Evaluation of 2 different genetic markers for the detection of frameshift and missense mutagens in A. nidulans

21 chemicals, known to induce missense and/or frameshift mutations directly, were assayed for their ability to forward mutate a haploid strain of A. nidulans. 2 genetic markers for forward mutations were used, namely 8-azaguanine resistance and induction of meth A1 suppressors. Missense mutagens were usually active when tested with the plate-incorporation technique, whereas frameshift agents were ineffective; some of these, on the other hand, turned out to be positive when tested with a liquid-test procedure. The 2 genetic markers used showed a similar sensitivity (with only 2 exceptions) in detecting the chemical mutagens assayed.

Language delay in infants associated with middle ear disease and mild, fluctuating hearing impairment

We report on a study of the relationship between early persistent middle ear disease and early language learning for 35 infants. Three independent measurements were used to evaluate hearing sensitivity and the status of the middle ear. Language development was assessed using two standardized measurements for both comprehension and expression. The otitis-prone group had a 71.5% incidence of language delay with 42.9% delayed greater than 6 months. For the normal group 21.4% had language delay, with one child having delay greater than 6 months. The feasibility of including language screening for at-risk infants is discussed.

Metastatic potential of metastases, tumor cell heterogeneity, and therapeutic implications

The metastasizing capacity of spontaneous metastases of several murine tumors of different histology, origin, and disseminative pattern was investigated to test the hypothesis that metastases originate from various subpopulations within the primary tumor. Overall, tumor cells from individual metastases did not show greater metastasizing capacity than the cells of the original tumor, although a degree of heterogeneity was seen. Differences in the immunologic profile among metastases of the same tumor were also observed. The possible therapeutic implications of these findings are discussed.

Growth-mediated metabolic activation of promutagens in Aspergillus nidulans

7 procarcinogens belonging to different chemical classes (nitrosamines, hydrazoalkanes, oxazaphosphorines and aromatic amines) were tested in A. nidulans for the induction of point mutations with two genetic systems (8-AG resistance and induction of methionine suppressors). Dimethylnitrosamine, diethylnitrosamine, nitrosomorpholine, dimethylhydrazine, procarbazine and cyclophosphamide gave positive results with a good dose--effect relationship in the growth-mediated assay, whereas they gave negative or borderline positive results in the plate incorporation assay. 2-Aminoanthracene was completely negative with both experimental procedures. DMN, DEN and NM were also tested for their ability to induce somatic segregation: all were positive when assayed in the growth-mediated assay.

Different patterns of replication in influenza virus-infected KB cells

When KB cells were infected either with the fowl plague (FPV) Rostock strain (Hav1N1) or the WSN (H0N1) strain of influenza A virus the yield of cell-associated haemagglutinin and neuraminidase polypeptides was essentially comparable, but virus particles were not produced in the FPV-KB system. WSN virus-infected KB cells synthesized normal amounts of mature virus particles and had all the characteristics of a permissive replication cycle. Biosynthesis and transport of RNP antigen from nucleus to cytoplasm of infected cells were traced by immunofluorescent staining at 4 and 8 hours after the beginning of infection. While the fluorescent-stained material was totally confined to the nuclei in FPV-infected KB cells, RNP antigen migrated out of the nucleus during the replicative cycle of WSN virus in the same host cell. Patterns of virus-specific protein synthesis were studied by pulse-labelling with 35S-methionine. The most significant feature concerned the amplification of synthesis of virus-induced matrix (M) protein which did not occur in FPV-infected cells but occurred normally during WSN infection. The different patterns of replication in the same host cell when infected by different influenza A viruses is discussed.

Effects of estrogens P-1496 and P-1560 on the binding of estradiol with rat uterine estrogen receptors

The interference of two weak estrogens (P-1496 and P-1560) on the binding of estradiol with uterine estrogen receptors is comparatively studied. Both P-1496 and P-1560 decrease the estradiol binding capacity, but P-1560 is less effective than P-1496. Since P-1496 is a more potent estrogenic substance than P-1560, the results obtained confirm that the uterotrophic activity of estrogens is related to the binding capability to uterine estrogen receptors.

