Automatic measurement of LV wall thickness from 2D cardiac echocardiography

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): PIC from European Union"s Horizon 2020 Marie Skłodowska-Curie Actions ITN

Background

The wall thickness of the left ventricle (LV) is an important parameter in the diagnosis of hypertension and more specifically in hypertrophic cardiomyopathy. A user-dependent manual assessment of distances on 2D echocardiographic images is the current clinical gold-standard.

Purpose

The automation of LV wall thickness measurements in 2D echocardiography in order to improve robustness and reduce time of clinical reports where wall thickness is required, such as hypertrophy and the presence of Basal Septal Hypertrophy (BSH)(1).

Methods

A dataset of 4-chamber (4CH) echocardiograms on 118 patients with a diagnosis of hypertension (2) is used for this study. The images were segmented automatically (3) extracting the blood pool and the myocardium. Based on the curvature of the complete myocardial contour, the valve annular regions are removed leaving the endocardial and the epicardial walls as independent structures. The wall thickness along the myocardium is calculated as the distance from each endocardial border pixel to the closest epicardial point  (see Figure 1). A high pass gaussian filter was applied to remove high frequency noise. Ultimately, the basal-to-mid septal wall thickness ratio that defines BSH (ratio ≥ 1.4) was computed as the maximal of basal-septal segment divided by minimum of mid-septal segment. In order to validate the method for BSH detection, the wall thickness septal ratio was carefully measured by a clinical expert following the guidelines (2). The statistical agreement was accessed via linear correlation and Bland-Altman analysis.

Results

The automatic assessment of LV wall thickness along the myocardium is feasible in 2D echocardiography. The septal ratio showed an excellent agreement with manual measurements (R2 = 0.94, bias=-0.01, see Figure 2), leading to a detection of BSH in n = 19 vs the n = 18 detected manually (1 false-negative and 2 false-positives). In comparison to the intra and inter-observer variabilities of 12% and 42% respectively in the manual measurement (4), the automatic method had no variability for a given image acquisition.

Conclusions

The automatic measurement of myocardial wall thickness from a 2D echocardiographic images is accurate and reproducible. The implementation of the methodology in clinical practise has the potential to improve and automate the assessment of hypertrophic cardiac conditions. Abstract Figure. Pipeline for automatic measurement of WT  Abstract Figure. Agreement of BSH WT ratio

P735 Septal curvature - a novel, semi-automated parameter to aid in recognition of basal septal hypertrophy in arterial hypertension

Funding Acknowledgements

Horizon 2020 European Commission Project MSCA-ITN-2016 (764738), Grant from Fundacio La Marató de TV3 (040310).

Background and aim

Localized basal septal hypertrophy (BSH) is a known marker of increased afterload and localized deformation impairment, and can be seen in one-fifth of patients with arterial hypertension. Although there is variability in the classification, BSH is mainly defined from ratios between several wall thickness measurements. We hypothesize that the curvature of the septum is reflective of localized hypertrophy and will be significantly increased in patients with BSH. Speckle tracking endocardial delineations of the left ventricle (LV) can be used to quantify curvature, with the potential to create a novel, semi-automatized parameter for recognition of patients with an increased impact of afterload on cardiac structure and function.

Methods

An echocardiogram was performed on a total of 149 patients with a diagnosis of long-standing hypertension, treated with at least one antihypertensive drug and on 19 healthy age and sex-matched controls. The interventricular septum thickness was measured at basal and mid-level in the parasternal long axis (PLAX) and 4-chamber (4C) views. BSH was identified from a two-part criterion: both a positive visual assessment of an abrupt change in septal thickness seen in the 4C or PLAX views and a basal to mid-septal ratio ≥ 1.4. A dedicated software for speckle tracking was used to trace the endocardial border of the LV in 4C and 3C view. In post-analysis, we quantified the maximal curvature of the antero- and inferoseptal segments from the exported myocardial contour. Curvature, measured in m-1, was defined as the reciprocal value of the radius of the circle fitted into the curve defined by three subsequent neighboring points in the myocardial contour. Curvature was considered negative if the curve was convex with respect to the LV long-axis.

Results

Using septal wall thickness measurements, 19% (n = 28) of hypertensive patients were classified as having BSH, whereas all healthy controls had normal geometry. Basal antero- and inferoseptal wall thickness was significantly increased in the BSH group, which was coupled with regional deformation impairment (basal inferoseptum, controls vs. non-BSH vs. BSH: 16.1 ± 2.33 vs. 15.14 ± 2.8 vs. 13.02 ± 2.98 %, p < 0.001). The curvature of the basal inferoseptum was significantly higher in the BSH group (controls vs. non-BSH vs BSH: -23.4 (-27.2, -10.9) vs. -28.3 (-40.2, -19.3) vs. -50.5 (-66.8, -33.9) m-1, p < 0.001) (Figure 1), with the same trend seen in the basal anteroseptum. The inferoseptal curvature showed a moderately strong correlation with the inferoseptal basal-to-mid wall thickness ratio (R = 0.527, p <0.001).

Conclusion

Increased septal curvature is an easily quantifiable, single-value, semi-automated parameter reflective of localized thickening that could easily be incorporated into the output of the LV speckle tracking workflow, possibly aiding in the recognition of hypertensive patients in need of a closer clinical follow-up.

Abstract P735 Figure 1

155 Myocardial work in hypertension and mitral regurgitation- insights from non-invasive assessment of left ventricular pressure-strain relations

Funding Acknowledgements

Horizon 2020 European Commission Project H2020-MSCA-ITN-2016 (764738), Grant from Fundacio La Marató de TV3 (040310)

Background and aim

Non-invasive left ventricular (LV) pressure estimates and speckle-tracking deformation curves can be used to quantify an index of myocardial work (MWI) which may offer insight into the early changes and work distribution in hypertension (HTN) and mitral regurgitation (MR) – cardiac diseases related to pressure and volume overload. The aim is to assess segmental strain and MW indices in patients with HTN, MR, and in healthy controls.

