The iothalamate clearance in cats with experimentally induced renal failure

Plasma iothalamate (IOT) disappearance rates were measured after a single-injection of IOT (113.8 mg/kg, IV) in cats with experimentally induced renal failure. The disappearance rates especially fitted into the one compartment model. The mean value of plasma disappearance rates of IOT in these cats with induced renal failure (2.16 +/- 0.240 x 10(-3) micrograms/ml/min) was markedly lower than that of clinically healthy cats (4.10 +/- 1.00 x 10(-3) micrograms/ml/min). These results demonstrate that IOT clearance is available for evaluation of renal function in cats.

Effects of different inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, pravastatin sodium and simvastatin, on sterol synthesis and immunological functions in human lymphocytes in vitro

It has been shown previously that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (HMG-CoA RIs) such as compactin and lovastatin suppress human lymphocyte functions in vitro (Cuthbert and Lipsky, 1981; Cutts and Bankhurst, 1989). Although it is not fully understood what inhibitory role the HMG-CoA RIs perform in causing this suppression, we show in this study that a certain inhibition threshold (inhibition level > 90%) of lymphocytic HMG-CoA reductase is required for the HMG-CoA RIs to attain effective inhibitory action in human lymphocyte lymphocyte functions in vitro. Thus the inhibitory activity of simvastatin, a lipophilic inhibitor, on sterol synthesis (HMG-CoA reductase activity) in lymphocytes was as much as 430 times more potent than that of pravastatin sodium, a hydrophilic inhibitor (IC50; 0.013 microM and 5.6 microM, respectively), and although pravastatin sodium and simvastatin at concentration levels of 10 and 0.016 microM respectively, inhibited the sterol synthesis in just over 50%, they failed to inhibit the lymphocyte functions. Significant inhibition (P < 0.01) of lymphocyte functions, including lymphocyte proliferative response to a variety of stimuli and activated natural killer-cell cytotoxicity, was demonstrated only when greater than 90% of the sterol synthesis in lymphocytes was inhibited by either simvastatin or simvastatin sodium salt at concentrations above 2 microM. This simvastatin-induced inhibition of lymphocyte functions was almost completely reversed by the addition of a 1 mM solution of mevalonate. Although simvastatin at a lower clinical blood concentration of 0.016 microM failed to inhibit either lymphocyte functions or HMG-CoA reductase activity sufficiently, at this level it caused a significant increase in cyclosporin A-induced suppression of T-cell response. These results infer that insufficient inhibition (in the 50% region) of HMG-CoA reductase activity by a low clinical blood concentration of HMG-CoA RIs, could still render the lymphocytes susceptible to immunosuppressive treatments. Pravastatin sodium on the other hand, is inactive in inhibiting lymphocyte functions in vitro, and such inactivity can be explained solely of the basis of its failure to inhibit HMG-CoA reductase activity in lymphocytes sufficiently.

Prognostic value of monolayer culture patterning in primary cell culture of oesophageal cancer

The growth of primary cell cultures of oesophageal cancer was compared with the clinical outcome of patients from whom the cancers were taken. Ninety-three patients underwent curative resection, with no operative deaths, and were divided into three groups according to the monolayer culture pattern of the primary cell culture: culture from 43 patients (46 per cent) grew no malignant cells (group 1), 21 (23 per cent) produced monolayer epithelial growth (group 2) and the rest (from 29 patients) established cell lines (group 3). The 5-year survival rate of patients in group 2 (29 per cent) and group 3 (23 per cent) was significantly lower (P < 0.005) than that of those in group 1 (51 per cent). Monolayer epithelial growth potential is a significant prognostic factor in patients with oesophageal cancer.

Dynamic Structural Change of 3-D Illusory Surface Observed with Binocular Viewing

When adequate visual stimuli are suitably arranged, for example, partially along the surface boundary or beyond the covering illusory surface, an opaque or transparent illusory surface can be seen (Idesawa, 1991 Japanese Journal of Applied Physics30-4B L751 – 754; 30-7B L1289). By moving the visual stimuli of the occluding objects which were not physically depicted, several interesting phenomena have been observed.

