Focal coagulative necrosis of the liver in a patient with sustained virologic response to anti-hepatitis C virus therapy

A 69-year-old woman with chronic hepatitis C virus (HCV) infection was referred to our hospital due to liver enzyme abnormalities. Four years after anti-HCV therapy, the patient with sustained virologic response and no clinical symptoms developed an oval hepatic mass with mixed high and low internal echoes near the portal vein on ultrasound. Magnetic resonance imaging (MRI) of the liver lesion showed a slightly hypo intense pattern on T1-weighted images, a hyper intense pattern both on T2- and diffusion-weighted images, a slight rim enhancement pattern with no intra-lesional enhancement up to the late phase, and a very low intense pattern on hepatobiliary phase images. Positron emission tomography/computed tomography (PET / CT) showed no areas of avid radiotracer uptake in the liver. No tumor markers showed abnormally high values. All these images and laboratory findings led us to the assessment of the liver lesion as a non-neoplastic disorder. However, due to the patient's strong preference to get both definitive diagnosis and cure of the lesion, the patient underwent laparoscopic partial hepatectomy. Pathological study showed 2 necrotic areas surrounded by multiple lymph follicles, epithelioid cells, lymphocytes, collagen fibers, and plasma cells, leading to the diagnosis of focal coagulative necrosis of the liver (FCNL). Physicians should note that FCNL can occur without any symptoms and can be diagnosed at least as a non-neoplastic disorder with combined MRI and PET/CT analysis.

Successful endoscopic submucosal dissection of colorectal lipoma with an overlying adenoma

We report the case of a 65-year-old woman whose colonoscopy revealed a soft submucosal tumor approximately 7 cm in diameter in the ascending colon with an overlying flat lesion. The tumor was diagnosed as a lipoma with an overlying adenoma. Endoscopic submucosal dissection (ESD) was performed. Pathological examination revealed that the epithelium was a low-grade tubulovillous adenoma, while the submucosal yellow tumor was a lipoma. ESD appears to be a safe and effective treatment for colorectal lipomas overlying lipomas with colorectal adenomas.

Protein tyrosine phosphatase receptor type Q in cerebrospinal fluid reflects ependymal cell dysfunction and is a potential biomarker for adult chronic hydrocephalus

BACKGROUND AND PURPOSE

Protein tyrosine phosphatase receptor type Q (PTPRQ) was extracted from the cerebrospinal fluid (CSF) of patients with probable idiopathic normal-pressure hydrocephalus (iNPH) by proteome analysis. We aimed to assess the feasibility of using CSF PTPRQ concentrations for the additional diagnostic criterion of iNPH in Japanese and Finnish populations.

METHODS

We compared PTPRQ concentrations among patients with probable iNPH and neurologically healthy individuals (normal control [NC] group), patients with normal-pressure hydrocephalus (NPH) of acquired and congenital/developmental aetiologies, patients with Alzheimer's disease and patients with Parkinson's disease in a Japanese analysis cohort. A corresponding iNPH group and NC group in a Finnish cohort was used for validation. Patients in the Finnish cohort who underwent biopsy were classified into two groups based on amyloid and/or tau deposition. We measured PTPRQ expression levels in autopsied brain specimens of iNPH patients and the NC group.

RESULTS

Cerebrospinal fluid PTPRQ concentrations in the patients with NPH of idiopathic, acquired and congenital/developmental aetiologies were significantly higher than those in the NC group and those with Parkinson's disease, but iNPH showed no significant differences when compared with those in the Alzheimer's disease group. For the patients with iNPH, the area under the receiver-operating characteristic curve was 0.860 in the Japanese iNPH and 0.849 in the Finnish iNPH cohorts. Immunostaining and in situ hybridization revealed PTPRQ expression in the ependymal cells and choroid plexus. It is highly possible that the elevated PTPRQ levels in the CSF are related to ependymal dysfunction from ventricular expansion.

CONCLUSIONS

Cerebrospinal fluid PTPRQ levels indicated the validity of this assay for auxiliary diagnosis of adult chronic hydrocephalus.

Usefulness of "Nelaton Attachment" for endoscopic submucosal dissection of colorectal neoplasms

Background and study aims  Although colorectal endoscopic submucosal dissection (ESD) has enabled high en bloc resection rates regardless of tumor size, colorectal ESD is still a challenging procedure. We developed a novel device called the Nelaton Attachment, which allows endoscopists to manipulate the ESD knives using two fingers of their left hand while holding the endoscope with their right hand. We retrospectively investigated the efficacy and safety of the Nelaton Attachment for colorectal ESD. We compared efficacy and safety between Nelaton Attachment and non-Nelaton Attachment groups, and also conducted an ex vivo experiment to evaluate the effect of the Nelaton Attachment. Patients and methods  We retrospectively reviewed 36 consecutive patients with 37 colorectal tumors who had undergone ESD at Kishiwada Tokushukai Hospital and Naritatomisato Tokushukai Hospital between April 2016 and September 2018. The Nelaton Attachment was used for 22 of the 37 colorectal ESDs. In the ex vivo experiment, endoscopists inserted and withdrew an ESD knife 2 cm using two fingers of their left hand with and without the Nelaton Attachment. Results  Median procedure time was significantly shorter in the Nelaton Attachment group (38 min [range 6 - 195 min]) compared to the non-Nelaton Attachment group (75 min [range 17 - 198 min]; P  = 0.030). Median time to complete the ex vivo experiment five times was significantly faster with the Nelaton Attachment than without the Nelaton Attachment ( P  = 0.001). Conclusions  Use of the Nelaton Attachment for colorectal ESD is feasible and safe, and may facilitate colorectal ESD procedures.

BMI is associated with larger index tumors and worse outcome after radical prostatectomy

BACKGROUND

To investigate the impact of body mass index (BMI) on tumor characteristics and biochemical recurrence (BCR) after radical prostatectomy (RP) for prostate cancer (PCa) in Japanese men.

METHODS

We evaluated data from consecutive patients who had undergone RP. Data analyzed included age, preoperative serum PSA, prostatic volume, BMI (continuous or categorized (≤ 25 kg/m(2)) values), clinical and pathological findings including index tumor volume (ITV), and current status in areas such as smoker or nonsmoker and presence or absence of diabetes. We analyzed association between BMI and BCR, especially based on ITV using univariate and multivariate analysis.

