[New systems of mapping and navigation in electrophysiology]

The indications of radiofrequency ablation of arrhythmias have considerably increased since the introduction of the technique in the early 1990s. Interventional rhythmologists now treat arrhythmias which are more and more complex by their mechanism. This requires accurate representation of the ablation catheter position and the integration of spatial and temporal data to identify the arrhythmogenic substrate. The systems of mapping and navigation developed over the last ten years are important tools for interventional rhythmologists. They are very useful for the identification of complex arrhythmogenic substrates which require "individualised" ablations in specific cases. The aim of this article is to review different systems of mapping, and/or navigation currently on the market and their principal characteristics without entering into the details of their use in interventional electrophysiology.

Interpretation of expression-profiling results obtained from different platforms and tissue sources: examples using prostate cancer data

The analysis of expression signatures is a powerful tool for the classification of cancer and other tissue samples. Several protocols and platforms are available on the market, and these lead to both confirmatory and complementary results. We review the main processing techniques for cross-platform comparisons and the different tissue sources for cancer profiling. Some examples and the cross-interpretation of bibliographic data related to prostate cancer are also presented.

[A multicentre trial of the diagnostic value and cost of electrocardiography in symptoms suggesting arrhythmia with a new event recorder with transtelephonic transmission]

Events recorders are used for electrocardiographic documentation of symptoms of arrhythmia too sporadic and short lasting to be recorded by 24 hour Holter monitoring. However, there are no French studies comparing the value and cost of event recorders with conventional diagnostic methods. Recently, a new telediagnostic device has become available in France leading to an assessment of the technique. The aim of this study was to determine the value of this event recorder and the cost of diagnostic ECG in the assessment of presumed arrhythmic symptoms such as palpitations or rare tachycardia (<3 episodes per week) of short duration, compared with conventional techniques. Fifty-eight patients with these criteria were randomised, 30 to Survcard (Group I) and 28 to conventional diagnostic methods (Group II). The patients were comparable with respect to age, sex distribution, type of symptoms and associated cardiac disease. The ECG diagnosis of the symptoms was established in 20 cases (66.6%) of patients in Group I in 17 +/- 16 days, and in 14 cases (50.0%) of Group II in 23 +/- 28 days. The difference between the two groups was not statistically significant. The cost of a positive diagnosis for Group I (Survcard) varied from 0 to 228.47 Euro with an average of 71.22 +/- 117.02 Euro. The cost of positive diagnosis in Group II varied from 76.80 to 2340.41 Euro with an average of 480.39 +/- 797.41 Euro. In conclusion, this study showed that the percentage of patients with a positive diagnosis was comparable in the two groups but that the cost was 6 times higher in the group investigated by conventional methods than in the Survcard group because of more costly medical intervention.

Correlation between electrogram morphology and standard criteria to validate bidirectional cavotricuspid block in common atrial flutter ablation

AIM

Assessment of a bidirectional conduction block within the cavotricuspid isthmus (CTI) is critical during radiofrequency (RF) atrial flutter (AF) ablation. We investigated the use of bipolar atrial electrogram (BAE) morphology as an additional criterion identifying CTI block and tested it against two recognized criteria: differential pacing and reversal of the right atrial depolarization sequence during coronary sinus (CS) pacing.

METHODS AND RESULTS

An RF ablation procedure was performed during 600 ms CS pacing in 100 consecutive patients with a common AF. BAE recorded along the CTI were continuously monitored. CTI conduction block was achieved by RF ablation in all patients and a clear change in BAE polarity in the Electrogram recorded by the dipoles located on the CTI and immediately lateral to the intended line of block (RS to QR pattern) associated with a confirmed CTI conduction block was observed in all cases. BAE morphology changes predicted bidirectional CTI conduction blocks with a 100% positive and a 100% negative predictive value. At a mean follow-up of 33 +/- 11 months, there was a 5% AF recurrence rate.

CONCLUSIONS

Our study suggests that morphological changes in BAE recorded at sites lateral and adjacent to the target line of block may be used as a unique and robust criterion to validate CTI conduction block during AF ablation procedure.

