Fat Vacuoles Research Articles

The “fatty pancreas allograft”: anatomopathologic findings and clinical experience

Thirty-three hematoxylin and eosin–stained sections from 7 turned down pancreata from donors with body mass index (BMI) of 33.3 (range, 28–42) were examined. There was more fat infiltration between the superficial pancreatic lobules, interspersed with superficial islands of pancreatic tissue with its vessels and ductules. Thicker fatty interlobular septa were observed with numerous intralobular fat vacuoles. One organ had widespread autolysis. No microthrombi were noted. One pancreas from a 24-year-old donor with BMI of 30 was transplanted successfully. The “fatty pancreas” can be defatted and used for transplantation.

Adipogenic differentiation of human adult stem cells from bone marrow stroma (MSCs).

We assayed gene expressions during adipogenesis of human MSCs. Microarray assays demonstrated time-dependent increases in expression of 67 genes, including 2 genes for transcription factors that were not previously shown to be expressed during adipogenesis. INTRODUCTION Increased numbers of bone marrow adipocytes have been observed in patients with osteoporosis and aplastic anemia, but the pathological mechanisms remain unknown. Recently, microarray assays for mRNAs were used to follow adipogenic differentiation of the preadipocytic cell line, 3T3-L1, but adipogenic differentiation has not been examined in primary cells from bone marrow. Here we defined the sequence of gene expression during the adipogenesis ex vivo of human cells from bone marrow referred to as either mesenchymal stem cells or marrow stromal cells (MSCs). MSCs were plated at extremely low densities to generate single-cell derived colonies, and adipogenic differentiation of the colonies assayed by accumulation of fat vacuoles, time-lapse photomicroscopy, microarrays, and reverse transcriptase-polymerase chain reaction (RT-PCR) assays. RESULTS AND CONCLUSIONS About 30% of the colonies differentiated to adipocytes in 14 days and about 60% in 21 days. Cell proliferation was inhibited by approximately 50% in adipogenic medium. The differentiation occurred primarily at the center of the colonies, and a few adipocytes that formed near the periphery migrated toward the centers. RT-PCR assays demonstrated that the differentiation was accompanied by increases in a series of genes previously shown to increase with adipogenic differentiation: peroxisome proliferator activated receptor gamma, CCAAT enhancer-binding protein alpha, acylCoA synthetase, lipoprotein lipase, and fatty acid binding protein 4. We also followed differentiation with microarray assays. Sixty-seven genes increased more than 10-fold at day 1 and 20-fold at day 7, 14, or 21. Many of the genes identified were previously shown to be expressed during adipocytic differentiation. However, others, such as zinc finger E-box binding protein and zinc finger protein 145, were not. This study should serve as a basis for future study to clarify the mechanisms of adipocyte differentiation of MSCs.

Hepatic lipid characteristics and histopathology of laying hens fed CLA or n-3 fatty acids.

The effect of dietary CLA and n-3 PUFA on hepatic TAG accumulation, histopathology, and FA incorporation in lipid classes by laying chickens was investigated. One hundred twenty 30-wk-old single comb white leghorn laying hens were distributed randomly to four treatments (3 replications of 10 birds) and were fed diets containing CLA and animal fat (Diet I), 18:3n-3 (Diet II), or long-chain n-3 FA (Diet III). A sunflower oil (n-6 FA)-based diet vvas the control. Feeding Diet I resulted in an increase in hepatic total lipids (P < 0.05). The liver TAG content was 32.2, 18.9, 29.4, and 18.7 mg/g for hens fed Diet I, Diet II, Diet III, and the control diet, respectively (P< 0.05). The serum TAG was lowest in birds fed Diet II (P < 0.05). Diet I resulted in an increase in the total number of fat vacuoles and lipid infiltration in hepatocytes (P < 0.05). The number of cells with 75% or higher lipid vacuolation was observed only in birds fed Diet I. Feeding diets containing CLA resulted in an increase in the content of the c9,t11 CLA isomer in liver TAG and PC (P < 0.05). No difference was observed in the CLA concentration of hepatic PE fractions. The content of DHA (22:6n-3) was higher in the TAG, PC, and PE of hens fed Diet II and Diet III than Diet I and the control (P < 0.05). Feeding CLA resulted in an increase in total saturated FA in the TAG and PC fractions (P < 0.05). Long-term feeding of CLA in laying birds leads to an increase in liver TAG and may predispose birds to fatty liver hemorrhagic syndrome.

Magnetic resonance imaging and histologic findings of experimental cerebral fat embolism.

