PubMed Health⌕ Search

Biomedical subjects

J Such

Publications and source records attributed to J Such.

At least 19 recordsLinked to original sources
PubMed2006

Functional status of beta-2-adrenoceptor in isolated membranes of mature erythrocytes from patients with cirrhosis and oesophageal varices.

Propranolol is a widely used drug for prophylaxis of variceal bleeding in patients with cirrhosis, but not all patients show an adequate clinical response. This variability may be in relation to beta adrenoceptor activity, but no information is available in this setting. Thirty-nine patients with advanced cirrhosis and presence of oesophageal varices were sequentially included. We studied the function of beta-2-adrenoceptor in isolated membranes of mature erythrocytes obtained from patients by measuring cyclic AMP (cAMP) production before and after isoproterenol. Blood samples obtained from 11 healthy volunteers were used as control. Patients showed a six-fold increase in the mean basal cAMP production as compared to healthy volunteers. Isoproterenol produced a small, non-significantly and highly variable increase in the AC activity in patients compared with controls. cAMP values remain stable after three months of continuous treatment with oral beta-blockers in both groups. Patients without antecedent of variceal bleeding or with an active alcohol intake showed a significantly higher isoproterenol effect. In conclusion, beta-receptor function in human erythrocytes membranes is altered in patients with cirrhosis and oesophageal varices.

Adenylyl Cyclases↗
PubMed2006

A comparison of two different dosages of somatostatin combined with sclerotherapy for the treatment of acute esophageal variceal bleeding: a prospective randomized trial.

BACKGROUND: the association of somatostatin (SMT) with endoscopic therapy in patients with cirrhosis and variceal bleeding significantly improves the control of the bleeding episode, and hemodynamic data have shown that a dosage of 500 mg/h allows a more marked reduction of portal pressure versus the usual dosage of 250 mg/h. AIM: to assess if the 500 mg/h dosage is associated with an improved outcome. METHODS: sixty-two patients with variceal bleeding were included in the study. Patients were randomized to receive the usual dosage of SMT (group I: 250 mg/h), or a double dosage (group II: 500 mg/h), together with emergency endoscopic sclerotherapy. RESULTS: the control of the bleeding episode was similar in both groups of patients. Early rebleeding was less frequent in patients receiving double vs. single dosage of SMT (p = 0.06). When considering patients with advanced liver disease (Child-Pugh B or C) early rebleeding was significantly less frequent in patients receiving the 500 mg/h dose of SMT (39 vs. 13%, p = 0.03). CONCLUSIONS: the perfusion of higher doses of SMT (500 mg/h) in association with emergency sclerotherapy in patients with cirrhosis and esophageal hemorrhage significantly decreases the rate of early rebleeding in patients with more advanced stages of liver disease.

Acute Disease↗
PubMed2005

Norfloxacin decreases bacterial adherence of quinolone-resistant strains of Escherichia coli isolated from patients with cirrhosis.

BACKGROUND: Long-term administration of norfloxacin is recommended for secondary prophylaxis of spontaneous bacterial peritonitis in cirrhosis, but it may be associated with the development of quinolone-resistant bacteria in stools. However, these bacteria rarely cause infections. AIM: To assess bacterial adherence of either quinolone-sensitive or -resistant Escherichia coli obtained from stools of cirrhotic patients, as one of the main virulence factors, and its variations when sub-minimum inhibitory concentration of norfloxacin were added to the medium. METHODS: E. coli strains were co-cultured with oral epithelial cells obtained from patients in presence/absence of norfloxacin. Bacterial adherence was measured as percentage of cells exhibiting positive adherence and the number of bacteria attached to epithelial cells. RESULTS: 37 sensitive and 22 resistant E. coli strains were studied. Bacterial adherence was similar in both series (78% vs. 81%, P = N.S.), and these percentages were similarly and significantly reduced when subminimum inhibitory concentration of norfloxacin was added to the culture medium (P < 0.001). CONCLUSIONS: Bacterial adherence of E. coli obtained from patients with cirrhosis is unrelated to the sensitivity/resistance to quinolones, and is similarly reduced in both cases when subminimum inhibitory concentration of norfloxacin is added to the medium.

Anti-Infective Agents↗
PubMed2005

Detection and identification of bacterial DNA in serum from patients with acute pancreatitis.

