Suppressive effect of fetal testes on development of fetal ovaries transplanted into adult males in the rat

The age-related testicular effect on the ovarian primordia was studied by combined transplantation of fetal testes and ovaries in adult male hosts. First, ovarian primordia of 14-day fetal rats were transplanted into a renal subcapsular position of castrated or intact adult male rats. In both the castrated and the intact hosts, most of the ovarian transplants developed normally with only 3 of them having in part seminiferous tubule-like structures in addition to normal ovarian structure. Second, a 14-day ovary was combined with a fetal testis the age of which varied from 13- to 18-day, and the combination was transplanted. In the combination of a 14-day ovary and a 13-day testis, the results varied in such a way that the ovary or the testis alone developed or otherwise, both gonads developed well. In union with 15- to 18-day testes, the ovaries did not develop, although the testes developed well. These results suggest that the 14-day ovarian primordia have a slight reactiveness to androgens of host rats and that the 13-day fetal testes begin to inhibit the development of the 14-day ovaries co-transplanted with them.

Platinum/carbon multilayer reflectors for soft-x-ray optics

We have fabricated platinum/carbon (Pt/C) multilayer reflectors with 2d spacaings between 50 and 200 Å, using an electron-beam evaporator. We investigated the effects of 2d values, the number of layer pairs, substrate temperature, coatings, and the long-term stability on the reflectivity performance by using characteristic x rays and monochromatized synchrotron radiation in the 0.8-8-keV region. In this study we show that Pt/C multilayers with 10-20 layer pairs exhibit high and stable soft-x-ray reflectivity. The interfacial roughness was measured in the range of 5 Å and becomes lower for structures deposited at liquid-nitrogen temperatures. Coating these reflectors with a 100-Å-thick platinum layer increased the grazing angle reflectivity without significantly lowering the Bragg peak reflectivity.

Human cytoplasmic isoleucyl-tRNA synthetase: selective divergence of the anticodon-binding domain and acquisition of a new structural unit

We show here that the class I human cytoplasmic isoleucyl-tRNA synthetase is an exceptionally large polypeptide (1266 aa) which, unlike its homologues in lower eukaryotes and prokaryotes, has a third domain of two repeats of an approximately 90-aa sequence appended to its C-terminal end. While extracts of Escherichia coli do not aminoacrylate mammalian tRNA with isoleucine, expression of the cloned human gene in E. coli results in charging of the mammalian tRNA substrate. The appended third domain is dispensable for detection of this aminoacylation activity and may be needed for assembly of a multisynthetase complex in mammalian cells. Alignment of the sequences of the remaining two domains shared by isoleucyl-tRNA synthetases from E. coli to human reveals a much greater selective pressure on the domain needed for tRNA acceptor helix interactions and catalysis than on the domain needed for interactions with the anticodon. This result may have implications for the historical development of an operational RNA code for amino acids.

Corticobasal degeneration: a disease with widespread appearance of abnormal tau and neurofibrillary tangles, and its relation to progressive supranuclear palsy

The neuropathological findings, including immunohistochemistry and electron microscopy, of two patients with clinical findings consistent with corticobasal degeneration (CBD) are reported. Both patients showed degeneration of the precentral cortex, the substantia nigra, the pallidum, and the thalamus. Many ballooned neurons were seen in the cerebral cortex, and argentophilic, skein-like inclusions suggesting neurofibrillary tangles (NFTs) were found in the brain stem and precentral cortex in patient 1. In contrast, patient 2 clearly showed NFTs in the brain stem and dentate nucleus which were indistinguishable from those seen in progressive supranuclear palsy (PSP), while only a few ballooned neurons were found in the cerebral cortex. Gallyas silver stain showed many argentophilic inclusions suggesting NFTs in the brain stem, subcortical nuclei, and cerebral cortex in both patients. Immunohistochemistry for tau showed tau-positive neurons in the cerebral cortex, brain stem, subcortical nuclei and spinal cord, and tau-positive glial cells were seen in the cerebral cortex, white matter and subcortical nuclei, and thread-like structures were seen in the cerebral cortex and white matter. Electron microscopy of the brain stem showed NFTs consisting of paired helical filaments in patient 1, and paired helical filaments and straight tubules in patient 2. Immunoelectron microscopy revealed parallel tau-positive filaments in the cerebral cortex in patient 1. From the two patients, the wide-spread appearance of abnormal tau and NFTs is one of the essential pathological features in CBD, and it also appears that CBD and PSP have some common underlying pathological processes. Patient 2 is closer to PSP than patient 1 and suggests CBD would link to PSP.

