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Biomedical subjects

S Landas

Publications and source records attributed to S Landas.

At least 19 recordsLinked to original sources
PubMed1999

Prostatic intraepithelial neoplasia and apoptosis in benign prostatic hyperplasia before and after the Chernobyl accident in Ukraine.

The prevalence of prostatic intraepithelial neoplasia (PIN) in men who underwent surgery for benign prostatic hyperplasia (BPH) before and after the Chernobyl nuclear accident was studied. BPH samples were obtained by adenomectomy from 45 patients operated in 1984 before the accident (Group I), and 47 patients from the low contaminated Kiev City (Group II) and 76 from high contaminated area (Group III) operated between 1996 and 1998. Their BPH samples were examined histologically and immunohistochemically. The incidences of prostatic intraepithelial neoplasia (PIN) and high grade PIN (HGPIN) were 15.5 and 11.1% in Group I, 29.8 and 14.9% in Grpoup II, and 35. 5 and 19.7% in Group III. The difference between the incidences of PIN in Group I and III is significant (p<0.02). There was increased apoptosis in areas of PIN in Group II and III as compared to Group I (p<0.001). Since apoptosis has been shown to be associated with ionizing radiation and it is now found to be associated with PIN in patients diagnosed after the Chernobyl nuclear accident, this suggests that long-term low dose internal ionizing radiation potentially may cause prostate cancer.

Apoptosis↗
PubMed1998

Exogenous surfactant and positive end-expiratory pressure in the treatment of endotoxin-induced lung injury.

OBJECTIVE: To evaluate the efficacy of treating endotoxin-induced lung injury with single dose exogenous surfactant and positive end-expiratory pressure (PEEP). DESIGN: Prospective trial. SETTING: Laboratory at a university medical center. SUBJECTS: Nineteen certified healthy pigs, weighing 15 to 20 kg. INTERVENTIONS: Pigs were anesthetized and surgically prepared for hemodynamic and lung function measurements. Animals were randomized into four groups: a) Control pigs (n = 4) received an intravenous infusion of saline without Escherichia colilipopolysaccharide (LPS); b) the LPS group (n = 5) received an intravenous infusion of saline containing LPS (100 microg/kg); c) the PEEP plus saline group (n = 5) received an intravenous infusion of saline containing LPS. Two hours after LPS infusion, saline was instilled into the lung as a control for surfactant instillation, and the animals were placed on 7.5 cm H2O of PEEP; d) the PEEP plus surfactant group (n = 5) received an intravenous infusion of saline containing LPS. Two hours following LPS infusion, surfactant (50 mg/kg) was instilled into the lung and the animals were placed on 7.5 cm H2O of PEEP. PEEP was applied first and surfactant or saline was instilled into the lung while maintaining positive pressure ventilation. All groups were studied for 6 hrs after the start of LPS injection. At necropsy, bronchoalveolar lavage was performed and the right middle lung lobe was fixed for histologic analysis. MEASUREMENTS AND MAIN RESULTS: Compared with LPS without treatment, PEEP plus surfactant significantly increased PaO2 (PEEP plus surfactant = 156.6 +/- 18.6 [SEM] torr [20.8 +/- 2.5 kPa]; LPS = 79.2 +/- 21.9 torr [10.5 +/- 2.9 kPa]; p<.05), and decreased venous admixture (PEEP plus surfactant = 12.5 +/- 2.0%; LPS = 46.9 +/- 14.2%; p< .05) 5 hrs after LPS infusion. These changes were not significant 6 hrs after LPS infusion. PEEP plus surfactant did not alter ventilatory efficiency index (VEI = 3800/[peak airway pressure - PEEP] x respiratory rate x PacO2), or static compliance as compared with LPS without treatment at any time point. Cytologic analysis of bronchoalveolar lavage fluid showed that surfactant treatment significantly increased the percentage of alveolar neutrophils as compared with LPS without treatment (PEEP plus surfactant = 39.1 +/- 5.5%; LPS = 17.4 +/- 6.6%; p< .05). Histologic analysis showed that LPS caused edema accumulation around the airways and pulmonary vessels, and a significant increase in the number of sequestered leukocytes (LPS group = 3.4 +/- 0.2 cells/6400 micro2; control group = 1.3 +/- 0.1 cells/6400 micro2; p < .05). PEEP plus saline and PEEP plus surfactant significantly increased the total number of sequestered leukocytes in the pulmonary parenchyma (PEEP plus surfactant = 8.2 +/- 0.7 cells/6400 micro2; PEEP plus saline = 3.9 +/- 0.2 cells/6400 micro2; p <.05) compared with the control and LPS groups. CONCLUSIONS: We conclude that PEEP plus surfactant treatment of endotoxin-induced lung injury transiently improves oxygenation, but is unable to maintain this salutary effect indefinitely. Thus, repeat bolus dosing of surfactant or bolus treatment followed by continuous aerosol delivery may be necessary for a continuous beneficial effect.

