Cost assessment of different routes for phosphorus recovery from wastewater using data from pilot and production plants

Phosphorus (P) recovery from wastewater has considerable potential to supplement limited fossil P reserves. Reliable cost data are essential for investor and policymaker decisions. In this study, investment and operational costs for nine P recovery processes were calculated from the investor's perspective, taking into account all relevant side effects on the sludge treatment or the wastewater treatment plant. The assessment was based on pilot and full-scale data which were thoroughly consolidated and standardized with technical and cost data from the German wastewater-sludge treatment train to enable direct comparison. The cost influence of precipitation processes on the current wastewater-sludge treatment train ranges from -0.14 (generating profit) to 0.23 EUR per population equivalent (PE) and year, while the cost influence of sludge leaching processes is around 2.50 EUR/(PE y). The cost influence of processes using dry sludge and mono-incineration ash varies between 0.33 and 3.13 EUR/(PE y), depending on existing disposal pathways, mono-incineration, co-incineration or agricultural use of sludge. The specific costs per kg P recovered (-4 to 10 EUR/kg P) are in general higher than conventional fertilizer production (1.6 EUR/kg P). However, annual costs per PE represent less than 3% of the total costs for wastewater disposal.

Evaluating new processes and concepts for energy and resource recovery from municipal wastewater with life cycle assessment

Energy and resource recovery from municipal wastewater is a pre-requisite for an efficient and sustainable water management in cities of the future. However, a sound evaluation of available processes and pathways is required to identify opportunities and short-comings of the different options and reveal synergies and potentials for optimization. For evaluating environmental impacts in a holistic view, the tool of life cycle assessment (LCA, ISO 14040/44) is suitable to characterize and quantify the direct and indirect effects of new processes and concepts. This paper gives an overview of four new processes and concepts for upgrading existing wastewater treatment plants towards energy positive and resource efficient wastewater treatment, based upon an evaluation of their environmental impacts with LCA using data from pilot and full-scale assessments of the considered processes.

Comparing environmental impacts of tertiary wastewater treatment technologies for advanced phosphorus removal and disinfection with life cycle assessment

Different technologies for tertiary wastewater treatment are compared in their environmental impacts with life cycle assessment (LCA). Targeting very low phosphorus concentration (50-120 μg/L) and seasonal disinfection of wastewater treatment plant (WWTP) secondary effluent, this LCA compares high-rate sedimentation, microsieve, dual media filtration (all with UV disinfection), and polymer ultrafiltration or ceramic microfiltration membranes for upgrading the large WWTP Berlin-Ruhleben. Results of the LCA show that mean effluent quality of membranes is highest, but at the cost of high electricity and chemical demand and associated emissions of greenhouse gases or other air pollutants. In contrast, gravity-driven treatment processes require less electricity and chemicals, but can reach significant removal of phosphorus. In fact, dual media filter or microsieve cause substantially lower specific CO2 emissions per kg P removed from the secondary effluent (180 kg CO2-eq/kg P, including UV) than the membrane schemes (275 kg CO2-eq/kg P).

Proof of concept for a new energy-positive wastewater treatment scheme

For improved exploitation of the energy content present in the organic matter of raw sewage, an innovative concept for treatment of municipal wastewater is tested in pilot trials and assessed in energy balance and operational costs. The concept is based on a maximum extraction of organic matter into the sludge via coagulation, flocculation and microsieving (100 μm mesh size) to increase the energy recovery in anaerobic sludge digestion and decrease aeration demand for carbon mineralisation. Pilot trials with real wastewater yield an extraction of 70-80% of total chemical oxygen demand into the sludge while dosing 15-20 mg/L Al and 5-7 mg/L polymer with stable operation of the microsieve and effluent limits below 2-3 mg/L total phosphorus. Anaerobic digestion of the microsieve sludge results in high biogas yields of 600 NL/kg organic dry matter input (oDMin) compared to 430 NL/kg oDMin for mixed sludge from a conventional activated sludge process. The overall energy balance for a 100,000 population equivalent (PE) treatment plant (including biofilter for post-treatment with full nitrification and denitrification with external carbon source) shows that the new concept is an energy-positive treatment process with comparable effluent quality than conventional processes, even when including energy demand for chemicals production. Estimated operating costs for electricity and chemicals are in the same range for conventional activated sludge processes and the new concept.

[Clinical case of the month. Renovascular arterial hypertension complicated by diabetes insipidus: report of a case and review of the literature]

Mrs. A, a 62 year old patient with a history of hypertension, polyuria and polydipsia is hospitalized after a malaise. A severe hypokalemia, which is the cause of the polyuria and polydipsia, is discovered. The presence of hypertension and hypokalemia arises suspicion of a primary hyperaldosteronism and the plasma levels of renin and aldosterone are measured. Elevated aldosterone levels are combined with high plasma renin concentrations which permits to rule out primary hyperaldosteronism. Further explorations reveal a subocclusive ostial stenosis of the right renal artery. A treatment by sartan is instaured, which allows arterial pressure control and kalemia normalization. Chronic hypokalemia can be the cause of tubular nephropathy manifested by nephrogenic diabetes insipidus.