Methods

An echocardiogram was performed in 73 participants: 31 patients with a diagnosis of long-standing HTN with signs of LV hypertrophy, 22 patients with MR without hypertension, and 20 healthy age- and sex-matched controls. LV speckle-tracking was performed in 4C, 2C, and 3C apical views. MWI was calculated between mitral valve closing and opening. Average regional values of strain and MW indices were calculated by averaging the 4C, 3C, and 2C basal, mid, and apical segments, as based on the 18-segment model of the LV. Total MW per minute (MWI/min) was calculated by multiplying global MWI by the heart rate.

Results

LV ejection fraction and global longitudinal strain (GLS) were preserved and similar in all groups (GLS, controls vs. mild/moderate MR vs. severe MR vs. HTN: -21.28 ± 2.36 vs. -21.30 ± 1.49 vs. -20.93 ± 2.46 vs. -20.93 ± 2.46, p = 0.602). MR was classified as mild or moderate in 45% (n = 10) and severe in 55% (n = 12). A strong trend of higher global MWI (controls vs. mild/moderate MR vs. severe MR vs. HTN: 2098 ± 373 vs. 2036 ± 341 vs. 2237 ± 351 vs. 2297 ± 427 mmHg%, p = 0.171), as well as MWI/min could be noted in patients with hypertension and severe MR. Averaged regional deformation values showed a gradient increasing from base to apex in all groups, significantly more pronounced in the HTN patients. This deformation pattern was reflected in myocardial work distribution. In HTN, the basal region performed a lower percentage of total work, with the apex performing an increased workload. In the MR subgroups, the work was distributed similarly to the healthy controls Results are shown in Figure 1.

Conclusion

Non-invasive pressure strain relations offer additional information on cardiac function in HTN and MR with preserved LVEF and GLS. In HTN, MW is elevated and redistributed in the LV with an apex-to-base gradient signaling an apical compensation of basal impairment in the setting of increased afterload. Mild and moderate MR is associated with a compensated state of normal global MWI and work distribution, however, MWI/min in severe MR reveals an overall increase in workload - potentially predicting further LV remodeling in these patients over time.

Abstract 155 Figure 1

P3836Myocardial work distribution in hypertensive patients with basal septal hypertrophy - a non-invasive assessment with left ventricular pressure-strain relations

Background and aim

Localized basal septal hypertrophy (BSH) is a known marker of hypertension. However, the underlying functional significance of this morphologic finding is not clear. Non-invasive LV pressure estimates and speckle-tracking deformation curves can be used to quantify myocardial work (MW), which may offer insights into work distribution in increased afterload leading to better understanding of the early changes in hypertensive heart disease. The aim is to assess segmental strain and MW indices in hypertensive patients with and without BSH, as well as in healthy controls.

Methods

An echocardiogram was performed on a total of 149 patients with a diagnosis of long-standing hypertension and on 19 healthy age and sex-matched controls. The septum was measured at basal and mid-level in parasternal long-axis and four-chamber views. A two-part criterion - a positive visual assessment of an abrupt change in septal thickness seen in the 4C or PLAX view and a basal to mid-septal ratio ≥1.4 - was used to identify BSH. LV speckle-tracking was performed in 4C, 2C, and 3C views. Myocardial work index was calculated between mitral valve closing and opening. Average regional values of strain and MW indices were calculated by averaging the 4C, 3C, and 2C basal, mid, and apical segments.

Results

BSH was present in 19.2% (n=28) of the hypertensive cohort. There were no differences in LV ejection fraction or global longitudinal strain between the subgroups. The basal inferoseptum and anteroseptum were thicker in the hypertensive patients, significantly more so in the BSH subgroup, which was coupled with a proportional decrease in local deformation. Averaged regional deformation values showed a gradient increasing from base to apex in all subgroups, more pronounced in the BSH patients due to significantly impaired average basal deformation (controls vs. non-BSH vs. BSH: −18.33±1.92 vs. −17.24±2.14 vs. −15.56±2.08%, p<0.001). This deformation pattern was reflected in myocardial work distribution in hypertension, showing the basal region performing a lower percentage of global work, especially so in the BSH patients, while the apical region performed a significantly higher percentage, with a trend of further increase in the BSH subgroup (Figure 1).

Figure 1

Conclusion

Localised BSH, a structural finding in one-fifth of the hypertensive population, is related to functional impairment in regional systolic deformation and a pronounced redistribution of myocardial work during the cardiac cycle. An apex-to-base gradient in myocardial work signals an apical compensation of basal impairment in the setting of increased afterload. Clinical follow-up of patients is needed in order to assess the prognostic relevance of these findings.

Acknowledgement/Funding

Spanish Ministry of Economy and Competitiveness (TIN2014-52923-R), Fundacio La Maratό de TV3 (040310), H2020-MSCA-ITN-2016 (764738)

Unbounded Violation of Quantum Steering Inequalities

We construct steering inequalities that exhibit unbounded violation. The concept was to exploit the relationship between steering violation and the uncertainty relation. To this end, we apply mutually unbiased bases and anticommuting observables, known to exhibit the strongest uncertainty. In both cases, we are able to procure unbounded violations. Our approach is much more constructive and transparent than the operator space theory approach employed to obtain large violation of Bell inequalities. Importantly, using anticommuting observables we are able to obtain a dichotomic steering inequality with unbounded violation. Thus far, there is no analogous result for Bell inequalities. Interestingly, both the dichotomic inequality and one of our inequalities cannot be directly obtained from existing uncertainty relations, which strongly suggest the existence of an unknown kind of uncertainty relation.

