[Scrotal scintigraphy in varicocele compared with physical examination and venography]

Scrotal scintigraphy using a gamma-camera and 740 MBq of 99mTc-labeled human serum albumin was performed on 43 patients with suspected varicocele. In 39 patients (37 left-sided, 2 bilateral) with proven varicoceles, sensitivities by the static and dynamic images were 92.3% and 51.3%, respectively. There were no false positive cases in either image (4 cases with no varicocele). It has been suggested that static images are useful for the detection of varicocele in infertile men. A comparison between the static and clinical grades showed that the static grades appeared to become higher in proportion to the clinical grades. A comparison between the static grades and the diameter of the internal spermatic vein (ISV) showed that the mean value of the diameter of the ISV in SG 1, SG 2 and SG 3 was 4.1 +/- 0.66 mm, 5.1 +/- 0.68 mm, and 6.2 +/- 0.79 mm, respectively. Patients with higher static grades had ISVs of significantly larger diameter (SG 1 vs SG 2; p less than 0.05, SG2 vs SG3; p less than 0.01, SG 1 vs SG 3; p less than 0.01, t-test). A comparison between the dynamic images and the degree of reflux in the ISV showed that patients with positive dynamic images had a significantly greater degree of reflux (p less than 0.01, Chi-square test). From these observations, scintigraphic findings would reflect the degree of reflux in the ISV, the diameter of ISV, and the size of the varicocele. Furthermore, from the remarkable changes between pre- and post-therapeutic findings on the scintigrams, therapeutic effects could be easily and objectively assessed by scintigraphy.

A method for computing the derivative of noisy time-activity curves and its application to radioisotope dynamic analysis

A method for computing the slope or the derivative of time-activity curves containing statistical fluctuations is described. The algorithm presented employs digital differentiation as a digital filter. In designing an effective differentiating filter the Chebyshev-type min-max method and Remez exchange algorithm are used to minimise the weighted Chebyshev error. The validity of this method has been investigated using computer-based Monte Carlo simulation. Renogram curve analysis is presented as an example of an application of this method to radioisotope dynamic analysis. The ratio of the bilateral slopes of the renogram's second segments estimated using this method correlated well with the renal plasma flow ratio (r = 0.97, n = 16). The functional images of the slope of the renogram's second segments have been constructed and ascertained to be clinically useful. This method is considered to provide a powerful tool for extraction of quantitative information both in research and in routine nuclear medicine clinical work, and may be useful in various other fields.

[Role of CT and ultrasonography in acute blunt trauma of the abdomen]

From March 1985 to April 1989, one hundred thirty-one patients were examined using computed tomography (CT) and/or ultrasonography (US) in the evaluation of acute blunt trauma of the abdomen (CT and US in 36 patients, CT in 25 US in 70). Twenty-three out of the 131 cases (17.6%) showed positive findings of abdominal trauma on CT and/or US. Sixteen of the 23 patients with positive findings underwent therapeutic laparotomy, while all of the other 108 patients with negative findings were successfully managed conservatively. This fact suggests that one of the roles of CT and/or US is to pick up patients with negative findings who do not have any laparotomy. Free fluid collection was demonstrated in all of the 23 patients with positive findings in: all 22 on CT (100%), and 13 of 14 on US (92.9%). In all of the 23 patients but one with an injured mesenterium, injured organ was demonstrated by CT and/or US in: 21 of 22 by CT (95.5%), and 11 of 14 by US (78.6%). In one of the 11 patients, not an immediate US but a follow-up on the next day revealed an injured organ. In 6 out of the 12 patients who underwent both plain and contrast enhancement (CE), CT, CE-CT demonstrated the injured organ more clearly than plain CT. US with sector probe was also useful for demonstrating the injured lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

[Metastases to the brain--prognosis and surgical indications]

The prognosis of the patients with metastases to the brain is very poor. Based on the data obtained from the Brain Tumor Registry in Japan, relative survival rate curve of the cases with metastatic brain tumors is extremely similar to that of the cases with glioblastoma multiforme which is the most malignant primary brain tumor. Data obtained from the Department of Neurosurgery of Osaka University Medical School, the Center for Adult Diseases, Osaka demonstrated that the brain lesions were the direct causes of death only in 26% of the cancer patients with brain metastases. The result might have indicated that brain metastasis itself could be more controllable than the other lesions of systemic in most of the cases. The indications for surgical treatment of metastatic brain tumors are, in general, as follows; (1) the primary cancer is cured or to be cured, (2) no metastasis to other organs, (3) the brain metastasis is single, solitary and surgically accessible, and (4) the general condition is good enough. But recent advancement in the diagnosis, surgery and patient care are going to extend the indications for surgical treatment. Surgical mortality becomes less than a few percent. The changes of performance status by surgery were investigated in the patients treated in Department of Neurosurgery, Osaka University Medical School and the Center for Adult Diseases, Osaka. Improvement of the performance status after surgery was obtained in 57.8%, stationary in 30.5%, and worsening only in 11.8%.

Detection of the B waves in the oscillation of intracranial pressure by fast Fourier transform

Intracranial pressure (ICP) oscillation consists of a cardiac-induced component, a respiration-induced component and fluctuation of the base level of ICP. Lundberg reported three types of fluctuations of the base level of ICP with increasing ICP which were referred to as A, B and C waves. Computer algorithms for sampling, processing and displaying ICP data were investigated to depict the power spectrum of ICP oscillations by fast Fourier transform (FFT), thus enabling the B wave to be automatically detected. A power peak was found in the ICP power spectrum between 30 and 120 s, which corresponds to the frequency of the B wave. The maximum power, corresponding to the B-wave amplitude was above 0 dB. An appropriate sampling interval for FFT inputs was about 8 s for real-time processing of the ICP data. The mean ICP value was found useful for making the B-wave peak clearer by reducing the cardiac and respiratory components of ICP oscillations; the window function had no effect on B-wave detection in the ICP power spectrum.

