Evaluation of serum uric acid changes in different forms of hepatic vascular inflow occlusion in human liver surgeries

Uric acid values in serum have been analyzed as one of the markers to predict cellular damage due to ischemia reperfusion injury in the field of organ transplantation. The present study was conducted to confirm that uric acid values in serum could be an efficient marker of ischemic injury of liver parenchyma following hepatic vascular occlusion in human liver surgery. The changes in serum uric acid values were analyzed at fixed intervals during different liver surgeries. Significant increases in serum uric acid values were observed in patients who received the Pringle's maneuver in which hepatic vascular inflow was manipulated with a repetition of 15 min occlusion and 5 min perfusion, whereas almost no changes in uric acid values were found in both groups of patients who received the hemilobal occlusion of the Glisson's triad in which the right or left vessels were manipulated with a repetition of 30 min occlusion and 5 min perfusion and the "control method" in which the hepatic vessels of the lesion side were previously cut before liver resection. Uric acid values in serum increased in patients of Pringle's maneuver compared to those of the hemilobal occlusion of the Glisson's triad and the control method though these procedures were used in larger hepatectomies rather than Pringle's maneuver. The results indicated that serum uric acid values do not always reflect the severity of ischemia of the liver parenchyma but reflect intestinal congestion because marked intestinal congestion was observed in patients of Pringle's maneuver but not in patients of the hemilobal occlusion of the Glisson's triad and the control method. The evaluation of the severity of the ischemic injury of the liver should be done with caution when uric acid is used as a marker in human liver surgery.

Major organ function under mechanical support: comparative studies of pulsatile and nonpulsatile circulation

We examined a major organ function during 3 h biventricular assisted circulation after acute myocardial infarction model in the pig. In left ventricular circulation, the outflow cannula was placed in the ascending aorta and an inflow cannula through the mitral valve in the left ventricle. A pump (pulsatile group, Zeon Medical, Inc., Tokyo, Japan and nonpulsatile group, Nikkiso HPM-15, Nikkiso, Inc., Tokyo, Japan) was connected to each cannula. In right ventricular circulation, the outflow cannula was placed in the pulmonary artery and an inflow cannula in the right ventricle. The right ventricular circulation was supported by a nonpulsatile pump (Nikkiso HPM-15). The items measured were the regional blood flows of the cortex and medulla in the kidney, white matter and gray mater in brain, and liver; renal arterial flow; carotid arterial flow; portal vein flow; common hepatic arterial flow; arterial ketone body ratio (AKBR); and lactate/pyrubic acid (L/P). In the pulsatile group, the renal cortical blood flow increased, and the medulla blood flow decreased. On the other hand, in the nonpulsatile group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved rather than in the nonpulsatile assisted group. In addition the liver regional blood flow, AKBR, and L/P showed significant differences between the pulsatile and nonpulsatile groups. On the other hand, the white matter and gray matter regional blood flows and carotid arterial flow did not show significant differences between the groups. The results of our study indicated that pulsatile circulation produced superior circulation in the kidney and liver, and microcirculation on the cell level was superior as well in early treatment of acute heart failure.

Analysis of optical signals evoked by peripheral nerve stimulation in rat somatosensory cortex: dynamic changes in hemoglobin concentration and oxygenation

The origins of reflected light changes associated with neuronal activity (optical signals) were investigated in rat somatosensory cortex with optical imaging, microspectrophotometry, and laser-Doppler flowmetry, and dynamic changes in local hemoglobin concentration and oxygenation were focused on. Functional activation was carried out by 2-second, 5-Hz electrical stimulation of the hind limb under chloralose anesthesia. These measurements were performed at the contralateral parietal cortex through a thinned skull. Regional cortical blood flow (rCBF) started to rise 1.5 seconds after the stimulus onset, peaked at 3.5 seconds (26.7% +/- 9.7% increase over baseline), and returned to near baseline by 10 seconds. Optical signal responses at 577, 586, and 805 nm showed a monophasic increase in absorbance coincident with the increase in rCBF; however, the signal responses at 605 and 760 nm were biphasic (an early increase and late decrease in absorbance) and microanatomically heterogeneous. The spectral changes of absorbance indicated that the concentrations of both total hemoglobin and oxyhemoglobin increased together with rCBF; deoxyhemoglobin, increased slightly but distinctly (P = 0.016 at 1.0 seconds, P = 0.00038 at 1.5 seconds) just before rCBF increases, then decreased. The authors conclude that activity-related optical signals are greatly associated with a moment-to-moment adjustment of rCBF and metabolism to neuronal activity.

[Extraneural metastasis of pineal germinoma through a ventriculoperitoneal shunt, following histological change]

Primary germinoma of the central nervous system carries a good prognosis because of their radiosensitivity. Recurrence is rare and extraneural metastases are even more unusual. We report a unique case of a primary intracranial germinoma exhibiting complete response to radiotherapy, but recurring as an intra-abdominal yolk sac tumor. The presence of a VP shunt is thought to have facilitated metastatic spread of the intracranial neoplasm. An 21-year-old (corrected) male was admitted with headache and consciousness disturbance. Computed tomography (CT) revealed an enhanced tumor of the pineal region and hydrocephalus. A ventriculo-peritoneal shunt was emplaced immediately. No serum tumor markers such as alpha-fetoprotein or human chorionic gonadotropin were detectable. A test dose of radiotherapy (whole brain 20Gy) was given. The tumor size was remarkably decreased. Clinical diagnosis was germinoma. Additional whole brain radiation (total 45Gy) and whole spine radiation (20Gy) were given. The tumor and the hydrocephalus regressed completely and the patient returned to school. Three years later, he experienced a feeling of abdominal fullness. CT and echotomography of the abdomen showed a large peritoneal and intra-hepatic tumor. But MRI revealed no recurrent tumor of the pineal lesion or of the other areas in the central nervous system. Radiological and clinical findings showed no tumors in the testis, the retroperitoneal cavity, or the thymus. Laboratory investigation demonstrated elevated serum AFP (26,550 ng/ml). AFP level regressed after combined chemotherapy. However, the patient died due to pneumonia and multiple organ failure. Only needle necropsy was performed. The microscopic appearance of the peritoneal tumor was confirmed to be an endodermal sinus tumor. It was suspected to be a metastasis of the pineal tumor through the V-P shunt system.

