Post-translational reduction of cell surface expression of insulin receptors by cyclosporin A, FK506 and rapamycin in bovine adrenal chromaffin cells

Long-term (>/=3 h) treatment of cultured bovine adrenal chromaffin cells with cyclosporin A (CsA) decreased cell surface (125)I-insulin binding by 62% in a concentration (IC(50)=18 microM)- and time (t(1/2)=16 h)-dependent manner, but did not change the K(d) value. FK506 (1 microM) or rapamycin (3 microM) treatment reduced (125)I-insulin binding. Western blot analysis showed that CsA treatment decreased insulin receptor (IR) beta-subunit level (t(1/2)=15 h) in membrane fraction, but did not alter total cellular levels of IR precursor and IR beta-subunit. Internalization rate of cell surface IR measured by using brefeldin A, an inhibitor of vesicular exit from the trans-Golgi network, was comparable between non-treated and CsA-treated cells. Thus, CsA, FK506 and rapamycin inhibit peptidyl prolyl cis-trans isomerase activities of cyclophilin and FK506-binding protein, and down-regulate IR presumably by reducing cell surface externalization of IR.

[Relation between hippocampal damage and cerebral cortical function in Alzheimer's disease]

We investigated the relation between hippocampal damage and cerebral cortical dysfunction in Alzheimer's disease (AD) using MRI and SPECT. Nineteen patients with AD and 10 control subjects were studied. Hippocampal damage (including hippocampal formation, entorhinal cortex, and parahippocampal white matter) was assessed to evaluate the severity of atrophy and the magnetization transfer ratio (MTR) and cerebral cortical dysfunction was evaluated by quantitative cerebral blood flow (CBF) measurements using SPECT with 99mTc-ECD. Compared with controls, patients with AD had significantly more atrophy of the medial temporal lobe and a decrease in MTRs of the hippocampus and parahippocampus. There were significant correlations between the severity of hippocampal damage and regional CBF in temporoparietal lobes. Mini-Mental State Examination scores significantly correlated with the severity of hippocampal damage and regional CBFs in temporoparietal lobes. These results suggest that the functional effect of hippocampal damage occurs in temporoparietal lobes in AD, probably due to neuronal disconnections between hippocampal areas (including the entorhinal cortex) and temporoparietal lobes.

Lidocaine disrupts axonal membrane of rat sciatic nerve in vitro

Highly concentrated lidocaine has been reported to induce irreversible loss of membrane potential in crayfish nerve, which implies membrane disruption as one of the direct mechanisms of lidocaine-induced neurotoxicity. To confirm lidocaine-induced membrane disruption in mammalian nerve, a lactate dehydrogenase (LDH) leakage from rat sciatic nerve was measured in vitro. Before applying lidocaine, the desheathed nerve was incubated for 60 min in Krebs-Ringer solution at 37 degrees C to examine basal LDH activity. It was then incubated in 80 mM lidocaine solution at pH 7.3 for 15, 30, 60, or 120 min. Other nerves were immersed in 800 mM choline solution for 120 min. Total LDH activity per wet weight of nerve tissue was assayed using spectrophotometry. It was also determined using nerves cut into 10 segments and incubated in distilled water for 60 min. The LDH activity in the lidocaine group showed a time-dependent increase. After the 60- and 120-min incubation with lidocaine, the amount of LDH activity was significantly increased compared with the choline group and was similar to that of the group incubated in distilled water. We conclude that 80 mM lidocaine may be sufficient to cause membrane damage and facilitate the leakage of enzymes from cytoplasm.

IMPLICATIONS

This study demonstrates that exposing the rat myelinated nerve to lidocaine at a clinically used concentration for more than 30 min causes enough membrane damage to allow enzyme leakage. In clinical practice, the smallest effective dose should be used.

[Comparison of epidural anesthesia and general anesthesia for patients with bronchial asthma]

We prospectively investigated the incidence of asthmatic attacks in 94 patients (1.5%) who were diagnosed as definite asthma. We separated the patients into three groups: epidural anesthesia (n = 10) including combined spinal/epidural anesthesia (n = 7), combined epidural and general anesthesia (n = 23), and general anesthesia (n = 54). General anesthesia was induced with propofol or midazolam and maintained with N2O and O2 with sevoflurane in adults. Patients who underwent epidural anesthesia and combined spinal and epidural anesthesia showed no asthmatic attacks. The incidence of bronchospasm with combined epidural and general anesthesia was 2/23. The incidence of bronchospasm with general anesthesia was 4/54. Bronchoconstriction occurred after tracheal intubation in 5 patients except in one patient, in whom it occurred after induction of anesthesia with midazolam. All episodes of bronchospasm in the operative period were treated successfully. The frequency of bronchospasm did not depend on the severity of asthmatic symptoms or the chronic use of bronchodilators before operation. These findings suggest that tracheal intubation, not the choice of anesthetic, plays an important role in the pathogenesis of bronchospasm.

Multi-effective properties of homogentisic acid revealed in reactions with human hemoglobin and human erythrocytic hemoglobin

Homogentisic acid (HGA) causes oxidation of human oxyhemoglobin and reduction of methemoglobin. The rate of oxidation of oxyhemoglobin by HGA is greatly accelerated in the presence of myo-inositol hexakis-phosphate (P6-inositol) or superoxide dismutase (SOD), but is inhibited in the presence of catalase. The reduction rate of methemoglobin by HGA is accelerated in the presence of P6-inositol but is greatly inhibited in the presence of SOD. It is suggested that the semiquinone and quinone form of HGA and oxygen radicals may be involved in the mechanism of oxido-reductive reactions of human hemoglobin with HGA. In addition, a new anodic hemoglobin found by isoelectric focusing electrophoresis was produced during the reaction of oxyhemoglobin with HGA. When human erythrocytes were exposed to HGA for several hours at 37 degrees C (pH 7.4), the anodic oxyhemoglobin (HGA-modified hemoglobin) and its half met-form hemoglobin [(alpha3+beta2+)2 of HGA-modified hemoglobin] were produced in significant amounts. HGA-modified hemoglobin was stably purified and showed increased oxygen affinity, absence of titratable sulfhydryl groups, and the absorption spectrum of normal oxyhemoglobin. Our results demonstrate that HGA shows multiple effects on human hemoglobin and erythrocytic hemoglobin, which is consistent with the evidence that HGA is involved in various pathological conditions such as arthritis and carcinogenesis in humans.

[Clinical findings of arteriosclerosis and serum lipoprotein(a) concentration in elderly patients]

This study was conducted to evaluate the relationship between arteriosclerosis and lipoprotein(a) [Lp(a)] from the point of view of aging. A total of 354 patients (167 men) aged 60 or more were enrolled and serum Lp(a) levels, vascular risks, and complications were studied. Patients were divided into 3 groups according to age: group I (n = 73: aged 60 to 69), group II (n = 144: aged 70-79), and group III (n = 137: aged 80 or more). Vascular complications were assessed by carotid ultrasonography (US), ECG, and ankle pressure index (API), US findings were stratified according to the distribution of plaque lesions in unilateral and bilateral lesions, while plaque types were subdivided based on the morphology and US echogenicity. Male patients with risk factors (diabetes, hypercholesterolemia, cigarette smoking) as well as stroke were frequent in group I, indicating some selection bias. However, there was no difference in Lp(a) level among the three groups. Carotid lesions, especially bilateral lesions with more thickened plaques, and low API were both significantly frequent in group III. Logistic regression analysis showed that carotid lesions were influenced not only by aging, but also independently by high Lp(a) levels in group III, and by hypertension in group II. A high Lp(a) level was related to hypercholesterolemia and hypoechoic plaque. These findings indicated that atherosclerosis, which developed in both the carotid and peripheral arteries with aging, was related to different risks in each decade of life. Furthermore, it seems that a long period of high Lp(a) levels may promote the formation of hypoechoic plaque.