Identifying energy and carbon footprint optimization potentials of a sludge treatment line with Life Cycle Assessment

This study exemplifies the use of Life Cycle Assessment (LCA) as a tool to quantify the environmental impacts of processes for wastewater treatment. In a case study, the sludge treatment line of a large wastewater treatment plant (WWTP) is analysed in terms of cumulative energy demand and the emission of greenhouse gases (carbon footprint). Sludge treatment consists of anaerobic digestion, dewatering, drying, and disposal of stabilized sludge in mono- or co-incineration in power plants or cement kilns. All relevant forms of energy demand (electricity, heat, chemicals, fossil fuels, transport) and greenhouse gas emissions (fossil CO(2), CH(4), N(2)O) are accounted in the assessment, including the treatment of return liquor from dewatering in the WWTP. Results show that the existing process is positive in energy balance (-162 MJ/PE(COD) * a) and carbon footprint (-11.6 kg CO(2)-eq/PE(COD) * a) by supplying secondary products such as electricity from biogas production or mono-incineration and substituting fossil fuels in co-incineration. However, disposal routes for stabilized sludge differ considerably in their energy and greenhouse gas profiles. In total, LCA proves to be a suitable tool to support future investment decisions with information of environmental relevance on the impact of wastewater treatment, but also urban water systems in general.

Energy analysis of conventional and source-separation systems for urban wastewater management using Life Cycle Assessment

This study investigates the cumulative energy demand (CED) of different systems for the management of urban wastewater, following the methodology of Life Cycle Assessment. In a hypothetical case study for an urban area (5,000 inhabitants), all relevant processes for wastewater collection and treatment and the construction of infrastructure are described in a substance flow model. The conventional system requires 1,250 MJ/(pe*a), with the operation contributing 45%, the infrastructure 7%, and the system expansion (production of mineral fertilizer and electricity) 48% to the total CED. The separation systems have a CED of 930-1,182 MJ/(pe*a) depending on their configuration. Results of the impact assessment show that recovering energy from the organic matter of toilet wastewater and household biowaste in a digestion process can decrease the cumulative energy demand by 13-26%. Energetic benefits of mineral fertilizer substitution are relatively small compared to the energy recovered from organic matter. Decisive parameters for the energy analysis are the amount of biowaste which is co-digested with toilet wastewater and the energy demand of the vacuum plant.

Sustainable wastewater management: life cycle assessment of conventional and source-separating urban sanitation systems

Conventional and source-separating urban sanitation systems are compared with regard to their ecological sustainability using the methodology of Life Cycle Assessment. A substance flow model of all relevant processes in a settlement with 5,000 inhabitants is set up and evaluated with environmental indicators for resource demand and emissions to air, water, and soil. The comparison shows that source separation does not necessarily result in a system with less environmental impacts. If the conventional system is energetically optimized and equipped with extended nutrient removal, its impact is comparable to the source-separating systems. However, source separation has the potential to offer ecological benefits depending on the system configuration. Especially the input of toxic heavy metals to agriculture with sewage sludge can be substantially lowered if separately collected urine and faeces are used as organic fertilizer.

Meta-analysis of epidural analgesia versus parenteral opioid analgesia after colorectal surgery

Background

Epidural analgesia (EA) with local anaesthetic is considered to play a key role after colorectal surgery. However, its effect on postoperative recovery is still a matter of debate.

Methods

A systematic review of randomized controlled trials comparing postoperative EA and parenteral opioid analgesia after colorectal surgery was performed. The effect on postoperative recovery was evaluated in terms of length of hospital stay, pain intensity, duration of postoperative ileus, incidence of postoperative complications and side-effects.

Results

Sixteen trials published between 1987 and 2005 were included. EA significantly reduced pain scores and duration of ileus (weighted mean difference − 1·55 (95 per cent confidence interval (c.i.) − 2·27 to − 0·84) days). On the other hand, it was associated with a significant increase in the incidence of pruritus (odds ratio (OR) 4·8 (95 per cent c.i. 1·3 to 17·0)), urinary retention (OR 4·3 (1·2 to 15·9)) and arterial hypotension (OR 13·5 (4·0 to 57·7)). EA did not influence duration of hospital stay.

Conclusion

Despite improved analgesia and a decrease in ileus, EA has some adverse effects and does not shorten the duration of hospital stay after colorectal surgery.