A prospective evaluation of quality of life (QOL) in a phase II trial of pemetrexed (P) plus carboplatin (Cb) ± enzastaurin (E) versus docetaxel (D) plus Cb as first-line treatment of patients (pts) with advanced non-small cell lung cancer (NSCLC)

e19050

Background: E is a selective, oral serine/threonine kinase inhibitor. PCb has shown promising clinical activity in two phase 2 trials of advanced NSCLC. This open-label, three-arm trial was designed to assess PCb ± E versus a control arm of DCb. QOL may be an important consideration with the introduction of targeted agents such as E that have a different toxicity profile than traditional chemotherapeutic agents. Methods: Pts with Stage IIIB (with pleural effusion) or IV NSCLC, ECOG PS of 0 or 1, and no prior systemic therapy were enrolled. Pts were equally randomized to one of three arms: (A) P 500 mg/m2 and Cb AUC 6 every 3 wks X 6 cycles with E given orally as a loading dose of 1200 mg or 1125 mg followed by 500 mg daily until disease progression; (B) The same regimen of PCb without E; or (C) D 75 mg/m2 and Cb AUC 6 every 3 wks X 6 cycles. Pts receiving P were also administered folic acid, vitamin B12 and steroid prophylaxis. Pts on D also received steroid prophylaxis. The Functional Assessment of Cancer Therapy-Lung (FACT-L) Questionnaire and FACT-Taxane toxicity subscale were used to evaluate QOL at baseline and every 3 weeks up to 18 weeks during treatment. A best overall response of improved or worsened was defined as an increase or decrease from baseline to last patient visit of ≥ 0.5 standard deviations of baseline scores. Results: The intent-to-treat population of this study consisted of 218 randomized pts (PCE: 72, PC: 74, DC: 72). Baseline and ≥ 1 post-baseline score was obtained from 54 pts receiving PCE (75%), 62 pts receiving PC (84%), and 54 pts receiving DC (75%). QOL data are summarized in the table below. Conclusions: Across treatment groups, differences in mean scores were not statistically significant. In addition, differences in classification of improved, stable, or worsened were not statistically significant across treatment groups.

[Table: see text]

[Table: see text]

Psychosocial impact of cancer-related symptoms among patients with lung cancer

6621

Background: Patients with lung cancer may experience adverse physical symptoms due to cancer, cancer treatment, or comorbid medical conditions. These cancer-related symptoms (CRS) may be associated with functional impairment (FI), and may affect psychosocial functioning. Methods: We conducted a retrospective analysis of self reported symptom burden with the 38-item Patient Care Monitor survey (PCM), collected as part of routine clinical care in 1,384 lung cancer patients identified by ICD-9 codes at 8 community oncology practices in the US. Structural equation models were built among 672 randomly selected patients to examine the relationships of CRS and of FI on psychosocial symptoms and to determine whether FI mediates the effect of CRS. Results: Patients were 47.7% female, with mean age of 66 years (23–91), 65% Caucasian, 16% African American, 19% other/unknown race. Stage of disease was 19% stage IV, 22% stage I-III, and 59% unspecified. Histological type was 36% adenocarcinoma, 18% squamous cell, 37% unspecified, and 9% other. The most common comorbidities were anemia, other malignancies, and respiratory disease. Depressive disorder was recorded for < 5% of patients. Surveys were collected between 2005 and 2008, ranging up to 5 years after the start of treatment (median 79 days after start of chemotherapy). Half (50.4%) of surveys were collected while the patient was in active treatment. Model findings supported a 1 factor measurement model of 19 CRS items, and a 1 factor measurement model of 8 FI items. Findings supported a 2 factor model of 11 psychosocial items, with resulting factors reflecting acute distress and despair. CRS were less severe longer after the start of chemotherapy, and not significantly worse during vs. off chemotherapy. More severe CRS significantly predicted more severe acute distress and despair, and more severe FI. In contrast to expectations and some previous research, FI was not significantly related to acute distress and despair, and did not mediate the effect of CRS on acutedistress and despair. Conclusions: Cancer related symptoms are associated with FI and with psychosocial outcomes in lung cancer patients. However, FI does not appear significantly related to psychosocial outcomes.

[Table: see text]

One or Two Drains after Lobectomy? A Comparison of Both Methods in the Immediate Postoperative Period

BACKGROUND

The conventional method of double chest tube drainage after lobectomy is well established. The aim of the study was to compare the efficacy of the two-drain versus the single-drain approach after this procedure.

METHODS

The data of 183 consecutive patients who underwent lobectomy between January 2000 and May 2005 were analyzed: 93 had two drains and 90 had a single, midposition drain. All patients were operated on by one surgeon with the same surgical technique.

RESULTS

Patients with one drain had a shorter hospital stay (7.6 days vs. 9.0 days; P = 0.001). There were no significant differences in the amount of drainage, the necessity of redrainage or broncho-aspiration, and postoperative mortality or complications. The period in which opioids (4.8 days vs. 5.6 days; P = 0.0001) and nonsteroidal anti-inflammatory drugs (6.8 days vs. 7.7 days; P = 0.002) were required was shorter in patients with one drain. The fourth postoperative day was more painful for patients with a double drain. The cost savings in the one-drain group were approximately 125 Euros per patient.

CONCLUSION

A single-drain method is effective, reduces hospitalization times and the cost of treatment in patients who undergo lobectomy.

Surgical treatment of lung cancer in patients under 45 years of age

AIM

The aim of the study was to evaluate the characteristics and prognosis of radical surgical treatment in young patients under the age of 45 with lung cancer.

