Prognosis of a large cohort of patients with hepatocellular carcinoma in a single European centre

BACKGROUND/AIM: Only a few follow up data are available for patients with hepatocellular carcinoma (HCC) in Europe and the USA. Therefore, we analysed all HCC patients admitted to our hospital between 1988 and 1999. METHODS: We documented aetiology, stage (HCC: Okuda and UICC classifications, liver cirrhosis: Child-Pugh score), and diagnostic and therapeutic measures of 281 consecutive HCC patients. Survival time was calculated as a function of staging and therapy. RESULTS: Cirrhosis was diagnosed in all patients. Seventy-two patients underwent liver resection, 28 liver transplantation, 31 transarterial chemoembolization and 14 percutaneous ethanol injection. One hundred and thirty-six patients received no treatment. The Okuda and the Child-Pugh classification predicted a significant decrease of median survival time, whereas the UICC classification was less powerful. CONCLUSIONS: HCC occurred only in patients with liver cirrhosis. Survival time correlated with therapy (or no therapy) and with the Child-Pugh Score. In European patients the Okuda classification is superior to the UICC classification and should be compared to novel classification systems.     

Limiting glutamate transmission in a Vglut2-expressing subpopulation of the subthalamic nucleus is sufficient to cause hyperlocomotion

The subthalamic nucleus (STN) is a key area of the basal ganglia circuitry regulating movement. We identified a subpopulation of neurons within this structure that coexpresses Vglut2 and Pitx2, and by conditional targeting of this subpopulation we reduced Vglut2 expression levels in the STN by 40%, leaving Pitx2 expression intact. This reduction diminished, yet did not eliminate, glutamatergic transmission in the substantia nigra pars reticulata and entopeduncular nucleus, two major targets of the STN. The knockout mice displayed hyperlocomotion and decreased latency in the initiation of movement while preserving normal gait and balance. Spatial cognition, social function, and level of impulsive choice also remained undisturbed. Furthermore, these mice showed reduced dopamine transporter binding and slower dopamine clearance in vivo, suggesting that Vglut2-expressing cells in the STN regulate dopaminergic transmission. Our results demonstrate that altering the contribution of a limited population within the STN is sufficient to achieve results similar to STN lesions and high-frequency stimulation, but with fewer side effects.The subthalamic nucleus (STN) has long been a structure of interest for researchers and clinicians alike. There is ample evidence that high-frequency stimulation of the STN improves symptoms such as tremor, rigidity, and slowness of movement, so called bradykinesia, in patients with Parkinson disease (see ref. 1 for review), but the mechanism through which this is achieved is still unknown. Some studies suggest that electrical stimulation causes a hyperexcitation of this structure (2), whereas others find evidence that the opposite is true (3–5). Other possible interpretations include the activation of the zona incerta, a neighboring white-matter structure (6) or of fibers coming from the motor cortex (7). Bilateral lesions of the STN improve locomotion (8), a result that is consistent with the inactivation hypothesis. However, previous studies have also found cognitive side effects when using high-frequency stimulation of the STN (9), findings supported by lesion studies in experimental animals, which led to abnormalities in operant tasks involving attention and impulsivity (10, 11). The projections of the STN to other regions help explain the multiple roles of this structure: It sends projections to other targets in the basal ganglia, such as the internal segment of the globus pallidus [also termed the entopeduncular nucleus (EP) in rodents] and the substantia nigra pars reticulata (SNr) (12, 13). The STN is also part of a circuit that includes the prefrontal cortex and the nucleus accumbens (14). It is currently unknown, however, whether these different roles reflect a heterogeneous population of cells, characterized by distinct gene expression. If that is the case, it would allow direct control over each cell population, facilitating the investigation of their respective roles. In rodents, the STN is believed to be composed solely of glutamatergic neurons, characterized by expression of the subtype 2 Vesicular glutamate transporter (Vglut2), whereas the other two subtypes (Vglut1 and Vglut3) have not been detected (15, 16). Selective targeted deletion of Vglut2 expression in this nucleus would therefore provide a specific loss-of-function model that would bypass a common problem presented by traditional lesions with pharmacological agents, which have patterns of diffusion that likely affect surrounding structures (17). It is known, however, that Vglut2 is expressed in many other parts of the brain (18), and a complete knockout in the mouse is not viable (19, 20). There is also evidence that the promoter driving expression of the Paired-like homeodomain 2 (Pitx2) gene is strong in the mouse STN (21) but is also not specific to this structure and a full knockout of Pitx2 expression results in premature death (22). To achieve the desired level of specificity, using a conditional knockout technique previously used to eliminate glutamatergic transmission in other cell types (23), we crossed Pitx2-Cre and Vglut2-lox mice, producing Vglut2^{f/f;Pitx2-Cre} conditional knockout (cKO) mice in which Vglut2 expression in the STN was strongly reduced in comparison with expression levels in littermate control mice. To understand the physiological contribution of the selected subpopulation of STN cells, we characterized these cKO mice with regard to anatomical, electrophysiological, and molecular properties, as well as their performance in a range of behavioral tasks.     

Identification and characterization of recombinant plasmids carrying the complete qa gene cluster from Neurospora crassa including the qa-1+ regulatory gene.

