Defective T cells from gld mice play a pivotal role in development of Thy-1.2+B220+ cells and autoimmunity

The gld mouse represents a fascinating animal model of autoimmune disease, which is characterized by massive development of Thy-1.2+B220+ CD4-CD8- cells. These cells thus have double positive markers for T and B cells, but are double negative for CD4 and CD8 markers and are thus designated DN cells in the present context. An additional important feature in gld mice is a defect in expression of Fas ligand. To investigate the regulatory role of bone marrow-derived cells for the development of these DN cells and of gld autoimmunity, we constructed chimeric mice transplanted with fetal liver cells or fetal thymus from gld mice into nonirradiated severe combined immunodeficient (SCID) mice. These chimeric mice regenerated, developed both these DN cells and the gld autoimmune syndrome and also generalized lymphoproliferative disorders. However, when fetal liver cells from both gld and non-gld mice (C57BL/10 Thy-1.1 mice) were co-transplanted into SCID mice, the development of DN cells was apparently inhibited. Further, this inhibition was also seen in SCID mice that had been grafted with both gld and non-gld fetal thymus revealing the pivotal role played by T cells in development of DN cells. When B cells purified from non-gld (C3H+/+) mice were transplanted into SCID mice grafted with gld fetal thymus, the development of DN cells was not inhibited. Taken together, these findings indicate that T cells from non-gld mice inhibit the expression of gld features, e.g., lymphoproliferation, immune-based nephritic disease, and autoantibody production. These findings also suggest that the Fas ligand is selectively expressed on T cells.

Defective T cells from gld mice play a pivotal role in development of Thy-1.2+B220+ cells and autoimmunity

The gld mouse represents a fascinating animal model of autoimmune disease, which is characterized by massive development of Thy-1.2+B220+ CD4-CD8- cells. These cells thus have double positive markers for T and B cells, but are double negative for CD4 and CD8 markers and are thus designated DN cells in the present context. An additional important feature in gld mice is a defect in expression of Fas ligand. To investigate the regulatory role of bone marrow-derived cells for the development of these DN cells and of gld autoimmunity, we constructed chimeric mice transplanted with fetal liver cells or fetal thymus from gld mice into nonirradiated severe combined immunodeficient (SCID) mice. These chimeric mice regenerated, developed both these DN cells and the gld autoimmune syndrome and also generalized lymphoproliferative disorders. However, when fetal liver cells from both gld and non-gld mice (C57BL/10 Thy-1.1 mice) were co-transplanted into SCID mice, the development of DN cells was apparently inhibited. Further, this inhibition was also seen in SCID mice that had been grafted with both gld and non-gld fetal thymus revealing the pivotal role played by T cells in development of DN cells. When B cells purified from non-gld (C3H+/+) mice were transplanted into SCID mice grafted with gld fetal thymus, the development of DN cells was not inhibited. Taken together, these findings indicate that T cells from non-gld mice inhibit the expression of gld features, e.g., lymphoproliferation, immune-based nephritic disease, and autoantibody production. These findings also suggest that the Fas ligand is selectively expressed on T cells.

A convenient screening test for hypoxic cell radiosensitizers/cytotoxins

A convenient in vitro screening test using E. coli B/r for evaluating a variety of hypoxic cell radiosensitizers/hypoxic cell cytotoxins has been developed for the initial selection of candidates in medicinal/organic chemistry laboratories. E. coli cells were used for convenience since: (1) the bacterium is grown using commercially available broths, where it multiplies rapidly, and requires little specialized equipment for growth and handling. (2) More is known about the genetics and biochemistry of the radiation damage to these cells and their repair than any other organism.

