Eradication of small intestinal bacterial overgrowth reduces symptoms of irritable bowel syndrome

OBJECTIVES

Irritable bowel syndrome is the most common gastrointestinal diagnosis. The symptoms of irritable bowel syndrome are similar to those of small intestinal bacterial overgrowth. The purpose of this study was to test whether overgrowth is associated with irritable bowel syndrome and whether treatment of overgrowth reduces their intestinal complaints.

METHODS

Two hundred two subjects in a prospective database of subjects referred from the community undergoing a lactulose hydrogen breath test for assessment of overgrowth were Rome I criteria positive for irritable bowel syndrome. They were treated with open label antibiotics after positive breath test. Subjects returning for follow-up breath test to confirm eradication of overgrowth were also assessed. Subjects with inflammatory bowel disease, abdominal surgery, or subjects demonstrating rapid transit were excluded. Baseline and after treatment symptoms were rated on visual analog scales for bloating, diarrhea, abdominal pain, defecation relief, mucous, sensation of incomplete evacuation, straining, and urgency. Subjects were blinded to their breath test results until completion of the questionnaire.

RESULTS

Of 202 irritable bowel syndrome patients, 157 (78%) had overgrowth. Of these, 47 had follow-up testing. Twenty-five of 47 follow-up subjects had eradication of small intestinal bacterial overgrowth. Comparison of those that eradicated to those that failed to eradicate revealed an improvement in irritable bowel syndrome symptoms with diarrhea and abdominal pain being statistically significant after Bonferroni correction (p < 0.05). Furthermore, 48% of eradicated subjects no longer met Rome criteria (chi2 = 12.0, p < 0.001). No difference was seen if eradication was not successful.

CONCLUSIONS

Small intestinal bacterial overgrowth is associated with irritable bowel syndrome. Eradication of the overgrowth eliminates irritable bowel syndrome by study criteria in 48% of subjects.

Association of human herpes virus 6 (HHV-6) with multiple sclerosis: increased IgM response to HHV-6 early antigen and detection of serum HHV-6 DNA

Viruses have long been suggested to be involved in the etiology of multiple sclerosis (MS). This suggestion is based on (1) epidemiological evidence of childhood exposure to infectious agents and increase in disease exacerbations with viral infection; (2) geographic association of disease susceptibility with evidence of MS clustering; (3) evidence that migration to and from high-risk areas influences the likelihood of developing MS; (4) abnormal immune responses to a variety of viruses; and (5) analogy with animal models and other human diseases in which viruses can cause diseases with long incubation periods, a relapsing-remitting course, and demyelination. Many of these studies involve the demonstration of increased antibody titers to a particular virus, whereas some describe isolation of virus from MS material. However, no virus to date has been definitively associated with this disease. Recently, human herpesvirus 6 (HHV-6), a newly described beta-herpes virus that shares homology with cytomegalovirus (CMV), has been reported to be present in active MS plaques. In order to extend these observations, we have demonstrated increased IgM serum antibody responses to HHV-6 early antigen (p41/38) in patients with relapsing-remitting MS (RRMS), compared with patients with chronic progressive MS (CPMS), patients with other neurologic disease (OND), patients with other autoimmune disease (OID), and normal controls. Given the ubiquitous nature of this virus and the challenging precedent of correlating antiviral antibodies with disease association, these antibody studies have been supported by the detection of HHV-6 DNA from samples of MS serum as a marker of active viral infection.

Early dexamethasone therapy in preterm infants: a follow-up study

OBJECTIVES

To study the outcome at 2-year corrected age of infants who participated in a double-blind controlled trial of early (<12 hours) dexamethasone therapy for the prevention of chronic lung disease (CLD).

METHODS AND MATERIALS

A total of 133 children (70 in the control group, 63 in the dexamethasone-treated group) who survived the initial study period and lived to 2 years of age were studied. All infants had birth weights of 500 to 1999 g and had severe respiratory distress syndrome requiring mechanical ventilation within 6 hours after birth. For infants in the treatment group, dexamethasone was started at a mean age of 8.1 hours and given 0.25 mg/kg every 12 hours for 1 week and then tapered off gradually over a 3-week period. The following variables were evaluated: interim medical history, socioeconomic background, physical growth, neurologic examinations, mental and psychomotor development index score (MDI and PDI), pulmonary function, electroencephalogram, and auditory and visual evoked potential.

