The pathogenesis of OSA-related hypertension: what are the determining factors?

Sleep-disordered breathing has a relatively high prevalence, which varies from 3-7% in males and from 2-5% in females in the adult population. Studies published in the literature have shown that sleep apnea is closely related to an increased risk of developing various pathologies, among which arterial hypertension stands out. The prevalence of hypertension in patients suffering from obstructive sleep apnea (OSA) ranges from 35-80% and appears to be related to OSA severity. Approximately 40-50% of patients affected by hypertension are also affected by OSA and this association seems to be stronger in young and middle-aged adults (<50 years of age). The primary objective of this narrative review is to provide an update on what are the main contributing comorbidities to the development of a hypertensive state in patients suffering from OSA, an independent risk factor for diurnal hypertension, implicated as a risk factor for the first stroke, recurrent stroke, and post-stroke mortality. There are a lot of factors that contribute to developing a hypertensive state in OSA patients, some more decisive, others less. More evidence from longitudinal studies is needed on the impact of OSA on cardiovascular risk in females, on the causal link between OSA and arterial hypertension or metabolic diseases, like diabetes and glucose intolerance, and the effect of different kinds of OSA treatment.

Touching reality: Bridging the user-researcher divide in upper-limb prosthetics

Realistically improving upper-limb prostheses is only possible if we listen to users' actual technological needs.

Prevalence of sleep disruption and determinants of sleepiness in a cohort of Italian hospital physicians: The PRESOMO study

Nightshift work can cause daytime somnolence and decreased alertness, and can increase risk of medical errors, occupational injuries and car accidents. We used a structured questionnaire, including the Epworth Sleepiness Scale (ESS), to assess the prevalence and the determinants of sleep disruption in 268 Italian University hospital physicians from Cagliari (N = 57), Milan (N = 180) and Pisa (N = 31), who participated in the multicentre study on the prevalence of sleep disturbance among hospital physicians (PRESOMO); 198 of them (74%) were engaged in nightshift work. We explored the association between history of nightshift work and poor sleep quality and daytime somnolence with multivariate logistic regression, adjusting by personal and lifestyle covariates. Age, female gender, taking medication interfering with sleep and an elevated ESS score were significant predictors of poor sleep quality and daytime somnolence. Nightshift work was associated with a higher prevalence of unrestful sleep (84% versus 70%; odds ratio [OR] = 2.4, 95% confidence interval [CI] 1.18–5.05) and daytime dozing (57% versus 35%; OR = 1.9, 95% CI 1.03–3.64), with an upward trend by years of engagement in nightshift work for both conditions (p = .043 and 0.017, respectively), and by number of nightshifts/year for unrestful sleep (p = .024). Such an association was not detected with the ESS scale. Our results suggest that nightshift work significantly affects sleep quality and daytime somnolence in hospital physicians, who might underestimate their daytime dozing problem, when asked to subjectively scale it.

Pelvic floor rehabilitation for defecation disorders

Pelvic floor rehabilitation is frequently recommended for defecation disorders, in both constipation and fecal incontinence. However, the lack of patient selection, together with the variety of rehabilitation methods and protocols, often jeopardize the results of this approach, causing difficulty in evaluating outcomes and addressing proper management, and above all, in obtaining scientific evidence for the efficacy of these methods for specific indications. The authors represent different gastroenterological and surgical scientific societies in Italy, and their aim was to identify the indications and agree on treatment protocols for pelvic floor rehabilitation of patients with defecation disorders. This was achieved by means of a modified Delphi method, utilizing a working team (10 members) which developed the statements and a consensus group (15 members, different from the previous ones) which voted twice also suggesting modifications of the statements.

Different perception of chronic constipation between patients and gastroenterologists

BACKGROUND

There is a certain number of subjects that consider themselves to be constipated (self diagnosed constipation; SDC). The Rome Criteria separate FC from IBS-C, but some SDC patients do not meet the Rome criteria (no Rome Constipation; NRC). Our aims were to evaluate the percentage of SDC subjects with a diagnosis of FC and IBS-C and to compare demographic and clinical features, symptoms, and quality of life in the different SDC groups (FC, IBS-C, NRC).

METHODS

During a 2-month period, 934 patients and 980 accompanying persons (AP) were asked to complete a survey. The presence of FC or IBS-C was assessed. SDC subjects were invited to record the stool consistency (Bristol scale) and to fill in the Constipation Severity Index (CSI), obstructed defecation syndrome (ODS) and patient assessment of constipation-quality of life (PAC-QoL). The use of laxatives and enemas was evaluated.

KEY RESULTS

The probability of the ROME III criteria being present was higher in SDC compared with no-SDC (OR 20.5). NRC was present in 13.5% of the SDC. In the patients' group the agreement between a diagnosis of Rome III and SDC was good (K 0.62), whereas in the AP it was moderate (K 0.56). NRC showed lower mean values of ODS, CSI and PAC-QoL, higher Bristol scale and a lower use of laxatives and enemas compared to IBS-C and FC. No differences were found between IBS-C and FC.

CONCLUSIONS AND INFERENCES

The Rome III criteria identify subjects with a greater clinical impact, but separation of FC and IBS-C does not seem justified.

Effects of Endocrine Disruptor Compounds, Alone or in Combination, on Human Macrophage-Like THP-1 Cell Response

The aim of the present study was to evaluate the immunological effects on human macrophages of four endocrine disruptor compounds (EDCs) using the differentiated human THP-1 cell line as a model. We studied first the effects of these EDCs, including Bisphenol A (BPA), di-ethylhexyl-phthalate (DEHP), dibutyl phthalate (DBP) and 4-tert-octylphenol (4-OP), either alone or in combination, on cytokine secretion, and phagocytosis. We then determined whether or not these effects were mediated by estrogen receptors via MAPK pathways. It was found that all four EDCs studied reduced strongly the phagocytosis of the differentiated THP-1 cells and that several of these EDCs disturbed also TNF-α, IL-1 β and IL-8 cytokine secretions. Furthermore, relative to control treatment, decreased ERK 1/2 phosphorylation was always associated with EDCs treatments-either alone or in certain combinations (at 0.1 μM for each condition). Lastly, as treatments by an estrogen receptor antagonist suppressed the negative effects on ERK 1/2 phosphorylation observed in cells treated either alone with BPA, DEHP, 4-OP or with the combined treatment of BPA and DEHP, we suggested that estrogen receptor-dependent pathway is involved in mediating the effects of EDCs on human immune system. Altogether, these results advocate that EDCs can disturb human immune response at very low concentrations.

Analysis of regulation of pentose utilisation in Aspergillus niger reveals evolutionary adaptations in Eurotiales

Aspergilli are commonly found in soil and on decaying plant material. D-xylose and L-arabinose are highly abundant components of plant biomass. They are released from polysaccharides by fungi using a set of extracellular enzymes and subsequently converted intracellularly through the pentose catabolic pathway (PCP).

