Imaeda, Tamotsu (Instituto Venezolano de Investigaciones Cientificas, Caracas, Venezuela) and Jacinto Convit. Electron microscope study of Mycobacterium leprae and its environment in a vesicular leprous lesion. J. Bacteriol. 83:43-52. 1962.-Biopsied specimens of a borderline leprosy lesion were observed with the electron microscope. In this lesion, the majority of Mycobacterium leprae were laden with cytoplasmic components. The bacilli were separated from the cytoplasm of host cells by an enclosing membrane, thus differing from the environment of well-developed lepra cells in lepromatous lesions. The cell wall is composed of a moderately dense layer. A diffuse layer is discernible outside the cell wall, separated from it by a low density space. It is suggested that the cell wall is further coated by a low density layer, although the nature of the outermost diffuse layer has not yet been determined. The plasma membrane consists of a double layer, i.e., dense inner and outer layers separated by a low density space. The outer layer is closely adjacent to the cell wall. In the region where the outer layer of the plasma membrane enters the cytoplasm and is transformed into a complex membranous structure, the inner layer encloses this membranous configuration. Together they form the intracytoplasmic membrane system. In the bacterial cytoplasm, moderately dense, presumably polyphosphate bodies are apparent. As neither these bodies nor the intracytoplasmic membrane system are visible in the degenerating bacilli, it seems probable that these two components represent indicators of the state of bacillary activity.

Journal Article↗

PubMedDate not supplied

Hepatocellular carcinoma with tumor thrombus in the inferior vena cava and right atrium.

Tumor thrombus (TT) in the inferior vena cava (IVC) and right atrium (RA) is rarely encountered. We have diagnosed before death and treated a case of hepatocellular carcinoma (HCC) with TT in the IVC and RA, accompanied by a brain metastasis. The image characteristics on computed tomography (CT), magnetic resonance imaging (MRI), and conventional angiography are discussed.

Brain Neoplasms↗

PubMedDate not supplied

Hemodynamics of small hepatocellular carcinomas (5 cm or less in diameter): cases with discrepant findings between dynamic MR images and hepatic arteriograms.

BACKGROUND: The degrees and patterns of contrast enhancement of small hepatocellular carcinomas (HCCs) on dynamic magnetic resonance (MR) images were compared with those on hepatic arteriograms in 61 patients. METHODS: Dynamic MR imaging was performed within 1 week before hepatic angiography prior to treatment, 3-4 weeks after treatment, and then once every 1-3 months if necessary. Hepatic arteriography was carried out with a coaxial microcatheter inserted into the proper hepatic artery or its distal branches. RESULTS: In 58 of 61 cases, the degrees of contrast enhancement of the tumor in dynamic MR imaging were roughly consistent with those in hepatic arteriography before treatment. In the remaining three cases, however, the tumors were depicted as hyperintense in the arterial dominant phase of the dynamic MR imaging, whereas the tumors were not detected by hepatic arteriography. The tumor detectability is 97% by dynamic MR imaging and 92% by hepatic arteriography. Furthermore, when an HCC nodule was not clearly enhanced by hepatic arteriography after treatment, it was possible by dynamic MR imaging to obtain accurate information on whether the HCC nodule had parasitic arteries. CONCLUSIONS: Dynamic MR imaging was superior to hepatic angiography in contrast resolution. It was therefore considered to be useful in assessing the degrees and patterns of contrast enhancement of small HCCs before and after treatment.

Aged↗

PubMedDate not supplied

Lipiodol retention and massive necrosis after lipiodol-chemoembolization of hepatocellular carcinoma: correlation between computed tomography and histopathology.

This retrospective study examined the computed tomography (CT) criteria for judging the effectiveness of transcatheter arterial Lipiodol-chemoembolization (Lp-chemo-TAE) in 35 cases with hepatocellular carcinoma (HCC). Massive necrosis, defined as involving 97% or more of the HCC nodule, was observed in 15 cases after Lp-chemo-TAE, whereas nonmassive necrosis, defined as involving < or = 96% of the HCC nodule, was observed in the remaining 20 cases. In 12 of 15 cases (80%) with massive necrosis, uniform dense retention of Lipiodol (Lp) was observed throughout the HCC nodule on CT images 3-4 weeks after Lp-chemo-TAE as opposed to only one (5%) of 20 cases with nonmassive necrosis (p < 0.01). Eight of nine cases (89%) with massive necrosis had tumor attenuation values of 365 Hounsfield units (HU) or greater on CT images 3-4 weeks after embolization, as opposed to only four (27%) of 15 cases with nonmassive necrosis (p < 0.01). We conclude that the effectiveness of the Lp-chemo-TAE can be judged on CT from the degree and duration of Lp retention in the HCC nodule and the measurement of the attenuation value of the HCC nodule.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Demonstration of false-negative findings on CT hepatic angiography.