RESULTS

Infants in the control group tended to have a higher incidence of upper respiratory infection and rehospitalization than did the dexamethasone-treated group because of respiratory problems. Although there was no difference between the groups in somatic growth in girls, the dexamethasone-treated boys had significantly lower body weight and shorter height than the control boys (10.7 +/- 3.0 vs 11.9 +/- 2.0 kg; 84.9 +/- 5.7 vs 87.5 +/- 4.8 cm). The dexamethasone-treated group had a significantly higher incidence of neuromotor dysfunction (25/63 vs 12/70) than did the control group. The dexamethasone-treated infants also had a lower PDI score (79 +/- 26) than did the control group (87 +/- 23), but the difference was not statistically significant. Both groups were comparable in MDI, incidence of vision impairment, and auditory and visual evoked potential. Significant handicap, defined as severe neurologic defect and/or intellectual defect (MDI and/or PDI </= 69), was seen in 22 children (31.4%) in the control group and 26 (41.2%) in the dexamethasone-treated group.

CONCLUSIONS

Although early postnatal dexamethasone therapy for 4 weeks significantly reduces the incidence of CLD, this therapeutic regimen cannot be recommended at present because of its adverse effects on neuromotor function and somatic growth in male infants, detected at 2 years of age. A longer follow-up is needed. If early dexamethasone therapy is to be used for the prevention of CLD, the therapeutic regimen should be modified. The proper route of administration, the critical time to initiate the therapy, and the dosage and duration of therapy remain to be defined further.

Endotoxemia in patients with chronic liver diseases: relationship to severity of liver diseases, presence of esophageal varices, and hyperdynamic circulation

Plasma endotoxin levels were investigated using a quantitative Limulus assay in patients with chronic liver diseases and correlated with the severity of liver diseases, the presence of esophageal varices, and hemodynamic parameters. The plasma endotoxin levels were significantly higher in chronic hepatitis patients with acute exacerbation (10.1 +/- 1.3 pg/ml, n = 13, p < 0.05) and patients with cirrhosis (7.0 +/- 0.7 pg/ml, n = 126, p < 0.05) than in healthy subjects (2.9 +/- 0.2 pg/ml, n = 45). Chronic hepatitis patients (n = 30) had plasma endotoxin levels which were similar to those in healthy subjects (4.6 +/- 0.5 vs. 2.9 +/- 0.2 pg/ml, p > 0.05) but lower than those in chronic hepatitis patients with acute exacerbation (4.6 +/- 0.5 vs. 10.1 +/- 1.3 pg/ml, p < 0.05). Endotoxemia (plasma endotoxin level > 5.7 pg/ml) was found in 27%, 85% and 41% of patients with chronic hepatitis, chronic hepatitis with acute exacerbation, and cirrhosis, respectively. In patients with cirrhosis, the plasma endotoxin levels progressively increased in relation to the severity of liver dysfunction (Pugh's class A/B/C = 4.9 +/- 0.5/7.9 +/- 1.4/10.2 +/- 2.0 pg/ml, p < 0.05). In contrast, plasma endotoxin levels were comparable between patients with cirrhosis with and without esophageal varices (p > 0.05). Chronic hepatitis patients with acute exacerbation (no collaterization) had much higher plasma endotoxin levels than those in patients with cirrhosis and large varices (p < 0.05), whereas compensated patients with cirrhosis and large esophageal varices had plasma endotoxin levels similar to those seen in chronic hepatitis patients (no collaterization) (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effectiveness of silver diamine fluoride and sodium fluoride varnish in arresting dentin caries in Chinese pre-school children

Untreated dental caries in Chinese pre-school children is common. This prospective controlled clinical trial investigated the effectiveness of topical fluoride applications in arresting dentin caries. Three hundred seventy-five children, aged 3-5 years, with carious upper anterior teeth were divided into five groups. Children in the first and second groups received annual applications of silver diamine fluoride solution (44,800 ppm F). Sodium fluoride varnish (22,600 ppm F) was applied every three months to the lesions of children in the third and fourth groups. For children in the first and third groups, soft carious tissues were removed prior to fluoride application. The fifth group was the control. Three hundred eight children were followed for 30 months. The respective mean numbers of arrested carious tooth surfaces in the five groups were 2.5, 2.8, 1.5, 1.5, and 1.3 (p < 0.001). Silver diamine fluoride was found to be effective in arresting dentin caries in primary anterior teeth in pre-school children.

