Stimulus-dependent modulation of smooth muscle intracellular calcium and force by altered intracellular pH

Measurements of simultaneous force and intracellular Ca²⁺ concentration ([Ca²⁺]_i) in rat uterine smooth muscle have been made to elucidate the mechanisms involved when force produced spontaneously, by high-K⁺ depolarization or carbachol is altered by a change of intracellular pH (pH_i). Rises in force and [Ca²⁺]_i were closely correlated for all forms of contraction, with the Ca²⁺ transient peaking before force. In spontaneously active preparations, alkalinization significantly increased, and acidification decreased, force and [Ca²⁺]_i. Inhibition of the sarcoplasmic reticulum ATPase (cyclopiazonic acid) did not affect these changes, whereas removal of external Ca²⁺ abolished both responses, suggesting that the effect of pH_i is on Ca²⁺ entry. Alkalinization caused a prolongation of the action potential complex, associated with a potentiation of contractile activity. Acidification produced hyperpolarization and abolition of action potentials and spontaneous activity, but did not prevent brief applications of carbachol or high-K⁺ from producing depolarization and increasing force, suggesting no impairment of the mechanism of generation of the action potential. For depolarized preparations, acidification increased tonic force and [Ca²⁺]_i; the increase in the calcium signal persisted in zero-external calcium. In the presence of carbachol, acidification transiently increased force and [Ca²⁺]_i, followed by a reduction in both. It is concluded that changes in pH_i act at more than one step in excitation-contraction coupling and that changes in [Ca²⁺]_i can account for most of the changes in uterine force. Received: 1 April 1996 /Accepted: 8 May 1996     

Role of neutrophils in controlling early stages of a Chlamydia trachomatis infection.

Inoculation of mice with the granulocyte-depleting monoclonal antibody RB6-8C5 showed that neutrophils are critical protective effector cells during a Chlamydia trachomatis infection. In addition, administration of monoclonal antibody 2E6 demonstrated that extravasation of neutrophils into the peritoneal cavity in response to inoculation with the C. trachomatis MoPn biovar is dependent on the surface beta-2 integrin molecule CD18.     

A novel autosomal dominant condition consisting of congenital heart defects and low atrial rhythm maps to chromosome 9q

Congenital heart defects (CHDs) occur mostly sporadic, but familial CHD cases have been reported. Mutations in several genes, including NKX2.5, GATA4 and NOTCH1, were identified in families and patients with CHD, but the mechanisms underlying CHD are largely unknown. We performed genome-wide linkage analysis in a large four-generation family with autosomal dominant CHD (including atrial septal defect type I and II, tetralogy of Fallot and persistent left superior vena cava) and low atrial rhythm, a unique phenotype that has not been described before. We obtained phenotypic information including electrocardiography, echocardiography and DNA of 23 family members. Genome-wide linkage analysis on 12 affected, 5 unaffected individuals and 1 obligate carrier demonstrated significant linkage only to chromosome 9q21–33 with a multipoint maximum LOD score of 4.1 at marker D9S1690, between markers D9S167 and D9S1682. This 48-c critical interval corresponds to 39 Mb and contains 402 genes. Sequence analysis of nine candidate genes in this region (INVS, TMOD1, TGFBR1, KLF4, IPPK, BARX1, PTCH1, MEGF9 and S1PR3) revealed no mutations, nor were genomic imbalances detected using array comparative genomic hybridization. In conclusion, we describe a large family with CHD and low atrial rhythm with a significant LOD score to chromosome 9q. The phenotype is representative of a mild form of left atrial isomerism or a developmental defect of the sinus node and surrounding tissue. Because the mechanisms underlying CHD are largely unknown, this study represents an important step towards the discovery of genes implied in cardiogenesis.     