What is the 'true' function of skin?

Conventional textbook wisdom portrays the skin as an organ that literally enwraps whatever each of us stands for as a more or less functional, individual member of the mammalian species, and has it that the skin primarily establishes, controls and transmits contacts with the external world. In addition, the skin has long been recognized to protect the organism from deleterious environmental impacts (physical, chemical,microbiological), and is well-known as crucial for the maintenance of temperature, electrolyte and fluid balance. Now, ever more studies are being published that show the skin to also operate as a huge and highly active biofactory for the synthesis,processing and/or metabolism of an astounding range of e.g. structural proteins, glycans, lipids and signaling molecules. Increasingly, it becomes appreciated that the skin, furthermore, is an integral component of the immune, nervous and endocrine systems, with numerous lines of cross-talk between these systems established intracutaneously (e.g. Ann NY Acad Sci Vol 885, 1999; Endocrine Rev 21:457-487, 2000; Physiol Rev 80:980-1020, 2001; Exp Dermatol 10: 349-367, 2001). All these emerging cutaneous functions beyond the classical image of the skin as a barrier and sensory organ are immediately relevant for many of the quandaries that clinical dermatology, dermatopathology, and dermatopharmacology are still struggling with to-date, and offer the practising dermatologist attractive new targets for therapeutic intervention. Yet, many of these skin functions are not even mentioned in dermatology textbooks and await systematic therapeutic targeting. Following a suggestion by Enno Christophers, the current 'Controversies' feature brings together an unusually diverse council of biologists and clinicians, who share their thought-provoking views with the readers and allow us to peek into the future of research in cutaneous biology, not the least by reminding us of the -- often ignored -- evolutionary and embryonal origins of our favorite organ. Hopefully, this unique discussion feature will foster an understanding of the 'true' skin functions that is both more comprehensive and more profound than conventional teaching on this topic, and will stimulate more than 'skin-deep' reflections on the full range of skin functions.

The keratinocyte growth-differentiation switch

Growth/differentiation control of normal epithelial cells has been relatively understudied, because of the complexities involved in their cultivation and characterization. The present review is focused on progress in this area using the mouse primary keratinocyte system. This system reproduces under well defined culture conditions the switch between epithelial cell growth and differentiation which occurs in vivo, and enables the study of cells derived from wild type mice as well as mice with specific genetic alterations.

Growth regulatory proteins that repress differentiation markers in melanocytes also downregulate the transcription factor microphthalmia

Expression of basic fibroblast growth factor cDNA or dominantly acting oncogenes, e.g., E1A, in immortalized mouse melanocytes leads to autonomous growth in vitro, depigmentation, and in the case of the oncogenes, tumorigenesis. Because downregulation of pigmentation is a common event in human metastatic melanoma cells grown in culture, we determined the molecular basis of depigmentation in a mouse melanocyte model system. We tested the effect of E1A mutants deficient in their ability to neutralize several regulatory proteins and determined changes in melanogenic gene expression. We identified Microphthalmia as the affected, downregulated transcription factor in melanocytes rendered amelanotic by E1A, basic fibroblast growth factor, or the oncogenes ras or neu, and in an amelanotic cell variant of Cloudman S91 mouse melanoma. Against expectations, sequestration of p300, a transcriptional adaptor that mediates responses to cyclic adenosine monophosphate, was not required for the full transforming effects of E1A. Our results suggest that in addition to controlling tyrosinase (albino locus) and tyrosinase-related protein 1 (TR-P1/gp75/brown locus), both known to possess the DNA consensus site for binding the Microphthalmia protein, this transcription factor also controls other melanocyte-specific genes such as pink-eyed dilution and Pmel 17 (silver), but not tyrosinase-related protein 2 (slaty locus). Furthermore, these findings show that microphthalmia is downregulated not only by experimentally introduced dominantly acting oncogenes but also by the aberrant expression of basic fibroblast growth factor and by spontaneous tumorigenic transformation.

