Stenting for Extracranial Stenotic Lesions of Carotid and Vertebral Arteries

We evaluated the feasibility of stenting in four patients. Two cases were vertebral osteal stenosis and the others were carotid stenosis at high position with ulcers. We placed balloon expandable coronary stents by a bared stent technique. The mean preprocedural stenosis (86.58%) was reduced to 13.05%. Patients were examined clinically and angiographically at 1, 3 and 6 months after stenting. There was no minor nor major stroke during and after the procedures. Asymptomatic restenosis occurred in the cases of proximal vertebral arteries. One of these patients needed to repeat balloon dilatation. There were no angiographic restenoses in the location of stenting in the carotid artery.

In the treatment for atherosclerotic stenoses, stent placement is a feasible and safe method. However restenosis in a vertebral osteal lesion should be carefully followed after stent placement.

Endovascular Stent Placement of Cervical Internal Carotid Artery Dissection Related to a Seat-Belt Injury: A Case Report

OBJECT

The incidence of carotid artery dissection related to blunt injury is very low, but the mortality rate is high. Rapid diagnosis and proper treatments are discussed.

CLINICAL PRESENTATION

A 48-year-old woman presented diplopia and pulsating tinnitus of the left ear. An angiography showed a carotid cavernous fistula (CCF) and dissection of the extra-cranial internal carotid artery (ICA). To treat the dissection, a self-expanding endovascular stent was used. She has been followed for 6 years without any event and the ICA is patent.

CONCLUSION

Prompt diagnosis without delay and intimate follow-up is the key for the treatment of a carotid injury. Those patients who exhibit cervical bruits and/or seat-belt signs should be examined aggressively. Angioplasty with stents is amenable for patients with traumatic carotid dissections requiring vascular reconstruction in the acute stage.

Symptomatic cavernous internal carotid artery aneurysms treated with detachable coils

SUMMARY

We reviewed the cranial nerve dysfunctions of eight patients with symptomatic cavernous internal carotid (CSIC) aneurysms treated by endovascular intraaneurysmal occlusion. Aneurysms were classified into three types according to their location and direction of growth. Anterior type aneurysms, which involved anterior bend of CSIC represented third nerve dysfunction. Posterior type aneurysms, which located posterior bend of CSIC preferred to affect sixth nerve function. CSIC aneurysms that extended over the both bends had total ophthalmoplegia. All patients responded to endovascular treatment, though partial resolution was recorded in the case of upward gaze or lateral gaze impairment. Endovascular treatment with detachable coils offers an excellent alternative with acceptable risks of morbidity.

[Dissecting aneurysm of the anterior cerebral artery with later development of collateral circulation: a case report]

Intracranial dissecting aneurysm (DA) is much less frequent than berry aneurysm. Such dissection involves mostly the vertebral and basilar arteries, followed by the internal carotid and middle cerebral arteries. DA of the anterior cerebral artery (ACA) is relatively rare and little is known about its natural Development. Only 23 cases have been reported previously. Our present patient, a 44-year-old man, suddenly developed paresis of the left leg while bathing. Diffusion magnetic resonance imaging indicated an area of high signal intensity in the territory of the ACA. Angiography on day 3 following onset showed a DA involving the left A2 segment. Antiplatelet therapy was administered. Further luminal narrowing in the lesion was demonstrated by repeat angiography on day 17. Occlusion of the distal A2 segment was demonstrated together with sufficient collateral supply on day 41. Symptoms resolved completely. DA of the ACA usually presents with ischemic attacks. Its etiology remains uncertain, and its natural course is unclear. Surgical intervention is recommended for patients with intracranial hemorrhage, while non surgical therapies have achieved good outcomes in ischemic cases.

Initial and long-term results and peri-procedural complication in 35 extracranial stentings

We undertook stent-supported angioplasty for 35 lesions of extracranial stenosis in 31 patients from May 1996 to October 1998. We succeeded in the stenting at the predetermined sites of all lesions and excellent initial results were obtained. The mean % stenosis decreased from 81% to 7.1% after stenting. Four patients had neurological complications related to the procedure. There were two transient ischemic attacks (one in carotid and one in vertebral stenting), and permanent deficits occurred in two patients treated for carotid stenosis. In carotid stenting, we observed long-term patency for over six months in all 17 patients (18 lesions). Mean angiographic, asymptomatic restenosis was 20% and 21% at three and six months, respectively (range, 4 to 38%). No further stenosis was observed thereafter. Deformity of the stents were not noted in any patient. In vertebral stenting, four out of nine cases revealed significant restenosis between three and six months later, while these were dilated by repeated PTA. On strict definition of indication or application of a cerebral protection, stent-supported angioplasty is an effective method for the treatment of extracranial stenotic lesions.