Dynamic fusion and separation of illusory surfaces have been observed when the visual stimuli were changed continuously between two different conditions; only one illusory surface was perceived in the first condition and two separate illusory surfaces were perceived in the second condition. Hysteresis was recognised in the geometrical positions between fusion and separation of the surfaces.

In addition, elastically distorting illusory surfaces have been observed when the positions of two occluding objects, placed on opposite sides, were moved continuously in a sinusoidal way in opposite phase between two positions where the two illusory surfaces could not be bridged together when they were stationary. The phenomena have been observed both for opaque and for transparent illusory surfaces. They could be interpreted as reflections of the surface-perceiving process in our visual system. Probably our visual system tends to contain the previously perceived structure; then the transition from one structure to another is delayed until the geometrical conditions change sufficiently to break the previously perceived structure.

Cavernous hemangioma of the adrenal gland: MRI appearance

We describe a case of cavernous hemangioma of the adrenal gland in which MR imaging showed low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, and dynamic MR imaging using Gd-DTPA showed late and delayed enhancement, allowing definitive diagnosis.

Spinal subdural hematoma

We report the case of a 68-year-old patient with a traumatic spinal subdural hematoma. MRI demonstrated an area of abnormal intensity and a black line in the inner part of the intradural space. We anticipate that MRI will help to make one more confident in the preoperative diagnosis of spinal subdural hematoma. The symptoms completely disappeared immediately after the operation. Spinal subdural hematoma requires immediate surgical evacuation. The prognosis for functional recovery is good if the condition is appropriately diagnosed and treated before development of irreversible paralysis. We recommend MRI to make an early diagnosis and early evacuation of spinal subdural hematoma.

Growth suppression of esophageal cancer cells by p16INK4 and p15INK4B in vitro

PURPOSE

We investigate whether p16INK4 and p15INK4B inhibit cellular proliferation and exert a growth suppressive effect on esophageal cancer cells.

MATERIALS AND METHODS

The growth suppressive effects of p16INK4 and p15INK4B were evaluated by transfecting vectors containing the p16INK4 cDNA or the p15INK4B cDNA, or both, constitutively driven by a cytomegalovirus promoter, into two human esophageal cancer cell lines containing or lacking endogenous p16INK4 and/or p15INK4B.

RESULTS

These experiments demonstrated that in both cells lines tested, the numbers of cells surviving dramatically decreased in p16INK4-transfected and p15INK4B-transfected cells compared with control vector-transfected cells. There was no significant difference in the degree of growth inhibition between p16INK4-transfected and pI5INK4B-transfected cell lines.

CONCLUSIONS

These results suggest that p16INK4 and p15INK4B play important roles in the initiation or promotion of esophageal cancer. The inactivation of p16INK4 and p15INK4B may contribute to uncontrolled growth in human cancer.

[Prognostic factors for esophageal cancer--from the viewpoint of molecular biology]

The prognostic factors for esophageal cancer from the viewpoint of molecular biology are reviewed. Among several oncogenes and suppressor genes erbB, int2/hst1/Cyclin D1 and MDM2 gene amplifications are significant prognostic factors for esophageal cancer. The value of p53 mutation, and expression of matrix metalloproteinase (MMPs) in the prediction of patients' survival are controversial, so further research is needed. High expression of tumor proliferation-related factors (Ki67, PCNA, and AgNOR), abnormalities of adhesion molecule (E-Cadherin, alpha-Catenin), activation of autocrine mechanism of growth factor (EGFR-TGF alpha, EGF), and DNA ploidy pattern, which is thought to be the result of an accumulation of genomic abnormalities are also prognostic factors for esophageal cancer.