Modification of anoxic neuronal injury by human recombinant epidermal growth factor and its possible mechanism

A primary culture of cortical neurons was established from a 17-day rat embryo. Twenty-four hours after plating, the culture medium was changed to a chemically defined one, and human recombinant EGF (rEGF) was added to the medium at concentrations of 1, 10, and 100 ng/ml. Anoxic stress was exerted on the cultured neurons for 4 hr. Without anoxia, rEGF at a concentration of 10 ng/ml supported neuronal survival. When rEGF was not present in the culture medium, anoxic stress reduced neuronal density to one-tenth that of the nonanoxic group. The rEGF improved neuronal recovery from anoxia significantly, with survival dependent on rEGF dosage. Monoclonal antibody for EGF receptors canceled the effect of rEGF on survival of neurons in a dose-dependent manner. Therefore, rEGF functioned to support neuronal survival from anoxia through EGF receptors. Ontogeny of the EGF receptors was detected immunocytochemically with anti-EGF receptor antibody. About 70% of the cultured neurons were stained by the anti-EGF receptor antibody 3 days after change of medium, and immunoreactivity for EGF receptors was found to be located on the soma of neurons. Binding activity of EGF receptors was detected 5 days after change of medium with receptor binding assay and Scatchard analysis. High-affinity binding sites were detected only in neurons cocultured with rEGF (10 ng/ml) for 5 days. The data indicate that rEGF in sufficient concentration induces high-affinity sites of the EGF receptor and that EGF may have an antianoxic effect through the EGF receptors.

RNA synthesis and processing in the gerbil brain after transient hindbrain ischaemia

Ribonucleic acid (RNA) synthesis was investigated in gerbils subjected to 15 min transient hindbrain ischaemia using [2-14C]uridine autoradiography. Distribution of synthesized RNA in the subcellular fraction of the tissue was detected by differential centrifugation and density gradient separation using Whittaker's method. In [2-14C]uridine autoradiography, uptake of the tracer into the RNA fraction was not reduced after transient ischaemia. Distributional analysis of [2-14C]uridine in the subcellular fractions revealed that tracer activity in the P3 (microsomes) fraction decreased in the ischaemic regions and tended to decrease in the P4 (ribosomes) fraction, although not significantly. Tracer activity in the P1 (nuclei and cell debris) and P2 (mitochondria, myelin and nerve ending particles) fractions did not decrease. These results indicate that RNA synthesis in the nuclei is not inhibited by ischaemia, but RNA processing is disturbed by the level of the transport. Modification of RNA synthesis and processing by transient ischaemia may influence protein synthesis.

[The role of gallium-67 citrate scintigraphy in gastro-intestinal malignant lymphoma]

To evaluate the clinical usefulness of gallium-67 scintigraphy in the detection of the gastrointestinal (GI) non-Hodgkin's lymphoma (NHL) and in the assessment of the therapeutic effects, gallium-67 scintigraphy was reviewed on 24 cases (25 lesions; stomach in 20, ileum in 2, and terminal ileum and/or cecum in 3). Twenty-three out of the 25 lesions (92.0%) were detected by gallium-67 scintigraphy, while barium study could detect all of the 25 lesions. The sizes of the gallium-67 negative 2 lesions were the smallest of all (2.5 and 3.0 cm). The tumor size was considered to the most important factor in the detection by gallium-67 scintigraphy, while the histological classification and the location of the tumor were not related to its detectability. Findings in follow-up gallium-67 scintigraphy after therapy on 10 cases were correlated well with the therapeutic effects. These data suggest that gallium-67 scintigraphy is useful for the detection of GI involvement of NHL and for the assessment of therapeutic effects.

Single photon emission computed tomography (SPECT) using N-isopropyl-p-(123I) iodoamphetamine (IMP) in the evaluation of patients with epileptic seizures

To evaluate the clinical usefulness of IMP SPECT in the diagnosis of epilepsy, 6 normals and 52 patients in the interictal phase were studied. Thirty min after an intravenous injection of 111 MBq IMP, SPECT was performed using a rotating gamma camera. Of 21 patients with simple partial seizures, a localized decrease of uptake was shown in 16, and an increase in 3. Topologically, these findings corresponded well to the ictal symptoms. Nine of 13 patients with localized epileptic EEG had a good correspondence between the findings on EEG and IMP SPECT. In 20 of 23 with complex partial seizures, the coronal images showed laterality of uptake in the temporal lobes, whereas the CT was normal in 14. However, these findings on IMP SPECT agreed with the EEG in the temporal leads in only 5 cases. Of 8 patients with primary generalized seizures, a diffuse cerebral decrease was shown in 3 of 4 patients with convulsive seizures (grand mal), and a normal uptake in 3 of 4 patients with non-convulsive seizures (petit mal). However, 2 patients showed a localized decrease, therefore, we determined that they suffered from partial seizures evolving to secondarily generalization. From these data, we concluded that IMP SPECT could be a useful method in the diagnosis of epilepsy.

Validity of microsphere model in cerebral blood flow measurement using N-isopropyl-p-(I-123) iodoamphetamine

A microsphere model is sometimes used when calculating cerebral blood flow (CBF) using N-isopropyl-p-[I-123]iodoamphetamine (IMP), and is based on the assumption that there is essentially no washout of IMP. The validity of a microsphere model was investigated by comparison with the values of CBF obtained by means of a model which takes into consideration the diffusion of IMP from brain tissue to blood (nonmicrosphere model). When calculating CBF by the latter model, the look-up table method was used with expression of the double integral in the model equation by the recursion relations, a method which is useful for obtaining pixel-by-pixel values. The average rate constants for diffusion from brain to blood of gray and white matter were 0.021 and 0.0016 min-1, respectively. The values of CBF obtained by applying a microsphere model to the data acquired from 0 to 3.2 min after IMP injection were overestimated by approximately 23% compared with those values obtained using a nonmicrosphere model. This is considered to be due to the effect of the IMP activity in the vascular space. Values obtained using the data acquired from 3.2 to 6.4 min were underestimated by approximately 15%. When the values of CBF obtained by a microsphere model were interpolated, they became nearly equal to those obtained using a nonmicrosphere model at about 4 to 5 min after injection. This is suggested to be the reason why the underestimation due to diffusion from brain to blood is cancelled out by the overestimation due to the IMP in the vascular space. Our preliminary results suggest that it is necessary to take the diffusion of IMP from brain tissue to blood into account for the quantification of CBF using IMP.

[Expression of major histocompatibility complex on human medulloblastoma cells]

Medulloblastoma is one of the most common malignant brain tumors in childhood. These cells are immature bipotential cells that could differentiate into both neuronal and glial cells. The authors established two human medulloblastoma cell lines. One was derived from a 2-year-old girl with cerebellar tumor (designated as ONS-76) and another was from a 9-year-old girl with metastatic tumor in the right frontal lobe (ONS-81). Immunohistochemical studies showed that both cell lines possessed 145 and 200 kDa neurofilament proteins and neuron-specific enolase, without glial fibrillary acidic protein and S-100 protein. It was shown that interferon gamma could enhance or induce the expression of the major histocompatibility complex (MHC) antigens which play a major role in immune response. Also shown for the first time was the expression of MHC class II antigens on human medulloblastoma (ONS-76 and 81) with neuronal differentiation.