Inhibition by Guan-mu-tong (Caulis aristolochiae manshuriensis) of the growth of spontaneous mammary tumors in SHN virgin mice

Multiparous SHN mice with spontaneous mammary tumors (5-10 mm in size) were given water extract of Guan-mu-tong (Gmt; Caulis aristolochiae manshuriensis) (0.5%) ad libitum as drinking water for 10 days. This treatment retarded significantly the growth of mammary tumors compared with the controls. By contrast, normal mammary gland growth, histology of adrenals and ovaries, and body weight were affected little by the Gmt treatment. Gmt appears to be the first agent inhibiting the growth of spontaneous mouse mammary tumors of palpable size by per os treatment.

gamma delta T cells play a crucial role in the expression of 65,000 MW heat-shock protein in mice immunized with Toxoplasma antigen

Toxoplasma gondii is an obligate intracellular protozoan parasite and cellular immunity plays a crucial role in protection against infection with this pathogen. When mice are immunized with Toxoplasma homogenate, they readily acquire resistance against infection with a lethal dose of a low virulence Beverley strain of T. gondii. We have reported previously that expression of 65,000 MW heat-shock protein (hsp 65) in host macrophages closely correlates with protective potentials of hosts, while this protein is not expressed in Toxoplasma themselves. In this study, we examined the mechanism of expression of hsp 65 in mice immunized with Toxoplasma homogenate. Heat-shock protein was detected in peritoneal macrophages of BALB/c mice immunized 7 days previously by electroblot assay with a specific monoclonal antibody (mAb) for microbial hsp 65. Furthermore, an immunogold ultracytochemistry assay demonstrated that this protein was expressed on the cell surface of peritoneal macrophages in immune mice. This expression was not induced in those of immune athymic nude mice and SCID mice. Treatment of BALB/c mice with anti-Thy-1.2 mAb 1 day before immunization led to an almost complete loss of the expression of hsp 65. To determine the subsets of T cells responsible for induction of this protein, mice were depleted of gamma delta T cells, alpha beta T cells, CD4+ T cells or CD8+ T cells by treating with corresponding antibodies before immunization. From these experiments, gamma delta T cells were shown to be essential for the expression of hsp 65, although CD4+ alpha beta T cells also contributed to some extent. Thus, gamma delta T cells appear to play an important role in protective immunity against infection with T. gondii through mediating the expression of hsp 65 in host macrophages.

Effects of 5-fluorouracil derivatives on papillomas induced by application of 7,12-dimethylbenz(a)anthracene in mice

We examined the effects of an application of 5-fluorouracil (5-FU) ointment and a chronic oral administration of 1-(2-tetrahydrofuryl)-5-FU plus uracil (UFT) on 7,12-dimethyl-benz(a)-anthracene-induced squamous cell papillomas in mice. Although application of 5-FU ointment reduced the growth of papillomas slightly, chronic oral administration of UFT could prevent tumorigenesis and suppress the growth of papillomas, resulting in the reduction of the tumorous viability and DNA synthesis.

Amino acid sequence of sardine calcitonin and its hypocalcemic activity in rats

A novel calcitonin (CT) was isolated from the spotlined sardine, Sardinops melanostictus. The primary structure of sardine CT was determined as follows: H-Cys-Ser-Asn-Leu-Ser-Thr- Cys-Ala-Leu-Gly-Lys-Leu-Ser-Gln-Glu-Leu-His-Lys-Leu-Gln-Ser-Tyr-Pro-Arg- Thr- Asn-Val-Gly-Ala-Gly-Thr-Pro-NH2. This amino acid sequence was different from that of salmon CT in 4 amino acid residues at positions 8th, 21th, 27th and 29th. As judged by the international method of CT bioassay, hypocalcemic activity of sardine CT was calculated as 4156 IU/mg. When compared for durability of CTs, it was found that sardine CT was significantly more potent than that of salmon CT. This is the first report of CT from a marine species of teleost.

