The role of interstitial collagens in cleft formation of mouse embryonic submandibular gland during initial branching

An interstitial collagenase was purified from the explant medium of bovine dental pulp and was shown to degrade collagens I and III but not IV and V. The enzyme halted cleft initiation in the epithelium of 12-day mouse embryonic submandibular glands in vitro, indicating the active involvement of interstitial collagens in the branching morphogenesis. Transmission electron microscopic observation of the intact 12-day gland without any clefts showed the scattered localization of a few collagen fibrils at the epithelial-mesenchymal interface of the bulb and also revealed the presence of numerous microfibrils around the stalk. Collagen bundles were regularly seen close to the wavy basal lamina at the bottom of clefts of the intact 13-day gland and 12-day gland cultured for 17 h under normal conditions. Mesenchymal cells were found in the clefts together with the frequent localization of peripheral nerve fibres and capillary endothelial cells. The collagen bundles were more often observed in the 12-day gland cultured in the presence of bovine dental pulp collagenase inhibitor, which had been shown to enhance cleft formation. In contrast, collagen fibrils were rarely found at the epithelial-mesenchymal interface of the 12-day gland cultured in the presence of Clostridial or bovine dental pulp collagenase. The findings indicated that the formation of interstitial collagen bundles is essential to form clefts in the epithelium both in vivo and in vitro.     

In Vitro Binding of Wheat-Germ Proteins to the 5'-Upstream Region of the rolC Gene of Ri Plasmid

In vitro binding of nuclear proteins from wheat germ to the5'-upstream region of the rolC gene of Ri plasmid was investigated.The specific DNA sequences interacting with proteins were detectedby DNase I footprinting. (Received October 8, 1990; Accepted November 30, 1990)     

Cervicovaginal and endometrial cytology in ovarian cancer

The clinical significance of cytologic examination was studied in 114 patients with ovarian cancer who had received preoperative cytologic examinations. The overall positive rate of the cytologic examinations was 26.3% (30 of 114): 22 (19.3%) of the 114 cases had positive cervicovaginal smears while 13 of 31 endometrial aspiration smears (41.9%) were positive. The positive rate was not related to the volume of ascites but rather to its presence or absence. Thus, if ascites was observed, the positive rate was about 2.1 times higher than if it was absent. In two of four cases of ovarian cancer with no endometrial invasion but a positive cytologic examination of ascitic fluid, fallopian tube specimens contained cancer cells; this suggests that ovarian cancer cells may reach the cervix and/or vagina by passing through the fallopian tube, particularly if ascites is present. Since cytologic examination, especially of endometrial aspiration smears, shows a high positive rate if ovarian cancer cells are observed in the abdominal cavity, cytology should be used as an important ancillary method for the assessment of ovarian cancer.     

Postoperative changes in vaginal smears after vaginal reconstruction with a free skin graft

Surgical vaginal reconstruction was performed by a free skin graft in two patients without a vagina. The postoperative changes in vaginal smears collected from the artificial vaginas were observed for about two years. Marked operation-induced inflammatory changes were observed until the second postoperative month. After the third postoperative month, the background became relatively clear. Cyanophilic and eosinophilic superficial cells, intermediate cells and D?derlein bacilli were observed occasionally in addition to keratotic cells. Six to 12 months after surgery, the vaginal smears showed little abnormality, except for the presence of keratotic cells. The changes in the vaginal smears after the third month show that the artificial vaginal epithelium changed cytologically to an almost normal vaginal mucosa that, although not histologically complete, responded to hormones. The presence of D?derlein bacilli suggests that the regional environment of the artificial vagina was almost the same as that of the normal vagina.     

Human recombinant interleukin-1 alpha-mediated stimulation of procollagenase production and suppression of biosynthesis of tissue inhibitor of metalloproteinases in rabbit uterine cervical fibroblasts

Influence of human recombinant interleukin-1 (hrIL-1) on collagen metabolism was investigated with rabbit uterine cervical fibroblasts. Enzyme-linked immunosorbent assays for collagenase and tissue inhibitor of metalloproteinases (TIMP) indicated that hrIL-1 participates in both stimulation of procollagenase production and suppression of TIMP synthesis by uterine cervical cells. IL-1 did not modulate collagen synthesis. In addition, the sensitivity to IL-1 of uterine cervix from ovariectomized rabbits was augmented by estradiol-17 beta treatment. Thus it is proposed that IL-1 accelerates collagenolysis in the cervical tissue and its effect on uterine cervix is hormonally regulated.     

Purification and characterization of thylakoid-bound Mn-superoxide dismutase in spinach chloroplasts

Thylakoid-bound superoxide dismutase (SOD; EC 1.15.1.1) was solubilized by Triton X-100 from spinach and purified to a homogeneous state. The molecular weight of thylakoid-bound SOD was 52000; the enzyme was composed of two equal subunits. Its activity was not sensitive to cyanide and hydrogen peroxide, and the isolated SOD contained Mn, but neither Fe nor Cu. Thus, the thylakoid-bound SOD is a Mn-containing enzyme. The subunit molecular weight of thylakoid Mn-SOD is the highest among Mn-SODs isolated so far, a fact which might reflect its binding to the membranes.     