Neural transplantation in mouse Parkinson's disease

A complete recovery from the methamphetamine-induced rotational response was shown in C57BL/6 (H-2b) mice which had had unilateral 6-OHDA lesions in the nigrostriatal pathway about 60 days after transplantation of approximately 1 x 10(6) dopamine-rich cells from syngeneic or allogeneic (C3H/HeN, H-2k) mouse embryos (ED 15), without immunosuppressive agents. Morphological examination showed tyrosine-hydroxylase-immunoreactive cell clusters around the needle tract in the mice which were transplanted not only with syngeneic cells but also with allogeneic cells. This might indicate that so-called immunosuppressive agents are not necessary for grafted embryonic cells to survive in an allogeneic mouse brain.

[In situ nick translation for detection of DNA damages in glioma cells]

DNA damaging agents such as nitrosoureas are widely used for the treatment of malignant gliomas. Therefore, quantitative measurement of DNA damages induced by antineoplastic drugs is useful to judge the efficacy of the drug and understand the pharmacological action of the drug. We have utilized in situ nick translation method to demonstrate "nicks" in DNA of glioma cells treated by various antineoplastic agents. Exponentially growing rat 9 L glioma cells (4 x 10(4] were seeded in the chamber slide. After fourty eight hours, the medium was changed to that containing various concentration of the drug (ACNU, cis-DDP, BLM, ADM and VP-16) and the cell was treated for 1 hour. Then, the cell was fixed for 10 minutes in methanol-acetic acid (v/v 3:1). Following fixation, the cell was incubated in the nick translation mixture containing E. coli DNA polymerase I, 3H-TTP, and 4 dNTP's (ATP, GTP, CTP, CTP and TTP) for 10 minutes at room temperature. The slide was dipped in the autoradiographic emulsion, exposed for 4 days at 4 degrees C, and then developed, the number of the silver grains over nuclei was counted under the microscope. For comparison of the effect of the drug to glioma cells, IC50 (inhibitory concentration of the drug for 50% cell kill) of each drug was determined by treating the cell for 48 hours at the various concentration of the drug. Small number of the silver grains was noted in cells with no treatment. Over IC50 as the concentration of the drug increased, the number of the nick increased in cells treated with bleomycin or adriamycin which are known to produce single strand breaks in DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

[Capillary permeability factor produced by C 6 glioma cells: role in peritumoral brain edema and possible mechanism of glucocorticoid action]

We studied whether C6 glioma cells produce a diffusible factor that increases capillary permeability of rat brains. Culture supernatant after 4 hours' incubation of C6 glioma cells in serum-free medium was obtained (SUP-N). SUP-N was concentrated 80-fold by dialysis-concentration (MW cut off was 10 kd) (SUP-C). These two supernatant fractions were tested for capillary permeability activity by their infusion into normal rat brains (right caudate-putamen). Control materials (MEM or concentrated MEM) were also infused into the left caudate-putamen as well as supernatants. Capillary permeability was measured by a quantitative autoradiographic method with 14C-aminoisobutyric acid (AIB) and expressed as an unidirectional blood-to-brain transfer constant (K). Effects of infusates were quantitatively estimated by two parameters, i.e., the highest K value (Kmax) (microliter/g/min) and the spatial extent (D1/2) (mm). The protein concentration of SUP-N and SUP-C was 15 and 950 micrograms/ml, respectively. SUP-N showed a slight increase of capillary permeability, particularly, around the needle track (infusion site) in the brain, but it was not significantly different from the control on the value of Kmax. On the other hand, SUP-C markedly increased capillary permeability (Kmax; SUP-C: 10.83 +/- 0.99, control: 2.53 +/- 0.22, p less than .001) and the effect was much more extensive than that of SUP-N (D1/2; SUP-C: 2.23 +/- 0.26, SUP-N: 0.83 +/- 0.07). A factor in SUP-C increased capillary permeability after a lag phase of 1.5 hours reaching the maximum after 6 hours of infusion, and 24 hours later the effect declined to 30% of Kmax at 6 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Recovery of gonadal function after resection of an oligodendroglioma localized in the anterior horn of the lateral ventricle: relation to pulsatile secretion of luteinizing hormone

A 21-year-old man with an oligodendroglioma in the anterior horn of the right lateral ventricle complained of sexual dysfunction and showed lowered concentrations of serum testosterone (1.1 ng/ml) with normal pituitary function. Human chorionic gonadotropin testing revealed a good testosterone response (1.1 to 4.9 ng/ml) and a clomiphene test revealed no gonadotropin response. Pulsatile secretion of luteinizing hormone (LH) was absent preoperatively. After removal of the tumor, serum concentration of testosterone increased to the normal range, LH pulsatility appeared, and the patient had no complaints of sexual dysfunction. In this patient, the loss of LH pulsatility responsible for his hypogonadism was caused by the lateral ventricle tumor compressing the surrounding structures, and this was corrected by tumor resection.

[High yielding culture of LAK cells by the concentration rotary tissue culture system and its clinical application]

The concentration rotary tissue culture system (Kawasumi Laboratories, Inc. Japan) was utilized to induce LAK cells from the peripheral blood lymphocytes (PBLs) of brain tumor patients. These LAK cells were administrated into the tumor cavity or cerebrospinal space of the patients. Under our culture system, the final administration of LAK cells increased tenfold of the initial PBLs, which were collected by leukapheresis. Around 4 weeks after the culture, these cells could not increase in number, with the decrease in cytotoxicity activity against Daudi and human glioblastoma (ONS-12) cells. The level of ammonium and lactate in the culture medium were comparatively kept low. IL-2 receptors were amplified with the increase in T cell population, especially helper T cells. This system may be a good tool to induce LAK cells for adoptive immunotherapy.

Expression of major histocompatibility complex on human medulloblastoma cells with neuronal differentiation

Medulloblastomas are among the most common malignant brain tumors in children. These tumors consist of immature bipotential cells that may differentiate into neuronal and glial cells. We have established two cell lines for human medulloblastoma. One was derived from a 2-year-old girl with a cerebellar tumor (designated as ONS-76) and another from a 9-year-old girl with a metastatic tumor in the right frontal lobe (ONS-81). The in vitro population-doubling times were 18.6 and 19.2 h, respectively. Immunohistochemical studies showed that both cells possessed neurofilament protein (Mr 145,000 and 200,000) and neuron-specific enolase, without glial fibrillary acidic protein or S-100 protein. Human gamma-interferon enhanced class I major histocompatibility complex antigens on these medulloblastoma cells. Class II major histocompatibility complex antigens were also induced by human interferon-gamma. We here report for the first time the expression of class II major histocompatibility antigens, which play an important role in immune response, on human medulloblastoma cells with neuronal differentiation.