The purpose of this study was to determine whether cerebral fat embolism demonstrated reversible or irreversible findings in magnetic resonance (MR) imaging over time and to compare the features in MR images with histologic findings in a cat model. MR images were obtained serially at 2 hours, 1 and 4 days, and 1, 2, and 3 weeks after embolization with 0.05 mL of triolein into the internal carotid artery in 19 cats. Any abnormal signal intensity and change in the signal intensity were evaluated on T2-weighted images, T1-weighted images, diffusion-weighted images (DWIs; including apparent diffusion coefficient [ADC] maps), and gadolinium-enhanced T1-weighted images (Gd-T1WI) over time. After MR imaging at 3 weeks, brain tissue was obtained and evaluated for light microscopic (LM) examination using hematoxylin-eosin and Luxol fast blue staining. For electron microscopic examination, the specimens were obtained at the cortex. The histologic and MR findings were compared. The embolization lesions showed hyperintensity on T2-weighted images, hyperintensity, or isointensity on DWIs, hypointensity, or isointensity on ADC maps and contrast enhancement on Gd-T1WIs at 2 hours. The T2-weighted hyperintensity extended to the white matter at day 1 and decreased thereafter. Contrast enhancement decreased continuously from day 1, and hyperintensity on DWI decreased after day 4. Hypointensity on ADC maps became less prominent after day 4. By week 3, most lesions had reverted to a normal appearance on MR images and were correlated with LM findings. However, small focal lesions remained in the gray matter of 8 cats and in the white matter of 3 cats on MR images, and this correlated with the cystic changes on LM findings. Electron microscopic examination of the cortical lesions that reverted to normal at week 3 in MR images showed that most of these lesions appeared normal but showed sporadic intracapillary fat vacuoles and disruption of the endothelial walls. The embolized lesions of the hyperacute stage were of 2 types: type 1 lesions, showing hyperintensity on DWIs and hypointensity on ADC maps, have irreversible sequelae, such as cystic changes; whereas type 2 lesions, showing isointensity or mild hyperintensity on DWIs and ADC maps, reverted to a normal appearance in the subacute stage.

Leptin-resistant obese mice have paradoxically low biliary cholesterol saturation

Background. Human obesity is associated with leptin resistance, elevated serum glucose and lipids, hepatic steatosis, and cholesterol gallstone formation. These gallstones are thought to result from hypersecretion of biliary cholesterol as well as biliary stasis. Leptin-resistant Lepdb obese mice, which are known to have elevated serum leptin, glucose, and lipids, as well as hepatic steatosis, should be an appropriate model for human gallstone formation. Therefore, we tested the hypothesis that leptin-resistant mice would have increased gallbladder volume, biliary cholesterol saturation, and cholesterol crystal formation. Methods. Sixty lean control mice and 60 Lepdb obese mice on a low cholesterol chow diet were studied. Gallbladder volumes were measured and bile was pooled to calculate cholesterol saturation index. Serum cholesterol, glucose, and leptin levels were determined from pooled serum. Hepatic fat vacuoles were counted. Bile from a second group of 90 lean control and 59 obese mice was observed microscopically for cholesterol crystal formation. Results. Leptin-resistant obese mice have significantly higher serum cholesterol, glucose, and leptin levels, hepatic fat vacuoles, and gallbladder volume than lean control mice. However, biliary cholesterol saturation index and cholesterol crystal formation were significantly diminished in the obese mice. Conclusions. These data suggest that leptin-resistant Lepdb obese mice have (1) increased gallbladder volume, (2) decreased biliary cholesterol saturation despite elevated serum cholesterol and hepatic steatosis, and (3) decreased in vitro cholesterol crystal formation. We conclude that the link between obesity and gallstone formation does not require hypersecretion of biliary cholesterol. (Surgery 2003;134:372-7.)

Lipogranuloma of the Cervix

OBJECTIVE.: A case report of lipogranuloma of the cervix with review of the literature is reported. MATERIALS AND METHODS.: In a 53-year-old woman, an incidental lesion was noted in the cervical biopsy as part of an evaluation for postmenopausal bleeding. RESULTS.: The biopsy revealed a stromal lesion consisting of fat vacuoles with foreign body type giant cells and scattered lymphocytes. CONCLUSION.: Lipogranuloma of the cervix is a rare entity of uncertain etiology that can clinically mimic neoplastic or benign disease.

Dietary CLA alters yolk and tissue FA composition and hepatic histopathology of laying hens.