A short course of corticosteroids prior to surveillance colonoscopy to decrease mucosal inflammation in inflammatory bowel disease patients: Results from a randomized controlled trial

BackgroundInflammation is a known pitfall of surveillance colonoscopy for inflammatory bowel disease (IBD) as it is difficult to differentiate between inflammation and true dysplasia. This randomized controlled trial assessed the effectiveness of a low dose of corticosteroids prior to surveillance colonoscopy to decrease mucosal inflammation.MethodsIBD-patients scheduled for surveillance colonoscopy between July 2008–January 2010 were eligible to participate. Patients were randomized to either two weeks daily 20 mg prednisone and calcium plus vitamin D prior to surveillance colonoscopy or no treatment. All biopsies were reviewed by an expert gastrointestinal pathologist who was blinded for medication-use. Statistics were performed using chi-square tests, non-parametric tests and binary logistic regression.ResultsSixty patients (M/F 30/30, UC/CD 31/29) participated: 31 (52%) in the treatment arm and 29 (48%) in the control group. In the treatment arm, 247 biopsies were scored against 262 in the control group. In the treatment arm 27 out of 247 biopsies (10.9%) had a score > 1 on the Geboes scale, against 50 out of 262 biopsies (19.1%) in the control group, p = 0.013. In total, 58% of the treatment arm against 66% of the control group had endoscopic or histological mucosal inflammation (p = 0.6). There was a trend for patients in the treatment arm to have less severe inflammation compared with the control group, however this was not significant (p = 0.12).ConclusionsIn our cohort, a short course of corticosteroids decreases the overall histological disease activity in individual biopsies without major side-effects. Moreover, there is a trend for corticosteroids to decrease the maximum severity of both endoscopic and histological disease activity per patient.     

Puzzling With Online Games (BAM-COG): Reliability,Validity, and Feasibility of an Online Self-Monitor for Cognitive Performance in Aging Adults

Background

Online interventions are aiming increasingly at cognitive outcome measures but so far no easy and fast self-monitors for cognition have been validated or proven reliable and feasible.

Objective

This study examines a new instrument called the Brain Aging Monitor–Cognitive Assessment Battery (BAM-COG) for its alternate forms reliability, face and content validity, and convergent and divergent validity. Also, reference values are provided.

Methods

The BAM-COG consists of four easily accessible, short, yet challenging puzzle games that have been developed to measure working memory (“Conveyer Belt”), visuospatial short-term memory (“Sunshine”), episodic recognition memory (“Viewpoint”), and planning (“Papyrinth”). A total of 641 participants were recruited for this study. Of these, 397 adults, 40 years and older (mean 54.9, SD 9.6), were eligible for analysis. Study participants played all games three times with 14 days in between sets. Face and content validity were based on expert opinion. Alternate forms reliability (AFR) was measured by comparing scores on different versions of the BAM-COG and expressed with an intraclass correlation (ICC: two-way mixed; consistency at 95%). Convergent validity (CV) was provided by comparing BAM-COG scores to gold-standard paper-and-pencil and computer-assisted cognitive assessment. Divergent validity (DV) was measured by comparing BAM-COG scores to the National Adult Reading Test IQ (NART-IQ) estimate. Both CV and DV are expressed as Spearman rho correlation coefficients.

Results

Three out of four games showed adequate results on AFR, CV, and DV measures. The games Conveyer Belt, Sunshine, and Papyrinth have AFR ICCs of .420, .426, and .645 respectively. Also, these games had good to very good CV correlations: rho=.577 (P=.001), rho=.669 (P<.001), and rho=.400 (P=.04), respectively. Last, as expected, DV correlations were low: rho=−.029 (P=.44), rho=−.029 (P=.45), and rho=−.134 (P=.28) respectively. The game Viewpoint provided less desirable results with an AFR ICC of .167, CV rho=.202 (P=.15), and DV rho=−.162 (P=.21).

Conclusions

This study provides evidence for the use of the BAM-COG test battery as a feasible, reliable, and valid tool to monitor cognitive performance in healthy adults in an online setting. Three out of four games have good psychometric characteristics to measure working memory, visuospatial short-term memory, and planning capacity.     

