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Biomedical subjects

P Werner

Publications and source records attributed to P Werner.

At least 91 records · Page 5Linked to original sources
PubMed1997

Management of verbally disruptive behaviors in nursing home residents.

BACKGROUND: Verbally disruptive behaviors (VDB) are verbal or vocal behaviors that are inappropriate to the circumstances in which they are manifested. These behaviors are a source of concern because they disturb persons around the older person and may be an indicator of distress. METHODS: Three interventions were tried and compared to a control no-intervention phase. The interventions were: (1) Presentation of a videotape of a family member talking to the older person, (2) in vivo social interaction, and (3) use of music. RESULTS: Thirty-two nursing home residents suffering from dementia and manifesting VDB were observed before, during, and after the interventions, and the duration of VDB was recorded. The behaviors decreased by 56% during the social interaction, 46% during the videotape, 31% during the music, and 16% during the no-intervention. CONCLUSIONS: The effects of the interventions were clinically and statistically significant, indicating the importance of providing stimulating activities and a richer environment to cognitively impaired nursing home residents.

Aged↗
PubMed1997

Evaluation of an inservice training program on dementia and wandering.

This study assessed the impact of an inservice training program in four nursing homes on nursing staff's knowledge of dementia, pacing/wandering behavior and management strategies, staff satisfaction, and their perceptions of work difficulty and quality of care. Additionally, unit-level behavioral observations of agitated behavior and the nature of resident interactions with staff members and other residents were also performed to assess whether changes in nursing staff's knowledge impacted the residents or interactions with the residents. Analyses revealed that quiz scores were significantly improved immediately following the inservice program as compared to pretest but returned to near pretest levels at the 1-month follow-up. Additionally, nursing staff reported that residents were allowed to pace/wander to a greater extent at follow-up compared to pretest. Methods for improving the effectiveness of inservice training are discussed.

Aged↗
PubMed1997

[Technical differences in various CPAP and BiLevel CPAP devices].

PURPOSE: Since the first presentations of CPAP by Sullivan 1983 und BiPAP by Sanders 1990 as a successful treatment in obstructive sleep apnoea syndrome, many CPAP and BiLevel-CPAP devices have been developed by several companies around the world. Although all devices work on the same principle of continuous positive airway pressure delivered through nasal or facemasks, there are, however, significant technical differences between these devices, mainly due to different size and different maximum speed of the turbines. As far as we know, the only study concerning this technical difference in the devices was conducted by Raschke in 1995, who found significant differences in the pressure stability of the devices using a very complicated measurement model on volunteers who were breathing on the different devices. We intended to study the technical differences of the devices using a more simple technique in static conditions, but with very exact measurement. METHODS: We measured pressure stability on different inspiration flows and different pressure levels of 8 CPAP's and 4 BiLevel-CPAP's under static conditions using the "Höntzsch Exact ASD-G Messrohr ms 20201-18" flow-measurement device and the "Thommen HM 18.0020.A" pressure-measurement devixe. We measured the noise emission by these devices at different frequency levels using the "Brüel and Kjer Dual Channel Real Time Frequency Analyzer", and measured the speed to reach the adjusted pressure level with the "Multimeter Phillips PM 2518X" and "Oszillograph Phillips PM3350" using the voltage change due to different working of the electric engines at different turbine speeds. We also investigated the different construction of the devices by opening them and analysing the materials used in the devices. RESULTS: The real pressure levels at an adjusted pressure of 10 mbar and at an inspiration flow of 1 Liter/sec range from 8.7 mbar to 15.6 mbar in CPAP's and from 9 mbar to 9.7 mbar in BiLevel devices. At higher inspiration flows the differences are larger, at lower flows smaller. The maximum noise emission in the 10 Hhz spectrum at a distance of 100 cm from the device at an adjusted pressure level of 10 mbar ranged from 29.6 dB to 39.9 dB in CPAP's and 30.4 dB to 42.2 dB in BiLevel-CPAP's. The time to reach an adjusted pressure level of 10 mbar after closing the airway of the device ranged from 0.26 to 0.66 sec in CPAP's and from 0.46 to 0.80 sec in BiLevel devices. CONCLUSION: There are significant technical differences in the different CPAP and BiLevel devices due to different construction of the turbines and electrical engines of these devices. This should be considered when prescribing a device for a sleep apnoea patient. Not every device is suitable for every patient, and quality differences should be considered by all persons involved in the production and prescribing process.

