Detection and quantification of protein phosphatase inhibitor-1 gene expression in total rat liver and isolated hepatocytes

The mRNA expression of protein phosphatase inhibitor-1 (inhibitor-1) in rat liver was demonstrated using highly sensitive semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Quantification by real-time RT-PCR (LightCycler technology) yielded the same copy number of inhibitor-1 mRNA in total rat liver and isolated hepatocytes (12 copies per cell). This novel finding shows that rat liver expresses indeed inhibitor-1 mRNA, albeit in low amounts. The low copy number explains why the mRNA had not been detected by Northern blotting so far. For comparison, about 425 copies/cell were detected in brain and 2500 copies/cell in skeletal muscle from rat. The full-length coding sequence of rat liver inhibitor-1 was cloned and sequenced, 100% homology with the muscle cDNA was obtained, indicating the expression of the same gene in liver and muscle. In vitro transcription and translation yielded a protein (Mr approximately 30 kDa) which could be detected with a specific antibody by immunoblotting. This indicates an intact open reading frame of inhibitor-1 in rat liver. Immunoblotting of liver extract yielded a very weak band which comigrated with the inhibitor-1 proteins from muscle and brain. It is concluded that mRNA expression of inhibitor-1 may have implications for the regulation of protein phosphatase-1 (PP1) in rat liver.

Aberrant cyclooxygenase isozyme expression in human intrahepatic cholangiocarcinoma

METHODS

Cellular localisation of the cyclooxygenase (COX) isozymes COX-1 and COX-2 was analysed in 24 cholangiocarcinomas, including 17 matched tissues originating from non-tumorous liver tissue adjacent to tumours and seven biopsies of normal human liver, by immunohistochemistry using isozyme selective antibodies.

RESULTS

In normal liver, constitutive expression of COX-2 protein was a characteristic feature of hepatocytes whereas no COX-2 immunosignal was detectable in normal bile duct epithelium, Kupffer, and endothelial cells. In cholangiocarcinoma cells, COX-2 protein was strongly expressed at high frequency. The intensity, percentage of positive cells, and pattern of COX-2 expression were found to be independent of the stage of tumour differentiation. In hepatocytes of matched non-tumorous tissue, COX-2 expression was unaltered. In contrast, strong COX-1 expression was frequently localised to Kupffer cells, endothelial cells, and occasionally to hepatocytes, but not to bile duct epithelial cells. In approximately half of moderately and poorly differentiated but not well differentiated cholangiocarcinomas, weak to moderate COX-1 staining was found in tumour cells while COX-1 expression in Kupffer cells was much more pronounced.

CONCLUSION

Aberrant COX-2 expression occurs during the early stage while COX-1 over expression seems to be related to later stages of cholangiocarcinogenesis.

Down-regulation of insulin-like growth factor-I receptor and insulin receptor substrate-1 expression in advanced human breast cancer

The ligands, receptors and related signaling proteins of the insulin-like growth factor family are involved in the regulation of breast-cancer cell growth. We investigated the expression pattern of insulin-like growth factor-I receptor (IGF-IR), insulin receptor (IR) and insulin receptor substrate-1 (IRS-1), a core downstream signaling protein, in 69 primary breast-cancer specimens of different grades and in 21 control tissues by immunohistochemistry. In addition, cell proliferation (percentage of Ki67(+) nuclei) and estrogen receptor (ER) expression were determined. IGF-IR, IRS-1 and IR were expressed mainly in epithelial cells. IRS-1 and IGF-IR were expressed at high levels in control tissues and in well and moderately differentiated carcinomas but at low levels in poorly differentiated breast cancers. IR expression did not show a significant correlation with the differentiation grade of the tissues investigated. Statistical analysis (ROC analysis for tumor grade) demonstrated that down-regulation of IGF-IR and IRS-1 correlated better with tumor progression than reduction of ER expression or increase in cell proliferation, IGF-IR showing the best correlation, followed by IRS-1 and, less significant, ER and Ki67. Our findings clearly show that progression of breast cancer is accompanied by a reduction of IGF-IR/IRS-1 expression and that IGF-IR/IRS-1 expression inversely correlates with high proliferation rate in dedifferentiated breast cancers. The strong correlation of IGF-IR and IRS-1 down-regulation with tumor progression suggests the use of IGF-IR and IRS-1 as a novel set of marker proteins for tumor grading.

Quantification of fMRI artifact reduction by a novel plaster cast head holder

In light of artifact-induced high variability of activation in fMRI repeat studies, we developed and tested a clinically useful plaster cast head holder (PCH) with improved immobilization, repositioning, and comfort. With PCH, there were considerably lower levels of translational and rotational head motion components compared to head fixation with conventional restraining straps (CRS). Rotational components cannot be fully compensated by realignment and lead to "false activations." In addition, task-correlated head motion, which highly increases the risk of artifacts, was considerably reduced with PCH, especially in a motion prone subject. Compared with PCH, head motion was 133% larger with CRS in a highly cooperative subject. With a motion prone subject, head motion range was increased by 769% (PCH: 0.9 mm, CRS: 7.8 mm), which may indicate the usefulness of PCH for restless patients. In functional activation maps, PCH alone yielded fewer residual motion artifacts than CRS + image registration. Subject tolerance of the head holder during the long measurement times of up to 2.5 hr was good, and slice orientation on different days confirmed the quality of repositioning.

Internet supply ordering. Helping medical group practices improve business operations

Technology has opened the door to a new world of management tools in the physician practice environment. Productivity aids on the Web promise to alter forever the way we do everything--from interacting with vendors to caring for patients. Online medical, surgical and pharmaceutical supply acquisition sites, for example, already offer more efficient alternatives to phone and fax ordering, back-order challenges and supply cost monitoring. Not all sites are the same, however, and physicians and practice administrators must compare and contrast their needs with site offerings.