Combined treatment of autoimmune MRL/MP-lpr/lpr mice with a herbal medicine, Ren-shen-yang-rong-tang (Japanese name: Ninjin-youei-to) plus suboptimal dosage of prednisolone

Therapeutic effects of combined treatment with a Chinese medicine prescription, Ren-shen-yang-rong-tang (Japanese name: Ninjin-youei-to, NYT) and suboptimal doses of prednisolone (PSL) on pathological findings of autoimmune-prone MRL/lpr mice were examined. Six-week-old MRL/lpr mice were treated orally with 1000 mg/kg of NYT, 0.5 or 2 mg/kg of PSL, 1000 mg/kg of NYT plus 0.5 or 2 mg/kg of PSL (combined treatment) or solvent only (control) six times per week. The rates of signs and symptoms of autoimmune disease (lymphadenopathy, proteinuria, dermatitis, loss of hair) were suppressed significantly in groups given PSL (2 mg/kg) alone, NYT alone and combined treatment with PSL (2 mg/kg) plus NYT (1000 mg/kg) compared with control, respectively, whereas treatment with PSL (0.5 mg/kg) alone did not inhibit their occurrence. ConA response and IL-2 production were also improved significantly in lymphocytes of mice given the combined treatment. Interestingly, treatment with NYT alone enhanced further the augmented IFN-gamma production in MRL/lpr mice but the combined treatment suppressed such an augmented production. The combined treatment dramatically reduced the level of anti-DNA antibodies in serum of MRL/lpr mice. By contrast, NYT alone treatment had no effect on autoantibodies production. These results suggest that combined treatment with NYT plus a suboptimal dose of PSL could be effective for systemic lupus erythematosus without severe side-effects.

Pathogenesis of late airway changes in long-term surviving lung allografts

Late airway changes are frequently observed in long-term surviving rat lung allografts. In this present study, we investigate this problem using the mixed lymphocyte reaction, graft-versus-host assay (popliteal lymph node assay), skin grafting from the donor strain to the lung allograft recipient, and histology to evaluate this problem. The results show that spleen cells from recipient rats with long-term surviving lung allografts possessed alloreactivity in mixed lymphocyte reaction against both donor and third-party ACI antigens. Suppressor cell activity was not detected in spleen cells from these recipient rats. The popliteal lymph node assay showed that the response to recipient spleen cells was detectable but weaker than that of naive spleen cells from the same strain. Mean survival time of skin grafts from the donor strain to long-term allograft survivors was significantly longer than that between donor and recipient strains. Chest roentgenograms revealed opacification of long-term surviving lung allografts at 2 to 3 wk after skin transplantation that was coincident with the rejection of the skin grafts, and histologic examination of the lung allografts revealed changes compatible with acute rejection. We conclude that alloreactivity can be demonstrated in rats with long-term surviving lung allografts and suggest that late airway changes in these lungs are immunologically mediated.

Relationship between gamma-ray-induced G2/M delay and cellular radiosensitivity

Seven human and rodent cell lines with markedly differing cellular radiosensitivities were examined by the anti-Br-dUrd antibody and flow cytometric method in order to measure the progression of S phase cells and their accumulation in the G2 phase of the cell cycle after gamma-irradiation. Exponentially growing cells were labelled with 10 microM BrdUrd for 2 h, gamma-irradiated, then washed and cultured at 37 degrees C. At 2-h intervals postirradiation, the cells were harvested and fixed for flow cytometric analysis. Two parameter distributions of BrdUrd content and DNA content were analysed. The time intervals for unirradiated labelled cells to progress from S to G2/M phase were about 450 min for the human squamous cell carcinoma cell lines SCC-12B.2 (D0 = 2.66 Gy), SQ-20B (D0 = 2.39 Gy) and SCC-61 (D0 = 1.07 Gy) as well as for wild-type CHO cells (D0 = 2.62 Gy). After irradiation with 2 Gy, SCC-12B.2, SQ-20B, CHO and human diploid AG1521 cells showed similar small G2/M delays (about 1 h), whereas, a G2/M delay of about 2.2 h occurred in radiosensitive SCC-61 cells and delays of 5.0-7.7 h were observed in two extremely radiosensitive mutant cell strains (human AT homozygote and CHO xrs-5 respectively). When the cells were irradiated with doses yielding similar levels of survival (about 10%), however, the duration of the G2/M delay was generally similar (2-4 h) in all seven cell lines indicating a parallel relationship between radiation-induced G2/M delay and cellular radiosensitivity. These results suggest that the delay time may be related to the level of unrepaired damage present in the cell as it approaches mitosis.