Animals↗
PubMed1996

The role of estradiol, progesterone, and transforming growth factor on human endometrioma cell culture.

The present study demonstrates several aspects of endometrioma cells in culture, namely, 1) cell growth, proliferation, and morphology, 2) effect of cell culture on estrogen and progesterone receptor concentration, 3) effect of estradiol, progesterone, and transforming growth factor. The tissue sample was obtained from ovarian endometriomas that were removed via laparotomy or laparoscopy. The tissue sample was digested with collagenase. After washing, the tissue was cultured in endothelial cell culture medium. Cell count was done by flow cytometry. Receptor study was done by immunohistochemistry. The results demonstrated the growth and proliferation of endometrioma cell in culture medium. Electron microscopy showed stroma-like cells. The cells lost their estrogen and progesterone receptors. Estradiol and progesterone added to these cultures did not affect the rate of growth and proliferation of the cells. Transforming growth factor significantly increased the rate of growth and proliferation of these cells.

Cell Division↗
PubMed1995

Pleuropulmonary blastoma simulating an empyema in a young child.

Pleuropulmonary blastoma is a rare childhood malignancy that may simulate an empyema both clinically and radiographically. A 3-year-old boy with fever, cough, and abdominal pain developed complete opacification of the left hemithorax with contralateral mediastinal shift over the course of several weeks. At thoracotomy, a pleuropulmonary blastoma was discovered. The radiology, pathology, and clinical course of this rare neoplasm are discussed.

Child, Preschool↗
PubMed1994

Acute gastritis associated with spiral organisms from cats.

Numerous studies implicated Helicobacter pylori as one causative agent producing gastritis and dyspepsia. Recent reports focus on another bacterium, Gastrospirillum hominis, as a possible pathogen producing gastritis. We report a 30-year-old researcher who became acutely ill with epigastric pain indicative of esophagitis or peptic ulcer disease. Gastritis and a gastric ulcer were observed endoscopically. Histological examination of the gastric mucosa revealed an acute gastritis and large spiral-shaped organisms. The spiral forms were present in large quantities in the gastric mucosa of experimental animals (cats) handled by the patient in his research. Electron microscopy confirmed that the organisms from the cat and patient were morphologically identical. The patient was successfully treated with bismuth subsalicylate. His symptoms resolved and the organisms were cleared from his stomach. This study provides evidence that another bacterium, a Gastrospirillum, may cause gastritis in man and may be transmitted from animal to man.

Adult↗
PubMed1993

Endovascular canine anastomotic stenting.

The healing characteristics and morphological features of a trans-anastomotic endovascular multifilament flexible metallic stent (Wallstent, Schneider) were investigated in a canine end-to-end arterial model. Both femoral arteries of 12 conditioned mongrel dogs were exposed, then transversely divided and reanastomosed. One anastomosis was randomly chosen for stent placement. Stents were chosen to match the diameter of the femoral arteries and were 25 mm in unconstrained length. Animals were sacrificed at intervals of 3, 6, 9, and 12 weeks. The anastomotic segments were pressure perfusion fixed and sectioned. The cross-sectional luminal, intimal, and medial areas were calculated from computer digitized images of the individual sections. Data were analyzed by univariate repeated measures analysis of variance. Stented anastomoses had an increased luminal area as compared with the anastomosis of non stented sections (P < 0.002). However, stended segments had a significantly increased intimal area when compared to control segments in the same animal (P < 0.001). Stented anastomoses had a significantly increased lumen area over controls despite a marked intimal response to the stent.

Anastomosis, Surgical↗
PubMed1992

The effect of interstitial hyperthermia on the Dunning prostate tumor model.