Anti-tumor-promoting activity of lignans from the aerial part of Saussurea medusa

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Compositae plants were screened. Consequently, the lignans, arctiin (ARC) and arctigenin (ARC-G), were obtained from the aerial part of Saussurea medusaas active constituents. These compounds exhibited the remarkable anti-tumor-promoting effect on two-stage carcinogenesis test of mouse skin tumors induced by 7, 12-dimethylbenz[a]anthracene as an initiator and 12-O-tetradecanoyl phorbol-13-acetate as a promoter by both topical application and oral administration. Furthermore, ARC-G exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse pulmonary tumors induced by 4-nitroquinoline-N-oxide as an initiator and glycerol as a promoter.

Dietary short-chain fructooligosaccharides increase calbindin-D9k levels only in the large intestine in rats independent of dietary calcium deficiency or serum 1,25 dihydroxy vitamin D levels

Dietary short-chain fructooligosaccharides (Sc-FOS) increase mucosal calbindin-D9k (CaBP) levels in the large intestine whereas levels in the small intestine are decreased in rats. In the present study, we investigated the mechanism by which Sc-FOS induce this increase in CaBP in the large intestine by measuring intestinal CaBP levels in rats fed normal and calcium-deficient diets. Dietary groups included a calcium-containing (0.5%) diet with or without Sc-FOS (100 g/kg diet) and a calcium-deficient (abt. 0.01%) diet with or without Sc-FOS (100 g/kg diet). The rats were fed these diets for 10 days following which they were killed and the intestine removed for collection of the entire mucosa which was divided into four segments, i.e., proximal and distal segments of the small intestine, the cecum and the colorectum. Mucosal CaBP and plasma calcium (Ca), 1,25-dihydroxycholecalciferol (1,25(OH)2D3), 25-hydroxycholecalciferol (25(OH)D3), parathyroid hormone (PTH) and calcitonin levels were measured. Feeding of calcium deficient diet resulted in an increase in CaBP levels in the small intestine, but did not influence levels in the large intestine. Moreover, a significant positive correlation between plasma 1,25(OH)2D3 and CaBP levels in the case of both small intestinal segments (proximal, r = 0.77012, p < 0.00007; distal, r = 0.75056, p < 0.00014) was observed, but not in the case of the large intestinal segments. Sc-FOS increased CaBP levels in the large intestine. These results suggest that the large intestinal CaBP levels do not change in response to dietary calcium conditions and are not regulated by circulating 1,25(OH)2D3 indicating that the effect of Sc-FOS on CaBP levels in the large intestine is independent of the action of 1,25(OH)2D3.

Cancer chemopreventive activity of an iridoid glycoside, 8-acetylharpagide, from Ajuga decumbens

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Labiatae plants were screened. Consequently, the iridoid glycoside derivative, 8-acetylharpagide (8-AcHarp), was obtained from the flowering whole plant of Ajuga decumbens as an active constituent. This glycoside exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin tumors induced by nitric oxide (NO) donor, (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexen eamide (NOR 1) as an initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as a promoter. Further, 8-AcHarp exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse hepatic tumor using N-nitrosodiethylamine (DEN) as an initiator and phenobarbital (PB) as a promoter.

Simultaneous activation of N-methyl-D-aspartate and neurokinin-1 receptors modulates c-Fos and Zif/268 expression in the rat trigeminal nucleus caudalis

We examined the acute expression of c-Fos or Zif/268 by simultaneous activation of N-methyl-D-aspartate receptor and neurokinin-1 receptor of the trigeminal nucleus caudalis in anesthetized rats. A selective N-methyl-D-aspartate receptor agonist, N-methyl-D-aspartate, and/or a selective neurokinin-1 receptor agonist, substance P, was applied topically to the dorsal surface of the spinal trigeminal tract. Immunohistochemically stained nuclei for c-Fos and Zif/268 at laminae I and II of the trigeminal nucleus caudalis were counted. Ipsilateral c-Fos and Zif/268 were increased significantly dose-dependently by N-methyl-D-aspartate (at 136 and 340 microM, and at 68, 136 and 340 microM, respectively). On the contralateral side, only Zif/268 increased significantly (at 68, 136 or 340 microM). These increases were abolished by D-2-amino-5-phosphonovaleric acid (at 25 mM), a selective N-methyl-D-aspartate receptor antagonist. Substance P (at 3.7 or 7. 4 microM) significantly increased dose-dependently ipsilateral c-Fos and Zif/268. On the contralateral side, only c-Fos was significantly increased (at 3.7 and 7.4 microM). These increases were abolished by D-2-amino-5-phosphonovaleric acid (at 25 mM) and L-703,606 (at 10 microM), a selective neurokinin-1 receptor antagonist. The combined application of N-methyl-D-aspartate 340 microM + substance P (at 0.74 or 3.7 microM) significantly increased ipsilateral c-Fos compared to either agent alone. Combined application of N-methyl-D-aspartate 340 microM + substance P at 0.74, 3.7 or 7.4 microM significantly increased ipsilateral Zif/268 expression compared to either drug alone. Other combinations did not increase c-Fos and Zif/268. Our results indicate that activation of N-methyl-D-aspartate or neurokinin-1 receptor of the trigeminal nucleus caudalis contributes to the acute induction of both c-Fos and Zif/268 on the ipsilateral superficial layer of this nucleus and simultaneous activation of both receptors by their agonists with specific concentrations produces a marked expression of these proteins. Simultaneous activation of N-methyl-D-aspartate and neurokinin-1 receptors under some specific conditions may augment synaptic transmission, contributing to long-term neuronal change.

A study of peripheral airway findings using an ultrathin bronchofiberscope and bronchoalveolar lavage fluid with diffuse panbronchiolitis

We investigated the peripheral airways using an ultrathin bronchofiberscope and analyzed bronchoalveolar lavage fluid (BALF) in 10 patients with diffuse panbronchiolitis (DPB; refractory and responsive to treatment with macrolide antibiotics) and 10 healthy volunteers. Refractory DPB patients had obstruction at the 11th or 12th level of bronchial branches and secretion from the 5th to 6th order bronchi to the 11th-12th level of bronchial branches. In responsive DPB patients, there was no obstruction of peripheral airways, but secretion in the bronchial lumens still remained in nearly all observed bronchial branches. Despite macrolide therapy, BALF from patients with refractory DPB contained a high percentage of neutrophils and had a lower CD4/CD8 ratio. Two-color analysis of T cell subsets in BALF revealed a high percentage and number of CD8+S6F1+ cells (activated cytotoxic T cells) in refractory DPB patients. Our findings suggest that obstruction around the terminal bronchioles may be correlated with BALF abnormalities and may be irreversible despite macrolide therapy in progressive DPB.

Magnetization transfer measurements of the hippocampus in patients with Alzheimer's disease, vascular dementia, and other types of dementia

BACKGROUND AND PURPOSE

Although atrophy of structures in the medial temporal lobe has been considered an indication of Alzheimer's disease (AD), atrophic changes on MR images have also been associated with other dementing diseases and are not specific to AD. This study was undertaken to determine whether characteristic alterations in the hippocampus of patients with AD are detectable with magnetization transfer (MT) imaging.

