Do contaminants compromise the use of recycled nutrients in organic agriculture? A review and synthesis of current knowledge on contaminant concentrations, fate in the environment and risk assessment

Use of nutrients recycled from societal waste streams in agriculture is part of the circular economy, and in line with organic farming principles. Nevertheless, diverse contaminants in waste streams create doubts among organic farmers about potential risks for soil health. Here, we gather the current knowledge on contaminant levels in waste streams and recycled nutrient sources, and discuss associated risks. For potentially toxic elements (PTEs), the input of zinc (Zn) and copper (Cu) from mineral feed supplements remains of concern, while concentrations of PTEs in many waste streams have decreased substantially in Europe. The same applies to organic contaminants, although new chemical groups such as flame retardants are of emerging concern and globally contamination levels differ strongly. Compared to inorganic fertilizers, application of organic fertilizers derived from human or animal feces is associated with an increased risk for environmental dissemination of antibiotic resistance. The risk depends on the quality of the organic fertilizers, which varies between geographical regions, but farmland application of sewage sludge appears to be a safe practice as shown by some studies (e.g. from Sweden). Microplastic concentrations in agricultural soils show a wide spread and our understanding of its toxicity is limited, hampering a sound risk assessment. Methods for assessing public health risks for organic contaminants must include emerging contaminants and potential interactions of multiple compounds. Evidence from long-term field experiments suggests that soils may be more resilient and capable to degrade or stabilize pollutants than often assumed. In view of the need to source nutrients for expanding areas under organic farming, we discuss inputs originating from conventional farms vs. non-agricultural (i.e. societal) inputs. Closing nutrient cycles between agriculture and society is feasible in many cases, without being compromised by contaminants, and should be enhanced, aided by improved source control, waste treatment and sound risk assessments.

Reaction of Pertechnetate in Highly Alkaline Solution: Synthesis and Characterization of the Nitridotrioxotechnetate Ba[TcO3 N]

The preparation of novel technetium oxides, their characterization and the general investigation of technetium chemistry are of significant importance, since fundamental research has so far mainly focused on the group homologues. Whereas the structure chemistry of technetium in strongly oxidizing media is dominated by the Tc O 4 - ${{\left[{\rm { Tc}}{{\rm { O}}}_{{\rm { 4}}}\right]}^{-}}$ anion, our recent investigation yielded the new Tc O 3 N 2 - ${{\left[{\rm { Tc}}{{\rm { O}}}_{{\rm { 3}}}{\rm { N}}\right]}^{{\rm { 2}}-}}$ anion. Brown single crystals of Ba[TcO₃ N] were obtained under hydrothermal conditions starting from Ba(OH)₂  ⋅ 8H₂ O and NH₄ [TcO₄ ] at 200 °C. Ba [ Tc O 3 N ] ${{\rm { Ba[Tc}}{{\rm { O}}}_{{\rm { 3}}}{\rm { N]}}}$ crystallizes in the monoclinic crystal system with the space group P2₁ /n (a=7.2159(4) Å, b=7.8536(5) Å, c=7.4931(4) Å and β=104.279(2)°). The crystal structure of Ba [ Tc O 3 N ] ${{\rm { Ba[Tc}}{{\rm { O}}}_{{\rm { 3}}}{\rm { N]}}}$ consists of isolated Tc O 3 N 2 - ${{\left[{\rm { Tc}}{{\rm { O}}}_{{\rm { 3}}}{\rm { N}}\right]}^{{\rm { 2}}-}}$ tetrahedra, which are surrounded by Ba²⁺ cations. XANES measurements complement the oxidation state +VII for technetium and Raman spectroscopic experiments on Ba[TcO₃ N] single crystals exhibit characteristic Tc-O and Tc-N vibrational modes.

