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Biomedical subjects

D M Jensen

Publications and source records attributed to D M Jensen.

At least 73 records · Page 4Linked to original sources
PubMed1995

Randomized, prospective study of cyanoacrylate injection, sclerotherapy, or rubber band ligation for endoscopic hemostasis of bleeding canine gastric varices.

The purpose of this randomized, nonblinded study was to compare the effectiveness, safety, and technical ease of three different endoscopic techniques for the treatment of bleeding gastric varices in a canine model. Twenty dogs with large, bleeding gastric varices underwent endoscopic hemostasis with rubber band ligation, sclerotherapy, and cyanoacrylate injection. The time and number of attempts required to achieve definitive hemostasis were evaluated for each technique, and each method was assessed for ease of use. Ulceration rates, ulcer size and depth, and stigmata of ulcer hemorrhage were assessed at 1 week. Intravariceal sclerotherapy was the fastest and easiest to perform. Rubber band ligation was intermediate in technical ease, but it caused the largest and deepest ulcers and had the highest rates of stigmata of ulcer hemorrhage and secondary bleeding. Cyanoacrylate injection was the most cumbersome endoscopic method to perform. All three treatments were effective for controlling gastric variceal bleeding. Intravariceal sclerotherapy had the most favorable results overall because of its technical ease, efficacy, and modest complication rates.

Animals↗
PubMed1995

Randomized, controlled study of various agents for endoscopic injection sclerotherapy of bleeding canine gastric varices.

The purpose of this study was to compare the relative efficacy and technical ease of use of eight different agents for endoscopic hemostasis and obliteration of bleeding gastric varices in a canine model, as no comparative data are available on gastric variceal sclerotherapy. Large bleeding gastric varices in 20 heparinized dogs were randomized to endoscopic injection treatment with one of the following agents: cyanoacrylate; a 1:1:1 mixture of sodium tetradecyl sulfate 3%, ethanol 98%, and normal saline solution; ethanolamine oleate 5%; sodium morrhuate 5%; sodium tetradecyl sulfate 1.5%; polidocanol 1%; normal saline solution with epinephrine 1:10,000; or normal saline solution (control). The number and volume of injections and the time required to achieve complete hemostasis were evaluated; follow-up endoscopy was performed at 1 month to assess gastric variceal obliteration. Cyanoacrylate was the best agent overall in terms of immediate efficacy, low volume requirement, time required for initial hemostasis, and reduction of gastric variceal size. Cyanoacrylate, tetradecyl sulfate, and polidocanol were the most effective agents for reducing gastric variceal size. Epinephrine was effective for controlling induced or secondary bleeding caused by puncture of the gastric varices with the sclerotherapy needle during intravariceal injections. Ongoing studies are evaluating combinations of agents with different mechanisms of action, such as epinephrine (for vasoconstriction to minimize secondary bleeding) plus alcohol, and/or tetradecyl sulfate (for variceal thrombosis and sclerosis).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Transjugular intrahepatic portosystemic shunt in nonliver transplant candidates: is it indicated?

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is an effective treatment of severe portal hypertension complications. Liver transplantation (LT) candidacy has not been a prerequisite to TIPS placement in some medical centers. OBJECTIVES: To investigate the outcome and survival of non-LT candidates after TIPS. METHODS: From November 1991 to February 1994, all patients referred for TIPS placement were evaluated for LT candidacy. Exclusions for LT included: age (> 70 yr), other significant medical conditions, or noncompliance. Indications for TIPS included refractory variceal bleeding during an acute bleed, recurrent bleeding after more than or equal to four sessions of sclerotherapy, or refractory ascites. RESULTS: Sixty patients received TIPS. Nineteen were considered non-LT candidates. Over a 2-yr follow-up, 14 of these non-LT candidates did not survive. Their median age was 63.5 compared with 56.5 yr for LT candidate nonsurvivors (p < 0.05). Among the 14 non-LT candidate nonsurvivors, 10 were Childs C class, and eight had emergent TIPS placement. The 2-year mortality rate was 84% for non-LT candidates versus 24% for LT candidates. Median survival time for non-LT candidates was 2.6 months compared with 20 months in the LT candidates (p < 0.001). Only one death was due to a TIPS-related complication. CONCLUSIONS: TIPS is unquestionably an advancement in the management of patients with portal hypertension complications. Non-LT candidates, compared with LT candidates, tended to be older and of a Child-Pugh C class, and they had survival rates often less than 90 days post-TIPS. Given these high mortality rates, we need to address whether TIPS is indicated in these non-LT candidates.

