The effect of mastic gum on Helicobacter pylori: a randomized pilot study.

Our aim was to study the effect of pure mastic gum on Helicobacter pylori (H. pylori) eradication in patients suffering from an H. pylori infection Fifty two patients were randomized to receive either 350mg three times a day (tid) of pure mastic gum for 14 days (Group A), or 1,05g tid of pure mastic gum (Group B) for 14 days, or pantoprazole 20mg twice a day (bd) plus pure mastic gum 350mg tid for 14 days (Group C) or pantoprazole 20mg bd plus amoxicillin 1g bd plus clarithromycin 500mg bd for 10 days (Group D). All patients harboured H. pylori before entering the study and that was confirmed by a (13)C urea breath test (UBT). H. pylori eradication was tested by a UBT 5 weeks after completion of the eradication regime. Eradication of H. pylori was confirmed in 4/13 patients in Group A and in 5/13 in Grour B. No patient in Group C achieved eradication whereas 10/13 patients in Group D had a negative UBT. There were no statistically significant differences in mean UBT values in Groups A, B, C although there was a trend in Group A (p=0.08) and in Group B (p=0.064). The difference was significant in Group D (p=0.01). All patients tolerated mastic gum well and no serious adverse events were reported. Mastic gum has bactericidal activity on H. pylori in vivo.

The simulated microgravity environment maintains key metabolic functions and promotes aggregation of primary porcine hepatocytes.

The high aspect ratio vessel allows the culture of primary porcine hepatocytes in an environment of low shear stress and simulated microgravity. Primary porcine hepatocytes have been difficult to maintain in culture long term while preserving their metabolic functions. This study was carried out in order to characterise key metabolic functions of cell aggregates formed by primary porcine hepatocytes cultured in a high aspect ratio vessel for a predetermined period of 21 days. 10(8) porcine hepatocytes were loaded into the high aspect ratio vessel and continuously rotated during the experiments. 0.7 ml of the culture medium was sampled on days 1, 2, 4, 7, 10, 14 and 21. 1H nuclear magnetic resonance spectroscopy of the culture medium, using the presaturation technique, assessed the following: glucose metabolism, glutamine synthesis and ketogenesis. There was glucose breakdown anaerobically during the first 10 days as manifested by lactate production and pyruvate and threonine consumption. After day 10 there was significantly smaller lactate production (day 1 vs day 10 P < 0.01), and significantly smaller pyruvate (day 1 vs day 14 P < 0.03) and threonine consumption (day 1 vs day 10 P < 0.002), indicative of an aerobic metabolic pattern. Significantly more glutamate was produced after day 10 (day 1 vs day 10 P < 0.031), and more glutamine was consumed after day 14. There was a steadily diminishing production of acetate which reached a minimum on day 14 (day 2 vs day 14 P < 0.00014). After an initial 10 day period of acclimatisation cell aggregates formed in the high aspect ratio vessel switched from the anaerobic pattern of metabolism to the more efficient aerobic pattern, which was exhibited until the experiments were terminated. The high aspect ratio vessel is suitable for long-term culture of porcine hepatocytes and it is worthwhile carrying out scale-up feasibility studies.

An improved ex vivo method of primary porcine hepatocyte isolation for use in bioartificial liver systems.

INTRODUCTION: Primary porcine hepatocytes are commonly, used in bioartificial liver devices and for in vitro studies of hepatocyte function. Although in vivo isolation of porcine hepatocytes can give high yield and viability, such methods are time-consuming and expensive, requiring specialist surgical facilities. AIM: To develop a simple, low-cost, high viability, high yield, reproducible ex vivo method for obtaining functional porcine hepatocytes for use in bioartificial liver systems. METHODS: Weanling piglets (12 kg) were killed with pentobarbitone sodium, the infra-hepatic inferior vena cava was clamped and the supra-hepatic inferior vena cava cannulated. The whole liver was retrogradely perfused in situ with cold saline and excised, followed by an ex vivo open-loop and re-circulating perfusion method (at 37 degrees C) in five steps. The liver was disrupted, sequentially filtered in washing buffer, purified by centrifugation and resuspended in Williams E medium. Viability and cell number were assessed using trypan blue exclusion. The cells were subsequently cultured in serum-free chemically-defined medium and function was assessed. RESULTS: The time interval from when the animals were killed to the final cell wash was 105+/-5 min (n = 20). Cell viability was 85+/-6% with a yield of (2.4+/-0.5) x 10(10) from 12+/-1 kg piglets using 0.03% (w/v) collagenase (n = 20). Hepatocytes from all isolations were successfully plated and grown in monolayer culture. In freshly isolated hepatocytes (day 0) total protein content (TP) was 1.2+/-0.1 mg/10(6) cells (n = 5) and 1.2+/-0.3 mg/10(6) cells (n = 5) for day 2 monolayer cultures, corresponding to approximately 9x10(6) hepatocytes per dish. The percentage of total LDH released into the medium was 13+/-4% for day 0 and 8+/-4% at day 2; conversely, intracellular LDH activities were 87+/-4% and 92+/-4% of the total, respectively. The urea synthesis rate was 196+/-36 nmol/h/mg total protein at day 0 (n = 5) and 292+/-62 nmol/h/mg protein (n = 9) at day 2. The total P450 content was 99+/-11 pmol/mg total protein for fresh cells (n = 5) and maintained at 89+/-35 pmol/mg total protein in day 2 cultures. CONCLUSIONS: This ex vivo method provides a high viability, high yield, cost-effective and rapid technique for isolating functional porcine hepatocytes with high plating efficiency, which compares favourably with results obtained using complex in vivo techniques.

Comparison between theophylline and spironolactone in the management of cirrhotic ascites: a randomized controlled study.

BACKGROUND: It has been suggested that adenosine is involved in the renal haemodynamic and tubular abnormalities observed in cirrhosis. Low-dose theophylline is an adenosine antagonist and recent studies have shown that this drug can improve renal blood flow and sodium excretion in cirrhotic patients. METHODS: Fifteen patients with newly diagnosed cirrhotic ascites were randomized to receive either 100 mg spironolactone daily for 7 days or 250 mg theophylline on days 1, 2, 4 and 6. Baseline clinical and urinary and serum biochemical data were collected and compared following therapy. RESULTS: After 7 days of spironolactone there were increases in urinary sodium excretion (43.5 +/- 15.6 vs. 106.8 +/- 34.7 mmol/day; P < 0.05) and urine volume (769.1 +/- 206.5 vs. 1541.6 +/- 342.6 mL/day; P < 0.05). No changes in the patients' weight, creatinine clearance or serum electrolytes were observed. No change was detected in any of these parameters following theophylline therapy. CONCLUSION: Adenosine antagonism in the form of low-dose theophylline is less efficacious than spironolactone in the management of cirrhotic ascites.