Fast echo planar based correlation-peak imaging: demonstration on the rat brain in vivo

Two-dimensional correlation spectroscopy (2D-COSY) was combined with a fast echo planar based spectroscopic imaging technique in a new sequence. It can be optimized according to the coupling patterns of particular metabolites by using a constant time (CT) variant of COSY with chemical shift selective excitation and refocusing. Experiments were performed with an evolution time of 110 ms which was determined by simulating the CT-COSY experiment at several evolution times for the spin systems of myo-inositol (Ins) and taurine (Tau). The sequence has a minimum total measurement time of 17 min and was tested on a spherical phantom filled with a solution of Ins. The in vivo application of this method on the healthy rat brain demonstrates its improved spectral resolution as cross-peak signals from both Ins and Tau can be separated clearly. Magn Reson Med 44:23-28, 2000.

Modulation of spatial orientation processing by mental imagery instructions: a MEG study of representational momentum

Under appropriate conditions, an observer's memory for the final position of an abruptly halted moving object is distorted in the direction of the represented motion. This phenomenon is called "representational momentum" (RM). We examined the effect of mental imagery instructions on the modulation of spatial orientation processing by testing for RM under conditions of picture versus body rotation perception and imagination. Behavioral data were gathered via classical reaction time and error measurements, whereas brain activity was recorded with the help of magnetoencephalography (MEG). Due to the so-called inverse problem and to signal complexity, results were described at the signal level rather than with the source location modeling. Brain magnetic field strength and spatial distribution, as well as latency of P200m evoked fields were used as neurocognitive markers. A task was devised where a subject examined a rotating sea horizon as seen from a virtual boat in order to extrapolate either the picture motion or the body motion relative to the picture while the latter disappeared temporarily until a test-view was displayed as a final orientation candidate. Results suggest that perceptual interpretation and extrapolation of visual motion in the roll plane capitalize on the fronto-parietal cortical networks involving working memory processes. Extrapolation of the rotational dynamics of sea horizon revealed a RM effect simulating the role of gravity in rotational equilibrium. Modulation of the P200m component reflected spatial orientation processing and a non-voluntary detection of an incongruity between displayed and expected final orientations given the implied motion. Neuromagnetic properties of anticipatory (Contingent Magnetic Variation) and evoked (P200m) brain magnetic fields suggest, respectively, differential allocation of attentional resources by mental imagery instructions (picture vs. body tilt), and a communality of neural structures (in the right centro-parietal region) for the control of both RM and mental rotation processes. Finally, the RM of the body motion is less prone to forward shifts than that of picture motion evidencing an internalization of the implied mass of the virtual body of the observer.

Supplementary motor area activation preceding voluntary movement is detectable with a whole-scalp magnetoencephalography system

Despite the fact that the knowledge about the structure and the function of the supplementary motor area (SMA) is steadily increasing, the role of the SMA in the human brain, e.g., the contribution of the SMA to the Bereitschaftspotential, still remains unclear and controversial. The goal of this study was to contribute further to this discussion by taking advantage of the increased spatial information of a whole-scalp magnetoencephalography (MEG) system enabling us to record the magnetic equivalent of the Bereitschaftspotential 1, the Bereitschaftsfeld 1 (BF 1) or readiness field 1. Five subjects performed a complex, and one subject a simple, finger-tapping task. It was possible to record the BF 1 for all subjects. The first appearance of the BF 1 was in the range of -1.9 to -1.7 s prior to movement onset, except for the subject performing the simple task (-1 s). Analysis of the development of the magnetic field distribution and the channel waveforms showed the beginning of the Bereitschaftsfeld 2 (BF 2) or readiness field 2 at about -0.5 s prior to movement onset. In the time range of BF 1, dipole source analysis localized the source in the SMA only, whereas dipole source analysis containing also the time range of BF 2 resulted in dipole models, including dipoles in the primary motor area. In summary, with a whole-head MEG system, it was possible for the first time to detect SMA activity in healthy subjects with MEG.

Portal vein thrombosis in adults undergoing liver transplantation: risk factors, screening, management, and outcome

BACKGROUND

Portal vein thrombosis (PVT) has been seen as an obstacle to liver transplantation (LTx). Recent data suggest that favorable results may be achieved in this group of patients but only limited information from small size series is available. The present study was conducted in an effort to review the surgical options in patients with PVT and to assess the impact of PVT on LTx outcome. Risk factors for PVT and the value of screening tools are also analyzed.

METHODS

Adult LTx performed from 1987 through 1996 were reviewed. PVT was retrospectively graded according to the operative findings: grade 1: <50% PVT +/- minimal obstruction of the superior mesenteric vein (SMV); grade 2: grade 1 but >50% PVT; grade 3: complete PV and proximal SMV thrombosis; grade 4: complete PV and entire SMV thrombosis.

RESULTS

Of 779 LTx, 63 had operatively confirmed PVT (8.1%): 24 had grade 1, 23 grade 2, 6 grade 3, and 10 grade 4 PVT. Being male, treatment for portal hypertension, Child-Pugh class C, and alcoholic liver disease were associated with PVT. Sensitivity of ultrasound (US) in detecting PVT increased with PVT grade and was 100% in grades 3-4. In patients with US-diagnosed PVT, an angiogram was performed and ruled out a false positive US diagnosis in 13%. In contrast with US, angiograms differentiated grade 1 from grade 2, and grade 3 from grade 4 PVT. Grade 1 and 2 PVT were managed by low dissection and/or a thrombectomy; in grade 3 the distal SMV was directly used as an inflow vessel, usually through an interposition donor iliac vein; in grade 4 a splanchnic tributary was used or a thrombectomy was attempted. Transfusion requirements in PVT patients (10 U) were higher than in non-PVT patients (5 U) (P<0.01). In-hospital mortality for PVT patients was 30% versus 12.4% in controls (P<0.01). Patients with PVT had more postoperative complications, renal failure, primary nonfunction, and PV rethrombosis. The overall actuarial 5-year patient survival rate in PVT patients (65.6%) was lower than in controls (76.3%; P=0.04). Patients with grade 1 PVT, however, had a 5-year survival rate (86%) identical to that of controls, whereas patients with grades 2, 3, and 4 PVT had reduced survival rates. The 5-year patient survival rate improved from the 1st to the 2nd era in non-PVT patients (from 72% to 83%; P<0.01), in grade 1 PVT (from 53% to 100%; P<0.01), and in grades 2 to 4 PVT (from 38% to 62%; P=0.11).