[Antenatal detection of developing nervous system abnormalities and perinatal surgical management]

As the use of prenatal ultrasound sonographic study becomes more popular, it is likely that several fetal anomalies of the central nervous system will be diagnosed in utero more frequently and accurately. Obstetric sonogram correlates well with the results of postnatal CT scanning. Now, with improved diagnosis and support facilities for the newborn, neurosurgical intervention is being requested, as more concern is expressed for such fetus. We have experienced seven cases of fetal disorders of the central nervous system-meningocele, meningoencephalocele, myeloschisis, arachnoid cyst and maximal hydrocephalus. When diagnosed late in gestation (after the 2nd trimester), it may be reasonable to consider early delivery at the time of pulmonary maturity, and extrauterine management to decrease secondary damage to the developing central nervous system. The method of delivering a fetus must be tailored to suit each case. We present our program for the management of fetal hydrocephalus-placement of a subcutaneous low profile Ommaya's reservoir for neonate immediately after birth, and then subsequently conversion to a ventriculoperitoneal shunt three or four weeks later. As advances are made in antenatal diagnostic techniques and appropriate therapy, prognostic data on congenital abnormalities of the central nervous system will increase and become more pertinent.

[Adoptive immunotherapy in patients with medulloblastoma by LAK cells]

Medulloblastoma is one of the most popular malignant brain tumors in children. It accounts for about 15% of all pediatric brain tumors. Radiochemotherapy has prolonged the 5-year survival rate up to 60-85% for patients with medulloblastoma. But the conventional therapy is not so effective to recurrent cases, especially with meningeal dissemination, and generally fatal. There remains a big problem of the neurotoxicity to infants in a growth process under the whole-neuraxis irradiation and chemotherapy. Aiming to relieve the radiation and antitumor drugs, adoptive immunotherapy is greatly expectant. We have had clinical trials of adoptive immunotherapy for 8 patients with medulloblastoma by lymphokine-activated killer (LAK) cells. They were from 2-9 years in age and had cerebrospinal fluid (CSF) dissemination of the tumors. All patients underwent the whole-neuraxis irradiation and chemotherapy. After they had CSF dissemination, they were submitted to an adoptive transfer of allogeneic LAK cells. LAK cells were induced from peripheral blood lymphocytes (PBL) of their relatives with human recombinant interleukin-2. 3-15 x 10(9) LAK cells were transferred intrathecally in 2-3 months. In 3 of 8 patients, neurological signs were improved and malignant cells had never been detected on CSF cytology after the adoptive immunotherapy. One among these 3 patients showed complete response in 20 months. Thus, this is an attractive treatment for patients with medulloblastoma, especially with CSF dissemination, which cannot be cured by current therapeutic intervention.

Neuronal network disturbance after focal ischemia in rats

We studied functional disturbances following left middle cerebral artery occlusion in rats. Neuronal function was evaluated by [14C]2-deoxyglucose autoradiography 1 day after occlusion. We analyzed the mechanisms of change in glucose utilization outside the infarct using Fink-Heimer silver impregnation, axonal transport of wheat germ agglutinin-conjugated-horseradish peroxidase, and succinate dehydrogenase histochemistry. One day after occlusion, glucose utilization was remarkably reduced in the areas surrounding the infarct. There were many silver grains indicating degeneration of the synaptic terminals in the cortical areas surrounding the infarct and the ipsilateral cingulate cortex. Moreover, in the left thalamus where the left middle cerebral artery supplied no blood, glucose utilization significantly decreased compared with sham-operated rats. In the left thalamus, massive silver staining of degenerated synaptic terminals and decreases in succinate dehydrogenase activity were observed 4 and 5 days after occlusion. The absence of succinate dehydrogenase staining may reflect early changes in retrograde degeneration of thalamic neurons after ischemic injury of the thalamocortical pathway. Terminal degeneration even affected areas remote from the infarct: there were silver grains in the contralateral hemisphere transcallosally connected to the infarct and in the ipsilateral substantia nigra. Axonal transport study showed disruption of the corticospinal tract by subcortical ischemia; the transcallosal pathways in the cortex surrounding the infarct were preserved. The relation between neural function and the neuronal network in the area surrounding the focal cerebral infarct is discussed with regard to ischemic penumbra and diaschisis.

[Transcatheter arterial embolization of hemangiomas in the perioral region]

This paper presents four cases with successful transcatheter arterial embolization (TAE) for oral and perioral hemangiomas. Four TAEs were performed without major complications and the tumors disappeared in one case and decreased in size in the other 3 cases.

[Meningeal gliomatosis--clinical features and results of treatment]

Fifteen (15.6%) patients of 97 with malignant glioma developed meningeal gliomatosis during at least 2 years after the initial treatment. The time between the first surgery and diagnosis of meningeal gliomatosis was less than 1 year in 10 cases, 1 to 2 years in 2 and over 2 years in 2. In the younger age group less than 20 years, the incidence of meningeal gliomatosis was higher (46%) than that (12%) in the older group. Despite intrathecal chemotherapy (cytosine arabinoside, bleomycin and methotrexate), all patients died 2 to 24 weeks after the diagnosis of meningeal gliomatosis. Experimental studies suggest that intrathecal ACNU may be promising for the treatment of meningeal gliomatosis.

[Ischemic axonal injury and its recovery after focal cerebral ischemia]

After focal cerebral infarction by occluding the middle cerebral artery (MCA) of the rat, the neuronal death occurred in the ipsilateral thalamic neurons, because axons of the thalamic neurons were injured by infarction and retrograde degeneration occurred in the thalamic neurons. However, cortical neurons adjacent to the infarction survived despite their axons injured by ischemia. We employed immunohistochemical staining for 200 kilodalton (kD) neurofilament (NF), in order to study those responses of cortical and thalamic neurons against axonal injury caused by focal cerebral infarction. In the sham operated rats the immunoreactivity to the anti-200 kD NF antibody was only detected in the axon but not in the cell bodies and dendrites. At 3 days after MCA occlusion, axonal swelling proximal to the site of ischemic injury was found in the caudoputamen and internal capsule of the ipsilateral side. At 7 days after occlusion, cell bodies and dendrites of the neurons in the ipsilateral cortex and thalamus were strongly stained with anti-NF antibodies. At 2 weeks after occlusion these responses disappeared in the cortex, but lasted in the thalamus. These phenomena are caused by stasis of the slow axonal transport, because the NF is transported by slow axonal transport. In the cortical neurons impairment of slow axonal transport recovered in the early phase after injury, but in the thalamic neurons the impairment prolonged up to 3 weeks after occlusion. The early recovery of axonal transport from ischemia seemed to be essential for survival of neurons after ischemic axonal injury.