International mobility of students in the medical disciplines from a comparative perspective

Objective: We analyze the extent to which students of human, veterinary and dental medicine complete study-related stays abroad (frequency, type and duration of stays abroad and countries visited). Furthermore, we investigate the possible correlations between completed stays abroad and the duration of studies, the completion of a doctorate and entering professional life. Methods: The data come from a written cross-sectional survey of 742 graduates of their respective study programs at Bavarian universities. The evaluation was carried out using descriptive and inferential statistical methods. Results: Slightly more than half of the surveyed students completed study-associated stays abroad, with notable differences between the three study programs. The students most frequently completed internships abroad lasting an average of nine weeks. Switzerland was the most common country of destination for the stays abroad. Furthermore, there were no or only weak correlations between stays abroad, the duration of studies and progress towards a doctorate or the commencement of professional employment abroad. There were no correlations with the stress experienced as part of initial employment after graduation. Conclusion: The results clearly indicate that stays abroad are quite usual for students in the medical disciplines and are almost standard in the study of human medicine. The selection of the countries visited indicates that the primary goal of the students' stays abroad is to deepen their competence with a view to later employment in their home country.

Impact of suggestion on the human experimental model of cold hyperalgesia after topical application of high-concentration menthol [40%]

BACKGROUND

Human experimental pain models in healthy subjects offer unique possibilities to study mechanisms of pain within a defined setting of expected pain symptoms, signs and mechanisms. Previous trials in healthy subjects demonstrated that topical application of 40% menthol is suitable to induce cold hyperalgesia. The objective of this study was to evaluate the impact of suggestion on this experimental human pain model.

METHODS

The study was performed within a single-centre, randomized, placebo-controlled, double-blind, two-period crossover trial in a cohort of 16 healthy subjects. Subjects were tested twice after topical menthol application (40% dissolved in ethanol) and twice after ethanol (as placebo) application. In the style of a balanced placebo trial design, the subjects received during half of the testing the correct information about the applied substance (topical menthol or ethanol) and during half of the testing the incorrect information, leading to four tested conditions (treatment conditions: menthol-told-menthol and menthol-told-ethanol; placebo conditions: ethanol-told-menthol and ethanol-told-ethanol).

RESULTS

Cold but not mechanical hyperalgesia was reliably induced by the model. The cold pain threshold decreased in both treatment conditions regardless whether true or false information was given. Minor suggestion effects were found in subjects with prior ethanol application.

CONCLUSIONS

The menthol model is a reliable, nonsuggestible model to induce cold hyperalgesia. Mechanical hyperalgesia is not as reliable to induce.

SIGNIFICANCE

Cold hyperalgesia may be investigated under unbiased and suggestion-free conditions using the menthol model of pain.

Investigation on the acquisition of scientific competences during medical studies and the medical doctoral thesis

Background: Not only the amount of research related contents in German medical studies are objects of criticism, but also the medical doctoral thesis. However, the question which research competences are truly acquired within medical school and the doctoral phase is empirically open, and is thus pursued in the following research study. Methods: We used data from the Bavarian Medical Graduate Panel Survey (MediBAP) (N=455), where respondents assessed their own research competences. To consolidate the data, we analysed qualitative interviews with doctoral medical graduates and students from the E-Prom study (N=14). Results: The quantitative analyses show that medical graduates evaluate the medical curriculum's research contents and their acquired competences as rather low. Doctoral graduates rate their competence of pursuing research independently higher than medical graduates who have not finished their doctorate. The qualitative analyses are in line with these results, as they point to the predominant development of competences during the doctoral phase. Despite this clearly positive trend, the majority of the respondents don't feel confident enough to undertake research independently also after attaining their doctoral degree. Conclusion: The results of this study emphasize the need for a more systematic and targeted mediation and review of research competences within the regular medical curriculum.

Prediction of response to tapentadol in chronic low back pain

BACKGROUND

Many chronic low back pain (cLBP) patients do not satisfactorily respond to treatment. The knowledge of responders and non-responders before initiating treatment would improve decision making and reduce health care costs. The aims of this exploratory prediction study in cLBP patients treated with tapentadol were to identify predictors of treatment outcome based on baseline characteristics, to evaluate quality-of-life and functionality as alternative outcome parameters and to develop nomograms to calculate the individual probability of response.

METHODS

In a retrospective analysis of an open-label phase 3b trial, 46 baseline characteristics were included into statistical prediction modelling. One hundred and twenty-one patients were followed up during the titration and treatment period and 67 patients were analysed who discontinued the trial.