Therapeutic effect of adriamycin encapsulated in long-circulating liposomes on Meth-A-sarcoma-bearing mice

Long-circulating liposomes modified with a uronic-acid derivative, palmityl-D-glucuronide (PGIcUA), have been developed previously for the passive targeting of liposomes to tumor tissues. In this study, we examined the therapeutic effect of adriamycin (ADM) encapsulated in PGIcUA liposomes composed of dipalmitoylphosphatidylcholine (DPPC), cholesterol (Chol) and PGIcUA (molar ratio, 40/40/10) since this amount of PGIcUA was enough to endow liposomes with long-circulating activity. Long-circulating activity was also observed with palmityl-D-galacturonide (PGalUA) modified liposomes, suggesting that uronic acid plays an important role in preventing liposomes from being trapped in the reticuloendothelial system (RES). ADM was loaded in liposomes by a remote-loading method. Free or liposomal ADM was injected i.v. into BALB/c mice bearing s.c.-implanted Meth-A sarcoma. The liposomal formulation was efficient for reducing tumors, prolonging survival time and curing the animals, especially in the case of large tumors where free ADM was not. Furthermore, PGlcUA liposomes were more effective than conventional liposomes containing dipalmitoylphosphatidylglycerol (DPPG) instead of PGlcUA for prolonging survival time in mice. It might therefore be appropriate to use PGlcUA liposomes as the carriers of anticancer drugs.

Secretion-recapture process of apolipoprotein E in hepatic uptake of chylomicron remnants in transgenic mice

To investigate the role of apoE in hepatic uptake of chylomicron remnants, we studied chylomicron metabolism in transgenic mice overexpressing apoE in the liver. Plasma clearance of injected 125I-labeled human chylomicrons was fivefold faster in transgenic mice than in controls. Immunohistochemistry demonstrated that apoE was specifically localized at the basolateral surface of hepatocytes from fasted transgenic mice. After injection of a large amount of chylomicrons, the density of the cell surface apoE was markedly reduced and vesicular staining was observed in the cytoplasm, suggesting that the cell surface apoE was used for hepatic endocytosis of chylomicrons and remnants. Polyacrylamide gel analysis of chylomicrons and remnants that had been reisolated from plasma and from liver membrane after the injection of chylomicrons showed the particles to be enriched with apoE mainly after their influx into the liver rather than during their residence in plasma. These results provide strong evidence for the secretion-recapture process of apoE, whereby chylomicron remnants enter the sinusoidal space, acquire apoE molecules, and subsequently are endocytosed. Data from experiments with very low density lipoprotein and LDL showed that this system is specific for chylomicron remnants.

Scintigraphic detection of neural-cell-derived small-cell lung cancer using glioma-specific antibody

Radiolabeled GA-17, a murine monoclonal antibody that reacts specifically with glioma cells, bound to a small-cell lung cancer (SCLC) cell line NCI-H69 derived from neural cells, both in vitro and in vivo. The affinity constant of GA-17 F (ab')2 fragment binding to NCI-H69 was 1.02 x 10(8)/M while that to the glioma cell line U87MG was 1.22 x 10(8)/M. Iodine-125-labeled GA-17 F(ab')2 fragments injected i.v. localized well in NCI-H69 cells xenografted in nude mice. The percentage of the injected dose per gram accumulated in the xenografted tumor was 6.87 +/- 1.34% g-1 (mean +/- SD, n = 5) 24 h after injection. On the other hand, control monoclonal F(ab')2 fragments accumulated in the xenografted tumor at 0.75 +/- 0.30% g-1. The tumor-to-blood ratio was 1.8 for NCI-H69, while that of control F(ab')2 was 0.60. In conclusion, the radiolabeled GA-17 F(ab')2 fragment is expected to be useful clinically to visualize the small-cell lung cancer and in radioimmunotherapy.