In this study, the L-arabinose responsive transcriptional activator (AraR) is identified in Aspergillus niger and was shown to control the L-arabinose catabolic pathway as well as expression of genes encoding extracellular L-arabinose releasing enzymes. AraR interacts with the D-xylose-responsive transcriptional activator XlnR in the regulation of the pentose catabolic pathway, but not with respect to release of L-arabinose and D-xylose.

AraR was only identified in the Eurotiales, more specifically in the family Trichocomaceae and appears to have originated from a gene duplication event (from XlnR) after this order or family split from the other filamentous ascomycetes. XlnR is present in all filamentous ascomycetes with the exception of members of the Onygenales. Since the Onygenales and Eurotiales are both part of the subclass Eurotiomycetidae, this indicates that strong adaptation of the regulation of pentose utilisation has occurred at this evolutionary node. In Eurotiales a unique two-component regulatory system for pentose release and metabolism has evolved, while the regulatory system was lost in the Onygenales. The observed evolutionary changes (in Eurotiomycetidae) mainly affect the regulatory system as in contrast, homologues for most genes of the L-arabinose/D-xylose catabolic pathway are present in all the filamentous fungi, irrespective of the presence of XlnR and/or AraR.

Improvement of functional bloating by an enterovaccine: a preliminary study

BACKGROUND

Bloating is a fastidious symptom reported by many patients who also have other gastrointestinal functional disorders. Bloating is more common in women, and it is often associated with meals and improves or disappears overnight. No specific treatments are to date available for this disturbing symptom.

AIMS

to evaluate the effects of an oral enterovaccine (Colifagina) on bloating and other abdominal symptoms in patients with prevalent complaints of functional bloating.

PATIENTS AND METHODS

One hundred and forty-eight patients with functional bloating according to Rome III criteria were recruited. Questionnaires and a VAS scale on their symptoms were administered at baseline and after four weeks of therapy with Colifagina.

RESULTS

After treatment, a significant amelioration of bloating (p < 0.0001), abdominal pain (p < 0.0001) and flatus (p < 0.0001) was observed; nausea and vomiting scores were not significantly different at the end of the treatment. Subjective wellbeing was also generally improved (p < 0.001) in treated patients.

CONCLUSION

Treatment with an enterovaccine may help improve symptoms in patients with functional bloating.

Rationale of the combined use of inspiratory and expiratory devices in improving maximal inspiratory pressure and maximal expiratory pressure of patients with chronic obstructive pulmonary disease

OBJECTIVE

To examine the rationale of the combined use of a new expiratory device in association with a previously assessed inspiratory device in improving 3 indicators of the respiratory muscle strength, for example, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and dyspnea grade.

DESIGN

Randomized trial.

SETTING

Home-based pulmonary rehabilitation.

PARTICIPANTS

Adults (N=32; mean age, 68y).

MAIN OUTCOME MEASURE

We instructed 32 patients with mild to very severe COPD to use the devices, and randomized them in a 1:1 ratio: they were assigned to the sham training control group (16 patients who trained at a load not able to improve MIP and MEP) or to the training group (16 patients). The patients trained at home twice daily for 15 minutes, 7 days a week, for 12 months. MIP and MEP as well as dyspnea perception were evaluated at 1, 6, and 12 months from the beginning of the training. The impact of additional work of breathing was measured at baseline and after the use of the expiratory device.

RESULTS

The patients who performed the respiratory training showed significant and progressive improvements of MIP (81+/-4 at 12 months vs 57+/-7 as basal values expressed in cm H2O; P<.05) and MEP (97+/-2 at 12 months vs 62+/-4 as basal values; P<.05) at the end of the training. In addition, they showed a significant reduction of dyspnea perception (1.18+/-0.29 vs 2.93+/-0.32 as basal values; P<.05) at the end of the training.

CONCLUSIONS

This study suggests that home exercise with the combined use of our expiratory and inspiratory devices leads to a significant improvement of respiratory muscle function in patients with mild to very severe COPD.

Water load test before and after PPI therapy in patients with gastro-oesophageal reflux disease

BACKGROUND

Patients with gastro-oesophageal reflux disease may complain of epigastric pain, bloating, early satiety, epigastric fullness, epigastric burning, nausea and vomiting.

AIMS

To evaluate the symptoms in response to gastric distension and its relationship to a therapeutic course in patients with gastro-oesophageal reflux disease using the water load test, compared to healthy controls.

METHODS

Thirty gastro-oesophageal reflux disease patients with grade A oesophagitis (studied before and after 4 weeks of therapy with esomeprazole, 40 mg per day) and 15 patients with reflux-related symptoms demonstrated at wireless pH monitoring (non-erosive reflux disease) were compared to 30 healthy volunteers.

RESULTS

Patients with grade A oesophagitis and with reflux-related symptoms ingested significantly lower water volumes than did controls, before onset of fullness, without statistically significant difference between erosive or non-erosive gastro-oesophageal reflux disease; this variable improved in patients after treatment. Nausea scores were higher basally in patients, pre- and post-therapy, and improved after therapy. Thirty-minute fullness and bloating scores improved after therapy in all gastro-oesophageal reflux disease patients compared to controls and pre-therapy. In all pre-treatment patients, a significant correlation was found only with epigastric fullness; after treatment, there was no significant relationship between the water load and the symptom scores.

CONCLUSIONS

In patients with reflux-related symptoms, with or without grade A oesophagitis, the water load test is frequently abnormal, suggesting an altered gastric function. This could explain the incomplete resolution of symptoms after treatment in some patients, and should lead to additional studies aimed at exploring gastric function in gastro-oesophageal reflux disease patients.

Home respiratory muscle training in patients with chronic obstructive pulmonary disease

OBJECTIVE AND BACKGROUND

The benefits of inspiratory muscle strength training in decreasing symptoms, disability or handicap of patients affected by COPD are not well established. The objective of this study was to assess the efficacy of the constant use of a new flow-volumetric inspiratory exerciser, named Respivol, in improving respiratory functional parameters in COPD patients.

METHODS

Twenty consecutive ambulatory patients affected by COPD were enrolled. Each patient was assessed, before and after 3 and 6 months inspiratory exercise with Respivol, for the following clinical parameters: maximal inspiratory pressure, maximal expiratory pressure, dyspnoea grade, quality of life by a self-administered St George questionnaire and a 6-min walking test. After a brief progressive ambulatory training programme, inspiratory exercise with Respivol was performed at home for 6 months. All patients used Respivol together with medical treatment.

RESULTS

Maximal inspiratory pressure and maximal expiratory pressure values were significantly increased after 3 and 6 months of exercise. Dyspnoea grade was significantly reduced and the 6-min walking test showed an increase in effort tolerance, after 6 months of home training. Quality of life assessment showed an improvement, associated with a decrease of respiratory disease symptoms.

CONCLUSIONS

Inspiratory muscle strength training with Respivol seems to be efficient in reducing symptoms and improving quality of life in adults with COPD.

Treatment with botulinum toxin of octo-nonagerians with oesophageal achalasia: a two-year follow-up study

BACKGROUND

Treatment of oesophageal achalasia with intrasphincteric injections of botulinum toxin has proved to be a successful alternative treatment modality. However, little is known about its long-term effects in very old patients.