[Unilateral visual field defect due to optic nerve compression by sclerotic internal carotid artery: a case report]

A case of unilateral visual field defect due to optic nerve compression by a sclerotic internal carotid artery was reported. A 71-year-old woman was admitted to our department because of constricted visual field of the right eye. MRI showed elevation of the right optic nerve compressed by an internal carotid artery. The right carotid angiography revealed elevation and distortion of the C1-2 portion. Frontal craniotomy was carried out and the optic nerve was visualized on this side. The right optic nerve was found to have been compressed by the sclerotic internal carotid artery. The optic canal was then unroofed. The post-operative course was uneventful. The visual field was improved. When last seen 6 months after surgery, her visual field remained in the improved condition. Nasal field abnormalities are most frequently encountered in retinal and anterior optic nerve pathology. Our success in improving the visual field disturbance may be accounted for by the fact that the preoperative period was short and the operation was performed before atrophy of ocular fundi occurred. Nasal field loss caused by intracranial lesions of the optic pathway is rare. It is probably impossible to determine degree of the symptomatology caused by direct-pressure compression as opposed to that caused by ischemia secondary to occlusion of small arterial supply branches. Vascular compressive neuropathy of optic nerve should not be diagnosed simply by the radiological finding of the optic nerve dislocation. However, optic nerve compression by surrounding arteries should be remembered as one of the possible causes of visual field defect which needs to be treated surgically.

High predictive value of red cell volume measurement using carboxy-haemoglobin in a rabbit model of haemorrhage

We have studied the accuracy of blood volume measurements using carbon monoxide (CO)-labelled haemoglobin (COHb) injection and dilution (CO method) by comparing changes in red cell volume (RCV) measured using the CO method and 51Cr-labelled erythrocyte dilution (51Cr method) in a haemorrhage and infusion model in rabbits. RCV was measured repeatedly using the CO method at four different blood volume stages (stages I-IV). At stages I and IV, RCV was measured simultaneously using the 51Cr method. In comparing the sum of the circulating RCV and extracted RCV (SUM RCV) using the CO method, the values were almost equal and there were no significant differences between the values at the four stages. In comparing circulating RCV measured using the CO method and the 51Cr method, mean difference between the two methods was 0.80 (SD 0.76) ml kg-1 or 4.7 (4.6)%, and a positive correlation was observed (r = 0.91). We conclude that the CO method can be used to measure blood volume during perioperative periods in infants because it avoids use of a radioactive tracer, is simple and repeated measurements are possible.

[Microcirculation of kidney and skin during left ventricular assisted circulation--comparative studies of pulsatile and nonpulsatile assists]

We examined microcirculation of the kidney and skin over a six-hour period in an acute myocardial infarction model in pigs. The outflow cannula was placed in the ascending aorta, the inflow cannula was placed the in left atrium, and a pump was connected to each (pulsatile group, Zeon Medical pneumatic pump; nonpulsatile group, Nikkiso HPM-15). Items examined included the regional blood flow of the cortex and medulla in the kidney and skin, renal and carotid arterial flow, arterial ketone body ratio (AKBR), lactate/pyruvic acid (L/P), BUN, creatinine, and beta 2-microglobulin. After the experimental study, the major organs were removed and a pathological study was performed. The mean aortic pressure after the assist could be maintained at about 100 mmHg. There were no significant differences between the two groups in mean aortic pressure and total cardiac output. Under assisted circulation, the pulse pressure was maintained at about 15 mmHg in the nonpulsatile group and about 40 mmHg in the pulsatile group. After the assist, there were no significant differences in the carotid arterial blood flow between the two groups. However, there were significant differences between the two groups in the renal arterial, renal cortical, and regional skin blood flows. In the laboratory data, there were significant differences between the two groups in AKBR, L/P, and beta 2-microglobulin. Pathological findings on the kidney in the nonpulsatile group showed expansion of the proximal tubes, retention of red blood cells, and expansion of blood capillaries within the glomerulus. On the other hand, the pulsatile group showed almost normal formation. In the lungs, the nonpulsatile group showed edematous change in the air cells and the pulsatile group showed almost normal formation. The results of the previous and current study indicated that the pulsatile assist produced superior circulation in the kidney and peripheral organs and superior cellular metabolism in the early treatment of acute left cardiac failure. On the other hand, nonpulsatile assisted circulation was found to be ineffective in maintaining the circulation in the body, and to be potentially capable of causing irreversible damage of major organs if continuous for more than three hours. The results also indicated that pulsatility was necessary to maintain normal circulation in the peripheral organs and cellular metabolism in the early treatment of acute left cardiac failure.

Effects of granisetron, a selective 5-HT3 receptor antagonist, on ouabain-induced emesis in ferrets

The antiemetic effect of granisetron, a selective 5-HT3 receptor antagonist, on ouabain-induced emesis was studied using ferrets. In order to clarify the relationship between ouabain-induced emesis and serotonin (5-HT), we examined its effects on 5-HT release from the isolated ileum. Afferent vagal nerve activity was also determined. An intravenous bolus injection of ouabain (0.1-1.0 mg/kg) produced emesis in a dose-dependent manner. Ouabain-induced emesis was inhibited by pretreatment with granisetron. In the isolated ileum, ouabain induced a concentration-dependent increase of 5-HT. This release of 5-HT was suppressed by granisetron. Increases in vagal nerve discharges were observed immediately after the intravenous administration of ouabain (0.1-1.0 mg/kg). These increases were suppressed by granisetron. Taken together, ouabain activates 5-HT release from the mucosa in the gastrointestinal tract. Released 5-HT may activate the vagal afferent nerves, resulting in vomiting. Granisetron inhibited the ouabain-induced elevation of 5-HT and vagal nerve activity. Ouabain may induce emesis as well as negative chronotropic effects by activating the vagus. Our results suggest that ouabain-induced emesis is in part mediated by the 5-HT3 receptors of the peripheral gastrointestinal tract.