METHODS

Coronal MT imaging was performed in 35 patients with probable AD, in 14 patients with vascular dementia, in 13 patients with other types of dementia, and in 23 control subjects to measure MT ratios of the hippocampus. Medial temporal lobe atrophy was graded subjectively on a five-point scale.

RESULTS

Scores of medial temporal lobe atrophy in all dementia groups were significantly higher than those in control subjects, but no differences were found among the dementia groups. MT ratios in the hippocampus were significantly lower in patients with AD than in those with non-AD dementia and in the control subjects; however, no differences were found between the non-AD dementia patients and the control subjects. MT ratio measurements were better than visual analysis of atrophy for differentiating AD patients from those with non-AD dementia (an overall discrimination rate of 77% versus 65%). MT ratios significantly correlated with scores on the Mini-Mental State Examination and with medial temporal lobe atrophy in AD patients but not in patients with non-AD dementia.

CONCLUSION

MT measurements may be more specific than visual analysis in detecting structural damage of the hippocampus in AD patients and might be useful in discriminating AD from vascular dementia and other types of dementia.

[Hemodynamics of the lower extremities in patients with decubitus ulcers using the ultrasonic Doppler method]

Our clinical experience indicates that decubitus ulcers with tissue loss/necrosis extending beyond the subcutaneous fat in aged patients are liable to become refractory and that most of these patients experience a cold feeling/cyanosis in the lower extremities. In order to determine the relationship between the severity of the decubitus ulcers and the hemodynamics in the lower extremities, we conducted a blood flow test using the ultrasonic Doppler method on the lower extremities in patients. Sixty-eight inpatients (38 men, 30 women, with an average age of 80.5 +/- 7.6 years old) were selected. B-mode tomographs were obtained with an ultrasonic diagnostic apparatus. The power Doppler method was used to measure blood flow rate, vascular lumen diameter, and intravascular blood flow at the dorsalis pedis artery, posterior tibial artery, peroneal artery furcation, and femoral artery. The subjects were divided into three groups: patients without decubitus ulcers; patients with mild to moderate decubitus ulcers of IAET Classification grade I-III; and patients with severe decubitus ulcers (IAET Classification grade IV), and the measurements were compared among the groups. The results revealed a tendency for the vascular lumen to become narrowed and intravascular blood flow to be reduced at all sites as decubitus ulcers increased in severity and showed the hemodynamics in the lower extremities to be particularly poor in the severe group. We measured the hemodynamics in the lower extremity with the ultrasonic Doppler method from the viewpoint of decubitus ulcer prevention and found differences in blood flow in the lower extremities according to the severity of decubitus ulcers. A reduction in blood flow in the lower extremities is considered to indirectly indicate a susceptibility to decubitus ulcers and to serve as a sign of its exacerbation. We consequently considered the test to be useful and concluded that deterioration of hemodynamics due to the progress of arteriosclerosis is one of the causes of decubitus ulcer exacerbation.

[Factors influencing platelet function in elderly patients with chronic phase thrombotic diseases]

To clarify the factors influencing platelet function in elderly patients with chronic thrombotic disease, platelet aggregability was studied in 839 blood samples from 497 patients with a variety of diseases. Clinical stage (thrombotic disease), vascular risk factors, and data concerning any administration of antiplatelet drugs were assessed, as well as brain computerized tomographic and carotid ultrasonographic findings. Platelet aggregability was determined spectrophotometrically with an aggregometer (PAM-8T) and adenosine-5'-diphosphate as an agonist to determine new parameters: the grading curve (GC) type, and platelet aggregability threshold index (PATI). Multiple regression analysis showed that the antiplatelet therapy greatly influenced the GC type. Platelet aggregability, which accelerated with aging, was strongly suppressed by ticlopidine. Furthermore, excluding samples with antiplatelet therapy, statistical analysis showed that platelet aggregability was accelerated in women, and in patients with bilateral or complicated carotid lesions, although these patients were significantly older than the others. These findings suggested that accelerated aggregability in the elderly substantially reflected the progress of arteriosclerosis with age. Moreover, the findings indicated that the determination of GC type and PATI were useful in monitoring elderly patients receiving antiplatelet therapy, especially with ticlopidine.

Flavonoid and benzophenone glycosides from Coleogyne ramosissima

A benzophenone glucoside and two flavonol glycosides were isolated together with 27 known polyphenols from the aerial parts of Coleogyne ramosissima, and their structures were elucidated by spectroscopic and chemical methods as iriflophenone 2-O-beta-glucopyranoside, isorhamnetin 3-O-2G-rhamnopyranosylrutinoside-7-O-alpha-rhamnopyranoside and limocitrin 3-O-rutinoside-7-O-beta-glucopyranoside, respectively.

Cancer chemopreventive activity of euglobal-G1 from leaves of Eucalyptus grandis

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Eucalyptus plants were screened. Consequently, the phlorogrucinol-monoterpene derivative, euglobal-G1 (EG-1), was obtained from the leaves of Eucalyptus grandis as an active constituent. EG-1 exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin tumors induced by 7, 12-dimethylbenz[a]anthracene (DMBA) as an initiator and fumonisin-B1, which has been known as one of mycotoxins produced by Fusarium monifliforme, as a promoter. Further, EG-1 exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse pulmonary tumor using 4-nitroquinoline-N-oxide (4-NQO) as an initiator and glycerol as a promoter.

Longitudinal evaluation of early Alzheimer's disease using brain perfusion SPECT

The aim of this SPECT study was to determine the initial abnormality and longitudinal changes in regional cerebral blood flow (rCBF) in early Alzheimer's disease (AD) using statistical parametric mapping (SPM).

METHODS

rCBF was noninvasively measured using (99m)Tc-ethyl cysteinate dimer SPECT in 32 patients complaining of mild cognitive impairment, with a Mini-Mental State Examination score more than 24 at the initial study, and 45 age-matched healthy volunteers. All patients satisfied the diagnostic criteria of AD during the follow-up period of at least 2 y. Follow-up SPECT studies were performed on the patients at a mean interval of 15 mo. We used the raw data (absolute rCBF parametric maps) and the adjusted rCBF images of relative flow distribution (normalization of global cerebral blood flow [CBF] for each subject to 50 mL/100 g/min with proportional scaling) to compare these groups with SPM.

RESULTS

In the baseline study, the adjusted rCBF was significantly and bilaterally decreased in the posterior cingulate gyri and precunei of patients compared with healthy volunteers. In the follow-up study, selected reduction of the adjusted rCBF was observed in the left hippocampus and parahippocampal gyrus. These areas showed the most prominent reduction in absolute rCBF on each occasion. Moreover, further decline of the absolute rCBF was longitudinally observed in extensive areas of the cerebral association cortex.

CONCLUSION

SPM analysis showed the characteristic early-AD rCBF pattern of selective decrease and longitudinal decline, which may be overlooked by a conventional region-of-interest technique with observer a priori choice and hypothesis. This alteration in rCBF may closely relate to the pathophysiologic process of this disease.