BACKGROUND AND AIMS: Bacterial infections are common complications in patients with acute pancreatitis, and translocation of bacteria from the intestinal lumen is probably the first step in the pathogenesis of these infections. As blood cultures in afebrile patients are usually negative, more sensitive methods to investigate this hypothesis in patients are needed. Our group has recently developed a method to detect the presence of bacterial DNA in biological fluids, and we aimed to detect bacterial DNA in patients with acute pancreatitis, as molecular evidences of bacterial translocation. METHODS: Samples of blood were obtained on three consecutive days within the first six days after admission. Bacterial DNA was detected using a polymerase chain reaction based method, and an automated DNA nucleotide sequencing process allowed identification of bacteria species. RESULTS: Thirty one consecutively admitted patients with acute pancreatitis were studied. Bacterial DNA was detected in six patients (19.3%), and the sequencing process allowed identification of Citrobacter freundii and Pseudomonas aeruginosa. In two patients the same bacteria detected at admission was detected 24 hours later (above 99.9% homology of nucleotide sequence). Basic clinical and biochemical characteristics were similar among patients with or without the presence of bacterial DNA. CONCLUSION: Detection of gram negative bacteria derived bacterial DNA in our series supports the contention that bacterial translocation is a systemic process in approximately 20% of patients with acute pancreatitis that does not seem to be related to the severity of the episode or immediate development of infection.

Acute Disease↗
PubMed2004

Pharmacokinetic variations of acetaminophen according to liver dysfunction and portal hypertension status.

AIM: To study the pharmacokinetic and metabolism profiles of a single dose of acetaminophen in patients with cirrhosis. METHODS: Oral acetaminophen (1000 mg) was administered to seven healthy subjects and 14 patients with cirrhosis (nine Child-Pugh A or B and five Child-Pugh C grade), being five without and nine with oesophageal varices. Plasma levels of acetaminophen and its metabolites were determined by HPLC. RESULTS: Patients showed a higher mean area under the curve concentration-time (67.4 +/- 22.4 mg h/L vs. 38.8 +/- 4.3 mg h/L; P = 0.01), a lower clearance (166.7 +/- 85.0 mL/min vs. 367.8 +/- 62.5 mL/min; P = 0.01) and higher elimination half-life (3.8 +/- 1.1 h vs. 2.0 +/- 0.4 h; P = 0.01) of acetaminophen than healthy volunteers. The appearance in blood and the urinary excretion of metabolites in patients did not differ from healthy subjects. Absorption profile was faster in patients. Patients with lower mean and systolic arterial pressure had lower AUC of acetaminophen, independently of liver dysfunction stage. CONCLUSIONS: Patients with cirrhosis had a higher AUC and lower clearance of acetaminophen. Acetaminophen attained earlier therapeutic concentrations in patients with oesophageal varices. Mean and systolic arterial pressures were significantly associated with AUC suggesting the importance of the haemodynamic function on the pharmacokinetics of acetaminophen in patients with cirrhosis.

Acetaminophen↗
PubMed2004

Bacterial DNA activates cell mediated immune response and nitric oxide overproduction in peritoneal macrophages from patients with cirrhosis and ascites.

BACKGROUND AND AIMS: Translocation of intestinal bacteria to ascitic fluid is probably the first step in the development of episodes of spontaneous bacterial peritonitis in patients with cirrhosis. We have recently reported the detection of bacterial DNA in blood and ascitic fluid from patients with advanced cirrhosis, what we consider as molecular evidence of bacterial translocation. Several studies have shown the immunogenic role of bacterial DNA in vitro, and we hypothesised that the presence of bacterial DNA could activate the type I immune response in peritoneal macrophages from these patients, leading to greater cytokine synthesis (interleukin (IL)-2 and IL-12, tumour necrosis factor alpha, and interferon gamma) and effector molecules such as nitric oxide. METHODS: Peritoneal macrophages obtained from patients with cirrhosis and culture negative non-neutrocytic ascitic fluid were collected and characterised by flow cytometry. Inducible nitric oxide synthase, nitric oxide levels, and cytokine production were measured by immunoenzymometric assays in basal and harvested conditions according to the presence/absence of bacterial DNA. RESULTS: The ability of peritoneal macrophages to synthesise nitric oxide and levels of all cytokines were significantly increased in patients with bacterial DNA. There was a positive correlation between inducible nitric oxide synthase and nitric oxide levels. CONCLUSIONS: The presence of bacterial DNA in patients with decompensated cirrhosis is associated with marked activation of peritoneal macrophages, as evidenced by nitric oxide synthesising ability, together with enhanced cytokine production.