[Antitumor efficacy of FK 973 on malignant glioma cells]

FK 973, a new substituted dihydrobenzoxazine, was obtained by chemical modification of a novel antibiotic which was isolated from the fermentation products of streptomyces sandaensis No. 6897. FK 973 had cytotoxic effects against in vitro cultured human and murine glioma cells. The concentration of FK 973 required to inhibit cell growth by 50% was 0.06-5 micrograms/ml, after 2-day exposure of this drug against human glioblastoma (ONS-6, 12, 23, and ONS-12/ACNU), human medulloblastoma (ONS-76, 81), human neuroblastoma (ST), and murine glioblastoma (RSV-M glioma). FK 973 showed antitumor efficacy in the meningeal gliomatosis models by RSV-M glioma cells. The median survival time (MST) of models treated by FK 973 (i.t.) was 30 days. However, the MST of control group was 23 days. In the in vitro neurotoxicity test, FK 973 proved to be slightly more toxic than ACNU and MTX, but it had no crucial problems, compared with ADM.

[Extracellular purine catabolites and tissue nucleotides and purine catabolites during progression and recovery of ischemia]

During progression and recovery of ischemia, extracellular purine catabolites were measured and compared with purine catabolites and adenine nucleotide levels in the tissue. Ischemia was induced by bilateral occlusion of the common carotid arteries in gerbil. Extracellular purine catabolites were sampled by in vivo brain microdialysis technique, and tissue adenine nucleotides and purine catabolites were extracted from in situ frozen and lypholized brain tissue. These metabolites were measured with simple method of isoclatic condition by HPLC system. Ischemia depleted tissue ATP and ADP, whereas AMP and purine catabolites accumulated strikingly. In parallel, extracellular purine catabolites increased as consecutive degradation on the biochemical metabolic pathway in the same animal. Levels of tissue ATP and adenosine normalized in the recovery phase of ischemia immediately. However, extracellular purine catabolites during the recovery are much higher than those during the progression of ischemia. These data indicated extracellular high levels of purine catabolites during the ischemic insult, and especially adenosine as neuromodulator which may turn off spontaneous neuronal activity and exert antiepileptic effects during the recovery rather than the progression of ischemia.

Nodding attacks (infantile spasms) associated with temporal lobe astrocytoma--case report

A 2-year-old boy suffered nodding attacks (infantile spasms) that were refractory to anticonvulsants. Computed tomography showed a mass with cystic components in the right temporal lobe, and electroencephalography (EEG) disclosed polyspike and wave discharges in the bilateral temporoparietal regions. At surgery, a firm, gray, well circumscribed tumor was radically removed. The nodding attacks disappeared immediately after surgery and EEG improved gradually. The pathological diagnosis was grade 1 astrocytoma with abundant capillaries and calcospherites. He remained free of seizures during the following 6 years.

[Immunohistochemical study of c-myc oncogene product in human brain tumors]

C-myc oncogene is widely distributed in eukaryotic cells and is supposed to play an important role in the cellular proliferation and differentiation. Enhanced expression of this oncogene is reported in many kind of tumors, which is often associated with increased malignancy. It seems, therefore, important to study the expression of this oncogene in analyzing the cell biologic features of brain tumors. In the present paper we investigated the distribution of this oncogene product in paraffin-embedded tissue of various kind of brain tumors with a monoclonal antibody to synthetic c-myc peptide. The results demonstrated that c-myc product was detectable in most of the astrocytoma lineage. The immunoreaction within the cell nuclei was more intense in grade 3 and grade 4 astrocytomas than in grade 2 tumors. The expression in grade 4 tumors was, however, rather weaker that in grade 3 tumors. In benign, non-glial tumors like meningiomas and neurinomas, the nuclear immunoreaction was usually absent or only weak, although it was enhanced in a case of acoustic and spinal neurinomas associated with von Recklinghausen's disease.

Epidermal growth factor receptor in human glioma

Distribution of the epidermal growth factor (EGF) receptor in the surgical specimen of the human glioma was studied by immunohistochemical techniques using a monoclonal anti-EGF receptor antibody. Of 11 gliomas examined, EGF receptors were detected in nine glioblastomas and in one fibrillary astrocytoma. In the majority of cells, staining was observed over the cell membrane. Nuclear and cytoplasmic staining was also seen. In four glioblastomas, EGF receptor-positive cells were diffusely distributed in the tumor tissue. In one glioblastoma and one fibrillary astrocytoma, only a few positive cells were observed. These results imply the possible role of EGF receptors in the cellular proliferation of the human glioma.

[Single photon emission computed tomography (SPECT) with N-isopropyl-p-(123I) iodoamphetamine in partial epilepsy--evaluation of delayed image]

Thirty eight patients with partial seizures in the interictal phase were studied using single photon emission computed tomography performed 30 min. (early image) and 4-4.5 hrs. (delayed image) after an injection of 111 MBq (3 mCi) N-isopropyl-p(123I) iodoamphetamine (IMP). Five types of distribution changes were observed on IMP-SPECT between the early and delayed images. Eight patients, Type 1, exhibited an unchanged distribution of IMP between the early and delayed images. Fifteen patients, Type 2, showed a smaller area of low uptake on the IMP-SPECT (delayed image) compared to that on the IMP-SPECT (early image)-redistribution. The Type 3 patients exhibited an initial uptake area on the IMP-SPECT (early image) which later became a lower uptake area on the IMP-SPECT (delayed image)-reversed redistribution. This type was further classified into three categories according to the initial uptake pattern including (a) Type 3A, 3 patients with increased uptake area, (b) Type 3B, 6 patients with normal uptake area, and (c) Type 3C, 6 patients with decreased uptake area. With Type 2, the epileptic findings on the present interictal electroencephalography (EEG) were shown in 11 of 15 patients. However, we could not find any other remarkable correlation among these 5 types and the clinical factors (the types of seizures, the X-CT findings, the present interictal EEG data, the present frequency of seizures, and the intervals from the last seizure). In 2 patients with Type 3B who suffered from simple partial seizures, a region of the normal distribution on the IMP-SPECT (early image) became a lower uptake area on the IMP-SPECT (delayed image), corresponding topologically to the ictal symptoms. In this experience, we determined that the IMP-SPECT (delayed image) could be useful in patients with the epileptic lesions unable to be detected on the IMP-SPECT (early image).

