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Biomedical subjects

J L Olson

Publications and source records attributed to J L Olson.

At least 73 records · Page 4Linked to original sources
PubMed1984

Role of heparin as a protective agent following reduction of renal mass.

To determine the mechanism by which heparin affords protection from damage to the remnant kidney following reduction of renal mass, either whole heparin or a low molecular weight fraction of heparin was administered to Munich-Wistar rats which had had 90% ablation of renal mass. The low molecular weight fraction differed from the whole heparin in that it had greatly decreased anticoagulant activity as measured by the United States Pharmacopoeia (USP) assay, and increased antifactor Xa activity. The morphological alterations were examined and various physiological features were studied. The administration of whole heparin to rats with reduction of renal mass resulted in prolonged clotting time, reduced BP elevation, elimination of albuminuria, and lessening of renal damage. No such differences were observed in the rats receiving the fraction of heparin or the control group to which no therapy was given. The inability of the fraction of heparin to prolong clotting time suggested that it was unable to inactivate the serine proteases of the coagulation cascade. It is probable that the protective effect of whole heparin in this model is due to its ability to inhibit serine proteases such as kallikrein and components of the coagulation cascade resulting in a beneficial alteration in glomerular hemodynamics, lowering of systemic BP, and anticoagulation.

Albuminuria↗
PubMed1983

Shortened luteal phase after ovulation induction with human menopausal gonadotropin and human chorionic gonadotropin.

Serum hormonal profiles were characterized in 126 treatment cycles from 24 anovulatory women who underwent ovulation induction therapy with sequential human menopausal gonadotropin (hMG) and human chorionic gonadotropin (hCG). Of the 98 presumptively ovulatory treatment cycles, 18 had luteal phases lasting 11 days or less. Sixteen of these 18 cycles had one or more of the following features: serum hCG concentrations of less than 75 mIU/ml 24 hours after hCG administration or peak preovulatory estradiol (E2) levels either less than 200 pg/ml or greater than 2000 pg/ml. Midluteal serum progesterone levels were less than 10 ng/ml in seven of the shortened cycles. Only one of these features (E2 greater than 2000 pg/ml) was present in any cycle (n = 2) resulting in pregnancy. Our observations suggest that serum E2 and hCG levels will reflect the apparent adequacy of luteal function during hMG/hCG treatment cycles.

Adult↗
PubMed1981

Ehlers-Danlos syndrome with abnormal collagen fibrils, sinus of Valsalva aneurysms, myocardial infarction, panacinar emphysema and cerebral heterotopias.

A 30 year old woman with marked joint hypermobility had severe, progressive lung disease, seizures, aneurysms of the sinuses of Valsalva and myocardial infarction documented during life. She died of intractable ventricular fibrillation, and postmortem examination showed myocardial injury in the distribution of the left coronary artery but no occlusive coronary artery disease. Severe panacinar emphysema was found in the lungs. Cerebral heterotopias with peculiar vascularization were present and were a likely cause of the seizure disorder. Electron microscopy showed dermal collagen fibrils to be heterogeneous in size, reduced in number, and irregular and frayed in appearance. This patient had a form of the Ehlers-Danlos syndrome, different from the 10 distinct variants described thus far, associated with lethal internal manifestations.

Adult↗
PubMed1981

Hyperfiltration in remnant nephrons: a potentially adverse response to renal ablation.

