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[Cerebral anatomy on computerised tomograms (author's transl)].

An attempt has been made to show which anatomical structures of the skull and brain can be demonstrated by analysing 668 computerised tomograms of normal brains. Many parts of the bony skull, the cisterns and ventricles and physiological calcification of the pineal body, choroid plexus and falx can be clearly identified. Frequently it is possible to distinguish between grey and white matter in the basal ganglia. After intravenous contrast injection it is sometimes possible to identify arteries and other pathways and vascular structures by their increased contrast. Because of the constant topographic relations in the brain, it is possible to identify these structures with certainty on the computerised tomogram.

Brain

A comparative study of physiologic intracranial calcifications.

It has been the impression of clinicians that pineal calcification is infrequent in Shiraz, Iran. In order to evaluate this clinical impression 2000 consecutive skul X-rays taken at Saadi Hospital, Shiraz, Iran, were reviewed for the presence of physiologic intracranial calcifications. The incidence of these clasifications in male and female in consecutive age groups of 10 years from 0 to over 70 years of age were assessed and compared with previous reports from other countries. The average incidence of pineal calcification for those over 20 years of age was 18.29% in this study compared with 55% in the U.S.A. The incidence of calcification in the choroid plexus and the falx cerebri was also considerably less than previously reported. The literature is reviewed and the possible causes for the geographical differences in the reported frequency of physiologic intracranial calcifications is discussed. It is possible that racial and dietary factors may be significant in the variation in the incidence of pineal and other cranial calcifications noted in different countries. Within a population group, age and sex are additional factors.

Adolescent

The presence of gamma-carboxyglutamic acid-containing protein in atheromatous aortae.

It has been established that a gamma-carboxyglutamic acid-containing protein is present in rat aortae after long term atherogenic diet administration. A similar protein was proven to be present in turkey tibial tendons that are predisposed to undergo physiological calcification. The molecular weight and amino acid composition of both proteins were identical. They contained six glutamic acid residues per molecule, three of which were gamma-carboxylated. The proteins studied were also identical in their N-terminal sequence over six residues. This sequence was fully coincident with that published for osteocalcin (Price, P.A., Poser, J.W. and Raman, N. (1976) Proc. Natl. Acad. Sci. U.S.A. 73, 3374--3375). In the region corresponding to residues 20--26 in osteocalcin, a single replacement of valine for isoleucine was found in turkey tendon protein. From the physiological point of view it should be mentioned that the level of the gamma-carboxyglutamic acid containing protein in atherogenic diet fet rat aortae exceeds that found normally in bone or in tissues predisposed for physiological calcification.

1-Carboxyglutamic Acid

[Axial computer tomography of the brain].

Computertized tomography of the brain, developed by Hounsfield - has decisively altered neuroradiologic procedures. Without the need of contrast media, cerebral structures (ventricles cisternes, sulci and physiological calcifications) and pathologic lesions (infarctions, hemorrhage, edema, tumors and malformations) may be visualized. Tumors can be diagnosed in 95 to 99% by this method. Tumors of the midline structures and of the posterior fossa are more easily detected than by conventional methods. In head injuries epidural and subdural hematoma, contusional edema and hemorrhage may be differentiated. Hydrocephalus externus and internus can be shown by computertized tomography. Probably computertized tomography will become the most frequently applied neuroradiological method in the future.

Brain

Pyrophosphate and diphosphonates in skeletal metabolism. Physiological, clinical and therapeutic aspects.

Pyrophosphate and diphosphonates produce striking results on calcium metabolism in experimental animals and man. Compounds containing P-O-P- bonds (e.g. inorganic pyrophosphate [PP-ii1 or P-C-P bonds (diphosponates) inhibit both the formation and dissolution of calcium phosphate crystals in vitro. PP-i may have a physiological function in regulating calcification and bone turnover, and obnormalities in its metabolism may occur in some human diseases notably hypophosphatasia and pseudogout. Diphosphonates inhibit ectopic calcification, and slow down resorption and bone turnover in several experimental systems in vivo. They have helped in studies of various aspects of the regulation of calcium metabolism. The diphosphonate, disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) has been shown in clinical studies to be effective against ectopic calcification particularly in myositis ossificans progressiva and in disorders of increased bone resorption such as Paget's diseases and some types of osteoporosis. -99mTechnetium complexes of EHDP, PP-i and other polyphosphates have also recently been used successfully as bone scanning agents.

Animals

[Some problems of space medicine].

The paper discusses the problems to be resolved by space medicine and the main stages in the development of this branch of science, beginning with the vertical launches of rockets and ending with the flights of orbital stations. On the basis of ground-based simulation experiments and real space flights it presents a classification of the major symptomocomplexes that may occur inflight. The paper describes the main stages of adaptation to weightlessness and physiological changes in the weightless state. The paper also outlines further pathways in the development of space medicine.

Adaptation, Physiological

Interrelationships of dental maturity, skeletal maturity, height and weight from age 4 to 14 years.

The correlations of dental mineralization stages, skeletal mineralization, body-height and weight were determined for each year between age 4 and 14 for 121 boys and 111 girls of the serial experimental group of the Burlington Growth Centre. Dental development related more strongly to morphological development than to skeletal development in both sexes, and skeletal age was more strongly related to morphological age than to dental stage. The relationship of individual teeth to skeletal age, height and weight were different but consistent in a sex-specific pattern. In males, both skeletal mineralization and dental mineralization, particularly of the first molars, were more closely related to height than to weight. In the females, skeletal and dental mineralization, especially of the second molars, were more closely related to weight from age 7 than to height. These relationships were significant in both pre-adolescent and adolescent years. In both these periods, skeletal age and body size related most strongly to late stages of tooth formation. Hence, from an early age, the stages of dental, skeletal and morphological maturation were significantly interrelated in a pattern that was specific for individual teeth and for sex.

Adolescent

Calcified arteries in a gastropod.

The anterior aorta and major arteries of the land pulmonate snail Anguispira alternata have large calcium deposits in their walls. These deposits occur inside spherule cells, which line the walls of these vessels. The calcium occurs as amorphous calcium carbonate, in the form of intracellular spherules having alternating layers of organic and inorganic material. The spherule cells appear to be degenerating connective tissue cells; they are characterized by large numbers of spherules and by a cytoplasm which is totally empty except for a nucleus, scattered glycogen particles and a few membrane remnants. The injection of 45Ca into the foot of the snail results in rapid incorporation of this calcium into the spherule cells. Although calcium-containing spherules are now known from a wide variety of invertebrate tissues, they have not been previously recorded from arterial walls. The physiologic significance of these deposits is not known.

Animals

Mineralization of dentin, bone and tendon in vitro.

Bovin dentin, bone and tendon slices, and rat bone, readily mineralize to variable degrees after demineralization by (EDTA) at pH 7.4, but they fail to mineralize after dimeralzation with acetic acid (HAc) at pH3.0. The demineralized dentin, but neither bone nor tendon, contained organically bound phosphate. The EDTA-demineralized dentin contained less phosphate than HAc-demineralized dentin. HAc-demineralized rat dentin contained high levels of phosphate. Since the EDTA- and HAc-demineralized rat dentin contained widely different levels of phosphate, yet both mineralized, it was concluded that phosphoprotein had little effect on nucleation. The reason why HAc-demineralized tissue other than rat dentin failed to nucleate and mineralize was not clarified.

Acetates