Localization of calcineurin in the mature and developing retina

We studied the localization of calcineurin by immunoblotting analysis and immunohistochemistry as a first step in clarifying the role of calcineurin in the retina. Rat, bovine, and human retinal tissues were examined with subtype-nonspecific and subtype-specific antibodies for the A alpha and A beta isoforms of its catalytic subunit. In mature retinas of the three species, calcineurin was localized mainly in the cell bodies of ganglion cells and the cells in the inner nuclear layer, in which amacrine cells were distinctively positive. The calcineurin A alpha and A beta isoforms were differentially localized in the nucleus and the cytoplasm of the ganglion cell, respectively. Calcineurin was also present in developing rat retinas, in which the ganglion cells were consistently positive for it. The presence of calcineurin across mammalian species and regardless of age shown in the present study may reflect its importance in visual function and retinal development, although its function in the retina has not yet been clarified. (J Histochem Cytochem 49:187-195, 2001)

Occurrence of a transcription factor, signal transducer and activators of transcription 3 (Stat3), in the postsynaptic density of the rat brain

Distribution of a signal transducer and activators of transcription 3 (Stat3) was examined in the rat brain. Immunoreactivity was distributed in the neurons, as well as glia cells, throughout the rat brain. Western blotting of subcellular fractions showed distribution in the synaptic fractions (synaptosome, synaptic plasma membrane, and postsynaptic density, PSD). The occurrence of Stat3 in the synaptic site, especially in the PSD, was confirmed by immunoelectron microscopic examination. The PSD fraction had an activity that phosphorylated Stat3 at the tyrosine-705 site, which was confirmed by both Western blotting and immunoprecipitation. The PSD fraction also had a janus kinase 2 (Jak2)-like molecule, Jak2, believed to phosphorylate Stat3. These results indicate that the Jak2/Stat3 signaling system, a major pathway of cytokine signaling in the immune response system, may also play a role at the postsynaptic sites.

Sex-dependent regulation of hepatic peroxisome proliferation in mice by trichloroethylene via peroxisome proliferator-activated receptor alpha (PPARalpha)

The mechanism of trichloroethylene-induced liver peroxisome proliferation and the sex difference in response was investigated using wild-type Sv/129 and peroxisome proliferator-activated receptor alpha (PPARalpha)-null mice. Trichloroethylene treatment (0.75 g/kg for 2 weeks by gavage) resulted in liver peroxisome proliferation in wild-type mice, but not in PPARalpha-null mice, suggesting that trichloroethylene-induced peroxisome proliferation is primarily mediated by PPARalpha. No remarkable sex difference was observed in induction of peroxisome proliferation, as measured morphologically, but a markedly higher induction of several enzymes and PPARalpha protein and mRNA was found in males. On the other hand, trichloroethylene induced liver cytochrome P450 2E1, the principal enzyme responsible for metabolizing trichloroethylene to chloral hydrate, only in males, which resulted in similar expression levels in both sexes after the treatment. Trichloroethylene influenced neither the level of catalase, an enzyme involved in the reduction of oxidative stress, nor aldehyde dehydrogenase, the main enzyme catalyzing the conversion to trichloroacetic acid. These results suggest that trichloroethylene treatment causes a male-specific PPARalpha-dependent increase in cellular oxidative stress.

Quantification of protein A-gold staining for peroxisomal enzymes by confocal laser scanning microscopy

The protein A-gold technique has been widely applied for visual localization and quantification of various antigens by electron microscopy. Observation of specimens stained by the protein A-gold technique with conventional light microscopy is difficult because of insufficient sensitivity of the staining. Light microscopic visualization and quantification of the reaction products were attempted employing a confocal laser scanning microscope (CLSM). Liver tissues of normal and peroxisome proliferator-treated rats were fixed and embedded in Lowicryl K4M resin. Ultrathin and thin sections were stained for catalase and a peroxisome-specific beta-oxidation enzyme by the protein A-gold technique. Ultrathin sections were observed by electron microscopy and the labeling density for each enzyme was analyzed with an image analyzer. Thin sections were observed with a CLSM in the reflection mode and the intensity of the light reflection was analyzed under the same conditions for all specimens. A comparison of these two observation procedures was also attempted using liver tissues stained with various concentrations of the antibody for catalase. The intensity of the reflection for each, as observed by CLSM, correlated well with the labeling density observed by electron microscopy. CLSM made it possible to quantify and to directly observe protein A-gold staining at the light microscopic level.(J Histochem Cytochem 47:1343-1349, 1999)