Characterization of the Erwinia carotovora pelB gene and its product pectate lyase

The pelB gene encodes pectate lyase B, one of three pectate lyases identified in Erwinia carotovora EC. Pectate lyase B was purified from Escherichia coli containing the pelB gene on a recombinant plasmid. The activity of the protein was optimal at a pH of 8.3. The amino acid composition, N-terminal amino acid sequence, and C-terminal peptide sequence were determined and compared with the polypeptide sequence deduced from the DNA sequence of pelB. Purified pectate lyase B started at amino acid 23 of the predicted sequence, suggesting that a 22-amino-acid leader peptide had been removed. Pectate lyase B of E. carotovora EC and pectate lyase B of E. chrysanthemi EC16 contain 352 and 353 amino acids, respectively (N. T. Keen, S. Tanaki, W. Belser, D. Dahlbeck, and B. Staskawicz, J. Bacteriol. 168:595-606, 1986). The two proteins are 72% homologous on the basis of DNA sequence data, and 75% of the amino acids are identical.

DDR2 receptor promotes MMP-2-mediated proliferation and invasion by hepatic stellate cells

Type I collagen provokes activation of hepatic stellate cells during liver injury through mechanisms that have been unclear. Here, we tested the role of the discoidin domain tyrosine kinase receptor 2 (DDR2), which signals in response to type I collagen, in this pathway. DDR2 mRNA and protein are induced in stellate cells activated by primary culture or in vivo during liver injury. The receptor becomes tyrosine phosphorylated in response to either endogenous or exogenous type I collagen, whereas its expression is downregulated during cellular quiescence induced by growth on Matrigel. We developed stellate cell lines stably overexpressing either wild-type DDR2, a constitutively active chimeric DDR2 receptor (Fc-DDR2), a truncated receptor expressing the extracellular domain, or a kinase-dead DDR2 Cells overexpressing DDR2 showed enhanced proliferation and invasion through Matrigel, activities that were directly related to increased expression of active matrix metalloproteinase 2 (MMP-2). These data show that DDR2 is induced during stellate cell activation and implicate the phosphorylated receptor as a mediator of MMP-2 release and growth stimulation in response to type I collagen. Moreover, type I collagen-dependent upregulation of DDR2 expression establishes a positive feedback loop in activated stellate cells, leading to further proliferation and enhanced invasive activity.

Cardiovascular effects of nitric oxide in the brain stem nuclei of rats

Nitric oxide, synthesized from the semiessential amino acid L-arginine by nitric oxide synthase, is a remarkable regulatory molecule and plays an important role in physiological functions. However, the physiological role of nitric oxide in cardiovascular regulation by the central nervous system is not well understood. In this study we investigated the cardiovascular effects of nitric oxide in the lateral ventricle, nucleus tractus solitarii, area postrema, and rostral ventrolateral medulla in urethane-anesthetized male Sprague-Dawley rats. Microinjection of NG-monomethyl-L-arginine, a nitric oxide synthase inhibitor, into the cerebral ventricle of rats elicited a dose-dependent increase in blood pressure and heart rate. This suggests that nitric oxide may be involved in central cardiovascular regulation. Unilateral microinjection (60 nL) of L-arginine (1 to 100 nmol) into the nucleus tractus solitarii and rostral ventrolateral medulla produced prominent dose-related depressor and bradycardic effects and reduced renal sympathetic nerve activity. However, L-arginine had no significant cardiovascular effects in the area postrema. In addition, 4 to 6 hours after intravenous injection of bacterial endotoxin-lipopolysaccharide (10 mg/kg), there was a time-related potentiation of the L-arginine-induced depressor and bradycardic effects in the nucleus tractus solitarii. These results indicate that nitric oxide is involved in central cardiovascular regulation. The depressor effect of nitric oxide in the nucleus tractus solitarii and rostral ventrolateral medulla may be through inhibition of renal sympathetic nerve activity.

Synthesis of Two-Dimensional Polymers

A synthetic pathway is described to construct "in bulk" two-dimensional (2D) polymers shaped as molecular sheets. A chiral oligomeric precursor is used that contains two reactive sites, a polymerizable group at one terminus and a reactive stereogenic center near the middle of the molecule. The bulk reaction yields bilayer 2D polymers of molecular weight in the order of millions and a monodisperse thickness of 50.2 angstroms. The 2D molecular objects form through molecular recognition by the oligomers, which self-organize into layers that place the reactive groups within specific planes. The oligomers become catenated by two different stitching reactions involving the reactive sites. At room temperature, stacks of these molecular objects can organize as single crystals and at higher temperatures melt into smectic liquid crystals. Nonlinear optical experiments reveal that solid films containing the 2D polymers form structures that are thermally and temporally more stable than those containing analogous 1D polymers. This observation suggests that the transformation of common polymers from a 1D to a 2D architecture may produce generations of organic materials with improved properties.

