Abnormalities of auditory evoked magnetic fields and structural changes in the left hemisphere of male schizophrenics--a magnetoencephalographic-magnetic resonance imaging study

Functional and structural changes in 10 DSM-III-R male schizophrenics and 10 healthy volunteers were investigated using magnetoencephalographically (MEG) detected long-latency (N100 m) auditory evoked fields (AEFs) and magnetic resonance imaging (MRI). The AEFs were characterized by single moving equivalent dipoles, which were superimposed on MRIs. There were significant differences in dipole orientations and in AEF latencies in the left hemisphere of schizophrenics, when compared to the controls. The MEG-detected alterations were found to be associated with a bilateral volume reduction of the posterior superior temporal gyrus (pSTG), which was more pronounced in the left hemisphere. Separate analysis of white and gray matter has shown that the pSTG volume reduction resulted from decreased gray matter volumes without white matter changes. Both the functional and the morphological data indicate a left-hemispheric disturbance in our patients.     

Effects of vitamins A and E on the antioxidative metabolism of weaning pigs given dietary fats of different qualities

Early weaned piglets were divided into eight groups of 6 animals each. The animals were fed diets differing in fat quality (4% soybean oil, POZ 5 or 176) and in the content of the vitamins A (5,000 or 20,000 I.U./kg) and E (25 or 125 I.U./kg) over a period of 7 weeks. At the beginning, on day 25 and 47 blood samples were taken and analysed for vitamin A and E. In liver, heart, M. longissimus dorsi and M. semitendinosus vitamin A, E and the TBA-reactive substances were analysed. Induced lipid peroxidation was assessed by the ethane and pentane production rate in the skeletal muscle. During the weaning period a decrease in the alpha-tocopherol level was observed. In groups with the lower doses of vitamin E this effect was more pronounced. After 47 days the alpha-tocopherol concentrations in plasma and heart and skeletal muscle fell about 25-30% by offering high doses of vitamin A compared to those groups fed low doses. Oxidized fats also led to lower tocopherol concentrations in muscle tissues. Hydrocarbon production in M. longissimus dorsi and M. semitendinosus was significantly reduced in groups with the high supplement of vitamin E. A tendentially opposite effect was seen in groups supplied with high levels of vitamin A or oxidized fat. Although retinyl esters in plasma are a minor fraction of the vitamin A activity, they present 99% of the vitamin A in the liver. The distribution pattern of the different retinyl esters was independent of the amount of supplementary vitamin A. In the present experiment 20,000 U of Vitamin A reduced plasma and tissue vitamin E levels. This effect led to an increase of lipid peroxidation indicated by the higher production of hydrocarbons. The results raise concerns about further increases of vitamin A supplementation in piglet feed.     

Active electronic cochlear implants for middle and inner ear hearing loss--a new era in ear surgery. I: Basic principles and recommendations on nomenclature

Hearing aids have fundamental disadvantages: (1) stigmatization of the patient; (2) the sound is often found to be unsatisfactory due to the limited frequency range and undesired distortion; (3) in many patients, the ear canal fitting device generally necessary leads to an occlusion effect; (4) acoustic feedback when amplification is high. Conventional hearing aids transmit sound into the ear canal via a small microphone. Sound has the disadvantage of requiring high output sound pressure levels for its transmission. This along with the necessary miniaturization of the loudspeaker as well as the resonances and reflections in the closed ear canal contribute to the disadvantages mentioned. In contrast, implantable hearing aids do not make sound signals but micromechanical vibrations. An implantable hearing aid has an electromechanical transducer instead of the loudspeaker of a conventional hearing aid. The hearing signal does not leave the transducer as sound but as a mechanical vibration which is directly coupled to the auditory system bypassing the air. This implantable hearing aid is either coupled to the tympanic membrane, the ossicular chain, the perilymph of the inner ear, or the skull. An implantable hearing aid is expected to have: 1 Better sound fidelity than a hearing aid 2 No ear canal fitting device, free ear canal 3 No feedback 4 Invisibility Requirements on electronic hearing implants designed for patients with conductive hearing loss differ from those on implants for sensorineural hearing loss. Conductive hearing loss requires the implant to replace the impedance transformation, thus being an impedance transformation implant (ITI). In various respects, the demands on an ITI are lower than the demands on an electronic hearing aid for patients with sensorineural hearing loss. The latter are mostly patients with a failure of the cochlea amplifier (CA). A damage to the CA is clinically discernible by a positive recruitment and loss of otoacoustic emissions (OAE). Since these patients form the majority of cases with sensorineural hearing loss, an active hearing implant for such patients should partially replace the function of the CA. Therefore, the suggestion is to refer to a CAI (cochlea amplifier implant). The implant expressions ITI (for patients with conductive hearing loss) and CAI (for patients with sensorineural hearing loss) used in this context allow nomenclatural association with the CI (cochlear implant) for complete inner ear failure as well as with the BSI (brainstem implant) in the case of hearing nerve failure.     