Split tolerance between spleen and lymph node cells in severe combined immunodeficiency mice grafted with AKR fetal liver cells

Severe combined immunodeficient (SCID) mice defective in stem cells for T and B cells appear to be an ideal host for construction of chimeric mice. When bone marrow cells are used as a source of stem cells, however, host SCID mice do not always show sufficient reconstitution. In this study, fetal liver cells from AKR embryos were transplanted into SCID mice without prior irradiation. This treatment induced full reconstitution of lymphopoiesis as evaluated by flow cytometry analysis and serum Ig production 2 months after transplantation. Thus, fetal liver cells seem to be a better source for reconstitution of SCID mice than bone marrow cells. Lymph node (LN) cells of these mice (FLT mice) had no proliferative or cytotoxic activities against either host-type (C.B-17) or donor-type (AKR) spleen cells. However, spleen cells from FLT mice exhibited marked proliferative and cytotoxic activities against C.B-17 cells, with no activities against AKR cells. Split tolerance against C.B-17 cells in spleen and LN cells was not a transient phenomenon, since similar results were obtained from a cytotoxic T lymphocyte assay 4 months later. In spite of the strong host reactivity in vitro, aberration of clonal deletion or development of a graft-versus-host disease was not seen in FLT mice. As IL-2 induced the host reactivity of LN cells in a mixed lymphocyte reaction, potentially host-reactive T cells were present in LN but were rendered anergic. Tolerance in FLT mice seems to be regulated by a peripheral mechanism. We supposed that the split tolerance in FLT mice was induced by the different antigenicity between the spleen and LN.

Different gene expression of mouse transforming growth factor alpha between pregnant mammary glands and mammary tumors in C3H/He mice

Mouse transforming growth factor alpha (TGF alpha) gene expression was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) method in pregnant mammary glands and mammary tumors in C3H/He mice. Both normal pregnant and tumorous mammary tissues expressed mRNA for mouse TGF alpha. When primers from rat TGF alpha cDNA sequence as well as those in the previous report [12] were used, the PCR amplified products were the same sizes in both normal pregnant mammary gland and tumor. However, there were obviously different PCR products between pregnant mammary gland and tumor in case of using primers according to the mouse TGF alpha cDNA sequence. In tumors, various sizes of PCR products were detected in addition of a predicted size. This is unlikely the experimental artifact, but the polymorphic TGF alpha gene expression is induced in mammary tumors.

Alteration of adenosine A1 receptor binding in the post-ischaemic rat brain

Chronological changes of adenosine A1 receptor binding of the rat brain were determined by in vitro [3H]cyclohexyladenosine (CHA) autoradiography after 90 min of middle cerebral artery (MCA) occlusion and after such occlusion followed by different periods of recirculation. One day after the ischaemia, [3H]CHA binding sites decreased significantly in the cerebral cortex (p < 0.05) and lateral segment of the caudate putamen (p < 0.01), both supplied by the occluded MCA; thereafter, the binding sites decreased progressively in those ischaemic foci. On the contrary, there was no alteration on day 1, but 3 days after ischaemic insult, a significant decrease of [3H]CHA binding sites was first detected in the ipsilateral thalamus and the substantia nigra, both areas which had not been directly affected by the original ischaemic insult. This post-ischaemic delayed phenomenon observed in the thalamus and the substantia nigra developed concurrently with 45Ca accumulation, which was studied in our previous study. Based on the present study, alteration of adenosine A1 receptor binding activities is involved not only in the ischaemic foci, but also in the remote areas associated neuroanatomically with the ischaemic foci. We suggest that multi-focal post-ischaemic alterations of adenosine A1 binding activities may exacerbate clinical symptoms of patients at a chronic stage of stroke.

