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Biomedical subjects

D M Jensen

Publications and source records attributed to D M Jensen.

At least 91 records · Page 5Linked to original sources
PubMed1987

Gastrointestinal angiomas. Source of recurrent bleeding.

Angiomas are mucosal and/or submucosal lesions that cannot be visualized on routine barium x-ray films. Endoscopy can establish the diagnosis in lesions of the upper gastrointestinal tract, and colonoscopy and arteriography are used for examination of the colon. Various endoscopic coagulation devices are available to stop the bleeding and treat the angioma. Our experience indicates that the patient, rather than the type of endoscopic treatment, often dictates outcome. Patients with abnormal bleeding times, chronic renal failure, or severe heart disease often have poorer palliation results, higher complication rates, and faster recurrence rates. Even patients without these poor prognostic factors tend to have recurrences of angiomas and bleeding.

Gastrointestinal Hemorrhage↗
PubMed1987

Endoscopic control of gastroduodenal hemorrhage.

Several methods of endoscopically controlling acute, nonvariceal upper gastrointestinal bleeding have been developed. Some, such as the laser, heater probe, and bipolar electrocoagulation, have been evaluated in controlled clinical trials. The purpose of this paper is to discuss endoscopic control of nonvariceal gastroduodenal hemorrhage and to consider whether improvement in outcome is likely with any of these devices. Techniques and results of controlled clinical trials are reviewed.

Aged↗
PubMed1987

Pancreatic enzymes in chronic renal failure.

Serum was obtained from 55 patients, including 43 with stable chronic renal failure (CRF) (28 receiving chronic hemodialysis [CHD] and 15 receiving chronic ambulatory peritoneal dialysis [CAPD]), nine with peritonitis receiving CAPD, and three with pancreatitis receiving CAPD. Total serum amylase activity, lipase activity, isoamylase fractionation, and lipase concentration were used to measure pancreatic enzymes. Amylase activity was increased in 35 of 43 patients with CRF but was greater than threefold elevated in only three. Pancreatic isoamylase activity was greater than 80% in only one patient with CRF but was greater than 80% in all three patients with pancreatitis receiving CAPD. Lipase activity was increased in 26 patients and lipase concentration was elevated in 27. Peritoneal fluid from three patients with pancreatitis receiving CAPD contained high levels of amylase. Serum amylase and lipase are frequently elevated in patients with CRF in the absence of clinical pancreatitis. However, serum amylase activity greater than threefold elevated or the presence of pancreatic enzymes in the peritoneal fluid may suggest coexistent pancreatitis.

Amylases↗
PubMed1987

Serum alanine aminotransferase levels and prevalence of hepatitis A, B, and delta in outpatients.

We investigated the relationship between alanine aminotransferase (ALT) levels and the prevalence of serologic markers of hepatitis A, hepatitis B, and delta hepatitis in an outpatient population. Sera submitted for routine biochemical testing from 4669 patients were grouped according to ALT level (normal and 1 to 2.5, 2.5 to 5.0, and more than five times the upper limit of normal). Serologic evidence of acute hepatitis A or acute or chronic hepatitis B was detected in 6.1% of specimens with elevated ALT levels compared with 1.3% with normal ALT levels. Patients with ALT levels greater than 2.5-fold and fivefold elevated were associated with a 9.3% and a 15.1% prevalence, respectively, of markers of acute or chronic hepatitis. Antibody to delta hepatitis was detected in nine subjects, all of whom also had serologic evidence of chronic hepatitis B. A retrospective chart review of 80 patients with serologic evidence of acute or chronic hepatitis revealed that 51% of cases were previously undiagnosed, most of which were in the low ALT groups. Hepatitis serologic testing may be indicated in outpatients with unexplained elevations of the ALT level.

Acute Disease↗
PubMed1986

Economic and health aspects of peptic ulcer disease and H2-receptor antagonists.

The costs of peptic ulcer disease to society are very high. Costs can be expressed as either direct or indirect. Direct costs include hospitalization or clinic visits, physicians' fees, and medication. Indirect costs are loss of productivity due to absenteeism from work or loss of income from death of an employee. The daily cost of different ulcer drugs such as the histamine (H2)-receptor antagonists for intravenous treatment, acute healing, and maintenance can easily be compared. As newer anti-ulcer drugs such as H2-receptor antagonists have been introduced into the marketplace, the number of prescriptions and medication costs have increased rather than decreased. In part, this may be accounted for by the high frequency with which H2 antagonists are prescribed for patients with non-ulcer dyspepsia. Some patients have chronic peptic ulcer disease with multiple painful recurrences or complications such as hemorrhage, perforation, or obstruction. They may require long-term care or drug maintenance, hospitalization, or surgery. For patients with chronic ulcer disease or complications, randomized controlled trials to compare the efficacy, safety, and costs of different forms of therapy (maintenance drugs, surgery, or placebo) have not been reported. However, based upon good efficacy and safety for acute healing and long-term drug maintenance for painful duodenal ulcer disease, long-term maintenance with H2-receptor antagonists is now prescribed for many patients. No controlled randomized trials have been reported to document that long-term maintenance with H2-receptor antagonists actually reduces peptic ulcer complications. However, by current cost estimates, long-term H2-receptor antagonist therapy is less expensive than ulcer surgery for uncomplicated ulcer disease for up to eight years. However, maintenance drug therapy after eight years may be more expensive than elective ulcer surgery in patients with chronic peptic ulcer disease who are good surgical candidates. Patients with complications of peptic ulcer disease seem to represent a different subset than patients with symptomatic ulcer disease. Further studies in these subsets are needed to ascertain the most effective, safest, and least expensive management such as surgery, long-term drug maintenance, or intermittent drug therapy to prevent recurrent ulceration or complications.(ABSTRACT TRUNCATED AT 400 WORDS)

