What is the true clinical relevance of Simkania negevensis and other emerging Chlamydiales members?

Waddlia chondrophila and Simkania negevensis are emerging Chlamydia-related bacteria. Similar to the pathogenic organisms Chlamydia pneumoniae and Chlamydia trachomatis, these emerging bacteria are implicated in human genital infections and respiratory diseases. We used a screening strategy based on a newly developed S. negevensis-specific quantitative real-time PCR (qPCR) and a pan-Chlamydiales qPCR. We could not detect S. negevensis in 458 respiratory, genitourinary, cardiac and hepatic samples tested. One urethral swab was positive for W. chondrophila. We observed a low prevalence of Chlamydiales in respiratory samples (1/200, 0.5%), which suggests that C. pneumoniae is an uncommon respiratory pathogen. Furthermore, we screened 414 human serum samples from Switzerland, England and Israel and observed a low prevalence (<1%) of exposure to S. negevensis. Conversely, humans were commonly exposed to W. chondrophila, with seroprevalences ranging from 8.6% to 32.5%. S. negevensis is not a clinically relevant pathogen, but further research investigating the role of W. chondrophila is needed.

Prevalence and diversity of Chlamydiales and other amoeba-resisting bacteria in domestic drinking water systems.

A growing number of human infections incriminate environmental bacteria that have evolved virulent mechanisms to resist amoebae and use them as a replicative niche. These bacteria are designated amoeba-resisting bacteria (ARB). Despite the isolation of these ARB in various human clinical samples, the possible source of infection remains undetermined in most cases. However, it is known that the ARB Legionella pneumophila, for instance, causes a respiratory infection in susceptible hosts after inhalation of contaminated water aerosols from various sources. The Chlamydiales order contains many ARB, such as Parachlamydia acanthamoebae or Simkania negevensis, previously implicated in human respiratory infections with no identified contamination sources. We thus investigated whether domestic water systems are a potential source of transmission of these Chlamydiales to humans by using amoebal culture and molecular methods. Other important ARB such as mycobacteria and Legionella were also investigated, as were their possible amoebal hosts. This work reports for the first time a very high prevalence and diversity of Chlamydiales in drinking water, being detected in 35 (72.9%) of 48 investigated domestic water systems, with members of the Parachlamydiaceae family being dominantly detected. Furthermore, various Legionella and mycobacteria species were also recovered, some species of which are known to be causal agents of human infections.

Undressing of Waddlia chondrophila to enrich its outer membrane proteins to develop a new species-specific ELISA.

Waddlia chondrophila, an obligate intracellular bacterium of the Chlamydiales order, is considered as an agent of bovine abortion and a likely cause of miscarriage in humans. Its role in respiratory diseases was questioned after the detection of its DNA in clinical samples taken from patients suffering from pneumonia or bronchiolitis. To better define the role of Waddlia in both miscarriage and pneumonia, a tool allowing large-scale serological investigations of Waddlia seropositivity is needed. Therefore, enriched outer membrane proteins of W. chondrophila were used as antigens to develop a specific ELISA. After thorough analytical optimization, the ELISA was validated by comparison with micro-immunofluorescence and it showed a sensitivity above 85% with 100% specificity. The ELISA was subsequently applied to human sera to specify the role of W. chondrophila in pneumonia. Overall, 3.6% of children showed antibody reactivity against W. chondrophila but no significant difference was observed between children with and without pneumonia. Proteomic analyses were then performed using mass spectrometry, highlighting members of the outer membrane protein family as the dominant proteins. The major Waddlia putative immunogenic proteins were identified by immunoblot using positive and negative human sera. The new ELISA represents an efficient tool with high throughput applications. Although no association with pneumonia and Waddlia seropositivity was observed, this ELISA could be used to specify the role of W. chondrophila in miscarriage and in other diseases.

Impact of on-site initiation visits on patient recruitment and data quality in a randomized trial of adjuvant chemotherapy for breast cancer.

