Predicting cholangiocarcinoma in patients with primary sclerosing cholangitis before transplantation

Patients with primary sclerosing cholangitis are at an increased risk of developing cholangiocarcinoma, which is difficult to diagnose because the biliary tree is already distorted. Eleven patients with primary sclerosing cholangitis who underwent orthotopic liver transplantation at this hospital were evaluated. Four patients had coincidental histologically proved cholangiocarcinoma. Patients with cholangiocarcinoma in contrast to patients without tumour presented with rapid onset of persistent jaundice, pruritus, and weight loss associated with an appreciable rise in bilirubin (8x v 2x) and alkaline phosphatase (3.5x v 1.2x) over one year. Cholangiography and computed tomography showed appreciably dilated intrahepatic bile ducts (3/4 v 0/7). The diagnosis of cholangiocarcinoma could only be established before operation in one patient by fine needle aspiration cytology. Tumour was recognised at operation in one other. Histological examination of hepatectomy specimens showed that patients with cholangiocarcinoma had less advanced histological features of primary sclerosing cholangitis. Multiple areas of carcinoembryonic antigen positive epithelial atypia and carcinoma in situ were found in all patients with cholangiocarcinoma. Cholangiocarcinoma recurred in two patients at 14 and 39 months after transplantation. Superimposed cholangiocarcinoma can be predicted in most patients with cholangitis before transplantation, although a definitive diagnosis is difficult to make. Their prognosis after successful transplantation is guarded.

Malnutrition in children with chronic liver disease accepted for liver transplantation: clinical profile and effect on outcome

The nutritional profiles of 37 children (aged 0.5-14.0 years) with chronic liver disease at the time of acceptance for orthotopic liver transplantation (OLTP) have been evaluated using clinical, biochemical and body composition methods. Nutritional progress while waiting for a donor has been related to outcome, whether transplanted or not. At the time of acceptance, most children were underweight (mean standard deviation (s.d.) weight = -1.4 +/- 0.2) and stunted (mean s.d. height = -2.2 +/- 0.4), had low serum albumin (27/35) and had reduced body fat and depleted body cell mass (measured by total body potassium--mean % expected for age = 58 +/- 5%, n = 15). Mean ad libitum nutrient intake was 63 +/- 5% of recommended daily intake (RDI). Those who died while waiting (n = 8) had significantly lower mean initial s.d. weight compared with those transplanted. The overall actuarial 1 year survival of those who were transplanted (mean waiting time = 75 days) was 81% but those who were initially well nourished (s.d. weight greater than -1.0) had an actuarial 1 year survival of 100%. There were no significant differences in actuarial survival in relationship to age, type of transplant (whole liver or segmental), liver biochemistry or the presence or absence of ascites. Of the total group accepted for OLTP, whether transplanted or not, the overall 1 year survival for those who were relatively well nourished was 88% and for those undernourished (initial s.d. weight less than -1.0) was 38% (P less than 0.003). Declining nutritional status during the waiting period also adversely affected outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Vasoactive intestinal polypeptide induces tyrosine hydroxylase in PC12 cells

Physiological stress induces tyrosine hydroxylase, the rate-limiting enzyme for catecholamine biosynthesis, via trans-synaptic mechanisms within the adrenal medulla. Previous studies have implicated cAMP as a second messenger capable of inducing tyrosine hydroxylase; however, it is unclear whether any receptor coupled to adenylate cyclase mediates tyrosine hydroxylase induction. Recently, vasoactive intestinal polypeptide, whose receptor is coupled to adenylate cyclase in many tissues, has been shown to meet many of the criteria for a neuromodulator within the adrenal medulla. We therefore undertook a series of studies to determine whether vasoactive intestinal polypeptide may induce tyrosine hydroxylase in PC12 cells, a cell line derived from rat adrenal medulla. Here we report that vasoactive intestinal polypeptide produces a transient, time- and concentration-dependent increase in tyrosine hydroxylase mRNA levels which is followed by a stable increase in tyrosine hydroxylase protein. The increase in tyrosine hydroxylase mRNA does not occur in a mutant PC12 cell line deficient in cAMP-dependent protein kinase activity, indicating that the effect of vasoactive intestinal polypeptide is mediated through the cAMP second messenger pathway. This is the first report demonstrating that a neuromodulator which acts on an adenylate cyclase-coupled receptor can induce tyrosine hydroxylase.