The early reactions in the catabolism of quinic acid in Neurospora crassa are controlled by at least four genes which are clustered on linkage group VII. Three of the loci (qa-2, qa-4, and qa-3) encode enzymes that convert quinic acid to protocatechuic acid. The fourth gene (qa-1) encodes a positive regulatory protein which, in the presence of quinic acid, leads to the de novo synthesis of the other proteins in the qa cluster. This communication describes a series of recombinant plasmids that span 36.5 kilobases of linkage group VII and contain the coding sequences for qa-2, qa-4, qa-3, and the qa-1 regulatory protein. The plasmids were obtained by partial digestion of wild-type N. crassa DNA with EcoRI and ligation into the cosmid cloning vehicle pHC79. Two independently derived plasmids (pMSK331 and pMSK335), each containing 36.5-kilobase inserts, were shown by transformation back into N. crassa to contain the entire qa gene cluster. A preliminary physical organization of the gene cluster is presented. An improved procedure for the transformation of N. crassa with plasmid DNA is also described.     

Lovastatin controls signal transduction in vascular smooth muscle cells by modulating phosphorylation levels of mevalonate-independent pathways

Lovastatin has been proven to effectively lower circulating LDL cholesterol and to exert antiproliferative effects on various cell lines, the latter effect being only incompletely understood. We found that lovastatin modulates the signal transducing phosphorylation cascade in vascular smooth muscle cells in a mevalonate-independent manner. Lovastatin was found to distinctively increase total phosphotyrosine levels in smooth muscle cells, an effect which could not be restored by mevalonate. At a concentration of 5 μmol/L lovastatin had a highly specific effect on the mitogen-activated protein kinase pathway. The expression of p42/44 mitogen-activated protein kinase (MAPK) was clearly reduced, but could be restored by addition of mevalonate, while the phosphorylation of p44 was mildly suppressed and the phosphorylation of p42 MAPK was reduced to non-detectable levels. While the phosphorylation of p44 MAPK could partially be restored by addition of mevalonate, the reduced phosphorylation of p42 MAPK could not be restored by addition of excessive doses of mevalonate or stimulation of the cells with basic fibroblast growth factor. Concurrently the expression of the GTP-binding Ras protein was significantly elevated at 5 and 20 μmol/L lovastatin, this effect being attenuated by addition of mevalonate to cell cultures. The data indicate that lovastatin is capable of modulating cellular signaling independently of the cholesterol synthesis pathway. Received: 30 August 2000, Returned for 1. revision: 20 September 2000, 1. Revision received: 14 November 2000, Returned for 2. revision: 28 November 2000, 2. Revision received: 11 December 2000, Accepted: 12 December 2000     

Hepatocellular carcinomas do not compromise quantitative tests of liver function

BACKGROUND/AIMS: Hepatocellular carcinoma, which usually develops in cirrhotic livers, is one of the most frequent cancers worldwide. If and how far hepatoma growth influences liver function is unclear. Therefore, we compared a broad panel of quantitative tests of liver function in cirrhotic patients with and without hepatocellular carcinoma. METHODOLOGY: Patients with (n=40) and without (n=40) hepatocellular carcinoma were matched according to Child-Pugh grade and subjected to testing of aminopyrine demethylation capacity, galactose elimination capacity, sorbitol clearance and indocyanine green clearance. RESULTS: Compared to healthy controls, patients with cirrhosis Child-Pugh grade B and grade C revealed reduced metabolic (aminopyrine demethylation capacity, galactose elimination capacity) and perfusion-dependent QTLF (sorbitol clearance, indocyanine green clearance). Comparing values of quantitative tests of liver function in matched patients with and without hepatocellular carcinoma, no differences in liver function parameters were observed. CONCLUSIONS: Quantitative tests of liver function correlated inversely with the Child-Pugh grade. Since these parameters are not affected by the occurrence of hepatocellular carcinoma, the emergence of hepatic neoplasia in cirrhotics does not appear to be determined by the degree of hepatic functional deterioration.     

Comparison between vildagliptin and metformin to sustain reductions in HbA1c over 1 year in drug‐naïve patients with Type 2 diabetes

Aims To evaluate the ability of vildagliptin and metformin to sustain reductions in HbA_1c over a 1‐year treatment period in drug‐naïve patients with Type 2 diabetes (Type 2 DM). Methods Double‐blind, randomized, multicentre, active‐controlled, parallel‐group study of 52‐week treatment with vildagliptin (100 mg daily, n = 526) or metformin (titrated to 2000 mg daily, n = 254) in drug‐naïve patients (baseline HbA_1c = 7.5–11.0%). HbA_1c was measured periodically over 1 year. Results Vildagliptin and metformin each rapidly decreased HbA_1c from an equal baseline of 8.7%. Most of the HbA_1c reduction was attained by week 12, and the efficacy was sustained throughout 1‐year treatment with both agents. At the study end, significant HbA_1c reductions from baseline were seen with both vildagliptin (–1.0 ± 0.1%, P < 0.001) and metformin (–1.4 ± 0.1%, P < 0.001); however, statistical non‐inferiority of 50 mg vildagliptin twice daily to 1000 mg metformin twice daily was not established. Body weight did not change during the 1‐year treatment with vildagliptin (0.3 ± 0.2 kg, P = 0.17) and decreased in metformin‐treated patients (–1.9 ± 0.3 kg, P < 0.001). The proportion of patients experiencing an adverse event was 70.1 vs. 75.4% in patients receiving vildagliptin and metformin, respectively. The proportion of patients experiencing a gastrointestinal adverse event was twofold higher in the metformin group, driven by a 3–4‐fold greater incidence of diarrhoea, nausea and abdominal pain. The incidence of hypoglycaemia was similarly low in both groups (< 1%). Conclusions A clinically meaningful decrease in HbA_1c that was sustained throughout a 1‐year treatment in drug‐naïve patients with Type 2 DM was seen with both metformin and vildagliptin monotherapy.