An improved DNA sequencing strategy

A modification of Hong's systematic DNA sequencing strategy is described. The original procedure has been simplified and transfectant yield increased. After DNase I limited cleavage in the presence of Mn2+, the single-cut linear DNA does not have to be separated from supercoiled or open circular DNA on an agarose gel. After ligation, the DNA is digested with a second restriction endonuclease for which a unique cleavage site resides between the insert and the first restriction endonuclease cutting site. The original intact DNA is linearized whereas the deleted subclone is not. The background is decreased to an undetectable level. This DNA sequencing strategy was tested on a 1.4-kb DNA fragment containing the araC regulatory gene from Erwinia carotovora. A set of subclones sufficient to sequence the fragment on both strands was produced in 2 days and the yield was at least 60-fold higher than in the original protocol.

Increased level of exhaled nitric oxide and up-regulation of inducible nitric oxide synthase in patients with primary lung cancer

Monocyte-macrophage series have an important role in host surveillance against cancer. The cytotoxic/cytostatic activity of macrophages is, to a great extent, attributed to the up-regulation of inducible nitric oxide synthase (iNOS) and production of nitric oxide (NO). Here, in 28 patients with primary lung cancer and 20 control subjects, we measured the concentration of exhaled NO and nitrite in epithelial lining fluid (ELF) using a chemiluminescence NO analyser, and studied NOS expression in alveolar macrophages (AM) and lung tissues by flow cytometry; immunohistochemical analysis was also undertaken. The mean fluorescence intensity (FI) of iNOS expression in AM was significantly increased in patients with lung cancer (tumour side 263.5 +/- 15.2 FI, normal side 232.4 +/- 18.6 FI; n = 28) compared with that in control subjects (27.3 +/- 3.2 FI; n = 20, P< 0.001). The level of exhaled NO from cancer patients (16.9 +/- 0.9 p.p.b.; n = 28) was significantly higher than that in the control group (6.0 +/- 0.5 p.p.b.; n = 20, P < 0.001). The level of nitrite was also significantly higher in ELF from cancer patients (tumour side 271.1 +/- 28.9 nM and normal side 257.4 +/- 19.6 nM vs control subjects 32.9 +/- 4.1 nM; P< 0.001). The intensity of iNOS expression in AM was correlated with the level of exhaled NO (rs = 0.73, n = 76, P< 0.001) and the nitrite released in ELF (rs = 0.56, n = 76, P< 0.001). The nitrite generation of cultured AM from patients with lung cancer was significantly enhanced compared with that of control subjects after culture for 24 h (tumour side 5.75 +/- 0.69 and normal side 5.68 +/- 0.58 microM per 106 cells vs control group 38.3 +/- 3.6 nM per 106 cells; P< 0.001). The distribution of iNOS was identified in AM, tumour-associated macrophages, endothelium, chondrocytes, airway epithelium of both lungs and malignant cells (adenocarcinoma and alveolar cell carcinoma) of cancer patients. cNOS was labelled in alveolar macrophages, endothelial cells and nerve elements from lung tissue. Our results indicate that, in patients with primary lung cancer, the production of NO from alveolar macrophages was increased as a result of the up-regulation of iNOS activity. The increased NO production was not specific to the tumour side and might be attributed to the tumour-associated non-specific immunological and inflammatory processes of the host.

Increased exhaled nitric oxide in active pulmonary tuberculosis due to inducible NO synthase upregulation in alveolar macrophages

Nitric oxide (NO) plays an important role in resistance to Mycobacterium tuberculosis infection. Our aim was to determine whether inducible NO synthase (iNOS) expression and generation of reactive nitrogen intermediates (RNI) by alveolar macrophages (AM) are increased in patients infected with M. tuberculosis. NO levels in the exhaled air of 19 active pulmonary tuberculosis (TB) and 14 control subjects were measured using a chemiluminescence NO analyser. The expression of iNOS on AM was studied by labelling AM with anti-mac iNOS polyclonal antibody analysed with a flow cytometer. The spontaneous generation of RNI by cultured AM was also measured. Data are presented as mean+/-SEM. The level of NO in exhaled air was higher in patients with active TB (16.2+/-1.2 parts per billion (ppb)) compared to control subjects (6.5+/-0.9 ppb), p<0.0001. Exhaled NO decreased with anti-TB treatment. Compared to control subjects (29.0+/-4.5 fluorescence intensity (FI)), iNOS expression on AM was upregulated in TB patients (86.3+/-12.5 FI) p<0.001 and the capacity for spontaneous generation of nitrite was enhanced. Nitrite production was inhibited by N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of iNOS. The expression of iNOS on AM was related to the concentration of exhaled NO (r=0.66, p<0.001) and the nitrite generation capacity of AM (r(s)=0.77, p<0.001). We conclude that the increase in exhaled nitric oxide observed in patients with active pulmonary tuberculosis is due to an upregulation of inhaled NO synthase expression in alveolar macrophages which have an enhanced capacity for nitric oxide production.

