Small intestinal bacterial overgrowth recurrence after antibiotic therapy.

OBJECTIVES: Current treatment for small intestinal bacterial overgrowth (SIBO) is based on courses of broad-spectrum antibiotics. No data concerning SIBO recurrence are available. The aims of the present study were to investigate SIBO recurrence as assessed by glucose breath test (GBT) after antibiotic treatment and conditions associated to SIBO recurrence. METHODS: Eighty consecutive patients affected by SIBO and decontaminated by rifaximin (1,200 mg per day for 1 wk) were enrolled. Diagnosis of SIBO was based on GBT. GBT was reassessed at 3, 6, and 9 months after evidence of GBT normalization. GBT positivity recurrence, predisposing conditions, and gastrointestinal symptoms were evaluated. RESULTS: Ten (10/80, 12.6%), 22 (22/80, 27.5%), and 35 (35/80, 43.7%) patients showed positivity to GBT at 3, 6, and 9 months after successful antibiotic treatment, respectively. At multivariate analysis, older age (OR 1.09, 95% CI 1.02-1.16), history of appendectomy (OR 5.9, 95% CI 1.45-24.19), and chronic use of proton pump inhibitors (PPIs) (OR 3.52, 95% CI 1.07-11.64) were significantly associated to GBT positivity recurrence. All gastrointestinal symptoms significantly increased at 3, 6, and 9 months in patients with evidence of GBT positivity recurrence. CONCLUSIONS: GBT positivity recurrence rate was high after antibiotic treatment. Older age, history of appendectomy, and chronic use of PPIs were associated with GBT positivity recurrence. Patients with evidence of GBT positivity recurrence showed gastrointestinal symptoms relapse thus suggesting SIBO recurrence.

Late haemodynamic and functional consequences of radial artery removal on the forearm circulation.

BACKGROUND: We aimed at evaluating the late haemodynamic and functional consequences on the forearm circulation of radial artery removal for coronary artery bypass grafting. METHODS: Ten years after surgery we performed basal and stress echo-Doppler evaluation of the forearm circulation, baseline and stress transcutaneous oxymetry and determination of reactive oxygen metabolites in the operated and control arm in 20 asymptomatic patients submitted to radial artery removal. RESULTS: The peak systolic velocity of the ulnar artery of the operated side was significantly higher than the control site. Transcutaneous oxymetry revealed asymptomatic hand ischemia at moderate level of muscular effort in the operated arm, but reactive oxygen metabolites measurement did not differ between the two arms. CONCLUSIONS: Even in patients with good ulnar compensation, radial artery removal leads to subtle degree of hand ischemia in conditions of sustained muscular effort. Although the clinical significance of this observation remains to be determined, this finding can have important implications for conduit selection in patients involved in manual activities.

Association between hypothyroidism and small intestinal bacterial overgrowth.

OBJECTIVES: Small intestinal bacterial overgrowth is defined as an abnormally high bacterial population level in the small intestine. Intestinal motor dysfunction associated with hypothyroidism could predispose to bacterial overgrowth. Luminal bacteria could modulate gastrointestinal symptoms and interfere with levothyroxine absorption. The aims of the present study were to assess the prevalence and clinical pattern of bacterial overgrowth in patients with a history of overt hypothyroidism and the effects of bacterial overgrowth decontamination on thyroid hormone levels. METHODS: A total of 50 consecutive patients with a history of overt hypothyroidism due to autoimmune thyroiditis was enrolled. Diagnosis of bacterial overgrowth was based on positivity to a hydrogen glucose breath test. Bacterial overgrowth positive patients were treated with 1,200 mg rifaximin each day for a week. A glucose breath test, gastrointestinal symptoms, and thyroid hormone plasma levels were reassessed 1 month after treatment. RESULTS: A total of 27 patients with a history of hypothyroidism demonstrated a positive result to the breath test (27 of 50, 54%), compared with two in the control group (two of 40, 5%). The difference was statistically significant (P < 0.001). Abdominal discomfort, flatulence, and bloating were significantly more prevalent in the bacterial overgrowth positive group. These symptoms significantly improved after antibiotic decontamination. Thyroid hormone plasma levels were not significantly affected by successful bacterial overgrowth decontamination. CONCLUSIONS: The history of overt hypothyroidism is associated with bacterial overgrowth development. Excess bacteria could influence clinical gastrointestinal manifestations. Bacterial overgrowth decontamination is associated with improved gastrointestinal symptoms. However, fermenting carbohydrate luminal bacteria do not interfere with thyroid hormone levels.