RESULTS

Demographic data were not relevant for response prediction. Nine baseline co-variables were robust: painDETECT score, intensity of burning and painful attacks, SF36 Health Survey score (MCS, PCS), EuroQol-5, Hospital Anxiety/Depression Scale. Gender had a minor influence. Alternative outcomes (quality-of-life, functionality) were more important for response prediction than conventional pain intensity measures. Neuropathic symptoms (high painDETECT score) had a positive predictive validity. Painful attacks and classical yellow flags (depression, anxiety) negatively influenced the treatment response. High depression scores, female gender and low burning predicted discontinuation during titration.

CONCLUSION

In this exploratory study, predictive baseline characteristics have been identified that can be used to calculate the individual probability of tapentadol response in cLBP. The small sample size in relation to the number of initial variables is a limitation of this approach.

SIGNIFICANCE

Predictors for treatment response of tapentadol were identified in patients with chronic low back pain based on clinical pre-treatment characteristics that can guide personalized treatment. Quality-of-life and functionality were the most relevant outcomes for response prediction.

Individualized pharmacological treatment of neuropathic pain

Patients with the same disease may suffer from completely different pain symptoms yet receive the same drug treatment. Several studies elucidate neuropathic pain and treatment response in human surrogate pain models. They show promising results toward a patient stratification according to the mechanisms underlying the pain, as reflected in their symptoms. Several promising new drugs produced negative study results in clinical phase III trials. However, retrospective analysis of treatment response based on baseline pain phenotyping could demonstrate positive results for certain subgroups of patients. Thus, a prospective classification of patients according to pain phenotype may play an increasingly important role in personalized treatment of neuropathic pain states. A recent prospective study using stratification based on pain-related sensory abnormalities confirmed the concept of personalized pharmacological treatment of neuropathic pain.

Demonstration of an 8-dimensional modulation format with reduced inter-channel nonlinearities in a polarization multiplexed coherent system

We demonstrate a polarization-managed 8-dimensional modulation format that is time domain coded to reduce inter-channel nonlinearity. Simulation results show a 2.3 dB improvement in maximum net system margin (NSM) relative to polarization multiplexed (PM)-BPSK, and a 1.0 dB improvement relative to time interleaved return-to-zero (RZ)-PM-BPSK, for five WDM channels propagating over 1600 km ELEAF with 90% inline optical dispersion compensation. In contrast to the other modulations considered, the new 8-dimensional format has negligible sensitivity to the polarization states of the neighboring WDM channels. High-density WDM (HD-WDM) measurements on a 5000 km dispersion-managed link show a 1.0 dB improvement in net system margin relative to PM-BPSK.

Anti-inflammatory effect of Inonotus obliquus, Polygala senega L., and Viburnum trilobum in a cell screening assay

AIM OF THE STUDY

The purpose of the study was to assess the anti-inflammatory effects of the mushroom Inonotus obliquus (Chaga), Polygala senega (Senega) and Viburnum trilobum (Cranberry) bark extract fractions from locally produced materials in lipopolysaccharide (LPS) induced murine macrophage RAW 164.7 cells.

MATERIALS AND METHODS

Four fractions from each of the three extracts were obtained: (80% ethanol extracted; Fa), (water-soluble polysaccharide fraction; Fb), (Polyphenolic fraction; Fc) and (ETOAc/H(2)O extracted fraction; Fd). These extract fractions were tested in the cell screening system at 50,100 and 500 microg/ml for their ability to inhibit LPS induced inflammatory cytokines IL-1beta, TNFalpha and IL-6. Supernatants from LPS alone treated cells were used as control. The cytokines in the cell culture supernatants following treatments with extract fractions were quantified by ELISA method, using 96 well ELISA plates.

RESULTS

All fractions of the extracts significantly inhibited (p<0.05) the levels of IL-1beta, IL-6 and TNFalpha except the polyphenolic Fc fraction of Senega which showed an increased production of IL-6. Furthermore, each fraction showed a dose-dependant anti-inflammatory effect. Nitric oxide production was not affected by cranberry and senega, while Chaga significantly reduced NO production in murine macrophage cell assay.

