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Biomedical subjects

L Wise

Publications and source records attributed to L Wise.

At least 55 records · Page 3Linked to original sources
PubMed1992

Prognostic factors in node-negative breast cancer.

One hundred patients with node-negative breast cancer were examined to analyze the influence of tumor size, nuclear grade, and DNA content determined by flow cytometry on overall survival. Patients with diploid cancers lived significantly longer than those with aneuploid cancers (126 +/- 8 vs 80 +/- 11 months). Patients with an S-phase fraction less than 10% lived significantly longer than those with S-phase fractions 10% or greater (122 +/- 8 vs 85 +/- 10 months). Tumor size had the major impact on survival, and multivariate analysis of variance by the Cox proportional hazards model showed the greatest effect on prognosis. Tumor grade did not significantly influence overall survival.

Breast Neoplasms↗
PubMed1992

Prognostic significance of DNA measurement determined by image analysis in human breast carcinoma.

The nuclear DNA of human breast carcinoma cells was studied by image analysis using archival paraffin-blocked tissues from two groups of patients with breast cancers. One group had survived greater than 10 years (N = 20) and the other less than 3 years (N = 26) after the initial diagnosis. Cellular preparations were made from pepsin-digested deparaffinated sections. The nuclear DNA was stained with Feulgen stain and measured by a computerized image analysis system. The data show that in addition to nodal status the pattern of DNA histograms obtained from image analysis can provide powerful prognostic information in breast carcinoma. The prognostic value of DNA histogram patterns may be independent of nodal status.

Breast↗
PubMed1992

Increased intestinal permeability: implications for thoracoabdominal aneurysm repair.

Coagulopathy and massive bleeding plays a major role in the mortality of thoraco-abdominal aneurysm repair. Increasing supraceliac aortic cross-clamp time from 0 to 90 minutes increases the degree of disseminated intravascular coagulation, which occurs as a result of occlusion and reperfusion of the superior mesenteric artery. The purpose of this study was to investigate the mechanism of the superior mesenteric artery reperfusion disseminated intravascular coagulation. Twenty dogs were divided into four groups: cross-clamp time of 30 minutes; cross-clamp time of 60 minutes; cross-clamp time of 90 minutes; and control. Permeability was determined by lactulose/mannitol absorption. The venous effluent was sampled for endotoxin, potassium, bacteria, and pH every hour and urine was collected for six hours. Lactulose absorption was significantly higher in all of the experimental groups. There was increased permeability in the 60 and 90 minute groups which correlated significantly with time. Venous endotoxin, potassium, and blood cultures for bacteria did not change significantly. The pH was significantly lower every hour for six hours in the 90 minute group. These data suggest that intestinal permeability is increased with supraceliac aortic clamping and can be kept to a minimum for clamp times of under one hour.

Animals↗
PubMed1992

Smooth muscle cell elastase, atherosclerosis, and abdominal aortic aneurysms.

Smooth muscle cells (SMC) were obtained by outgrowth of human aortic explants from abdominal aortic aneurysm (AAA) patients, aortic occlusive disease (AOD) patients, and transplant donors (controls). Specimens were incubated with medium alone or medium with either elastin-derived peptides (EDP, 5 micrograms/mL) or low-density lipoproteins (LDL, 5 micrograms/mL). Elastase activity (ng/mg total protein) was assayed from 4-week-old cultures. Control aortas obtained from patients significantly younger secrete an increased amount of elastase at baseline compared with AOD and AAA patients (p less than 0.05). Elastin-derived peptides caused a significant increase in elastase secretion in all groups. The increase in elastase secretion in response to EDP in AAA patients was significantly higher compared with AOD or control. Low-density lipoprotein had no effect on SMC elastase secretion. These data suggest that (1) aortic SMCs secrete elastase in response to EDP, (2) SMC elastase is age dependent, and (3) AAA SMC secrete an abnormally high amount of elastase compared with AOD and control aortas in response to EDP. Like the neutrophil, the SMC is highly responsive to the degradation products of elastin and in AAA patients secrete significantly increased amounts of elastase in response to the breakdown products of atherosclerosis.

Adult↗
PubMed1992

Cardiovascular changes during laparoscopic cholecystectomy.