METHODS

We retrospectively analysed the data of 85 young patients and 211 older patients who underwent anatomical lung resections in Wroclaw Thoracic Surgery Centre.

RESULTS

Less lobectomies were performed (p = 0.048), the incidence of carcinoid was significantly higher (p < 0.0001), stage I of lung cancer was observed less frequently (p = 0.023), the frequency of metastasis to subcarinal lymph nodes was higher (p = 0.007), a bronchial stump was microscopically infiltrated more frequently, the complete resection was noted rarer (p = 0.016) and 3-year survival rate of squamous cell carcinoma patients was worse in younger group (p = 0.017). The statistical significance was not observed between the frequency of recurrences and overall survival.

CONCLUSIONS

Lung cancer in younger patients seems to be more advanced at the time of surgery. It is probable that the group of younger patients with squamous cell carcinoma will require additional treatment after surgery.

Regional differences in systolic active stress profiles in the normal beating heart. Assessment using an ultrasound based mathematical model

Active stress (sigmaA) developed by cardiac muscle has been measured in isolated muscle preparations, under physiological loading conditions, by subtracting the passive stress (sigmaP) from the total stress (sigmaT). We previously developed a mechanical model based on M-mode ultrasound imaging to calculate these stresses in beating hearts. However, this model was based on one-dimensional imaging information and could not estimate regional differences in sigmaA. In the current study this model was improved by including two-dimensional B-mode echocardiographic data.

METHODS

In a porcine model a micro-manometer tipped catheter was used to measure left-ventricular pressure (LVP) and B-mode ultrasound images were recorded in a short-axis view. On the ultrasound image points in the mid-wall were selected and tracked to completely define the deformation of the myocardium. A kinematic model of the LV was then constructed from the displacement vectors of these points. sigmaT was calculated from the LVP. The material parameters for an exponential stress/strain relation were estimated during the diastolic E-wave when it was assumed that sigmaA = 0. These parameters were used to calculate sigmaP during systole and by subtracting this from sigmaT, sigmaA was calculated.

RESULTS

The timing and shape of sigmaA profiles match those obtained from isolated muscle experiments. SigmaA was higher and peaked sooner in the posterior wall than in the anterior wall.

CONCLUSION

Regional active stress estimation is possible in normal beating hearts.

Acromegaly due to GHRH-secreting large bronchial carcinoid. Complete recovery following tumor surgery

A case of acromegaly, secondary to GHRH secretion by a large bronchial carcinoid is reported. A 61-year-old woman presented with typical symptoms and signs of acromegaly for at least 10 years. She suffered from recurrent pneumonias, but repeated chest X-ray examinations failed to demonstrate the bronchial tumor. The diagnosis was confirmed by elevated GH, IGF-1 and GHRH secretion. We have shown an enlarged pituitary gland without focal lesions together with a cerebral meningioma on MRI and the presence of a bronchial carcinoid tumor. The latter was confirmed by histology carried out after bronchoscopy and tumor excision. We observed partial suppression of GH secretion following short-term oral bromocriptine administration in this patient. Surgical removal of the carcinoid tumor resulted in a complete clinical, hormonal and radiological cure of acromegaly. This case of acromegaly due to ectopic GHRH secretion by bronchial carcinoid differs from others described in the literature by an atypical large tumor size, the suppression of elevated GH secretion by oral bromocriptine and a concomitant meningioma.

Errors involved in the application of an imperfect peritoneal volume marker

Peritoneal volume markers have been used in numerous studies on fluid transport in peritoneal dialysis. The basic assumption used was that the macromolecular marker was stable and that the free fraction of a label (usually radiolabel) was negligibly small. In this study are presented theoretical investigations on the errors involved in application of an imperfect volume marker containing free fraction of a label. These investigations were used in assessing the errors in calculation of peritoneal volume time course, V, and fluid absorption rate (estimated by volume marker clearance, kE) using data from 20 clinical dwell studies with 1.36% Dianeal dialysis solution and radioiodinated human serum albumin as a volume marker. It has been shown that with an in vitro measured 125I free fraction of 2.72%, the error of kE estimation was 11%. However, the maximal error in estimation of V was only 0.2%. In conclusion, the performed analysis implies that calculation of the peritoneal volume time course during the dwell (with correction for the volume marker elimination) is very reliable, and the existence of a free fraction of a volume marker label results in a negligibly small error. However, even small free fraction of the label results in a significant overestimation of the fluid absorption rate.

Effect of Carbon Deposits on the Structure of Hybrid C/TiO2/SiO2 Adsorbents

The structural characteristics of pyrocarbon/X (X = fumed silica, mesoporous silica gel, fumed titania/silica, CVD-TiO2/fumed silica, CVD-TiO2/silica gel) prepared using several precursors [CH2Cl2, cyclohexene and TiO(AcAc)2, where Ac = acetylacetonate] were studied using the nitrogen adsorption/desorption method and an improved technique to allow the calculation of pore size distributions applying regularization procedures. Various pore models were used for the carbon phase. The pyrocarbon structure and distribution on the TiO2/SiO2 supports depends primarily on the structural features of the titania phase which exhibits catalytic activity in the pyrolysis of organic materials. The formation of relatively large concentrations of pyrocarbon typically reduces the porosity and specific surface area of the hybrid adsorbents produced.

