cerebral oxygenation were well maintained during hypotension.

Effect of docosahexaenoic acid on smooth muscle cell functions

There is increasing evidence that fish oil-enriched diets attenuate the progression of several types of human and experimental renal, intestinal and cardiovascular disorders, including hypertension. Docosahexaenoic acid (DHA), may be one of the active biological component. We previously reported that dietary DHA suppressed the progression of hypertension in stroke-prone spontaneously hypertensive rats (SHRSP). The purpose of this study is to clarify the in vitro effect of DHA on cultured smooth muscle cell functions such as cell growth, hypertrophy, NO release, and intracellular Ca2+ metabolism, which are involved in the regulatory mechanisms of vascular tone. Addition of DHA to the culture medium of aortic smooth muscle cells isolated from SHRSP and normotensive Wistar Kyoto rats (WKY) had no significant effects on cell growth or on cell hypertrophy induced by angiotensin II as measured by flow cytometry. DHA had no stimulatory effect on interleukin-1beta (10 ng/ml)-induced nitric oxide release from smooth muscle cells of SHRSP, but rather slightly inhibited it. However, the treatment of smooth muscle cells with DHA (30 microM) for 2 days significantly suppressed the increase in intracellular Ca2+ concentration induced by angiotensin II, but not by thapsigargin. This was due to the suppression of Ca2+ influx, as determined by Mn2+ influx experiment. These results indicate that DHA specifically suppresses Ca2+ mobilization into smooth muscle cells. This may be one of the mechanisms by which dietary DHA prevents the development of hypertension in SHRSP.

Effect of 5-hydroxytryptamine on intracellular calcium dynamics in cultured rat vascular smooth muscle cells

The present study elucidated the precise mechanism of 5-hydroxytryptamine (5-HT)-induced increase of intracellular Ca2+ concentration ([Ca2+]i) in cultured vascular smooth muscle cells isolated from rat aortic media. [Ca2+]i was measured using fluorescent Ca2+ indicator, fura-2. 5-HT caused a dose-dependent increase in [Ca2+]i, which was completely inhibited by ketanserin. alpha-Methyl-5-HT had an equipotent effect to 5-HT. Diltiazem at 10 microM partially suppressed the 5-HT-induced increase in [Ca2+]i. 5-HT also augmented Mn2+ influx, when monitored by Mn2+ quenching of fura-2 fluorescence. When extracellular Ca2+ (1.3 mM) was removed, a decrease in resting level and a small, transient increase in [Ca2+]i were observed. 5-HT stimulation also induced an increase in the production of inositol triphosphate. 5-HT-induced increase in [Ca2+]i was significantly, but partially inhibited by staurosporin and H-7. Phorbol 12-myristate 13-acetate induced an increase in [Ca2+]i, which was abolished by removal of extracellular Ca2+. 5-HT-induced increase in [Ca2+]i was not affected by the pretreatment with pertussis toxin (PTX), and was not accompanied by a change in cyclic AMP content. These results suggest that, in cultured rat aortic smooth muscle cells, 5-HT increases [Ca2+]i via 5-HT2 receptor subtype by inducing influx of extracellular Ca2+ partially through L-type voltage-dependent Ca2+ channel, as well as by mobilizing Ca2+ from its intracellular stores. Activation of protein kinase C may be positively involved in the regulatory mechanism of Ca2+ influx, but PTX-sensitive G protein and cyclic AMP seem to be not involved.

[A case of aortic dissection after the termination of cardiopulmonary bypass]

We report, a case of aortic dissection after the termination of cardiopulmonary bypass (CPB), which was diagnosed by transesophageal echocardiography (TEE). A 70-year old male with aortic regurgitation received aortic valve replacement. After the termination of CPB, the aortic dissection was diagnosed by TEE. Furthermore wall motion abnormality was found by TEE, and aorto-coronary bypass was performed after observation by TEE. This case report suggests that TEE is useful not only for diagnosis but also for therapeutic orientation of aortic dissection.

[Diastolic function in patients with coronary artery disease before and after CABG]

We evaluated diastolic cardiac function in 16 patients with coronary artery disease before and after coronary angioplasty using transesophageal echocardiography. Peak early diastolic and late diastolic filling velocities (E wave and A wave) and velocity time integrals of early and late diastolic filling (VTI-E and VTI-A) were measured by pulsed doppler echocardiography. The patients were divided into two groups: Group A; E/A > or = 1. Group B; E/A < 1. There were statistical differences between the two groups in E-acceleration time and VTI 0-33%/ total VTI at pre-coronary angioplasty period (P < 0.05). There were statistical differences in E-decelaration time and E-decelaration slope of group B before and after coronary angioplasty (p < 0.05). These results suggest that the left ventricular diastolic function in group B has recovered partly at one hour after coronary angioplasty.