Although the technique of laparoscopic cholecystectomy has increasing appeal, physiologic data to support the safety of this procedure are lacking. We studied the cardiovascular changes in 16 patients undergoing laparoscopic cholecystectomy, using impedance cardiography as a noninvasive means of continuous monitoring of cardiac output. Serial measurements of mean arterial pressure (MAP), heart rate (HR), intraperitoneal pressure and expired carbon dioxide tension (PECO2) were also recorded. Results revealed a decrease of 30 percent (p < 0.001) in cardiac index and 5 percent (p = 0.089) in HR, along with increases of 15 percent (p < 0.001) in MAP and of 79 percent (p < 0.001) in the calculated total peripheral resistance index. This elevation in afterload could lead to both an increase in myocardial oxygen consumption and to the potential risk of myocardial ischemia and possibly infarction or congestive heart failure, or both, in patients who are susceptible. The data suggest that patients with a history of cardiac disease should have preoperative cardiac evaluation and be closely monitored during laparoscopic cholecystectomy, as in any other extensive operation.

Adult↗
PubMed1991

Stress-induced gastric lesions and the synthesis of prostaglandins and leukotrienes.

Prostaglandin E2 renders the mucosa of the GI tract more resistant to acute injury by aspirin, acid, bile salts, and stress, whereas leukotrienes promote inflammation and retard healing of ulcers. The relationship of stress ulcer formation to changes in the activities of prostaglandin synthetase and lipoxygenase was evaluated in this study. After a 24 hr fast, 10 rats were stressed by the cold-restraint method for 4 hr and 10 rats were not stressed. Rats were terminated, stomachs were excised, the number of lesions were counted, and the nonulcerated mucosa was assayed for prostaglandin E2 and leukotriene synthesis. The mucosa was minced, washed in buffered saline, and then incubated for 10 min in a 1.3 mM sodium arachidonate solution containing a nonionic detergent (poloxamer 188), NaCl, KCl, KPO4, glutathione, hemin, MgSO4 and Hepes at pH 8.0. An ANOVA was used to compare the groups. Following stress the number of gastric lesions increased from 0.7 +/- 0.6 to 13.5 +/- 2.6, while leukotriene synthesis increased from 173 +/- 20 to 2170 +/- 187 pg/mg/min. A shift in synthesis from prostaglandins to leukotrienes in the mucosa appears to be detrimental to cytoprotection.

Animals↗
PubMed1991

Preliminary study of the protective effect of the calcium channel blocker, nifedipine, on adriamycin-induced tissue injury.

The effect of nifedipine, an oral calcium-channel blocker, on adriamycin-induced wound healing was studied. Nifedipine was administered to animals prior to treating with adriamycin. The healing strengths of cecal, fascial, and skin anatomoses were measured. Animals treated with adriamycin alone had significant decreases in healing strength compared to controls: for cecum at postoperative days (POD) 7 and 14; for skin at PODs 14, 21, and 28; for fascia at POD 28. Overall, nifedipine reduced the impact of adriamycin injury on the strength of healing incisional anastomoses. Nifedipine also appeared to protect collagen synthesis at anastomotic sites from adriamycin-induced impairment.

Animals↗
PubMed1991

Effect of allopurinol on adriamycin-induced impairment of wound healing.

Use of antineoplastic drugs perioperatively requires an understanding of their potential effects on healing wounds. Adriamycin is an antineoplastic drug with a wide range of antitumor activity. Prior studies have demonstrated that adriamycin impairs skin wound healing but these studies have offered limited explanations for the mechanism of action of the drug vis á vis impairment of healing wounds. In this study we investigated the effect of a xanthine oxidase inhibitor, allopurinol, on adriamycin-induced tissue injury to determine the role oxyradicals might play in reducing wound-breaking strength. Sixty-four Buffalo rats were studied. Eight animals were used to establish drug tolerances. Fifty-six animals were divided into four experimental groups; saline control (2 mL IP), allopurinol control (4.3 mg/kg po), allopurinol-adriamycin (4.3 mg/kg po + 6 mg/kg IV, respectively), and adriamycin (6 mg/kg IV). Animals treated with adriamycin alone had significantly reduced weight at postoperative day (POD) 7 compared to control groups (p less than .025). Bowel-bursting strength (BBS) of the animals treated with adriamycin alone was also significantly decreased at POD 7, compared to controls (p less than .025), and by POD 14 the animals treated with adriamycin alone had a significantly decreased fascial tensile strength, compared to the saline control (p less than .05). At no point did the animals treated with both allopurinol and adriamycin show a significantly decreased weight, BBS, or fascial tensile strength compared to control animals. Allopurinol appeared to protect against adriamycin toxicity on healing wounds. These results suggest that xanthine oxidase and possibly superoxide radicals play an important role in mediating adriamycin toxicity on healing wounds.

Allopurinol↗
PubMed1991

Neutrophil chemotaxis and neutrophil elastase in the aortic wall in patients with abdominal aortic aneurysms.