Heterogeneous aging of macrophage-lineage cells in the capacity for TNF production and self renewal in C57BL/6 mice

We examined age-related changes in both tumor necrosis factor-alpha (TNF) producing ability and the replicative capacity of macrophage-lineage cells from different anatomical tissues concomitantly in mice. We have previously demonstrated that alveolar macrophages of aged mice secreted decreased amounts of TNF activity compared with that of younger counterpart. In this study, it is demonstrated that peritoneal macrophages exhibited increased TNF activity with aging, while the bone marrow-derived adherent cells secreted less TNF activity. In addition, we showed that the numbers of their progenitor cells (GM-CFUs) in the bone marrow increased with age, whereas those in the spleen did not change with aging. We conclude that age associated changes in functions and proliferative capacities of macrophage-lineage cells are tissue dependent.

[Care of esophageal cancer patients with diabetes mellitus--preoperative management and treatment]

The care of esophageal cancer patients with diabetes mellitus is described. The main points are as follows. 1. Prevention and control of infection. 2. Sufficient nutritional support (2000 Kcal/day) and hydration. 3. Control of plasma glucose level (150 mg/dl-250 mg/dl) by means of insulin. 4. An absence of ketone bodies and minimum glucose level (< 10 g/day) in the urine. 5. Prevention and control of hypoglycemia. Good control of diabetes mellitus in esophageal cancer patients may contribute to reduced surgical rislcs.

Lipoprotein lipase activity of post-heparin plasma in Japanese black cattle affected with fat necrosis

Post-heparin plasma (PHP) lipoprotein lipase (LPL) activity and serum lipoprotein concentration were examined in Japanese Black cows affected with fat necrosis. The PHP-LPL activity in the affected cows was significantly (P < 0.001) higher than in normal animals and tended to reduce 4 weeks after treatment with isoprothiolane. This finding indicates that affected cows have a predisposition to deposit more fat into adipose tissue than normal animals. The serum concentrations of triglyceride in beta-lipoprotein and of cholesterol, phospholipid and total lipid in alpha-lipoprotein were significantly (P < 0.05) lower in the affected cows. Elevated levels of phospholipid and total lipid in alpha-lipoprotein as well as decreased levels of non-esterified fatty acid (NEFA) were observed after medication. It is suggested that isoprothiolane produces an improvement in hepatic lipid metabolism including acceleration of plasma NEFA uptake and alpha-lipoprotein secretion in affected cows.

Temperature-dependent cardioprotection of exogenous substrates in long-term heart preservation with continuous perfusion: twenty-four-hour preservation of isolated rat heart with St. Thomas' Hospital solution containing glucose, insulin, and aspartate

BACKGROUND AND METHODS

Using an isolated working rat heart model, we determined the effects of glucose, insulin, and aspartate on recovery of cardiac function when used as components of preservation solution at different temperatures. After measurement of baseline cardiac function, hearts (n = 6 per group) were perfused with oxygenated St. Thomas' Hospital solution containing (1) vehicle, glucose (9 mmol/L) or aspartate (20 mmol/L) for 12 hours at either 20 degrees or 4 degrees C; (2) glucose or glucose + insulin (10 U/L) at 20 degrees C for 20 hours; and (3) glucose + insulin at 20 degrees C or glucose + insulin + aspartate at either 20 degrees or 4 degrees C for 24 hours. Cardiac function was measured after preservation and expressed as a percentage of baseline values.

RESULTS

At 20 degrees C, both glucose and aspartate increased recovery of cardiac output (vehicle, 57.7% +/- 3.8%; glucose, 76.5% +/- 2.4% [p < 0.05 versus vehicle]; aspartate, 79.9% +/- 1.4% [p < 0.05 versus vehicle]). At 4 degrees C, glucose decreased recovery of cardiac output, whereas aspartate did not change the value (vehicle, 74.4% +/- 2.2%; glucose, 61.4% +/- 2.8% [p < 0.05 versus vehicle]; aspartate, 80.5% +/- 1.7%). The addition of insulin to glucose increased recovery of cardiac output (glucose, 24.6% +/- 4.0%; insulin + glucose, 69.2% +/- 2.0%: p < 0.05). The combined use of these three agents showed an additive effect in improvement of recovery of cardiac output at 20 degrees C (glucose + insulin, 64.2% +/- 2.2%; glucose + insulin + aspartate, 76.0% +/- 1.1%; p < 0.05), but the recovery at 4 degrees C (63.1% +/- 1.8%) was significantly lower than at 20 degrees C.