CONCLUSIONS

These results demonstrate that the extracts obtained from the root of Polygala senega L., bark of Viburnum trilobum, and the mushroom Inonotus obliquus possess anti-inflammatory properties when tested in a RAW 264.7 macrophage cell system.

Effect of manure on glyphosate and trifluralin mineralization in soil

Manure additions to soil may alter soil chemical, physical, and biological characteristics, and thereby change pesticide fate processes in soil. This is the first study to examine the impact of liquid hog manure amendments on glyphosate and trifluralin mineralization in soil. Experiments were conducted in soil microcosms in the laboratory for a total of 332 (glyphosate) and 430 (trifluralin) days. The rate and amount of mineralization of both glyphosate and trifluralin were significantly influenced by the additions of fresh manure to soil in the laboratory and by the history of manure applications in the field. However, the maximum difference in herbicide mineralization between soils that were free of manure application and those amended with manure in the field or in the laboratory was only 6.1% and 7.3% of that initially applied, for trifluralin and glyphosate, respectively. Therefore, we conclude that liquid hog manure application to soil will have no significant effect on the mineralization of glyphosate and trifluralin under field conditions.

Nurses begin a national plan for the integration of supportive care in health research, practice, and policy

The demand for and use of health, social, and other human services is related not to the type or severity of disease but rather to a person's socio-economic, cognitive, and emotional characteristics and environmental circumstances. A workshop on supportive care was held to promote a robust research environment, the creation of new knowledge, the setting of an integrated health research agenda, a focusing of attention on the evolving health-care system, and anticipation of emerging health challenges. While the workshop was intended to address a research mandate for the Canadian Institutes of Health Research, a larger vision emerged, to include advocacy, information system, surveillance, and policy development required by institutional, community, voluntary, private sector, family caregiver, and provider systems. The development of a national supportive care strategy will enable Canadians with disease and disability to live with all of their challenges, and could engage researchers, clinicians, advocacy groups, and people experiencing major health challenges.

The clinical, cerebrospinal fluid, and histopathologic effects of epidural ketorolac in dogs

OBJECTIVE

To evaluate the clinical, cerebrospinal fluid (CSF), and histopathologic effects of epidural ketorolac.

STUDY DESIGN

Blinded, randomized, placebo controlled study.

ANIMALS

Twenty-two adult mixed breed dogs with 16 treatment and 6 control dogs, weighing 14.4 to 29.8 kg.

METHODS

Dogs were anesthetized and epidural catheters were placed at the lumbosacral space. Catheter placement was evaluated fluoroscopically. Ketorolac (0.4 mg/kg) or placebo (5% ethanol) was administered epidurally over a 52-hour period, with 5 injections given at 12-hour intervals. At 1, 2, 4, or 8 hours after the first and last injection of ketorolac, dogs were anesthetized and CSF was obtained. Control dogs had CSF sampled 1 hour after the first and last ethanol injection. Neurologic function and pain responses were evaluated before and during the study. Selected dogs were then killed and necropsies performed.

RESULTS

None of the dogs exhibited any clinical or neurologic abnormalities during the study. No statistical difference was noted in pain response or CSF analysis between treatment and control dogs. Gross necropsy revealed gastrointestinal ulceration of varying degrees in all treatment dogs. Histopathologic analysis of the spinal cord and meninges revealed minimal focal leptomeningeal phlebitis in 2 of 8 treatment dogs and minor subdural inflammation in 1 control dog. No changes to the neural structures were noted in any dogs.

CONCLUSIONS

Epidural administration of ketorolac did not cause clinical signs, alteration in CSF values, or pathologic changes to the spinal cord when used for short duration. Gastrointestinal ulceration was common when ketorolac was administered epidurally at 0.4 mg/kg every 12 hours for 5 treatments.

CLINICAL RELEVANCE

This study documented the neurologic safety of epidural ketorolac in dogs before an efficacy trial can be performed. Gastrointestinal ulceration may limit use to short duration or a single injection.