CONCLUSIONS

The value of US diagnosis in patients with PVT depends on the PVT grade, and false negative diagnoses occur only in incomplete forms of PVT (grades 1-2). The degree of PVT dictates the surgical strategy to be used, thrombectomy/low dissection in grade 1-2, mesoportal jump graft in grade 3, and a splanchnic tributary in grade 4. Taken altogether, PVT patients undergo more difficult surgery, have more postoperative complications, have higher in-hospital mortality rates, and have reduced 5-year survival rates. Analysis by PVT grade, however, reveals that grade 1 PVT patients do as well as controls; only grades 2 to 4 PVT patients have poorer outcomes. With increased experience, results of LTx in PVT patients have improved and, even in severe forms of PVT, a 5-year survival rate >60% can now be achieved.

Immune responses to Mycoplasma conjunctivae in alpine ibex, alpine chamois, and domestic sheep in Switzerland

The humoral immune response of three alpine chamois (Rupicapra rupicapra rupicapra), two alpine ibex (Capra ibex ibex) and three domestic sheep naturally affected with infectious keratoconjunctivitis (IKC), and four ibex and two sheep experimentally infected with Mycoplasma conjunctivae was analysed. In addition, the local immune response to M. conjunctivae was analysed using conjunctival washes from chamois and sheep. Immunoblot analysis of sera using whole cell antigens of M. conjunctivae revealed the major immunogenic proteins which had molecular masses of 175, 83, 68, 60, 50, 42, 36, and 33 kDa. Major antigens were found at 83, 68, 60, and 42 kDa in both sera and conjunctival washes from naturally infected animals of all three Caprinae species. In experimentally infected animals, antibodies to the 68 and 60 kDa antigens were dominant. Naturally infected animals showed much stronger immune reactions than those experimentally infected, and specific antibodies appeared 2 to 4 wk after experimental infection. To evaluate possible cross-reactions, whole cell antigen of M. conjunctivae was analysed by immunoblot against hyperimmune sera of closely related Mycoplasma spp. Antibodies to the 175, 73, 68, 60, and 33 kDa antigens appeared to be specific to M. conjunctivae. Cross-reactions mainly with 83, 50, and 42 kDa antigens were detected, in particular with M. ovipneumoniae and M. bovoculi hyperimmune sera, but also with antisera against M. capricolum capricolum and M. putrefaciens.

Sonographic measurement of thickened bowel wall segments as a quantitative parameter for activity in inflammatory bowel disease

Inflammatory bowel disease (IBD) is associated with morphological changes of the bowel wall that can be visualized by abdominal ultrasound (US). This method is a tool to detect the extent of bowel wall thickening and the length of involved segments. The purpose of this study was to determine the value of sonographic measurement of inflamed bowel wall segments as a quantitative parameter for disease activity. 137 patients with Crohn's disease (CD) and 32 patients with ulcerative colitis (UC) were included in the present study. A total 356 US examinations were performed within a one-year period. In a segment-by-segment analysis we determined the "volume of inflamed bowel wall" (VIB) by measuring wall thickness and longitudinal extent of pathologically altered bowel segments. VIB was used as a quantitative parameter for disease activity based on sonomorphological findings. At the same time the following parameters were also determined: CD activity index (CDAI) in patients with CD, clinical activity index (CAI) in patients with UC, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). We found no relevant correlation between VIB and biochemical indices of inflammation (ESR, CRP) and between VIB and clinical activity of IBD (CDAI, CAI). All correlation coefficients were below 0.5. It can be concluded that the extent of inflammatory changes of the bowel wall detected by US is not strictly associated with clinical activity and laboratory parameters of inflammation.

A marker for differentiation of capabilities for processing of musical harmonies as detected by magnetoencephalography in musicians

This investigation was designed to study the characteristics of a marker for harmonic processing and to test whether it could be used for differentiating harmonic processing capabilities. The first three chords of an ordinary musical cadenca were presented to the left ear to establish a harmonic context followed by a harmonic or non-harmonic target tone. Cadencas were presented rapidly and randomly in different keys to render the task difficult. Results showed a specific P3m (magnetic P300) effect to the non-harmonic targets which was only visible in subjects with low target recognition errors. Low resolution electro-magnetic tomography current density maps showed P3m sources in the right temporoparietal, left temporoparietal and frontocentral brain areas with right temporoparietal sources being strongest and most reliable. The results offer new possibilities to selectively study harmonic variables in music processing.

Perception of the form of stimulus increment as a method in assessment of the psychophysical relationship

Among numerous procedures for determination of the psychophysical relation, one approach has seldom been applied. Essential in this method is to present a set of stimuli whose intensity increases in fixed time following different forms. The objective stimulus increment, which the subjects perceive as linear growth directly, represents the inverse psychophysical relation. In this paper the method was tested in the fields of click frequency and sound pressure. This procedure was named "Perception of the Form of Stimulus Increment in Time". In comparison to other psychophysical approaches, this one has several advantages. The principal ones are the following: (1) In assessing the psychophysical relation it is not necessary to try to measure the perceptual magnitude; and (2) the psychophysical relation is directly determined by its dynamic pattern. In this paper modifications to the method are reported which facilitate the subject's task and avoid some differences in subjects' individual approaches to the task. The modified procedure leads to results satisfactory independent of the influence of the factors irrelevant to the psychophysical relationship.

Central hemodynamic effects of an oxytocin receptor antagonist (atosiban) in the isolated, perfused rat heart

OBJECTIVE

Atosiban is a selective oxytocin receptor antagonist capable of inhibiting oxytocin-induced contractility of the uterus. Trials of this agent in intact animals and women as a tocolytic agent for preterm labor have shown atosiban to be devoid of cardiac effects. This is in contrast to other tocolytic agents, which have profound hemodynamic effects. We conducted this study to determine the cardiac effect of atosiban in the isolated, perfused rat heart model.