[Specific modulation of vascular smooth muscle cell functions by docosahexaenoic acid]

There are increasing evidences that fish oil-enriched diets attenuate the progression of several types of human and experimental renal, intestinal and cardiovascular disorders including hypertension. Docosahexaenoic acid (DHA) may be one of the active biological component. We previously reported that dietary DHA suppressed the progression of hypertension in stroke-prone spontaneously hypertensive rats (SHRSP). The purpose of this study was to clarify the in vitro effect of DHA on vascular smooth muscle cell functions such as cell growth, hypertrophy, NO release, and intracellular Ca+2 dynamics which involves in the regulatory mechanisms of vascular tone. Addition of DHA to the culture medium of aortic smooth muscle cells isolated from SHRSP and normotensive Wistar Kyoto rats (WKY) had no significant effects on the cell growth, and cell hypertrophy induced by angiotensin II as measured by flow cytometer. DHA did not have a significant effect on interleukin-1 beta (10 ng/ml)-induced nitric oxide release from smooth muscle cells of SHRSP. However, the treatment of smooth muscle cells with DHA (30 microM) for 2 days significantly suppressed the increase in the intracellular Ca2+ concentration induced by 5-hydroxytryptamine, angiotensin II, depolarizing concentration of KCl, but not by thapsigargin. This suppression seems to be due to the suppression of Ca2+ influx, as determined by Mn2+ influx experiment. These results suggest that DHA specifically suppresses receptor-mediated Ca2+ influx in smooth muscle cells. This may be one of the mechanisms by which dietary DHA prevents the development of hypertension in SHRSP.

Breast conserving treatment versus modified radical mastectomy in Japanese patients with operable breast cancer

From January, 1988 to October, 1995, 96 patients with operable breast cancer were treated by breast conserving treatment (BCT) including wide excision and axillary dissection followed by breast radiation. During the same period, 188 patients were treated by modified radical mastectomy (MRM) with or without breast reconstruction. In order to compare the survival of BCT and MRM groups, univariate and multivariate analyses were performed in this retrospective study. Univariate analysis revealed that the 5-year survival rates in the BCT and MRM groups were 97% +/- 2% and 87% +/- 3%, respectively (p < 0.05 with the Cox-Mantel test). However, the baseline variables were different between the groups. The adjusted Cox regression analysis revealed that the results of BCT were almost equivalent with those of MRM. Moreover, no breast recurrence was found in the BCT group. Therefore, it is suggested that our technique of BCT is as effective as modified radical mastectomy in treating operable breast cancer in Japanese patients.

[A case of prosthetic valve malfunction found by transesophageal echocardiography soon after the termination of cardiopulmonary bypass]

We present a case of mitral prosthetic valve malfunction soon after the termination of cardiopulmonary bypass. One leaflet of the St. Jude prosthetic mitral valve was found immobilized in the closed position during diastole by transesophageal echocardiography, with no abnormal hemodynamic changes. We started cardiopulmonary bypass again, and removed residual chordae. TEE is an essential tool for evaluating prosthetic valve function after the valve replacement.

[The change of oxygen consumption and oxygen delivery in patients undergoing heart surgery during perioperative period]

We examined the changes of oxygen consumption (Vo2), oxygen delivery (Do2) and Vo2/Do2 in 38 patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) during perioperative period. There were no significant correlations between Svo2 and cardiac index. The Vo2/Do2 showed a good level at pre-CPB and 1 hour after CPB, but the value became deteriorated 4 and 12 hours after CPB. These data suggest that we should be careful about the oxygen debt in tissue 4 and 12 hours after CPB.

Cyclothialidine analogs, novel DNA gyrase inhibitors

DNA gyrase inhibitors, cyclothialidines B, C, D and E were isolated from four Streptomycete strains (NR 0659, NR 0660, NR 0661 and NR 0662). Their structures have been elucidated based on the amino acid analysis of the hydrolysates, NMR and HRFAB-MS experiments and shown to be cyclothialidine analogs. The absolute stereochemistry has been determined by the chiral HPLC analysis of the hydrolysates. Cyclothialidines B, D and E are novel and potent inhibitors of DNA gyrase.

The expression of E-cadherin as a prognostic factor in breast cancer

We examined the clinical significance of E-cadherin expression in 98 patients with breast cancer. E-cadherin expression significantly correlated with histologic grade (p=0.0323) and tended to correlate with the absence of axillary lymph node metastases (p=0.0646). The expression of E-cadherin was associated significantly with the recurrence rate (p=0.0334) and marginally associated with disease-free (p=0.0597) but not overall survival, in univariate analysis. The association between E-cadherin expression and disease-free survival was lost in multivariate analysis. The prognostic value of E-cadherin expression in breast cancer appears to be limited. A larger, prospective study with long-term follow-up is needed.