RESULTS

We analyzed data from a total of 703 patients. The median follow-up time was 38.4 months. BCR was diagnosed in 154 patients (21.9%) at a median of 9.7 months postoperatively. Multivariate linear regression analysis adjusted for preoperative variables showed a significant positive association between BMI and ITV (continuous BMI: P=0.002; categorical BMI: P<0.001, respectively), especially for higher-grade tumors (Gleason score ≥ 7). Cox proportional hazards analysis showed a significant association between continuous BMI and BCR after surgery (preoperative variables, hazard ratio (HR) 1.09, 95% confidence interval (CI) 1.02-1.16, P=0.008), independent of clinical and pathological findings. In patients with high-risk cancer, the positive association between BMI and BCR was strengthened (preoperative variables, continuous BMI, HR 1.16, 95% CI 1.07-1.26, P<0.001; categorical BMI, HR 2.11, 95% CI 1.29-3.45, P=0.003, respectively).

CONCLUSIONS

Greater BMI significantly correlates with higher rates of BCR after surgery; BMI is a preoperative variable associated with high-grade ITV. Our results suggest that the biological environment created by greater BMI may contribute to increasing tumor aggressiveness.

Abstract P2-12-04: Evaluation of BRCA 1/2 mutation-carrier probability models, BRCAPRO and myriad II, in the Japanese population

Background:

It is important to select high-risk group with a BRCA1/2 mutation and recommend them to provide genetic counseling and genetic testing. BRCAPRO and Myriad II are widely used for predicting BRCA mutation-carrier probability and useful for selecting eligible person of genetic testing. However, It is reported that BRCAPRO tends to underestimate the risk of BRCA1/2 mutation probability in Asian. The validation of these models are not sufficiently known in Japanese population.

Methods:

Twenty-six hundred sixty-five people visited to Ishinomaki Red Cross Hospital between 2011 and 2012.They were surveyed family history as a risk factor of inheriting breast cancer according to NCCN guideline. We calculated BRCA1/2 mutation probability by BRCAPRO and Myriad II. Those who had more than 10% mutation probability and early-onset breast cancer, triple negative breast cancer were received genetic counseling and genetic testing for applicants. We analyzed association between family history of the probands and BRCA 1/2 mutation. We also calculated sensitivity, specificity and positive predictive value(PPV) at the10% threshold in BRCAPRO and Myriad II.

Results:

Two handred forty-three(9.1%) people were selected as a risk of inheriting breast cancer, of which sixty-eight people (2.5%) were constructed family tree. The number of people who had more than 10% and 30% mutation probability by BRCAPRO was eight (0.30%) and five (0.18%).Fourteen people performed BRCA1/2 genetic testing (proband : thirteen, relative: one). Seven people carried a deleterious BRCA mutation (BRCA1: five, BRCA2: two). In the cases which had more than 30% mutation probability, all of them carried a deleterious BRCA mutation. Most of their mutation site was L63X which was most frequent in Japan.

People who had personal or family history of breast and ovarian cancer, triple negative breast cancer were significantly associated with BRCA1/2 mutation.(p = 0.035,p = 0.015,p = 0.009)

Using a 10% threshold, sensitivity, specificity, positive predictive value in BRCAPRO was 75%,83%,85% and 63%,67%,71% in Myriad II respectively. When it comes to the cases which had more than 30% mutation probability, Sensitivity, specificity, positive predictive value were all 100% in BRCAPRO.

Conclusions:

It is recommended to perform genetic testing for especially those who have personal or family history of both breast and ovarian cancer, triple negative breast cancer. 10% threshold of BRCAPRO and Myriad II is generally applicable to selecting eligible person in the Japanese population. BRCAPRO is superior to Myriad II in terms of sensitivity, specificity, PPV in our study. The cases which have more than 30% mutation probability need to have genetic testing.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-12-04.

Molecular Characterization and Diagnosis of QoI Resistance in Cucumber and Eggplant Fungal Pathogens

ABSTRACT The molecular mechanism of QoI fungicide resistance was studied using isolates of cucumber Corynespora leaf spot fungus (Corynespora cassiicola) and the eggplant leaf mold (Mycovellosiella nattrassii). In both pathogens, a mutation at position 143 from glycine to alanine (G143A) was detected in the cytochrome b gene that encodes for the fungicide-targeted protein. Moreover, the nucleotide sequence at amino acid position 143 was converted from GGT or GGA in sensitive (wild-type) to GCT or GCA in resistant (mutant-type) isolates. The methods of polymerase chain reaction restriction fragment length polymorphism commonly used for QoI resistance monitoring were employed successfully, leading to the amplified gene fragment from resistant isolates being cut with the restriction enzyme ItaI. However, heteroplasmy (the coexistence of wild-type and mutated alleles) was found when the resistant isolates of C. cassiicola, M. nattrassii, and Colletotrichum gloeosporioides (strawberry anthracnose fungus) were subcultured in the presence or absence of QoI fungicides. QoI resistance of cucumber powdery and downy mildew isolates persisted for a few years following the removal of the selection pressure imposed by the fungicide under both laboratory and commercial greenhouse conditions. The proportion of mutated sequences in cytochrome b gene decreased over time in the pathogen population. The protective efficacy of the full dose of azoxystrobin decreased when the populations of powdery and downy mildews contained resistant isolates at 10%. Using FMBIO, a fluorescence bio-imaging analyzer, the mutant allele from the QoI-resistant isolates could be detected at the level of 1%, whereas the detection sensitivity of ethidium-bromide-stained gels was approximately 10 times lower.

Severe hypertension associated with multiple intrarenal microaneurysms in a patient with systemic lupus erythematosus and antiphospholipid antibodies

Abstract  A 26-year-old Japanese woman with systemic lupus erythematosus (SLE) developed severe hyperten-sion and an increased active renin concentration (ARC), ischemic colitis, and splenic infarction. She had antiphospholipid antibodies (APA), multiple intrarenal microaneurysms, and multiple stenoses of the mesenteric arteries. Combination therapy with antihypertensive agents, aspirin, warfarin, and corticosteroids (30 mg daily) controlled her abdominal symptoms and hypertension. Multiple intrarenal microaneurysms in SLE with APA may be the cause of severe hypertension and elevated serum ARC.