AIM

To evaluate the effects of such treatment in octo-nonagerians during a 2-year follow-up period.

PATIENTS AND METHODS

Thirty-three patients with idiopathic oesophageal achalasia (range 81-94 years) entered the study. After basal evaluation and screening procedures, 100 U of botulinum toxin was injected at the lower oesophageal sphincter, and the procedure was repeated 1 month later. Data were collected at baseline and were compared after 1 and 2 years following the procedure.

RESULTS

Seventy-eight per cent of patients were considered responders at 1 year and 54% were considered responders at 2 years. The weight gain at the end of the follow-up period was 2 (0-3) kg. No significant relationship was found between baseline lower oesophageal sphincter pressure and symptoms score after 1 and 2 years of follow-up; moreover, no major complications of botulinum toxin therapy were reported.

CONCLUSION

Treatment of very old achalasic patients with botulinum toxin is safe, effective and yields good quality of life in a substantial proportion of these subjects.

Brainstem involvement in Legionnaires' disease

OBJECTIVE

To report a case of Legionella pneumonia with unusual neurologic involvement.

INTERVENTION

Chest X-ray, lumbar puncture, magnetic imaging of the brain, electroencephalography, audiometry, brainstem acoustic evoked potentials and institution of oral antibiotics and steroids.

MAIN RESULT

Gradual clinical improvement of neurologic and pulmonary illness within 4 weeks.

CONCLUSION

Legionellosis should be considered in the differential diagnosis of neurologic involvement in the setting of pneumonia.

Interstitial cells of Cajal, enteric nerves, and glial cells in colonic diverticular disease

BACKGROUND

Colonic diverticular disease (diverticulosis) is a common disorder in Western countries. Although its pathogenesis is probably multifactorial, motor abnormalities of the large bowel are thought to play an important role. However, little is known about the basic mechanism that may underlie abnormal colon motility in diverticulosis.

AIMS

To investigate the interstitial cells of Cajal (the gut pacemaker cells), together with myenteric and submucosal ganglion and glial cells, in patients with diverticulosis.

PATIENTS

Full thickness colonic samples were obtained from 39 patients undergoing surgery for diverticulosis. Specimens from tumour free areas of the colon in 10 age matched subjects undergoing surgery for colorectal cancer served as controls.

METHODS

Interstitial cells of Cajal were assessed using anti-Kit antibodies; submucosal and myenteric plexus neurones and glial cells were assessed by means of anti-PGP 9.5 and anti-S-100 monoclonal antibodies, respectively.

RESULTS

Patients with diverticulosis had normal numbers of myenteric and submucosal plexus neurones compared with controls (p = 0.103 and p = 0.516, respectively). All subtypes of interstitial cells of Cajal were significantly (p = 0.0003) reduced compared with controls, as were glial cells (p = 0.0041).

CONCLUSIONS

Interstitial cells of Cajal and glial cells are decreased in colonic diverticular disease, whereas enteric neurones appear to be normally represented. This finding might explain some of the large bowel motor abnormalities reported to occur in this condition.

Delivery of radiofrequency energy to the gastroesophageal junction (Stretta procedure) for the treatment of gastroesophageal reflux disease

BACKGROUND

Radiofrequency (RF) energy treatment is increasingly offered before invasive surgical procedures for selected patients with gastroesophageal reflux disease (GERD).

METHODS

Thirty-two patients undergoing the Stretta procedure were prospectively evaluated with upper endoscopy, manometry, 24-hour pH testing, SF-36 surveys, and GERD-specific questionnaires (GERD HRQL).

RESULTS

Significant clinical improvement was observed in 91% of patients (29/32). Mean heartburn and GERD HRQL scores decreased (p = 0.001 and p = 0.003, respectively), and physical SF-36 increased (p = 0.05). At a minimum follow-up of 12 months, median esophageal acid exposure decreased (p = 0.79) and was normalized in eight patients. Median lower esophageal sphincter (LES) pressure was unchanged. Esophagitis healed in six of eight patients, but two patients with nonerosive disease developed asymptomatic grade A esophagitis during follow-up. At 12 months, 56% of patients were off proton pump inhibits. Morbidity was minimal.

CONCLUSIONS

RF delivery to LES is safe and significantly improves symptoms and quality of life in selected GERD patients.

Acute recurrent diverticulitis is prevented by oral administration of a polybacterial lysate suspension

AIM

The main cause of acute diverticulitis is the abnormal accumulation of fecal bacteria within the diverticular lumen, leading to a balancing between normal probiotic microflora and pathogenic species; Gram negative Entero-bacteriaceae, mainly Escherichia coli and Proteus spp, are the genders that usually cause the disease-related symptoms, due to their ability to adhere to intestinal mucosa. The intestine is well known as the largest human lymphoepithelial organ and daily produces more antibodies, mainly secretory IgAs, than do all other lymphoid tissues. IgAs have different immune and anti-inflammatory properties. The aim of this study was to verify the efficacy of an oral immunostimulant highly-purified, polymicrobial lysate in the prevention of recurrent attacks of diverticulitis and in the improvement of symptoms.

METHODS

The study was carried out on 83 consecutive patients suffering from recurrent symptomatic acute diverticulitis and with at least 2 attacks in the previous year; patients were randomly assigned to receive (group A) an oral polybacterial lysate suspension or to a no-treatment clinical follow-up as controls (group B).

RESULTS

A total of 76 patients (41 in group A and 35 in group B) terminated the study period. the sums of the scores for symptoms, reported on day schedules, were calculated and examined by means of ANOVA statistical analysis. Statistical differences between group A vs group B were recorded after 1 month (p<0.05) and 3 months (p<0.01) of treatment with the oral polybacterial lysate suspension.

CONCLUSIONS

Our data suggest that the administration of an oral enterovaccine for the prophylaxis of recurrent diverticulitis is effective and well tolerated, probably due to a direct stimulation of IgA-mediated mucosal defences.

Relationship between lipids and bone mass in 2 cohorts of healthy women and men

A number of recent findings seem to indicate that fat and bone metabolism are strictly connected. We investigated the relationship between lipid profile and bone mineral density (BMD) in 236 either pre- or postmenopausal women, aged 35-81 years, attending our osteoporosis center ("clinic group"). In order to verify the consistency of the results, 265 men and 481 women aged 68-75, participating in a population-based epidemiological investigation ("community cohort"), were also studied. Lumbar spine, femoral neck, total hip and total body BMD, total body fat, % fat mass and lean mass were measured using dual energy X-ray absorptiometry (DXA). In the clinic group, lumbar spine and hip BMD Z score values were both strongly related to all measured serum lipids: the relationship was negative for HDL cholesterol ( P < 0.05) and Apo A lipoprotein ( P < 0.000) and positive for LDL cholesterol ( P < 0.05), Apo B lipoprotein ( P < 0.001) and triglycerides ( P < 0.05). When BMD values were adjusted for body weight and BMI, most relationships remained statistically significant. In the community cohort, total body and hip BMD values were strongly related in both men and women to age, body weight, height, BMI, fat mass, lean mass, % fat mass. Total body and hip BMD were significantly related to serum lipids in both women and men. The relationship was negative for HDL cholesterol and positive for total cholesterol, triglycerides and LDL cholesterol. Most of these relationships (triglycerides, HDL cholesterol, LDL/HDL cholesterol ratio in women, and all measured lipids in men) remained statistically significant ( P values ranging from 0.000 to 0.03) when the BMD values were adjusted also for anthropometric measures (body weight, height, fat mass). This study demonstrates for the first time that the lipid profile is strictly related to bone mass in both men and women. The interpretation of this association remains hypothetical but it might open new perspectives for understanding the mechanisms controlling bone metabolism.

