Application of the Target Lipid Model and Passive Samplers to Characterize the Toxicity of Bioavailable Organics in Oil Sands Process-Affected Water

Oil sand operations in Alberta, Canada will eventually include returning treated process-affected waters to the environment. Organic constituents in oil sand process-affected water (OSPW) represent complex mixtures of nonionic and ionic (e.g., naphthenic acids) compounds, and compositions can vary spatially and temporally, which has impeded development of water quality benchmarks. To address this challenge, it was hypothesized that solid phase microextraction fibers coated with polydimethylsiloxane (PDMS) could be used as a biomimetic extraction (BE) to measure bioavailable organics in OSPW. Organic constituents of OSPW were assumed to contribute additively to toxicity, and partitioning to PDMS was assumed to be predictive of accumulation in target lipids, which were the presumed site of action. This method was tested using toxicity data for individual model compounds, defined mixtures, and organic mixtures extracted from OSPW. Toxicity was correlated with BE data, which supports the use of this method in hazard assessments of acute lethality to aquatic organisms. A species sensitivity distribution (SSD), based on target lipid model and BE values, was similar to SSDs based on residues in tissues for both nonionic and ionic organics. BE was shown to be an analytical tool that accounts for bioaccumulation of organic compound mixtures from which toxicity can be predicted, with the potential to aid in the development of water quality guidelines.

Endoultrasonography (EUS) examination of the esophagus in the diagnosis of esophageal duplication: a case report and a review of a literature

Esophageal duplication cysts are a rare medical entity. In most cases they are located at the level of the distal esophagus. Although our case is not unique, we want to focus on it as a reflection on diagnostic methods. The aim of this article is to show through the report on a case of esophageal duplication treated by us, followed by a review of similar cases in the literature, the utility of EUS in the diagnosis of upper-diaphragmatic and not communicating esophageal duplication. We report a case of a 43 year-old woman. She came to our attention for heartburn and retrosternal sense of space. The patient underwent an endoultrasonography (EUS) examination of the esophagus. The framework put EUS diagnosis of cystic formation of the esophagus (esophageal duplication cysts likely). We demonstrate that only EUS has a correlation with the determination of the pre-operative diagnosis with a statistical significance (p <0.001). In the diagnosis of esophageal not communicating duplication cysts EUS is the most specific diagnostic exam.

Clinical target volume localization using conventional methods (anatomy and palpation) and ultrasonography in early breast cancer post-operative external irradiation

PURPOSE

To evaluate the accuracy of three methods, anatomy (A), palpation (P) and ultrasounds (US) in localizing the clinical target volume (CTV) in patients (pts) with early breast cancer (EBC) undergoing breast external irradiation as part of conservation therapy.

MATERIAL AND METHODS

One hundred consecutive pts with EBC (T(is) 1%, T1 78%, T2 21%, N- 68%, N+ 32%), treated with conservation surgery and breast irradiation with opposed tangential portals, were prospectively analyzed. Anatomically, palpatory or ultrasound defined field borders for CTV localizations were determined in the same position thanks to the utilization of a vacuum-formed cellulose acetate immobilization cast, removed during CTV definitions.

RESULTS

P and US CTV localizations have been found to coincide on the four margins (superior, inferior, medial, lateral) in only 1/100 pts, while no pt showed identical A and US CTV localizations. Only 31/397 (8%) field measurements with A, and 98/395 (25%) with P corresponded to US border definition. If mean and median values of each field border were considered, the CTV was generally overestimated with P appearing more accurate than A in a gross definition of the target (P < 0.01). However, a geographical miss of at least one field border of CTV occurred in 55% of pts with A and in 36% of pts with P. The most critical margin to be defined with conventional methods was the superior one: an underestimation of the cranial border of CTV with A was observed in 51% and with P in 22% of pts (22% and 8%, respectively, when an underestimation by more than 1.5 cm was considered). When pre-menopausal and peri/post-menopausal groups of pts were separately analyzed, conventional methods were highly inaccurate to define the superior border in younger pts, in which a geographical miss was noted with A in 62% and with P in 35% of cases (P < 0.05). When an underestimation of more than 1.5 cm was evaluated, these values were reduced to 33% and 12%, respectively (P = 0.02). Also, in the subgroup of pre-menopausal patients the CTV defined by palpatory reference lines appeared to be more accurate than A-method (P < 0.01).

CONCLUSIONS

Conventional methods frequently appear inadequate to localize residual mammary gland in EBC post-operative external irradiation. This analysis evidentiates the inaccuracy of empirical CTV definition, and suggests that palpation or anatomical reference borders should be critically used and that state of art imaging methods should be included in treatment planning, particularly in pre-menopausal pts. If economical or individual variables have to be taken into account, palpation might be considered in post-menopausal women.