[A comparison of bullard laryngoscope and intubating laryngeal mask using fiberoptic guidance for tracheal intubation]

The purpose of this study is to compare the success rate of tracheal intubation, intubation time and laryngoscopic view of the larynx by Bullard laryngoscope or by intubating laryngeal mask using fiberoptic guidance in 50 patients. Following a standardized induction protocol, conventional laryngoscopic view by Macintosh's laryngoscope was obtained and classified by Cormack's grades. We measured the times from incertion of laryngoscopy or laryngeal mask until obtaining the best view of the larynx and until tracheal intubation. A best view by Bullard laryngoscopy or by fiberoscopy through the laryngeal mask was classified by Cormack's grades. The success rate of tracheal intubation was higher by Bullard laryngoscopy than by intubating laryngeal mask. The durations of laryngoscopy and tracheal intubation were significantly shorter and Cormack's grades were significantly lower by Bullard laryngoscopy than by laryngeal mask and fiberscopy. These results demonstrate that tracheal intubation by Bullard laryngoscope is faster and more successful compared with intubating laryngeal mask using fiberoptic guidance.

The cecum and dietary short-chain fructooligosaccharides are involved in preventing postgastrectomy anemia in rats

Dietary short-chain fructooligosaccharides (Sc-FOS) stimulate absorption of calcium and magnesium in the large intestine of rats. In this study, we examined whether Sc-FOS stimulate iron absorption in the large intestine by monitoring recovery from anemia in gastrectomized rats, with or without cecectomy. The rats were divided into four groups, i.e., sham-operated (Sham), gastrectomized only (GX), cecectomized only (CX) and both gastrectomized and cecectomized (GCX). Half of the rats in each group were fed a control diet (AIN-93G) and the other half were fed a Sc-FOS-containing diet (75 g/kg diet) for 28 d. Hematocrit (Ht) and hemoglobin concentration (Hb) were measured at the start, and on d 14 and 28 after the start of feeding. On the final day of the study, total blood was collected. Gastrectomy significantly decreased Ht and Hb, but cecectomy did not influence these variables. Dietary Sc-FOS prevented the decrease in Ht and Hb significantly. In the gastrectomized rats, the effectiveness of Sc-FOS in preventing postgastrectomy anemia was significantly diminished by cecectomy. These results suggest that the effect of Sc-FOS in increasing absorption of iron in gastrectomized rats takes place in part in the cecum. The cecum plays an important role in the mechanism by which Sc-FOS prevent postgastrectomy anemia.

Combination chemotherapy of continuous 5-FU infusion and low-dose cisplatin infusion for the treatment of advanced and recurrent gastric and colorectal adenocarcinomas

We evaluate the efficacy and toxicities of low-dose FP therapy in the treatment of advanced and recurrent gastric and colorectal adenocarcinomas. 104 patients (gastric adenocarcinoma: 52, colorectal adenocarcinoma: 52) were enrolled. Low-dose FP therapy consisted of 5-FU (160 mg/m2/day every day by continuous infusion) and cisplatin (3 mg/m2/day in 100 ml of normal saline by infusion over 30 minutes on days 1-5/W). Patients were treated for 4 consecutive weeks with subsequent one-week rest period. Ninety-four of 104 patients completed this therapy, and the treatment accomplishment rate was 90%; 82% in gastric adenocarcinomas, 96% in colorectal adenocarcinomas. Two cases had CR, and 47 cases had PR, with an overall response rate of 52.1%. Response rates, 50% survival time, 1-year survival rates, and 2-year survival rates were 65.9%, 249 days, 33.7%, 19.7% in gastric adenocarcinomas, and 40.0%, 466 days, 56.7%, 29.4% in colorectal adenocarcinomas, respectively. Nausea/vomiting was the most common toxicity, occurring in 44.2% of patients treated and was predominantly mild to moderate (up to Grade 2). In 5 cases Grade 3 toxicity was observed. Low-dose FP therapy has a high antineoplastic effect and low-grade toxicity, and this therapy should become the first-choice chemotherapy for the treatment of advanced and recurrent gastric and colorectal adenocarcinomas.

Optimum contact conditions for miniaturized surface acoustic wave linear motor

This paper reports the successful operation of a 70 MHz driving surface acoustic wave (SAW) linear motor with a miniaturized stator transducer. This paper also deals with an investigation into an optimized slider design for the miniaturized SAW linear motor. The performance of three silicon type sliders, with different projection size, was compared. Output forces of the three sliders were measured with change of pre-load. It was found that the slider with smaller projection tended to produce greater output force.

[Ultrasonographic findings of carotid arteries in female patients with arteriosclerosis obliterans and aortic aneurysm]

To clarify carotid arterial changes in female patients with arteriosclerosis obliterans (ASO) and aortic aneurysm (AA), ultrasonographic (US) findings of the extra-cranial carotid arteries were studied in 26 patients with ASO (ASO group), and 31 patients with AA (AA group), compared to 38 controls (control group) with neither ASO nor AA. ASO was diagnosed with an ankle pressure index less than 0.9, while AA was done with computed tomography or angiography. Half of the patients with ASO were in stage II of the Fontaine clinical staging, and angiography, performed in 12, showed femoral arterial obstruction in 10. Most AA patients were abdominal aortic aneurysm. Using a high-resolution, real-time, B-mode US instrument, the diameter and wall thickness of the common carotids were measured bilaterally in the end-diastolic phase, and occlusive changes and plaque were estimated. As a risk factor for arteriosclerosis, hypertension, diabetes, hyperlipidemia, and cigarette smoking were assessed, in addition to the age, body height and weight. Mean ages of each group were 73 to 76.3 year-old. There was no significant difference between them in body height and weight. Diabetes, cigarette smoking, and cerebrovascular disease were frequent in the ASO group, whereas ischemic heart disease was frequent in the AA group. US findings revealed that carotid lesions were mostly plaque, and bilateral carotid lesions were significantly more frequent in the ASO and AA groups. The mean wall thickness of the carotids was greater in the AA and ASO groups, although dilated carotid arteries, namely arteriomegaly, was more frequent in the AA group than in the ASO and control groups. Stepwise regression analyses demonstrated that strong correlations were seen between carotid lesion and two variables [vessel diseases (ASO/AA) and cigarette smoking], between carotid diameter and three variables (age, AA, and wall thickness), and between the wall thickness and three variables (age, vessel diseases and diameter). These findings showed that atherosclerosis was not only frequent in female patients with ASO and AA, but arteriomegaly was characteristic in female patients with AA. Therefore, it suggested that circulatory disturbance in whole organs due to arteriosclerosis should be paid attention even in female patients with ASO and AA as well as male patients. Furthermore, it is considered that systemic fragility of the arterial media and ectasia could be present extensively in patients with AA.

Boron nutrition of cultured tobacco BY-2 cells. III. Characterization of the boron-rhamnogalacturonan II complex in cells acclimated to low levels of boron

Cultured cells of tobacco (Nicotiana tabacum L.) BY-2 which could propagate at the same rate as the parent cells (1 mg B liter(-1)) under a lower level of boron (0.01 mg B liter(-1)) were obtained. The selected cells had swollen cell walls. In the parent cells, all the RG-II occurred as a B-RG-II complex, however, two-thirds of the RG-II occurred in a monomeric form in the selected cells.

Ephedrine, dopamine, or dobutamine to treat hypotension with propofol during epidural anesthesia

PURPOSE

To compare the efficacy of ephedrine, dopamine and dobutamine for circulatory support during thoracic epidural anesthesia after anesthetic induction with propofol.

METHODS

Forty patients undergoing lobectomy or mastectomy were divided into four groups of 10: a control group received no vasopressor; an ephedrine group received 5 mg ephedrine when the mean arterial pressure (MAP), measured every 2.5 min, decreased by 10% from baseline; dopamine and dobutamine groups received 5 microg x kg(-1) x min(-1) dopamine or 3 microg x kg(-1) x min(-1) dobutamine from five minutes after epidural injection of local anesthetic to the end of tracheal intubation. Anesthesia was induced with 2 mg x kg(-1) propofol. The MAP and heart rate (HR) were measured at baseline, 20 min after epidural injection, three minutes after propofol, and one minute after tracheal intubation.