Intravenous intermittent neridronate in the treatment of postmenopausal osteoporosis

Bisphosphonates have been used with success in the treatment of osteoporosis, but oral therapy often lacks compliance. Here we report the results of clinical trial with aminobisphosphonate neridronate administered intravenously (i.v.). The study included 78 postmenopausal women with spine bone mineral density (BMD) at least -2.5 SD below peak. Patients were randomized to receive for 2 years either 50 mg i.v. neridronate bimonthly and 500 mg calcium plus 400 U vitamin D supplements daily (n=39) or calcium-vitamin D supplements alone (control group, n=39). Treatment was continued over 2 years with an additional 1 year follow-up of calcium-vitamin D supplements alone. Neridronate was well tolerated with the appearance of typical clinical signs of an acute phase reaction in only 3 of the patients after the first infusion. In the control group no significant changes in BMD or bone markers were observed. In the neridronate group BMD rose progressively at the spine rose up to 7.4% +/- 6.1% (SD) and at the femoral neck up to 5.8% +/- 8.2% (SD) at the end of the second year. In the succeeding follow-up these gains were maintained at both skeletal sites. Serum bone alkaline phosphatase (bone ALP) and serum type I collagen C-telopeptide (s-CTX) significantly decreased within 2 months. The bone ALP values reached a -35% plateau after 6 months, while s-CTX attained the lowest mean value (-47%) only by the end of the treatment with neridronate. Both bone markers returned almost to baseline values 1 year after treatment discontinuation. Treatment of postmenopausal osteoporosis with 50 mg i.v. neridronate bimonthly results in clinically relevant increases in BMD, among the largest so far observed with any other bisphosphonate.

Are colonic regular contractile frequency patterns in slow transit constipation a relevant pathophysiological phenomenon?

BACKGROUND

Pathogenesis of slow transit constipation still remains elusive. Some studies have shown several colonic motor abnormalities; however, it is not easy to understand the relative importance of the single ones.

AIMS

Since it has been hypothesized that an excess of periodic distal motor activity may be of pathophysiological importance in patients with slow transit constipation, we evaluated regular colonic contractile frequencies in a homogeneous cohort of these patients.

PATIENTS

A total of 26 female patients (age range 34 to 67 years) fulfilling the Rome II criteria for constipation entered the study. No patient had evidence of secondary forms of constipation and distal obstruction.

METHODS

Twenty-four hour colonic manometric studies were obtained for each patient. Regular contractile patterns (with frequencies ranging from 2 to 8 cycles/min) were calculated for the entire recording period and in single colonic segments.

RESULTS

Overall, regular patterns accounted for about 3% of the total colonic motor activity (average 30 min/day per subject), with the 3 cycles/min being the predominant contractile rhythm. Most of this activity was present in the sigmoid colon, accounting for >50% of the total amount of motility, and it was more prevalent than in the descending and transverse colon; no differences were revealed in the descending with respect to the transverse colon. No daily fluctuations of regular contractile activity, nor a cyclic pattern, nor migration between recording points were observed.

CONCLUSIONS

Regular colonic frequency patterns are probably of minor pathophysiological importance in slow transit constipation, even in the light of the scant amount of such phenomena previously documented in healthy subjects.

Twenty-four hour recordings of colonic motility in patients with diverticular disease: evidence for abnormal motility and propulsive activity

INTRODUCTION

Diverticular disease of the colon is one of the most common pathologic entities in western countries. Although altered motility of the large bowel is commonly believed to be one of the major pathophysiologic mechanisms, no convincing evidence has been reported yet. In fact, only a few conflicting studies concerning distal colonic motility (with no information on forceful propulsive activity) are available in the literature.

PURPOSE

The purpose of the present study was to investigate basal and stimulated (postprandial) colonic motility from the transverse (not affected), descending, and sigmoid colon in patients with diverticular disease, together with detection of high-amplitude propagated contractions (mass movements). Motility data from patients were compared with those obtained in healthy control subjects.

METHODS

Ten patients and 16 control subjects of both sexes were recruited for the study. In all subjects, colonic motility was recorded for a 24-hour period by a colonoscopically positioned manometric catheter. Two 1000-kcal mixed meals were served during the study.

RESULTS

Compared with control subjects, patients with diverticular disease displayed significantly increased amounts of motility in the affected segments; the response to a physiologic stimulus (meal) was also abnormal in the patients' group. Diverticular disease patients also had a significant increase of forceful propulsive activity compared with control subjects (average = 10.3 +/- 2.7/subject/day high-amplitude propagated contractions for patients and 5.5 +/- 0.8/subject/day for control subjects; P = 0.051); interestingly, about 20 percent of such activity was abnormal, being propagated in a retrograde fashion.

CONCLUSIONS

We concluded that patients with diverticular disease of the colon have abnormal motor and propulsive activities of the large bowel, which are confined to the affected segments.

Regioselective and stereospecific glucuronidation of trans- and cis-resveratrol in human

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a polyphenol present in wine, which has been reported to have anti-inflammatory, anti-platelet, and anti-carcinogenic effects. The glucuronidation of this compound and that of the cis-isomer also naturally present, has been investigated in human liver microsomes. Both isomers were actively glucuronidated. The reaction led to the formation of two glucuronides (3-O- and 4'-O-glucuronides), whose structure was characterized by LC-MS and proton NMR. Glucuronidation was regio- and stereoselective. It occurred at a faster rate with the cis-isomer and preferred the 3-position on both isomers. In addition, the glucuronidation of resveratrol was tested using several recombinant UDP-glucuronosyltransferase (UGT) isoforms. The reaction was catalyzed by UGT of the family 1A (UGT1A1, 1A6, 1A7, 1A9, 1A10). The bilirubin conjugating UGT1A1 was mainly involved in the 3-O-glucuronidation of trans-resveratrol, whereas the phenol conjugating UGT1A6 activity was restricted to cis-resveratrol. The UGT1A9 and 1A10 were active toward both isomers. The activity supported by UGT2B7 and UGT2B15 was very low and restricted to cis-resveratrol. UGT1A3, 1A4, 2B4, and 2B11 were unable to form resveratrol glucuronides.

