Failing Compensatory Mechanisms During Working Memory in Older Apolipoprotein E-ε4 Healthy Adults

How and when the known genetic risk allele, apolipoprotein E-ε4 (APOEε4), confers risk to Alzheimer’s disease has yet to be determined. We studied older adults and found that APOEε4 carriers had greater neural activation in the medial frontal and parahippocampal gyrus during a memory task (cluster-corrected p < .01). When compared to a group of younger adults, interactive effects of age and APOEε4 were found in the inferior frontal—anterior temporal region, one of the first areas to develop amyloid plaques in patients with Alzheimer’s disease, and, in the posterior cingulate, one of the earliest areas to show decreased cerebral metabolism in Alzheimer’s disease. Thus, abnormally high activation in fronto-temporal areas are present in both younger and older APOEε4 carriers confronted with a working memory task when compared to non-APOEε4 carriers. This effect, however, appears to diminish with age.     

Auditory outcomes following implantation and electrical stimulation of the semicircular canals

We measured auditory brainstem responses (ABRs) in eight Rhesus monkeys after implantation of electrodes in the semicircular canals of one ear, using a multi-channel vestibular prosthesis based on cochlear implant technology. In five animals, click-evoked ABR thresholds in the implanted ear were within 10 dB of thresholds in the non-implanted control ear. Threshold differences in the remaining three animals varied from 18 to 69 dB, indicating mild to severe hearing losses. Click- and tone-evoked ABRs measured in a subset of animals before and after implantation revealed a comparable pattern of threshold changes. Thresholds obtained five months or more after implantation--a period in which the prosthesis regularly delivered electrical stimulation to achieve functional activation of the vestibular system--improved in three animals with no or mild initial hearing loss and increased in a fourth with a moderate hearing loss. These results suggest that, although there is a risk of hearing loss with unilateral vestibular implantation to treat balance disorders, the surgery can be performed in a manner that preserves hearing over an extended period of functional stimulation.     

Impact of electrostatic and conventional sprayers characteristics on dispersion of barrier spray

A study was conducted to analyze the performance of 3 electrostatic (Electrolon BP-2.5, Spectrum Electrostatic 4010, and Spectrum Electrostatic head on a Stihl 420) and 2 conventional (Buffalo Turbine CSM2 and Stihl 420) sprayers for barrier sprays to suppress an adult mosquito population in an enclosed area. Sprayer characteristics such as charge-mass ratio, air velocity, flow rate, and droplet spectra were measured while spraying water. Dispersion of the spray cloud from these sprayers was determined using coverage on water-sensitive cards at various heights (0.5 m, 1.0 m, 1.5 m, 2.0 m, 2.5 m, and 3.0 m) and depths (1 m, 3 m, and 5 m) into the under-forest vegetation while spraying bifenthrin (Talstar 7.9% AI; FMC Corporation, Philadelphia, PA) at the rate of 21.8 ml/300 m of treated row. The charge-mass ratio data show that Electrostatic head on a Stihl 420 did not impart enough charge to the droplets to be considered as an electrostatic sprayer. In general, the charged spray cloud moved down toward the ground. The Electrolon BP 2.5 had significantly lower spray coverage on cards, indicating lack of spray dispersion. This sprayer had the lowest air velocity and did not have the air capacity needed to deliver droplets close to the target for electrostatic force to affect deposition. The analysis shows that these 2 sprayers are not a suitable choice for barrier sprays on vegetation. The results indicate that the Buffalo Turbine is suitable for barriers wider than 3 m, and the Spectrum 4010 and Stihl 420 are suitable for 1-3-m-wide barriers.     

