Interinstitutional variation in glycohemoglobin monitoring and glycemic control of diabetic patients.

OBJECTIVES: To compare how frequently institutions monitor glycohemoglobin in diabetic patients, the level of glycemic control achieved and to identify institutional factors associated with higher rates of monitoring and lower glycohemoglobin levels. METHODS: A total of 212 institutions retrospectively abstracted laboratory and outpatient records of up to 30 diabetic patients who had initial glycohemoglobin monitoring performed in their laboratories. Data from a cohort of 5586 diabetic patients and 17 365 assays were analyzed. RESULTS: Overall, 31.3% of patients underwent glycohemoglobin monitoring at least quarterly, the frequency recommended by the American Diabetes Association (ADA) to stabilize patients at target hemoglobin A(1c) (HbA(1c)) levels. A total of 64.9% of patients were monitored at least semiannually, the ADA recommendation for patients with stable diabetes in glycemic control (final HbA(1c) level <7%). When we compared the top and bottom deciles of the 212 institutions, there was more than an eightfold difference in the proportion of patients monitored at least quarterly and more than a twofold difference in the proportion of patients monitored at least semiannually. Glycemic control was assessed by examining the value of the last glycohemoglobin determination on record after at least 8 months of management. For all 5586 diabetic patients, the median value of the last HbA(1c) assay was 7.4%. Comparing the top and bottom deciles, there was almost a fourfold difference among institutions in the proportion of diabetic patients in glycemic control. The use of reminders to order glycohemoglobin monitoring was associated with higher rates of semiannual monitoring (P <.05) and tighter glycemic control (P <.05). In addition, patients who were monitored more frequently experienced glycohemoglobin reductions of greater magnitude (P <.001). The presence of diabetes clinics and the use of rapid methods for testing glycohemoglobin were not associated with monitoring frequency or glycohemoglobin levels. CONCLUSIONS: There is wide interinstitutional variation in the frequency with which diabetic patients are monitored and the level of glycemic control achieved. The use of prompting systems to remind providers to order glycohemoglobin monitoring was associated with more frequent monitoring and superior glycemic control.

Ethylene glycol toxicity: the role of serum glycolic acid in hemodialysis.

OBJECTIVE: To correlate serum glycolic acid levels with clinical severity and outcome in ethylene glycol poisoning and to determine if glycolic acid levels are predictive of renal failure and the need for hemodialysis. METHODS: We measured serum ethylene glycol and glycolic acid levels by gas chromatography/mass spectrometry for 41 admissions (39 patients) for ethylene glycol ingestion and performed retrospective chart reviews. RESULTS: Eight patients died, all of whom developed acute renal failure. Of the survivors, 15 also developed acute renal failure, whereas 18 did not. Of those with normal renal function, 8 had glycolic acid levels below detection limits (< 0.13 mmol/L) despite ethylene glycol levels as high as 710 mg/dL; 7 of these patients coingested ethanol. Pertinent initial laboratory data for each group are as follows (mean; range): Deceased: pH 6.99 (6.82-7.22); bicarbonate, 4.8 mmol/L (2-9); anion gap, 28.6 mmol/L (24-40); glycolic acid, 23.5 mmol/L (13.8-38.0); ethylene glycol, 136.5 mg/dL (6-272). Survived/acute renal failure: pH 7.07 (6.75-7.32); bicarbonate, 5.6 mmol/L (1-12); anion gap, 28.7 mmol/L (18-41); glycolic acid, 20.2 mmol/L (10.0-30.0); ethylene glycol, 238.8 mg/dL (12-810). No acute renal failure with glycolic acid > 1.0 mmol/L: pH 7.29 (7.12-7.46); bicarbonate, 14.7 mmol/L (4-23); anion gap, 16.5 mmol/L (10-26); glycolic acid, 6.8 mmol/L (2.6-17.0); ethylene glycol, 269.1 mg/dL (6-675). No acute renal failure with glycolic acid < 1.0 mmol/L: pH 7.41 (7.38-7.47); bicarbonate, 23.4 mmol/L (17-25); anion gap, 11.8 mmol/L (8-18); glycolic acid, 0.1 mmol/L (0-0.66); ethylene glycol, 211 mg/dL (8-710). The mean time postingestion to admission generally correlated with severity as follows: deceased, > or = 10.4 h; survived/acute renal failure, > or = 9.9 h; no acute renal failure with glycolic acid > 1.0 mmol/L, > or = 6.2 h; no acute renal failure with glycolic acid < 1.0 mmol/L, > or = 3.7 h. Hematuria was more prevalent than oxaluria (86% and 41%, respectively), but neither was individually predictive of acute renal failure. Good correlations were found between glycolic acid levels and anion gap (r2 = 0.7724), pH (r2 = 0.7921), and bicarbonate (r2 = 0.6579); poor correlations (r2 < 0.0023) occurred between ethylene glycol levels and glycolic acid, pH, anion gap, and bicarbonate. Measured ethylene glycol values were highly correlated with ethylene glycol values calculated from the osmolal gap (r2 = 0.9339), but the latter overestimates the true value by about 7%, on average. An initial glycolic acid level > or = 10 mmol/L predicts acute renal failure with a sensitivity of 100%, a specificity of 94.4%, and an efficiency of 97.6%. Ethylene glycol levels are not predictive of acute renal failure or central nervous system manifestations of toxicity. If only ethylene glycol values are available (measured or calculated), an initial anion gap > 20 mmol/L is 95.6% sensitive and 94.4% specific for acute renal failure when ethylene glycol is present. Likewise, initial pH < 7.30 is 100% sensitive and 88.5% specific for acute renal failure. CONCLUSION: We propose glycolic acid > 8 mmol/L as a criterion for the initiation of hemodialysis in ethylene glycol ingestion. Patients with glycolic acid < 8 mmol/L probably do not need dialysis, regardless of the ethylene glycol concentration, when metabolism of ethylene glycol is therapeutically inhibited. In the absence of glycolic acid values, an anion gap > 20 mmol/L or pH < 7.30 predicts acute renal failure.

