Dehydrated amniotic membrane allografts for the treatment of chronic wounds: a case series.

A retrospective case series demonstrating the use of dehydrated human amniotic membrane (dHAM) allografts in the treatment of wounds of various aetiologies. Amniotic membrane was applied to a series of chronic wounds referred to a formal wound clinic for aggressive management, after prior, traditional treatment methods were found ineffective, over a period of 1 month. In each case, failure of traditional therapy was followed by placement of a dehydrated amniotic membrane allograft and the healing time course was documented with charted measurements. Wounds treated with the amniotic membrane allograft demonstrated improved healing, with a change in the healing trajectory from that previously noted. Dehydrated human amniotic membrane represents a potentially effective addition to existing wound care therapies, with further formal clinical studies indicated.

Solvating gas chromatography with chemiluminescence detection of nitroglycerine and other explosives.

A separation technique known as solvating gas chromatography (SGC), which utilizes packed capillary columns and neat carbon dioxide as mobile phase, was used for the separation of nitroglycerine (NG) and other nitrogen-containing explosives including 2,6-dinitrotoluene (2,6-DNT), 2,4-dinitrotolulene (2,4-DNT), 2,4,6-trinitrotoluene (2,4,6-TNT), and pentaerythritol tetranitrate (PETN). SGC was coupled for the first time to a selective chemiluminescence thermal energy analyzer (TEA) detector for nitro-functional group specificity and sensitive detection of these compounds. TEA calibration curve for NG showed linearity in the sub-microg ml(-1) range. Soil samples containing NG were used to test the validity of the technique. Detector response of SGC-TEA versus SGC-flame ionization detection for NG was also evaluated.

A framework for evaluating underutilization of health care services.

Underutilization is becoming increasingly recognized as an area of importance in managed care, where aggressive measures to control overutilization are creating concern among the general public. The author sought solid definition of underutilization and methods for its evaluation in the medical literature but was impressed at the small number of peer-reviewed articles on the subject. A review of key issues is discussed, including a number of methods a health plan may use to approach the identification of underutilization within its domain. Methods include the use of "gold standard" population health requirements; statistically defined underutilization; second-order, combined variables; and socially defined underutilization. Sample statistics identified within the author's plan are identified, and recommendations for their implementation and use are made.

The use of inexpensive computer-based scanning survey technology to perform medical practice satisfaction surveys.

The recent availability of inexpensive document scanners and optical character recognition technology has created the ability to process surveys in large numbers with a minimum of operator time. Programs, which allow computer entry of such scanned questionnaire results directly into PC based relational databases, have further made it possible to quickly collect and analyze significant amounts of information. We have created an internal capability to easily generate survey data and conduct surveillance across a number of medical practice sites within a managed care/practice management organization. Patient satisfaction surveys, referring physician surveys and a variety of other evidence gathering tools have been deployed.

The use of imperfect data in managed care organizations.

Two critical milestones appear to be occurring in the development of medical groups moving to improve medical care effectiveness. These include the abilities to work with imperfect and unflattering data. There is a clear linkage between these two concepts, because forward clinical improvement or business planning is often delayed as individual physicians seek to await "perfect data" when confronted with unflattering information. In the form of "profiles" in particular, providers often react negatively, with complaints that the information is "imperfect" or that it fails to capture some nuance of their sicker or unique patient populations. The translation of imperfect information to effective clinical practice anyway remains a success fundamental to managing highly competitive medical groups and health plans. It is centrally dependent on the understanding, use, and application of "imperfect data".

The Highmark Pegasus Project report: characteristics of highly successful health plans.

The Highmark Blue Cross/Blue Shield Pegasus Project was created in the fall of 1996 to benchmark best practices at health plans around the United States through extensive interviews, literature searches, and other measures. Characteristics of highly successful health plans across a number of major categories are summarized in the final recommendations presented by this report.

Recommendations for new medical directors and physician advisors. Administrative clinical pearls.

Presented here are "administrative pearls" that evolved out of a health plan's program to help new physician advisors and medical directors in their daily operations and decision-making process. The list of eight recommendations represents accumulated wisdom from experienced medical directors, physician advisors, and nurse managers.

The use of hair analysis to document a cocaine overdose following a sustained survival period before death.

Hair analysis for cocaine was used in the investigation of a case of accidental cocaine poisoning. A 25-year-old man consumed an entire bottle of Pony Malta, an imported Colombian soft drink. Unbeknownst to him, the 6.2-oz bottle contained a large quantity of cocaine. It was subsequently discovered that this bottle was one of 45 recovered that contained cocaine as part of a smuggling scheme. The subject was hospitalized for acute cocaine intoxication but died 24 days later. The admission blood contained 2.3 mg/L of cocaine and 4.5 mg/L of benzoylecgonine. Subsequent segmental analysis by MS/MS of hair samples taken at the autopsy revealed a peak cocaine concentration in the segment corresponding to the time he ingested the tainted beverage. The use of hair analysis as an adjunct to traditional analytical techniques may help document drug use history and is especially useful in situations have blood and urine specimens have not been collected in a timely fashion.

