Awareness and opinions of non-alcoholic fatty liver disease by hospital specialists.

BACKGROUND/AIM: Subjects with metabolic risk factors for non-alcoholic fatty liver disease (NAFLD) are commonly seen by hospital specialists other than gastroenterologists/hepatologists. The aim of this study was to assess the awareness of NAFLD and opinions regarding management among non-hepatologists at two major tertiary hospitals in Brisbane. METHODS: A face-to-face questionnaire assessing current beliefs and practices regarding NAFLD was administered to specialists and specialists-in-training across six specialties (internal medicine, cardiology/cardiac surgery, endocrinology, thoracic medicine, rheumatology and nephrology). RESULTS: One hundred clinicians were surveyed with 99% returning completed questionnaires (>89% questions answered). The majority of respondents (75%) believe the prevalence of NAFLD in the general population to be ≤ 10%, although two-thirds feel that its incidence will rise markedly. The vast majority (>90%) appreciate that traditional cardiovascular risk factors (obesity, hypertriglyceridaemia and diabetes) are risk factors for NAFLD and acknowledge that these are common in non-hepatology patients. Despite this, most believe that NAFLD is uncommon in their own patients (89% indicated a prevalence ≤ 30%). The vast majority (93%) agree that non-alcoholic steatohepatitis (NASH) is associated with increased overall mortality, but 60% also believe that simple steatosis confers increased liver-related mortality. Most (74%) agree that a diagnosis of NASH cannot be made using liver enzymes, but 67% support 6-monthly liver function tests as the most effective way to monitor progression of NAFLD. Most respondents (71%) make no referrals to hepatology for suspected NAFLD. CONCLUSIONS: Non-hepatologists appreciate the seriousness of NAFLD but appear to underestimate its prevalence, especially among their own patients despite known risk factors. Attitudes regarding simple steatosis versus NASH and appropriate monitoring of suspected NAFLD suggest that more can be done to improve the understanding of this disease among non-hepatologists. This has implications for targeting 'at-risk' populations and appropriate referral of patients to hepatology clinics.

A combination of genetic polymorphisms increases the risk of progressive disease in chronic hepatitis C.

BACKGROUND: There is increasing interest in the influence of host genetic factors on hepatic fibrosis, and whether genetic markers can reliably identify subjects at risk of developing severe disease. We hypothesised that hepatitis C virus (HCV) infected subjects with progressive fibrosis, classified using strict criteria based on histology at biopsy in addition to disease duration would be more likely to inherit several genetic polymorphisms associated with disease progression compared with subjects with a low rate of disease progression. METHODS: We examined polymorphisms in eight genes that have been reported to have an association with hepatic fibrosis. RESULTS: Associations between polymorphisms in six genes and more rapidly progressing fibrosis were observed, with individual adjusted odds ratios ranging from 2.1 to 4.5. The relationship between rapidly progressing fibrosis and possession of > or =3, > or =4, or > or =5 progression associated alleles was determined and the adjusted odds ratios increased with increasing number of progression associated alleles (9.1, 15.5, and 24.1, respectively). Using logistic regression analysis, a predictive equation was developed and tested using a second cohort of patients with rapidly progressing fibrosis. The predictive equation correctly classified 80% of patients in this second cohort. CONCLUSIONS: This approach may allow determination of a genetic profile predictive of rapid disease progression in HCV and identify patients warranting more aggressive therapeutic management.

Clinical, biochemical and genetic approaches to the detection of familial hyperaldosteronism type I.

