Mikihiro Shamoto

Some problems on the histopathological diagnosis of non-Hodgkin's malignant lymphoma -- a proposal of a new type.

A new classification for non‐Hodgkins 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 of peripheral T‐cell nature including the so‐called adult T‐cell leukemia is much higher in Japan than in the Western countries.

Ascorbic acid and adriamycin toxicity.

Adriamycin (ADR) is effective against a wide range of human neoplasms. However, its clinical use is compromised by serious cardiac toxicity, possibly through induction of peroxidation in cardiac lipids. Ascorbic acid, a potent antioxidant, was examined for effect in reducing ADR toxicity in mice and guinea pigs. Ascorbic acid had no effect on the antitumor activity of ADR in mice inoculated with leukemia L1210 or Ehrlich ascites carcinoma, but it significantly prolonged the life of animals treated with ADR. ADR elevated lipid peroxide levels in mouse heart, and ascorbic acid prevented the elevation. The significant prevention of ADR-induced cardiomyopathy in guinea pigs by ascorbic acid was proved by electron microscopy. Ascorbic acid and the derivatives may delay general toxicity of ADR and also prevent the cardiac toxicity. The results also suggest the clinical efficacy of the combined treatment of ADR and ascorbic acid or the derivatives.

Comprehensive screening for antigens overexpressed on carcinomas via isolation of human mAbs that may be therapeutic

Although several murine mAbs that have been humanized became useful therapeutic agents against a few malignancies, therapeutic Abs are not yet available for the majority of the human cancers because of our lack of knowledge of which antigens (Ags) can become useful targets. In the present study we established a procedure for comprehensive identification of such Ags through the extensive isolation of human mAbs that may become therapeutic. Using the phage-display Ab library we isolated a large number of human mAbs that bind to the surface of tumor cells. They were individually screened by immunostaining, and clones that preferentially and strongly stained the malignant cells were chosen. The Ags recognized by those clones were isolated by immunoprecipitation and identified by MS. We isolated 2,114 mAbs with unique sequences and identified 21 distinct Ags highly expressed on several carcinomas. Of those 2,114 mAbs 356 bound specifically to one of the 21 Ags. After preparing complete IgG1 Abs the in vitro assay for Ab-dependent cell-mediated cytotoxicity (ADCC) and the in vivo assay in cancer-bearing athymic mice were performed to examine antitumor activity. The mAbs converted to IgG1 revealed effective ADCC as well as antitumor activity in vivo. Because half of the 21 Ags showed distinct tumor-specific expression pattern and the mAbs isolated showed various characteristics with strong affinity to the Ag, it is likely that some of the Ags detected will become useful targets for the corresponding carcinoma therapy and that several mAbs will become therapeutic agents.

Experimental study on phototoxicity and the photosensitization potential of ketoprofen, suprofen, tiaprofenic acid and benzophenone and the photocross‐reactivity in guinea pigs

Background: Ketoprofen, suprofen and tiaprofenic acid are arylpropionic anti‐inflammatories. Their chemical structures share the same elements as the benzoyl radical and the tiophene ring. We experienced nine cases of ketoprofen photoallergy, seven cases of suprofen photoallergy and three cases of tiaprofenic photoallergy.

A case of contact urticaria syndrome due todi(2‐ethylhexyl) phthalate (DOP) in work clothes

We previously reported a case of contact urticaria syndrome (CUS) due to di(2‐ethylhexyl) phthalate (DOP) in a polyvinyl chloride (PVC) grip on cotton gloves. The patient reported in this previous paper was careful not to have any contact with PVC products in his daily life or in his working environment. He discontinued the use of protective gloves with a PVC grip that was the cause of CUS. When working, he used cotton gloves without a PVC grip. We prescribed antihistamines which slightly improved his condition. However, when he wore work clothes while on duty, CUS relapsed. This condition was severe and made him feel anxious. When we advised him to wear a cotton shirt under his work clothes, the contact urticaria did not develop. We suspected that some component of the work clothes was the cause of his symptoms. A prick test with the extract solution of his work clothes showed a wheal and flare at the 15 min reading. The common component of the grip and the work clothes was found by analysis to be DOP.

Emperipolesis of hematopoietic cells in myelocytic leukemia. Electron microscopic and phase contrast microscopic studies.

SummaryIn a 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 contrast 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 phase contrast microscope are indispensable for distinguishing emperipolesis from phagocytosis.

Differentiation of Langerhans Cells from Interdigitating Cells Using CD1a and S-100 Protein Antibodies

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.

Cells containing Langerhans cell granules in human lymph nodes of "atypical hyperplasia" with fatal outcome and leukemic reticuloendotheliosis.

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.

Studies on Intranuclear Inclusions and Nuclear Grooves in Papillary Thyroid Cancer by Light, Scanning Electron and Transmission Electron Microscopy

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.

Migration and maturation of Langerhans cells in squamous metaplasia of the rat trachea induced by vitamin A deficiency

SummaryThe migration and maturation of Langerhans cells (LCs) in rat tracheal squamous metaplasia due to vitamin A deficiency were investigated immunohisto-chemically 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 charcteristics 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. Ultrastructually 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 was 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. These findings suggest that the precursors of LCs without BGs migrate into metaplastic squamous epithelium and mature into LCs forming BGs after exposure to the microenvironment of the squamous epithelium.