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The dermal histology and the regional draining superficial lymph node of a new mutant strain of hairless rats (ISh) were investigated. The homozygote ISh rat was characterized as having naked and wrinkled skin. The comedo-like cysts in the skin resembled human acne and vulgaris. Histopathologically, many Langerhans' cells positive for anti-protein kinase C type II antibody (PKC-II) were recognized in the epidermis. The superficial lymph nodes were significantly larger than those of the heterozygote. The paracortex of these lymph nodes was expanded and the number of Langerhans' cells mainly increased in these areas. These lymph node lesions were similar to those of human dermatopathic lymphadenopathy. The ISh rats should be a very useful animal model for studying dermatopathic lymphadenopathy in humans. Furthermore, they may be a valuable animal model for investigating the mechanisms of not only maturation, movement and migration of Langerhans' cells, but also of their function for antigen presentation.

Although the presence of nuclear grooving in papillary carcinomas of the thyroid has been well-described, so far the attention paid to similar structures in endometrial cell samples has been limited. In order to investigate the occurrence of nuclear grooves in endometrial specimens from patients with various pathologic conditions of the endometrium, we compared their appearance with papillary thyroid cancers. A total of 10 cases was studied (age range, 40-72 yr), all cases demonstrating nuclear grooves. In each case, 10 random high-power fields (HPFs) were investigated, and the numbers of fields in which nuclear grooving could be seen were recorded. Nuclear grooves were observed in 3-36 of each HPFs and were more often observed in atypical endometrial cells than in their normal-appearing counterparts; however, these nuclear alterations were thought to be nonspecific findings.

Rat interferon beta (IFN beta) was cloned from a part of rat genomic DNA by the polymerase chain reaction (PCR) with reference to the nucleotide sequence data of a mouse IFN beta. The sequence result showed that the clone had 555 bp of open reading frame (ORF) which encoded a 184-amino acid polypeptide. Comparison of our data with those of mouse and human IFN beta revealed 86.7 and 67.6% homology at the nucleotide level, and 76.2 and 48.9% homology at the amino acid level, respectively. This ORF was inserted into an expression vector, pCAGGS, and COS-1 cells were then transfected with the plasmid encapsulated in cationic multilamellar liposomes. From the results of reverse transcription-PCR and cytopathic activity assay, this ORF expressed IFN beta in COS-1 cells. When the cultured cells of rat glioma cell line T9 were transfected with the plasmid, their growth was markedly suppressed due to the expression of rat IFN beta.

Objective: To successively examine intranuclear inclusions and nuclear grooves in the same papillary thyroid cancer specimens using a light microscope (LM), scanning electron microscope (SEM) and transmission electron microscope (TEM)., Study Design: We stained cells by the Papanicolaou method after fixation in 1.25% glutaraldehyde for LM and then attempted to observe them successively by SEM-TEM after fixation in 2% paraformaldehyde and 2% osmium tetroxide., Results: On SEM, intranuclear inclusions were observed as elevated parts, like hills, and nuclear grooves were observed as deep fissures or shallow cracks, sometimes with a few in one cell. On TEM, both intranuclear inclusions and nuclear grooves seemed formed by the nuclear membranes. Intranuclear inclusions also possessed cytoplasm and/or cytoplasmic organelles within some expanded areas in the nuclear grooves., Conclusion: It was evident from our three-step technique that intranuclear inclusions and nuclear grooves were essentially the same structures.

In the present study, immunohistochemical and immuno-electron microscopic techniques were used to differentiate Langerhans cells (LC) from interdigitating cells (IDC) in the lymph nodes (LN) of dermatopathic lymphadenopathy. The majority of the dendritic cells that existed in the LN of dermatopathic lymphadenopathy were positive for OKT-6 (CD 1a) antibody. It was concluded that these dendritic cells were not IDC, but LC. Electron microscopically, LC in these LN contained a few Birbeck granules (BG). In order to prove the fact that these dendritic cells were LC, the existence of BG was investigated ultrastructurally by examining serial sections, and immunoelectron microscopically for CD 1a positive cells. Most of the LC in the lymph nodes we examined were negative for the anti-proliferating nuclear antigen (PCNA) antibody. This finding may mean that LC in the LN are fully developed cells and do not divide in the LN. Langerhans cells may migrate from the skin lesions to the paracortical areas in the LN, which then may become enlarged.