Structural and Energetic Nonuniformities of Pyrocarbon-Mineral Adsorbents

Several series of pyrocarbon-mineral adsorbents (carbosils) were studied using the nitrogen adsorption method to compute structural and energetic parameters within the scope of overall adsorption isotherm approximation applying a regularization procedure with consideration for surface heterogeneity. A portion of pyrocarbon deposits (graphene clusters) fills mesopores of the oxide supports, but another portion represents relatively large nonporous pyrocarbon globules formed on the outer surfaces of the oxide matrices. Contributions of these two types of pyrocarbon deposits depend on the nature of oxide matrices and carbonized precursors. The characteristics of pyrocarbon formed on the silica (silica gel, fumed silica) surfaces differ from those for deposits prepared on the surfaces of titania/silica and alumina/silica or by the pyrolysis of metal acetylacetonates (Zr(AcAc)(4), TiO(AcAc)(2), Ni(AcAc)(2), Zn(AcAc)(2), Cr(AcAc)(3), Co(AcAc)(2)) on mesoporous silica gel. The structural and energetic characteristics estimated using the adsorption method with consideration for the adsorbent heterogeneity are fruitful for comparative analysis of the (1)H NMR spectra of water adsorbed on carbosils from the gas phase or unfrozen in the aqueous suspensions at T < 273 K. Copyright 2001 Academic Press.

Revision hip arthroplasty in aseptic loosening of total hip replacement

Background. Problems encountered during revision hip arthroplasty are presented, based on 30 years of experience at the Orthopedic Clinic of the Medical University of Lodz.<br /> Material and methods. During this period of time 96 cases (5,13%) with aseptic hip loosening were diagnosed. All patients were evaluated clinically based o the Merle d'Aubigne-Postel criteria, and radiologically by means of De Lee and Gruen migration zones.<br /> Results. In our material hip loosening was most frequently observed in cases where a McKee-Farrar hip prosthesis had been used, and in cases with a PM uncemented acetabulum or uncemented Mittelmeier pin.<br /> Conclusions. The study showed that surgical technique plays the most significant role in aseptic loosening of hip replacement. The aseptic loosening of hip prostheses should be diagnosed early, and revision hip arthroplasty should be performed as soon as possible. This surgery must be preformed in specialized centers with adequate equipment and a team of experienced surgeons.

Highly Dispersed X/SiO(2) and C/X/SiO(2) (X=Alumina, Titania, Alumina/Titania) in the Gas and Liquid Media

Fumed oxides, such as silica, alumina, titania, and mixed X/silicas (X=Al(2)O(3) (AS), TiO(2) (TS), CVD-TiO(2), Al(2)O(3)/TiO(2) (AST)), pristine or covered by carbon deposits formed due to pyrolysis of cyclohexene, were studied using nitrogen adsorption-desorption, photon correlation spectroscopy particle sizing, and electrophoresis. A significant influence of the nature of surface-active sites and structural features of oxides (individual silica, mixed fumed, or prepared using chemical vapor deposition (CVD)) on the pyrolysis of cyclohexene is observed with respect to the pore size distributions due to differences between primary particles in aggregates and on their outer surfaces in the filling of channels by pyrocarbon, resulting also in a decrease in fractal dimension. Structural characteristics and dependences of the particle size distribution and electrokinetic potential of X/SiO(2) and C/X/SiO(2) on the pH of aqueous suspensions suggest that the carbon deposit covers mainly acidic sites at the X/SiO(2) interfaces and X phase patches possessing catalytic activity in pyrolysis, as the negative charge of particles is reduced by pyrocarbon grafting. Copyright 2000 Academic Press.

Characterization of Titania/Silica Gel by Means of Low-Pressure Nitrogen Adsorption

Adsorbents synthesized by grafting of titania onto mesoporous silica gel surfaces at different temperatures were studied by means of nitrogen adsorption-desorption and water desorption. The pore size distribution f(R(p)) of titania/silica gel depends on the titania concentration (C(TiO(2))) and the temperature of titania synthesis. Nonuniformity of TiO(2) phase is maximal at a low C(TiO(2)) value (3.2 wt.% anatase deposited at 473 K), and two peaks of the fractal dimension distribution f(D) are observed at such a concentration of titania, but at larger C(TiO(2)) values, only one f(D) peak is seen. More ordered filling of pores and adsorption sites by nitrogen, reflecting in the shape of adsorption energy distributions f(E) at different pressures of adsorbate, is observed for adsorbent with titania (rutile+anatase) grafted on silica gel at a higher temperature (673 K). Copyright 2000 Academic Press.

Cigarette consumption and sales of nicotine replacement products

BACKGROUND

The first nicotine replacement product, Nicorette Gum, was marketed in 1984 as an adjuvant to help smokers quit smoking. In 1992, sales of nicotine patches were begun. Before 1996, nicotine gums and nicotine patches were prescribed by physicians and supplemented with behavioural counselling. Since 1996, nicotine gums and patches became available over the counter.

OBJECTIVES

To examine the effect of sales of nicotine replacement products on national cigarette consumption.

DESIGN

National time series quarterly cigarette consumption, sales of nicotine gums and patches data between 1976 and 1998 are used to estimate a time series autoregressive moving average intervention model.

PARTICIPANTS

National reported statistics.

MAIN OUTCOME MEASURES

Per capita cigarette sales.

RESULTS

A 10% increase in sales of nicotine replacement products will lead to a 0.04% reduction in cigarette sales. The model indicates that a 0.076% reduction in cigarette consumption is associated with the availability of nicotine patches after 1992. The over the counter dummy variable (after 1996) has a negative sign, but is not significant, perhaps due to only a few quarters of data in the study period.

CONCLUSIONS

Nicotine replacement products (nicotine gums and nicotine patches) play a significant role in reducing cigarette consumption, in addition to the negative effect of increasing cigarette price and the overall trend of declining cigarette consumption (as reflected by the time trend variable). The findings of this study suggest that additional efforts for promoting sales of nicotine replacement products will be another effective alternative to discouraging cigarette consumption.

