Sensitivity, specificity and accuracy of stress SPECT myocardial perfusion imaging for detection of coronary artery disease in the distribution of first-order branch vessels, using an anatomical matching of angiographic and perfusion data

We sought to investigate the utility of stress single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the identification of coronary artery disease (CAD) in the distribution of first-order branch vessels. We evaluated 135 consecutive patients with coronary angiography and stress SPECT MPI. We anatomically matched angiography and SPECT to assess the sensitivity, specificity and accuracy of SPECT MPI for the detection of CAD in the distribution of first-order branches. Subgroup analysis for stress test performance and previous coronary artery bypass grafting (CABG) was also performed. The sensitivity, specificity and accuracy of stress SPECT MPI for the detection of CAD in the distribution of first-order branch vessels were all 67%. For isolated branch vessel CAD, stress SPECT MPI had a sensitivity of 44%. In patients without CABG, the sensitivity, specificity and accuracy for the detection of CAD in the distribution of first-order branch vessels were 71%, 67% and 68%, compared with 60%, 67% and 64% for patients with CABG. The sensitivity for isolated branch vessel CAD was 50% for patients without CABG, but only 29% for patients with CABG. The sensitivity and specificity for CAD in the distribution of branch vessels were similar for all patients for all stress test modalities and heart rate response (sensitivity, 64-69%; specificity, 61-69%). Stress SPECT MPI offers intermediate sensitivity, specificity and accuracy for the detection of CAD in the distribution of first-order coronary artery branch vessels. However, for isolated branch vessel CAD, stress SPECT has a lower sensitivity, particularly in patients with previous CABG.

Validation of a model of left ventricular segmentation for interpretation of SPET myocardial perfusion images

Several models of left ventricular segmentation have been developed that assume a standard coronary artery distribution, and are currently used for interpretation of single-photon emission tomography (SPET) myocardial perfusion imaging. This approach has the potential for incorrect assignment of myocardial segments to vascular territories, possibly over- or underestimating the number of vessels with significant coronary artery disease (CAD). We therefore sought to validate a 17-segment model of myocardial perfusion by comparing the predefined coronary territory assignment with the actual angiographically derived coronary distribution. We examined 135 patients who underwent both coronary angiography and stress SPET imaging within 30 days. Individualized coronary distribution was determined by review of the coronary angiograms and used to identify the coronary artery supplying each of the 17 myocardial segments of the model. The actual coronary distribution was used to assess the accuracy of the assumed coronary distribution of the model. The sensitivities and specificities of stress SPET for detection of CAD in individual coronary arteries and the classification regarding perceived number of diseased coronary arteries were also compared between the two coronary distributions (actual and assumed). The assumed coronary distribution corresponded to the actual coronary anatomy in all but one segment (#3). The majority of patients (80%) had 14 or more concordant segments. Sensitivities and specificities of stress SPET for detection of CAD in the coronary territories were similar, with the exception of the RCA territory, for which specificity for detection of CAD was better for the angiographically derived coronary artery distribution than for the model. There was 95% agreement between assumed and angiographically derived coronary distributions in classification to single- versus multi-vessel CAD. Reassignment of a single segment (segment #3) from the LCX to the LAD territory further improved the model's fit with the anatomic data. It is concluded that left ventricular segmentation using a model with assumed coronary artery distribution is valid for interpretation of SPET myocardial perfusion imaging.

Early cardioversion of atrial fibrillation facilitated by transesophageal echocardiography: short-term safety and impact on maintenance of sinus rhythm at 1 year

BACKGROUND

For patients presenting with atrial fibrillation of only a few weeks duration, the use of transesophageal echocardiography offers the opportunity to markedly abbreviate the duration of atrial fibrillation before cardioversion. We sought to determine if the shorter duration of atrial fibrillation allowed by a transesophageal echocardiography strategy had an impact on the recurrence of atrial fibrillation and prevalence of sinus rhythm during the first year following cardioversion.

METHODS

Transesophageal echocardiography was attempted in 539 patients (292 men, 247 women; 71.6 +/- 13.0 years.) with atrial fibrillation > or =2 days (66.1% <3 weeks) or of unknown duration before elective cardioversion of atrial fibrillation. Therapeutic anticoagulation at the time of transesophageal echocardiography was present in 94.6% of patients, and 73.4% of subjects were discharged on warfarin.

RESULTS

Atrial thrombi were identified in 70 (13.1%) patients. Successful cardioversion in 413 patients without evidence of atrial thrombi was associated with clinical thromboembolism in 1 patient (0.24%, 95% confidence interval: 0.0--0.8%). In patients with atrial fibrillation <3 weeks at the time of cardioversion (a duration incompatible with conventional therapy of 3 to 4 weeks of warfarin before cardioversion), the 1-year atrial fibrillation recurrence rate was lower (41.1% vs. 57.9%, P <0.01), and the prevalence of sinus rhythm at 1 year was increased (65.8% vs. 51.3%, P <0.03). No other clinical or echocardiographic index was associated with recurrence of atrial fibrillation or sinus rhythm at 1 year.