Degeneration of the cholinergic innervation of the locus ceruleus in Alzheimer's disease

Choline acetyltransferase (Acetyl-CoA: choline O-acetyltransferase: EC 2.3.1.6) (ChAT) enzyme activity and neuron density were measured in the locus ceruleus (LC) of autopsied brains of neurologically normal individuals and patients who had Alzheimer's disease. Neuron density in the LC of individuals with Alzheimer's was significantly reduced to approximately 50% of normal values. ChAT activity was also reduced by about 50%. Furthermore, the number of pigmented neurons in the LC was highly correlated with presynaptic ChAT activity. These findings were specific for the LC, since deficits in ChAT and neuron density were not found in two adrenergic brainstem nuclei (C1 and C2). We measured mitogen activity in LC extracts in order to determine whether loss of cholinergic afferents to the LC, as evidenced by loss of ChAT, was related to putative trophic factors. Mitogen activity was significantly reduced (50%) in the Alzheimer's group as compared to normals. Mitogen activity was significantly correlated with ChAT activity and the density of neurons in the LC. The loss of cholinergic nerve terminals in the LC in Alzheimer's disease may be functionally significant, since acetylcholine has important effects on LC physiology. The highly significant relationships between ChAT, neuron density and mitogen activity has important implications for our understanding of mechanisms of neurodegeneration in Alzheimer's disease.

GABA receptor modulation of tyrosine hydroxylase gene expression in the rat adrenal gland

Chromaffin cell gamma-aminobutyric acid (GABA) receptors play a role in modulating catecholamine secretion. The present experiments examined the role of GABA receptors in modulation of tyrosine hydroxylase (TH) induction in rat adrenal gland. Administration of bicuculline, a GABA antagonist, had no effect on TH activity or TH mRNA. However, bicuculline potentiated reserpine's effect on TH activity and TH mRNA induction. These data suggest that GABA receptors modulate induction of TH and TH mRNA in the adrenal gland.

Pre-operative nutritional support in children with end-stage liver disease accepted for liver transplantation: an approach to management

Pre-operative nutritional support was studied in 28 children with end-stage liver disease awaiting orthotopic liver transplantation. Nasogastric supplemental administration of a standard semi-elemental enteral nutritional formula was compared with a similar formula enriched with branched chain amino acids, and with a group receiving oral nutrition only. The duration of treatment in all groups was similar (mean 90 days). Energy intakes in the supplemented groups were 120-150% of recommended daily intakes (RDI), whereas ad libitum intakes in the oral group ranged 58-100% RDI. A significant improvement in mean Z-score for body weight (denoting catch-up) was noted only in those children who received nasogastric supplements enriched with branched-chain amino acids. The standard enterally-fed group maintained their body weight and Z-scores did not change significantly. In contrast, body weight Z-scores in those fed orally declined significantly. Nutritional supportive therapy of malnourished children with end-stage liver disease can minimize or improve nutritional status in children awaiting liver transplantation. The use of nutritional formulae rich in branched-chain amino acids may have nutritional advantages in children with chronic liver disease which require further study and evaluation.

Modulation of tyrosine hydroxylase gene expression in the rat adrenal gland by age and reserpine

Tyrosine hydroxylase (TH), TH messenger RNA (TH mRNA) and dopamine (DA) were measured simultaneously in adrenal glands of individual Fischer 344 rats aged 2, 6, 13 and 23 months. Between 2 and 23 months TH activity rose 2-fold as compared to the youngest group. TH mRNA content of the adrenal gland rose 3-fold between 2 and 23 months. A 3-fold increase in adrenal DA content, the first catecholamine product of TH, provides evidence that the increases in TH gene expression are functionally significant. To determine if mechanisms that regulate gene expression are altered by aging, the effects of reserpine on induction of TH mRNA and TH activity were compared in another group of rats aged 2, 12 and 27 months. Consistent with the results of the first experiment, there were age-related increases in both TH activity and TH mRNA in the age-matched control groups. TH activity rose 2-fold and TH mRNA rose more than 6-fold between 2 and 27 months. The discrepancy in the relative magnitudes of increases in TH mRNA and TH protein suggest an uncoupling of regulation of TH mRNA and TH protein levels. Moreover, there were significant age-related differences with respect to modulation of TH gene expression by reserpine treatment. TH activity was induced by reserpine in the youngest group, but not in the two older age-groups. In contrast, reserpine caused significant induction of TH mRNA in all age groups. These results provide evidence that aging is accompanied by alterations in transcriptional and post-transcriptional mechanisms involved in regulation of TH gene expression.

