Rheology of human faeces and pathophysiology of defaecation.

BACKGROUND: Rectal evacuation involves multiple mechanisms that are not completely understood. The aim of this study was to quantify the rheologic property, i.e., yield stress, which governs the ease of deformation of a range of faeces of differing consistency and understand its influence on the pathophysiology of defaecation. METHODS: Yield stresses of faeces of differing consistencies and Bristol scores were determined by the Vane test. We then explored the effects of this property on ease of defecation using a simple static model of the recto-anal junction based on the laws of flow for yield stress pastes and checked the conclusions by X-ray defaecography experience. RESULTS: The yield stress of faeces increased exponentially with their solid content, from 20 to 8000 Pa. The static model of the recto-anal junction showed that evacuation of faeces of normal consistency and yield stress is possible with moderate dilatation of the anal canal, whilst the evacuation of faeces with higher yield stress requires greater dilatation of the anal canal. X-ray defaecography showed that such increases occurred in vivo. CONCLUSIONS: The diameter of the recto-anal junction is increased to enable the passage of feces with high yield stress. The finite limits to such dilation likely contribute to fecal impaction. Hence, difficulties in defaecation may result either from unduly high yield stress or pathologies of reflex recto-anal dilatation or a combination of the two.

Short term memory properties of sensory neural architectures.

A functional role of the cerebral cortex is to form and hold representations of the sensory world for behavioral purposes. This is achieved by a sheet of neurons, organized in modules called cortical columns, that receives inputs in a peculiar manner, with only a few neurons driven by sensory inputs through thalamic projections, and a vast majority of neurons receiving mainly cortical inputs. How should cortical modules be organized, with respect to sensory inputs, in order for the cortex to efficiently hold sensory representations in memory? To address this question we investigate the memory performance of trees of recurrent networks (TRN) that are composed of recurrent networks, modeling cortical columns, connected with each others through a tree-shaped feed-forward backbone of connections, with sensory stimuli injected at the root of the tree. On these sensory architectures two types of short-term memory (STM) mechanisms can be implemented, STM via transient dynamics on the feed-forward tree, and STM via reverberating activity on the recurrent connectivity inside modules. We derive equations describing the dynamics of such networks, which allow us to thoroughly explore the space of possible architectures and quantify their memory performance. By varying the divergence ratio of the tree, we show that serial architectures, where sensory inputs are successively processed in different modules, are better suited to implement STM via transient dynamics, while parallel architectures, where sensory inputs are simultaneously processed by all modules, are better suited to implement STM via reverberating dynamics.

Dynamic cystocolpoproctography is superior to functional pelvic MRI in the diagnosis of posterior pelvic floor disorders: results of a prospective study.

AIM: The accuracy of dynamic cystocolpoproctography (DCP) and dynamic MRI were compared in diagnosing posterior pelvic floor disorders. METHOD: Fifty consecutive female patients (mean age 51 years) complaining of posterior compartment pelvic floor disorder and referred to a tertiary centre entered the prospective study. The Institutional Review Board stated that informed consent from the patients was not necessary for this study. Patients underwent a DCP and a supine functional MRI by two different radiologists. Assessment of radiological examinations was prospective and blind. All patients underwent surgery that led to the final diagnosis. Agreement between the operative diagnosis and the diagnoses following DCP and MRI was assessed using the weighted kappa statistic. A matched-pairs McNemar's test was applied to demonstrate whether or not one radiological method was superior to the other. RESULTS: Full-thickness rectal prolapse was best diagnosed by clinical examination. Internal rectal prolapse and peritoneocele were best diagnosed by DCP. A better agreement with the operative diagnosis, which is not true superiority, was observed for DCP compared with functional pelvic MRI for full-thickness rectal prolapse, internal rectal prolapse and peritoneocele. There was no significant difference between DCP and functional pelvic MRI in the diagnosis of internal rectal prolapse (P = 0.125) or peritoneocele (P = 0.10). CONCLUSION: As full-thickness rectal prolapse, internal rectal prolapse and peritoneocele might be missed by functional pelvic MRI, there should still be a place for DCP in particular cases where the clinical diagnosis is not clear in women with symptomatic posterior pelvic floor disorders.

[Lung cancer screening with low-dose thoracic CT-scan in the Somme area]. / Dépistage des cancers bronchopulmonaires par tomodensitométrie thoracique à faible dose dans la Somme.