Quality assurance without tears.

The drive to improve the quality of our health care system is daily forced by numerous factors which need little elaboration. Needless to say, major changes are about to occur in the way health care is delivered, not only regionally but also nationally. Farsighted individuals or institutions will take steps to survive in a destabilizing health care market. They must learn the new language of quality.

An enzyme-linked immunosorbent assay (ELISA) for trinitrotoluene (TNT) residue on hands.

An enzyme-linked immunosorbent assay (ELISA) developed for the detection of trinitrotoluene (TNT) in munitions wastewater has been adapted to the detection of TNT residue on hands following contact. Using the procedure developed, as little as 50 pg of TNT could be detected. Accounting for sample size and dilution, the 50 pg equates to 15 ng of TNT recovered from the hands. Following contact with TNT, amounts ranging from 53 ng to more than 1500 ng were recovered from hands. The monoclonal anti-TNT antibodies showed no cross-reactivity with several other explosives or common contaminants. These preliminary results indicate promise for the development of a simple-to-use, immunoassay-based field test kit for TNT and, ultimately, other explosives.

Metabolism studies of the antischistosomal drug praziquantel using tandem mass spectrometry: qualitative identification of 17 hydroxylated metabolites from mouse urine.

Schistosomiasis is a parasitic liver infection which is known to affect many aspects of drug metabolism. Praziquantel (PZQ) is the drug of choice for treating this disease. PZQ is known to be highly metabolized, but the effect of the disease on its metabolism has not been investigated. Control mice and mice infected with Schistosoma mansoni were dosed with PZQ and their urines were examined for the presence of metabolites using a triple-quadrupole mass spectrometer (tandem mass spectrometer). The collisionally induced dissociation of PZQ was remarkable in its structurally significant fragments. From this we were able to identify 17 hydroxylated metabolites of PZQ from purified urine samples without further chemical separation, including three monohydroxylated, six dihydroxylated, and eight trihydroxylated metabolites. There were no qualitative differences in metabolite production between control and infected animals.

Metabolism studies of the antischistosomal drug praziquantel using tandem mass spectrometry: distribution of parent drug and ten metabolites obtained from control and schistosome-infected mouse urine.

The collisionally activated dissociation spectrum of the antischistosomal drug praziquantel (PZQ) has many structure-specific fragmentations which permit identification of PZQ and seventeen of its hydroxylated metabolites in mouse urine. These fragmentations may also be used to quantify the metabolic pattern of PZQ. In the present study, a triple-quadrupole mass spectrometer system has been used to generate [M + H]+ ions for PZQ and its monohydroxy, dihydroxy and trihydroxy metabolites which yield daughter ions capable of quantifying PZQ and ten of these metabolites. The goal of these experiments was to evaluate the effect of this hepatic infection on drug metabolism. This was accomplished in two steps. First, the amount of unmetabolized, mono- and dihydroxylated PZQ was established from the [M + H]+ ions. Then the specific metabolites at each level of hydroxylation were determined from daughter ion spectra. The product of these two values produces the metabolite pattern. The reproducibility of these assays ranged from good, with a coefficient of variation of 3% for the most abundant metabolite, to poor (43%) for PZQ, which is only 1% of the total elimination pattern. The excretion of unchanged PZQ and two dihydroxylated metabolites was enhanced in animals bearing schistosomiasis compared to control mice, while a third dihydroxylated metabolite was depressed.

Effects of elevated lead and cadmium burdens on renal function and calcium metabolism.

To assess the pathophysiologic significance of increased body burdens of lead and cadmium, detailed renal function studies and evaluation of calcium, phosphorus, and vitamin D metabolism were carried out in 38 industrial workers exposed to lead and cadmium for 11 to 37 yr. Body burden of lead, as assessed by x-ray fluorescence measurement of tibia lead content, was elevated in 58% of the men and, when assessed by excretion of lead after Ca-EDTA infusion, was elevated in 36%. Liver or kidney cadmium burden, as assessed by neutron activation analysis, was elevated in 31%. Creatinine clearance was normal in all workers. One worker was hyperuricemic and two were proteinuric; three had increased beta 2 microglobulin excretion and one had diminished urinary acidifying ability. Maximal urinary concentrating ability was abnormal in a significant fraction, i.e., 52% of the men. Individuals with a high lead burden had a slight decrease in mean serum phosphorus but no accompanying phosphaturia. There was no abnormality of serum calcium. Twenty-two percent of subjects were hypercalciuric and two had low vitamin D levels, but these abnormalities bore no relation to heavy metal burden. In this carefully characterized group of men with chronic lead and calcium exposure, definite, if subclinical, effects on renal function and serum phosphorus but not calcium or vitamin D metabolism were demonstrable.