Peripheral but not central axotomy promotes axonal outgrowth and induces alterations in neuropeptide synthesis in the nodose ganglion of the rat

We investigated the effects of central and peripheral axotomy of the sensory neurons in the nodose ganglion on neurite outgrowth and neuropeptide expression. Axonal outgrowth was studied in ganglia subjected to a conditioning lesion of the vagus nerve 6 days prior to in vitro explantation. In such cultures, a conditioning effect, i. e. a shorter initial delay and faster axonal outgrowth, was observed after peripheral axotomy, while central axotomy had no effect. Neuropeptide expression was measured by immunocytochemistry 3 days after axotomy. Peripheral axotomy induced an increase in the number of neurons expressing the C-terminal flanking peptide of neuropeptide Y (C-PON), galanin (GAL) and vasoactive intestinal peptide (VIP). In contrast, central axotomy did not affect neuropeptide expression. These results suggest that both axonal outgrowth and expression of neuropeptides in the sensory neurons of the nodose ganglion could be regulated by the contact of the cells with their peripheral, but not their central targets.

Increased expression, axonal transport and release of pituitary adenylate cyclase-activating polypeptide in the cultured rat vagus nerve

The expression and axonal transport of pituitary adenylate cyclase-activating polypeptide (PACAP) was studied in the cultured vagus nerve of the rat by immunocytochemistry and in situ hybridization. The number of neurons immunoreactive for PACAP increased markedly within the nodose ganglion during a 24-48 h culture period, as did the number of cells containing messenger RNA for PACAP. PACAP was found to be axonally transported and accumulated at the site of a crush injury. The peptide was also released at this site. Addition of PACAP to regenerating nerves in culture did not affect axonal outgrowth, neither did antibodies against PACAP. Separate experiments showed that neither PACAP-27 nor PACAP-38 affected proliferation of non-neuronal cells measured as the incorporation of [3H]thymidine. In contrast, forskolin, another potent stimulator of adenylate cyclase besides PACAP, dramatically decreased [3H]thymidine incorporation. The results showed that, during regeneration of peripheral nerves, PACAP expression increases and the peptide is transported into the regenerating nerve, where it is released. The functional significance of this release is unknown, but it does not seem to be directly related to the initiation of proliferation of Schwann cells or initial axonal outgrowth.

Regeneration of axons from central neurons into microchips at the level of the spinal cord

Axons from central neurons can regenerate into the tissue matrix formed within a silicone tube capped with two pieces of peripheral nerve, one of which had been sutured to a lesion in the spinal cord. Such axons can grow through a transversely positioned microchip in the tube. These observations suggest that it is feasible to establish functional contact between external electronic equipment and regenerating central nervous axons making it possible to monitor and control their electrical activity. The findings open new perspectives for restoration of motor and sensory functions following spinal cord lesions.

Comparative results of bracing and interlocking nailing in the treatment of humeral shaft fractures

A comparison was made between 44 humeral fractures treated conservatively with functional bracing (Group 1) and 45 treated by operation with a locking nail (Group 2). Thirty-eight of the 44 patients in Group 1 (86%) and 22 of the 45 patients in Group 2 (47%) regained full movement of the shoulder joint. The functional end results were somewhat better in Group 1 although over 90% of patients in both groups were able to clasp their fingers behind their necks and to reach up their backs without restriction. Two patients developed a pseudarthrosis in Group 1, and 2 patients in Group 2 required operative revision due to a haematoma in 1 case and as a result of an infection in the other. There were 6 cases of primary radial nerve damage in both groups, and 6 had to be decompressed operatively. Residual sensory and motor disturbance remained in 2 patients in Group 1. Both methods are useful for the treatment of humeral shaft fractures. We advocate functional bracing as the method of choice if no contraindications exist.