CONCLUSIONS

Early cardioversion facilitated by transesophageal echocardiography has a favorable safety profile and provides the associated benefit of reduced recurrence of atrial fibrillation for patients in whom the duration of atrial fibrillation is <3 weeks.

Evaluation of the cardiac STATus CK-MB/myoglobin card test to diagnose acute myocardial infarctions in the ED

A study was undertaken to evaluate a Card Test called "Spectral Diagnostics Inc Cardiac STATus CK-MB/Myoglobin" (Toronto, Canada), which is distributed by Dade International Inc, Miami, FL, for the simultaneous qualitative determination of CK-MB and myoglobin levels in human serum. The Card Test is advertised by the manufacturer as an aid in diagnosing acute myocardial infarction (AMI) in the emergency department (ED). Fifty-eight consecutive serum samples were obtained from 25 patients being evaluated for AMI in an ED. Qualitative CK-MB and myoglobin results from the Card Test were compared with quantitative CK-MB and myoglobin results using the ACS-180 instrument (Ciba Corning Diagnostics, Medfield, MA) and Stratus IIntellect T (Dade International Inc, Miami, FL), respectively. Qualitative results from the STATus CK-MB/Myoglobin Card Test were similar, diagnostically, to quantified results using these automated instruments.

Accelerated gastric emptying in hypertensive subjects

The phenomenon of accelerated gastric emptying has been previously reported in two conditions that are considered to be part of the insulin-resistance syndrome: namely, noninsulin-dependent diabetes (NIDDM) and increased body mass index (BMI). No previous studies have assessed the rate of gastric emptying in patients with essential hypertension, another disease considered to be part of the insulin-resistance syndrome.

METHODS

Scintigraphic gastric emptying studies were performed on nine hypertensive subjects and on nine sex-, age-, ethnicity and BMI-matched controls.

RESULTS

Subjects with hypertension had significantly more rapid gastric half-emptying times (gastric T50) (40.0 +/- 6.9 min versus 56.6 +/- 3.7 min, p = 0.02) than controls. There was an inverse relationship between average glucose during the first 30 min and 60 min of the oral glucose tolerance test with the gastric half-emptying time (Spearman rank correlation coefficient rs = -0.64, p = 0.0045 and rs = -0.48, p = 0.0428, respectively).

CONCLUSION

The occurrence of accelerated gastric emptying in hypertensive subjects, in addition to that previously reported in subjects with NIDDM or increased BMI, suggests the possibility that accelerated gastric emptying may be a common finding in insulin resistant states.

Accelerated gastric emptying of glucose in Zucker type 2 diabetic rats: role in postprandial hyperglycaemia

Patients with early non-insulin-dependent diabetes mellitus (NIDDM) empty glucose solutions from their stomachs more rapidly than non-diabetic control subjects, and this exacerbates postprandial hyperglycaemia. To determine if accelerated gastric emptying occurred in a rat model of NIDDM and influenced postprandial hyperglycaemia, gastric emptying of glucose was measured, and the effect of slowing the gastric emptying rate on postprandial hyperglycaemia was observed. We tested eight male obese Zucker diabetic rats and eight age-matched lean Zucker controls at 10-13 weeks of age to measure gastric emptying of glucose (by gamma scintigraphy). Rats fasted overnight were gavaged with 30% glucose at 1 ml/100 g body weight. Separately, six Zucker diabetic rats and six lean controls were tested for sensitivity to the inhibitory effects of cholecystokinin and secretin on gastric emptying. The diabetic rats emptied glucose significantly faster than controls (t1/2 = 37.3 +/- 1.5 vs 58.8 +/- 2.3 min in controls), and aging exaggerated this differential. Camostat, a stimulant of cholecystokinin and secretin release, added to the glucose meal significantly slowed gastric emptying (t1/2 = 123 +/- 23 and 166 +/- 19 min, diabetic vs lean, respectively), and significantly reduced postprandial hyperglycaemia in diabetic rats. Compared to Zucker lean controls, Zucker diabetic rats were as sensitive (cholecystokinin) or more sensitive (secretin) to gastrointestinal hormones that inhibit gastric emptying. The results demonstrate accelerated gastric emptying in a rat model of NIDDM, consistant with similar observations in humans with early NIDDM. These results also support the proposal that interventions to slow gastric emptying improve glucose control in this disease.

Use of a physiologic oral glucose solution for screening for impaired glucose tolerance and non-insulin-dependent diabetes mellitus

OBJECTIVE

To evaluate a lower osmolar, more physiologic oral glucose solution as part of an oral glucose tolerance test and to compare it to the standard glucose solution to see if it could serve as an effective screening agent for patients with impaired glucose tolerance or non-insulin-dependent diabetes mellitus.

METHODS

A total of 100 subjects were given both the standard (1.38 mol/L) 75-g oral glucose tolerance test solution and the lower osmolar (0.62 mol/L) 50-g glucose solution. Each test was separated by at least 3 days. Blood samples were drawn at baseline and 30, 60, and 120 minutes after ingestion of each glucose solution. The 1- and 2-hour blood glucose values obtained using the 75-g oral glucose tolerance test beverage were used as the gold standard to diagnose diabetes according to World Health Organization criteria.