CONCLUSIONS

These results suggest that glucose and aspartate afford differential cardioprotective effects depending on the temperature of the preservation solution and that combined use of glucose, insulin, and aspartate at the optimal temperature may extend graft preservation time.

Alterations in spectral characteristics of heart rate variability as a correlate of cardiac autonomic dysfunction after esophagectomy or pulmonary resection

BACKGROUND

Both esophagectomy and pulmonary resection are associated with postoperative cardiac complications, partly because of autonomic perturbations involving the heart. This study was undertaken to determine whether heart rate variability (HRV), employed as an index of cardiac autonomic function, changes in patients undergoing esophagectomy or pulmonary resection.

METHODS

Electrocardiographic RR intervals were measured in 20 esophagectomized patients, 10 undergoing right and 10 undergoing left pulmonary resection on the preoperative day as baseline data and on postoperative days 1, 3, 5, 7, 14, and 30. Instantaneous heart rate was calculated every 250 ms from 416-s data of RR intervals. Power spectra of HRV for 128 s were computed using a fast Fourier transform and normalized by squared mean heart rate. The average ten sets of normalized HRV power were obtained by integrating the following power spectral bands: the low-, (0.06-0.10 Hz), high- (0.15-0.40 Hz), and total-frequency regions (0.01-0.40 Hz).

RESULTS

In the esophagectomy group, mean low-, high-, and total-frequency HRV power decreased after surgery to 17%, 6%, and 15% of their preoperative values, respectively, and these indexes remained suppressed for up to 30 days. After right pulmonary resection, low- and total-frequency HRV power decreased through 30 and 7 postoperative days, respectively. In the left pulmonary resection group, HRV remained unchanged. In the esophagectomy group, mean (+/- SEM) heart rate increased from 78 (+/- 3) bpm to more than 90 bpm throughout the study, and body temperature from 36.5 (+/- 0.1) degrees C to more than 37.0 degrees C through 14 postoperative days. Heart rate and body temperature remained increased for 3 days after pulmonary surgery. Mean arterial pressure remained unchanged in the three surgical groups.

CONCLUSIONS

Reductions indicate HRV after esophagectomy or right pulmonary resection indicate a substantial and prolonged surgical injury to the autonomic nervous control of pulse rate.

Effects of water ingestion on gastric electrical activity and heart-rate variability in healthy human subjects

Electrogastrography (EGG) is a method to record electrical activity of the stomach using cutaneous electrodes. Power ratio (PR) is one of the parameters and means the relative change of EGG power of gastric activity from before to after certain stimulations (e.g., meals, water or drugs). Autonomic nervous function is an important modulator of gastric activity, but its relation with the EGG parameters has not been well clarified. We recorded EGG and the R-R interval simultaneously both before and after drinking 150 ml water for 400 s, and spectrally analyzed them using the maximum entropy method in 12 healthy volunteers. We calculated PR from before to after water ingestion, and the power of the high-frequency component of R-R interval variability before (pre-HF) and after water ingestion (post-HF), and their ratio (rHF = post-HF/pre-HF). PR was positively correlated with rHR (r = 0.727; P < 0.05) and negatively correlated with pre-HF (r = 0.706; P < 0.05), and rHF was negatively correlated with pre-HF (r = 0.776; P < 0.05). These results suggest that simultaneous recording of EGG and ECG for frequency domain analysis is necessary to estimate the vagal nervous activity.