Ten-year Echo-Doppler evaluation of forearm circulation following radial artery removal for coronary artery bypass grafting.

OBJECTIVE: To investigate the chronic consequences of radial artery removal for coronary artery bypass surgery on the forearm circulation. METHODS: Thirty-nine patients submitted to radial artery removal for coronary artery bypass were submitted to serial Echo-Doppler evaluation of the flow and morphology of the forearm arteries until 10 years follow-up. RESULTS: The peak systolic velocity of the ulnar artery of the operated side was significantly higher than the control site. The intima-media thickness of the ulnar artery was always significantly higher on the operated side, and this difference reached statistical significance at 10 years follow-up. There was a significantly higher prevalence of atherosclerotic plaques in the ulnar artery (UA) of the operated versus control arm (11/39 vs 0/39; p=0.005). CONCLUSIONS: Radial artery removal for coronary artery bypass surgery leads to a chronic increase in ulnar flow accompanied by increased intima-media thickness and accelerated atherosclerotic disease. These findings may have potentially important implications for surgical indications and patients management.

Chronic compensatory increase in ulnar flow and accelerated atherosclerosis after radial artery removal for coronary artery bypass.

BACKGROUND: Only scant information is available on the chronic consequences of radial artery removal for coronary artery bypass surgery on forearm circulation. METHODS: Twenty-five patients submitted to radial artery removal for coronary artery bypass were submitted to serial Doppler echocardiographic evaluation of the flow and morphology of the forearm arteries. RESULTS: The peak systolic velocity of the ulnar artery of the operated side was significantly higher than that of the control site. The intimal-medial thickness of the ulnar artery was always significantly higher on the operated side, and this difference reached statistical significance at 10 years' follow-up. There was a significantly higher prevalence of atherosclerotic plaques in the ulnar artery of the operated versus control arm (7/25 vs 0/25, P = .03). CONCLUSION: Radial artery removal for coronary artery bypass surgery leads to a chronic increase in ulnar flow accompanied by increased intimal-medial thickness and accelerated atherosclerotic disease. These findings might have potentially important implications for surgical indications and patient management.

Polymorphisms of the macrophage inhibitory factor and C-reactive protein genes in subjects with Alzheimer's dementia.

Neuroinflammation is a central feature of Alzheimer's disease (AD). C-reactive protein (CRP) is a key molecule of the acute phase of inflammation that has been localized in the two characteristic lesions of AD brain, senile plaque and neurofibrillary tangles. On the other hand, the macrophage migration inhibitory factor (MIF) is a cytokine with multiple biological activities, including the ability to act as potent amyloid beta (A-beta)-binding protein. Two common polymorphisms have been recently detected in the genes encoding for CRP and MIF and have been associated with significant modifications of plasma levels and activity of the corresponding proteins. Following these observations, we hypothesized that CRP and MIF gene polymorphisms might contribute to the development and progression of neurodegenerative disorders and evaluated their association with AD. CRP and MIF gene polymorphisms were examined by polymerase chain reaction and restriction enzyme analysis in 116 Italian subjects affected by probable AD and 184 age- and sex-matched controls. We did not find a statistically significant difference in the distribution of CRP and MIF genotypes and alleles between AD subjects and controls. Although these data need further confirmation, they indicate that CRP and MIF gene polymorphisms are not associated with AD.

Monocyte chemoattractant protein-1 (MCP-1) gene polymorphism and risk of Alzheimer's disease in Italians.