To test the hypothesis that elastin-derived peptides (EDP) from human aortic tissue may be chemotactic for inflammatory cells, we studied the chemotaxis of neutrophils and monocytes to EDP derived from abdominal aortic aneurysm (AAA), aortic occlusive disease (AOD), and control aortas. In addition, we determined if neutrophils deliver neutrophil elastase to the aorta in vivo by staining for neutrophil elastase (NE) throughout the course of abdominal aortic aneurysms with the monoclonal antibody to human NE. EDP from AAA, AOD, and control tissue demonstrated significant chemotactic activity for both neutrophils and monocytes. All neutrophils had a greater attraction to EDP from AAA tissue compared to AOD and control aorta. Neutrophils from AAA patients were more attracted to EDP of AAA tissue than were neutrophils of AOD or control patients attracted to their respective aortic EDP. Neutrophil elastase stained positive in the adventitia and thrombus throughout the course of the aneurysm, but was not found in the intima, media, or plaque of the aorta.

Aorta, Abdominal↗
PubMed1991

Is colonoscopy safe in the early postcolectomy period?

Colonoscopy was performed preoperatively and 1, 2, 3 and 7 days following a left hemicolectomy with a primary anastomosis in 11 dogs. The remaining colon and anastomosis were adequately visualized. Maximal intraluminal pressures achieved were from 15 to 35 mmHg. No leakage of air or intra-abdominal abscesses were present. In ten patients undergoing colonoscopy for lower gastrointestinal symptoms, the pressures were similarly measured. Although pressures were slightly higher in patients, averaging 30 mmHg, the results suggest that colonoscopy can be safely performed during the early postcolectomy period.

Air↗
PubMed1991

Hospital costs, resource characteristics, and the dynamics of death for general surgery patients.

The world of health care finance and quality assessment is undergoing rapid change. We analyzed a large group of general surgical patients who died regarding hospital resource consumption. General surgical patients who died generated much greater resource consumption than survivors per DRG; increasing hospital LOS for general surgical patients who died was associated with increasing financial risk under DRGs. Patients who died after non-emergency admission generated similar financial risk to patients who died after emergency admission. General surgical patients who died who were referred from another clinical service generated, on average, similar resource consumption to non-referred patients who died. The results of this study support those of previous studies suggesting the payment inequities of DRGs for general surgical patients who die and suggest that attention should be directed at improving the DRG hospital payment system for these patients.

Aged↗
PubMed1991

Measurement of prostaglandin G/H synthase and lipoxygenase activity in the stomach wall by HPLC.

A method for the determination of prostaglandin G/H synthase and lipoxygenase activities in tissues was developed and employed with rat gastric mucosa samples. Tissues and microsomes were incubated in a buffer containing nonionic detergent and 1.32 mM arachidonic acid for 10 min. Following extraction with ethyl acetate, the oxidation products of arachidonic acid were derivatized with panacyl bromide. A reversed-phase column and a quaternary mobile phase were used to separate and quantitate the panacyl bromide esters of prostaglandin E2 and leukotriene C4/D4. Prostaglandin G/H synthase and lipoxygenase activities were determined in gastric mucosa and were 371 +/- 66 and 173 +/- pg/mg/min, respectively.

Animals↗
PubMed1991

Massive rectal bleeding from a Dieulafoy's type ulcer of the rectum: a review of this unusual disease.

Dieulafoy's ulcer is an uncommon lesion that usually presents with massive bleeding. Although it has been observed, for the most part, in the stomach, it has also been identified in the small bowel and colon. Both endoscopy and angiography have been used for diagnosis; however, endoscopy has had a high failure rate for localizing colonic disease during active bleeding. Treatment has been primarily surgical, but endoscopic coagulation and sclerotherapy have been recently employed. A 20-year-old male presented with massive lower gastrointestinal bleeding, which was found to be caused by a Dieulafoy's ulcer in the rectum. Observation of Dieulafoy's ulcer in the rectum has not been reported previously. Diagnosis was by rigid sigmoidoscopy. This lesion was treated by widely oversewing the vessel after endoscopic therapy failed. The etiology of this lesion is most likely congenital. Hemorrhage probably occurs as a result of mechanical damage of the mucosa, combined with erosion of the vessel by fecal flow. Unlike colonic Dieulafoy's ulcers, it should be possible to diagnose rectal lesions by rigid sigmoidoscopy. This diagnosis may be difficult with high rectal ulcers, and angiography may have to be employed. Endoscopic therapy failed here, as in other reports on colonic disease. Thus, we would recommend widely oversewing rectal lesions as the primary treatment. Resection should be reserved for cases that have failed this therapy.