RATIONALE: This feasibility trial proposes to set up in the department of the Somme an annual screening for lung cancer with low-dose thoracic CT. It responds to the first objective of the third cancer plan and follows the publication of the results of the National Lung Screening Trial in 2011. METHODS: The method of this study is to use the existing networks among and between healthcare professionals and the departmental cancer screening structure. The inclusion criteria will be those of the National Lung Screening Trial. Screening will be proposed by treating physicians and chest physicians. The CT-scan will be performed in radiological centers that adhere to the good practice charter for low radiation scanning. A copy of CT results will be sent to the departmental structure of cancer screening (ADEMA80) which will ensure traceability and will perform statistical analysis. The study received funding from the Agence régionale de santé de la Picardie and la ligue contre le cancer. EXPECTED RESULTS: The primary endpoints of this screening will be the number of cancers diagnosed and the survival of the patients. The follow-up of positive examinations, delays in management and the level of participation will also be assessed.

Therapeutic management of laryngeal cancer. Results of a study of 356 patients from the Cancer Registry of the Somme, France.

CONCLUSIONS: The global survival rate was low compared to those reported in the literature, in which the analyzed populations were selected according to the tumor stage or treatment. This study should be prolonged and should also involve other cancer registries in France in order to increase the number of patients and to analyze tumors of comparable stage and therapeutic management. OBJECTIVE: To analyze the survival rate of a non-selected laryngeal cancer population from the Cancer Registry of the Somme, a French region. MATERIAL AND METHODS: A total of 356 patients were included in a retrospective study covering the period 1987-1997. Survival and prognostic factors were analyzed. Statistical analysis was performed using the Kaplan-Meier method, the Cox model and the chi2 test. RESULTS: The 5-year global survival rate was 42% for males and 55% for females. Tumor localization, T, N and M stages and surgery were found to be significant prognostic factors. Sex and age were not statistically significant factors. For stage I tumors, surgery alone gave better results than radiotherapy alone in terms of global survival. No difference occurred in terms of local recurrence. A similar comparison was not possible for stage II-IV tumors owing to the small number of cases.

Expression of vascular endothelial growth factor-b in human astrocytoma.

Growth of human malignant gliomas is stringently dependent on an angiogenic process that probably involves vascular endothelial growth factor (VEGF). Expressions of mRNA coding for the different forms of VEGF were analyzed in surgical specimens from human astrocytomas. Low levels of placental growth factor (PGF) and VEGFC mRNA were observed in polymerase chain reaction, but not in Northern blot experiments. VEGF mRNA was found in some but not all grade and grade IV astrocytomas. VEGFB mRNA was observed in all tissue samples analyzed irrespective of the tumor grade. A new splice variant of VEGFB (VEGFB155) that lacks exons 5 and 6 is described. Expressions of VEGF mRNA in cultured glioblastomas cells were upregulated by hypoxia, but the sensitivity of the cells to hypoxia was reduced as compared with normal rat astrocytes. VEGF expression was depressed by dexamethasone. Expressions of VEGFB mRNA were affected neither by hypoxia nor by dexamethasone. The results indicate a coexpression of VEGF mRNA and VEGFB mRNA in human astrocytomas. Expression of VEGFB is markedly different from that of VEGF. Possible roles of VEGFB as a cofactor for hypoxia-induced angiogenesis in human astrocytomas are discussed.

Tropane alkaloid production by hairy roots of Atropa belladonna obtained after transformation with Agrobacterium rhizogenes 15834 and Agrobacterium tumefaciens containing rol A, B, C genes only.

Atropa belladonna leaf disks were infected by a wild strain Agrobacterium rhizogenes 15834 harboring the Ri-TL-DNA and by a disarmed Agrobacterium tumefaciens strain harboring a construction with only rol ABC and npt II genes. Thirteen root lines were established and examined for their growth rate and alkaloid productivity to evaluate the possible role of rol genes in morphological differentiation and in tropane alkaloid formation. A great diversity has been observed in the growth rate of these 13 root lines. The root biomass increased up to 75 times. The total alkaloid contents were similar in the root lines obtained by infection with A. rhizogenes 15834 and A. tumefaciens rol ABC. The last ones accumulated between 4 (1.1 mg g(-1) DW) and 27 (8 mg g(-1) DW) times more alkaloids than the intact roots (0.3 mg g(-1) DW). This work has shown that the rol ABC genes were sufficient to increase tropane alkaloid production in A. belladonna hairy root cultures.

