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Biomedical subjects

J L Doppman

Publications and source records attributed to J L Doppman.

At least 379 records · Page 21Linked to original sources
PubMed1977

Computed tomography of spinal cord arteriovenous malformations.

Computed tomography (CT) of the spine after intravenous contrast enhancement has been used in 4 patients with arteriovenous malformation (AVM) of the spinal cord. The enlarged, contrast-filled vessels constituting the malformation are visualized on CT scans. There was good correspondence between CT and selective angiography. CT may be a useful screening and follow-up method for AVM of the spinal cord and a safe procedure for assessing the results of therapy.

Angiography↗
PubMed1977

Computed tomographic demonstration of hepatic tumor with the aid of intravenous iodinated fat emulsion. An experimental study.

Computed tomography showed improved visualization of carcinogen-induced hepatoma in monkeys following intravenous injection of an experimental contrast material AG 60-99; selective opacification of the liver and spleen was accomplished with a dose of greater than or equal to 0.1 ml/kg, a fraction of the dose used in conventional x-ray tomography. This marked reduction was made possible by the improved density resolution of the CT scanner. This may be the first organ-specific contrast material intended primarily for use with CT scanners.

Animals↗
PubMed1977

Computed tomography in the diagnosis of subcapsular and perirenal hematoma.

Six patients are described in whom subcapsular and perirenal hematomas were demonstrated by computed tomography. This new diagnostic tool provided a rapid noninvasive means of visualizing the hematoma, its extent, location, and relationship to renal parenchyma. Serial examinations were used to follow progress of the hematomas toward resolution. Correlation is made with conventional rediography, angiography, and gray scale ultrasound.

Adolescent↗
PubMed1977

Experimental intraoperative localization of retained intracerebral bone fragments using transdural ultrasound.

Precise intraoperative localization of retained bone fragments and foreign bodies avoids extensive brain disseciton, cerebral edema, damage to vital structures, incomplete debridement, and prolonged surgical procedures. Such localization after head trauma is often hampered by cerebral distortion, previous incomplete debridement, fragment migration, and surgical draping. Our intraoperative technique of transdural A-scanning using aspiration-biopsy transducers precisely localized 3.5-mm fragments without damage to underlying cortical tissue and vessles. Transdural A-mode echoencephalography was found to be more reliable for intracerebral depth estimations but epidural B-mode sonography was more useful for determining the size of fragments. Transdural ultrasound offered an intraoperative alternative to stereotaxic localization of retained bone fragments in experimental head trauma.

Animals↗
PubMed1977

Absence of vasospastic response of the anterior spinal artery to subarachnoid blood.

Autologous blood (0.3 to 5.0 ml) was introduced into the lumbar subarachnoid space of nine monkeys. Serial spinal cord arteriography was performed at frequent intervals over a 24-hour period. Magnification techniques permitted direct measurement of the anterior spinal artery and posterior spinal vein. Neither immediate nor delayed spasm was observed in any animal. Similar techniques have routinely produced spasm of intracranial arteries in our laboratory.

Animals↗
PubMed1977

Computed tomography in the diagnosis, staging, and management of abdominal lymphoma.

Computed tomography (CT) was performed in 30 patients with histologically proven lymphoma within 1 week of bipedal lymphangiography to assess the relative sensitivity of each diagnostic modality in defining the location and extent of lymphomatous involvement. In 11 patients, lymphangiography significantly underestimated the volume of the periaortic nodal mass and its cephalad extent. In 13 additional patients, CT defined significant renal hilar, mesenteric, splenic hilar, and splenic pulp extension not visualized by lymphangiography. Sequential CT scans performed in five patients proved an excellent way to follow therapeutic response. CT scans were also performed in 26 patients with nonlymphomatous intraabdominal malignancy within a week of lymphangiography. It was of value in staging patients with carcinoma of the testis but was not overly helpful in patients with carcinoma of the ovary or pancreas.