[Haemoptysis after anesthesia]

Postobstructive pulmonary oedema is a complication after extubation that occurs rarely . It can be associated with haemoptysis. We report two cases of haemoptysis occuring in ASA 1 otherwise healthy patients who underwent uncomplicated anaesthesia. Understanding of the mechanism and prompt treatment lead to rapid recovery of this dramatic complication.

[Clinical case of the month. Turner's syndrome and aortic dissection]

A patient, born in 1961, is hospitalised for pubic abdominal pain with irradiation to the right and left sides. She has a Turner's syndrome. At first evaluation, an abdominal tomography demonstrates a right pyelonephritis. The patient is treated with quinolones and she evolves favourably, except that she continues to present some abdominal pain. She leaves the hospital, but because of permanent abdominal pain, a new abdominal tomography is performed: an aortic dissection type B for (Stanford), or III anterograde for (De Bakey), is diagnosed. Cardiovascular anomalies are frequent in Turner's syndrome. Aortic dissection is a rare complication. Histological analysis shows a cystic medial necrosis. Medical and cardiological follow-up is needed.

[Balloon-assisted percutaneous vertebroplasty in patients with osteoporotic vertebral body compression fractures--first results]

PURPOSE

To determine the feasibility, efficacy and safety of balloon-assisted percutaneous vertebroplasty (BA-VP) in patients with osteoporotic vertebral compression fractures (VCFs).

MATERIALS AND METHODS

In 47 patients (29 women, 18 men; mean age: 70 years and 4 months) with severe VCFs, 66 BA-VPs were performed via a unipedicular access. After initial puncture (under combined fluoroscopy and CT guidance) of the vertebral body (VB), the needle was retraced by 1.5 cm, and a 12-mm Fogarty balloon catheter was introduced and inflated using 2-4 ml diluted contrast media (CM). After the subsequent removal of the catheter and repositioning of the needle, vertebroplasty was performed.

RESULTS

The mean volume of PMMA injected was 4.4 ml (2.5-7.2 ml). Pain reduction (measured by the Visual Analogue Scale) was achieved in 95 % of the patients, dropping from on average 8.0 pre-intervention to 2.2 after a mean follow-up of 8 months. A reduction of the pain relieving medication was achieved in 68 % of the cases and patient activity improved markedly. No severe or clinically relevant complications were observed. Cement leakage occurred by filling of epidural and paravertebral veins in 9.1 and 6.1 % of the cases, respectively. Leakage into the paravertebral soft tissues was seen in 3.0 % of the patients and to the adjacent disc space in 10.6 % of the cases.

CONCLUSION

Vertebroplasty and kyphoplasty are currently used to treat osteoporotic VCFs but show either a comparatively high leakage rate or are rather complex and expensive. Balloon-assisted vertebroplasty seems to combine advantages from both methods and is effective, safe and comparatively inexpensive.

Place de l’imagerie de perfusion par irm dans la prise en charge des tumeurs cérébrales, gliales en particulier

OBJECT

To discuss the pertinency of perfusion MR imaging for initial diagnosis and follow up of brain tumors.

METHODOLOGY

Dynamic susceptibility contrast MR imaging was applied. Images were thus obtained with intensities proportional to the cerebral blood volume (CBV). Relative cerebral blood volume (rCBV) maps were then generated by normalizing the signal intensities with respect to measurements made in healthy tissue.

RESULTS

The method provided interesting data for establishing the differential diagnosis between different kinds of lesions, in particular between lymphoma and pilocytic astrocytoma, and for grading gliomas.

DISCUSSION AND CONCLUSION

Limits of the approach are discussed, in particular with respect to quantification aspects and interpretation of the results. The approach could be particularly useful for grading oligodendrogliomas, for which histological diagnosis on biopsy is sometimes difficult.

Effects of acetaminophen on morphine side-effects and consumption after major surgery: meta-analysis of randomized controlled trials † †Presented in part at the Annual Meeting of the Société Française d’Anesthésie-Réanimation, Paris, April 2004

BACKGROUND

Acetaminophen is commonly used for the management of perioperative pain. However, there is a marked discrepancy between the extent to which acetaminophen is used and the available evidence for an analgesic effect after major surgery. The aim of this systematic review is to determine the morphine-sparing effect of acetaminophen combined with patient-controlled analgesia (PCA) with morphine and to evaluate its effects on opioid-related adverse effects.

METHODS

MEDLINE and the Cochrane Library were searched to select randomized controlled trials which compared PCA morphine alone with PCA morphine plus acetaminophen administered orally or intravenously. Studies were evaluated for their quality based on the Oxford Quality Scale. Outcome measures were morphine consumption over the first 24 h after surgery, patient satisfaction and the incidence of morphine side-effects, including nausea and vomiting, sedation, urinary retention, pruritus and/or respiratory depression.