AIM: Since detection of familial hyperaldosteronism type I (glucocorticoid-suppressible hyperaldosteronism) allows specific treatment of hypertension with dexamethasone, we compared clinical, biochemical and genetic approaches to detection. PATIENTS AND METHODS: We studied 22 affected patients, 21 from a single, large family and an additional adopted male. Plasma aldosterone, plasma renin activity and urinary 18-oxo-cortisol were measured by radioimmunoassay. The hybrid gene was demonstrated using either Southern blotting or a long polymerase chain reaction technique. RESULTS: Thirteen out of 22 (59%) patients with familial hyperaldosteronism type I, but only four out of 12 (33%) under 20 years of age, were hypertensive. Plasma potassium and aldosterone were each normal in 20 out of 22 (91%), and unhelpful in diagnosis. Plasma renin activity, the aldosterone: plasma renin activity ratio and 18-oxo-cortisol were more sensitive, being abnormal in 20 out of 22 (91%), 19 out of 22 (86%) and 20 out of 20 (100%) patients, respectively. Aldosterone was unresponsive (<50% rise) to 2 h of upright posture following overnight recumbency in 15 out of 15 (100%) patients studied, and to angiotensin II infusion (2 ng/kg per min for 1 h) in 14 out of 14 patients (100%). Whereas all the abovementioned abnormalities are also characteristic of angiotensin II-unresponsive aldosterone-producing adenoma, marked aldosterone suppression following 4 days of dexamethasone (0.5 mg every 6 h) was sensitive and specific for familial hyperaldosteronism type I (n = 11). The hybrid gene was detectable in peripheral blood leucocyte DNA in all 22 affected patients by Southern blotting, and by a faster, long polymerase chain reaction method developed in our laboratory, both methods requiring only a single blood collection. CONCLUSIONS: Should studies in other families confirm its universal applicability, long polymerase chain reaction should prove to be the most practical means of detecting familial hyperaldosteronism type I in laboratories equipped with this technique.

Novel surveillance and cure of a donor-transmitted lymphoma in a renal allograft recipient.

BACKGROUND: In this report we describe a malignant lymphoma of donor origin inadvertently transplanted into two renal allograft recipients, despite standard comprehensive donor screening. The successful clearance of the tumor from both patients and a novel method of surveillance are detailed. METHODS: Initial management consisted of withdrawal of immunosuppression to promote rejection of the allograft and the transplanted tumor in both patients, followed by graft removal. Peripheral blood microchimerism was assessed in both recipients using nested polymerase chain reaction to detect the DYZ3 gene on the Y chromosome (donor male, recipients female). RESULTS: Although microchimerism was detected on day 6 after transplantation and day 1 after explantation, repeat peripheral blood examination at 1, 3, and 6 months after explantation demonstrated no microchimerism. Both patients remain well at 12 months and have been relisted for transplantation. CONCLUSION: Despite inadvertent transplantation of a previously undiagnosed malignancy of donor origin, the recipients' immune response was able to eliminate donor tumor cells after the withdrawal of immunosuppression. Repeated surveillance of peripheral blood from both recipients, using a novel application of the technique of nested polymerase chain reaction to amplify donor DNA, demonstrated no persistence of donor cells, supporting effective eradication of the donor malignancy.

Role of donor leukocyte chimerism in establishing the etiology of neutropenia after liver transplantation.

BACKGROUND: The quantitation of donor leukocyte chimerism may aid in establishing the etiology of neutropenia after liver transplantation. METHODS: The incidence and clinical and laboratory characteristics of severe neutropenia were studied in adults who have undergone liver transplantation at our institution over the last 4 years. RESULTS: Severe neutropenia developed in 5 of 156 patients (3%). The clinical and pathological features were nonspecific. In two patients with a delayed diagnosis of graft-versus-host disease (GVHD), donor leukocytes comprised > or = 50% of the circulating peripheral blood mononuclear cells. In a third patient, an earlier diagnosis of GVHD was suspected on the basis of a donor leukocyte count of 3-10% in the peripheral blood. In contrast, donor leukocyte chimerism was < or = 0.01% in two patients with probable drug-induced neutropenia CONCLUSIONS: The determination of donor leukocyte chimerism has an important role in the investigation of neutropenia after liver transplantation, allowing early diagnosis and treatment of GVHD.

Effect of alpha 1-adrenoceptor blockade on the development of hypertension in the spontaneously hypertensive rat.

