Equilibrium, kinetic and thermodynamic studies on the adsorption of phenol onto chitin.

The adsorption of phenol onto chitin, a naturally occurring material was studied as a function of initial pH, temperature and initial phenol concentration. The highest phenol adsorption capacity was determined as 21.5 mgg(-1) for 300 mgdm(-3) initial phenol concentration at pH 1.0 and 40 degrees C. Adsorption data were well described by the Freundlich Model, although they could be modeled by the Langmuir equation. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data. The pseudo-second-order kinetic model provided the best correlation of the experimental data compared to the pseudo-first-order model. The thermodynamic constants of the adsorption process; DeltaG degrees , DeltaH degrees and DeltaS degrees were evaluated as -19.4 kJmol(-1) (at 40 degrees C), 10.2 kJmol(-1) and 0.093 kJmol(-1)K(-1), respectively. These showed that adsorption of phenol on chitin was endothermic and spontaneous.

Survival in patients with hypoechoic muscularis propria lesions suggestive of gastrointestinal stromal tumors in gastric wall.

BACKGROUND: Subepithelial lesions (SEL) on upper gastrointestinal endoscopy are frequently encountered and referred to endoscopic ultrasound (EUS). Management of small gastric hypoechoic SELs of muscularis propria (MP) is controversial since EUS-assisted fine needle aspiration may be inconclusive, and surgical excision may be too invasive. We aimed to analyze our gastric MP-SELs in terms of survival and confounding factors. METHODS: Data from gastric hypoechoic MP-SELs suggestive of gastrointestinal stromal tumor (GIST) by EUS were retrospectively reviewed. Surgically resected GISTs were stratified according to the current pathological risk criteria. RESULTS: Sixty-one patients were identified. The mean age was 55.5 ± 13.2 years and 45.6% were male. Mean follow-up duration was 53.4 ± 26.7 (12-110) months. Twenty-eight (45.9%) patients were managed conservatively (diameter 15.3 ± 10.1 mm). There were no metastasis- or tumor-related deaths and no significant size changes (≥ 5 mm) in this group during follow-up. Thirty-three (54.1%) patients underwent complete resection (diameter 34.2 ± 14.1 mm) among which 25 (75.8%) had the final diagnosis of GIST; 2 (8.0%), 14 (56%) and 6 (24%) patients were classified in no-risk, very-low-risk, low-risk categories respectively, while 2 (8.0%) were in moderate-risk and only 1 (4.0%) was in high-risk category. CONCLUSIONS: The excellent survival of patients with small hypoechoic gastric MP-SELs with conservative management represents indolent course of those lesions. We suggest re- consideration of the recommendations in the current guidelines towards extending the follow-up intervals for small MP-SELs.

Refractory duodenal ulcer healing and relapse: comparison of omeprazole with Helicobacter pylori eradication.

OBJECTIVE: To investigate differences between omeprazole and Helicobacter pylori eradication in patients with duodenal ulcers refractory to H2-receptor antagonists and to compare the recurrence rates after the two treatments. DESIGN AND METHODS: Forty-five patients with endoscopically proven duodenal ulcers refractory to H2-receptor antagonists and H. pylori infection were randomly assigned to 8 weeks of treatment with omeprazole 40 mg/day or 4 weeks of treatment with colloidal bismuth subcitrate 480 mg/day plus metronidazole 750 mg/day and tetracycline 1000 mg/day from day 1 to day 14. Patients were evaluated endoscopically and clinically at the end of treatment. Patients with healed ulcers were followed up for 1 year after cessation of the treatment. Endoscopy was performed at 3 and 12 months. RESULTS: Ulcer healing occurred in 100% (21/21) of patients on triple therapy and 70.5% (12/17) of those treated with omeprazole alone (P = 0.0123). The relapse rate at the 3rd month was 11.7% (2/17) in the triple therapy group and 60% (6/10) in the omeprazole group (P = 0.0248). Of the patients followed to study endpoint (relapse or endoscopy at 12 months) three of 12 (25%) receiving triple therapy, compared to six of eight (75%) receiving omeprazole, relapsed (P = 0.0648). CONCLUSION: These results show that triple therapy is more effective than omeprazole in the treatment of refractory duodenal ulcers and reduces the rate of ulcer relapse.

