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Biomedical subjects

P Madarnas

Publications and source records attributed to P Madarnas.

At least 19 recordsLinked to original sources
PubMed1995

Innocuity of agents for radiocontrast enhancement of urinary tract stones.

OBJECTIVES: Mineral kidney stones are frequently difficult to detect due to their radiotranslucency. We have recently developed a method that enhances the visibility of such stones by retrograde infusions of certain heavy metal salt solutions such as cesium or lanthanide gadolinium. This report describes toxicologic studies carried out on the use of those contrast agents to introduce this technique eventually into clinical trials. METHODS: Systemic absorption was assessed in dogs through infusion of radioactive contrast agent into the renal pelvis with or without ureteral obstruction. Radioactivity in urine and blood was monitored. Local toxicity was studied in animals infused with the contrast agent at intervals up to 4 weeks. RESULTS: Reabsorption studies under high intrapelvic pressures (70 cm H2O or higher), demonstrated reabsorption of cesium. However, at normal intrapelvic pressures, only a moderate reabsorption of cesium was observed. No gadolinium reabsorption was detected even at high intrapelvic pressures. Histopathologic studies showed no major urothelial lesions but only a transient inflammatory reaction that was undetectable 4 weeks following exposure to gadolinium salts. CONCLUSIONS: Gadolinium salt solutions are good positive radiocontrast agents for mineral kidney stones without having serious toxic effects or systemic reabsorption.

Absorption↗
PubMed1995

Meniscal repair by synovial flap transfer. Healing of the avascular zone in rabbits.

We studied repair of a longitudinal incision of the right medial meniscus in 44 rabbits after the transfer of a pedunculated synovial flap, without immobilization of the knee. The left medial meniscus was used as the control, after creating the same lesion without synovial flap. Healing was analyzed by histologic studies, including India ink perfusion after 8, 12, 24, and 48 weeks. In three quarters of the cases, the meniscus showed healing with vascularization of an originally avascular zone.

Animals↗
PubMed1991

Radio-contrast enhancement of urinary tract stones.

Most urologists treating stone disease with any method (ESWL, PCL, URS) have encountered problems of poor stone visualization with fluoroscopy. This difficulty to localize urinary tract (UT) stones or fragments may result in incomplete stone extraction, prolonged surgery and increased risk of recurrence and post-operative complications. We have sought and found means to increase the radioopacity of mineral UT stones by a simple pre-operative perfusion technique. The capacity of radioopacification has first been demonstrated in in vitro incubations of fragments of human mineral stones with aqueous solutions of barium, of the lanthanides and of the two natural actinides. Most of the incubations led to considerable radio-contrast enhancement and heavy metal incorporation, measured by X-ray fluorescence analysis. Dogs with implanted human stone fragments were used as an in vivo model. The UT were perfused through a retrograde pyelic catheter with heavy metal salts solutions, the ensuing radioopacification of the implanted UT-stones was estimated by abdominal radiographies and the metal incorporation was measured on the retrieved stones. Considerable radioopacity enhancement together with heavy metal incorporation was observed for the following elements: Sr, Ba and the lanthanides Gd and Yb. The pathological evaluation of the urothelial linings from animals treated with lanthanide salt showed no toxic effects.

Animals↗
PubMed1989

The reliability of routine pathologic diagnosis of colorectal adenocarcinoma.

The diagnosis of colorectal adenocarcinoma is generally considered as being reliable. However, the reproducibility of the classification of specific histologic patterns and the interrater agreement on the gradings have not been firmly established. A panel of three independent expert pathologists reviewed histologic sections from 128 patients selected among 1848 with colorectal cancer, diagnosed in 11 hospitals of the same region. The panel agreed with 92.6% of the original diagnoses of colorectal adenocarcinoma. As for agreement between panel members, the kappa value was 0.78 for the diagnosis of adenocarcinoma and 0.62 for confirmation of colorectal origin. The intraclass correlation coefficient for tumor differentiation features was 0.75. The proportion of villous and adenomatous components also generated good agreement. However, the grading of mucin secretion showed poor agreement (intraclass correlation coefficient = 0.44). Results confirm the reliability of routine pathological diagnosis and also demonstrate the reproducibility of basic diagnostic categories and pathognomonic features. Thus, to obtain reliable information from medical records for epidemiologic and clinical studies, data should be limited to well-defined diagnostic and histopathologic categories.