[A case of neurofibromatosis type 1 associated with arteriovenous fistula caused by re-bleeding of a vertebral dissecting aneurysm]

We described a dissecting aneurysm of the vertebral artery (VA), which was associated with neurofibromatosis type 1 (NF1). A 41-year-old man was referred to our hospital because of abrupt, severe headache. A CT scan revealed diffuse subarachnoid hemorrhage (SAH) predominantly in the prepontine cistern. The angiograms showed a string sign in the left VA, just distal to the posterior inferior cerebellar artery (PICA). The vertebral dissection was considered responsible for SAH, and endovascular occlusion of the left VA was attempted. During the intervention, the patient complained of severe neck pain at the time of selective vertebral angiography, which revealed an arteriovenous fistula. The VA was occluded proximal to the PICA with GDC, which covered the fistula. Open surgery confirmed the two unruptured aneurysms. Intracranial dissection is rarely reported in association with NF1. However, ateriovenous fistula is not an uncommon combination with dissecting aneurysm and the extracranial segment of the VA is a characteristic target. Anatomical feasibility is conceivably the pathogenesis.

[Four cases of abducens palsy caused by a vascular lesion of the vertebrobasilar system]

Several pathological conditions are responsible for abducens palsy, but a lesion of the vertebral artery (VA) has rarely been recognized as one of the causes. It has been reported that a high percentage of cases of abducens palsy are involved with ruptured dissecting aneurysms of the VA. We investigate the vertebrobasilar anatomy in 4 patients, suffering with abducens palsy. One patient revealed a fusiform dilatation of the vertebral artery on the same side as the abducens palsy. Three patients were noted to have stenosis of the vertebral artery from the origin of the posterior inferior cerebellar artery (PICA) to the union. Finally, four patients were found to have abnormal vertebrobasilar anatomy, which was on the same side as the abducens palsy. It is conceivable that changes of vertebrobasilar circulation may cause abducens palsy through direct compression, or ischemic events.

[A case of peduncular hallucination after aneurysmal subarachnoid hemorrhage]

We reported a case of peduncular hallucination after aneurysmal subarachnoid hemorrhage (SAH). The patient underwent endovascular embolization of an intracranial aneurysm using the Guglielmi detachable coils (GDCs) 9 days after SAH. On the 11th day, she reported visual hallucination: a maggot was on the ceiling, or a soldier who wore green clothes was standing by a locker. The hallucination was vivid, well-formed and associated with insomnia, suggesting peduncular hallucination. A computed tomographic (CT) scan revealed small infarctions of right frontal lobe, which were not responsible for the visual hallucination. Hyperdynamic therapy relieved the visual hallucination 23 days after SAH. It was conceivable that vasospasm was the cause of the infarction and visual hallucination. Only 4 cases with peduncular hallucination after SAH were reported in conjunction with vasospasm. The symptom may be concealed by disturbance of consciousness. Visual hallucination should be considered as a sign of cerebral vasospasm, and an appropriate treatment should be done at right time.

Stenting of the extracranial carotid artery in a high-risk population

SUMMARY

The results of nine patients with carotid stenosis in a high-risk surgical population that were treated by stent supported angioplasty are reported. There were eight males and one female between the ages of 53 to 74. A balloon expandable stent was deployed by a transfemoral approach. Technical success was achieved in all cases. There were no periprocedural complications. The mean % stenosis decreased from 84% to 5.2% after stenting. No arterial dissection was recorded and smooth contour of the vessel was demonstrated in all patients. We have observed long term patency for over 6 months in seven patients. Mean angiographic stenosis was 20% and 21% at 3 and 6 months, respectively (range, 5 to 32%). No further stenosis was recorded. Carotid stenting is an alternative strategy to carotid endoarterectomy (CEA) for high-risk patients, for whom the complications of CEA may exceed the potential benefits.

Single stranded DNA as an immunocytochemical marker for apoptotic change of ischemia in the gerbil hippocampus

The light and electron microscopic localizations of single stranded DNA (SSD) protein, a marker of apoptosis and programmed cell death, in the gerbil hippocampus were examined by immunocytochemistry after transient brain ischemia. SSD-immunoreactive (IR) cells appeared from post-operative day 1 (PO 1) to PO 7 after 5- or 10-min ischemia. Immunoreaction was recognized in the nucleus of the CA1 pyramidal neurons without remarkable morphological changes on PO 1. These findings suggest that SSD degradation can occur during delayed neuronal death in the CA1, preceding the appearance of double strand breaks, one of the characteristic features of apoptosis.

