Calibration as a source of imprecision in cholesterol testing. Ramifications for patient risk classification.

Routine calibration of a cholesterol assay system may compromise rather than improve precision. We compared an enzymatic assay on a centrifugal analyzer using a fixed factor with a factor recalculated from the response of standards assayed with each run. Over 36 batch runs, using three quality control materials, we found no statistically significant difference between the two methods in mean value, but in every case the fixed factor values were significantly more precise.

Clinical performance of the EMIT vancomycin assay.

In evaluating the EMIT system for vancomycin used in the Cobas Bio centrifugal analyzer, we found two potential problems, each of which may have important clinical ramifications. First, precision, though acceptable in concentrations up to 30 mg/L, was marginal in the range above 30 mg/L. Second, when EMIT values were compared with those by fluorescent polarization immunoassay (TDx), we found a good correlation but a significant proportional bias: [EMIT] = (0.

Reducing adult phlebotomy blood loss with the use of pediatric-sized blood collection tubes.

The feasibility of collecting smaller blood volumes during phlebotomy for diagnostic laboratory testing was evaluated by substituting pediatric-size for adult-size blood collection tubes. The volume of blood drawn with the use of pediatric-size tubes from 41 patients in an intensive care unit (120.2 mL total; 32.

Nasoduodenal tubes in short-stay cholecystectomy.

To assess the importance of the role of the Moss nasoduodenal tube (Moss Tubes, Inc.) in short-stay cholecystectomy, 50 patients were prospectively randomized into two groups. Patients in group 1 (n = 25) had placement of a Moss nasoduodenal tube with esophagogastric decompression and immediate enteral feedings after cholecystectomy; patients in group 2 (n = 25) did not have a nasoduodenal tube placed.

Effect of total parenteral nutrition on whole body protein kinetics in cachectic patients with benign or malignant disease.

The metabolic effects of total parenteral nutrition on malnourished cancer and noncancer patients were investigated by determining whole-body protein metabolism before and during intravenous nutritional support. The results were compared to similar studies reported in normal subjects. Primed-continuous infusion of 15N glycine was used and the isotopic enrichments in urinary urea and ammonia were measured.

Usefulness of lactate dehydrogenase and lactate dehydrogenase isoenzymes for diagnosis of acute myocardial infarction.

The usefulness of lactate dehydrogenase (LD) and LD isoenzymes in the diagnosis of acute myocardial infarction (AMI) is controversial. The present study reviewed 507 consecutive patients in whom creatine kinase, creatine kinase isoenzymes, LD and LD isoenzymes were ordered over a 1-month period. Of these, 249 had an insufficient number of serial enzyme determinations to establish a laboratory diagnosis of AMI.

Effect of starvation and total parenteral nutrition on electrolyte homeostasis in normal man.

Elemental balances, and skeletal muscle membrane potential (Em) and biopsy were utilized to evaluate electrolyte homeostasis and body composition in 11 healthy adult volunteers after 10 days of starvation. This controlled, acute malnutrition was followed by refeeding for 10 days with two different, commonly used, total parenteral nutrition (TPN) solutions. Six subjects were refed with crystalline amino acids and dextrose (dextrose group), while five subjects received amino acids, dextrose, and lipid (lipid group).

What is a complete work-up for dementia?

As the elderly population grows proportionately larger, the clinician may anticipate seeing more hapless souls present with intellectual decline. It should be remembered that not all of these individuals in fact demonstrate dementia and that not all the cases of dementia are irreversible. Through a detailed history, neurologic examination, and the use of appropriate studies, the clinician may be able to establish the diagnosis, offer a prognosis, and exclude those diseases that are potentially remediable.

Antibiotic release from an experimental biodegradable bone cement.