Adenocarcinoma↗
PubMed1988

Mitogenic, immunoadjuvancy, and genetic studies on fatty acyl maltose.

Three synthetic glycolipids, maltose tetrapalmitate (MTP), maltose hexastearate (MHS), and maltose hexalinoleate (MHL) prepared as nontoxic lipid A analogs, and Escherichia coli lipopolysaccharide (LPS) were assayed for their mitogenic activity using spleen lymphocytes in nine inbred mouse strains and three F1 hybrids. The MTP and LPS were also assayed for their ability to enhance plaque-forming cell (PFC) responses using sheep red blood cells as the antigen in the same inbred mouse strains and F1 hybrids, The mitogenic activity of synthetic glyco-lipids was several fold lower than that of LPS and MHL was inferior to MTP and MHS. DBA/2J was the most responsive strain for MTP and DBA/1J and C3H/HeJ the least. The mitogenic activity of MTP was generally in agreement with the PFC response stimulation by it. Low-dose cyclophosphamide treatment of mice synergized MTP for PFC response augmentation. Genetic studies on MTP mitogenicity revealed that 90% of responder DBA/2J X nonresponder C3H/HeJ F1 hybrids had intermediate mitogenic activity. Among F2, 73% had intermediate-high activity and 27% were nonmitogenic. Among F1 X C3H/HeJ backcrosses 11% had high, 56% intermediate, and 33% had no mitogenic activity, whereas, for the F1 X DBA/2J backcross, 14% had high, 36% intermediate, and 50% low or negligible activity. The data favored a single gene for MTP activation of immune cells.

Animals↗
PubMed1986

Pleomorphic lipoma of the tongue: case report and literature review.

A case of pleomorphic lipoma of the tongue in a 60-year-old woman is reported. Recently described by Enzinger (1977), pleomorphic lipoma is a rare benign tumor, occurring mostly in elderly males. The subcutaneous tissues of the neck and back are the most common sites involved. Differentiation from some histological variants of liposarcoma remains difficult. Complete surgical excision is the treatment of choice. To our knowledge, this is the first case of pleomorphic lipoma of the tongue reported in the English literature.

Female↗
PubMed1983

A comparative study of the intravesical MTP and BCG treatment of transplantable bladder cancer.

We induced transitional cell cancer of the urinary bladder in Fischer rats by feeding them N-[4(5-nitro-2-furyl)-2-thiazolyl] formamide (FANFT). Tumors were subsequently transplanted orthotopically in the bladder submucosa of Fischer rats. This animal model was used to compare the therapeutic effects of maltose tetrapalmitate (MTP), and bacillus Calmette Guérin (BCG). The routes of administration compared were intravesical alone or intravesical and oral for MTP, and intravesical alone or intravesical and subcutaneous for BCG. The intravesical and oral MTP treatment was more effective than the intravesical and subcutaneous BCG as regards the tumor size, incidence of tumor metastasis and the immunologic status of the tumor bearing host.

Adjuvants, Immunologic↗
PubMed1983

Nuclear androgen receptors of human prostatic tissue--a quantitative histological study.

The objective of this study was to determine the nuclear dihydrotestosterone (DHT) nuclear receptors content in tissues of normal prostate, benign prostatic hypertrophy (BPH), and prostatic cancer. We also attempted to correlate this with the histological pattern of these tissues. Specimens were obtained from five normal subjects, 24 BPH, and 19 prostatic cancer patients. Nuclear receptors content was determined. All histological sections were reviewed by three independent pathologists. The criteria for the quantitative analysis were the degree of cellularity and the stromal content. The mean receptor content was not significantly different between neoplastic tissue (52.6 fmol/mg protein) and hyperplastic tissue (38.9 fmol/mg protein). The number of binding sites in normal prostatic tissue was 8.5 fmol/mg protein. The correlation between the degree of cellularity and DHT receptors showed no significant difference for both BPH, as well as prostatic cancer. Similar results were obtained when stromal content was compared.