A Pro12Ala substitution in PPARgamma2 associated with decreased receptor activity, lower body mass index and improved insulin sensitivity

The peroxisome proliferator-activated receptor-gamma (PPARgamma) is a transcription factor that has a pivotal role in adipocyte differentiation and expression of adipocyte-specific genes. The PPARgamma1 and gamma2 isoforms result from alternative splicing and have ligand-dependent and -independent activation domains. PPARgamma2 has an additional 28 amino acids at its amino terminus that renders its ligand-independent activation domain 5-10-fold more effective than that of PPARgamma1. Insulin stimulates the ligand-independent activation of PPARgamma1 and gamma2 (ref. 5), however, obesity and nutritional factors only influence the expression of PPARgamma2 in human adipocytes. Here, we report that a relatively common Pro12Ala substitution in PPARgamma2 is associated with lower body mass index (BMI; P=0.027; 0.015) and improved insulin sensitivity among middle-aged and elderly Finns. A significant odds ratio (4.35, P=0.028) for the association of the Pro/Pro genotype with type 2 diabetes was observed among Japanese Americans. The PPARgamma2 Ala allele showed decreased binding affinity to the cognate promoter element and reduced ability to transactivate responsive promoters. These findings suggest that the PPARgamma2 Pro12Ala variant may contribute to the observed variability in BMI and insulin sensitivity in the general population.

The new-concept full-face-type helmet with removable cheek pads

BACKGROUND

The American College of Surgeons proposed a method of removing helmets. But the problem with full-face-type helmets is that their shape makes them difficult to remove.

METHODS

A dummy doll was fixed to a smooth bed surface in the supine position, and a full-face-type helmet with a hook attached to the vertex was placed on the doll's head. A spring balance was attached to the hook, traction was applied to the helmet through the spring balance, and the maximum tension needed to completely remove the helmet was measured.

RESULTS

A tension of 13.2 +/- 1.8 kg was found. But when cheek pads were removed, the tension required to remove the helmet was 1.7 +/- 0.2 kg.

CONCLUSION

We devised a full-face-type helmet that uses removable cheek pads so that helmet removal can be performed safely by removing only the cheek pads in the event of an accident.

Viscosity of diluent and sensory level of subarachnoid anaesthesia achieved with tetracaine

PURPOSE

Our objective was to evaluate the effect of viscosity in determining the cephalad spread of tetracaine administered by the subarachnoid route.

METHODS

We studied 42 patients that were randomly assigned to receive subarachnoid anaesthesia for arthroscope of the knee. They received 8 mg tetracaine dissolved in either glucose 10%, sodium chloride (NaCl) 5%, glucose 5%, or NaCl 2.5%. The specific gravity and viscosity of each solvent was also measured. Cephalad spread was defined as the level of sensory block achieved.

RESULTS

The specific gravity of the glucose 5% and the NaCl 2.5% solutions were similar (1.0197 +/- 0.0001 vs 1.0177 +/- 0.0001 (mean +/- SD)). That was also true for the more concentrated pair of solutions (1.0385 +/- 0.0001 for glucose 10% vs 1.0353 +/- 0.0003 in NaCl 5%). However, the viscosities of the 10% and 5% solutions of glucose (0.01178 +/- 0.0002 and 0.01020 +/- 0.0002 (g.cm-1.sec-1)) were higher (P < 0.05) than that of the other two solutions, being 0.00955 +/- 0.0001 for NaCl 5% and 0.00934 +/- 0.0002 for NaCl 2.5%. The median maximal extent of sensory block achieved was significantly higher (P < 0.05) with a solution of tetracaine in glucose 10% injected into the subarachnoid space at the L3-4 interspace than that observed in the two groups administered tetracaine in NaCl. The level of sensory block 30 min after the injection of anaesthetic was; T3 [T1-6] (median [range]) with glucose 10%, T6 [T4-10] with NaCl 5%, T5 [T2-11] with glucose 5%, and T5.5 [T2-11] with NaCl 2.5%.

CONCLUSION

Viscosity was shown to be one of determinants of the clinical extent of spread of a subarachnoid anaesthetic such as tetracaine.

Pirfenidone prevents collagen accumulation in the remnant kidney in rats with partial nephrectomy

Pirfenidone (PFD) is a new compound that prevents and even reverses the extracellular matrix accumulation in several organs as shown by experimental and clinical studies. In the present study, we examined the effect of PFD (500 mg/kg daily in the food) on the progression of chronic renal failure (CRF) in the 5/6 nephrectomy rat model. Proteinuria progressively increased in rats with renal ablation (C) at 12 weeks. Urinary protein excretion in PFD-treated rats (P) was numerically lower than C, but the difference did not reach statistical significance. In contrast, in the chronic phase, PFD improved renal function and reduced collagen accumulation detected by hydroxyproline content (OH-Pro) in the cortex of the remnant kidney. Although creatinine clearance decreased with time in C, the values in P were significantly better at 10 and 12 weeks. The OH-Pro in C at 12 weeks was significantly higher than that of no-ablation, sham-operated rats, whereas OH-Pro in CRF was lower in (P). Expression of mRNA for type IV and I collagen in the cortex also increased in C, but it was inhibited in (P). To study the role that TGF-beta plays in the regulatory process following CRF, we examined the expression of TGF-beta mRNA in this model. Levels of cortical TGF-beta mRNA in C were significantly elevated at 12 weeks. The increase was suppressed by PFD. These results demonstrate that PFD attenuates the development of CRF by preventing collagen accumulation in this model, and suggest that PFD can be clinically useful for treating CRF.

Renal circulation and cellular metabolism during left ventricular assisted circulation: comparison study of pulsatile and nonpulsatile assists

We examined left ventricular assist during 6 h for an acute myocardial infarction model in pigs. The outflow cannula was placed in the ascending aorta and an inflow cannula in the left atrium. A pump (Pulsatile group: Zeon Medical and Nonpulsatile group: Nikkiso HPM-15) was connected to each cannula. Items measured were the regional blood flow of the cortex and the medulla in the kidney, renal arterial flow, arterial blood ketone body ratio (AKBR), lactate/pyruvic acid, BUN, creatinine and beta 2-microglobulin. After experimental study, the kidneys were removed, and a pathological study was performed. In the pulsatile assisted group, renal cortical blood flow increased but medulla blood flow decreased. On the other hand, in the nonpulsatile assisted group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved, rather than in the nonpulsatile assisted group. The results of our study indicated that pulsatile assist produced superior circulation in the kidney, and the microcirculation on the cell level was superior as well in early treatment of acute left heart failure.