Thrombophilia and inflammatory bowel disease: does factor V mutation have a role?

BACKGROUND: An increased tendency for thromboembolism is a well known problem of inflammatory bowel disease (IBD). Microvascular thrombosis has also been claimed as a pathogenic factor in IBD. Recently a point mutation in the gene coding factor V (FV Leiden) has been identified in various thromboembolic diseases, but the role in IBD is unknown. OBJECTIVE: To determine the frequency of FV Leiden in IBD patients and compare with a group of controls. METHODS: Sixty-three IBD patients [43 ulcerative colitis (UC) patients and 20 Crohn's disease (CD) patients] and 36 healthy controls were included in the study. Only one of the UC patients had a history of cerebral thromboembolism. The extracted DNA from frozen blood was subjected to polymerase chain reaction for the amplification of FV gene. The amplicons were hybridized both with the mutant and wild-type probes to detect FV mutation. Readings of optical density above 0.3 were considered as positive results. According to the patterns of ELISA, heterozygosity and homozygosity for normal and mutant alleles were determined. RESULTS: Eight (18%) of UC patients were heterozygous normal and one (2%) patient had homozygous mutation. Eight (45%) of the 20 CD patients had a heterozygous pattern and one (5%) had a homozygous pattern. In the control group four (11%) subjects showed a heterozygous genotype. FV Leiden was found to be statistically more frequent in CD patients (P < 0.005) (odds ratio 6.5, 95% confidence interval 1.3-18.), but not in the UC patients as compared with controls (P> 0.05). There was no significant correlation between FV Leiden presence and disease activity, gender or disease duration for both UC and CD. CONCLUSION: The results suggest that FV Leiden is more frequent in CD patients, but not in the UC patients as compared with controls. The high rate of factor V mutation in our CD patients suggests the need for further studies to confirm a relationship between this mutation and aetiology of the disease.

Adrenomedullin in cirrhotic and non-cirrhotic portal hypertension.

AIM: Adrenomedullin (ADM) is a potent vasodilator peptide. ADM and nitric oxide (NO) are produced in vascular endothelial cells. Increased ADM level has been linked to hyperdynamic circulation and arterial vasodilatation in cirrhotic portal hypertension (CPH). The role of ADM in non-cirrhotic portal hypertension (NCPH) is unknown. plasma ADM levels were studied in patients with NCPH, compensated and decompensated cirrhosis in order to determine its contribution to portal hypertension (PH) in these groups. METHODS: There were 4 groups of subjects. Group 1 consisted of 27 patients (F/M: 12/15) with NCPH due to portal and/or splenic vein thrombosis (mean age: 41+/-12 years), group 2 consisted of 14 patients (F/M: 6/8) with compensated (Child-Pugh A) cirrhosis (mean age: 46+/-4), group 3 consisted of 16 patients (F/M: 6/10) with decompensated (Child-Pugh C) cirrhosis (mean age: 47+/-12). Fourteen healthy subjects (F/M: 6/8) (mean age: 44+/-8) were used as controls in Group 4. ADM level was measured by ELISA. NO was determined as nitrite/nitrate level by chemoluminescence. RESULTS: ADM level in Group 1 (236+/-61.4 pg/mL) was significantly higher than that in group 2 (108.4+/-28.3 pg/mL) and group 4 (84.1+/-31.5 pg/mL) (both P<0.0001) but was lower than that in Group 3 (324+/-93.7 pg/mL) (P=0.002). NO level in group 1 (27+/-1.4 micromol/L) was significantly higher than that in group 2 (19.8+/-2.8 micromol/L) and group 4 (16.9+/-1.6 micromol/L) but was lower than that in Group 3 (39+/-3.6 micromol/L) (for all three P<0.0001). A strong correlation was observed between ADM and NO levels (r=0.827, P<0.0001). CONCLUSION: Adrenomedullin and NO levels were high in both non-cirrhotic and cirrhotic portal hypertension and were closely correlated, Adrenomedullin and NO levels increased proportionally with the severity of cirrhosis, and were significantly higher than those in patients with NCPH. Portal hypertension plays an important role in the increase of ADM and NO. Parenchymal damage in cirrhosis may contribute to the increase in these parameters.