31P magnetic resonance spectroscopy in the frontal lobe of major depressed patients

Most research with 31P-magnetic resonance spectroscopy (31P-MRS) in affective disorders has been done in the field of bipolar disturbances. Reduced frontal and temporal lobe phosphomonoester (PME) concentrations were measured in the euthymic state, whereas increased values were found in the depressed state. In bipolar-II patients reduced phosphocreatine (PCr) concentrations were reported in the euthymic, depressed, and manic state. The aim of the present study was to explore whether PME and PCr were also altered in the frontal lobe of major depressed, unipolar patients. Therefore, we used 31P-MRS to investigate the relative phospholipid and high-energy phosphate concentrations in the frontal lobe of 14 unipolar patients, mostly medicated, and 8 age-matched controls. We found increased PME and decreased ATP values. Other 31P-MRS parameters were not different in both groups. Phosphomonoester percentages correlated negatively with the degree of depression. Thus, the main alterations found in bipolar depressed patients could also be demonstrated in unipolar depressed patients. The results are discussed with regard to disturbed phospholipid and intracellular high-energy phosphate metabolism in depressed patients.     

Use of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) to assist with triage of patients with chest pain or other symptoms suggestive of acute cardiac ischemia. A multicenter, controlled clinical trial

BACKGROUND: Approximately 6 million U.S. patients present to emergency departments annually with symptoms suggesting acute cardiac ischemia. Triage decisions for these patients are important but remain difficult. OBJECTIVE: To test whether computerized prediction of the probability of acute ischemia, used with electrocardiography, improves the accuracy of triage decisions. DESIGN: Controlled clinical trial. SETTING: 10 hospital emergency departments in the midwestern, southeastern, and northeastern United States. PATIENTS: 10689 patients with chest pain or other symptoms suggestive of acute cardiac ischemia. INTERVENTION: The probability of acute ischemia predicted by the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI), either automatically printed or not printed on patients' electrocardiograms. MEASUREMENTS: Emergency department triage to a coronary care unit (CCU), telemetry unit, ward, or home. Other measurements were the bed capacity of the CCU relative to that of the telemetry unit; training or supervision status of the triaging physician; and patient diagnoses and outcomes based on clinical, electrocardiographic, and creatine kinase data. RESULTS: For patients without cardiac ischemia, in hospitals with high-capacity CCUs and relatively low-capacity cardiac telemetry units, use of ACI-TIPI was associated with a reduction in CCU admissions from 15% to 12%, a change of -16% (95% CI, -30% to 0%), and an increase in emergency department discharges to home from 49% to 52%, a change of 6% (CI, 0% to 14%; overall P=0.09). Across all hospitals, for patients evaluated by unsupervised residents, use of ACI-TIPI was associated with a reduction in CCU admissions from 14% to 10%, a change of -32% (CI, -55% to 3%); a reduction in telemetry unit admissions from 39% to 31%, a change of -20% (CI, -34% to -2%); and an increase in discharges to home from 45% to 56%, a change of 25% (CI, 8% to 45%; overall P=0.008). Among patients with stable angina, in hospitals with high-capacity CCUs, use of ACI-TIPI was associated with a reduction in CCU admissions from 26% to 13%, a change of -50% (CI, -70% to -17%), and an increase in discharges to home from 20% to 22%, a change of 10% (CI, -29% to 71%; overall P=0.02). At hospitals with high-capacity telemetry units, use of ACI-TIPI was associated with a reduction in telemetry unit admissions from 68% to 59%, a change of -14% (CI, -27% to 1%), and an increase in emergency department discharges to home from 10% to 21%, a change of 100% (CI, 22% to 230%; overall P=0.02). Among patients with acute myocardial infarction or unstable angina, use of ACI-TIPI did not change appropriate admission (96%) to the CCU or telemetry unit at hospitals with high-capacity CCUs or telemetry units. CONCLUSIONS: Use of ACI-TIPI was associated with reduced hospitalization among emergency department patients without acute cardiac ischemia. This result varied as expected according to the CCU and cardiac telemetry unit capacities and physician supervision at individual hospitals. Appropriate admission for unstable angina or acute infarction was not affected. If ACI-TIPI is used widely in the United States, its potential incremental impact may be more than 200000 fewer unnecessary hospitalizations and more than 100000 fewer unnecessary CCU admissions.     