A newly developed silicone-coated membrane oxygenator for long-term cardiopulmonary bypass and cardiac support

The surface of polypropylene hollow fiber was successfully coated with a very thin (0.2 micron) silicone layer. Experimental studies were performed in long-term (6 h) normothermic cardiopulmonary bypass (CPB) using 10 goats. A conventional membrane oxygenator (Mera Excelung HPO-15H, MERA, Tokyo, Japan) was used for 5 goats as a control (Group C) and a new silicone-coated membrane oxygenator, which is of the same construction as that of the one used for Group C, for 5 (Group S). The O2 transfer and CO2 removal functions showed the same ranges. In the other parameters, there were no differences between the 2 groups. As for hemolysis, however, the plasma free hemoglobin of Group S was lower than that of Group C. Currently, 3 chronic percutaneous cardiopulmonary support (PCPS) experimental models have been conducted, and there has been no evidence of thromboembolism or deterioration of the oxygenator. In conclusion, this new oxygenator is suitable not only for CPB, but also for long-term cardiac support.

[Changes in metabolism and peritumoral circulation after radiosurgery of metastatic brain tumors: evaluation by three dimensional dual isotope SPECT]

Concurrent use of two different isotopes, 201T1C1 and 123I-IMP, in SPECT is useful in separative evaluation of tumor metabolism and peritumoral circulation. Three dimensional SPECT employed in our study has an obvious advantage over two dimensional SPECT for its accurate imaging of tumors and peritumoural areas. Changes of tumor metabolism and regional circulation in peritumoral edematous tissues were investigated by fused 3-D SPECT images using 201T1C1 and 123I-IMP. In this study, the volume of isotope accumulative and isotope defective regions were measured. Fusion of SPECT images was performed by the use of panning visualization software; Application Visualization System Medical View (K.G.T.). The threshold of 3-D rendering was determined by conforming the volume of the hemisphere and of the tumor estimated on CT to the volume of 123I-IMP and 201T1C1 accumulating area respectively. Accumulative volume of 201T1C1 in the tumor decreased remarkably at 7 days after radiosurgery (p < 0.01). Defective volume of peritumoral hypoperfusion was measured on 3-D SPECT. The average volume was 80.5 + 32.5cm3 before radiosurgery. It decreased by approximately 60% at 7 days after radiosurgery (p < 0.05). Analysis of 3-D SPECT images using two different isotope tracers is reliable and useful to evaluate early the changes of metabolism and peritumoral circulation in or around intracerebral tumors.

Effects of talipexole on emesis-related changes in abdominal afferent vagal activity and ileal serotonin metabolism in rats

The involvement of abdominal afferent vagal activity and serotonergic mechanisms were examined following intravenous administration of talipexole, a dopamine D2 receptor agonist used for treatment of Parkinson's disease, in anesthetized rats. Intravenous administration of dopamine receptor agonists including D1/D2 components increased the spontaneous firing of afferent vagal neurons as did 2-methyl-5-hydroxytryptamine. Both talipexole (0.25-1.0 mg/kg) and bromocriptine (1.0-10.0 mg/kg) increased vagal nerve activity in a dose-dependent manner, and the effect of 10 mg/kg of bromocriptine was significantly greater than that noted with 1.0 mg/kg of talipexole. Increasing vagal firing induced by talipexole was prevented by pretreatment with granisetron, but not with metoclopramide or by spinal section, indicating that afferent vagal firing was mediated via stimulation of the 5-HT3 receptors on the neurons and secondarily caused by stimulation of dopamine receptors. On the other hand, bromocriptine at 5 mg/kg increased 5-HIAA concentration in the ileum, and serotonin turnover (5-HIAA/5-HT) was increased approximately 4-fold when compared to the vehicle group. Bromocriptine also increased the activities of tryptophan hydroxylase and monoamine oxidase. Talipexole at 0.5 mg/kg did not affect ileal 5-HT metabolism and the enzymatic activities. These findings suggest that dopamine receptor agonists may induce changes in abdominal afferent vagal activity and ileal 5-HT metabolism similar to those observed with emetic compounds, and that talipexole has a much smaller influence on serotonin-mediated responses than does bromocriptine with equipotent antiparkinsonian doses. One of the possible reason why talipexole showed fewer emetic side effects in patients with Parkinson's disease may be that the emetic responses triggered by D2 receptor stimulation may secondarily cause an increase of abdominal afferent vagal activity, which may be weakened by the 5-HT3 receptor antagonistic property of talipexole.

[Measurement of the common carotid arterial flow during parabolic flight in the anesthetized rat]

To measure the blood flow of a common carotid artery (CCA) during parabolic flight in the rat, we developed an animal double hold box (ADHB) made of styrene expanded form for the anesthetized rat to keep the animal at a proper posture in an aircaft. Twelve anesthetized rats weighing 291-342 g were surgically operated to mount a ultrasound flowmeter probe (1 mm size,1RS:Transonic Systems Inc.) around the right CCA and to insert a catheter into the right axillar artery for blood pressure measurement. These animals were held comfortably in ADHBs which were placed on the rack installed in the aircraft (MU-300). A total of 27 parabolic flights was performed and the blood flow was measured accurately in 9 rats. This special animal holding facility is useful for various types of animal experiments in an aircraft.

The role of pulsatility in end-organ microcirculation after cardiogenic shock

To estimate the effectiveness of pulsatility in end-organ microcirculation after cardiogenic shock, experimental studies using swine were done. Cardiogenic shock was produced in 14 pigs by ligating the left anterior descending branches so that mean aortic pressure dropped to 60% of the control value. After inducing shock, left atrial to ascending Ao bypass was initiated. A pneumatic pulsatile pump (Zeon Medical Inc, Tokyo, Japan) was used in seven pigs (Group P) and a centrifugal pump (BP-80, BioMedicus Inc, Minneapolis, MN) in seven (Group NP). In both groups, about half the usual cardiac output was supported for 3 hr, maintaining mean aortic pressure at approximately 100 mm Hg. The pulse pressure was 36.6 +/- 4.6 mm Hg in Group P, and 14.3 +/- 1.5 mm Hg in Group NP. Epicardial and endocardial regional flows recovered after assist in both groups. There were no significant differences between the two groups. However, liver tissue flow, renal cortex flow, and stomach mucous flow in Group P was significantly higher than those of Group NP after support (p < 0.05). In addition, arterial blood ketone ratio in Group P was 0.61 +/- 0.13 vs 0.39 +/- 0.06 in Group NP, a significant difference (p < 0.05). These results suggest that in uneven blood flow distribution of end organs after cardiogenic shock, pulsatility was effective in improving and maintaining function and microcirculation of end organs, preventing multiorgan failure.

