O6-methylguanine methyltransferase activity and sensitivity of Japanese tumor cell strains to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)- 3-nitrosourea hydrochloride

Using 40 tumor cell strains derived from various organs of Japanese tumor patients and also 12 normal cell strains, we have measured the activity of O6-methylguanine-DNA methyltransferase (MT), which can repair O6-methylguanine produced in DNA by alkylating agents. Then, the lethal sensitivities of the strains to the anti-tumor drug 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-)2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) were measured. The MT activity was assayed by measuring the 3H radioactivity transferred from the substrate DNA containing [methyl-3H]-O6-methylguanine to acceptor molecules in the cell extracts. Extracts from the majority of tumor strains and all normal cell strains contained substantial MT activity of varying degree, while the extracts of 6 tumor strains showed virtually undetectable MT activity. Hence these 6 strains were assigned as Mer-, the phenotype which is characterized by the inability to repair O6-methylguanine in DNA due to the lack of MT. The Mer- tumor strains were much more sensitive to ACNU than the rest of Mer+ strains, as measured by colony-forming ability. Furthermore, with all the tumor and normal strains tested, a good correlation was observed between MT activity and cellular resistance to ACNU. These results indicate that the frequency of Mer- strain is about 15% among Japanese tumor cell strains so far analyzed, and further suggest that MT may be the only system able to repair lethal DNA damage induced by ACNU.

Idiopathic portal hypertension associated with polyclonal hyperimmunoglobulinemia. A case report and review of the literature

We report a case of idiopathic portal hypertension associated with prominent polyclonal hyperimmunoglobulinemia and plasmacytosis in the bone marrow and the spleen. Microscopic examination of the liver showed chronic inflammation in the portal area and abnormal vasculature adjacent to the portal tracts. In the spleen, polyclonal plasma cell proliferation was demonstrated histochemically in addition to the presence of remarkable sinus hyperplasia and periarterial fibrosis. In the present case, a chronic inflammatory state such as connective tissue disease was strongly suspected to exist in the liver, since pancytopenia and hyperimmunoglobulinemia persisted even after splenectomy. It is suggested that the pathogenesis in the present case may have been due to this chronic inflammatory state.

Immunohistochemical study of carbonic anhydrase in mixed tumours and adenomas of sweat and sebaceous glands

Immunohistochemical distribution of carbonic anhydrase II (CA) in mixed tumours and adenomas of sweat gland origin and in sebaceous adenomas was demonstrated by the PAP method. Normal sweat glands, both eccrine and apocrine, clear cells of the secretory coils, and ductal epithelial cells all showed conspicuous staining for CA, and sebaceous glands were also positive. Mixed tumours of the skin indicated strongly positive staining for CA in the luminal cells of tubular and duct-like or cystic structures, while most of the other tumour cells were negative. In solid or massive foci, CA positive cells were found scattered among the cellular mass. Sebaceous adenomas were usually moderately positive for CA throughout the tumour.

Comparative analysis of O6-methylguanine methyltransferase activity and cellular sensitivity to alkylating agents in cell strains derived from a variety of animal species

Using 26 cultured cell lines derived from 17 different animal species, we have measured both the activity of O6-methylguanine (O6-MeG) methyltransferase (MT) in cell extracts and the sensitivity of the strains to the lethal effects of the alkylating agents, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU). The MT activity was assayed by measuring the amount of 3H radioactivity transferred from methyl-[3H]-labeled O6-MeG in DNA to acceptor protein molecules in the extracts. In all the 21 mammalian cell strains, lethal sensitivity to ACNU as measured by colony-forming ability correlated well with cellular MT activity, indicating that the major lethal ACNU damage is reparable by the MT. On the other hand, MNNG sensitivity did not necessarily correlate with the MT activity.

Expression of the truncated E. coli O6-methylguanine methyltransferase gene in repair-deficient human cells and restoration of cellular resistance to alkylating agents

We have constructed a truncated E. coli O6-methylguanine methyltransferase (MT) gene (ada gene) to express the MT activity for O6-methylguanine and O4-methylthymine but not for methylphosphotriester in human cells and transferred it into Mer- HeLa MR cells. The transfectant cells expressed the truncated E. coli MT were resistant to alkylating agents as same as the transfectant cells with the intact ada gene in cell killing, sister-chromatid exchange induction and host-cell reactivation of adenovirus 5. These results strongly suggest that methylphosphotriester may not contribute to the biological effect of alkylating agents in human cells.