Mutagenicity of halogenated aliphatic hydrocarbons in Salmonella typhimurium, Streptomyces coelicolor and Aspergillus nidulans

Eight structurally related halogenated aliphatic hydrocarbons mono-, di- and trichloroacetaldehyde (the last in the anhydrous and hydrate form), moni-, di- and trichloroethanol and allyl chloride, were tested for their ability to induce gene mutations in prokaryotic and eukaryotic microorganisms. The genetic systems employed were the Salmonella reversion test with strain TA1535 and TA100, with and without metabolic activation, a forward and a back-mutation system in S. coelicolor and two forward mutation systems in A. nidulans. Each compound was tested with the spot and plate incorporation assay techniques. Mono-, di- and trichloroacetaldehyde were mutagenic in all the microorganisms employed; all the halogenated ethanols were positive in A. nidulans, while in S. typhimurium and in S. coelicolor the only active forms were respectively the mono- and dichloroderivatives. Allyl chloride was active in S. typhimurium and S. coelicolor and negative in A. nidulans. The technical approach as well as the complex influence of different factors (toxicity, volatility and stability) on the genetic response of each of the compounds under test did not allow to obtain more than a qualitative relationship between mutagenic potency and chemical structure.

Mutational studies with diquat and paraquat in vitro

Diquat and paraquat were assayed in the following tests. (1) Ames test in Salmonella typhimurium (strains TA1535, TA1537, TA1538, TA98 and TA100) with and without rat-liver microsomal fractions. (2) Resistance to 8-azaguanine in Salmonella typhimurium (strain hisG46, TA92 and TA1535. (3) Repair test in Salmonella typhimurium (strains TA1538 and TA1978). (4) Gene mutations in Aspergillus nidulans: 8-AG resistance and methionine suppression (meth A1 locus). (5) Lethal recessive damage in Aspergillus nidulans. (6) Unscheduled DNA synthesis (UDS) in human epithelial-like cells (EUE). Diquat and paraquat were positive in S. typhimurium (in the repair test and the 8-AG resistance system), in A. nidulans (for gene mutations and lethal recessive damage induction) and in EUE cells (UDS induction).

A new in vitro method for testing plant metabolism in mutagenicity studies

A rapid method was proposed to detect whether a harmless agricultural chemical can be converted into a mutagenic one by plant metabolism. The method is based on the use of Nicotiana alata cell cultures. Results obtained with five pesticides (atrazine, dichlorvos, tetrachlorvinphos, Kelevan, and maleic hydrazide) suggest that the proposed method simulates the metabolism of the whole plant. This procedure was also successfully applied to the genetic system of Aspergillus nidulans. One pesticide, atrazine, induced mutations and somatic segregation only after metabolism during cocultivation with N. alata cells.

[Reasons for treatment failures in carpal scaphoid fractures]

Are taken into examination the principal causes of mechanical, biological, anatomical order, of incorrect treatment to whom to give the evolution in pseudoarthrosis of scaphoid fractures and of unsuccess for their bloody treatment. Cases of insuccesses is presented for whom is tried to give to each one of them an etiopathogenetical explanation and the most recent techniques adopted are shown.

In vitro generation of nonspecific suppressor cells and their characterization

In vitro preculture of C3H/He splenocytes for 48 to 96 hr induces aspecific suppressor cells evaluated by their ability to reduce 3H-TdR uptake by fresh syngeneic splenocytes stimulated by different amounts of Concanavalin A (Con A) in vitro. This suppressive activity is obtained in medium containing 10% heat-inactivated fetal calf serum (FCS) or similar amounts of heat-inactivated bovine serum, syngeneic, or allogeneic murine sera but not by unheated FCS. Suppressive activity is resistant to mitomycin C and radiation up to 5,000 R. Exposure of precultured cells to carbonyl iron or plastic adherence, but not to anti-Thy 1.2 serum plus complement, results in removal of the suppressive activity.

[Plasma renin activity in hypertensive patients under basal conditions and in various postures: preliminary data]

We have studied PRA levels in 10 healthy subjects compared with 10 patients affected with essential hypertension (with low PRA) on venous blood samples collected after 8 hours of rest and after 15-20 minutes of slow plain walk. Contemporarely we have taken up arterious pression levels in each class of subjects of these studies. No significant differences of PRA are demonstrable in healthy subjects and in patients affected with essential hypertension. Postural changes in hypertension produces significant rise of PRA, not related to arterial pressure.

[Oxoprenolol and plasmatic renin activity in essential hypertension: preliminary data]

We have studied PRA levels in 10 healthy subjects compared with 10 patients affected with essential hypertension (with low PRA) on venous blood samples collected after 8 hours of rest and after 15-20 minutes of slow plain walk and 15 minutes after intravenous administration of oxoprenolol (mg 2). Contemporarely we have taken up arterious pression levels in each class of subjects of these studies. Postural changes produces significant rise of PRA in subjects affected with essential hypertension, that is significantly inhibited by pharmacologic interference produced by beta-blocking agents. This occurrence is independent of arterial pressure changes.