In vivo radiosensitizing effect of nitroimidazole derivative KIN-804

PURPOSE

In vivo characteristics of 2-nitroimidazole-1-methylacetohydroxamate (KIN-804), which is a newly developed hypoxic cell radiosensitizer, are presented.

METHODS AND MATERIALS

The toxicity, pharmacokinetics, and radiosensitizing effect of KIN-804 were studied by in vivo experiments using C3H/He mice bearing the SCC-VII tumor. Results were compared with misonidazole (MISO).

RESULTS

LD50(7) of KIN-804 and MISO were 3200 mg/kg and 2000 mg/kg, respectively. The peak of concentrations of KIN-804 in the tumor occurred 20 min after intraperitoneal injection and reached about 62% of the maximum concentration in the blood. The concentrations in brain and sciatic nerve were very low and clearance from sciatic nerve was rapid. Enhancement ratios of KIN-804 calculated using the growth delay method were 1.22, 1.50 and 1.71 at doses of 50, 100, and 200 mg/kg, respectively, compared with 1.36 for MISO at a dose of 100 mg/kg. In the TCD50 assay, enhancement ratios at a dose of 200 mg/kg were 1.69 for KIN-804 and 1.52 for MISO, respectively.

CONCLUSION

KIN-804 is a promising radiosensitizer since it shows less toxicity and higher radiosensitizing activity than MISO.

[Improved perseveration with amantadine]

We report here 3 patients who showed marked improvement of clonic and intentional perseverations following the administration of amantadine. Patient 1 had a subacute encephalitis of unknown etiology. Magnetic resonance imaging documented lesions predominantly in the bilateral putaminal and frontal subcortical areas, and positron emission tomography revealed frontal glucose hypometabolism. Daily amantadine hydrochloride of 200 mg with or without 10 mg of trihexyphenidyl, reduced his clonic and intentional perseverations. The diagnosis of patients 2 and 3 was vascular dementia with multiple subcortical ischemic lesions, and single photon emission CTs showed reduced cerebral blood flow in the frontal lobes. Their clonic perseveration subsided and intentional perseveration disappeared after the administration of 150 mg of daily amantadine hydrochloride. Associated Parkinsonism and confusional state also improved in patient 1, but not in patients 2 or 3. Amantadine increases the pre-synaptic synthesis and release of dopamine, and works as a dopamine system activator. Our findings suggest that the disturbance of dopamine system, especially meso-limbofrontal projection, has some contributions to the perseveration of these patients.

Metabolic disturbances in exo-focal brain areas after cortical stroke studied by positron emission tomography

We have reported that exo-focal delayed neuronal damage was observed in the ipsilateral thalamus and the substantia nigra of the rat brain after occlusion of the middle cerebral artery (MCA). To determine if that phenomenon also occurs in humans, we measured cerebral metabolic rates for glucose (CMRGlc) in the remote brain areas at a chronic stage after cortical infarction using 2-[18F]fluoro-2-deoxy-D-glucose and position emission tomography (PET). The subjects studied were 11 patients who were affected by unilateral cerebral infarction in the cortex supplied by MCA. There were significant decreases of CMRGlc as compared with control values (p < 0.01), not only in the cerebral cortex directly damaged by the ischemic insult, but also in the ipsilateral thalamus and in the contralateral cerebellum, areas in which no lesions had been detected by MRI or CT scan. The present study indicates that different mechanisms may be responsible for multi-focal metabolic disturbances in the remote areas after stroke. The reduction of CMRGlc in the contralateral cerebellum may be explained by the crossed cerebellar diaschisis theory and in the ipsilateral thalamus as being due to retrograde degeneration associated with the infarcted cortex. We suggest that these multi-focal brain dysfunctions caused by neuronal network disturbances may exacerbate clinical symptoms at a chronic stage of stroke.