Concomitant administration of vitamin E does not change the side effects of isotretinoin as used in acne vulgaris: a randomized trial.

BACKGROUND: Isotretinoin treatment is frequently associated with reversible, dose-related side effects. Recent studies claimed that combining vitamin E with high-dose isotretinoin ameliorated isotretinoin-induced side effects. OBJECTIVE: The purpose of this double-blind, randomized study was to determine the effects of a fixed dose of vitamin E on the side effects of isotretinoin for treatment-resistant acne vulgaris. METHODS: One hundred forty subjects were randomly assigned to one of two treatment programs with isotretinoin (1 mg/kg) together with either vitamin E (800 IU/day) or a vitamin E placebo for 20 weeks. The incidence, severity, and duration of the side effects (eg, dry eyes, dry lips) were assessed. RESULTS: A fixed 800 IU/day dose of vitamin E did not improve the incidence, severity, or duration of side effects associated with isotretinoin (1 mg/kg per day). CONCLUSION: Vitamin E did not significantly ameliorate retinoid side effects when combined with 1 mg/kg of isotretinoin in the treatment of acne.

A case of aggressive multiple myeloma with cleaved, multilobated, and monocytoid nuclei, and no serum monoclonal gammopathy.

Multiple myeloma is a B-cell malignancy characterized by proliferation of neoplastic plasma cells. A few cases have been reported identifying variant forms of neoplastic plasma cells with atypical nuclei that secrete myeloma protein. We report a highly unusual case of plasma cell myeloma that presented with cleaved, multilobated, and monocytoid nuclei, without detectable myeloma protein in the serum or urine. The bone marrow contained sheets of plasma cells exhibiting pleomorphic nuclei with cleaved, multilobated, and monocytoid features that were negative for myeloperoxidase and dual esterase. Flow cytometric analysis revealed CD38high/CD45low cells expressing cytoplasmic kappa light chain, without evidence of myeloid or lymphoid differentiation. Following chemotherapy, the patient developed secondary plasma cell leukemia. A high plasma cell labeling index was obtained from bone marrow and peripheral blood, indicating a poor prognosis. In addition to quantitative immunoglobulins, serum protein electrophoresis, and immunofixation electrophoresis of serum and urine, we recommend cytochemical and flow cytometric studies for evaluation of suspected plasma cell myeloma with atypical cellular features.