Origin of nerves supplying the posterior portion of lumbar intervertebral discs in rats

STUDY DESIGN

The authors studied the origin of nerves supplying the posterior portion of lumbar intervertebral discs in rats by resection of the sympathetic trunks.

OBJECTIVE

To understand discogenic low back pain from the innervation of the lumbar intervertebral discs.

SUMMARY OF BACKGROUND DATA

The afferent pathways of discogenic low back pain have not been studied thoroughly. It has been reported that stimulation of an inflamed lower spinal nerve root elicits leg pain but not low back pain and that stimulation of the posterior portion of lumbar intervertebral discs evokes only low back pain. These facts suggest that pain sensation from the posterior portion of lumbar discs is not transmitted via the lower spinal nerve roots.

METHODS

Forty-five Wistar rats were used. Seven days after the resection of sympathetic trunks with ganglia at different levels, the whole lumbar spine was stained by an acetylcholinesterase histochemical method. The posterior portions of lumbar intervertebral discs were observed.

RESULTS

The dense nerve network on the posterior portion of lumbar intervertebral discs had disappeared almost completely after total resection of bilateral sympathetic trunks at L2-L6. However, there was a slight decrease in the network after bilateral single-level resection or unilateral multisegmental resection.

CONCLUSIONS

The results showed that the posterior portion of lumbar intervertebral discs was innervated by the sympathetic nerves multisegmentally and bilaterally.

Inter- and intrahemispheric EEG coherence during light drowsiness

The present study was conducted to examine inter- and intrahemispheric EEG coherence in 14 healthy, right-handed adults during wakefulness and light drowsiness as assessed by eye movement and EEG activity. Interhemispheric coherence was significantly lower during light drowsiness than during wakefulness for O1-O2 in the alpha-1 band and for F3-F4 in the beta-1 band. Intrahemispheric EEG coherence was significantly higher during light drowsiness for C4-O2 in the theta-1 and beta-1 bands. These findings indicate that light drowsiness can alter both inter- and intrahemispheric EEG coherence when compared with wakefulness, suggesting that cerebral functional organization changes during light drowsiness. It is important, therefore, to control arousal level of subjects in future studies dealing with the relationship between EEG coherence and various pathological conditions.

The mechanism of comparable serum cholesterol lowering effects of pravastatin sodium, a 3-hydroxy-3-methylglutaryl coenzyme A inhibitor, between once- and twice-daily treatment regimens in beagle dogs and rabbits

In dogs, no significant difference in the reduction of serum cholesterol was observed among three dosing regimens of pravastatin: once in the morning (3 mg/kg), once in the evening (3 mg/kg), and twice-daily (1.5 mg/kg x 2) for 21 days. In rabbits, pravastatin was administered at a dose of 50 mg/kg once-daily given in the evening or 25 mg/kg twice-daily for 14 days; the respective serum and liver cholesterol levels were decreased by 41% and 7% in the once-daily dosing and by 51% and 11% in the twice-daily dosing. The amount of low density lipoprotein (LDL) receptor protein was increased 1.2-1.3-fold (P < 0.05) by both treatments, and no significant difference was noted between these treatment regimens. In addition, there was no significant difference in the extent of up-regulated LDL receptor protein between once-daily dosing in the evening and once-daily dosing in the morning. In the experiments with rabbit hepatocytes, the up-regulated LDL receptor activity induced by preincubation with pravastatin was retained even 24 hr after the removal of pravastatin. These results suggest that the comparable efficacy of pravastatin between once- and twice-daily treatment could be explained by retention of up-regulated LDL receptor activity for more than 24 hr in vitro and in vivo.