Abdominal Neoplasms↗
PubMed1977

Whole body computed tomography in the diagnosis of abdominal and thoracic malignancy: review of 600 cases.

Whole-body computed tomography (CT) was performed on 600 patients with known or suspected malignancy at the National Institutes of Health. This new diagnostic modality utilizes a finely columnated X-ray source mounted opposite a computer-linked detector bank to generate anatomic cross-sectional images of the body part being scanned. CT proved valuable in defining many pathologic processes and was, at times, deemed the only test short of exploratory surgery that yielded diagnostic information. This latter benefit was most acutely emphasized in lesions affecting the retroperitoneum, adrenal glands, pelvis, liver, and immediate subpleural pulmonary parenchyma.

Abdominal Neoplasms↗
PubMed1976

Elevated plasma proglucagon-like component with a glucagon-secreting tumor. Effect of streptozotocin.

To determine the character of the glucagon secretion and its modification by streptozotocin, were studied the plasma of a patient with recurrent pancreatic alpha-cell carcinoma. The plasma immunoreactive glucagon level before treatment of 4.80 ng per milliliter. Biogel column separation of the plasma immunoreactive glucagon revealed four components; the predominant component had a molecular weight of 9000 daltons and was designated as proglucagon-like. This fraction constituted 60 to 90 per cent of the total circulating immunoreactive glucagon, and had a biologic activity of 32 percent of that of an immunoequivalent amount of normal (porcine) pancreatic glucagon. After treatment with streptozocin (1.5 g per square meter) the plasma immunoreactive glucagon level decreased to 0.24 ng per milliliter. Treatment was accompanied by a marked reduction in the proglucagon-like component and the appearance of pancreatic glucagon (molecular weight of 3500 daltons) as the major post-therapy fraction. These findings support the use of streptozotocin in the management of unresectable glucagon-secreting tumors.

Adenoma, Islet Cell↗
PubMed1976

Segmental renal vein renin assay and segmental nephrectomy for correction of renal hypertension.

Selective segmental renal vein catheterization was used to obtain venous blood samples for renin assay. With this technique a localized source of hypersecretion of renin was identified in 2 patients. Using samples from the main renal veins we found no significant difference in renin activity and, therefore, the etiology of the hypertension in these 2 patients would have been missed. Segmental nephrectomy resulted in a cure of the hypertension in both patients who were followed for a minimum of 14 months.

Adolescent↗
PubMed1976

Intravenous hepatosplenography. Experiment evaluation of a new contrast material.

A new, lipoid-based experimental contrast material (AG 60-99) was intravenously infused into 29 rhesus monkeys. The injections resulted in dense hepatosplenograms, preserving diagnostic quality for over 24 hours, and enabling routine utilization of tomography. This technique is capable of demonstrating simulated hepatic masses as small as 5 mm in diameter in vivo. Limited histopathologic and toxicity studies showed no serious or lasting toxic manifestations from AG 60-99 and none of the animals died from it. AG 60-99 is felt to be potentially useful in the radiographic detection of early metastic or lymphomatous involvement of the liver and spleen.

Animals↗
PubMed1976

Paraspinal muscle infarction. A painful complication of lumbar artery embolization associated with pathognomonic radiographic and laboratory findings.

Severe, prolonged back pain was observed in 2 patients following lumbar artery embolization with Gelfoam for angiomatous spinal lesions. Dense, persistent staining of the paravertebral muscles with a characteristic striated pattern and elevated levels of creatine phosphokinase suggested muscle infarction and necrosis. Similar angiographic and laboratory findings were reproduced in monkeys following arterial embolization with Gelfoam.

Adult↗
PubMed1976

Biochemical and histochemical studies of biogenic amines in spinal cord trauma.

Highly sensitive enzymatic assays, microdissection techniques, and histochemical methods were used to investigate the effects of blunt trauma on rabbit spinal cord serotonin, norepinephrine, and dopamine concentrations. Within 5 minutes after trauma, norepinephrine and serotonin in gray matter decreased considerably at the lesion center. In white matter, norepinephrine decreased or was unchanged, but at the lesion edges serotonin increased. No changes in dopamine concentration were detected. Substantial changes in monoamines do occur after spinal cord trauma and serotonin may play a role in injury development.

