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Biomedical subjects

J Ryan

Publications and source records attributed to J Ryan.

At least 235 records · Page 13Linked to original sources
PubMed1988

Cefoperazone versus combination antibiotic therapy of hospital-acquired pneumonia.

Cefoperazone monotherapy was compared with combination antibiotic therapy in a randomized prospective evaluation of patients with hospital-acquired pneumonia. Cefoperazone was as effective as either clindamycin/gentamicin or cefazolin/gentamicin (cure rate: 45 of 52 cefoperazone-treated patients [87 percent], versus 44 of 61 combination-therapy patients [72 percent], p = 0.069). With the exception of hypoprothrombinemia in those patients who did not receive prophylactic vitamin K, there was no difference in the incidence of side effects. In addition, no difference was noted in the incidence of superinfections or secondary pneumonias. When antibiotic costs, administration costs, and laboratory costs were considered, cefoperazone monotherapy was the least expensive antibiotic regimen. Cefoperazone is a suitable alternative to combination antibiotic therapy for the treatment of hospital-acquired pneumonia.

Anti-Bacterial Agents↗
PubMed1988

Sarcoidosis in a patient presenting with clinical and histological features of primary Sjögren's syndrome.

A patient presenting with bilateral enlargement of parotid and lacrimal glands, xerostomia, and keratoconjunctiva sicca, whose labial biopsy specimen showed changes consistent with Sjögren's syndrome, is described. The patient was initially misdiagnosed as having primary Sjögren's syndrome (SS). Subsequent investigations, however, performed to exclude an associated lymphoma or sarcoidosis, showed histological changes of the latter. The possibility that early infiltrates of the salivary glands in sarcoid may mimic those of SS is discussed.

Diagnosis, Differential↗
PubMed1988

Cardiorenal endocrine dynamics during volume expansion in hypothyroid dogs.

To address the role of atrial natriuretic factor (ANF) in hypothyroidism in the control of cardiorenal-endocrine function during volume loading, the relationships between atrial pressure, ANF, the renin-angiotensin-aldosterone system, and renal hemodynamic and excretory function were examined during and after acute 10% body wt saline volume infusion in pentobarbital-anesthetized hypothyroid dogs (n = 8). Hormonal changes before and after thyroidectomy were also evaluated. Four to 6 wk after thyroidectomy, ANF decreased and arginine vasopressin (AVP) and plasma renin activity (PRA) increased. Acute saline volume expansion caused an increase in ANF and decreases in AVP and PRA. Atrial pressure increased throughout volume expansion. Despite the absence of an increase in glomerular filtration rate (GFR) during volume expansion, urinary sodium excretion increased due to a marked rise in fractional excretion of sodium. These studies demonstrate that in hypothyroidism 1) ANF is decreased; 2) despite the decrease in basal ANF, increases in atrial pressure can stimulate relase of ANF; 3) despite the absence of an increase in GFR during volume expansion, fractional excretion of sodium increases associated with an increase in ANF; and 4) a lack of an increase in GFR during volume expansion is not related to an inability to increase ANF.

Aldosterone↗
PubMed1988

The relation of thyroid indices in the critically ill patient to prognosis and nutritional factors.

Thyroid indices and nutritional assessment values were measured in 73 critically ill euthyroid patients within 48 hours of admission to the medical or surgical intensive care unit. Significantly increased rates of mortality were observed among patients with decreased T3 or T4 levels or elevated T3UR or rT3 values. Alterations in thyroid function tests were associated with changes in certain putative nutritional indices, including serum albumin and transferrin concentrations, triceps skin fold and skin test reactivity. The data indicated that thyroid parameters measured early in the critical phase of illness are predictive of subsequent outcome. The pathogenesis of altered thyroid hormone metabolism is unknown, but nutritional deprivation may be an important contributing factor.

Adolescent↗
PubMed1987

A comparative study of the pharmacokinetics and pharmacodynamics of atenolol, hydrochlorothiazide and amiloride in normal young and elderly subjects and elderly hypertensive patients.

Six normal young and six normal elderly volunteers and six elderly hypertensive patients took part in an acute and chronic dose study of a combination capsule containing atenolol (50 mg), hydrochlorothiazide (25 mg) and amiloride (2.5 mg) designed for the treatment of hypertension. No difference in any of the drug pharmacokinetic parameters could be detected between the hypertensives and the normal elderly subjects. The bio-availability and the 24-h blood concentrations of all three drugs, half-life of atenolol and amiloride and the peak concentration of hydrochlorothiazide was significantly greater in the elderly. The 24-h blood concentrations of atenolol and hydrochlorothiazide did not alter with chronic dosing, but amiloride concentrations were significantly higher at this time in all groups. A significant fall in the blood pressure was observed in the hypertensive group. Heart rate fell more in the normal and hypertensive elderly subjects than in the young. The combination has shown to be an effective and well tolerated antihypertensive in the elderly patient with a 24-h duration of action.