Stability of the replicative Mcm3 protein in proliferating and differentiating human cells

Mcm proteins are abundant nuclear proteins involved in the regulation of genome replication. Previous experiments had shown that levels of Mcm-specific mRNAs increase at the G1/S phase transition of the cell cycle, but that the amounts of Mcm proteins do not change much during the cell cycle. To learn more about the stability of an Mcm protein we performed experiments which showed that: (i) more than 60% of [35S]methionine pulse-labeled Mcm3 protein appears to be degraded during a 24-h chase in HeLa cells; (ii) the amount of Mcm3 protein significantly decreases during the differentiation of HL60 cells in vitro (whereas another replication-initiation protein, hOrc2, remains fairly constant); and (iii) according to immunohistochemical staining, Mcm3 protein is present in nuclei of cells in the proliferating zone of human epidermal tissue, but in decreasing amounts in nuclei of differentiating cells of the upper cell layers. Our interpretation is that Mcm3 protein is no longer synthesized after initiation of differentiation and slowly disappears at a half-life of approximately 24 h.     

Causes and consequences of natal dispersal in root voles, Microtus oeconomus

To test the causes and consequences of variation in natal dispersal in root voles we released 53 matrilines (mothers with newly weaned litters) separately in field enclosures, during nine consecutive periods. The matrilines could disperse and distribute themselves among three pre-emptied habitat patches. Two dispersal measures were recorded: short-distance dispersal defined as individuals immigrating to a neighbouring patch, and long-distance dispersal defined as unsettled individuals captured along the fence of the enclosures. We analysed the role of social factors (i.e. maternal and litter characteristics), habitat quality (i.e. seasonal effect) and experimentally manipulated shape of the natal patch in dispersal. The consequences of dispersal were analysed with respect to the spatial distribution of kin, and to pregnancy in females and sexual maturation in males. Dispersal was unrelated to patch shape. In agreement with the inbreeding avoidance hypothesis, long-distance dispersal was male biased and philopatric males were most frequently reproductively inactive. Whilst young males avoided their mother, they seemed to disperse, settle and mature sexually independently of their sisters. In agreement with the resource competition hypothesis, young females avoided their mother and were most frequently reproductively inactive when residing in their mother's patch. We conclude that inbreeding avoidance was underlying the male dispersal pattern. For females, long-distance dispersal was most in agreement with the inbreeding avoidance hypothesis while short-distance dispersal could be explained by the resource competition hypothesis. (c) 1998 The Association for the Study of Animal Behaviour.     

MPEG digital audio coding

The Moving Pictures Expert Group (MPEG) within the International Organization of Standardization (ISO) has developed a series of audio-visual standards known as MFEG-1 and MPEG-2. These audio-coding standards are the first international standards in the field of high-quality digital audio compression. MPEG-1 covers coding of stereophonic audio signals at high sampling rates aiming at transparent quality, whereas MPEG-2 also offers stereophonic audio coding at lower sampling rates. In addition, MPEG-2 introduces multichannel coding with and without backwards compatibility to MPEG-1 to provide an improved acoustical image for audio-only applications and for enhanced television and video-conferencing systems. MPEG-2 audio coding without backwards compatibility, called IMPEG-2 Advanced Audio Coding (AAC), offers the highest compression rates. Typical application areas for MPEG-based digital audio are in the fields of audio production, program distribution and exchange, digital sound broadcasting, digital storage, and various multimedia applications. We describe in some detail the key technologies and main features of MPEG-1 and MPEG-2 audio coders. We also present the MPEG-4 standard and discuss some of the typical applications for MPEG audio compression     

Is Kaposi's sarcoma--associated herpesvirus ubiquitous in urogenital and prostate tissues?

Controversy exists as to whether Kaposi's sarcoma-associated herpesvirus (KSHV) is more widespread than originally reported. Recently, Monini et al reported that KSHV is ubiquitous in urogenital and prostate tissues and sperm of healthy Italian adults using nested polymerase chain reaction (PCR). We have examined for the presence of KSHV in 10 normal prostates from Italian men and 10 from men from the United States, as well as 32 prostatic, 30 vulvar, 24 ovarian, 20 cervical, and 30 testicular cancer specimens from patients from the United States. None of the patients had a history of human immunodeficiency virus infection. The samples were tested by nested PCR. The sensitivity of this assay was determined by a dilution study performed by diluting KSHV DNA from the KS-1 cells (a primary effusion lymphoma cell line which is estimated to have 16 copies of KSHV per cell) in DNA from a K562 myeloid cell line. The nested PCR that we used can detect 2.4 copies of KSHV sequences on a background of K562 DNA. All the samples were negative for KSHV sequences. Therefore, we cannot confirm the finding that KSHV sequences are ubiquitous in urogenital and prostate tissues. Furthermore, because our samples were from both the United States and Italy, the discrepancy between results is unlikely to be explained by either ethnic or environmental factors. False-positive results easily occur using nested primer PCR because of contamination. Our data argue that KSHV is not widely disseminated in urogenital tissues from nonimmunosuppressed individuals.