Concentrations of seven trace elements in different hematological matrices in patients with type 2 diabetes as compared to healthy controls.

This study aimed to compare the trace element status of patients with type 2 diabetes (n = 53) with those of nondiabetic healthy controls (n = 50). The concentrations of seven trace elements were determined in the whole blood, blood plasma, erythrocytes, and lymphocytes of the study subjects. Vanadium and iron levels in lymphocytes were significantly higher in diabetic patients as compared to controls (p < 0.05 for iron and p < 0.01 for vanadium). In contrast, lower manganese (p < 0.01) and selenium (p < 0.01) concentrations were detected in lymphocytes derived from patients with type 2 diabetes versus healthy subjects. Furthermore, significantly lower chromium levels (p < 0.05) were found in the plasma of diabetic individuals as compared to controls. Trace element concentrations were not dependent on the degree of glucose control as determined by correlation analysis between HBA1c versus metal levels in the four blood fractions. In summary, this study primarily demonstrated that trace element levels in lymphocytes of patients with type 2 diabetes could deviate significantly from controls, whereas, in general, no considerable differences could be found when comparing the other fractions between both patient groups. Therefore, it seems reasonable to analyze metal levels in leukocytes to determine trace element status in patients with type 2 diabetes and perhaps in other diseases.

Numerical density of mu opioid receptor expressing neurons in the frontal cortex of drug related fatalities.

In animal and cell culture experiments, chronic morphine treatment has been followed by 'up'- as well as 'down-regulation' of the mu opioid receptor (mu OR) number. The present postmortem morphometric study of morphine-related fatalities of drug addicts (n=12, and 22-35 years old, with blood unconjugated morphine levels from 27.1 to 458 ng/ml, m.v. 198.5 ng/ml) versus a non-addicted control group (n=13 and 10-44 years old) was intended to examine whether chronic opiate exposure affects the numerical density of mu OR expressing neurons in the human neocortex (area 10 according to Brodmann). For the immunohistochemical procedure, thick (100 microm) vibratome sections were incubated with a monoclonal antibody against the mu OR [Arvidsson et al., J. Neurosci. 15 (1995) 3328] and immunoreactive sites were visualized using an immunoperoxidase protocol. The numerical densities of mu OR-expressing and Nissl-stained neurons were assessed morphometrically (camera lucida-drawings). In both collectives, the anti-mu OR immunoreactivity was mainly found in pyramidal neurons of layers (L) II/III and V and in multiform neurons of L VI. In the drug-related fatalities and the control group, the density of neurons expressing mu OR protein was similar, amounting for 2698 +/- 153 and 2688 +/- 172/mm(3), respectively. These findings extend the binding studies of opioid ligands in postmortem brains of heroin addicts [Gabilondo et al., Psychopharmacology 115 (1994) 135] revealing similar receptor densities and affinities by showing no difference in the density of mu OR-positive neurons.

Numerical density of delta-opioid receptor expressing neurons in the frontal cortex of drug-related fatalities.

In animal experiment and in cell culture, chronic morphine treatment has been followed by a reduction as well as an increase of the delta-opioid receptor (OR) number. The present postmortem morphometric study of morphine-related fatalities of drug addicts (n=12, 22-35 years old, with blood unconjugated morphine levels from 27.1 to 407 ng/ml, m.v. 176.9 ng/ml) versus a non-addicted control group (n=13, 10-44 years old) is intended to examine whether chronic opiate exposure also affects the numerical density of deltaOR expressing neurons in the human neocortex (area 10 according to Brodmann (Vergleichende Lokalisationslehre der Grosshirnrinde (1909) Johann Ambrosius Barth, Leipzig)). For the immunohistochemical procedure, vibratome sections (100 microm) were incubated with a monoclonal antibody against the deltaOR diluted 1:100, and immunoreactive sites were visualized using an immunoperoxidase protocol. The numerical densities of OR expressing and Nissl-stained neurons were assessed morphometrically (camera lucida drawings). In both collectives, the anti deltaOR immunoreactivity was predominantly localized in pyramidal neurons of layers (L) II/III and V as well as in round and ovoid neurons of L VI. In the drug-related fatalities, the density of neurons expressing deltaOR protein amounted for 2515+/-240/mm(3), in the control group for 2616+/-204/mm(3), thus displaying no statistically significant difference. These findings go along with the binding behavior of opioid ligands in postmortem brains of heroin addicts revealing similar receptor densities and affinities in the control subjects and addicts.

Determination of Ca, Mg, Fe, Cu, and Zn in blood fractions and whole blood of humans by ICP-OES.

Inductively coupled plasma-optical emission spectrometry (ICP-OES) was applied to the determination of the elements Ca, Mg, Fe, Cu, and Zn in blood plasma, erythrocytes, lymphocytes, and whole blood to obtain reliable data on their distribution in blood fractions. The samples were carefully collected to avoid contamination. Two different nebulizers (Babington and Meinhard) were tested and optimized for this analytical problem. Line selections for all elements of interest were performed (LODs were 0.8 microg/L for Ca, 1.7 microg/L for Cu, 3.0 microg/L for Fe, 1.1 microg/L for Mg, and 4.2 microg/L for Zn). Recoveries were determined as approx. 100%, and standard reference material was analyzed to obtain reliable data on element distribution. The optimized method was applied to the determination of Ca, Mg, Fe, Cu, and Zn in the course of a clinical study on blood and blood fractions of two groups of humans of differing health. The concentrations measured in blood fractions were verified by balancing with the values found in whole blood.