Esophageal and Gastric Varices↗
PubMed1994

A controlled study of ranitidine for the prevention of recurrent hemorrhage from duodenal ulcer.

BACKGROUND: Hemorrhage is the most common complication of duodenal ulcer disease, but there is little information about the effectiveness and safety of long-term maintenance therapy with histamine H2-receptor blockers. METHODS: We conducted a double-blind study in patients with endoscopically documented hemorrhage from duodenal ulcers. Patients were randomly assigned to maintenance therapy with ranitidine (150 mg at night) or placebo and were followed for up to three years. Endoscopy was performed at base line (to document that the ulcers had healed), at exit from the study, and when a patient had persistent ulcer symptoms unrelieved by antacids or had gastrointestinal bleeding. Symptomatic relapses without bleeding were treated with ranitidine; if the ulcer healed within eight weeks, the patient resumed taking the assigned study medication. RESULTS: The two groups were similar at entry, which usually occurred about three months after the index hemorrhage. After a mean follow-up of 61 weeks, 3 of the 32 patients treated with ranitidine had recurrent hemorrhage, as compared with 12 of the 33 given placebo (P < 0.05). Half the episodes of recurrent bleeding were asymptomatic. One patient in the ranitidine group withdrew from the study because of asymptomatic thrombocytopenia during the first month. CONCLUSIONS: For patients whose duodenal ulcers heal after severe hemorrhage, long-term maintenance therapy with ranitidine is safe and reduces the risk of recurrent bleeding.

Double-Blind Method↗
PubMed1994

Evaluation of abnormal liver tests.

The evaluation of elevated serum aminotransferase levels requires attention to clinical clues obtained in the history and physical examination. The likelihood that an aminotransferase abnormality reflects significant liver disease is enhanced if the following occur: (1) more than one liver enzyme is abnormal; (2) the abnormalities are associated with clinical signs or symptoms of liver disease; (3) the enzyme level is high; or (4) the abnormalities are present for > 6 months. The subsequent laboratory investigation becomes relatively straightforward in confirming a cause for the abnormalities before initiating therapy.

Adult↗
PubMed1993

Immunogenicity of two recombinant hepatitis B vaccines in older individuals.

PURPOSE: Currently available hepatitis B vaccines are recombinant, yeast-derived preparations given in 10-micrograms or 20-micrograms doses. The optimum dose remains controversial. We sought to assess the relative immunogenicity of two hepatitis B vaccines, given in different doses, in older individuals. PATIENTS AND METHODS: In a multicenter, double-blind, randomized clinical trial, a total of 460 healthy subjects between 39 and 70 years of age were screened and immunized with either Engerix-B 20 micrograms or Recombivax HB 10 micrograms in standard, intramuscular, 3-dose regimens. Of these, 397 subjects were eligible to continue vaccination. Immunogenicity was measured by determination of antibody to hepatitis B surface antigen (anti-HBs). Seroconversion and seroprotection rates, and geometric mean titers of anti-HBs were calculated at 1, 3, 6, and 8 months after the initial dose of vaccine. RESULTS: Seroprotection rates for subjects receiving the 20-micrograms dose of vaccine were slightly, but not significantly, greater than for subjects receiving the 10-micrograms dose, at each time point. However, at 3 months, males receiving the higher dose had significantly higher seroprotection rates than males receiving the lower dose: 63% versus 37% (p < 0.001). At 8 months, geometric mean titers for the group receiving Engerix-B 20 micrograms were significantly greater than that for the group receiving Recombivax HB 10 micrograms: 840 mIU/mL versus 340 mIU/mL (p = 0.001). CONCLUSIONS: Immunization with the 20-micrograms dose of recombinant hepatitis B virus vaccine appeared to result in more rapid development of seroprotective anti-HBs titers in older men and in higher titers of anti-HBs at the completion of vaccination when compared to the 10-micrograms dose. The latter data suggest that the 20-micrograms dose may result in a longer duration of seroprotective anti-HBs titers.