Altered expressions of glutamate transporter subtypes in rat model of neonatal cerebral hypoxia-ischemia

Glutamate transporters are essential for maintaining the extracellular levels of glutamate at synaptic clefts and are regulated developmentally in a subtype-specific manner. We investigated chronological changes of immunoreactivities for glial glutamate transporters GLAST and GLT-1 and a neuronal glutamate transporter, EAAC1, in postnatal 7-day-old rat neocortices and hippocampi at 12, 24, 48 and 72 h after hypoxia-ischemia. Glutamate transporter subtypes are differentially expressed in the ischemic core and the boundary area of the neonatal rat brain with hypoxia-ischemia. Expressions of these glutamate transporters decreased in the ischemic core at 12 h, then immunoreactivities for GLAST and GLT-1 were recovered at the hippocampus. This was accompanied by a GFAP-positive gliosis at 72 h, whereas these immunoreactivities were reduced at the neocortex in the ischemic core. Glial glutamate transporters, especially GLAST, were noted in some astrocytes appearing as apoptosis as well as shrunken pyramidal neurons mainly in the boundary area of the neocortex. Increased perikaryal expression of EAAC1 was associated with that of MAP2 at the border of the boundary area. These temporal and regional expressions of glutamate transporters may contribute towards understanding the excitotoxic cell death mechanism in hypoxic-ischemic encephalopathy during the perinatal period.

Effect of oral treatment of Perilla frutescens and its constituents on type-I allergy in mice

Perilla frutescens Britton (perilla, Labiatae) is a medicinal herb prescribed in Saiboku-to [Japanese letters: see text], which is a Kampo formula effective for allergic diseases such as bronchial asthma. The present study was conducted to evaluate the anti-allergic effect of orally administered perilla decoction and to identify the active constituents using mice ear-passive cutaneous anaphylaxis (PCA)-reaction, which is one of the animal models for type I allergy. Perilla decoction significantly suppressed PCA-reaction, and the inhibition % at the dose of 500 mg/kg was 43%. The perilla decoction contains 5.3% of luteolin 7-O-[beta-glucuronosyl(2-->1)beta-glucuronide], 1.6% of apigenin 7-O-[beta-glucuronosyl(2-->1)beta-glucuronide], 0.49% of scutellarin, and 2.5% of rosmarinic acid (weight of compound/dried weight of perilla decoction %), respectively. When these constituents were orally administered to mice at the dose equivalent to 500 mg/kg of perilla decoction, rosmarinic acid and apigenin 7-O-[beta-glucuronosyl(2-->1)beta-glucuronide] significantly suppressed PCA-reaction, and their inhibition % was 41% (p<0.01) and 32% (p<0.05), respectively. Since the inhibition % or perilla decoction and rosmarinic acid were nearly equal, the anti-allergic effect of perilla decoction depends primarily on rosmarinic acid. The standard Saiboku-to decoction contained 0.013% of rosmarinic acid, which was too low to exhibit anti-allergic activity in a daily dose of Saiboku-to in adults, suggesting that perilla would be prescribed in Saiboku-to to exhibit other pharmacological effects than its anti-allergic activity, such as a sedative.

Expression of hMTH1 in the hippocampi of control and Alzheimer's disease

The oxidized purine nucleoside triphosphatase, hMTH1, has a critical role towards preventing errors caused by oxidized purine nucleoside triphosphates such as 8-oxo-dGTP and 2-hydroxy-dATP. We investigated the immunohistochemical expression of hMTH1 in human hippocampal postmortem tissues representing non-neurological disease and Alzheimer's disease (AD). In the non-neurological subjects the hMTH1 protein was enriched in the stratum lucidum at CA3 corresponding to mossy fiber synapses. In AD subjects, the synaptic immunoreactivities at CA3 were significantly decreased, whereas they tended to be increased at the entorhinal cortex. We suggest that the expression of hMTH1 indicates indirect evidence of oxidative stress and its regulation is regionally differentiated in AD.

Magnesium deficiency differentially affects the retina and visual cortex of intact rats

To determine the influence of magnesium (Mg) on the visual system, electroretinograms (ERG) and visual evoked potentials (VEP) were recorded under dark-(DA) and light-adapted (LA) conditions in intact rats. Weanling rats were fed either a Mg-deficient (Mg-D) or a control diet for 17 d before the tests, and ERG, VEP and immunohistopathological analyses of retinae and cortices were made. In the Mg-D rats, ear congestion, hair loss and loss of body weight were observed, and serum Mg concentration was approximately 25% of that in the control rats (P < 0.01). The amplitudes of the DA a-wave and the second positive peak of the oscillatory potentials (OP2) of the ERG, and the negative component of the VEP (N1) in Mg-D rats were significantly greater than those of control rats. However, the amplitudes of the DA b-wave, LA 2 Hz b-wave, the 20 Hz flicker responses and the implicit times of all response components did not differ between the two groups. The immunohistopathologic results also were not altered in the Mg-D rats. We suggest that the functional abnormalities induced by Mg deficiency may depend not only on the hyperactivity of the N-methyl-D-aspartate (NMDA) receptor, but also on the behavior of the Ca(2+) and Mg(2+) ions in the intact eye.

Resveratrol, a naturally occurring polyphenol, induces sister chromatid exchanges in a Chinese hamster lung (CHL) cell line

We tested the genotoxicity of 3,5,4'-trihydroxystilbene (resveratrol), a polyphenolic phytoalexin found in grapes, in a bacterial reverse mutation assay, in vitro chromosome aberration (CA) test, in vitro micronucleus (MN) test, and sister chromatid exchange (SCE) test. Resveratrol was negative in the strains we used in the bacterial reverse mutation assay (S. typhimurium TA98 and TA100 and E. coli WP2uvrA) in the absence and presence of a microsomal metabolizing system. It induced structural CAs at 2.5-20 microg/ml and showed weak aneuploidy induction in a Chinese hamster lung (CHL) cell line. It induced MN cells and polynuclear and karyorrhectic cells after 48h treatments in the in vitro MN test. In the SCE test, resveratrol caused a clear cell-cycle delay; at 10 microg/ml, the cell cycle took twice as long as it did in the control. Resveratrol induced SCEs dose-dependently at up to 10 microg/ml, at which it increased SCE six-fold, and the number was almost as large as mitomycin C, a strong SCE inducer. No second mitoses were observed at 20 microg/ml even after 54h. Cell cycle analysis by FACScan indicated that resveratrol caused S phase arrest, and 48h treatment induced apoptosis. Our results suggest that resveratrol may preferentially induce SCE but not CA, that is, it may cause S phase arrest only when SCEs are induced.

Limbic encephalitis associated with recurrent thymoma: a postmortem study

The authors report an autopsied patient with limbic encephalitis and recurrent thymoma. The immunohistochemical study showed selective depositions of immunoglobulin G on the neurons in the limbic system and the tumor cells of the recurrent thymoma. The immunoblotting study detected two types of antibodies that react with the human brain, rat brain, and rat thymus.