Calcium-calmodulin binding in ischemic rat neurons after calcium channel blocker therapy

Calcium channel blockers such as nicardipine improve outcome after global cerebral ischemia and may attenuate ischemic neuronal injury by preventing calcium influx and binding to calmodulin. We followed the temporal and regional sequence of neuronal calcium-calmodulin binding in normal rats (n = 6), untreated ischemic rats (n = 15), and ischemic rats treated with 0.05 mg/kg/hr s.c. nicardipine (n = 13). After 30 minutes of four-vessel occlusion, 40-microns brain sections were incubated in an anti-calmodulin antibody specific for calmodulin not bound to calcium and brain protein. Light-microscopic sections were examined immediately after ischemia and after 2 and 24 hours of reperfusion. Extensive staining of unbound calmodulin was seen in all hippocampal regions and in the cortex in normal rats. In untreated ischemic control rats, staining was lost, indicating calcium-calmodulin binding immediately after ischemia in all regions. However, after 24 hours, staining returned to normal in the cortex and dentate, and minimal staining returned in CA1 and CA3. Nicardipine-treated animals had significantly less calcium-calmodulin binding in CA1 and in the dentate after 2 hours of reperfusion. This study demonstrates that in clinically relevant doses nicardipine has a limited effect on calcium-calmodulin binding in selectively vulnerable regions after severe ischemia.

Improvement in chronic hepatocerebral degeneration following liver transplantation

Chronic progressive hepatocerebral degeneration with spastic paraparesis, dementia, dysarthria, ataxia, tremor, and neuropsychiatric symptoms follows long-standing portal-systemic shunting, is associated with structural changes in the central nervous system, and does not respond to conventional therapy for hepatic encephalopathy. A case of advanced chronic liver disease with severe, progressive hepatocerebral degeneration after 23 yr of portal-systemic shunting is reported in whom there was significant objective improvement in intellectual function and in the chronic neurological signs 3 mo after orthotopic liver transplantation and further improvement 12 mo after transplantation.

Post-choledochoenterostomy 'sump syndrome'

The 'sump syndrome' is an uncommon, late complication of a side-to-side choledochoenterostomy. Five patients with this syndrome were encountered over a 5-year period. Pain or cholangitis was the clinical presentation in four patients, whereas one patient presented with secondary septic arthritis and a hepatic abscess. Liver function tests were mildly abnormal in each patient. All patients had a stomal size of less than 1 cm as assessed by forward- or side-viewing endoscopy. Endoscopic retrograde cholangiography revealed either stones or debris in the distal common bile ducts of all patients. Four patients had a surgical clearance of their duct with concurrent closure of the choledochoduodenostomy in three patients and the creation of a Rouxen-Y end-to-side choledochojejunostomy in the fourth patient. The other patient had an endoscopic sphincterotomy performed. After 1-4 years of follow-up, four patients have had a total resolution of symptoms. The other patient with follow-up for 4 years has had one episode of cholangitis which resolved rapidly with antibiotic treatment. The pathogenesis and clinical spectrum of the sump syndrome are reviewed and current management strategies are discussed.

Baclofen does not protect against cerebral ischemia in rats

Presynaptic release of glutamate into the extracellular compartment and activation of receptor-operated calcium channels may contribute to ischemic neuronal damage. We evaluated the effect of baclofen, a selective inhibitor of presynaptic glutamate release, on mortality, working memory, and light microscopic hippocampal and cortical damage in the four-vessel occlusion model of cerebral ischemia using 64 male Wistar rats. Baclofen (10 mg/kg i.p.) given 1 hour before and 30-60 minutes after 20 minutes of global ischemia did not lessen mortality, prevent ischemic cellular damage, or significantly improve working memory compared with no treatment. We conclude that preischemic and postischemic administration of baclofen does not protect neurons from ischemic injury.