RESULTS

In the control group, MAP and HR decreased from 86+/-9 mmHg, 74+/-8 bpm to 62+/-9 mm Hg; P<0.0001, 60+/-8 bpm; P = 0.0003 after propofol. After tracheal intubation, MAP was restored to (81+/-13 mmHg, 70+/-13 bpm). In the ephedrine, dopamine, and dobutamine groups, MAP and HR remained unchanged during epidural anesthesia and propofol induction. However, after tracheal intubation, MAP and HR increased in the ephedrine (104+/-11 mm Hg; P = 0.004, 87+/-11 bpm; P<0.0001) and dobutamine (117+/-13 mm Hg; P = 0.0005, 100+/-11 bpm; P<0.0001) groups, but not in the dopamine group compared with baseline.

CONCLUSION

Dopamine is preferable to ephedrine and dobutamine in providing hemodynamic stability during propofol induction and tracheal intubation following epidural anesthesia.

Comparisons of the anesthetic potency and intracellular concentrations of S(-) and R() bupivacaine and ropivacaine in crayfish giant axon in vitro

Levobupivacaine and ropivacaine are both single S(-) enantiomers that have less severe cardiotoxic and convulsant effects than racemic bupivacaine. We compared the anesthetic actions of S(-) bupivacaine, R(+) bupivacaine, and ropivacaine in vitro by studying their effects on action potential amplitude and the maximal rate of rise of action potential in crayfish giant axon. To clarify the difference of intracellular anesthetic concentration, the intracellular ionized anesthetic concentration was measured. Desheathed crayfish axons were stimulated at a frequency of either 0. 1 or 5 Hz and perfused with 1 mM of each anesthetic at pH 7.0. Intracellular anesthetic concentration was measured by us- ing local anesthetic-sensitive glass microelectrodes. At 0.1-Hz stimulation, no differences were observed in their potency. At 5-Hz stimulation, the order of magnitude of the mean percentage decrease in maximal rate of rise of action potential was S(-) bupivacaine > R(+) bupivacaine > ropivacaine. Intracellular local anesthetic concentration did not differ among the three anesthetics at 0.1 Hz and 5 Hz. We conclude that, compared with ropivacaine, S(-) bupivacaine has a more potent phasic blocking effect in crayfish giant axon. The intracellular local anesthetic concentrations of S(-), R(+) bupivacaine and ropivacaine were not significantly different, regardless of differences in blocking effect and stimulation frequency.

IMPLICATIONS

S(-) bupivacaine has a more potent phasic blocking effect than ropivacaine or R(+) bupivacaine in crayfish giant axons in vitro. An equivalent intracellular local anesthetic concentration for the three anesthetics was found, suggesting that the intracellular cationic local anesthetic concentration is not directly correlated with the intensity of block.

[Dementia and disability after initial cerebral thrombosis evaluated by MRI and their clinical course]

This study was conducted to clarify the relationship between long-term prognosis of functional status after stroke and the magnetic resonance imaging (MRI) findings as well as complications in the course. A total of 98 patients with initial cerebral thrombosis were enrolled, and 65 patients surviving 5 years after the event, were studied in terms of cognitive function and activity of daily living (ADL). Mean age at registration (3 months after the event) was 72.0 years-old and 44 were male. MRI findings were divided into eight categories including the size and laterality of infarction, in addition to six categories as previously described. The presence of dementia was identified according to the HDS-R and the DSM-III-R scales, and the extent of dementia, assessed with the CDR scale, was divided into 3 grades: none, mild, and severe. The extent of ADL status was also graded into 3 classes: independent, partially dependent, and completely dependent. Recurrence of stroke, pneumonia, and motor disorders (hip joint fracture) were counted as complications during the course. At baseline, dementia was identified in 44, consisting of 30 mild and 14 severe dementias. During 5 years, 11 cases with mild dementia showed deterioration, and 1 case without dementia developed mild dementia. At registration, there were 46 cases with partially dependent ADL status and 22 cases completely dependent, while deterioration of ADL was seen in 17 during 5 years. Multiple regression analyses showed that diffuse PVH and pneumonia were contributory factors to the development of dementia, while dementia, pneumonia and motor disorders were risk factors for deterioration of ADL. These findings suggested that in patients with cerebral thrombosis, especially in patients with diffuse PVH, pneumonia and motor disorders should be taken care of in order to prevent functional decline.

[Preliminary clinical evaluation of low-dose CDDP and continuous 5-FU therapy for advanced gallbladder cancer]

5-fluorouracil (5-FU) has been widely used for the treatment of gastrointestinal cancers. Low-dose cisplatin (CDDP) and continuous venous infusion of 5-FU have recently shown additive or synergistic antitumor effects in experimental models. In this study, we evaluated the clinical effects of low-dose CDDP and 5-FU (low-dose FP therapy) in patients with advanced gallbladder cancer. From December, 1993 to June, 1998, 13 patients with advanced gallbladder cancer were treated with low-dose FP therapy. Patients were eligible for this study if they had a bidimensionally measurable tumor. 5-FU (160 mg/m2/day) was continuously infused over 24 hours using an implantable port, and CDDP (3 mg/m2/day) was infused for one hour. The administration schedule consisted of 5-FU for 7 consecutive days and CDDP for 5 days followed by a 2-day rest, each for four weeks according to response and tolerance. Low-dose FP therapy was given to 12 patients (92.3%). The response rate was 66.7% and the median survival time was 151 days. The regimen was tolerable, with the most common toxicity being nausea (38.5%). There were no severe side effects except for one patient who suffered from grade 3 nausea. We conclude that low-dose FP therapy may be useful as a palliative chemotherapy for cases of advanced gallbladder cancer.

[Effects of healthy aging on the regional cerebral blood flow measurements using 99mTc-ECD SPECT assessed with statistical parametric mapping]

To clarify the effects of normal aging on the cerebral blood flow, regional cerebral blood flow measurements++ using a Patlak Plot method of 99mTc-ECD were performed in 53 normal volunteers aged 18 to 87 years old (mean = 47.9 years). The subjects, 29 men and 24 women, were normal on clinical examination, and had neither a history of neurological nor psychiatric disease and no abnormal CT or MRI images. Statistical parametric mapping (SPM) was used for automatching and an objective approach to analysis of SPECT image data. Global cerebral blood flow showed a significant decline with age (r = 0.406). The SPM analysis (voxel height; p < 0.001, Bonferroni correction; p < 0.05) demonstrated significant age-related decrease of relative rCBF in prefrontal cortices, anterior cingulate giri, and insular cortices-temporal poles bilaterally, these affected areas belonged to limbic or association cortices. Therefore, these decreases in rCBF may suggest cognitive changes that occur during normal aging.

Peripheral airway findings in chronic obstructive pulmonary disease using an ultrathin bronchoscope

The authors performed bronchoscopic examination using an ultrathin bronchoscope to determine the characteristics of the peripheral airways in chronic obstructive pulmonary disease (COPD). The study population comprised 13 healthy control subjects, 10 patients with chronic bronchitis without airflow limitation, and 20 patients with COPD. The COPD patients were divided clinically into 10 with chronic bronchitis and 10 with pulmonary emphysema. The peripheral airways were examined using an ultrathin bronchoscope. In chronic bronchitis, peripheral airways of the 11th or 12th generation showed a high frequency of obstruction and mucosal changes such as granulation. In pulmonary emphysema, the peripheral airways frequently showed a net-like appearance of the bronchial epithelium and obstruction at the 11th or 12th generation. Morphological changes of the small airways in chronic obstructive pulmonary disease can be detected by an ultrathin bronchoscope, and this method is likely to be useful for investigating the small airways in vivo.