RESULTS

Both solutions were shown to have a high sensitivity and specificity for detecting diabetes and impaired glucose tolerance at 30 and 60 minutes.

CONCLUSIONS

The physiologic 50-g solution uses less glucose, is highly palatable, and is similar in sweetness and carbohydrate concentration to commonly consumed soda beverages. A larger study including more patients with impaired glucose tolerance will need to be performed to verify our conclusions. The ability to perform high-sensitivity and high-specificity screening for patients with diabetes or impaired glucose tolerance with a single timed blood sample could make mass screening more practical.

Decelerating gastric emptying: therapeutic possibilities in type 2 diabetes

There is clear evidence of a positive correlation between carbohydrate absorption, plasma concentration of glucose, and the rate of gastric emptying. This suggests that clinical manipulation of gastric emptying rates may have therapeutic potential in glycaemic control. Cholecystokinin (CCK-8) has been shown to delay gastric emptying in individuals with Type 2 diabetes, but its potential as a therapy is limited by the need to administer it intravenously. The preferred routes of administration would be intramuscular injections, an intranasal spray or the use of orally ingested CCK analogues. Alternatively, the oral administration of an agent that enhances endogenous release of CCK could represent an important approach to the treatment of Type 2 diabetes. Agents such as POT II may have a therapeutic indication in patients with recently diagnosed Type 2 diabetes.

Gastric emptying of beer in Mexican-Americans compared with non-Hispanic whites

Gastric emptying studies were performed on 11 nondiabetic Mexican-Americans and 11 nondiabetic non-Hispanic whites following ingestion of 450 mL beer. Plasma glucose, serum insulin, and serum alcohol levels were measured in the fasting state and at 7, 15, 30, 45, and 60 minutes following ingestion of the beer. The area under the gastric emptying curve was significantly larger for non-Hispanic whites compared with Mexican-Americans (P = .0492), indicating that Mexican-Americans had faster stomach emptying. Partial correlation coefficients (adjusted for ethnicity, gender, age, and body mass index [BMI]) showed the gastric half-emptying time was inversely related to the incremental levels of glucose (r = -.709, P = .0010) and alcohol (r = -.650, P = .0035). The faster the rate of gastric emptying of beer, the higher the glucose and alcohol levels. There were no significant correlations between insulin and the rate of gastric emptying. The caloric emptying rate for the beer was much more rapid than previously reported for other liquid meals.

Rapid gastric emptying of a solid pancake meal in type II diabetic patients

OBJECTIVE

To estimate the rate of gastric emptying of a solid pancake carbohydrate meal in recently diagnosed asymptomatic type II diabetic patients compared with nondiabetic control subjects.

RESEARCH DESIGN AND METHODS

Gastric emptying studies using radiolabeled meals were performed on eight recently diagnosed asymptomatic diabetic patients and on eight sex-, BMI- and age-matched nondiabetic control subjects. Although a liquid protein drink was administered along with the pancake meal, the radioactivity was adherent to only the pancake portion of the meal. Plasma glucose and serum insulin levels were measured in fasting and postprandial blood samples collected at 15-min intervals up to 120 min after ingestion of the mixed nutrient meal.

RESULTS

The average gastric half-emptying time (time it takes for one-half of the meal to empty) was significantly more rapid for the diabetic patients (45.3 +/- 4.8 min) when compared with the nondiabetic control subjects (60.4 +/- 5.1 min; P = 0.05). The serum insulin concentrations were not statistically different between the two groups. Plasma glucose values were significantly higher in the diabetic patients compared with the nondiabetic control subjects.

CONCLUSIONS

Type II diabetic patients with no clinical evidence of neuronal dysfunction have a significantly more rapid rate of gastric emptying of a solid high-carbohydrate meal when compared with nondiabetic control subjects.

Gastric emptying in Mexican Americans compared to non-Hispanic whites

Mexican Americans, a group at high risk for type II diabetes mellitus, have higher postprandial insulin and glucose levels when compared to non-Hispanic whites. A rapid rate of gastric emptying contributes to an increased rate of nutrient absorption and subsequent greater elevation of postprandial glucose and insulin levels. A more rapid rate of gastric emptying and hyperinsulinemia have been observed in patients with recently diagnosed type II diabetes mellitus. In this study, we examined whether Mexican Americans have a more rapid rate of gastric emptying than non-Hispanic whites. Gastric emptying studies were performed on 32 nondiabetic Mexican Americans and on 31 nondiabetic non-Hispanic whites. The rate of gastric emptying following a liquid glucose meal was measured. Serum insulin, plasma glucose, and GIP levels were measured in fasting and postprandial blood samples collected at 15-min intervals for 2 hr. Adjusting for age, body mass index, and gender, the gastric half-emptying time of a glucose meal was significantly (P < 0.05) more rapid for the Mexican American subjects (56.5 +/- 3.4 min) compared to the non-Hispanic white subjects (66.4 +/- 3.5 min). Nondiabetic Mexican Americans empty a liquid glucose meal more rapidly from their stomachs than nondiabetic non-Hispanic whites. Rapid gastric emptying is associated with hyperinsulinemia as a normal physiologic response to increased nutrient availability. The rapid gastric emptying observed in nondiabetic Mexican Americans is associated with hyperinsulinemia and could be a contributing factor for the increased risk of obesity and type II diabetes in this population.