There is a large body of evidence to suggest that the sympathetic nervous system plays a critical role in the development of hypertension and vascular medial hypertrophy in the spontaneously hypertensive rat (SHR). The synthesis of a water soluble, specific alpha 1-adrenoceptor antagonist (terazosin) has permitted an examination of the influence of alpha 1-adrenoceptors on those two phenomena. Thus, in the present study, terazosin (43 mg/kg per day) was administered to SHR and Wistar-Kyoto (WKY) rats from 4.5 to 12 weeks of age, and a number of assessments made in vitro and in vivo. In the SHR, the development of hypertension was not prevented by terazosin. The drug did not influence blood pressure in the WKY. This was despite the fact that animals which had been chronically treated with terazosin displayed marked alpha-adrenoceptor blockade in vivo. The response of systolic blood pressure to tyramine and noradrenaline was significantly reduced in animals which had been chronically treated with terazosin. In both the SHR and WKY, chronic administration of terazosin did not influence vascular concentrations of 3-methylhistidine, a biochemical marker for contractile proteins and vascular medial hypertrophy. The results therefore argue against a role of alpha 1-adrenoceptors in the development of hypertension and vascular medial hypertrophy in the SHR.

Plasma histamine levels following administration of radiographic contrast media.

The effect of two conventional high-osmolality and two new low-osmolality contrast media on plasma histamine levels has been examined. The study population included 25 patients undergoing intravenous urography with Urovison 58% (sodium and meglumine diatrizoate), 24 patients receiving intravenous Hexabrix 320 (sodium and meglumine ioxaglate) for urography, 16 patients receiving intravenous Iopamiro 370 (iopamidol) for urography and 12 patients receiving Urografin 76% (sodium and meglumine diatrizoate) for coronary angiography. Seventy-four percent of the 77 patients studied suffered adverse reactions ranging from a feeling of warmth and nausea to laryngeal oedema and bronchospasm. Hexabrix 320 and Iopamiro 370 were associated with the least patient discomfort. All contrast agents usually produced a rise in plasma histamine following injection (Iopamiro 370 causing the least change) and the histamine levels then fell towards preinjection values over a space of about 10 minutes. No relationship was observed between the magnitude of the increase in histamine and the severity of the reaction that occurred. However, a relationship was suggested between the mean peak plasma histamine level achieved and the occurrence of a Grade II reaction (i.e., dry retching/vomiting, mild urticaria or rash). These findings raise the probability that histamine contributes to the more severe grades of reaction to radiographic contrast media.

Non-response to antiviral therapy is associated with obesity and increased hepatic expression of suppressor of cytokine signalling 3 (SOCS-3) in patients with chronic hepatitis C, viral genotype 1.

BACKGROUND: Interferon alpha (IFN-alpha) activated cellular signalling is negatively regulated by inhibitory factors, including the suppressor of cytokine signalling (SOCS) family. The effects of host factors such as obesity on hepatic expression of these inhibitory factors in subjects with chronic hepatitis C virus (HCV) are unknown. OBJECTIVES: To assess the independent effects of obesity, insulin resistance, and steatosis on response to IFN-alpha therapy and to determine hepatic expression of factors inhibiting IFN-alpha signalling in obese and non-obese subjects with chronic HCV. METHODS: A total of 145 subjects were analysed to determine host factors associated with non-response to antiviral therapy. Treatment comprised IFN-alpha or peginterferon alpha, either alone or in combination with ribavirin. In a separate cohort of 73 patients, real time-polymerase chain reaction was performed to analyse hepatic mRNA expression. Immunohistochemistry for SOCS-3 was performed on liver biopsy samples from 38 patients with viral genotype 1 who had received antiviral treatment. RESULTS: Non-response (NR) to treatment occurred in 55% of patients with HCV genotypes 1 or 4 and 22% with genotypes 2 or 3. Factors independently associated with NR were viral genotype 1/4 (p < 0.001), cirrhosis on pretreatment biopsy (p = 0.025), and body mass index > or = 30 kg/m2 (p = 0.010). Obese subjects with viral genotype 1 had increased hepatic mRNA expression of phosphoenolpyruvate carboxy kinase (p = 0.01) and SOCS-3 (p = 0.047), in comparison with lean subjects. Following multivariate analysis, SOCS-3 mRNA expression remained independently associated with obesity (p = 0.023). SOCS-3 immunoreactivity was significantly increased in obesity (p = 0.013) and in non-responders compared with responders (p = 0.014). CONCLUSIONS: In patients with chronic HCV viral genotype 1, increased expression of factors that inhibit interferon signalling may be one mechanism by which obesity reduces the biological response to IFN-alpha.