Sympathetic and cardiovascular actions of orexins in conscious rats

The novel hypothalamic peptides orexin-A and orexin-B are known to induce feeding behavior when administered intracerebroventricularly, but little is known about other physiological functions. The renal sympathetic nerves play important roles in the homeostasis of body fluids and the circulatory system. We examined the effects of intracerebroventricularly administered orexins on mean arterial pressure (MAP), heart rate (HR), renal sympathetic nerve activity (RSNA), and plasma catecholamine in conscious rats. Orexin-A (0.3, 3. 0 nmol) provoked an increase in MAP (94.3 +/- 0.7 to 101.9 +/- 0.7 mmHg and 93.1 +/- 1.1 to 108.3 +/- 0.8 mmHg, respectively) and RSNA (28.0 +/- 7.0 and 57.9 +/- 12.3%, respectively). Similarly, orexin-B (0.3, 3.0 nmol) increased MAP (93.9 +/- 0.9 to 97.9 +/- 0.9 mmHg and 94.5 +/- 1.1 to 105.3 +/- 1.7 mmHg, respectively). Orexin-A and -B at 3.0 nmol also increased HR. In other conscious rats, a high dose of orexin-A and -B increased plasma norepinephrine. Plasma epinephrine only increased with a high dose of orexin-A. These results indicate that central orexins regulate sympathetic nerve activity and affect cardiovascular functions.

Cancer chemopreventive activity of majonoside-R2 from Vietnamese ginseng, Panax vietnamensis

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Panax plants were screened. Consequently, the ocotillol-type saponin, majonoside-R2 (MR2), was obtained from the rhizome and root of Panax vietnamensis (Vietnamese ginseng) as an active constituent. MR2 exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse hepatic tumor using N-nitrosodiethylamine (DEN) as an initiator and phenobarbital (PB) as a promoter. Further, MR2 exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin induced by nitric oxide (NO) donor/12-O-tetradecanoylphorbol-13-acetate (TPA) or peroxynitrite/TPA.

[Ambulatory and domiciliary cancer chemotherapy with forearm implant catheter system and low-dose CDDP + 5-FU therapy]

Shortening the period of hospitalizations and improving QOL attracting a great deal of attention in the field of medicine recently. Therefore, ambulatory and domiciliary treatment has become more important. This is not an exception in cancer therapy; the conversion from hospital treatment to ambulatory and domiciliary treatment is promoted. However, there is the danger of a lowered QOL as a resistant side effect, when the conventional cancer chemotherapy in the hospital is used as the ambulatory and domiciliary treatment. Recently, low-dose CDDP + 5-FU therapy (LFP therapy) that applies biochemical modulation has been developed for advanced gastrointestinal cancers. This therapy is thought to have a good antitumor effect and slight side effects, so it can be widely used. However, this therapy needs the continuous injection of 5-FU, so the hospital treatment was necessary, and ambulatory treatment was difficult with the usual administration method. Thus, we implanted a forearm central venous catheter system (forearm IVH reservoir), through which we can administer medication safely and conveniently without limiting the patient activity. LFP therapy was attempted in ambulatory and domiciliary treatment. Low-dose FP therapy consisted of 5-FU (160 mg/m2/day every day by continuous infusion) and cisplatin (3 mg/m2/day in 100 ml of normal saline by infusion over 30 minutes on days 1-5/W). Patients were treated for 4 consecutive weeks with a subsequent one-week rest period. The overall response rate was 52.1%. Grade 3 toxicity was observed in 5% of patients. An advantage was that in the ambulatory and domiciliary cancer chemotherapy the hematotoxicity was slight, and LFP therapy could be continued safely. In addition, it was also possible to attempt the improvement in QOL with the forearm IVH reservoir system. LFP therapy using the forearm IVH reservoir system may develop as a standard method of ambulatory and domiciliary cancer chemotherapy in the future.

[Brain computerized tomographic and ultrasonographic findings in patients with asymptomatic carotid bruits]

This study was conducted to clarify brain and carotid lesions in patients with asymptomatic carotid bruits and their characteristics. We studied 37 patients with carotid bruits, who had various diseases other than stroke and were all neurologically normal, using by brain computerized tomography (CT) and ultrasonography (US). On CT, localized low density areas (LDAs) and their distribution were assessed, as well as the grade of periventricular lucency (PVL). Carotid lesions on US were classified into 3 categories: plaque (locally thickened intima-media complex of 2.1 mm or more in thickness), stenosis (narrowed lumen between 50% and 90% of the linearly measured diameter), and occlusion (severely narrowed lumen more than 90%). Ankle pressure index (API) less than 0.9 was defined as low. Mean age was 73.2 years-old and 28 of them were men. Bruits were heard bilaterally in 15 patients. CT findings showed LDA in 13 patients (35%) and severe PVL in 12 patients (32%). Twenty-three LDAs (13 in the left hemisphere and 10 in the right hemisphere) were seen and all were considered to be infarctions. Nineteen LDAs, 13 of them seen in the basal ganglia, were lacunae. Another 3 LDAs were seen in the watershed zone between the middle and posterior cerebral arteries, whereas the remaining one was a small cortical infarction in the left premotor area in the middle cerebral artery territory. Ultrasonography showed carotid lesions in 65 of 74 carotid arteries (plaque in 28, stenosis in 26, and occlusion in 11) and low API in 18 of 37 patients. Compared with patients with normal CT finding, the frequency of hypertension (92% vs 50%) and ischemic heart disease (69% vs 29%) was significantly high in 13 patients with silent infarction, although there was no difference in US findings. In the hemisphere ipsilateral to the carotid with bruits, which was frequently stenotic, the frequency of infarction was similar to that in the hemisphere ipsilateral to the carotid with no bruit. Regression analysis revealed that hypertension significantly correlated with the presence of cerebral infarction. These findings indicated that incidence of infarction in the elderly patients with asymptomatic carotid bruits was high and was associated with hypertension and advanced atherosclerosis in many organs, including the carotid and peripheral arteries. The reason for the lack of symptoms was considered to be that most of the infarctions were lacunae and located in the basal ganglia, although infarction did not significantly correlate with bruits or carotid lesions.

[Is hippocampal atrophy a specific change for Alzheimer's disease?]

Although detection of hippocampal atrophy has been proposed for the diagnosis of Alzheimer's disease (AD), atrophic changes in MRI can be found in other dementia diseases. This study was undertaken to determine whether hippocampal atrophy was a specific change for AD. Coronal T 1-weighted images were performed in 36 patients with AD, 40 patients with non-AD including vascular dementia, frontemporal dementia, Parkinson's disease with dementia, dementia with Lewy bodies, progressive supranuclear palsy, and normal pressure hydrocephalus, 9 patients with age-associated memory impairment (AAMI), and 24 control subjects. Hippocampal atrophy was graded subjectively on a 5-point scale. Scores of hippocampal atrophy for AD (2.11 +/- 0.95) and non-AD (1.80 +/- 0.91) were significantly higher than those for controls (0.79 +/- 0.72). Scores for AD were also significantly higher than those for AAMI (1.11 +/- 0.160), but no difference was found between AD and non-AD. These results suggest that hippocampal atrophy is not a specific marker for AD and appears to be a common phenomenon in dementia syndromes.

