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Biomedical subjects

W Oliver

Publications and source records attributed to W Oliver.

47 records · Page 3Linked to original sources
PubMedDate not supplied

Modification of hypoxic pulmonary vasoconstriction by aerosolized cromolyn sodium.

We have previously demonstrated the role of mast cell degranulation in the mediation of hypoxic pulmonary vasoconstriction, and its prevention by intravenous cromolyn sodium. In the present investigation, we studied the modification of the hypoxic pulmonary vascular response by aerosolized cromolyn sodium. In seven conscious sheep on two separate days, pulmonary arterial pressure, pulmonary arterial wedge pressure and cardiac output were measured for the calculation of pulmonary vascular resistance (Rpv) along with arterial oxygen tension (Pao2) during room air breathing and breathing a hypoxic gas mixture (13% O2-87% N2), without and with cromolyn sodium administration. Cromolyn sodium (20 mg X kg-1) was administered as an aerosol before and during 13% O2 breathing. The sheep had comparable degrees of hypoxia during low oxygen breathing on both days (mean PaO2: 43 and 46 mmHg). Breathing hypoxic gas mixture caused pulmonary vasoconstriction, with increases in mean Rpv of 89% (p less than 0.05). Aerosolized cromolyn sodium blunted the hypoxic pulmonary vascular response; mean Rpv increased by 27% (p less than 0.05), which was significantly different from the increase during hypoxia without cromolyn sodium treatment (p less than 0.05). We conclude that aerosolized cromolyn sodium (a mast cell membrane stabilizing agent) modifies hypoxic pulmonary vasoconstriction; however, unlike the intravenous form, aerosolized cromolyn sodium (at the dosage used) offers a partial protection.

Aerosols↗
PubMedDate not supplied

Effects of nitric acid on carbachol reactivity of the airways in normal and allergic sheep.

The airway effect of a 4-hr exposure (via a Plexiglas hood) to 1.6 ppm nitric acid vapor were evaluated in seven normal and seven allergic sheep, i.e., animals that have a history of reacting with bronchospasm to inhalation challenge with Ascaris suum antigen. The nitric acid vapor was generated by ultrasonic nebulization of a 2% nitric acid solution. Airway effects were assessed by measuring the change in specific pulmonary flow resistance before and after a standard inhalation challenge with 2.5% carbachol aerosol. Nitric acid exposure did not produce bronchoconstriction in either group. Pre-exposure increases in specific pulmonary flow resistance after carbachol inhalation were 68% (SD +/- 13%) and 82% (SD +/- 35%) for the normal and allergic sheep, respectively. Within 24 hr, the largest post exposure increased in specific pulmonary flow resistance for the normal and allergic sheep were 108% [SD +/- 51% (P less than .06)] and 175% [SD +/- 87% (P less than .02)], respectively. We conclude that a short-term exposure to nitric acid vapor at levels below the industrial threshold limit (2 ppm), produces airway hyperreactivity to aerosolized carbachol in allergic sheep.

Airway Resistance↗
PubMedDate not supplied

[Macroscopic and histopathological aspects of atypical gastric epithelium].

Atypical Epithelium is a localized lesion, which has histological and macroscopic findings similar to gastric cancer. In this paper we evaluated 44 cases of atypical epithelium studied and treated in our institute. We found 3 cases of atypical epithelium associated with early gastric cancer. That is 2.66% of the total of all cases. We established the relationship of these lesions and following variables: age, size, localization, macroscopic shape and intestinal metaplasia. We found atypical epithelium in patients older than 50 years old, most of then smaller than 2 cm., localized in antrum and body gastric, and macroscopically were slight elevated lesions. Histologically all of them had intestinal metaplasia.

Adenocarcinoma↗
PubMedDate not supplied

[Early gastric cancer: main objective in a mass screening program for gastric cancer].

In Táchira's State, Venezuela, there is a high incidence of Gastric Cancer. Screening for early gastric cancer (EGC) detection began in 1981. It observes the Japanese model, with Indirect Radiological (IR) as the move to the various Municipalities, offering the screening test. Subjects with IR abnormalities receive an invitation for an endoscopic examination. If lesions at endoscopy, biopsies were taken. Treatable patients went to surgery; the diagnosis on the surgical specimen was fulfilled by trained Pathologists. CGs cases are actively followed up. From 1981 to 1992 we did 150.023 radiological studies 52.562 gastric endoscopies and 18,480 endoscopic biopsies. We diagnosed 612 CGs:450 were advanced: 102 patients with 113 EGCs with confirmation after surgery; 60 cases were suspected by radiology and endoscopy as EGCs but were nor confirmed because the patients were not operated. 89 patients underwent gastroectomies, and 13 endoscopy resections. The EGCs were depressed (Types IIc, III) in 49% elevated (Types I, IIa) 26%, flat (Type IIb) 6% and intermediate (Types IIa + IIc) 19%. The invasion was confined to the mucosa in 60% and to the submucosa in 40%. By histopathology 60% were differentiated and 40% undifferentiated. In 9% we found metastasis in lymph nodes, only in 2% of the mucosal ones. Survival of patients with EGC after 5 year was 93%. We think a secondary prevention can be done in high risk regions through an appropriate screening for EGC.