Novel approach for determination of correlation between in vivo and in vitro dissolution using the optimization technique

A new approach to determination of good correlations between in vivo and in vitro dissolution was studied using the optimization technique. Ibuprofen, which exhibits dissolution rate-limiting absorption, was used as a model drug. Ibuprofen capsules of two different release types were prepared, and their in vivo dissolution profiles were obtained from measurements of plasma concentration following oral administration of the capsules to beagle dogs by the mathematical deconvolution method using solution data of oral administration as a weight function. For the dissolution test to correspond to the in vivo dissolution profiles, the test was carried out at 12 levels (9 different sets of conditions) and results were analyzed with the optimization technique to deal with two factors. The first-order rate constant (kappa d) and the dissolution time at 50% (t50%) of the in vivo dissolution were selected for use as the response variables. Regression analysis was performed to describe the in vitro dissolution characteristics as functions of the pH of dissolution medium and paddle rotation speed in the paddle method. The in vivo/in vitro correlation obtained from the kappa d was better than that obtained from the t50%. The optimum conditions for dissolution testing corresponding to the in vivo kappa d were determined to be a pH 6.6 for the dissolution medium and a 56 rpm paddle rotation rate. The experimental data obtained by dissolution testing was well fit by the predicted curve derived from in vivo and in vitro dissolution profiles. This dissolution test is applicable to the formulations containing ibuprofen of particle size within the experimental range.

[High uptake of N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) demonstrated by dynamic SPECT in some cases of glioma]

Selective high uptake of N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) in the brain tumors is not common, the mechanism of uptake in the brain tumor is not yet clearly understood. Among 26 cases of gliomas investigated by dynamic SPECT, 4 cases including 2 cases of anaplastic astrocytoma and 2 cases of oligodendroglioma, showed high uptake of 123I-IMP. New three detector type camera which enables us to investigate rapid successive scanning, was used in our study. In dynamic SPECT, 15 successive scans of 2 minutes interval were made for 30 minutes after administration of 123I-IMP. In addition, quick dynamic SPECT was tried in 2 cases, in which 10 quick successive scans of 24 seconds interval were investigated for initial 4 minutes immediately after administration of 123I-IMP. Radioactivity in the region of interest inside the tumor (T) and radioactivity of the corresponding site in the contralateral hemisphere (C) was measured respectively, and T/C ratio was calculated. Time course change of radioactivity (time activity curve: TAC) was analyzed in all cases. Radioactivity was always higher in the tumor and the average T/C ratio was 1.40. TAC showed rapid increase of 123I-IMP in the tumor during initial 2 minutes after administration and keeping its high plateau level for 30 minutes. Angiography in these cases revealed a remarkable tumor stain. On the other hand, these gliomas showed no or slight enhancement effect in CT or MRI. These findings are interpretable as that early high uptake of 123I-IMP in some gliomas is attributable to an increased vascular bed and blood flow with no or minimal derangement of blood brain barrier in these tumors.

[Atlantoaxial dislocation with ventilatory insufficiency--report of two cases]

We performed electromyography and polysomnography in two cases of atlantoaxial dislocation with ventilatory insufficiency to determine the patients' respiratory patterns. The results showed that hypertrophic sternocleidomastoid muscles (SCMs) played an important part in their respiration. The diaphragm and intercostal muscles did not display marked electromyographic (EMG) activity, but the SCMs showed a great deal of phasic inspiratory activity during the daytime that decreased or disappeared during sleep. A 6-year-old boy with atlantoaxial dislocation related to spinal abnormalities was chiefly dependent on the SCMs for respiration and required mechanical ventilation when a sleep because the SCMs were completely inactive. A 4-year-old girl with atlantoaxial dislocation as the result of an automobile accident was partially dependent on the SCMs. She had no trouble breathing during the daytime, but polysomnography recordings showed recurrent hypopnea and desaturation during the night synchronous with decreased EMG activity of the SCMs. She also required mechanical ventilation to improve her long-term prognosis. Polysomnography should be performed in severe cases of atlantoaxial dislocation with respiratory failure in addition to routine respiratory function tests.

Comparison studies of major organ microcirculations under pulsatile- and nonpulsatile-assisted circulations

In these comparison studies, we examined changes in major organ microcirculations during circulatory support using pulsatile and nonpulsatile pumps. Acute myocardial infarction was created by left anterior descending (LAD) branch ligation. After the animals in these studies fell into cardiogenic shock, they were supported by mechanical assist devices: a pulsatile ventricular assist device (VAD) in 4 pigs, a nonpulsatile VAD in 4 pigs, and an intraaortic balloon pumping (IABP) plus nonpulsatile VAD in 4 pigs. Each group was supported for 3 h with an identical mean aortic pressure being maintained. As for parameters, the stomach mucosa, liver regional blood flow, stomach mucosal pH, and arterial blood keton body ratio (AKBR) were measured. Both regional blood flow and AKBR increased in the pulsatile group as compared with the nonpulsatile group. There were no differences in the stomach mucosal pH among the 3 groups. These results suggest that pulsatile assist rather than the nonpulsatile assist plays a significant role in the recovery of deteriorated splanchnic organs due to cardiogenic shock.