Changes in the concentration of uterine cytoplasmic oestrogen receptors induced by doxorubicin and methotrexate

The effects of doxorubicin and methotrexate on the oestradiol-induced depletion, replenishment and subsequent increase beyond the normal value (overshoot) in the number of uterine cytoplasmic oestrogen receptors were investigated in intact rats. Injection of doxorubicin (0.5 mg/kg, i.v.) or methotrexate (1mg/kg, i.m.) 5 min after a single i.p. injection of 10 ng oestradiol-17beta (which is able to induce a 50% depletion in the number of oestrogen receptors) caused a significant increase in the oestradiol-induced depletion. Both drugs inhibited the replenishment and the overshoot phases until 48 h after treatment, although the effect was more marked with doxorubicin. Experiments in vitro showed that both methotrexate and doxorubicin affected the capacity of oestradiol-17beta to bind to specific cytoplasmic receptors, inducing an increase in binding when used at low concentrations and a decrease at higher concentrations. The effects of doxorubicin and methotrexate on the depletion, replenishment and overshoot of oestrogen receptors seemed to be partly dependent on the inhibition of protein synthesis and partly due to direct action on the binding of oestradiol-17beta to its receptors.

Suppression of mitogen responses and graft-versus-host reaction by splenocytes from mice bearing Lewis lung carcinoma

The presence of suppressor cells in the spleens of C57BL/6 mice bearing Lewis lung carcinoma was investigated with the use of the in vitro lymphoproliferative response to mitogens and the graft-versus-host reaction (GVHR) as test systems. Splenocytes from tumor-bearing mice showed a lower response to mitogens when obtained 15-27 days after tumor transplant. In parallel, these cells were capable of suppressing the response of normal spleen cells to mitogens and their capacity to mount a GVHR in allogeneic hosts. Treatments with procedures known to remove adherent phagocytes, but not treatments with anti-Thy 1.2 serum plus complement, removed the suppressive activity observed.

Microbiological titration of proteins and of single amino acid content in biological materials without purification and hydrolysis

A method is described for the microbiological determination of the protein content of biological materials. This method can also be adopted to titrate the concentration of a single amino acid in the protein and has the following advantages: (1) titration can be done without purification and hydrolysis of proteins; (2) the titration graph is a straight line between 25 and 800 microgram/ml; (3) protein values agree with those obtained using the Kjeldhal method; and (4) each mutant requiring one amino acid may be used to titrate the concentration of a single amino acid of the protein. The leucine content of various kinds of flour was measured with this system.

Interference of gestagens and androgens with rat uterine oestrogen receptors

The inhibitory effect of some gestagens and calusterone on the binding of oestradiol-17beta to its specific uterine receptors has been investigated in intact rats. Progesterone, medrogestone, clogestone, medroxyprogesterone acetate and calusterone reduce the specific oestradiol-receptor interaction in vitro; this effect is dose-dependent and does not differ significantly from one drug to the other. A more relevant decrease in the amount of oestradiol-17beta bound to specific receptors has been observed with calusterone. Progesterone, clogestone, medrogestone, medroxyprogesterone acetate and calusterone given orally induce a marked decrease (between 30 and 70% depending on the dose) in the binding capacity of oestradiol-17beta to specific uterine receptors in vivo. Results from a Scatchard plot analysis suggest that the interference with the binding of oestradiol-17beta caused by both progestogens and calusterone is due to a non-competitive interaction.

[1H-pyrazolo/1,2-b/phthalazines with anti-inflammatory activity]

The synthesis of forty-one 2,2,6,7-substituted 2,3,5,10-tetrahydro-1H-pyrazolo[1,2-b]phthalazine-1,3-diones A) by reaction of 4,4-di-substituted pyrazolidine-3,5-diones with substituted or unsubstituted alpha,alpha'-dibromoxylene and B) by tetrahydrophthalazine and 2-substituted malonic acid chlorides is described. The antinflammatory activity was tested on carrageenan oedema in comparison with phenylbutazone.

Sur le comportement des mastocytes chez le rat en conditions d'hypo- et d'hypervitaminose A

The behaviour of rat mast cells under conditions of high and low vitamin A

The authors have studied the mast cells in normal rats and in rats under hypo- and hypervitaminosis A. The main results of their studies are: (a) in the skin (dermis), in the case of A hypervitaminosis, there is a significant rise in the number of the mastocytes with swelling and dcgranulation; (b) in lung and bone marrow, the number of mastocytes is increased under hypovitaminosis A and there is also blood congestion and lipomatosis of bone marrow.

The authors give an interpretation of their results.