[A case of repeated hematomyelia caused by cavernous hemangioma in the spinal cord]

A case is reported of repeated hematomyelia caused by cavernous hemangioma in the spinal cord. A 47-year-old woman first noticed a sudden onset of numbness in her thigh and then it gradually disappeared. Four months after the onset, she began to experience weakness and numbness in both of her legs, and difficulty in voiding and defecating. She recovered gradually for several months, but felt numbness in both legs. Myelography showed swelling at Th5 level. T2-weighted MRI showed a reticulated core of mixed intensity with rims of decreased intensity. During the subsequent operation, a dark brown lesion was detected at Th5 level, which consisted of multicystic cavities with old hematoma. But there were no abnormal vessels, or active bleeding. This lesion was almost completely removed and was diagnosed as cavernous hemangioma.

[Astrocytic proliferation in the brain adjacent to infarcted lesion: immunohistochemical study of astroprotein (GFAP) and bromodeoxyuridine (BrdU)]

Although cerebral infarction is a destructive process of nerve cells and brain tissue, the nature is not exclusively disintegrating but also includes active cellular reaction which may modify the progression of tissue damage. Most prominent cellular reaction in the area surrounding infarction can be recognized as a trophic or proliferative change of glial cells. In the present study we produced a focal cerebral ischemia in Mongolian gerbils and investigated the dynamic change of astrocytes in the brain adjacent to thalamic infarction. Using immunohistochemical methods, astrocytes were identified with the antibody to astroprotein (GFAP) and the DNA synthesizing (S phase) cells were detected with the antibody to bromodeoxyuridine (BrdU). The posterior communicating artery of a gerbil was occluded by coagulation through the trans-tympanic bulla approach under general anesthesia with ketamine hydrochloride (80 mg/kg, i.p.). Thirty min after intravenous administration of BrdU (200 mg/kg), animals were sacrificed by transcardiac perfusion with 75% ethanol on days 1, 2, 3, 5 and 7 post-infarction. Ethanol-fixed, paraffin-embedded blocks were cut coronally into 6 microns-thick sections at the level of dorsal hippocampus. Double-labeled immunohistochemical technique (avidin biotin peroxidase-complex method) was carried out with each antibody using 3,3'-diaminobenzidine tetrahydrochloride and 4-chloro-1-naphthol as chromogens. The population of GFAP-positive cells and their S-phase fraction (the number of BrdU-positive nuclei divided by the number of GFAP-positive cells expressed in per cent, %) were examined. The data demonstrated that the regional GFAP-positive cells increased continuously between days 1 to 5 (105.9 to 528.8 cells/mm2) postinfarction (44.6 cells/mm2 in normal brain).(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical treatment of tumors in the anterior skull base using the transbasal approach

Five patients with tumors in the anterior skull base were surgically treated using the transbasal approach, which permits removal of the tumor, repair of the dura mater, and reconstruction of the skull base in a one-stage procedure. By using autologous materials for the bone graft and pedunculated pericranial flap for the reconstruction, the intracranial structures are separated from the air-filled nasal and paranasal cavities. No postoperative complications such as wound infection and leakage of cerebrospinal fluid were encountered. The use of this surgical technique makes it possible to extirpate brain tumors that heretofore have been considered unresectable.

[Effects of anticonvulsants on cellular immunity]

The effects of anticonvulsants on cellular immunity were examined in murine models. Fresh splenocytes were obtained from mice which had been intraperitoneally given 1 mg of phenytoin, 2 mg of phenobarbital, or 20mg of valproate for 28 days. The serum concentration of phenytoin, phenobarbital and valproate in these animals were 10-20 micrograms/ml, 30-40 micrograms/ml and 50-70 micrograms/ml, respectively. The proliferative response of splenocytes to mitogens was assessed by 3H-thymidine incorporation. The cytotoxic activities of cells such as natural killer (NK) cells, cytotoxic T lymphocytes (CTL), and lymphokine-activated killer (LAK) cells were estimated by a 4 hr-51Cr release assay. Phenytoin suppressed lymphocyte proliferation, NK activity, and CTL activity, but never LAK activity. Phenobarbital suppressed proliferative response to rIL-2 and CTL activity, but did not suppress NK activity nor LAK activity. In turn sodium pyruvate never suppressed any activity on cellular immunity.

[Visualization of epileptic lesions using single photon emission computed tomography (SPECT) with N-isopropyl-p-(123I) iodoamphetamine after intravenous loading of bemegride--report of a case]

Single photon emission computed tomography (SPECT) was performed 30 minutes and 4 hours after injection of 111 MBq (3 mCi) N-isopropyl-p-(123I) iodoamphetamine (IMP) which was injected 5 minutes after the completion of intravenous bemegride loading. A 31-year-old female with simple partial seizures evolving to complex partial seizures evolving to generalized tonic-clonic convulsive seizures with a history of hospitalization, suffering from low-grade fever, generalized convulsive seizures, and impaired consciousness at the age of 27 years was studied. Angiographic examinations, X-CT, MRI, CSF examinations, and interictal neurological examinations were normal. She suffered from clonic convulsions in her right shoulder and arm, and hallucinations and dysmnesia which were characteristic of temporal lobe epilepsy. More recently she suffered from impaired consciousness once or twice a month. While the controlled IMP-SPECT study was normal, the IMP-SPECT study examined after the activation by intravenous bemegride loading showed the pattern of a regional increased uptake of IMP in the epileptic lesions corresponding with the epileptic symptoms, and a surrounding border of decreased uptake which might be the inhibition of surrounding neuronal activity and metabolism. In conclusion, the bemegride loading IMP-SPECT study could be a potential diagnostic method in patients with seizures whose epileptic lesions were not determined by the conventional methods or in whom the surgical interventions were considered, by reason of its capability to demonstrate positively the epileptic lesions.