[Changes of regional perfusion in metastatic brain tumor and peritumoral area after radiosurgery: a study by 123I-IMP dynamic SPECT]

Changes of regional perfusion in the tumor, peritumoral edematous area and juxtatumor brain after radiosurgical treatment for metastatic brain tumor were investigated by dynamic SPECT using 123I-IMP. The SPECT was performed in 12 patients before and 1, 7 and 30 days after stereotactic irradiation. A region of interest (ROI) was selected each in the tumor, peritumoral edematous area, juxtatumor brain and ipsilateral cerebellum. Radioactivity in each ROIs was counted on early SPECT based on dynamic SPECT from 0 to 5 minutes. Mean count/pixel in each ROIs was divited by mean count/pixel in the ROI of the ipsilateral cerebellum and its value was designated as a count ratio (CR). Assuming the pre-treatment CRs are 1.0, relative changes of post-treatment CRs investigated. rCR in the tumor did not show any significant change after radiosurgical treatment. rCR in the edematous area and the juxtatumor brain increased at 7 days after irradiation [Mean +/- SD 1.43 +/- 0.409 (p < 0.05), 1.248 +/- 0.228 (p < 0.05) by Mann-Whitney test] and at 30 days [1.359 +/- 0.245 (p < 0.01), 1.301 +/- 0.287 (p < 0.01)] respectively. Computed tomography revealed no change in the maximum diameter of the tumor at 1 month after irradiation but a significant reduction in the diameter [0.744 +/- 0.227 (p < 0.02)] at 2 months. Early improvement of regional cerebral blood flow in the juxtatumor areas after radiosurgery suggested that radiosurgery could be effective treatment for metastatic brain tumor.

The reactivity of taurine with hypochlorous acid and its application for eye drops

The ability of taurine to protect biomembranes attacked by HOCl was examined using canine erythrocytes which had been pre-treated with HOCl. Of the amino acids tested, taurine was the most effective in inhibiting attack by HOCl, followed by glycine, alpha-alanine and beta-alanine. During the incubation of HOCl-treated erythrocytes with taurine, an appreciable amount of monochlorotaurine (TauNHCl) was detected in the supernatant. This suggests that taurine may remove the oxidized chlorine from HOCl-treated erythrocytes, resulting in the production of TauNHCl. The effect of taurine on the removal of Cl+ moiety was examined using Sepharose gel with amino groups. Taurine removed Cl+ from HOCl-treated Sepharose gel. The yield of TauNHCl depended on the concentration of taurine. The effectiveness of taurine in preventing ocular surface damage caused by HOCl was investigated in albino rabbits. The activity of lactate dehydrogenase (LDH) released from ocular tissues into tears during eye irritation was used as an index of ocular surface damage. Taurine effectively protected ocular surface tissues from damage induced by HOCl, and arrested the progression of tissue damage that had already been initiated by HOCl. These finding suggest that taurine may be clinically useful in the treatment of ocular surface damage caused by oxidants such as HOCl.

[Complete eradication by endoscopic injection sclerotherapy reduces the recurrence of esophageal varices]

Endoscopic intravariceal injection sclerotherapy (EIS) using sclerosant mixed with contrast medium was done in 100 patients without hepatocellular carcinoma. They were followed longer than 12 months (mean; 58 +/- 29 months) after EIS. The recurrence rate of esophageal varices in cases with complete eradication (n = 79) and cases with incomplete eradication of (n = 21) was 8.9% and 85.7%, respectively (p < 0.01). In 21 cases, complete eradication was achieved by intravariceal injection and additional therapy using paravariceal injection was not performed. The recurrence rate of this group was only 4.8%. Endoscopic varicealography during injection sclerotherapy were evaluated in 91 cases. At final session of EIS, narrowing of diameter (less than 1 mm) and irregularity of vessel walls were observed in small vessels (devastated vessels). Appearance rate of devastated vessel in 75 cases with completely eradicated esophageal varices was 65.3%. In contrast, among 16 cases with incomplete eradication of varices, devastated vessels were seen only in 6.3% (p < 0.01). It is concluded that the important point in preventing the recurrence of esophageal varices after EIS was the complete eradication of esophageal varices by intravariceal injection sclerotherapy resulting in the eradication of the routes to esophageal varices from port-splenic venous system. For the sake of accomplishment of this treatment, appearance of devastated vessel is very useful.

[Deterioration of liver function following endoscopic injection sclerotherapy of esophageal varices--significance of the new liver function test "intravariceal injection (I.I.) index"]

Changes of liver functions associated with endoscopic injection sclerotherapy (EIS) were investigated in 143 patients with remarkable esophageal varices. The index used for evaluating hepatic reserve was the ratio between the increase of total bilirubin and the increase of LDH after EIS [I.I. index = (delta T.Bil./delta LDH) x 100] in cases treated by intravariceal injection of 5% ethanolamine oleate. I.I. index value caused by hemolysis was stable and always below 0.2, while the elevation of I.I. index above 0.2 was regarded as the reflection of the deterioration of liver function. After the entire sessions of EIS, the changes of liver function tests before and after EIS were estimated in 104 cases using 3 factors as follows; (1) delta T.Bil.; increase of total bilirubin more than 0.5 mg/dl (2) delta PT; decrease of prothrombin time more than 5% (3) delta ICG R15; increase of ICG R15 more than 5%. I.I. index of group I (without any changes of 3 factors mentioned above; n = 66) was 0.22 +/- 0.16, approximately within normal range. However, in group II (with 1 factor; n = 29), group III (with 2 factors; n = 5), group IV (with all factors; n = 4), I.I. index was elevated according to the severity of their liver dysfunction. The cases whose I.I. index value increased gradually during the course of EIS, were apt to deteriorate the liver functions and therefore, should be carefully observed. Also, I.I. index seems to reflect the prognosis of the patients treated by EIS for some extent, since the survival period of the cases treated by EIS were correlative with the value of I.I. index (r = -0.542, p < 0.01), and I.I. index of 32 cases who survived for longer than 5 years after EIS was almost normal (0.22 +/- 0.15).

Reactivity of taurine with aldehydes and its physiological role

The chemical reactions of the amino group of taurine with aldehydes were investigated. Glucose, acetaldehyde, and malondialdehyde were used as aldehydes. After taurine had reacted, the amounts of remaining taurine and aldehydes were measured, and the reactivity was evaluated. Amino acids such as glycine, alpha-alanine, and beta-alanine were compared because of their structural resemblance to each other. Taurine showed a high reactivity with each one of the aldehydes tested. It is known that protein is altered through reactions of the amino group with various aldehydes. Low density lipoprotein (LDL) was used as a model protein and the inhibiting effect of taurine against the modification of LDL by malondialdehyde was examined. It was shown that the inhibiting effects of taurine correlated with the reactivity of malondialdehyde with amino acids. Further, the taurine-glucose reaction product showed an antioxidative effect on the peroxidation of liposomes made of yolk phosphatidylcholine as a biomembrane model. The results suggest the possibility of an inhibiting effect of taurine against the modification of protein, as well as an antioxidative effect through the reactions of taurine with aldehydes in vivo.