RESULTS

Seven prospective randomized controlled trials, including 265 patients in the group with PCA morphine plus acetaminophen and 226 patients in the group with PCA morphine alone, were selected. Acetaminophen administration was not associated with a decrease in the incidence of morphine-related adverse effects or an increase in patient satisfaction. Adding acetaminophen to PCA was associated with a morphine-sparing effect of 20% (mean, -9 mg; CI -15 to -3 mg; P=0.003) over the first postoperative 24 h.

CONCLUSION

Acetaminophen combined with PCA morphine induced a significant morphine-sparing effect but did not change the incidence of morphine-related adverse effects in the postoperative period.

[Evaluation of severity in partial intractable epilepsy]

A large number of factors have to be taken into consideration to evaluate the severity of intractable partial epilepsy. These inter-related factors change with compliance and with the frequency of seizures as well as the psycho-social context. We discuss here the different factors which are directly or indirectly related with epilepsy. In clinical practice, only some of these factors are used as criteria of severity. The only truly effective method of determining the real consequences of epilepsy are quality of life could measurements.

Abcès cérébral : aspects caractéristiques en imagerie morphologique et fonctionnelle

Although rare in non immunodeficient patients, the correct diagnosis of brain abscess is essential in order to initiate urgent medical and surgical treatment. We describe the imaging features including spectroscopy and diffusion MRI.

Chordoid glioma of the third ventricle: CT and MRI, including perfusion data

Chordoid glioma is a homogeneous tumour involving the third ventricular region of middle-aged women, containing a small central cyst or necrosis. Histologically the tumour has a chordoid appearance. We report a new case with a haemodynamic imaging approach which indicates tumour angiogenesis at the capillary level.

Endovascular treatment of peripheral artery disease with expanded PTFE-covered nitinol stents: interim analysis from a prospective controlled study

PURPOSE

Current covered peripheral stent designs have significant drawbacks in terms of stent delivery characteristics and flexibility. The aim of this study was to analyze the technical performance, safety and initial clinical efficacy of expanded polytetrafluoroethylene (PTFE)-covered nitinol stents for arteriosclerotic peripheral artery disease.

METHODS

Eighty-two patients underwent implantation of PTFE-covered nitinol stents for iliac and/or femoral obstructions. The study was conducted prospectively in seven European centers and one Canadian center. Patients were controlled clinically and by duplex ultrasound follow-up. Data up to discharge were collected in 79 patients. Seventy-four patients have thus far received 1 month follow-up and 32 patients, 6 month follow-up examinations.

RESULTS

The average lesion length measured 47 mm for the common and external iliac arteries and 50 mm for the femoral arteries. The mean severity of the stenoses was reduced from 94% to 4% in the iliac arteries and from 98% to 7% in the femoral arteries after stent placement and dilatation. One device deviation (inadvertent stent misplacement) and one puncture-related severe adverse event with formation of a pseudoaneurysm occurred. There were occlusions of the stent in five patients. No infections were noticed.

CONCLUSION

The interim analysis of this trial using PTFE-covered nitinol stents indicates that a strategy using primary implantation of this stent type is technically feasible, has an acceptable safety profile and is effective from a short-term perspective.

Cerebral blood volume mapping by MR imaging in the initial evaluation of brain tumors

PURPOSE

To assess the contribution of magnetic resonance (MR) cerebral blood volume (CBV) mapping in the initial evaluation of brain tumors.

METHODS

63 patients presenting a brain tumor underwent dynamic susceptibility-contrast MR imaging before surgery or biopsy: 28 high grade gliomas, 8 low grade gliomas, 2 pilocytic astrocytomas, 4 lymphomas, 12 metastases, 9 meningiomas. The CBV maps were obtained for each patient and the relative CBV (rCBV) in different areas was calculated using the ratio between the CBV in the pathological area (CBVp) and in the contralateral normal tissue(CBVn). The maximum rCBV (rCBVmax) for each tumor was determined and the mean values of rCBVmax in each group of tumors were compared using an unpaired Student t test (p=0.05).

RESULTS

The rCBVmax for high grade gliomas (mean +/- SD: 2.6 +/- 1,2) was statistically different from low grade gliomas (0.9 +/- 0.4) (p<0.001), lymphomas (0.7 +/- 0.2) (p=0.002), meningiomas (9.1 +/- 4.4) (p<0.001) and kidney metastases (8.9 +/- 2.1) (p<0.001). The two pilocytic astrocytomas had a much lower rCBVmax than high grade gliomas. No statistically significant difference was found between high grade gliomas and lung metastases (2.4 +/- 0.9) (p=0.72).

CONCLUSION

CBV mapping provides additional information on the vascularity of the lesions, which is not available with conventional MR imaging. It might be useful for differentiating certain lesions showing contrast enhancement, mainly high grade gliomas from kidney metastases, meningiomas, lymphomas or pilocytic astrocytomas.

