[Segmental anatomy of the liver--a sonomorphological viewpoint]

The liver is an ideal organ for ultrasonography. In this context, intrahepatic structures allow the identification of segments according to Couinaud by ultrasonography. This article describes, step by step, the ultrasonographic segmental anatomy of the liver.

Tracing cellular and molecular mechanisms involved in endometriosis

The aetiology and pathogenesis of endometriosis, defined as the presence of endometrium-like tissue outside the uterine cavity, is largely unknown. In this paper we present and discuss possibilities to study the putative pathogenic properties of endometriotic cells in vitro. The current focus of our investigations is on the invasive phenotype of the disease, assuming that this might contribute to the pathogenesis of endometriosis. So far, we have shown that: (i) cytokeratin-positive and E-cadherin-negative endometriotic cells have an invasive phenotype in a collagen invasion assay in vitro similar to metastatic carcinoma cells; (ii) the invasiveness of endometriotic but not of eutopic endometrial cells can be stimulated by a heat-stable protein present in peritoneal fluid; and (iii) the endometriotic cell line EEC145T, which we established, may be a useful tool for the identification of gene products which are, positively or negatively, invasion-related. Finally, our studies suggest that the invasive phenotype in endometriosis shares aspects with tumour metastasis, but might also have unique mechanisms.

Invasive pulmonary aspergillosis in a critically ill neonate: case report and review of invasive aspergillosis during the first 3 months of life

We report a fatal case of invasive pulmonary aspergillosis in a severely ill neonate and review 43 additional cases of invasive aspergillosis reported from 1955 through 1996 that occurred during the first 3 months of life. Eleven of the 44 patients had primary cutaneous aspergillosis, 10 had invasive pulmonary aspergillosis, and 14 had disseminated disease. Most infections were nosocomial in origin. Prematurity (43%); proven chronic granulomatous disease (14%); and a complex of diarrhea, dehydration, malnutrition, and invasive bacterial infections (23%) accounted for the majority of underlying conditions. At least 41% of the patients had received corticosteroid therapy before diagnosis, but only one patient had been neutropenic. Among patients who received medical and/or surgical treatment, outcome was relatively favorable, with an overall survival rate of 73%. Invasive aspergillosis may occur in neonates and young infants and warrants consideration under certain circumstances. Current therapeutic approaches consist of high-dose amphotericin B and appropriate surgical interventions.

Hepatic and portal vein flow pattern in correlation with intrahepatic fat deposition and liver histology in patients with chronic hepatitis C

OBJECTIVE

The flow pattern in hepatic veins depends on cardiac physiology and liver histology. The aim of our study was to determine the dependence of the flow pattern of hepatic and portal veins in relation to histologic features in patients with chronic hepatitis C.

SUBJECTS AND METHODS

In 135 patients with chronic hepatitis C, the Doppler sonography spectrum of the right hepatic vein was classified as triphasic, biphasic, or monophasic. The flow of the portal vein was characterized according to the undulation (velocity(max,min)). A liver biopsy was performed during sonography, and biopsy specimens were semiquantitatively evaluated on a histologic activity index and a score of the hepatic fat content. Multiple logistic regression analysis was used to identify the histologic features that might contribute to the type of flow pattern.

RESULTS

The hepatocyte fat content was the only variable associated with an independent effect on the type of flow pattern (monophasic versus triphasic; odds ratio, 16.26; 95% confidence interval, 6.38-41.45; p < .0001). A pronounced undulation in the portal vein was associated with portal inflammation but not with other parameters of the histologic activity index or the intrahepatic fat deposition.

CONCLUSION

On sonography, the normal flow pattern in the right hepatic vein is triphasic. The monophasic flow pattern in the right hepatic vein is mainly caused by intrahepatic fat deposition and occasionally by inflammatory or fibrotic changes. Conversely, the flow pattern of the portal vein is mainly influenced by portal inflammation.