Resveratrol inhibits TNF alpha-induced endothelial cell activation

Resveratrol, a phytoalexin found in grapes and wine, has been shown to have anti-inflammatory properties. Since endothelium is activated during inflammation by some cytokines released by macrophages and many other cells, we tested whether resveratrol could modulate endothelial cell activation. We studied the effect of resveratrol treatment in vitro on the expression of vascular cell adhesion molecule-1 by tumour necrosis factor alpha-stimulated human umbilical vein endothelial cells. In addition, we studied the effect of resveratrol treatment in vivo (in a murine experimental model) on the modulation of tumour necrosis factor alpha-induced vascular permeability. Resveratrol, used at the concentrations present in human plasma following moderate wine consumption, was demonstrated to be an inhibitor of the adhesion molecule expression by tumour necrosis factor alpha-stimulated endothelial cells. In addition, resveratrol significantly prevented the cytokine-induced vascular leakage. Our results (both in vitro and in vivo) may explain some aspects of the anti-inflammatory effects of resveratrol.

[Esophageal motility disorders]

Esophageal motility abnormalities are usually diagnosed when esophageal manometry is performed in patients with unexplained non-cardiac chest pain, non obstructive dysphagia or as a part of the preoperative evaluation for surgery of gastroesophageal reflux. Classification of these abnormalities has been a subject of controversy. These esophageal contraction abnormalities can be separated manometrically from the motor pattern seen in normal subjects, however, their clinical relevance is still unclear and debated. Many patients demonstrate motility abnormalities in the manometry laboratories, but may lack correlation with their presenting symptoms. Medical treatment can decrease symptoms particularly chest pain or acid reflux but there is no significant changes in the manometric patterns. Such motor abnormalities may not reflect a true disease state, but they could be markers of other abnormalities and they can modify the initial manometric findings in time.

A unique multifunctional transporter translocates estradiol-17beta -glucuronide in rat liver microsomal vesicles

A wide array of drugs, xenobiotics, and endogenous compounds undergo detoxification by conjugation with glucuronic acid in the liver via the action of UDP-glucuronosyltransferases. The mechanism whereby glucuronides, generated by this enzyme system in the lumen of the endoplasmic reticulum (ER), are exported to the cytosol prior to excretion is unknown. We examined this process in purified rat liver microsomes using a rapid filtration technique and [(3)H]estradiol-17beta-d-glucuronide ([(3)H]E(2)17betaG) as model substrate. Time-dependent uptake of intact [(3)H]E(2)17betaG was observed and shrinkage of ER vesicles by raffinose lowered the steady-state level of [(3)H]E(2)17betaG accumulation. In addition, rapid efflux of [(3)H]E(2)17betaG from rat liver microsomal vesicles suggested that the transport process is bidirectional. Microsomal uptake was saturable with an apparent K(m) and V(max) of 3.29 +/- 0.58 microm and 0.19 +/- 0.02 nmol.min(-1).mg protein(-1), respectively. Transport of [(3)H]E(2)17betaG was inhibited by the anion transport inhibitors 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid and probenecid. Specificity of the transport process was investigated by studying the cis-inhibitory effect of anionic metabolites, as well as substrates of the plasma membrane multidrug resistance-associated proteins on the uptake of [(3)H]E(2)17betaG. Collectively, these data are indicative of a novel multifunctional and bidirectional protein carrier for E(2)17betaG and other anionic compounds in the hepatic ER. This intracellular membrane transporter may contribute to the phenomenon of multidrug resistance.

Mechanism of inhibition of rat liver bilirubin UDP-glucuronosyltransferase by triphenylalkyl derivatives

A series of potent and competitive inhibitors of UDP-glucuronosyltransferase derived from 7,7,7-triphenylheptanoic acid has been synthesized in order to probe the active site of the isozyme involved in the glucuronidation of the endogenous toxic compound, bilirubin IX alpha. Like triphenylalkylcarboxylic acids, triphenyl alcohols were found to be very effective competitive inhibitors of the reaction (Ki 12 to 180 microM). Superimposition of the best inhibitors with bilirubin by computer modeling showed a marked spatial similarity, which accounts for the observed competitive-type inhibition. The bulky triphenylmethyl moiety of the inhibitor superimposed well on the part of the bilirubin molecule containing three of the four pyrrole rings. In agreement, substitution of the triphenylmethyl moiety by planar structures such as fluorenyl or indenyl rings completely suppressed the inhibition. In addition, the weak inhibition exerted by the shortest carboxylic acids could be related to the higher acidity of these molecules. The inhibition potency depended on the acidity of the molecules; the more acidic, the less inhibitory, suggesting that the presence of a negative charge on the inhibitor molecule prevents bilirubin glucuronidation. Based on these results, a reaction mechanism for bilirubin glucuronidation is postulated.

Manometric investigation of anorectal function in early and late stage Parkinson's disease

Abnormal gastrointestinal function is relatively frequent in Parkinson's disease, and constipation is a disturbing symptom in many patients. However, it remains to be established whether anorectal abnormalities are characteristic of the late stages of the disease. Clinical and anorectal manometric function were investigated in groups of early and late stage parkinsonian patients. Thirty one patients (19 men, 12 women, age range 22 to 89 years) entered the study. The disease severity was assessed by Hoehn and Yahr staging: there were four (12.9%) stage I, seven (22.6%) stage II, 10 (32.2%) stage III, and 10 (32.2%) stage IV patients. Anorectal variables were measured by standard manometric equipment and techniques. Values obtained in early stage patients (Hoehn and Yahr stage I and II) were compared with those obtained in late stage patients (Hoehn and Yahr stage III and IV). Overall, more than 70% of patients complained of chronic constipation, with chronic laxative use reported in more than 30%. Late stage patients were slightly older than their early stage counterparts. Pelvic floor dyssynergia was documented in more than 60% of patients. Manometric variables were not different in the two groups. In conclusion, defecatory dysfunction is frequent in Parkinson's disease, it is not confined to late stage patients, and it is found early in the course of the disease. This has potential implications for a targeted therapeutic approach.

Platelet-activating factor enhances vascular endothelial growth factor-induced endothelial cell motility and neoangiogenesis in a murine matrigel model

We previously reported that platelet-activating factor (PAF) enhances the angiogenic activity of certain polypeptide mediators such as tumor necrosis factor and hepatocyte growth factor by promoting endothelial cell motility. The purpose of the present study was to evaluate whether the synthesis of PAF induced by vascular endothelial growth factor (VEGF) might affect endothelial cell motility, microvascular permeability, and angiogenesis. The neoangiogenesis and synthesis of PAF induced by VEGF were studied in vivo in a murine Matrigel model. Dermal permeability was studied in mice by injection of (125)I-albumin. The synthesis of PAF, cell motility, and the increased (125)I-albumin transfer across endothelial monolayers were studied in vitro by using cultures of human umbilical cord vein-derived endothelial cells (HUVECs). The results obtained demonstrate that the neoangiogenesis induced by VEGF in vivo was associated with a local synthesis of PAF and was inhibited by WEB2170 and CV3988, 2 chemically unrelated, specific PAF-receptor antagonists. In contrast, WEB2170 did not inhibit VEGF-enhanced dermal permeability, suggesting that the latter was independent of the synthesis of PAF. In vitro, it was found that VEGF induced the synthesis of PAF by HUVECs in a dose- and time-dependent manner. The cell motility induced by VEGF was inhibited by PAF-receptor antagonists. In contrast, VEGF-induced proliferation of HUVECs and albumin transfer through HUVEC monolayer were unaffected by PAF-receptor antagonists. These results suggest that the synthesis of PAF induced by VEGF enhances endothelial cell migration and contributes to the angiogenic effect of VEGF in the in vivo Matrigel model.