Immunoelectron microscopy of peroxisomes employing the antibody for the SKL sequence PTS1 C-terminus common to peroxisomal enzymes

Immunohistochemistry employing a new hapten antibody that detects the SKL sequence and its variants of the PTS1 C-terminus of peroxisomal enzymes was attempted to visualize peroxisomes across species. Rabbits were immunized with the SKL sequence coupled with KLH, between which an arm molecule was interposed. IgG fractions of antisera were affinity-purified against the hapten and employed for immunochemical analyses and immunoelectron microscopy. The specificity of the antibody was examined by immunoblot analyses for various purified enzymes of rat liver peroxisomes and by dot-blot analyses inhibited by SKL peptide and its variants. Various animal and plant tissues were subjected to immunoelectron microscopy with the protein A-gold technique. The antibody reacted with various enzymes in the peroxisome with the SKL motif. The affinity of the antibody for tripeptides, which varied depending on their structures, was higher for SKL than for its variants. Hepatic and renal peroxisomes of vertebrates, peroxisomes in the fat body of an insect, and the cotyledon of a plant were visualized by immunoelectron microscopy. Immunohistochemistry employing this SKL antibody may provide specific staining that can detect peroxisomes across different species.

Three-dimensional structure of the micro-blood vessels in thyroid tumors analyzed by immunohistochemistry coupled with image analysis

The structure of micro-blood vessels, one of the most important factors influencing the tumor growth and tumor metastasis among histological types of thyroid malignancy, was analyzed immunochemically by staining tissues for platelet endothelial cell adhesion molecule-1 (PECAM-1). Human thyroid tumor tissue obtained at surgery, consisting of 18 cases of papillary carcinoma, 9 cases of follicular carcinoma, and 9 cases of anaplastic carcinoma were fixed in formalin solution, and paraffin sections were made. They were stained for PECAM-1 using the avidin-biotin complex (ABC) technique. The volume of the blood vessels and their three-dimensional (3D) structure were analyzed using an image analyzer. The volume ratios of blood vessels in thyroid tissues were: normal tissues, 1.10%; papillary carcinoma, 3.01%; follicular carcinoma, 8.13%; and anaplastic carcinoma, 0.91%. Ratios in malignant tumors were larger than in normal tissues, except for anaplastic carcinoma. The typical 3D structure of micro-blood vessels was histopathologically varied: branching tree-like blood vessels in papillary carcinomas; vessels of varied diameter surrounding follicle structure in follicular carcinomas; and simple and immature vessels in anaplastic carcinomas. The volume and 3D structure of micro-blood vessels in thyroid malignant tumors differed from those in normal tissues, and varied according to histological classification.

Rat peroxisome proliferator-activated receptors and brown adipose tissue function during cold acclimatization

Brown adipose tissue (BAT) hyperplasia is a fundamental physiological response to cold; it involves an acute phase of mitotic cell growth followed by a prolonged differentiation phase. Peroxisome proliferator-activated receptors (PPARs) are key regulators of fatty acid metabolism and adipocyte differentiation and may therefore mediate important metabolic changes during non-shivering thermogenesis. In the present study we have investigated PPAR mRNA expression in relation to peroxisome proliferation in rat BAT during cold acclimatization. By immunoelectron microscopy we show that the number of peroxisomes per cytoplasmic volume and acyl-CoA oxidase immunolabeling density remained constant (thus increasing in parallel with tissue mass and cell number) during the initial proliferative phase and the acute thermogenic response but increased after 14 days of cold exposure, correlating with terminal differentiation of BAT. A pronounced decrease in BAT PPARalpha and PPARgamma mRNA levels was found within hours of exposure to cold, which was reversed after 14 days, suggesting a role for either or both of these subtypes in the proliferation and induction of peroxisomes and peroxisomal beta-oxidation enzymes. In contrast, PPARdelta mRNA levels increased progressively during cold exposure. Transactivation assays in HIB 1B and HEK-293 cells demonstrated an adrenergic stimulation of peroxisome proliferator response element reporter activity via PPAR, establishing a role for these nuclear receptors in hormonal regulation of gene transcription in BAT.