MR cholangiography in the diagnosis of sclerosing cholangitis in Langerhans' cell histiocytosis

Langerhans' cell histiocytosis (LCH) is a disorder of histiocytic proliferation that primarily affects infants. Imaging findings of a rare case of lung and liver involvement in an adult are presented. High-resolution computed tomography (HRCT) of the lungs showed confluent thin-walled cystic air spaces compatible with advanced LCH. Liver CT and MRI revealed unspecific signs of fatty infiltration. Irregular widening of peripheral bile ducts was displayed in breath-hold MR cholangiography. This pattern is considered characteristic for sclerosing cholangitis and should support the diagnosis of LCH in case of concomitant cystic pulmonary disease, even in adult patients.

[Radiation exposure during spiral-CT of the paranasal sinuses]

PURPOSE

Determination of the radiation doses in spiral CT of the paranasal sinuses using a variety of mAs values and scan protocols.

MATERIAL AND METHODS

CT examinations of the paranasal sinuses were performed using an Alderson-Rando phantom. Radiation dose was determined by LiF-TLD at the level of high risk organs in the head and neck region for combinations of different scan parameters (2/3, 3/3, 3/4 mm) and decreasing charges (200, 150, 100, 50, 25 mAs) on a spiral CT. Additional measurements were performed on three other CT scanners using the 2/3 mm protocol at 50 mAs, and a single slice technique (5/5 mm) on one scanner.

RESULTS

The lowest dose values found were 1.88 mGy for the eye lenses, 1.35 mGy for the parotid gland, 0.03 mGy for the thyroid gland and 0.1 mGy for the medulla oblongata using 2 mm collimation and 3 mm table feed at 25 mAs. Maximal dose values resulted using the 3/3 mm protocol at 200 mAs (31.00 mGy for the eye lense, 0.65 mGy for the thyroid gland). There were no significant differences found between the different CT scanners.

CONCLUSIONS

Using up-to-date CT scanners, radiation exposure may be reduced by a factor of 15-20 compared to that of conventional CT technique. Thus, the exposure of the eye lens comes to only a thousandth of the value supposedly inducing a cataract, as published by the ICRP.

Piracetam in the treatment of cortical myoclonus

This paper reviews existing publications on the use of piracetam for the treatment of cortical myoclonus of various etiologies and includes the personal experience of the authors in progressive myoclonus epilepsy. Two double-blind comparisons with placebo provided results which allow recommendations for the dosage and usage of piracetam in cortical myoclonus. Wide individual variation (7-24g daily) exists in dosage requirements but responses are dose-related so that dosage should be increased until an optimum effect is obtained. Tolerability after long-term use of piracetam in high dosage has been very good and without toxicity or serious adverse effects. Side effects have been occasional, mild and transient. The authors present their experience of 12 patients with progressive myoclonus epilepsy in whom the administration of up to 45 g piracetam daily, when added to existing anti-epileptic treatment, caused marked and sometimes spectacular improvement and was without significant adverse effects. Improvement was maintained for up to 7 years. The use of piracetam for disabling cortical myoclonus of any etiology, either as an addition to existing antimyoclonic drugs or as monotherapy, may bring about profound improvement in disability and quality of life. Piracetam should be considered a first-line drug for the treatment of cortical myoclonus.

Differential actions of the dopamine agonist bromocriptine on growth of SMtTW tumors exhibiting a prolactin and/or a somatotroph cell phenotype: relation to dopamine D2 receptor expression

Dopamine (Da) and Da agonists are known to inhibit secretion and proliferation of normal and tumoral PRL cells, through receptors of D2 subtype. Because of the lack of an experimental model, the relationship between bromocriptine (BR) sensitivity and D2 receptor expression is poorly documented. Such a relationship was analyzed using five lineages of spontaneous transplantable rat pituitary tumors (SMtTW) exhibiting different PRL/GH phenotypes. From plasma PRL and GH concentrations of rats bearing the tumors and tumor messenger RNA contents, tumors were classified as PRL (SMtTW2), somatotroph (SMtTW10), or somatomammotroph (SMtTW5) tumors. Two lineages (SMtTW3 and SMtTW4) represented variants producing PRL and GH but with a high predominance of PRL. With the exception of SMtTW4 tumors, which were malignant, all the tumors were benign and differed in their growth rate. Hormone production and growth of tumors with a PRL or a somatomammotroph phenotype were reduced by about 90% under BR treatment, whereas somatotroph tumors and the PRL malignant tumors were totally insensitive to BR. D2 receptor messenger RNA was present in all BR-sensitive tumors and was not detected in BR-resistant tumors. In conclusion, using five lineages of SMtTW tumors that are representative of the most frequent tumors encountered in human pituitary pathology, we found a full concordance between tumor responses to BR and the expression of D2 receptor by the tumors. The identification of a tumor lineage with a malignant phenotype, secreting high amounts of PRL and presenting a resistance to BR, supports the idea that Da-resistant prolactinomas are aggressive tumors.