Adult↗
PubMedDate not supplied

[Gastric leiomyoblastoma. Histomorphologic and immunologic analysis of 3 cases].

We present three cases of Leiomioblastomas of stomach, diagnosed at the unit of Pathology of the Gastrointestinal Cancer Center "Dr Luis E. Anderson" -San Cristóbal-Táchira State Venezuela. The lesions are analyzed from the clinical, morphological and immunohistological points of view, utilizing Queratine and Vimentin techniques. This neoplasm is not frequent but it is interesting because its biologic behavior not always correspond to its histology-pattern.

Humans↗
PubMedDate not supplied

[Endoscopic sphincterotomy experience at the Cancer Control Center].

Endoscopy Sphincterotomy is an important therapeutic procedure in the treatment of some biliary and pancreatic disorders. In this paper, we report our experience over this subject. In our patients the main indication to perform this procedure was common bile duct stones; they were 83% of the total cases. In those cases, 67% were residual stones after cholecystectomy by laparotomy and laparoscopy. We performed sphincterotomy in 33% of patients with gallbladders in situ. In five patients (7.57%), we made the diagnosis of Oddi's sphincter dysfunction taken in account clinical, biochemical an radiological findings. No manometric measurements were done. We found some unusual cases, such as: choledococele and Sump syndrome. In five patients we had complications, 3 of them bled and the other two developed edematous pancreatitis. All these complications were solved with medical treatment.

Adult↗
PubMedDate not supplied

[The use of urea carbon 14 in breath tests as diagnostic method for Helicobacter pylori infections].

The Helicobacter Pylori has been indicated as a pathologic agent in the pathogenesis of antral gastritis, gastric and duodenal ulcers and probably in gastric cancer. Due to the high incidence of this infection in our place, we decided to look for a diagnostic method quick to perform, sensitive, reliable and no invasive. The breath test of 14C urea, based in the production of urea by the H. Pylori, represents this alternative. We have found, using does of 1 microCi, a high correlation with the diagnosis of H. Pylori by biopsies. We determined as negative less than 100 DPM, doubtful between 100 and 200 DPM and positive more than 200 DPM. The high pick of the curve keeps tight relation with the degree of infection. We checked this when we suppressed the H. Pylori with bismuth subsalicylate. The breath 14C Urea test showed high sensitivity (100%) and specificity (85.71%). We conclude that this breath test is an alternative way of diagnosing and follow up for H. Pylori infections. It is highly sensitive, reproducible and no invasive.

Adult↗
PubMedDate not supplied

[Macroscopic aspect and depth in early gastric cancer].

Depth of invasion in Early Gastric Cancer (E.G.C.) is very important to be evaluated. We reviewed 78 cases of E.G.C., in patients of our program that were operated on. We established the relationship among three macroscopic variables (localization, size and macroscopic shape) and depth of invasion. We realized that the lesions located in the fundus, though diagnosed less frequently, has more tendency to invade the submucosa (50%), in relation to other localizations. We did not find a significant statistic relation chi 2 = 3.76 P: .58 df:5 between size and invasion. The macroscopic types IIa + IIc and the E.G.C. type III have tendency to further invasion (58.8 and 66.67%). The polypoid lesions Type I and IIa are mostly intramucosal, so they could be treated endoscopically in high risk and old patients.

Gastric Mucosa↗
PubMedDate not supplied

[Inflammatory response associated with Helicobacter pylori infection in gastric mucosa with intestinal metaplasia in a population in high risk for gastric cancer].

Intestinal Metaplasia (IM) and Helicobacter Pylori (HP) infection had been related to gastric carcinogenesis. With the intention to know the relationship among HP infection, IM and inflammatory response of the mucosa in an area of high prevalence of gastric cancer, we studied 800 persons that attended the Gastric Cancer Mass Survey, ongoing in the State Tachira, Venezuela, since 1981. Out of these subjects, 259 had histology diagnosis of IM (32.4%) 52.1% were IM type Y, 19.3% type II and 22.8% type III (sulfomucin secretory). Histology demonstrated with Giemsa stain HP in 94.6% of the cases. Association between HP and inflammation response in gastric mucosa with IM, was statistically significant (p = 0.001). The are heavier bacteria overload in IM type I than in type III although it is not statistically significant. We ponder if gastric mucosa inflammation due to HP, conditions development of IM as a hostile way of the gastric environment to restrain bacterial growth. This phenomenon ally with other oncogeneous factors could induce to premalignant lesions and eventually gastric cancer.

Adult↗