Airway Resistance↗
PubMed1997

[The clinical use of an individually fitted nasal mask ("Freiburg Respiratory Mask") within the scope of a case report of controlled BiPAP ventilation].

PURPOSE: Noninvasive mechanical ventilation with nasal or face mask using either BiPAP or IPPV (intermittent positive pressure ventilation) modes is meanwhile the standard type of mechanical ventilation instead of endotracheal intubation or tracheostomy in many patients with chronic and acute respiratory failure. However, problems occur very often in noninvasive mechanical ventilation due to mask problems with leakage of air out of the mask or erasions and necrosis of the skin by constant pressure through the mask frame. Hence, some clinical work groups developed customized molded masks mostly in cooperation with dentistry labs. These masks, however, are often very expensive and take several weeks to be manufactured. Our aim was to develop an inexpensive (less than 600 USS) and easy-(in one day)-to-produce customized nasal mask, the so-called "Freiburg nasal mask". We wish to show by a case report the clinical efficacy of this customized mask in severe respiratory failure. CASE AND METHOD: A 52 y old women (BMI 19, nonsmoker) suffering from a severe hypercapnic respiratory failure (PCO2 over 100 mmHg) due to a severe kyphoscoliosis as result of a postpoliosyndrome and already on controlled nasal BiPAP with a standard respironics nasal mask, was referred to our clinic as an emergency case. After not succeeding to normalise blood gases and clinical status of the patient in mechanical ventilation on BiPAP mode and additional 2 lit/min of oxygen insufflation via the mask (patient was refusing invasive ventilation) for 12 days due to mask leakage and mask discomfort we made a mould of the patients face. Using this mould in a vacuum process the two EVA polymers Erkoflex and Erkodent were combined to build up the customized mask over the mould on the same day. In the first three days using the customized mask in the patient PCO2 decreased below 70 mmHg, on the 8th day after starting with the customized mask, blood gases almost normalised. Patient compliance in using the BiPAP device increased from 8 h a day to 16 h a day. CONCLUSION: This case shows that sometimes due to leakage of air in standard nasal masks noninvasive mechanical ventilation may fail in patients with severe respiratory failure. Therefore, in these patients customized moulded nasal or face masks should be used instead of standard masks. We think that the Freiburg nasal mask is an example of an easy to produce and nonexpensive customized mask and may be used in such patients, as this case report shows.

Equipment Design↗
PubMed1996

Domains of P2X receptors involved in desensitization.

ATP-gated ion channels (P2X receptors) are abundantly expressed in both neuronal and nonneuronal tissues, where they can serve as postsynaptic receptors. The response to ATP shows marked desensitization in some tissues but not others. Currents induced by ATP in Xenopus oocytes expressing cloned P2X1 (or P2X3) receptor had strong desensitization, whereas currents in cells expressing P2X2 receptors desensitized relatively little (90% vs. 14% decline of current in a 10-s application). In chimeric receptors, substitution into the P2X1 receptor of either one of two 34-residue segments from the P2X2 receptor removed the desensitization; these segments included the first or the second hydrophobic domain. In contrast, desensitization was introduced into the P2X2 receptor only by providing both these segments of the P2X1 (or P2X3) receptor. This suggests that desensitization requires interaction between the two hydrophobic domains of the receptor, and supports the view that these are membrane-spanning segments.

Adenosine Triphosphate↗
PubMed1996

Role of platelet-endothelial cell adhesion molecule (PECAM) in platelet adhesion/aggregation over injured but not denuded endothelium in vivo and ex vivo.

BACKGROUND AND PURPOSE: We previously demonstrated that a monoclonal antibody (MoAb) with anti-CD31, anti-platelet-endothelial cell adhesion molecule (PECAM)-like properties delayed platelet adhesion/aggregation at a site of minor endothelial injury. To our knowledge, this was the first in vivo demonstration of an effect of anti-CD31. There was no exposure of collagen or basal lamina at the injured site, and the modulation of adhesion/aggregation at such sites has not received much study. The present investigation attempted to replicate the first with the use of a different MoAb, definitely characterized as anti-PECAM. In addition, an ex vivo investigation was performed to see whether the in vivo action of anti-PECAM could have been caused by an effect of the MoAb on the platelets rather than on the endothelium. METHODS: A helium-neon laser, in the presence of intravascular Evans blue, was used to injure the endothelium of arterioles on the surface of the mouse brain. Intravital microscopy was used to determine the number of seconds required for the light to initiate the first recognizable platelet aggregate forming at the injured site. Mice injected with vehicle were compared with mice injected with 2 mg/kg anti-PECAM through the tail vein. The injection was 10 minutes before challenge with the laser. Additional studies were performed of aggregation produced in vitro by arachidonate and by ADP added to platelet-rich plasma (PRP) prepared from blood taken from MoAb-treated and vehicle-treated mice. RESULTS: Aggregation latency was significantly prolonged (P<.02) by anti-PECAM (121+/-59 versus 65+/-26 seconds in controls; n=10 each). Aggregation ex vivo was not affected. CONCLUSIONS: PECAM is an important modulator of platelet adhesion/aggregation at sites of minor endothelial damage in brain arterioles. The data are consistent with the hypothesis that PECAM sites on the endothelium are involved and may be exposed by the injury to promote adhesion/aggregation. Since the endothelial cell layer is intact at these sites, mechanisms such as this offer important alternatives to the more commonly studied pathways of platelet activation, which require exposure of collagen and are not applicable in this model.