Early postnatal dexamethasone therapy for the prevention of chronic lung disease in preterm infants with respiratory distress syndrome: a multicenter clinical trial

OBJECTIVES

To study whether early postnatal (<12 hours) dexamethasone therapy reduces the incidence of chronic lung disease in preterm infants with respiratory distress syndrome.

MATERIALS AND METHODS

A multicenter randomized, double-blind clinical trial was undertaken on 262 (saline placebo, 130; dexamethasone, 132) preterm infants (<2000 g) who had respiratory distress syndrome and required mechanical ventilation shortly after birth. The sample size was calculated based on the 50% reduction in the incidence of chronic lung disease when early dexamethasone is used, allowing a 5% chance of a type I error and a 10% chance of a type II error. For infants who received dexamethasone, the dosing schedules were: 0.25 mg/kg/dose every 12 hours intravenously on days 1 through 7; 0.12 mg/kg/dose every 12 hours intravenously on days 8 through 14; 0.05 mg/kg/dose every 12 hours intravenously on days 15 through 21; and 0. 02 mg/kg/dose every 12 hours intravenously on days 22 through 28. A standard protocol for respiratory care was followed by the participating hospitals. The protocol emphasized the criteria of initiation and weaning from mechanical ventilation. The diagnosis of chronic lung disease based on oxygen dependence and abnormal chest roentgenogram was made at 28 days of age. To assess the effect of dexamethasone on pulmonary inflammatory response, serial tracheal aspirates were assayed for cell counts, protein, leukotriene B4, and 6-keto prostaglandin F1alpha. All infants were observed for possible side effects, including hypertension, hyperglycemia, sepsis, intraventricular hemorrhage, retinopathy of prematurity, cardiomyopathy, and alterations in calcium homeostasis, protein metabolism, and somatic growth.

RESULTS

Infants in the dexamethasone group had a significantly lower incidence of chronic lung disease than infants in the placebo group either judged at 28 postnatal days (21/132 vs 40/130) or at 36 postconceptional weeks (20/132 vs 37/130). More infants in the dexamethasone group than in the placebo group were extubated during the study. There was no difference between the groups in mortality (39/130 vs 44/132); however, a higher proportion of infants in the dexamethasone group died in the late study period, probably attributable to infection or sepsis. There was no difference between the groups in duration of oxygen therapy and hospitalization. Early postnatal use of dexamethasone was associated with a significant decrease in tracheal aspirate cell counts, protein, leukotriene B4, and 6-keto prostaglandin F1alpha, suggesting a suppression of pulmonary inflammatory response. Significantly more infants in the dexamethasone group than in the placebo group had either bacteremia or clinical sepsis (43/132 vs 27/130). Other immediate, but transient, side effects observed in the dexamethasone group are: an increase in blood glucose and blood pressure, cardiac hypertrophy, hyperparathyroidism, and a transient delay in the rate of growth.

CONCLUSIONS

In preterm infants with severe respiratory distress syndrome requiring assisted ventilation shortly after birth, early postnatal dexamethasone therapy reduces the incidence of chronic lung disease, probably on the basis of decreasing the pulmonary inflammatory process during the early neonatal period. Infection or sepsis is the major side effect that may affect the immediate outcome. Other observable side effects are transient. In view of the significant side effects and the lack of overall improvement in outcome and mortality, and the lack of long term follow-up data, the routine use of early dexamethasone therapy is not yet recommended.

Annexin VI is required for budding of clathrin-coated pits

Isolated plasma membranes attached to a solid substratum at 4 degrees C have numerous clathrin-coated pits. These pits initially are flat but become deeply invaginated after warming to 37 degrees C. The pits remain tethered to the membrane in this rounded condition unless supplied with ATP, Ca2+, and cytosol. We now show that when cytosol is treated to remove the Ca(2+)-dependent, phospholipid-binding protein annexin VI, coated pit budding no longer takes place. Addition of purified annexin VI back to the annexin VI-depleted cytosol restores budding activity to normal. Purified annexin VI alone shows only a modest budding activity, suggesting that the cytosol contains a factor(s) in addition to annexin VI that is required for full activity. Cytosol-dependent activation of annexin VI requires both ATP and Ca2+. Annexin VI appears to be not only an active component in the detachment of coated pits from the membrane but also a site for regulating the formation of coated vesicles.