Toxicology: past, present, and future.

Toxicology is the study of poisons and poisoning and has an ancient and venerable history. Although there have been numerous notorious poisonings throughout the ages and rather astute descriptions of toxic agents, the scientific study of toxicology did not commence until the 19th century. There was rapid development of analytical methods in the late 19th century and then an acceleration of both method and scientific development in the latter half of the 20th century. Toxicology today can be subdivided into clinical toxicology, forensic toxicology, industrial or occupational toxicology, environmental toxicology, pharmaceutical toxicology, experimental toxicology, and workplace drug testing. The historical development of these overlapping areas of toxicology will be discussed, culminating in a prediction as to what the future may bring.

Quantification of vitamin D receptor mRNA by competitive polymerase chain reaction in PBMC: lack of correspondence with common allelic variants.

It has been recently claimed that polymorphism for the vitamin D receptor (VDR) influences several aspects of calcium and bone metabolism. To evaluate the physiologic plausibility of these claims, we compared the abundance of the VDR mRNA in peripheral blood mononuclear cells (PBMCs) between different VDR genotypes using a quantitative reverse transcribed polymerase chain reaction-based method. The method is based on the coamplification of VDR cDNA and an internal standard consisting of known concentrations of a human VDR CDNA mutated at a BglII restriction site; the interassay coefficient of variation is 11%. To validate the method, we made use of earlier receptor binding studies indicating that normal human monocytes and activated, but not resting, lymphocytes expressed the VDR. The concentration of the VDR mRNA was 10(-8) to 10(-7) g/g of total RNA in cell-sorted monocytes and in in vitro activated lymphocytes, but only 10(-12) g/g of total mRNA in resting lymphocytes, establishing that the VDR mRNA determined by our method in PBMCs is due to constitutive expression in monocytes. Following an initial genotype screening of 85 normal volunteers by polymerase chain reaction or restriction fragment length polymorphism analysis, 14 individuals with the Bb genotype, 12 with the bb genotype, and 12 with the BB genotype were selected. The concentration of the VDR mRNA, corrected for the number of monocytes, was similar among the three genotype groups, as were the other variables examined: serum calcitriol, serum osteocalcin, and vertebral and hip bone density. We conclude that VDR polymorphism does not affect the abundance of the VDR mRNA.

Vessel dilator is associated with survival after acute myocardial infarction.

To assess whether infarct size, ischemic area and/or survival correlates with circulating atrial natriuretic peptides (long acting sodium stimulator, vessel dilator, or atrial natriuretic factor), these peptides were measured in a canine model of acute myocardial infarction. Elevations in the circulating concentrations of atrial natriuretic factor, vessel dilator, and long acting sodium stimulator were significant (P < 0.05) within 6 min of coronary occlusion of the left anterior descending coronary artery. The percentage of ischemic myocardium ranged from 20 to 67% with a mean of 37 +/- 17%. The area of infarction ranged from 1 to 13% with the infarcted area of non-survivors being twice that of survivors. Both the ischemic and infarcted areas correlated (P < 0.05) with the circulating concentrations of these atrial natriuretic peptides. Survival correlated also with the circulating plasma concentrations of vessel dilator, atrial natriuretic factor and long acting sodium stimulator (P < 0.05). When these circulating concentrations were evaluated, however, by determining their area under their respective concentrations curves and expressing each as the log area under plasma concentration-time curve (area under the curve) per kg of weight (Y = 58.48X-23.62; r = 0.825; P = 0.0009), vessel dilator was the only atrial natriuretic peptide that correlated with survival.

Measurement of serum isopropanol and the acetone metabolite by proton nuclear magnetic resonance: application to pharmacokinetic evaluation in a simulated overdose model.