The development of pyloric mucosal metaplasia (PMM) with regard to cellular differentiation in the human gallbladder was studied by mucin staining (paradoxical concanavalin A (Con A), galactose oxidase-Schiff (GOS) and alcian blue (pH 2.5) PAS (AB-PAS) and immunohistochemistry (pepsinogen II (PgII) and SH-9, and proliferating cell nuclear antigen (PCNA). PMM was divided into three stages of development by three-dimensional (3D) computer graphic reconstruction analysis. In the early stage, a transitional zone of PCNA positive cells was observed between areas of SH-9 and/or GOS reactive cells and class III and/or Pg II positive cells in flat monolayered epithelium. In the middle stage, shallow pits became apparent as areas enlarged, with these becoming deeper in the advanced stage, whereby SH-9 and/or GOS reactive cells and class III and/or Pg II positive cells were observed at the upper and lower portion of the pits, respectively, with PCNA-positive cells forming a narrow zone between the two cell populations. Consequently, the structure of PMM gradually resembles that of the normal gastric pyloric mucosa.

We report a familial case of macrothrombocytopenia without inclusion bodies in polymorphonuclear cells or any congenital abnormalities. The results of the hemostatic and platelet function tests were all normal except for the platelet retention rate. The number of megakaryocytes increased slightly and some were relatively small. Electron microscopic studies revealed a unique morphological abnormality of the platelets' mitochondria.

The present study shows that Langerhans cells can be differentiated from interdigitating cells at the light microscopic level. Superficial lymph nodes and skin taken from necropsies and the lymph nodes of dermatopathic lymphadenopathy (DPL) were used for this experiment. Sections of lymph node and skin were embedded using the acetone, methyl benzoate and xylene (AMeX) method and dendritic cells were immunostained with anti S-100 protein antibody (S-100, and OKT-6 (CD1a) using the restaining method. Langerhans cells in the skin were positive for both CD1a and S-100. Dendritic cells positive for both CD1a and S-100, and dendritic cells positive for S-100, but not for CD1a were observed in superficial lymph nodes. In normal superficial lymph nodes, there were more interdigitating cells than Langerhans cells. The majority of the dendritic cells in the DPL were Langerhans cells. We conclude that the S-100 and CD1a positive cells are Langerhans cells, and the S-100 positive-CD1a negative cells are interdigitating cells.

It was elucidated that the majority of DC were LC which were positive for CD 1a, but negative for PCNA, and possessed BG in the lymph nodes with DPL. On the other hand, HCX cells were almost always positive for PCNA. From this point of view, it can be speculated that LC in the lymph nodes of the DPL are non dividing mature cells and migrate from the skin lesion. HCX cells which were positive for CD 4 may be more immature cells than LC in DPL, and may be pathological cells which can divide in the foci.

The identification of cells in body cavities of cancer patients is sometimes difficult to make. In order to make a definite cytological diagnosis, we observed the same cells by using light microscopy (LM)-scanning electron microscopy (SEM)-transmission electron microscopy (TEM). In this study we first stained cells by the Papanicolaou method after fixation in 1% glutaraldehyde for LM, and then attempted to observe them successively by SEM-TEM after fixation in 1% paraformaldehyde and 1.25% OsO4. Our method and procedures in examining successively one and the same cells in body cavity fluids by using LM, SEM, and TEM ensured accurate discrimination among adenocarcinoma cells, mesothelial cells, and macrophages. The results of this study suggest that LM-SEM-TEM may be of diagnostic value in distinguishing among mesothelial cells, macrophages, and adenocarcinoma cells. This method also succeeded in disclosing differences between the ultrastructure of the cell surfaces, and those of the cytoplasm, and of the nuclei. It is desirable that LM-SEM-TEM observation can be introduced into various aspects in order to obtain an improvement in the diagnosis by cytologic examination, the judgment of therapeutical effects, drug selection, and prognostic presumption.

