Abnormalities of DNA in human osteoarthritic articular cartilage.

The normal amount of DNA in human diploid nuclei was determined by the use of the Feulgen reaction measured by microdensitometry. The DNA-content of nuclei in normal human articular cartilage was determined in nuclei of zones 3 and 4 of cartilage of the femoral head removed from osteoporotic fractured necks of femur. Analysis of the results indicated that a degree of synthesis of DNA occurred even in these zones of very elderly persons. Results on these zones in the articular cartilage of osteoarthritic joints indicated that different populations occurred. In some there was DNA-synthesis related to tetraploidy; in others, the DNA was very stable to acid hydrolysis with no sign of biosynthetic activity; in the last group, which contained erosions of the superficial zones, the DNA was unstable to hydrolysis.

Behavioral factors in the etiology of asthma.

Evidence for the role of behavior in the etiology of asthma is reviewed here. Behavioral factors have not convincingly been shown to play a part in the inception of asthma. It has been suggested that asthma attacks can be precipitated by conditioning. Previous experiences leading to the expectation that an attack may occur can be regarded as a behavioral factor which may trigger an attack, possibly by inducing hyperventilation. Further research should focus on the possible role of behavioral factors in maintaining a state of hyperreactivity of the bronchi and psycho-immunologic aspects such as brain-controlled neuroendocrine immune mechanisms.

[Nerve grafts in iatrogenic intratemporal facial paralysis]. / La greffe du nerf dans la paralysie faciale intra-temporale iatrogène.

The paper reviews the question of nerve grafts in iatrogenic facial palsies caused lesion of the tympanic or mastoid portion. The approaches used by different specialists are discussed and the controverse on the question is analyzed. The authors present their experience in six cases of successful operations.

Effect of diltiazem on methacholine-induced bronchoconstriction in extrinsic asthmatics.

The protective effect of the calcium antagonist diltiazem on methacholine-induced bronchoconstriction was investigated in 19 extrinsic asthmatics. A double-blind cross-over design was used (diltiazem vs. placebo, administered orally for 1 week). We found no significant difference between the two treatment regimens when expressed as the provocation dose of methacholine causing a 20% drop in forced expired volume in 1 s (PD20 FEV1). Some individual patients might nevertheless gain some benefit from diltiazem as an additional treatment in difficult-to-manage asthma.

Fine structure of epidermal mucous cells of some Brazilian earthworms (Oligochaeta:Annelida).

Electron microscopic techniques were adopted to study the comparative morphology of the secretory granules of the epidermal mucous cells of 4 species of brazilian earthworms. 2 main types of secretory granules were described: A first type, presenting a central body with a high electron density and surrounded by a material with variable aspects and electron densities. The second type of secretory granule possesses an homogeneous aspect and a relatively low electron density. The size and the morphology of secretory granules reveal significant variations among the species and also inside a single specie.

Fine structure of the epidermal cuticle of some Brazilian earthworms (Oligochaeta: Annelida).

Electron microscopic techniques were adopted to study the epidermal cuticle of 4 species of brazilian earthworms. Basically this structure consists of collagenous fibers arranged in alternate layers and embedded in an amorphous and fibrillar matrix. Of characteristics, the ellipsoidal projections of the cuticle of P. hawayana were found to be enclosed between 2 parallel layers, where each layer consists of 2 electron dense lines, separated by a space filled with an electron dense material.

On the cross sectional area of skeletal muscle fibres of the rat.

Serial cryostat sections of M. gracilis (pars caudalis) were stained to demonstrate succinic dehydrogenase activity and then used to study the cross sectional area along the length of each category of muscle fibre. The results indicated that the mean area showed no appreciable variation. This finding support the evidence that the cross sectional area is the same along the course of a muscle fibre. Some sources of variation were also discussed.

Histochemical study of mucopolysaccharides in epidermal mucous cells and subjacent granular cells of Glossoscolex uruguayensis L. (Righi, 1978).

Histochemical study of mucopolysaccharides of both mucous secreting and subjacent granular cells of the epidermis of Glossoscolex uruguayensis L (Righi, 1978), has been done. Histochemical tests revealed two major types of mucous cells: large ortochromatic mucous cells and metachromatic mucous cells. The first ones possess alpha-amylase resistant, PAS-positive material, together with little mucic acid, and the latter present a very low rate of neutral mucopolysaccharides and to a variable degree, both carboxylate and sulphate mucopolysaccharides. A third cell type was also detected, presenting a frothy acid like material. Subjacent epidermal granular cells display alpha-amylase resistant, PAS-positive granules, with no acid mucus.

Lysosomal enhancement in hepatic cells of a teleost fish induced by cadmium.

The toxic effects of cadmium upon the hepatic cells of a freshwater fish were studied. The experiment was developed by the addition of cadmium chloride in the water and histochemical and EM methods were performed. The results showed that acute intoxication induces an increase of lysosomal activity related to the shape, distribution as well as different functional degrees of the organelle condensation. The authors analyze the different situations whose leading alterations of lysosomal behaviour and the probable mechanisms of cadmium action.

A congenital myopathy of unknown origin.

Parallel with the clinical and histochemical investigations, an ultrastructural examination of a muscle biopsy specimen was made, in order to detect any slight cellular alterations which cannot possibly be discovered through any other methods, and to identify a muscle disease of unknown origin.

The effect of thyrotrophin on oxidative activity in thyroid follicle cells.

Biochemical evidence, based on supra-physiological concentrations of thyrotrophin (TSH), has indicated that this hormone increases the NADP concentration in thyroid follicle cells. The hormone is believed to act both to enhance the reoxidation of the reduced coenzyme and to generate NADP from NAD. The latter effect, mediated by NAD-+-kinase, could be a major control mechanism in thyroid metabolism. In the present study increased sensitivity has been obtained by the use of maintenance culture and of microdensitometry for measuring enzyme activity in the follicle cells. Using low physiological (0.1 muU/ml), and sub-physiological concentrations of the hormone as are used in the cytochemical bioassay systems, it has been shown that the rate of reoxidation of NADPH is enhanced by TSH. Moreover the NAD-+-kinase activity is also greatly increased, and shows a direct relationship to the concentration of the hormone acting on the segments of the gland in vitro. It is possible that this phenomenon could be used to assay TSH. The results indicate that NAD-+-kinase activity may play a significant part in the control of pentose-shunt oxidation in thyroid follicle cells.