[Requirements and reality of the German ordinance for staff in psychiatric hospitals: results of a multi-moment study on a psychiatric ward for acute psychosis]. / Vorgaben und Realität der PsychPV : Ergebnisse einer Multimomentstudie auf einer allgemeinpsychiatrischen Aufnahmestation.

BACKGROUND: The regulation of personnel in psychiatry (PsychPV) stipulates time requirements for all relevant activities in inpatient psychiatric care as a function of the degree of disease severity of the patients treated. The demands made on employees in psychiatric care have risen substantially in recent years. Our aim was to examine whether the standard requirements of the PsychPV cover the actual work load. MATERIAL AND METHODS: With the help of a multi-moment study on a general psychiatric ward we examined which activities are performed to which extent by doctors and nurses. RESULTS: Physicians must spend an inordinate amount of time on documentation and the nursing staff on non-patient-related tasks. The causes are the higher number of external requests and higher clinical documentation requirements. This time is lost to the direct patient contact. CONCLUSION: The PsychPV requirements must be urgently adapted so that more time is again available for the direct patient contact.

Three-dimensional stress analysis of threaded cups - a finite element analysis.

A three-dimensional model of the left acetabulum with inserted threaded cup has been generated, based on the finite element method, to calculate stress patterns in the standing phase during walking. In this study, a hemispherical cup with sharp threads, a parabolic cup with flat threads and a conical cup with sharp threads were analysed and compared. Stress patterns in both implant components and adjacent bony structures were calculated in a directly postoperative situation. The different cups were found to induce different stress patterns, deformations and shifting tendencies. The inlays deform notably and show characteristic rotational movement patterns together with the shell. The inclination angle increases in the hemispherical cup and decreases in the parabolic cup. The conical cup levers outward almost parallel to the bone stock by approximately 0.05 mm. The pole surfaces of the various cups - especially the very convex area next to the threads - induce increased compressive stress in the superior section of the acetabular base. This is increased by a factor of three in the conical cup in comparison to the hemispherical cup and less so in comparison to the parabolic cup. This study illustrates that three-dimensional stress calculations are suitable for procuring additional biomechanical information to augment clinical studies, for evaluating implants and for establishing stability prognoses, especially for newly developed prototypes.

Dissolved natural organic matter (NOM) impacts photosynthetic oxygen production and electron transport in coontail Ceratophyllum demersum.

Dissolved natural organic matter (NOM) is dead organic matter exceeding, in freshwater systems, the concentration of organic carbon in all living organisms by far. 80-90% (w/w) of the NOM is made up of humic substances (HS). Although NOM possesses several functional groups, a potential effect on aquatic organisms has not been studied. In this study, direct effects of NOM from various origins on physiological and biochemical functions in the aquatic plant Ceratophyllum demersum are presented. Environmentally relevant concentrations of NOM cause inhibitory effects on the photosynthetic oxygen production of C. demersum. Various NOM sources and the synthetic humic substance HS1500 inhibit the photosynthetic oxygen production of the plant as observed with 1-amino-anthraquinone, a known inhibitor of plant photosynthesis. 1-Aminoanthraquinone may serve as an analogue for the quinoid structures in NOM and HS. Most likely, the effects of NOM may be related to quinoid structures and work downstream of photosynthesis at photosystem (PS) II.

Improvement of the reliability of ceramic hip joint implants.

The aim of this article is to present the optimization of a proof test procedure of ceramic hip joint ball heads. The proof test rejects defective samples in the production line before being implanted into human body. Thereby on every ceramic ball head a static load is applied, which is somewhat higher than the maximum physiological load. The magnitude of the applied load should not damage the samples which are free of flaws in the high stress area. The configuration of the proof test influences the stress distribution in the ball head, which should be similar to the physiological case. To determine the stress distribution, a non-linear finite element (FE) analysis was performed and the results were validated by measurements. With an iterative approach based on FE calculations the proof test configuration was optimized in such a way that the stress distribution in the ball head is similar to the stress distribution in vivo. In this study all ball heads showed very high fatigue resistance after being proof tested and fulfilled the requirements of the FDA (Food and Drug Administration, USA) described in the Guidance Document for the Preparation of Premarket Notifications for Ceramic Ball Hip System. The probability of a fracture of an implanted ceramic ball head can be decreased by the presented optimized proof test procedure. Latter can thus improve the reliability of ceramic hip joint ball heads. The study was supported by the KTI (Commission for Technology and Innovation, Switzerland).

[Modification of form, material and modularity of threaded acetabulum cups]. / Modifikationen von Form, Material und Modularität der Schraubpfannen.