Adenosine Diphosphate↗
PubMed1996

Longitudinal changes in cognitive functioning in adult day care participants.

This study examines longitudinal changes in cognitive functioning over the course of 2 years in participants of adult day cae programs. Cognitive measures included the Brief Cognitive Rating Scale (BCRS) and the Mini-Mental State Examination (MMSE). Longitudinal data were available for five measurement points over 2 years for 82 participants (22 males and 60 females). Overall, results from this study suggest that there were significant cognitive declines on BCRS and MMSE, even after only 1 or 2 years in the study. The rates of impairment over the 2 years for BCRS and MMSE were highly correlated. Within each measure, the individual rates of decline were very heterogenous and were influenced by the presence, type, and prognosis of dementia. Participants with multi-infarct dementia had greater cognitive decline than did those with other types of dementias. Initial cognitive functioning and physician's prognosis of dementia trajectory were also significant predictors of change over time. Results suggest a floor effect in the BCRS.

Activities of Daily Living↗
PubMed1996

Endovascular covered stent repair of an intercostal artery patch dehiscence from a descending thoracic aortic aneurysm graft.

PURPOSE: To describe the use of endovascular techniques to repair a descending thoracic aortic pseudoaneurysm at a site of patch dehiscence. METHODS AND RESULTS: A 63-year-old hypertensive, diabetic female with a 4-cm aneurysm in the descending thoracic aorta underwent surgical repair with a 35-mm Dacron graft. Dehiscence of the intercostal arterial patch produced a large, 6-cm-diameter pseudoaneurysm that extended into the left thoracic cavity. An endovascular repair was planned using a Dacron stent-graft. Despite induced hypotension and an exteriorized, stiff exchange wire to enhance control of the delivery balloon catheter, the initial attempt failed to close the suture line defect. A customized polytetrafluoroethylene-covered, balloon-expandable stent was successfully deployed using the original stent-graft as a landmark. At 6 months, the contrast-enhanced spiral computed tomographic scan showed patency of the stent-graft and resorption of the pseudoaneurysm. CONCLUSIONS: This communication describes the management of a surgical complication using balloon-expandable covered stents in contrast to either conventional surgery or self-expanding stent-grafts. Transesophageal ultrasound monitoring delineated the suture line leak, identified the position of the stent-grafts, and accurately demonstrated closure of the defect.

Aneurysm, False↗
PubMed1996

D2, D3, and D4 dopamine receptors couple to G protein-regulated potassium channels in Xenopus oocytes.

Human D2, D3, D4 and dopamine receptors were individually coexpressed in Xenopus oocytes with a G protein-regulated inwardly rectifying potassium channel (GIRK1). At -100 mV in 96 mM potassium, dopamine (0.1-100 nM) evoked an inward current; the current showed inward rectification, reversed polarity at 0 mV, and was blocked by barium (50% inhibition by 10 microM). The concentrations of dopamine activating 50% of the maximal current (EC50) were not different (2-4 nM) for D2, D3, and D4 receptors, but the maximal current was 3-fold larger for D2 and D4 than for D3 receptors. Dopamine evoked reproducible inward currents at D2 and D4 receptors when applied repeatedly, but second responses could not be observed in oocytes expressing D3 receptors. 7-Hydroxy-N,N-di-n-propyl-2-aminotetralin mimicked the effect of dopamine (EC50 of approximately 2, approximately 3, and approximately 19 nM at D2, D3, and D4, respectively). (-) Sulpiride reversibly blocked the dopamine-induced current with IC50 values of 5, 300, and 2000 nM for D2, D3, and D4 receptors, respectively. Dopamine was ineffective in oocytes injected 2 hr previously with pertussis toxin. We concluded that all three D2-like dopamine receptors share the potential to activate inwardly rectifying potassium channels.