Preliminary evidence of an association between the functional c-kit rs6554199 polymorphism and achalasia in a Turkish population.

BACKGROUND: C-kit-positive interstitial cells of Cajal (ICC) of the lower esophageal sphincter are reduced in achalasia. Two functional gene polymorphisms (rs2237025 and rs6554199) within the c-kit gene may affect its transcriptional activity. In this pilot study, we hypothesized that these polymorphisms would be associated with achalasia. METHODS: Genomic DNA was extracted and real-time PCR reactions were used to determine the rs2237025 and rs6554199 c-kit polymorphisms in 88 Turkish patients with achalasia and 101 healthy controls. KEY RESULTS: The frequency of the T allele of rs6554199 was significantly higher in patients with achalasia [odds ratio (OR): 1.55; 95% confidence interval (CI), 1.03-2.34; P = 0.038] compared with the G allele. Under a dominant model of inheritance, the carriage of at least one T allele was significantly more frequent in patients with achalasia (80.7%) than in controls (65.3%; OR: 2.21; 95% CI, 1.13-4.33; P = 0.022). No association of the c-kit rs2237025 polymorphism with achalasia was detected. CONCLUSIONS & INFERENCES: Despite the small sample size and the possibility of a false positive finding, our preliminary data support the hypothesis that the T allele of the c-kit rs6554199 polymorphism may be associated with achalasia in the Turkish population. These findings need to be replicated in other racial-ethnically diverse populations.

Randomised clinical trial: otilonium bromide improves frequency of abdominal pain, severity of distention and time to relapse in patients with irritable bowel syndrome.

BACKGROUND: Otilonium bromide (OB) is a spasmolytic agent that blocks L-Type Calcium channels in human colonic smooth muscle. AIM: To study the efficacy of OB in symptom control in irritable bowel syndrome (IBS). METHODS: A total of 356 patients (46.16±19years, 71% female) with IBS participated in a double-blind, randomised, parallel placebo-controlled phase IV study. OB (40mg t.d.s.) or placebo was administered for 15weeks, and follow-up was extended 10 additional weeks. RESULTS: Otilonium bromide (n=179) and placebo (n=177) groups had comparable demographics, symptom severity and IBS subtype. Both OB and placebo reduced abdominal pain and IBS symptoms. The effect of OB was significantly greater than placebo in the reduction of weekly frequency of episodes of abdominal pain at the end of treatment period (primary endpoint, -0.90±0.88 vs. -0.65±0.91, P=0.03), reduction of abdominal bloating (-1.2±1.2 vs. -0.9±1.1, P=0.02) and global efficacy by patient assessment (1.3±1.1 vs. 1.0±1.1, P=0.047). Intensity of abdominal pain, proportion of patient responders, safety and quality of life scores were similarly affected by OB and placebo. During follow-up, the therapeutic effect of OB remained greater than placebo in terms of withdrawal rate due to symptom relapse (10% vs. 27%, P=0.009), global efficacy of treatment and relapse-free probability (P=0.038). CONCLUSIONS: This placebo-controlled double-blind study shows that otilonium bromide is safe, well tolerated and superior to placebo in reducing the frequency of abdominal pain, severity of abdominal bloating and protecting from symptom relapse in IBS. These results further confirm that patients with IBS can improve during and following treatment with otilonium bromide.

Cellular and humoral immunity in prostitutes in Istanbul.

Acquired immunodeficiency syndrome (AIDS) can be transmitted through heterosexual intercourse and prostitutes may be responsible for this form of transmission. Thirty-four prostitutes were included in this study and their humoral and cellular immunological parameters were compared with control group. Prostitutes were divided in two subgroups according to their sexual practice and the use of illicit drugs and compared with each other. The only immunological parameter that is significantly different from the control group was the serum IgM level. In prostitutes who have more than 11 partners in a week, the mean number of E rosettes, EAC rosette forming cells and cells expressing surface immunoglobulins were significantly higher than prostitutes who have 0-10 sexual partner in a week.