Primary culture of postnatal rat suprachiasmatic neurons in serum-free supplemented medium

We have previously reported that postnatal hypothalamic neurons can be maintained in low density culture using astrocyte conditioned medium. The present study was designed to establish a method for the culture of postnatal hypothalamic neurons in a chemically defined medium. Neurons were dissociated from the suprachiasmatic nucleus (SCN) of the hypothalamus of 21-day-old rats and plated on plastic dishes. First, the effects of several factors which have been known to exert trophic effects on neuronal cells were examined in culture medium containing 10% fetal bovine serum. We have found that platelet-derived growth factor, interleukin-1 beta and vitronectin in combination markedly increased the number of surviving neurons bearing processes. Next we tested such effects in serum-free minimum essential medium. When these factors were added together the SCN neurons could be maintained in culture for up to 3 weeks without medium change. In this supplemented medium, SCN neurons gradually extended processes from 3-5 days after plating, and the cell number with processes reached maximal at days 8-11. The cells were identified as SCN neurons by the immunocytochemical staining for microtubule-associated protein 2 (MAP2) and vasoactive intestinal polypeptide. This culture method may be valuable for investigating the electrophysiological properties and the mechanisms of regeneration of mature central neurons.

Inhibition by 5-HT7 receptor stimulation of GABAA receptor-activated current in cultured rat suprachiasmatic neurones

1. Whole-cell voltage-clamp recordings were made from postnatal rat suprachiasmatic (SCN) neurones to investigate possible modulation by 5-hydroxytryptamine (5-HT) of gamma-aminobutyric acid (GABA)-activated current (IGABA). 2. 5-HT reversibly inhibited IGABA in a concentration-dependent manner (10(-10) to 10(-6) M). (+/-)-8-Hydroxy-2-N,N-dipropylaminotetralin (8-OH-DPAT, 10(-10) to 10(-5) M) and 5-carboxamidotryptamine (10(-6) M) also inhibited IGABA, whereas 1-(2,5-dimethyl-4-iodophenyl)-2-aminopropane (DOI, 10(-6) M) had no significant effect. 3. The effect of 8-OH-DPAT (10(-7) M) was blocked by ritanserin (10(-7) M), but not by pindolol (10(-7) M). The effect of 5-HT was also suppressed by ritanserin, but not by pindolol, ketanserin (10(-7) M) or ICS 205-930 (10(-6) M). 4. 8-Bromo-cAMP (10(-3) M) or forskolin (5 x 10(-5) M) suppressed IGABA. The effects of forskolin and 5-HT were not additive. Furthermore, the effect of 5-HT (10(-7) M) was significantly reduced by N-[2-(methylamino)ethyl]-5-isoquinoline sulphonamide (H-8, 10(-6) M). 5. It is concluded that 5-HT inhibits IGABA in the SCN neurones, which involves the activation of 5-HT7 receptors and cAMP-coupled systems.

Pharmacological characteristics of GABAA responses in postnatal suprachiasmatic neurons in culture

The suprachiasmatic nucleus (SCN) is considered to be an endogenous circadian pacemaker. Previous studies have suggested functional roles of gamma-aminobutyric acid (GABA) in the control of circadian rhythms. In this study, the responses to applied GABA in cultured SCN neurons dissociated from postnatal rat hypothalamus were investigated using whole-cell voltage-clamp techniques. GABA and muscimol induced a large current response (EC50 values 5.3 and 1.6 microM, respectively), which was blocked by the GABAA antagonist bicuculline. This current response was also blocked by Zn2+ (0.5-50 microM) in a concentration-dependent manner, but was not potentiated by diazepam (10 microM) or ethanol (21 mM). These characteristics seem to correspond to those of GABAA receptors that lack gamma-type subunits.

Possibility for induction of convulsion by fleroxacin and its disposition in the central nervous system in animals

Fleroxacin and its metabolites were examined for their possibility of the induction of convulsion in mice, inhibitory activity on GABA receptor binding, and disposition in the central nervous system of mice, rats and dogs. No convulsion was evoked in mice at high oral combination doses of fleroxacin and fenbufen. Brain-to-serum concentration ratios of fleroxacin after oral dose were 0.13 in mice, 0.19 in rats and 0.28 in dogs. Rats showed no accumulation of fleroxacin in brain and similar elimination from brain to that from serum after the oral dose. Dogs exhibited the similar distribution of fleroxacin into various brain regions. The inhibitory effect of fleroxacin on GABA receptor binding was relatively weak and slightly potentiated in the presence of 4-biphenylacetic acid. Demethyl fleroxacin showed more potent inhibitory activity on GABA receptor binding and potentiation with 4-biphenylacetic acid. The combination of intravenous demethyl fleroxacin and oral fenbufen showed no convulsion in mice. Fleroxacin N-oxide showed only slight inhibitory activity on GABA receptor binding, being not influenced with 4-biphenylacetic acid.