Rapid microsatellite analysis of paraffin embedded tumour specimens from patients with hereditary non-polyposis colorectal cancer

In screening for hereditary non-polyposis colorectal cancer (HNPCC)--an autosomal dominant disorder characterised by mutations in mismatch repair genes--detection of microsatellite instability is an important diagnostic criterion. The mono- or dinucleotide repeat DNA sequences are usually amplified from formalin fixed, paraffin embedded tissue by polymerase chain reaction after numerous time consuming steps including deparaffinisation, DNA extraction, and purification. A rapid single step method for direct DNA analysis is described, based on preincubation of paraffin embedded tissue with Triton X-100 followed by DNA amplification with fluorescence labelled primers and electrophoresis in an automated sequencer. This procedure allows precise allele sizing and analysis of genetic instability, is more efficient and time saving, reduces the risk of contamination, and is therefore of particular interest in screening for HNPCC.

Saccharomyces cerevisiae LIF1: a function involved in DNA double-strand break repair related to mammalian XRCC4

Saccharomyces cerevisiae DNA ligase IV (LIG4) has been shown previously to be involved in non-homologous DNA end joining and meiosis. The homologous mammalian DNA ligase IV interacts with XRCC4, a protein implicated in V(D)J recombination and double-strand break repair. Here, we report the discovery of LIF1, a S.cerevisiae protein that strongly interacts with the C-terminal BRCT domain of yeast LIG4. LIG4 and LIF1 apparently occur as a heterodimer in vivo. LIF1 shares limited sequence homology with mammalian XRCC4. Disruption of the LIF1 gene abolishes the capacity of cells to recircularize transformed linearized plasmids correctly by non-homologous DNA end joining. Loss of LIF1 is also associated with conditional hypersensitivity of cells to ionizing irradiation and with reduced sporulation efficiency. Thus, with respect to their phenotype, lif1 strains are similar to the previously described lig4 mutants. One function of LIF1 is the stabilization of the LIG4 enzyme. The finding of a XRCC4 homologue in S.cerevisiae now allows for mutational analyses of structure-function relationships in XRCC4-like proteins to define their role in DNA double-strand break repair.

Intraoperative gamma probe detection of neuroendocrine tumors

Previous studies of the intraoperative use of a handheld gamma probe to localize metastases and primary tumors of colorectal cancer have shown improved assessment of tumor spread and changes in surgical management based on added information gained by radioimmunoguided surgery. We conducted a prospective study to determine whether intraoperative radiodetection is able to reveal microscopic and occult disease of neuroendocrine tumors [medullary thyroid carcinomas (MTCs), gastroenteropancreatic (GEP) tumors].

METHODS

After the injection of 180 MBq [111In-diethylenetriaminepentaacetic acid (DTPA)-D-Phe1]pentetreotide and/or 500 MBq 99mTc-dimercaptosuccinic acid (DMSA) (both for double-nuclide scintigraphy), preoperative somatostatin receptor imaging (12 patients with GEP tumors) and double-nuclide scintigraphy (10 patients with relapsing MTCs were performed. The results were combined with the information obtained from conventional imaging modalities (CT and sonography). Intraoperative radiodetection was performed 24 hr after administration of [111In-DTPA-D-Phe1]pentetreotide or 4 hr after the injection of 99mTc-DMSA using a handheld gamma probe.

RESULTS

Intraoperative gamma counting localized 70 somatostatin receptor-positive lesions of GEP tumors, whereas preoperative receptor imaging visualized 74%, surgical palpation visualized 44% and radiological imaging modalities localized only 43%. In 10 patients with recurrent MTCs, the surgeon was successful in localizing and removing 30 tumor lesions using the gamma probe. Twenty-seven of 30 lesions demonstrated tumor involvement, whereas 3 lesions were false-positive (lymphadenitis). Double-nuclide scintigraphy revealed 67% (Octreoscan, 7 of 20; 99mTc-DMSA, 13 of 20), surgical palpation revealed 60% and conventional imaging methods (CT, sonography) revealed only 50% of all lesions detected intraoperatively by the handheld gamma probe. The smallest lesion identified by the handheld probe (not palpated by the surgeon) was a lymph node metastasis (5-mm diameter).

CONCLUSION

The preliminary data show that intraoperative handheld gamma probe detection of microscopic and occult endocrine tumors is feasible and more sensitive than external scintigraphy and conventional imaging.