Peroxisomal and mitochondrial fatty acid beta-oxidation in mice nullizygous for both peroxisome proliferator-activated receptor alpha and peroxisomal fatty acyl-CoA oxidase. Genotype correlation with fatty liver phenotype

Fatty acid beta-oxidation occurs in both mitochondria and peroxisomes. Long chain fatty acids are also metabolized by the cytochrome P450 CYP4A omega-oxidation enzymes to toxic dicarboxylic acids (DCAs) that serve as substrates for peroxisomal beta-oxidation. Synthetic peroxisome proliferators interact with peroxisome proliferator activated receptor alpha (PPARalpha) to transcriptionally activate genes that participate in peroxisomal, microsomal, and mitochondrial fatty acid oxidation. Mice lacking PPARalpha (PPARalpha-/-) fail to respond to the inductive effects of peroxisome proliferators, whereas those lacking fatty acyl-CoA oxidase (AOX-/-), the first enzyme of the peroxisomal beta-oxidation system, exhibit extensive microvesicular steatohepatitis, leading to hepatocellular regeneration and massive peroxisome proliferation, implying sustained activation of PPARalpha by natural ligands. We now report that mice nullizygous for both PPARalpha and AOX (PPARalpha-/- AOX-/-) failed to exhibit spontaneous peroxisome proliferation and induction of PPARalpha-regulated genes by biological ligands unmetabolized in the absence of AOX. In AOX-/- mice, the hyperactivity of PPARalpha enhances the severity of steatosis by inducing CYP4A family proteins that generate DCAs and since they are not metabolized in the absence of peroxisomal beta-oxidation, they damage mitochondria leading to steatosis. Blunting of microvesicular steatosis, which is restricted to few liver cells in periportal regions in PPARalpha-/- AOX-/- mice, suggests a role for PPARalpha-induced genes, especially members of CYP4A family, in determining the severity of steatosis in livers with defective peroxisomal beta-oxidation. In age-matched PPARalpha-/- mice, a decrease in constitutive mitochondrial beta-oxidation with intact constitutive peroxisomal beta-oxidation system contributes to large droplet fatty change that is restricted to centrilobular hepatocytes. These data define a critical role for both PPARalpha and AOX in hepatic lipid metabolism and in the pathogenesis of specific fatty liver phenotype.

Absence of spontaneous peroxisome proliferation in enoyl-CoA Hydratase/L-3-hydroxyacyl-CoA dehydrogenase-deficient mouse liver. Further support for the role of fatty acyl CoA oxidase in PPARalpha ligand metabolism

Peroxisomes contain a classical L-hydroxy-specific peroxisome proliferator-inducible beta-oxidation system and also a second noninducible D-hydroxy-specific beta-oxidation system. We previously generated mice lacking fatty acyl-CoA oxidase (AOX), the first enzyme of the L-hydroxy-specific classical beta-oxidation system; these AOX-/- mice exhibited sustained activation of peroxisome proliferator-activated receptor alpha (PPARalpha), resulting in profound spontaneous peroxisome proliferation in liver cells. These observations implied that AOX is responsible for the metabolic degradation of PPARalpha ligands. In this study, the function of enoyl-CoA hydratase/L-3-hydroxyacyl-CoA dehydrogenase (L-PBE), the second enzyme of this peroxisomal beta-oxidation system, was investigated by disrupting its gene. Mutant mice (L-PBE-/-) were viable and fertile and exhibited no detectable gross phenotypic defects. L-PBE-/- mice showed no hepatic steatosis and manifested no spontaneous peroxisome proliferation, unlike that encountered in livers of mice deficient in AOX. These results indicate that disruption of classical peroxisomal fatty acid beta-oxidation system distal to AOX step does not interfere with the inactivation of endogenous ligands of PPARalpha, further confirming that the AOX gene is indispensable for the physiological regulation of this receptor. The absence of appreciable changes in lipid metabolism also indicates that enoyl-CoAs, generated in the classical system in L-PBE-/- mice are diverted to D-hydroxy-specific system for metabolism by D-PBE. When challenged with a peroxisome proliferator, L-PBE-/- mice showed increases in the levels of hepatic mRNAs and proteins that are regulated by PPARalpha except for appreciable blunting of peroxisome proliferative response as compared with that observed in hepatocytes of wild type mice similarly treated. This blunting of peroxisome proliferative response is attributed to the absence of L-PBE protein in L-PBE-/- mouse liver, because all other proteins are induced essentially to the same extent in both wild type and L-PBE-/- mice.

