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Biomedical subjects

M Sakka

Publications and source records attributed to M Sakka.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Comparative anatomy of the velopharyngeal complex in human and non-human primates (2)].

The authors describe the soft palatal-pharyngeal unity, composed of the levator palati and palatopharyngeus muscles in the adult man, the new-born and the Saimiri. They recall the importance of the soft palatal-pharyngeal sphincter in the man's phonation. After having described the general evolution of the aerodigestive tract in the no human mammals and the man, notions of evolutive morphology of the soft palatal-pharyngeal unity are established. They are characterized by the gradual divergence of the axis of the 2 muscles forming the soft palatal-pharyngeal unity ending in the appearance met in the adult man, indispensable in view of a soft palatal-pharyngeal ability allowing a articulated language.

Adult↗
PubMed1987

[Effects of intracranial pressure on frontal sinus development].

Through a study of some syndromes of intra-cranial high and low pressure, the authors try to find out the relations between the intra-cranial stresses and the development of frontal sinuses. They account for the choice of frontal sinuses and the various factors determining this pneumatization. They study the morphology of the frontal sinuses in 20 cases of old and chronic hydrocephaly, in 13 cases of oxycephaly with a late diagnosis, and in 20 cases of adults suffering with infantile cerebral hemiatrophy. They show that in these syndromes, the development of frontal sinuses is an inverse ratio to the intracranial pressure. However, they point out that in standard people, the extreme differences in the morphology of their frontal pneumatization can be explained not only by various causes--a number of which is as yet not known--but also by an aleatory distribution.

Atrophy↗
PubMed1986

[Contribution of radiological technics to the study of the mandibular canal. Application to human fossils and comparison with modern man and Pongidae].

Fossil mandibles from the "La Chapelle-aux-Saints" Man and Cro-Magnon "old man" are considered to be representative of Neanderthal and Cro-Magnon era. Radiographic studies of such mandibles - including C. T. Scan and panoramic views in common use in maxillofacial surgery - allowed the authors to make useful comments: the mandibular canals are nearly similar to those in Modern Man and quite different from those in Pongidae; the imaging was of adequate quality for a good evaluation of fossil internal structures.

Animals↗
PubMed1986

[Variations as a function of time of the ossification of various bony elements of the cranial vault (experimental study in mice)].

Experimentally studied in the Mouse, ectocranial modeling bone processes are linked with stages of neuro-physiological development. More particularly, the weaning period is correlated with a complete change of periosteal growth processes in the cranial vault. This study details the different growth processes that model each bony unit of the cranial vault during the two distinct phases of post-natal development (before and after the weaning). Before the weaning, fast cerebral expansion involves generalised growth processes on the whole cranial vault area. A common pattern of growth is shared by several bones (or parts of bones), each bone showing particularities of growth rythm. The interparietal bone, the supraoccipital bone, and the anterior part of non-orbital frontal bone are excluded of that anatomical set of the cranial vault". After the weaning, bone modeling is dependent to muscular strengths. Local processes become more pronounced than generalised growth processes. Sutural and synchondral differential growth are playing a leading part in the craniofacial morphogenesis.

Aging↗
PubMed1982

Mass survey of gastric cancer and leukemia in Miyagi Prefecture, Japan.

A little more than 20,000 examinees of x-ray mass survey of gastric cancer and the controls were followed up from 1960 to 1977. Cumulative doses of x-rays were calculated for each examinee, and a collective dose in person-year-rads was constructed. Incidence of leukemia was ascertained from Miyagi Prefectural Cancer Registry. Seven cases of leukemia were found out of 242,689 person-year-rads in the irradiated population, and 9 cases out of 273,344 person-years in the controls. Incidence rate in the two groups was identical. Therefore, the risk of this mass survey was disproved.

Adult↗
PubMed1982

[Process of mandibular ossification in mice and evolutionary morphology (experimental study by means of vital staining)].

The injection in vivo of red alizarin S. in young mice during the post-natal period, enabled to show the mechanisms that were modeling the mandible during its development (by apposition-resorption). So it was possible to study : the processes of ossification involved in the eruption of the teeth, the modifications of the bony relief and the alterations of the mandibular angle. It has been attempted to find the links between these phenomena and muscular excitation, function and behaviour. The study of the osseous - muscular - mandibular anatomical set provided a good example of the principle described in Evolutionary morphology: "The comparatively free evolution of the elements in the anatomical set that they constitute (Sakka, 1973)."

Animals↗
PubMed1981

Implications of thymidine labeling index in the growth kinetics of human solid tumors.

The biological implication of the thymidine labeling index (LI) in the growth kinetics of human solid tumors were investigated by regression analysis of paired individual data in single tumors from the literature. The results indicate that LI correlated best with the corresponding growth fraction (GF) or ratio of duration of the S phase to the median cell cycle time (Tc). The LI also significantly correlated, but to a lesser degree, with Tc, the volume doubling time (TD) and/or the duration of the G1 phase (Tg1), and the correlation coefficients decreased in that order. LI did ot correlate with Ts, duration of the G2 phase or cell loss factor (CL). Although the regression coefficients and constants in the equations are significantly different in tumors of different histological types, the difference seem to be small. Further, the LI highly correlated with the calculated cell loss rate in terms of the number of cells lost per 109 cells per day, although it did not correlate with CL. This trend was seen not only with individual tumors, but also among tumors of various histological types. It is thus likely that individual tumors with higher LI tend to have higher GF, shorter Tg1 and Tc, and therefore shorter TD, which results in higher rates of cell production and cell loss.

Adenocarcinoma↗
PubMed1980

Cell population kinetics of human solid tumors: a statistical analysis in various histological types.

Pooled individual data from the literature on human tumor cell kinetics were statistically analyzed. The thymidine labeling index was obtained for 693 solid tumors and the geometric mean values (LI) were calculated for all tumors combined and for tumors grouped into 10 histological types. Lymphoma, undifferentiated lung carcinoma, childhood carcinoma and squamous epithelioma showed significantly higher LI than all tumors combined. On the other hand, melanoma, adenocarcinoma, brain tumors and mesenchymal sarcoma showed lower LI than all tumors combined, and the values decreased in that order. The geometric mean of the growth fraction (GF) was significantly different among different histological types and was highly correlated with LI when log (GF/LI) was plotted against log LI. With limited data, the mean cell cycle times (Tc) of squamous epithelioma and adenocarcinoma did not appear to be different. The data on the cell loss factor (CL) were insufficient to permit comparison of the differences among histological types. However, the CL values were distributed within a narrow range from 78 to 99%. Thus, GF seems to vary among histological types, and this is reflected by the variation of LI.

Biometry↗