False-negative findings on CT angiography (CTA) in two patients with hepatocellular carcinoma (HCC) were demonstrated. CTA images of one patient with an aberrant left hepatic artery branching from the left gastric artery and another patient whose right hepatic artery was occluded owing to an unknown cause failed to demonstrate HCCs. This report suggests one of the diagnostic pitfalls of CTA for diagnosis of liver tumors.

Aged↗

PubMedDate not supplied

Nonpathological focal enhancements on spiral CT hepatic angiography.

BACKGROUND: To assess the frequency and characteristics of nonpathological focal enhancements seen on spiral computed tomographic (CT) hepatic angiography (CTA). METHODS: Spiral CTA and spiral CT arterial portography (CTAP) were performed in 31 patients with suspected liver malignancy prior to potential liver resection. The CTA images were retrospectively reviewed for focal enhancements by two radiologists. After determining nonpathological focal enhancements on CTA images based on the other radiographic tests, surgical exploration including intraoperative sonography, follow-up imagings, the frequency, size, site, and shape of nonpathological focal enhancements with CTA were assessed. RESULTS: Thirty-six nonpathological focal enhancements with CTA from 4 to 23 (mean = 11. 4) mm were seen in 14 (45.2%) of 31 patients. Thirteen (36.1%) of 36 nonpathological focal enhancements with CTA were not depicted with CTAP. Nonpathological focal enhancements with CTA were frequent in Couinaud segments III (27.8%), V (22.2%), and VI (19.4%). Twenty-three (63.9%) of 36 nonpathological focal enhancements were located in the edge of the liver. Shapes of 36 nonpathological focal enhancements with CTA included circular (n = 16), worm (n = 7), irregular (n = 6), dot (n = 6), and wedge (n = 1). CONCLUSION: In nearly half of patients, spiral CTA shows various shapes of small nonpathological focal enhancements more frequently in the liver edge.

Aged↗

PubMedDate not supplied

Methodological assessment of combined spiral CT angiography and CT arterial portography.

BACKGROUND: To assess an optimal methodology of combined spiral computed tomographic (CT) angiography (CTA) and CT arterial portography (CTAP) for detection and characterization of liver tumors. METHODS: We performed spiral CTAP only in five patients with 30-32% contrast (subset A), CTAP combined with preceding spiral CTA using 30-32% contrast in 19 (subset B), and CTAP combined with preceding spiral CTA with 60-64% contrast in seven (subset C). The CT numbers of the aorta immediately before preceding CTA and subsequent CTAP and the CT numbers of malignant tumor and liver parenchyma with CTAP were measured. RESULTS: The differences of the CT number between the malignant tumor and liver parenchyma on CTAP were 61.1-161.8 (mean +/- SD, 114.5 +/- 39.3) HU, 50.7-164.8 (104.2 +/- 31.2) HU, and 101.2-368.3 (219.5 +/- 90.5) HU in subsets A, B, and C, respectively. Two cavernous hemangiomas showed pathognomonic findings with preceding CTA. CONCLUSION: Combination of preceding spiral CTA and subsequent spiral CTAP using 30% contrast with a 5-min interval is an optimal method for detection and characterization of liver tumors.

Aged↗

PubMedDate not supplied

Tumor thrombus in the branches of the distal portal vein: CT demonstration.

Punctate and linear low density structures adjacent to the tumor nodules in the CT images of eight patients with hepatocellular carcinomas were followed for greater than 5 months to investigate the evolution of these low density structures. During the period of follow-up, patients were given anticancer therapy. Computed tomographic, angiographic, and autopsy examinations indicated that the CT finding of punctate or linear low density structures represented a tumor thrombus in the portal branches of the third and more distal orders. In two cases that showed punctate or linear low density structures adjacent to the distal side of the tumor nodules to the porta hepatis, a daughter nodule was detected by CT at 6.5 and 9.2 months, respectively, after the appearance of the low density structures. In two cases that showed punctate or linear low density structures adjacent to the proximal side of the tumor nodules to the porta hepatis, rapid and extensive tumor growth was found by CT at 5.4 and 8.0 months, respectively, after the appearance of the low density structures.

Aged↗

PubMedDate not supplied

Liver hypertrophy and portal hypertension in association with tumor thrombus in the portal vein: CT findings.