Fat-induced ileal brake in the dog depends on peptide YY

BACKGROUND & AIMS

Fat in the distal gut inhibits transit through the proximal small intestine as the ileal brake. Although the mediator of this response is not established, peptide YY (PYY) has been considered the most likely peptide candidate because inhibition of intestinal motility by fat in the distal gut correlated with the release of PYY but not other distal gut peptides such as enteroglucagon or neurotensin. Although intravenous administration of PYY inhibits intestinal transit, the role of this peptide remains to be confirmed because systemic PYY may not exert its effect by the same regulatory pathway as fat-induced ileal brake. The aim of this study was to definitively test the hypothesis that PYY mediates fat-induced ileal brake using the technique of peptide immunoneutralization.

METHODS

In a fistulated dog model, intestinal transit during perfusion of the distal gut with 60 mmol/L oleate (ileal brake) was examined after intravenous administration of 0.5 mg/kg of PYY antibody (anti-PYY), nonspecific immunoglobulin G (control), or 0.15 mol/L NaCl. Intestinal transit result (cumulative percent recovery of 99mTc) was normalized within each animal against the transit result of the 0.15 mol/L NaCl experiment.

RESULTS

Intestinal transit accelerated with PYY immunoneutralization, increasing cumulative percent recovery from 25.9 +/- 6.2 (control) to 81.2 +/- 6.3 (anti-PYY).

CONCLUSIONS

Fat-induced ileal brake depends on PYY.

Healthcare-associated outbreak due to pan-drug resistant Acinetobacter baumannii in a surgical intensive care unit

Acinetobacter baumannii is ubiquitous and has recently become one of the most important healthcare-associated (HA) pathogens in hospitals. Infection caused by this organism often leads to significant morbidity and mortality. Outbreaks of pan-drug resistant Acinetobacter baumannii (PDRAB) have rarely been reported. During a two-month period, an outbreak of PDRAB colonization and infection affecting 7 patients occurred in our surgical intensive care unit (SICU). The colonized sites were respiratory tract (N = 7) and central venous catheter (N = 2). One of the patients had a surgical wound infection. Extensive environmental contamination was identified, including sites such as bed rails, bedside tables, surface of ventilators and infusion pump, water for nasogastric feeding and ventilator rinsing and sinks. All of the isolates were analysed by pulsed-field gel electrophoresis (PFGE) and showed an identical pattern. After use of strict cohort nursing, hand hygiene environmental cleaning, and replacement of a dysfunctional high-efficiency particulate air filter (HEPA), the outbreak was controlled.

A link between irritable bowel syndrome and fibromyalgia may be related to findings on lactulose breath testing

BACKGROUND

An association between irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO) has been found.

OBJECTIVE

To compare the prevalence and test results for bacterial overgrowth between IBS and fibromyalgia.

METHODS

Subjects with independent fibromyalgia and IBS were compared with controls in a double blind study. Participants completed a questionnaire, and a lactulose hydrogen breath test was used to determine the presence of SIBO. The prevalence of an abnormal breath test was compared between study participants. Hydrogen production on the breath test was compared between subjects with IBS and fibromyalgia. The somatic pain visual analogue score of subjects with fibromyalgia was compared with their degree of hydrogen production.

RESULTS

3/15 (20%) controls had an abnormal breath test compared with 93/111 (84%) subjects with IBS (p<0.01) and 42/42 (100%) with fibromyalgia (p<0.0001 v controls, p<0.05 v IBS). Subjects with fibromyalgia had higher hydrogen profiles (p<0.01), peak hydrogen (p<0.0001), and area under the curve (p<0.01) than subjects with IBS. This was not dependent on the higher prevalence of an abnormal breath test. The degree of somatic pain in fibromyalgia correlated significantly with the hydrogen level seen on the breath test (r = 0.42, p<0.01).

CONCLUSIONS

An abnormal lactulose breath test is more common in fibromyalgia than IBS. In contrast with IBS, the degree of abnormality on breath test is greater in subjects with fibromyalgia and correlates with somatic pain.

