A soluble transforming growth factor-beta (TGF-beta ) type I receptor mimics TGF-beta responses.

Transforming growth factor-beta (TGF-beta) signaling requires a ligand-dependent interaction of TGF-beta receptors Tau beta R-I and Tau beta R-II. It has been previously demonstrated that a soluble TGF-beta type II receptor could be used as a TGF-beta antagonist. Here we have generated and investigated the biochemical and signaling properties of a soluble TGF-beta type I receptor (Tau beta RIs-Fc). As reported for the wild-type receptor, the soluble Tau beta R-I does not bind TGF-beta 1 on its own. Surprisingly, in the absence of TGF-beta1, the Tau beta RIs-Fc mimicked TGF-beta 1-induced transcriptional and growth responses in mink lung epithelial cells (Mv1Lu). Signaling induced by the soluble TGF-beta type I receptor is mediated via the obligatory presence of both TGF-beta type I and type II receptors at the cell surface since no signal was observed in Mv1Lu-derivated mutants for TGF-beta receptors R-1B and DR-26. The comparison between the structures of TGF-betas and a three-dimensional model of the extracellular domain of Tau beta RI has shown that five residues of the supposed binding site of TGF-beta 1 (Lys(31), His(34), Glu(5), Tyr(91), and Lys(94)) were found with equivalent biochemical properties and similar spatial positions.

Urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine and 5-(hydroxymethyl) uracil in smokers.

Cigarette smoke is known to generate free radicals by various mechanisms. In this study involving 30 non-smokers and 30 smokers, we show that urinary excretion of 5-(hydroxymethyl) uracil (HMUra) was not different in the two groups (6.54+/-2.07 vs. 6.70+/-1.68 nmol/mmol creatinine). In contrast, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo) excretion increased by 16% (1.16+/-0.35 vs. 1.35+/-0.50 nmol/mmol creatinine, p = 0.039). Results concerning 8-oxo-dGuo are in agreement with those of previous studies. We observed significant multiple correlations between HMUra and creatinine (r(p) = 0.44), BMI (r(p) = -0.27) and nicotine derivatives (r(p) = 0.26). Multiple correlation analysis showed relations between 8-oxo-dGuo on the one hand, and: creatinine (r(p) = 0.36), nicotine derivatives (r(p) = 0.29), BMI (r(p) = -0.24) on the other.

Urine 8-oxo-7,8-dihydro-2-deoxyguanosine vs. 5-(hydroxymethyl) uracil as DNA oxidation marker in adriamycin-treated patients.

We measured the base 5-(hydroxymethyl) uracil (HMUra) and the nucleoside 8-oxo-7,8-dehydro-2'-deoxyguanosine (8-oxo-dGuo) in urine of adriamycin-treated cancer patients. Adriamycin has been shown to generate oxygen free radicals by various mechanisms. HMUra and 8-oxo-dGuo are two known lesions of DNA, produced by oxygen free reaction on thymine and 2'-deoxyguanosine, respectively. HMUra was measured by GC-MS/isotopic dilution and 8-oxo-dGuo by HPLC/EC, both after prepurification by semipreparative HPLC. Here we report the results of a study involving 20 cancer patients treated with flash doses of ADR. We found that urine HMUra is significantly increased (HMUra (nmol/24h): 80.8 8.44 vs. 98.7+/-6.87; p < 0.01) 24h after administration of the drug, while 8-oxo-dGuo did not show any significant variation. Urine HMUra seems to be a suitable short-term marker of DNA alterations by oxygen free radicals.

Measurement of oxidative base damage to DNA by using HPLC-32P-postlabelling and GC/MS-selective ion monitoring assays.