The effect of dietary CLA along with n-3 PUFA on yolk FA profile and hepatic lipid accumulation was investigated. Laying hens (n = 40) were randomly assigned to four experimental diets containing 0, 0.5, 1.0, or 2.0% CLA. Menhaden oil was used as the source of n-3 PUFA. Dietary CLA did not affect the total lipid content of egg yolk (P > 0.05). The amounts of CLA isomers (cis-9 trans-11, trans-10 cis-12) in the egg yolk were proportional to the levels of CLA in the diet (P < 0.05). The total CLA content in the egg yolk was 0, 0.97, 2.4, and 5.3 wt%, respectively (P < 0.05). Addition of CLA resulted in an increase in saturated FA (P < 0.05) with a concomitant reduction in monounsaturated FA (P < 0.05) in the yolk, liver, abdominal fat, breast, and thigh muscle. No difference in saturated and monounsaturated FA content in heart and spleen tissue was noted. Dietary CLA at all concentrations resulted in an increase (P < 0.05) in the total number of fat vacuoles and lipid infiltration in hepatocytes. The number of cells with 75% or higher lipid vacuolation in the cytoplasm was also increased (P < 0.05) by 2.0% CLA. Dietary CLA at 0.5% levels resulted in an increase (P < 0.05) in the total lipid content of hepatic tissue. The total lipid content in leg muscle was lower (P < 0.05) in CLA-fed birds. However, no effect of CLA on lipid content of breast muscle, heart, spleen and adipose tissue was observed (P > 0.05). The current study used CLA in a FFA form. The effects of using CLA in other form such as TG on avian hepatic tissue need to be investigated.

Kupffer Cell Aggregation and Perivenular Distribution in Steatohepatitis

Cytokine release from inflammatory cells, endotoxin, lipid peroxidation, and generation of reactive oxygen species are among the factors currently thought to be important in the pathogenesis of alcoholic and nonalcoholic steatohepatitis (SH). To more fully evaluate the role of mononuclear inflammatory cells in SH, 11 needle liver biopsies showing SH were selected for immunohistochemical staining to analyze the type and distribution of mononuclear inflammatory cells, including T and B lymphocytes and Kupffer cells (using immunostains for CD3, CD4, CD8; CD20; and CD68, respectively). An additional seven biopsies showing normal or fatty liver were also selected for CD68 immunostaining. Immunohistochemistry showed mild to moderate (1+ to 2+) numbers of T cells, with equal representation of CD4 and CD8 cells. T cells were found in portal tracts and in regions of SH. B cells were only rarely present. CD68 staining of simple fatty liver and normal liver showed elongated, spindle-shaped Kupffer cells diffusely distributed along the sinusoids throughout the lobules. In contrast, in cases of SH, there was prominent enlargement and aggregation of Kupffer cells in perivenular regions. Scattered large vacuoles of fat that had appeared to be within hepatocytes on routine stain were found actually to be within Kupffer cells. These results support the concept that hepatic Kupffer cells are a major immune effector cell in the pathogenesis of steatohepatitis. A potential direct Kupffer cell role in hepatic lipid processing is also postulated.

Magnetic Resonance Imaging and Histologic Findings of Acute and Subacute Stage of Experimental Cerebral Fat Embolism in Cats

Purpose: To determine the magnetic resonance imaging (MRI) findings and natural history of cerebral fat embolism in a cat model, and to correlate the MRI and histologic findings. Materials and Methods: Using the femoral arterial approach, the internel carotid artery of 11 cats was injected with 0.1 ml of triolein. T2-weighted (T2WI), T1-weighted (T1WI) and Gd-enhanced T1-weighted (Gd-T1WI) images were obtained serially at 2 hours, 1 and 4 days and 1, 2 and 3 weeks after embolization. Any abnormal signal intensity (SI) was evaluated. After MR imaging at 3 weeks, brain tissue was obtained for light microscopic (LM) examination using hematoxylin-eosin and Luxol fast blue staining, and for electron microscopic (EM) examination. The histologic and MRI findings were correlated. Results: At 2 hours, lesions showed high SI at T2WI, iso- or low SI at T1WI, and strong enhancement at Gd-T1WI. The high SI seen at T2WI decreased thereafter, and most lesions became iso-intense. At week 3, however, small focal areas of high SI were seen in the grey matter of eight cats and in the white matter of three. The low SI noted at acute-stage T1W1 subsequcntly became normal, though in the areas in which T2W1 had depicted high SI, focal areas of low SI remained. Lesion enhancement demonstrated by Gd-T1WI decreased continuously from day 1, and at week 3, weak enhancement was seen at the margin of the remained hypointense lesions in the gray matter in five cats. At LM examination with hematoxylin-eosin staining revealed normal histologic findings in the greater park of an embolized lesion. Cystic change was observed in the gray matter of eight cats, and in the gray and white matter of three of the eight. At LM examination, Luxol fast blue, staining demonstrated demyelination around the cystic change occurring in the white matter, and EM examination of the embolized cortex revealed sporadic intracapillary fat vacuoles (n=11) and disruption of the blood-brain barrier (n=4). Most lesions were normal, however, and perivascular interstitial edema and cellular swelling were mild compared with the control side. Conclusion: Experimental cerebral fat embolism was clearly demonstrated by T2WI and Gd-T1WI images obtained at all time points. The greater part of an embolized lesion showed reversible findings at MR and histologic examination; irreversible focal necrosis was, however, observed in gray and white matter at week 3.