Metabolism of chylomicron remnants in transgenic mice expressing apolipoprotein E in the intestine

Apolipoprotein E (apoE) has high affinity for the cell surface low density lipoprotein (LDL) receptor. To determine the role of apoE in plasma chylomicron clearance, a transgenic mouse line which overexpresses apoE in the intestine was established. Immunohistochemistry demonstrated that considerable amounts of apoE were localized to mucosal cells of the intestine. In an oral retinyl palmitate challenge test, both the peak height and area under the curve in transgenic mice were less than 25% of those in controls. We speculate that the apoE molecules produced in the intestine of transgenic mice were incorporated onto newly synthesized chylomicron particles before their secretion into the plasma and thereby contributed to rapid plasma clearance of chylomicron remnants. Gene expression of apoE in the intestine would be a promising way to control postprandial hyperlipemia.

Immunohistochemical and in situ hybridisation detection of adenovirus early region 1A (E1A) gene in the microglia of human brain tissue

To investigate whether brain tissue is infected latently by adenovirus via a monocyte/microglia-mediated entry mechanism, brain tissue resected at necropsy from seven senile subjects (five with senile dementia of Alzheimer type (SDAT) and two subjects without pathological changes) was examined for adenovirus early region 1A (E1A) gene and its expression using in situ hybridisation and immunohistochemical staining. HLA-DR positive, reactive microglial cells in both SDAT and normal brain tissue showed positive hybridisation and immunoreactive expression of adenovirus E1A. Thus there may be monocyte/microglia-mediated entry of adenovirus in the central nervous system which would be a novel and presumably common interaction between brain tissue and adenovirus.

Synaptophysin and chromogranin A immunoreactivities of Lewy bodies in Parkinson's disease brains

Lewy bodies commonly observed in brains with Parkinson's disease (PD) histochemically contain both protein and lipid as chemical components. Ultrastructurally, they are composed of filamentous, vesicular and granular structures. We investigated PD brains with light and electron microscopic immunohistochemistry using antibodies against two marker proteins for neuronal secretory vesicles, synaptophysin and chromogranin A. Both antibodies immunolabeled the peripheral zones and occasionally central cores of Lewy bodies of the classical and intraneuritic types. In addition, the diffuse immunolabeling was observed in Lewy bodies of the cortical type. Furthermore, the ultrastructural immuno-decoration was found mainly in the vesicular structures, and also in the filamentous and granular structures of Lewy bodies. Immuno-blot analysis of each antibody showed no difference between PD and normal control brains. The present observations suggest that vesicular profiles of Lewy bodies represent presynaptic and dense core secretory vesicles, and therefore that the lipid elements of Lewy bodies are derived from membrane lipids of these vesicles.

A high frequency of apolipoprotein E4 isoprotein in Japanese patients with late-onset nonfamilial Alzheimer's disease

Phenotypes of apolipoprotein E (apo E) were determined by the iso-electric focusing method in 42 Japanese patients with nonfamilial late-onset Alzheimer's disease (AD) and 96 age-matched controls without hyperlipidemia and/or diabetes. There was a striking difference in the distribution of apo E phenotypes between patients with AD and controls (P < 0.0001). Such a difference was mostly attributable to different frequencies of phenotypes E4/3 and E3/3. The apo E4/3 phenotype was detected in 24 (57.1%) of 42 patients with AD, more than six times oftener than in nine (9.4%) of 96 controls. In contrast, apo E3/3, which is the most common apo E phenotype in various ethnic groups, was detected in only 15 (35.7%) patients with AD. These results indicate a strong association between apo E4 isoprotein and Japanese late-onset nonfamilial AD, and that apo E4 is a possible risk factor for the development of this type of AD.