Animals↗
PubMed1996

Evidence of neuronal oxidative damage in Alzheimer's disease.

Oxidative stress has been proposed as a pathogenetic mechanism in Alzheimer's disease. One mechanism of oxidative damage is the nitration of tyrosine residues in proteins, mediated by peroxynitrite breakdown. Peroxynitrite, a reaction product of nitric oxide and superoxide radicals, has been implicated in N-methyl-D-aspartate receptor-mediated excitotoxic damage. Reported evidence of oxidative stress in Alzheimer's disease includes increased iron, alterations in protective enzymes, and markers of oxidative damage to proteins and lipids. In this report, we demonstrate the presence of nitrotyrosine in neurofibrillary tangles of Alzheimer's disease. Nitrotyrosine was not detected in controls lacking neurofibrillary tangles. Immunolabeling was demonstrated to be specific nitrotyrosine in a series of control experiments. These observations link oxidative stress with a key pathological lesion of Alzheimer's disease, the neurofibrillary tangle, and demonstrate a pathogenetic mechanism in common with the other major neurodegenerative diseases of aging, Parkinson's disease and amyotrophic lateral sclerosis. These findings further implicate nitric oxide expression and excitotoxicity in the pathogenesis of cell death in Alzheimer's disease.

Adolescent↗
PubMed1996

[Analysis of microsatellite polymorphisms in Bernese mountain dogs and Newfoundlands].

As the number of detected inherited diseases in dogs is increasing, linkage mapping offers an opportunity for the localisation of the responsible genes. In humans microsatellites are ideal markers for constructing high-resolution genetic maps. Twenty-five dog specific microsatellites which are highly polymorphic in mixed dog breeds, were tested by PCR in a group of unrelated Newfoundlands and Bernese Mountain dogs. The polymorphisms found in this two breeds were clearly lower than in the mixed breeds suggesting that only 40% of the markers tested would be useful for linkage analysis. In addition the allele frequencies and distributions differed among this two purebred but related breeds. Our data suggest that a selection for useful markers for each specific breed has to be performed prior to linkage analysis.

Animals↗
PubMed1996

"Open-word" questions: an effective tool in gauging education of patients with COPD.

For evaluation of the success of patient education in patients suffering from chronic obstructive pulmonary disease (COPD), multiple-choice tests are commonly used. Using these tests, however, only passive knowledge can be examined. We attempted to evaluate, with the help of "open-word" questions and keywords, as used in examinations of students of arts, the active knowledge achieved by 12 patients who had been participants in one of our indepth courses of patient education. The results of this "open-word" test were compared with the results of multiple-choice tests with 91 participants. The average results of the "open-word" tests, with 36% correct answers, were remarkably worse than those of the multiple-choice tests with 80% correct answers. In our opinion, this allows the conclusion that the active knowledge attained in the patient-education courses is clearly lower than the passive knowledge achieved, and that, on the other hand, multiple-choice tests cannot be considered as the exclusive method to evaluate the success of patient education because their questions may quite often prove to be too easy.

Female↗
PubMed1996

[Is early extubation after surgery for esophageal cancer possible?].

In a series of 50 patients undergoing elective oesogastrectomy through a laparotomy and a right thoracotomy, the avoidance of overnight ventilatory support was made possible by the agreement of anaesthetists and surgeons on suitable policies. The attempt to extubate the patients immediately postoperatively differentiated two groups. For the first group (32 patients; 64%), early extubation could be performed and only one patient was reintubated and required prolonged ventilation. A second group comprised 18 patients who could not be extubated early (36%). For most of the patients in this second group extubation was only delayed until the next day, and recovery was otherwise uneventful. In three cases, however, pulmonary atelectasis with infection was a major problem, and these patients required broncho-endoscopies, and prolonged ventilatory support. Nevertheless, morbidity and mortality after oesophagectomy were significantly reduced in this series, compared with a previous study in the same hospital. Careful postoperative assessment of the patient is essential. The main factors leading to the decision for early extubation appeared to be: absence of serious cardiovascular history, absence of peroperative surgical complications, adequate rewarming, normal chest X-ray, and the presence of clinical criteria for extubation along with adequate arterial blood gases. If the above criteria can be achieved, then early extubation should be routine and can be safely performed in the majority of cases.

Adult↗