ETAAS method for the determination of Cd, Cr, Cu, Mn and Se in blood fractions and whole blood.

An electrothermal atomic absorption method (ETAAS) for the direct determination of trace elements (Cd, Cr, Cu, Mn, Se) both in blood fractions (erythrocytes, plasma and lymphocytes) and whole blood was developed. Zeeman background correction and graphite tubes with L'vov platforms were used. Samples were diluted with HNO3/Triton X-100 and pipetted directly into the graphite tube. Ashing, pretreatment and atomization steps were optimized carefully for the different fractions and elements applying different matrix modifiers for each element. For the lymphocyte fraction a multi-fold injection technique was applied. Low detection limits of the ETAAS method (Cd 0.13 microgram/L, Cr 0.11 microgram/L, Cu 0.52 microgram/L, Mn 0.13 microgram/L, Se 0.7 microgram/L of whole blood) combined with small quantities of sample necessary for analysis allow determination of trace elements in this matrix. Verification of possible differences in the trace element status of humans was performed with statistical significance (P < 0.05). In addition, a contribution to the determination of normal values of essential elements was achieved. The method was applied for determination of trace elements in human blood and blood fractions of two groups (n = 50) different in health status.

Determination of Cu, Fe, Mn, and Zn in blood fractions by SEC-HPLC-ICP-AES coupling.

The binding of Cu, Fe, Mn, and Zn to proteins in blood and in blood fractions was investigated, since their interactions in free radical metabolism in humans is of great interest. An HPLC-ICP-AES technique was developed allowing adequate separation of metalloproteins and of inorganic and organic metal species. For the separation of metalloproteins in erythrocytes and blood plasma a Merck Superformance Fractogel EMD BioSEC 650 (S) column was used. Size exclusion chromatography (SEC)-HPLC was hyphenated to ICP-AES both on-line and off-line for the detection of trace elements in the fractions resulting from HPLC separations. HPLC parameters, pH, temperature, flow rate and salt concentration were optimized for the protein separation and the optimal conditions were applied for the hyphenation to the ICP-AES detector. The separation column was calibrated with five standard proteins. For the element determination by ICP-AES a line selection with respect to the sensitivity was performed. Three different methods were used for the determination of trace elements in blood: direct determinations, on-line and off-line SEC-HPLC-ICP-AES measurements. For the optimizing experiments blood samples of one female subject were used. The direct determination by ICP-AES of the elements was performed in blood and blood fractions of ten different subjects to obtain the average concentration ranges. From the results the identification of the protein Cu/Zn superoxide dismutase in erythrocytes was possible. The LOD were 0.03 microgram mL-1 for Cu, 0.026 microgram mL-1 for Fe, 0.8 ng mL-1 for Mn, and 0.09 microgram mL-1 for Zn in a synthetic blood matrix.

Cost containment through therapeutic substitution of aminoglycosides.

A therapeutic substitution policy (TSP) for tobramycin and gentamicin sulfate was implemented at the University of Texas Medical Branch (UTMB). The policy was designed by various physician-chaired hospital committees and clinical departments that collaborated with the pharmacy service. The goal was to encourage the medical house staff to use the most economical yet safe and effective aminoglycoside, without limiting the medical team's prerogative to select among alternatives within this antibiotic group. Cost data from the first 6 months of aminoglycoside use under the new policy projected an annual savings of $139,071 in drug expenditures and $242,472 in patient charges. Following the implementation of the TSP, a concurrent drug utilization review (DUR) was performed in 50 consecutive inpatients prescribed amikacin, tobramycin, or gentamicin sulfate. The objectives were to identify those aspects of prescribing and monitoring of aminoglycosides by house staff that could be improved by specific policy and/or education, and to evaluate those specific cases in which attending physician's approval allowed house staff to prescribe an aminoglycoside other than designated in the TSP. The audit revealed that house staff were compliant with 72% of the DUR criteria; however, at least one instance (mean of 5.04 +/- 2.21) of noncompliance occurred during the treatment of each patient. The most frequently encountered deficiencies were failure to monitor for ototoxicity, incorrect orders for at least one set of serum aminoglycoside concentrations, and improper dosage adjustments for those patients with renal insufficiency. In three cases, the attending physician approved house staff use of tobramycin instead of gentamicin sulfate for reasons of organism resistance, pre-existing renal impairment, and long-term treatment of osteomyelitis.

A utilization review of theophylline assays: sampling patterns and use.

Use of the theophylline assay was reviewed for two months in 121 hospital inpatients who received 426 evaluations at a university medical center. Clinicians adapted published audit criteria for the collection and use of theophylline assays. The charts of all patients receiving theophylline were examined daily, and the following data, among others, were collected: pulmonary function tests, arterial blood gases, liver function tests, vital signs, and physician assessments. Only 29.8 percent of the evaluations complied with all criteria. When the audit categories of rational indication, correct performance, and appropriate dosage adjustment were evaluated independently, compliance rates were 69.1, 72.3, and 67.2 percent, respectively. In 171 cases (48.6 percent), the physicians' instructions for the assay were inadequate to ensure proper collection time by the phlebotomist. Hospital laboratory charges for unnecessary, incorrectly performed, or inappropriately used theophylline assays were estimated to exceed +77000 annually. This audit demonstrates the need for a collaborative pharmacokinetics service with reimbursement through the physician billing charge.