Expression of the lysosome-associated membrane proteins in myopathies with rimmed vacuoles

Lysosome-associated membrane proteins (LAMPs) are structural glycoproteins located on the lysosomal membrane and are thought to have an important role in protein degradation. Increased lysosomal activity is associated with the formation of rimmed vacuoles, which are observed in various muscle disorders such as inclusion body myositis (IBM) and distal myopathy with rimmed vacuole (DMRV). In the present study, we examined LAMP-1 and LAMP-2 in biopsied muscle specimens from four cases of sporadic IBM and two of DMRV, as well as six of myopathies without rimmed vacuoles. In all cases of IBM and DMRV, immunohistochemistry showed accumulation of LAMPs in the rimmed vacuoles and the subsarcolemmal portion of the vacuolated fibers. Immunoreactivities of LAMPs in the vacuolated fibers were often associated with those of cathepsin D; however, cathepsin D was not expressed on some LAMP-positive fibers. Further, atrophic muscle fibers were sometimes positive for LAMPs expression. These findings were more prominent in LAMP-2 than in LAMP-1. Thus, LAMP-2 may play an important role in the increased protein degradation in diseased muscle fibers. The increased expression of LAMPs in the vacuolated muscle fibers may be associated with the formation of rimmed vacuoles in IBM and DMRV.

Accumulation of 8-oxo-2'-deoxyguanosine and increased expression of hMTH1 protein in brain tumors

Oxidative DNA damage generated by an attack of reactive oxygen species causes mutation or cell death that may lead to various diseases and may be related to initiation or progression of carcinogenesis. 8-Oxo-2'-deoxyguanosine (8-oxo-dG) is a major oxidative DNA damage product that can result in mutation, and hMTH1, human MutT homolog protein 1, has been identified as an enzyme that hydrolyzes 8-oxo-dGTP to the monophosphate, thus preventing accumulation of 8-oxo-dG in DNA. With immunohistochemical approaches, we investigated accumulation of 8-oxo-dG and expression of hMTH1 in brain tumor tissues obtained from surgical and autopsy cases, including 42 neuroepithelial tumors, 5 meningiomas, 2 metastatic brain tumors, and 1 schwannoma. 8-Oxo-dG accumulation and hMTH1 expression were increased in various brain tumors. Nuclei of brain tumor cells were immunoreactive for 8-oxo-dG in all cases. In most cases, both nuclei and cytoplasm of the tumor cells were immunoreactive for hMTH1. Both 8-oxo-dG accumulation and hMTH1 expression were most evident in high-grade gliomas, indicating that oxidative stress was high in these gliomas. Thus, the defense mechanism against such oxidative stress may be enhanced as well. These results suggest that oxidative stress may play a role in tumor progression.

Dorsal horn lesion resulting from spinal root avulsion leads to the accumulation of stress-responsive proteins

The aim of this study was to demonstrate acute to subacute molecular episodes in the dorsal horn following root avulsion using immunohistochemical methods with the markers for synapses, astrocytes and such stress-responsive molecules as heat shock proteins (Hsps) and p38 MAP kinase (p38). Among them, Hsp27 was accumulated selectively in the injured substantia gelatinosa 24 h after avulsion injury. The localization of Hsp27 in astrocytes within the substantia gelatinosa was confirmed by the double immunofluorescence method using anti-Hsp27 antibody and either anti-synaptophysin antibody or anti-glutamine synthetase antibody and by immunoelectron microscopy for Hsp27. The pattern of Hsp27 expression subsequently changed from glial pattern to punctate pattern by 7 days. Immunoelectron microscopy revealed that the punctate pattern in the subacute stage corresponded to distal parts of the astrocytic processes. Hsp27 immunoreaction was decreased 21 days after root avulsion. In the distal axotomy model, Hsp27 was accumulated later in the ipsilateral dorsal horn in a punctate pattern from 7 days after the axotomy. Phosphorylation of p38 was detected in microglia in the dorsal horn following both avulsion and axotomy. Substance P was slightly decreased in the injured substantia gelatinosa in both the avulsion and axotomy models around 14-21 days. We conclude that Hsp27 is a useful marker for demonstrating dorsal horn lesions following avulsion injury and that avulsion injury may induce Hsp27 in the dorsal horn more rapidly than distal axotomy.

Incidence of bone fracture in patients receiving luteinizing hormone-releasing hormone agonists for prostate cancer

OBJECTIVE

To investigate the incidence of bone fractures in patients receiving luteinizing hormone-releasing hormone agonists (LHRH-a) for prostate cancer (in whom a continued low testosterone level after the long-term administration of these drugs reduces bone mineral density), and thus determine the risk of secondary osteoporosis.

PATIENTS AND METHODS

Between 1994 and 1999, 218 patients (mean age 77.3 years) were treated for >/= 6 months with LHRH-a for prostate cancer; of these, 14 (6%) had a bone fracture during their treatment. Patients with fracture associated with motor vehicle accidents were excluded. The bone density in the third lumbar vertebra was meas-ured using quantitative computed tomography. Osteocalcin, 1,25-(OH)2 vitamin D, urinary type 1 collagen cross-linked N-telopeptides (NTx), parathyroid hormone and calcitonin were measured as metabolic markers.

RESULTS

The mean age of the patients with fracture was 78 years; the mean (range) interval from the start of treatment to fracture was 28 (11-46) months. There was no case of a bone fracture at the site of a metastasis from prostate cancer. The bone density was significantly lower in the patients with a fracture than in those without. Of the bone metabolic markers, NTx was higher in those with a fracture.

CONCLUSION

There is a need to measure bone mineral density and bone metabolic markers periodically, and to evaluate secondary osteoporosis in patients receiving long-term LHRH-a for prostate cancer.

[Effects of calcium channel blockers on nocturnal polyuria in the elderly]

Factors reducing the quality of life (QOL) related to micturition and their treatment were studied based on frequency volume chart for 52 consecutive patients with hypertension (the administration of calcium channel blockers) and 28 controls without hypertension, aged 50 years and over (mean age 68.6, range 50-85) without lower urinary tract dysfunction. The micturition records for two days and the QOL index related to urinary symptoms were reviewed. The factors reducing the QOL were increase of the voided volume and frequency during the night and the ratio of night-time voided volume to 24-hour urine output, which significantly increased in the controls (p < 0.05, respectively). Especially, the voiding frequency during the night and the ratio of night-time voided volume increased significantly in the controls aged 70 years and over (p < 0.01, p < 0.05, respectively). Overall, it was suggested that the administration of calcium channel blockers for control of blood pressure might be effective to reduce the nocturnal polyuria in the elderly.

