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Biomedical subjects

M Kunnen

Publications and source records attributed to M Kunnen.

At least 109 records · Page 6Linked to original sources

Interactions of human cytomegalovirus with human fibroblasts.

Vonka, Vladimir (Baylor University College of Medicine, Houston, Tex.), and Matilda Benyesh-Melnick. Interactions of human cytomegalovirus with human fibroblasts. J. Bacteriol. 91:213-220. 1966.-Virus attachment of human cytomegalovirus to human embryo lung fibroblasts was found to be temperature-independent, from 4 to 37 C. Prolonged incubation at 4 C, however, resulted in inactivation of a high proportion of attached virus. Virus penetration seemed to be temperature-dependent, occurring at 37 C but not at 4 C. Detailed studies of the growth curve of the virus were made. Cell-associated virus preceded the appearance of virus in the fluid phase by 2 to 5 days. Complement-fixing antigen could be detected, but only when the cytopathic effect was advanced, and it was demonstrable only in the cell-associated fraction. Under methyl cellulose, decreasing the bicarbonate concentration in the overlay from 0.225 to 0.15% resulted in marked increase in plating efficiency with all strains tested. However, varying the concentration of bicarbonate from 0.3 to 0.15% in fluid medium did not influence the growth of virus.

Culture Media↗

Dynamic contrast-enhanced MR imaging of musculoskeletal tumors: basic principles and clinical applications.

The purpose of this article is to review the basic principles and clinical applications of dynamic contrast-enhanced MRI in the musculoskeletal system. This method of physiologic imaging provides clinically useful information by depicting tissue vascularization and perfusion, capillary permeability, and composition of the interstitial space. Different imaging, evaluation, and postprocessing techniques are described. The most important applications in the musculoskeletal system are identification of areas of viable tumor for biopsy, tissue characterization, and monitoring of preoperative chemotherapy. Practical guidelines for performing a dynamic contrast-enhanced MR examination are proposed.

Adolescent↗

Jejunal arteriovenous malformation, diagnosed by angiography and treated by embolization and catheter-guided surgery: case report and review of literature.

A case of chronic gastrointestinal hemorrhage caused by a small jejunal arteriovenous malformation (AVM) is reported. Treatment by endovascular embolization was temporarily successful. Subsequently, the patient underwent laparoscopic resection, guided by intraoperative catheter localization with methylene blue. Histopathology confirmed a true AVM. Eighteen months after treatment, the patient is free of symptoms. Literature of jejunal AVMs is reviewed.

Aged↗

Modified intra-arterial calcium stimulation with venous sampling test for preoperative localization of insulinomas.

BACKGROUND: To determine the accuracy and safety of a modified intra-arterial calcium stimulation with the venous sampling test (ASVS) for preoperative localization of insulinomas. Modification included stimulation with a fixed low dose of calcium gluconate, additional stimulation in the distal splenic artery, and no insulin sampling in the left hepatic vein. METHODS: In 10 patients showing biochemical evidence of organic hyperinsulinemia, 0.45 mmol of Ca2+ was injected into the gastroduodenal, superior mesenteric, proper hepatic, proximal, and distal splenic arteries during angiography. Insulin levels were measured in samples taken from the right hepatic vein before and 30, 60, 90, 120, 180, and 300 s after Ca2+ injection. RESULTS: Insulin gradients with an increase of more than fourfold indicated direct tumor supply, two- to fourfold correlated with collateral supply, and less than twofold correlated with normal tissue vascularization. ASVS localized all the adenomas of the pancreatic head (n = 3) and body (n = 2) and two of four adenomas of the tail correctly, as confirmed by surgery. Two adenomas of the proximal pancreatic tail were erroneously localized to the body segment, but the fault was rectified by angiography. In one patient with a negative ASVS and without exploration, the diagnosis of an insulinoma was revised. CONCLUSION: ASVS with a fixed low dose of calcium gluconate is a highly accurate and safe method for preoperative localization of insulinomas. Sampling in the left hepatic vein can be routinely omitted. Additional stimulation in the distal splenic artery seems helpful in surgical decision making, but additional experience is needed.

Adult↗

Spontaneous thrombosis of a pseudoaneurysm complicating pancreatitis.

Patients with a visceral aneurysm are at high risk for acute transpapillary, intra-, or retroperitoneal hemorrhage, necessitating either surgical or endovascular therapy. We report an instance of spontaneous thrombosis of a pseudoaneurysm complicating pancreatitis before endovascular treatment could be performed. Causality and the literature of spontaneous thrombosis in pseudoaneurysms are discussed.

Aged↗

Intratumoral steatosis in focal nodular hyperplasia coinciding with diffuse hepatic steatosis: CT and MRI findings with histologic correlation.

Focal nodular hyperplasia (FNH) is a benign tumorlike condition that is thought to be a hyperplastic response to increased blood flow in an arterial malformation rather than a true neoplasm. Radiologically, FNH usually shows typical findings on unenhanced and enhanced computed tomography (CT) and magnetic resonance images (MRI), with atypical features being the exception rather than the rule. We report an unusual case of FNH with extensive fatty infiltration of the lesion illustrated on CT and MRI and proven by histopathology.

Biopsy↗