METHODS

Hearts were excised from 60 female Sprague-Dawley rats and attached to a Langendorff apparatus. Left ventricular systolic pressure, heart rate, and contractility were measured. Hearts from half of the animals were exposed serially to 300 micrograms/min, 600 micrograms/min, and 1200 micrograms/min of atosiban. The remaining hearts formed the control group and were exposed to aerated Krebs solution.

RESULTS

There were no significant differences between hearts exposed to atosiban and hearts within the control group for heart rate, left ventricular systolic pressure, and contractility. P values ranged from .12 to .73.

CONCLUSIONS

Using a classic physiologic model to study cardiac performance and drug effects, we were unable to detect any central hemodynamic effects of atosiban. This is in contrast to oxytocin, which we previously studied and found negative chronotropic and positive ionotropic effects.

Insulin receptor substrate-1 is over-expressed in glycogenotic but not in amphophilic preneoplastic hepatic foci induced in rats by N-nitrosomorpholine and dehydroepiandrosterone

Insulin receptor substrate-1 (IRS-1) is over-expressed in preneoplastic glycogenotic hepatic foci (GSF) and is gradually down-regulated during progression of these lesions, via mixed cell foci (MCF), to the basophilic neoplastic phenotype. The aim of the present study was to investigate the effect of dehydroepiandrosterone (DHEA), a weak hepatocarcinogen and tumour enhancer, on IRS-1 expression. Hepatocellular lesions were induced by N-nitrosomorpholine followed by DHEA. Under these conditions, many glycogen-poor amphophilic (APF) and intermediate cell foci (ICF) appear, in addition to GSF and MCF. IRS-1 was over-expressed in 215 out of 295 GSF, in 50 out of 53 MCF and in a glycogen-rich mixed cell adenoma. IRS-1 expression was not shown in 147 APF, 51 ICF and 5 amphophilic hepatocellular adenomas, and 3 out of 5 hepatocellular carcinomas showed a weak IRS-1 expression. The results suggest a close association of IRS-1 over-expression with the glycogenotic hepatocellular phenotype. The modulation and enhancement of tumour progression by DHEA is associated with a shift from glycogenosis to amphophilia and basophilia, and a down-regulation of IRS-1 expression.

Dehydroepiandrosterone increases the zone [correction of in zone] of glutamine synthetase-positive hepatocytes in female rat liver: a putative androgenic effect

The adrenal steroid dehydroepiandrosterone (DHEA) is a hepatocarcinogen and peroxisome proliferator in the rat, producing an increase in peroxisomes mainly in perivenular parts of the liver lobule. Glutamine synthetase (GS) is expressed exclusively in hepatocytes that directly surround the central terminal vein in rat liver. The GS-positive zone is wider in males than in females, covering about two to three cell layers in males and one to two cell layers in females. Treatment of rats with DHEA at a concentration of 0.6% in the diet for 4, 20, 32, 70 and 84 weeks resulted in an enlargement of the GS-positive zone in females, whereas no change was observed in males. In females treated for up to 32 weeks with DHEA, the relative mean width (RMW) of the GS-positive zone was as large as that observed in males. The increase in the RMW was paralleled by an increase in the number of GS-positive hepatocytes. Upon longer treatment, the width of GS expression decreased to that observed in untreated controls. The findings suggest an androgenic effect of DHEA. The areas of peroxisome proliferation, identified in haematoxylin and eosin- and periodic acid-Schiff-stained sections, and GS expression were not identical. Furthermore, preneoplastic and neoplastic liver lesions induced by DHEA were all negative for GS, indicating that they do not derive from the perivenular cells which show the most pronounced peroxisomal proliferation.

Vitamin E prevents induction of carbonyl group formation in microsomal protein by dehydroepiandrosterone

The effect of dehydroepiandrosterone (DHEA), a free radical- and lipid peroxide-inducing agent, and of vitamin E (alpha-tocopherol), a free radical chain terminator, on protein carbonyl group formation was investigated in rat liver microsomes. Administration of alpha-tocopherol at 25-50 mg/kg diet for seven days resulted in high Fe(2+)-NADPH-ADP-dependent production of protein carbonyl groups in liver microsomal protein isolated from otherwise untreated rats. However, alpha-tocopherol administered at > 100 mg/kg diet caused a decrease in the production of protein carbonyl groups. In animals simultaneously receiving alpha-tocopherol at 50 mg/kg diet and DHEA at 500 mg/kg diet, no additional stimulatory effect of the steroid on microsomal protein carbonyl group production was observed. Protein carbonyl group production was significantly enhanced by DHEA in rats given a diet containing 400 mg alpha-tocopherol/kg diet. Microsomes isolated from rats fed 1,000 mg alpha-tocopherol/kg diet with DHEA (500 mg/kg diet) and without DHEA produced small but similar amounts of protein carbonyl groups. These results provide evidence that vitamin E is an important protective agent against DHEA-mediated oxidative damage of intracellular components, including proteins.

Intracellular expression of Fc gamma RIII (CD16) and its mobilization by chemoattractants in human eosinophils

We characterized the existence, translocation, and reabsorption during cellular activation of a constitutively expressed intracellular CD16 in the human eosinophil. By two-color flow cytometry, we showed that 6.5+/-0.3% of nonpurified eosinophils expressed surface CD16. After digestion with phosphatidylinositol-specific phospholipase C, surface CD16 on both neutrophils and eosinophils decreased substantially, suggesting that eosinophil CD16 is a glycosyl-phosphatidylinositol-linked isoform. However, CD16 was substantially expressed intracellularly in human eosinophils. Epitope-specific binding to CLB-gran11 mAb from non-NA2/NA2 donors demonstrated that intracellular eosinophil CD16 also differed from the transmembrane isoform of CD16 expressed on NK cells or macrophages. Western blot analysis performed with 3G8 or DJ130c mAb showed a broad band at approximately 65 to 80 kDa, which was the same as neutrophil CD16 from the same NA2/NA2 donors. Upon stimulation by chemoattractants C5a, FMLP, or platelet-activating-factor, eosinophilic intracellular CD16 was rapidly translocated to the eosinophil surface, expressed maximally at 30 s, and then gradually disappeared from the cell surface during the next 10 min. Intracellular flow cytometry of stimulated eosinophils and sandwich ELISA of stimulated eosinophil supernatants demonstrated that the disappearance was due to its rapid release into medium and reabsorption by the cells. Our data identify a CD16B that is consistently expressed intracellularly but only rarely on the surface of nonactivated human eosinophils. This CD16 is transiently expressed during stimulation by chemoattractants.