Risk factors of duodenal ulcer bleeding: the role of smoking and nicotine

Several studies have shown that cigarette smoking affects duodenal ulcer (DU) recurrence. To verify any correlation between smoking and complications of ulcer disease, we studied 33 DU smokers, 16 DU ex-smokers and 87 DU non-smokers for up to 48 months, recording age, sex, family history of ulcer, ulcer symptoms, non-steroidal anti-inflammatory drug use, length of DU history, alcohol consumption, smoking habit, relapses and bleeding episodes. Nicotine contents were also obtained for the type of cigarettes smoked. Statistics used were: Analysis of variance with Bonferroni's test. Pearson's chi-squared test and stepwise logistic regression analysis. Smokers were found to have significantly more relapses but fewer bleeding episodes than ex-smokers and non-smokers (63.3%, 31.2% and 34.5%, p = 0.029; 12.1%, 43.7% and 34.5%, p = 0.017). Bleeders were significantly more often males than non-bleeders (82.9% vs. 61.0%, p = 0.01) and had ulcer symptoms less frequently (9.7% vs. 26.3%, p = 0.02). Multivariate analysis confirmed sex as a risk factor (OR = 3.0) and smoking as a "protective" factor (OR = 0.4) for bleeding, while nicotine intake was found to be unrelated to this complication. We concluded that smoking (but not nicotine intake) and male sex are factors to take into account in evaluating the risk of DU bleeding.

Intermittent negative pressure ventilation may increase urine flow in normal subjects

In order to analyze the effect of intermittent negative pressure ventilation (NPV) on renal function, we studied 20 healthy male volunteers (mean age 29 +/- 4.1 years). NPV was performed with an "Emerson Chest Respirator Pump", adjusted to a breathing frequency of 10 respirations per minute, with inspiratory time/total respiratory time ratio of 0.4 and negative pressure of 25 cmH2O. The experimental protocol was carried out in two phases of two hours each--spontaneous breathing and NPV breathing. At the end of each phase, urine volume of the whole period was collected as well as venous blood sample for biochemical determinations. During NPV there was significant increase (P < 0.05) in urine flow rate (1.43 +/- 0.81 to 2.76 +/- 1.95 ml/min) as well as in natriuresis (258 +/- 201 to 389 +/- 175 mcEq/min), kaliuresis (61 +/- 45 to 98 +/- 49 mcEq/min), fractional sodium excretion (1.38 +/- 0.88 to (1.96 +/- 0.98%), osmolar clearance (3.13 +/- 1.82 to 4.32 +/- 1.24 ml/min) and pH (7.37 +/- 0.04 to 7.41 +/- 0.07) with unchanged creatinine and free water clearances. We concluded that NPV increases urine flow rate, kaliuresis and natriuresis but the data we have do not allow us to explain the mechanisms underlying such a phenomenon.

Pepsin concentration in gastroduodenal biopsy homogenates in chronic ulcer disease

A modification of Berstad's spectrophotometric method was tested and proved capable of detecting pepsin concentrations in mucosal perendoscopic biopsy homogenates. The relationship between this parameter and pepsin in gastric juice and pepsinogen group I in serum and in biopsy homogenates was analyzed. From the biochemical point of view, the assay was found sufficiently accurate. Mucosal pepsinogen group I, but not mucosal pepsin, concentration was found higher in gastric and duodenal ulcer patients than in controls. Patients with corpus-fundic gastric ulcer showed significantly lower mucosal pepsin and mucosal pepsinogen group (PG) I. Aging and smoking did not influence either parameter but male duodenal ulcer subjects presented higher mucosal pepsinogen group I concentration. The lack of any relationship between serum and mucosal PG I and between pepsin in gastric juice and in mucosa raises a question, at least in methodological terms, about the validity of using serum pepsinogen group I and pepsin as indicators of peptic output.

Helicobacter pylori infection, cigarette smoking and alcohol consumption. A histological and clinical study on 286 subjects

Helicobacter pylori (Hp) is connected with active/chronic gastritis, gastric gastric and duodenal ulcer. It is not known whether exogenous factors are involved in Hp infection. The aim of this prospective study, performed on 286 consecutive subjects undergoing upper gastrointestinal endoscopy, was to evaluate the influence of smoking and alcohol consumption on Hp infection. For each patient the following parameters were taken into account: sex, age, smoking (no, < 10, > 10 cig/day) and alcohol (no, < 40, > 40 g ethanol/day) intake, antiulcer therapy (no, H2-blockers, omeprazole, sucralfate), presence of gastric or duodenal ulcer (DU). At least two biopsies from both the antrum and the corpus were obtained for histological examination; the gastritis was classified and scored according to the Sydney system.