Normal and neoplastic mammary gland growth in MMTV/TGF alpha transgenic mice

Biochemical and Dynamic change of mammary glands in different reproductive states were studied in comparison with histological structures in female and male transgenic mice bearing human transforming growth factor alpha (TGF alpha) cDNA under the control of the mouse mammary tumour virus enhancer/promoter. Female and male F1 mice between SHN female and transgenic male mice were divided into TGF alpha (+) and TGF alpha (-) groups according to the presence of TGF alpha gene at approximately 50 days of age. While there was little difference in mammary gland contents of DNA and RNA in females at 2 months of age, both nucleic acid contents were elevated markedly in TGF alpha (+) female mice with large variations at 4 months. These extremely high DNA and RNA contents in the TGF alpha (+) group declined to the level of the TGF alpha (-) group in the middle of pregnancy and at the end of pregnancy, respectively. Thymidine kinase (TK) activity in the mammary glands as an index of DNA synthesis was significantly higher in TGF alpha (+) mice than in TGF alpha (-) mice at both 2 and 4 months of age and the high TK in TGF alpha (+) mice also declined to the level of TGF alpha (-) mice with pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Multi-focal metabolic disturbances in human brain after cerebral infarction studied with 18FDG and positron emission tomography

We measured cerebral metabolic rates for glucose (CMRGlc) in the remote brain areas of 7 patients, who were affected by unilateral cortical infarction, at a chronic stage using 2[18F]-fluoro-2-deoxy-D-glucose and positron emission tomography. There were significant decreases of CMRGlc compared with each control value (p < 0.01), not only in the cerebral cortex directly damaged by the ischaemic insult, but also in the ipsilateral thalamus and in the contralateral cerebellum, areas in which no lesions had been detected by MRI or CT scan. The present study indicates that different mechanisms may be responsible for multi-focal metabolic disturbances in the remote areas after stroke. We suggest that these multi-focal brain dysfunctions may exacerbate clinical symptoms at a chronic stage of stroke.

Regulatory role of transforming growth factor-beta, bone morphogenetic protein-2, and protein-4 on gene expression of extracellular matrix proteins and differentiation of dental pulp cells

The expression of developmental stage-specific genes during pulp cell differentiation into preodontoblasts was examined in bovine adult pulp cell culture. When proliferation was down-regulated after 14 days of primary culture, expression of fibronectin and type I and type III collagen mRNAs was increased. Expression of alkaline phosphatase was gradually increased, and mRNA for osteocalcin, a marker of preodontoblast, appeared just before the onset of mineralization. Contrarily, in expanded culture, the expression of mRNA for the extracellular matrix proteins was gradually increased from the beginning of culture up to Day 28. Similarly, mRNA levels of alkaline phosphatase and osteocalcin were also increased gradually. Expression of TGF-beta 1 mRNA disappeared on Day 21 in the primary culture when expression of alkaline phosphatase mRNA was increased. BMP-4 mRNA was expressed on Day 14 when the expression of the extracellular matrix proteins was increased. BMP-2 mRNA was expressed on Day 28 when osteocalcin appeared. Recombinant TGF-beta 1 inhibited alkaline phosphatase activity, while BMP-2 and BMP-4 stimulated it. BMP-4 increased expression of alpha 1(I) collagen mRNA, and BMP-2 increased osteocalcin synthesis. These results demonstrate the regulatory role of these TGF-beta superfamily members on the gene expression of extracellular matrix proteins and the differentiation of pulp cells into preodontoblasts.

Cause of failure of lactation in mouse mammary tumor virus/human transforming growth factor alpha transgenic mice

