Effects of sensorineural hearing loss on formant-frequency discrimination: Measurements and models.

This study concerns the effect of hearing loss on discrimination of formant frequencies in vowels. In the response of the healthy ear to a harmonic sound, auditory-nerve (AN) rate functions fluctuate at the fundamental frequency, F0. Responses of inner-hair-cells (IHCs) tuned near spectral peaks are captured (or dominated) by a single harmonic, resulting in lower fluctuation depths than responses of IHCs tuned between spectral peaks. Therefore, the depth of neural fluctuations (NFs) varies along the tonotopic axis and encodes spectral peaks, including formant frequencies of vowels. This NF code is robust across a wide range of sound levels and in background noise. The NF profile is converted into a rate-place representation in the auditory midbrain, wherein neurons are sensitive to low-frequency fluctuations. The NF code is vulnerable to sensorineural hearing loss (SNHL) because capture depends upon saturation of IHCs, and thus the interaction of cochlear gain with IHC transduction. In this study, formant-frequency discrimination limens (DLFFs) were estimated for listeners with normal hearing or mild to moderate SNHL. The F0 was fixed at 100 Hz, and formant peaks were either aligned with harmonic frequencies or placed between harmonics. Formant peak frequencies were 600 and 2000 Hz, in the range of first and second formants of several vowels. The difficulty of the task was varied by changing formant bandwidth to modulate the contrast in the NF profile. Results were compared to predictions from model auditory-nerve and inferior colliculus (IC) neurons, with listeners' audiograms used to individualize the AN model. Correlations between DLFFs, audiometric thresholds near the formant frequencies, age, and scores on the Quick speech-in-noise test are reported. SNHL had a strong effect on DLFF for the second formant frequency (F2), but relatively small effect on DLFF for the first formant (F1). The IC model appropriately predicted substantial threshold elevations for changes in F2 as a function of SNHL and little effect of SNHL on thresholds for changes in F1.

Multiple stressors and the role of hydrology on benthic invertebrates in mountainous streams.

Hydrological alteration of rivers is recognised as a major threat to lotic biodiversity acting at broad spatial scales, however, the effect size and pathways of hydrology are rarely quantified in comparison with other stressors such as land use and physico-chemistry. Here we present a multiple stressor study that aims to disentangle the effect sizes and pathways of hydrological alteration on benthic invertebrate community structure and functional metrics. Therefore, we analyse the following four multiple stressor groups: land use, hydrology, physical habitat structure, and physico-chemistry at 51 sites including 72 surveys in the German mountain range. Stressor data were contrasted to benthic invertebrate data using partial canonical correspondence analysis to quantify the community-level response and path analysis to investigate the cause-effect pathway structure of single stressors affecting benthic invertebrate metrics either directly or indirectly (i.e. mediated by other stressors). Hydrological stressors showed a strong impact on community structure, with its unique effects being more dominant than those of any other stressor group. Path analysis confirmed strong direct effects of hydrological stressors on biological metrics but revealed land use to be the most influential stressor group in terms of the sum of direct and indirect effects on biology. Notably, indirect land use effects are mediated by hydrology. Our findings suggest a key role of hydrological stressors in lotic ecosystem assessment, which, however, are rarely addressed in operational river monitoring and management. In light of the wide-spread availability of hydrological data from gauging stations throughout Europe, we plea for a better involvement of hydrological data in river basin management.

Riverine regime shifts through reservoir dams reveal options for ecological management.