Levothyroxine suppressive therapy for solitary thyroid nodule

In order to evaluate the efficacy of a TSH suppressive dose of levothyroxine to reduce the volume of a single thyroid nodule we studied 55 euthyroid patient: 45 (group A) were suppressed with LT4 (mean 1.7 +/- 0.9 micrograms/Kg/day) for 21.3 +/- 5.3 months, and 10 patients (group B) served as controls. All the nodules were "cold" at scintiscanning, solid at ultrasonography and benign by fine-needle aspiration cytology. As responders were assumed the nodules shrinked at the end of treatment of 50% in volume. Thyroid function values (TSH, T4, FT4, T3, FT3, thyroid peroxidase and thyroglobulin antibodies), clinical and ultrasonographic findings were evaluated initially and at the end of the study. A significant nodular volume decrease occurred in 8 treated patients (17.8%) while 37 (82.2%) amongst the group suppressed and all controls showed no change (A vs B = NS). In two untreated patients new nodules were noted; no new nodules were discovered in the treated group (A vs B p < 005). No side effects occurred in any treated patient, even if at the end of treatment a significant T4 and FT4 (p < 0.01) increase was observed. No one onset parameter can predict the response to the therapy. These results suggest that only a small group of patients affected by a single thyroid nodule seems to respond to a TSH suppressive therapy.

[Combined therapy, oral hypoglycemic agent and low-dose insulin, in type 2 diabetes mellitus in secondary failure: a year's experience]

We have evaluated, for a period of 12 months, the response to the combined therapy with oral hypoglycaemic agents and insulin at low doses in a group of 21 patients with type 2 diabetes mellitus in secondary failure. A clear improvement of the parameters considered (fasting and postprandial glycaemia, glycated haemoglobin) was obtained, while maintaining the endogenous secretion of insulin. Important side effects were not observed and the increases of body weight and insulin dose registered in the course of one year were of minor importance.

[Altered diastolic function of the left ventricle in juvenile diabetes. Computerized echocardiographic study]

Using digitized M-mode ecocardiography, 26 young subjects with type I diabetes mellitus of at least three years duration, without any clinical evidence of heart disease have been studied, searching for subclinical impairment of left ventricular function. Patients have been divided in two groups according to the presence (Group I, N degrees 7 patients) or absence (Group II, N degrees 19 patients) of retinopathy. The time interval from the shortest left ventricular diameter to the onset of mitral valve opening was significantly increased as compared with the control Group (10.20 +/- 8.88 control Group; 29.21 +/- 12.99 Group II, p less than 0.001; 41.00 +/- 12.29 Group I, p less than 0.001). Furthermore, a close correlation between the above named time interval and the duration of diabetes was found (r = 0.496, p less than 0.01). Finally, the change of left ventricular dimension during the time interval from the shortest left ventricular diameter to the onset of mitral valve opening, expressed as a percentage of left ventricular end-diastolic diameter, was increased (3.20 +/- 3.43 control Group; 8.21 +/- 5.51 Group II, p less than 0.02; 12.43 +/- 5.56 Group I, p less than 0.001). Our results suggest an impairment of ventricular relaxation due to increased wall stiffness. We conclude that there are often subclinical cardiac abnormalities in young diabetics resulting in impairment of diastolic function that is correlate with the duration of diabetes and with the presence of clinical complications such as retinopathy.

Drug-induced alterations of the hypothalamus-hypophysis axis

Omitting hormonal variations caused by other drugs already objects of research, the behaviour pattern of GH, PRL, TSH, following acute administration of cimetidine, nomifensine, domperidone has been considered in normal subjects, in patients with pituitary non-secreting and PRL-secreting adenomas and in patients with amenorrhea-galactorrhea syndrome without evidence of adenoma. The results confirm the influence which drugs employed in the therapy of non-endocrine diseases provide a way to alter the functions of the hypothalamus, sometimes relatively specifically, and the secretion of pituitary hormones provides us with a possibility of analyzing the CNS output.

[Echo-angiocardiographic correlations in congenital abnormalities of the mitral valve (author's transl)]

Echocardiographic findings satisfactorily compared with angiocardiographic data in six infants affected by congenital abnormalities of the mitral valve. Peculiar echocardiographic features were as follows: a) mitral stenosis: reduced E-F slope of the anterior mitral leaflet, paradoxical diastolic movement of the posterior leaflet, enlargement of the left atrium; b) "parachute mitral valve": small, dysmorphic, stiff mitral valve, with an extra echo projecting between those of the two leaflets; c) "cor triatriatum": enlarged left atrium whose cavity is divided in two portions by an extra echo; d) "hypoplastic left heart syndrome": the mitral leaflets are thin, short. The ventricular cavity and the diameter of the aorta are small; the right ventricle and the pulmonary artery are on the contrary markedly dilated.