Pituitary adenylate cyclase-activating peptide (PACAP) and PACAP type 1 receptor expression in regenerating adult mouse and rat superior cervical ganglia in vitro

Pituitary adenylate cyclase-activating polypeptide (PACAP), a regulatory peptide belonging to the vasoactive intestinal peptide (VIP) family, is widely distributed in the central and peripheral nervous system. Recent studies have shown that PACAP expression is upregulated in sensory neurons in response to axonal injury. Here we report that PACAP and PACAP type 1 receptors are located in rat and mouse superior cervical ganglia (SCG). PACAP-immunoreactivity (-IR) was demonstrated in preganglionic fibers, whereas only occasional PACAP-IR cell bodies could be observed. In situ hybridization histochemistry using 35S-labeled deoxyribonucleotide probes confirmed that PACAP mRNA was present only in occasional cell bodies. In contrast, PACAP type 1 receptor mRNA was expressed in virtually all cell bodies within the ganglia. After removal and culturing of the SCG for 24 h, there was a marked increase in PACAP mRNA, whilst PACAP type 1 receptor mRNA expression appeared to be downregulated in most nerve cell bodies except for a few scattered neurons displaying a strong upregulation. The total specific binding of PACAP to isolated SCG membranes as assayed by [125I]PACAP-27 binding showed an increase in SCG cultured for 48 h. PACAP-27 neither affected axonal outgrowth from the cultured SCG nor the survival of cells within the SCG. We conclude that PACAP and PACAP receptors are rapidly upregulated in sympathetic ganglia in response to axonal injury and that PACAP may play a role during nerve regeneration.

The effects of axotomy and preganglionic denervation on the expression of pituitary adenylate cyclase activating peptide (PACAP), galanin and PACAP type 1 receptors in the rat superior cervical ganglion

The effects of axotomy, chemical sympathectomy and preganglionic denervation on the expression of the neuropeptides, pituitary adenylate cyclase-activating peptide (PACAP), galanin (GAL), and the PACAP type 1 receptor in the rat superior cervical ganglion (SCG) were investigated by immunocytochemistry, in situ hybridization and receptor autoradiography. An antibody recognizing the rat vesicular acetylcholine transporter (VAChT) was used for the detection of preganglionic cholinergic fibers. In the normal SCG, PACAP-immunoreactivity (-IR) was present in numerous, basket-forming, preganglionic nerve fibers, while very few SCG neurons expressed PACAP. GAL-IR was restricted to occasional neurons, and a few nerve fibers, most of which were, in addition, PACAP-IR. PACAP type 1 receptors were expressed in all nerve cell bodies. Axotomy resulted in a rapid and prominent upregulation of PACAP in a large number of nerve cell bodies. There was a large increase also in GAL expression in many nerve cell bodies. In contrast, there was a marked decline in PACAP type 1 receptor expression. Chemical sympathectomy by administration of the catcholaminergic neurotoxin, 6-hydroxydopamine (6-OHDA), gave rise to similar changes. Preganglionic denervation led to the disappearance of PACAP- and VAChT-IR baskets and to the upregulation of PACAP and GAL expression in neurons located close to the entrance of the sympathetic chain, whereas PACAP type 1 receptor expression was not affected. PACAP and GAL were coexpressed in most neurons after axotomy and chemical sympathectomy. Taken together, these results indicate that disruption of target contact and/or the infliction of an injury to the axons of the sympathetic neurons, rather than the preganglionic output, regulates the expression of PACAP, GAL and the PACAP type 1 receptor.

Functional treatment of humeral shaft fractures: indications and results

OBJECTIVE

To determine effectiveness of closed functional bracing for humeral shaft fractures.

DESIGN

Retrospective.

SETTING

University.

PATIENTS

Eighty-seven patients with humeral shaft fractures.

INTERVENTION

All patients were treated with closed functional bracing.

MAIN OUTCOMES MEASURED

Both subjective and objective criteria were measured. Objective criteria consisted of range of motion and radiographic measurements. Subjective data were recorded using the Hannover Shoulder Score.

RESULTS

Eighty-six percent of the follow-up group showed no restrictions in the movement of their shoulder and elbow joints. On the basis of subjective criteria, 95% of the patients were content with the functional treatment, 65% claimed to be pain free in their daily activities and at work, and 35% felt pain only when doing vigorous activities or heavy physical work. Although malposition with an angulation greater than 10 degrees was observed in ten patients (12.6%), functional outcome was good or excellent in two thirds of the cases followed up.