Double immunostaining for OKT-6 and S-100 protein antibodies was carried out. However, it was impossible to stain using two antibodies at the same time, or using one antibody prior to another. We first stained using FITC labeled OKT-6 antibody, and secondary stained for S-100 protein by the ABC method, after taking photographs and removing OKT-6 reaction products. The exact same cells could be stained by both OKT-6 and S-100 protein antibodies. It has been elucidated that both OKT-6 and S-100 protein positive cells are LCs, and only S-100 protein positive, but OKT-6 negative cells are IDCs. LCs only exist in the superficial and hilar lymph nodes. However IDCs exist not only in these lymph nodes, but also in the mesenteric lymph nodes and spleens.

LCs in the tracheal squamous metaplasia of vitamin A deficient rats were studied. The first appearance of LCs with Birbeck granules (BGs) was in the stage of stratification. The number of LCs increased along with the development of metaplasia, but decreased in number in the later stage, where basal cells also differentiate into flattened epithelium. In the area where only basal cells differentiated into flatter epithelium, without a cornified layer, LCs with BGs could also be found. These findings suggest that LCs which originate in bone marrow mature in squamous epithelium. The distribution and morphology of LCs are dependent on the state of keratinocytes, but not the presence of a cornified layer.

The migration and maturation of Langerhans cells (LCs) in rat tracheal squamous metaplasia due to vitamin A deficiency were investigated immunohistochemically and electron microscopically. In the early stage of metaplasia, i.e. basal cell hyperplasia, no LCs with Birbeck granules (BGs) could be found, but there were desmosome-free cells which had the morphological characteristic of immature LCs. They were clearly different from inflammatory cells such as macrophages and lymphocytes, and were, therefore, considered to be precursors of LCs. In the stage of stratification, small numbers of Ia- and protein kinase C type II (PKCII)-positive cells were recognized. Ultrastructurally they were immature LCs with ovoid nuclei, many free ribosomes and few dendrites. The cytoplasm was dark and a few BGs and atypical granules (AGs) could be seen in the Golgi area. In the early stage of cornification, LCs with partially intended nuclei, prominent nucleoli and well-developed Golgi complexes were found. There were many BGs and AGs and structures transitional between them in the Golgi areas. In epithelium showing mature squamous metaplasia, many Ia- and PKCII-positive dendritic cells could be seen. Most of these were typical mature LCs with lobulated nuclei, clear cytoplasm and prominent dendritic processes. The number of BGs and AGs were fewer than in the LCs found in the early stage of cornification, and these granules were distributed throughout the cytoplasm. In the final stage, where the basal cells had differentiated into a flatter epithelium, few LCs could be seen.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

A new mutant strain of inbred Sprague Dawley rats with autosomal recessive hyperbilirubinuria, were studied by biochemical, histologic, and ultrastructural methods. The plasma bilirubin concentration in the homozygote was significantly higher than that of the heterozygote, and about 80% of the bilirubin was conjugated. Plasma BSP and ICG clearance were both severely delayed in the homozygote. Plasma BSP elimination kinetics suggested that the pathophysiologic defect was not hepatic uptake or storage but rather in secretion into bile. Histopathology of the liver demonstrated brown pigment in the hepatocytes that appeared to be lipofuscin. The electron microscopic features of the hepatic pigment resembled those of the Dubin-Johnson syndrome. Homozygote histopathology also revealed glomerular lesions with mesangial expansion and proliferation in the kidneys. Immunohistologic studies disclosed mesangial granular deposition of IgG, IgA, and to a lesser degree, IgM and C3. These renal changes resembled those of IgA nephropathy. The spontaneous hyperbilirubinuric rat (EHBR) may be a useful animal model for studying constitutive conjugated hyperbilirubinemia, bilirubin metabolism, cholestasis, and glomerulonephropathy subsequent to hepatic dysfunction.

