Serum biochemical changes and chemiluminescent responses of whole blood in Holstein cattle with leukocyte adhesion deficiency

Serum biochemical profile and whole blood chemiluminescent (CL) responses in 8 Holstein cattle affected with leukocyte adhesion deficiency (LAD) were evaluated. Concentrations of sodium, chloride and calcium in serum from cattle affected with LAD were significantly (p < 0.05) decreased as compared with controls. The characteristic changes in serum proteins were hypoalbuminemia and hyperglobulinemia, and the concentrations of albumin and gammaglobulin in serum from normal cattle and cattle affected with LAD were significantly (p < 0.01) different. Significantly (p < 0.01) diminished CL indices and prolonged peak time of CL responses in whole blood were detected in cattle affected with LAD. These findings indicate that the CL response associated with iC3b receptor mediated phagocytic activity is impaired in cattle affected with LAD. The whole blood CL assay appeared to be practical and useful for routine evaluation of blood samples from cattle affected with LAD.

Effect of epidermal growth factor on mouse sperm acrosome reaction induced by zona pellucida

PROBLEM

The effect of epidermal growth factor (EGF) on the acid-solubilized zona pellucida (ZP)-induced acrosome reaction was investigated in mouse sperm.

METHOD

Mouse epididymal sperm were capacitated in modified Krebs-Ringer bicarbonate buffer (m-KRB) for 120 min and further treated with acid-solubilized ZP(4 zona/microliters) for an additional 60 min to induce the acrosome reaction. The chlortetracycline fluorescence assay was used to monitor the acrosome reaction. The acrosome reacted sperm featured the acrosome reacted (AR) pattern, which demonstrates the lack of fluorescence on the head and bright midpiece.

RESULTS

EGF caused an early increase in the AR pattern in response to the acid-solubilized ZP in a dose-dependent manner. The EGF-dependent stimulation of the ZP-induced acrosome reaction was inhibited by an inhibitor of protein tyrosine kinases, genistein or activators of Ca++ and phospholipid-dependent protein kinase (protein kinase C). Furthermore, the stimulatory effect of EGF was not attenuated when sperm were capacitated in the presence of islet-activating protein, an inactivator of inhibitory guanine nucleotide-binding regulatory protein (Gi protein).

CONCLUSION

EGF stimulates the ZP-induced acrosome reaction in a manner that is independent of the Gi protein. The EGF action is regulated by protein tyrosine kinase and protein kinase C.

Effect of epidermal growth factor on human sperm capacitation

OBJECTIVE

To examine the effect of epidermal growth factor (EGF) on human sperm capacitation and the involvement of protein phosphorylation in the regulation of the EGF action.

DESIGN

Human sperm were capacitated in modified Krebs-Ringer's bicarbonate medium of Biggers, Whitten, and Whittingham in the presence of EGF and various agents known to phosphorylate the EGF receptor. The chlortetracycline fluorescence assay was used to monitor capacitated sperm. Capacitation was confirmed by the ability of sperm to undergo the acrosome reaction in response to solubilized mouse zonae pellucidae (ZP).

RESULTS

In 15 minutes, the appearance of the clear perimeter pattern increased significantly in the sperm treated with 100 ng/mL EGF compared with the controls. In EGF-treated sperm, the percent clear perimeter pattern remained stable for 3 hours without affecting the acrosome reaction pattern and the motility. Epidermal growth factor stimulated the appearance of the clear perimeter pattern at concentrations > 100 pg/mL. The stimulation by EGF was attenuated by the treatment with genistein, 12-O-tetradecanoylphorbol-13-acetate, or thapsigargin. In sperm that were incubated in the presence of 100 ng/mL EGF for 30 minutes and further induced the acrosome reaction by mouse ZP, the percent acrosome reaction pattern increased significantly compared with the controls.

CONCLUSION

Epidermal growth factor stimulates human sperm capacitation by activating the tyrosine kinase of the EGF receptor which is regulated by multisite phosphorylation.