Adult↗
PubMed1991

Experience in managing 70 patients with ruptured abdominal aortic aneurysms.

Seventy cases of ruptured abdominal aortic aneurysms (RAAAs) repaired over a 14-year period from 1975 to 1989 were analyzed. Age, heart disease, chronic obstructive pulmonary disease (COPD), hypertension, diabetes, or specific postoperative complications did not correlate with mortality. If the time interval from arrival at the hospital to skin incision (emergency room (ER) or operating room (OR] was less than six hours, there was no correlation with survival. Mortality correlated significantly with admitting systolic blood pressure, blood pressure at the time of skin incision, a comparison of ER to OR time of less than or more than six hours, blood loss of less than compared to more than ten units, and time in the operating room of less than five hours compared to more than five hours. Both time in the operating room and blood loss correlated with technical problems. Prior to 1985, 11 general and vascular surgeons had repaired RAAAs with a mortality of 76%. Since 1985, six vascular surgeons repaired RAAAs with a significant decrease in mortality (54%). Our data indicate that patients profoundly hypotensive on admission or at the time of incision are unlikely to survive regardless of other factors; patients with a systolic blood pressure greater than 100 mm Hg have the best chance of survival; a delay of up to six hours prior to surgery in patients with a systolic blood pressure greater than 100 mm Hg does not increase mortality; and a smaller number of surgeons operating on RAAAs increases survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Measurement of 5-fluorouracil and its active metabolites in tissue.

The 5-fluorouracil content of serum, bile, pancreatic juice, liver, pancreas and muscle was measured by reversed-phase high-performance liquid chromatography using a mobile phase of 5 mM 1-heptanesulfonic acid in 5 mM acetic acid. Free or unmetabolized 5-fluorouracil was extracted from samples with a mixture of light petroleum-n-propanol (40:60). The active metabolites of 5-fluorouracil were hydrolyzed with hot perchloric acid to free 5-fluorouracil and the combined 5-fluorouracil content was extracted. The active metabolite fraction was calculated from the difference between the combined and the free fractions. A straight line plot of the peak areas against concentration was achieved and the detection limit was 50 ng/ml. Five minutes after stopping an intravenous infusion of 15 mg/kg of 5-fluorouracil in a dog, the serum contained only the free form, but other body fluids and tissues contained both free and metabolite fractions. The method may be useful to determine the amount of total drug in patient samples.

Animals↗
PubMed1990

Hospital readmissions, otolaryngology, and the diagnosis related group hospital payment system.

An analysis of otolaryngologic patients requiring readmission was conducted at our institution during a 4-year period to determine the number of readmissions per patient and the time between discharge and hospital readmission. Readmitted otolaryngologic patients were found to have had greater hospital resource utilization, financial risk under diagnosis-related group payment, and mortality, compared with those patients not readmitted to our facility. For patients readmitted to otolaryngologic services (21.2% of total otolaryngologic patients), 20.4% of the readmissions occurred within 30 days of hospital discharge. Of these, 39.3% required one hospital readmission, 16.3% required two readmissions, and 46.4% of the patients called for three or more hospital admissions. Clinical factors were identified that resulted in a greater incidence of otolaryngologic readmission. Otolaryngologic patients readmitted to other clinical services were also studied. This analysis loads to the conclusion that inequities exist within the diagnosis related group hospital payment system vis-à-vis otolaryngologic readmissions. The results of these data also demonstrate leverage points in which we will be able to focus outpatient services for otolaryngologic patients requiring readmission and potentially decrease inpatient hospital expenditures in the days ahead.

Academic Medical Centers↗
PubMed1990

Costs, quality, and the volume of surgical oncology procedures.

We tested the hypothesis that hospital costs and outcome (ie, mortality) would differ for each surgeon by the volume of patients treated per diagnosis related group by individual surgical oncologists. All elective surgical oncologic admissions (N = 2627) to our hospital from 1985 to 1987 were divided into those patients treated by low-volume surgeons vs those patients treated by high-volume surgeons; 11.9% of patients not fitting these categories were excluded. Patients of the 57 low-volume surgeons utilized greater hospital resources (which resulted in losses instead of profits) and had a higher mortality compared with patients of the 17 high-volume surgeons. This was due, in part, to a greater severity of illness. These findings suggest that hospital costs and perhaps outcome may be related, at the individual surgeon level, to the volume of surgical procedures performed, and that the diagnosis related group prospective payment system may provide disincentives for low-volume surgeons.

Academic Medical Centers↗