A new monitor with a zinc-oxide thin film semiconductor sensor for the measurement of volatile sulfur compounds in mouth air

Halitosis, defined as unpleasant oral odor, is a concern among the general public. Halitosis is generally diagnosed by organoleptic examination and by gas chromatographic analysis of the main source of halitosis, volatile sulfur compounds, such as hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. Gas chromatography requires a large-scale system and a long running time. We investigated the use of a zinc-oxide thin film semiconductor sensor for measuring trace volatile sulfur compounds in mouth air. Mouth air samples collected in teflon bags from 21 volunteers were analyzed by 3 methods: the monitor analysis, gas chromatography, and organoleptic examination by 3 judges. The readings of the monitor were correlated with the values of the total volatile sulfur compounds measured by gas chromatography (r = 0.75, P < 0.01) and also with the organoleptic scores given by the judges (r = 0.76, P < 0.01). The organoleptic scores were correlated with the gas chromatographic values (r = 0.71, P < 0.01). These results suggest that this new monitor with a zinc-oxide thin film semiconductor sensor may be used for the diagnosis of halitosis. Its small size and simplicity of handling may enable its use for routine chair-side study and field surveys of halitosis.

Embolization of cerebral aneurysms with a liquid embolus, EVAL mixture: report of three cases

Embolization of three surgically difficult cerebral aneurysms was performed using our newly developed non-adhesive embolic material, EVAL mixture (ethylene vinyl alcohol copolymer). Conventional embolic materials such as detachable balloons or microcoils were not used because of a large or irregular aneurysmal neck. After temporary occlusion of the parent artery with a superselective balloon catheter, the EVAL mixture was slowly injected through a microcatheter placed in the aneurysm or parent artery. The locations of the aneurysms were anterior communicating artery, basilar artery-posterior cerebral artery and basilar artery-anterior inferior cerebellar artery (BA-AICA). One aneurysmal occlusion and 2 parent artery occlusions were performed. Patients had no persistent deficits. The patient with the BA-AICA aneurysm associated with an arteriovenous malformation died of rupture of the residual AVM due to haemodynamic change 2 weeks after embolization. In selected and limited cases, embolization of surgically difficult cerebral aneurysms using EVAL mixture was more effective and safer than embolization using conventional embolic materials such as balloons and microcoils.

Attenuation of reperfusion arrhythmias by selective inhibition of angiotensin-converting enzyme/kininase II in the ischemic zone: mediated by endogenous bradykinin?

We studied the effects of angiotensin-converting enzyme (ACE)/kininase II inhibition selectively in the ischemic zone on reperfusion arrhythmias, and the role of bradykinin versus angiotensin II (produced locally in this zone) in modulating the severity of such arrhythmias. Isolated rat hearts (n = 12 per group) were subjected to independent perfusion of left and right coronary beds. The left coronary bed received the ACE/kininase II inhibitor ramiprilat, alone or in combination with either HOE140 (bradykinin B2 receptor antagonist) or angiotensin II, before induction of regional ischemia (10 min) by discontinuation of flow to the bed. Ramiprilat (1, 10, or 100 nM) did not significantly alter the incidence of reperfusion-induced ventricular tachycardia (VT) or fibrillation (VF), but reduced the incidence of sustained VF from 83% in controls to 75, 50, and 25% (p < 0.05). The protective effects of 100 nM ramiprilat were abolished by coinfusion of HOE140 (10 or 100 nM) but not affected by coinfusion of angiotensin II (1 nM). HOE140 (10 nM), when infused alone into the left coronary bed before 7-min ischemia, increased the incidence of sustained VF from 42 to 100% (p < 0.05). Although HOE140 caused vasoconstriction in the left coronary bed when given alone or in combination with ramiprilat, its proarrhythmic effects were not due to a reduction of flow to the bed. We conclude that selective inhibition of ACE/kininase II in the ischemic zone moderately attenuates reperfusion arrhythmias and that enhanced bradykinin availability rather than reduced angiotensin II in synthesis contributes to such an effect.