Cells immunostained with antibodies against both OKT-6 and S-100 protein were observed only in superficial and hilar lymph nodes draining tissues with predominantly squamous epithelia. In contrast, in mesenteric lymph nodes and the spleen, only S-100 protein-positive, but OKT-6-negative cells were found. We suspect that the S-100 and OKT-6-positive cells might be Langerhans cells (LC) and the S-100-positive, OKT-6-negative cells, interdigitating reticulum cells (IDC). We further postulate that the LC in superficial and hilar lymph nodes might migrate from squamous epithelia, with which contact is required for the formation of Birbeck granules.

A novel cultured cell line, NCU-L-1, was established from a 71-year-old Japanese woman with acute lymphoblastic leukemia, L3 FAB, Burkitt's type. The NCU-L-1 cells were shown to have a mature B-cell phenotype on the basis of immunologic surface marker analysis; including IgG Lambda surface immunoglobulins, CD19, CD20 and la-like antigen which were all detected on the cells. Intracytoplasmic immunoglobulin was not detected, but IgG was present in the cell culture supernatant. Cytogenetic studies revealed that the NCU-L-1 cells had t(2; 8) and an additional 14q+, a genotype which has not been identified previously in the usual Burkitt's cell lines. The NCU-L-1 cell line should prove to be useful for studying oncogenic events associated with the t(2; 8) translocation and karyotype evolution.

A new classification for non-Hodgkin's malignant lymphoma is proposed as the one suited for the Lymphomas in Japan, which is to provide a new subtype "pleomorphic" for those more or less rapid-growing lymphomas of peripheral T-cell nature, along with another subtype lymphoblastic, after Nathwani et al. for those of central T-cell nature. The proposal is based on the result of the investigation by the Study Group for Histopathological Diagnosis on Malignant Lymphoma that (1) the presence of a significant number of T-cell lymphomas with peculiar "pleomorphism" is responsible for the very low reproducibility rate of histopathological diagnosis on the diffuse, mixed L&H type of Rappaport classification, and (2) the relative incidence of lymphoms as peripheral T-cell nature including the so-called adult T-cell leukemia is much higher in Japan than in the Western countries.

In case of blast crisis of chronic myelocytic leukemia, the blast cells contained several kinds of normal hematopoietic cells. The peroxidase reaction was strongly positive in the neutrophilic granules of the engulfed neutrophils. These engulfed cells appeared to be normal and the limiting membranes of the engulfing cells seemed to be intact. We speculated therefore that this phenomenon might be emperipolesis. In a case of chronic myelocytic leukemia and a case of acute myelocytic leukemia, some megakaryoblasts showed the same phenomenon. These megakaryoblasts did not phagocytize latex particles. The limiting membranes of the engulfing megakaryoblasts were stained with ruthenium red but those of the engulfed hematopoietic cells were not stained. By phase microscopy, the engulfed cells were actively moving inside the megakaryoblasts and it was observed that the engulfed cells were actually living within the engulfing cells. These results demonstrated that this phenomenon was emperipolesis. Observations with an electron microscope and the phase microscope are indispensable for distinguishing emperipolesis from phagocytosis.

A case of thymic tumor, composed of both epithelial and myoid cells, was presented. The myoid cells occurred in clusters, and showed prominent proliferation between the nests of epithelial cells. The myoid cells had intracytoplasmic myofibrils, and there were foci of electron dense Z-lines along the course of these fibrils. Some of these cells possessed sarcomeres identical to those of striated-muscle cells. Histochemically, a significant amount of glycosaminoglycans was observed on the surface of the myoid cells.