STATISTICS

chi-squared test (corrected), Fisher's exact test.

RESULTS

43 pts had Hp (27M, 16F; age 57.8 yrs, range 23-91), 47 Hp ++ (25M, 22F; age 61.1, range 19-86), 81 Hp + (48H, 33F; age 56, range 16-84), 115 Hp- (75M, 40F; age 57.8, range 19-84). Hp infection was found to be significantly correlated with presence of ulcer symptoms, gastritis, lymphoid follicles and, among DU patients, with active DU. The other parameters considered did not influence Hp infection. In conclusion smoking habits and alcohol consumption do not affect Hp infection of the stomach.

Markers of slow-healing peptic ulcer in the elderly. A study on 1,052 ranitidine-treated patients

Little is known about ulcer outcome in the elderly. The aims of the present paper were to establish whether risk factors of slow-healing peptic ulcer can be demonstrated in the elderly and whether clinical differences exist between ulcer patients whose age of onset of the disease was before or after 65 years old. The short-term, open study, involving 1052 elderly patients (over 65 years) in 37 gastroenterology centers throughout Italy aimed to compare two schedules of ranitidine treatment: 150 mg twice daily versus 300 mg at bedtime. As nonsignificant differences were found between these two schedules, the sample was considered as a whole. It included 319 gastric ulcer (GU) patients, 699 duodenal ulcer (DU) patients, and 34 concomitant GU and DU cases. Ninety-three patients dropped out of the trial; 79/294 GU, 138/635 DU, and 10/30 GU+DU were found still unhealed after four weeks and 20 GU, 15 DU, and 1 GU+DU remained so after eight weeks. Statistical analysis was performed using likelihood-ratio and Pearson's chi-squared tests and Cox's models. Univariate analysis showed that the indicators of slow-healing GU were ulcer size (P = 0.002) and persisting ulcer symptoms (P = 0.0001); indicators of slow-healing DU were ulcer size (P = 0.0001), persisting ulcer symptoms (P = 0.0001), alcohol (P = 0.0003), and NSAID (P = 0.0088) consumption. DU patients taking antiplatelet drugs have significantly better results after four weeks and worse results after eight weeks (P = 0.0352).(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric bicarbonate secretion in high-relapsing, smoking duodenal ulcer patients

Gastric bicarbonate secretion has been evaluated by Feldman's method in 48 duodenal-ulcer patients. The relationship between smoking, clinical ulcer outcome (healing and recurrence) and bicarbonate secretion has been analysed. Heavy smokers secreted higher bicarbonate ions than did non-smokers. High-relapsing patients produced lower bicarbonate output. These preliminary data suggest that an impaired gastric bicarbonate secretion is associated with smoking, a well-known ulcer-associated factor; further-more, it may single out high-relapsing duodenal ulcer patients.

Effects of H2 blockers and omeprazole on peptic secretion: a prospective, randomized study in duodenal ulcer subjects

Aim of the present study has been to investigate the possible modifications of peptic secretion after a period with H2 blockers and omeprazole, evaluating in the same patient pepsinogen group A levels in gastric mucosa and pepsin in gastric juice. 54 active duodenal ulcer were studied: during an upper gastrointestinal endoscopy a sample of gastric juice and one fundus biopsy were taken before and after four weeks 300 mg/daily ranitidine (23 patients), 40 mg/daily famotidine (7 patients), 300 mg/daily nizatidine (12 patients) therapy and 40 mg/daily omeprazole (12 patients) therapy.

RESULTS

H2-blockers and omeprazole treatment determines a non statistically significant decrease of pepsin in gastric juice and in pepsinogen group A in gastric mucosa.