Effects of acidic reperfusion on arrhythmias and Na(+)-K(+)-ATPase activity in regionally ischemic rat hearts

We studied the effects of acidic reperfusion on 1) the incidence of ventricular fibrillation (VF) and 2) sarcolemmal Na(+)-K(+)-adenosinetriphosphatase (ATPase) activity. Isolated rat hearts (n = 12/group) were subjected to independent perfusion (15 min) of left and right coronary beds with pH 7.4 buffer followed by zero-flow ischemia (10 min) of the former bed. This was then reperfused for 5 min, with acidic (pH 6.6) buffer for the first 0 (control), 0.5,1,2, or 4 min and with pH 7.4 buffer thereafter. In the control group, 92% of hearts developed VF within 20 s of reperfusion and remained in VF. In the 0.5-, 1-, 2-, and 4-min acidic reperfusion groups, only 17, 17, 42, and 25% of hearts (P < 0.05 vs. control for all groups), respectively, exhibited VF during acidic reperfusion. However, on switching to pH 7.4, VF occurred in a further 50, 58, 0, and 0% of hearts, respectively; thus the overall incidences of VF were 67, 75, 42 (P < 0.05 vs. control), and 25% (P < 0.05 vs. control), respectively. Additional hearts (n = 8/group) were used for cytochemical determination of sarcolemmal Na(+)-K(+)-ATPase activity in both the ischemic/reperfused left ventricular (LV) and the nonischemic right ventricular (RV) free walls. Ischemia (10 min) reduced LV Na2(+)-K(+)-ATPase activity from 110 +/- 8 to 25 +/- 3% of the RV value. After 0.5, 1, 2, 3, and 4 min of acidic reperfusion, LV Na(+)-K(+)-ATPase activity was 24 +/- 3, 29 +/- 3, 37 +/- 5, 55 +/- 6, and 70 +/- 4, respectively (P < 0.05 vs. 10-min ischemia). No significant recovery of LV Na(+)-K(+)-ATPase activity occurred following up to 4 min of pH 7.4 reperfusion. In conclusion, 1) at least 2 min of acidic reperfusion is required to achieve sustained protection against VF and 2) the protective mechanism may involve enhanced recovery of Na(+)-K(+)-ATPase activity as well as inhibition of Na+ influx.

Role of neuropeptide Y and its receptor subtypes in neurogenic pulmonary edema

The effect of neuropeptide Y on the number of perivascular carbon deposits, assessed as a measure of lung vascular permeability, was examined in isolated perfused lung preparations of rats. The number of carbon particle deposits after bronchial application of neuropeptide Y was increased in a dose-dependent manner. In the presence of a beta-adrenoceptor antagonist, norepinephrine augmented the effects of neuropeptide Y. Peptide YY, an analog of neuropeptide Y, demonstrated a much lower potency for increasing the number of carbon deposits, and neuropeptide Y-(18-36), which elicits a weak antagonist action on the neuropeptide Y Y3 receptor, significantly decreased the neuropeptide Y-induced increase. Furthermore, examination of the influence of neuropeptide Y-(18-36) pretreatment on fibrin-induced neurogenic pulmonary edema, in rats, revealed a reduction of the protein concentration ratio of tracheal fluid to serum. Therefore, we conclude that neuropeptide Y may elevate vascular permeability in the pulmonary circulation, conceivably through the neuropeptide Y Y3 receptor, and that neuropeptide Y may in fact play a physiological role even in the in-situ pulmonary circulation.

Impact of extracellular buffer composition on cardioprotective efficacy of Na+/H+ exchanger inhibitors