Adult↗
PubMed1992

Clinical results of piezoelectric gallstone lithotripsy.

The safety and efficacy of piezoelectric extracorporeal shockwave lithotripsy in the treatment of symptomatic gallbladder stones were evaluated in 53 consecutively treated patients. All treatments were performed as outpatients without anesthesia; over 95 per cent of 109 treatments were performed without analgesia or sedation. Ursodeoxycholic acid was administered post-treatment. Seventy per cent of patients had multiple sessions. Cumulative stone-free rates of 38 per cent at 6 months, 65 per cent at 12 months, and 75 per cent at 15 months were achieved. There was no difference in eventual stone clearance between patients with single stones less than 20 mm diameter, single stones greater than or equal to 20 mm diameter, or multiple (two or three) stones, although patients with single smaller stones required significantly fewer total shocks to become stone-free (P = .02). Stone clearance correlated with estimated stone volume. Biliary pain occurred in 62 per cent of patients after treatment but ceased in stone-free patients. Biliary complications of pancreatitis (7.5%) and choledocholithiasis (3.8%) were successfully treated by endoscopic papillotomy. Nonbiliary complications were virtually nonexistent. Three patients (5.7%) had elective cholecystectomy. Results indicate that piezoelectric lithotripsy is a safe, minimally painful treatment that, in conjunction with oral bile acids, can produce stone-free rates of 75 to 100 per cent in selected patients.

Adult↗
PubMed1989

Controlled study of different sclerosing agents for coagulation of canine gut arteries.

Excellent clinical results have been reported with sclerotherapy for control of nonvariceal gastrointestinal hemorrhage. However, there are few controlled or comparative data on different sclerosing agents for treatment of lesions with active arterial bleeding or nonbleeding visible vessels. In a controlled, randomized study of canine small bowel arteries our purposes were (a) to evaluate the efficacy for arterial coagulation of six sclerosing agents compared with normal saline control, (b) to compare the resultant tissue injury of agents, and (c) to elucidate the possible mechanisms of arterial coagulation and tissue injury of the agents. The agents evaluated were (a) 98% ethanol, (b) TES, a mixture with final concentration of 1% tetradecyl sulfate, 32% ethanol, and 0.3 normal saline, (c) 1% polidocanol (Ethoxysclerol), (d) 1:10,000 epinephrine, (e) 7.2% hypertonic saline, (f) 3.6% hypertonic saline, and (g) 0.9% saline (normal saline control). Agents were injected from the mucosal side of the small bowel into and around the pentrating serosal arteries in the subserosal space. Ethanol and TES were the most effective agents for arterial coagulation. Polidocanol was less effective than ethanol and TES. However, it was the only other agent that induced significant arterial coagulation. Alcohol and TES also caused significant injury in surrounding tissue. The degree of this injury was dependent on the total volume injected. Epinephrine induced significant mucosal damage without significant serosal injury or arterial coagulation. The coagulation and tissue injury effects of hypertonic saline injections were not significantly different from normal saline control.

Animals↗
PubMed1988

Comparison of low-power YAG laser and BICAP tumor probe for palliation of esophageal cancer strictures.