Neuronal integrity and astrocytic reaction in cold injury: an immunohistochemical investigation

The relationship between extravasation of serum albumin and damage to the neuronal elements as well as the astrocytic reaction was investigated following cold injury, using immunohistochemistry for albumin, microtubule-associated protein I and II (MAPs) and glial fibrillary acidic protein (GFAP). After 30 min, spreading of albumin to the neuropil and uptake into nerve cell bodies and dendrites were clearly observed in the area surrounding the cold lesion. Extravasation of albumin was maximal at 24 h and extended to the ipsilateral hippocampus and thalamus as well as to the paramedian part of the contralateral cerebral hemisphere. Uptake of albumin was seen in neurons with and without loss or reduction of the reaction for MAPs, but the former was confined to the area surrounding the cold lesion. When extravasated albumin receded from the neuropil, the positive reaction for albumin also disappeared from the neuronal elements and those neurons recovered immunoreactivity for MAPs. Astrocytes immunopositive for albumin were observed at 24 h in the white matter, and reactive astrocytes became notable even in the gray matter surrounding the cold lesion. Although reactive astrocytes persisted even after resolution of cerebral edema, immunopositivity for albumin disappeared from astrocytes soon after the disappearance of the reaction from the neuropil. As to the mechanism, rapid endo- and exocytosis may take place in response to the amount of edema fluid in the surrounding extracellular space, where albumin may be eliminated through the transvascular route and/or via the cerebrospinal fluid space.

[A case of olfactory neuroblastoma with intracranial, intraorbital extension and multiple metastases]

A 51-year-old man presented with headache, vomiting and exophthalmus. Neurological examination revealed anosmia, papilledema, decrease in visual acuity, and disability in ocular movement. MRI showed a huge mass which occupied the whole nasal cavity and compressed the frontal lobe upwards and the eyes laterally. CT revealed an extensive bony destruction of the frontal base and bilateral orbits. The mass was biopsied transnasally, and was histologically diagnosed as olfactory neuroblastoma. It was highly radiosensitive and disappeared with a local irradiation of 40 Gy. Three months later the patient complained of a pain radiating from the neck to the right arm. MRI demonstrated a metastasis at the vertebral body of C5. Local irradiation of 30 Gy was performed. The metastatic lesion was removed, and a bone graft taken from the iliac bone was transplanted via an anterior cervical approach. Three weeks later, however, a hard mass appeared in the right of his neck and was surgically removed. By histological examination, it was also identified as a metastatic neuroblastoma to the cervical lymph node. A week after the removal of the cervical metastatic lesion, the metastasis extended rapidly to the left cervical and the bilateral hilar lymph nodes of the lungs. Chemotherapy was performed with a total doses of 800mg of cyclophosphamide, 1.5mg of vincristine, 40mg of pirarubicin, and 80mg of cisplatin. The lesions disappeared within 7 days. However, the patient died from disseminated intravascular coagulation 10 months after the onset. Olfactory neuroblastoma is usually an intranasal neoplasm, but it rarely extends intracranially and intraorbitally as is shown in our case. Basically, olfactory neuroblastoma is a relatively slow-growing tumor though it has a tendency to develop local recurrences over long periods even after aggressive primary treatment, and accompanied with distant metastases. However, our patient showed a very short survival time. Invasive extension and multiple metastases occurred during a short period, followed by disseminated intravascular coagulation. Combined chemotherapy at the initial treatment may be recommended in such an extensive case.

Asymptomatic hypothalamic hamartoma associated with an arachnoid cyst--case report

A 42-year-old male presented with the complaint of mild left facial numbness. Magnetic resonance imaging demonstrated a solid tumor in the interpeduncular cistern and a huge arachnoid cyst in the left middle cranial fossa. The tumor appeared isointense to the surrounding cerebral gray matter on T1-weighted images and hyperintense to that on T2-weighted images. The tumor was partially resected. Histological findings were characteristic of hamartoma. The mild left facial numbness was probably due to compression of the left trigeminal nerve by the arachnoid cyst. Asymptomatic hypothalamic hamartomas may occur in adults with atypical clinical presentations.