Monocyte chemoattractant protein-1 (MCP-1) is a key molecule for monocyte chemotaxis and tissue extravasation and for the modulation of leukocyte function during inflammation. Upregulation of MCP-1 may occur in the brain of subjects affected by Alzheimer's disease (AD) and MCP-1 levels in plasma and cerebrospinal fluid have been proposed as biological markers for the inflammatory process that accompanies AD pathogenesis. Importantly, serum levels and biological activity of MCP-1 protein are strongly influenced by a single nucleotide polymorphism occurring at position -2518 of the MCP-1 gene promoter. A recent study has investigated the possible association between this gene polymorphism and AD in a Spanish population, with negative results. Here, we performed a case-control study to test whether the risk for AD might be influenced by the -2518 A/G polymorphism of the MCP-1 gene in an ethnically homogeneous Italian population. The GG genotype and the G allele of the MCP-1 gene polymorphism were significantly more common in the AD group than in control individuals (P<0.0001) A logistic regression analysis indicated that the GG genotype was an independent risk factor for AD in our population. This effect was not influenced by the presence of the APOE 4 high-risk allele, nor by the presence of other gene variations associated with a pro-inflammatory phenotype. These findings indicate that the -2518 A/G polymorphism of the MCP-1 gene is associated with AD in Italians and confirm that inflammatory gene variations may be important contributors in the development and progression of neurodegenerative disorders.

CagA-positive cytotoxic H. pylori strains as a link between plaque instability and atherosclerotic stroke.

AIMS: Previous studies suggested an association between infection by cytotoxic CagA-positive Helicobacter pylori strains and atherosclerotic stroke. It has been hypothesized that CagA strains could increase the risk for stroke by affecting carotid plaque irregularity. Our aims were: (1) to confirm the association between CagA strains and atherosclerotic stroke, and (2) to assess the association between CagA strains and carotid plaque irregularity. METHODS AND RESULTS: We enrolled 105 consecutive patients affected by atherosclerotic stroke and 130 sex, age, social background-matched controls without relevant vascular diseases. Risk factors for atherosclerotic stroke, H. pylori infection and CagA status were evaluated in all subjects. The presence of plaque instability was evaluated by colour Doppler ultrasound. The prevalence of CagA-positive strains was significantly higher in patients than in controls (adjusted OR 2.99, 95% CI 1.52-5.88, P=0.002). The CagA seropositivity was the only factor independently associated with carotid plaque irregularity (adjusted OR 8.42, 95% CI 1.58-44.64, P=0.004). CONCLUSION: The evidence of significant associations between CagA-positive H. pylori strains and the presence of carotid plaque instability support their possible involvement in the pathophysiology of atherosclerotic stroke.

Atherosclerotic involvement of the radial artery in patients with coronary artery disease and its relation with midterm radial artery graft patency and endothelial function.

BACKGROUND: The radial artery has recently been proposed as an alternative arterial conduit for surgical myocardial revascularization. This study was conceived to evaluate the degree of atherosclerotic involvement of the radial artery in patients with coronary artery disease and the eventual influence of a subtle degree of preoperative atherosclerosis on the midterm results of radial artery grafts. METHODS AND RESULTS: The intima-media thickness of the radial artery, common carotid artery, and internal thoracic artery was evaluated in 42 coronary artery disease patients and in 26 control patients. All radial arteries were then used for myocardial revascularization; 30 patients submitted to control angiography after 5 years. The mean intima-media thickness was 0.92 +/- 0.22 mm for the common carotid artery, 0.54 +/- 0.16 mm for the internal thoracic artery, 0.55 +/- 0.11 mm for the radial artery in coronary artery disease patients versus 0.79 +/- 0.14 mm, 0.52 +/- 0.11 mm, and 0.56 +/- 0.09 mm, respectively, in control patients (P =.001 only for the common carotid artery). No correlation was found between the intima-media thickness of the carotid, internal thoracic, and radial artery. No correlation was found between the preoperative intima-media thickness of the radial artery and the midterm patency and endothelial-mediated vasodilating capacity of radial artery grafts. CONCLUSION: In coronary artery disease patients, radial artery atherosclerotic involvement is more frequent than that of the gold standard internal thoracic artery but still by far less severe than that of the common carotid artery. The early atherosclerotic signs often observed in the radial artery do not seem to have the potential to influence radial artery graft patency and endothelial function.