Reactivity of taurine with aldehydes and its physiological role

Chemical reactions of the amino group of taurine with aldehyde were investigated. Glucose, acetaldehyde, and malondialdehyde (MDA) were used as aldehydes. After taurine was reacted with the aldehydes, the amounts of remaining taurine and aldehydes were measured, and thereby the reactivity was evaluated. The amino acids such as glycine, alpha-alanine, and beta-alanine were compared because of their structural resemblance to each other. Taurine showed a high reactivity with each one of the aldehydes tested. It is known that protein is altered through reactions of the amino group with various aldehydes. Low density lipoprotein (LDL) was used as a model protein, and the inhibiting effect of taurine against the modification of LDL by MDA was examined. Our results indicate that taurine inhibited the production of LDL modified by MDA. It was shown that the inhibiting effects correlated with the reactivity of MDA with the amino acids. Further, the taurine-glucose reaction product showed an antioxidative effect on the peroxidation of liposomes made of yolk phosphatidylcholine as a biomembrane model. The results suggest the possibility of an inhibiting effect of taurine against the modification of protein, as well as an antioxidative effect through the reactions of taurine with aldehydes in vivo.

[Studies of WBN/Kob rat, 18th report: effect of 1 alpha-OH-D3 on diabetic osteopenia]

We examined the effect of 1 alpha-OH-D3 on diabetic osteopenia in spontaneously-developed diabetic WBN/Kob rats. Diabetic male WBN/Kob rats aged 12 to 15 months were randomly divided into 1 alpha-OH-D3-treated group (n = 6) and control group (n = 5). 1 alpha-OH-D3 was administered 3 times a week at an oral dose of 0.1 microgram/kg and triglyceride was administered in the control group during the observation period of 12 weeks. Although plasma Ca level decreased significantly in the vehicle-treated group, there was no significant change in plasma Ca level in the 1 alpha-OH-D3-treated group. Urinary Ca excretion significantly increased in the 1 alpha-OH-D3-treated group compared with that in the vehicle-treated group. As for plasma vitamin D metabolites levels after the 12 week-treatment, although there was no significant difference in plasma 25-OH-D and 24,25(OH)2D levels, plasma 1,25(OH)2D level was significantly increased in the 1 alpha-OH-D3-treated group compared with that in the vehicle-treated group. There was no significant difference in plasma bone-Gla protein level between 1 alpha-OH-D3-treated and vehicle-treated groups. As for bone mineral content (BMC) in the femur measured by a dual energy absorptiometer, BMC was significantly increased in the 1 alpha-OH-D3-treated group compared with than in the vehicle-treated group. In conclusion, 1 alpha-OH-D3 ameliorated diabetic osteopenia in WBN/Kob rats through the normalization of vitamin D metabolism.

The protective effect of taurine on the biomembrane against damage produced by oxygen radicals

The effect of taurine in protecting biomembrane against oxygen radicals was investigated using canine erythrocytes. 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH), a water-soluble azo-compound, was used as the oxygen-radical generator. Taurine suppressed erythrocyte hemolysis more effectively than alpha-alanine, used for comparison. To clarify the relationship to the lipid peroxidation, the amount of lipid peroxide was measured using liposomes prepared with egg yolk lecithin. However, the peroxidation was not suppressed by taurine. When intact erythrocytes were subjected to hemolysis by hyposmotic solutions, taurine suppressed the osmotic hemolysis more effectively than alpha-alanine. These results suggest that taurine does not have an antioxidative effect like vitamin E, but interacts with the biomembrane, and helps to protect it against damage caused by AAPH.

Stable positively charged liposome during long-term storage

The effect of taurine, as an isotonic solute, and of benzalkonium chloride (BZC), as a positive membrane component, on the long-term stability of liposomal suspensions was investigated by measuring surface potential. The surface potential, which introduced electrostatic repulsion to liposomes against aggregation, increased dose-dependently with the addition of BZC, which gave a positive charge. However, a further addition of BZC caused unexpected aggregation during storage, so the optimum addition of BZC was defined. On the other hand, taurine, which forms a zwitter ion in an aqueous solution, did not reduce the surface potential, suggesting that taurine is of possible utility as an isotonic solute. As the result of stability testing, the liposomal system using taurine and BZC was stable against aggregation during 6 months at 40 degrees C. We were successful in developing a stable, positively charged liposomal system during long-term storage, and our liposomal system is believed to be of wide utility as a drug carrier for therapeutic drugs applied topically to negatively charged mucosal tissues. We applied the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to estimate the colloidal stability of liposomes. As a result of stability testing, positively charged liposomes had a good correlation between maximum total repulsive energy (VT(max)/kT) between two liposome particles and colloidal stability, suggesting that the VT(max)/kT value is useful for estimating stability and for designing liposomal preparations containing some ionic substances.

Unruptured aneurysms associated with ischaemic cerebrovascular diseases. Surgical indication

Out of 3435 patients with ischaemic cerebrovascular disease 2540 cases were investigated using cerebral angiography. In 127 of them (5%) aneurysms were found, but without clinical evidence of subarachnoid haemorrhage (SAH). 45 cases were operated upon and 82 were treated conservatively. Five of these 82 cases (6%) suffered from SAH 3 months to 10 years (mean interval 5.6 years) after the angiographic diagnosis. Four of these 5 patients with SAH died. Among the 45 surgical cases follow-up was uneventful in 29 (64%). The other 16 cases postoperatively showed neurological deterioration (36%), which was transient in 6 but with only minor improvement in 10. Of these 10 cases 2 died from cerebral infarction related to intra-operative temporary vascular occlusion respectively myocardial infarction. Thus surgical mortality was 4% and permanent morbidity 18%. Causes of postoperative neurological deterioration were partly related to general arteriosclerotic changes and special fragility of the ischaemic brain, and partly to operative technique (excessive brain retraction, damage to cortical veins, occlusion of major vessels or damage to perforators, temporary artery occlusion). Apparently in cases with ischaemic cerebrovascular diseases operative procedures, which in other cases as a rule are well tolerated, may produce harmful effects. Therefore, in these cases, the indication for operative treatment of so far silent aneurysms should be restricted to patients who are in good general condition with longer life expectancy as far as the vascular disease is concerned, and without major neurological deficit. Furthermore, the operative technique should be especially gentle and atraumatic.