Chronic captopril treatment reverses the enhanced vascular concentrations of 3-methylhistidine in the spontaneously hypertensive rat.

Morphometric studies conducted on the blood vessels of the spontaneously hypertensive rat have provided evidence that medial hypertrophy is a key characteristic of the vascular change which occurs in hypertension. In the present study, we determined whether 3-methylhistidine (3MH), a post-translationally modified amino acid which is found uniquely in the actin and myosin of muscle, could provide a biochemical marker of such change. Our results indicated that the concentrations of 3MH were selectively elevated in the blood vessels from the spontaneously hypertensive rat, when compared with concentrations in vascular tissues from the Wistar-Kyoto rat. The concentrations of 3MH in non-vascular tissues were similar in the two strains. Chronic captopril treatment prevented the development of hypertension in the spontaneously hypertensive rat and was associated with a reduction of the vascular concentrations of 3MH. We therefore conclude that blood vessel concentrations of 3MH are a useful biochemical index of the changes in vascular smooth muscle contractile protein which occur during the development of hypertension in the spontaneously hypertensive rat.

The effect of captopril treatment and its withdrawal on the gene expression of the renin-angiotensin system.

The mRNA expression of renin, angiotensinogen and angiotensin converting enzyme (ACE) was determined in the kidneys and livers from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) during chronic treatment with captopril and following its withdrawal. Chronic captopril treatment was associated with a dramatic rise in renin mRNA in the kidney and an elevation in mRNA for ACE in the liver. The release from captopril treatment was associated with a reversal of the increase in kidney renin mRNA but no reversal of the sustained elevation of ACE mRNA in the liver. In situ hybridisation revealed a localisation of renin to the area of the juxtaglomerular apparatus in the kidneys from untreated animals, but recruitment of vascular sites of renin expression in kidneys from captopril-treated animals. In kidneys from released animals, renin mRNA expression was once again confined to the juxtaglomerular apparatus. ACE mRNA was expressed in hepatocytes throughout the livers from animals in all treatment groups. The results highlight a differential effect of captopril withdrawal upon the gene expression of the components of the renin-angiotensin system in kidney and liver.

Pulmonary extraction of catecholamines in critically ill patients.

Plasma catecholamine concentrations in blood obtained simultaneously from the pulmonary and radial arteries of ten critically ill patients have been measured. The mean mixed venous concentrations of noradrenaline, adrenaline and dopamine were extremely high, noradrenaline 11.3 pmol/ml (SD 11.6), adrenaline 2.7 pmol/ml (SD 3.0) and dopamine 7.1 pmol/ml (SD 12.3). An appreciable drop in the concentrations occurred as the blood passed from the pulmonary artery to the radial artery (mean fall 24.1, 29.7 and 45.8% respectively). Four patients receiving a therapeutic dopamine infusion were also studied and demonstrated similar trends in catecholamine concentrations. The results suggest a substantial pulmonary clearance mechanism for all three catecholamines.

The effects of suxamethonium and D-tubocurarine on the pressor and plasma catecholamine responses to tracheal intubation.

Changes in mean arterial pressure (MAP) and plasma catecholamine concentrations in response to endotracheal intubation were examined in 8 patients who had received d-tubocurarine and 10 who had received suxamethonium. MAP fell after induction of anaesthesia and administration of the relaxant by a mean of 11 mmHg in those who had received suxamethonium and 19 mmHg in those who had received d-tubocurarine (p less than 0.05 for each). MAP rose sharply when the trachea was intubated, by a mean of 29 mmHg for the suxamethonium group, and 35 mmHg for the curare group (p less than 0.001 for each). A significant rise in plasma noradrenaline was also noted after intubation in each group, 51% (p less than 0.01) for the suxamethonium group and 28% (p less than 0.05) for the d-tubocurarine. The results suggest that the fall in MAP after administration of d-tubocurarine does not attenuate the pressor response associated with intubation.