Monitoring of cerebrospinal fluid pressure during embolization of AVM

We experienced that therapeutic embolization of a large cerebral arteriovenous malformation (AVM) led to venous outflow obstruction resulting in intracranial hypertension in a patient who had undergone external decompression. To evaluate hemodynamic changes after embolization, we monitored the cerebrospinal fluid pressure in the next four patients who underwent endovascular treatment. The embolization of a medium AVM resulted in a slight increase in the cerebrospinal fluid pressure. In two medium AVMs, embolization produced slight decreases in the cerebrospinal fluid pressure. In a small AVM, we did not observe any changes in the cerebrospinal fluid pressure during the endovascular treatment. We discuss the mechanism of changes in the intracranial pressure after embolization and conclude that monitoring of the cerebrospinal fluid pressure immediately yields useful information for hemodynamic changes during endovascular treatment.

Traumatic subarachnoid hemorrhage as a predictable indicator of delayed ischemic symptoms

This report provides findings of an investigation of the influence of traumatic subarachnoid hemorrhage on the development of delayed cerebral ischemia caused by vasospasm. The authors prospectively studied 130 patients with closed-head trauma, who exhibited subarachnoid blood on admission computerized tomography (CT) scans. Ten (7.7%) of these patients developed delayed ischemic symptoms between Days 4 and 16 after the head injury. They consisted of three (3.0%) of 101 patients with small amounts of subarachnoid blood and seven (24.1%) of 29 patients with massive quantities of subarachnoid blood on admission CT scans. In each of the 10 patients, severe vasospasm was demonstrated by angiography performed soon after development of ischemic symptoms. There was a close correlation between the main site of the subarachnoid blood and the location of severe vasospasm. In seven of the patients, follow-up CT scans showed development of focal ischemic areas in the cerebral territories corresponding to the vasospastic arteries. These results demonstrate that traumatic subarachnoid hemorrhage, especially if massive, is a predictable indicator of delayed ischemic symptoms.

A new animal model of cerebral infarction: magnetic embolization with carbonyl iron particles

A new animal model of cerebral infarction was developed by magnetic embolization with carbonyl iron particles. An electromagnet was placed upon the lateral portion outside the orbit of Mongolian gerbils and charged with a current intensity of 2 A, 3 V (400 G) for 10 min. By intracardiac injection of iron particles at the beginning of the electric charge, infarction was selectively produced in the cerebral cortex. Two days after the operation, microhemorrhaging was seen in the necrotic region. Multiple scattered infarctions accompanied with microhemorrhagic signs closely resembled embolic infarction encountered in the human brain.

Remote subarachnoid haemorrhage in the posterior fossa following supratentorial surgery. Clinical observation of 6 cases

Haemorrhage in regions remote from the site of following intracranial operations is rare, but they do occur. We performed supratentorial craniotomy on 639 patients between the time of introduction of computed tomography (CT) for clinical use in 1983 and June 1992; subarachnoid haemorrhage (SAH) in the posterior fossa occurred postoperatively in six of these cases. These included four patients with tumours in the sellar region, one with an arteriovenous malformation (AVM) and one who underwent superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis. The ages of the six patients ranged from 17-72 years. Haemorrhage occurred on the day of operation in one case and was detected on CT examination on the day following surgery in the remaining five cases. Of three patients with disturbance of consciousness, two underwent suboccipital craniectomy for reduction of intracranial pressure, while one received barbiturate therapy and later underwent cerebrospinal fluid (CSF) shunt surgery. No special treatment was necessary for the remaining three patients with less serious lesions. Five of the six patients ultimately recovered their pre-operative neurological status apart from the primary diseases. Factors inducing such haemorrhages seem likely to include displacement of the cerebellum by reduced CSF pressure during and after operations, and stretching and tearing of the veins and venules in the sulci of the tentorial surface of the cerebellum. Consideration should therefore be given to the maintenance of an appropriate CSF pressure during operation; this is particularly important in elderly patients and those with an atrophied cerebral cortex.

Interstitial chemotherapy with biodegradable ACNU pellet for glioblastoma

For patients with nonresectable glioblastoma (GB) or recurrent GB, we have recently been using an interstitial chemotherapy with biodegradable polylactic acid pellets containing nimustine chloride (ACNU), in combination with superselective arterial ACNU injection, routine irradiation and chemotherapy. The ACNU pellets are prepared by mixing polylactic acid powder and ACNU, and then melting the mixture at low temperature and moulding it into a thin pellet. Pharmacological anticancer activity was experimentally demonstrated by the finding that a region of suppression was present surrounding an ACNU pellet placed in a B6 melanoma cell culture disc, but that no such suppression was present around a control pellet. In order to determine the spatial and temporal distribution of ACNU, a small pellet (ACNU: 0.6 mg) was implanted in the frontal lobe of rats. ACNU concentration determined by HPLC was 61.0 micrograms/g brain tissue on day 1. 22.5 on day 3, and 5.5 on day 7; small amounts of ACNU were in fact released for at least 4 weeks after implantation. This pellet was used for the clinical treatment of 11 GB patients. Four patients had several pieces of pellets implanted immediately after CT-guided stereotactic biopsy, and the other 7 had pellets placed in residual tumor after partial removal at craniotomy. No ACNU was detectable in serum. CT studies obtained at subsequent appropriate intervals disclosed gas formation around the pellets, a slight increase in edema, and necrosis or decrease in CT enhancement of tumor beginning around day 12 after implantation. Bone marrow suppression did not occur, since ACNU was administered interstitially and in the range of 50-200 mg (average: 126 mg) per patient.(ABSTRACT TRUNCATED AT 250 WORDS)