Anterior, posterior, left anterior oblique, and geometric mean views in gastric emptying studies using a glucose solution

Previous research has shown that the single anterior view of the stomach overestimates the gastric half-emptying time of a solid meal compared to the geometric mean of the anterior and posterior views. Little research has been performed comparing the various views of gastric emptying of a glucose solution. After an overnight fast, 49 nondiabetic subjects were given a 450 ml solution containing 50 g of glucose and 200 microCi of technetium-99m sulfur colloid. Sequential 1-min anterior, posterior, and left anterior oblique views were obtained every 15 min. The mean percent solution remaining in the stomach for all three views differed from the geometric mean by 1.9% or less at all time points. Average gastric half-emptying times were: geometric mean, 62.7 +/- 3.3 min; anterior, 61.9 +/- 3.2 min; posterior, 63.5 +/- 3.5 min; and left anterior oblique, 61.6 +/- 3.3 min. These half-emptying times were not statistically different. For individual patients, differences between all three views and the geometric mean were not clinically important. Approximately 95% of all patients are expected to have gastric half-emptying times measured by any of the three single views within 17 min of the gastric half-emptying time obtained using the geometric mean. The imaging of gastric emptying using glucose solutions can be performed using a convenient single view which allows continuous dynamic imaging.

Munchausen's syndrome and the laboratory. Self-injection of human chorionic gonadotropin

A woman presented to our emergency center after self-injection of human chorionic gonadotropin in an attempt to gain admission to the hospital. Her initial urine pregnancy test (an assay for beta-hCG) was negative. Subsequent blood samples received from the patient the same day revealed markedly elevated beta-hCG levels, suggesting possible laboratory error. Although the patient's sonogram was negative for an intrauterine pregnancy, an ectopic pregnancy could not be ruled out and the patient was taken to surgery, where no evidence of pregnancy was found. Retrospective evaluation of the patient's medical history revealed that she had 30 previous surgical procedures, for which most were performed for alleged gynecological reasons. The authors suggest that this case of Munchausen's syndrome illustrates one of the more interesting solutions for a "laboratory error."

Measurements of fentanyl and sufentanil in blood and urine after surgical application. Implication in detection of abuse

An increase in cases of death from overdose and abuse from fentanyl or sufentanil is being encountered by the Bexar County Forensic Science Center in San Antonio, Texas. These drugs have been abused almost solely by health care professionals. The fentanyl derivatives cannot currently be detected by routine laboratory drug-screening programs. Forensic toxicology assays that identify the specific analyte must be used. We report a sensitive assay for detection of fentanyl and sufentanil with a detection limit of -0.5 ng/ml. In addition, results from the analysis of urine and blood samples obtained up to 72 h after drug administration to five patients undergoing cardiac bypass surgery who had received either fentanyl or sufentanil are described. The new procedure enables detection of these drugs more readily, in smaller amounts, and for a longer period of time after use than previously possible. We hope this will lead to intervention and treatment in those abusing the drugs.

Determination of tricyclic antidepressants for ED analysis

Both the Biosite Triage (Biosite Diagnostics, San Diego, CA) method and the Du Pont aca (Du Pont Company, Wilmington, DE) method give qualitative tricyclic antidepressant (TCA) results to aid in the diagnosis of a TCA overdose. The Triage method uses urine samples and the aca uses serum samples. Although the cutoff values vary considerably between the two methods, the Triage results agreed well with the aca results. The Triage test has an advantage in instrument maintenance and time savings, allowing a reduction in turn-around time for our emergency department. Both urine and serum samples were obtained from 44 patients who were admitted to the emergency department with a diagnosis of "possible tricyclic overdose." Discrepancies between the two methods were resolved by thin layer chromatography (Toxi-Lab, Ansys, Inc, Irvine, CA). Both methods were in agreement with the exception of five patients' samples. In this study, the Triage method allowed for detection of TCA using urine that is simple for the user and yielded higher sensitivity and specificity results compared with the Du Pont aca method.

Use of a more physiologic oral glucose solution during screening for gestational diabetes mellitus

OBJECTIVES

We sought to compare in pregnant women deviations in glucose values, insulin values, and the occurrence of side effects between a "standard" 50 gm oral glucose solution (50 gm of glucose in 150 ml of fluid, 1.85 mol/L) versus a modified "physiologic" 50 gm oral glucose solution (50 gm of glucose in 450 ml of fluid, 0.62 mol/L) as a screening test for gestational diabetes mellitus.

STUDY DESIGN

A total of 132 pregnant women underwent (1) a standard 50 gm, 1-hour oral glucose screening test, (2) a 50 gm, 1-hour oral glucose screening test using the modified solution, and (3) a 3-hour oral glucose tolerance test (with 100 gm of glucose in 300 ml of fluid, 1.85 mol/L).