The purpose of this investigation was to 1) compare the performance of proton nuclear magnetic resonance spectroscopy to gas chromatography head-space analysis in the measurement of serum isopropanol and its metabolite, acetone, obtained during a simulated overdose, and 2) compare pharmacokinetic parameters obtained using the two analytical techniques. Three healthy volunteers ingested 0.6 mL/kg of 70% isopropanol and blood samples were obtained at baseline, 0.16, 0.33, 0.66, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12.0, and 24.0 hours post-ingestion. Resulting sera were analyzed by gas chromatography head-space analysis and proton nuclear magnetic resonance spectroscopy for determination of isopropanol and acetone concentrations. A correlation between concentrations quantitated by gas chromatography head-space analysis versus proton nuclear magnetic resonance spectroscopy was determined using linear regression. Pharmacokinetic disposition parameters were determined from serum concentration-time data and compared using analysis of variance. For isopropanol, the linear regression equation which describes the relationship between gas chromatography head-space analysis and proton nuclear magnetic resonance spectroscopy was y = 1.041x - 2.180 (r2 = 0.995, p < 0.0001); for acetone, y = 1.022x - 0.946 (r2 = 0.984, p < 0.0001). Pharmacokinetic disposition parameters derived from the two analytical methods were comparable. Proton nuclear magnetic resonance spectroscopy can be used to rapidly quantitate serum isopropanol and acetone concentrations in the same sample when gas chromatography head-space analysis is unavailable. Also, proton nuclear magnetic resonance spectroscopy can be used to follow serial serum concentrations during an ingestion for the purpose of pharmacokinetic analysis.

Phenytoin and plasmapheresis: importance of sampling times and impact of obesity.

The effect of plasmapheresis (PP) on total and free phenytoin clearance is reported. An obese patient with the diagnosis of thrombotic thrombocytopenic purpura (TTP) was treated with PP. Twelve episodes of PP, having exchange volumes of 1.5-2.25 times the plasma volume with a mean +/- SD 7.7 +/- 0.8 L of plasma removed, were studied. A significant (p < 0.05) difference was observed with a mean change in plasma phenytoin concentrations from pre- to end-PP of 7.32 +/- 2.5 mg/L compared to 1.98 +/- 0.7 mg/L observed pre-PP to 1 h post-PP. These values corresponded to 48.4 +/- 11.6 and 15.0 +/- 6.7% decreases in phenytoin concentrations at the two aforementioned time periods. To prevent misinterpretation of plasma phenytoin concentrations, samples should not be obtained for at least 2 h after PP.

An introductory orientation to clinical pathology core and on-call responsibilities.

An introductory 4-week orientation for clinical pathology is described. There were 76 hours of lectures, 74 hours of conferences, and 68 hours of laboratories for a total of 221 hours. During the orientation, all calls handled by the residents were evaluated as to resolution, patient outcome, and interaction required. Eighty calls were received during the orientation from 57 technologists (71%), 16 physicians (20%), and seven nurses (9%). The calls originated concerning the following: blood banking, 37 (46%); hematology, 21 (27%); chemistry, 14 (18%); microbiology, five (6%); and administration, three (4%). Sixty percent of the calls were consultative and 40% were supervisory. Ninety-nine percent were handled appropriately by the residents. Patient outcome was moderately or significantly affected in 44% of all calls, divided between 67% of all consultative calls and 9% of all supervisory calls. Significant pathologist interaction was required in 49% of all calls, divided between 71% of the consultative calls and 16% of the supervisory calls. Using this integrated, dynamic system of resident instruction, on-call experience, and evaluation, residents quickly gain confidence in handling call, didactic clinical consultation, and patient management. The orientation and on-call system described provides for a relevant and dynamic system for resident education.

Prevention of chronic radiation enteropathy by dietary glutamine.