Estimation and filtering of potential protein-protein docking positions

MOTIVATION

Software systems predicting automatically whether and how two proteins may interact are highly desirable, both for understanding biological processes and for the rational design of new proteins. As a part of a future complete solution to this problem, a bundle of programs is presented designed (i) to estimate initial docking positions for a given pair of docking candidates, (ii) to adjust them, and (iii) to filter them, thus preparing more detailed computations of free energies.

RESULTS

The system is evaluated on a test set of 51 co-crystallized complexes aiming at redocking the subunits. It works completely automatically and the evaluation is performed using one single set of parameters for all complexes in the test set. The number of solutions is fixed to 50 positions with a median CPU time of 26 min. For 30 complexes, these contain a near-correct solution with root mean square deviation ( RMSD ) </=5.0 A, which is ranked first in five cases. For all complexes, the best solution is scored on rank 16 as the worst case, and has a median RMSD of 4.3 A. Alternatively to this initial estimation of docking positions, a global sampling of rotations was tested. Whereas this yields top-ranked solutions with RMSD </=3.0 A for all 51 complexes, the median CPU time increases to 11 h. This shows that this blind sampling is not feasible for most applications.

AVAILABILITY

The system and its components are available on request from the authors.

CONTACT

friedric@techfak.uni-bielefeld or posch@techfak.uni-bielefeld.de

A sparsely vascularised zone in the cortex of the bovine ovary

We consider that the microvascular bed may play a role in the initiation and maintenance of growth from primordial to primary follicles. Therefore, using immunochemistry, we examined microvessels in calf and cow ovaries to identify the presence of factor VIII-related antigen endothelial cells. A vessel-poor zone was observed in the cortex of immature and mature cow ovaries. Primordial and primary follicles were assembled in this zone. It is concluded that follicular dormancy is likely to be maintained by the scarcity of microvessels and thus by the consequent poverty of the blood supply.

Quantification of the initial decline of serum hepatitis C virus RNA and response to interferon alfa

Although several virus- and host-related predictive factors for the response to interferon alfa (IFN-alpha) have been defined in patients with chronic hepatitis C, no pretreatment parameter can definitely predict the response to antiviral treatment. Assessment of the initial response by quantification of serum hepatitis C virus RNA before and 4 weeks after initiation of therapy may be a clinically applicable and reliable parameter to predict long-term response. Therefore, the aims of the present study were to test the predictive value of a decline in HCV RNA of at least 3 log in the first 4 weeks of treatment (deltaHCV RNA) in patients treated with 3 x 10(6) units of recombinant IFN-alpha2a (rIFN-alpha2a) three times per week subcutaneously and to compare deltaHCV RNA with other established predictive factors, such as HCV genotype and pretreatment viremia. Serum HCV RNA was measured by a validated quantitative reverse transcription-polymerase chain reaction (RT-PCR). Geno/subtyping of HCV was performed by direct sequencing of the nonstructural (NS) 5B region of PCR-amplified isolates and subsequent phylogenetic analysis. Stable HCV RNA levels (deltaHCV RNA < or = 1 log) within the first 4 weeks of IFN-alpha treatment were present in 42 of 70 patients. A decline in HCV RNA levels between 1 to 3 log and more than 3 log was observed in 9 (13%) and 19 patients (27%), respectively. In 21 of 70 patients (30%), HCV RNA was not detectable at the end of 12 months' treatment. Three of 26 patients (11%) with a pretreatment viremia of < or = 10(6) copies/mL (all HCV subtype 3a) and 6 of 44 patients (14%) with a pretreatment viremia of > 10(6) copies/mL (HCV subtypes 1b, 2a, 2c, 3a [two patients], and 4) achieved a virological sustained response to interferon-alpha2a treatment. All patients with a virological sustained response had an initial deltaHCV RNA of more than 3 log. In a stepwise discriminant-function analysis, the initial deltaHCV RNA was confirmed as the strongest predictor of virological sustained response (P < .0001). In conclusion, the data of the present study suggest that IFN-alpha treatment can be terminated after 4 weeks in patients with a decrease in HCV RNA levels of less than 3 log, when apparent HCV eradication is considered the therapeutic target. The predictive value of deltaHCV RNA clearly exceeds the significance of HCV genotype and pretreatment viremia as predictors of successful IFN-alpha treatment.