Differential expression of metallothioneins in human prion diseases

We herein report an immunohistochemical and a Western blot analysis on metal/free radical chelating proteins, metallothioneins (MTs; MT-I/II and MT-III), in the brains of human prion disease patients with or without prion protein gene mutation and polymorphism. Irrespective of the isoforms of MTs, the immunoreaction was detected in the cytoplasm and processes of the astrocytes in the cerebral cortex and white matter in normal controls and prion disease brains. Although the immunoreactivities for MTs in Creutzfeldt-Jakob disease (CJD) brains varied from case to case, they were generally dependent upon the disease duration. In CJD patients with a relatively long disease course, the immunoreaction for both MT-I/II and MT-III in the astrocytes was significantly reduced, and this finding was not modified by the genotypes of the patients. On the other hand, in patients with Gerstmann-Sträussler-Scheinker syndrome, MT-I/II immunoreactivity in the astrocytes was exclusively reduced, while the immunoreaction for MT-III was relatively well preserved. Especially the astrocytes in the vicinities of the kuru plaques exhibited a weak or no immunoreaction even for MTs but a strong immunoreaction for glial fibrillary acidic protein. A quantitative Western blot analysis also revealed that MT-I/II protein accumulated in CJD brain with a short disease duration, whereas MT-III in CJD brain with a long disease duration was statistically significantly reduced in comparison to the normal brains. These findings suggest that the protein expression of MTs in the astrocytes is thus regulated differentially among human prion diseases and modified locally by such abnormal prion protein depositions as kuru plaques.

[A clinical study of secondary osteoporosis induced by endocrine therapy for prostate cancer]

PURPOSE

There is one of the big problems that endocrine therapy for prostate cancer causes to induce secondary osteoporosis. The risk factors and future treatments for osteoporosis were investigated.

MATERIALS AND METHODS

31 patients treated with luteinizing hormone releasing hormone agonists (LHRH-a) or combination of chlormadinone acetate (CMA) and LHRH-a, and 19 patients with no treatments for prostate cancer were included in the analysis. Lumber spine bone mineral density (BMD) was measured by quantitative computed tomography.

RESULTS

Aging had much influence on decreases of BMD than the other risk factors (p < 0.01). There were statistically decreases of BMD in the patients with CMA + LHRH-a compared with no treatments (p < 0.05). Adrenal androgen which had an important role of maintenance in BMD was statistically decreased by the administration of CMA (p < 0.01).

CONCLUSIONS

Measurement of BMD before endocrine therapy is necessary for the patients with prostate cancer. It is important for the patients with decreases of BMD that CMA is not combined or the therapy for osteoporosis is preventively employed.

Ubiquitin-immunoreactive skein-like inclusions in the neostriatum are not restricted to amyotrophic lateral sclerosis, but are rather aging-related structures

We examined the presence of ubiquitin-immunoreactive skein-like inclusions (SLI) in the neostriatum and spinal cord in normal individuals and patients with different neurodegenerative diseases. Ubiquitin-immunoreactive SLI in the neostriatum were observed both in the normal individuals and in the patients with a variety of neurodegenerative diseases. In particular, SLI were frequently seen in normal aged subjects and certain neurodegenerative diseases, such as progressive supranuclear palsy and myotonic dystrophy. In contrast, the occurrence rate of SLI in cases with Pick's disease and multiple system atrophy tended to decrease. On the other hand, SLI in the spinal anterior horn were detected in cases of amyotrophic lateral sclerosis, but not in any cases with other neurodegenerative diseases. SLI in the neostriatum were also identifiable using phosphotungstic acid-hematoxylin and Gomori trichrome staining. Ubiquitin immunoelectron microscopy demonstrated that the SLI in the neostriatum corresponded to bundles of filaments. These features of SLI in the neostriatum were quite similar to those of intracytoplasmic rod-like inclusions (RLI) in the large neurons of caudate nucleus, which were first described by Kojima and Ogawa in 1974. Our findings indicate that SLI in the neostriatum are ubiquitin-related structures whose occurrence increases by aging, and less frequently accompany several neurodegenerative diseases, and are identical to at least some RLI.

[Bone fracture receiving LH-RH agonists for prostatic cancer]

BACKGROUND

Luteinizing hormone-releasing hormone (LHRH) agonists are popularly used drugs in the treatment of prostatic cancer. However, it has been reported that continuation of a low testosterone level following a longterm administration of these drugs reduces the bone mineral density and makes for osteoporosis, which is accountable for fracture, we measured the bone mineral density and bone metabolic markers in the cases who suffered fracture receiving LHRH agonists for prostatic cancer.

PATIENTS AND METHODS

Between 1994 and 1998, 196 patients (mean age 78.1 years) were treated with LHRH agonists for prostatic cancer. Of these patients, 13(7%) who had bone fracture during treated with LHRH agonists were divided into fracture group, and 70 patients who had not bone fracture divided into non-fracture group. Fracture by traffic accident was excluded. The bone density in the third lumbar vertebra was measured using quantitative computed tomography (QCT). Osteocalcin, 1, 25- (OH)2 vitamin D, urinary type 1 collagen cross-linked N-telopeptides (NTx), parathyroid hormone (PTH) and calcitonin were measured as bone metabolic markers.

RESULTS

The mean age of fractured cases was 78 years. The period from the start of treatment to fracture was 11 to 45 months (mean 27 months). No case of fracture at the site of metastasis of prostatic cancer was found. The bone density was significantly low in the fracture group compared with that of non-fracture group. Of the bone metabolic markers, NTx showed high values in the fracture group.

CONCLUSION

There is a need to measure bone mineral density and bone metabolic markers periodically and to evaluate secondary osteoporosis in the patients receiving LHRH agonists for prostatic cancer.

[Clinical efficacy of low-dose weekly docetaxel combined with oral 5'-deoxy-5-fluorouridine (5'-DFUR) in advanced or metastatic breast cancer: a pilot trial]

Docetaxel (TXT) has been shown to be an up-regulator of human pyrimidine nucleoside phosphorylase (PyNPase) in tumors. We have tried to use the combination of low-dose weekly TXT with 5'-DFUR (LD + D) in patients with advanced or metastatic breast cancer. In this study, we compared the clinical efficacy of LD + D with that of conventional full-dose TXT (FD) and that of low-dose weekly TXT (LD). Twenty-one patients received 3 or 4 cycles of FD 60 mg/m2 every 3 or 4 weeks (group I), 14 patients received 8 cycles of LD 20-30 mg/m2 every week (group II) and 25 patients received 8 cycles of LD 20-30 mg/m2 weekly with oral 5'-DFUR 600-1,200 mg per day (group III). The overall response rates of groups I, II and III were 29%, 29% and 52% (p = 0.24), respectively. Grade 3-4 neutropenia was observed in 91% of group I, 6% of group II and 3% of group III. Nausea was present in 27% of group I, 28% of group II and 40% of group III. Higher incidence of gastrointestinal symptoms was found in LD + D, but the symptoms abated when the doses of 5'-DFUR were reduced. Low-dose weekly TXT with oral 5'-DFUR produced a higher response rate, but less hematologic toxicity than full-dose TXT, suggesting that this combination therapy is clinically useful and may be effective for patients with advanced or metastatic breast cancer.