Characterization of Fumed Alumina/Silica/Titania in the Gas Phase and in Aqueous Suspension

Fumed oxide alumina/silica/titania was studied in comparison with fumed alumina, silica, titania, alumina/silica, and titania/silica by means of XRD, (1)H NMR, IR, optical, dielectric relaxation, and photon correlation spectroscopies, electrophoresis, and quantum chemical methods. The explored Al(2)O(3)/SiO(2)/TiO(2) consists of amorphous alumina ( approximately 22 wt%), amorphous silica ( approximately 28 wt%), and crystalline titania ( approximately 50 wt%, with a blend of anatase (88%) and rutile (12%)) and has a wide assortment of Brønsted and Lewis acid sites, which provide a greater acidity than that of individual fumed alumina, silica, or titania and an acidity close to that of fumed alumina/silica or titania/silica. The changes in the Gibbs free energy (DeltaG) of interfacial water in an aqueous suspension of Al(2)O(3)/SiO(2)/TiO(2) are close to the DeltaG values of the dispersions of pure rutile but markedly lower than those of alumina, anatase, or rutile covered by alumina and silica. The zeta potential of Al(2)O(3)/SiO(2)/TiO(2) (pH of the isoelectric point (IEP) equals approximately 3.3) is akin to that of fumed titania (pH(IEP(TiO2)) approximately 6) at pH > 6, but it significantly differs from the zeta of fumed alumina (pH(IEP(Al2O3)) approximately 9.8) at any pH value as well as those of fumed silica, titania/silica, and alumina/silica at pH < 6. The particle size distribution in the diluted aqueous suspensions of Al(2)O(3)/SiO(2)/TiO(2) studied by means of photon correlation spectroscopy depends relatively slightly on pH in contrast to the titania/silica or alumina/silica dispersions. Theoretical calculations of oxide cluster interaction with water show a high probability of hydrolysis of Al-O-Ti and Si-O-Ti bonds strained at the interface of alumina/titania or silica/titania due to structural differences in the lattices of the corresponding individual oxides. Ab initio calculated chemical shift delta(H) values of H atoms in different hydroxyl groups at the oxide clusters and in bound water molecules are in agreement with the (1)H NMR data and show a significant impact of charged particles (H(3)O(+) or OH(-)) on the average delta(H) values of water droplets with (H(2)O)(n) at n between 2 and 48. Copyright 1999 Academic Press.

Structure of Chemical Vapor Deposition Titania/Silica Gel

The structure of porous silica gel/titania synthesized using chemical vapor deposition (CVD) of titania via repeated reactions of TiCl(4) with the surface and subsequent hydrolysis of residual Ti-Cl bonds at different temperatures was investigated by means of low-temperature nitrogen adsorption-desorption, X-ray diffraction (XRD), IR spectroscopy, and theoretical methods. A globular model of porous solids with corpuscular structure was applied to estimate the porosity parameters of titania/silica gel adsorbents. The utilization of this model is useful, for example, to predict conditions for synthesis of titania/silica with a specified structure. Analysis of pore parameters and fractal dimension suggests that the porosity and fractality of samples decrease with increasing amount of TiO(2) covering the silica gel surface in a nonuniform layer, which represents small particles embedded in pores and larger particles formed at the outer surface of silica globules. Theoretical simulation shows that the Si-O-Ti linkages between the cover and the substrate can be easily hydrolyzed, which is in agreement with the IR data corresponding to the absence of a band at 950 cm(-1) (characteristic of Si-O-Ti bridges) independent of the concentration of CVD-titania. Copyright 1999 Academic Press.

[The assessment of changes of the plate growth in Blount disease by MRI]

The changes within growth plates around the knee in Blount disease have been analyzed with MRI in 4 patients with late onset tibia vara. Extensive changes were found in both tibial and femoral growth plate. General widening of the plate, invagination into metaphysis and high intensity irregularities of the shape were observed. Lateral aspect of both physes was involved to higher degree. Our study supports mechanical etiology of the late onset tibia vara. In our opinion long lasting distraction stress on the lateral aspect of the knee due to the varus deformity might be responsible for the changes observed in MRI.

[Evaluation of peritoneal solute transport parameters in diabetics treated with continuous ambulatory peritoneal dialysis]

Increasing number of diabetics (D) on CAPD induced us to perform detailed kinetic evaluation of these patients. The purpose of the study was to characterize peritoneal solute transport parameters in diabetics and non-diabetics (ND) treated with CAPD and furthermore to assess clinical implications of eventual differences, especially with regard to programming the long-term CAPD in D. Twelve patients (7D and 5ND) on CAPD for 3-55 months were qualified to the investigation. They were clinically stable, with no impairment of ultrafiltration and free of peritonitis for at least 3 months. Four hours dwell studies with 2.0L of 3.86% glucose dialysis fluid were performed and mass transport coefficients (KBD) for glucose, potassium, sodium, total protein, urea and creatinine were calculated. No statistical differences for KBD between D and ND were found. However for every solute the average KBD values were higher in D that in ND. The observed differences do not justify any different treatment modality for D on peritoneal dialysis (PD). However high SD values, resulting from differences of peritoneal solute transport between patients, indicate the necessity of individualization of PD program.