BACKGROUND: Nearly 50% of all cancer patients receive therapeutic radiation during the course of their disease. The risk of late complications is the main dose-limiting factor in the delivery of radiation therapy. The small intestine, the major site of chronic radiation enteropathy, is also the principal organ of glutamine consumption. We therefore hypothesized that the provision of supplemental glutamine may have a protective effect on the development of chronic radiation enteropathy. METHODS: This study evaluated the effects of supplemental oral glutamine on the development of chronic radiation (XRT) enteropathy. After scrotalization of a loop of small intestine, rats were randomized to receive 1 g/kg/day glutamine (GLN) or glycine (GLY) by gavage. After 2 days of prefeeding, rats were randomized to 1 of 4 groups: GLN + XRT (n = 10), GLY + XRT (n = 10), GLN only (n = 10), GLY only (n = 10). Twenty Gy was delivered to the scrotalized bowel in the GLN + XRT and GLY + XRT groups via a collimated beam. Gavage was continued for 10 days. Animals were then pair-fed chow. Rats were killed at 2 months postirradiation. Chronic radiation injury was assessed microscopically. RESULTS: Injury scores in GLN + XRT were similar to those of unirradiated bowel and significantly different from GLY + XRT (1.89 +/- 0.48 in XRT + GLN vs. 6.42 +/- 1.55 in the XRT + GLY, p < 0.01). Elevated Injury Scores in the XRT + GLY group correlated with gross thickening and fibrosis, a 10-fold decrease in gut GLN extraction (1.40 +/- 4.3% in GLY + XRT vs. 16.0 +/- 5.1% in GLN + XRT, p < 0.05), and a 30% decrease in glutathione content (2.46 +/- 0.19 and GLY + XRT vs. 3.17 +/- 0.17 GLN + XRT, p < 0.05). CONCLUSIONS: Provision of GLN during abdominal/pelvic XRT may prevent XRT injury and decrease the long-term complications of radiation enteropathy.

Analysis of saturated phosphatidylcholine in amniotic fluid by 31P NMR.

A technique using solubilization with sodium cholate to resolve 31P NMR resonances of phospholipid molecular species was applied to amniotic fluid samples from 16 subjects. Gestational ages from 25 to 40 weeks were represented, and two subjects were sampled sequentially. Fitting of the partially resolved 31P NMR signal of phosphatidylcholine (PC) generated an estimate of percent disaturated acyl PC (%dsPC) which correlated more highly with gestational age than did several other potential indices of fetal lung maturation, such as the ratio of PC to inorganic phosphate from the solubilized spectra, or PC to sphingomyelin from extract spectra. In a few cases, enzyme-catalyzed PC hydrolysis limited the precision, but did not appear to affect the accuracy, of the %dsPC estimates. Resolution of palmitoyl and oleoyl lyso-PC species was observed for both the 1- and 2-acyl isomers. Upfield shifts due to the presence of cis double bonds in the lone acyl chain of the lyso-PCs were analogous to those observed for the diacyl PCs.

The application of a rapid D-dimer test in suspected pulmonary embolus.

A prospective, consecutive series of plasma D-dimer (D-D) using a rapid, sensitive, and semiquantitative latex agglutination test from 169 patients clinically suspected of having acute pulmonary embolus (PE) was performed to determine its clinical utility in acute PE. All patients had ventilation/perfusion (V/Q) scans and 20 patients (12%) subsequently had pulmonary arteriography (PAG). The 20 patients who subsequently had PAG were used to establish the predictive value(s). In 10 patients with normal D-D results, none had PE according to PAG. In 10 patients with abnormal D-D results, seven showed PE by PAG and three did not show PE by PAG. The sensitivity, specificity, positive predictive values, and negative predictive values of the plasma D-D tests for acute PE based on PAG were 1.00, 0.77, 0.70, and 1.00, respectively. In nine patients with indeterminate V/Q scans who had PAG, four had PE and the D-D result was abnormal. Five of these patients did not have PE and the D-D result was abnormal in three and normal in two. Seventeen patients had high-probability V/Q scans, all of whom had abnormal D-D results. Only one had PAG that showed PE in this group. A normal D-D result using a rapid latex agglutination method can effectively exclude the diagnosis of acute PE. The negative predictive value of the rapid latex agglutination method is as good as the more cumbersome enzyme-linked immunosorbent assay methods. An abnormal result is nonspecific and is not useful in the diagnosis of acute PE. While some "false positives" did occur, there were no false-negative results. The best use of the D-D test is in the examination of the patient with indeterminate V/Q studies. We conclude that the D-D test can rapidly provide information in determining whether a patient needs further angiographic studies.

High-resolution proton nuclear magnetic resonance spectroscopy in the detection of low molecular weight volatiles.