The localization of Tac antigen in adult T-cell leukemia-associated antigen (ATLA)-positive lymphomas was studied ultrastructurally with the use of the immunoperoxidase technique. The antigen was observed on the plasma membranes of a portion of the characteristic cells with convoluted nuclei and a majority of the cells with less irregular nuclei, which were larger than the former. In addition, the cisternae of the rough endoplasmic reticulum, perinuclear cisternae, and Golgi cisternae of the latter cells were also positively stained with anti-Tac antibody. It is thought that the positive reaction of the plasma membranes may correspond to interleukin 2 (IL 2) receptors, the cytoplasmic and perinuclear reaction sites may well correspond to the precursor of IL 2 receptors, and Tac antigen may be produced in the cytoplasm of the ATLA-positive lymphoma cells.

A T-cell line, ATN-1, was established by culturing peripheral blood mononuclear cells derived from a patient with adult T-cell leukemia/lymphoma (ATL/L). Identities of the patterns of chromosomal abnormalities, cell surface phenotypes, morphologic findings, rearrangement patterns of T-cell receptor beta chain gene, and an integration site of human T-cell leukemia virus I proviral genome indicated that ATN-1 was derived from original leukemic cells. Both ATN-1 and the original leukemic cells showed a variety of patterns of chromosomal abnormalities that include 3q-, 6q-, rearrangements involving 2q31, 7q11.2, 8q11, 8q24, 19p13.3, and also 14q11 and 14q32, where genes for the T-cell receptor alpha chain and the immunoglobulin heavy chain are located. Availability of a genuine ATL/L cell line with these chromosomal abnormalities may greatly facilitate the biologic analysis of ATL/L.

Hepatitis B surface antigen (HBsAg) in epoxy-embedded liver tissues can be stained by aldehyde-fuchsin stain. Sections are oxidized in KMnO4 acidified with H2SO4, then bleached in NaHSO3, both at 70 C. Heating for oxidation and bleaching are absolutely necessary. Diluted aldehyde-fuchsin stain adjusted to pH 1.5 to 1.8 with NaOH is used for staining. HBsAg is specifically stained purple. Other components such as mitochondria and bile pigments are also strained, but are easily distinguished from HBsAg. This staining method is advantageous for the identification of HBsAg-positive cells for electron microscopic observation.

Several mitotic histiocytes containing Langerhans cell granules were found in the lymph nodes of Letterer-Siwe disease. Some histiocytes of Hand-Schüller-Christian disease contained Langerhans cell granules within the nuclei. These Langerhans cell granules were not in 'nuclear pseudo-inclusions,' but were freely scattered inside the nuclei. We suggest that the Langerhans cell granules may get trapped in the nucleus during mitosis, since several investigators have suggested that mitosis causes other intranuclear organelles to get trapped. We also speculate that cells containing Langerhans cell granules may divide and increase by mitosis.

Ultrastructural comparison between helper/inducer and suppressor/cytotoxic type cells in peripheral T-cell lymphomas was made using the immunoperoxidase technique. The nuclei of T4 positive cells were more irregular in outline than those of T8 positive cells, and nuclear irregularity was further pronounced in the cells of the adult T-cell leukemia/lymphoma which were of helper/inducer type cells. The suppressor/cytotoxic type cells possessed in their cytoplasm scattered dense bodies encircled by distinct membranes, although they also contained clustered dense bodies. On the other hand, the helper-inducer type cells had only clustered dense bodies. No other significant differences were observed regarding other cytoplasmic organelles between T4 positive cells and T8 positive cells. The existence of the peripheral T-cell lymphomas with "double-markers" which possessed surface antigens for both helper/inducer and suppressor/cytotoxic subsets was also demonstrated.