RESULTS

Compared with the "standard" regimen, both glucose and insulin values were significantly higher in the "modified" regimen 30 minutes after ingestion, indicating a more rapid absorption of glucose. Nausea and vomiting were greatly decreased with the modified glucose solution. The 1-hour glucose values were not statistically different.

CONCLUSIONS

A more dilute, more palatable oral glucose solution can be used to screen for gestational diabetes mellitus, yielding more accurate results and eliminating unpleasant side effects.

Treatment with an oral proteinase inhibitor slows gastric emptying and acutely reduces glucose and insulin levels after a liquid meal in type II diabetic patients

OBJECTIVE

To determine whether an oral trypsin/chymotrypsin inhibitor, POT II, will delay the rate of gastric emptying in recently diagnosed type II diabetic patients and improve their postprandial metabolic parameters.

RESEARCH DESIGN AND METHODS

Two gastric emptying studies were performed on each of six type II diabetic patients. During one study, the patient ingested a glucose/protein solution, and during the other study, the patient ingested the same glucose/protein solution with the addition of 1.5 g of POT II, a putative stimulant of cholecystokinin (CCK) release. Each patient served as their own control subject. Each of the two oral solutions were administered to the patients in a counter-balanced order separated by at least 1 week.

RESULTS

Serum insulin, plasma glucose, plasma gastric inhibitory polypeptide (GIP) values, and the rate of gastric emptying were all significantly (P < 0.05) decreased over the 2-h testing period when POT II was added to the oral glucose/protein meal. The area under the curve above baseline for glucose with POT II was 75% of the glucose value without POT II. The area under the curve above baseline for insulin with POT II was 68% of the value without POT II. Plasma CCK was significantly increased by POT II 15 min postprandially.

CONCLUSIONS

A trypsin/chymotrypsin inhibitor, POT II, can delay the rate of gastric emptying, and decrease postprandial plasma glucose levels, GIP levels, and serum insulin levels in type II diabetic patients diagnosed recently. Delay of gastric emptying in diabetic patients may provide a unique or adjunctive approach to the treatment of type II diabetes.

Reduced postprandial blood glucose levels in recently diagnosed non-insulin-dependent diabetics secondary to pharmacologically induced delayed gastric emptying

In a previous study we demonstrated that patients with recently diagnosed non-insulin-dependent diabetes mellitus (NIDDM) had significantly increased gastric emptying rates of glucose solutions compared with those of nondiabetic sex- and age-matched controls. This finding of rapid gastric emptying contrasts with the delayed gastric emptying often exhibited as a late manifestation of diabetes mellitus that is attributed to autonomic neuropathy. The purpose of this study was to determine, in seven of the patients previously studied, whether (1) an intravenous infusion of cholecystokinin-8 (CCK-8) would delay the gastric emptying of a liquid glucose meal and, if so, (2) whether the delay in gastric emptying would result in reduced postprandial blood glucose concentrations due to prolongation of the absorption of the glucose in the liquid meal. Each patient underwent two separate gastric emptying studies, one during a saline infusion and one during a CCK-8 infusion. Blood samples were obtained at 15-min intervals for measurement of glucose, insulin, CCK-8, and gastric inhibitory polypeptide (GIP) concentrations. The average gastric half-emptying time was 41 min with the saline infusion and 94 min with the CCK-8 infusion (P = 0.0042). The average glucose concentration over the 2-hr period following glucose ingestion was 17.1 mmol/liter with the saline infusion and 14.0 mmol/liter with the CCK-8 infusion (P = 0.0073). The average glucose excursion value over the 2-hr period was reduced from 5.6 mmol/liter to 3.7 mmol/liter with the CCK-8 infusion (P = 0.0550).(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid gastric emptying of an oral glucose solution in type 2 diabetic patients

Gastric emptying of a liquid glucose meal was measured with scintigraphic techniques in nine recently diagnosed Type 2 diabetic patients and nine sex- and age-matched nondiabetic control subjects. Seven of the nine Type 2 diabetic patients were receiving oral hypoglycemic therapy which was discontinued the evening prior to the study. The other two diabetic patients were taking no medication. The average gastric half-emptying time was 33.6 min (s.e.m. = 3.2) for the diabetic patients and 64.6 min (s.e.m. = 4.2) for the nondiabetic controls (p = 0.0005). These measurements indicate rapid gastric emptying in Type 2 diabetic patients which may contribute to worsening of glucose control in these patients.

Use of a more physiologic oral glucose solution during testing for gestational diabetes mellitus

A lower osmolar oral glucose solution (50 g glucose in 450 mL fluid, 0.62 mol/L) was administered in addition to the standard hyperosmolar oral glucose solution (100 g glucose in 300 mL fluid, 1.85 mol/L) for oral glucose tolerance testing 1 week apart to 102 pregnant women. The standard oral glucose solution creates delayed gastric emptying and is associated with frequent nausea and vomiting. Results using the modified, lower osmolar glucose solution, when compared to the standard hyperosmolar glucose solution showed (1) statistically equivalent glucose excursion values 30 minutes after ingestion, (2) statistically significant decreased plasma glucose values greater than or equal to 60 minutes, (3) no statistically significant difference in insulin excursion values 30 minutes after ingestion, (4) equal area under the curve for glucose at 30 minutes using either solution, and (5) a markedly decreased incidence of nausea and vomiting. These data suggest that the modified, lower osmolar glucose solution empties rapidly from the stomach and allows the glucose to be absorbed and enter the peripheral circulation in an expeditious manner.

