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Biomedical subjects

R F Dodson

Publications and source records attributed to R F Dodson.

At least 73 records · Page 4Linked to original sources
PubMed1980

A comparison of ultrastructural characteristics of bronchoalveolar macrophages in perfused parenchyma with those obtained by a fixative or physiological saline lavage.

A comparison was made of the ultrastructural characteristics of bronchoalveolar macrophages from perfused lung parenchyma with those obtained from lavage procedures using either a balanced salt solution or buffered fixative. In comparing morphology by scanning and transmission electron microscopy, it was observed that the macrophages recovered through the fixative lavage procedure were more nearly like those found in perfused parenchyma. These characteristics included polarized surface extensions and pleomorphic forms. The cells collected via balanced salt lavage were consistently oval in shape and had randomly distributed peripheral processes. The ultrastructural features were found to be superior in the fixative lavage preparation when compared with those cells obtained in balanced salt solution.

Animals↗
PubMed1979

Morphological definition of a case of 'usual' interstitial pneumonia.

A 61-year-old Caucasian female complained of shortness of breath, fever, and a period of rapid weight loss. After routine studies, the patient underwent an open lung biopsy in order to define the characteristics of the interstitial lung disease, and initiate appropriate therapeutic intervention. Typical fibrotic and cellular proliferation were evident in the parenchyma, as determined by standard light microscopy. However, in a correlated study using light microscopy of plastic embedded tissue, as well as scanning and transmission electron microscopy, a major proliferating cell type was identified as a type II pneumocyte. These cells were the predominant lining cells of the alveoli and clearly protruded into and limited available respiratory air spaces. The predominance of type II pneumocytes in the pathogenesis of certain respiratory diseases requires that a better explanation be sought for this phenomenon.

Female↗
PubMed1978

Differences in the time course of regional cerebral hemo-dynamics of gray and white matter during experimental hypertension.

Investigations concerned with the pathogenesis of hypertensive encephalopathy have reported two opposing changes in cerebral hemodynamics during induced hypertension: (1) vasospasm or vasoconstriction of the leptomeningeal arteries and (2) increase of cerebral blood flow which has been termed "breakthrough" of the cerebral autoregulation. To resolve this apparent conflict, continuous measurements of focal cerebral flow and oxygen availability were made in 17 baboons by the use of implanted platinum electrodes placed in both gray and white matter during induced hypertension. Autoregulation was initially well maintained in gray matter followed by "breakthrough" but the autoregulatory response was poorly maintained in the cerebral white matter. The vasoconstriction of the leptomeningeal arteries reported in earlier investigations from observations made through a skull window appears to be due to a marked autoregulatory response to hypertension rather than vasospasm. The autoregulatory response appears to be efficient in gray matter but relatively deficient in white matter.

Acute Disease↗
PubMed1978

Cerebral tissue response to electrode implantation.

Tissue response to platinum electrodes was assessed after an eight-day implantation period. The regions of study included the cortical areas at the opercular gyri and at the sulcus parieto-occipitalis externus, as well as the sub-cortical white matter in these cases. Perivascular and intraparenchymal hemorrhagic lesions as well as edematous changes characterized both by extensive intra and extracellular swelling were noted. Numerous phagocytic elements and degenerative strucutres were present at the electrode/parenchymal interface. Tissue alterations were asymmetrical as observed both around and at the tip of the implanted electrode. The parenchymal alterations extended from 0.2mm to 3.5mm distance from the electrode path/parenchymal interface. Greater tissue involvement was found in the subcortical white matter as compared to the adjacent cortical gray matter.

Animals↗
PubMed1978

Cerebral tissue response to reserpine: a morphological study.

The acute influence of reserpine injection on cerebral tissue was studied in baboon and rat models. Five h after the infusion of reserpine, bilateral cortical areas were found to contain perivascular changes only, whereas basal ganglia regions contained advanced oedematous responses. Mitochondrial swelling was commonly found in the latter regions, as were loci containing microvascular crenation with accompanying pericytic changes.

Animals↗
PubMed1977

Mitochondrial abnormalities in progressive external ophthalmoplegia.

Three cases of chronic progressive external ophthalmoplegia demonstrated ragged-red fibers. Histochemical stains showed that the ragged-red fiber appearance was produced by abnormal mitochondria in the muscle. Electron microscopic studies demonstrated the ultrastructural origin of the intramitochondrial inclusions seen in ragged-red fibers. The associated abnormalities in lactic acid metabolism possibly represent an underlying generalized defect in metabolism. This evidence suggests that chronic progressive external ophthalmoplegia is a diffuse disease of the mitochondria.

Adult↗
PubMed1977

Acute tissue response to cerebral ischemia in the gerbil. An ultrastructural study.

The Mongolian gerbil, because of the uniqueness of the anatomical features of its circle of Willis, has become an increasingly useful model in the study of cerebrovascular disease. The present work defines acute changes at the ultrastructural level following ischemic insult. The pathomorphological responses include initial astrocytic involvement and, when the degree of insult is increased, a progression of morphological changes is evident in neuronal and other parenchymal elements. Animals with vessels occluded for more than 3 hr without neurological signs suggestive of ischemia exhibited limited perivascular edema. Contralateral changes (perivascular astrocytic) were observed in the basal ganglia at 24 hr in animals with neurological deficit. Astrocytic and basal ganglia susceptibility to ischemia was consistent with previous findings in primate models. An additional association was found in that limited edematous involvement could exist in animals without neurological deficit but neuronal changes were only present in animals with signs of ischemic neurological deficit.

