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Biomedical subjects

S J Bell

Publications and source records attributed to S J Bell.

At least 73 records · Page 4Linked to original sources

Modular enteral diets: cost and nutritional value comparisons.

For selected patients, especially those with hepatic or renal failure, it may be necessary to restrict fluid, protein, electrolytes, and/or other micronutrients. The provision of enteral formulas with fixed percentages of nutrients that need to be restricted often results in the patient's receiving inadequate amounts of many that do not need to be restricted. One means of avoiding this problem is to use a micronutrient-free commercial solution, thus allowing the controlled addition of specific micronutrient "modules" needed to meet nutritional goals. There are only two formulas of this type available; however, they are more costly than any other product in our formulary and contain specific amino acid patterns developed for a specific disorder. We have designed, from macronutrient and micronutrient modules, modular tube feeding diets that can vary according to patient needs. We report on five patients treated. The protein quality (chemical score) provided by the modular diet is better than that provided by the nonmodular diet. The average daily cost to the hospital for a modular diet, including labor, is approximately one-third the cost of the nonmodular commercial diet, including labor ($7.72 vs $28.93). One anticipated difficulty is the high level of nutrition knowledge required by the prescribing individual.

Adult↗

Weight maintenance in pediatric burned patients.

Weight change, defined as the difference between the preadmission and discharge weights, has often been used as an indicator of the adequacy of nutrition support. Weight change has been found to be uninterpretable in burned patients because excision and grafting contribute to weight loss but do not reflect systemic physiology. Also, normal growth during hospitalization contributes to weight gain but is not included in traditional methods of assessing weight change of children. We examined weight change corrected for escharectomies and growth in 42 adult and pediatric burned patients. Thirty-five of the patients had weight loss within 10% of their premorbid weight. Moreover, weight loss was correlated with three observable patient characteristics: age, percent initial burn size, and preburn weight. It was concluded that the dietary regimen of providing twice the predicted basal metabolic rate in terms of calories, based on ideal body weight, was adequate to prevent significant weight loss in most patients but that further refinement is necessary to improve individual reliability. Furthermore, significant weight losses may not affect morbidity/mortality as previously thought.

Adolescent↗

Nutrition guidelines for burned patients.

Among all hospitalized patients, burned patients have been shown to have the greatest increase in metabolic demand. However, the temptation to overfeed those patients must be recognized, as that practice may lead to increased morbidity. Care must be taken to provide an appropriate nutritional regimen in order to minimize protein catabolism and to promote wound healing. Several formulas for calculating energy and protein needs for burned patients have been reviewed for this article, along with guidelines for estimating other nutrients for such patients. Methods for providing nutrition therapy depend on many factors, such as extent and degree of injury and gastrointestinal function. The feeding methods most commonly used are parenteral (peripheral and central venous alimentation) and enteral (oral and naso-gastric tube feeding). Guidelines for using both parenteral and enteral feedings are discussed, as well as reliable methods for evaluating the nutrition assessment of the burned patient. It must be noted that standard assessment parameters are often unreliable, and their limitations are also addressed. In addition, several new parameters are introduced, including compliance with caloric goal, corrected weight change, and prediction of total urinary nitrogen to be used to calculate nitrogen balance.

Anthropometry↗

Adequacy of a modular tube feeding diet for burned patients.

Recent research on nutrition needs following thermal injury suggests that carbohydrate and caloric excess must be avoided while an attempt is made to meet relatively large protein requirements. The nutrition regimen in this investigation for adult and pediatric burned patients provides calories at twice the predicted basal metabolic rate, protein at 2.5 gm/kg/day, and carbohydrate at 5 mg/kg/minute. Lipids are provided to meet the caloric deficit after protein and carbohydrate administration. Even though such nutrients are readily provided parenterally, the high carbohydrate content of standard tube feedings makes it difficult to provide adequate protein without excess of carbohydrate and calories. As a result, a modular tube feeding, containing appropriate macro- and micronutrients and tailored to the individual patient, has been used in our burn units. The adequacy of the diet was assessed by the effect on nitrogen balance, weight change, selected serum indexes of visceral metabolism, and compliance with planned dietary goals. Patients remained in positive nitrogen balance more than 80% of the time while the modular diet was used in conjunction with other modes of therapy (parenteral and/or oral). More than 90% of the time, positive balance was achieved when the modular diet was used as the sole source of nutrition. Compliance with the caloric goal and physicians' diet orders for the modular diet exceeded, on average, the 80% level, which has previously been the established lower limit. The results in this study suggest that the modular diet is an appropriate method of nutrition support.