[Effect of epidermal growth factor (EGF) on mouse sperm capacitation]

The effect of epidermal growth factor (EGF) on the kinetics of mouse sperm capacitation was examined. The chlortetracycline (CTC) fluorescence assay was used to monitor capacitated sperm, featuring a B pattern. One hundred ng/ml EGF significantly stimulated capacitation at 15 minutes after the addition. However, 0.1 pg/ml EGF did not stimulate capacitation. EGF affected neither the motility nor the appearance of the S or AR pattern. The EGF-induced stimulation of capacitation was attenuated by 20 micrograms/ml genistein, an inhibitor of protein tyrosine kinase, or by 100 ng/ml thapsigargin, a non-phorbol tumor promoter, which inhibits EGF action by enhancing phosphorylation of the threonine 669 residue of the EGF-receptor. However, 3 ng/ml 12-O-tetradecanoly phorbol 13-acetate (TPA), a stimulator of protein kinase C, did not attenuate the appearance of the B pattern enhanced by 100 ng/ml EGF. These data suggest that EGF stimulates mouse sperm capacitation by activating the tyrosine kinase of the EGF-receptor which is regulated by multisite phosphorylation.

Effects of modulators of protein kinase C on human sperm capacitation

OBJECTIVE

To examine the effects of stimulators or inhibitors of protein kinase C on capacitation and protein phosphorylation in human sperm.

DESIGN

Capacitated sperm treated with or without modulators of protein kinase C were monitored by the chlortetracycline fluorescence assay. Capacitation was confirmed by the ability of sperm to undergo the acrosomal reaction in response to mouse zonae pellucidae. 32P-labeled sperm phosphoproteins were analyzed by one-dimensional gel electrophoresis to detect the effect of protein kinase C stimulator, 12-O-tetradecanoyl-phorbol-13-acetate, on protein phosphorylation.

RESULTS

The treatment of sperm with protein kinase C stimulators resulted in the following: [1] the rapid appearance of the clear perimeter pattern, featuring distribution of fluorescence over the entire head exhibiting a bright perimeter and bright midpiece; [2] an accelerated ability to undergo the acrosomal reaction; and [3] an enhanced phosphorylation of 57.5-kd sperm phosphoprotein. Furthermore, these stimulatory effects were inhibited by protein kinase C inhibitors.

CONCLUSION

Protein phosphorylation mediated by protein kinase C may be involved in the regulation of human sperm capacitation.

Two-step selective photoionization of rubidium by using a Ti:sapphire laser

A pulsed Ti:sapphire laser (TSL) is applied for what is, to our knowledge, the first time to laser isotope separation. A collimated beam of a rubidium atom with a natural isotope composition ((85)Rb, 72%; (87)Rb, 28%) is excited selectively from the ground state to the 5(2)P(3/2) state by irradiation of the single-longitudinalmode TSL, and is photoionized by successive UV radiation. Ion spectra of each isotope indicate that each isotope is selectively photoionized.

Analysis of IMP-SPECT in cerebral infarcts

We performed single photon emission computed tomography with N-isopropyl[123I]-p-iodoamphetamine in 22 normal volunteers (mean age, 68.3 +/- 9.5 years) and 190 patients with unilateral cerebral infarcts (66.1 +/- 11.4 years). We then compared visual and semiquantitative assessment of the left/right ratio of the early images. Cerebral blood flow in the patients with cerebral infarcts was compared with data from normal volunteers. An abnormal left/right ratio was recognized in 110 of 136 (81%) patients in whom X-ray computed tomography (CT) showed an abnormality, while visual inspection revealed abnormalities in only 99 (73%). In 54 patients no abnormality on CT, an abnormal left/right ratio was found in 28 (52%), and visual abnormalities in only 9 (17%). Altogether, the left/right ratio was abnormal in 138 of 190 (73%) patients, and abnormalities were detected visually in 108 (57%). Of 95 patients, 56 (59%) showed markedly larger lesions using the left/right ratio method than with the visual method.