Toxicity of a family from vacuumed mercury

A family of four developed toxic blood levels of mercury after the mother vacuumed a spilled jar of liquid mercury from a closet in their apartment. The youngest son developed severe thrombocytopenia which was initially diagnosed as idiopathic thrombocytopenic purpura secondary to viral illness. A possible association between acute mercury toxicity and idiopathic thrombocytopenic purpura has not been previously reported. Chelation therapy with penicillamine for the older child was administered soon after toxic blood mercury levels were known by the physician. Because thrombocytopenia has been reported to occur in up to 5% of patients receiving penicillamine therapy, the younger child was treated with dimercaptosuccinic acid. The mother was also treated with dimercaptosuccinic acid. The father received dimercaprol therapy. The toxic effects and rationale for now outdated therapeutic uses of mercury are discussed.

Occult metastatic mesothelioma--diagnosis by fine-needle aspiration. A case report

Fine-needle aspiration biopsy of an enlarged right axillary lymph node was performed on a 33-year-old woman with Ebstein's cardiac anomaly. Microscopic examination of the cytologic material revealed large discohesive cells with abundant pale cytoplasm, "ruffled" cytoplasmic borders, and prominent central nucleoli. Immunocytochemical analysis of the aspirate confirmed the mesothelial origin of these cells and prompted the diagnosis of metastatic mesothelioma. Autopsy examination revealed a large pericardial mesothelioma with metastases to mediastinal and axillary lymph nodes. This case report demonstrates the usefulness of fine-needle aspiration biopsy in the diagnosis of metastatic mesothelioma.

Eye injuries with metal missiles presenting to an emergency center: a three year study

The authors retrospectively evaluated 33 eye injuries due to metal missiles in 31 patients presenting to our emergency center over the last 3 years. Injuries occurred most frequently when the patients were grinding metal or working on their cars. The type of metal involved in the injury often dictates the type of ophthalmic reaction that will occur. A discussion of intraocular metallic foreign bodies with an emphasis on electroretinograms and metal analysis is presented.

Linear gastric emptying of hyperosmolar glucose solutions

We performed a total of 12 gastric emptying studies on 6 normal subjects with a hyperosmolar (1.85 mol/l) 400-kcal glucose solution commonly used for diagnosing diabetes and a more dilute (0.62 mol/l) 200-kcal glucose solution. The gastric half-emptying time was greatly prolonged with both glucose solutions; 107 min for the (1.85 mol/l) 400-kcal glucose solution compared to 66 min for the more dilute (0.62 mol/l) 200-kcal glucose solution. Although the 200-kcal glucose solution contained one-half the amount of glucose (50 g) compared to the 400-kcal solution (100 g), the blood glucose values obtained during a 2-hr period were only slightly lower with the former solution. This study demonstrates significantly delayed gastric emptying of glucose solutions in normal subjects and a linear pattern of gastric emptying formerly associated only with solid meals.

Accuracy of common drug screen tests

Forty consecutive urine specimens, obtained from patients seen in the emergency center, positive for either cocaine and/or marijuana, were analyzed using five methods of analysis. A new latex agglutination inhibition assay, Abuscreen OnTrak, (Roche Diagnostic Systems, Nutley, NJ), was compared with four other drug abuse assays: mass spectrometry, (Hewlett-Packard Co, Richardson, TX); an automated homogeneous enzyme immunoassay technique, ETS System, (Syva Co, Palo Alto, CA); a manual enzyme multiplied immunoassay technique; EMIT-st, (Syva); and a fluorescence polarization immunoassay, TDx, (Abbott Laboratories, Chicago, IL). For statistical purposes, mass spectrometry was the reference point for the presence or absence of a specific substance. All instrument sensitivities, with the exception of mass spectrometry, were set with the same "cut off" point of 100 micrograms/L for marijuana and 300 micrograms/L for cocaine and its metabolites. Efficiency in the detection of cocaine and its metabolites was 95% by all methods. Efficiency for the detection of marijuana and its metabolites ranged from 70% (Roche's OnTrak) to 90% (Syva's ETS). Simple to use, assays of minimal cost are presently available for rapid, accurate drug of abuse screening.

Fine needle aspiration cytology of malignant melanoma of soft parts. Report of two cases

Two cases of malignant melanoma of soft parts were diagnosed by fine needle aspiration (FNA) biopsy. One case involved the right thumb of a 22-year-old woman; the other involved a submental mass in a 36-year-old man who had been previously diagnosed as having malignant melanoma of soft parts. The FNA smears showed discohesive polygonal or oval and fusiform cells with eccentric nuclei, irregular nuclear chromatin and prominent nucleoli. FNA cell block sections contained polygonal or fusiform cells with clear cytoplasm, eccentrically placed nuclei and prominent nucleoli. Ultrastructural and immunocytochemical studies on aspirated material supported the diagnosis of malignant melanoma.