Psoralen photoactivation promotes morphological and functional changes in fibroblasts in vitro reminiscent of cellular senescence

Premature aging of the skin is a prominent side effect of psoralen photoactivation, a treatment used widely for various skin disorders. The molecular mechanisms underlying premature aging upon psoralen photoactivation are as yet unknown. Here we show that treatment of fibroblasts with 8-methoxypsoralen (8-MOP) and subsequent ultraviolet A (UVA) irradiation resulted in a permanent switch of mitotic to stably postmitotic fibroblasts which acquired a high level of de novo expression of SA-beta-galactosidase, a marker for fibroblast senescence in vitro and in vivo. A single exposure of fibroblasts to 8-MOP/UVA resulted in a 5.8-fold up-regulation of two matrix-degrading enzymes, interstitial collagenase (MMP-1) and stromelysin-1 (MMP-3), over a period of &gt;120 days, while TIMP-1, the major inhibitor of MMP-1 and MMP-3, was only slightly induced. This imbalance between matrix-degrading metalloproteases and their inhibitor may lead to connective tissue damage, a hallmark of premature aging. Superoxide anion and hydrogen peroxide, but not singlet oxygen, were identified as important intermediates in the downstream signaling pathway leading to these complex fibroblast responses upon psoralen photoactivation. Collectively, the end phenotype induced upon psoralen photoactivation shares several criteria of senescent cells. In the absence of detailed molecular data on what constitutes normal aging, it is difficult to decide whether the changes reported here reflect mechanisms underlying normal cellular aging/senescence or rather produce a mimic of cellular aging/senescence by quite different pathways.

Composition of ibotenic acid-induced calcifications in rat substantia nigra

Agonists of the excitatory neurotransmitter glutamate have neurotoxic properties and are, therefore, frequently used to place locally circumscript brain lesions. In certain vulnerable brain areas, especially the substantia nigra and globus pallidus, the ensuing neurodegeneration is accompanied by the formation of calcium deposits. In the present study, we investigated the structure and chemical composition of calcium deposits formed in rat substantia nigra upon local application of ibotenic acid. Using scanning and transmission electron microscopy in combination with X-ray analysis and analysis of the electron diffraction patterns, we demonstrate that the inorganic components of the calcifications consist of calcium and phosphate. The calcium phosphate is deposited in a polycrystalline manner in degenerating neurons and in a matrix surrounding the degenerated complexes. New matrix is continuously added around the enlarging calcium deposits. Content of inorganic material is always higher in the center of the deposits than in the margin, but in every case the diffraction pattern reveals that the calcium phosphates are present in the form of hydroxyapatite. Thus, organic and inorganic components of the calcifications are subject to a continuous process of growth and maturation. The ibotenic acid-induced calcium deposits in rat substantia nigra provide a reliable model system to study the pathogenesis of non-arteriosclerotic calcifications.

Is pancreatoscopy of any benefit in clarifying the diagnosis of pancreatic duct lesions?

BACKGROUND AND STUDY AIMS

Modern fine-caliber endoscopes enable clinicians to directly visualize the pancreatic duct. They allow intraductal manipulation under optical control. We tried to evaluate the additional diagnostic potential of pancreatoscopy in assessing inconclusive intraductal pancreatic changes.

PATIENTS AND METHODS

We prospectively performed 20 pancreatoscopies in 18 patients with inconclusive ductal abnormalities that had been previously investigated by computed tomography (CT) scan, abdominal ultrasound and endoscopic retrograde cholangiopancreatography (ERCP). The CHF-BP 30 (Olympus Optical Co., Japan) endoscope with an outer diameter of 3.1 mm and an instrumentation channel of 1.2 mm was used. Biopsies, cytological brushing and fluid collection were carried out, and the site of ductal abnormality was visualized. Endoscopic sphincterotomy (EST) was carried out in every patient prior to insertion of the pancreatoscope.