Evaluation of an algorithm to identify incident breast cancer cases using DRGs data.

Hospital databases have the potential to be inexpensive, timely and nationally representative sources of information about cancer. This study examines the utility of the French hospital database adapted from the Diagnosis Related Group (DRG) classification and named 'Programme de médicalisation des systèmes d'information (PMSI)', as an independent source to identify incident cancer cases. From the 19 679 women hospitalized and treated in 1998 in the public hospitals of the Somme area in France, we identified those diagnosed with breast cancer in the PMSI database. These women were matched with women in the cancer registry of the Somme area who had been diagnosed with breast cancer in 1998. An algorithm was used to identify cancer-related diagnoses and procedures reported to PMSI. The sensitivity, specificity and positive predictive value (PPV) of the PMSI database were calculated using the cancer registry as a gold standard. The PMSI database had 85% sensitivity, 99.9% specificity and 97% PPV for women hospitalized with breast cancer as a principal diagnosis. The sensitivity was higher by 9% for hospitalization with breast cancer as a secondary diagnosis but had a lower PPV (78%). In conclusion, the PMSI database seems to offer an interesting potential to assess breast cancer incidence, because of its high sensitivity, in particular when secondary diagnosis was considered, and its very high specificity and PPV. However, these preliminary results need to be confirmed by other studies in France before such databases are used, particularly in areas without cancer registries.

Interval cancers in a French breast cancer-screening programme (Somme Department).

The objective of this study is to analyse the detection rates and tumour diameter of interval cancers in the breast cancer mass-screening programme of Somme Department (France), launched in 1990. Interval cancers are defined as breast cancers diagnosed within 36 months after a negative screening assessment, for women attending the programme between December 1990 to December 1993. Age-adjusted incidence rates were 0.51 per 1000 woman-years of follow-up in the 3-year interval after initial and subsequent screens. Diagnosis is made at early stage (sizes < or = 10 mm) in 20% of interval cancers. This stage is higher than that in screened women (9% of in situ cases and 35% of very small tumours). Interval cancer rates are low during the first year (0.18 per 1000 woman-years of follow-up) but higher in the second and third years.

Prevalence of alcohol problems among elderly patients in a university hospital.

AIMS: To assess the prevalence of alcohol abuse and the prevalence of alcohol-related discharge diagnosis in an elderly general hospital population. DESIGN: On a randomly selected day, all patients aged 65 years and over admitted to a university hospital were screened. SETTING: University Hospital of Amiens, France. PARTICIPANTS: All patients aged 65 years and over were approached and requested to take part in the study. They were interviewed using the CAGE questionnaire and with a structured questionnaire regarding life-style, and asked about their usual daily alcohol consumption. The medical history of each patient was taken. In total, 612 patients fulfilled the age criteria, but 205 patients (33.6%) had to be excluded owing to predefined exclusion criteria (e.g. dementia, aphasia, terminal illness ...) and 37 patients (6%) refused to participate. FINDINGS: The data were derived from 370 patients. The median age was 79 years; 54% reported no alcohol consumption; 9% of patients scored positive on the CAGE questionnaire. The prevalence of patients with a CAGE questionnaire positive was significantly higher among male patients (17%) than female patients (2.5%). The prevalence of patients with alcohol-related discharge diagnosis was 7%. The frequency of higher socio-economic status or divorced status increased significantly with alcohol consumption. CONCLUSIONS: There may be a substantial prevalence of alcohol problems in elderly hospital patients. Research is needed to examine how generalized this problem is.

High bone-mass density as a marker for breast cancer in post-menopausal women.

Bone mass has been proposed as a marker of cumulative exposure to oestrogen in women. We have studied the association between bone mass and breast cancer in postmenopausal women. In 126 cases of breast cancers and 126 controls, the bone mineral density (BMD) of the lumbar spine (L2-L4), femoral neck, trochanter and Ward's triangle was measured by dual-energy X-ray absorptiometry. All cases of cancer were confirmed by pathological reports. A questionnaire including information on reproductive history and other variables was collected. BMD was significantly higher among breast cancer patients than controls at all sites, except at the femoral neck where BMD was increased in the cancer group, but not significantly. After adjustment for potential confounding factors, the estimated relative risk of breast cancer in the highest quartile of BMD compared to the lowest quartile ranged from 2.5 to 4.8 for various sites of measurement. These results confirm that bone-mass density is a strong predictor for breast cancer in postmenopausal women. Women in the lowest quartile of bone mass appear to be protected against breast cancer. The mechanisms underlying this relation may be explained by cumulative exposure to oestrogen.