[Alcohol-dependent mast cell activation in ulcer]

Numerous studies have shown that alcohol causes both acute and chronic damage to gastroduodenal mucosa. The methods of damage differ however, and experimental studies in animals have shown that the degranulation of mast cells in gastric mucosa causes acute hemorrhagic lesions after the consumption of alcohol. It is not known whether this mechanism also operates in man. The aim of the present study was therefore to evaluate whether there is a correlation between mast-cell activation, determined by assaying tryptase levels in gastric mucosa, and the consumption of alcohol in patients with ulcerative diseases. Thirty-one patients with cicatrized ulcerative lesions (13 gastric ulcers, 18 duodenal ulcers) were included in the study. Biopsies at the level of the gastric fundus and antrum and the duodenal bulb were performed in all patients to determine tryptase levels. Biopsy material was frozen and subsequently homogenized; the enzyme was assayed in the supernatant using a radioimmunometric method. The mean daily alcohol consumption was calculated in clinical terms for each patient over the past 5 years and patients were subdivided into non-drinkers and moderate (< 60 g alcohol/day) and excessive (> 60 g alcohol/day) drinkers. It was found that tryptase concentrations were higher in the fundus compared to the gastric antrum and duodenal bulb, irrespective of alcohol consumption both in patients with gastric ulcer and duodenal ulcer. The importance of mast cells in provoking alcohol-dependent damage was studied at a gastric level. Alcohol leads to their degranulation and therefore contributes to the formation of gastric lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Esaprazole effect on acid, peptic and alkaline secretion in duodenal ulcer patients

To study the effect of Esaprazole, a new antiulcer drug, on acid, peptic and alkaline secretion a modified gastric acid test was performed in 18 duodenal ulcer patients. Pentagastrin was administered as bolus 30' and 75' after the beginning of the test, followed by Esaprazole 300 mg i.v. at 90'. Gastric juice was collected every 15' for determination of: total volume, volume of non parietal secretion, acid, bicarbonate and pepsin output. Serum pepsinogen group I was determined by radioimmunoassay. Esaprazole had a significant inhibitory effect on the total volume of gastric secretion and on volume of non parietal secretion. Pepsin output and serum pepsinogen group I were not affected by Esaprazole, while bicarbonate secretion was reduced. Antiulcer activity of Esaprazole seems to be due to the reduction of total volume of gastric secretion.

Individualized treatment of duodenal ulcer disease. A pilot study

A substantial number of duodenal ulcer (DU) patients relapse despite maintenance treatment with antisecretory drugs. The influence of certain risk factors and the heterogeneity of the disease could explain such behavior. The present prospective, open study compares the one-year clinical outcome (with upper GI endoscopy at the beginning of the study, at 6 and 12 months, and at every symptomatic relapse) of four groups of DU subjects, consecutively recruited from December 1987 to December 1988, separated in accordance with whether or not a bleeding DU episode had previously occurred, and whether or not an evaluation of gastric acid secretion had been made. Thus, Group I (17 patients; 12 males, 5 females) included heavy smokers and/or gastric acid hypersecretors; Group II (13 patients; 12 males, 1 female) non- or light smokers non-hypersecretors; Group III (34 patients; 22 males, 12 females) subjects with unknown gastric acid secretion; Group IV (33 patients; 30 males, 3 females) previously bleeding DU patients. All patients, except those in Group II (who were left untreated), were given ranitidine 150 mg at bedtime. The outcome of Groups I+II was compared with that of Group III (considered as "standard therapy") and Group IV patients, the latter presumably with a low risk of relapse because of the low prevalence of smokers.