Aspirin and salicylic acid do not inhibit methyl jasmonate-inducible expression of a gene for ornithine decarboxylase in tobacco BY-2 cells

Similar to the prostanoid-mediated inflammatory response in mammals, jasmonate-mediated wound response in plant leaves is inhibited by salicylic acid (SA) or acetylsalicylate (aspirin). In tobacco BY-2 cells, expression of the gene for ornithine decarboxylase (ODC) involved in putrescine synthesis is rapidly inducible by methyl jasmonate (MeJA). A nuclear gene for ODC isolated from tobacco, gNtODC-1, was an intron-less gene and MeJA induced the expression of a GUS fusion gene with the gNtODC-1 promoter in transformed tobacco cells. Although SA alone did not induce the expression, 0.2 to 20 microM SA increased the MeJA-induced expression of the fusion gene to about two-fold. A similar increase was observed with aspirin but not with 3- or 4-hydroxybenzoic acids. SA at concentrations up to 200 microM did not inhibit the MeJA-induction of mRNAs for the GUS fusion gene and the endogenous gene for ODC.

Immunohistochemical analysis in a case of idiopathic Lennox-Gastaut syndrome

We herein report a neuropathological and immunohistochemical analysis of a brain from a 25-year-old male with idiopathic type of Lennox-Gastaut syndrome (LGS). The clinical pictures, such as seizure type and progressive mental deterioration with an initial normal psychomotor and mental development in a man were typical of LGS. A routine neuropathological examination showed no pronounced changes, such as neuronal loss, morphologically abnormal neurons, inflammation, vascular changes, Lafora bodies and tumor cells, except that mild gliosis was seen only in CA4 of the hippocampus. Numerous corpora amylacea were observed throughout the cerebral cortices subjacent to the pia mater. An immunohistochemical analysis showed no marked findings for such proteins as glutamate transporters, glutamate decarboxylase, glutamine synthetase, neuronal cytoskeleton proteins and heat-shock proteins. However, intense ubiquitin-immunostained neurons were only found in CA4 of the hippocampus, whereas numerous astrocytes showed a strong immunoreaction for glial fibrillary acidic protein, but showed an exclusively reduced immunoreactivity for metallothionein-I/II, zinc-chelating protein. Our findings thus suggest that the pathology in the hippocampus is either causally or consequentially associated with the seizures occurring in LGS.

[Magnetic resonance imaging of breast cancer: correlation between contrast enhancement and tumor angiogenesis]

PURPOSE

To evaluate the association between enhancement characteristics of breast cancers obtained by three-dimensional dynamic MRI and histopathologic findings, especially tumor angiogenesis.

MATERIALS AND METHODS

Forty-four women with invasive breast cancer under went preoperative MR imaging. Three-dimensional fast low angle shot (3D-FLASH) images of the whole breast (section thickness, 2 mm; gap, 0 mm; number of sections, 50; acquisition time, 87 sec) were obtained at 90-second intervals for three images (the first image before the injection of Gd-DTPA). Microvessel densities were evaluated in specimens immunohistochemically stained with anti-CD34 antibody. Pearson correlation tests were used to determine the strength of the relationships between enhancement parameters and microvessel densities. Univariate and multivariate analyses were performed to explore the associations with histopathologic factors, including histological grade.

RESULTS

The enhancement parameters were correlated with microvessel densities (p < 0.0001). The peripheral microvessel densities were significantly higher than central microvessel densities (p < 0.0001). A significant association with histological grade was observed for the steepest slopes of the dynamic curve and microvessel densities (p < 0.05).

CONCLUSION

A correlation between three-dimensional dynamic MRI parameters and microvessel densities, and associations with histological grade were seen. This may allow MRI to be used in the prediction of tumor angiogenesis and tumor grade.

Cost-sharing and pharmaceutical utilisation and expenditure in Russia

This paper presents estimates of the impact of exemption status, and other socio-economic variables, on pharmaceutical use in Russia. Estimates are derived from a newly collected household survey covering around four thousand households. Separate results for a zero-inflated negbin model of utilisation of prescriptions and for a two-part model of the overall level of household expenditure on pharmaceuticals are presented. Full exemption from prescription charges is shown to increase the utilisation of prescription items and reduce the probability of the households incurring drug expenditure.

[Percutaneous resection of renal pelvic fibroepithelial polyp with medullary sponge kidney: a case report]

Benign polyp of the renal pelvis is extremely rare. We report a case of fibroepithelial polyp in the renal pelvis complicated with medullary sponge kidney successfully treated by percutaneous resection. The patient had recurrent bilateral renal stones because of medullary sponge kidney. Percutaneous resection of renal pelvic polyps was carried out through a 26 Fr Amplatz sheath using a 24 Fr resectoscope. Pathological diagnosis was a fibroepithelial polyp. The etiology of this polyp was suggested to be chronic irritation of renal stone.

High-performance liquid chromatography-fluorescence determination of dinitropyrenes in soil after column chromatographic clean-up and on-line reduction

In order to quantify 1,3-dinitropyrene (DNP), 1,6-DNP and 1,8-DNP in soil, we developed an efficient clean-up procedure and a sensitive determination method using fluorescence detection. DNP isomers were efficiently cleaned by three stages of fractionation, i.e., a silica gel open column chromatography using stepwise elution and two further purification steps by high-performance liquid chromatography (PPLC) using a monomeric-type octadecylsilyl (ODS) column and a polymeric-type ODS column. The recoveries of DNPs during the whole clean-up process were 94% or more. The fraction corresponding to DNPs was injected into an analytical polymeric-type ODS column for HPLC to separate DNP isomers. The effluent from the analytical ODS column was directly introduced to a catalyst column, which was packed with 5 microns alumina coated with platinum and rhodium (Pt-Rh), in order to reduce DNPs to diamino compounds, and then the fluorescence of diaminopyrenes was detected. The immediate detection of diaminopyrene isomers after on-line reduction afforded a sensitive detection of DNP isomers. The detection limits for DNPs were in the range of 0.7 to 4 pg. These developed methods were applied to four soil samples collected at parks in residential areas.