Expression of CD40 and its ligand, CD40L, in intestinal lesions of Crohn's disease

OBJECTIVE

Selected mechanisms of the immune system participate in the development of inflammatory bowel disease. Recently, overexpression of the ligand for CD40 (CD40L), a lymphocyte costimulatory molecule, was shown to induce severe inflammatory bowel disease in transgenic mice. In the present study, we examined the expression of CD40 and CD40L on surgical specimens of ileum from 12 patients with Crohn's disease and 10 patients with diverticulitis.

METHODS

Several CD40L+ cells were present in the affected tissue of patients with Crohn's disease, whereas few scattered CD40L+ cells were detected in sections of histologically normal ileum, resected distantly from the affected tissue, in patients with diverticulitis and in normal ileum portions obtained from colorectal cancer undergoing extensive surgery. The phenotype of CD40L+ cells was mainly CD4+.

RESULTS

In patients with Crohn's disease, several CD40+ cells were detectable in the same areas of lymphocytes expressing CD40L, whereas in patients with diverticulitis, the number of CD40+ cells was significantly lower. Most of the CD40+ cells costained with CD20, thus showing to be B-lymphocytes, and only a few were CD14+ macrophages. Several von Willebrand-positive vessels were also positive for CD40. In addition, several infiltrating macrophages were found to express B7-1 and B7-2 molecules, the ligands of CD28 and CTLA-4, which cooperate with the CD40-CD40L pathway in lymphocyte activation. Staining of ileal lesions with anti-CTLA-4 antibodies resulted in detection of none or very few positive cells. In contrast, in patients with diverticulitis, an enhanced number of B7-1 and B7-2 and CTLA-4 was observed.

CONCLUSION

The local accumulation of CD40L+ together with CD40+ cells within intestinal lesions of Crohn's disease suggests the involvement of this co-stimulatory pathway.

Structural and functional studies of UDP-glucuronosyltransferases

UDP-Glucuronosyltransferases (UGTs) are glycoproteins localized in the endoplasmic reticulum (ER) which catalyze the conjugation of a broad variety of lipophilic aglycon substrates with glucuronic acid using UDP-glucuronic acid (UDP-GIcUA) as the sugar donor. Glucuronidation is a major factor in the elimination of lipophilic compounds from the body. In this review, current information on the substrate specificities of UGT1A and 2B family isoforms is discussed. Recent findings with regard to UGT structure and topology are presented, including a dynamic topological model of UGTs in the ER. Evidence from experiments on UGT interactions with inhibitors directed at specific amino acids, photoaffinity labeling, and analysis of amino acid alignments suggest that UDP-GIcUA interacts with residues in both the N- and C-terminal domains, whereas aglycon binding sites are localized in the N-terminal domain. The amino acids identified so far as crucial for substrate binding and catalysis are arginine, lysine, histidine, proline, and residues containing carboxylic acid. Site-directed mutagenesis experiments are critical for unambiguous identification of the active-site architecture.

Photoaffinity labeling probe for the substrate binding site of human phenol sulfotransferase (SULT1A1): 7-azido-4-methylcoumarin

A novel fluorescent photoactive probe 7-azido-4-methylcoumarin (AzMC) has been characterized for use in photoaffinity labeling of the substrate binding site of human phenol sulfotransferase (SULT1A1 or P-PST-1). For the photoaffinity labeling experiments, SULT1A1 cDNA was expressed in Escherichia coli as a fusion protein to maltose binding protein (MBP) and purified to apparent homogeneity over an amylose column. The maltose moiety was removed by Factor Xa cleavage. Both MBSULT1A1 and SULT1A1 were efficiently photolabeled with AzMC. This labeling was concentration dependent. In the absence of light, AzMC competitively inhibited the sulfation of 4MU catalyzed by SULT1A1 (Ki = 0.47 +/- 0.05 mM). Moreover, enzyme activity toward 2-naphthol was inactivated in a time- and concentration-dependent manner. SULT1A1 inactivation by AzMC was protected by substrate but was not protected by cosubstrate. These results indicate that photoaffinity labeling with AzMC is highly suitable for the identification of the substrate binding site of SULT1A1. Further studies are aimed at identifying which amino acids modified by AzMC are localized in the binding site.

Photoaffinity labeling of the aglycon binding site of the recombinant human liver UDP-glucuronosyltransferase UGT1A6 with 7-azido-4-methylcoumarin

7-Azido-4-methylcoumarin (AzMC) is a fluorescent photoactive compound structurally related to 4-methylumbelliferone (4-MU), a marker substrate of the human liver recombinant UDP-glucuronosyltransferase (UGT) 1A6. AzMC was synthesized and utilized to label the substrate binding site of UGT1A6. AzMC exhibits a fluorescence spectrum with maximum excitation and emission wavelengths of 380 and 442 nm, respectively. Upon irradiation, the probe irreversibly inhibited glucuronidation activity measured with para-nitrophenol (pNP) as substrate and interacted with UGT1A6 according to a saturable process indicative of reversible binding before covalent incorporation of the photoaffinity label. This inhibition was both time and concentration dependent and led to the calculation of an inhibition constant, k(2) = 0.113 mM min(-1), and dissociation constant, K(d) = 2.89 mM, for the reaction. Partial photoinactivation of UGT1A6 with AzMC revealed that the probe decreased the apparent V(max) of the pNP glucuronidation reaction, but not the K(m). Moreover, inhibition was partially prevented by 1-naphthol, a surrogate substrate for the enzyme, or by preincubation with an active-site directed inhibitor, 5'-O-[[(2-decanoylamino-3-phenyl-propyloxycarbonyl)amino]-su lfonyl]-2 ',3'-O-isopropylideneuridine. In contrast, UDP-glucuronic acid (UDP-GlcUA) did not have any protective effect against photoinactivation and AzMC did not affect the photoaffinity labeling of UGT1A6 by 5-[beta-(32)P]N(3)UDP-GlcUA, a photoaffinity analog of UDP-GlcUA. Additionally, in the absence of irradiation, AzMC was found to be a competitive inhibitor of 4MU glucuronidation. Collectively, these results strongly indicate that AzMC specifically binds to the UGT1A6 aglycon binding site. Amino acid alignment of phenol-binding proteins revealed a conserved motif, YXXXKXXPXP. It is possible that this motif is involved in phenol binding to UGT1A6 and other phenol-accepting proteins.

Identification of thiopurine methyltransferase (TPMT) polymorphisms cannot predict myelosuppression in systemic lupus erythematosus patients taking azathioprine

OBJECTIVE

To determine whether the presence of polymorphisms associated with reduced or absent activity of thiopurine methyltransferase (TPMT), an enzyme involved in azathioprine metabolism, can predict side-effects, particularly myelosuppression, in patients taking this drug.