PURPOSE: To provide empirical evidence on the impact of on-site initiation visits on the following outcomes: patient recruitment, quantity and quality of data submitted to the trial coordinating office, and patients' follow-up time. PATIENTS AND METHODS: This methodological study was performed as part of a randomized trial comparing two combination chemotherapies for adjuvant treatment of breast cancer. Centers participating to the trial were randomized to either receive systematic on-site visits (Visited group), or not (Non-visited group). RESULTS: The study was terminated after two years, while the main randomized trial continued. Of the 135 centers that had expressed an interest in the trial, only 69 randomized at least one patient (35/68 in the Visited group, 34/67 in the Non-visited group). Almost two-thirds of the patients were entered by 17 centers (10 in the Visited group, seven in the Non-visited group) that accrued more than 10 patients each. None of the prespecified outcomes favored the group of centers submitted to on-site initiation visits (ie, mean number of queries par patient: 6.1 +/- 9.7 versus 5.4 +/- 6.4, respectively for the Visited and Non-visited groups). Spontaneous transmittal of case report forms, although required by protocol, was low in both randomized groups (mean number of pages per patient: 1.5 +/- 2.0 versus 2.1 +/- 2.3, respectively), with investigators submitting about one-third of the expected forms on time (29% and 39%, respectively). LIMITATIONS: This study could not evaluate the impact of repeated on-site visits on clinical outcomes. CONCLUSION: Systematic on-site initiation visits did not contribute significantly to this clinical trial.

Prevalence of methicillin-resistant Staphylococcus aureus carriage at the time of admission in two acute geriatric wards.

Studies on methicillin-resistant Staphylococcus aureus (MRSA) in the elderly have been concerned with patients hospitalized in nursing homes or long-term care facilities. Our objective was to estimate the prevalence of MRSA at the time of admission in two acute geriatric wards with high endemic MRSA incidence in a French teaching hospital. A prospective screening of MRSA carriers was conducted by swabbing nares and wounds during five weeks for all patients on the day of admission. For each patient demographic, administrative, clinical and therapeutic data were recorded. Their associations with MRSA carriage were studied by logistic regression analysis. On the day of admission, 35 patients (14.6%) were MRSA carriers. Variables independently associated with carriage were hospitalization within the six last months (OR = 4.64; P < 0.001) and the existence of wounds or bedsores (OR = 2.864; P = 0.02). The high prevalence of MRSA carriage at the time of admission could explain in part the high incidence of MRSA in these wards. A systematic selective screening targeted on patients with high risk of carriage should be helpful to implement barrier precautions and reduce cross-transmission.

Effect of vocal effort on spectral properties of vowels.

The effects of variations in vocal effort corresponding to common conversation situations on spectral properties of vowels were investigated. A database in which three degrees of vocal effort were suggested to the speakers by varying the distance to their interlocutor in three steps (close--0.4 m, normal--1.5 m, and far--6 m) was recorded. The speech materials consisted of isolated French vowels, uttered by ten naive speakers in a quiet furnished room. Manual measurements of fundamental frequency F0, frequencies, and amplitudes of the first three formants (F1, F2, F3, A1, A2, and A3), and on total amplitude were carried out. The speech materials were perceptually validated in three respects: identity of the vowel, gender of the speaker, and vocal effort. Results indicated that the speech materials were appropriate for the study. Acoustic analysis showed that F0 and F1 were highly correlated with vocal effort and varied at rates close to 5 Hz/dB for F0 and 3.5 Hz/dB for F1. Statistically F2 and F3 did not vary significantly with vocal effort. Formant amplitudes A1, A2, and A3 increased significantly; The amplitudes in the high-frequency range increased more than those in the lower part of the spectrum, revealing a change in spectral tilt. On the average, when the overall amplitude is increased by 10 dB, A1, A2, and A3 are increased by 11, 12.4, and 13 dB, respectively. Using "auditory" dimensions, such as the F1-F0 difference, and a "spectral center of gravity" between adjacent formants for representing vowel features did not reveal a better constancy of these parameters with respect to the variations of vocal effort and speaker. Thus a global view is evoked, in which all of the aspects of the signal should be processed simultaneously.