CONCLUSIONS

When the correct indications are present, functional treatment of humeral shaft fractures has proven to be an excellent method that is both reliable and cost effective.

Indicators of quality in long-term care facilities

Quality of care is of particular importance to residents of long-term care facilities because of the permanency of their situation. In this study indicators of quality of care were generated from data obtained at a primary level from those most affected by the care. The critical incident technique was used to identify the indicators as perceived by 52 residents, 58 significant others, and 37 nursing staff in five long-term care facilities in Calgary, Canada. The 14 major indicators so identified are discussed in this paper.

[Morphometric findings of the healthy pediatric gallbladder in ultrasound]

AIM

Ultrasonographic determination of gallbladder wall thickness, volume and excretion in children.

METHOD

In 76 children (1-16 years) we determined the volume of the fasting and stimulated gallbladder by the ellipsoid formula (length X width X depth X 0.523). We also measured the gallbladder wall thickness. Stimulation was performed with a standardised breakfast.

RESULTS

We always measured the gallbladder wall thickness 3 mm or less and did not find a difference between fasting and stimulation. There was no correlation between gallbladder wall thickness and status of contraction. The healthy gallbladder should excrete at least 25% of the fasting volume within 1 hour.

CONCLUSION

Ultrasound is a suitable method to determine the excretion of the gallbladder. In children standardised meals can be used as stimulus instead of commercial stimulating meals.

Wear of CAD/CAM ceramic inlays: restorations, opposing cusps, and luting cements

Six standard mesio-occlusodistal restorations in extracted mandibular human molars and six opposing palatal cusps from maxillary human first molars were prepared per group. The occlusal contact areas of the restorations and of the opposing enamel cusps were digitized with a three-dimensional scanner. The specimens were exposed to a clinically correlated long-term in vitro wear test. Dicor MGC, Cerec Vita Mk I porcelain, Cerec Vita Mk II V7R porcelain, and Cerec Mk II Vita V7K porcelain were tested. The mean wear of these ceramic materials at the end of the long-term test ranged from 24.3 +/- 10.3 microns (Cerec Vita Mk II V7R) to 88.0 +/- 37.3 microns (Dicor MGC). The mean wear of the opposing human enamel cusps ranged from 93.5 +/- 30.8 microns (Cerec Vita Mk II V7R) to 224.3 +/- 117.4 microns (Cerec Vita Mk I). All ceramic materials except Dicor MGC wore less than did previously measured standards, such as natural human enamel and amalgam. However, because the wear of opposing enamel cusps was high with Dicor MGC and with Cerec Vita Mk I the total wear of these two materials--the sum of the restoration's and the opposing tooth's wear--was higher than that of the standards. Only the new fine porcelain Cerec Vita Mk II V7R showed a total wear comparable to that of enamel, because of its moderate abrasivity against opposing enamel. The wear of the two luting composite resins was measured at the end of the test. Both luting composite resins wore more than did the ceramic inlays and surrounding enamel, leaving a shallow ditch around the restorations.

Wear of ceramic inlays, their enamel antagonists, and luting cements

The wear of ceramic inlay materials and antagonist enamel cups was measured in vitro. Per group, six MOD inlays were adhesively cemented in extracted molars. Castable glass ceramic, pressed glass ceramic, and feldspathic porcelain were used as inlay materials. A microfilled and a fine hybrid composite served as luting agents. The restorations were exposed to an in vitro wear test that corresponds to approximately 5 years of clinical service. The wear in the occlusal contact area was quantified during and at the end of the test with a three-dimensional scanner. Final wear measurements on the inlays (mean +/- SD) ranged from 21.8 +/- 8.8 microns for pressed glass ceramic to 59.0 +/- 37.9 microns for castable glass ceramic. The mean wear of the enamel antagonists ranged from 74.6 +/- 32.9 microns for pressed glass ceramic to 153.2 +/- 61.5 microns for feldspathic porcelain. The wear of the luting composites at the end of the test ranged from 4.9 +/- 5.1 microns for microfilled to 12.3 +/- 6.3 microns for fine hybrid.