Safety Assessment of DHA-Rich Microalgae from Schizochytrium sp.: I. Subchronic Rat Feeding Study

The purpose of this study was to determine the potential toxicity of docosahexaenoic acid-rich microalgae from Schizochytrium sp. (DRM), administered in the diet to rats for at least 13 weeks. DRM was administered in the diet to groups of 20 male and 20 female Sprague–Dawley derived rats (Crl:CD(SD)BR) to provide dosages of 0, 400, 1500, and 4000 mg/kg/day for at least 13 weeks. DRM contained high levels of fat (approximately 41% w/w) of which long-chain highly unsaturated fatty acids (PUFAs) were a major component. Vitamin E acetate was added to DRM at manufacture to provide supplementary dietary antioxidant given the highly unsaturated fat content of DRM. Untreated controls received the basal diet only. An additional group of 20 males and 20 females received basal diet mixed with fish oil (Arista) to provide a target dosage of 1628 mg/kg/day, an amount of fat comparable to that received by rats administered the highest dose of DRM. Vitamin E acetate was also added to the fish oil to provide a comparable level of dietary antioxidant provided to high-dose DRM rats. There were no treatment-related effects in clinical observations, body weights or weight gains, food consumption, hematologic or urinalysis values, gross necropsy findings, or organ weights and there were no deaths. The only treatment-related changes in clinical chemistry parameters were decreases in high-density lipoproteins and cholesterol in the DRM and fish oil groups when compared to the untreated controls. These changes were expected based on the high PUFA content of DRM and fish oil. There were no microscopic findings suggestive of toxicity. Periportal hepatocellular fat vacuolation (accumulation of fat) was observed only in the livers of female rats in both the DRM (all dosages) and fish oil groups. This finding was expected given the higher fat content of both the DRM and the fish oil diets compared to the basal diet fed to the untreated controls. A slight increase in the incidence, but not severity, of cardiomyopathy was observed only in the 4000 mg/kg/day DRM males. This finding was not considered adverse because cardiomyopathy occurs spontaneously in rats and especially male rats of the Sprague–Dawley strain when fed high levels of fat. Since cardiomyopathy does not develop in other species including primates fed high-fat diets, its occurrence in rats is considered to have little relevance to human health. This study demonstrates that administration of DRM did not produce any treatment-related adverse effects in Sprague–Dawley rats of relevance to humans at dosages up to 4000 mg/kg/day for 13 weeks.

Correction to: Proximal Atrioventricular Bundle, Atrioventricular Node, and Distal Atrioventricular Bundle Are Distinct Anatomic Structures With Unique Histological Characteristics and Innervation