Expression of calbindin-D decreases with age in intestine and kidney

The calbindins are Ca-binding proteins whose expression is regulated by 1,25-dihydroxyvitamin D3, the active metabolite of vitamin D3. The calbindins are found in high amounts in the proximal intestine (calbindin-D-9k) and the kidney (calbindin-D-28k), and they are thought to play a role in Ca transport by these tissues. Ca absorption by the intestine and perhaps the kidney declines with age, and this could be due to decreased expression of calbindin. Therefore, the expression of calbindins-D-9k and -D-28k was measured in F344 rats aged 2, 6, 13, and 24 months. mRNA levels were measured by dot blot hybridization to synthetic cDNA oligonucleotide probes, and protein levels were measured by enzyme-linked immunosorbent assay using specific antisera. Intestinal calbindin-D-9k mRNA decreased markedly between 2 and 6 months of age, but it then increased significantly between 13 and 24 months. Calbindin-D-9k protein paralleled the decrease in mRNA between 2 and 6 months, but continued to decline at 13 and 24 months despite the rise in mRNA. In the kidney, calbindin-D-28k mRNA declined between 2 and 13 months and then plateaued. Calbindin-D-28k protein followed a similar pattern. In the same studies expression of calmodulin by the intestine and kidney did not change with age. Plasma 1,25-dihydroxyvitamin-D3 correlated well with the expression of calbindin-D-9k in the intestine at 2 and 6 months of age and with the expression of calbindin-D-28k in the kidney at all ages. Decreased expression of calbindin-D with age may contribute to the age-related decrease in Ca transport in intestine and kidney.

Immunohistochemical determination of calcium-calmodulin binding predicts neuronal damage after global ischemia

Since ionic Ca2+ binds with intracellular calmodulin (CaM) before activating proteases, kinases, and phospholipases, demonstration of persistent Ca2+-CaM binding in neurons destined to show ischemic cellular injury would support the concept that elevated intracellular Ca2+ plays a causative role in ischemic neuronal damage. In order to characterize Ca2+-CaM binding, we used a sheep anti-CaM antibody (CaM-Ab) which recognizes CaM that is not bound to Ca2+ or brain target proteins. Therefore, immunohistochemical staining of brain sections by labeled CaM-Ab represented only unbound CaM. Six normal rats were compared to 15 animals rendered ischemic for 30 min by a modification of the four-vessel occlusion model. Animals were killed immediately after ischemia, and after 2 and 24 h of reperfusion. Brain sections through hippocampus were incubated in CaM-Ab, and a diaminobenzadiene labeled anti-sheep secondary antibody was added to stain the CaM-Ab. Staining in the endal limb of dentate, dorsal CA1, lateral CA3, and parietal cortex was graded on a 4-point scale. All normal animals had grade 4 staining indicating the presence of unbound CaM in all four brain regions. Ischemic animals demonstrated reduced (grade 0 to 2) staining in the CA1 and CA3 regions immediately and 2 and 24 h after ischemia (p less than 0.01 for both regions at all three time intervals) indicating persistent binding of CaM with Ca2+ and target proteins in these regions. Staining decreased in dentate and cortex up to 2 h after ischemia (p = 0.02 for both regions) but returned toward normal by 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Phosphorylation of ferredoxin and regulation of renal mitochondrial 25-hydroxyvitamin D-1 alpha-hydroxylase activity in vitro