Biochemical effects of calcium supplementation in postmenopausal women: influence of dietary calcium intake.

We studied the biochemical effects of calcium supplementation during a 2-mo course in postmenopausal women (x +/- SD: 64 +/- 5 y of age and 14.5 +/- 6.7 y since menopause). The effects on calcium homeostasis and bone remodeling were assessed after 1 and 2 mo of daily administration of either calcium carbonate (1200 mg elemental Ca/d, n = 60) or a placebo (n = 56). The daily dietary calcium intake assessed before the beginning of calcium supplementation was 786 mg/d. We found a significant inverse relation between baseline intact parathyroid hormone (iPTH) and dietary calcium intake before supplementation (r = -0.48, P = 0.0002). A significant increase in urinary excretion of pyridinoline was observed when the dietary calcium intake was lower than the median value. Calcium supplementation resulted in a significant increase in 24-h urinary calcium (39%, P < 0.02) and a significant reduction of bone alkaline phosphatase at 2 mo and of all bone-resorption markers (hydroxyproline, pyridinoline, and deoxypyridinoline) at I and 2 mo without significant changes in 44-68 PTH fragments or iPTH concentrations. When the dietary calcium intake was low (mean +/- SD: 576 +/- 142 mg/d), calcium supplementation was responsible for a greater increase in urinary calcium excretion and a greater decrease in markers of bone turnover. The greatest variations were observed for deoxypyridinoline at 1 and 2 mo (-18.5%, P < 0.05) and for pyridinoline at 1 mo (-16.3%, P < 0.01). Two months of calcium supplementation in postmenopausal women was efficient in reducing markers of bone turnover, with a greater effect in women with a low dietary calcium intake.

Normal left ventricular volumes and ejection fraction: assessment with quantitative digital cardioangiography.

The aim of this study was to assess the accuracy and precision of a digital angiography system, the General Electric DX system, as compared to conventional left ventricular cineangiography. After a phantom study, sixty patients with normal coronary arteries and normal left ventricles (LV) were studied. The LV contours were manually traced from raw or subtracted digital runs and from the cine films in an independent manner. A regression formula was used to adjust the DX derived data to the cine film results (Vcorrected = 0.693 Vmeasured +8.65 ml). There was an excellent correlation between the two methods in the end-diastolic volume index (r = 0.97, sd = 4.2 ml/m2), the end-systolic volume index (r = 0.95, sd = 2.7 ml/m2), the stroke volume index (r = 0.93, sd = 4.1 ml/m2), and the ejection fraction (r = 0.85, sd = 3.45%). We conclude that manual tracing of LV contours from either raw or subtracted digital images provides reliable and accurate measurement of LV volume and ejection fraction.

[Optimization of coronary angiographic views. Qualitative and quantitative evaluation of a new system]. / Optimisation des vues angiographiques coronaires. Evaluation qualitative et quantitative d'une nouvelle fonctionnalité.

A coronary angiographic view is said to be "optimal" when the directing radius of the X-ray beam is perpendicular to the long axis of a stenosis. The object was to fulfill two criteria: 1) the accurate calculation of the spatial orientation of the stenosis to obtain the optimal position, 2) rapid and optimal positioning of the angiographic material with easy rotation around the axis of the stenosis. Two combined solutions were proposed:the Advantx L/C (GE Medical systems) angiocardiographic system with three motorised axes of rotation and a specific software. This software takes into account two longitudinal axes of the stenosis traced by the operator in two conventional incidences and then determines the angles of optimal positioning (accuracy +/-5 degrees). During 97 consecutive coronary angiograms, the software was used in 23 cases (24%) and judged to be useful in 16 cases (70%). In 2 of the 23 cases (8%) the mechanical angles calculated could not be used, the incidences being incompatible with the patient's position. During the angiograms, the best two images of stenosis (one conventional, one optimal) were retained to form a pair of images. Eight observers analysed 37 pairs of images shown side by side. 65% of the images selected from each pair as being the best descriptive appearance of the stenosis came from the optimised system. During quantitative analysis, only the length of stenosis differed statistically between the two modes of acquisition (1.26 +/- 0.36 mm; p = 0.0014). This system is useful during coronary angiography for providing optimal views of stenosis free from any geometric distorsion and without superimposition of adjacent branches.