HomeCirculationVol. 101, No. 25Correction to: Proximal Atrioventricular Bundle, Atrioventricular Node, and Distal Atrioventricular Bundle Are Distinct Anatomic Structures With Unique Histological Characteristics and Innervation Free AccessCorrectionPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessCorrectionPDF/EPUBCorrection to: Proximal Atrioventricular Bundle, Atrioventricular Node, and Distal Atrioventricular Bundle Are Distinct Anatomic Structures With Unique Histological Characteristics and Innervation Originally published27 Jun 2000https://doi.org/10.1161/01.CIR.101.25.2991Circulation. 2000;101:2991–2994This article corrects the followingProximal Atrioventricular Bundle, Atrioventricular Node, and Distal Atrioventricular Bundle Are Distinct Anatomic Structures With Unique Histological Characteristics and InnervationIn the article by Racker and Kadish that appeared in a previous issue of the journal (Circulation 2000;101:1049–1059 ), Figures 2, 3, 6, and 9 did not reproduce well. Better quality images follow.In addition, the final sentence of the Methods and Results section of the Abstract should read as follows: “Sheaves of nerve terminals are found, including boutons as in skeletal muscle.” Download figureDownload PowerPoint Figure 2. Direct 3-dimensional analysis of AV junction region in selected serial orthogonal sections. A and B, Vertical lines indicate section level in C. B, C1, Coronary sinus ostium (CSO) and black dot identify a regularly appearing sinus in lateral, inferoanterior lip of coronary sinus ostium. A, Parallel plane: the PAVB, AVN, and DAVB span AV junction region as a myocardial continuum confluent with right bundle-branch (RBB); medial atrionodal bundle (MAB) and lateral atrionodal bundle (LAB) are located on either side of coronary sinus (CS); and superior atrionodal bundle (SAB) is superior to AVN. Dashed lines, Koch’s triangle. B, Perpendicular plane: collagen encasement imparts a gray tone to PAVB, AVN, and DAVB in contrast to dark staining of medial atrial wall (MAW) and ventricular septum (VS) myocardium. White arrowheads delineate MAW annular, subepicardial circumferential lamina. Thin sleeve of central fibrous body connective tissue separates AVN from MAW. C, Transverse plane. C1, MAB and LAB converge. C2, Collagen septa separate vertical stack of PAVB fascicles atop VS. C3, Convergence of SAB and PAVB. C4, SAB is superior to AVN, which is surrounded by halo of central fibrous body connective tissue. Perpendicular lamina myofibers cascade over central fibrous body and descend into medial leaflet. C5, DAVB within central fibrous body and astride VS. Note specialized tissues are outside MAW. C1, CSFo and star indicate CS fossa; LA, left atrium; n, noncoronary posterior aortic valve sinus wall; TT, tendon of Todaro. Calibration bar in A and B, C1. (Goldner’s trichrome.)Download figureDownload PowerPoint Figure 3. A, Orthogonal parallel plane PAVB is a loose aggregate of linearly arrayed myocardium intermixed with fat vacuoles that condenses at PAVB-AVN junction (Junct) and is separated from MAW by a large blood vessel (white arrows). B, From box in A, myocytes with uniform cross-striations (black arrowheads) and unusual broad intercalated disks (open arrows) that display a central density (inset). C, Sheaves of nerve terminals (curved black arrows) impinge along lengths of myofibers. Myocytes contain evenly distributed cross-striations (black arrowheads). D, From box in A, parallel fine fascicles (Fasc) composed of strands of twisted myofibers (black and white arrowheads), many showing fine finger-like processes (inset). Sheaves of nerve endings (curved black arrows) contact fascicles and capillaries (top right). Collagen is interspersed between fascicles. Inset, Myocyte end processes are >30 μm long.Download figureDownload PowerPoint Figure 6. A, Orthogonal parallel plane AVN displays a tightly interwoven mass of myocardium, and its fascicles abruptly become parallel at AVN-DAVB junction. B, From A, myofibers and a sheaf of thin myocyte processes with uniform cross-striations (arrowheads) containing a stack of short intercalated disks (open arrows). Sheaves of nerve endings (curved black arrow) pass over myocyte thin processes. C, Fascicles display twisting myofibers and myocytes with perinuclear clear regions (arrows). D. From box in A, swirls of interweaving fascicles containing spiraling myofibers, thin myocyte processes (curved open arrows) are embedded in a rich capillary bed (short curved black arrows). Sheaves of nerve endings (curved black arrows) with varicosities (top left), boutons (see inset), or nerve tendrils (white arrows) terminate on myofibers. Intercalated disks are randomly dispersed (short open arrows). (Goldner’s trichrome.)Download figureDownload PowerPoint Figure 9. A, Orthogonal parallel plane DAVB displays large parallel fascicles separated by collagen lamina. B, From region in A, fascicle with twisting myofibers (arrowheads) contain myocytes with uniform cross-striations and clear cytoplasmic perinuclear zones (arrows). C, Intercalated disks (open arrow) are narrow. D, From A, large parallel fascicles with twisting myofibers, thin myofiber branches (arrowheads), intercalated disks (open arrows), and capillaries (small curved arrows). (Goldner’s trichrome.) Previous Back to top Next FiguresReferencesRelatedDetailsRelated articlesProximal Atrioventricular Bundle, Atrioventricular Node, and Distal Atrioventricular Bundle Are Distinct Anatomic Structures With Unique Histological Characteristics and InnervationDarlene K. Racker, et al. Circulation. 2000;101:1049-1059 June 27, 2000Vol 101, Issue 25 Advertisement Article InformationMetrics Copyright © 2000 by American Heart Associationhttps://doi.org/10.1161/01.CIR.101.25.2991 Originally publishedJune 27, 2000 PDF download Advertisement

Experimentally Induced Cerebral Fat Embolism with Linoleic Acid: MR Imaging and Pathologic Correlation