Revision of the oral glucose tolerance test: a pilot study

Nausea and vomiting have been recurrent problems with the oral glucose tolerance tests (OGTT) used to diagnose diabetes. We believe the nausea is associated with delayed gastric emptying caused by the high osmolarity of the glucose solution. In our pilot study, both the "standard" 100-g glucose OGTT and our new modified (lower osmolar) glucose solution were evaluated. Considerably delayed gastric emptying (along with severe nausea) was consistently noted with the standard OGTT. No nausea and a much more rapid gastric emptying time were recorded when the modified glucose solution was administered. We were able to diagnose diabetes (by using Wilkerson's point system) when our modified OGTT was administered to type 2 diabetics. We plan to develop a more physiological, more reproducible, and better tolerated OGTT to diagnose diabetes more accurately in the general population.

Revision of the oral glucose tolerance test: a pilot study

Nausea and vomiting have been recurrent problems with the oral glucose tolerance tests (OGTT) used to diagnose diabetes. We believe the nausea is associated with delayed gastric emptying caused by the high osmolarity of the glucose solution. In our pilot study, both the "standard" 100-g glucose OGTT and our new modified (lower osmolar) glucose solution were evaluated. Considerably delayed gastric emptying (along with severe nausea) was consistently noted with the standard OGTT. No nausea and a much more rapid gastric emptying time were recorded when the modified glucose solution was administered. We were able to diagnose diabetes (by using Wilkerson's point system) when our modified OGTT was administered to type 2 diabetics. We plan to develop a more physiological, more reproducible, and better tolerated OGTT to diagnose diabetes more accurately in the general population.

Fine needle aspiration cytology of metastatic malignant schwannoma. A case report

A metastatic malignant schwannoma diagnosed by fine needle aspiration (FNA) biopsy in a 56-year-old man is reported. Cytologic examination of smears and cell blocks prepared from aspirates of a vertebral mass suggested the presence of metastases from a previously excised malignant schwannoma on the right leg. Electron microscopic and immunocytochemical studies on the aspirate supported the diagnosis, as did the patient's clinical history and previous pathology and the radiographic demonstration of metastatic lesions in the lung. The cytologic findings (cells with oval-to-spindled nuclei and ill-defined cellular borders suspended within a delicately fibrillar eosinophilic matrix) are discussed in light of the histologic diversity of this lesion and the problems of distinguishing it from other sarcomas. The ability to diagnose metastatic malignant schwannoma by FNA emphasizes the value of this technique.

Serum creatine kinase isoenzyme BB is a poor index to the size of various brain lesions

We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.

Serum creatine kinase isoenzyme BB is a poor index to the size of various brain lesions

We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.

Clinical and analytical evaluation of different methods for measurement of creatine kinase isoenzyme MB

We evaluated the clinical and analytical performance of the new immunochemiluminometric assay (ICMA; Ciba Corning) for measurement of creatine kinase isoenzyme MB (CK-MB), and compared it with three other methods: immunoradiometric assay (IRMA; International Immunoassay Labs); immunoinhibition assay (Seradyn); and an immunoinhibition/column method (Du Pont). Intra-test precision for all kits was good. We evaluated 32 patients' samples by all four methodologies. Only one of the four methods (aca, Du Pont) showed evidence of linearity. Efficiency in the diagnosis of myocardial injury in our study ranged from 53% (Seradyn) to 96% (Du Pont). We evaluated serial specimens from 20 separate patients by the IRMA and the ICMA to determine whether myocardial injury could be diagnosed earlier by the ICMA. In patients with acute myocardial infarction, the ICMA displayed positive values earlier and longer than the IRMA, suggesting that the ICMA is suited for screening for myocardial damage in hospitalized patients.

Clinical and analytical evaluation of different methods for measurement of creatine kinase isoenzyme MB

We evaluated the clinical and analytical performance of the new immunochemiluminometric assay (ICMA; Ciba Corning) for measurement of creatine kinase isoenzyme MB (CK-MB), and compared it with three other methods: immunoradiometric assay (IRMA; International Immunoassay Labs); immunoinhibition assay (Seradyn); and an immunoinhibition/column method (Du Pont). Intra-test precision for all kits was good. We evaluated 32 patients' samples by all four methodologies. Only one of the four methods (aca, Du Pont) showed evidence of linearity. Efficiency in the diagnosis of myocardial injury in our study ranged from 53% (Seradyn) to 96% (Du Pont). We evaluated serial specimens from 20 separate patients by the IRMA and the ICMA to determine whether myocardial injury could be diagnosed earlier by the ICMA. In patients with acute myocardial infarction, the ICMA displayed positive values earlier and longer than the IRMA, suggesting that the ICMA is suited for screening for myocardial damage in hospitalized patients.

