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Biomedical subjects

M L Moss

Publications and source records attributed to M L Moss.

At least 91 records · Page 5Linked to original sources
PubMed1977

The effect of methylazoxymethanol on growth of the spheno-occipital synchondrosis in rats.

Methylazoxymethanol (MAM) causes a reduced development of cerebellum and medulla oblongata in rats. To study the effect of external factors on growth of the spheno-occipital synchondrosis, four litters of rats each of five animals were treated with MAM within 12 h after birth and sacrificed after 30 days. A similar number od control rats were sacrificed at the time when their skull length was equal to that of the experimental rats. Microradiographical and histological investigations showed that the cranial base lordosis was more pronounced in the MAM rats than in the controls, and that the width of the spheno-occipital synchondrosis was reduced mainly due to reduction in the central zone.

Animals↗
PubMed1977

A functional analysis of fusion of the tibia and fibula in the rat and mouse.

The distal diaphyseal shafts of the rat tibia and fibula fuse postnatally, a process initiated by the seventh day with the formation of secondary cartilage that is subsequently replaced by endochondral ossification. The histological appearance of this fusion process is described. A homologous process occurs postnatally in the mouse. An analysis of some of the pertinent recent developmental, comparative and paleontological data indicated that extrinsic, biomechanical factors probably played a significant causal role in tibia-fibula fusions. The production of secondary cartilage is evoked by extrinsic forces, and these fusions were analyzed within the present concepts of intrinsic and extrinisic factors in skeletogenesis. It was concluded that the fusions currently reported fit well within the hypothesis of the functional matrix and that, such fusions between skeletal tissues are secondary, compensatory and mechanically obligatory responses to the prior demands of functionally related nonskeletal tissues and organs.

Animals↗
PubMed1976

Epinephrine in the angiographic evaluation of experimental kidney trauma.

Selective nephroangiography was performed in the dog following percutaneous needle biopsy to evaluate epinephrine response. Traumatized vessels respond normally to epinephrine, often with increased extravasation as the vessel recovers from epinephrine. A selective inability of the traumatized vessel to constrict was not noted.

Animals↗
PubMed1976

Idiopathic pulmonary fibrosis. Clinical, histologic, radiographic, physiologic, scintigraphic, cytologic, and biochemical aspects.

Idiopathic pulmonary fibrosis is a fatal disorder that starts as an alveolitis and progresses to interstitial fibrosis. Correlative morphologic, physiologic, and biochemical studies in 29 patients have shown that the inflammatory process in best followed by serial bronchoalveolar lavage and 67 Ga citrate scanning, and the fibrotic process is best followed by quantitation of the exercise-induced drop in arterial oxygen tension per unit of oxygen consumed. Although biopsies in idiopathic pulmonary fibrosis seem to show increased amounts of fibrotic tissue, biochemical studies suggest that the disease is probably one of collagen rearrangement rather than collagen increase. Perhaps becasue of this, peripheral lymphocytes of these patients recognize collagen as "non-self" and, when exposed to it in vitro, produce lymphokines and cell lysis. The fibrotic process is probably irreversible, but the inflammatory and immune processes that cause it may be amenable to therapy if diagnosed early.

Adult↗
PubMed1975

Functional anatomy of cranial synostosis.

An understanding of how sutural growth processes relate to the totality of cranial growth is necessary to cure the cause and not just the symptoms of cranial synostosis. There is no direct genetic determination for the origin, growth, size, shape or maintenance of bones. Rather, phenotypic expression of skeletal tissues is regulated via genetic information encoded in the cells of functional matrices. The primary morphogenetic event in neurocranial growth is the volumetric expansion of the neural mass, which causes the surrounding neurocranial capsule to expand. Calvarial bones arise at widely separated ossification centers and spread centrifugally towards each other. Premature synostosis of the human metopic suture was noted as a frequent characteristic of the cleft-palate skull. Primary morphological event associated with premature synostosis was a cranial base malformation. Cranial sutures permit passage of the neonatal head through the birth canal, permit slight relative variations between adjacent bones while keeping these same bones relatively approximated. All morphological attributes of carnial bones and of their sutures are extrinsically determined and regulated, including both the normal and premature synostosis of the cranial sutures. It seems reasonable to the author that premature synostosis originates in the early embryonic prosencephalic head organizer, which makes it developmentally understandable.

Animals↗
PubMed1975

Studies on dentin 2. transient vasodentin in the incisor teeth of a rodent (perognathus longimembris).

Vascular inclusions regularly occur in the lingual dentin of the constantly erupting teeth of the pocket mouse (P. longimembris). The inclusion of a capillary loop and surrounding perivascular tissues is associated with odontoblasts whose cytodifferentiation is relatively immature. These same cells produce dentinal tubules which are more irregular in their course, more arborescent, with more lateral branches, wider in diameter and less numerous than are the tubules of the labial orthodentin. The patent vascular inclusions are surrounded by a broad halo of incompletely mineralized dentin. With further maturation complete obliteration of the vessels occurs, accompanied by complete dental matrix mineralization. A literature review supports the contention that vasodentinogenesis is related operationally to lower stages of odontoblastic cytodifferentiation although the processes by which this occurs are not yet clear.

Animals↗
PubMed1975

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: appendix II. Evaluation of oral, dental, and skeletal tissues.

A sparse neutrophilic leukocytic infiltrate was found in the gingival sulcus, both in the flight and the control animals, while no changes were observed in the palate. Mitoses in gingival and palatal tissues were in approximately equal numbers in all animal groups. The tongues of flight mice and controls contained areas characterized by vascular dilatation, separation of muscle bundles, and regressive and degenerative changes in muscle fibers. Mucous glands in the posterior part of the tongue of flight and control animals exhibited acinar distension. Also examined were the vertebral column; femur, knee joint, tibia and fibula of the right hindlimb; and the tracheal cartilages. No evidence of cosmic ray particle effects was found in any of these tissues.

Animals↗
PubMed1975

New studies of cranial growth.

Additional experimental data indicate that cranial base elongation is secondarily responsive to prior alterations of the neural mass, further supporting the functional matrix concept. Additional studies of epithelial growth and of muscle regeneration suggest that neurotrophic processes, regulating functional matrices, may play a significant role in both normal and abnormal cephalogenesis.

Animals↗