Tumor imaging with technetium-99m-DTPA encapsulated in RES-avoiding liposomes

For passive targeting of liposomes to tumor tissues, we earlier developed reticuloendothelial system (RES)-avoiding liposomes modified with a uronic acid derivative, palmityl-D-glucuronide (PGlcUA). In the present study, we encapsulated technetium-99m (99mTc)-diethylenetriaminepentaacetic acid (DTPA) in PGlcUA-liposomes (dipalmitoylphosphatidylcholine:cholesterol:PGlcUA = 40:40:20 as a molar ratio) and studied the biodistribution of the liposomes in tumor-bearing mice. 99mTc-DTPA encapsulated in liposomes effectively accumulated in tumor tissues after intravenous administration. Corresponding to these results, tumor was strongly imaged by a gamma-camera when 99mTc-DTPA-encapsulated PGlcUA-liposomes were used.

Neurofibrillary tangles in the neurons of spinal dorsal root ganglia of patients with progressive supranuclear palsy

Neurofibrillary tangles (NFTs) occur in neurons of human central nervous system (CNS) both in aged subjects and patients with several degenerative diseases, with a certain topographical predilection. In surveying the NFT distribution in nervous tissue of patients with progressive supranuclear palsy (PSP), we found silver-positive fibrillary tangles in the neurons of dorsal root ganglia (DRG) in two of five patients. By immunohistochemistry, these tangles were stained with antibodies to human tau protein, paired helical filaments (PHFs) and ubiquitin. Electron microscopy revealed that they were mainly composed of PHFs that were morphologically indistinguishable from PHFs in the NFTs of CNS typically seen in Alzheimer's disease brains. Our data demonstrate for the first time that the neurons of DRG produce NFTs in PSP and suggest that the pathological process(es) leading to tangle formation can occur in the neurons of the peripheral nervous system in this disease condition.

Antitumour activity of an immunoconjugate composed of anti-human astrocytoma monoclonal antibody and neocarzinostatin

Neocarzinostatin (NCS) linked to the thiol group on the hinge region of the Fab' fragment of GA-17, a murine monoclonal antibody reacting with tyrosine-specific phosphorylated antigens, which are exclusively expressed on the cell surface of human astrocytomas, was evaluated for in vivo activity. GA-17-NCS immunoconjugates significantly suppressed the growth of human malignant glioma cell line U87-MG subcutaneous xenografts in nude mice until day 50 when administered intravenously into the tail vein. Disulphide- and thioether-linked GA-17-NCS were nearly equipotent immunoconjugates, but thioether-linked GA-17-NCS was more effective than disulphide-linked conjugates with 250 U/kg NCS content on day 50 (P < 0.05). Thioether-linked GA-17-NCS was significantly more effective on day 50 than free NCS with 500 U/kg or 250 U/kg NCS content (P < 0.05, P < 0.01, respectively). These results suggest that GA-17-NCS may prove useful in the treatment of human malignant gliomas.

Human T cell L-plastin bundles actin filaments in a calcium-dependent manner

The amino acid sequences deduced from cDNA analyses revealed that human leucocyte L-plastin phosphorylated in response to interleukin 1, 2 closely resembles a chicken intestinal microvilli protein, fimbrin, that bundles actin filaments [de Arruda et al. (1990) J. Cell Biol. 111, 1069-1079]. In the present work, it was observed that unphosphorylated L-plastin isolated from human T cells bundled F-actin just as fimbrin does. L-Plastin acted on T cell beta-actin, but hardly acted on muscle alpha-actin or chicken gizzard gamma-actin, whereas fimbrin bundled muscle alpha-actin. Unlike fimbrin, L-plastin's actin-bundling action was strictly calcium-dependent: the bundles were formed at pCa 7, but not at pCa 6. Under suitable conditions, approximately one molecule of L-plastin bound to 8 molecules of actin monomer in the actin filament.