[Changes in myocardial metallothionein on isoproterenol-induced myocardial injury]

The amounts of myocardial metallothionein (MT) and heavy metal (Zn, Cu) levels during the early stage of the experimental myocardial infarction model induced by isoproterenol (Isp) administration were measured by an atomic absorption spectrophotometry. MT was measured by the Cd-hem method. Myocardial infarction was induced by the administration of 75 mg/kg i.p. of Isp to rats weighing 270 +/- 10 g. Thirty minutes after Isp injection, Zn and Cu levels began to decrease and 12 h later, reached the minimal values compared with the control value. The level of MT began to increase 3 h after the Isp injection and reached the maximal value at 12 h, although MT remained undetectable in the control myocardial tissue by the Cd-hem method. MT levels in the liver increased and total Zn and Cu were elevated compared with the control value 12 h after Isp administration. These results suggest that MT is produced in the myocardium after Isp administration, and that the roles of MT in the heart and the liver are different. It was thought that a rise in MT was induced for the protection of the myocardial cells to injury.

Morphological properties of human thyroid tumor cells in collagen gel culture and metastatic or invasive ability

Using normal human thyroid cells and tumor cells, the reconstruction of various diseased cells in collagen gel as well as the relationship between the morphology of colonies in collagen-embedded culture and the biological behavior (benignity, malignancy, metastasis, and invasion) of the original tumors were studied. In collagen gel culture, normal thyroid cells reorganized follicle-like constructions, and follicular adenoma cells showed in vivo-like constructions. However, two different types of colonies were observed in cultures of cells from papillary carcinomas. One was the branching type with many outgrowths projecting to three dimensions and the other was the spherical type without any outgrowths. These spherical colonies were observed in all cases of papillary carcinoma, but varied from one case to another. Metastasis and invasion were detected during pathological examination in cases with a high ratio of spherical colonies. Our results indicate that cells from highly metastatic and invasive thyroid cancer form spherical colonies in the collagen gel culture, and that this collagen culture is a useful method for studying the heterogeneity of tumor cells as well as the metastasis and invasive ability of tumor cells in vitro.

Manganese superoxide dismutase content and localization in human thyroid tumours

Manganese-containing superoxide dismutase (Mn-SOD) content and its immunohistochemical localization in human thyroid tumours and some other thyroid diseases were examined and compared with adjacent normal thyroid tissue. Enzyme-linked immunosorbent assay (ELISA) was used in this study for the measurement of Mn-SOD. The content of Mn-SOD tended to increase in diffuse hyperplasia, adenomatous goitre, and follicular adenoma. In papillary carcinoma, it was significantly higher than in adjacent normal thyroid tissue. Follicular carcinoma also revealed a markedly high Mn-SOD content. In the immunohistochemical study, adjacent normal thyroid tissue showed granular positive staining of Mn-SOD in the cytoplasm. An increase of Mn-SOD was observed in the papillary proliferative lesion of diffuse hyperplasia and in the follicles adjacent to lymphoid tissue in chronic thyroiditis with hypothyroidism. Strong positive staining of Mn-SOD was observed in papillary and follicular carcinomas, whereas in anaplastic carcinoma staining was markedly less intense. These results indicate that the Mn-SOD content varies according to the degree of differentiation of thyroid carcinomas.

Identity of the dorsal hippocampal region most vulnerable to cerebral ischemia

Our previous investigations demonstrated that neurons in the area between the subiculum and the medial CA1 region and another area between the lateral CA1 and the CA3 region of the hippocampus are very vulnerable to cerebral ischemia in gerbils, where irreversible damages have been observed occur as early as 4-5 min after unilateral or bilateral common carotid artery occlusion. The present study was aimed to characterize these areas anatomically by using the immunohistochemical and zinc histochemical as well as Golgi silver impregnation methods. Our results indicated that these two areas which are topographically apart on the coronal section actually had a common origin in the rostral part of the hippocampus and that they were separated by insertion of the Ca1 neurons between them in the more caudal part of the hippocampus. The distribution pattern of mossy fibers indicated that these areas belonged to the CA2 region. The double immunohistochemical and zinc histochemical procedure confirmed that these areas developed ischemic lesions promptly even without reperfusion but that the CA1 region did not develop similar lesions until after reperfusion for 12-24 h if the ischemic period was brief. While the reason for the observed susceptibility of the CA2 region is not certain at the present time, it is important to distinguish the ischemic lesions in the CA2 region from those in the CA1 and CA3 regions.