A new method for flat-embedding large native cryostat sections for targeting small preneoplastic lesions in comparative ultrastructural and ultracytochemical investigations

Ultrastructural studies of rare and small cellular lesions in pathologically altered tissue are difficult to perform by applying conventional electron microscopic preparation. The search for lesions, often consisting of only a few cells in randomly obtained small specimen blocks, is time consuming and often without success. The methodological requirements for comparative enzyme cytochemical and morphological studies, i.e., preservation of both enzyme activity and ultrastructure, are divergent. By processing large native cryostat sections for electron microscopy, small preneoplastic focal lesions were successfully targeted in liver and kidney. Glucose-6-phosphatase, alkaline phosphatase, acid phosphatase, catalase, and cytochrome c oxidase activities were distinctly localized to endoplasmic reticulum, canalicular membrane, lysosomes, peroxisomes, and mitochondria, respectively, in the morphologically altered cells. Fixation of serial cryostat sections and enzyme reactions were both carried out through a semipermeable membrane except those for cytochrome c oxidase, which was demonstrated after fixation through the membrane by floating the section in incubation medium containing cytochrome c. Thereafter, the sections were flat embedded and polymerized between epoxy resin disks and aluminum dishes fitting exactly together. The objects of interest were identified in the light microscope, cut out, and reembedded in reversed gelatine capsules. By using this technique an ultrastructural preservation was achieved similar to that seen after immersion fixation. The enzyme activities were clearly localized without diffusion of the reaction product or unspecific deposits. The procedure permits precise targeting and complex studies of rare and small lesions, and opens new perspectives for the use of cryo-preserved tissue.

Nursing management of the patient with bone metastases

OBJECTIVES

To review the problem of bone metastases and strategies aimed at the management of bone metastases.

DATA SOURCES

Review articles, book chapters, research studies, and clinical practice.

CONCLUSIONS

As patients survive for longer periods, effective management of bone metastases becomes critical to maintaining or improving quality of life. Controlling pain, preventing fractures and oncologic emergencies, and promoting mobility and function are the outcomes of successful management.

IMPLICATIONS FOR NURSING PRACTICE

Use of a clinical algorithm may assist the nurse in identifying bone metastases and managing the clinical sequelae, such as pain.

Comparison of different endocrine stimulation tests in nondiabetic patients with chronic pancreatitis

BACKGROUND/AIMS

The purpose of this study was to evaluate endocrine functional impairment in nondiabetic patients with chronic pancreatitis and to determine its reliability in the staging of this disease.

METHODOLOGY

Eighteen patients with chronic pancreatitis and fasting normoglycemia (fasting blood glucose level < 100 mg/dl) and 10 healthy subjects underwent an oral glucose tolerance test (OGTT), an intravenous glucose test (IGT) and an arginine stimulation test (AST). Blood glucose and serum concentrations of insulin, C-peptide and glucagon were measured before and after stimulation. Exocrine pancreatic function was assessed by the pancreolauryl serum test (PLT), and morphological changes were staged by endoscopic retrograde pancreaticography (ERP), which were rated as I (mild), II (moderate) or III (severe).

RESULTS

Glucagon and C-peptide secretions after arginine stimulation were reduced in patients with moderate and severe chronic pancreatitis while no parameter was able to show impaired endocrine function in the early stage (ERP I) of the disease. Serum insulin concentrations proved to be of no use in the diagnosis of pathological B-cell function, since even patients with severe chronic pancreatitis and fasting normoglycemia demonstrated normal insulin secretion.

CONCLUSIONS

We conclude that there is a close correlation between morphological changes of the pancreas and functional endocrine reserve capacity, whereas endocrine stimulation tests were not shown to be helpful in the clinical assessment of nondiabetic patients with chronic pancreatitis.

Differential expression of key enzymes of energy metabolism in preneoplastic and neoplastic rat liver lesions induced by N-nitrosomorpholine and dehydroepiandrosterone

Preneoplastic liver foci and neoplasms of different morphological phenotypes were induced in rats with N-nitrosomorpholine (NNM; 120 mg/l in drinking water for 7 weeks) and the peroxisome proliferator dehydroepiandrosterone (DHEA; 0.6% in the diet for up to 84 weeks). Preneoplastic glycogen storage foci (GSF) occurred mainly upon treatment with NNM, and amphophilic cell foci (APF) were mainly observed in rats treated with DHEA alone or in combination with NNM. The 2 types of lesions belong to 2 different cellular lineages, the glycogenotic/basophilic lineage and the amphophilic lineage, which are characterized by distinct patterns of alterations in key enzymes of energy metabolism. Whereas in GSF enzymes of glucose metabolizing pathways were modified (increase in glucose-6-phosphate dehydrogenase and pyruvate kinase, decrease in glucose-6-phosphatase), APF mainly demonstrated alterations in mitochondrial enzymes (increase in cytochrome c oxidase, succinate dehydrogenase and glycerol-3-phosphate dehydrogenase) and, to a lower extent, in peroxisomal enzymes (increase in peroxisomal hydratase and acyl-CoA oxidase). The alterations in enzyme expression reflect an insulinomimetic effect in GSF and a thyromimetic effect in APF. Neoplasms resulting from APF show a more differentiated phenotype than those arising from GSF. We suggest that the different and in many aspects opposite effects of the 2 carcinogens on key enzymes of distinct pathways of energy metabolism modulate the process of neoplastic liver cell transformation and result in phenotypically different preneoplasias and neoplasias reflecting different cellular lineages.