Structure and composition of microcalcifications in benign and malignant lesions of the breast: study by light microscopy, transmission and scanning electron microscopy, microprobe analysis, and X-ray diffraction

Microcalcifications previously located by radiography were extracted from 25 fresh specimens obtained from patients who had undergone tumorectomy or systematized mammary exeresis. Two principal types of microcalcifications were distinguished: Type I microcalcifications were amber in color and generally crystalline on scanning electron microscopy, with only one calcium peak on microprobe analysis; x-ray diffraction revealed that weddellite was involved. Type II microcalcifications were whitish, nonbirefringent under polarized light, and generally ovoid or fusiform, with two peaks, one calcium and the other phosphorus, on microprobe analysis; these microcalcifications were composed of calcium phosphate, the most characteristic form of which is hydroxyapatite, in the form of needles arranged in rosettes on transmission electron microscopy. Type I microcalcifications were observed in four of eight benign breast lesions, in two of three in situ lobular carcinomas, and in no intraductal adenocarcinomas or infiltrating carcinomas. Type II microcalcifications were present in all infiltrating carcinomas and intraductal adenocarcinomas; they were also found in benign lesions (four of eight) and even associated with type I microcalcifications in one in situ lobular carcinoma. There are, therefore, no "benign" or "malignant" microcalcifications; however, the presence of weddellite is a strong indication that a lesion is benign or, at most, an in situ lobular carcinoma.

DDR2 receptor promotes MMP-2-mediated proliferation and invasion by hepatic stellate cells

Type I collagen provokes activation of hepatic stellate cells during liver injury through mechanisms that have been unclear. Here, we tested the role of the discoidin domain tyrosine kinase receptor 2 (DDR2), which signals in response to type I collagen, in this pathway. DDR2 mRNA and protein are induced in stellate cells activated by primary culture or in vivo during liver injury. The receptor becomes tyrosine phosphorylated in response to either endogenous or exogenous type I collagen, whereas its expression is downregulated during cellular quiescence induced by growth on Matrigel. We developed stellate cell lines stably overexpressing either wild-type DDR2, a constitutively active chimeric DDR2 receptor (Fc-DDR2), a truncated receptor expressing the extracellular domain, or a kinase-dead DDR2 Cells overexpressing DDR2 showed enhanced proliferation and invasion through Matrigel, activities that were directly related to increased expression of active matrix metalloproteinase 2 (MMP-2). These data show that DDR2 is induced during stellate cell activation and implicate the phosphorylated receptor as a mediator of MMP-2 release and growth stimulation in response to type I collagen. Moreover, type I collagen-dependent upregulation of DDR2 expression establishes a positive feedback loop in activated stellate cells, leading to further proliferation and enhanced invasive activity.

Identification of a prodromal period in Crohn's disease but not ulcerative colitis

OBJECTIVES

Irritable bowel syndrome, a common gastrointestinal diagnosis, has not been clearly studied in inflammatory bowel disease. Some of the residual symptoms in subjects treated with Crohn's disease and ulcerative colitis are thought to be related to irritable bowel syndrome. The aims of this study were 1) to describe the duration and nature of complaints before the diagnosis of Crohn's disease and ulcerative colitis (prodromal period), and 2) to determine the role of IBS in this prodromal period.

METHODS

A total of 66 patients with confirmed inflammatory bowel disease were enrolled in the study. The subjects received a questionnaire to ascertain the nature and duration of symptoms preceding the diagnosis of Crohn's disease or ulcerative colitis, including features described under the Rome criteria for irritable bowel syndrome.

RESULTS

Of the 66 subjects analyzed, 45 had Crohn's disease and 21 had ulcerative colitis. The prodromal period was 7.7 +/- 10.7 yr for Crohn's disease and 1.2 +/- 1.8 yr for ulcerative colitis (p < 0.05). Once patients meeting the Rome criteria for irritable bowel syndrome during the prodrome were excluded, the duration of the prodromal period (non-IBS) for ulcerative colitis dropped to 0.8 +/- 1.3 yr compared to 6.9 +/- 9.8 yr in the Crohn's disease group (p < 0.05). The symptoms of the non-IBS prodrome in subjects with Crohn's disease were bloating, diarrhea, stomach pain, heartburn, fever, weight loss, and fatigue. Further analysis demonstrated that subjects whose Crohn's disease initially began as colonic disease had a longer prodrome than with small bowel. In the non-IBS Crohn's group, there was also a correlation between the age at the time of diagnosis and the duration of prodrome (r = 0.67, p < 0.0001).

CONCLUSIONS

There is a significant prodromal period before the time of diagnosis of Crohn's disease that is not found in ulcerative colitis even after exclusion of subjects with IBS.

The effect of ciprofloxacin in the prevention of bacterial infection in patients with cirrhosis after upper gastrointestinal bleeding

OBJECTIVES

Cirrhotic patients with upper gastrointestinal bleeding are prone to bacterial infection. The aim of this study was to investigate the efficacy of prophylactic intestinal decontamination with oral ciprofloxacin for the prevention of bacterial infections in cirrhotic patients with upper gastrointestinal bleeding.