METHODS

The TPMT genotype was determined in 120 patients with systemic lupus erythematosus (SLE) together with 15 patients with inflammatory bowel disease (IBD) and correlated with the effects of clinical exposure to azathioprine.

RESULTS

TPMT polymorphisms were detected in eight patients. Severe marrow toxicity occurred in the single homozygote identified. Azathioprine was generally well tolerated, but 11 drug-associated neutropenias were detected. In only one of the 11 cases was a TPMT polymorphism identified.

CONCLUSION

Homozygous TPMT deficiency was associated with severe marrow suppression. In the majority of cases, however, TPMT genotyping prior to azathioprine therapy would not have predicted myelosuppressive events and may augment, but not replace, regular blood monitoring.

Thrombopoietin stimulates endothelial cell motility and neoangiogenesis by a platelet-activating factor-dependent mechanism

In this study, we demonstrate that human umbilical cord vein-derived endothelial cells (HUVECs) expressed c-Mpl, the thrombopoietin (TPO) receptor, and that TPO activates HUVECs in vitro, as indicated by directional migration, synthesis of 1-alkyl-/1-acyl-platelet-activating factor (PAF) and interleukin-8 (IL-8), and phosphorylation of the signal transducers and activators of transcription (STAT) STAT1 and STAT5B. The observation that WEB 2170 and CV3988, 2 structurally unrelated PAF receptor antagonists, prevented the motility of HUVECs induced by TPO suggests a role of PAF as secondary mediator. Moreover, kinetic analysis of TPO-induced tyrosine phosphorylation of STAT demonstrated that STAT5B activation temporally correlated with the synthesis of PAF. PAF, in turn, induced a rapid tyrosine phosphorylation of STAT5B and PAF receptor blockade, by WEB 2170, preventing both TPO- and PAF-mediated STAT5B activation. The in vivo angiogenic effect of TPO, studied in a mouse model of Matrigel implantation, demonstrated that TPO induced a dose-dependent angiogenic response that required the presence of heparin. Moreover, the in vivo angiogenic effect of TPO was inhibited by the PAF receptor antagonist WEB 2170 but not by the anti-basic fibroblast growth factor neutralizing antibody. These results indicate that the effects of TPO are not restricted to cells of hematopoietic lineages, because TPO is able to activate endothelial cells and to induce an angiogenic response in which the recruitment of endothelial cells is mediated by the synthesis of PAF. Moreover, biochemical analysis supports the hypothesis that STAT5B may be involved in the signaling pathway leading to PAF-dependent angiogenesis.

Endoluminal instillation of bisacodyl in patients with severe (slow transit type) constipation is useful to test residual colonic propulsive activity

BACKGROUND

Chronic constipation is a frequent symptom among the general population, and a minority of cases do not respond to any therapeutic measures, except surgery. The purpose of this study was to test the residual colonic motor propulsive activity with a pharmacologic stimulus in a series of patients referred for severe constipation.

PATIENTS

Twenty-five chronically constipated patients, slow transit type, age range 16-71 years, unresponsive to conventional medical treatment and referred for functional evaluation, entered the study.

METHODS

Colonic manometry by means of an endoscopically positioned probe was carried out in all patients. Following a basal recording period, a placebo solution followed by 10 mg bisacodyl solution was infused into the colon through the more proximal recording port.

RESULTS

After bisacodyl infusion, about 90% of patients showed a motor response characterized by the appearance (within on average 13 +/- 3 min) of one or more high-amplitude propagated contractions, the manometric equivalent of mass movements, and about 75% of these were followed (mean 18.5 +/- 4 min) by defecation.

CONCLUSIONS

Physiological and pharmacological testing of colonic motor activity may be important in severely constipated patients, especially in those labeled as 'intractable', in whom more in depth investigation planning may encourage further therapeutic efforts.

The nutcracker esophagus: a late diagnostic yield notwithstanding chest pain and dysphagia

The nutcracker esophagus, a primary motor disorder, is frequently associated with noncardiac chest pain. However, there are no data on whether its diagnosis, as in other esophageal motility disorders, is delayed. Since the disorder is frequently heralded by alarming symptoms such as chest pain and dysphagia, diagnosis should be made as soon as possible. In this study we assessed the diagnostic delay, if any, in patients with the nutcracker esophagus. Moreover, we were interested in whether the abnormalities described in the distal esophagus could also involve the entire viscus. Fifty-four subjects (age range 23-78 yr) with the nutcracker esophagus were assessed for clinical and manometric variables as an overall group and after dividing them into subgroups according to their symptoms. The manometric variables were compared with those obtained in 61 controls (age range 21-67 yr). Overall, a diagnosis of nutcracker esophagus was made after an average period of 36 +/- 6 months, and surprisingly, this was not different in the various subgroups complaining of either chest pain, dysphagia, or both. Analysis of manometric variables showed that the mean amplitude of contractions was significantly higher in the patients' group at all esophageal body levels, even in the proximal portions. Again, there were no significant differences among the subgroups of nutcracker esophagus with respect to the symptoms. Notwithstanding the presence of alarming symptoms, such as chest pain and dysphagia, the nutcracker esophagus is diagnosed on average after 3 years from the onset of symptoms. Manometric assessment seems to confirm that this entity may indeed represent a primary esophageal motor disorder. The major dysfunction is due to an abnormal increase of contraction amplitude of the entire esophageal body.

Interaction of periodate-oxidized UDP-glucuronic acid with recombinant human liver UDP-glucuronosyltransferase 1A6

Sodium periodate reacts with UDP-glucuronic acid (UDP-GlcUA) to generate a reactive derivative [periodate-oxidized UDP-GlcUA (o-UDP-GlcUA)]. The ability of this analog of UDP-GlcUA to inactivate and label the human recombinant UDP-glucuronosyltransferase (UGT) UGT1A6 via the UDP-GlcUA binding site was investigated. At an o-UDP-GlcUA concentration of 20 mM, the enzymatic activity of UGT1A6 was totally inactivated after 30 min of incubation at pH 7.4. Inhibition was irreversible, time-dependent, and concentration-dependent and exhibited pseudo-first order kinetics (kinact = 4.0 M-1.min-1). Cosubstrate protection with UDP-GlcUA was biphasic, with no protection in the first phase and almost total protection in the second phase, suggesting that at least 65% of the cross-linking occurs at the cosubstrate binding site. Partial inactivation by o-UDP-GlcUA led to a decrease in Vmax, suggesting that o-UDP-GlcUA can act as an active site-directed inhibitor. Furthermore, proteins, including the UGTs, from membrane fractions of a recombinant V79 cell line expressing the UGT1A6 enzyme and from rat liver microsomes were cross-linked by in situ periodate oxidation of [beta-32P]UDP-GlcUA. The present results suggest that periodate-oxidized UDP-GlcUA, which inactivates UGT1A6 by the possible formation of a Schiff base adduct with active site lysyl residues, can be used as a new affinity label for the UDP-GlcUA binding site.

