Chord length sampling with memory effects for spatially heterogeneous Markov media: Application to the rod model.

In this work we propose a modified Chord Length Sampling (CLS) algorithm, endowed with two layers of "memory effects," aimed at solving particle transport problems in one-dimensional spatially nonhomogeneous Markov media. CLS algorithms are a family of Monte Carlo methods which account for the stochastic nature of the media by sampling on-the-fly the random interfaces between material phases during the particle propagation. The possibility for the particles to remember the last crossed interfaces increases the accuracy of these models with respect to reference solutions obtained by solving the Boltzmann equation on a large number of realizations of the Markov media. In previous investigations, CLS models with memory have been tested exclusively for spatially uniform stochastic media: in this paper we extend this class of Monte Carlo methods to the case of spatially nonhomogeneous configurations. The effectiveness and the robustness of the modified CLS are probed considering several benchmark problems with varying material cross sections and Markov media densities. The obtained results are a stepping stone towards a generalization to three-dimensional models.

Duration of untreated bipolar disorder: missed opportunities on the long road to optimal treatment.

OBJECTIVE: Duration of untreated illness represents a potentially modifiable component of any diagnosis-treatment pathway. In bipolar disorder (BD), this concept has rarely been systematically defined or not been applied to large clinically representative samples. METHOD: In a well-characterized sample of 501 patients with BD, we estimated the duration of untreated bipolar disorder (DUB: the interval between the first major mood episode and first treatment with a mood stabilizer). Associations between DUB and clinical onset and the temporal sequence of key clinical milestones were examined. RESULTS: The mean DUB was 9.6 years (SD 9.7; median 6). The median DUB for those with a hypomanic onset (14.5 years) exceeded that for depressive (13 years) and manic onset (8 years). Early onset BD cases have the longest DUB (P < 0.0001). An extended DUB was associated with more mood episodes (P < 0.0001), more suicidal behaviour (P = 0.0003) and a trend towards greater lifetime mood instability (e.g. rapid cycling, possible antidepressant-induced mania). CONCLUSION: Duration of untreated bipolar disorder (DUB) will only be significantly reduced by more aggressive case finding strategies. Reliable diagnosis (especially for BD-II) and/or instigation of recommended treatments is currently delayed by insufficient awareness of the early, polymorphous presentations of BD, lack of systematic screening and/or failure to follow established guidelines.

A study of the real-world effectiveness of group psychoeducation for bipolar disorders: Is change in illness perception a key mediator of benefit?

BACKGROUND: Findings from efficacy trials of group psychoeducation (PE) for bipolar disorders (BD) led to its inclusion in evidence-based guidelines as a first-line mandatory treatment. However, pragmatic trials and observational studies are needed to determine its real-world effectiveness, impact on outcomes deemed important to patients and to clarify potential mediators of any benefits. METHODS: Individuals with BD were offered the opportunity to participate in 20h of PE and asked to complete pre- and post-intervention ratings of symptoms, knowledge about BD, medication adherence, and illness perception. A priori, two key patient outcomes were identified (social functioning and self-esteem); sample attrition due to dropout or relapse was recorded. RESULTS: Of 156 individuals who completed the pre-PE assessments, 103 completed the program and post-PE assessments. Only 4 of 53 dropouts were associated with BD relapse. Post-intervention, the PE completers demonstrated a statistically significant improvement in social functioning (p = 0.003, Effect Size (ES) = 0.26) and a trend towards improved self-esteem (ES = 0.14). Whilst there were significant changes in medication adherence (p = 0.002, ES = 0.28), knowledge of BD (p < 0.001, ES = 1.20), and illness perception (p < 0.001, ES = -0.37), mediational analysis demonstrated that only change in illness perception was associated to change in functioning (p=0.03) with no contribution from changes in knowledge of BD or medication adherence. CONCLUSIONS: In real-world settings, over 60% individuals completed 10-session course of PE. After controlling for demography and baseline clinical state, change in illness perception, rather than change in knowledge or medication adherence, emerged as a potential mediator of some benefits of PE.

Calcium absorption from milk in lactase-deficient subjects.

Intestinal calcium absorption from milk containing lactose (+) and from another containing glucose (-) was studied in eight patients with normal lactase (NL) and seven lactase-deficient (LD) subjects to determine if lactase deficiency is implicated in Ca absorption. The results were compared with data obtained from Ca ingestion in a water solution. Ca absorption was measured by a double-isotope technique and the kinetic indices were obtained by a deconvolution method. With (-), Ca absorption was identical in NL and LD subjects and slightly higher than with water solution (15%, NS). With (+), Ca absorption in NL subjects was identical with that from water solution; in LD subjects it increased (23%, p less than 0.02). These data indicate that: Ca is absorbed equally well from milk as from water solution; (+) favors Ca absorption in LD subjects, which suggests that milk ingestion might be encouraged in LD subjects to avoid Ca deficiency; and (-) should be a valuable alternative for lactose-intolerant patients.

[Influence of chronic renal failure on the D-xylose test in man]. / Influence de l'insuffisance rénale chronique sur le test au D-xylose chez l'homme.