Transport of lanthanides in milk into suckling rats

The aim of this paper was to examine the transport of lanthanides in milk of contaminated rats into their sucklings and the retention of lanthanides in the sucklings. The research involved 55 female Wistar rats contaminated in the period of lactation and their offspring (400 infant rats). The study showed that in the period of lactation the transport in milk from the mother to the offspring of the lanthanide radionuclides under examination (144Ce, 147Nd, 152Sm, 155Eu and 160Tb) increased with their mass numbers: CE < Nd < Sm < Eu < Tb, and varied from 0.01% for 144Ce to 17.7% for 160Tb of the administered dose per litter. It was demonstrated that lanthanides were not absorbed from the digestive tract of sucklings because they were not detected beyond its area. Because of its highest concentration in milk 160Tb was chosen for further investigation of the kinetics of transport in individual segments of the digestive tract. The model for determining the function of lanthanide retention in separate parts of the digestive tract of sucklings and the half life of effective accumulation and elimination of 160Tb in the whole organism as well as in individual segments of the digestive tract are presented. Terbium-160 accumulation in sucklings increased whereas its elimination decreased with the age of the infant. No significant differences in 160Tb specific activity in stomach, and small and large intestines were observed in sucklings one to 21 days old. Biological half lives for retention of the contaminated milk were as follow: 0.25 +/- 0.021 per day for the stomach, 0.92 +/- 0.12 per day for the small intestine and 5.03 +/- 0.22 per day for the large intestine. The data obtained can be used in the evaluation of the doses absorbed from 160Tb and from other lanthanide radionuclides that are nonabsorbable from the digestive tract, as well as in estimation of the radiation risk to the offspring of mothers contaminated in the period of lactation.

Bombesin plasma levels in patients with benign and malignant breast disease

Some reports suggest a role for bombesin-like peptides in the pathology of breast tumors. Bombesin and related gastrin-releasing peptides have been shown to influence the inositol phospholipid signalling pathway and stimulate growth of some cells, including some human breast cancer cell lines. We measured the plasma concentration of bombesin in 23 breast cancer patients, 32 patients suffering from benign breast disease and in 21 healthy controls. The bombesin concentration in plasma taken from the thoracodorsal vein, in the vicinity of the tumor in breast cancer patients was higher than that in the peripheral circulation (mean +/- SEM, 91.3 +/- 54.3 vs. 40.9 +/- 27.4 pg/ml; p < 0.05). Bombesin concentrations in the cubital vein in breast cancer patients and in those with benign breast disease (61.7 +/- 49.3 pg/ml) was significantly higher than that in the control group (23.7 +/- 5.06 pg/ml; p < 0.05). Our findings suggest storage or synthesis of bombesin-like peptides within the affected breast and may confirm the role of these peptides in the growth of breast tumors.

[Anterior transposition of the ulnar nerve in the cubital area-- a contribution to the treatment of reflex sympathetic dystrophy]

A variety of symptoms makes difficult the diagnosis and causes therapeutic problems after blunt limb trauma, particularly after long time from the immediate treatment. Three cases of sympathetic reflex dystrophy of the ulnar nerve as a late consequence of blunt upper limb traumas are presented. Long-term medical and surgical treatment produced temporary remission only. Full efficiency of the limb and remission were achieved only when anterior transposition of the nerve was done.

[Intracranial hematoma as a complication after surgical treatment of meningiomas]

The causes of postoperative haematomas after operations for intracranial meningiomas are analysed. The percentage of this complication in this material was 5.2%. The most frequent concomitant disease in this series was arterial hypertension. The majority of postoperative haematomas was observed after longer lasting operations with totally excised large tumour. Perhaps, one of a large number of causes, is slight coagulopathy.

Morphometric ultrastructural analysis of muscle fibers and neuromuscular junction in rats kept under conditions of weightlessness for 21 days

The aim of the study was qualitative and quantitative analysis of muscles and neuromuscular junctions of m. quadriceps, m. diaphragma and m. soleus in rats after being kept for 21 days under conditions of weightlessness. Degenerative changes were noted in both of these subjects and their intensity depended on the kind of fibres. The disorders were most pronounced in fibres and neuromuscular junctions of the soleus muscle in which red fibres prevail.

[Oculomotor nerve paralysis in intracranial aneurysm]

The authors analysed the data in 257 cases treated surgically for intracranial aneurysms. In 8 of these cases evidence of damage to the oculomotor nerve was found, as a result of aneurysms of the posterior communicating artery or the internal carotid near the site where the posterior communicating artery branches off. Six patients had oculomotor nerve paralysis and two had only partial involvement of the nerve. In 4 cases the aneurysm was not ruptured but manifested itself as headache followed by oculomotor damage. The authors stress the necessity of carrying out arteriography in each not clear case of oculomotor damage.

The effect of toxic doses of lanthanum and cerium on the placental barrier and the blood/organ barrier in mice after intravenous injection of these elements

In earlier studies the toxicity of the lanthanides was determined on the basis of the LD50/30 value, increase of serum ornithine carbamoyltransferase activity, and the degree of passage of the lanthanides to the fetuses and milk. The purpose of the present work was to investigate the effects of toxic doses of lanthanum and cerium on the function of the placental barrier and the blood/organ barrier in mice using substances of known molecular weight labelled with radionuclides (14C-aminoisobutyric acid--AIB, 3H-thymidine and 125I-albumin). Increased uptake of 14C-AIB and 3H-thymidine was demonstrated in the liver, spleen and placenta of mice after toxic doses of La and Ce indicating disturbances in the function of the blood/organ barrier (liver, spleen, placenta) due to damage to the vascular endothelium or cell membranes. No disturbances were shown in the function of the placental barrier (which would have caused increased passage of these markers to the fetus), and rupture of the cell membranes in the studied tissues was not demonstrated (it would have caused increased passage of 125I-albumin, a macromolecular compound) in any of the studied organs in mice.

Regeneration of axonal endings of neuromuscular junctions of the soleus muscle in rats under conditions of hypodynamia

The purpose of the experiments performed was morphometric ultrastructural evaluation of the regeneration of axonal endings after sectioning of nerves in rats kept under conditions of hypodynamia. The investigation indicated a retardation of regeneration of the axonal endings of neuromuscular junctions after denervation of the soleus muscle in rats kept under conditions of hypodynamia as compared with those of the control group. The retarded regeneration of the axonal endings of neuromuscular junctions in experimental animals as compared with that in the control group may be referred to the above mentioned enzymatic and electrolytic disturbances caused by restriction of mobility.