Parameters that influence accuracy and precision of quantitative coronary arteriography.

The limited resolution of any imaging system causes edge blurring of objects acquired with X-ray. In digital angiography, this effect combined with noise gives rise to systematic and random errors in the determination of vessel dimensions. The influence of bandwidth limitation on the estimation of tube diameter is established by a theoretical approach: it leads to over and underestimations of catheter and vessel diameter dimensions. Therefore a correction is proposed that counterbalances the point spread function (PSF) offset. The residual inaccuracy and the variability of measurement of phantom tubes are analyzed and evaluated in controlled conditions. Some of the parameters which govern their extent are identified: field-of-view, catheter size, concentration of contrast agent.

Can we optimize our angiographic views every time? Qualitative and quantitative evaluation of a new functionality.

RATIONALE AND OBJECTIVES: For determining the optimum angulations of the x-ray beam with respect to the vascular morphology of a given patient, the authors present a solution combining a single-plane angiographic system and a dedicated procedure. METHODS: The clinical evaluation of the vessel profiling acquisitions focuses on qualitative appraisal and quantitative analysis of conventional and optimum projections. RESULTS: The qualitative evaluation demonstrates the pitfall for an operator to discern optimum from conventional projections. The 70% of preferences for vessel profiling bear witness to the constraints imposed occasionally by the optimum angulations, which may be impracticable for various reasons. However, vessel profiling yields lesions inspection at an optimum view, free of geometric foreshortening. Moreover, there is less risk of superimposition with other branches. From a quantitative standpoint, vessel profiling unveils the lesion with a length significantly longer than in conventional view. CONCLUSIONS: Vessel profiling offers a qualitative optimization of angiographic images and more exact quantitative analysis.

[Seroprevalence of viral hepatitis A in at the Amiens University Hospital]. / Séroprévalence de l'hépatite virale A au CHU d'Amiens.

OBJECTIVES AND METHODS: The epidemiology of viral hepatitis A has been evolved in the past few years, resulting in an increasing number of people without immunity to this virus. Health care workers are usually considered to be a group at risk of contamination by hepatitis A. A sero-epidemiologic study was performed in 525 members of the Pediatry, Gastroenterology, Internal medicine, Digestive radiology, kitchen and maintenance department staffs in the Amiens University Hospital. The aim of this study was to describe the epidemiology of hepatitis A and to estimate the level of occupational hazard it represents in the hospital. RESULTS: Age, low education level, country of origin in an endemic region and more than 2 siblings or children were significantly associated with the presence of anti-HAV antibodies. The prevalence of 50% was similar to that observed in other hospitals, but lower than that found in the general population. Seroprevalence was not higher in departments exposed to stools (Pediatry, Digestive endoscopy and laboratories) than in others. A higher rate of seroprevalence was observed in kitchen and maintenance staffs than in medical, laboratory and Radiology staffs, in Internal medicine than in the Gastroenterology Department, and in the laboratory than in Radiology Department. These differences disappeared after adjustment for extraprofessional parameters which appeared to be most important for hepatitis A epidemiology. CONCLUSIONS: The hospital occupational hazard for hepatitis A virus did not seem higher than that observed in the general population.

Interest of gallium hepatic scintigraphy in hepatic abscess: a case study.

The interest of 67Ga-citrate scintigraphy in the diagnosis of hepatic abscess is illustrated by a study of a 56-year-old man, who was admitted to the hospital for upper abdominal pain. Ultrasound (US) and X-ray CT scan examinations suggested the presence of a liquid mass, the origin of which was unclear. Liver scintigraphy with 67Ga-citrate disclosed a lacunar zone surrounded by a rim of increased uptake, an image strongly suggestive of abscess or necrotic tumor. A US-guided needle aspiration of the hepatic mass yielded a purulent liquid, from which Streptococcus milleri were grown. This observation suggests that, despite the development of other diagnostic procedures, hepatic gallium scintigraphy still remains sometimes useful for the investigation of poorly characterized hepatic masses.