Proton nuclear magnetic resonance spectroscopy (1H MRS) has been used to identify ethanol in vivo and to detect other exogenous low molecular weight volatiles in human serum. 1H MRS was used to detect and quantitate 15 human sera containing various concentrations and combinations of ethanol, isopropanol, acetone, and methanol as previously quantitated by headspace gas chromatography. The 1H MRS method was linear for each alcohol. The lowest detectable alcohol concentration was 15 mg/L (peak height equal to three times the signal-to-noise ratio), and 30 mg/L (+/- 10% relative standard deviation) was the lowest level reproducibly quantitated. Within-run and day-to-day coefficients of variation (CV) ranged from 0.8 to 2.0% and 0.9 to 1.2%, respectively, for methanol; 0.5 to 1.9% and 0.6 to 1.3% for acetone; and 0.5 to 1.6% and 0.3 to 2.2% for isopropanol. In all cases, the lowest CVs for a particular compound were obtained for the highest measured concentration (1500 mg/L), and the highest CVs were observed for the lowest concentration (250 mg/L). The 1H MRS method for detection of these volatiles does not require sample pretreatment and is nondestructive, which allows for further analysis by other methods.

High-resolution proton nuclear magnetic resonance spectroscopy in the detection and quantitation of ethanol in human serum.

A precise, accurate, and nondestructive method for the detection and quantitation of serum ethanol in humans using proton (1H) nuclear magnetic resonance spectroscopy (MRS) was developed. The 1H MRS method was linear within the range of 30-1500 mg/L. The lowest detectable ethanol concentration was 15 mg/L, with 30 mg/L being the lowest level reproducibly quantitated. Within-run and day-to-day coefficients of variation (CV) ranged from 0.6 to 2.7% and 0.5 to 3.5%, respectively. The excellent day-to-day CVs indicate a negligible loss of ethanol due to volatilization during analysis. Fifteen human serum samples found to be negative for ethanol by headspace gas chromatography (HSGC) had no ethanol as detected by 1H MRS. Twenty-eight human serum samples with ethanol concentrations (determined by HSGC) ranging from 370 to 4440 mg/L were accurately reproduced by 1H MRS. The 1H MRS method required no pretreatment and was nondestructive, thereby allowing for further analysis by confirmatory methods.

Plasma D-dimer: a useful tool for evaluating suspected pulmonary embolus.

Although ventilation-perfusion lung scanning is widely used in evaluating patients with suspected pulmonary embolus, additional rapid screening tests are needed to supplement scintigraphy in patients in whom the scan is indeterminate or the scan results are discordant with clinical suspicion. D-dimer is a fibrin degradation product which should be elevated in the presence of intravascular coagulation. We prospectively studied patients referred for lung scanning by obtaining a plasma D-dimer latex agglutination assay at the time of the scan. Of 64 patients who had pulmonary angiography to confirm the diagnosis, 16 were positive for pulmonary embolus and only one had a normal D-dimer. The D-dimer was normal in 27 of 48 patients without embolus and elevated in 21. Although an elevated D-dimer level is a nonspecific finding, we conclude that a normal D-dimer is a good negative predictor for pulmonary embolus, with a negative predictive value of 0.97.

The use of delta osmolality to predict serum isopropanol and acetone concentrations.

We investigated whether serum delta osmolality will predict the total serum concentration of isopropanol and acetone metabolite. Three isopropanol ingestions were monitored by delta osmolality determinations followed by quantification of serum isopropanol and acetone concentrations. The delta osmolality was established by routine chemical analysis and standard freezing point depression osmometry. Serum isopropanol and acetone levels were quantified by gas chromatography-head space analysis (GC-HS). Patients were initially suspected of having isopropanol intoxication secondary to an elevated delta osmolality discrepancy (measured - calculated > 10 mOsm). Serum concentrations versus delta osmolality were analyzed by linear regression (correlation coefficient r = 0.713; p < 0.05). The delta osmolality paralleled and decreased relative to the total low molecular weight of volatile concentration in each case. In emergencies, delta osmolality may be a screening test to identify rapidly patients at risk for complications associated with isopropanol ingestion when GC-HS is not available.

Deoxyribonucleic acid (DNA) ploidy and proliferative characteristics of metastatic squamous cell carcinoma determined by flow cytometric analysis.