Aged↗
PubMed2003

[Etiology of upper gastrointestinal bleeding of peptic origin: role of Helicobacter pylori and NSAIDs].

INTRODUCTION: Upper gastrointestinal bleeding continues to be a severe and frequent complication in ulcerative disease. Etiologic diagnosis in these patients is highly important in order to initiate appropriate treatment and prevent bleeding recurrence. OBJECTIVE: 1. To investigate the prevalence of Helicobacter pylori infection and use of NSAIDs in patients with upper gastrointestinal hemorrhage of peptic origin. 2. To analyze the strategy used for the diagnosis of H. pylori in our previous work. PATIENTS AND MEHTODS: Seventy-three patients with endoscopically-diagnosed upper gastrointestinal bleeding of peptic origin were included in the study. The use of NSAIDs was investigated. H. pylori infection was diagnosed if one of the following tests was positive: urease test, histology, breath test. RESULTS: H. pylori infection was found in 92% of duodenal ulcers and in 88% of gastric ulcers. Fifty-six percent of the patients had taken NSAIDs. Excluding these patients resulted in an H. pylori infection rate of 96.7%. The diagnosis was based on urease test in 46%. In the remaining patients, breath test and histology were required. CONCLUSIONS: The main etiology in patients with upper gastrointestinal bleeding of peptic origin is H. pylori infection followed by the use of NSAIDs, and these two factors frequently coexist. The strategy of performing a urease test and, when this is negative, performing histological study and a breath test, is valid and allows a diagnosis of H. pylori infection to be made even if patients are receiving treatment that could make diagnosis difficult.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

[Toxic hepatitis associated with tamoxifen use. A case report and literature review].

Tamoxifen is an antiestrogenic drug that acts by binding to the estrogen receptor. The drug is used as a co-adjuvant treatment in advanced breast cancer expressing the oestrogen-receptor protein. Clinical trials of tamoxifen have shown its efficacy in reducing mortality and recurrence rates over a five-year treatment. Cases of tamoxifen-associated hepatotoxicity have been described, including cholestasis with or without cytolysis and steatohepatitis. We report the case of a female patient who developed hepatic alterations while undergoing continuous tamoxifen treatment. We also present an overview of similar cases published to date and comment on the advisability of continuing or suppressing this treatment in patients with hepatotoxicity or after a five-year treatment period.

Antineoplastic Agents, Hormonal↗
PubMed2001

Tumor necrosis factor-alpha, interleukin-6, and nitric oxide in sterile ascitic fluid and serum from patients with cirrhosis who subsequently develop ascitic fluid infection.

Ascitic fluid infection probably results from repeated episodes of bacteremia and seeding of ascitic fluid. The outcome of these episodes of colonization is probably a function of serum and ascitic fluid defense mechanisms and the virulence of the organism. Patients who develop spontaneous bacterial peritonitis may have serum and ascitic fluid characteristics that are different from those who do not develop infection. We prospectively collected serum and ascitic fluid specimens at the time of admission from patients with sterile cirrhotic ascites, and tested these specimens for interleukin-6, tumor necrosis factor-alpha, and nitric oxide and compared these results as well as other characteristics of patients who did not develop infection to those who did. An elevated baseline serum tumor necrosis factor-alpha as well as an increased proportion of polymorphonuclear leukocytes in sterile ascitic fluid from patients who subsequently developed infection probably represent a subclinical activation of defense mechanisms from prior silent colonizations with bacteria.

Adult↗
PubMed2001

Comparison of diagnostic methods for Helicobacter pylori infection in patients with upper gastrointestinal bleeding.