In vivo bone lead measurements: a rapid monitoring method for cumulative lead exposure.

Lead concentrations (microgram/g wet weight) in human bone (tibia) were measured noninvasively in vivo employing an X-ray fluorescence technique. Forty-five workers who had been subjected to chronic industrial exposure were found to have a mean bone lead content of 52.9 micrograms/g wet weight (0 to 198 micrograms/g). In addition to bone lead content, blood lead, body burden of lead as assessed by urinary lead excretion after EDTA chelation, zinc protoporphyrin, and unstimulated urinary lead excretion were evaluated. The results suggest that the in vivo measurement of tibia lead content may serve as an acceptable indicator of body lead burden and provide a practical technique for lead screening purposes. The correlation coefficient between X-ray fluorescence findings and lead excretion following Ca-EDTA administration is 0.69; p less than 0.001.

Oxygen fixation into hydroxyproline in etiolated maize seedlings : verification by tandem mass spectrometry.

Etiolated maize (Zea mays L.) seedlings were grown in the dark for 5 days in an atmosphere enriched with 10.0 atom% (18)O(2). Hydroxyproline was isolated from root and shoot tissues, purified, and methylated. It was not possible to determine (18)O incorporation into hydroxyproline by conventional mass spectrometry because the final product was not sufficiently pure. The final product was analyzed successfully by tandem mass spectrometry. The (18)O content of the hydroxyl oxygen atom was 10 +/- 0.7 atom%. This result demonstrates that the hydroxyl oxygen atom in hydroxyproline was derived exclusively from molecular oxygen.

Gamma-Glutamyltransferase: kinetic properties and assay conditions when gamma-glutamyl-4-nitroanilide and its 3-carboxy derivative are used as donor substrates.

The kinetics of human serum gamma-glutamyltransferase (EC 2.3.2.2) were investigated, with use of glycylglycine as a gamma-glutamyl acceptor substrate and gamma-glutamyl-4-nitroanilide and its carboxy derivative, gamma-glutamyl-3-carboxy-4-nitroanilide, as donor substrates. The simultaneous occurrence of both gamma-glutamyltransfer and autotransfer was established by descending paper chromatography. Constant-ratio double-reciprocal plots confirm that the enzyme mechanism is nonsequential (ping-pong bi-bi). Inhibition by either donor was not found, and inhibition by glycylglycine was only observed at concentrations above those of clinical interest. Kinetic constants obtained by nonlinear regression analysis of initial velocity data were used to determine reagent substrate concentrations for the assay of this enzyme. An assay with use of 4 mmol of gamma-glutamyl-3-carboxy-4-nitroanilide and 100 mmol of glycylglycine per liter yielded equivalent activities to those by assay with use of 4 mmol of gamma-glutamyl-4-nitroanilide and 40 mmol of glycylglycine per liter. These concentrations of the carboxy donor and glycylglycine are also "cost optimal" and present no procedural problems when used.

Determination of the mechanism and kinetic constants for hog kidney gamma-glutamyltransferase.

The initial-velocity kinetics of hog kidney gamma-glutamyltransferase were studied. Glutamate gamma-(4-nitroanilide) and its 3-carboxy derivative, glutamate gamma-(3-carboxy-4-nitroanilide), served as gamma-glutamyl donors, and glycylglycine as an acceptor. Reaction products were identified by paper chromatography and amino acid analysis. Inhibited Ping Pong mechanisms and a comprehensive initial- velocity expression were developed which account for the observed simultaneous gamma-glutamyl transfer and autotransfer, competitive inhibition by glycylglycine, and non-competitive inhibition by the carboxy donor. The validity of the proposed Ping Pong mechanisms are supported by enzyme-velocity data obtained with constant ratios of acceptor to donor concentrations. Kinetic constants were determined by a non-linear regression analysis. With glutamate gamma-(4-nitroanilide) as the donor, Michaelis constants for the donor, acceptor and donor-acting-as-acceptor are 1.87, 24.9, and 2.08 mM respectively. With glutamate gamma-(3-carboxy-4-nitroanilide) as the donor, these Michaelis constants are 1.63, 16.6, and 12.3 mM. Glyclyglycine competitive inhibition constants with the parent donor and its carboxy derivative are 275 and 205 mM respectively; the non-competitive inhibition constant of the carboxy donor is 34 mM.