A 32P-postlabelling assay has been developed for singling out specific oxidized base lesions. Emphasis was placed on the quantitative aspect and the accuracy of the assay, which require the use of calibration curves and microreactions, respectively. The method was successfully applied to the detection and the measurement of adenine N1-oxide and 5-hydroxymethyluracil in cells exposed to agents inducing oxidative stress including H2O2 and UV-A radiation. The sensitivity of the assay allows the detection of one lesion in 10(6) normal bases in 1 microgram of DNA. The GC/MS method when coupled to the selective ion monitoring (SIM) technique is about twenty times less sensitive, even for suitable substrates such as 5-hydroxymethyluracil and 5-hydroxyuracil, than the 32P-postlabelling assay. However, the former assay is much easier to apply, even though a derivatization step is necessary, and provides unambiguous structural information on the compound to be measured. Accurate quantitative measurements can be obtained when stable, isotopically labelled standards are available.

IMOCUR stimulates production of immunoglobulins; preliminary results concerning a correlation between in vitro and in vivo experiments.

The bacterial extract IMOCUR is described as an in vivo stimulant of antibody production during animal testing and human clinical trials. Using a slightly modified procedure (13) dealing with in vitro immunoglobulin production by C57B1/6 mouse spleen cells, we have shown that IMOCUR potentiates spontaneous IgM production. In order to explore the putative relation between this in vitro activity and the current in vivo control test (stimulation of plaque-forming cell production after sheep red blood cell injection to Balb/c mouse), we have assayed 10 lyophilisates in vitro and in vivo before and after heat inactivation (80 degrees C, 7 days in a saturated water atmosphere). Results have shown that this treatment inhibits, respectively, totally and partially in vivo and in vitro activities. Thus the in vitro technique seems to be appropriate for the control of activity of the various batches of IMOCUR. Experiments are under way to clarify the mathematical correlation which may exist between the in vitro and in vivo experiments.

Determination of the major zinc fractions in human serum by ultrafiltration.

In this paper we report a method for measuring ultrafiltrable zinc in human serum by electrothermal atomic absorption spectrophotometry. We show also that ultrafiltration permits to determine alpha-2-macroglobulin bound zinc and loosely bound zinc if a strong zinc ligand (EDTA) is added to serum before ultrafiltration. This last fraction, after deduction of ultrafiltrable zinc, represents roughly all albumin bound zinc. In 20 controls we found that ultrafiltrable zinc amounted 0.311 mumol/L (S.D. = 0.117 mumol/L), alpha-2 macroglobulin bound zinc 3.08 mumol/L (S.D. = 0.221 mumol/L), and albumin bound zinc 12.11 mumol/L (S.D. = 1.95 mumol/L). Our method needs only a small volume of serum, it is simple and rapid but also very accurate and reliable. The loosely bound fraction is very dynamic and, representing the physiologically active part of serum zinc, it could be a good marker of zinc deficiency.

Canine distemper infection in mice: characterization of a neuro-adapted virus strain and its long-term evolution in the mouse.

The Onderstepoort strain of canine distemper virus (CDV) which has been adapted to newborn Swiss mice was used in a study in weanling mice. Intracerebral inoculation of newborn mice with either the parent or mouse-adapted virus strain led to mortality in 100% of the animals. In weanling mice the parent virus produced less than 10% mortality, whereas the mouse-adapted strain killed approximately 40% of the animals and this was not dose-dependent. Although a meningitis was observed in the surviving mice, the occurrence of viral antigens was less widespread in the brain of weanling mice than in the brain of newborn mice, and could not be detected more than 5 months after infection. In long-term experiments two phenomena were observed. At 4 to 6 months post-infection up to 30% of the mice became obese; however, no viral antigens were detected in the brains. At 13 to 17 months post-infection a number of mice became paralysed and virus antigen could be detected in the brain and lymph glands; however, infectious virus could not be isolated. These observations are discussed in relation to neurological infection and metabolic disease.

Hexachlorophene and the central nervous system. Toxic effects in mice and baboons.