Adult↗
PubMed1987

Coagulation and the expression of cell-mediated immunity.

Induction of monocyte/macrophage procoagulants may occur as the result of activation of the cell-mediated immune (CMI) response. Macrophage procoagulant inducing factor (MPIF), a soluble product of stimulated TDTH lymphocytes, may act together with two monokines, interleukin 1 and tumour necrosis factor alpha, which induce thromboplastin on endothelial cells, to initiate the fibrin deposition which is a common feature of many diseases in which CMI plays a role. Murine MPIF is chemically distinct from a number of other well characterized lymphokines in that the two major activities, MPIF alpha and MPIF beta are heparin-binding proteins with high isoelectric points. Fractions highly enriched for MPIF induced interstitial fibrin deposition when injected intradermally. In addition, intense infiltration of polymorphonuclear leucocytes (PWN) and mononuclear cells was seen 4-24 h following intradermal injection. In vitro experiments have confirmed that this lymphokine is a potent chemotactic agent for these cells. These results suggest that MPIF plays a central role in the expression of histopathological features of delayed-type hypersensitivity reactions. Monocyte and macrophage procoagulants induced by MPIF would contribute significantly to the activation of coagulation which not only results in fibrin deposition but also in the production of activated serine proteases and fibrinopeptides which may potentiate an inflammatory response.

Animals↗
PubMed1987

Hyalinizing trabecular adenoma of the thyroid gland.

The hyalinizing trabecular adenoma, a distinctive lesion, is important because it may mimic medullary and papillary carcinoma microscopically. We describe 11 such tumors obtained from women ages 27-72 years (mean, 46 years). The initial pathologic diagnoses were carcinoma (five cases), adenoma (two cases), paraganglioma (one case), and "indeterminate" (three cases). None of the tumors recurred or metastasized (mean follow-up, 10 years). Grossly, the neoplasms measured 0.3-4 cm in diameter, and were yellow-tan and circumscribed. Microscopically, they were encapsulated or circumscribed and solid, or vaguely lobulated. The polygonal, oval, and elongated tumor cells were arranged in trabeculae, clusters, or both, and were often inserted vertically into capillaries. The sharply outlined cells had finely granular cytoplasm that was either acidophilic, amphophilic, or clear. Typical features included oval and elongated nuclei, perinucleolar vacuoles, acidophilic nuclear inclusions, fine nuclear grooving, and infrequent mitotic figures. Perivascular hyaline fibrosis and cell degeneration mimicked amyloid, but these tumors were Congo red-negative. Occasional trabeculae featured round or irregularly shaped follicles, sometimes with papillary infoldings, that were either empty or contained colloid-like material and psammoma bodies. Immunostaining of tumor cells was positive for thyroglobulin and negative for calcitonin. Among six tumors analyzed by flow cytometry, five displayed a diploid pattern and one showed an aneuploid peak.

Adenoma↗
PubMed1987

Delayed neck infection following anterior spine surgery.

Pharyngoesophageal perforation and neck abscess formation is a rare complication of anterior cervical spine surgery. This complication usually manifests itself within the early postoperative period and is associated with soft tissue trauma at the time of surgery. We describe two cases of retropharyngeal abscesses and persistent pharyngocutaneous fistulae which occurred in a delayed fashion several months after cervical spine surgery. The etiology, diagnosis, and treatment of this problem is discussed with a review of the current literature.

Abscess↗
PubMed1987

KRAS2 as a genetic marker for lung tumor susceptibility in inbred mice.

An Eco-RI restriction fragment length polymorphism occurring in a DNA fragment containing the first exon of the murine KRAS2 gene was shown to correlate with the inherited susceptibility of inbred strains of mice to urethan (CAS: 51-79-6)-induced pulmonary adenomas. Eco-RI digestion of murine DNA yielded four KRAS2-specific fragments. Polymorphic variation occurred in the smallest molecular-weight fragment with alleles of either 0.70 or 0.55 kb in size. Genotyping of 14 inbred strains of mice revealed a correlation between KRAS2 Eco-RI polymorphic variation and the differential susceptibility among inbred strains to development of pulmonary adenomas. Strains with a high incidence of pulmonary adenomas, either spontaneously occurring or in response to carcinogen induction, had the 0.55-kb KRAS2 allele whereas adenoma-resistant strains had the 0.70-kb allele. Analysis of a series of recombinant inbred strains (AXB, BXA) that developed from reciprocal crosses between a highly susceptible strain (A/J) and a highly resistant strain (C57BL/6J) revealed a statistically significant threefold difference in lung tumor susceptibility on the basis of KRAS2 genotype. Further analysis of individual F2 mice of a C57BL/6 female X A/J male cross also demonstrated a threefold difference in tumor susceptibility on the basis of KRAS2 allelic variation.