Association between Klinefelter syndrome and focal nodular hyperplasia.

Focal nodular hyperplasia is a benign lesion of the liver, predominantly affecting women. Its etiology is unknown. Elevated levels of estrogens have been invoked to play a role in the disease. Klinefelter syndrome is the most common sex chromosome disorder, characterized by 47, XXY karyotype, resulting in male hypogonadism and sex hormone imbalance. We present a case of a 25-year-old man affected by Klinefelter syndrome, admitted to our hospital for aspecific dyspeptic symptoms. During admission he underwent: blood test for the liver function and sexual hormonal status, ultrasonography, echo color power Doppler and computerized tomography scan of the liver, and liver biopsy. A hypergonadotropic hypogonadism was present. Imaging of the liver showed an hepatic lesion that liver biopsy confirmed to be a focal nodular hyperplasia. Although the association could be casual, the sex hormone imbalance present in Klinefelter syndrome may suggest a role in the development of this benign liver lesion.

Risks of using internal thoracic artery grafts in patients in chronic hemodialysis via upper extremity arteriovenous fistula.

BACKGROUND: In patients in chronic hemodialysis via upper extremity arteriovenous fistula in whom ipsilateral internal thoracic artery graft was used for myocardial revascularization, hemodynamic interference between the fistula and the graft during dialysis can be hypothesized. METHODS AND RESULTS: In 5 patients undergoing chronic hemodialysis via upper extremity arteriovenous fistula, ipsilateral to an internal thoracic to left anterior descending graft mammary flow was studied by means of transthoracic echo-color Doppler at baseline and during hemodialysis. Flow in the contralateral mammary artery was used as control. Transthoracic echocardiography was performed in concomitance with flow evaluation to assess eventual modifications of left ventricular segmental wall motion. Immediately after hemodialysis pump start there was a marked reduction of peak systolic and end-diastolic velocities and time average mean velocity and flow in the ITA ipsilateral to the fistula, whereas no substantial hemodynamic modification was evident in the contralateral artery. Dialysis-induced reduction of ipsilateral ITA flow was accompanied by evidence of hypokinesia of the anterior left ventricular wall. Three cases also experienced clinical angina. CONCLUSIONS: Hemodynamically evident flow steal and consequent myocardial ischemia develop during hemodialysis in patients with upper extremity arteriovenous fistula and ipsilateral internal thoracic artery to coronary graft. These data have major implications for patients' management, both for nephrologists and cardiac surgeons.

Synergistic effect of -174 G/C polymorphism of the interleukin-6 gene promoter and 469 E/K polymorphism of the intercellular adhesion molecule-1 gene in Italian patients with history of ischemic stroke.

BACKGROUND AND PURPOSE: Interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) are involved in the pathogenetic mechanisms responsible for several ischemic cardiovascular disorders, including cerebral ischemia. IL-6 and ICAM-1 plasma levels and/or function may be genetically influenced. We sought to evaluate distribution and reciprocal interaction of IL-6 G/C gene promoter polymorphism and ICAM-1 E/K gene polymorphism in Italian patients with history of ischemic stroke. METHODS: One hundred nineteen patients with history of ischemic stroke and 133 age- and sex-matched controls were studied. IL-6 and ICAM-1 genotypes were evaluated by polymerase chain reaction and restriction enzyme analysis. RESULTS: The GG genotype of -174 IL-6 G/C gene polymorphism was significantly associated with history of ischemic stroke at both univariate (P<0.0001) and multivariate analysis (odds ratio [OR], 8.6; P<0.0001). Additionally, the EE genotype of ICAM-1 E/K gene polymorphism was significantly more common in the group of patients with history of ischemic stroke (P=0.003) and was an independent variable associated with stroke history (OR, 4.0; P=0.002). Interestingly, a further increased risk of stroke was found in subjects who concomitantly carry the IL-6 GG and ICAM-1 EE genotypes (IL-6 GG/ICAM-1 EE double-homozygous subjects) (OR, 10.1; P=0.004). CONCLUSIONS: There is a synergistic effect of IL-6 G/C and ICAM-1 E/K gene polymorphisms in patients with stroke history. Reciprocal interactions between genotypes may contribute in determining the risk profile for cardiovascular diseases and may merit further investigation as potential therapeutic targets.

