To evaluate the usefulness of intraarterial digital subtraction angiography (IADSA) in hepatocellular carcinoma, IADSA was prospectively performed, combined with conventional film-screen angiography, in 40 patients in whom the tumor was histologically proven or highly suspected. Of the 16 main tumors less than 2 cm, IADSA detected 7 that were missed by film-screen angiography; 6 of these were less than 1 cm in size. With other diagnostic modalities including ultrasound, routine CT study, and CT after intraarterial Lipiodol injection, the detection rate of these tumors was low. IADSA's contribution is important in the detection of small hepatocellular carcinomas.

Adult↗

PubMedDate not supplied

Facilitation of passive avoidance response by newly synthesized cationized arginine vasopressin fragment 4-9 in rats.

The effects of a newly synthesized cationized arginine vasopressin fragment 4-9 analogue (C-AVP-(4-9)) on learning and memory in rats were studied by the passive avoidance test. C-AVP-(4-9) and its parent peptide, arginine vasopressin fragment 4-9 (AVP-(4-9)), a well known potent neuropeptide, were subcutaneously injected 1.5 hr prior to the retention test. The most effective doses of C-AVP-(4-9) and AVP-(4-9) were 8.6 x 10(-2) and 1.3 nmol/kg, respectively. To evaluate the distribution of C-AVP-(4-9) in the control nervous system (CNS), apparent tissue-plasma concentration rations (Kp.app) of intravenously administered radioiodinated C-AVP-(4-9) (125I-C-AVP-(4-9)) in the CNS in mice were determined. At the apparent steady state of plasma concentration of 125I-C-AVP-(4-9), the Kp.app values of the 125I-C-AVP-(4-9) in the cerebrum, cerebellum and spinal cord were over 12 times higher than that of the vascular space marker which slightly penetrates the BBB. Moreover, the rat cerebral homogenate converted C-AVP-(4-9) into its parent peptide AVP-(4-9). These results suggest that the potent effects of C-AVP-(4-9) on learning and memory may be due to AVP-(4-9) generated as a result of distribution and metabolism of peripherally administered C-AVP-(4-9) in the CNS.

Animals↗

PubMedDate not supplied

Metabolic dechlorination of toxaphene in rats.

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Animals↗

PubMedDate not supplied

A case of exaggerated mosquito-bite hypersensitivity with Epstein-Barr virus-positive inflammatory cells in the bite lesion.

We describe a unique patient with mosquito-bite hypersensitivity who had extremely high titres of Epstein-Barr virus antibodies. For many years he developed intractable ulcers on the sites of mosquito-bite. Epstein-Barr virus infection was detected in almost all inflammatory cells in the ulcers and in the peripheral blood lymphocytes by using in situ hybridization to Epstein-Barr virus-encoded small ribonucleic acids and by polymerase chain reaction to Epstein-Barr virus DNA. The inflammatory cells in the ulcers were positive for T-cell marker. Our results suggest that the Epstein-Barr virus infection in T cells may participate in the pathogenesis of exaggerated mosquito hypersensitivity and in delayed healing of ulcers on the sites of mosquito-bite.

Adolescent↗

PubMedDate not supplied

Chemical shift and the double-line sign in MRI of early femoral avascular necrosis.

The double-line sign (DLS) on T2-weighted images in femoral avascular necrosis (AVN) is formed by a high-intensity rim at the reactive interface inside a low-intensity margin. A hypothesis has been advanced that the sign may be seen in early AVN whether or not there is bony sclerosis. On change of direction of the frequency-encoding axis, the high-intensity area rimmed with low-intensity margin was generated on the side where chemical shift misregistration artifact was seen. Transposition of frequency-encoding and phase-encoding axes yielded the same results. The thickness of the low-density rim was almost equal to the amount of expected offset distance due to chemical shift misregistration. Therefore, chemical shift misregistration artifact is the most reasonable explanation for the DLS observed in early femoral AVN.

Artifacts↗

PubMedDate not supplied

CT pixel mapping in the diagnosis of small angiomyolipomas of the kidneys.

In six small renal angiomyolipomas (7-17 mm) the superiority of displaying the CT numbers of pixels within a lesion (pixel mapping) over the usual region of interest (ROI) measurement is described in the detection of small amounts of fat tissue. On precontrast 5 mm CT the ROI measurements were > 0 in four cases whereas pixel maps revealed pixels with values < 0 in six cases.

Adipose Tissue↗

PubMedDate not supplied

Effect of water fraction in selection of optimal TI value for STIR sequences.

OBJECTIVE: This article describes the effect of the water fraction in the selection of the optimal TI value in a STIR sequence. This effect has been given little consideration in previous studies. MATERIALS AND METHODS: Therefore, using both STIR combined with the Dixon method (opposed-phase STIR) and conventional STIR (in-phase STIR), we have investigated the effect of the water fraction in the selection of an optimal TI value for the STIR sequence. RESULTS: Our findings have indicated that the water protons rather than the olefinic protons (-CH = CH-) play a major role in the opposed-phase effect in vivo. CONCLUSION: Thus, it has been concluded that the most effective fat suppression can be achieved when the intravoxel phase cancellation effect between the water and lipid protons is maximal, rather than when the longitudinal magnetization of the lipid protons is minimal.

Adipose Tissue↗