[Double cancer observed from bladder cancer]

BACKGROUND

In recent years, despite of the improvement of treatment results for cancer and long life, the occurrence of second primary cancer was increased. In this paper, we analyzed present condition of double cancer observed with bladder cancer in our hospital.

METHOD

Last 21 years, we have treated 969 cases (828 male and 141 female) of primary bladder cancer. For those cases, we analyzed in term of frequency, involved organ, age, interval between two cancer occurrence, risk factor and prognosis of double cancer patients.

RESULT

Of 969 cases with bladder cancer, 81 cases (8.36%) had double cancer involving 6 cases (0.61%) of triple cancer. In sex, 70 males (9.78%) and 11 females (7.80%) had double cancer. As involved organs, 25 cases (3.02%) had in prostate, 23 cases (2.37%) in stomach, 3 case (2.13%) in breast, 14 cases (1.44%) in colon and rectum. In diagnosis timing of complicated cancer from bladder cancer, 28 cases (34.6%) were diagnosed previously to bladder, 28 cases (34.6%) were simultaneously and 31 cases (38.3%) were secondary. An average interval of diagnosis of two cancer were 49 +/- 42.5 months. An average age of occurrence of second cancer was 70.3 +/- 8.8 years. Actual survival rate from diagnosis of bladder cancer were 90.8%, 68.6%, 53.3% and 30.3%, after 1, 3, 5 and 10 years, respectively. Ten cases were dead by bladder cancer, 21 cases by complicated cancer and 16 cases by another cause.

CONCLUSION

The incidence of double cancer with bladder cancer were increased. Prostate cancer, colorectal cancer and breast cancer were gradually increased as complicated organs in Japan. The prognosis of double cancer patients with bladder cancer was poor than single bladder cancer patients.

Laminar segregation of the cortical plate during corticogenesis is accompanied by changes in glutamate receptor expression

We tested the hypothesis that subtypes of glutamate receptors (GluRs) are differentially expressed during corticogenesis. The neocortex of fetal sheep (term = approximately 145 days) was evaluated by immunoblotting and immunohistochemistry to determine the protein expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (GluR1, GluR2/GluR3 [GluR2/3], and GluR4), kainate (KA) receptors (GluR6/GluR7 [GluR6/7]), and a metabotropic GluR (mGluR5). AMPA/KA receptors and mGluR5 were expressed in neocortex by midgestation. GluR1 and mGluR5 expression increased progressively, with expression being maximal just before birth and then decreasing postnatally. GluR2/3 and GluR6/7 levels increased progressively during corticogenesis to reach adult levels near term. GluR4 was expressed at low levels during corticogenesis and in adult neocortex. The localizations of GluRs in the developing neocortex were distinct. Each GluR had a differential localization within the marginal zone, cortical plate, and subplate. GluR subtypes were expressed in laminar patterns before major cytoarchitectonic segregation occurred based on Nissl staining, although connectional patterns were emergent by midgestation based on labeling of corticostriatal projections with DiI. The GluR localizations changed during cortical plate segregation, resulting in highly differential distributions in the neocortex at term. AMPA/KA receptors were expressed transiently in proliferative zones and in developing white matter. Oligodendrocytes in fetal brain expressed AMPA receptors. The expression of ion channel and metabotropic GluR subtypes is dynamic during corticogenesis, with subtype- and subunit-specific regulation occurring during the laminar segregation of the cortical plate and differentiation of the neocortex.

Changes in concentrations of serum amyloid A protein, alpha 1-acid glycoprotein, haptoglobin, and C-reactive protein in feline sera due to induced inflammation and surgery

To identify candidates for feline acute phase proteins, the concentrations of serum amyloid A protein (SAA), alpha 1-acid glycoprotein (alpha 1-AG), C-reactive protein (CRP), and haptoglobin (Hp) were measured in sera isolated from clinically normal and hospitalized (or diseased) cats, from cats with experimentally induced inflammation, and cats subjected to surgery for urinary diversion. Measurements were made by sandwich enzyme-linked immunosorbent assay and single radial immunodiffusion. The concentrations of SAA, alpha 1-AG, and Hp in sera from hospitalized cats were 7-11 times higher than in clinically normal cats. Similar results were obtained for the concentrations of SAA, alpha 1-AG, and Hp in cats with induced inflammation and cats subjected to surgery. By contrast, the serum concentration of feline CRP did not change significantly between clinically normal cats and hospitalized cats or inflammation-induced or post-surgery cats. Feline SAA concentration was found to increase earliest, with alpha 1-AG and Hp beginning to increase thereafter. From these results, feline SAA is concluded to be an acute phase reactant at the early stage of inflammation.

Molecular cloning and expression of the rat EAAT4 glutamate transporter subtype

Glutamate transport is a primary mechanism for the synaptic inactivation of glutamate. Excitatory amino acid transporter 4 (EAAT4) is a novel glutamate transporter with properties of a ligand-gated chloride channel that was recently cloned from human brain. Here we report the cloning of rat EAAT4 (rEAAT4) cDNA from rat cerebellum. The nucleotide sequence of rEAAT4 was 88% identical to the human sequence, and the predicted peptide was 89% identical to the human protein. The transport activity encoded by rEAAT4 has high affinity for L-glutamate. In Xenopus laevis oocytes expressing rEAAT4, L-glutamate and other transporter substrates elicited a current predominantly carried by chloride ions. Like human EAAT4, the rEAAT4 mRNA was largely restricted to cerebellar Purkinje cells; the rEAAT4 protein was localized to Purkinje cell somas and dendrites.

[Bladder cancer in patients over 80 years old]

We studied 86 patients with bladder cancer who were 80 years old and over. All were studied at the time of their first presentation for treatment in our hospital. About 40% of then were somewhat limited in performing usual daily activities before the first treatment, and they could not come to the hospital by themselves. Tumors in patients were larger, of higher grade and more invasive than those in younger patients. Transurethral resection of the bladder tumor (TUR-Bt) was done in 94% of patients with a superficial tumor and in 56% of those an invasive tumor. The recurrence rates after TUR-Bt for superficial tumor were 48%, 64% and 89% in 1 year, 3 years and 5 years, respectively. Recurrence rates were significantly different in younger patients. Overall cancer related survival rates were 86%, 60%, and 56% in 1 year, 3 years and 5 years, respectively. The outcome were significantly worse in patients over 80 years old than in those under 79 years old. To improve the outcome of treatment for bladder cancer in patients over 80 years old, cooperation among doctors, patients and families was important.