STATISTICS

Chi-square test, Fisher's exact test, analysis of variance and the logrank test. During the year of follow-up, 27/97 patients withdrew from the study, while 18 had a DU relapse (remission rates 82.1% +/- 7.4% in Groups I+II, 70.5% +/- 8.4% in Group III, 87.5% +/- 5.9% in Group IV).(ABSTRACT TRUNCATED AT 250 WORDS)

The natural history of duodenal ulcer disease

With a view to describing the natural history of duodenal ulcer, currently linked with powerful and widely used drugs, we retrospectively reviewed all patients followed-up at our unit between 1978 and 1989. All DU subjects with at least 5 years of clinical-endoscopic follow-up were admitted to the study. Concomitant gastric ulcer, previous gastrointestinal surgery and treatment other than with H2-blockers (where necessary) were considered exclusion criteria. Forty-four patients (35 males, 9 females, mean age 44.5) proved eligible for this study. At monthly intervals in the patients' history of ulcer disease (starting from a baseline month 0 when ulcer symptoms first appeared), we compared all cases in which the duration of disease coincided, i.e. for each month of the clinical course of the ulcer there was a certain number of patients at the same point in time; patients' histories coincided variously over a period ranging from 0 to 15 years. We considered endoscopically-diagnosed relapses (both symptomatic and asymptomatic) and hemorrhages as marker events for the activity of DU disease. A year-by-year duodenal ulcer activity rate was obtained for both treated and untreated subjects, as follows: No. of events/mean No. of patients followed-up per month x 100. Fisher's exact test and multivariate analysis (stepwise logistic regression) were used to investigate risk factors of poor outcome. We found that the years between the 1st and 5th and between the 10th and 15th from the onset of duodenal ulcer disease had higher peaks of activity, mostly in untreated subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Peptic ulcer in cirrhotic patients: a short- and long-term study with antisecretory drugs

The clinical course of gastric and duodenal ulcer and the efficacy of H2 blockers in ulcer healing and the prevention of relapse in cirrhotic liver patients were studied. Seventy-four cirrhotic patients with endoscopically proven acute gastric ulcer (30), duodenal ulcer (34) or a combination of both gastric and duodenal ulcers (10) were treated for six weeks with either Cimetidine 800 mg/daily (27) or Ranitidine 300 mg/daily (47). Of the 77 patients 49 (66.2%) were healed after therapy, 11 cases (14.8%) remained unhealed even after two additional cycles of the same treatment and four were lost to follow-up. After an endoscopically proven healing of the active ulcer, 51 patients took part in the long-term study over a mean period of 24 months: 21.5% of the 27 patients were treated with a maintenance dosage of H2 blockers and 29.1% of the 24 patients left without therapy relapsed during the first year. We conclude that the ulcer healing rate with H2 blockers is lower and the relapse rate higher in cirrhotic patients than in the general ulcer population.

[Ulcer and hepatic cirrhosis. Epidemiologic and clinical correlations]

Peptic ulcer has been reported with increased frequency in patients with liver cirrhosis, its prevalence ranging form 5% to 20%. The aim of the present study is twofold: 1) to define the frequency of peptic ulcer in chronic liver disease in a large sample of cirrhotic patients, 2) to investigate the epidemiological and clinical features of a group of subjects affected by both peptic ulcer and liver cirrhosis. Two years of admission have been retrospectively investigated to define the frequency of peptic ulcer in chronic liver disease. In 237 subjects affected by both cirrhosis and peptic ulcer, epidemiological and clinical data were collected. Peptic ulcer was present in 16% of cirrhotic patients. There were no differences between ulcer subjects who drank and those did not. A linear positive correlation between smoking habit and frequency of ulcer disease has been found in the words. A positive history for peptic ulcer was described in a little subgroup of the studied sample, suggesting a low importance of the genetic factor in the pathophysiological pattern of ulcer disease in chronic hepatitis.

[Cigarette smoking and group I pepsinogen levels. Study in a normal population]

Several studies have shown an influence of cigarette smoking on serum pepsinogen group I (PGI) levels in duodenal ulcer patients and in control subjects. The elevation of PGI in smokers has just been interpreted as reflecting some degree of smoking-induced inflammation of the gastric mucosa. We have determined fasting serum PGI by radioimmunoassay in 163 healthy subjects investigated by a survey conducted on a sample population of an urban area in the North-East of Italy by means of a random selection based on the public registers of home addresses. The data reported confirmed that PGI levels are increased by smoking in a healthy population. The main contribution of this study consists in demonstrating in a non-selected population an increase of the only parameter up to date claimed to be a possible serological predictive index for ulcer disease.