Neurotrophic factor-like effect of FPF1070 on septal cholinergic neurons after transections of fimbria-fornix in the rat brain

FPF1070 is an aqueous protein-free solution, which consists of 85% free amino acids and 15% small peptides. Our previous study showed a potent neurotrophic factor-like activity in cultured embryonic cells of dorsal root ganglia. The present study investigated whether FPF1070 regenerated the cholinergic cells in the medial septal nucleus after axonal transections by cutting the fimbria-fornix. Fimbrial transection reduced the number of septal cholinergic cells by 30 +/- 3.6%, compared with the number on contralateral sides at 4 weeks. Intraperitoneal injections of FPF1070 caused 49.9 +/- 6.3% of the cholinergic neurons to survive. Furthermore, the cell sizes of the cholinergic neurons were significantly different: 16.4 +/- 4.2 microns, 14.3 +/- 3.8 microns in FPF1070 treatment and vehicle treatment, respectively. These results indicated that FPF1070 prevents the degeneration and atrophy of impaired cholinergic neurons by systemic administration.

Intracerebral distribution of albumin after transient cerebral ischemia: light and electron microscopic immunocytochemical investigation

The blood-brain barrier breaks down following cerebral ischemia, but the exact sequence of events for extravasation of serum proteins and their parenchymal distribution remain uncertain. We studied the distribution of serum albumin in the hippocampus of the gerbil brain using light and electron microscopic immunocytochemical techniques. With light microscopy, there was no reaction for albumin for the first 12 h after unilateral common carotid artery occlusion for 10 min and reperfusion. At 12 h, the reaction was weak and limited to the neuropil in the subiculum-CA1 region (between the subiculum and the medial CA1 region). After 24 h, the reaction became intense in the neuropil and neuronal perikarya in the subiculum-CA1 and medial CA1 regions. The electron microscopic immunocytochemical study of the subiculum-CA1 and medial CA1 regions revealed electron-dense immunoprecipitates in the extracellular space and the peripheral part of the apical dendrites as early as 30 min after reperfusion and in the astrocytic cytoplasm after reperfusion for 1 h. However, immunoprecipitates were not found in the neuronal perikarya until after reperfusion for 24 h. The present study demonstrated prompt appearance of albumin in the extracellular space of the brain parenchyma after re-establishment of cerebral circulation and prompt accumulation in the peripheral part of the dendrites with spreading to neuronal perikarya, likely in the process of degeneration and death.

Intense immunoreactivity for Mn-superoxide dismutase (Mn-SOD) in cholinergic and non-cholinergic neurons in the rat basal forebrain

The immunohistochemical localization of manganese (Mn)-superoxide dismutase (Mn-SOD) was studied in the rat basal forebrain using polyclonal antibodies to Mn-SOD. Neurons of the basal forebrain exhibit a high density of Mn-SOD immunoreactivity. Double immunostaining with a monoclonal antibody to choline acetyltransferase demonstrated that both cholinergic and non-cholinergic neurons in the basal forebrain are intensely immunoreactive for Mn-SOD.

Ultrastructural investigation of the CA1 region of the hippocampus after transient cerebral ischemia in gerbils

Ultrastructural damage leading to delayed neuronal death was investigated in the mid-CA1 region of the hippocampus from the stratum (str.) moleculare to oriens after transient bilateral forebrain ischemia in Mongolian gerbils. After ischemia for 5 min without recirculation, mild swelling of the peripheral part of the apical and basal dendrites was already apparent in the str. moleculare and str. oriens. Mitochondria in the dendrites were also swollen in the same area. During recirculation for 12 h to 3 days, swelling of the dendritic cytoplasm persisted with formation of microvacuoles, but swelling of mitochondria receded. Microvacuolation and loss of microtubules were also observed in the proximal part of the dendrites during this period, and swelling and disruption of internal cristae were observed in mitochondria after recirculation for 3 days. The dendrites became severely degenerated after recirculation for 4 days. In the pyramidal cell bodies, no abnormality was observed at the end of ischemia for 5 min, but disaggregation of polyribosomes and swelling of the endoplasmic reticulum were observed 12 h after recirculation. Proliferation of the endoplasmic reticulum in parallel arrays occurred after recirculation for 1 day and persisted. Severe degeneration of the pyramidal cell bodies was obvious after recirculation for 4 days. The findings observed in the present investigation suggested that the neuronal structure most vulnerable to ischemia was the peripheral part of the dendrites and postischemic neuronal damage occurred early in this part of the dendrites.

