PubMed Health⌕ Search

Biomedical subjects

M B Popp

Publications and source records attributed to M B Popp.

32 records · Page 2Linked to original sources

A pathophysiologic study of the hypertension associated with burn injury in children.

Measurements of cardiac output, blood volume, plasma renin activity (PRA), serum aldosterone, plasma and urinary catecholamine levels, serum and urinary electrolyte levels, and of transfusion and fluid therapy have been made in eight hypertensive and seven normotensive burned children. Studies were conducted during the acute phase of burn injury when hypertension was first diagnosed and were repeated just before discharge from the hospital. Hypertensive patients perfused at an inappropriately high total peripheral resistance and hypervolemia was demonstrated in the hypertensive patients. No differences could be demonstrated between hypertensive or normotensive patients in PRA, aldosterone, catecholamine, or electrolyte levels. These data indicate that both the hypervolemia and the vasoconstrictor activity of PRA and/or catecholamines are present when hypertension develops in these patients. These data suggest that the renin-angiotension-aldosterone system is directly stimulated as part of the neuroendocrine response to trauma.

Acute Disease↗

Long-term vascular access in the rat: importance of asepsis.

Chronic indwelling vascular catheters have been used in the rat for many types of experimental studies. Most experiments have been of short duration with little attention to aseptic technique during catheter placement. In this study, rats subjected to a sterile superior vena cava (SVC) catheterization technique, a convential clean but nonsterile SVC catheterization technique, or sham operation were compared. Male Fischer 344 rats (wt 175-200 g) were catheterized or sham operated and then received food and water ad libitum for 25 days. At time of spontaneous death or being killed the SVC was examined grossly and microscopically for infection. Three of six nonsterile conventionally catheterized animals died, and five of these six animals had infected catheters. All sterilely catheterized and sham-operated rats lived 25 days, and none had catheter infection. Sterilely catheterized rats gained weight (1.9 g/day), were in positive nitrogen balance, and had organ weight and blood studies similar to sham-operated noncatheterized controls. Nonsterile catheterization resulted in catheter infection such that normal physiological studies would be uninterpretable.

Animals↗

A prospective randomized study of adjuvant parenteral nutrition in the treatment of advanced diffuse lymphoma: influence on survival.

The efficacy of adjuvant parenteral nutrition (PN) in cancer patients is not well defined. Twenty-one of 42 patients with advanced diffuse lymphoma were randomly selected to receive PN during an aggressive program of multiple-drug chemotherapy. These patients received 56 courses of central venous PN support during the first 14 days of the 28-day cycles of early and late phases of chemotherapy. PN patients received an average of 2,216 kcal/day, and their oral intake was 836 kcal/day during therapy. PN patients had marked weight gains, and standard nutrition (SN) patients had stable weights both during cycles of therapy and over the entire course of therapy. Lean body mass, as indicated by total body potassium, anthropomorphic measurements, serum albumin, creatinine-to-height ratio, total iron-binding capacity, and total lymphocyte count, was not improved in PN patients as compared to SN patients. PN therapy was complicated by symptomatic subclavian vein thromboses, septic catheters, and pneumothoraxes. The actuarial survival rate at 2 years was 68.8% +/- 10.9% (estimate +/- SD) for PN patients and 65.8% +/- 12.2% (estimate +/- SD) for SN patients. These results suggest that the weight gained by PN patients was composed of fat, water, or both. A lack of improvement in nutritional status and survival rates and a significant complication rate were associated with adjuvant PN during chemotherapy.

Adult↗

A prospective randomized study of adjuvant parenteral nutrition in the treatment of diffuse lymphoma: effect on drug tolerance.

Total parenteral nutrition (TPN) has been suggested as a useful addition to chemotherapy of malignant disease in the hope of decreasing drug toxicity and increasing drug tolerance. In this study, 17 of 36 patients given chemotherapy for advanced diffuse lymphoma were randomly selected to receive TPN. The dose of the chemotherapeutic agents to be administered was decreased according to predetermined toxicity guidelines. A comparison of drug dosage in the group receiving TPN and the group receiving standard nutrition is a measure of drug tolerance in these patients. Drug dosage was evaluable in 15 TPN and 18 standard nutrition patients. No difference in tolerance of any specific drug or total drug dose occurred when all patients in both groups were compared. Similar comparisons in subgroups of malnourished patients and responding patients also revealed no difference. A cycle-by-cycle analysis demonstrated no difference in any phase of therapy. The wbc count, platelet count, and albumin level, on the first day of each cycle, the nadir during cycles and the day of nadir were compared in TPN and standard nutrition patients. No differences were found. This study does not suggest improved drug tolerance in lymphoma patients as a result of TPN support. Further controlled studies are needed to determine which groups of cancer patients might benefit from TPN and how these benefits occur.

Antineoplastic Agents↗

Total parenteral nutrition in a methylcholanthrene-induced rat sarcoma model.