The effect of hyperthermia was examined on the Dunning prostate tumor model in rats. Hyperthermia was created by heating self-regulating interstitial seeds with an external oscillating magnetic field. The seed alloy was comprised of 70% nickel and 30% copper. One treatment with 50C seeds for two hours did not provide significant delay in tumor growth compared to controls. However, regimens with two treatments separated by either 48 hours or one week did cause significant delay (p = 0.0013 and p = 0.0096, respectively). These results suggest that an interstitial hyperthermia seed may provide an efficacious outpatient therapy for prostate cancer. Further, interstitial hyperthermia may be readily combined with existing radiotherapy with interstitial gold coated seeds to provide additive or synergistic anti-tumor effects.

Adenocarcinoma↗
PubMed1991

The in vivo effect of regional hyperthermia on dunning R3327 prostatic tumor.

This report describes the in vivo effect of regional hyperthermia on male Copenhagen rats implanted with Dunning R3327 prostatic carcinoma. In six rats, a 22-gauge 1.5-cm needle was inserted into the tumor and heated to 46.5 degrees C for 2 hr. Two hyperthermia treatments were administered 48 hr apart. In a separate group of six rats, the needle was inserted into the tumor, but not heated. After treatment, serial measurements of tumor volume and body weight were made twice a week for 4 weeks. From the first day of measurement to day 22, the tumor size in the treated group compared to control was significantly smaller, P = 0.02. In the first 12 days following treatment, the mean value of body weight in the treated and control groups decreased 7% and 3%, respectively. Following this, body weights increased to baseline levels by the end of the study. No other side effects related to hyperthermia were observed and no immediate mortality occurred. In the control group, two rats died from lung metastasis of the prostatic carcinoma after day 22. In the treated group, no lung metastases were found and no rats died before being sacrificed on day 29. Our experiments show that local elevation of the temperature of the Dunning tumor results in the death of tumor cells; at 46.5 degrees C for 2 hr there is marked tumor damage while the rats tolerated the hyperthermia well.

Adenocarcinoma↗
PubMed1990

Regional hyperthermia combined with high energy shock wave treatment on Dunning prostate tumors.

Male Copenhagen rats implanted with Dunning R3327 prostate carcinoma were treated with regional hyperthermia and high energy shock waves (HESW). Twenty-four rats were divided into four equal groups. All rats in one group were matched with the corresponding rats in the other three groups according to tumor size. Hyperthermia was created by the resistive heating of a 22-gauge 1.5-cm needle; HESW were generated by the Dornier XL-1 experimental lithotripter. In two hyperthermia treatments administered 48 hours apart, the tumor was heated to 46.5 degrees C for 2 hours; HESW treatment involved 1,600 shocks at 18 kV. Twenty-nine days after initiation of this study, animals were sacrificed and tumor growth calculated. Tumor growth in group 1 (combined hyperthermia and HESW) was significantly delayed between the 7th and 29th day (p = 0.05). In group 2 (HESW alone), tumor growth was significantly delayed between the 7th and 22nd day (p = 0.01), while tumor growth in group 3 (hyperthermia alone) was delayed between the 3rd and 22nd day (p = 0.02). On day 22, mean percent change in tumor growth in the control group exceeded that of group 1 by 449% (p = 0.015) as well as that of groups 2 and 3, by 350% (p = 0.034) and by 268% (p = 0.049), respectively. As previous reports demonstrate the efficacy of hyperthermia in combination with irradiation or chemotherapy for the treatment of prostate carcinoma, our results indicate hyperthermia in combination with HESW may also be a useful treatment modality.

Animals↗
PubMed1988

IgM antitrophoblast antibodies in a patient with a pregnancy-associated lupuslike disorder, vasculitis, and recurrent intrauterine fetal demise.

We describe herein circulating IgM antitrophoblast antibodies in a patient with recurrent pregnancy-associated vasculitis and intrauterine fetal demise. The patient also exhibited a lupus anticoagulant. Direct and indirect immunofluorescence studies were carried out with the patient's placenta, normal placentas, the patient's serum, and normal serum controls. The antitrophoblast antibodies may have contributed further to the risk of intrauterine death, already known to be associated with lupus anticoagulants. More information about the frequency of such antibodies is desirable and could be obtained in similar cases by the methods discussed.

Adult↗
PubMed1987

Digoxin-like immunoreactive substance in fetuses with and without cardiac pathology.