Purpose: To investigate the correlation between the MRI findings of cerebral fat embolism induced by injecting linoleic acid into ten cats, and pathologic diagnosis. Materials and Methods: Using a microcatheter, 30 μl of linoleic acid was injected into the internal carotid artery of ten cats. MR T2-weighted (T2WI), diffusion-weighted (DWI), and Gd-enhanced T1-weighted images (Gd-enhanced T1WI) were obtained after 30 minutes and after 2 hours of embolization. We pathlogically ex-amined endothelial cell damage, cellular change, perivascular abnormality and fat vacuoles, and then determined the correlation between MRI and the pathologic findings. Results: After 30 minutes of embolization, lesions of very high signal intensity were detected by T2WI in six cats, and of slightly high signal intensity in two; in the remaining two, signal intensity was normal. DWI showed lesions of very high intensity in nine animals and of slightly high intensity in one, while Gd-enhanced T1WI showed well-enhanced lesions in nine and a minimally enhanced lesion in one. After 2 hours of em-bolization, T2WI revealed lesions of very high signal intensity in nine cats, and of slightly high signal intensity in one, while DWI detected lesions of very high signal intensity in all cats. On Gd-enhanced T1WI, lesions in all cats were well enhanced. According to the findings of light microscopic examination, infarcted lesions mainly involved the gray matter, but also some white matter. In the lesions, neurophil matrix edema, neuronal degeneration, perivascular swelling, the widening of extracellular space, extravascular hemorrhage, and fat vacuoles were evident. Conclusion: During the initial two hours following injection, MR imaging of cerebral fat embolism induced by linoleic acid through the internal carotid artery in cats showed high signal intensity on T2WI and DWI, and clear enhancement on Gd-enhanced T1WI. In cases involving cellular edema, cerebrovascular injury and extracellular space widening, the pathologic evidence suggested the coexistence of cytotoxic and vasogenic edema.

An Experimental Study on the Effect of Mixture of Absolute Ethanol and Lipiodol Injected into Normal Liver ofRabbit: CT Features and Histopathologic Changes

Purpose: To investigate the safety and usefulness of Lipiodol-percutaneous transhepatic ethanolinjection(L-PEI) and to determine the appropriate concentration of Lipiodol during L-PEI. This was achieved by evalvating CT findings and histopathologic changes according to the concentration of Lipiodol, amount of ethanol, and the time interval after injection into normal rabbit liver. Materials and Methods: This experimental study involved 18 New Zealand rabbits under US guidance. They were divided into five groups according to injected materials; two rabbits with 0.4cc of normal saline(group I), six with 0.4cc of ethanol in the left hepaticlobe(group II), and 0.4cc of Lipiodol in the right hepatic lobe(group III), five rabbits with 5%Lipiodol-ethanol(5% vol. of Lipiodol+95% vol. of ethanol), 0.2cc in the right hepatic lobe, and 0.4cc in theleft(group IV); and five rabbits with 10% Lipiodol-ethanol as per group IV(group V). CT was performed immediately, one week, two weeks, and three-four weeks after injection, and pathologic specimens were obtained on the third day(acute phase) and during the third or fourth week(chronic phase) after injection. Results: On CT, intrahepatic localization of the L-PEI injection site was well demonstrated as a focal high attenuated area which gradually decreased in attenuation on follow up CT. The opacification of the inferior vena cava by Lipiodol, the linear distribution of Lipiodol along portal veins or fissures, and peritoneal leakage were clearly demonstrated in groups III-V, though the effects gradually disappeared during follow-up CT. There was no remarkable difference in gross CT attenuation between group IV and group V. The main pathologic findings during the acute phase of group II were coagulation necrosis surrounded by macrophage, inflammatory reaction, and early periportal and subcapsular fibrosis. The findings in group IV and V were similar to those in group II and additional fat vacuole accumulations in the necrotic area were also seen. During the chronic phase of group II, areas of necrosis were absent or smaller and were surrounded or replaced by more organized fibrosis, macrophage or multinucleated giantcell infiltration. Periportal, subcapsular fibrosis was also found. In group IV and V, the findings were similarto those of group II, though additional fat vacuoles in fibrotic or necrotic areas, foreign body reaction to fatvacuole, regenerating nodule and calcification were also observed. Conclusion: L-PEI is more useful for thedetection by CT of an injection site than PEI alone, and with regard to CT and histopathologic findings, there wasno significant difference between the 5% and 10% Lipiodol-ethanol groups. Compared to PEI, L-PEI provoked nosighificant additional hepatic injury; only fatty change and foreign body reaction were noted. Thus, L-PEI is moreuseful than PEI for the management of HCC.

Fat metabolism during total parenteral nutrition: a biochemical and ultra‐structural study