Effect of diltiazem on renal function in patients with liver cirrhosis.

Calcium channel blockers have strong vasodilator, natriuretic and diuretic actions in normal and hypertensive subjects. The aim of this study was to evaluate the effect of diltiazem on renal function, renin-angiotensin-aldosterone axis (RAA) and atrial natriuretic factor (ANF) in patients with liver cirrhosis. Seven patients (3 females and 4 males) with a mean age of 56.3 +/- 11.1 years (36-68) entered the trial. All of the patients had HBV (6 cases) or HCV (1 case) related Child A (3 cases) or Child B (4 cases) liver cirrhosis proven by liver biopsy. Patients were given placebo for 15 days followed by p.o. diltiazem 30 mg t.i.d. for 15 days. Urinary volume, natriuresis, creatinine clearance, plasma renin activity (PRA), ANF and aldosterone (ALD) levels were determined after the washout period and during the first and second weeks of drug treatment. Urinary volume increased by 25-170% in 5 cases but this difference did not reach statistical significance. Slight increases in natriuresis occurred in some cases on the 3rd day of the trial but the overall results were not statistically significant (191.50 +/- 26.85 vs 204.07 +/- 39.83 mmol/l). Diltiazem induced no significant changes in PRA, ALD and ANF levels or creatinine clearance during the first or second weeks of the trial. There was a significant drop in the pulse rate on the first or second weeks of the treatment (p less than 0.01 and p less than 0.05, respectively). No significant changes were noted on mean arterial pressure (MAP).(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B virus related hepatocellular carcinoma in the non-cirrhotic liver.

To complement investigations of hepatitis B virus infection in hepatocellular carcinoma associated with cirrhosis, we studied hepatitis B virus infection in 137 hepatoma patients without cirrhosis. Ninety-five were from the U.K. (where the prevalence of hepatitis B virus markers is very low) and 42 were from overseas. Of these 137 patients, seven (5%) were hepatitis B surface antigen seropositive. None of the hepatitis B surface antigen positive patients had any recognisable risk factors other than birth in an area of high hepatitis B virus prevalence in four of the patients. Of the 95 U.K. patients three (3%) were hepatitis B surface antigen positive as compared to a carriage rate of less than 0.1% in the normal population. The frequency of antibodies to hepatitis B surface and core antigens alone (both 7.5%) was also higher than that seen in the normal U.K. population (2.4%). Histological examination of the non-tumorous liver showed fine fibrous septa in three patients, more extensive subcapsular scars in one, chronic persistent hepatitis in two and non-specific inflammation in one. On immunohistochemical examination five patients had hepatitis B surface antigen (but not core antigen) detectable in the non-tumorous liver tissue. Hepatitis B virus infection appears to be a small, but significant, risk factor for the development of hepatoma in the non-cirrhotic group.

Therapeutic biliary endoscopy.

Therapeutic biliary endoscopy continues to evolve; some small but important developments were seen during the last year. Competing technologies are continuing to develop.

Intraarterial adriamycin and lipiodol for inoperable hepatocellular carcinoma: a comparison with intravenous adriamycin.

The technique of 'targeting' cytotoxic drugs by mixing them with the contrast medium lipiodol is now widely used in Japan and the Far East where it has been reported to enhance response rates in patients with hepatocellular carcinoma. In the present study 19 patients with this tumour were treated with intra-(hepatic) arterial adriamycin (60 mg/m2), at least one course of which was combined with lipiodol (10-20 ml). Two patients (11%) had a remission as indicated by a significant fall in serum alphafetoprotein and there was a reduction of tumour size in one of these. The median survival period was 3 months (range 1-18) with the two responding patients surviving 8 and 12 months. This response rate was no better than the figure of 14% seen in 31 consecutive patients treated with intravenous adriamycin at the same dose, and the survival curves of the two groups of patients were not significantly different. Lipiodol in combination with adriamycin is not superior to intravenous adriamycin administered alone.