METHODS

A total of 120 cirrhotic patients with acute upper gastrointestinal bleeding were enrolled. Sixty patients received ciprofloxacin 500 mg twice daily given orally or through nasogastric tube immediately after upper gastrointestinal endoscopic examination; drug administration continued for 7 days. The remaining 60 patients, who received placebo, served as controls.

RESULTS

The incidence of proven bacterial infection in the ciprofloxacin-treated group was significantly lower than that of placebo group (10% vs 45%, p < 0.001). The incidences of bacteremia, spontaneous bacterial peritonitis, and urinary tract infection in the ciprofloxacin-treated group were significantly lower than those in the placebo group (0% vs 23%, 3.3% vs 13%, and 5% vs 18%, respectively; p < 0.05, respectively). Multivariate logistic regression analysis showed that a lack of prophylactic treatment with ciprofloxacin and severity of cirrhosis were the independent significant predictors for cirrhotic patients with acute gastrointestinal bleeding with infection.

CONCLUSIONS

Prophylactic intestinal decontamination with oral ciprofloxacin is effective in the prevention of bacterial infections in patients with cirrhosis who were suffering from acute upper gastrointestinal hemorrhage.

Randomized trial on fluorides and sealants for fissure caries prevention

To investigate the effectiveness of topical fluorides in preventing fissure caries, we conducted a randomized controlled trial with parallel groups. In total, 501 children (1,539 molars, 3,078 sites), mean age 9.1 years, who had at least one sound permanent first molar with deep fissures or fissures with signs of early caries were recruited. They were randomly allocated among four groups: (1) resin sealant, single placement; (2) 5% NaF varnish, semi-annual application; (3) 38% silver diamine fluoride (SDF) solution, annual application; and (4) placebo control. Follow-up examinations were conducted every 6 months by a masked examiner. After 24 months, 485 children (97%) were examined. Proportions of pit/fissure sites with dentin caries in the sealant, NaF, SDF, and control groups were 1.6%, 2.4%, 2.2%, and 4.6%, respectively. A multi-level logistic regression analysis accounting for the effects of data clustering and confounding factors showed that fissures in any of the three treatment groups had significantly lower risks of carious cavity development into dentin than did controls (p < 0.05). We concluded that placement of resin sealant, semi-annual application of NaF varnish, and annual application of SDF solution are all effective in preventing pit and fissure caries in permanent molars (ClinicalTrials.gov number CT01446107).

The ileal brake: a fifteen-year progress report

The "ileal brake" is the primary inhibitory feedback mechanism to control transit of a meal through the gastrointestinal tract in order to optimize nutrient digestion and absorption. Neurohormonal factors mediating this response continue to be identified. Recently, additional brakes that fine-tune transit have been described. When gut traffic control is disrupted, pathologic states characterized by malabsorption and impaired drug bioavailability manifest as diarrhea and malnutrition. An understanding of the importance of these nutrient-triggered brakes provides essential clues to future treatments of chronic diarrhea, malnutrition, and drug malabsorption.

Colon mucosal cell damage by ammonia in rats

Colons of male Sprague-Dawley rats were perfused, in situ, with ammonium (NH4+) or sodium (Na+) and acetate (CH3COO-) or chloride (Cl-) to determine the effects of the cations and anions or their interactions on the colon mucosa. Solutions simulating ileal fluid were delivered at 0.4 mL/min at 38 degrees C via cannulae inserted at the cecal-colonic junction. Effluents were collected by cannulae inserted in the anus. In the first experiment, perfusion with the control solution or with the control solution having 35 mmol/L NaCl replaced by equimolar amounts of ammonium acetate, ammonium chloride or sodium acetate showed that only ammonium-containing solutions caused histological damage, loss of mucus, and significant losses of carbohydrate and DNA (P less than 0.05). The losses of carbohydrate and DNA expressed in microgram.cm-1.30 min-1 were as follows: control, 13.4 and 1.0; ammonium acetate, 31.8 and 1.6; sodium acetate, 16.0 and 0.6; ammonium chloride, 24.1 and 1.3, respectively. In the second experiment, perfusion with control fluid containing 35 or 70 mmol/L ammonium acetate at pH 6.8, 7.4 or 8.0 increased carbohydrate and DNA losses into the effluents compared with the pretest period (P less than 0.05), without significant effects related to influent pH. These studies are consistent with the concept that the life span of colon cells is shortened by concentrations of ammonia found in the colon under normal conditions and that ammonia enhances cell proliferation in the colon mucosa.