Background: Before the introduction of Intralipid in 1961, the incidence of adverse reactions to intravenous fat emulsions was quite common. Concurrent with hyperlipidaemia, multiple organ dysfunction could occur, but the most prominent symptoms were high fever and anaemia, and the reaction was called “the fat overloading syndrome”. Although the reports are quite rare today the reaction does still appear, and we have observed that some patients develop severe fever during or after incidental retention of exogenous fat in the blood during total parenteral nutrition (TPN). The pathophysiological background to these adverse reactions, as well as the final destiny and the effects of the retained exogenous fat particles, are largely unknown. These questions initiated the present study, which focuses on two factors of importance for the clearance of infused fat from the circulation: the lipoprotein lipase (LPL) system and the reticluloendo‐thelial system.Methods: An introductory analysis of the clinical course of a head‐injured patient suffering from fat intolerance during TPN implied that observed adverse reactions could be due to influence on macrophages by retained exogenous fat particles.Results: During infusion of lipid emulsions, cholesterol and phospholipids accumulated in non‐high‐density lipoproteins, while high‐density lipoproteins were enriched in triglycerides. Triglycerides also accumulated in hepatic tissue, and the activity of hepatic lipase decreased.Although lipoprotein lipase activity in the heart was up‐regulated and serum levels of triglycerides were normal, suggesting that the total elimination rate of triglycerides was not impaired, ultra‐structural investigations indicated that Kupffer cells were involved in clearing exogenous lipids from the blood during the infusion of long‐chain triglycerides. Furthermore, the Kupffer cells were activated, according to morphological criteria. When high doses of fat were given intravenously, the Kupffer cells were grossly distended by fat vacuoles, and serum levels of lactate dehydrogenase increased.During treatment with fat emulsions containing medium‐chain triglycerides and long‐chain triglycerides in equal amounts, the alterations in lipid transport were less pronounced, and signs of Kupffer cell activation were weaker than during infusion with long‐chain triglycerides only.Conclusion: The experimental studies showed that infusion of exogenous fat particles interfered with the regulation of lipid transport, and there were signs of increased demands on various aspects of lipid metabolism. Although the capacity of the LPL was sufficient in most situations in healthy rats, the Kupffer cells seemed to be involved in the clearance of exogenous lipids. The present investigations identified one factor, LCT fat emulsion, which was necessary for the appearance of fat vacuoles in the Kupffer cells during TPN.To some extent, the experimental findings may be related to clinical observations of a head‐injured patient who developed signs of acute, severe macrophage activation with haemophago‐cytosis during and after accumulation of exogenous fat in the blood after treatment with intravenous fat emulsions. The condition was considered to be a consequence of impaired lipid elimination and altered macrophage function during clearance of fat from the blood, a consideration supported by the morphological changes of rat Kupffer cells after TPN in the present study.

Reductions and new inventions dominate oogenesis of Strepsiptera (Insecta)

The endoparasitic life of strepsipterans (Insecta), especially neotenic females, reduces to a great extent external and internal organs. Light and electron microscopic investigation of ovaries of Elenchus tenuicornis (Kirby) confirms the following: (1) somatic tissues of ovaries are totally reduced, with the exception of some cells surrounding germ cell clusters; (2) a previtellogenic growth phase of oocytes is reduced; (3) nurse cells remain diploid and their membranes degenerate at the onset of vitellogenesis; (4) vitellogenesis is reduced, vitellin and fat vacuoles contribute only 50% to the final egg volume; and (5) chorionogenesis is reduced to a vitellin membrane. However, some features of normal development remain, allowing classification of the ovary type as polytrophic meroistic: (1) germ cells undergo synchronized, incomplete divisions, following the 2 n rule, where all former intercellular bridges become localized in one cystocyte, while the other has none; and (2) only one cell is determined as the oocyte, all other cystocytes serve as nurse cells and the surrounding somatic cells transform into follicular cells. Novel events in oogenesis of strepsipterans include fission of clusters during the phase of cluster mitoses, and protection of oocyte nuclei, while nurse cell nuclei degenerate in the same cytoplasm.

The Spectrum of Diffuse and Focal Liver Lesions in Workers Exposed to Vinylchloridemonomer

The Spectrum of Diffuse and Focal Liver Lesions in Workers Exposed to Vinylchloridemonomer

Morphological alterations associated with HIV infection of CD4−/GalCer+ human intestinal epithelial cells

The ultrastructural alterations induced by human immunodeficiency virus type 1 (HIV-1) in the human colon epithelial cell line HT-29 infected in vitro have been evaluated. These cells express high levels of galactosyl ceramide (GalCer), an alternative receptor for HIV-1 surface envelope glycoprotein gp120. Using immunolabelling for electron microscopy and immunofluorescence techniques, we detected the GalCer receptor in both the apical and basolateral membranes of differentiated HT-29 subclones. This nonpolar distribution is consistent with our previous observation that HIV infects both the apical and basolateral surfaces of epithelial cells in vitro. A transmission electron microscopy study demonstrated two major ultrastructural perturbations in the HIV-producing cells: (i) an unusual number of secretory granules; and (ii) the appearance of intracellular lumina with disorganized microvilli, indicating a defect in striated border assembly and differentiation. In addition to these morphological alterations, our study revealed the presence of fat vacuoles, concentric membranous bodies, tubuloreticular inclusions and giant mitochondria in the cytoplasm of HIV-infected cells. Taken together, these abnormalities could account for HIV-induced enteropathy, consisting of chronic diarrhea and malabsorption in the absence of enteric pathogens.