Chronic Disease↗
PubMed1986

Portal-systemic encephalopathy and hepatic coma.

Decompensation in the cirrhotic patient is typically manifested as hepatic encephalopathy or coma. This may be precipitated by azotemia, gastrointestinal bleeding, infection, hypokalemic alkalosis, excess dietary protein, or the use of sedative, tranquilizer, or analgesic medications. The pathogenesis of hepatic encephalopathy associated with portal-systemic shunting is unknown, but theories purporting major roles for ammonia, AAAs, false neurotransmitters, and GABA have been advanced. Treatment is aimed at removing precipitating factors and eliminating nitrogenous substances from the gastrointestinal tract.

Amino Acids↗
PubMed1986

Esophageal varix hemorrhage and sclerotherapy--animal studies.

Although endoscopic sclerosis for control of variceal hemorrhage is an old technique, many questions remain about the technique, its applications, and outcomes after use. This report summarizes recent data from animal studies that relate to clinical questions concerning esophageal varix hemorrhage and sclerotherapy. A reproducible canine model of portal hypertension and esophageal varices is described. Three different studies with this model are summarized and discussed including: comparison of methods for endoscopic control of active variceal hemorrhage, comparison of sclerosing agents using canine venous collaterals and efficacy and safety of sclerosing agents in endoscopic sclerotherapy. In our opinion, these data should assist clinicians who are evaluating or planning clinical sclerotherapy trials.

Abdomen↗
PubMed1986

Current status of argon laser hemostasis of bleeding ulcers.

Endoscopic argon laser photocoagulation has been extensively studied in animals. Clinical pilot studies and randomized controlled trials have demonstrated that argon laser endoscopic hemostasis is both safe and efficient. Specific guidelines for successful endoscopic hemostasis have been determined. The limitations of the argon laser for emergency hemostasis are a strong absorption by blood, its expense and lack of portability, the inability to tamponade or to treat tangentially, and the vaporization potential. The Nd:YAG laser shares all these limitations except that it is less absorbed by blood. Because of these limitations, GI lasers are at present being used less for emergency hemostasis than for elective tumor ablation. Some new, non-laser, thermal devices which do not have these limitations have been developed. They are currently being evaluated in randomized trials. Perhaps because of these factors, the good results obtained with lasers for emergency hemostasis of bleeding ulcers have not been translated into clinical practice at most hospitals.

Argon↗
PubMed1984

Health and economic aspects of peptic ulcer disease.

The costs to society of peptic ulcer disease have become exorbitant. These costs are incurred either directly (hospitalization, physician care, and medication costs) or indirectly (loss of productivity due to absenteeism, the loss to society of functioning persons or death of productive persons). Although the results of many studies show that hospitalization for duodenal ulcer disease has decreased, the incidence of perforation, which may be a better index of the disease, has not changed significantly. For many patients and for society, peptic ulceration is a chronic and costly disease. The cost effectiveness of the available treatment modalities are variable and dependent on preventing recurrence. Medical treatment, including the use of antacids and the newer H2-receptor antagonists, seems to be promising. Cimetidine, for example, is effective in treating the acute stage of the disease, but some studies have shown that once the treatment period is over, the ulcers tend to recur. Ranitidine, a newer H2-receptor antagonist, is as effective as cimetidine for healing peptic ulcers and may be more useful as long-term therapy to prevent recurrences. If so, costs to society of this disease can be greatly reduced.

Absenteeism↗
PubMed1984

Development of an agarose gel electrophoresis technique for determining alpha-amylase isoenzymes.

Evaluation of alpha-amylase isoenzymes as a clinical diagnostic aid by previous methodologies has been either too insensitive or too cumbersome for routine clinical laboratory use. With use of an agarose gel electrophoresis system (Worthington Diagnostic Systems, Inc.) serum amylase activity can easily be resolved into at least nine isoenzymes, the resolution being comparable with that of isoelectric focusing. Samples can be analyzed in less than one working day, with use of conventional reagents.

Adult↗
PubMed1984

Antibodies directed against human liver specific membrane lipoprotein (LSP) in marmosets experimentally infected with the hepatitis A virus.