RESULTS

Seven intraductal tumors were histologically confirmed, i.e. five intraductal papillary mucinous tumors and two adenocarcinomas. Benign appearance of the intraductal lesion plus negative histopathological examinations were confirmed by a follow-up of two years in eight patients. Five had chronic pancreatitis, and a further three had pancreatitis with strictures, blood clot obstruction, and idiopathic benign stricture, respectively. There were no complications with the exception of one bleeding episode after EST; no pancreatitis occurred.

CONCLUSIONS

Pancreatoscopy is of diagnostic value in addition to CT, transabdominal ultrasound and ERCP in the differential diagnosis of poorly defined pancreatic lesions, particularly when assessing alterations of the ductal caliber without parenchymatous lesions.

Sonographic detection of focal changes in the liver hilus in patients receiving corticosteroid therapy

OBJECTIVE

While diffuse deposition of fat may occur with corticosteroid (CS) administration both in the liver and in other organs, comparatively little is known about focal changes in the liver under corticosteroid medication. Therefore, we evaluated pattern and extent of focal hepatic steatosis by ultrasound (US) in patients receiving corticosteroids.

SUBJECTS AND METHODS

93 patients with known inflammatory bowel disease (IBD) received corticosteroids during a period of at least six weeks prior to the ultrasound examination and 28 IBD-patients had no corticosteroids within the last three years. 13 additional patients received corticosteroids for other reasons than IBD for > 1 year. 80 healthy volunteers served as controls. Focal changes of the liver as assessed by high resolution ultrasound (Acuson 128, 3.5 and 5 MHz) were defined as areas of brighter echogenicity compared to the general aspect of the liver. The size of the hyperechoic areas was documented (photoprint).

RESULTS

40/93 IBD-patients with corticosteroids (43%) had definite areas of brighter echos in the hilus region of the liver. In IBD-patients without corticosteroids only one patient showed a focal brighter echogenicity, whereas in the non-IBD group with corticosteroids 8/13 had focal lesions (62%). In the control group only four healthy subjects showed brighter areas (5%).

CONCLUSION

Bright focal areas in the liver hilus occur in > 40% of IBD-patients during corticosteroid medication. This phenomenon occurs in IBD-patients as frequently and as intense as in other patients with longstanding corticosteroid therapy. There is a hilar area of the liver with typical size and location which reacts to corticosteroid administration with hyperechoic reflexes at ultrasound investigation. This is important to know when it comes to the differential diagnosis of focal changes.

Evidence for the development of macrophage-like cells in long-term culture of bovine aortic endothelial cells

Macrophages are known to be derived from monocytes which proliferate in the bone marrow. The proliferation of monocytes may occur in other places as well. In the present study, we describe the morphological behaviour of macrophage-like cells in endothelial cell cultures obtained from bovine aorta. These cells resembled hemopoietic clones containing progenitor-like cells. Immature and mature macrophage-like cells were rich in acid phosphatase activity, and expressed the CD18 molecule using immunolocalisation. Mature cells contained intracellular lipid droplets. "Actin" globules were apparent only in the peripheral cell areas without lamellipodia or filipodia. At the ultrastructural level, the mature cells were crowded with granules which could be lysosomes, phagolysosomes, or endocytotic vesicles. Multinuclear giant cells which behaved in a different way to the macrophage-like cells were observed. The development and maintenance of macrophage-like cells appears to be dependent on the coculture with endothelial cells. It may signify that endothelial cells are involved in the proliferation of monocytes outside the bone marrow.

Detection of normal mediastinal lymph nodes by ultrasonography

PURPOSE

The detection by US (in contrast to CT) of lymph nodes of any size in the mediastinum is usually considered to be a pathological finding. The aim of this study was to find out whether it was possible to detect normal lymph nodes by high-resolution mediastinal US.

MATERIAL AND METHODS

Six different mediastinal regions in 80 healthy asymptomatic volunteers and in 20 human cadavers were examined by means of US (with colour Doppler imaging) to assess US access to the respective regions and to demonstrate the number and size of detectable lymph nodes. All the cadaveric lymph nodes that were detected were examined histologically to exclude inflammatory or malignant infiltration.