H2O2 induces apoptosis of pig thyrocytes in culture

Apoptosis might be involved in the reduction of the thyroid cell population in physiopathological situations such as goitre involution and autoimmune deleterious processes. Up to now, little attention has been paid to the apoptotic phenomenon in the normal thyroid gland the specialized metabolism of which is expected to generate reactive oxygen species. Indeed, thyroid cells have the capacity to synthesize H2O2. In this study, we have analyzed the capacity of H2O2 to trigger apoptosis of pig thyrocytes in culture to try to determine whether thyrocytes exhibit a particular resistance to apoptosis induced by an oxidative stress. We show that exposure of thyrocytes cultured as monolayers to exogenous H2O2 induced cell death with characteristics of apoptosis. The effect of H2O2 was concentration-dependent; apoptotic cells were already observed after exposure to 50 micro M H2O2. At high concentrations (millimolar range), H2O2 exerted toxic effects leading to rapid cell disruption. Within the first hour after the onset of exposure to 50-300 micro M H2O2, early signs of apoptosis, i.e. DNA fragmentation, appeared in a low (0.1-1%) but definite fraction of thyrocytes. The proportion of adherent cells exhibiting DNA fragmentation remained fairly constant after 6, 15 and 24 h. During the 24-h period, an increasing number of cells detached from the culture dish and up to 30-40% of cells in suspension displayed apoptotic features. The fraction of cells that lost contact with the culture dish amounted to up to 25% 24 h after addition of 300 micro M H2O2. In conclusion, as reported for other cell types, low H2O2 concentrations are capable of triggering apoptosis in thyrocytes cultured as monolayers. Thyrocytes that undergo apoptosis secondarily lose contact with neighbour cells and the substratum; cell detachment from the monolayer probably happens within 1-2 h after initiation of DNA fragmentation. Our data show that the apoptotic commitment can take place many hours after initiation of the oxidative stress.

Relationship between seizure frequency and costs and quality of life of outpatients with partial epilepsy in France, Germany, and the United Kingdom

PURPOSE

The relationship between seizure frequency and both health care costs and quality of life (QOL) was investigated in a retrospective, cross-sectional, multicenter study in France, Germany, and the United Kingdom.

METHODS

Three hundred outpatients with stable partial epilepsy were approximately evenly distributed among five seizure-frequency groups, ranging from seizure-free in the last 3 months (group 1) to daily seizures (group 5). Economic data, obtained through patient interviews and record abstraction, comprised direct medical costs, direct nonmedical costs, and indirect costs for the preceding 3 months. Total societal costs in the three countries were pooled and converted to United States dollar equivalents. QOL was assessed through a self-administered questionnaire, the Functional Status Questionnaire (FSQ).

RESULTS

Mean total costs increased from $780 in group 1 to $2,171 in group 5 (p = 0.0001), with significant increases in each cost category as seizure frequency increased. Greater seizure frequency also significantly (p = 0.0270) correlated with lower employment rates, which ranged from 57% in group 1 to 30% in group 5. QOL declined as seizure frequency increased. Particularly affected were basic and intermediate activities of daily living (ADL), mental health, social activity, and feeling about health.

CONCLUSIONS

The study results show that higher seizure frequencies are associated with higher direct and indirect costs and with reduced QOL for patients with epilepsy.

[The outcome of the patient treated with methadone]

The treatment of drug addiction by methadone is questioned: there is a shift from "all of abstinence" to "all for risk limitation". There is a modification of the clinical relationship, due to specific resources allocated for methadone treatment, modifying also the connections between medicine, Public Health and Public Security.

Cell-to-cell communication in the anterior pituitary: evidence for gap junction-mediated exchanges between endocrine cells and folliculostellate cells

The ability of rat anterior pituitary cells to communicate through gap junctions (GJ) was studied using a fluorescent molecule, Lucifer Yellow (LY), which freely passes through GJ channels. The probe was introduced into the cell cytoplasm by using either the cut-end loading method on intact tissue, or cell microinjection on cultured cells. The identification of communicating cells was performed by immunofluorescence labeling of specific hormones in endocrine cells and of S100 protein in folliculostellate (FS) cells. Rat anterior pituitary cells in their physiological organization, i.e. in the intact tissue, exhibited a high level of coupling through GJ. LY-labeled cells were found up to 300-microns apart from its site of introduction. The communicating cells were primarily PRL cells, GH cells, and FS cells. Only a few LH, TSH, and ACTH cells were labeled with LY. Anterior pituitary cells, isolated from the rat tissue by mild protease treatment and cultured for 3 days, reestablished functional GJ as demonstrated by microinjection of LY into individual cells. By immunolabeling of specific hormones and/or S100 protein, we found a GJ coupling between FS cells, and between FS cells and endocrine cells, including PRL cells. The communication between FS cells was by far the most frequent. In conclusion, we demonstrate the presence of functional GJ between anterior pituitary cells of the same type and between anterior pituitary cells having distinct differentiated functions.