Prenatal diagnosis of peroxisomal D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein deficiency

The prenatal diagnosis of peroxisomal D-3-hydroxyacyl-coenzyme A (CoA) dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein (D-BP) deficiency was performed by peroxisomal beta-oxidation assay, indirect immunofluorescence staining, immunoblot analysis, and gene analysis of cultured amniocytes obtained from a fetus at 16 weeks' gestational age. beta-Oxidation activity, measured by [1-14C] lignoceric acid oxidation, was markedly decreased compared with the controls. Large peroxisomes were readily identified by immunofluorescence staining with anti-human catalase, as was found in the reported patients. Immunoreactive D-BP material was absent on immunoblot analysis and immunofluorescence staining with anti-human D-BP. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis revealed the presence of the same 237-bp deletion in the cDNA as that detected in a sibling (the proband). The autopsied fetus showed the characteristic facial appearance and D-BP was deficient on immunoblot and immunohistopathological studies of the fetal tissues. No neuronal migration disorder was identified. This seems to be the first prenatal diagnosis of D-BP deficiency.

Presence of molecular chaperones, heat shock cognate (Hsc) 70 and heat shock proteins (Hsp) 40, in the postsynaptic structures of rat brain

The synaptic localization of molecular chaperones, heat shock cognate protein 70 (Hsc70) and Hsp40, was investigated immunohistochemically in the normal rat brain. Postsynaptic density (PSD) fractions contained a constitutive form of HSP70, heat shock cognate protein 70 (Hsc70 or p73) but not inducible form of HSP70 (p72). The immunoreactivities of Hsc70 (p73) were distributed throughout the rat brain, in neuronal somata, dendrites and axons. Their immunoreactivity in neurons was localized in the cytoplasmic matrix, dendrites, and spines at the electron microscopic level. Presynaptic terminals, but less frequently than postsynaptic staining, were also reactive. Postsynaptic areas immediately beneath the synaptic contact or PSDs were immunoreactive for Hsc70. The Hsp40 was highly concentrated in PSD fractions. The staining of Hsp40 immunoreactivity was punctate and distributed widely in the brain. Hsp40 immunoreactivity was localized in dendritic spines, especially in the subsynaptic web, with weak staining of PSDs at the electron microscopic level. Double immunofluorescent staining and confocal microscopy revealed that Hsc70 and Hsp40 were co-localized on somata and neuronal processes of cultured cerebral neurons, on which synaptophysin immunoreactive spots were scattered. These results suggest that Hsp40 and Hsc70 are co-localized at postsynaptic sites and postsynaptic chaperone activity may be mediated by these two heat shock proteins.