Animals↗
PubMed1977

Biosynthesis of type I and III collagens by cultured smooth muscle cells from human aorta.

The synthesis of collagen by human aortic smooth muscle cells was studied after incubating the cells with [3H]proline and [3H]glycine for 48 hr. The culture medium and cells were lyophilized and then digested with cyanogen bromide (CNBr) in 70% (wt/vol) formic acid. The resultant peptides were subjected to ion exchange chromatography on CM-cellulose and gel filtration on agarose. On the basis of the molar ratios of the alpha1(I)-CB8 and alpha1(III)-CB8 peptides of the alpha1(I) and alpha1(III) chains, approximately one quarter of the collagen synthesized by these cells was identified as type III and three quarters as type I. These data indicate that the smooth muscle can synthesize at least two types of collagen found in the arterial wall.

Aorta↗
PubMed1977

Hepatitis-associated lipid storage myopathy.

We report the case of a 23-year-old woman who developed severe myalgias in association with mild hepatitis B surface antigen-positive hepatitis. Muscle biopsy showed myriads of microvacuoles filled with neutral lipid. Prednisone therapy was associated with complete clearing of all clinical and laboratory abnormalities. Since muscle carnitine levels were normal before treatment, we conclude that infection with hepatitis virus may induce non-carnitine-deficient lipid storage myopathy in man.

Adult↗
PubMed1976

Acute ultrastructural changes in the middle cerebral artery due to the injury and ischemia of surgical clamping.

Ultrastructural changes in the zone of clamping of the middle cerebral artery of the squirrel monkey are described after application of a surgical clip. The experimental model utilized has been widely applied to the study of cerebral ischemia and possibly has relevance to clamps applied to the cerebral vessels during neurosurgical treatment of patients with cerebrovascular disorders. The earliest changes within the arterial wall were found in the smooth muscle (media) and accompanying fasciculi of nerves. Changes within the nerve bundles were sufficiently advances following 4 hours of vascular clipping to suggest temporary or permanent impairment of neurogenic innervation of the cerebral vessels distal to the trunk of the vessel clipped.

Animals↗
PubMed1976

Hyperlipidemic neuropathy and dementia.

Mixed types of sensory and motor peripheral neuropathy and dementia occurred as neurological complications in patients with established type IV and type V hyperlipoproteinemia. These complications were remedial by control of the hyperlipoproteinemia with diet and/or clofibrate resulting in symptomatic improvement as well as restitution of nerve conduction velocities toward normal. Diabetes mellitus as well as systemic metabolic and toxic disorders which commonly produce neurological complications were excluded. Segmental demyelination with disorganization of myelin lamellae were striking morphological features found on sural nerve biopsy. Fluctuations in memory performance correlated inversely with plasma lipid levels and appear to be a characteristic feature of hyperlipidemic dementia. Hyperlipidemic neuropathy and dementia, although rare, are remediable neurological disorders which should be considered in patients with neuropathy and/or dementia of unknown origin.

Adult↗
PubMed1976

Mitochondrial abnormalities in progressive ophthalmoplegia.

A clinically diagnosed case of progressive external ophthalmoplegia was biopsied and ultrastructurally evaluated. The disease was found to be characterized by numerous giant mitochondria. The intramitochondrial changes consisted of either swirls of cristae or of paracrystalline structures which were in apposition with the membranes of the cristae. The internal structure of the paracrystalline units consisted of parallel bands of material which were aligned in the same plane as the membranes of the related cristae.

Humans↗
PubMed1975

The effects of glycerol on cerebral ultrastructure following experimentally induced cerebral ischemia.

Ultrastructural changes in cerebral tissue subjected to temporary occlusion on the right middle cerebral artery for intervals of 30 min, 1, 2, 3, and 4 hr were studied after daily injections of 10% glycerol in saline. These changes were compared with previously reported data from untreated animals. The extent of tissue involvement was appreciably less in the glycerol-treated group as evidenced by the reduction of intracellular edema and fewer changes in the membranes of ultrastructural elements (mitochondria, endoplasmic reticulum, Golgi complex, and plasmalemma) known to be essential for cellular metabolism and function in the central nervous system.

Animals↗
PubMed1975

The ultrastructure of the middle cerebral artery and its associated nerve fibers in the squirrel monkey and baboon.

This study describes the ultrastructural characteristics of the middle cerebral artery and its related neural elements in the squirrel monkey and baboon. The cytoarchitecture of the M-1 segment as well as that of the smaller extracerebral and intracerebral vessels is comparable in both animals. Smooth muscle elements are occasionally found within the intimal lining. The nerve bundles associated with vessels contain fewer myelinated fibers as the vessel diameter decreases. The cytological relationship between the neural structures and the smooth muscle cells are discussed.

Animals↗