Determination of capillary leakage due to recombinant interleukin-2 by means of noninvasive conductivity measurements

Summary One of the most common side effects of treatment with recombinant interleukin-2 (IL-2) is capillary leakage. Its genesis is not completely understood. The aim of the study was to determine whether capillary leakage can be monitored by means of a non-invasive conductivity technique and to study its starting point. Eight patients with advanced renal cell cancer were studied in a medium care section of the Department of Medical Oncology, University Hospital over 4 days during treatment sessions of continuous, intravenously administered IL-2 (mean dose of 15.6 × 10⁶ IU · m^–2 · day ^–1). The fluid shift from the intravascular to the extra- and intracellular compartments was monitored by means of noninvasive conductivity measurements. Changes in blood volume were calculated from serial erythrocyte counts. The clinical parameters of capillary leakage (oliguria, positive fluid balance, and gain in mass) were recorded. The mean gain in mass was 9% after 4 days of IL-2 treatment. The extracellular fluid volume increased significantly [46 (SD 23.2)%; P < 0.01], whereas the intracellular fluid volume did not change. The increase in blood volume (BV) amounted to 7% (P < 0.05). The decline in albumin concentration was significantly more than the increase in BV [38 (SD 4.3) %; P < 0.01], indicating capillary albumin leakage. The main changes were observed after the 2nd day of treatment. From this study, it is suggested that conductivity measurements are a suitable method to monitor capillary leakage induced by IL-2, and could be used to detect the exact onset and severity of this leakage. The leakage started within the first 24 h of treatment and was detected as a fluid shift from the intravascular to the extracellular space, while the intracellular compartment remained stable. These measurements could be useful during intervention studies with the aim of preventing this adverse effect of IL-2.     

Kinetics of lymphocytes in Hodgkin's disease

Summary Lymphocyte kinetics was studied in 4 patients withHodgkin's disease (Stage III A and IV B) by means of a single i. v. injection of³H-thymidine (0.15 Ci/g body weight) and autoradiographic analysis of the labelling pattern of blood and tissue lymphocytes over a period of 7–25 days.The cause of the blood lymphocytopenia in the three lymphopenic patients was the accelerated turnover of the majority of the blood lymphocytes. The average turn-over time of the blood lymphocytes in these patients was about 5 days as compared to 27 days in aHodgkin patient without lymphopenia and to 50 days in non-lymphopenic tumour patients. The turnover times of the small blood lymphocytes were about 14 days in the lymphopenic Hodgkin patients and 70–115 days in hematologically normal patients. Lymphocytopoiesis seemed to be increased in the lymph nodes and in the blood inHodgkin's disease. The blood lymphocyte production index was was 61–259 lymphocytes/mm³/day as compared to 40–50 lymphocytes/mm³/day in hematologically normal patients. The generation time of the lymphopoietic cells was estimated to be approximately 24 hours.Our data suggest that the activity of the disease was correlated with accelerated turnover of lymphocytes and increased lymphocytopoiesis.

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Zusammenfassung Bei 4 Patienten mit Lymphogranulomatose (Stadium III A und IV B) wurde die Kinetik von Blut- und Gewebslymphozyten nach einer Einzelinjektion von³H-Thymidin autoradiographisch untersucht.Bei den 3 lymphopenischen Patienten war die Lymphopenie des Blutes durch einen gesteigerten Umsatz der Blutlymphozyten bedingt. Die mittlere Umsatzzeit der Blutlymphozyten betrug bei diesen Patienten 5 Tage, verglichen mit einer mittleren Umsatzzeit von 27 Tagen bei einem Lymphogranulom-Patienten ohne Lymphopenie und von etwa 50 Tagen bei nicht-lymphopenischen Tumorpatienten. Die mittlere Umsatzzeit der kleinen Blutlymphozyten wurde bei den lymphopenischen Lymphogranulomatose-Patienten mit 14 Tagen und bei nicht-lymphopenischen Tumorpatienten mit 70–115 Tagen berechnet. Die Lymphozytopoese bei den Lymphogranulomatose-Patienten war erhöht. Das galt gleichermaßen für die vergrößerten Lymphknoten und das Blut. Der Blutlymphozyten-Produktionsindex betrug 61-259 Lymphozyten/mm³/Tag im Vergleich zu 40–50 Lymphozyten/mm³/Tag bei hämatologisch normalen Patienten. Die Generationszeit der lymphopoetischen Zellen ließ sich auf 24 Stunden schätzen.Die Befunde weisen darauf hin, daß bei der Lymphogranulomatose die Aktivität des Krankheitsprozesses mit gesteigertem Lymphozytenumsatz und stimulierter Lymphozytopoese korreliert ist.