Immunohistochemical localization of taurine in various tissues of the mouse

The localization of taurine was investigated in several tissues of the mouse. Immunohistochemical methods using a polyclonal antibody for taurine derived from rabbits was used in these studies. This method was used since it is a simple procedure and the results are clear and reliable. Tissues were fixed with paraformaldehyde, embedded in paraffin and treated in a microwave oven before using an avidin-biotin-complex method (ABC method). Control staining was accomplished by employing absorption staining using various amino acids: taurine, arginine, cysteine, hypotaurine and others. For purposes of comparison, radioautography (RAG) with 3H-taurine was performed to confirm the reliability of the immunohistochemical staining compared with the localization of the 3H-taurine incorporation in endothelial cells of the blood vessels of several tissues. In this investigation, immunoreactivity was broadly observed in many tissues: Purkinje cells of the cerebellum, glia cells of brain tissue, cardiac muscle cells, matrices of the bone, mucus granules of goblet cells of the intestines, and brown adipose cells of the fetus. Although the meaning of this widespread localization of taurine can not be explained completely, we surmise that taurine may have a different function in each of the tissues. In addition, taurine reactivity was observed in cell nuclei which was evidence of the presence of taurine in the nuclei.

Occurrence of a transcription factor, cAMP response element-binding protein (CREB), in the postsynaptic sites of the brain

The postsynaptic density (PSD) fraction prepared from the rat forebrain contained a transcription factor, cAMP response element-binding protein (CREB). The occurrence of CREB in the PSD was confirmed by immunoelectron microscopic examination. CREB in the PSD fraction was phosphorylated both by protein kinase A and Ca2+/calmodulin-dependent protein kinase II (CaMKII) endogenous to the fraction, and dissociated from the PSD after phosphorylation, especially under CaMKII-activated conditions. The fraction containing CREB that was released from PSD after phosphorylation possessed cAMP response element (CRE)-binding activity. Thus, PSD anchors functionally active CREB. These results suggest that CREB anchored to the PSD is liberated by phosphorylation upon specific synaptic stimulation, translocates into the nucleus, and then triggers synaptic activity-dependent changes in gene expression.

Immunohistochemical localization of peroxisomal enzymes in developing rat kidney tissues

We studied the developmental changes in the localization of peroxisome-specific enzymes in rat kidney tissues from embryonic Day 16 to postnatal Week 10 by immunoblot analysis and immunohistochemistry, using antibodies for the peroxisomal enzymes catalase, d-amino acid oxidase, l-alpha-hydroxyacid oxidase (isozyme B), and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase bifunctional protein. Peroxisomal enzymes were detected in the neonatal kidney by immunoblot analysis and their amount increased with kidney development. By light microscopic immunohistochemistry, they were first localized in a few proximal tubules in the juxtamedullary cortex of 18-day embryos. The distribution of proximal tubules positive for them expanded towards the superficial cortex with development. The full thickness of the cortex became positive for the staining by 14 days after birth. Peroxisomes could be detected by electron microscopy in structurally immature proximal tubules in 18-day embryos. Their size increased and the ultrastructure of subcompartments became clear with continuing development of proximal tubules. These results show that peroxisomal enzymes appear in the immature proximal tubules in the kidney of embryos and that the ultrastructure of the peroxisomes and localization of the peroxisomal enzymes develop along with the maturation of proximal tubules and kidney tissues.

Ultrastructural and immunohistochemical analysis of biopsy-proven chronic active mycocarditis with numerous clusters of lymphocytes

A 60-year-old women was admitted to our hospital with deteriorating congestive heart failure. Although the diagnosis of active myocarditis was confirmed by right ventricular endomyocardial biopsy, this patient died of refractory heart failure during corticosteroid treatment. Numerous lymphocytic clusters were observed microscopically in the heart at autopsy. Most of the infiltrating cells in the clusters were positive for CD 8, HAM 56 or MHC class 2 antigen; few cells were positive for CD 56. Expression of perforin was found in some of the infiltrating cells. Electron microscopic examination revealed small lymphocytes adhering to the surface of injured cardiac myocytes. Close contact of these lymphocytes to macrophages was shown in the clusters. ICAM-1 and MHC class 1 antigens were strongly expressed in the cardiac tissue. These results indicate that cytotoxic T lymphocyte-mediated cytotoxicity had continued to operate during immunosuppressive therapy. Corticosteroids may not be suitable for the treatment of chronic active myocarditis when persistent expression of ICAM-1 is observed.