Calyculin A, protein phosphatase inhibitor, enhances capacitation of human sperm

OBJECTIVE

To examine the effects of protein phosphatase inhibitors on capacitation and protein phosphorylation in human sperm.

DESIGN

The chlortetracycline (CTC) fluorescence assay was used to monitor capacitated sperm treated with or without protein phosphatase inhibitors. Capacitation was confirmed by the ability of sperm to undergo the acrosome reaction in response to Ca++ ionophore A23187 or mouse zonae pellucidae. 32P-labeled sperm phosphoproteins were analyzed by one-dimensional gel electrophoresis to detect the effects of protein phosphatase inhibitors on protein phosphorylation.

RESULTS

The treatment of sperm with calyculin A resulted in the following: [1] the rapid appearance of the clear perimeter pattern, specifically, distribution of fluorescence over the entire head exhibiting a bright perimeter and bright midpiece, in a dose-dependent manner in the 1 to 100 nM range; [2] an accelerated ability to undergo the acrosome reaction; and [3] an enhanced phosphorylation of sperm phosphoproteins in a dose-related fashion in the 1 to 100 nM range. A similar stimulatory effect was observed only with a 100-fold higher concentrations of okadaic acid, another protein phosphatase inhibitor.

CONCLUSION

Our results strongly suggest that protein phosphorylation and dephosphorylation may be involved in the regulation of human sperm capacitation.

[Laboratory data in chronic dialysis patients]

The principle of prescribing dialysis therapy is treatment of uremic symptoms and morbidity, and adequate therapy to prevent complication of long term dialysis. For this purpose careful measurement and monitoring of various parameters should be done in chronic dialysis patients. We analyzed the laboratory data of 82 patients treated at our dialysis center. We started correction of renal anemia with erythropoietin from 1987, and the mean hematocrit was improved from 24% to 28%. The blood transfusion volume was decreased markedly. There was a significant correlation between plasma alpha-human atrial natriuretic peptide (HANP) levels and the size of the heart. Plasma HANP seems to be a reliable parameter of the so-called dry weight in patients on maintenance dialysis. We analyzed the parameters of bone for the recent four years. Alkaline phosphatase (ALP) and C-PTH increased throughout the duration of dialysis, while bone mineral density (BMD) decreased. Annual changes of sigma GS/D were negatively correlated with ALP and C-PTH. In relation to duration of dialysis, changes of sigma GS/D were less in the group treated for less than 3 years. Nine patients (60% of patients on dialysis more than 10 years) had carpal tunnel syndrome (CTS) with symptoms and signs. Median nerve distal motor latency was positively correlated with the duration of dialysis. The beta 2-microglobulin (beta 2-MG) level of dialysis patients was very high and even though the beta 2-MG level was lowered by hemodiafiltration CTS was not improved.

Effects of modulators of protein kinases and phosphatases on mouse sperm capacitation

We examined effects of modulators of protein kinases and phosphatases on the kinetics of mouse sperm capacitation. The chlortetracycline fluorescence assay was used to monitor the process of capacitation (in terms of the appearance of the B pattern). The treatment of sperm with dibutyryl cyclic AMP (cAMP) or dibutyryl cGMP resulted in a higher percentage B pattern at various times during capacitation compared with the control. The addition of 100 microM H8 inhibited the cyclic nucleotide-dependent stimulation of capacitation. Tumor promotors, 12-O-tetradecanoyl phorbol 13-acetate (TPA; a stimulator of protein kinase C) and okadaic acid (an inhibitor of protein phosphatases 1 and 2A), induced a rapid appearance of the B pattern (15 min after addition) and maintained a percentage B pattern similar to that of the control in the later period of capacitation. An inhibitor of protein kinase C, staurosporine, inhibited the TPA-dependent acceleration of capacitation. Furthermore, the addition of genistein, an inhibitor of protein tyrosine kinases, resulted in a strong inhibition of capacitation. All agents tested did not affect sperm motility. These data suggest that protein phosphorylation and dephosphorylation may play regulatory roles in mediating mouse sperm capacitation.