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Research carried out in the Forschergruppe für Experimentelle und Klinische Leukämieforschung, supported by the Deutsche Forschungsgemeinschaft.     

Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses

Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256‐channel EEG coupled with an liquid crystal display (LCD) tachistoscope to characterize the spatio‐temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time‐wise, assumption‐free nonparametric randomization statistics on the strength and on the topography of high‐density scalp‐recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post‐stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. Hum Brain Mapp 36:1470–1483, 2015. © 2014 Wiley Periodicals, Inc.     

Determinants of quality of life in patients with refractory focal epilepsy who were not eligible for surgery or who rejected surgery

The aim of the study was to assess the determinants of quality of life (QOL) in adult patients with refractory focal epilepsy who were not eligible for surgery or who rejected surgery after presurgical evaluation. The QOLIE-31, the Hospital Anxiety and Depression Scale and PESOS questionnaire were mailed in 2009 to all adult patients who had been evaluated for suitability for epilepsy surgery between 2001 and 2007 in the Bethel Epilepsy Center and had been deemed not eligible for surgery or had decided against surgery. Questionnaires were sent by post to 359 patients: 172 (47.9%) replied, and of these, 125 patients were eligible for this study. The remaining 47 patients were excluded mainly because they did not fulfill the criteria of refractory epilepsy. Out of the included 125 patients, 106 were considered to be poor surgical candidates for medical reasons, and 19 had decided against surgery. The mean follow-up was 4.1±2.1 years. In the past 6 months, 13.9% of the patients were seizure free, 12 of them (9.6%) were seizure free for one year, 10.7% had 1-2 seizures, 11.5% had 3-5 seizures, 27.0% had one or more seizures a month, 23.0% had one or more seizures a week, and 13.9% had one or more seizures a day. Patient-perceived changes in their seizures since presurgical evaluation were rated by 15.6% of the patients as 'improved significantly', by 28.7% as 'improved', by 46.7% as 'no change', by 6.6% as 'deteriorated' and by 2.5% as 'significantly deteriorated'. Quality of life in patients with refractory epilepsy was much lower compared to operated patients from our center. Multivariate analysis of QOL showed that depression and anxiety are strong predictors but not exclusively. Furthermore, tolerability and efficacy of AEDs are significant predictors of most QOLIE-31 subscales. Employment, seizure frequency, patient-perceived change in their seizures, number of AEDs and the degree of comorbidity appeared as predictors for some aspects of QOL as well. When excluding anxiety and depression, the most important predictors of QOL were tolerability of AEDs and employment. For other aspects of QOL, efficacy of AEDs, gender, number of AEDs, degree of comorbidity and a certificate of disability were additional predictors. The results of the multivariate analysis did not essentially change when seizure-free patients were excluded. Conclusion: Quality of life in non-operated patients with refractory epilepsy is significantly lower than in operated patients from the same center. Besides depression and anxiety, patient-rated tolerability and efficacy of AEDs, seizure frequency and employment are the main determinants of QOL.     

MR imaging features in Marinesco-Sjögren syndrome: severe cerebellar atrophy is not an obligatory finding

BACKGROUND AND PURPOSE: Cerebellar atrophy is considered the most prominent neuroradiologic finding in Marinesco-Sj?gren syndrome (MSS). Our purpose was to investigate this neuroradiologic feature in a series of patients with MSS. METHODS: Five patients with MSS (age range, 5-19 years) underwent native MR imaging of the brain. The findings were assessed with particular attention to the cerebellum and the supratentorial structures. RESULTS: Only two patients had slight cerebellar atrophy; the cerebellum was normal in size and configuration in the other patients. Additional supratentorial findings were present in some of the patients, with an apparently small anterior pituitary gland in two and the absence of the posterior pituitary bright spot in three of the patients. CONCLUSION: Cerebellar atrophy is not an obligatory finding in MSS, and almost normal cranial MR imaging results are compatible with the diagnosis. Morphologic changes of the pituitary gland seem to be common in patients with MSS and are not associated with endocrine dysfunction.