Oral L-ornithine-L-aspartate therapy of chronic hepatic encephalopathy: results of a placebo-controlled double-blind study

BACKGROUND/AIMS

In the current state of knowledge of the pathophysiology of hepatic encephalopathy, a reduction in hyperammonemia is the most important evidence of effective treatment. Therefore, the therapeutic efficacy of oral L-ornithine-L-aspartate, which improves impaired ammonia detoxification, was investigated in patients with cirrhosis, hyperammonemia and stable, overt, chronic hepatic encephalopathy, and in subclinical hepatic encephalopathy in a randomized, double-blind, placebo-controlled clinical trial.

METHODS

Oral L-ornithine-L-aspartate was administered three times daily at fixed times for 14 consecutive days in a total dose of 18 g per day. The design was chosen to prevent an increase in ammonia induced by a protein meal of 0.25 g/kg body weight, given at the start of the daily treatment period. Efficacy variables were: fasting and postprandial ammonia concentration, Number-Connection-Test time, mental state grades, and a Portosystemic Encephalopathy Index. Analyses were based on the total study sample of 32 placebo- and 34 L-ornithine-L-aspartate-treated patients as well as on the subgroup samples in the overt (20 placebo- and 23 L-ornithine-L-aspartate-treated) and subclinical hepatic encephalopathy (12 placebo- and 11 L-ornithine-L-aspartate-treated) patients.

RESULTS

Number Connection Test performance times (p<0.01) as well as fasting (p<0.01) and postprandial (p<0.05) venous blood ammonia concentrations in the L-ornithine-L-aspartate-treated group showed improvement in comparison to placebo. Also, the mental state grade (p<0.05) and the Portosystemic Encephalopathy Index (p<0.01), improved to a much greater degree in the L-ornithine-L-aspartate group than in the placebo group. Adverse events were observed in neither the placebo nor the L-ornithine-L-aspartate-treated patients.

CONCLUSION

Oral L-ornithine-L-aspartate is a safe, well-tolerated treatment with a good compliance rate and a beneficial therapeutic effect in patients with cirrhosis and stable, overt, chronic hepatic encephalopathy.

Effects of oral dosing with calcium propionate on total calcium and glucose concentrations in the plasma of the cow

This study aimed to determine the effect of oral drenching with molasses, calcium propionate and MgO on plasma glucose and calcium concentrations of dairy cows. Four trials were undertaken, each using three lactating and three non-lactating Jersey cows. In Trial 1, the effect of drenching with 200 ml molasses was measured. Trial 2 measured the effect of a single treatment with 349 g calcium propionate in 200 ml molasses. In Trial 3, the effect of 60 g MgO in molasses alone and in combination with calcium propionate was measured. Trial 4 tested the effect of repeating treatments with 349 g calcium propionate in 200 ml molasses 24 h apart. Dosing with 349 g calcium propionate in molasses increased plasma total calcium (Catot) concentration by 10% in lactating and non-lactating cows for periods less than 7 h, and this was not augmented by simultaneous administration of MgO or treatment 24 h earlier with 349 g calcium propionate in molasses. Treatment with 200 ml molasses alone resulted in increased plasma Catot of 7%. Plasma glucose concentrations were elevated by 11% for less than 3 h after treatment with calcium propionate. For the prevention of subclinical hypocalcaemia and ketosis in early lactation, drenching with calcium propionate solutions is unlikely to be of value due to the short duration of its effects, but the inclusion of calcium propionate in the postpartum ration deserves further investigation.

Cytochemical and biochemical studies on adenylate cyclase activity in preneoplastic and neoplastic liver tissue and cultured liver cells

The ATP-analogue adenylyl(beta,gamma-methylene)diphosphonate was chosen as substrate for the cytochemical localization of adenylate cyclase (AC) activity. The tissues investigated covered normal rat liver and liver from carcinogen-treated animals with preneoplastic lesions and hepatocellular neoplasms, as well as cultured liver cells. The AC reaction product methylene diphosphonate was precipitated with Pb2+ immediately at the place of production. This approach permitted a precise localization of AC activity by light and electron microscopy. The specificity of the AC reaction was demonstrated by control reactions, including inhibition of AC with 2'5'-dideoxyadenosine and activation with forskolin, glucagon, and cholera toxin. Endogenous phosphatases were inhibited with tetramisole and NAD. In normal liver, AC activity was mainly localized in the sinusoidal membrane of hepatocytes. A distinct gradient in activity was observed within the liver lobule. Hepatocytes localized around the terminal hepatic venule showed a significant higher AC activity compared to hepatocytes near the portal tract. AC was clearly decreased in focal preneoplastic liver lesions of the glycogenotic-basophilic cell lineage leading to hepatocellular carcinomas. Cytochemically detected intensity of AC activity corresponded to data obtained by microbiochemical assays in laser-dissected tissue samples. A remarkable interdependence of AC activity and degree of differentiation was also seen in epithelial rat liver cell lines: Highly differentiated cells show high enzyme activity and vice versa, as shown by both cytochemical and biochemical examinations. It is concluded that alterations in cellular signal transduction caused by alterations in AC activity play an important role in hepatocarcinogenesis.

Does epidural analgesia cause dystocia?

STUDY OBJECTIVE

To analyze the effects of epidural analgesia for labor when dystocia occurs.

DESIGN

Retrospective cohort study.

SETTING

Academic health center.

PATIENTS

641 low risk, nulliparous women in spontaneous labor.

INTERVENTIONS

406 (63%) women received epidurals analgesia and 253 (37%) did not. Sixty women (9.4%) required an abdominal delivery for dystocia.