Quantitative evaluation of the effectiveness of taurine in protecting the ocular surface against oxidant

Quantitative evaluation of the effectiveness of taurine against ocular surface damage caused by hypochlorous acid (HOCl) was investigated using albino rabbits. The activity of lactate dehydrogenase (LDH) released from ocular tissues into meniscus tears at eye irritation was used as an index of ocular surface damage. Instead of collecting meniscus tears directly with a glass micropipette, a new sampling method, where 150 microliters of saline was instilled into the cul-de-sac of rabbit eyes and collected all of the diluted tears within 10 s, was developed. The LDH activity after serial instillations of HOCl increased dose-dependently with increasing HOCl concentration. After serial instillation of taurine, HOCl was instilled in the same way. Pre-application of taurine effectively suppressed (p < 0.01, n = 11) the HOCl-induced LDH release as compared to saline, suggesting that the residual taurine in ocular surface tissues was still effective in protecting the tissues against HOCl by scavenging HOCl. LDH activity at 30 in after post-application of taurine was significantly lower (p < 0.01, n = 10) than that in the case of saline. This result indicates that taurine is effective in protecting the ocular surface after it has been attacked by HOCl. LDH activity in meniscus tears became a good index of quantitatively estimating ocular surface damage due to HOCl by devising the new sampling method. By using this method, we were able to prove objectively and quantitatively that taurine is effective in protecting the ocular surface against HOCl. It was suggested that taurine is clinically useful in the treatment of ocular surface damage caused by oxidants, such as HOCl.

Neuroepithelial (colloid) cyst of the cerebellar vermis containing a xanthogranuloma

A case of a neuroepithelial cyst of the cerebellar vermis is presented. The cyst contained a viscous fluid and a xanthogranulomatous nodule. The fluid showed high signal on T1- and low signal on T2-weighted MR images. The xanthogranuloma showed mixed intensities with partial contrast enhancement. The correlation of the cyst contents and MR signals is discussed.

Interaction between polyethylene films and bromhexine HCl in solid dosage form. V. Effect of packaging materials on the sorption of bromhexine HCl

A prevention method of the sorption of bromhexine HCl to plastic materials used in packaging was investigated. Four kinds of plastic packaging materials were used: Polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP) and polyacrylonitrile (PAN). Three polyethylenes having different densities were used. No effect of PE density on the sorption of bromhexine HCl from granules was observed. The effects of different kinds of plastics on the sorption of bromhexine HCl from solution and granules were studied. The sorption of bromhexine HCl to PAN, which had a high relative dielectric constant, was the most depressed among the four plastics. The sorption of meclizine HCl to PAN from the solution was also lowest, the same as bromhexine HCl.

Interaction between polyethylene films and bromhexine HCl in solid dosage form. IV. Prevention of the sorption by addition of magnesium aluminum silicate

The effects of magnesium aluminum silicate (MAS) addition on the sorption of bromhexine HCl to polyethylene film in tablets were studied. The addition of MAS prevented the sorption of bromhexine HCl to polyethylene film. In order to investigate the mechanism, the interaction between bromhexine HCl and MAS was studied by the powder X-ray diffraction method. It was observed that bromhexine HCl was preferentially adsorbed to the surface of MAS rather than to polyethylene film. The adsorption was accelerated at high temperature and reduced pressure conditions. The sorption of bromhexine base and bromhexine HCl to packaging material were compared using tablet dosage forms. The sorption of bromhexine base to polyethylene film was greater than that of bromhexine HCl.

[Problems of surgical treatment for multiple intracranial aneurysms]

A series of 105 patients presenting with multiple aneurysms and subarachnoid hemorrhage (SAH) were operated on for ruptured and unruptured aneurysms between 1976 and 1984. Clinical factors other than the severity of SAH affecting the outcomes included: 1) Misdiagnosis of the location of a ruptured aneurysm among multiple aneurysms resulted in poor outcomes because of multiple surgical approaches or rebleeding during the acute period. 2) Combinations of aneurysmal locations requiring multiple surgical approaches, such as interhemispheric and transsylvian, during the acute stage caused worse outcomes than with multi-stage surgeries. If an unruptured aneurysm could not be reached during the initial exposure, multi-stage surgery was safe if the ruptured aneurysm had been clipped during the acute period. 3) Complications occurring during unruptured aneurysm surgery. The patient's age, the location and size of the unruptured aneurysms were significant factors in the clinical prognosis. Surgery for unruptured aneurysm caused 1.8% morbidity in patients between 28 and 55 years, but 18.0% morbidity in patients over 56 years of age. Surgery for internal carotid artery aneurysms resulted in 14.8% overall morbidity. Surgery for middle cerebral and anterior cerebral artery aneurysms caused below 5% morbidity. Postoperative morbidity in patients with aneurysms less than 5 mm in diameter was 1.3%, and with aneurysms measuring 10 mm or more, 20%. The optimum treatment for multiple aneurysms with SAH should be based on all factors of the patient's condition, including the unruptured aneurysms.

Induction of metallothionein and stimulation of calcification by dexamethasone in cultured clonal osteogenic cells, MC3T3-E1

To clarify the effects of dexamethasone (Dex) on metallothionein (MT) synthesis and calcification in osteoblastic cells, a clonal osteogenic cell line (MC3T3-E1) was used in the present study. Under culture conditions designed not to cause calcification, MT synthesis of cells at 3 days after inoculation increased with increasing concentration of Dex (2.5-50 nM) for a 24-h culture period. Cells at 6 or 9 days after inoculation also synthesized MT by a 24-h exposure to Dex. These show that undifferentiated osteoblasts have the ability to synthesize MT by Dex. Under culture conditions designed to cause calcification, cells at 6 days after inoculation were cultured with 50 nM Dex in the presence of 7 mM beta-glycerophosphate (beta-GP) for 7 days. Ca content of Dex-treated cells was about 7.5 times as high as that of untreated cells. Dex-treated cells showed a high activity of alkaline phosphatase (ALP). The Zn content of the MT fraction in Dex-treated cells was about 8 times as high as that of untreated cells. These results show that Dex has the ability to induce MT synthesis in osteoblastic cells and to cause a high calcification which is due at least partly to an enhanced activity of ALP.