[Neurofunctional disturbances as related to cortical ischemia and white matter ischemia]

We evaluated regional cerebral blood flow (rCBF) by means of hydrogen clearance method as well as [14C]-iodoantipyrine autoradiographic method, cortical auditory evoked potentials (AEP), somatosensory evoked potentials (SEP) induced by forelimb (median nerve) stimulation (SEP-F), and SEP induced by hindlimb (tibial nerve) stimulation (SEP-H) in cats after occlusion of the left middle cerebral artery (MCA) under alpha-chloralose anesthesia. According to the degree of ischemia, the experimental animals were divided into two groups. One was the critical ischemia which was defined as permanent total suppression of AEP, and low residual blood flow in the auditory cortex. And the other was the non-critical ischemia which included transient suppression and spontaneous recovery of the cortical sensory evoked potentials, and high residual blood flow (greater than 15 ml/100 g/min). In one cat with transient suppression of three kinds of sensory evoked potentials, the [14C]-iodoantipyrine (IAP) autoradiograph revealed only a limited ischemic area of subcortical white matter. In the critical ischemia group, ischemia of the primary sensory cortex ranged from the mostly affected primary auditory cortex (supplied by the MCA) to the least affected hindlimb projection area within primary somatosensory cortex (supplied by the ACA). The forelimb projection area of the primary somatosensory cortex (supplied by both ACA and MCA) showed a mild or moderate reduction of rCBF after occlusion. The [14C]-IAP autoradiograph showed severe reduction of the white matter including the somatosensory pathway in the wide range. However, rCBF in the thalamus and hindlimb projection area within somatosensory cortex was almost intact in the cat with ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleviation of gallbladder complications by treatment of hepatic arterial embolization with caerulein

Transcatheter arterial embolization (TAE) with the concurrent use of caerulein was assessed for the purpose of preventing gallbladder complications often seen after TAE of hepatic carcinoma. Ninety-six cases with primary hepatic carcinoma, who had undergone TAE in the right hepatic arterial region over the past 4 years, were divided into three groups: 22 cases for which embolization was possible on a selective basis by passing the catheter to the peripheral side beyond the bifurcated region of the cystic artery; 40 cases who had undergone TAE in which caerulein was not administered, from the central side of the bifurcated region of the cystic artery; and 34 cases given 20 micrograms caerulein 15-30 min before TAE. A comparison was made using the abdominal pain, pyrexia, rate of leukocytosis and the US findings of the gallbladder as the indices of the gallbladder complications. As a result, it became evident that it was possible to prevent or alleviate gallbladder complications if caerulein were administered before TAE in cases where the embolizing substances were infused in the right hepatic artery from the central side of the bifurcated region of the cystic artery. It was conclusively shown that the gallbladder blood flow decreases if the organ is contracted by caerulein, which in turn causes a decrease in the inflow of the embolizing substances whereby complications are alleviated.

SPECT volume measurement using an automatic threshold selection method combined with a V filter

The volume measurement of various organs by single photon emission computed tomography (SPECT) has generally been performed by summing up the voxels lying within the outer edge of the organ determined by thresholding as a function of the maximum reconstructed counts within a volume of interest. The optimum threshold level, however, is influenced by various factors. To eliminate this problem, Mortelmans et al. (1986) proposed to use an automatic threshold selection method (ATSM) based on discriminant criteria and to correct the errors induced by the imperfect system response using the method based on linear regression analysis, which has some problems in practical application. We tried to use ATSM combined with a V filter. The correlation coefficient (r) and the regression equation between the true (x) and the calculated volume (y) obtained by experimentation using 22 phantoms with a volume ranging between 26 ml and 380 ml were as follows: r = 0.994 and y(ml) = 1.015 x +1.09 using ATSM combined with a V filter, while r = 0.993 and y(ml) = 1.110 x +30.55 using only ATSM. The relative error between the true and the calculated volumes decreased significantly (P less than 0.01) from 37.7% +/- 26.9% to 5.5% +/- 4.2%. The results suggest that ATSM combined with a V filter is useful for correcting the errors caused by an imperfect system response, and is available and reliable for SPECT volume determination even when the organ volume is small.

Intrathecal ACNU--a new therapeutic approach against malignant leptomeningeal tumors

Pharmacokinetics, toxicity and therapeutic efficacy of intrathecal ACNU, 3-[4-amino-2-methyl-5-pyrimidinyl)methyl)-1-(2-chloroethyl)-1-nitroso urea, were studied in rats to determine if it is a new and effective method for the treatment of malignant leptomeningeal tumors. Pharmacokinetics of intracisternally administered ACNU was studied by macroscopical autoradiography using 14C-labeled ACNU. It was demonstrated that intracisternally administered ACNU distributed in the subarachnoid space and subpial layer of the brain in high concentration and was rapidly eliminated into the systemic circulation. The diffusional transport of ACNU into the deeper part of the brain was limited. More than 3.0 mg/kg of intracisternal ACNU induced progressive loss of the weight of body in normal rats, and 80% of the rat given 6.0 mg/kg died. Increase of capillary permeability, neuronal loss and gliosis were observed in the marginal layer of the brain facing to the subarachnoid space in the rat given more than 3.0 mg/kg of ACNU. Systemic and local toxicity was not observed in the rat given less than 1.5 mg/kg. Therapeutic effect of intrathecal ACNU against leptomeningeal tumors was evaluated in the rat with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells. The median survival time of the rat treated with 1.5 mg/kg of intracisternal ACNU once on day 2 or on day 5 after tumor inoculation was significantly prolonged by 173%, and 214% at maximum, respectively, as compared with that of the untreated animal. These findings suggest that intrathecal ACNU may be of value for clinical trial against leptomeningeal tumors.

[Effect of ACNU against experimental brain tumor--immunohistochemical study using anti-BrdU monoclonal antibody]

We have studied the efficacy of intrathecal ACNU against experimental leptomeningeal tumors. In the present report, the effect of ACNU on the growth kinetics of the tumor was evaluated by the immunohistochemical technique using anti-BrdU monoclonal antibody. The experimental leptomeningeal tumor was developed by inoculation of Walker 256 carcinosarcoma cells into the cisterna magna of rats. Seven days after the inoculation of tumor cells, the animals were treated either by intravenous (15 mg/kg) or intrathecal (1.5 mg/kg) ACNU. Four, 12, 24, 48, 96 or 144 hours after treatment, the animals received intravenous BrdU (200 mg/kg). Thirty minutes thereafter, they were sacrificed and the brain was removed. L. I. was calculated by counting the immunoreactive tumor cells. L. I. of the tumor without treatment on the seventh day after inoculation was over 40%. L. I. began to decrease 24 hours after intravenous ACNU, and remained 11% up to 96 hours. On the other hand, L. I. already decreased to 20% 4 hours after intrathecal ACNU and remained to be low (17%) up to 48 hours. However, L. I. increased to 38% at 96 hours. Thus, the effect on the growth kinetics of the tumor differs between intravenous and intrathecal ACNU. These results are considered to be useful informations for determining the optimal dosage of the antineoplastic agent against the brain tumor and developing the effective combination chemotherapy.