Immunocytochemical localization of manganese superoxide dismutase (Mn-SOD) in the hippocampus of the rat

The immunocytochemical distribution of manganese superoxide dismutase (Mn-SOD) was determined in the rat hippocampus. The enzyme was localized in the mitochondria. CA1 pyramidal cells were weakly immunostained, whereas CA3 pyramidal cells were strongly reactive. These differences in the intensity of the Mn-SOD immunostaining reactions may relate to variations in the sensitivity of subfields of the hippocampus to ischemia.

Prediction of stroke before and after unilateral occlusion of the common carotid artery in gerbils

A method was developed to predict the severity of cerebral ischemia before permanent occlusion of a common carotid artery in gerbils by observing the diameter and appearance of the artery after temporary occlusion and observing clinical signs after permanent occlusion. The severity of cerebral ischemia was confirmed by a sensitive immunohistochemical method and measurement of focal cerebral blood flow after 30 minutes' ischemia. All gerbils with greater than 40% reduction of the diameter and a white arterial margin distal to temporary occlusion developed severe neurologic signs following permanent occlusion, but no gerbils with reduction of less than 30% and a red arterial margin developed neurologic signs. With the cumulative neurologic score, gerbils could be divided into classes with no, mild, moderate, and severe symptoms, mostly after 10 minutes. Severely symptomatic gerbils were identified in 3 minutes. Extensive ischemic damage was observed in severely symptomatic gerbils, but no immunohistochemical lesion was detected in mildly symptomatic gerbils. Cerebral blood flow was markedly reduced in severely symptomatic gerbils but more selectively reduced in the cortical structures of moderately symptomatic gerbils. This prediction method is useful for investigating early cerebral ischemia and for evaluating the effectiveness of pharmacologic agents.

Immunohistochemical investigation of cerebral ischemia after middle cerebral artery occlusion in gerbils

Progression and recovery of ischemic and postischemic damage after occlusion of the middle cerebral artery and subsequent reperfusion were investigated in the gerbil. This study was performed by immunohistochemical reaction testing for tubulin and creatine kinase BB-isoenzyme to visualize the neuronal structure and by immunohistochemical reaction testing for astroprotein (an astrocyte-specific protein) to visualize reactive astrocytes. The earliest ischemic lesion became visible in the frontoparietal cortex after 7 minutes of ischemia as a laminar loss of the reaction for tubulin involving the neuropil, neuronal perikarya, and dendrites. The earliest lesion in the caudoputamen evolved after 30 minutes of ischemia. After reestablishment of cerebral circulation, the immunohistochemical ischemic lesions in the neuronal structure disappeared if the ischemic period was 10 minutes or less and partially disappeared even after ischemia for 15 minutes in the cerebral cortex, while the postischemic lesion in the caudoputamen disappeared even after ischemia for 15 minutes. Reactive astrocytes were detected in the cerebral cortex and caudoputamen as early as 24 hours after reperfusion, both in the areas with and without the neuronal lesions. No lesion was identified in the hippocampus or thalamus. This experimental model is suitable for investigation of rapidly progressive regional ischemia in the cerebral cortex and for comparison with other regional or global cerebral ischemia in the gerbil or other animal species.

Lectin (UEA-1) reaction of capillary endothelium with reference to permeability in autopsied cases of cerebral infarction

The relationship between endothelial reactivity to Ulex europaeus agglutinin-1 (UEA-1) and the permeability of the vascular wall in human autopsied cases of cerebral infarction was studied. Sections from the cerebral cortex were reacted with horseradish peroxidase UEA-1 to demonstrate the surface membrane of endothelial cells. Albumin in the neuropil of sections was demonstrated for the estimation of increased vascular permeability. The results showed that endothelial reactivity to UEA-1 was reduced in cases where death had occurred 3 to 5 days after onset of cerebral infarction. Reactivity was also diminished in cases where death had occurred after 13 and 25 days; these cases showed fresh ischemic lesions caused by re-attacks of infarction. Albumin extravasation into the neuropil was demonstrated in these intermediate cases. Chronic cases, dying after more than 52 days, showed no reduction of endothelial reactivity to UEA-1 and no albumin extravasation was proved. It was concluded that UEA-1 can be employed as a useful morphological marker for evaluation of endothelial function and vascular permeability.