Effects of lead microparticles on the growth characteristics of the BHK21 fibroblast cell line.

BHK21 fibroblastic cells were exposed in vitro to lead microparticles produced by pyrolysis of the organic lead used as an antiknock agent in gasoline. Although non-cytolethal, 10 micrograms of lead/10(6) cells rapidly inhibited cell growth kinetics as well as [3H]thymidine and L-[3H]leucine incorporation by the BHK21 cell line. The growth rate inhibition provoked by chronic exposure to lead microparticles became reversible when the cells were cultured without the microparticulate pollutant. The cloning efficiency of BHK21 cells was impaired by lead concentrations above 1 mg/10(6) cells.

Influence of abnormal screens on delays and prognostic indicators of screen-detected breast carcinoma.

BACKGROUND: Delay to diagnosis following an abnormal screening result is associated with morbidity such as anxiety, but its effect on prognosis is unknown. METHODS: Using data from the Somme area breast cancer screening programme (France), we identified 29,511 women aged 50-69 years who underwent screening between 1996 and 2000. We prospectively followed women with an abnormal screening result until completion of the assessment process and evaluated the effect of delay to notification, diagnosis and treatment on prognostic indicators. RESULTS: Women with high-suspicion screens (n=976) compared with those with intermediate-suspicion screens (n=1008) were investigated more promptly, presented larger tumours (62% vs 42%, p=0.03), and were more likely to be lymph node positive (36% vs 17%, p=0.02). Compared with a delay to diagnosis 6 months. Similarly, a 1.4-fold and 2-fold increased risk of lymph node involvement was observed for delays of >3 to 6 months, respectively, compared with the reference interval. CONCLUSION: The authors' findings suggest that women with high-suspicion mammograms were investigated more promptly, and that delays to diagnosis of asymptomatic breast carcinoma >6 months were associated with progression of the cancer measured by tumour size >10 mm and lymph node metastasis.

Cytotoxic quantification of maitotoxin-like activity from the dinoflagellate Gambierdiscus toxicus.

Gambierdiscus toxicus is a marine dinoflagellate involved in the food-borne disease ciguatera. Its toxicity is mainly due to maitotoxin, a hydrophilic toxin, the chemical structure of which has recently been described. This toxin increases internal Ca(2+) concentration and triggers phosphoinositide breakdown. Three cytotoxic tests were set for the detection and quantification of toxicity in G. toxicus extracts, further purified by HPLC: the neutral red uptake assay (NRU), observation of morphological alterations on baby hamster kidney fibroblasts (BHK 21/C13) and the measurement of internal Ca(2+) concentration on human lymphocytes (Jurkat D). In order to evaluate cytotoxicity tests, results were compared with the mouse bioassay. A positive correlation was observed between the minimum lethal dose (MLD), estimated at 24 hr by the mouse bioassay, and the IC(50), estimated by the NRU assay, for extracts of increasing degree of purity. By the use of the NRU assay, a precise detection and quantification of toxicity in multiple extracts was possible after 8 hr. Cell blebbing was generally highest for extracts that strongly inhibited NRU. The analysis of the correlation between the two cytological tests facilitates monitoring of the progression of purification. An indication of the presence of maitotoxin activity was supported by the increase of internal Ca(2+) concentration in Jurkat D lymphocytes, which was maximal in cells exposed to the purest extracts.

Comparative studies of the actin cytoskeleton response to maitotoxin and okadaic acid.

The specific cytotoxic effects of phycotoxins on BHK 21 C13 fibroblasts in culture were studied with maitotoxin (MTX), okadaic acid (OA) and crude extracts from Gambierdiscus toxicus Adachi and Fukuyo and Prorocentrum lima Ehrenberg. These dinoflagellates produce MTX and OA respectively. MTX and G. toxicus crude extracts caused large blebs within minutes after exposure, in a dose-dependent manner. F-actin fibres decreased in number, then disappeared. An increase in fluorescence was observed at the periphery of the nucleus. For one strain of G. toxicus F-actin granules were also observed. Cells exposed to OA or P. lima crude extracts became polygonal in shape and then round. At low doses this effect occurred only after a 24-hr exposure. F-actin fibres crossing the cytoplasm were reduced in size and number then disappeared, while peripheral F-actin fibres became shorter giving the cell first a polygonal and then a round shape. According to these specific responses we have defined an MTX-like effect which is distinct from an OA-like effect. In both cases the amount of F-actin diminished at doses that did not affect cell viability.