Adult↗

Allocation of feeding pumps: an ethical question.

Situations arise in clinical practice that force the dietitian to make a moral/ethical decision. Traditional undergraduate dietetic programs have not routinely included learning activities on ethical decision making. Therefore, a dietitian confronted with such an issue may defer to someone else the responsibility for finding a viable ethical solution. If the dietitian does accept the challenge, she/he must develop a systemic way to solve the problem. This case study demonstrates how a nutrition support dietitian solves a complex ethical problem involving the allocation of two enteral feeding pumps to seven critically ill patients. The three tools used to aid in the decision making were the Standards of Professional Responsibility of The American Dietetic Association, the Four-Step Process of Moral Judgment and Action of Purtilo and Cassel, and the Nutrition Support Team. It is hoped that this case example will provide some insight to other dietitians faced with similar ethical dilemmas.

Adult↗

Prediction of total urinary nitrogen from urea nitrogen for burned patients.

Although many of the current nutrition assessment techniques are inappropriate for burned patients, we have found nitrogen balance to be a helpful measure of the effectiveness of nutrition therapy if it is used in conjunction with other measures of nutritional status. Many clinicians suggest that a 24-hour urinary urea nitrogen (UUN) measurement, in addition to a correction term of 2 to 4 gm nitrogen, will accurately represent all nitrogen losses (urinary non-urea nitrogen, fecal, integumental). However, since no burned patients were used in the development of that method, its use may not be appropriate for burned patients. As an alternative to total urinary nitrogen (TUN), which is costly and time consuming, we have developed a simple way to predict TUN from UUN, percent initial total body surface area burn, and age for pediatric and adult burned patients. We propose that nitrogen balance may then be determined from the predicted TUN by an equation showing that nitrogen balance equals daily nitrogen intake minus predicted TUN plus fecal and normal nitrogen loss.

Adolescent↗

A trial of razoxane (ICRF-159) in patients with prior therapy for Hodgkin's lymphoma.

Razoxane (ICRF-159) was administered to 11 patients with Stage IV nodular sclerosing Hodgkin's lymphoma. A weekly schedule was employed with a starting dose of 1000 mg/m2 in divided doses. The dose was escalated up to 2000 mg/m2 weekly as tolerated. One objective partial remission was observed. The toxicity of the program was quite tolerable. Further trials of razoxane in this situation are not recommended.

Adolescent↗

Mutagenicity of benzidine and benzidine-congener dyes and selected monoazo dyes in a modified Salmonella assay.

We have evaluated the mutagenic activity of a series of diazo compounds derived from benzidine and its congeners o-tolidine, o-dianisidine and 3,3'-dichlorobenzidine as well as several monoazo compounds. The test system used was a modification of the standard Ames Salmonella assay in which FMN, hamster liver S9 and a preincubation step are used to facilitate azo reduction and detection of the resulting mutagenic aromatic amines. All of the benzidine and o-tolidine dyes tested were clearly mutagenic. The o-dianisidine dyes except for Direct Blue 218 were also mutagenic. Direct Blue 218 is a copper complex of the mutagenic o-dianisidine dye Direct Blue 15. Pigment Yellow 12, which is derived from 3,3'-dichlorobenzidine, could not be detected as mutagenic, presumably because of its lack of solubility in the test reaction mixture. Of the monoazo dyes tested, methyl orange was clearly mutagenic, while C.I. Acid Red 26 and Acid Dye (C.I. 16155; often referred to as Ponceau 3R) had marginal to weak mutagenic activity. Several commercial dye samples had greater mutagenic activity with the modified test protocol than did equimolar quantities of their mutagenic aromatic amine reduction products. Investigation of this phenomenon for Direct Black 38 and trypan blue showed that it was due to the presence of mutagenic impurities in these samples. The modified method used appears to be suitable for testing the mutagenicity of azo dyes, and it may also be useful for monitoring the presence of mutagenic or potentially carcinogenic impurities in otherwise nonmutagenic azo dyes.