Clinical efficacy and toxicity of standard dose adriamycin in hyperbilirubinaemic patients with hepatocellular carcinoma: relation to liver tests and pharmacokinetic parameters.

A standard dose of Adriamycin (60 mg m-2) was administered to 30 patients with inoperable hepatocellular carcinoma, 16 of whom were hyperbilirubinaemic (18-37 mumol l-1). The hyperbilirubinaemic patients experienced marked myelosuppression, but only minor symptomatic side-effects. The degree of neutropenia was directly related to the serum bilirubin concentration, but not to any other standard liver test, presence or absence of cirrhosis, or any pharmacokinetic parameter studied including the area under the Adriamycin or adriamycinol concentration-time curve to 48 h or infinity, or the terminal half-life of Adriamycin. The area under the log concentration-time curve was significantly greater for both Adriamycin and adriamycinol in patients who were hyperbilirubinaemic compared to those with normal bilirubin. Whilst hyperbilirubinaemic patients may tolerate a full dose of Adriamycin, we found no evidence that this was associated with a better response rate, which was disappointingly low at only 18%.

Corticosteroid therapy augments gastroduodenal permeability to sucrose.

OBJECTIVE: The aim of the present study was to investigate whether corticosteroid therapy alters gastroduodenal mucosal permeability and whether permeability alteration is associated with macroscopic mucosal damage. METHODS: Eight patients taking oral corticosteroid therapy (total prednisone-equivalent dose, 1.5+/-0.1 g; duration, approximately 30 days), nine patients with multiple sclerosis taking high-dose intravenous methyl-prednisolone therapy (total dose, 11.7+/-0.5 g; duration, approximately 9 days), and 20 age- and gender-matched controls were studied. Gastroduodenal permeability was determined using sucrose as a site-specific permeability probe. Five-hour urine was collected after ingesting 100 g of sucrose and its urinary excretion rate was measured using high-pressure liquid chromatography. Gastroduodenal endoscopy was performed before steroid therapy to exclude subjects with evidence of macroscopic mucosal lesions. The sucrose test and endoscopy were repeated after completion of corticosteroid therapy. RESULTS: The urinary sucrose excretion rates were similar in the control group and in patient groups before corticosteroid therapy. The median excretion rate of sucrose increased four (one to 28)- and eight (two to 35)-fold, respectively, as compared with pretreatment values in patients taking oral steroid and high-dose intravenous methyl-prednisolone therapy (p < 0.01). Considering all patients together, subjects who received a mean prednisone-equivalent dose of 8.4+/-1.5 g exhibited mucosal lesions, whereas patients who received 3.3+/-1.8 g did not (p = 0.06). The post-therapy increments in sucrose excretion rates were associated with neither the presence of macroscopic lesions nor with the total steroid dose received. CONCLUSIONS: Corticosteroid therapy augments gastroduodenal permeability and high doses are associated with macroscopic mucosal lesions. Steroid-induced permeability increase does not appear to be associated with the presence of macroscopic mucosal lesions.

Pharmacokinetics and toxicity of intraarterial adriamycin for hepatocellular carcinoma: effect of coadministration of lipiodol.

To determine the effect of coadministration of lipiodol on the pharmacokinetics and systemic toxicity of intraarterial Adriamycin in patients with hepatocellular carcinoma, nine patients were studied in detail. Each received two courses of a bolus injection of Adriamycin (60 mg/m2), in one of which the Adriamycin was mixed with 10 ml of lipiodol. Analysis of the paired data, and additional 'non-paired' data from a further seven patients, showed that there was no significant difference in the area under the concentration-time curve for Adriamycin or adriamycinol or, in the case of Adriamycin, the terminal half-life. Likewise the fall in haemoglobin concentration, white cell count and platelet count following treatment, and the degree of nausea and vomiting were not significantly different. Comparison with a series of 12 patients receiving intravenous Adriamycin, in the same dose schedule, revealed no difference in terms of pharmacokinetic parameters or toxicity with intraarterial administration of Adriamycin, with or without lipiodol.