Lack of association between Alzheimer's disease and Gln-Arg 192 Q/R polymorphism of the PON-1 gene in an Italian population.

Alzheimer's disease (AD) is characterized by deposition of oxidized low-density lipoprotein (LDL) forming the senile plaque and by structural changes and cell death in acetylcholine-producing neurons. Paraoxonase-1 (PON-1) is a secreted protein primarily associated with high-density lipoproteins (HDL) and participates in the prevention of LDL oxidation. PON-1 is also an arylesterase that hydrolyzes paraoxon, an active toxic metabolite of parathion, thus providing protection against organophosphate poisoning and metabolization of environmental neurotoxins that might be responsible for neurodegeneration with aging. Serum levels of PON-1 are genetically determined and strongly influenced by a common polymorphism on the position 192 of the PON-1 gene. The aim of this study was to evaluate whether the polymorphism of the PON-1 gene is associated with AD. We studied 124 Italian subjects affected by probable AD and 135 age- and sex-matched controls. The distribution of PON-1 genotypes was 64 QQ, 46 QR, 14 RR in the AD patients and 57 QQ, 59 QR, 19 RR in the control subjects. No statistically significant difference was found between the two groups in our population (p = 0.130 for homozygous QQ, p = 0.279 for heterozygous QR, and p = 0.502 for homozygous RR). These results suggest that the human Gln-Arg 192 Q/R polymorphism of the PON-1 gene is not associated with AD in an Italian population.

Intercellular adhesion molecule-1 K469E gene polymorphism and Alzheimer's disease.

Inflammatory processes are considered important in the pathogenesis of Alzheimer's disease (AD). Intercellular adhesion molecule-1 (ICAM-1) is an important mediator of inflammatory response and immune cell activation, is expressed on cerebrovascular endothelium and neuritic plaques in brain of AD patients, and seems to be implicated in the process of neuro-degeneration. A common polymorphism of the ICAM-1 gene (K469E) has been recently reported. In this case-control study, we evaluated the distribution of E/K alleles and genotypes of the ICAM-1 gene in 98 patients affected by sporadic AD and 115 age- and sex-matched controls. The frequency of the EE genotype was significantly higher in AD patients (P<0.01). Logistic regression analysis indicated that the presence of EE genotype significantly increased the risk of AD (odds ratio 3.01 [1.1-8.0], P<0.05). This study shows for the first time an association between ICAM-1 E/K gene polymorphism and AD, suggesting that polymorphisms of the ICAM-1 gene may be clinically important and confirming that inflammatory mechanisms may be crucial in the pathophysiology of neuro-degenerative diseases.

Association between intercellular adhesion molecule-1 E/K gene polymorphism and probable vascular dementia in humans.

Intercellular adhesion molecule-1 (ICAM-1) is implicated in the pathogenesis of ischemic cardiovascular disorders, including cerebral ischemia. A common polymorphism of the ICAM-1 gene (K469E) has been recently reported. In this case-control study, we evaluated the association between this polymorphism and vascular dementia (VD) by studying 107 patients affected by probable VD and 115 age- and sex-matched controls. The frequency of the EE genotype was significantly higher in VD patients than controls (P=0.009). Logistic regression analysis indicated that the presence of the EE genotype significantly increased the risk of VD (odds ratio 3.25, P=0.024). Our findings support the hypothesis that ICAM-1 plays a role in the physiopathology of ischemic cerebrovascular disorders and suggest that genetic polymorphisms of ICAM-1 might be clinically important in the development and progression of neurodegenerative diseases.