A functional role for histidyl residues of the UDP-glucuronic acid carrier in rat liver endoplasmic reticulum membranes

Previous studies have documented the presence of protein-mediated transport of UDP-glucuronic acid (UDP-GlcUA) in rat liver endoplasmic reticulum (ER). To determine the crucial amino acids of the membrane transporter and evaluate their function in regulating the glucuronidation reaction, we examined the effect of histidyl-specific irreversible inhibitors on the uptake of radiolabeled UDP-GlcUA in rat liver ER. Inactivation of uptake (initial rate) was more pronounced with hydrophobic reagents [diethyl pyrocarbonate (DEPC), p-bromophenacyl bromide] as compared to the more hydrophilic reagent (p-nitrobenzenesulfonic acid methyl ester). DEPC was used to further characterize the inhibition because of its greater specificity for protein histidyl residues. While initial [14C]UDP-GlcUA uptake rates were diminished by DEPC treatment of intact microsomes, the accumulation of isotope at equilibrium was not significantly affected, indicating no loss of vesicle integrity. A pKa of approximately 7 for the modified residue(s) of the transporter supported the alkylation of imidazole moieties. Protection against inactivation was observed with UDP-GlcUA as well as other nucleotide-sugars known for their interaction with this transporter. Uptake activity of the transporter (Vmax) but not UDP-GlcUA binding (Km) was affected by a limited inactivation. Furthermore, a partial inactivation of the transporter impaired the binding of the photoaffinity label [beta-32P]5-azido-UDP-GlcUA to UDP-glucuronosyltransferases (UGTs) in intact, but not in detergent-disrupted, ER vesicles. These results demonstrate the involvement of histidyl residue(s) in the UDP-GlcUA uptake process in rat liver ER, provide additional evidence for the lumenal orientation of the UGT active site, and support the view that translocation of the UGT cosubstrate is a rate-limiting step of the glucuronidation reaction.

Esophageal dysfunction in scleroderma: relationship with disease subsets

OBJECTIVE

To investigate the relationship between esophageal function and the extent of disease in a nonselected group of scleroderma patients, and to study gastric and small bowel motility in a group of scleroderma patients with more severe clinical manifestations.

METHODS

Esophageal function in 125 scleroderma patients was investigated by radiologic, endoscopic, manometric, and pH-metric techniques. Ten patients also underwent gastrointestinal (GI) manometric recording, both during fasting and after a standard meal.

RESULTS

Radiologic abnormalities of the esophagus were found in 55 of 81 patients (68%) and esophagitis in 45 of 125 (36%). No significant relationship was disclosed between GI symptoms, radiologic abnormalities, esophagitis grade, and the various disease subsets. However, the overall incidence of endoscopic esophagitis (irrespective of the degree) was significantly (P < 0.05) correlated with the patient subgroups, with 100% incidence of esophagitis in those having the more severe cutaneous involvement (type III). Manometric abnormalities were documented in 80% of patients, and pathologic reflux in 78%. The severity of esophageal abnormalities on manometry significantly correlated with the severity of the disease, whereas no correlations were found with pH-metric data. Ninety percent of the 10 female patients undergoing antroduodenal manometry displayed abnormal findings; of these, 60% showed neuropathic, and 30% myopathic, patterns. The latter were recorded in patients with a more severe stage of the disease (type III).

CONCLUSION

A direct relationship was observed between scleroderma subsets and the severity of esophageal (and, probably, more distal gut) motor involvement. Since no correlation was found between esophageal symptoms and the severity of manometric abnormalities, manometry should be considered the single most important GI test to document the severity of the "esophageal" disease. Gastric and small bowel manometry may also offer evidence of widespread gut involvement, and provide a rationale for a more targeted therapeutic approach.

Gluten-free diet normalizes mouth-to-cecum transit of a caloric meal in adult patients with celiac disease

The mechanisms responsible for bowel disturbances in celiac disease are still relatively unknown. Recent reports suggested that small bowel motor abnormalities may be involved in this pathological condition; however, there are no studies addressing small bowel transit in celiac disease before and after a gluten-free diet. We studied the mouth-to-cecum transit time of a caloric liquid meal in a homogeneous group of celiac patients presenting with clinical and biochemical evidence of malabsorption and complaining of diarrhea. Sixteen patients were recruited and investigated by means of hydrogen breath test through ingestion of 20 g lactulose together with an enteral gluten-free diet formula. A urinary D-xylose test was also done in each patient. Both breath tests and D-xylose tests were carried out basally and after a period of gluten-free diet. Twenty healthy volunteers were recruited as a control group and underwent the same breath testing. At the time of the diagnosis, mouth-to-cecum transit time was significantly prolonged in celiacs with respect to controls (243 +/- 10 vs 117 +/- 6 min, P = 0.0001). The D-xylose test was also abnormal (average urinary concentration 2.8 +/- 0.25 g, normal values >4.5). No correlation was found in patients between mouth-to-cecum transit time and urinary D-xylose output (r = 0.22). After the gluten-free diet period, mouth-to-cecum transit time in celiacs was significantly reduced compared to prediet transit (134 +/- 8 vs 243 +/- 10 min, P = 0.0001) and did not show statistical difference when compared to that found in controls (P = 0.1). The D-xylose test reverted to normal in all but two subjects, who were found to be noncompliant with the diet. Mouth-to-cecum transit time is significantly prolonged in patients affected by untreated celiac disease when compared to healthy controls. This alteration might not be correlated to intestinal malabsorption, and the prolonged orocecal transit could be due to impaired small bowel function (deranged motility?). Since intestinal transit returned to normal values after an adequate gluten-free period, a link with severe active mucosal lesions is suggestive.

Nitric oxide mediates angiogenesis induced in vivo by platelet-activating factor and tumor necrosis factor-alpha

We evaluated the role of an endogenous production of nitric oxide (NO) in the in vitro migration of endothelial cells and in the in vivo angiogenic response elicited by platelet-activating factor (PAF), tumor necrosis factor-alpha (TNF), and basic fibroblast growth factor (bFGF). The NO synthase inhibitor, N omega-nitro-L-arginine-methyl ester (L-NAME), but not its enantiomer D-NAME, prevented chemotaxis of endothelial cells induced in vitro by PAF and by TNF. The motogenic activity of TNF was also inhibited by WEB 2170, a specific PAF-receptor antagonist. In contrast, chemotaxis induced by bFGF was not prevented by L-NAME or by WEB 2170. Angiogenesis was studied in vivo in a murine model in which Matrigel was used as a vehicle for the delivery of mediators. In this model, the angiogenesis induced by PAF and TNF was inhibited by WEB 2170 and L-NAME but not by D-NAME. In contrast, angiogenesis induced by bFGF was not affected by L-NAME or by WEB 2170. TNF, but not bFGF, induced PAF synthesis within Matrigel. These results suggest that NO mediates the angiogenesis induced by PAF as well as that induced by TNF, which is dependent on the production of PAF. In contrast, the angiogenic effect of bFGF appears to be both PAF and NO independent.