The kidney is the principal physiologic site of production of biologically active 1,25-dihydroxyvitamin D. The 25-hydroxyvitamin D-1 alpha-hydroxylase (1-OHase) activity found in renal mitochondria is under tight hormonal control. Parathyroid hormone stimulates the renal conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D in young animals, which is accompanied by dephosphorylation of ferredoxin (Fx), a component of the mitochondrial 1-OHase enzyme complex (Siegel, N., Wongsurawat, N., and Armbrecht, H. J. (1986) J. Biol. Chem. 261, 16998-17003). The present study investigates the capacity of Fx to be phosphorylated in vitro and to modulate the 1-OHase activity of a reconstituted system. Fx was phosphorylated by renal mitochondrial type II protein kinase. Phosphorylation did not alter Fx mobility on sodium dodecyl sulfate gels but did decrease the pI as measured by isoelectric focusing. Amino acid analysis demonstrated that 1 mol of serine and 1 mol of threonine were phosphorylated per mol of Fx. Peptide mapping of phosphorylated Fx was consistent with phosphorylation of serine 88 and threonine 85 or 97. Fx was selectively dephosphorylated by rabbit skeletal muscle protein phosphatase C2 but not C1. Phosphorylation of Fx significantly inhibited the 1-OHase activity of a reconstituted system consisting of Fx reductase, Fx, and renal mitochondrial cytochrome P-450. These findings suggest that phosphorylation/dephosphorylation of Fx may play a role in modulating renal 1,25-dihydroxyvitamin D production.

The effect of aging and dietary restriction on DNA repair

DNA repair was studied as a function of age in cells isolated from both the liver and the kidney of male Fischer F344 rats. DNA repair was measured by quantifying unscheduled DNA synthesis induced by UV irradiation. Unscheduled DNA synthesis decreased approximately 50% between the ages of 5 and 30 months in both hepatocytes and kidney cells. The age-related decline in unscheduled DNA synthesis in cells isolated from the liver and kidney was compared in rats fed ad libitum and rats fed a calorie-restricted diet; calorie restriction has been shown to increase the survival of rodents. The level of unscheduled DNA synthesis was significantly higher in hepatocytes and kidney cells isolated from the rats fed the restricted diet. Thus, calorie restriction appears to retard the age-related decline in DNA repair.

Time-course of effects of oral cinnarizine and hyoscine on task performance

Investigations into antimotion sickness drugs fall into two main categories: efficacy ('benefits') and side-effects ('costs'). This study was of the second type. Oral cinnarizine (30 mg: normal dose; and 75 mg: 2.5 x normal dose) and placebo, were investigated using a battery of automated mental, motor, physiological and other tests in twelve young healthy male volunteers. The higher cinnarizine dose level was chosen to exaggerate effects and make it easier to track them. Oral hyoscine (1.2 mg: 2 x normal dose) was employed as a positive internal control. Side-effects were almost exclusively due to hyoscine whereas cinnarizine was almost free of significant effects even at the higher dose of 75 mg. Hyoscine impaired performance 1-3 hours postdrug, whereas the effects of cinnarizine occurred approximately 5-7 hours postdrug. This paralleled the slower time-course for the protective action of cinnarizine against motion sickness noted in earlier studies. These results, taken in conjunction with previous trials, suggest that oral cinnarizine would seem less likely than hyoscine to produce unwanted decrements in performance.

Modulation of age-related changes in serum 1,25-dihydroxyvitamin D and parathyroid hormone by dietary restriction of Fischer 344 rats

The purpose of this study was to determine the effect of food restriction on age-related changes in serum 1,25-dihydroxyvitamin D and PTH, two important regulators of Ca metabolism. Starting at 6 wk, male F344 rats were fed a purified diet either ad libitum (non-restricted) or 60% of ad libitum (restricted). Rats from each group were killed at 5, 13, 22 and 28 mo of age. Dietary restriction increased the median lifespan from 24 to 31 mo. It delayed the rapid decrease in serum 1,25-dihydroxyvitamin D from 1.5-5.0 mo in the non-restricted group to 5-13 mo in the restricted group. It also completely suppressed the marked rise in serum PTH which occurred at 22 and 28 mo in the non-restricted group. Dietary restriction had these effects even though both groups of animals consumed the same amount of Ca per gram body weight. Diet had no effect on serum Ca and P, except at 28 mo. These effects of dietary restriction on serum 1,25-dihydroxyvitamin D and PTH may result in altered Ca metabolism in dietary restricted F344 rats.