BACKGROUND: The deoxyribonucleic acid (DNA) index and the proliferative index (the fraction of cells in the S phase) can be independent prognostic indicators of the biologic aggressiveness of certain malignant neoplasms. OBJECTIVE: To determine whether the DNA index or proliferative index could predict metastases in cutaneous squamous cell carcinoma. METHODS: Nineteen different metastases from 15 patients with primary cutaneous squamous cell carcinoma (SCC) were reviewed, graded, and had DNA proliferative indexing performed by fluorescent activated cytometry. A control group of 13 patients with primary cutaneous SCC without metastases were studied in a similar manner. RESULTS: No significant difference between the metastatic and the nonmetastatic SCC groups for either DNA index or proliferative index (non-paired t-test) was observed. No correlative association with histologic grading with DNA index or proliferative index was observed for either group. CONCLUSION: We conclude that aneuploidy and S-phase fraction by fluorescent activated cytometry are not significant predictors of potential metastases in cutaneous squamous cell carcinoma.

Glutamine facilitates chemotherapy while reducing toxicity.

Dose intensification of chemotherapy is thought to increase survival. With recent advances in hemopoietic cell modulators such as granulocyte colony stimulating factor, the limiting toxicity of intensifying chemotherapeutic regimens has become the severity of the associated enterocolitis. In animal models, glutamine protects the host from methotrexate-induced enterocolitis. This study evaluates the effects of a glutamine-supplemented diet on the tumoricidal effectiveness of methotrexate. Sarcoma-bearing Fisher 344 rats (n = 30) were pair-fed an isocaloric elemental diet containing 1% glutamine or an isonitrogenous amount of glycine beginning on day 25 of the study. Rats from each group received two intraperitoneal injections of methotrexate (5 mg/kg) or saline on days 26 and 33 of the study. On day 40, rats were killed, tumor volume and weight were recorded, and tumor glutaminase activity and tumor morphometrics were measured. Blood was taken for arterial glutamine content, complete blood count, and blood culture. The gut was processed for glutaminase activity and synthesis phase of the deoxyribonucleic acid. In rats receiving methotrexate, the tumor volume loss was nearly doubled when glutamine was added to the diet. Significant differences in tumor glutaminase activity and morphometrics were not detected. The toxicity to the host was ameliorated. Significantly increased synthesis phase of deoxyribonucleic acid of the whole jejunum, decreased bacteremia, "sepsis," and mortality were demonstrated. Glutamine supplementation enhances the tumoricidal effectiveness of methotrexate while reducing its morbidity and mortality in this sarcoma rat model.

Effect of supplemental dietary glutamine on methotrexate concentrations in tumors.

This study evaluated the effects of supplemental dietary glutamine (GLN) on methotrexate sodium concentrations in tumors and serum of sarcoma-bearing rats following the initiation of methotrexate. After randomization to a GLN diet (+GLN) or GLN-free diet (-GLN), tumor-bearing rats received 20 mg/kg of methotrexate sodium by intraperitoneal injection. The provision of supplemental GLN in the diet increased methotrexate concentrations in tumor tissues at 24 and 48 hours (38.0 +/- 0.20 nmol/g for the +GLN group vs 28.8 +/- 0.10 nmol/g for the -GLN group and 35.6 +/- 0.18 nmol/g for the +GLN group vs 32.5 +/- 0.16 nmol/g for the -GLN group, respectively). Arterial methotrexate levels were elevated only at 48 hours (0.147 +/- 0.007 microns/L for the +GLN group vs 0.120 +/- 0.006 microns/L for the -GLN group). Tumor morphometrics were not different between the groups but significantly greater tumor volume loss was seen even at 24 hours (-2.41 +/- 1.3 cm3 for the +GLN group vs -0.016 +/- 0.9 cm3 for the -GLN group). Tumor glutaminase activity was suppressed in both groups at 48 hours, but more so in the +GLN group (0.94 +/- 0.13 mumol/g per hour for the +GLN group vs 1.47 +/- 0.22 mumol/g per hour for the -GLN group). This study suggests that GLN may have therapeutic as well as nutritional benefit in oncology patients.