MEASUREMENTS AND MAIN RESULTS

Women receiving epidural analgesia were more likely to be white, receive care from an attending physician, need labor augmentation, and deliver a heavier infant. Multivariate analysis identified five variables predictive of dystocia and abdominal delivery: pitocin augmentation odds ratio (O.R.) = 3.9 (2.0 to 7.6), duration of labor more than 20 hours O.R. = 2.4 (1.3 to 4.4), high epidural dose O.R. = 2.2 (1.2 to 4.1), birthweight over 4,000 grams O.R. = 2.0 (1.0 to 4.2), and early placement of epidural O.R. = 1. 9 (1.0 to 3.5). Repeating the regression after excluding the 20 women who developed abnormal labor prior to epidural placement (18 of 20 women had protracted dilatation) demonstrated that pitocin augmentation O.R. = 4.0 (1.8 to 4.), high epidural dose O.R. = 3.0 (1.9 to 6.2), duration of labor greater than 20 hours O.R. = 2.7 (1.3 to 5.7), and birthweight over 4,000 grams O.R. = 2.1 (0. 9 to 4.8) were associated with dystocia.

CONCLUSION

Epidural analgesia appears to be a marker of abnormal labor rather than a cause of dystocia. High concentration anesthetics and epinephrine should be avoided, as they may influence labor. Randomized, controlled trials of this technique will be difficult to do; our work should reassure patients and their clinicians that epidural analgesia does not adversely affect labor.

Enhancement and phenotypic modulation of N-nitrosomorpholine-induced hepatocarcinogenesis by dehydroepiandrosterone

Hepatocarcinogenesis was induced in male and female rats by continuous administration of the adrenal steroid dehydroepiandrosterone (DHEA; 0.6% in the diet) with and without previous treatment with N-nitrosomorpholine (NNM; 120 mg/l drinking water for 7 weeks). DHEA treatment alone resulted in hepatocellular adenomas (HCA) and carcinomas (HCC) after 72-84 weeks, the incidence of both benign and malignant neoplasms being higher in females than in males. After DHEA administration for up to 32 weeks subsequent to NNM, the incidence of HCA and HCC was significantly higher (HCA, 42%; HCC, 42%) than after NNM alone (HCA, 33%; HCC, 28%). While total tumor incidence was similar in male (63%) and female (60%) rats after NNM treatment alone, it was higher in females (87%) than in males (80%) after NNM/DHEA treatment. The difference between the genders was mainly due to the higher incidence of HCC in females. Morphometric analysis of preneoplastic foci of altered hepatocytes (FAH) yielded that DHEA treatment did not increase the average total number of FAH induced by NNM, but caused a modulation of the phenotype of FAH from the glycogenotic/basophilic to the amphophilic cell lineage. The results confirm that DHEA acts as a hepatocarcinogen and show for the first time that it enhances NNM-induced hepatocarcinogenesis in rats.

Portal vein thrombosis and multiple liver abscesses in Crohn's disease--an example for successful conservative treatment

We report about a 27-year-old patient with Crohn's disease presenting with two complications; Portal vein thrombosis and multiple liver abscesses. Conservative treatment with antibiotics and percutaneous catheter drainage was successful, the liver abscesses disappeared. 18 months later the patient presented in best condition. Ultrasound showed cavernous transformation of the portal vein system and splenomegaly, discrete esophageal varices were seen by esophagogastroscopy. This is an example for an excellent course under conservative therapy of liver abscesses, on the other hand it is the first reported case of a patient with a combination of portal vein thrombosis and multiple liver abscesses in Crohn's disease.

Early bioenergetic changes in hepatocarcinogenesis: preneoplastic phenotypes mimic responses to insulin and thyroid hormone

Biochemical and molecular biological approaches in situ have provided compelling evidence for early bioenergetic changes in hepatocarcinogenesis. Hepatocellular neoplasms regularly develop from preneoplastic foci of altered hepatocytes, irrespective of whether they are caused by chemicals, radiation, viruses, or transgenic oncogenes. Two striking early metabolic aberrations were discovered: (1) a focal excessive storage of glycogen (glycogenosis) leading via various intermediate stages to neoplasms, the malignant phenotype of which is poor in glycogen but rich in ribosomes (basophilic), and (2) an accumulation of mitochondria in so-called oncocytes and amphophilic cells, giving rise to well-differentiated neoplasms. The metabolic pattern of human and experimentally induced focal hepatic glycogenosis mimics the phenotype of hepatocytes exposed to insulin. The conversion of the highly differentiated glycogenotic hepatocytes to the poorly differentiated cancer cells is usually associated with a reduction in gluconeogenesis, an activation of the pentose phosphate pathway and glycolysis, and an ever increasing cell proliferation. The metabolic pattern of preneoplastic amphophilic cell populations has only been studied to a limited extent. The few available data suggest that thyromimetic effects of peroxisomal proliferators and hepadnaviral infection may be responsible for the emergence of the amphophilic cell lineage of hepatocarcinogenesis. The actions of both insulin and thyroid hormone are mediated by intracellular signal transduction. It is, thus, conceivable that the early changes in energy metabolism during hepatocarcinogenesis are the consequence of alterations in the complex network of signal transduction pathways, which may be caused by genetic as well as epigenetic primary lesions, and elicit adaptive metabolic changes eventually resulting in the malignant neoplastic phenotype.

Evaluation of the 13C-methacetin breath test for quantitative liver function testing

Noninvasive 13C-breath tests are used for the assessment of hepatocellular dysfunction. 13C-methacetin is metabolized in the liver by O-demethylation to 13CO2 and acetaminophen. The aim of the study was to evaluate the 13C-methacetin breath test in comparison to the Child-Pugh score and other quantitative liver function tests (MEGX-test and indocyanin green-clearance). 2 mg/kg 13C-methacetin were orally given to 31 patients with histologically proven liver cirrhosis of different etiology and severity (nine Child A, 13 Child B, nine Child C), ten patients with chronic viral hepatitis and ten healthy volunteers. The increase of exhaled 13CO2 was expressed as delta over baseline (DOB; delta /1000). Different DOB-values were compared as parameters for assessing hepatocellular dysfunction. All breath test parameters analyzed provided an excellent discrimination between cirrhotic and noncirrhotic individuals. The DOB-value at 20 min showed a superior correlation with the Child-Pugh score (r = 0.67) than did MEGX-test or indocyanine green clearance results (r = 0.39 and r = 0.43, respectively). With a cut-off value of < or = 25 delta /1000 at 20 min, sensitivity and specificity to discriminate between cirrhotic and noncirrhotic individuals was 93.5% and 95%, respectively. The 13C-methacetin breath test is a safe and precise quantitative liver function test. Using one single breath sample 20 min after substrate administration, the test discriminates well between cirrhotic and noncirrhotic patients. Its prognostic value remains to be established.