Sevoflurane induced suppression of inhibitory synaptic transmission between soma-soma paired Lymnaea neurons

The cellular and synaptic mechanisms by which general anesthetics affect cell-cell communications in the nervous system remain poorly defined. In this study, we sought to determine how clinically relevant concentrations of sevoflurane affected inhibitory synaptic transmission between identified Lymnaea neurons in vitro. Inhibitory synapses were reconstructed in cell culture, between the somata of two functionally well-characterized neurons, right pedal dorsal 1 (RPeD1, the giant dopaminergic neuron) and visceral dorsal 4 (VD4). Clinically relevant concentrations of sevoflurane (1-4%) were tested for their effects on synaptic transmission and the intrinsic membrane properties of soma-soma paired cells. RPeD1- induced inhibitory postsynaptic potentials (IPSPs) in VD4 were completely and reversibly blocked by sevoflurane (4%). Sevoflurane also suppressed action potentials in both RPeD1 and VD4 cells. To determine whether the anesthetic-induced synaptic depression involved postsynaptic transmitter receptors, dopamine was pressure applied to VD4, either in the presence or absence of sevoflurane. Dopamine (10(-]5) M) activated a voltage-insensitive K(+) current in VD4. The same K(+) current was also altered by sevoflurane; however, the effects of two compounds were nonadditive. Because transmitter release from RPeD1 requires Ca(2+) influx through voltage-gated Ca(2+) channels, we next tested whether the anesthetic-induced synaptic depression involved these channels. Individually isolated RPeD1 somata were whole cell voltage clamped, and Ca(2+) currents were analyzed in control and various anesthetic conditions. Clinically relevant concentrations of sevoflurane did not significantly affect voltage-activated Ca(2+) channels in RPeD1. Taken together, this study provides the first direct evidence that sevoflurane-induced synaptic depression involves both pre- and postsynaptic ion channels.

Excitatory synaptogenesis between identified Lymnaea neurons requires extrinsic trophic factors and is mediated by receptor tyrosine kinases

Neurotrophic factors have well established roles in neuronal development and adult synaptic plasticity, but their precise role in synapse formation has yet to be determined. This paper provides the first direct evidence that neurotrophic factors in brain conditioned medium (CM) differentially regulate excitatory and inhibitory synapse formation. Somata of identified presynaptic and postsynaptic neurons were isolated from the CNS of Lymnaea and were cultured in a soma-soma configuration in the presence (CM) or absence [defined medium (DM)] of trophic factors. In DM, excitatory synapses did not form. When they were paired in CM or in DM containing Lymnaea epidermal growth factor (EGF); however, all presynaptic neurons reestablished their specific excitatory synapses, which had electrical properties similar to those seen in vivo. CM-induced formation of excitatory synapses required transcription and de novo protein synthesis, as indicated by the observations that synapse formation was blocked by the protein synthesis inhibitor anisomycin and the protein transcription blocker actinomycin D; the CM factor was inactivated by boiling. They were also blocked by receptor tyrosine kinase inhibitors (lavendustin A, genistein, K252a, and KT5926) but not by inactive analogs (genistin and lavendustin B), suggesting that the effect was mediated by receptor tyrosine kinases. These results, together with our previously published data, demonstrate that trophic factors are required for excitatory, but not inhibitory, synapse formation and extends the role of EGF from cell proliferation, neurite outgrowth, and survival to excitatory synapse formation.

Anti-carcinogenic activity of the roots of Panax notoginseng. II

The extract of the roots of Panax notoginseng (Araliaceae) exhibited a significant anti-tumor-promoting activity on two-stage carcinogenesis of mouse skin tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and a mycotoxin, fumonisin B1, as a non-12-O-tetradecanoylphorbol-13-acetate (non-TPA) type promoter. Further, the extract exhibited the anti-tumor-initiating activity on two-stage carcinogenesis of mouse skin tumors induced by a nitric oxide donor, (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexen amide (NOR-1) as an initiator and TPA as a promoter.

Nociceptin modulates renal sympathetic nerve activity through a central action in conscious rats

Nociceptin, an endogenous agonist of the opioid receptor-like(1) receptor, is expressed in the hypothalamus, where it is implicated in autonomic nervous system control. However, the central actions of nociceptin on sympathetic nerve activity have not been studied. We investigated the effect of intracerebroventricularly administered nociceptin (2-10 nmol) on blood pressure, heart rate (HR), and renal sympathetic nerve activity (RSNA) in conscious rats and sinoaortic-denervated (SAD) rats. Intracerebroventricularly administered nociceptin resulted in a dose-dependent decrease in mean arterial pressure (MAP) and HR in intact rats. RSNA decreased 31.5 +/- 2.1 and 19.9 +/- 5.0% at a dose of 2 and 5 nmol, respectively. In SAD rats, MAP, HR, and RSNA decreased in a dose-dependent manner, and the maximum responses were larger than those in intact rats. The decrease in HR induced by nociceptin was blocked by propranolol but not by atropine, which indicates that nociceptin is acting by inhibiting cardiac sympathetic outflow. These nociceptin-induced depressor and bradycardic responses were not antagonized by pretreatment with naloxone and nocistatin. These findings suggest that central nociceptin may have a functional role in regulating cardiovascular and sympathetic nervous systems.

Effects of levobupivacaine, bupivacaine, and ropivacaine on tail-flick response and motor function in rats following epidural or intrathecal administration

BACKGROUND AND OBJECTIVES

Commercially available bupivacaine is a racemic mixture of S (-)- and R(+)-enantiomers. Although the S(-)-enantiomers levobupivacaine and ropivacaine are less toxic to the cardiovascular and central nervous systems than bupivacaine, their relative efficacy has not been determined. This study directly compares the dose response of levobupivacaine, ropivacaine, and bupivacaine following epidural and intrathecal administration in the rat.

METHODS

The time course of change in tail-flick latency and qualitative motor function was studied in rats following epidural or intrathecal administration of 0.25-0.75% levobupivacaine, ropivacaine, or bupivacaine in blinded, randomized fashion.

RESULTS

Levobupivacaine and bupivacaine produced comparable and significantly enduring antinociceptive effects compared with ropivacaine at all test concentrations following both epidural and intrathecal administrations. Duration of motor block at lower local anesthetic concentrations (epidurally and intrathecally) was comparable with levobupivacaine and ropivacaine but significantly shorter than with bupivacaine. Epidural 0.75% levobupivacaine and bupivacaine showed more enduring motor block than ropivacaine.

CONCLUSIONS

Levobupivacaine, given epidurally or intrathecally, produces longer lasting antinociceptive action than ropivacaine at equivalent concentrations and similar motor blocking effect at lower concentrations in both epidural and intrathecal administrations. Levobupivacaine-induced prolongation of the tail-flick latency is comparable to that of bupivacaine, as is motor blocking effect at higher concentrations. The possibility of significant differential block with levobupivacaine compared with bupivacaine warrants further study.