Animals↗
PubMed1976

Angiographic changes following acute spinal cord compression: an experimental study in monkeys.

Acute paraplegia was produced in monkeys by abruptly inflating a balloon catheter within the epidural space. The arteriographic and epidural venous changes following such trauma were serially evaluated. Spinal-cord arteriograms following cord injury remained normal during an acute (four-hour) follow-up. Serial epidural venograms demonstrated obstruction of epidural veins within four hours at the site of contusion in less than half of the animals studied. Neither spinal arteries nor epidural showed consistent diagnostic changes following trauma due to acute epidural compression.

Acute Disease↗
PubMed1976

Increased serum calcitonin levels in bronchogenic cancer.

A study of 26 men with bronchogenic cancer demonstrated high serum calcitonin levels in 62 percent (16). Levels were particularly high in patients with small-cell cancer and adenocarcinoma. Two varieties of hypercalcitonemia have been encountered: (1) ectopic hypercalcitonemia, in which the hormone is secreted by the tumor, and (2) thyroidal hypercalcitonemia, in which the high values emanate from the thyroid gland. In several patients, serum calcitonin levels decreased following therapy for the cancer. Further studies are needed to evaluate the diagnostic value and clnical utility of serum calcitonin levels as a marker substance in bronchogenic cancer.

Adenocarcinoma↗
PubMed1976

Angiographic study of the effect of laminectomy in the presence of acute anterior epidural masses.

Laminectomies were performed in 16 monkeys to decompress simulated acute epidural masses in front of the spinal cord. When decompression restored normal arterial and venous hemodynamics, the monkeys were neurologically intact in spite of considerable mechanical distortion of the cord. When either the anterior spinal artery or the posterior spinal vein remained obstructed following laminectomy, the monkeys were paraplegic. Acute anterior epidural masses larger than 4 mm in diameter could not be adequately decompressed via the posterior approach. Only minor posterior displacement of the cord is observed following laminectomy in the presence of large anterior masses.

Angiography↗
PubMed1976

Atypical radiographic features in Pneumocystis carinii pneumonia.

In a review of clinical, pathologic, and radiographic findings from 30 patients with confirmed pneumocystis pneumonia, the disease presented a typical radiographic picture of acute bilateral perihilar and basilar infiltrate progressing to diffuse alveolar consolidation within 3-5 days and unassociated with adenopathy or pleural changes in 13 patients. However, the incidence of atypical radiographic features was appreciable (17 of the 30 patients showed at least one atypical finding) and, in addition, few radiographic findings completely excluded the diagnosis of pneumocystis infection.

Biopsy↗
PubMed1976

Saline lavage: a rapid, effective, and acceptable method for cleansing the gastrointestinal tract.

The standard preparation for cleansing the gastrointestinal tract for diagnostic studies such as barium enema usually involves dietary restrictions, purgatives, and cleansing enemas. This preparation is time consuming, often uncomfortable for the patient, and frequently unsuccessful. In this study, we examined the efficacy of saline lavage (without dietary restrictions or cleansing enemas) as a gentle, alternative method for cleansing the bowel, and compared lavage to the standard castor oil method of bowel preparation. Lavage cleansing was preferred by 75% of patients who had previously experienced a castor oil preparation. Although 11% of patients could not consume an adequate (4-liter) lavage volume, there was no significant difference in preparation success rate between the remaining lavage patients and the castor oil patients. Total preparation time for lavage (3 +/- 1 hr) was 60% less than for castor oil. The anticipated dehydration produced by castor oil and the hydration produced by lavage were confirmed. No significant changes were noted, however, in serum electrolytes with either method of preparation. Additional early studies are promising for the lavage method when used in inflammatory bowel disease patients and as a cleansing preparation for colonoscopy.

Barium Sulfate↗