Protein phosphorylation regulates the mouse sperm acrosome reaction induced by the zona pellucida

Recently, the ligand-receptor signal transduction mechanism has been implicated in mediating the zona pellucida (ZP)-induced acrosome reaction. Little is known about the role of protein phosphorylation in this specific event. We examine whether modification of protein phosphorylation and dephosphorylation affects the kinetics of the acid-solubilized ZP-induced acrosome reaction of mouse sperm. Mouse epididymal sperm were incubated in modified Krebs-Ringer bicarbonate medium for a period of 90 to 120 min and then treated with 2 acid-solubilized ZP/microliters for an additional 60 min. The chlortetracycline fluorescence assay was used to monitor the acrosome reaction. Capacitated sperm were inhibited from undergoing acid-solubilized ZP-induced acrosome reaction in the presence of an inhibitor of cyclic nucleotide-dependent protein kinase, H8; activators of the Ca(2+)- and phospholipid-dependent protein kinase (protein kinase C); an inhibitor of phosphatases 1 and 2A, okadaic acid; or an inhibitor of protein tyrosine kinases, genistein. The addition of inhibitors of protein kinase C, such as staurosporine, H7, and protein kinase C [19-36] pseudosubstrate, inhibited the phorbol ester-dependent inhibition of the acid-solubilized ZP-induced acrosome reaction. The present study suggests that protein phosphorylation and dephosphorylation play a regulatory role in the process of the ZP-induced acrosome reaction.

[Delayed traumatic vasospasm: correlation between cerebral vasospasm and contusion]

The pathogenesis of delayed traumatic vasospasm is not yet fully understood. We present six cases of delayed traumatic symptomatic vasospasm along with CT scan and angiographic findings. The cases ranging in age from 16 to 78 years all had head injury caused by traffic accidents. The Glasgow coma scale on admission was 9 - 15 except in one severe case GCS 6. Initial CT scans were obtained on the day of injury in four patients and on the 2nd and 3rd days in the other two cases respectively. There was no distinct subarachnoid hemorrhage in the suprasellar cistern. Subarachnoid hemorrhage in the Sylvian cistern was observed with particular care in all patients. However the severity of subarachnoid hemorrhage was mild (isodensity or slight high density by CT) in 4 cases. Brain contusions on CT scan were observed in the temporal and/or frontal region of 5 of 6 patients. Ischemic symptoms occurred during the period between 5 and 13 days after head injury. The cerebral angiogram taken after the occurrence of these symptoms revealed spasms in all patients, the spasm being bilateral in 2 of them. Spasms were recognized on the main arteries at the base of the brain such as C1, M1, M2 and A1. In 5 cases, the cerebral contusion and the spasm were located on the same side. Angiographically the vasospasms lasted 2 to 5 weeks. The prognosis based on the Glasgow outcome scale was good recovery in 3 patients and moderate disability in one. Two elderly patients with bilateral spasms were in a vegetative state and severe disability, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Two cases of ruptured fusiform aneurysm of the proximal anterior cerebral artery (A1 segment)]

Two rare cases of fusiform aneurysms of A1 segment of the anterior cerebral artery are reported. Case 1: A 62-year-old woman was admitted with sudden onset of severe headache and loss of consciousness, on August 22, 1982. CT scan showed subarachnoid hemorrhage at the basal cisterns. Left carotid angiography revealed a spindle shaped aneurysmal dilatation in the A1 segment of the anterior cerebral artery. Four-vessel angiography was performed twice but no other aneurysm was found. She was treated conservatively and the clinical course was not eventful. She was discharged with no neurological deficit one month after the admission. Case 2: A 49-year-old man complained of sudden onset of severe headache, nausea and vomiting on August 24, 1986. He was transferred to a local hospital and CT scan showed subarachnoid hemorrhage at the basal cisterns. Angiography revealed a fusiform aneurysm of the proximal anterior cerebral artery. He was referred to our hospital on the day of onset. He was operated on via bifrontal interhemispheric approach. The fusiform aneurysm of A1 segment was trapped successfully using temporary occlusion of A1 and A2 bilaterally under the administration of Sendai-Cocktail. V-P shunt was performed 1 week after the aneurysmal operation. The post-operative course was uneventful. He was discharged with no neurological deficit three months after operation. As far as we know, there are 6 cases of fusiform aneurysm of A1 segment of anterior cerebral artery in the literature. In this report, our two cases were described and treatment of such aneurysms were discussed.