Real-time distortionless high-factor compression scheme.

Nowadays, digital subtraction angiography systems must be able to sustain real-time acquisition (30 frames per second) of 512 x 512 x 8 bit images and store several sequences of such images on low cost and general-purpose mass memories. Concretely, that means a 7.8 Mbytes per second rate and about 780 Mbytes disk space to hold a 100-s cardiac examination. To fulfill these requirements at competitive cost, a distortionless compressor/decompressor system can be designed: during acquisition, the real-time compressor transforms the input images into a lower quantity of coded information through a predictive coder and a variable-length Huffman code. The process is fully reversible because during review, the real-time decompressor exactly recovers the acquired images from the stored compressed data. Test results on many raw images demonstrate that real-time compression is feasible and takes place with absolutely no loss of information. The designed system indifferently works on 512 or 1024 formats, and 256 or 1024 gray levels.

Colonic angiodysplasia. Follow-up of patients after endoscopic treatment for bleeding lesions.

Endoscopic electrocoagulation or photocoagulation is now the method of choice for treating colonic angiodysplasia. Follow-up of such patients has not been extensive. The authors report 26 patients with typical and symptomatic lesions who have been treated endoscopically. Follow-up (mean duration, 29.3 months) revealed that 21 patients remained symptom-free after a single procedure. Two patients needed a second procedure before being considered cured. In two others, the need for transfusions was lessened considerably after treatment. The last patient died of terminal cardiac failure. No complications occurred during treatment. Endoscopic treatment is a safe and efficient method for treating bleeding colonic angiodysplasia.

[Risk of recurrence of colorectal polyps following endoscopic resection]. / Risques de récidive des polypes colo-rectaux après résection endoscopique.

From 1976 to 1985, 1063 patients (614 men, 449 women, mean age: 63 years) underwent the excision of 1887 adenomatous or villous colonic or rectal polyps. Regular controls by barium enema or total colonoscopy have been proposed to these patients. A first control, performed in 715 patients (67%) after a mean of 27 months, revealed the presence of polyps in 162 of them (23%). A second control performed in 331 of the 535 controllable patients (61%), was positive (presence of polyps) in 82 of them (24%). During the follow-up period, 16 cancerous lesions were observed. Comparing the initial status of the patients with the results of the different controls, 3 risk factors for developing a new colonic or rectal polyp emerged: 1) male sex, 2) the presence of multiple lesions at the initial examination, 3) a recurrence at a previous control.

[Villous tumors of the rectum. Endoscopic treatment using monopolar coagulation]. / Tumeurs villeuses du rectum. Traitement endoscopique par coagulation monopolaire.

UNLABELLED: Many methods are used to treat villous adenomas of the rectum. The best choice between these methods is not well established. Ninety-six patients (47 men, 49 women) treated with endoscopic monopolar coagulation were studied. The mean age was 66 years (range 37-84). The lesions were located in the lower third of the rectum in 27 cases, in the middle third in 35 cases and in the upper third in 34 cases. The circumferential extent of the lesions was less than 1/3 in 70 cases (C1), greater than 1/3-less than 2/3 in 23 (C2) and greater than 2/3 in 3 cases (C3). The follow-up of 2 patients (1 C1 and 1 C2) was not sufficient. Healing was not achieved in 8 of the 94 evaluated patients. Eighty-six patients were totally healed: 68 C1, 16 C2 and 2 C3 with a follow-up of 2 to 132 months (median: 36 months). The treatment was achieved after a mean of 2.1 sessions per patient (range 1-13). CONCLUSIONS: 1) Endoscopic monopolar coagulation of villous adenoma of the rectum is a simple and efficient treatment. 2) This method is complementary to surgery for extensive lesions (C3).