Mechanism of interferon gamma-induced protection of human gliosarcoma cells from lymphokine-activated killer lysis: division of lymphokine-activated killer cells into natural killer- and T-like cells

The mechanism by which interferon gamma (IFN-gamma) decreases the susceptibility of the established cultured gliosarcoma line Gl-1 to lymphokine-activated killer (LAK) lysis was analyzed. The results of monolayer depletion and lectin-dependent cellular cytotoxicity assays by LAK cells revealed that the resistance to LAK lysis of IFN-gamma-treated Gl-1 cells is manifested at the stage of LAK cell target recognition alone. We have also divided LAK cells into populations of phenotypically natural killer (NK)- and T-like cells with monoclonal antibodies and complement, respectively. We have used these cells to examine the mechanism of IFN-gamma-induced protection of Gl-1 cells from LAK lysis in cold target inhibition, monolayer depletion, and direct binding assays. The results revealed that NK-like cells do not recognize IFN-gamma-treated Gl-1 cells as efficiently as they do untreated targets, whereas T-like cells show the opposite tendency. In conclusion, we have demonstrated that the IFN-gamma induced protection of tumor cells from LAK lysis is predominantly regulated by the target recognition of NK-like cells. On the other hand, IFN-gamma-treated tumor cells may bind to T-like cells but fail to trigger them to initiate further stages for lysis as effectively as NK-like cells.

Polyclonal and monoclonal antibodies monospecific to MMTV LTR orf protein produced in E. coli

Monoclonal and polyclonal antibodies specific to an open reading frame of the mouse mammary tumor virus long terminal repeat were generated using an open reading frame-beta-galactosidase fusion protein produced in E. coli. Both antibodies reacted with the open reading frame-beta-galactosidase fusion protein but not with beta-galactosidase alone using an immunoblotting technique. It is concluded that these antibodies were specific for the protein encoded by the open reading frame of the mouse mammary tumor virus long terminal repeat.

Glial fibrillary tangles with straight tubules in the brains of patients with progressive supranuclear palsy

A recent report has described the appearance of silver positive, tau-immunoreactive astrocytes in the brains of patients with progressive supranuclear palsy (PSP) (Neurosci. Lett., 135 (1992) 99-102). In this study we confirmed this finding in two cases of PSP by using Bodian silver staining and immunohistochemistry with antibody to human tau protein. By electron microscopy we demonstrated that fibrillary masses present in these unique astrocytes were made up of straight tubules that were indistinguishable from those of neurofibrillary tangles of PSP. The term 'glial fibrillary tangle' was proposed for these structures.

A morphological and ultrastructural investigation of normal mouse brain tissue after intracerebral injection of tumor necrosis factor

Morphological and ultrastructural changes in normal mouse brain tissue were investigated after intracerebral stereotactic injections of tumor necrosis factor (specific activity: 2.0 x 10(6) U/mg protein) into the right frontal lobe. The mice received either a single infusion or multiple tumor necrosis factor infusions in three different dose groups (10, 100, or 500 U). Compared with sham-treated control mice that received adjusted intracerebral injections of purified albumin, the tumor necrosis factor-treated mice in all dose groups did not show any specific in vivo behavioral abnormalities during the 2 months of study following the infusions. Histological studies revealed hemorrhage attributable to the mechanics of the intracerebral infusions, a thickening of the arachnoid membranes, a reactive gliosis, and neutrophilic and/or mononuclear cell infiltration along the infusion pathway. A local neutrophilic response was prominent 1 day after tumor necrosis factor injection. An immunohistochemical analysis indicated that the mononuclear cell infiltration consisted of lymphocytes and macrophages. Except for the transient neutrophilic infiltration, these histological alterations did not differ from those seen in the sham-treated control groups, and most nonspecific reactive changes disappeared within 8 weeks after the injections. Furthermore, an ultrastructural study showed no apparent pathological changes in the cytoplasmic organelles of neuronal, glial, and endothelial cells in the tumor necrosis factor-injected mouse specimens. These results suggest that the tumor necrosis factor injections caused no specific toxicity and did not alter the parenchymal and stromal cells comprising normal mouse brain tissue.