Lipid deposition in Kupffer cells after parenteral fat nutrition in rats: a biochemical and ultrastructural study.

To study fat metabolism and evaluate lipid deposition in hepatocytes and Kupffer cells during parenteral nutrition (PN) with or without fat. 20 male Sprague-Dawley rats, divided into four groups, were investigated. Rats fed orally were used as a reference group and compared to three groups of rats receiving PN either without fat or with 33% of non-protein energy as fat or with 66% of non-protein energy as fat. The PN regimens were equicaloric and administered continuously via a jugular catheter for 7 days. After suffocation, blood was collected for determination of serum lipids. Epididymal fat and heart were collected for analysis of lipoprotein lipase activities, and pieces of liver were saved for analyses of liver triglyceride concentration and hepatic lipase activity. Light and electron microscopy were used for examination of lipid deposition in Kupffer cells. Directly after termination of parenteral feeding, the serum levels of triglycerides were similar in all PN groups, while the levels of non-high-density lipoprotein (HDL) cholesterol and non-HDL phospholipids were significantly increased in parallel with increased doses of fat. Lipid-free PN resulted in significantly less liver steatosis than high-fat PN. Lipid PN also resulted in downregulated hepatic lipase activity, signs of lipid accumulation in Kupffer cells and hepatocytes and an increased number of phagosomes in Kupffer cells. Fat vacuoles were found in Kupffer cells after lipid PN, although serum levels of triglycerides were not elevated and lipoprotein lipase activity were not depressed. The cells were distended by fat vacuoles after administration of PN solutions with a high fat concentration. Morphological signs of increased Kupffer cell activity were also found, suggesting that intravenous fat emulsions may activate macrophages.

Clinicopathologic study on clear cell hepatocellular carcinoma.

In order to study the clinicopathologic characteristics of the clear cell variant of hepatocellular carcinoma (HCC), 215 consecutive cases measuring less than 5 cm in diameter were reviewed. The cases were divided into clear cell HCC (20 cases); focal clear cell HCC (77 cases); and non-clear cell HCC (118 cases). Clinical and pathological findings were compared among these groups. Clear cell HCC was moderately differentiated in 80% of cases and the incidence was not related to tumor size. The male to female ratio was 2.3:1, lower than the 6.9:1 of non-clear cell HCC. The association rate with liver cirrhosis was 90%, higher than the 59.3% of non-clear cell HCC. Three- and five-year survival rates, and no recurrence time were 54.5%, 33.3%, and 564 days, respectively, lower than the findings of 74.3%, 46.1%, and 770 days for non-clear cell HCC. But there is no significant difference in prognosis between both groups. Ultrastructurally, clear cells showed abundant glycogen storage and a variable degree of fat vacuoles, with a marked reduction of the number and size of organelles in the 8 cases examined. Non-clear cells of focal clear cell and non-clear cell HCC showed a moderate degree of glycogen storage in 85.7% and 28.6% of the seven cases examined from each group, with significant difference. It was concluded that clear cell HCC occurs mostly in the moderately differentiated form and is characterized by high female prevalence, high rate of association with liver cirrhosis, and has no significant difference in prognosis compared with non-clear cell HCC.

The Lesions of Hepatic Fatty Cirrhosis in Sheep

During a natural outbreak of hepatic fatty cirrhosis (HFC) in western Texas, 500 2-6-year-old Rambouillet ewe sheep were sequentially studied to determine the pattern of lesion development. All sheep developed lesions of HFC. Grossly, changes first began in the subcapsular hepatic parenchyma along the porta hepatis and spread peripherally until, in the final stages of the disease, approximately 80% of the liver was affected. Ascites, hydropericardium, and acquired hepatic vascular shunts were present in sheep with severe HFC. Light microscopic lesions initially appeared as accumulations of fine lipid droplets in the cytoplasm of periacinar hepatocytes but, with time, involved all hepatocytes of the lobule. The fat vacuoles in the periacinar hepatocytes coalesced to form larger vacuoles; and after rupture of adjacent fat-laden hepatocytes, fatty cysts appeared. Fibrosis began in the periacinar zone associated with the ruptured fatty cysts and continued until there was widespread bridging periacinar fibrosis. Islands of regenerating hepatocytes were frequently sequestered within the bands of fibrous tissue. Characteristically, the hepatic and posterior mediastinal lymph nodes, lung, and spleen contain ceroid. No lesions of hepatic encephalopathy were found in any animal. HFC is a progressive, chronic disease of sheep, and the morphology of the hepatic lesions is similar to lipotrope-deficient forms of nutritional cirrhosis. These findings are discussed in relation to similar nutritional deficiencies and toxicoses in sheep.