The aim of this study was to investigate the effect of chronic renal insufficiency on absorption, distribution and elimination of D-xylose which was chosen as a "test substance". Pharmacokinetic analysis was based on eighteen D-xylose tests carried out either by the enteral or parenteral route in a randomized fashion on nine patients suffering from chronic renal insufficiency. These results were compared with those obtained in healthy volunteers. The renal clearance was simultaneously measured with the 51Cr-EDTA test. In the experimental conditions the intestinal absorption of D-xylose was not modified qualitatively (absorption rate) nor quantitatively (systemic availability). Inspite of this, the maximal concentration of the D-xylose was higher in these patients and was reached later than in healthy volunteers. This fact should be taken into consideration when interpreting the results of a D-xylose test in patients suffering from chronic renal insufficiency.

[Excess mortality in out-patients psychiatry: first results of a Geneva study]. / Surmortalité en psychiatrie ambulatoire: premiers résultats d'une étude à Genève.

The project intends to prove an excess of mortality among the out-patients of the official psychiatric center of Geneva. The study is of the follow-up retrospective type. The primary results confirm the hypothesis. They show an increased relative risk of death by suicide and other non natural causes, for both sexes, as well as by natural causes (especially respiratory diseases) but only among women.

Affect intensity measure in bipolar disorders: a multidimensional approach.

BACKGROUND: Emotional dysregulation, characterized by high levels of both arousal and intensity of emotional responses, is a core feature of bipolar disorders (BDs). In non-clinical populations, the 40-item Affect Intensity Measure (AIM) can be used to assess the different dimensions of emotional reactivity. METHODS: We analyzed the factor structure of the AIM in a sample of 310 euthymic patients with BD using Principal Component Analysis and examined associations between AIM sub-scale scores and demographic and illness characteristics. RESULTS: The French translation of the AIM demonstrated good reliability. A four-factor solution similar to that reported in non-clinical samples (Positive Affectivity, Unpeacefulness [lack of Serenity], Negative Reactivity, Negative Intensity), explained 47% of the total variance. Age and gender were associated with Unpeacefulness and Negative reactivity respectively. 'Unpeacefulness' was also positively associated with psychotic symptoms at onset (p=0.0006), but negatively associated with co-morbid substance misuse (p=0.008). Negative Intensity was positively associated with social phobia (p=0.0005). LIMITATIONS: We cannot definitively exclude a lack of statistical power to classify all AIM items. Euthymia was carefully defined, but a degree of 'contamination' of the self-reported levels of emotion reactivity may occur because of subsyndromal BD symptoms. It was not feasible to control for the possible impact of on-going treatments. CONCLUSIONS: The AIM scale appears to be a useful measure of emotional reactivity and intensity in a clinical sample of patients with BD, suggesting it can be used in addition to other markers of BD characteristics and sub-types.

Clinical features associated with trait-impulsiveness in euthymic bipolar disorder patients.

BACKGROUND: A strong association has been reported between trait-impulsiveness and bipolar disorder (BD). Much attention has been focused on this association, but subgroup analysis has generated conflicting results, raising questions about the role of trait-impulsiveness in suicidal behavior and substance misuse in bipolar patients. METHOD: We compared Barratt Impulsiveness Scale-10 scores between 385 euthymic bipolar patients and 185 healthy controls. We then investigated possible association between impulsiveness scores and the following clinical characteristics: suicide attempt (SA), lifetime alcohol/cannabis misuse, rapid cycling and mixed episodes. RESULTS: Bipolar patients and healthy controls had significantly different BIS-10 total score and subscores (motor, attentional and nonplanning impulsiveness) (all p values <0.0001). No association was observed between BIS-10 total score, personal history of SA, number of SA, age at first SA and history of violent SA. Higher BIS-10 total scores were associated with alcohol misuse (p=0.005), cannabis misuse (p<0.0001), with an additive effect for these two substances (p=0.005). Higher BIS-10 total scores were also associated with rapid cycling (p=0.006) and history of mixed episodes (p=0.002), with an additive effect of these two variables (p=0.0006). LIMITATIONS: We used only one clinical measurement of impulsiveness and did not carry out cognitive assessment. CONCLUSION: This study demonstrates that trait-impulsiveness may be considered as a dimensional feature associated with BD and with a more severe clinical expression of the disease, characterized by a history of substance misuse, rapid cycling and mixed episodes. We found no association between impulsiveness and SA characteristics in bipolar patients, confirming some previous negative results.

Clinical and dimensional characteristics of euthymic bipolar patients with or without suicidal behavior.