Tumor accumulation of novel RES-avoiding liposomes

For passive targeting of liposomes to tumor tissues, we earlier developed reticuloendothelial system (RES)-avoiding liposomes modified with a uronic acid derivative, palmityl-D-glucuronide (PGlcUA) (Namba, Y., Sakakibara, T., Masada, M., Ito, F. and Oku, N. (1990) Chem. Pharm. Bull. 38, 1663-1666). In this present study, we examined the blood clearance and biodistribution of PGlcUA-liposomes (dipalmitoylphosphatidylcholine/cholesterol/PGlcUA = 40:40:20 as a molar ratio) in normal and tumor-bearing mice. Liposomes containing dipalmitoylphosphatidylglycerol (DPPG) instead of PGlcUA was also examined as a control. When [3H]inulin-encapsulated PGlcUA-liposomes and DPPG-liposomes were intravenously injected into normal mice, approx. 50% of the 3H radioactivity was recovered from the liver, the bulk of RES, at 12 h after administration of DPPG-liposomes, while only approx. 20% of it was found there when PGlcUA-liposomes were administered. Radioactivity remaining in the plasma at 12 h after injection was 5-fold higher when PGlcUA-liposomes were injected than when DPPG-liposomes were used. Biodistribution of liposomes in tumor-bearing mice was also examined. Mice were inoculated with 10(7) S180 cells into the hind leg. After 1 week, liposomes were injected. Radioactivity of [3H]inulin originally encapsulated in the PGlcUA-liposomes accumulated in the tumor to an extent 3-4-fold higher than that of the marker in DPPG-liposomes. Liver/tumor ratio of the radioactivity was 12 for DPPG-liposomes and only 2 for PGlcUA-liposomes. This latter value is the lowest of various liposome formulations ever reported.

Human glioma-specific antigens detected by monoclonal antibodies

Three murine monoclonal antibodies, designated GA-17, GB-4, and GC-3, were prepared by the hybridization of murine myeloma cells (NS-1) and spleen cells of BALB/c mice immunized with the crude membrane fraction of cultured human gliosarcoma cells (GI-1). Two of them (GA-17 and GB-4) reacted exclusively with the membrane of glioma cells, and the other (GC-3) reacted with the membrane of glioma cells and a T cell line (MOLT-4). Although these antibodies reacted with almost all of the gliomas, the reactions differed. GA-17 reacted equally well with all glioblastoma (17 cases) and low-grade astrocytoma (10 cases), whereas GB-4 reacted poorly with 7 cases of glioblastoma and GC-3 did not react with 7 cases of low-grade astrocytoma. The antigens, exclusively expressed on the cell surface, were analyzed by surface labeling with 125I followed by a cell lysis and immunoprecipitation with these antibodies. The findings obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that GA-17, GB-4, and GC-3 reacted with Mr 140,000-145,000, Mr 160,000, and Mr 145,000-150,000 proteins, respectively. Some evidence has been obtained indicating that these antigens are composed of the same polypeptide chain (Mr 120,000) with the carbohydrate chains being different.

Apolipoprotein B immunoreactivity in senile plaque and vascular amyloids and neurofibrillary tangles in the brains of patients with Alzheimer's disease

Based upon our previous finding of the association of apolipoprotein E (apoE) immunoreactivity with cerebral amyloids and neurofibrillary tangles (NFTs), we examined immunohistochemically whether this is also the case for apolipoprotein B (apoB). Polyclonal antibody to apoB immunosustained senile plaque amyloid, vascular amyloid, subpial amyloid deposits and intracellular NFTs in formalin-fixed, paraffin-embedded brain sections from patients with Alzheimer disease. Hydrated autoclave pretreatment of the sections enhanced the staining of plaque amyloid. The results may suggest a role of apoB in amyloid and NFT formation.

Alzheimer's disease beta-amyloid precursor protein in rat neural cells in culture

Immunochemical studies were performed on Alzheimer's beta-amyloid precursor protein (APP) in rat brain and cultured rat neural cells. Multiple APP subtypes were detected on immunoblots of brain homogenate with several antisera specific for subsequences of APP. In rat neural cell cultures, it was demonstrated that the composition of APP subtypes differed among cell types and subcellular fractions, and that APP subtypes in PC12h cells varied in their heparin binding affinity, suggesting distinct functional roles for different APP subtypes. Compatible with the possible role of APP in cell-matrix interaction, an increase in oligodendroglial APP was observed following their attachment onto poly-L-lysine substratum.