Micropuncture studies were performed in three groups of male Munich-Wistar rats 1 wk after surgery: group I, eight control rats that underwent laparotomy and were fed a normal diet; group II, nine rats that underwent right nephrectomy and segmental infarction of five-sixths of the left kidney and were fed a normal diet; and group III, seven rats that underwent the same renal ablative procedure and were fed a low protein diet. Single nephron glomerular filtration rate (SNGFR) was higher in the remnant kidney of group II rats compared with group I rats due to higher average values for mean glomerular transcapillary hydraulic pressure difference (delta P) and initial glomerular plasma flow rate (QA) in group II. Glomeruli in remnant kidneys of group II showed striking alterations in morphology, including epithelial cell protein reabsorption droplets, foot process fusion, and mesangial expansion. Group III rats demonstrated a mean SNGFR not statistically different from that of group I, but significantly less than that of group II rats. This lack of absolute hyperfiltration in remnant glomeruli of group III rats relative to group I obtained because QA and delta P did not increase above values found in group I. The glomerular structural lesions seen in group II were also largely attenuated in group III. These studies demonstrate that alterations in glomerular hemodynamics associated with renal ablation are accompanied by structural lesions and suggest that sustained single nephron hyperfiltration may have maladaptive consequences by damaging remnant glomeruli.

Animals↗
PubMed1981

Alterations in the charge and size selectivity barrier of the glomerular filter in aminonucleoside nephrosis in rats.

The aminonucleoside of puromycin induces proteinuria and renal damage when given to rats. Aminonucleoside of puromycin was administered to male Wistar-Furth rats as a single intravenous injection in a dose of 15 mg. per 100 gm. of body weight. The animals were studied 9 days later when the mean urinary protein was 175 mg. per 24 hours. Evidence of glomerular epithelial cell injury included massive obliteration of foot processes, appearance of microvilli, protein reabsorption droplets, extreme attenuation of cytoplasm with formation of blebs, and focal detachment of epithelial cells from glomerular basement membrane. An increase in both the amount of mesangial matrix and the number of mesangial cells was also observed. The fractional clearance (C/GFR) of anionic horseradish peroxidase had increased 18.5 times as compared to control values and was nearly equal to the C/GFR of neutral horseradish peroxidase in the experimental rats. The C/GFR of cationic horseradish peroxidase was decreased by one-third so that it approximated the C/GFRs of both anionic and neutral horseradish peroxidase. These findings indicate a nearly complete loss of the charge-selective barrier to filtration. In addition, C/GFRs of tritiated uncharged dextrans with a range of molecular radii from 18 to 58 Angstrom (A) were determined. The C/GFRs of dextrans (alpha e less than 30 A) were decreased in the experimental rats as compared to C/GFRs of dextrans of corresponding molecular size in control rats. However, the C/GFRs of dextrans (alpha e greater than 38A) were increased in experimental as compared to control rats. Further, both anionic and cationic ferritin (alpha e = 61 A) were observed in the urinary space near denuded areas of glomerular basement membrane. These results indicate that the size-selective properties of the glomerular barrier to filtration have been modified with decreased C/GFR of small molecules and increased C/GFR of large molecules. Thus, the proteinuria of aminonucleoside nephrosis in rats occurs secondary to alterations in both the charge- and size-selective barriers to glomerular filtration.

Animals↗
PubMed1979

Adenomatoid odontogenic tumor: ultrastructural demonstration of two cell types and amyloid.

A typical adenomatoid odontogenic tumor removed from a 13-year-old female was studied by light and electron microscopy. The tumor was composed of two types of epithelial cells: Type I cells were cuboidal and occurred in nests or formed ductlike structures and Type II cells were smaller and spindle shaped. The formation of extracellular masses of amyloid was found in association with Type I epithelial cells, and amyloid formation was not observed in association with Type II cells. Results suggest that the lesion is of enamel organ origin, derived from cells of the inner enamel epithelium at the pre-ameloblastic stage, stellate reticulum and stratum intermedium. The origin of this amyloid material is unknown; however, it may be of enamel protein origin which, like amyloid, may have a beta-protein conformation.

Adolescent↗
PubMed1979

Mucoepidermoid carcinoma of the bronchus: an electron microscopic study of the low grade and the high grade variants.