3,3'-Dichlorobenzidine↗

Dietary compliance for pediatric burned patients.

Physician diet orders written for pediatric burned patients frequently differ from the diets patients actually receive. At Shriners Burns Institute in Boston, such deviations from the diet order were generally not recognized for at least two days. In order to increase compliance with physician diet orders, changes in the nutritional support program were implemented which included physician diet orders containing specific macronutrient requirements in addition to the caloric goal, which was changed in response to recent research demonstrating that the previously used formula provided excessive calories; introduction of modular diets for parenteral and enteral feedings; institution of daily nutrition flow sheets; and a change of the time at which daily caloric intake records were calculated. In order to assess the benefits of the new measures, the average deviation from the caloric goal was calculated for patients who did not receive the new assessment tools (control group, N = 51), compared with those who did (study group, N = 50). Least squares regression analysis indicated a trend toward improved compliance and less deviation from the calculated caloric goal following implementation of the four measures.

Adolescent↗

Cadmium-113 NMR of carbonic anhydrases: effect of pH, bicarbonate, and cyanide.

113Cd-Substituted human and bovine erythrocyte carbonic anhydrases have been studied by 113Cd NMR as a function of pH and bicarbonate concentration. Plots of chemical shift versus pH give sigmoidal titration curves in the pH range of the study, 6.9 to 10.5. The pKa values vary from 9.2 to 9.7, which correlates well with available activity profiles for the Cd-enzymes. Because the samples contain no buffers and no anions other than hydroxide, the results point to the existence of high and low pH forms of the enzymes in rapid exchange and differing in inner sphere coordination. When bicarbonate is added to the samples, upfield shifts are produced which eventually level off. Only a single CN- binds to the metal for all three enzymes. These observations are best explained by a rapid exchange among three species in which the open coordination site of the metal ion is occupied by hydroxide, water, or bicarbonate, as in the scheme: E--OH- in equilibrium or formed from E--H2O in equilibrium or formed from E--HCO-3.

Animals↗

Antibiotic action of N-methylthioformohydroxamate metal complexes.

The antibiotic activity of metal complexes of N-methylthioformohydroxamic acid against gram-negative Escherichia coli NIHJ and gram-positive Staphylococcus aureus 209P was investigated. The kinetically labile, square-planar, divalent (Cu, Ni, and Pd) and octahedral, trivalent (Fe, Co, and Cr) complexes displayed activity, whereas the more inert platinum(II) or rhodium(III) complex displayed no activity, or activity only at elevated concentrations. The free ligand did not suppress the growth of the above organisms, and the sulfur atom of the ligand in its metal complexes appears crucial for activity. Uptake studies of radioactively labeled N-methylthioformohydroxamic acid, its nickel(II), platinum(II), iron(III), and rhodium(III) complexes were conducted in the Escherichia coli K-12 RW193 mutant, which is defective in the production of its native iron(III) transport agent, enterobactin. Uptake of (55)Fe or (63)Ni label from their metal complexes appeared to occur as free inorganic metal ions. The antibiotic activity of the iron(III) and nickel(II) complexes was not due merely to an enhanced accumulation of metal ions by the cell. Metal complexes of [(35)S]N-methylthioformohydroxamic acid enhanced the accumulation of (35)S label compared to that of the free ligand. The antibiotic activity and uptake data are discussed in terms of possible modes of action.

Anti-Bacterial Agents↗

Preparation and spectral compilation of FD&C Red No.40 intermediates and subsidiary dyes.

FD&C Red No. 40 may contain higher or lower sulfonated subsidiary dyes, depending on the purity of intermediates used. Samples of 10 possible subsidiaries were prepared and purified. They are to serve as analytical standards to aid in the identification of unknown compounds frequently appearing during the analysis of certification samples. Visible, ultra-violet, and infrared spectra as well as absorptivites and molar extinction coefficients are given for each dye.

Aniline Compounds↗