BACKGROUND: The clinical and dimensional features associated with suicidal behaviour in bipolar patients during euthymic states are not well characterised. METHODS: In a sample of 652 euthymic bipolar patients, we assessed clinical features with the Diagnostic Interview for Genetics Studies (DIGS) and dimensional characteristics with questionnaires measuring impulsivity/hostility and affective lability/intensity. Bipolar patients with and without suicidal behaviour were compared for these clinical and dimensional variables. RESULTS: Of the 652 subjects, 42.9% had experienced at least one suicide attempt. Lifetime history of suicidal behaviour was associated with being a woman, a history of head injury, tobacco misuse and indicators of severity of bipolar disorder including early age at onset, high number of depressive episodes, positive history of rapid cycling, alcohol misuse and social phobia. Indirect hostility and irritability were dimensional characteristics associated with suicidal behaviour in bipolar patients, whereas impulsivity and affective lability/intensity were not associated with suicidal behaviour. LIMITATIONS: This study had a retrospective design with no replication sample. CONCLUSIONS: Bipolar patients with earlier onset, mood instability (large number of depressive episodes, rapid cycling) and/or particular addictive and anxiety comorbid disorders might be at high risk of suicidal behaviour. In addition, hostility dimensions (indirect hostility and irritability), may be trait components associated with suicidal behaviour in euthymic bipolar patients.

[Stercoraceous perforations of the colon. 2 unusual presentations]. / Perforations stercorales du côlon Deux présentations inhabituelles.

Two cases of stercoraceous perforation of the colon are described in a psychiatric patient and a hemodialysis patient. The unusual symptomatology was acute respiratory failure with hypovolemic shock in one case and acute rectal bleeding in the other. The etiology, clinical manifestations, and treatment are discussed.

[Incidence of lactose intolerance in postmenopausal osteoporosis]. / Incidence de l'intolérance au lactose dans l'ostéoporose post-ménopausique.

The incidence of lactose intolerance was determined in 31 women with idiopathic postmenopausal osteoporosis. Nine subjects exhibited a pathological rise in blood glucose (less than 20 mg/100 ml) after receiving 50 g lactose. The absorption of glucose and galactose, xylose, and fat was normal in the 31 patients. Daily intake of calcium was below the normal range in 3 subjects with and in 6 subjects without lactose intolerance. The association between lactase deficiency and osteoporosis is stressed.

[The exhaled hydrogen test: its value in the quantitative diagnosis of carbohydrate malabsorption]. / Test de l'hydrogéne expiré: sa valeur dans l'appréciation quantitative des malabsorptions glucidiques.

A study has been conducted to determine the accuracy of breath-H2 measurements for quantitating the malabsorption of small amounts of carbohydrate. H2 pulmonary excretion was measured after an overnight fast at 30-min intervals for 4 h in 7 healthy subjects after ingestion of 4 doses of lactulose (2.5,5,10 and 50 g). In 3 subjects the test was repeated without lactulose. The volume of H2 excreted was directly proportional to the amount of ingested lactulose: mean cumulative H2 excretion over a 2-h period after 5, 10 and 50 g was 2.9, 6.6 and 37.6 ml H2 respectively; H2 response after the 2.5-g dose was not perceptible. Individual H2 excretion before lactulose ingestion was highly variable: 0.096 +/- 0.075 mlH2 (mean +/- 1 SD); the individual base line rate over a fasting period showed marked fluctuations. It is concluded that the inter- and intraindividual variations of H2 excretion limit the accuracy of the H2 breath test for quantitating malabsorption of small amounts of carbohydrate.

[D-xylose absorption test. A pharmacokinetic and statistical study]. / Test d'absorption du d-xylose. Etude pharmacocinétique et statistique.

D-xylose pharmacokinetics has been studied in 6 healthy subjects by serial measurement of blood and urinary levels following oral and intravenous administration of two doses of D-xylose (5 and 25 g successively). Furthermore, patients with obesity, renal or hepatic insufficiency, or with a T-drain after cholecystectomy, are also investigated. Both the rate and completeness of D-xylose absorption and the apparent distribution volume of D-xylose present noteworthy interindividual variations, so that the time and value of the peak blood level are highly variable as between healthy subjects. Renal insufficiency increases the apparent elimination half-life of D-xylose and notably reduces D-xylose renal excretion. This study provides pharmacokinetic evidence of the very wide range of blood and urinary levels observed in the D-xylose tolerance test, and emphasizes the fact that D-xylose urinary excretion alone is not a reliable index of intestinal absorption.

Peutz-Jeghers syndrome associated with gastrointestinal carcinoma. Report of two cases in a family.

Patients with the Peutz-Jeghers syndrome carry a slight, though definite, increased risk of gastrointestinal carcinoma. The malignant potentiality of Peutz-Jeghers hamartomatous polyps, generally considered benign, is supported by this report. Two cases of metastasising gastrointestinal carcinoma associated with the Peutz-Jeghers syndrome are described in a 56 year old female and her 29 year old son. Both mother and son died from duodenal and gastric carcinomas respectively, which developed in hamartomatous polyps with extensive metastases. Both cases also showed dysplastic areas within hamartomatous polyps. These features indicate that hamartomatous polyps may, in some cases, be the precursors of digestive tract carcinomas.

Asphyxia caused by laryngeal impaction of an esophageal polyp.

We report a case of asphyxia due to laryngeal obstruction by an esophageal polyp with subsequent cerebral anoxia and death. We review the clinical manifestations and pathological aspects of benign esophageal tumors, with emphasis on the importance of an early diagnosis if a patient has repeated sensations of a regurgitated pharyngeal mass.