Zum Sturz ins Wasser

Ohne ZusammenfassungUnsere Ausführungen, die Herrn Geheimrat Prof. Dr.Ungar, dem Altmeister der Gerichtlichen Medizin auf deutschem Sprachgebiete, anläBlich seines 80. Geburtstagsfestes als Zeichen unserer aufrichtigen Verehrung gewidmet werden, bestätigen also vollinhaltlich die auf theoretischem Wege gewonnenen Schlußfolgerungen der in der Einleitung zitierten Abhandlung. Sie liefern aber auch noch — und dies erscheint uns als ihr wesentliches Ergebnis — eine experimentell gefestigte Stütze für unsere durch die Problemstellung bedingte indirekte Beweisführung, die uns jeglichen Zweifel bezüglich der Richtigkeit der Behauptung, daß unter Umständen beim Fall eines Menschen ins Wasser aus großer Höhe selbst Knochenbrüche durch das Aufschlagen des Körpers aufs Wasser entstehen können, benimmt.     

Family history of depression and alcoholism in Alzheimer patients and age-matched controls

Depression and depressive symptoms are reported to occur frequently in patients with Alzheimer's disease; however, familial and psychobiological contributions associated with depression in Alzheimer patients are poorly understood. In this study, we compared family history of depression and alcoholism in 44 patients with probable Alzheimer's disease and 38 aged-matched cognitively intact controls. Results from comparison showed no overall difference between the occurrence of depression in first-degree relatives of Alzheimer patients compared to first-degree relatives of controls. There was, however, significantly lower incidence of alcoholism in relatives of Alzheimer patients, particularly male relatives (p<0.05). This finding suggests that family history and depression alone may not fully explain the high rate of depression in Alzheimer patients and that other factors including neurochemical changes in the brains of Alzheimer patients should be considered.     

Survival from hepatic transplantation. Relationship of protein synthesis to histological abnormalities in patient selection and postoperative management

Forty-one patients, all in end stage hepatic failure, underwent 46 liver transplantations with a long-term survival rate of 63%. Six patients died of uncontrollable bleeding due to primary graft malfunction at or immediately after operation. Nine died early or late with overwhelming infection. In addition to clinical assessment, needle liver biopsy, central plasma clearance rate of amino acids (CPCR-AA), and routine "liver function tests" were employed to aid in selection of patients for transplantation and for guidance in postoperative management. Although liver biopsies usually afforded an exact diagnosis, neither they nor the routine liver function tests quantitated the extent to which hepatocyte function was impaired. CPCR-AA, which measures the rate of amino acid uptake by the liver and other central tissues for oxidation, gluconeogenesis, and protein synthesis was 91 +/- 9 ml/M2/min in the preoperative transplant group. This compares with a value of 97 +/- 16 in a previously studied series of cirrhotics who died following other forms of surgery and a CPCR-AA of 220 +/- 26 ml/m2/min in those who survived. In addition, the preoperative CPCR-AA was found to correlate with the in vitro hepatic protein synthetic rate of slices from the resected recipient liver (r = 0.72, p less than 0.02). After operation, serial hepatic needle biopsies were classified by histology into four grades of injury, ranging from normal liver transplant (Grade I) to mild hypoxic or rejection injury (Grade II), viral hepatitis (Grade III), and severe hypoxic or rejection injury (Grade IV). Significant relationships of the histological grades to ultimate mortality, CPCR-AA, and prothrombin times were found. CPCR-AA and prothrombin time correlate inversely (r = 0.57, p less than 0.001), further demonstrating the relationship of CPCR-AA to protein synthesis of clotting factors. These patterns of posttransplant response were delineated by serial CPCR-AA values. "Early" responders had values over 290 ml/M2/min and all survived. Twelve patients with delayed response were characterized by values of 150 +/- 12, rising to over 200 ml/M2/min after 2 weeks. Two who failed to increase CPCR-AA died. In six "poor" responders, CPCR-AA with Grade IV injury remained below 110 ml/M2/min. All died except for one whose CPCR-AA subsequently rose following retransplantation. It is concluded that percutaneous hepatic needle biopsies and CPCR-AA measurements in combination are of proven value, not only in understanding the nature of injury and functional impairment of the liver, but are also important as guides to selection of patients and for their posttransplant management.