RESULTS

In almost all subjects, we obtained US access to the supra-aortic (100%), paratracheal (95%), prevascular (99%), and pericardial (98%) regions, and to the aorticopulmonary window (98%). US access to the subcarinal region was more difficult (75%). In the healthy subjects, lymph nodes were detected in the paratracheal region (in 35% of these subjects, mean lymph-node diameter 12 x 7 mm), in the aorticopulmonary window (45%, 14 x 8 mm), and in the subcarinal region (13%, 13 x 7 mm). In the cadavers, histologically normal lymph nodes were detected frequently in the paratracheal region (85%, mean size 11 x 6 mm) and in the aorticopulmonary window (90%, 11 x 5 mm).

CONCLUSION

These results indicate that normal lymph nodes (and not only pathological lymph nodes) can be demonstrated by high-resolution mediastinal US.

Detection of the adrenal glands by endoscopic or transabdominal ultrasound

BACKGROUND AND STUDY AIMS

The value of transabdominal and endoscopic ultrasound (EUS) in detecting normal adrenal glands is not yet established. The aim of our study was to evaluate whether these techniques can be routinely used to visualize the adrenal glands in patients without suspected adrenal pathology.

PATIENTS AND METHODS

Transabdominal ultrasound was validated by examination of 10 corpses and was performed in 80 healthy volunteers (3.5 and 5 MHz). EUS of the left adrenal gland was performed in 154 consecutive patients referred for various other reasons. In 20 patients we attempted to visualize the right adrenal gland as well.

RESULTS

Both adrenal glands were correctly identified in all of the 10 corpses once they were opened. In healthy volunteers, the right adrenal gland was visualized by transabdominal ultrasound in 79/80 patients (99 %) and the left adrenal gland in 55/80 patients (69 %). EUS allowed detection of the left adrenal gland in 151/154 patients (98%). In three patients EUS failed because of grossly distorted anatomy. In 6/20 patients we were also able to detect the right adrenal gland by EUS, which was obvious in two cases because of incidentalomas.

CONCLUSION

Visualization of the right adrenal gland is almost always possible by transabdominal ultrasound, while its detection by EUS is successful only in some cases. The left gland is more difficult to detect by transabdominal ultrasound, while it can nearly always be seen using EUS. Therefore, a combined transabdominal and endoscopic ultrasonographic approach is useful for visualization of the adrenal glands and may enable diagnosis of even small adrenal masses.

[Sonographic detection of lymph nodes in the hepatoduodenal ligament]

BACKGROUND AND OBJECTIVE

In patients with chronic inflammatory liver disease modern methods of ultrasound can visualize enlarged lymph nodes in the porta hepatis. Number, size and total volume of lymph nodes in the hepatoduodenal ligament in healthy subjects and in patients with chronic viral hepatitis without cirrhotic changes were investigated.

PATIENTS AND METHODS

Sonographic localization of the perihepatic lymph nodes was validated at post-mortem and intraoperatively. Following this, 92 healthy persons (57 men, 35 women; average age 33 +/- 9 years) and 48 patients (30 men, 18 women; average age 35 +/- 8 years) with serologically and histologically confirmed chronic viral hepatitis (30 with hepatitis C, 18 with hepatitis B) were investigated by abdominal ultrasound (Acuson 128, 3.5 and 5 MHz). The hepatoduodenal ligament was assessed according to a standardized procedure with demonstration of the lymph node positions ventral to the portal vein and between the portal vein and the inferior vena cava.

RESULTS

Satisfactory imaging of the hepatoduodenal ligament was achieved in 83 of the 92 healthy persons (90.2%) and in 44 of the 48 patients with chronic viral hepatitis (91.7%). Lymph nodes were demonstrated in 60 of the 83 healthy subjects (72.3%) and in 43 of 44 patients with chronic hepatitis (97.7%). The mean perihepatic lymph node volume was 2.8 +/- 2.6 cm3 (0-9.7 cm3) and was thus significantly smaller (P = 10(-9)) than in the patients with chronic viral hepatitis (19.8 +/- 15.7 cm3 [0-62.4 cm3]). There was no significant difference in lymph node volume between patients with hepatitis B and those with hepatitis C (23.1 +/- 14.9 cm3 vs 18.9 +/- 15.6 cm3; P = 0.16).