Respiratory tract epithelium in primary culture: Effects of ciliotoxic compounds.

Acrolein ciliotoxicity was studied on primary cultures from rabbit tracheal epithelium. The inhibition of ciliary beat was chosen as a criterion for ciliotoxicity. The measurement of ciliary beat was accomplished using an original image analysis process.

The use of sea urchin eggs as a model to investigate the effects of crassolide, a diterpene isolated from a soft coral.

Crassolide, a monocyclic diterpene isolated and purified from the soft coral Lobophytum crassum, inhibited the cell cleavage of sea urchin eggs without affecting fertilization. The effect was observed with concentrations above 2 x 10(-5)m in egg suspensions. Addition of crassolide between 5 and 40 min post-fertilization totally blocked the first cleavage, which in the control occurs 1 hr after fertilization. When added between 50 and 60 min post-fertilization, crassolide produced polynucleated cells in embryos. Crassolide did not affect the egg permeability to Na(+) and Ca(2+), but caused an increase of 0.2 units in the intracellular pH of fertilized eggs coupled with a proton efflux. Crassolide, which does not affect Ca(2+) influx or permeability at the level of storage in reticular vesicles, could be used as a negative control when analysing calcium changes in short-term toxicological studies. The relationship between the pH increase and the cell cleavage needs further investigation.

Enhanced production of scopolin bySolanum aviculare cells immobilised within Ca-alginate gel beads.

Different matrices, obtained by varying calcium (0.1 to 1.5M) and alginate (1 to 1.5%) concentrations, were used to study the influence of immobilisation parameters on the behaviour ofS. aviculare. A significant modulation of cell growth, cell release, and scopolin production and excretion has been observed. Physiological and morphological characteristics ofSolanum aviculare cells immobilised within Ca-alginate beads were notably different from those of suspended cells. ImmobilisedS. aviculare have accumulated scopolin (up to 120 µg·g-1 FWB) within beads and excreted it into the culture medium (up to 8 µg·g-1 FWB). Contrary to suspended cells which have accumulated only traces of this metabolite within intracellular compartments (1 µg·g-1 FWB), no scopolin has been found into the culture medium.

In vitro cytotoxicity of cadmium microparticles for rabbit pulmonary alveolar macrophages.

A cytotoxic effect of cadmium monoxide microparticles on rabbit pulmonary alveolar macrophages was observed in vitro from 1 to 2 microg of metal cadmium per million cells (and per milliliter of incubation medium). This threshold was close to the one observed with lead microparticles, which in addition appeared to have a faster cytotoxic action. On the other hand, cadmium microparticles inhaled in vivo are known to be much more toxic to the respiratory system and much more slowly cleared from it than lead particles. These contradictions can be partially explained by our observation that in vitro the ability of alveolar macrophages to phagocytize microparticles was significantly lower for cadmium monoxide than for lead monoxide microparticles.

Toxic effects of cadmium microparticles on the respiratory system. An experimental study on rats and mice.

An experimental study on rats and mice. Scand. j. work environ. & health 3 (1977) 116--121. Experiments on male, specific pathogen-free rats (193) and mice (66) are reported. The test and control animals received a single 15-min exposure to cadmium (cadmium oxide) and aluminum (alumina) microparticles, respectively. The air cadmium content was 10 mg/m3, and 4 microgram of this metal was retained by the lungs of the rats. The animals were observed for 24 days. The following significant differences appeared between the control and test groups: in the cadmium exposed rats the relative lung weight (percentage of body weight) became temporarily higher; the absolute number of alveolar macrophages decreased at first and then increased; numerous polymorphonuclear and lymphocytic cells appeared in the alveoli. According to these inflammatory phenomena, at the 48th h after exposure, there was an alteration in the clearance kinetics of inhaled bacteria and an increase in the death rate of cadmium exposed animals following a test infection with Salmonella enteritidis (rats) or Pasteurella multocida (mice) aerosols. The mechanism of cadmium toxic action on the respiratory system is discussed.