BACKGROUND: Accuracy of the most frequently used tests for diagnosing Helicobacter pylori infection in patients with upper gastrointestinal bleeding of peptic origin is determined. METHODS: Seventy-eight patients with endoscopically-proven upper gastrointestinal bleeding of peptic origin were included. The presence of H. pylori was considered when observed from the histology or, if negative, when serology and breath test were both positive. Accuracy of the rapid urease test was estimated in accordance with results obtained with other diagnostic methods. RESULTS: Lesions causing gastrointestinal bleeding were 56 duodenal ulcers, 13 gastric ulcers, 7 pyloric channel ulcers, 13 acute lesions of the gastric mucosa and 16 erosive duodenitis. H. pylori infection was present in 68 patients (87.2%). Forty-four patients had received non-steroidal anti-inflammatory drugs. The sensitivity/specificity (%) of the diagnostic methods was 48.5/100 for the rapid urease test, 91/77.8 for the breath test, 89.5/80 for serology and 86.3/100 for histology. The prior consumption of proton-pump inhibitors and antibiotics induced false-negative results in the rapid urease test and breath test, with no effect on serology and histology. CONCLUSIONS: The prevalence of H. pylori infection in patients with upper gastrointestinal bleeding from peptic lesions is high. Sensitivity of the rapid urease test for diagnosing H. pylori is low in this setting. Cases with negative rapid urease test need the combination of two or more additional tests if diagnosis is to be achieved. Cases with positive rapid urease test do not need further investigation for diagnosis.

Biopsy↗
PubMed1999

[Development of Escherichia coli strands resistant to quinolones in stools of patients with liver cirrhosis submitted to selective bowel decontamination].

BACKGROUND: Selective intestinal decontamination (SID) with norfloxacin in patients with cirrhosis may promote the development of quinolone-resistant (QR) gram-negative bacteria in stools. It is not known wether this fact may become a predisposing factor for the development of infections due to these bacteria. MATERIAL AND METHODS: We designed a prospective study to evaluate the incidence of Escherichia coli in stools at admission in patients with cirrhosis that had previously received norfloxacin as primary or secondary prophylaxis of spontaneous bacterial peritonitis (SBP) (group I, n = 28) vs those who did not (group II, n = 55). RESULTS: QR strains of E. coli were observed in 37.5 and in 1.47% of patients from groups I and II, respectively (p < 0.001). During admission, 36 patients underwent norfloxacin prophylaxis (group III), and 40 did not (group IV). Eleven patients from group III and one patient from group IV showed QR E. coli in stools. We observed 5 bacterial infections in group III and 14 in group IV (p = 0.0039). No patient with QR E. coli in stools developed infections due to this bacteria. CONCLUSION: The incidence of QR E. coli in stools of patients with cirrhosis is significantly increased in patients previously treated with prophylactic norfloxacin. However, this fact seems not to be associated with an increment in the prevalence of QR E. coli infections.

Aged↗
PubMed1999

Development of quinolone-resistant strains of Escherichia coli in stools of patients with cirrhosis undergoing norfloxacin prophylaxis: clinical consequences.

BACKGROUND/AIM: Norfloxacin prophylaxis decreases the incidence of bacterial infections in high-risk cirrhotic patients, but may promote the development of quinolone-resistant gram-negative bacteria in stools, and eventually lead to infections due to these bacteria. The aim of the study was to evaluate the prevalence of quinolone-resistant strains of E. coli in stools on admission, and the characteristics of any nosocomial infections. METHODS: Eighty-three consecutively hospitalized cirrhotic patients were included in this prospective study. The presence of quinolone-resistant strains of E. coli in stools on admission, and the characteristics of any nosocomial infections were recorded. RESULTS: Fourteen out of 83 patients (16.8%) showed quinolone-resistant E. coli in stools (Group I), and 69 did not (Group II). Thirteen out of 14 from Group I (92.8%) and 17/69 (24.6) from Group II had received primary or secondary prophylaxis with norfloxacin (p<0.001). During hospitalization, 12/12 (100%) of patients from Group I and 25/66 (37.8%) of patients from Group II underwent norfloxacin prophylaxis. Three bacterial infections in patients from Group I, 3 from Group II patients receiving norfloxacin and 16 from Group II patients not receiving norfloxacin were recorded (p<0.05). No infections due to quinolone-resistant E. coli were observed in patients colonized with these bacteria. Treatment with norfloxacin induced the development of quinolone-resistant E. coli in 6/14 (42.8%) patients in a mean time of 18.5+/-9.8 days. CONCLUSIONS: The development of quinolone-resistant strains of E. coli is significantly associated with previous administration of norfloxacin prophylaxis. However, in our series this fact is not associated with an increased incidence of quinolone-resistant E. coli or other gram-negative infections.

Aged↗