Transgenic female mice bearing human transforming growth factor-alpha (TGF alpha) cDNA under the control of the mouse mammary tumor virus enhancer/promoter became pregnant but failed lactation. TGF alpha mRNA was detected in the mammary glands of these mice by the reverse transcriptase-polymerase chain reaction. By the use of collagenase-dissociated mammary epithelial cells, the binding of prolactin to its receptor was determined before and after parturition. At the end of pregnancy, the binding in TGF alpha transgenic (TGF alpha [+]) mice was small and its amount was comparable to that in the TGF alpha negative (TGF alpha [-]) mice. On the day of parturition, prolactin binding in TGF alpha (+) mice increased approximately 1.9-fold (insignificant), while that in TGF alpha (-) mice elevated over 5.3-fold (P < 0.01). The binding sites per cell were also higher in TGF alpha (-)mice. Radioimmunoassay of prolactin suggested that in TGF alpha (+) mice the low level of prolactin binding after parturition was not due to masking effect of serum prolactin. Among six TGF alpha (+) mice assayed, one mother with the highest prolactin binding activity (3.7-fold increase) initiated lactation, but the others did not. As there was little difference between groups in the growth and synthesis in the mammary glands, it was concluded that the failure of lactation in TGF alpha (+) mice is principally due to the lack of elevation of mammary prolactin receptor after parturition. At present, the role of TGF alpha in this process is obscure; however, TGF alpha was revealed not to interfere with the binding of prolactin to the receptor.

Structure and activity of Bombyx PBAN

Two structurally related molecular species of pheromone biosynthesis activating neuropeptides (PBANs), PBAN-I and -II, were isolated from adult heads of the silkworm, Bombyx mori, and characterized. PBAN-I is a carboxyl-terminally amidated 33-residue peptide. Structure-activity relationship studies revealed that 1) its carboxyl-terminal pentapeptide is the smallest size showing activity, 2) the carboxyl-terminal amide is indispensable for activity, and 3) oxidation of three Met residues in PBAN-I to Met(O) (methionine sulfoxide) caused marked enhancement of activity, and the three Met(O) residues contribute equally to the enhancement of activity. Molecular design of PBAN analogs using a carboxyl-terminal hexapeptide showed that modification of the amino-terminal amino group brought about a dramatic increase in activity. This increase was presumed to be mainly due to the increased stability in hemolymph. PBANs share the common carboxyl-terminal sequence, -Phe-Xaa-Pro-Arg-Leu-NH2, with myotropic peptides isolated from locust and cockroach. Examination of cross-activity of these two groups of peptides revealed that PBAN and its analogs exhibited myotropic activity comparable to myotropic peptides, while myotropic peptides showed extremely high pheromonotropic activity. In B. mori, PBAN activates sex pheromone (bombykol) production presumably by promoting the reduction reaction from acyl to alcohol, which is the last step in the biosynthesis of bombykol.

Oestrogen and progesterone receptors in mammary tumours of male SHN mice grafted with pituitaries in comparison with females

Mammary tumour induced by pituitary grafting in SHN male mice is promising as an animal model for male breast cancer. In this study, these mice (group MC) were found to differ little from the intact female SHN (group FC) in cytosolic oestrogen receptor (OR) level in either normal or neoplastic mammary glands. On the other hand, Progesterone receptor (PR) level in normal glands tended to be lower in group MC than in group FC, which was recovered by chronic treatment with oestradiol benzoate (group OB). Little difference in PR level in mammary tumours was seen between groups MC and FC. Mammary tumorigenesis was significantly inhibited by chronic treatment with dihydrotestosterone to male mice with pituitary grafts (group DHT). This is associated with the significant decline in PR level in normal mammary glands, while not in mammary tumours. There were no significant correlations between OR and PR levels in normal or neoplastic mammary glands, or between normal and neoplastic mammary glands in OR or PR in all groups except group MC, in which the correlation between OR and PR in mammary tumour was significant. All findings indicate that OR and PR states in mammary tumours of male mice induced by pituitary grafting are essentially similar to the spontaneous mammary tumours of females as postulated in the human.

Suppression by kampo medicine, sho-saiko-to, on papillomas induced by 7,12-dimethylbenz(a)anthracene in mice

Sho-saiko-to (SST) is a Japanese modified, traditional Chinese herbal medicine (Kampo medicine) consisting of seven medical plants. We examined the effects of SST on formation and growth of squamous cell papillomas induced by 7,12-dimethylbenz(a)anthracene application in mouse skin. Chronic oral administration of SST reduced the incidence and growth of papillomas with the reduction of activities of succinate-dehydrogenase and thymidylate synthetase, which were evaluated as the cell viability and DNA synthesis via the de novo pathway, respectively.