Clinical pharmacokinetics and tolerance of fleroxacin in healthy male volunteers

The tolerance and pharmacokinetics of fleroxacin were studied in healthy male adult volunteers. The peak serum concentrations of unchanged fleroxacin were about 1.5, 3 and 5 mg/l at 1-2 h after single oral doses of 100, 200 and 400 mg, respectively. The apparent serum elimination half-life was about 10 h, independent of the dose. Fleroxacin, demethyl fleroxacin and fleroxacin N-oxide excreted in urine over 3 days accounted for about 75%, 5% and 5%, respectively, of the doses. The urine concentrations of unchanged drug were dose-related; the mean concentrations, sustained over 24 h, were about 50, 100 and 150 mg/l after 100, 200 and 400 mg doses, respectively. Food intake did not significantly influence the serum concentration and urinary excretion. Steady state serum concentrations were achieved from day 3 onwards by repeated doses of twice-a-day dosage regimen and were 2-4 and 5-9 mg/l after 200 and 400 mg bid, respectively. The mean concentrations of unchanged drug in urine were about 200 and 300 mg/l at the respective dosages. The pattern of urinary metabolites was not changed by repeated doses and 90% of repeat doses was recovered in urine, including metabolites. The serum protein binding of fleroxacin was 32%. The saliva concentration was 40% of the total serum concentration or 60% of the free serum concentration. The faecal recovery over 3 days was 3% of the dose following a single 200 mg dose after a meal. The unchanged drug concentrations in faeces during 400 mg repeated dosing were 100-150 mg/kg. No severe dose-related side-effects were observed during the study.

High-performance liquid chromatographic determination of 6,8-difluoro-1-(2-fluoroethyl)-1,4- dihydro-7-(4-methyl-1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid and its metabolites in laboratory animals

A simple, sensitive and specific high-performance liquid chromatographic method for a new quinolone antimicrobial agent, 6,8-difluoro-1-(2-fluoroethyl)-1,4- dihydro-7-(4-methyl-1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid (AM-833, I), and its metabolites in serum and urine has been developed for their simultaneous determination. This method is based on ion-pair extraction and separation by ion-pair reversed-phase chromatography with ultraviolet or fluorescence detection. The major metabolites in the serum and urine of mice, rats, dogs and monkeys were N-desmethyl I (compound II) and I N-oxide (compound III). Rabbit serum and urine contained N-desmethyl-3-oxo I (compound IV), 3-oxo I (compound V) and N-desmethyl-4-formyl I (compound VI) in addition to compounds I, II and III. Unchanged drug accounted for 80-90% of total serum concentrations in mice and more than 90% in rats, dogs and monkeys up to 6 h after dosing, whereas the fraction of compound I in rabbits was 34-67%. Unchanged drug was the most predominant in the urine of mice, rats, dogs and monkeys, whereas compound II was the most abundant in rabbit urine. Although rabbits and monkeys excreted 70-80% of dose in three-day urine, the total urinary excretion of mice, rats and dogs was relatively low, 40-50% of oral dose. The fraction of compound I in total urinary excretion was 63, 73, 27, 55 and 78% in mice, rats, rabbits, dogs and monkeys, respectively. These results suggest that there is a species difference in the metabolism and excretion pathway of compound I.

Oscillation of enzyme networks in spleen triggered by an immunopotentiator, bestatin

In order to understand the effects of an immunomodulator in vivo, we performed time series analysis on mice given an aminopeptidase inhibitor, bestatin. This agent, which is known to be an immunopotentiator, caused peculiar oscillation of the activities of various hydrolytic enzymes in spleen. Autocorrelation curves obtained from serial data of each enzymatic activity revealed that sine curve-type oscillations are brought about in enzyme networks by this inhibitor. Judging from the pattern of the variations of enzymatic activities, it seems that metabolic homeostasis is strongly affected by this agent. The inhibitor probably initiated the homeostatic movements directly and secondarily caused extensive changes in the enzyme networks in vivo. This effect of bestatin may be useful in altering the pathological homeostasis (such as the one in autoimmune diseases) by affecting the dynamic equilibrium among the various components in the immunological system.