CONCLUSIONS

With adequate ultrasound technique enlarged lymph nodes can be demonstrated in the porta hepatis of almost all patients with chronic hepatitis B or C. Lymph nodes of normal size can often be imaged also in healthy persons if their localization is known. The demonstration of lymph nodes in the hepatoduodenal ligament in the area of the porta hepatis and the determination of their volume can be helpful in the diagnosis of chronic inflammatory liver disease.

Local immunosuppression with budesonide after liver transplantation in the rat: a preliminary histomorphological analysis

BACKGROUND

In this study we have analyzed the local immunosuppression with budesonide, a topically selective glucocorticosteroid, in rats after orthotopic liver transplantation. Because of its high first-pass hepatic clearance budesonide can be given orally, achieving high intrahepatic and low systemic concentrations.

METHODS

Using an acute rejection model from Dark Agouti (DA) to Lewis rats, the histomorphological degree of rejection was assessed on histological sections at the ninth postoperative day.

RESULTS

Livers of the DA to Lewis study group without immunosuppression revealed severe allograft rejection with vast cellular infiltrates, massive endothelialitis, and hepatocyte necrosis. In the three budesonide study groups (250 microg, 500 microg, and 1 mg/kg/day) a moderate to mild liver allograft rejection was seen. Rejection was most prominent in the 250 microg group, whereas the 1 g group showed almost no signs of rejection, similar to the Lewis to Lewis control group. Aspartate and alanine transaminase (sGOT, sGPT) as well as alkaline phosphatase serum levels correlated with the degree of rejection, achieving highest levels in the DA to Lewis group without immunosuppression. Animals treated with 1 g of budesonide had serum levels similar to Lewis to Lewis control animals.

CONCLUSIONS

These results implicate a beneficial effect of local immunosuppression with budesonide in rats based on the histomorphological degree of liver allograft rejection.

Prevalence and clinical and histological manifestation of hepatitis G/GBV-C infections in patients with elevated aminotransferases of unknown etiology

BACKGROUND/AIMS

Hepatitis G virus (HGV) and hepatitis GB virus-C (GBV-C) are recently identified non-A-E hepatitis-associated viruses. The prevalence of HGV/GBV-C in the general population is high (1.0-1.7%), but data on the clinical and histological manifestations of the new viruses are sparse. In the present study we investigated the prevalence and clinical and histological manifestation of HGV/GBV-C infections in patients with elevated aminotransferase levels of unknown etiology.

METHODS

In 52 of 630 consecutive patients referred for evaluation of elevated aminotransferases the underlying liver disease remained unknown. Serum samples of these 52 patients with elevated aminotransferase levels of unknown etiology were tested for HGV/GBV-C RNA by reverse transcription-polymerase chain reaction (RT-PCR) using primers deduced from nonstructural regions. Cloned PCR products were sequenced and compared by phylogenetic analysis.

RESULTS

HGV/GBV-C RNA was consistently detected in 7 of the 52 patients (13%). Sequence and phylogenetic analysis revealed the presence of only one subtype, with nucleotide sequence homologies between 86 and 91%. All seven patients had persistent viremia for at least 9 months. In six patients liver function test results normalized, and alanine aminotransferase levels remained persistently elevated in only one patient. Four HGV/GBV-C positive and ten HGV/GBV-C negative patients consented to a liver biopsy, which revealed similar results with minimal to mild chronic hepatitis and mild portal fibrosis.

CONCLUSIONS

The prevalence of HGV/GBV-C infections in patients with elevated aminotransferases of unknown etiology is low. Since clinical, biochemical and histomorphologic features of patients with elevated aminotransferases of unknown etiology with and without HGV/GBV-C infection are indistinguishable, the role of HGV/GBV-C in the pathogenesis of chronic liver disease appears insignificant.