Two cases of mucoepidermoid carcinoma of the bronchus--one a low grade tumor and the other a high grade tumor--are presented with findings by light and electron microscopy. This represents the first report of the ultrastructure of mucoepidermoid carcinoma of the bronchus and demonstrates the ultrastructural similarities between the low grade exophytic tumor confined to the bronchus and the high grade infiltrating tumor with lymph node and pulmonary metastases. The ultrastructural features are similar to those described for mucoepidermoid carcinoma of the salivary gland and are consistent with the proposed origin of the tumor from the submucosal bronchial gland duct. These two cases and a review of previously reported cases indicate that, analogous to mucoepidermoid carcinoma of the salivary glands, mucoepidermoid carcinoma of the bronchus may occur as either a low grade or high grade variant which can be identified on the basis of growth characteristics and histologic features.

Adult↗
PubMed1979

Vasoactive intestinal peptide and its relationship to ganglion cell differentiation in neuroblastic tumors.

Immunohistochemical studies have demonstrated that immunoreactive vasoactive intestinal peptide is present in, and restricted to, the differentiating and mature ganglion cells in a variety of normal and neoplastic neural tissues. In a composite pheochromocytoma-ganglioneuroma (associated with the syndrome of watery diarrhea, hypokalemia, and hypochlorhydria), five ganglioneuroblastomas, five ganglioneuromas (two of which were associated with diarrheal syndromes), an unusual mixed neuroblastoma-ganglioneuroma, and four normal sympathetic ganglia, vasoactive intestinal peptide was present in differentiating and mature ganglion cells. The peptide was also demonstrated in isolated ganglion cells in two pheochromocytomas but was not present in pheochromocytes, Schwann cells, or undifferentiated neuroblastic cells in the neuroblastomas and ganglioneuroblastomas. These studies indicate that the presence and presumably the production of vasoactive intestinal peptide thus reflect a particular line of neuroblastic differentiation and are not merely a reflection of common derivation of these tissues. Our identification of vasoactive intestinal peptide in neurogenic tumors associated with diarrhea supports the contention that the peptide might be an important diarrheogenic factor in these tumors.

Adrenal Gland Neoplasms↗
PubMed1979

Malignant melanoma with renal dense deposits containing tumor antigens.

A patient with disseminated malignant melanoma developed mild renal failure with proteinuria four months following the diagnosis of his neoplasm. Renal biopsy showed a membranoproliferative glomerulonephritis. Electron microscopy revealed intramembranous dense deposits in the glomeruli as well as in tubular basement membranes and Bowman's capsule. Immunofluorescence microscopy demonstrated granular staining for C3 in these same locations and granular deposits of immunoglobulins in the glomerular capillary loops. Light and electron microscopy of the autopsy kidney obtained 5 months later revealed progression of the number, size and density of the deposits. Eluates from both autopsy and biopsy kidney contained melanoma antigen and anti-melanoma antibodies. This case illustrates the association between the dense deposits and neoplasia with the dense deposits representing immune complexes with the tumor as antigen.

Antigen-Antibody Complex↗
PubMed1978

Mediastinal paragangliomas (aortic body tumor): a report of four cases and a review of the literature.

Four cases of paraganglioma originating in the supra-aortic or aortico-pulmonary bodies are described. A review of the reported examples of aortic body tumors and a study of these four cases indicate that there is a high incidence of aggressive tumor growth in the mediastinum, with resultant important morbidity or death in 16 of 35 cases. The morphologic features of aortic body tumors are identical to those of paragangliomas of other locations, and the occurrence of invasive growth and/or metastasis cannot be predicted on histologic grounds.

Adolescent↗
PubMed1978

Pheochromocytomas.

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Adrenal Gland Neoplasms↗
PubMed1978

Congenital cystic adenomatoid malformation of the lung.

Ultrastructural study of a congenital cystic adenomatoid malformation of the lung revealed a persistence of type 2 pneumocytes lining the alveolar and gland-like spaces. The larger cystic areas were lined by normal bronchiolar-type epithelium and were surrounded by a few smooth muscle cells. The interstitium contained undifferentiated mesenchymal cells. No cartilage or bronchial glands were present. These features suggest that this lesion is developmental in nature, with a failure of maturation resulting from an insult occurring early in embryonic life, prior to the onset of cartilaginous differentiation within the lungs.

Epithelium↗