Laryngectomy: Grieving disfigurement and dysfunction

When I (Weber) was three, my father had a total laryngectomy. His stoma did not bother me, and it was common to see him cough through his neck, though I never became used to the excessive secretions produced. My father mastered esophageal speech well, so communication was normal. No one in my family can remember what his voice was like before the operation. Knowing that people stared and whispered about my father, I warned new friends that my dad had a hole in his neck so he could breathe and that he might sound funny to them because he had no voice box. I did not want my friends to be frightened by a stoma that many people see as revolting.

Marginal adaptation and fit of adhesive ceramic inlays

This in vitro study compared the marginal adaptation of CAD/CAM and laboratory-made ceramic inlays before, during and after loading. Six MOD inlay preparations of standardized design with one cervical margin in dentine and the other in enamel were prepared for each inlay type: CAD/CAM fabricated MGC-glass ceramic inlays, CAD/CAM fabricated feldspathic porcelain inlays, laboratory-made glass ceramic inlays and laboratory-made feldspathic porcelain inlays. Appropriate luting composite materials were used. The restored teeth were subjected to occlusal loading, thermal cycling, toothbrush-toothpaste abrasion and chemical degradation in vitro. Marginal adaptation was quantitated along the entire length of the cavosurface margin and along selected sections of the margin using SEM, following in vitro testing corresponding to 0, 0.5, 1.0, 2.7 and 5.0 years of clinical service. In addition, marginal fit of the cemented inlays was evaluated in the SEM. The initial marginal adaptation in enamel was excellent in all groups. After in vitro testing, significant marginal discrepancies were found in all groups. A high percentage of marginal openings was recorded, notably in the cervical portions of the margins in both enamel and dentine.

Aggressive behavior and the brain: a different perspective for the mental health nurse

Mental health nurses often provide care to individuals who have the potential for aggressive behavior. The expression of such behavior is influenced by the functioning of the central nervous system (CNS). The authors present a framework to assist the reader to understand the interrelationships among the limbic system, and frontal and temporal lobes as they relate to the expression of aggressive behavior. The implications for mental health nursing practice include detecting contributing factors such as head injury, temporal lobe epilepsy, alcoholism, and dietary imbalances, and interpreting patient behaviors to colleagues. Suggestions for proactive interventions are also included.

Rural hospital nursing as an elective

A rural hospital elective in a diploma nursing program is described. A need and opportunity for this unique practicum was identified in a Canadian province where one-third of the acute care beds are in hospitals of under 100 beds, located primarily in towns outside of metropolitan areas. The six week course offers students 35 hours of classroom content focusing on rural health care concepts plus a 150 hour practicum in one of three participating hospitals. The course is seen as unique in that it focuses on rural health care and is offered within the context of a diploma nursing program. Five student outcomes are identified: awareness of the differences between rural and urban health care; integration of knowledge and experience from previous nursing courses as it relates to the rural context; increasing understanding of how rural population groups affect health care delivery; awareness of rural employment opportunities; and, preparation for the graduate role. A shared vision and collaborative effort on the part of the School of Nursing, the rural hospitals and the host communities has been necessary to establish and maintain such a course.

Polygraphic recordings in subacute sclerosing panencephalitis. A study of the pathophysiology of the periodic EEG complexes

Polygraphic whole night recordings were performed in 10 patients with SSPE. In most cases sleep states could not be classified according to the usual criteria, but two different states with differing EEG patterns were always seen. A significant correlation was obtained between EEG complexes and phase of the respiratory cycle in 8 out of 9 patients, irrespective of the sleep state. Slowing of heart rate for one R-R interval was observed to occur during the onset of the complex in 7 patients in both sleep states, and in 2 patients only in one state. Periodic occurrence of complexes was stable throughout the night. This stability seems to be maintained by a mechanism regulating the duration of an interval according to the duration of the preceding one. It is suggested that diffuse involvement of subcortical structures rather than a localized change is responsible for the generation of the EEG complexes in SSPE.