Modulation of memory consolidation for olfactory learning by reversible inactivation of the basolateral amygdala

The role of the basolateral amygdala (BLA) in the consolidation of an association between an olfactory stimulus and footshock was investigated with a reversible lesion technique of post-training intra-BLA infusions of tetrodotoxin. Rats receiving tetrodotoxin infusions following paired odor-shock presentations spent more time near the odor, and reacted differently on contact with the odor when tested 24 hr after training, than did rats receiving paired presentations and saline infusions, but they did not differ from rats receiving unpaired presentations and saline infusions. The results indicate that the BLA plays a similar role in influencing consolidation of olfactory-based memory as it does for memory based on other modalities. Thus, these findings strengthen the view that the BLA plays a general role in modulation of memory storage for emotionally arousing events.     

Acute flaccid paralysis from echovirus type 33 infection

During a community echovirus type 33 outbreak, the virus was detected in the feces and cerebrospinal fluid of a 3-year-old boy with right arm weakness that followed a mild nonspecific febrile illness. This is the first time an association between echovirus type 33 infection and acute flaccid paralysis has been reported.     

Reduced abundance of Ixodes scapularis (Acari: Ixodidae) and the tick parasitoid Ixodiphagus hookeri (Hymenoptera: Encyrtidae) with reduction of white-tailed deer

The principal vector for the pathogens of Lyme disease, human granulocytic ehrlichiosis, and human babesiosis is the tick Ixodes scapularis Say. A chalcid wasp, Ixodiphagus hookeri, in the family Encyrtidae parasitizes populations of the tick on several islands or other geographically isolated sites in New England with high densities of these ticks and white-tailed deer (Odocoileus virginianus), the principal host for adult I. scapularis. Deer densities were reduced at a forested tract in Bridgeport and the Bluff Point Coastal Reserve in Groton, Connecticut, from levels exceeding 90 animals per km2 in 1992 (Bridgeport) and 1994 (Bluff Point) to 17 and 10 animals per km2, respectively, by fall 2001. Tick densities declined with sustained reductions in the population of white-tailed deer. Similarly, prevalence of tick parasitism by Ixodes hookeri declined at both sites from 30 to 25% to <1.0% and was significantly correlated with previous year's deer density at both sites (r(s) = 0.933 and r(s) = 0.867, P < or = 0.0001) and with nymphal tick densities at Bridgeport (r(s) = 0.867, P < or = 0.0001), but was not as well correlated with tick densities in Groton. The virtual disappearance of I. hookeri in this study corresponds with a lack of I. hookeri in mainland I. scapularis at comparable deer and tick densities, suggesting that there is a threshold deer density of approximatley 10-20/km2, with corresponding tick densities necessary for I. hookeri to successfully parasitize I. scapularis.     

Mannan-binding lectin and its role in innate immunity

Mannan-binding lectin (MBL) is a plasma collectin (C-type lectin with a collagen-like domain) and is considered an important component of innate immunity. Circulating MBL is genetically determined for the major part, but plasma concentration is also markedly influenced by nongenetic factors. The carbohydrate-binding ability of MBL can be inhibited by simple sugars like mannose, fucose and N-acetylglucosamine, but its greatest avidity appears to be for repeating mannose-based structural patterns typical of microbial surfaces. By this means, MBL can bind to a wide variety of bacteria and other microbes, neutralizing them and/or opsonizing them by activating complement using the recently discovered lectin pathway of complement activation. Individual humans differ 1000-fold in MBL concentration, and individuals with low circulating MBL appear to be more vulnerable to infections in a number of clinical settings, especially when combined with secondary immune deficiency. The best evidence that MBL deficiency or insufficiency is physiologically relevant comes from a rapidly expanding literature of clinical studies. MBL insufficiency appears to be a significant risk factor for infections in infants, and for individuals of any age undergoing chemotherapy or post-transplant immunosuppression. Moreover, MBL appears to have a significant influence on the course of certain chronic diseases like rheumatoid arthritis and cystic fibrosis. Replacement therapy with a plasma-derived product is safe and seems promising, while recombinant MBL provides hope for large-scale therapeutic applications. Randomized clinical trials of MBL therapy, which are now on the horizon, should provide unambiguous evidence for the physiological significance of MBL in innate immunity.     