Worldwide, dams are a main threat reducing river ecological functioning and biodiversity by severely altering water temperature, flow, and sediment regimes up- and downstream. Sustainable dam management therefore has a key role in achieving ecological targets. Here, we present an analysis of the effects of reservoir dams and resulting regime shifts on community structure and function of lotic macroinvertebrates. Our study derived management options to improve ecological integrity of affected streams. To do this, we contrasted time series data for water temperature (15-min intervals over one year), discharge (daily means over 10 yr), and records of deposited fine sediments against macroinvertebrate samples from pairs of river reaches downstream of dams and of comparable tributaries not affected by dams in the German low mountain range. We observed a decline in the density and diversity of disturbance-sensitive macroinvertebrates (Ephemeroptera, Plecoptera, and Trichoptera) and a correlation between hydrologic metrics and macroinvertebrate deterioration downstream of the dams. Typical "rhithral" (flow-adapted) species changed to "littoral" (flow-avoiding) species below dams, thus indicating a hydrologic regime shift. Increased fine sediment accumulations and deficits of pebbles and small cobbles below dams indicated a severe habitat loss below dams. Additional comparison with undisturbed reference streams allowed us to derive management options that could mitigate the negative impact of hydrologic alterations and accumulations of fine sediments downstream of dams. These options are conditional on the season and in particular address the frequency and duration of low and high flow events.

Proposing priorities of intervention for the recovery of native fish populations using hierarchical ranking of environmental and exotic species impact.

The freshwater populations of native fish species (Ns) have reached critical levels in many parts of the world due to combined habitat deterioration by human interventions and exotic fish species (Es) invasions. These alarming conditions require combined and well-designed interventions for restoring environmental quality and restricting Es invasion. The aim of the study is to propose a method to design spatially explicit priorities of intervention for the recovery of Ns populations in highly impacted freshwater systems by exotic multi-species invasion and water quality (WQ) degradation. WQ and Es are used as Ns descriptors, which require intervention. The method uses gradient analysis (ordination method of Canonical Correspondence Analysis) for assessing the weights of Ns descriptors' effects, which are further used to develop weighted severity indices; the severity index of WQ (Swq) and Es invasion (Se), respectively. Swq and Se are further merged to one combined total severity index St. The proposed method provides a) a ranking of the sites, based on the values of St, which denotes the priority for combined intervention in space and can be visualized in maps, b) a ranking of the most important Ns descriptors for each site to perform site-specific interventions, and c) Es rankings based on their potential threat on Ns for species-specific interventions. WQ, Es and Ns data from 208 sampling sites located in the Emilia-Romagna Region (Northern Italy) were used as a case study for the presentation of the proposed method. The application of the method showed that the north and northwestern lowland areas of Emilia-Romagna region presented the higher priority for intervention since the Ns of these areas are the most impacted from combined Es invasions and WQ degradation. Specific Es belonging to cyprinids, which are mostly responsible for the decline of aquatic vegetation and the increase of water turbidity, and a top Es predator (Wels catfish) were mostly present in these areas. Additionally, the most important WQ stressors of Ns were found to be COD, BOD and temperature that are all connected to oxygen depletion. The aforementioned conditions in the areas described by high priority for intervention can be used as a basis for the development of specific Ns conservation practices targeting the containment of the most harmful Es, the restoration of aquatic vegetation and the improvement of oxygen conditions.

[76-year old patient with suspected but not confirmed "idiopathic myelofibrosis"]. / 76-jähriger Patient mit nicht bestätigtem Verdacht auf "idiopathische Myelofibrose"

A 76-year old patient was referred to our Oncology Unit due to hepatosplenomegaly, anemia, thrombocytopenia, eosinophilia, elevation of lactat dehydrogenase and leucocytosis with occurrence of myeloid and erythroid precursors in the peripheral blood. Histopathological examination of the bone marrow and molecular genetics showing a c-kit-D816V-mutation confirmed the diagnosis of systemic mastocytosis without evidence of idiopathic myelofibrosis. After starting of prednisone treatment anemia, thromocytopenia and the patient's performance status rapidly improved.

Reference to psychiatric consultation in the discharge letter of general hospital inpatients.