Histamine levels in human synovial fluid.

Histamine levels have been measured in plasma and synovial fluid (SF) obtained from patients with various arthritides, using a radioenzymatic assay procedure. The concentration of the amine in the plasma of these patients was, in general, found to be considerably greater than that seen in a group of control patients without inflammatory joint disease. SF always contained higher levels of histamine than corresponding plasma samples. The results of our preliminary study suggest that the production of histamine within the synovium may be an important factor in the genesis of joint effusions.

Morphine responders with unexplained pain after cholecystectomy may have sympathetic overactivity.

In patients with unexplained pain after cholecystectomy, morphine often induces pain and may increase plasma aspartate aminotransferase activity because of exaggerated or prolonged rises in pressure within the biliary system. Previous studies have demonstrated that patients showing increases in aspartate aminotransferase have increases in plasma concentrations of noradrenaline and dopamine prior to and soon after induction of pain. The purpose of this study was to assess sympathetic activity under basal conditions in patients with (responders) and without (non-responders) increases in aspartate aminotransferase after challenge with morphine. When compared to non-responders, morphine responders had higher plasma concentrations of noradrenaline (p = 0.0001) and dopamine (p = 0.02) and higher urinary excretion of noradrenaline over 24 h (p = 0.03). Plasma and urinary levels of adrenaline were similar in the two groups. These observations indicate higher basal levels of sympathetic activity in the subgroup of patients showing increases in aspartate aminotransferase after challenge with morphine.

A new genetic test for familial hyperaldosteronism type I aids in the detection of curable hypertension.

In Familial Hyperaldosteronism Type I (FH-I, glucocorticoid-suppressible hyperaldosteronism), a curable form of hypertension inherited in an autosomal dominant fashion, the underlying genetic defect is a "hybrid gene" in which 11 beta-hydroxylase gene regulatory elements are fused to the coding region of the aldosterone synthase gene. The detection of this hybrid gene by Southern blotting is time consuming and involves the use of radioactive isotopes. We describe a new, long polymerase chain reaction-based method for detecting the hybrid gene which greatly reduces the time required to obtain a result, avoids exposure of laboratory workers to radioactive materials, and will thereby facilitate the screening of patients for the presence of FH-I.

The expression and localisation of the angiotensin-converting enzyme mRNA in human adipose tissue.

Recent evidence in rats has indicated that angiotensinogen may be synthesised in adipose tissue surrounding blood vessels and that a local renin-angiotensin system may regulate adipose tissue blood supply and the efflux of fatty acids from fat in that species. This hypothesis is critically dependent on the local expression of the angiotensin converting enzyme gene in adipocytes. Thus the current study set out to examine whether the angiotensin converting enzyme gene was expressed in human adipose tissue and, if it was present, to localise the individual sites of that expression. Northern analysis indicated the presence of mRNA for angiotensin converting enzyme in both subcutaneous and extraperitoneal adipose tissue. In situ hybridisation showed that the gene was expressed in adipocytes. The foregoing results therefore suggest that components of the renin-angiotensin cascade are also present in human adipose tissue and support the hypothesis that adipose tissue may play a role in the local production of Angiotensin II and hence participate in vascular function and blood pressure control in the human.

Phaeochromocytoma: intraoperative changes in blood pressure and plasma catecholamines.

