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Biomedical subjects

W Pirsig

Publications and source records attributed to W Pirsig.

167 records · Page 10Linked to original sources
PubMedDate not supplied

Differentiation of nerve endings in the cochlear nucleus on morphological and experimental basis.

The axo-somatic terminals which synapse with the large spherical cells in the antero-ventral cochlear nucleus of the guinea pig are subdivided into three groups by means of different stereological form of their synaptic vesicles. Unilateral stimulation as well as long-term degeneration of the cochlear nerve produce significant changes of the cross sectional area of the terminals and the number of their mitochondria, when compared to the contralateral control. Both parameters are increased after stimulation and decreased following degeneration. These changes occur in different extent in the three groups of terminals. The discussion of these findings has led to the following conclusions: (1) The volume of synaptic terminals and the number of the enclosed mitochondria display the most pronounced plastic changes. Therefore these parameters seem to be very indicative for the study of function-related changes. (2) The volume of terminals, the quantity of their mitochondria, and the total sum of membranes may be increased under stimulation by actual acceleration of the axoplasmatic flow rate and by incorporation of the preterminal portion of the axon. (3) The presence of at least three types of terminals is evident from the different form of their synaptic vesicles and in addition, from their different response to our experimental conditions. It is not decided from the present findings, whether the bouton-like terminals and bulbs of the afferent cochlear nerve axons contain the same type of synaptic vesicles or whether these axons produce heterotypic terminals.

Animals↗
PubMedDate not supplied

Postnatal growth of the human septal cartilage. Preliminary report.

Growth activities in different areas of the human septal cartilage were determined by the extent of DNA synthesis and matrix synthesis in 20 patients aged 6 to 40 years. DNA synthesis measured by in vitro incorporation of 3H-labelled thymidine was markedly elevated in the anterior free end and the central area of the septum in all age groups. Matrix synthesis measured by in vitro incorporation of labelled sulphate into proteoglycans showed a comparable age-independent activity in the anterior free end, whereas in the suprapremaxillary area, matrix synthesis displayed its greatest activity during childhood, showing thereafter a continuous decline during puberty and adulthood. A similar age-dependent pattern in this area, though at a much lower level, could also be demonstrated for the extent in DNA synthesis.

Adolescent↗
PubMedDate not supplied

[Regeneration of septal cartilage in children after septoplasty. A histological study].

In eight boys aged 6.3 to 11.7 years a septoplasty had been performed according to the technique of either Cottle or Goldman. Because of new nasal obstruction 1.2 to 3.9 years later a second septoplasty was carried out. In this operation, little pieces of cartilage were excised from the formerly resected base, middle, and columellaborder of the septum for histological examination. In all pieces a regeneration of the septal cartilage by appositional and interstitial growth could be found: in a smaller amount at the resected borders of the septal base, in a larger amount at the corrected borders of the septum in the columella and in the septal middle. These histological findings of a regenerative potential of surgically traumatized septal cartilage in children by conservative septoplasty can be compared with the experiences in the growing septum of rodents.

Cartilage↗
PubMedDate not supplied

[Surgical findings in an Egyptian mummy's skull].

Reports of hard and soft tissue injuries of the head in ancient Egypt were first published in the surgical "Book of Wounds" of E. Smith's Papyrus, which dates back to the 16th century B.C., and is assumed (Pahl, 1986) to be a collection of experiences gained over a thousand years. Diagnostic clues and guidelines for the treatment of fractures of the maxilla and the zygomatic bone are described in several cases.

Cephalometry↗