Adenocarcinoma↗
PubMed1983

Orthotopic implantation of primary N-[4-(5-Nitro-2-furyl)-2-thiazolyl]formamide-induced bladder cancer in bladder submucosa: an animal model for bladder cancer study.

Primary bladder tumors induced in Fischer 344 inbred rats by N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide were transplanted in syngeneic rats by the intravesical, s.c., i.v., and orthotopic routes. Attempts were made to establish bladder cancer cell lines in vitro. No success was achieved in transplantation by either the s.c., i.v., or intravesical routes when primary tumor cells were transplanted as cell suspensions. Cell suspensions of primary tumors also failed to grow in culture. However, orthotopic implantation into the bladder submucosa gave 45% success. Tumor fragments obtained from either the primary tumor or its lung metastases resulted in 10.6 and 36% tumor takes, respectively, when implanted s.c. However, after one orthotopic passage in the bladder submucosa, the tumor cells injected as cell suspension grew s.c. in 14% and orthotopically in 79% of the animals. Tumor fragments obtained from orthotopic tumors and implanted s.c. resulted in 15% tumor takes. After the second orthotopic passage, tumor cells could be grown in cultures and orthotopically in 100% of animals. The technique of orthotopic implantation as well as the usefulness of this tumor model for bladder cancer studies are described.

Animals↗
PubMed1980

Small erythematous mucosal plaques: an endoscopic sign of Crohn's disease.

A non-ulcerated granulomatous lesion of the large bowel mucosa has been found in 11 patients, nine of whom already had or eventually developed classical features of Crohn's disease. These lesions, which are multiple, consist of small well-circumscribed raised erythematous plaques surrounded by normal mucosa. At biopsy there is focal haemorrhage of the lamina propria, rupture of the crypts, release of mucus, and frank granulomatous reaction with giant cell formation. The lesion may be reversible or be followed by the classical mucosal ulcerations. They may occur in the presence or the absence of classical lesions of Crohn's disease elsewhere in the gastrointestinal tract. As this non-ulcerated lesion may occur in isolation, it may provide the initial clue to the diagnosis of Crohn's disease.

Adult↗
PubMed1979

Ischemic colitis associated with hypertension.

A 48-year-old man with accelerated hypertension developed right-sided ischemic colitis. There was no evidence of another cause of vascular inadequacy. Microscopically, the bowel showed ischemic alterations of different stages. The arterial alterations of different stages. The arterial vessels showed minimal changes. In older lesions, fibrosis was prominent and the mucosa was atrophic. In more recent lesions, some vessels of the submucosa were plugged with fibrin and the overlying mucosa was infiltrated by nonorganized hemorrhage and cellular elements.

Arteries↗
PubMed1977

Epidermoid cysts of the spleen.

The authors report three cases of epidermoid cyst of the spleen. A squamous cell lining was found in all three. One patient had a history of antecedent trauma, and in the surgical specimen the gross and histologic features were compatiible with splenic damage. No hematologic alteration was recognized on presentation. Angiography and spleen scanning were valuable aids in the diagnosis. All three patients were well 1 year after operation.

Adult↗
PubMed1974

[Scleronodular type of Hodgkin's disease: experience at the Sherbrooke University Hospital Center].

Scleronodular type of Hodgkin's disease: experience at the Centre hospitalier universitaire de SherbrookeThe nodular sclerosis type of Hodgkin's disease appears to be a distinct clinical entity. However, the incidence, the initial localization of the tumour and the survival of the patients are variable. The present study was carried out on a group of 17 patients, all French Canadians living in the province of Quebec, from a total of 31 with Hodgkin's disease, an incidence of 55%. There were more males (10) than females (7). The mean age of the group was 37 years, but that of the females was lower than that of the males. The mediastinum was involved at the onset in 47% of the patients. The initial staging (according to the classification of Rye) in 76% of the patients was I or II.Four patients showed disease below the diaphragm. The lungs were infiltrated three times, the spleen six times, and the liver five times. The duration of survival of the 17 patients was twice that of the patients with the three other types of the disease.

Adolescent↗