Cerebral protective effect of flunarizine in a canine model of cerebral ischaemia

To test the effect of flunarizine on cerebral ischaemia, 15 dogs were subjected to ischaemia, using the 'canine model of the completely ischaemic brain regulated with a perfusion method' in which the cerebral blood flow (CBF) can be fully regulated. Five animals served as untreated controls, 10 received flunarizine, a calcium antagonist (1 mg/kg in 5 dogs and 3 mg/kg in 5 dogs), before the ischaemic period. After 1 h CBF was restored and recovery of the electrical activity of the brain and the degree of brain swelling were observed for 3 h. At the end of the experiments, the degree of extravasation of Evans blue was examined. Remarkable recovery of EEG was found in the groups given flunarizine when compared with untreated controls. However, no significant difference was found between untreated controls and flunarizine treated groups for the degree of brain swelling and the degree of extravasation of Evans blue. These results suggest that the treatment of flunarizine is of benefit for functional recovery against cerebral ischaemia, but does not suppress ischaemic brain oedema.

Experimental study on the reversibility of cerebral ischemia. Residual blood flow and duration of ischemia

The flow threshold and time threshold for reversibility of cerebral ischemia were studied using a canine model of cerebral ischemia regulated by controlled perfusion of cerebral blood flow (CBF). CBF was continuously monitored with a laser Doppler flow meter, the brain was brought to a constant level of ischemia for a defined period of time, after which recirculation was instituted. The electroencephalogram (EEG) and somatosensory evoked potentials (SEP) were monitored and used as an index of brain function. No recovery of brain function was found following recirculation if the CBF was reduced to a level below 20% of the normal state for more than one hour. When residual blood flow was 30% of the normal level, however, recirculation after one hour of ischemia resulted in nearly complete recovery of brain function. Significant functional recovery was not seen after two or more hours of such ischemia. Nearly complete recovery was also seen following reperfusion within three hours with 40% of normal CBF. It was demonstrated that the reversibility in the ischemic brain was critically correlated to the level of blood flow and its duration. If these results can be applied to the human brain, emergency cerebral revascularization for ischemic stroke should be attempted when critical flow and time thresholds have not been crossed, namely, in less than 1 hour and 3 hours of insult when the residual blood flow is reduced to 30 and 40% of the normal state, respectively. In clinical situations, this "critical time" may be too short for acute revascularization unless cerebral protective measures are applied pre-operatively to prolong the viability period of ischemic cerebral tissue.

[Cerebral protective effect of flunarizine in a canine model of cerebral ischemia]

Recently there is the hypothesis proposing that ischemic brain damage is associated with intracellular accumulation of calcium (Ca++). Therefore a variety of experiments have been carried out to investigate whether a Ca++-entry blocker was able to protect against brain damage caused by ischemia. The purpose of the present experiment is to study the protective effects of a Ca++ antagonist, flunarizine, on cerebral ischemia. In this experiment fifteen dogs were subjected to ischemia, using the "canine model of the completely ischemic brain regulated with a perfusion method" in which the cerebral blood flow (CBF) can be fully regulated. Five animals served as untreated controls, ten received treatment with flunarizine (1 mg/kg in five dogs and 3 mg/kg in five dogs, respectively). This agent was administered intravenously 20 minutes prior to the production of ischemia, when cerebral blood flow was reduced to one-tenth its normal value while monitoring CBF by means of a laser-Doppler flow meter. After one hour CBF was restored and the recovery of electrical activity of the brain and the degree of brain swelling were observed for three hours. At the end of the experiments, the degree of extravasation of Evans blue in the excised brain was examined. With regard to the recovery of EEG, no recovery of EEG was seen subsequent to recirculation except one dog in the control group. Whereas in the groups treated with flunarizine, remarkable recovery of EEG was found following recirculation in a dose dependent fasion.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of phenytoin and its enhanced action by combined administration with mannitol and vitamin E in cerebral ischaemia

