David P. Shreiner

Impairment of gallbladder emptying in diabetes mellitus.

Individuals with diabetes mellitus are reported to have a twofold to threefold increase in the incidence of cholesterol gallstones. A frequently cited but unproven pathophysiologic mechanism for this phenomenon is reduced gallbladder muscle function, which results in stasis and allows for cholesterol gallstone crystal formation and gallstone growth. To date, gallbladder motor function has not been investigated in a well-characterized diabetic population. Therefore, using radionuclide cholescintigraphy, gallbladder filling and subsequent emptying produced in response to an infusion of the octapeptide of cholecystokinin in 30 diabetic patients and 20 control individuals were studied. No difference in any parameter used to assess gallbladder filling was demonstrated in the diabetics when compared with controls. In contrast, gallbladder emptying induced with cholecystokinin-octapeptide (20 ng/kg body wt . h) was reduced in diabetics compared with controls (55% +/- 5% vs. 74% +/- 4%, p less than 0.01). The peak emptying rate in the diabetics was also decreased (5.0% +/- 0.5% per minute) compared with the controls (7.0% +/- 0.6% per minute, p less than 0.02). The observed decreased gallbladder emptying found in diabetics was not related to obesity, type of diabetes, diabetic control, or presence or absence of peripheral neuropathy. The most severe impairment of gallbladder emptying occurred, however, in diabetics with an associated autonomic neuropathy. This subgroup demonstrated a significant reduction in the percentage of gallbladder emptying (40% +/- 8% vs. 62% +/- 5%, p less than 0.04) and the peak ejection rate (3.5% +/- 0.5% per minute vs. 5.6% +/- 0.6%, p less than 0.02) compared with the diabetics without autonomic neuropathy.

Detection of thrombopoietic activity in plasma by stimulation of suppressed thrombopoiesis

Rabbits in which thrombocytosis had been produced by five daily transfusions of platelet concentrates had suppressed endogenous thrombopoiesis, as reflected by decreased incorporation of selenomethionine-(75)Se ((75)SeM) into the circulating platelet mass. Rabbits in which endogenous thrombopoiesis had been suppressed by transfusion-induced thrombocytosis were used to detect thrombopoietic activity in rabbit plasma. Thrombopoietic activity was demonstrated in the plasma of both normal and thrombocytopenic donor rabbits. A dose response relationship was observed between the incorporation of (75)SeM into platelets and the dose of plasma administered. Infusion of 20-150 ml of plasma from thrombocytopenic donors increased the incorporation of (75)SeM into platelets from 52 to 107% above control values. A dose response effect also was seen after infusion of normal plasma, but normal plasma produced less effect than comparable doses of plasma from thrombocytopenic donors. Rabbits with transfusion-induced thrombocytosis appear to be more sensitive assay animals for the detection of thrombopoietic activity than animals with normal platelet counts. Changes in the rate of appearance and levels of (75)SeM may primarily indicate changes in platelet protein or platelet size and are apparently more sensitive indicators of the state of thrombopoiesis than are alterations in the numbers of circulating platelets. The results strongly support the concept of a humoral agent, i.e. thrombopoietin, that acts on megakaryocytes to regulate platelet production.

Ameloblastoma of the Mandible with Pulmonary Metastasis

A patient with ameloblastoma of the mandible with histologically confirmed pulmonary metastases 9 years after onset of tumor is described. The effectiveness of three chemotherapeutic agents (cyclophosphamide, methotrexate, Adriamycin), each given alone intravenously, were evaluated. Marked symptomatic improvement was noted with Adriamycin therapy. Ten previous cases of metastatic ameloblastoma are reviewed. The incidence of metastases cannot be predicted on the basis of histology. Three commonly discussed modes of metastasis are via hematogenous and lymphatic routes and the unusual mechanism of aspiration of tumor cells.

Left ventricular diastolic filling in patients with left ventricular dysfunction

The pattern of abnormal left ventricular diastolic filling and its specificity in coronary disease patients with severe left ventricular dysfunction has received little attention. We evaluated the left ventricular diastolic filling curve derived from gated blood pool scans in 21 normals, 61 coronary disease patients with ejection fractions less than or equal to 30%, and 51 congestive cardiomyopathy patients with ejection fraction less than or equal to 30%. The peak filling rate (PFR), peak ejection rate (PER), PFR/PER and the % stroke volume filled at 1/3 of diastole (%SV-1/3 DT) and at the end of the rapid filling period (%SV-RFP) were determined for each group. The PFR and PER were reduced in both coronary disease and congestive cardiomyopathy groups. The PFR/PER was increased in the coronary disease group (1.19 +/- 0.28) and congestive cardiomyopathy group (1.21 +/- 0.32) as compared to normals (0.93 +/- 0.20, P less than 0.001). A greater %SV-1/3 DT and %SV-RFP were noted in both coronary disease and congestive cardiomyopathy groups. Coronary disease and congestive cardiomyopathy patients with a mean pulmonary capillary pressure (PCP) greater than or equal to 18 mm Hg had a greater PFR/PER, %SV-1/3 DT, and %SV-RFP than patients with a PCP less than 18 mm Hg. An abnormal and nonspecific pattern of left ventricular diastolic filling is present in both coronary disease and congestive cardiomyopathy patients and is characterized by an increased PFR/PER, a greater %SV-1/3 DT, and a greater %SV-RFP. This pattern may be related to elevated PCPs.

Unsuspected purulent pericarditis detected by gallium-67 scanning: a case report.

A Ga-67 scan performed because of a suspected intraabdominal infection demonstrated marked pericardial uptake of the isotope instead, and thus provided the first clue to the diagnosis of purulent pericarditis. Susequent studies and surgery revealed an esophagopericardial fistula, gas in the pericardial sac, and purulent pericarditis casued by multiple bacteria. This report presents an unusual cause of pericardil uptake of Ga-67. The use of Ga-67 scanning to diagnose purulent pericarditis in the absence of typical clinical findings is illustrated.

Simplified count-based estimates of left ventricular volume.

Accurate count-based radionuclide estimates of left ventricular volume without the use of a blood sample have not been well described. Resting gated blood pool scans were obtained within 24 hours of catheterization in 31 patients (group 1), and simultaneously with thermodilution cardiac outputs in 29 other patients (group 2) at rest and during an induced-volume change (intervention). End-diastolic and end-systolic volumes were calculated from the single-plane angiogram in Group 1 and from the combination of thermodilution stroke volume and radionuclide ejection fraction in group 2. Excellent correlations were noted between scintigraphic counts and angiographic volumes (r = 0.964), between scintigraphic counts and thermodilution-derived volumes (r = 0.979), and between interventional scintigraphic counts and interventional thermodilutionderived volumes (r = 0.941). Thermodilution and scintigraphic volume changes during the intervention were well correlated (r = 0.85). Accurate count based estimates of left ventricular volume without a blood sample are feasible at rest and during an intervention.