The concentration of digoxin-like immunoreactive substance was measured by immunoassay in umbilical venous blood from six normal and 19 fetuses with a variety of cardiac and noncardiac disorders. Fetal blood was obtained either by percutaneous umbilical blood sampling (n = 13) or at delivery (n = 12). Three women received digoxin for fetal indications. Healthy control fetuses had significantly less digoxin-like immunoreactive substance measured (mean concentration below the limit of the assay sensitivity) than was found in ill fetuses whose mothers received digoxin (p less than 0.005). However, the fetal concentrations of immunoreactive digoxin in fetuses with a cardiac abnormality were similar whether the mother had (0.93 +/- 0.4 ng/ml) or had not (1.27 +/- 0.4 ng/ml) received digoxin (p = 0.1452). Although there was a significant negative correlation between digoxin concentration and gestational age (R = -0.5079, p less than 0.01), the youngest fetuses examined were generally the sickest. The correlation with gestational age was not significant if the normal control fetuses were excluded. One fetus with a cardiac tachyarrhythmia was examined during and after transplacental therapy. There was no change. It is possible that previously measured "digoxin" in "treated" fetuses represents digoxin-like immunoreactive substance and that only small amounts of maternally administered digoxin actually reach the ill fetus. Our findings suggest that a randomized trial of maternal digitalization for the treatment of fetal supraventricular tachycardia is essential prior to its acceptance as effective therapy.

Blood Proteins↗
PubMed1986

Argyria: microanalytic-morphologic correlation using paraffin-embedded tissue.

Scanning electron microscopes, which have energy dispersive spectroscopy (x-ray microanalysis) capability, can provide accurate identification of the composition of inorganic deposits in tissue. We report a case of florid argyria in which the same deparaffinized 4-micron sections were sequentially examined by light microscopy, scanning electron microscopy, backscattered electron imaging, and x-ray microanalysis to confirm the clinical impression of argyria. We recommend the use of x-ray microanalysis of paraffin-embedded tissue as a simple, rapid and inexpensive means of precise identification of inorganic deposits of heavy elements in tissue sections.

Administration, Intranasal↗
PubMed1985

Demonstration of regional blood-brain barrier permeability in human brain.

The brain of a 78-year-old woman with argyria was examined at autopsy. Silver nitrate deposition was observed in circumventricular organs (CVO) and in the paraventricular and supraoptic nuclei of the hypothalamus. These findings parallel animal experiments of other investigators and are the best demonstration so far of regional absence of the blood-brain barrier in humans. These observations demonstrate similarities between humans and other mammals of CVO anatomy, permeability to blood-borne agents, and perhaps neural connections between CVOs and magnocellular nuclei.

Aged↗
PubMed1985

Adult Niemann-Pick disease masquerading as sea blue histiocyte syndrome: report of a case confirmed by lipid analysis and enzyme assays.

We present the clinical, pathologic, and metabolic findings of an adult woman with debilitating coronary artery disease and hepatosplenomegaly who was discovered to have multiorgan infiltration by sea blue histiocytes. A diagnosis of sea blue histiocyte (SBH) syndrome was made and no further workup performed. The patient suffered from progressive heart failure and sepsis following coronary artery bypass surgery and died 9 months after presentation. Tissues examined at autopsy showed pronounced infiltrates of both granular sea blue histiocytes and foamy, vacuolated histiocytes, which were morphologically compatible with Niemann-Pick cells. Ultrastructural examination of these cells revealed lamellar myelin-like figures as described in Niemann-Pick (N-P) disease. Fibroblast enzyme assay studies and liver lipid analyses performed after the patient's death revealed pronounced sphingomyelinase deficiency and a lipid profile diagnostic of N-P disease, type B. This case adds further support to the claim that some cases of apparent SBH syndrome actually represent a type of N-P disease.

Biopsy↗
PubMed1984

Demonstration of iron and thorium in autopsy tissues by X-ray microanalysis.

We performed x-ray microanalysis of autopsy specimens using a scanning-transmission electron microscopy mode. Tissues were obtained at necropsy from a patient with history of angiography using thorium dioxide and from a patient with hemochromatosis. X-ray microanalysis confirmed the presence of thorium and iron in their respective tissues. Effects of staining reagents were examined.

Angiography↗