To study the therapeutic effect of phenytoin on cerebral ischaemia and confirm whether or not the effectiveness of phenytoin could be enhanced by combined administration with free radical scavengers, twenty-five dogs were subjected to ischaemia, using the "canine model of the completely ischaemic brain regulated with a perfusion method". Five animals served as untreated controls, fifteen received treatment with several doses of phenytoin and five were treated with 10 mg/kg phenytoin, 2 g/kg mannitol and 30 mg/kg vitamin E. These drugs were administered prior to the production of ischaemia. After one hour ischaemia, cerebral blood flow was restored and the recovery of electrical activity of the brain and the degree of brain swelling were observed for three hours. With regard to the recovery of the EEG, the higher the administered dosage, the better was the degree of recovery of the EEG. And the group which was treated with a combination of phenytoin, mannitol and vitamin E exhibited remarkable recovery of the EEG. With regard to the degree of brain swelling, a similar dose-related suppressive effect was seen in the phenytoin-treated groups. Furthermore, in the combination therapy group, brain swelling was attenuated significantly. Based on these results, it is concluded that phenytoin has a protective effect in cerebral ischaemia and it shows its most remarkable effect when given together with radical scavengers, such as mannitol and vitamin E.

[Experimental study on reversibility of cerebral ischemia--residual blood flow and duration of ischemia]

This experimental study was designed to estimate the flow thresholds and the time thresholds for reversibility of cerebral ischemia. We used a "canine model of completely ischemic brain regulated with a perfusion method", in which the cerebral blood flow (CBF) could be controlled. The residual blood flow was reduced to 10%, 20%, 30% or 40% of normal CBF, and the recirculation was started after 1, 2, 3 or 4 hours of ischemia. CBF was measured by a laser doppler flow meter. EEG and somatosensory evoked potential (SEP) was monitored and used as a parameter expressing the brain function. In the 10% and 20% ischemia group, functional recovery could not be obtained even if reperfusion was started at 1 hour after the onset of ischemia. On the other hand, in the 30% ischemia group, nearly complete recovery of EEG and SEP could be seen when reperfusion was done at 1 hour from the onset of ischemia. But recirculation after 2 hours of ischemia did not lead to significant functional recovery. In the 40% ischemia group, reperfusion within 3 hours of ischemia allowed full recovery of ischemic brain. On the contrary, reperfusion after 4 hours of ischemia showed a gradual deterioration of EEG and SEP. Accordingly, it was clearly demonstrated that the reversibility of ischemic brain was critically correlated to severity and duration of cerebral ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Cooperative inhibitory effect of follicular fluid and cAMP on hamster oocyte maturation

Porcine or human follicular fluid inhibited the spontaneous maturation of isolated hamster oocytes in vitro during the first 1.5 h of culture. Moreover, the presence of 50% follicular fluid combined with 100 microM dbcAMP cooperatively reduced the incidence of germinal vesicle breakdown. The addition of FSH also inhibited the resumption of meiosis, and the presence of LH did not overcome the inhibitory effects of follicular fluid and tended to impede isolated hamster oocyte maturation in vitro.