Steatohepatitis, spontaneous peroxisome proliferation and liver tumors in mice lacking peroxisomal fatty acyl-CoA oxidase. Implications for peroxisome proliferator-activated receptor alpha natural ligand metabolism

Peroxisomal beta-oxidation system consists of four consecutive reactions to preferentially metabolize very long chain fatty acids. The first step of this system, catalyzed by acyl-CoA oxidase (AOX), converts fatty acyl-CoA to 2-trans-enoyl-CoA. Herein, we show that mice deficient in AOX exhibit steatohepatitis, increased hepatic H2O2 levels, and hepatocellular regeneration, leading to a complete reversal of fatty change by 6 to 8 months of age. The liver of AOX-/- mice with regenerated hepatocytes displays profound generalized spontaneous peroxisome proliferation and increased mRNA levels of genes that are regulated by peroxisome proliferator-activated receptor alpha (PPARalpha). Hepatic adenomas and carcinomas develop in AOX-/- mice by 15 months of age due to sustained activation of PPARalpha. These observations implicate acyl-CoA and other putative substrates for AOX, as biological ligands for PPARalpha; thus, a normal AOX gene is indispensable for the physiological regulation of PPARalpha.

Molecular cloning and characterization of a mitochondrial peroxisome proliferator-induced acyl-CoA thioesterase from rat liver

We have previously reported the purification and characterization of the peroxisome proliferator-induced very-long-chain acyl-CoA thioesterase (MTE-I) from rat liver mitochondria [L.T. Svensson, S.E. H. Alexson and J.K. Hiltunen (1995) J. Biol. Chem. 270, 12177-12183]. Here we describe the cloning of the corresponding cDNA. One full-length clone was isolated that contained an open reading frame of 1359 bp encoding a polypeptide with a calculated molecular mass of 49707 Da. The deduced amino acid sequence contains a putative mitochondrial leader peptide of 42 residues. Expression of the cDNA in Chinese hamster ovary cells, followed by immunofluorescence, immunoelectron microscopy and Western blot analyses, showed that the product was targeted to mitochondria and processed to a mature protein of 45 kDa, which is similar to the molecular mass of the protein isolated from rat liver mitochondria. The recombinant enzyme showed the same acyl-CoA chain-length specificity as the isolated rat liver enzyme. Sequence analysis showed no similarity to known esterases, but a high degree (approx. 40%) of identity with bile acid-CoA:amino acid N-acyltransferase cloned from human and rat liver. A putative active-site serine motif (Gly-Xaa-Ser-Xaa-Gly) of several carboxylesterases and lipases was identified. Western and Northern blot analyses showed that MTE-I is constitutively expressed in heart and is strongly induced in liver by feeding rats with di(2-ethylhexyl)phthalate, a peroxisome proliferator, suggesting a role for the enzyme in lipid metabolism.

Immunohistochemical expression of bcl-2 protein in squamous cell carcinoma and basaloid carcinoma of the esophagus

In the present study, the expression of bcl-2 protein in esophageal squamous cell carcinoma (SCC) and basaloid carcinoma (BC) was immunohistochemically examined, and its relation to tumor progression and postoperative survival was determined in SCC. A total of 42 SCC and 4 BC tumor samples were fixed with formalin, embedded in paraffin, and stained using monoclonal bcl-2 protein antibody, clone 124. Immunoreactivity was semiquantitatively scored, and the staining results were compared with the pathologic features and survival rates. The cytoplasm of basal cells from the normal esophageal epithelium was stained. In some well- and moderately differentiated SCCs, bcl-2 protein-positive reaction was observed in the peripheral part of the tumor cord, but in poorly differentiated SCC, the cells were weakly or hardly stained. However, in BC, the cells were strongly stained. The immunoreactivity was positive in 45.2% of the SCCs and all of the BCs. There were no significant differences in pathological features or patient survival between the bcl-2 protein-positive and protein-negative SCCs. In conclusion, the expression was not related to tumor progression and had no prognostic significance in SCC. Conversely, BC had strong immunohistochemical expression, probably associated with the differentiation of carcinoma cells simulating the basal cells of the esophagus.