The metabolism of 4-iodantipyrine--I125 (RIAP) in rat organism after intravenous injection

Radioactive antipyrine labelled with I125 (RIAP) is used in radioisotope diagnostic methods for determination of the total water content of the organism, and cerebral and cardiac blood flow. The purpose of this study was to investigate RIAP metabolism in rats after intravenous administration. The distribution, excretion and passage with milk to the newborn animals were studied. Electrophoresis of the urine of the rats treated with this radioisotope was done as well. A rapid accumulation of the radioisotope in the thyroid was observed (the T 1/2 value was about 4 hours, and the greatest accumulation of RIAP was after 15 hours). The biological time of RIAP elimination from the thyroid was 5 days. I125 concentration in other organs was below 1% of the injected dose. Excretion was mainly with urine in three phases. In the urine of the rats two I125-containing fractions were found (a iodide fraction and an unidentified fraction). RIAP administration to lactating females caused passage of between 10 and 20% of the administered dose to pass to the newborns with milk. RIAP administration to pregnant rats raised this proportion by several per cent. Thyroid blockade with potassium iodide had no effect on RIAP passage with milk to the newborns. These results suggest a rapid loss of iodine from RIAP after intravenous injection.

Persistence of nerve sprouting with features of synapse remodelling in soleus muscles of adult mice

An increase in the number of nerve branches of the unmyelinated axon terminals with increasing age was observed in normal adult mouse motor endplates. In addition, ultrastructural investigation revealed signs of nerve retraction. A combined light and electron microscopic investigation was performed on zinc-iodine-osmium stained endplates in soleus muscles. The number of branch points in a synapse, endplate length and muscle fiber diameter were evaluated in "young adult" (3 months) and adult (6 and 11 months) mice. For all 3 parameters, 3-month-old animals had the lowest values. Eleven-month-old animals had more branch points and larger endplate lengths than 6-month-old animals while there was no significant difference in fiber diameters. Branch point numbers and endplate length were correlated in each muscle while fiber diameters did not correlate with any of the other parameters. The ultrastructure of 15 thin nerve branches--likely candidates for new branches--was investigated in serial section and in 14 of them synaptic contacts were found. Near such contacts, empty gutters, possibly abandoned former synaptic sites, were present in several cases. It is concluded that there is continual nerve sprouting in synapses of adult mice and that sprouts form synaptic contacts. The possible signs of nerve retraction observed indicate that, as in the frog, synaptic contacts in mouse muscles undergo some continual remodeling.

Morphometric ultrastructural study of the regeneration of soleus muscle in hypokinesia

The aim of the present study was a morphometric ultrastructural evaluation of regenerating soleus muscle fibers after denervation under conditions of hypokinesia. It was found that in rats kept under conditions of hypokinesia degenerative changes in the soleus muscle after denervation are more pronounced than in the control. On the 36th day after denervation of muscle, symptoms of regeneration of muscle fibers were observed. It was more pronounced in the control than in the experimental groups. Denervation and immobilization applied simultaneously causes more severe degeneration and atrophy of muscle fibers than does the action of only one of these factors.

Morphometric ultrastructural evaluation of the axonal endings in the neuromuscular junctions of pigeons after long lasting limitation of movement

Ultrastructural quantitative and qualitative evaluations of axonal endings in the neuromuscular junctions of latissimus dorsi posterior muscle in the birds kept under limited mobility are performed. The investigation showed that as the time of hypodynamia is prolonged the degenerative changes appear in most of the axonal endings. In the earlier period of limited mobility the number and volume of internal structures of the axonal endings (mitochondria and synaptic vesicles) decreased. In the longer period of hypodynamia fragmentation of axonal endings and their resorption by the Schwann cell were observed. These changes are considered as the third, final period of degeneration of the investigated structures.

Influence of physical exercise after long-lasting hypodynamia on the morphological parameters of muscle fibers

The purpose of this research was morphometric ultrastructure evaluation of the fibers in muscles taking part in the flight of pigeons forced to exercise after a long period of hypodynamia. It was found that following physical exercise, after 12 and 18 months of mobility limitation, there appeared marked qualitative and quantitative changes: a diminution of the volume fraction and number of mitochondria, increase of smooth sarcoplasmic reticulum and sarcoplasm, and a significant decrease of the number of glycogen granules as compared with those after 18 months hypodynamia. The above described changes were more pronounced in the supracoracoideus than in the pectoralis muscle.

Effect of various doses of cerium on the serum level of ornithine-carbamyltransferase in rats

The relationships between different cerium doses administered intravenously as CeCl3 and the mortality of rats and their serum OCT level were studied. The LD50/30 value for cerium given intravenously to rats was 5.56 mg Ce/kg. A directly proportional correlation was demonstrated between intravenously administered Ce doses and the serum OCT level above a threshold dose.

Bivalent tin metabolism and toxicity after intravenous injection in rats

With progressing advances in radioisotope diagnostic methods in nuclear medicine new radiopharmaceutic agents have been introduced containing inorganic soluble compounds of bivalent tin (Sn+2). An important problem is to study the metabolism and toxicological effects of Sn+2. In the presently reported work the distribution of Sn+2 was determined in the organism of rats at different time intervals after intravenous administration of 113SnCl2 (from 10 minutes to 4 months) and the rate of its elimination from the whole body was studied. Sn+2 toxicity was determined calculating the LD50/30 dose of Sn+2 and by means of the OCT test (ornithine-carbamyltransferase level in the serum). The investigation demonstrated selective accumulation of Sn+2 in the liver and spleen where it remained for a long time, phasic elimination of tin from the whole body, and its moderate toxicity after intravenous administration.