The purposes of this study were (a) to determine the applicability of endoscopic palliation for patients with esophagogastric cancer strictures in a referral center, and (b) to compare the efficacy and safety of the BICAP tumor probe with the neodymiumyttrium-aluminum-garnet (YAG) laser for such palliation. Forty-two consecutive patients with weight loss and obstructive symptoms from an unresectable, malignant esophageal stricture were referred for endoscopic palliation. Fourteen patients did not meet the criteria for YAG laser or BICAP tumor probe treatment and other therapies were recommended. Twenty-eight patients were treated, the first 14 with low-power YAG laser and the last 14 with BICAP tumor probe. All patients had coagulation of malignant strictures in one session. Treated patients were similar in background variables and stricture lengths but twice as much thermal energy was needed for the YAG laser as the BICAP tumor probe treatment. Treatment results were not statistically different during the median follow-up and survival of 16 wk. As minor complications, either pain or edema requiring dilatation was more common in the YAG laser-treated group than the BICAP tumor probe group. Treatment-related esophageal strictures developed in 21% of patients treated with YAG laser. A fistula developed in 1 patient with noncircumferential cancer in the BICAP tumor probe group. Compared with only the intake of liquids before treatment, 86% of patients could eat a soft or solid diet after initial treatment with BICAP tumor probe or YAG laser. Our conclusions were that for BICAP tumor probe and YAG laser, endoscopic palliation efficacy and safety for circumferential esophageal cancer strictures were similar. The advantages of using the BICAP tumor probe were portability, lower equipment costs, and the ability to treat submucosal, long, or high esophageal cancer strictures in one session. Treatment with YAG laser was safer than BICAP tumor probe for exophytic, noncircumferential cancers because the laser could be directed endoscopically. Use of the BICAP tumor probe is not recommended for noncircumferential esophagogastric cancer strictures.

Adenocarcinoma↗
PubMed1988

Diagnosis and treatment of severe hematochezia. The role of urgent colonoscopy after purge.

The purpose of this study was to prospectively evaluate (a) the diagnosis and treatment of 80 consecutive patients with severe, ongoing hematochezia from unknown source and (b) the effectiveness and safety of urgent colonoscopy after oral purge. Fifty-two men and 28 women (mean age, 64.5 yr) received a mean of 6.5 U of blood and had negative anoscopy, rigid sigmoidoscopy, and nasogastric tube aspiration before our evaluation. Because of ongoing severe hematochezia in the intensive care unit, urgent diagnosis and treatment was recommended by the attending physicians and surgeons. Emergency panendoscopy was performed before purge. Urgent colonoscopy was performed in the intensive care unit after patients received oral purge and their gut was cleared of blood, clots, and stool. The final diagnosis in these patients was 74% colonic lesions (30% angiomata, 17% diverticulosis, 11% polyps or cancer, 9% focal ulcers, 7% other), 11% upper gastrointestinal lesions, and 9% presumed small bowel lesions. No lesion site was identified in 6%. Clinically significant fluid retention (medically controlled) occurred in 4% of patients after purge. Sixty-four percent of patients had intervention for control of bleeding: 39% had therapeutic endoscopy, 24% surgery, and 1% therapeutic angiography. For 22 patients who also had emergency visceral angiography, the diagnostic yield was 14% and the complication rate was 9%. Our conclusions for patients with severe ongoing hematochezia from an unknown site were as follows. (a) Oral purge was effective and safe for cleansing the colon of stool, clots, and blood. Sulfate purge appeared to be safer than saline purge. (b) Before urgent colonoscopy and purge, emergency panendoscopy was indicated to exclude an upper gastrointestinal bleeding source. (c) Urgent colonoscopy after purge was effective, safe, and often diagnostic. (d) Compared with urgent colonoscopy, urgent visceral angiography was often nondiagnostic. However, the examinations may be complementary. (e) Hemostasis via colonoscopy has a definitive role in the treatment of some focal colonic lesions such as bleeding angiomata.

Adult↗
PubMed1988

Economic assessment of peptic ulcer disease treatments.