Enlargement of perihepatic lymph nodes in relation to liver histology and viremia in patients with chronic hepatitis C

Inflammatory processes in organs frequently lead to hyperplasia of regional lymph nodes. In the present study, we investigated whether lymph node enlargement within the hepatoduodenal ligament may reflect the inflammatory activity within the liver of patients chronically infected with the hepatitis C virus (HCV). In 114 patients with chronic hepatitis C and 49 healthy controls, the total lymph node volume within the hepatoduodenal ligament was prospectively investigated by ultrasound. In patients with chronic hepatitis C, a liver biopsy was taken at the same occasion, and specimens were semiquantitatively evaluated by the histological activity index (HAI). Hepatitis C viremia was assessed by quantitative reverse transcription-polymerase chain reaction (RT-PCR). Genotyping was performed by a reverse hybridization assay. In 104 of 114 patients (91.2%) and in 45 of 49 healthy controls (91.8%), adequate visualization of the region of the hepatoduodenal ligament was achieved by ultrasound. Lymph nodes were detected in all patients with chronic hepatitis C and in 33 of 45 controls. The mean perihepatic lymph node volume in healthy controls (2.2 +/- 1.8 mL) was lower than in HCV-infected patients with mild to moderate inflammatory activity, severe inflammatory activity, and patients with cirrhosis (5.8 +/- 2.2 mL, 18.1 +/- 10.4 mL, and 22.8 +/- 18.8 mL, respectively). In patients with HCV-RNA levels of less than 10(6) copies/mL, the total lymph node volume was 5.8 +/- 1.6 mL and was significantly increased in patients with higher viremia (20.3 +/- 13.8 mL; P < 10(-6)). No correlation was found between the total lymph node volume within the hepatoduodenal ligament, HCV genotypes, and liver function test results. In conclusion, enlargement of perihepatic lymph nodes in patients with chronic hepatitis C is predictive for the presence of severe inflammatory activity. The mechanism of portal lymphadenopathy in patients with chronic hepatitis is unknown but appears to be related to viral replication within the liver and the immune-mediated inflammatory response of the host.

A newly identified DNA ligase of Saccharomyces cerevisiae involved in RAD52-independent repair of DNA double-strand breaks

Eukaryotic DNA ligases are ATP-dependent DNA strand-joining enzymes that participate in DNA replication, repair, and recombination. Whereas mammalian cells contain several different DNA ligases, encoded by at least three distinct genes, only one DNA ligase has been detected previously in either budding yeast or fission yeast. Here, we describe a newly identified nonessential Saccharomyces cerevisiae gene that encodes a DNA ligase distinct from the CDC9 gene product. This DNA ligase shares significant amino acid sequence homology with human DNA ligase IV; accordingly, we designate the yeast gene LIG4. Recombinant LIG4 protein forms a covalent enzyme-AMP complex and can join a DNA single-strand break in a DNA/RNA hybrid duplex, the preferred substrate in vitro. Disruption of the LIG4 gene causes only marginally increased cellular sensitivity to several DNA damaging agents, and does not further sensitize cdc9 or rad52 mutant cells. In contrast, lig4 mutant cells have a 1000-fold reduced capacity for correct recircularization of linearized plasmids by illegitimate end-joining after transformation. Moreover, homozygous lig4 mutant diploids sporulate less efficiently than isogenic wild-type cells, and show retarded progression through meiotic prophase I. Spore viability is normal, but lig4 mutants appear to produce a higher proportion of tetrads with only three viable spores. The mutant phenotypes are consistent with functions of LIG4 in an illegitimate DNA end-joining pathway and ensuring efficient meiosis.

Multiple coronary artery-left ventricular fistulae: haemodynamic quantification by intracoronary Doppler ultrasound

Multiple coronary artery-left ventricular fistulae involving all three major coronary arteries are extremely rare. Clinical findings are heterogeneous but include a history of typical or atypical angina pectoris in most cases. Coronary arteriography in a 65 year old woman who presented with chest pain at rest revealed multiple fine fistulae arising from the left anterior descending, left circumflex, and right coronary arteries. Left-to-left shunt was estimated by measurements of coronary artery flow velocity with intravascular Doppler ultrasound.