Effect of levofloxacin coadministration on the international normalized ratios during warfarin therapy

STUDY OBJECTIVE: To evaluate the effect of levofloxacin coadministration on the international normalized ratio (INR) in patients receiving warfarin therapy. DESIGN: Prospective analysis. SETTING: Outpatient clinic at a Veterans Affairs medical center. PATIENTS: Eighteen adult patients receiving warfarin. INTERVENTION: On the basis of clinical diagnosis and judgment, levofloxacin was prescribed to the 18 patients for treatment of various types of infection. The INR was measured before and at 2-8-day intervals after the coadministration of levofloxacin therapy, and once after completing therapy. Warfarin dosages were adjusted when necessary. MEASUREMENTS AND MAIN RESULTS: Warfarin dosages were changed in seven patients as a result of the first nontherapeutic INR values obtained after start of levofloxacin therapy. Owing to a concern regarding noncompliance and the adverse effect of bleeding, warfarin dosage was adjusted in one patient even though his first INR value was in the high end of the therapeutic range (2.98, therapeutic range 2-3). One patient withdrew from the study after the first INR measurement after levofloxacin coadministration. Because of a concern about the possible bleeding complication, warfarin dosage was also adjusted in this patient after obtaining his first INR value. Therefore, only the INR values obtained before and the first INR values obtained after levofloxacin administration were compared to evaluate the effect of levofloxacin on INR determination of warfarin therapy. The INR values obtained before levofloxacin administration did not differ significantly from the first INR values obtained after levofloxacin coadministration (mean +/- SD 2.61 +/- 0.44 vs 2.74 +/- 0.83, 95% confidence interval -0.449-0.196, p=0.419). CONCLUSION: The INR values measured before and after concomitant levofloxacin therapy were not significantly different. However, the ability to detect a significant difference may be affected by the small number of patients studied. Further studies with a larger sample are required to better determine the effect of levofloxacin coadministration on INR monitoring during warfarin therapy     

Motor performance and anatomic magnetic resonance imaging (MRI) of the basal ganglia in autism

This study was conducted to examine the volume of the basal ganglia in individuals with autism and to evaluate whether performance on specific motor tasks correlated with the volume of these structures. Volumetric measurements of the caudate nucleus and putamen were obtained from magnetic resonance images (MRI) of 40 non-mentally retarded individuals with autism and 41 healthy controls. Motor performance was assessed in these subjects by using the Finger Tapping Test, the Grooved Pegboard Test, and the measurement of Grip Strength. No volumetric differences of the basal ganglia were found between the two groups after adjusting for brain volume. The autistic subjects' performance was slower on the Grooved Pegboard Test and weaker on Grip Strength. Our findings suggest that the motor deficits observed in autism may not be related to structural abnormalities of the basal ganglia, and other brain regions, such as the cerebellum and the frontal lobe, may be involved in the pathophysiology of motor disturbances in autism.     

Trends of probable post-traumatic stress disorder in New York City after the September 11 terrorist attacks

The authors investigated trends in probable post-traumatic stress disorder (PTSD) prevalence in the general population of New York City in the first 6 months after the September 11 terrorist attacks. Three random digit dialing telephone surveys of adults in progressively larger portions of the New York City metropolitan area were conducted 1 month, 4 months, and 6 months after September 11, 2001. A total of 1,008, 2,001, and 2,752 demographically representative adults were recruited in the three surveys, respectively. The current prevalence of probable PTSD related to the September 11 attacks in Manhattan declined from 7.5% (95% confidence interval: 5.7, 9.3) 1 month after September 11 to 0.6% (95% confidence interval: 0.3, 0.9) 6 months after September 11. Although the prevalence of PTSD symptoms was consistently higher among persons who were more directly affected by the attacks, a substantial number of persons who were not directly affected by the attacks also met criteria for probable PTSD. These data suggest a rapid resolution of most of the probable PTSD symptoms in the general population of New York City in the first 6 months after the attacks. The psychological consequences of a large-scale disaster in a densely populated urban area may extend beyond persons directly affected by the disaster to persons in the general population.