The fixation principle of threaded cups ensures high primary stability. Inadequate results with first-generation threaded cups led to modifications of surface machining. 10 threaded cups of the first generation, and 27 of the second and third generations were systematically analysed and their shapes measured using a no-touch light section technique. In addition, measurements of surface roughness were performed. Implants of the first generation made of polyethylene, ceramic or cobalt-chrome have an average surface roughness (Ra) of 1.5 microns. Approximately one-half of these implants have a conical shape, and one-third a height that is greater than the radius. Threaded cups of the second generation are made either of CP-titanium or titanium alloy. The average corundum-blasted surface roughness is 4.5 microns. Hydroxyapatite-coated (HA) implants have a surface roughness of 5.0 microns. Approximately 45% of the implants have a conical, biconical or flattened-conical shape, while one-third are of hemispherical shape. Approximately 90% of the cups have a height that is up to 23% smaller than the radius. A few cups have a height that approximates the radius. Implants of the third generation with identical surface structure can be supplied with crosslinked-polyethylene inlays or, optionally, with metal/metal or ceramic/ceramic contact surfaces. Primary stability, biocompatible materials and a structured surface are essential for ensuring osseointegration over the long-term. Corundum-blasted pure titanium or titanium alloys with corundum-blasted or HA-coated implants can be considered standard for these cups.

Stress analysis of threaded cups.

Using finite element analysis we have studied the pelvic bony socket and compared it with radiological imaging using threaded acetabular cups of three different shapes (parabolic, conical, hemispherical). The two-dimensional model depicted a planar section through a left pelvic hemisphere. In all three cups the stress in the bony socket increased from lateral towards medial. Compressive stress was found on the superior and inferior parts of the cup, but mainly on the superior aspect, seen radiologically as new trabecular bone formation. The maximum compressive stresses were seen in the cranial curvature of the conical cup, with less in the parabolic form and least in the hemispheric form. The tensile stress at the bottom of the socket increased from the hemispheric to the conical shape. Radiological rarefaction gave an indication of lower stress. There was lower compressive stress between the teeth of the threads. This FE model uses computer simulation to predict bony changes with different designs of implant. The ability to simulate biological conditions is a valuable addition to the testing of mechanical strength.

Alloplastic implants. Their role in reconstruction of the mandible.

This article discusses the use of osseointegrated implants in mandibular reconstruction. Although the article presents the history, indications, and complications of this technique, the primary focus of the article is the technique itself, especially how the technique varies from patients not undergoing reconstruction to those who are. The effect of radiation therapy on the treatment planning of patients undergoing reconstruction also is discussed. Intraoral soft-tissue management also is addressed, as this area often differs significantly in patients undergoing radiation therapy from that in patients not undergoing radiation therapy and reconstruction.

Resin-bonded retainers with custom-made precision attachment for anterior alveolar ridge defect in patients with cleft.

A resin-bonded retainer with a custom-made attachment is an acceptable alternative for patients who have narrow anterior alveolar ridge defects. This restoration facilitates hygiene and satisfies the requirements of form, fit, function, and esthetics.

What to expect from a laboratory industry representative.

The role of the laboratory industry representative is changing. Today, industry representatives must play a much stronger role in providing the products, service, and information that physicians need to run their practices more effectively. They must not only continue to offer high-quality products that are accurate, reliable, and cost-efficient but also provide the product knowledge and services that enable their customers to use those products effectively. They must also be able to advise their customers on new legislation and changes in the market.

Brain function in psychiatric disorders. II. Regional cerebral blood flow in medicated unipolar depressives.

Regional cerebral blood flow was measured during resting baseline and the performance of a verbal and a spatial task in 14 medicated depressives and 25 matched controls. Overall resting flows did not differ, nor were there hemispheric or anteroposterior differences between patients and controls for resting flows. Differences between patients and controls were evident during cognitive activity, and the effects were different for male and female patients. Depressed female patients had higher than normal flows in all conditions, whereas depressed male patients had lower than normal resting flows, which increased to normal during cognitive activity. Their anterior flows increased for the verbal task but not for the spatial task.

Brain function in psychiatric disorders. I. Regional cerebral blood flow in medicated schizophrenics.

We measured regional cerebral blood flow during resting baseline and the performance of verbal and spatial tasks in 15 medicated schizophrenics and 25 matched controls. Patients did not differ from controls in resting flows but showed different blood-flow changes during task performance. Controls replicated earlier findings in normal subjects: flow increased during task performance, and the hemispheric increase was greater in the left for the verbal and in the right for the spatial task. In contrast, patients showed no flow asymmetry for the verbal task and greater left hemispheric increase for the spatial task. The latter finding is consistent with the hypothesis that schizophrenia is associated with left hemispheric overactivation for spatial tasks. In addition, schizophrenic women had unusual flow changes in that their highest flow increase was for the verbal task.

Response to dexamethasone in psychotic depression.

The utility of the dexamethasone suppression test (DST) in the diagnosis of psychotic depression was examined by comparing the responses of 11 psychotic and 18 nonpsychotic depressed inpatients. Nine of 11 psychotic patients (81.8%) and 10 of 18 nonpsychotic patients (55.6%) showed nonsuppression (nonsignificant). Using the 0800h cortisol level alone, we found that significantly more psychotic patients (7 of 11; 63.6%) than nonpsychotic patients (3 of 18; 16.7%) showed nonsuppression. Nonsuppression at 0800h postdexamethasone may be a useful biologic marker for patients with psychotic depression. Implications of these data for the nosologic status of psychotic depression are discussed.