In a 62 year-old male with chronic myelogenous leukaemia, an acute phase developed with appearance of large immature cells in the bone marrow. A significant proportion of these cells was found to have engulfed autologous immature and polymorphonuclear neutrophils, erythroblasts, red cells and platelets. These abnormal cells were Philadelphia chromosome positive, and considered to be derived from the leukaemic cell line. Electron microscopic examinations revealed, in the cytoplasm of engulfed cells, no lysosomes or phagosomes which are typically seen in phagocytic cells, nor any evidence of degenerative changes in either engulfing or engulfed cells. These findings suggest that this phenomenon be considered as emperipolesis rather than phagocytosis. The pathophysiological mechanism of this phenomenon is uncertain.

The effect of ascorbate in reducing Adriamycin toxicity has been examined in mice and guinea pigs. Ascorbate had no effect on the antitumor activity of Adriamycin in mice inoculated with leukemia L1210, but it significantly prolonged the life of mice and guinea pigs treated with Adriamycin. Adriamycin elevated lipid peroxide levels in serum and liver, and ascorbate prevented the elevation. The significant prevention of Adriamycin-induced cardiomyopathy by ascorbate was proved by means of electron microscopy. The earliest alterations of dilation of the sarcoplasmic reticulum and transverse tubular system and the appearance of a large number of cytoplasmic fat droplets, which were seen in cardiac tissue from guinea pigs receiving Adriamycin, were apparently reduced in animals that were treated with ascorbate.

A case of an epidermoid carcinoma which arose in a cystic adenolymphoma-like lesion of the parotid gland is presented. Histologically, in the major part, the tumor tissue showed a papillary cystadenoma lymphomatosum-like pattern with the stroma consisting of mainly plasma cells and lymphocytes, but the epithelial element was mostly multilayered, showing a keratinous differentiation. In some areas, sebaceous-like cells and oxyphilic cells were found in the epithelial component. In the surrounding fibrous tissue, the invasive growth of the epithelial cells could be observed. Microdeposit of amyloid substance was found in the lymphoid stromal tissue and also in the intercellular space of the epithelial element. A mass of epithelioid cells and cholesterol crystal clefts were observed in the granulomatous tissue which proliferated around the tumor tissues. About 4 months after surgical excision, a recurrent tumor, which was well differentiated squamous cell carcinoma, appeared on the same site as the primary tumor.

The correlation between the content of individual glycosaminoglycans and the histological patterns are studied on breast tumor tissues. The myxomatous stroma of intracanalicular fibroadenoma contained a large amount of glycosaminoglycans, which were mainly hyaluronic acid. The chondroitin 4- and 6-sulfate level was also high. As the supporting stroma of this tumor became denser and more fibrous, the level of hyaluronic acid content was reduced. In the case of pericanalicular fibroadenoma, glycosaminoglycans were small in amount and the levels of hyaluronic acid and chondroitin sulfate were low, but the ratio of dermatan sulfate content was higher. In the case of gynecomastia, the conent was almost the same as that of pericanalicular fibroadenoma. Scirrhous carcinoma tissues contained a relatively large amount of hyaluronic acid and chondroitin sulfate. No remarkable differences in heparan sulfate content were observed in any one of the breast tumors tested. Dermatan sulfate-chondroitin sulfate copolymers were detected in all the tumors. The presence of dermatan sulfate seemed to have an intimate relation with the fibrogenesis in the interstitial stromal element of the tumor tissues.

Four cases of malignant histiocytosis with leukemic manifestations and chronic course were reported. Light microscopic, ultrastructural and ultrastructural cytochemical details of these atypical cells were demonstrated. Ultrastructurally these cells resembled hairy cells most closely among the known varieties of leukemic cells. However, ribosome-lamella complexes were not found and some atypical cells had a few short cytoplasmic projections. In addition, tartrate-resistant acid phosphatase was absent from these cells. We speculate that this leukemic reticuloendotheliosis with a chronic course seen in Japan seems to be analogous to malignant histiocytosis with massive splenomegaly reported by Vardiman et al.