[Self concept and need for social approval in bulimia patients]

The present work concerns the relation between the need for social approval (assessed as social desirability) and bulimia with respect to gender-differences. Since bulimia is mainly a female issue, a relationship was predicted between the development of bulimia and the internalization of a socially desired feminine sex-stereotype with respect to the self-concept. The need for approval was assessed for male subjects, female subjects not suffering from eating-disorders, and female bulimic subjects. The results show that bulimic women have significant higher self-ratings concerning the need for approval. Without neglecting multicausal explications, the results suggest that social desirability as an expression of social approval should receive more attention as a facilitating factor in the development of bulimia.

Prolactin and growth hormone mRNA and protein characterization in SMtTW rat pituitary tumours

We have combined different techniques to analyse passages of five different rat spontaneous pituitary tumours (SMtTW) that were transplanted under the kidney capsule. These tumours were secreting prolactin (PRL), GH or both hormones. RIA, immunocytochemistry (ICC) and Western blot analysis were applied to characterize the hormone(s) stored (ICC and Western blot) and secreted (RIA). mRNA content was analysed by PCR, Northern blot analysis and in situ hybridization. The data point not only to the reliability of the techniques used at both protein and RNA levels for each tumour studied but also to the complementarity of some techniques. For example, whereas Northern blot analysis demonstrates the presence and size of hormone mRNA, in situ hybridization indicates the percentage of cells expressing a given hormone mRNA and allows the presence of one population (or more) of cells in a given tumour to be identified. Moreover, the tumours were compared with normal rat pituitary. Although the PRL and GH mRNAs were identical in size, the amount of mRNA was lower in the tumours. At the protein level, the PRL and GH variants exhibited a different pattern of expression in tumours compared with the normal rat pituitary. The biological significance of these differences is discussed.

[Nocturnal hypoglycemia in insulin-dependent diabetics]

OBJECTIVES

Repeated hypoglycaemia has been reported to impair recognition of subsequent hypoglycaemia with a high risk of severe hypoglycaemia. This intensified insulin therapy may be dangerous in insulin-dependent diabetes mellitus (IDDM) patients with unawareness of hypoglycaemia.

METHODS

We assessed the incidence of nocturnal hypoglycaemia and the benefit of an additional bedtime snack in IDDM patients treated by 2 or 3 daily injections. Capillary blood glucose was measured by finger strip at 10 p.m. and plasma venous glycaemia was determined at 0, 2, 4 and 8 a.m.

RESULTS

The study was composed of two phases. In the first phase, patients (n = 93) did not receive any snack at bedtime. Blood glucose fell to 2.75 mmol/l or less in 33%. Among the 40 patients with a 10 p.m. glycaemia of 9 mmol/l or less, 57.5% experienced nocturnal hypoglycaemia vs 15% of the 53 others. The second phase concerned 106 IDD patients. An additional bedtime snack was given when 10 p.m. blood glucose was 9 mmol/l or less. The incidence of hypoglycaemia fell to 32% (14 of 44 IDDM) i.e. a significant benefit of 44% (p < 0.01). However patients who received this additional bedtime snack had a slightly higher 8 a.m. glycaemia than those with 10 p.m. glycaemia at 9 mmol/l or less during the first phase (9.61 +/- 5.67 mmol/l vs 7.75 +/- 4.30 mmol/l) but this result is not significant.

CONCLUSION

Prevention of nocturnal hypoglycaemia may be achieved in IDDM patients by bedtime glucose determination and an additional snack when glycaemia is 9 mmol/l or less.

Clobazam in the treatment of epilepsy: a review of the literature

The literature was reviewed to define the role of clobazam (CLB) in the treatment of epilepsy. CLB is an effective antiepileptic drug (AED) in most varieties of seizures and epilepsies for both short-term and long-term treatment. Tolerability of CLB is satisfactory, better than for conventional benzodiazepines. CLB has no significant interaction with other drugs. Tolerance may develop, but this aspect may have been overemphasized: a long-term benefit figure of 28% can be expected without tolerance. When CLB maintains efficacy, patients continue to benefit for years without drug dependence or unwanted side effects. CLB appears to be a useful treatment for epilepsy as intermittent or short-term add-on therapy; but it should also be tried as long-term therapy in some situations, especially as add-on therapy for patients with refractory epilepsy, as add-on or monotherapy for patients with anxiety, or in some women in association with oral contraceptives.