Therapeutic efficacy of the angiogenesis inhibitor O-(chloroacetyl-carbamoyl) fumagillol (TNP-470; AGM-1470) for human anaplastic thyroid carcinoma in nude mice

TNP-470 (AGM-1470), a synthetic analog of fumagillin (6-chloroacetyl-carbamoyloxy-4-(1,2-epoxy-1,5-dimethyl- 4-hexenyl)-5-methoxy-1-oxaspiro [2,5] octane 1, has been reported to reduce the supply of nutrients to experimental tumors by inhibiting angiogenesis. In this study, we investigated anti-tumor activity of TNP-470 against human thyroid anaplastic carcinoma with a view to developing a new treatment for this thyroid tumor. A transplantable tumor was established from thyroid anaplastic carcinoma of a 78-year-old woman, as a xenograft in nude mice (BALB/c, nu/nu, male). This transplantable tumor, with chromosomal abnormality was shown to be non-functional in excretory hormones and to preserve morphological characteristics of the original anaplastic tumor tissue. TNP-470 was given at a dose of 50 mg/kg b.w. to nude mice transplanted with human thyroid anaplastic carcinoma by different routes of administration: intratumoral, peritumoral, subcutaneous and intraperitoneal. Intratumoral and peritumoral administration were effective, and especially the TNP-470 administered by the former route completely inhibited tumor growth. Immunohistochemical analysis using anti-factor VIII antibody revealed the density of microvessels to be significantly decreased by local administration of TNP-470 (intratumoral administration, 7.8 +/- 2.9/mm2, control, 27.0 +/- 6.3/mm2; peritumoral administration, 9.7 +/- 2.6/mm2, control, 21.1 +/- 5.1/mm2). Our findings suggested the possibility of clinical application of TNP-470 to control the growth of human anaplastic thyroid carcinoma.

Electron microscopic immunohistochemistry of ocular and extraocular pseudoexfoliative material

To investigate the nature of extraocular pseudoexfoliative (PSX) material, and to validate the hypothesis that the PSX syndrome is a systemic disorder, we studied the immunoreactivity of intraocular and extraocular PSX material from patients with the PSX syndrome using antibodies against proteins of extracellular matrices. Surgical specimens of four different tissues were obtained from human eyes with the PSX syndrome: nine trabecular tissues, three cataractous lenses, six bulbar conjunctivas, and seven lid skins. These tissues were processed for electron microscopic immunohistochemistry, and stained with antibodies against vitronectin, fibronectin, laminin, and elastin, by an indirect immunogold procedure. Density of the gold particles located on the PSX material was estimated by video image analysis. Statistical analysis of the data revealed that the PSX material from trabecular tissues, lenses, bulbar conjunctivas, and lid skins had almost identical immunoreactivity to the antibodies studied. PSX materials of trabecular tissues, lenses, bulbar conjunctivas, and lid skins were found to have not only a similar ultrastructure, but also almost identical immunohistochemical characteristics. These results support the hypothesis that the PSX syndrome is a systemic disorder.

Immunohistochemical studies of vascular volume and proliferative activity in squamous cell carcinoma of the esophagus

For immunohistochemical investigation and clarification of the relationship between the vascular volume in esophageal carcinoma and the proliferative activity of its tumor cells, we examined surgical specimens of squamous cell carcinoma (SCC) of the esophagus from 15 patients. The vascular volume was evaluated by immunostaining for platelet-endothelial cell adhesion molecule-1 with monoclonal antibody JC70, and the proliferative activity of the carcinoma cells was evaluated by immunostaining for proliferating cell nuclear antigen (PCNA) with antibody 19A2. The ratio of the vascular area to the tumor area and the labeling index (LI) for PCNA in the carcinoma cells was then calculated. The antibody JC70 was useful for immunohistochemically detecting blood microvessels in esophageal carcinoma. The vascular volume, expressed as the ratio mentioned above, was higher in well- and moderately differentiated SCCs than in poorly differentiated SCC (P < 0.01), and the PCNA LI did not depend on the degree of differentiation. However, there was a significantly inverse relationship between the ratio of the vascular area to that of carcinoma and the PCNA LI of the carcinoma cells (P < 0.01). These findings show that angiogenesis is greater in esophageal carcinomas with little proliferative activity.