Biomedical subjects
P W Blue
Publications and source records attributed to P W Blue.
Effects of verapamil and diltiazem on gastric emptying in normal subjects.
It has been suggested that calcium-channel blockers may delay gastric emptying by inhibiting gastric smooth muscle contraction. Most reports in man, however, reveal no significant delay in gastric emptying after using nifedipine; other calcium-channel blockers have not been studied in humans to date. We studied the effects of verapamil and diltiazem on solid-phase gastric emptying in 10 healthy volunteers. Each subject underwent a radionuclide gastric emptying determination (1) without preadministered medication, (2) after verapamil 80 mg orally every 6 hr for 10 doses, and (3) after diltiazem 60 mg by mouth given as one dose. Results revealed no significant difference in gastric emptying rates after pretreatment with verapamil or diltiazem when compared with no premedication (P greater than 0.37). We conclude that verapamil and diltiazem do not significantly delay gastric emptying in normal subjects. These data may be of clinical significance when prescribing calcium-channel blockers to patients with diseases associated with altered gastric emptying.
Reduced bone-mineral content is a risk factor for hip fractures.
To evaluate skeletal osteopenia as a risk factor for hip fractures, we measured bone-mineral content in 18 postmenopausal women (aged 50 to 85 years) within 5 days of sustaining a nontraumatic hip fracture. We compared these findings to those in 50 women without a hip fracture who were matched for age, postmenopausal years, height, and weight to the study participants. With the use of dual-photon absorptiometry, the hip fracture patients were found to have a significantly reduced mean bone-mineral content (P less than .005) at three sites in the unaffected hip and a marginally lower mean value (P less than .057) in the lumbar spine as compared to the controls. Other findings in the fracture group included a history of little physical activity, diminished visual acuity, and a somewhat high prevalence of psychiatric/organic brain disorders. Reduced bone mass is an important risk factor for hip fractures. However, other conditions such as physical inactivity, reduced visual acuity, and cognitive impairment may also affect the tendency to fall and/or the ability to cushion the impact of a fall and thus further increase the risk of fracture occurrence.
The need for oblique or lateral ventilation images in the diagnosis of pulmonary embolism.
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Methods for measuring GFR with technetium-99m-DTPA: an analysis of several common methods.
Several commonly used scintigraphic methods of GFR measurement were evaluated. Forty-three adult patients with a wide range of ages and renal function were studied. The two-sample plasma method of Russell and the urinary method of Jackson were the most accurate methods overall. The one-sample plasma method of Russell, the volume of distribution method of Fawdry, and a terminal slope method were less reliable, especially at low (0-60 ml/min) GFRs. The renal uptake method of Gates correlated poorly to the standards at all GFR levels even when corrected for body surface area or blood volume. The Russell two point and Jackson urinary GFR's can be used as complementary techniques and are recommended as primary methods of scintigraphic GFR determination.
Lymphocele: the spectrum of scintigraphic findings in lymphoceles associated with renal transplant.
Lymphocele is a well recognized complication of renal transplant surgery. We performed a retrospective review of 305 renal transplant patients with over 2,500 scintigraphic exams to describe the pattern of activity on technetium-99m-DTPA blood flow and dynamic imaging, and iodine-131-OIH studies. Diagnostic criteria for a lymphocele were ultrasonic evidence of a perirenal fluid collection and analysis of that fluid that demonstrated BUN, creatinine, and electrolytes similar to the patient's plasma. Scintigraphic findings were attributed to a lymphocele if abnormalities were in the same area as the ultrasound fluid collection. Scintigraphic findings attributable to lymphocele resolved in all patients following surgical drainage or peritoneal window placement. Six of the 11 documented lymphoceles demonstrated a cold defect on initial dynamic images that "filled in" to equal background activity and another exceeded background. Three cases showed a rim of increased activity surrounding the lymphocele ("rim sign").
Technetium-99m DTPA renal transplant imaging in the diagnosis of urinoma.
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Parathyroid subtraction imaging--pitfalls in diagnosis.
Since 1985 when parathyroid subtraction scintigraphy was presented in atlas form in this journal, the T1-201-Tc-99m computer subtraction studies have become more and more popular. Although the study has been quite accurate in localizing abnormal parathyroid pathology, the rate of false positive studies has been somewhat excessive, usually due to thyroid pathology. This atlas is an update of that previous work with the goal of presenting a scheme of interpretation that lessens the incidence of false positive studies as well as presenting many of the pitfalls in diagnosis of parathyroid disease.