The aim of this study was to assess the relationship between changes in plasma catecholamine concentrations and intra-arterial blood pressure (BP) measured simultaneously during resection of phaeochromocytoma (n = 14). Arterial plasma concentrations of noradrenaline (NA), adrenaline (A) and dopamine (DA) were measured by a radio-enzymatic method. Arterial NA concentrations (pmol/ml; median and Wilcoxon 95% CI) were 71.8 (46,162) before induction of anaesthesia, 113.0 (79,231) after intubation, 375.0 (285,931) during tumour handling and 32.5 (18,88) following tumour removal. Simultaneous mean BP values (mmHg; Mean +/- SEM) were 119 +/- 8, 114 +/- 7, 159 +/- 7 (p = 0.0001) and 72 +/- 6 (p < 0.0001) respectively. At the time of tumour handling there was a weak correlation between plasma NA and A combined and mean BP (r = 0.583, p = 0.029) and a stronger correlation between log plasma NA and A combined and pulse pressure (r = 0.749, p = 0.008). The very large rises in plasma catecholamine concentrations and in BP are likely to have been causally related. Individual patients maintained a constant ratio of NA to A in plasma from pre-induction to tumour handling (r = 0.916, p < 0.0001). The maintenance of a constant NA:A ratio suggests that the pattern of catecholamine synthesis and release may be a characteristic of the individual tumour.

Sympathetic suppression attenuates anomalous responses to morphine in unexplained pain after cholecystectomy.

Anomalous responses to morphine are common in patients with unexplained pain in the upper abdomen after cholecystectomy and may be linked to activation of the sympathetic nervous system. The hypothesis that sympathetic suppression would attenuate anomalous responses to morphine was tested by a randomized, cross-over trial using a standard challenge with morphine, with and without pretreatment with clonidine (300 micrograms orally, 1 h prior to the administration of morphine). In 13 of the 15 patients who completed the study, pre-treatment with clonidine decreased plasma concentrations of noradrenaline, dopamine and adrenaline by 56, 15 and 25% respectively. This was associated with a significant reduction in morphine-induced pain (p = 0.02) and nausea (p = 0.04) and attenuated increases in plasma aspartate aminotransferase (AST) activity (p = 0.03). Clonidine attenuates anomalous responses to morphine, perhaps through effects on sympathetic nervous activity or plasma concentrations of catecholamines.

Sympathetic activation: a mechanism for morphine induced pain and rises in liver enzymes after cholecystectomy?

In patients with biliary type pain after cholecystectomy, morphine often precipitates pain and may induce rises in plasma concentrations of liver enzymes because of exaggerated or prolonged rises in intrabiliary pressure. In this study, changes in plasma concentrations of catecholamines and histamine were determined after the administration of morphine in patients with and without a two-fold or greater rise in the plasma concentration of aspartate aminotransferase at four hours. Those showing rises in aminotransferase had higher concentrations of noradrenaline at 40 and 60 minutes after morphine and higher concentrations of dopamine at 40 minutes after morphine. The two groups had similar concentrations of adrenaline and histamine. Attempts to inhibit rises in aminotransferase after morphine by pretreatment with histamine, serotonin and alpha-receptor blockers were largely unsuccessful, although inhibition was observed with phenoxybenzamine in two of five patients. Higher plasma concentrations of noradrenaline and dopamine before and soon after induction of pain in patients showing rises in aminotransferase are consistent with sympathetic activation but heterogeneity appears to exist in the response to alpha-receptor blockade.

Responses to cholecystokinin octapeptide in patients with functional abdominal pain syndromes.

Clues to the pathogenesis of functional pain syndromes may be derived from the study of stimuli that precipitate or aggravate symptoms. In this study, cholecystokinin octapeptide (CCK-8, 0.06 microgram/kg) and placebo were given by intravenous infusion (5 min) in random order to control subjects and four groups of patients with unexplained abdominal pain. Induction of pain and nausea were assessed by linear analogue scales while sympathoadrenomedullary responses were assessed by serial changes in plasma concentrations of noradrenaline, adrenaline and dopamine. Scores for pain and nausea were low after infusion of placebo. After infusion of CCK-8, pain scores were significantly higher in patients with spontaneous pain than in control subjects, but significant increases in nausea were restricted to patients with irritable bowel syndrome and a subgroup of patients with pain after cholecystectomy. Although some groups showed increases in plasma concentrations of catecholamines after the infusion of CCK-8, the size of these increases was neither consistent among patients within each group nor predictive of scores of pain and nausea in individual subjects. Pain during the infusion of CCK-8 was a feature common to patients with diverse functional pain syndromes, and did not appear to be attributable to activation of the sympathetic nervous system.