The cost and economic outcomes of peptic ulcer disease (PUD) treatments are important but uncommonly assessed by clinical researchers in gastroenterology. There is a growing interest in these assessments because of their implications for patient management and health care planning. Also, cost assessments offer the clinical researcher a powerful method to analyze the socioeconomic impact of different therapies in randomized prospective studies. The purposes of this paper are 1) to present methods and results of cost and economic assessment of PUD and 2) to consider the impact of H2 receptor antagonists on PUD cost. As with any chronic disease, PUD has direct and indirect costs. Direct costs are for hospital and clinic care, physicians' and surgeons' services, pharmacy fees, and nursing home care. Indirect costs of PUD affect society and include costs of absenteeism from work, disability, and mortality. Direct and indirect costs can be estimated prospectively in short-term and maintenance PUD clinical research studies. Several cost and economic analyses of PUD have been reported by clinical investigators and medical economists of different countries. They report a significant change in the direct and indirect costs of peptic ulcer treatment after the introduction of the H2 receptor antagonists.

Absenteeism↗
PubMed1987

Use of amylase isoenzymes in laboratory evaluation of hyperamylasemia.

Amylase isoenzyme analysis by agarose gel electrophoresis and lipase concentration by radioimmunoassay were performed in 98 consecutive hyperamylasemic patients. Total pancreatic (P-type) isoamylase was elevated in 89% of patients with clinical evidence of pancreatitis, and in only 11% of those without pancreatitis. Of 43 patients in whom the clinical diagnosis was obscure, 44% demonstrated an increase in pancreatic amylase and three (7%) had an increase in salivary (S-type) amylase. Lipase concentration by radioimmunoassay correlated well with lipase activity (r = + 0.69, P less than 0.05) and was as effective as amylase isoenzymes in distinguishing patients felt likely to have pancreatitis from those who were unlikely. Amylase isoenzymes or serum lipase concentration may be useful tests in the laboratory evaluation of hyperamylasemia when the etiology is obscure.

Adolescent↗
PubMed1987

Experimental comparison of endoscopic yttrium-aluminum-garnet laser, electrosurgery, and heater probe for canine gut arterial coagulation. Importance of compression and avoidance of erosion.

We compared five endoscopic thermal devices that have been used clinically for control of arterial bleeding in the gastrointestinal tract: neodymium:yttrium-aluminum-garnet (YAG) laser, electrofulguration, monopolar and bipolar electrocoagulation, and heater probe. In canine models we determined the ability to coagulate arteries of varying size and depth. The most effective method for coagulation of medium size arteries was first to occlude the vessel by compression, then to apply heat to seal it (coaptive coagulation). For the contact probes (monopolar, bipolar, and heater probes), the depth of tissue coagulation was controlled by varying probe appositional force and energy, and coagulation of deep arteries was possible. Undesirable erosion of tissue and vessels was noted with electrical sparking from the monopolar electrode and with YAG laser at high power density. In contrast, heater probe and bipolar electrocoagulation did not produce tissue erosion at any instrument setting. In this comparative study of arterial coagulation, overall ranking was as follows: heater probe = bipolar electrocoagulation greater than monopolar electrocoagulation greater than neodymium:YAG laser greater than electrofulguration greater than control. In our opinion these data should assist the clinician or investigator who plans to coagulate arterial bleeding lesions such as peptic ulcers, although further clinical research will be needed to verify these experimental results.

Animals↗
PubMed1987

Gastroduodenal mucosal hemodynamics by endoscopic reflectance spectrophotometry.

The reflectance spectrophotometric technique measures an index of mucosal hemoglobin concentration and an index of oxygen saturation by spectral analysis of light reflected from the mucosal surface. Using a commercially available unit, a technique for obtaining reproducible endoscopic measurements with acceptable intraobserver and interobserver variability was developed in the anesthetized dogs. The reflectance spectrophotometric finding that experimentally induced prehepatic portal hypertension did not affect gastric mucosal blood flow was confirmed by hydrogen gas clearance measurements. Endoscopic studies in patients with active duodenal ulcer disease revealed a higher index of mucosal hemoglobin concentration and a normal index of oxygen saturation (i.e., an increase in blood flow) at the margin of the ulcer compared with the adjacent normal appearing mucosa.

Animals↗