Assignment of the gene locus for the sixth component (C6) of complement in mice to chromosome 15

A structural locus (C-6) for the sixth component of complement in mice is assigned to chromosome 15. Three-point linkage analysis indicated that the order of loci is C-6, Gpt-1, Gdc-1, and that the map distances are 25.9±4.9 between C-6 and Gpt-1, and 36.4±5.5 between C-6 and Gdc-1. Since Gdc-1 is more distal than Gpt-1, and C-6 is 26 cM away from Gpt-1, it is estimated that the C-6 is proximal to the centromere. In addition, a new C6 form found in AKR mice is described. We propose the designation C6B for it and C-6 ^b for the allele encoding C6B.Abbreviations used in this paper IEF isoelectric focusing - GPT glutamic-pyruvic transaminase - GDC L-glycerol 3-phosphate dehydrogenase - cM centimorgan     

Interaction of metals at the reaction center of lipoamidase

Various metals have been shown to inhibit porcine brain lipoamidase activity at 0.1 mM, but not ferrous and ferric ions. However, in the presence of ethylenediamine tetraacetic acid (EDTA) 0.1 mM iron ions did inhibit the activity. No other metals exhibited this type of increased inhibition with the addition of EDTA. The ferric- and ferrous-EDTA compounds were equally effective. Various Fe-containing compounds also inhibited the enzyme activity, the order of inhibition being: EDTA greater than o-phenanthroline greater than azide greater than citrate. Hemin also inhibited the enzyme activity strongly. However, Fe-proteins, e.g. cytochrome c, transferrin and peroxidases, were not inhibitory. These results indicate the importance of Fe ion chelates with structural and molecular size differences for interaction with the reaction center of this enzyme.     

Juvenile hormone esterase activity repressive factor in the plasma of parasitized insect larvae

A proteinaceous factor that represses plasma juvenile hormone esterase activity in parasitized insect larvae has been isolated and partially characterized from last instar larvae of the armyworm Pseudaletia separata parasitized with the wasp Apantales kariyai. Purification procedures consisted of extraction with 25% ethanol, gel filtration and reversed phase high performance liquid chromatography. Plasma juvenile hormone esterase activity in Day 3 last instar larvae was repressed by 50% when larvae were injected on Days 1 and 2 with 6.5 pmol of the purified peptide, which has a molecular weight of about 4,500 Da. The application of the factor also causes more than a 2-day delay in the onset of pupation. The sequence of 23 amino acid residues at the amino terminus of the factor was determined as follows: H-Glu-Asn-Phe-Ser-Gly-Gly-Xaa-Val-Ala-Gly-Tyr-Met- Arg-Thr-Pro-Asp-Gly-Arg-Xaa-Lys-Pro-Thr-Phe-Tyr-Gln-.     

Radioprotective effects of dimethyl sulfoxide in golden hamster embryo cells exposed to gamma rays at 77 K. I. Radical formation as studied by electron spin resonance

Formation of free radicals in golden hamster embryo (GHE) cells in the frozen living state by gamma irradiation has been studied by electron spin resonance spectroscopy at 4.2 and 77 K. The relative yields of H atoms, OH radicals, and organic radicals trapped in the irradiated GHE cells are 12, 72, and 16%, respectively, of total radical yields. When dimethylsulfoxide (DMSO) is added to GHE cells at 77 K, a large quantity of CH2SOCH3 radicals (DMSO radicals) are formed after gamma irradiation. The yields of OH radicals are not affected by the addition of DMSO. When the GHE cell-DMSO mixtures are irradiated with gamma rays at 77 K and then warmed to 111 K, the OH radicals decay, whereas the DMSO radicals do not increase complementarily. Moreover, the decay rates of the OH radicals at 111 K do not depend upon the concentration of DMSO. Thus OH radicals do not react with DMSO during warming of the irradiated sample. When H atoms are produced by gamma irradiation of acid ice at 60 K, the decay rates of the H atoms at 77 K increase with increasing DMSO concentration, indicating that DMSO reacts with H atoms (CH3SOCH3 + H----.CH2SOCH3 + H2) at 77 K by quantum-mechanical tunneling. When the GHE cell-DMSO mixture is irradiated with gamma rays at 77 or 4.2 K in the dark, DMSO ions are produced in addition to DMSO radicals. Therefore it is concluded that DMSO does not scavenge OH radicals, but does capture H atoms, holes and/or electrons in the gamma-irradiated cells, resulting in the remarkable formation of DMSO radicals. This scavenger effect of DMSO may be related to the radioprotection of DMSO against cell killing described in the companion paper (Watanabe et al., Radiat. Res., this issue).