Autoantibodies directed against liver plasma membrane antigens have recently been described in patients with acute viral hepatitis, type A (AVH-A). To further investigate this phenomenon, the antibody against one such liver membrane antigen, liver specific membrane lipoprotein (LSP), was assayed in six marmosets orally inoculated with hepatitis A virus (HAV). Using a sensitive radioimmunoassay technique, anti-human LSP antibodies were detected in five of six animals. Two peaks of 125I-HLSP binding were observed: a minor peak at 20 days post-inoculation (dpi) in two animals, and a major peak at 38-45 dpi in five animals. There was no correlation between 125I-HLSP binding and liver histology score, ALT level, IgG concentration, anti-HAV P/N ratio, or E rosette lymphocyte count. A statistically significant correlation was observed, however, between 125I-HLSP binding and IgM anti-HAV antibody P/N ratios. 125I-HLSP binding was blocked by both marmoset and human LSP, but not by a marmoset kidney protein prepared in an identical manner. In summary, marmosets infected with HAV are a suitable animal model for the further investigation of anti-LSP autoantibody formation in AVH-A.

Acute Disease↗
PubMed1983

The plasma membrane origin of liver-specific protein (LSP).

Liver-specific lipoprotein (LSP) is a potentially important target antigen for autoimmune liver cell injury, but the complexity of LSP "the preparation" has hindered investigation of anti-LSP immune responses. In the present study, rabbit LSP and isolated liver plasma membranes (LPM) were compared using electron microscopy and marker enzyme analysis to determine the subcellular site of origin of LSP. These results suggest that LSP "the preparation" is highly enriched with plasma membrane.

Animals↗
PubMed1983

A reproducible canine model of esophageal varices.

One of the most promising nonoperative techniques for control of variceal hemorrhage is sclerosis via the fiberoptic endoscope. Many questions remain, however, about sclerosing agents, guidelines for effective use, and limitations of endoscopic techniques. A reproducible large animal model of esophageal varices would facilitate the critical evaluation of techniques for variceal hemostasis or sclerosis. Our purpose was to develop a large animal model of esophageal varices. Studies in pigs and dogs are described which led to the development of a reproducible canine model of esophageal varices. For the final model, mongrel dogs had laparotomy, side-to-side portacaval shunt, inferior vena cava ligation, placement of an ameroid constrictor around the portal vein, and liver biopsy. The mean (+/- SE) pre- and postshunt portal pressure increased significantly from 12 +/- 0.4 to 23 +/- 1 cm saline. Weekly endoscopies were performed to grade the varix size. Two-thirds of animals developed medium or large sized esophageal varices after the first operation. Three to six weeks later, a second laparotomy with complete ligation of the portal vein and liver biopsy were performed in animals with varices (one-third of the animals). All dogs developed esophageal varices and abdominal wall collateral veins of variable size 3-6 wk after the first operation. After the second operation, the varices became larger. Shunting of blood through esophageal varices via splenic and gastric veins was demonstrated by angiography. Sequential liver biopsies were normal. There was no morbidity or mortality. Ascites, encephalopathy, or spontaneous variceal bleeding did not occur. We have documented the lack of size change and the persistence of medium to large esophageal varices and abdominal collateral veins in all animals followed for more than 6 mo. Variceal bleeding could be induced by venipuncture for testing endoscopic hemostatic and sclerosis methods. We suggest other potential uses of this reproducible canine model of esophageal varices.

Abdominal Muscles↗
PubMed1983

Comparison of different methods for endoscopic hemostasis of bleeding canine esophageal varices.

Despite advances in the therapy of acute esophageal variceal hemorrhage, morbidity and mortality remain high. Continued severe variceal hemorrhage remains a major clinical problem in poor risk patients who cannot tolerate emergency surgery for hemostasis. Several endoscopic hemostatic methods might be effective for variceal hemostasis, but they have not been systematically evaluated. Using a reproducible canine model of esophageal varices, several hemostatic modalities were tested and compared to determine which were most effective in stopping variceal bleeding. Methods tested were endoscopic sclerotherapy, organ laser, neodymium-yttrium-aluminum-garnet laser, monopolar electro-coagulation, bipolar electrocoagulation, ferromagnetic tamponade, and endoscopic heater probe. Both neodymium-yttrium-aluminum-garnet laser and endoscopic sclerotherapy provided reliable hemostasis in acutely bleeding canine varices. Large heater probe controlled bleeding 50% of the time, and all the other methods stopped bleeding in less than half the trials. Rebleeding after balloon inflation proximal to the coagulated bleeding site did not occur with neodymium-yttrium-aluminum-garnet laser or endoscopic sclerotherapy-treated varices but did occur with the other methods. The principal differences between neodymium-yttrium-aluminum-garnet laser and endoscopic sclerotherapy were the ease of application of neodymium-yttrium-aluminum-garnet laser, the higher frequency of esophageal ulcers or erosions with neodymium-yttrium-aluminum-garnet laser, and the lack of variceal obliteration with neodymium-yttrium-aluminum-garnet laser.

Animals↗