Hepatic zonation of the induction of cytochrome P450 IVA, peroxisomal lipid beta-oxidation enzymes and peroxisome proliferation in rats treated with dehydroepiandrosterone (DHEA). Evidence of distinct zonal and sex-specific differences

Dehydroepiandrosterone (DHEA) is an intermediate product in the synthesis of male and female sex hormones in the adrenal cortex of man. In livers of rats and mice DHEA increases the levels of cytochrome P450 IVA and peroxisomal beta-oxidation enzymes associated with peroxisome proliferation. Prolonged treatment of rats with DHEA induces liver tumors that are more frequent in females arising mainly in the periportal regions of the liver lobule (Metzger et al., Toxicol. Pathol. 23, 591-605, 1995). Because of paucity of information on hepatic zonation of peroxisomal response to DHEA and controversial reports on gender-specific differences of its effects the present study was undertaken using qualitative immunohistochemical and quantitative immunoelectron microscopical techniques in addition to Western blotting. Rats were treated for 24 weeks with 0.6% DHEA supplied with diet. Immunoblot analysis revealed marked induction of peroxisomal beta-oxidation enzymes, which by quantitative analysis was equally strong in male and female animals, whilst catalase and urate-oxidase were not increased. Cytochrome P450 IVA, in contrast, was induced significantly stronger in male than in female rats. Immunohistochemistry confirmed the induction of cytochrome P450 IVA showing a marked lobular gradient in female animals with strong induction in pericentral and almost no induction in periportal regions of the liver lobule. In male animals cytochrome P450 IVA was expressed more uniformly across the liver lobule. A similar sex specific zone-dependent response was observed for peroxisomes. DHEA induced in females a significant zonal gradient with marked peroxisome proliferation and a strong induction of peroxisomal hydratase/dehydrogenase in pericentral hepatocytes and a much smaller response in periportal regions. Livers of male animals, in contrast, showed a uniform peroxisomal proliferation to DHEA with only slight zonal differences. The striking homologies of the induction patterns of cytochrome P450 IVA and the peroxisome proliferation in both sexes support the notion of a functional relationship. In view of the almost exclusive periportal localization of DHEA-induced tumors in female rats in contrast to the pericentral localization of the peroxisomal proliferation shown by this study, it seems likely that other factors in addition to peroxisome proliferation may contribute to the hepatocarcinogenic effect of DHEA.

Lesions associated with infectious keratoconjunctivitis in alpine ibex

Following a severe infectious keratoconjunctivitis (IKC) epizootic in free-ranging alpine ibex (Capra ibex ibex) in Switzerland in 1993, 19 animals were examined from six different populations. Mucopurulent exudates, reddened conjunctiva and mononuclear inflammatory cell infiltration in the conjunctiva and the limbic area were observed in mild cases. In more severe cases, lesions ranged from perilimbic neovascularization to corneal edema, erosion, ulceration and neovascularization accompanied by infiltration of neutrophils. Sometimes an iridocyclitis was observed. In the most advanced stages, the cornea was perforated and an anterior synechia was present. Lesions found in ibex affected with IKC indicated a non-generalized, specific ocular disease. The other organs investigated did not show alterations suggestive of changes induced by agents which might cause IKC, including Chlamydia spp. and Mycoplasma. spp. The microbiological findings indicate that Mycoplasma conjunctivae is the primary pathogenic agent causing IKC in this species in Switzerland.

Isolated talus fractures: description of a new clinical sign

Isolated talus fractures are very uncommon and are usually associated with severe trauma. Five cases of isolated talus fracture associated with relatively minor trauma are reported. These five patients had one clinical sign in common, pain out of proportion to the severity of their injury. The treatment of talus fractures is reviewed.

Dietary alpha-tocopherol prevents dehydroepiandrosterone-induced lipid peroxidation in rat liver microsomes and mitochondria

Dehydroepiandrosterone (DHEA), an adrenal steroid, causes lipid peroxidation in rat liver microsomes and mitochondria and induces hepatocarcinogenesis. It was investigated whether alpha-tocopherol, a naturally occurring free radical chain terminator, could decrease lipid peroxidation. When DHEA-free diet supplemented with increasing concentrations of alpha-tocopherol (25, 50, 100, 200, 400 and 1000 mg/kg diet) was fed to rats for 7 days, a marked lipid peroxidation (measured as thiobarbituric acid reactive substances formation) was observed at concentrations 25 and 50 mg/kg in liver microsomes and mitochondria isolated from these animals. Lipid peroxidation was significantly reduced at concentrations > or = 100 mg/kg. When DHEA (500 mg/kg diet) was fed to rats simultaneously with increasing concentrations of alpha-tocopherol, strong lipid peroxidation was observed at alpha-tocopherol concentrations < or = 200 mg/kg diet. However, microsomes and mitochondria isolated from livers of rats fed alpha-tocopherol at doses of 400 and 1000 mg/kg diet produced only negligible amounts of thiobarbituric acid reactive substances. The data show that high concentrations of alpha-tocopherol in the diet decrease DHEA-induced microsomal and mitochondrial lipid peroxidation. Our results support the concept that alpha-tocopherol can protect against DHEA-induced lipid peroxidation and consequently against steroid-induced liver cell damage and, perhaps, also tumour development.