A morphological study on the effects of collagen gel matrix on regeneration of severed rat sciatic nerve in silicone tubes

The present study is a chronological morphological examination on the effects of collagen gel matrix on regeneration of severed sciatic nerves. The nerves (5 mm length) were resected, and both the distal and proximal stumps were inserted into a silicone tube with 5 mm gap in between. In the test side, the gap in the tube was then injected with liquid collagen which gels in the tissue when reconstructed with a certain buffer solution. The gap space in the tube of the control side was left empty. In a chronological examination of the tissue in the tube, considerably more rapid growth of sprouting axons toward the distal stump in the test side was revealed in comparison with the control side. The cells, including both fibroblasts and larger Schwann cells, were less in number. More orderly directions were observed in the collagen matrix than in the control tube. The result indicates that regeneration of the peripheral nerves in the silicone tube can be improved, by using appropriate exogenous fine materials, collagen matrix.

Experimental study of WGA binding on the endothelial cell surface in cerebral ischemia

The relationship between the saccharide chain on the endothelial cell surface and the permeability of intracerebral blood vessels has been studied. In the present study, wheat germ agglutinin (WGA) was perfused into capillaries in the area postrema of the normal Mongolian gerbil, where the blood brain barrier (BBB) is known to lack, and into intracerebral blood vessels, the BBB of which had been destroyed by experimentally induced brain ischemia. The light microscopic features of the sections from WGA-perfused brain tissues of the normal gerbil revealed that most of the blood vessels, including capillaries in the brain parenchyma, showed positive findings (the reaction induced a very distinct staining of the vascular wall) from which the course and structure of the fine vessels could be determined. The reaction to WGA on the diaphragma fenestra (DF) in capillaries in the area postrema was relatively weak, and DF without the reaction were occasionally revealed by electron microscopy. The gerbil, in which cerebral ischemia had been induced, also showed partial defect of the reaction with WGA on the luminal side of the endothelial cells. The results of the present experiment suggest some degree of correlation between the saccharide chains, including the specific monosaccharide of WGA, on the endothelial cell surface and permeability. It was considered that lectin can be used as an index for morphological observations, suggesting an alteration in function of the endothelial cell membrane. In addition, the perfusion method in this experiment suggested the possibility of distinguishing pinocytotic vesicles from pits of cell membranes.

Light and electron microscopic studies of calcitonin gene-related peptide-like immunoreactive neurons and axon terminals of the nucleus of the tractus solitarius of the rat

This study was an examination of the ultrastructural characteristic features of calcitonin gene-related peptide (CGRP)-like immunoreactive neurons and their axon terminals in the nucleus of the tractus solitarius of the rat. Some axon terminals were identified as receiving synaptic inputs from non-immunoreactive axon terminals. This may suggest that part, if not all, CGRP containing afferents are affected presynaptically by other afferents.

The synaptic relationship between vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons and their axon terminals in the rat small intestine: light and electron microscopic study

The present study demonstrates synaptic contacts between vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons and immunoreactive axon terminals in the submucous and myenteric plexuses of the rat small intestine. Our observations suggest that VIP afferents directly affect the VIP neurons in the small intestine via synapses.

Neuronal changes of hypokalemic myopathy. A light- and electron-microscopic study on muscle biopsy

Hypokalemic myopathy has been observed in various clinical conditions. There are many studies of the pathomorphological changes of muscle fibers but alterations in intramuscular nerves and motor end-plates are seldom mentioned. The present authors observed biopsied muscle from a 51-year-old housewife who had suffered from gradually increasing muscle weakness. Laboratory examinations revealed a severe hypokalemia of 1.5 mEq/1, 18304 U/1 of CPK, 1300 U/1 of LDH, 343 U/1 of SGOT and 297 IU/1 of adolase. Light-microscopic examination showed changes previously described, including twin-peaked distribution in the histogram of type I, IIA and IIB fibers, ballooning and thickening of terminal axon, and 2 or 3 end-plates closely spaced along the length of muscle fibers. The electron-microscopic examination revealed empty folds of basement membrane in end-plate regions, reduced secondary synaptic clefts, interposition of Schwann cell processes between nerve ending and primary synaptic cleft, and an increase of disarranged microtubules and neurofilaments in terminal axons. The findings suggest that severe hypokalemia primarily produces structural alterations of intramuscular peripheral nerves and motor end-plates as well as of muscle fibers.