Calcifying epithelioma of Malherbe with ossification. Special reference to lectin binding and immunohistochemistry of ossified sites

Lectin binding sites and immunohistochemically detectable fibronectin and carbonic anhydrase II (CA II) were examined in induced bone structure of calcifying epithelioma of Malherbe. Pathological features of ossification were particularly evident in the border zone between tumor epithelium and stroma, and epithelial foci adjacent to sites of bone formation were conspicuously basophilic. The use of lectin binding in these foci coincided with the basophilic epithelial zones: Con A, RCA-1, PNA, SBA, and WGA bound strongly, indicating the presence of glucose (Glu), mannose (Man), galactose (Gal), N-acetyl-D-galactosamine (GalNAC), and N-acetyl-D-glucosamine (GlcNAC). Fibronectin was also detected in the same epithelial-mesenchymal interacting layers as the positive lectin-binding sites. Staining for CA II was strongly positive in giant cells and in epithelial zones in the bone-inducing areas. The bond induction mechanism in the stromal tissue of calcifying epithelioma of Malherbe may initially involve the action CA II in the epithelial-mesenchymal interacting zone, which then brings about ossification of the matrix which is fibronectin-positive and rich in lectin-binding sites.

Plasma and testicular testosterone in experimental diabetic rats

Testicular and plasma testosterone levels were found to be decreased markedly in streptozotocin diabetic rats compared with those of controls. Treatment with 6 units NPH insulin daily for one week almost normalized plasma testosterone levels parallel to the increase in body and liver weights in diabetic rats, while testosterone levels in testicles were not significantly changed. Plasma prolactin and LH levels were unchanged among control, diabetic and diabetic insulin-treated rats. Thus, testosterone reduction in the testis might play a role in diabetic impotence.

Hodgkin's disease in Osaka, Japan (1964-1985)

In the present study, 96 cases of HD selected from 937 cases of malignant lymphomas in Osaka, Japan were reviewed to evaluate a time trend of HD. The results showed that, during the periods from 1964-74 to 1975-85, (1) ratio of HD among all malignant lymphomas decreased from 14.8% to 8.9%, (2) MC decreased and NS increased, and (3) the age of onset fell.

Transfer of the E. coli O6-methylguanine methyltransferase gene into repair-deficient human cells and restoration of cellular resistance to N-methyl-N'-nitro-N-nitrosoguanidine

We have constructed a plasmid on which the E. coli O6-methylguanine-DNA methyltransferase (MT) gene (ada gene) was linked with an SV40 promoter sequence and a poly(A) site. After transferring this plasmid into Mer- HeLa MR cells by DNA transfection, effective expression of E. coli MT was observed. Isolated stable transformant clones showed higher resistance to N-methyl-N'-nitro-N-nitrosoguanidine in colony formation and sister-chromatid exchange induction than HeLa MR cells.

Morphological changes in autonomic ganglionic cells of the heart in diabetic patients

To clarify the histological changes of the cardiac autonomic nervous system in diabetes mellitus, ganglionic cells of the hearts of autopsy cases were examined light microscopically. In 7 severely diabetic patients, the ganglionic neurons showed cellular contraction, cytoplasmic condensation and poor staining of Nissl substance. As neuronal alterations were obvious neither in the mild diabetic patients nor in the non-diabetic patients, these alterations therefore seemed to correlate with diabetes mellitus. The neuronal changes did not seem to correlate with major coronary arterial atherosclerotic narrowing.

An autopsy case of malignant hyperthermia

A report is made of a 44-year-old female who died of malignant hyperthermia during general anesthesia for an operation of left subtrochanteric femoral fracture. Symptoms began with increases in heart rate and blood pressure after the introduction of anesthesia with halothane and were accelerated by the administration of succinylcholine, followed by muscle rigidity and high temperature. The typical wine red urine was observed. The oral temperature of 42 degrees C was recorded within 1 h after succinylcholine. The rectal temperature was 30 degrees C 22 h after death. Severe pulmonary edema and tubular necrosis of the kidney were found by postmortem examination. No latent myopathy was observed. The creatine phosphokinase levels in plasma obtained after the onset of malignant hyperthermia and at the time of autopsy were abnormally high and were 5632 and 34,854 mU/ml, respectively. Plasma myoglobin levels were 130,000 and 2.8 X 10(6) ng/ml, respectively.