Adenoma↗
PubMed1987

Sulphate/molybdate interactions: in vivo and in vitro studies on the group VI oxyanion transport system in ovine renal tubule epithelial cells.

The study was undertaken to investigate the mechanism by which increased dietary sulphur compounds accelerate the excretion of molybdate in ruminants. Clearance studies show that [99Mo]molybdate and [35S]sulphate have similar behaviours in sheep; at plasma molybdate concentrations equal to or below the apparent t max the injection of sulphate accelerates the excretion of molybdate and vice-versa. The uptake of [35S]sulphate into brush-border membrane vesicles isolated from ovine kidney cortex by a Ca++ precipitation method was investigated by a rapid filtration technique. Transport of [35S]sulphate into the vesicles was stimulated in the presence of Na+ but not by K+. A typical "overshoot" phenomenon was observed in the presence of the Na+ gradient (initially 100 mM Na+ outside/zero mM Na+ inside). Both the rate and extent of accumulation was reduced by the presence of other group VI oxyanions, molybdate, selenate and tungstate and by an analogue thiosulphate, but not by other divalent anions such as phosphate or by pyruvate. Uptake was inhibited by HgCl2, N-ethyl-maleimide (NEM) and ouabain. The experiments indicate the presence of an electroneutral Na+/SO4- or group VI oxyanion co-transport system in ovine proximal tubule brush border membranes similar to that described in the rat. Sulphate/molybdate competition for sites in tubular reabsorption is another factor to be considered in the complex interactions of S and Mo compounds with copper in animal nutrition.

Animals↗
PubMed1986

Characterization and purification of mouse macrophage procoagulant-inducing factor.

Macrophage procoagulant-inducing factor (MPIF) is a product of mouse Lyt-1+2- cells that induces macrophage procoagulant activity (MPCA) on mouse peritoneal exudate cells or on the macrophage-like tumor cell line WEHI-265. Supernatants from Sepharose-bound concanavalin A-stimulated cells were fractionated by using DEAE-Sephacel, heparin-Sepharose, and isoelectric focusing. This procedure resolved three different MPIF: MPIF alpha (pI 8.5), MPIF beta (pI 8.8 to 9.2), and MPIF gamma (pI 5 to 5.5). MPIF alpha and beta were small molecules (approximately 14 kD and 20 to 25 kD) as determined by gel filtration on Sephadex G200 and Biogel P100. MPIF beta was sharply resolved as a peak eluting after lysozyme by gel filtration on HPLC columns I-150 and I-125, although SDS-PAGE of the HPLC-enriched material resolved two well-defined bands of 70 and 120 kD and some poorly defined material of 14 kD. Silver staining failed to detect components of MPIF alpha after SDS-PAGE. MPIF gamma activity was associated with material that separated over a broad range (20 to 60 kD and 60 to 200 kD), possibly due to aggregation with other components of the supernatants. Crude supernatants were stable to heating at 56 degrees C for 30 min and pH 2 treatment, although more highly enriched fractions were unstable to these treatments. Heating at 90 degrees C for 5 min totally destroyed MPIF activity. The properties of the two basic MPIF differ from other lymphokines known to affect macrophage function, e.g., colony-stimulating factor, migration-inhibition factor, interferon-gamma, and interleukin 1.

Animals↗
PubMed1986

Lymphokine-induced monocyte procoagulant activity is depressed in patients with advanced malignancies.

Fibrin deposition in the microenvironment of tumor cells may be critical to tumor growth and metastasis formation. Procoagulant activities of tumor cells themselves, or of infiltrating macrophages, activated by the host's immune system to the tumor, may both contribute to coagulopathies associated with metastases. Lymphokine (LK) supernatant activated procoagulant activity on normal peripheral blood monocytes but failed to induce activity on mononuclear cells from 18/22 patients with locally advanced or disseminated non-lymphoid tumors. Monocytes from the remaining patients had very low basal levels of MPCA and were less sensitive than normal cells to LK. Monocytes from 4 patients (3 with tumors with a high growth fraction) had extremely elevated levels of basal procoagulant activity, possibly due to maximal activation in vivo. Neither LK nor bacterial lipopolysaccharide (LPS) stimulated procoagulant production of these cells. By contrast, cells from 8/13 patients produced procoagulant in response to LPS. This study indicated that monocyte function of patients with disseminated cancer is suppressed with respect to LK stimulation, but that cells with normal basal levels of MPCA respond to LPS. Preactivation of mononuclear procoagulant in vivo precluded subsequent stimulation by either LPS or LK.

Adenocarcinoma↗