A commercial enzyme immunoassay method (EMIT) compared with liquid chromatography and bioassay methods for measurement of chloramphenicol

A new enzyme immunoassay method (EMIT; Syva Co.) was compared with conventional high-performance liquid chromatography (HPLC) and agar-diffusion bioassay methods for measurement of chloramphenicol in human serum. Forty-nine serum samples were assayed by each of the three methods. Excellent correlation was observed between values by EMIT and by the two conventional methods (r = 0.986 and 0.961). Precision was acceptable (CV less than 5%) with EMIT. Assay of samples containing chloramphenicol glucuronide and chloramphenicol succinate demonstrated that EMIT recognizes only the biologically active (base) form of the drug. The capability to test serum samples as small as 0.2 mL, adaptation to widely available instrumentation, and provision of rapid results are principal advantages of the EMIT method for routine chloramphenicol measurements.

A commercial enzyme immunoassay method (EMIT) compared with liquid chromatography and bioassay methods for measurement of chloramphenicol

A new enzyme immunoassay method (EMIT; Syva Co.) was compared with conventional high-performance liquid chromatography (HPLC) and agar-diffusion bioassay methods for measurement of chloramphenicol in human serum. Forty-nine serum samples were assayed by each of the three methods. Excellent correlation was observed between values by EMIT and by the two conventional methods (r = 0.986 and 0.961). Precision was acceptable (CV less than 5%) with EMIT. Assay of samples containing chloramphenicol glucuronide and chloramphenicol succinate demonstrated that EMIT recognizes only the biologically active (base) form of the drug. The capability to test serum samples as small as 0.2 mL, adaptation to widely available instrumentation, and provision of rapid results are principal advantages of the EMIT method for routine chloramphenicol measurements.

Primary lymphocutaneous Nocardia brasiliensis infection: three case reports and a review of the literature

The occurrence of human nocardiosis is increasing in both immunocompetent as well as immunosuppressed patients. We report three rare cases of primary lymphocutaneous Nocardia brasiliensis infection. The mode of inoculation in each case was that of a puncture wound that occurred 1-3 wk prior to the development of the clinically apparent infections. The original clinical diagnosis was erroneous in each case. A review of 16 previously reported cases is presented as well as a discussion of appropriate medical therapy.

Creatine kinase MB in cases of skeletal muscle trauma

Fifty-eight patients admitted through our emergency room with severe skeletal muscle injury but no obvious cardiac contusions were evaluated for creatine kinase isoenzyme MB (CK-MB). When such patients show an above-normal value for total CK, it is a question of whether or not myocardial injury has been sustained along with skeletal muscle injury when (a) there are no obvious chest contusions or (b) the patient is unconscious and unable to complain of chest pain. Whenever there is doubt concerning the cardiac status of a patient, lactate dehydrogenase (LD) isoenzymes, serial electrocardiograms, and CK isoenzymes are ordered. Our study revealed that serum of 8.6% of the trauma victims had CK-MB values exceeding 5.0 EU/L (reflecting abnormal CK-MB concentrations) as part of their increased total CK. All patients had normal electrocardiographic patterns along with negative results for LD isoenzymes; none had sustained any demonstrable myocardial injury. The CK-MB value must be interpreted together with the total CK value for appropriate diagnosis in patients with skeletal muscle trauma.

Creatine kinase MB in cases of skeletal muscle trauma

Fifty-eight patients admitted through our emergency room with severe skeletal muscle injury but no obvious cardiac contusions were evaluated for creatine kinase isoenzyme MB (CK-MB). When such patients show an above-normal value for total CK, it is a question of whether or not myocardial injury has been sustained along with skeletal muscle injury when (a) there are no obvious chest contusions or (b) the patient is unconscious and unable to complain of chest pain. Whenever there is doubt concerning the cardiac status of a patient, lactate dehydrogenase (LD) isoenzymes, serial electrocardiograms, and CK isoenzymes are ordered. Our study revealed that serum of 8.6% of the trauma victims had CK-MB values exceeding 5.0 EU/L (reflecting abnormal CK-MB concentrations) as part of their increased total CK. All patients had normal electrocardiographic patterns along with negative results for LD isoenzymes; none had sustained any demonstrable myocardial injury. The CK-MB value must be interpreted together with the total CK value for appropriate diagnosis in patients with skeletal muscle trauma.

Fine-needle aspiration biopsy of mycosis fungoides presenting as an ulcerating breast mass

A patient with previously diagnosed Hodgkin's disease presented with ulcerating lesions on her scalp and breast. Fine-needle aspiration of the breast lesion revealed convoluted cells consistent with mycosis fungoides. Review of the patient's previously obtained lymph node biopsy specimens revealed a diagnosis of mycosis fungoides rather than Hodgkin's disease. Better communication between hospitals, pathologists, and clinicians may have prevented the erroneous original diagnosis of Hodgkin's disease in this patient.

Nocardial osteomyelitis: a case report and review of the literature

The occurrence of human nocardiosis is increasing in both immunocompetent as well as immunosuppressed patients. A 63-yr-old male construction worker presented with complaints of left hip pain and rapidly enlarging masses on his left neck and chest. He had been treated for a pneumonia of unknown etiology 3 mo prior to admission. A debridement of the left femur was performed and the curetted material was positive for Nocardia asteroides. Osteomyelitis due to the hematogenous spread of Nocardia asteroides is rare, but will undoubtedly be seen with increasing frequency. The literature, as well as 11 reported cases of the hematogenous spread of this organism, are reviewed.