The growth rate of tumor thrombus in the portal vein and the concomitant enlargement of the volumes of the left lateral segment of the liver and the spleen were retrospectively investigated in 11 patients with hepatocellular carcinoma (HCC). In 7 of the 11 patients the left lateral segment of the liver enlarged as the tumor thrombus extended to the right second order branches and the more proximal order branches to the porta hepatis and eventually obstructed these branches. The volume of the left lateral segment was 1.3 to 2.7 times larger, compared with its original volume at the time of HCC detection. An increase in splenic volume was also found in 8 of the 11 patients. The increasing ratios of the splenic volume amounted to 1.3 to 2.1 times the volume found at the time of HCC detection. The growth of tumor thrombus in the right first order branch and portal trunk and the ensuing obstruction of these branches by the tumor thrombus resulted in the development of intractable ascites in 5 of the 11 patients and the development of hepatofugal collateral vessels in all 11 patients. These findings were not demonstrated prior to obstruction of these branches.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Extracapsular invasion of small hepatocellular carcinoma: MR and CT findings.

OBJECTIVE: The purpose was to examine whether MR and CT imaging can detect extracapsular invasion of hepatocellular carcinoma (HCC) and, if this is possible, to determine its characteristic signs on MR and CT images. MATERIALS AND METHODS: Thirty-eight patients with small HCC (< or = 3.0 cm in diameter) were studied to correlate the findings in surgically resected specimens with the findings on MR and CT images. RESULTS: Ten of 38 patients had histologically proven extracapsular invasion of HCC. Of these 10 patients with extracapsular invasion, partial projections of the tumor into the surrounding area or satellite nodules in the immediate vicinity of the tumor were observed in 9 patients on T1-weighted images and in 5 patients on postcontrast CT images. Partial tumor projection or satellite nodules were not observed in patients without extracapsular invasion of HCC. The detection rate for these characteristic signs was 90% on MR and 50% on CT. CONCLUSION: Magnetic resonance and CT imaging were useful for detection of extracapsular invasion of HCC. The characteristic signs for extracapsular invasion of HCC were partial tumor projection into the surrounding area and satellite nodules in the immediate vicinity of the tumor.

Adult↗

PubMedDate not supplied

Dynamic MRI of the diaphragm.

OBJECTIVE: To demonstrate the appearance of the diaphragm on single-slice dynamic MRI. MATERIALS AND METHODS: We evaluated the diaphragm using gadolinium-enhanced single-slice dynamic MR in 53 patients. RESULTS: The diaphragm was partially depicted in 49 cases (92.5%). Its thickest part measured 4.4 +/- 2.2 mm, range 3 to 15 mm. Enhanced high-intensity thin layer structures were partially identified between the diaphragm and liver parenchyma in 46 cases (86.8%) at 16 to 144 s (mean +/- SD, 65.7 +/- 32.6 s) after intravenous injection of Gd-DTPA. CONCLUSION: Dynamic MR has value and limitations in demonstrating the diaphragm.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Electron microscopy of leprosy lesions.

Explore the source record for details and available documents.

Humans↗

PubMedDate not supplied

A retrospective study on the patterns of sequential fluctuation of serum alpha-fetoprotein level during progression from liver cirrhosis to hepatocellular carcinoma.

The patterns of sequential fluctuation of serum alpha-fetoprotein levels were analysed in 218 patients with liver cirrhosis in whom the serum alpha-fetoprotein levels were regularly and serially measured for more than 1 year. In the group of patients with persistently abnormal high values (greater than 50 ng/mL) over a follow-up period of more than 1 year, the incidence of the subsequent development of hepatocellular carcinoma was statistically and significantly higher (44%) compared to the other groups which showed normal (less than 20 ng/mL) or low abnormal levels (21-50 ng/mL) (16%), and transient abnormal high levels (greater than 50 ng/mL for a period of less than 1 year, mostly within 5 months) or fluctuated repeatedly between normal and transient abnormal high levels (23%). Hepatocellular carcinoma developed in 48 patients more than 2 years after the diagnosis of liver cirrhosis, and the fluctuating patterns of serum alpha-fetoprotein levels were analysed in these patients. The serum alpha-fetoprotein levels in 10 of these 48 patients stayed below 50 ng/mL until about 2.0-10.0 months before the detection of hepatocellular carcinoma and then increased steadily until the time of hepatocellular carcinoma detection. In these 10 patients, the monthly increasing ratios were approximately 1.6-4.8 times the previous values.

Adult↗