[Comparison of the effect of rapid infusion of lactated and that of acetated Ringer's solutions on maternal and fetal metabolism and acid-base balance]

The maternal and neonatal metabolism and acid-base balance were investigated in 20 parturients undergoing combined spinal and epidural anesthesia for cesarean delivery. Patients received intravenous infusion at a rate of either 25 ml.kg-1.h-1 of lactated (LR group, n = 10) or acetated (AR group, n = 10) Ringer's solution before anesthesia, to prevent hypotension during anesthesia. We obtained venous blood samples as follows; maternal control before anesthesia, maternal sample A after the infusion, umbilical sample B, and neonatal pedal sample C 5 h after birth, and determined lactate, pyruvate, bicarbonate, and base excess concentrations, and pH in each sample. In sample A, the lactate level was significantly higher and base excess level was significantly lower in the LR group than in the AR group. The pH of sample A and B was significantly higher in the AR group than in the LR group. However, no differences in all parameters of sample C between the two groups were observed. These results demonstrated that acetated Ringer's solution is better than lactated Ringer's solution in rapid infusion before cesarean section because of the correction of neonatal lactic acidosis.

[Changes of bone marrow arteries with aging]

The purpose of this study was to investigate the mechanism of so-called senile anemia. Using bone marrow tissue specimens prepared from 168 patients autopsied at the Second Department of Pathology of Tokyo Medical University, we measured the area of fatty marrow tissue and the luminal cross-sectional area of feeding arteries for the marrow to assess the relationship of these parameters with aging. Conversion to fatty marrow progressed with aging, and fatty marrow made up more than 50% of the overall bone marrow area in patients aged over 60 years. The nucleated cell count decreased significantly (p < 0.01) in patients aged over 60 years. Furthermore, the luminal cross-sectional area of bone marrow feeding arteries also decreased gradually with aging, declining by 18% to 26% in patients aged over 50 years compared with patients in their third decade. A significant negative correlation (r = -0.228; p < 0.001) was found between the area of fatty marrow and the luminal cross-sectional area of the bone marrow feeding arteries. In conclusion, we suggest that artherosclerotic changes associated with aging in the bone marrow have an impact on hematopoietic function and may be one of the factors involved in the development of senile anemia.

Age-related changes in alpha-tocopherol dynamics with relation to lipid hydroperoxide content and fluidity of rat erythrocyte membrane

Age-related changes in alpha-tocopherol dynamics in plasma and erythrocyte membranes of 10- to 120-week-old rats were investigated by high-performance liquid chromatography (HPLC) with redox detection mode. Furthermore, changes in lipid hydroperoxide content and fluidity of erythrocyte membrane with age were assessed using chemiluminescence-HPLC and Fourier transform infrared spectrophotometer, respectively. A slight increase in the alpha-tocopherolquinone/alpha-tocopherol ratio in erythrocyte membrane and a decrease in the alpha-tocopherol in erythrocyte membrane/alpha-tocopherol in plasma ratio were observed. A significant increase in lipid hydroperoxide content and a marked decrease in the fluidity of erythrocyte membrane were seen with age. These findings suggest that alpha-tocopherol uptake in erythrocyte membrane declines, and utilization rate of alpha-tocopherol in erythrocyte membrane increases age-dependently. These changes, which enhanced lipid peroxidation and consequently reduced membrane fluidity, may be caused by the impairment of this transfer mechanism.

[Assessment of brain cell function using 123I-IMP SPECT of cerebral blood flow and visual evoked potential by photic stimulation in normal and demented elderly subjects]

Cerebral blood flow was quantitatively measured using 123I-IMP SPECT by photic stimulation and visual evoked potential (VEPs) in normal and dementia subjects: 8 with Alzheimer-type dementia, 9 with cerebrovascular dementia and 7 normal elderly subjects were divided into the three groups based on the Clinical Dementia Rating (CDR) grade: Group I (CDR 0), Group II (CDR 0.5-1), Group III (CDR 2-3). The 123I-IMP SPECT measurement was conducted at rest with the eyes closed and also during photic stimulation. VEPs were measured simultaneously. The results reveal prolongation of the P2 latency of the VEPs prolonged in accordance with the increasing severity of the dementia, and quantitative cerebral blood flow was lower in Group II and Group III than in Group I at rest, while during photic stimulation it significantly increased in Group I and II, but showed no change in Group III. The results suggest that quantitative measurement of cerebral blood flow using 123I-IMP SPECT by photic stimulation may enable more detailed assessment of brain cell function.

Dietary heme iron does not prevent postgastrectomy anemia but fructooligosaccharides improve bioavailability of heme iron in rats

Gastrectomized rats exhibit iron deficiency anemia. We observed the effects of dietary heme-iron and short chain frucooligosaccharides (Sc-FOS) in relation to prevention of postgastrectomy anemia in rats. Twelve laparotomized (sham-operated) rats were fed iron-citrate (control) as iron source diet without or with Sc-FOS (75 g/kg of diet) and twenty four totally gastrectomized (Bilroth II) rats, were fed a iron-citrate (control) or heme-iron (heme) as iron source diet without or with Sc-FOS (75 g/kg of diet) for 4 weeks. All rats received an intramuscular injection of vitamin B-12 every two weeks. Tail blood was collected every other week for determination of hematocrit and hemoglobin concentration. At the end of the experiment, the rats were killed and whole blood was collected. The total gastrectomy induced the postgastrectomy anemia. Dietary Sc-FOS increase iron absorption and thereby prevented completely this anemia in gastrectomized rats fed the control diet but this effect of Sc-FOS in rats fed heme diet was not complete. Dietary heme iron could not prevent postgastrectomy anemia itself, but fructooligosaccharides improve bioavailability of not only non-heme iron such as iron-citrate, but also heme-iron in rats.

Anti-tumor promoting activity of polyphenols from Cowania mexicana and Coleogyne ramosissima

Chemical investigation on polyphenol-rich fractions of Cowania mexicana and Coleogyne ramosissima (Rosaceae) which showed significant inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), has led to the characterization of 10 compounds including C-glucosidic ellagitannin monomers and dimers from the former plant, and 17 polyphenols including flavonoid glycosides from the latter. The effects of individual components and their analogues with related structures on the TPA-induced EBV-EA activation were then evaluated. Among the compounds isolated from C. mexicana, two C-glucosidic ellagitannins, alienanin B and stenophyllanin A and a nitrile glucoside (lithospermoside), and among the constituents from C. ramosissima, two flavonoid glycosides, isorhamnetin 3-0-beta-D-glucoside and narcissin were revealed to possess strong inhibitory effects on EVB-EA activation, the potencies of which were either comparable to or stronger than that of a green tea polyphenol, (-)-epigallocatechin gallate. These polyphenols except for nitrile glucoside, which was not tested owing to an insufficient amount, were also found to exhibit anti-tumor promoting activity in two-stage mouse skin carcinogenesis using 7,12-dimethylbenz[a]anthracene (DMBA) and TPA.

Diffusion-weighted and magnetization transfer imaging of the corpus callosum in Alzheimer's disease

We investigated structural changes of the corpus callosum in patients with Alzheimer's disease (AD) using sagittal diffusion-weighted (DW) and magnetization transfer (MT) imaging. Patients with AD (n=23) had a significantly decreased area only in the posterior portion of the corpus callosum. Apparent diffusion coefficient (ADC) values perpendicular to the commisural fiber orientation were significantly higher in the anterior portion of the corpus callosum without definite atrophy, as well as in the posterior portion with significant atrophy, in patients with AD than in controls (n=16) and thus diffusion in these regions showed a significantly lower degree of anisotropy in patients than in controls. MT ratios were also significantly lower in patients with AD in the anterior and posterior portions of the corpus callosum than in controls. These findings probably reflect structural changes in the corpus callosum including axonal loss and/or demyelination. DW and MT imagings may be useful in detecting degeneration of the corpus callosum in AD.