OBJECTIVE: The consultation-liaison psychiatrist is frequently confronted with the consultees' lack of adherence to the consultants' recommendations. The aim of this study was to investigate the question if and how the C-L psychiatrist's diagnoses and recommendations are mentioned in the consultee's final medical report and thus communicated to the physician responsible for the aftercare. METHOD: Psychiatric consult reports of a consecutive sample of 144 patients of the departments of neurology, internal medicine, and gynecology and obstetrics at the University Hospital of Zurich were compared to the content of the respective discharge letters. RESULTS: Some kind of information about the psychiatric consultation was found in 84 percent of the discharge letters (consultation as such: 71.5%; psychiatric diagnosis: 66.7%; recommendations: 76.2%. Length of stay, timing of the consultation, length of the consult report and type of recommendation correlated significantly with the mention of psychiatric aspects in the final medical report. Psychotropic medication and psychiatric hospitalization were the recommendations most reliably mentioned. CONCLUSIONS: Psychiatric consultation seems to be taken seriously by attending physicians and is communicated in a high percentage to the physicians responsible for the aftercare. Nevertheless, in patients where active post-discharge management is needed the C-L psychiatrist should actively manage referral to outpatient settings and/or instruct primary care providers.

[Overview, analysis and evaluation of the 1995 public health structural law and the federal social care law from the viewpoint of the trauma surgery department of a university clinic. Measures for preparation of a new reimbursement system and documentation requirements]. / Uberblick, Analyse und Bewertung des Gesundheitsstrukturgesetzes und der Bundespflegesatzverordnung 1995 aus der Sicht der Unfallchirurgischen Abteilung eines Universitätsklinikums. Massnahmen zur Vorbereitung der neuen Entgeltsysteme und Dokumentationspflichten.

All doctors in Germany are required to cooperate in the implementation of the health system reform and the new system for reimbursement of the hospitals to limit the negative consequences to the patients. It would be absolutely wrong to leave the medical services of the insurance companies to define the diagnosis-related groups and determine the charges. The revision of the health system is beneficial in that it supports the economical independence of hospital departments. It is a good idea for them to be paid by results; however, there are no established methods of measuring results or efficacy in medicine. Germany is about 10 years behind the USA in this, so that our country is not yet ready for this reform. Hospital departments do have the freedom to make economic decisions, being heavily dependent on the insurances and the government, because most people who work in hospital are paid from these sources. Departments of trauma or orthopaedic surgery are disadvantaged by the reform, because of the number and kind of diagnosis related groups and the method of reimbursement. This leads to a profit-oriented system of medical documentation, with possible upcoding of diagnoses in future. The present health reform most probably will not increase the efficiency of hospitals; it will not be possible to attain cost reductions with the same level of medical care. The reduced reimbursement will force doctors to cut down their expenses and restrict diagnostic and therapeutic procedures. On the other hand the administration sector in hospitals and insurances will expand dramatically in future.(ABSTRACT TRUNCATED AT 250 WORDS)

Radionuclide simultaneous dual-isotope stress myocardial perfusion study using the "three window technique".

Several methods are available for performing radionuclide stress myocardial perfusion studies. All of these methods require two separate acquisition and processing iterations, which is time-consuming and inconvenient for the patient. The authors introduce a new method using the "three window technique" that they developed to perform simultaneous dual-isotope imaging for stress myocardial perfusion studies. In addition to Tl-201 and Tc-99m windows centered at 70 KeV and 140 KeV, respectively, a third window centered at 105 KeV, representing scattered radioactivity from Tc-99m, is established. By subtracting the radioactivity in the third window from the radioactivity in the Tl-201 window, "crosstalk" interference is significantly reduced. The simultaneous dual-isotope imaging method acquires and processes resting and stress myocardial perfusion images simultaneously. It halves imaging time and doubles patient throughput, improves scheduling flexibility, and reduces patient waiting time and discomfort.

[Pediatric femoral shaft fracture in the 6-14 year age group. A retrospective therapy comparison between conservative treatment, plate osteosynthesis and external stabilization]. / Die kindliche Femurschaftfraktur in der Altersgruppe 6-14 Jahre. Ein retrospektiver Therapievergleich zwischen konservativer Behandlung, Plattenosteosynthese und externer Stabilisierung.