Problems with currently available studies of the effects of total parenteral nutrition (TPN) on rat tumor models include: inadequate definition of the natural history of the tumor model; use of nutritional techniques and solutions which have not been proven effective; failure to allow animals to recover from stress of catheterization before starting nutritional manipulation; short-term studies; failure to use sham-operated orally fed control animals; and inadequate evaluation of nutritional result. We have instituted TPN after a 4-day postcatheterization recovery period in a defined methylcholanthrene-induced rat sarcoma model. Preliminary results suggest that TPN increases tumor weight without changing tumor composition of water, nitrogen, or fat. TPN also increases carcass fat and water content, but not carcass protein. In tumor-bearing animals, the percentage of energy expended on activity decreases with increasing tumor burden in both TPN and orally fed controls. TPN in these studies appears to support fat stores and stimulate tumor growth.

Animals↗

Clinical characteristics of hypertension in burned children.

Although systemic arterial hypertension has been recognized as a common complication of thermal injury in children, its clinical characteristics have not been defined. This review of 987 burned children, treated over an 11-year period, documents development of hypertension in 195 patients (19.8%). The problem occurs most frequently in males and in the 7--10-year age group, but does not correlate with racial origin. Incidence increases with burn severity up to a 40% total surface burn. The incidence did not vary with the year of treatment when changes in patient population were eliminated. Fifteen of the 195 patients had hypertensive encephalopathy and seizure problems. No other complication or change in mortality could be related to hypertension. The problem could not be related to location of the burn wound, drug treatment, or differences in transfusion and fluid therapy. Comparison of the highest daily blood pressure measurements between matched hypertensive and normotensive groups demonstrated that the hypertensive and normotensive groups demonstrated that the hypertension is limited to the acute phase of burn wound treatment and that blood pressures are normal after complete autografting. The encephalopathy and seizure problems indicate the need for careful blood pressure monitoring and effective antihypertensive therapy in the treatment of burned children.

Adolescent↗

Energy expenditure and motor activity in rats receiving total parenteral nutrition.

Rats with intravascular catheters connected to infusion systems are frequently used in the investigation of nutritional and metabolic problems. Although the animal is often referred to as "unrestrained," there is no information on the effect of the catheter assembly or total parenteral nutrition (TPN) on total (TEE), activity (AEE), and resting (REE) energy expenditure (TEE = REE + AEE). Male Fischer 344 rats were studied in an analytical respiration calorimeter. Normal unoperated rats, aseptically catheterized orally fed rats from postoperative day 1 to 7, and TPN rats were studied. Orally fed catheterized rats had weight loss, negative nitrogen balance, negative energy balance, elevated REE, and normal AEE during the first 4 postoperative days. Their weight gain, positive nitrogen balance, AEE, and REE were almost identical to those of normal rats over postoperative days 5 through 7. REE and AEE in TPN rats were similar to values in normal rats. These data indicate that catheter operation and TPN cause no abnormality in AEE and REE if adequate time is allowed for recovery from catheter operation and strict attention is given to asepsis.

Animals↗

Amino acid requirements of a rat sarcoma as determined by a stem cell assay.

Knowledge of the amino acid requirements of a neoplasm is valuable in determining optimal nutritional support and antineoplastic therapy for the tumor-bearing host. The standard human tumor stem cell assay (HTSCA) was modified by reducing an individual amino acid below the normal plasma concentration of the Fischer 344 rat. All other amino acids were maintained at levels sufficient for normal HTSCA tumor colony growth. Twenty-two amino acids were tested at a mean concentration of 12% (range 3% to 35%) of their normal plasma level. Results indicated that all amino acids except L-glutamine and L-asparagine were present in sufficient quantity for normal tumor growth. Dose-response curves have shown more than 70% inhibition of tumor growth with a glutamine concentration of 50% and an asparagine concentration of 25%. Glutamine and asparagine levels of 4% and 1%, respectively, resulted in 100% inhibition. The data indicate that rat sarcoma stem cells are sensitive to decreased glutamine and asparagine concentrations.

Amino Acids↗

Accuracy of implanted port placement with the use of the electromagnetic CathTrack catheter locator system.

PURPOSE: To test whether an electromagnetic guidance system such as CathTrack would allow long-term central venous access devices to be reliably placed at a decreased cost and without radiation exposure to patients and staff. The following study was undertaken to verify accuracy of the CathTrack system for catheter placement and to develop guidelines for its use. METHODS: Twenty-nine consecutive patients were prospectively enrolled in the study and taken to the operating room for implantation of a permanent central venous access port. By protocol, the CathTrack system was used to guide initial catheter positioning using the center of the third intercostal space along the right sternal border as the desired external target. Fluoroscopy was then used to visualize tip position and relocate the catheter tip to the exact position desired by the surgeon. RESULTS: Catheter placement using the CathTrack system was successfully accomplished in 27 out of 29 patients. In two instances CathTrack was abandoned and fluoroscopy utilized because of difficulty in threading the initial guidewire into the superior vena cava. CONCLUSION: The CathTrack electromagnetic locator system can be used to reliably position catheters for the establishment of long-term central venous access. Decreased cost and elimination of radiation exposure are distinct advantages of this system over fluoroscopy.

Journal Article↗