There is controversy over whether the cardioprotective effects of Na+/H+ exchanger inhibitors are exerted primarily during ischemia or during subsequent reperfusion, possibly because of interstudy differences in experimental conditions. We studied the impact of perfusate buffer composition on the relative degree of protection afforded by Na+/H+ exchanger inhibition during ischemia vs. reperfusion. Isolated rat hearts (n = 8/group) were perfused (37 degrees C, 75 mmHg) with bicarbonate- or N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered medium and subjected to 20 min of global zero-flow ischemia and 45 min of reperfusion. One of two structurally distinct Na+/H+ exchanger inhibitors [5-(N,N-dimethyl)amiloride (DMA) or (3-methylsulfonyl-4-piperidinobenzoyl)guanidine methanesulfonate (HOE-694), 10 mumol/l] was transiently (5 min) infused 1) immediately before ischemia, 2) during initial reperfusion, or 3) during both of these periods. With bicarbonate-buffered medium, neither drug improved the postischemic recovery of left ventricular developed pressure (LVDP) when given only during reperfusion. In contrast, HOE-694 improved the postischemic recovery of LVDP from 39 +/- 5% in control to 66 +/- 6% (P < 0.05) when given before ischemia and from 33 +/- 4% in control to 65 +/- 4% (P < 0.05) when given before ischemia plus during reperfusion. With the latter protocol, the cardioprotective effect of HOE-694 occurred in a dose-dependent manner at 0.1-10 mumol/l. In contrast to the results with bicarbonate-buffered medium, in the presence of N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered medium, DMA and HOE-694 significantly improved recovery of LVDP (from 34 +/- 5% in controls to 56 +/- 3 and 71 +/- 8%, both P < 0.05) when given only during reperfusion. They also provided significant protection when given before ischemia or before ischemia plus during reperfusion; with the latter protocol, HOE-694 produced an almost complete recovery of LVDP (88 +/- 9 vs. 30 +/- 7% in controls, P < 0.05). In conclusion, our results suggest that the influence of Na+/H+ exchanger activity during reperfusion on the extent of functional recovery is modulated significantly by perfusate buffer composition. As a consequence, the cardioprotective efficacy of Na+/H+ exchanger inhibitors may be overestimated under bicarbonate-free conditions.

An early phase II study of etoposide (VP-16) in advanced gastric cancer

An early phase II study was conducted to evaluate the anti-tumor effects and toxicity of etoposide in patients with unresectable or relapsed advanced gastric cancer. From April 1991 to December 1992, 13 patients were enrolled into this study; one was subsequently considered ineligible. Before enrollment, all the patients had been treated with chemotherapy which did not include etoposide. Etoposide (100 mg/m2/day) was administered as an intravenous infusion over 120 min for five consecutive days and was repeated every four weeks. Seven patients received one course of this therapy and the remaining five received two. No patient showed a complete or a partial response. No change and progressive disease were observed in three and nine patients, respectively. The clinical toxicities (grade 3-4; WHO) of leukocytopenia, anemia and alopecia occurred in 50, 42, and 42% of the patients, respectively. We conclude that this dose of etoposide administered according to the present schedule is ineffective in previously treated patients with advanced gastric cancer.

[Quality evaluation on Paeoniae radix. I. Quantitative analysis of monoterpene glycosides constituents of Paeoniae radix by means of high performance liquid chromatography. Comparative characterization of the external figures, processing method and the cultivated areas]

The constituents of monoterpene in Paeoniae Radix were analyzed by means of high performance liquid chromatography (HPLC) using hitherto elucidated eight monoterpene glycosides, paeoniflorin 1, oxypaeoniflorin 2, benzoylpaeoniflorin, 3, benzoyloxypaeoniflorin 4, galloylpaeniflorin 5, galloyloxypaeoniflorin 6, albiflorin 7 and lactiflorin 8 and a monoterpene paeoniflorigenone 9. In sixty seven kinds of Paeoniae Radix collected in Japan, China, and South and North Korea those monoterpene constituents 1-9 were found to exist in the amounts of ranging 0.12-9.61% 1, 0.06-10.8% 2, 0.02-0.79% 3, 0.24-0.47% 4, 0.25-2.53% 5, 0.05-2.86% 6, 0.09-2.76% 7, 0.35-0.64% 8 and 0.01-0.49% 9 respectively. In addition, these results obtained by the quantitative analysis were discussed from the viewpoint of the external figures and processing methods.