A study on hexachlorophene encephalopathy in mice and baboons is reported. By light microscopy, a severe spongiform lesion of the central nervous system (CNS) was localized in the white matter, without myelin breakdown or cellular reaction. By electron microscopy, the myelin alteration was characterized by wide intralamellar spaces or "splitting" developed in the intraperiod line of compact sheaths. The acute changes described were induced by administration of the drug by the digestive or cutaneous routes at various dosage levels in an aqueous solution or in talcum powder. The toxic effects depended on the age of the animals, the survival times and the concentrations of hexachlorophene, i.e., 6%, 3%, and 0.5%. The findings are compared with previous reports on the neurotoxicity of hexachlorophene and other chemicals in human and experimental animals. Hexachlorophene cannot be recommended for use in young infants because of its neurotoxicity in very low doses as demonstrated in the present report.

Experimental hexachlorophene encephalopathy in mice and baboons: light and electron microscopic study.

An experimental study on acute Hexachlorophene (HCP) neurotoxicity is reported in mice and baboons: - by light microscopy, a severe spongiform lesion of the central nervous system is localized in the white matter without myelin breakdown or cellular reaction; - by electron microscopy, the myelin alteration is characterized by the presence of vacuolation of "splitting" in the intralamellar spaces of compact sheaths; myelinated axons are occasionally involved. The changes described are discussed according to various reports on HCP neurotoxicity in humans and experimental animals. The effects of this chemical agent on the central nervous system is related to the percentage of HCP in talcum powder or solution for topical use. The toxicity of very low dosage level is demonstrated in baboons. Therefore HCP use cannot be recommended for young infants.

[Comparative induction of viral antigen synthesis in various types of cells infected by polyoma virus]. / Induction comparée de la synthèse d'antigènes viraux dans différents types de cellules infectées par le virus polyome.

Induction of synthesis of the viral antigens T and V during polyoma virus infection was studied in primary Mouse and Hamster kidney and brain cultures, as well as in various types of human cells. The results show that: (1) Despite a very low percentage of positive cells by immunofluorescence, Hamster brain cells produced more viral antigen than kidney cells, as opposed to what was found in Mouse brain cells. (2) Most human cells produced neither T nor V antigens. Conversely, a large number of brain cells synthesized the T antigen very early after infection.

Tumorigenic clones of hamster brain cells transformed in vitro by polyoma virus. Ultrastructural and immunohistochemical study.

The morphological characteristics of three clones of hamster brain cells transformed in vitro by polyoma virus and of the tumors obtained after subcutaneous grafting of these cells in syngenic animals are reported. These clones appeared to be glial in nature by light and electron microscopy. The initial tumors induced by the three clones presented astrocytic features both by electron microscopy and immunohistochemistry. Analysis of the subsequent in vivo passages showed a decrease in cell differentiation, which was accompanied by a decrease in the latency period; after 2 years of serial transplantation, the tumors seemed poorly differentiated gliomas. A control cell line of hamster cerebellar cells evolved similarly.

Normal and benzo(a)pyrene-transformed fetal mouse brain cell. I. Tumorigenicity and immunochemical detection of glial fibrillary acidic protein.

Primary cultures of whole brain and cortex cells origination from 14-day-old A/Jax or C3H mouse fetuses were treated with benzo(a)pyrene (B(a)P) for 24 h. After 7 to 8 passages a malignant transformation was observed in the chemically treated whole brain and cortex cultures. Control cultures of cortex remained non-transplantable during the whole experiment (up to 14 passages) whereas in the control cultures originating from whole brain a spontaneous transformation appeared after 11 passages. With horseradish peroxidase-labelled antibody, the specific glial fibrillary acidic protein (GFAP) was detected in both control and transformed total brain and cortex cultures, and in the tumors initiated by the in vitro transformed cells. This finding shows that glialike cells persisted after a long in vitro maintanance and transformation.

Normal and benzo(a)pyrene-transformed fetal mouse brain cells. II. Ultrastructural study.