Evidence for retrograde degeneration of epinephrine neurons in Alzheimer's disease

Alzheimer's disease (AD) is associated with a progressive loss of locus ceruleus neurons. These noradrenergic neurons receive a major afferent projection from epinephrine neurons in epinephrine cell groups in the brainstem. The epinephrine neurons have a specific enzymatic marker, phenylethanolamine N-methyltransferase (PNMT), which allows them to be identified chemically and immunohistochemically. We have previously reported a decrease in PNMT in brains of patients with AD. We now report that the decrease in PNMT activity in projections to the locus ceruleus is not due to the loss of epinephrine neurons, although up to 33% of these neurons are atrophic. The decrease in presynaptic PNMT does, however, correlate with the loss of postsynaptic locus ceruleus neurons in brains from AD patients. The percentage of degenerating neurons in the epinephrine nuclei also correlates significantly with the amount of loss of locus ceruleus neurons in AD. In addition, there is a 55% decrease in mitogen activity, a nonspecific measure of growth or maintenance factors, in dialysed locus ceruleus extracts from the AD patients compared to those from control subjects. The mitogen activity in the locus ceruleus was significantly correlated with PNMT activity and with the density of locus ceruleus neurons in all cases examined. These findings provide evidence for the hypothesis that retrograde degeneration is a mechanism of neuronal degeneration in AD and suggest that trophic factors may play a role in this process.

Effect of flow on O2 consumption during progressive hypoxemia

Rabbit hindlimb preparations perfused with blood from donor rabbits were used to determine whether O2 consumption (VO2) during hypoxemia is limited by total O2 transport (TO2) or by capillary O2 driving pressure, as reflected by the venous PO2 (PVO2). The preparations were randomized into two groups: low flow (LF) and high flow (HF), perfused at 18 and 32 ml.min-1.kg of preparation wt-1, respectively. After a 1-h base-line period with arterial PO2 (PaO2) greater than 100 Torr, both groups were exposed to progressive decrements in PaO2 to less than 10 Torr. Sequential sets of arterial and venous blood gases were obtained, and VO2, TO2, and O2 extraction ratio (ERO2) were calculated. A plot of PVO2 vs. TO2 showed higher levels of PVO2 (P less than 0.05) in LF than HF, when compared at similar levels of TO2. Therefore the experimental protocol allowed the comparison of the separate effects of TO2 or PVO2 on VO2. Plotting VO2 as a function of TO2 revealed two distinct curves (P less than 0.05), with LF having a greater VO2 than HF at a given TO2. Conversely, a plot of VO2 as a function of PVO2 did not show a difference between the groups. The ERO2 of LF was greater than HF when compared at similar levels of TO2 (P less than 0.05). We conclude from these data that during progressive hypoxemia VO2 appears to be primarily limited by factors that determine capillary O2 diffusion. This conclusion supports the Kroghian theory of capillary O2 exchange.

Bioenergetics of rabbit skeletal muscle during hypoxemia and ischemia

A blood-perfused rabbit hindlimb preparation was exposed to total ischemia (n = 4) or to severe hypoxemia (n = 4) where arterial PO2 was 5 +/- 2 (SE) Torr. O2 consumption (VO2), O2 transport (TO2), venous PO2 (PVO2), venous lactate concentration, and venous glucose concentration were measured. The relative concentration of ATP, phosphocreatine (PCr), inorganic phosphate (Pi), and intracellular pH (pHi) were monitored with 31P magnetic resonance spectroscopy. PCr/Pi decreased with the onset of ischemia or hypoxemia. The preparation was reoxygenated and allowed to recover for 30 min once PCr/Pi was less than 1.0. The periods of hypoxemia and ischemia lasted 56.0 +/- 10.0 and 63.8 +/- 2.5 min, respectively (NS). During ischemia PCr decreased and Pi increased compared with control (P less than 0.05) but returned to control with reperfusion. With hypoxemia PCr also decreased and Pi increased with respect to control (P less than 0.01) but did not recover with reoxygenation. VO2 and PVO2 in both groups returned to control during recovery. ATP did not change with ischemia but decreased with hypoxemia (P less than 0.05). Venous lactate concentration did not change with ischemia but increased with hypoxemia (P less than 0.05) and continued to rise during recovery. During recovery pHi decreased in the hypoxemic group (P less than 0.05) but not in the ischemic group. These data show that, under the conditions tested, rabbit skeletal muscle does not resynthesize PCr after a severe hypoxemic episode. Furthermore it appears that VO2 and PVO2 fail to portray the true state of cellular bioenergetics after a severe hypotemic insult.