AMPA receptor protein in developing rat brain: glutamate receptor-1 expression and localization change at regional, cellular, and subcellular levels with maturation

We tested the hypothesis that the regional, cellular, and synaptic localizations of the glutamate receptor 1 (GluR 1) subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor are regulated developmentally in rat brain. By immunoblotting, GluR1 was first detected in whole brain at embryonic day E15.5, and levels increased progressively during late embryonic (E20) and early postnatal (P2-P11) days. Regionally, GluR1 increased in cerebral cortex but decreased in striatum with postnatal maturation. These changes occurred in the presence of increased presynaptic maturation, as determined by synaptophysin detection. By immunocytochemistry, distinct cellular populations showed different temporal profiles of GluR1 expression during postnatal maturation. The neocortex and hippocampus showed a progressive maturation-related enrichment of GluR1, whereas the striatum showed a gradual reduction in GluR1 during maturation. In cerebellum, GluR1 protein was expressed transiently at restricted times postnatally by granule cells (P0-P11) and Purkinje cells (P13-P19), but by P21 and thereafter these neurons had sparse GluR1 immunoreactivity. By immunoelectron microscopy. GluR1 was found in neurites, specifically in both dendritic and axon terminal components of developing synapses. GluR1 was clustered at the plasma membrane of apparent growth cone appositions, neuronal cell bodies, and dendrites of developing neurons. The presence of GluR1 at presynaptic sites dissipated with synaptic maturation, as GluR1 became confined to the somatodendritic compartment as maturation progressed. We conclude that the regional expression as well as the cellular and synaptic localizations of the GluR1 are developmentally regulated and are different in immature and mature brain. Differences in glutamate receptor expression and synaptic localization in immature and mature brain may be relevant to the phenomenon that the perinatal and adult brain differ in their regional vulnerability to hypoxia-ischemia and excitotoxicity.

Cellular and synaptic localization of the neuronal glutamate transporters excitatory amino acid transporter 3 and 4

Glutamate transport is a primary mechanism for the synaptic inactivation of glutamate. Excitatory amino acid transporter 4 (EAAT4) is a novel glutamate transporter with properties of a ligand-gated chloride channel that was recently cloned from human brain. The present study was an investigation of the protein expression and cellular localization of EAAT4 in human and rat brain, and comparison with another neuronal glutamate transporter, EAAT3 (rabbit excitatory amino acid carrier 1; EAAC1). Regional immunoblot analysis of EAAT4, using a monospecific oligopeptide (carboxy-terminal) affinity-purified polyclonal antibody, revealed that the protein was restricted to the central nervous system. The EAAT4 protein was largely expressed in cerebellum, with a much lower expression in hippocampus, neocortex, striatum, brain stem and thalamus. Immunohistochemical studies showed intense EAAT4 immunoreactivity in the human and rat cerebellar Purkinje cells with a somatodendritic localization. Other brain regions including neocortex, hippocampus, striatum showed faint neuropil staining of EAAT4. Immunogold localization identified EAAT4 protein at plasma membranes of Purkinje cell dendrites and spines. In the hippocampus and neocortex, EAAT4 immunoreactivity was found mainly at small calibre dendrites. Rarely, EAAT4 immunoreactivity was found in astrocytic cell processes of forebrain. In the cerebellum, EAAT4 localization partly overlapped with the neuronal localization of EAAT3 (EAAC1). Immunoreactivity for EAAT3 was enriched in the somatodendritic compartment of the Purkinje cells like EAAT4, but EAAT3 was also found in Purkinje cell axons and in boutons in deep cerebellar nuclei, as well as in granular cells and stellate cells. Our results indicate that EAAT4 protein is largely localized to cerebellar cortex and lower levels of EAAT4 protein are present in forebrain by immunoblot and immunohistochemistry. Both neuronal glutamate transporter EAAT3 (EAAC1) and EAAT4 are located at somatodendritic compartment of Purkinje cells, and probably contribute to glutamate re-uptake mechanisms at Purkinje cell synapses.

Distribution of glutamate transporter subtypes during human brain development

In the mature brain, removal of glutamate from the synaptic cleft plays an important role in the maintenance of subtoxic levels of glutamate. This requirement is handled by a family of glutamate transporters, EAAT1, EAAT2, EAAT3, and EAAT4. Due to the involvement of glutamate also in neuronal development, it is believed that glutamate transport plays a role in developmental processes as well. Therefore, we have used immunohistochemical and immunoblot analysis to determine the distribution of the four glutamate transporters during human brain development using human pre- and postnatal brain tissue. Regional analysis showed that each transporter subtype has a unique distribution during development. EAAT2 was the most prominent glutamate transporter subtype and was highly enriched in cortex, basal ganglia, cerebellum, and thalamus in all ages examined. EAAT1 immunoreactivity was lower than that of EAAT2, with predominant localization in cortex, basal ganglia, hippocampus, and periventricular region. EAAT3 was located mainly in cortex, basal ganglia, and hippocampus, and EAAT4 was found only in cortex, hippocampus, and cerebellar cortex. The distinct regional distribution of various EAAT subtypes and also the transient expression of specific EAAT subtypes during development suggest multiple functional roles for glutamate transporters in the developing brain.

Glutamate transporter protein subtypes are expressed differentially during rat CNS development

Extracellular glutamate concentrations are regulated by glial and neuronal transporter proteins. Four glutamate transporter subtypes have been identified in rat brain; GLAST and GLT-1 are primarily astrocytic, whereas EAAC1 and EAAT4 are neuronal. Using immunoblotting and immunohistochemistry with subtype-specific antipeptide antibodies, we examined the protein expression and regional and cellular localization of each glutamate transporter subtype in embryonic and postnatal rat CNS. Each transporter had a specific pattern of expression. GLAST immunoreactivity was low prenatally but became enriched in cerebellar Bergmann glia early postnatally and then was also present in forebrain later postnatally. The post-translational modification of GLAST was unique among the subtypes; glycosylated GLAST increased with maturation, whereas nonglycosylated protein decreased in abundance postnatally. GLT-1 was present in fetal brain and spinal cord, with expression progressively increasing to adult levels throughout the neuraxis by postnatal day 26. Transient expression of GLT-1 immunoreactivity along axonal pathways was observed prenatally, in contrast to the exclusive localization of GLT-1 to astrocytes in the adult CNS. EAAC1, localized to neurons, was enriched in forebrain, diencephalon, and hindbrain during prenatal and postnatal development. EAAC1 expression was greater in newborn brain compared with adult brain. EAAT4 had a region-specific distribution; EAAT4 was mainly in cerebellum, localized to Purkinje cells, with much lower levels in forebrain. EAAT4 levels increased in cerebellum with age. We conclude that during CNS development the expression of glutamate transporter subtypes is differentially regulated, regionally segregated, and coordinated.