An experimental biodegradable bone cement [poly(propylene fumarate)-methylmethacrylate] (PPF-MMA) has been compared in vivo with polymethylmethacrylate (PMMA) as a carrier agent for local release of antibiotics. This approach is potentially applicable to the treatment of chronic osteomyelitis where the clinical goal is to achieve sustained high concentrations of antibiotics locally in the infected bone. In our experiments, gentamicin- and vancomycin-impregnated cylindrical PMMA and PPF-MMA cement specimens were implanted subcutaneously in rats, and blood and wound fluid samples were obtained over a 2-week period.

Thermogenic and nitrogen response to submaximal exercise in parenterally repleted normal man.

To determine whole-body energy and nitrogen responses to submaximal exercise during repletion levels of intravenous feeding (IVF), five normal male volunteers were hospitalized and underwent serial changes in nutritional intake consisting of weight-maintaining oral feeding (4 d), starvation (10 d), and weight-increasing parenteral feeding (10 d). Twelve-hour aliquots for urinary nitrogen, creatinine, and 3-methylhistidine were collected during the final 36 h of oral feeding and IVF. During these experimental periods, indirect calorimetry was utilized to determine resting oxygen consumption and that occurring during a 1-h period of submaximal (40% of maximal) upright, bicycle exercise.

The abbreviated Burn-Specific Health Scale.

We have developed and validated an abbreviated Burn-Specific Health Scale. The scale is self-administered by the patient, easy to score, and divided for purposes of analysis into several domains of life function. This scale has potential usefulness in many areas of burn care.

Regional isolated limb perfusion of melanoma intransit metastases using mechlorethamine (nitrogen mustard).

Forty-two patients with intransit metastases of melanoma in a limb were treated by isolated regional perfusion chemotherapy using mechlorethamine (nitrogen mustard). Group 1 (n = 12) underwent treatment at low dose, less than 0.35 mg/kg, or low temperature, less than 38 degrees C.

Extremity amino acid metabolism during starvation and intravenous refeeding in humans.

This study was designed to evaluate peripheral tissue amino acid metabolism in normal subjects who underwent starvation followed by intravenous administration of a nutritional repletion regimen with varying nonprotein caloric sources. Extremity amino acid (AA), arteriovenous differences, and blood flow were measured across forearm and/or leg of 12 healthy male subjects. Plasma AA flux [(arterial concentration - venous concentration) X flow X (1 - hematocrit); ml X min-1 X 100 ml tissue-1] was determined postabsorptively (PA), after 10 days of starvation (ST) and on the 10th day of intravenous feeding (IVF).

Body protein kinetics during perioperative intravenous nutritional support.

The kinetics of whole body protein metabolism in eight patients with benign disease were evaluated during perioperative isocaloric and isonitrogenous intravenous feedings. A prime infusion of 15N-glycine with determination of urinary end product enrichment and stochastic analysis was used to determine protein kinetics. Surgically induced increases in body protein turnover, synthesis and breakdown were evident on the fifth postoperative day.

Basal glucagon replacement in chronic glucagon deficiency increases insulin resistance.

To evaluate the role of glucagon in insulin-mediated glucose metabolism, we studied four men and four women, ranging in age from 30-73 yr (mean +/- SEM, 54 +/- 5) who had undergone complete pancreatic resection for cancer or chronic pancreatitis 16-58 mo previously. The patients had undetectable C-peptide levels and established lack of biologically active 3500 mol wt glucagon. Euglycemic insulin clamp studies were performed with a 40 mU X m-2 X min-1 insulin infusion in the basal, post-absorptive, insulin-withdrawn state, before and during the last 3 h of a 72-h glucagon replacement-dose infusion (1.

Cancer cachexia and the rate of whole body lipolysis in man.

While malnutrition attending cancer cachexia may be associated with variable losses of body fat, lipid metabolism has been only minimally studied. To clarify potential aberrations of lipid metabolism in weight losing cancer patients, the whole body rate of lipolysis was determined in 9 cancer patients in the postabsorptive state and compared to that in 5 normal subjects. A primed-three stage infusion of glycerol was used to measure plasma glycerol clearance and turnover.