An ultrastructural study was performed on normal and Benzo(a)-pyrene(B(a)P)-transformed fetal mouse brain cells. Early subcultures of a strain initiated from whole brain presented three cell types in vitro: astroglial, poorly differentiated glial, and spongioblastic types. After B(a)P-treatment, there was an exclusive transformation and the growth of neuroglia sometimes without gliofibrillary maturation, but with the presence of glial fibrillary acidic protein (GFAP) in the cytoplasm. Early subcultures of another strain initiated from cortex only presented poorly differentiated neuroglial cells. After transformation, cell maturation as evidenced by gliofibrillogenesis and GFAP production by these cells was observed. In both cases, the potentiality of glial differentiation after in vitro malignant transformation by a chemical carcinogen seemed preserved.

[Ultrastructural study of meningiothelial meningioma with 'hyaline inclusions' (author's transl)]. / Etude ultrastructurale des corps hyalins d'un méningiome pseudo-epithélial.

One case of meningiothelial meningioma with "hyaline inclusions" (colloid-bodies or pseudopsammomas) as noted by Cushing and Eisenhardt (1938) and by Kepes (1961-1975) is reported by light and electron microscopy. Two types of these structures, either homogeneous or polymorphic, surrounded by microvilli are described and regarded as signs of secretory differentiation of tumor cells. In addition to Kepes' description, the authors show, at high magnification, the polymorphic material including homogeneous component, lamellar structures, microvesicles and dense bodies. The endocellular overproduction of the various types of "hyaline inclusions" and the nature of their material are discussed.

Neoplastic transformation of hamster brain cells in vitro by polyoma virus.

The transformation of cultivated hamster brain cells by polyoma virus is reported. The transformed cell line contained polyoma virus-specific nuclear, surface and transplantation antigens. Subcutaneous and intracranial inoculations revealed high tumorigenicity of the cells. Brain-specific S 100 protein was found in these tumors with immuno-peroxidase staining, suggesting that they were of a nervous nature. Both in vivo and in vitro, the cells had glial features as studied by phase contrast, light and electron microscopy. Type-H virus-like particles were found in the tumor cells and might have played a role in the viral transformation.

[In vitro malignant transformation of fetal hamster brain cells by methylnitrosourea]. / Transformation maligne in vitro de cellules de cerveau faetal de hamster par la méthylnitrosourée.

Using primary cultures originating from 14 day old fetal Hamster brain, we have obtained a cell line with glial morphology. These cell remain non transplantable during the first year of in vitro culture, but undergo spontaneous transformation during the second year. Following prolonged contact of the glial-like cells with 25 to 50 microgram/ml of methylnitrosourea (MNU), a malignant transformation is observed 5 months after the treatment. The lowest concentrations of (MNU) do not cause malignant transformation, but seem to inhibit (or postpone) the spontaneous transformation. After MNU treatment, cells retain their glial nature.

[Transformation, in vitro, of cerebral hamster cells by polyoma virus]. / Transformation in vitro de cellules cérébrales de hamster par le virus polyome.

A cell line called HCxPy was obtained in vitro by transformation of dissociated hamster brain cell cultures by polyoma virus. The first foci of transformed cells became evident 90 to 120 days after viral infection. This cell line is now at the 46th passage. The cells appear tumorigenic for hamsters after subcutaneous and intracerebral injection. They carry the polyoma virus T and cell surface antigens. Good evidence for astrocytic differentiation can be found by morphological examination of the tumours and of the cultured cells.

[Cerebral hemangiopericytoma. Ultrastructural study of one case]. / Hémangiopéricytome cérébral. Etude ultrastructurale d'un cas

The authors report electron-microscopic observations upon a primitive cerebral haemangiopericytoma. The vascular appearance of the tumour is due to the presence of abundant extracellular material which has a structure like that of vascular basement membranes. The fact that the tumour cells are pericytes is confirmed by the existence of intracytoplasmic microfilaments of 60-80 A in diameter, sometimes gathered into osmiophilic aggregations and forming simple cellular junctions (zonulae adherentes). Stress is laid upon the importance of differentiating this rare tumour from an angioblastic meningioma; the haemangiopericytoma is more rapidly growing and carries a more serious prognosis.