[Protective effect of phenytoin and its enhanced action by combined administration of mannitol and vitamin E in cerebral ischemia]

Phenytoin is well known as the anticonvulsant agent and also said to protect the brain against ischemic damage. The purpose of the present experiment is to study the therapeutic effect of phenytoin on cerebral ischemia and confirm whether the effectiveness of phenytoin could be enhanced by combination of free radical scavengers such as mannitol and vitamin E. In this experiment, twenty-five dogs were subjected to ischemia, using the "canine model of complete ischemic brain regulated with a perfusion method" in which it is possible to control the degree of blood flow to a cerebral hemisphere via a perfusion pump at will. Five animals served as untreated control, fifteen received treatment with phenytoin (7 mg/kg in five dogs, 10 mg/kg in five dogs and 30 mg/kg in five dogs) and five treated with 10 mg/kg phenytoin, 2 g/kg of mannitol and 30 mg/kg of vitamin E. These drugs were administered intravenously 20 minutes prior to the production of ischemia, when cerebral blood flow was reduced to one-tenth its normal volume. After one hour, cerebral blood flow was restored and the recovery of electrical activity of the brain and the degree of brain swelling were observed for three hours. With regard to the recovery of EEG, no recovery of EEG was seen subsequent to recirculation except one dog in the control group. Whereas in the group treated with phenytoin, gradual emergence of slow wave ws observed soon after recirculation. The higher the administered dosage is, the better the degree of recovery of EEG was seen. Thus, the dose-related recovery of EEG was observed within the dose ranges tested.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of cerebral protective agents in experimental cerebral ischemia. Relationship between the degree of ischemia and EEG]

We have previously demonstrated that the preischemic administration of perfluorochemicals (PFC) in combination with 20% mannitol, vitamin E and dexamethasone is effective in protecting the brain from cerebral ischemia. This experimental study was designed to evaluate the effect and limitation of the post-ischemic administration of those 4 agents on cerebral ischemia. We used "Canine model of complete ischemic brain regulated with a perfusion method." Using this model we were able to control the amount of blood flow to the left cerebral hemisphere by using an infusion pump. Infusion blood volume was reduced to 30%, 40% or 50% of the normal state, then the combined treatment was started 1,2,3,4,5 or 6 hours after the onset of ischemia in each ischemic group. By monitoring the EEG for 8 hours of ischemic period, we were able to evaluate the effect of the drugs on cerebral ischemia. In untreated groups, electrical activity deteriorated gradually. In the 30% ischemia group, the EEG became isoelectric within 1 hour following ischemia. In half of the 40% ischemia group, the EEG became isoelectric but in the other half low voltage slow wave were seen to last for 6-8 hours. In the 50% group, the EEG deteriorated gradually but did not disappear within 8 hours. The effectiveness of the treatment was judged by the degree of the recovery of electrical activity. The effectiveness of the treatment appeared to depend on the severity and the duration of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

The protective effect of combined administration of anti-oxidants and perfluorochemicals on cerebral ischemia

We previously published results of investigations which indicated that the combination of mannitol, which acts as a free radical scavenger, and perfluorochemicals (PFC), which have a strong oxygen-carrying capacity, can be therapeutic in cases of brain infarction. The present experiment tested the hypothesis that the effectiveness of such treatment could be increased by an optimal combination of such scavengers and other chemicals. Fifty-two dogs were used, employing the "canine model of a completely ischemic brain regulated with the perfusion method." A total of six drugs with free radical scavenger capacities were tested: mannitol, vitamin E, vitamin C, Nizofenone (Y-9197), dexamethasone (DEXA) and suloctidil (MY-103). These drugs were administered intravenously 15 minutes prior to the production of ischemia, when cerebral blood flow was reduced to one-tenth its normal volume. After one hour, recirculation was allowed and the recovery of electrical activity of the brain observed for three hours. Judged by the degree of recovery of brain electrical activity, five drugs were considered to have protective effect against brain ischemia: mannitol, vitamin E, MY-103, DEXA and Y-9197. Among these five drugs, mannitol, vitamin E and DEXA are known to be safe and easily used clinically. The combined administration of these three drugs, together with PFC, was also investigated. It was found that the speed and degree of recovery of brain electrical activity were greater when these drugs were given together than when one was administered alone.(ABSTRACT TRUNCATED AT 250 WORDS)