Langerhans cell granules could be found in atypical histiocytes in lymph nodes of three patients with "atypical hyperplasia" with fatal outcome and one patient with leukemic reticuloendotheliosis. These atypical histiocytes might be derived from immature mesenchymal cells in lymph nodes and the Langerhans cell granules might be induced in these cells by a particular condition. Only one of the Langerhans cell granules seemingly associated with the plasma membrane could be observed in these atypical histiocytes and all of the granules were seen within the cytoplasm. Quite a number of Langerhans cell granules were located near the Golgi apparatus. Several atypical granules very similar to the Langerhans cell granules could also be observed in these atypical histiocytes. These Langerhans cell granules were assumed to be directly derived from the Golgi apparatus and/or derived from the atypical granules which were secreted from the Golgi apparatus. The relationship between the Langerhans cell granules and the microtubules must also be considered, because Langerhans cell granules were found near the centrioles and microtubules.

The effect of 5-S-cysteinyl-L-3,4-dihydroxyphenylalanine (cys-dopa), an intermediate in the pathway from L-3,4-dihydroxyphenylalanine (L-dopa) to pheomelanin, on the growth of eight human tumor cell lines in culture was compared to that of L-dopa. The tumor cell lines tested comprise two neuroblastomas (NB-1 and YT-nu), two amelanotic melanomas (HMV and SEKI), a gastric carcinoma (MKN-28), and three squamous cell carcinomas (HeLa-S3, KB, and a salivary gland carcinoma). Cys-dopa at a concentration of 1 mM inhibited growth of NB-1 (66%), YT-nu (67%), HMV (44%), SEKI (60%), MKN-28 (47%), HeLa-S3 (24%), KB (64%), and salivary gland carcinoma (33%), while L-dopa exhibited similar or even lower degree of inhibition at a concentration of 6 mM. On the other hand, both catechols had little effect on the growth of two fibroblasts derived originally from normal tissues (mouse fibroblast L929 and Chinese hamster fibroblast Don-6). Cys-dopa and L-dopa inhibited DNA and protein synthesis in YT-nu cells, but RNA synthesis was less affected. Treatment with cys-dopa at a dose of 1000 mg/kg i.p. for 7 days prolonged by 50% the life span of mice inoculated with L1210 leukemia. Normal mice given cys-dopa at a dose of 1000 mg/kg for 12 days showed no signs of toxicity. These results suggest the potential of cys-dopa as an antitumor agent.

Morphological observations and biochemical analysis were made on glycosaminoglycans produced by MDCK cells of dog kidney origin growing on a glass surface as a mosaic of epithelium with many multicellular hemishperical vesicles. MDCK cells synthesized glycosaminoglycans, which consisted mainly of heparan sulfate and hyaluronic acid. The majority of the substances were contained in a cell-surface component removable with ethylenediaminetetraacetic acid-trypsin. In the radioautograph of tissue sections, high radioactivity of 35SO4 was observed on the medium-bathed cell surface, where Alcian blue-strained material could be observed. Ultrastructurally, the surface of microvillous processes which were abundant on the cell surface in contact with the medium was stained with ruthenium red. A small amount of chondroitin 4- and 6-sulfates were also synthesized. After 24 hr, the majority of chondrotin [35S] sulfates newly formed were secreted into the cultured medium, whereas haparan [35S] sulfate was released much less, remaining as a cellular component. The biological roles of glyconsaminoglycans produced by epithelial cells are discussed.

Mitochondria, rough endoplasmic reticulum, Golgi apparatus and other cytoplasmic organelles were found within the nuclei, not in 'nuclear pseudo-inclusions', of some cells in several hematopoietic disorders. Mitoses were fairly often observed in the atypical cells of these cases. We suggest that these intranuclear cytoplasmic organelles may be trapped in the nucleus during an abnormal mitosis.