[Postnatal cell proliferation in the rat cerebrum: immunohistochemical study with bromodeoxyuridine (BrdU)]

The postnatal cell proliferation in the rat cerebrum was studied immunohistochemically using a monoclonal antibody to bromodeoxyuridine (BrdU). Since BrdU, a halogenated analogue of thymidine, is incorporated into nuclear DNA during duplication, S-phase cells can be detected by demonstrating intranuclear BrdU. 200 mg/kg of BrdU was administered to normal Wistar rats intraperitoneally on the day of birth or intravenously 1, 2, 3, 5, 8 or 24 weeks after birth. Thirty minutes later, the brain was fixed by perfusion with ethanol, and the paraffin-embedded sections were processed for the avidin biotin peroxidase-complex method. BrdU-positive nuclei were counted among 500 to 10,000 cells in several regions of the brain to obtain the BrdU-labeling index (the number of BrdU-positive cells per 100 cells scored, LI, %). The present study demonstrated that (1) proliferating cells in the gray matter (cerebral cortex and caudate-putamen) are only few at birth (LI = 0.54-0.78%), which further decrease during the following few weeks, and disappear by adulthood, (2) in the white matter (corpus callosum), cell proliferation is relatively active within 1 week after birth (LI = 5.6-6.3%), but becomes inactive thereafter, (3) the proliferative activity of the cells in the subependymal layer of the lateral ventricle is very high at birth (LI = 15.5%), which somewhat decreases during the following few weeks, but still remains high in adulthood (LI = 7.5%). This kind of continued cell proliferation in the brain after birth seems important in the postnatal development of the normal cerebral structure, and in several pathologic processes such as tissue repair and the development of brain neoplasm.

[Factors affecting the prognosis of brain tumors]

A variety of tumors with different histologic types are included in a group of brain tumors. Although each histologic type of tumor has its own range of malignancy, the prognosis seems to be affected by several clinical, histologic and cell-biological factors. For example, relative survival rate of patients with glioblastoma is lower if the patient is older than 50 or 60 years. The leptomeningeal dissemination of glioma cells is a sign of poor prognosis. The presence of necrotic foci in the astrocytic tumors suggests shorter astrocytic tumors suggests shorter survival. Using a monoclonal antibody to bromodeoxyuridine (BrdU), the growth activity of the tumor can be estimated by BrdU labeling index (BrdU-LI, %). Higher BrdU-LI is correlated with more malignant histologic features in astrocytic tumors. In meningiomas, higher BrdU-LI is correlated with a more frequent or rapid recurrence of the tumor. The significance of growth factor receptors and oncogene of growth factor receptors and oncogene products as a cell-biologic marker of malignancy was investigated with an immunohistochemical method. Transferrin receptor was demonstrated in all tumors, and epidermal growth factor in about 40% of astrocytic tumors. The immunoreaction to c-myc oncogene product was detected in most astrocytic tumors; with higher intensity in anaplastic astrocytomas and glioblastomas than in low-grade astrocytomas. The role of these markers in the prognosis of brain tumors is, however, still unclear. Total or subtotal resection of glioblastoma results in longer resection of glioblastoma results in longer survival. Both postoperative radiotherapy and chemotherapy are effective. However, maintenance of chemotherapy longer than longer than 2 years does not significantly improve the prognosis.

[Transplant-induced recovery from 6-OHDA lesions of the nigro-striatal dopamine neurons in mice]

Attempts to reconstruct the damaged nigrostriatal pathway in experimental models of Parkinson disease have thus far been carried out in animals with neurotoxically induced dopamine deficiency. Our study established that unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal-dopamine (DA) neurons produced a well-characterized functional asymmetry in the behavior of C57BL/6 (H-2b) mice. The intraperitoneal administration of methamphetamine induced ipsilateral rotation at 7-20 turns/min. 11 x 10(6) syngenic DA-rich cells of embryonic ventral mesencephalon were stereotaxically transplanted in the caudate-putamen. A complete recovery of methamphetamine-induced rotational response was produced around the 60-th day after the syngenic cell suspension graft. And a complete compensation of the rotational response was also brought about with the DA-rich cells from embryonic ventral mesencephalon (crown-rump length; 10-13 mm) of allogenic C 3 H/HeN (H-2k) mice. The FACS IV analysis revealed no H-2 (Kk and Iak) antigens before transplantation of these embryonic cells. Immunohistochemistry showed that the dopaminergic fibers had grown predominantly into the ipsilateral caudate-putamen. These results provide evidence of integration of syngenic and allogenic grafts and host tissue. And the immunological response in the transplanted brain are under investigation.

[Malfunction of gene expression as a possible cause of delayed neuronal death]

To clarify a possible cause of delayed neuronal death, synthesis of protein and ribonucleic acid (RNA) following transient forebrain ischemia was evaluated autoradiographically. Mongolian gerbils were subjected to transient forebrain ischemia for 5 minutes by occluding bilateral common carotid arteries. They were used for autoradiographic study at 1, 2, and 5 days after ischemia. Tracer dose of 14C-valine or 14C-uridine was injected intravenously, and animals were sacrificed 45 minutes thereafter. Brains were frozen and thin sliced for macroautoradiography. After the first autoradiogram was obtained, tissue sections were incubated in cold 5% trichloroacetic acid for 1 hour, dried and again used for autoradiogram. With this preparation we could differentiate the tracer incorporated into protein or RNA fraction from the total tissue radioactivity. In the different set of animals, microautoradiograms of 3H-valine and 3H-uridine was obtained to detect subcellular distribution of synthesized protein or RNA. At 1 day after ischemia, protein synthesis in the CA 1 region of the hippocampus was reduced by 57% of the sham control, but RNA synthesis was not reduced quantitatively. Microautoradiogram of 3H-uridine however, indicated that silver grains in the cytoplasms of the CA 1 pyramidal cells were much reduced as compared to sham controls, though the amount of silver grains in the nucleus was the same as sham controls. Therefore, synthesized RNA in the nucleus was not transported to the cytoplasm. At 2 days after ischemia, protein and RNA synthesis was preserved to the same level as sham controls.(ABSTRACT TRUNCATED AT 250 WORDS)