The optimal choice between operative and conservative therapy in the treatment of femur shaft fractures in school age children remains controversial. Between 1985 and 1991, 34 children aged 6-14 years were treated in our institution for fractures of the femoral shaft: 8 were treated conservatively with traction, while 10 underwent plate fixation and 15 external fixation. The 34 cases were analyzed retrospectively. In the conservatively treated group a plate osteosynthesis become necessary in 2 patients because of delayed union and fracture malalignment. Hospitalization was the longest in these children, although their concomitant injuries were the least extensive. In the group with plating there were no serious complications but open surgery is needed for two major operations for insertion and removal. The average time on crutches after plate fixation was 56 days. In the group treated by external fixation four secondary plate osteosyntheses were performed, two at an early stage because of unacceptable fracture malalignment and two others because of fracture instability after removal of the fixateur. The stay in hospital was the shortest in this group. The 11 children who had been completely managed by external fixation achieved walking without crutches in the shortest time, viz. 15 days after the operation on average. The average time to removal of the fixateur was 67 days. Review was possible in 27 of the 28 children who had been completely managed by the initial treatment method. All had unlimited hip and knee motion. Two children in the conservative treatment group were seen on radiographical examination to have a varus angulation of more than 10 degrees. In the plate and fixator group no malalignment was present.(ABSTRACT TRUNCATED AT 250 WORDS)

1,25-Dihydroxyvitamin D3-mediated alterations in microtubule proteins isolated from chick intestinal epithelium: analyses by isoelectric focusing.

Recent work has indicated that vectorial Ca2+ transport across the intestinal epithelium occurs in vesicles and may involve the participation of microtubules [Nemere et al., 1986]. Since 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) stimulates this Ca2+ transport process, microtubule (MT) isotypes were studied as a potential regulatory point. The effect of 1,25(OH)2D3 status on tubulin isotypes was analyzed by isoelectric focusing (IEF) gels of taxol stabilized MTs prepared from intestinal epithelium of vitamin D-deficient chicks dosed with vehicle (-D) or 1.3 nmoles of 1,25(OH)2D3 (+D) 2.5, 5, 10, 15, or 43 h prior to sacrifice. Four bands, one of which was identified as alpha-tubulin on the basis of Western analysis, increased in Coomassie Blue staining intensity 5-15 h after 1,25(OH)2D3, corresponding to the time course of augmented vesicular Ca2+ transport. Dose-response studies revealed similar changes in tubulin isotype profiles in IEF gels, again corresponding to doses known to elicit enhanced Ca2+ absorption (52-6,500 pmoles of hormone). The role of Ca2+ transport was also examined. Isoelectrically focused intestinal epithelial tubulin from -D chicks allowed to transport Ca2+ for 30 min revealed increased staining of bands relative to nonabsorbing -D controls. By comparison, Ca2+ transport in +D chicks resulted in fainter bands relative to nonabsorbing, +D controls. MTs prepared from fasted or fed chicks revealed similar changes upon IEF, but of much smaller magnitude. Enhanced phosphorylation did not account for the appearance of the more acidic bands, although 1,25(OH)2D3 treatment resulted in decreased 32P content of a presumptive non-tubulin component, relative to preparations from -D controls. Glucocorticoids, which are known to suppress 1,25(OH)2D3-stimulated Ca2+ transport, led to severely diminished levels of total tubulin, as judged by SDS-PAGE, rather than altered tubulin isotypes. Thus, MTs of intestine are subject to regulation by hormonal status, as well as by the amount of Ca2+ available for transepithelial transport.

[Traumatology in the elderly. Problems exemplified by femoral neck fractures]. / Traumatologie beim alten Menschen. Problematik exemplarisch aufgezeigt an Schenkelhalsfrakturen.

The most frequent complications in response to a fracture of the femoral neck, a typical injury of the elderly, are necrosis of the head of femur and pseudoarthrosis of the femoral neck. Only the around dressed down fracture can be conveyed to conservative treatment. The classification of AO takes these problems into consideration. One possibility to preserve the femur head is by operative insertion of a dynamic hip screw (DHS). Specific problems of the diverse types of fracture and their surgical details are taken into special account.