Increased sensitivity of cultured fibroblasts from colon cancer-prone rats to cytotoxicity of carcinogens and to viral transformation: a comparison with fibroblasts from patients with adenomatosis coli

Lethal effects of mitomycin C (MMC), 4-nitroquinoline 1-oxide (4NQO) and ultraviolet light (UV) on fibroblast cell lines derived from a colon cancer-prone substrain of Wistar-Furth rats (WF/OSAKA rats) were measured in terms of the cellular colony-forming ability, and compared with the sensitivity to these agents of human fibroblasts from patients with adenomatosis coli and rectum (ACR). All 6 fibroblast strains from the cancer-prone WF/OSAKA rats were significantly more sensitive (though to various extents) to MMC as well as 4NQO than normal rat fibroblasts derived from the parental WF Hiroshima rats. These WF/OSAKA cell strains were slightly more sensitive to UV than normal rat cell strains. Similarly, 5 out of 6 fibroblast strains derived from ACR patients were hypersensitive to both MMC and 4NQO. Further, the WF/OSAKA cell strains were more susceptible to morphological transformation induced by Kirsten murine sarcoma virus than normal rat strains. The observed higher sensitivity to chemical agents and to viral transformation suggests a close similarity in cellular terms between the colon cancer-prone WF/OSAKA rats and human individuals affected with ACR.

[Malignant thymoma with diffuse extensive growth on the pleura]

A 71-year-old man was admitted complaining of cough and high fever. Chest X-ray and CT scanning showed diffuse thickening of both pleurae and malignant mesothelioma was suspected. Upon pleural biopsy, a diagnosis of lymphosarcoma, well differentiated type, was made. Postmortem examination revealed diffuse, extensive fibrous thickening of both pleurae with multifocal spreading of tumor cells. These occasional Hassal's bodies. The latter cells were spindle-shaped and ovoid. Therefore, the tumor was diagnosed as "malignant thymoma, mixed type".

Multiple malignancies (squamous cell carcinoma and sarcoma) arising in a dermoid cyst of the ovary

A case of multiple malignancies (squamous cell carcinoma and sarcoma) arising in an ovarian dermoid cyst of a 75-year-old woman is reported: this appears, to the best of our knowledge, to be the first well documented example of such a complex tumor. The two malignant components had a well-demarcated boundary except for at their junction, a feature more indicative of a collision tumor rather than carcinosarcoma of the ovary. The solid sarcomatous portion displayed a prominently myxoid and pleomorphic appearance with a focal whorling and storiform pattern, the features considered to be compatible with the myxoid varient of malignant fibrous histiocytoma recently defined by Weiss and Enzinger. The patient is alive and well 21 months after surgery.

Progesterone metabolism in vitro by rabbit testes at different stages of development

Testicular homogenates from white rabbits of 0.4, 1, 3, 4, 5, 8, 18, and 24 months of age were incubated with [3H]progesterone and NADPH. At 12 days of age, major C21-17-OH-and C19- steroids formed from progesterone were 17alpha-hydroxyprogesterone and testosterone. However, at 4-24 months of age, 17alpha-hydroxyprogesterone, 3beta,17alpha-dihydroxy-5alpha-pregnan-20-one, and 5alpha-reduced C19-steroids such as 17beta-hydroxy-5alpha-androstan-3-one, 3beta-hydroxy-5alpha-androstan-17-one, and 5alpha-androstane-3beta,17beta-diol were the major products. The formation of significant quantities of 5alpha-reduced C19-steroids, which had been demonstrated previously only in prepubertal testes of rats and mice, was present in prepubertal as well as adult testes of rabbits. These findings clearly indicate that the metabolic patterns of progesterone in the adult rabbit differ from those in the adult rat and mouse. The major C19-steroids formed by testes are testosterone in the adult rat and mouse, but 5alpha-reduced C19-steroids in the adult rabbit.

Pathway from progesterone to 5alpha-reduced c19 steroids not involving androstenedione and testosterone in immature mouse testes in vitro

Testicular homogenates from mice of 23 and 70 days of age were incubated for 3-120 min with either 3-H-progesterone, 14-C-progesterone, 3-H-5alpha-pregnane-3,20-dione or 14-C-progesterone plus 3H-5alpha-pregnane-3,20-dione in the presence of NADPH. After incubation, radioactive products were purified and identified by column and paper chromatography, with derivative formation and recrystallization to constant specific activity. In immature mouse testes, the results indicate two biosynthetic pathways leading to C19 steroids from progesterone, one from progesterone via 17-hydroxyprogesterone and androstenedione to testosterone and a second via 5alpha-reduced C21 steroids to 5alpha-reduced C19 steroids such as androsterone and 5alpha-androstane-3alpha,17beta-diol. In adult mouse testes, very few 5alpha-reduced metabolites of all the delta-4-3-ketosteroids are shown to be produced from progesterone, while evident 17alpha-hydroxylation of 5alpha-pregnane-3,20-dione followed by C17-20 lyase reaction is demonstrated.