Development of an enzyme immunoassay for arginine-vasopressin (AVP)-like insect diuretic hormone

1. The AVP-like insect diuretic hormone is a biologically active antiparallel dimer present, along with its non-active monomeric form (Cys-Leu-Ile-Thr-Asn-Cys-Pro-Arg-GlyNH2), in the African locust. 2. It exhibits diuretic activity by increasing fluid excretion at the level of the Malpighian tubules. 3. To date, both monomer and dimer have been assayed using a radioimmunoassay originally prepared for mammalian AVP. 4. We have developed here an original enzyme immunoassay based on the use of antibodies to insect AVP-like raised in rabbits against synthetic monomers and dimers, using acetylcholinesterase conjugate as an enzymatic tracer. 5. This enzyme immunoassay enables measurement of the dimer to be made with adequate sensitivity (0.3 nmol/l, i.e. 21 pg/well) and reproducibility while sensitivity of the monomer is somewhat lower (14 nmol/l, i.e. 480 pg/well). 6. The assay was validated by assaying native dimer and monomer throughout the different steps of purification (from a crude extract to reversed-phase liquid chromatographic fractions). 7. A good correlation was observed between radioimmunoassays and enzyme immunoassays. 8. The enzyme immunoassay was also used to measure the level of AVP-like peptides in several insect tissues not explored to date.

Phased spectroscopic images: application to the characterization of the 1H 1.3-ppm resonance in intracerebral tumors in the rat

Spectra obtained with phase-encoding techniques show phase-shifts varying from voxel to voxel. The procedure allowing voxel-dependent phase-shifts to be compensated is presented. The method has been applied to the characterization of the 1.3-ppm resonance observed in intracerebral tumors in the rat.

Intrarectal diazepam in epileptic adults

Intrarectally (i.r.) administered diazepam (DZP) solution at doses of 20 and 30 mg in the treatment of serial seizures was studied in 39 adult patients with refractory partial epilepsy. Patients were randomly distributed into two groups (20 mg, n = 21; 30 mg, n = 18). Plasma levels of DZP were assessed over 24 h following i.r. injection. The efficacy of i.r. DZP in the treatment of serial seizures in adults was confirmed; onset of effect was noted approximately 10 min after the injection, and the effective dose was 0.50 mg/kg. Tolerance and acceptability were good. Intrarectal injection of DZP can be performed even by unskilled personnel and may be recommended in patients with serial seizures in the hope of preventing development of status epilepticus.

Proton spectroscopic imaging: a tool for studying intracerebral tumor models in rat

Water-suppressed 2D 1H spectroscopic imaging was used with surface coils to study in vivo the cerebral metabolism changes in rat brain induced by a glial tumor growing in situ. To achieve slice selection without a chemical-shift artifact, we exploited the depth pulse properties of a spin-echo sequence. In order to give a spectral response which is independent of the position, the water suppression was achieved by using a spin-locking excitation and a binomial refocusing pulse. Spectroscopic images were obtained with an in-plane resolution of 1.1 X 1.1 mm and a slice thickness of roughly 3 mm. The growing of the tumor induced dramatic modifications in the proton spectra, including a nearly complete loss of N-acetyl aspartate, an increase of the 1.3-ppm peak, an increase in choline, and a decrease in creatine. The results demonstrate the potential of spectroscopic imaging in the study of intracranial tumor models in rats.

Failure to detect viral genomic sequences of three viruses (herpes simplex, simian virus 40 and adenovirus) in human and rat brain tumors

Little is known about oncogenesis in brain tumors. Viruses are thought to be involved in some neurological diseases, the presence of subfractions of viral DNA has been reported in various circumstances and the oncogenicity of some viruses has been demonstrated in animal experiments. The discovery of homologies between retroviral oncogenes and normal cellular genes (proto-oncogenes) has stimulated once again the search for viral responsibility in oncogenesis. Having a large bank of tumor material available, we systematically examined 39 brain tumors using Southern blot hybridization with DNAs of three viruses, known to be involved in neurological diseases: herpes simplex virus (HSV), simian virus 40 (SV40) and adenovirus type 2 (Ad2). We detected no homology between the DNAs of the examined material and the viral DNA probes. We compare these negative results with those of other published studies and discuss the experimental conditions, with special reference to the possibility of non-specific hybridization, which could account for the positive results reported. The present negative results could be interpreted either as absence of involvement of the three investigated viruses in brain tumor oncogenesis, or an indirect involvement through a hit-and-run mechanism or a highly dispersed state of the viral sequences among the host genome, which would prevent hybridization with the probe, as it has been supposed to be the case during the latency phase of herpes virus.