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Biomedical subjects

J L Doppman

Publications and source records attributed to J L Doppman.

At least 451 records · Page 25Linked to original sources
PubMedDate not supplied

Intraarterial calcium stimulation test for detection of insulinomas.

Occult insulinomas are adenomas not visualized by routine preoperative imaging studies, including ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and arteriography. Reliance for detecting occult insulinomas has been placed on portal venous sampling (PVS), a sensitive (> 75%) but invasive procedure that requires considerable experience to enable sampling of small veins about the pancreatic head. For the past 2 years we have attempted to localize insulinomas by stimulating the release of insulin with a selective intraarterial injection of calcium gluconate and sampling for insulin gradients in the hepatic veins. This study replaces PVS by indicating the region of the pancreas within which the tumor lies, although, like PVS, it does not directly visualize the tumor. Our experience in 9 patients with surgically proved insulinomas is reviewed, comparing the results with PVS as well as with US, CT, MRI, and arteriography.

Adult↗
PubMedDate not supplied

Undescended parathyroid adenoma: an important etiology for failed operations for primary hyperparathyroidism.

From July, 1982 to April, 1989, a total of 145 patients with persistent or recurrent primary hyperparathyroidism (HPT) were explored; 105 patients had an adenoma as the cause of HPT, and in 9 patients (9%), the abnormal gland was located at or superior to the carotid bifurcation (undescended parathyroid gland). These 9 patients had 14 prior explorations for HPT including 4 median sternotomies and 5 thyroidectomies. Each of the 9 patients was symptomatic of HPT, including bone disease in 8 of 9 patients and renal stones in 4 of 9 patients. Seven patients had an undescended parathyroid adenoma correctly localized preoperatively by ultrasound (n = 5), angiography (n = 5), venous sampling (n = 1), or computed tomography scan (n = 4). These 7 patients with accurate preoperative localization were explored by an incision anterior to the sternocleidomastoid muscle high in the neck that avoided the previous operative field and allowed rapid resection of the parathyroid adenoma. In the 2 patients who did not have accurate preoperative localization, the undescended adenoma was found after long tedious exploration including median sternotomy in 1 patient. Each patient (n = 9) who had an undescended parathyroid adenoma removed was cured of hypercalcemia, and 5 patients required postoperative 1,25-dihydroxy vitamin D3 for hypocalcemia. We conclude that undescended parathyroid adenomas comprise a significant proportion (9%) of adenomas during reoperations for persistent HPT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMedDate not supplied

Percutaneous aspiration for hormone levels in the diagnosis of functioning endocrine tumors.

Percutaneous aspiration to measure hormone levels in suspected functioning endocrine adenomas has been performed in 23 suspected cases of parathyroid adenomas, 7 cases of ACTH-producing thoracic carcinoid tumors, and 1 case of gastrinoma. When tumors secrete hormone or peptide markers, the biochemical assay can replace cytology to identify the lesion with greater specificity and at less expense.

ACTH Syndrome, Ectopic↗
PubMedDate not supplied

Pulse-spray treatment of subclavian and jugular venous thrombi with recombinant tissue plasminogen activator.

PURPOSE: To evaluate the efficacy of recombinant tissue plasminogen activator (rtPA) injected by pulse-spray in lysing subclavian and jugular venous thrombi. MATERIALS AND METHODS: Twelve patients with symptomatic, venogram-confirmed, occlusive thrombi of the subclavian-axillary or jugular veins were treated with one or two daily 15-minute injections of rtPA delivered directly into the clots with pulse-spray catheters. Twenty-four hours after each treatment, repeated venograms were obtained to assess venous patency. Successful thrombolysis was defined as antegrade flow through the previously occluded segments with minimal collateral venous flow. Continued patency was assessed with repeated venograms obtained after 1 and 2 months of oral anticoagulation. RESULTS: The 15-minute rtPA injections successfully lysed thrombi in eight of the 12 patients. Hypofibrinogenemia developed in only one patient. The technique had a high success rate with thrombi less than 2 weeks old (seven of eight) regardless of the length of the clot, but had limited success with thrombi more than 2 weeks old (one of four). Continued patency over a 2-month interval was documented in four of the eight patients whose thrombi were successfully lysed. However, patency could be maintained in only one of the four patients who retained a venous access device in the treated vein. CONCLUSION: Pulse spray rtPA is an effective, safe, and practical alternative to continuous infusions of thrombolytic agents to treat upper extremity venous thrombi.

Adult↗
PubMedDate not supplied

Calcitonin levels in thyroid-vein blood of man.

Radioimmunoassay determinations of calcitonin from blood samples obtained by selective venous catheterization have demonstrated a large peripheral to thyroid vein gradient for this hormone in both normocalcemic and hypercalcemic persons. These fingings indicate that in fasting humans the thyroid gland maintains peripheral levels of calcitonin by actively secreting the hormone, and are consistent with the suggestion that the role of plasma calcitonin is of physiologic significance.

Adult↗
PubMedDate not supplied

The mechanism of ischemia in anteroposterior compression of the spinal cord.

Intraspinal balloons were used in monkeys to simulate lateral and posterior epidural masses. Posterior masses flatten the cord and occlude the central vasculature while lateral balloons have less effect on central cord perfusion. The significance of these findings in relation to spondylotic myelopathy is discussed.

Animals↗