Malakoplakia of the adrenal gland.

The clinical and pathological features of a case of malakoplakia of the adrenal gland occurring in a woman with Escherichia coli infection are described. This lesion mimicked a neoplasm, the true diagnosis only being revealed by histological examination. The light and electron microscopic features are described and it is suggested that malakoplakia is due to an abnormal macrophage response to E coli infection.     

Competitive control of the self-renewing T cell repertoire

We develop a mathematical model for the self-renewing part of the T cell repertoire. Assuming that self-renewing T cells have to be stimulated by immunogenic MHC-peptide complexes presented on the surfaces of antigen-presenting cells, we derive a model of T cell growth in which competition for MHC-peptide complexes limits T cell clone sizes and regulates the total number of self-renewing T cells in the animal. We show that for a sufficient diversity and/or degree of cross-reactivity, the total T cell number hardly depends upon the diversity of the T cell repertoire or the diversity of the set of presented peptides. Conversely, for repertoires of lower diversity and/or cross-reactivity, steady-state total T cell numbers may be limited by the diversity of the T cells. This provides a possible explanation for the limited repertoire expansion in some, but not all, mouse T cell re-constitution experiments. We suggest that the competitive interactions described by our model underlie the normal T cells numbers observed in transgenic mice, germ-free mice and various knockout mice.      

Developmental Progression in Children's Knowledge of AIDS: Implications for Education and Attitudinal Change

The effectiveness of curricula designed to enhance a child'sunderstanding of AIDS may hinge partially upon incorporatinginformation adjusted to the child's developmental status. Accordingly,we examined the developmental progression of children's understandingof illness transmission in general and AIDS in particular, aswell as explored the relation between a child's knowledge ofAIDS and his/her attitudes toward persons with AIDS. Knowledgeof AIDS was manipulated through use of a brief educational intervention.Results support a developmental progression in knowledge aboutAIDS that is consistent with progressions related to illnessesin general. Knowledge enhancement was associated with positivechanges in attitude.     

Neural responses to free field and virtual acoustic stimulation in the inferior colliculus of the guinea pig

Virtual auditory space (VAS) stimuli based on outer ear transfer functions became increasingly important in spatial hearing research. However, few studies have investigated the match between responses of auditory neurons to VAS and free-field (FF) stimulation. This study validates acoustic spatial receptive fields (SRFs) of 183 individual midbrain units using both VAS and FF stimuli. The first-spike latency, which varied systematically across SRFs, was 14.9 +/- 8.3 (SD) ms in FF, and 15.1 +/- 8.3 ms in VAS. Spike-count-based SRFs measured 0-20 dB above the neural threshold covered on average 44.5 +/- 18.0% of the recorded sphere in FF and 45.5 +/- 18.7% in VAS. The average deviation of the centroid position of SRFs using FF and VAS stimuli was 7.4 degrees azimuth and 3.3 degrees elevation. The average spike rate remained unchanged. The SRF overlap recorded using FF and VAS stimuli (mean: 71.3 +/- 12.6%) or repeated FF stimuli (70.2 +/- 14.2%) was high and strongly correlated (r = 0.96; P < 0.05). The SRF match observed with FF and VAS stimuli was not significantly altered over a range of stimulus levels (paired t-test P = 0.51; n = 6). Randomized VAS barely affected SRF sizes, centroids, or maximum spike count but decreased the average minimum response to 59% compared with sequential stimulation (paired t-test; P = 0.05; n = 26). SRF recordings in VAS excluding the acoustic distortions of the recording equipment differed from those in VAS incorporating the equipment (paired t-test P = 0.01; n = 5). In conclusion, neurophysiological recordings demonstrate that individualized VAS stimuli provided a good simulation of a FF environment.     

Characterization of the sleep-wake patterns in mice lacking fatty acid amide hydrolase

STUDY OBJECTIVES: Oleamide and anandamide are fatty acid amides implicated in the regulatory mechanisms of sleep processes. However, due to their prompt catabolism by fatty acid amide hydrolase (FAAH), their pharmacologic and behavioral effects, in vivo, disappear rapidly. To determine if, in the absence of FAAH, the hypnogenic fatty acid amides induce an increase of sleep, we characterized the sleep-wake patters in FAAH-knockout mice [FAAH (-/-)] before and after sleep deprivation. DESIGN: FAAH (-/-), FAAH (+/-), and FAAH (+/+) mice were implanted chronically for sleep, body temperature (Tb), and locomotor activity (LMA) recordings. Sleep-wake states were recorded during a 24-hour baseline session followed by 8 hours of sleep deprivation. Recovery recordings were done during the 16 hours following sleep deprivation. Total amount of wake, slow-wave sleep, and rapid eye movement sleep were calculated and compared between genotypes. The electroencephalographic spectral analysis was performed by fast Fourier transform analysis. Telemetry recordings of Tb and LMA were carried out continuously during 4 days under baseline conditions. SETTING: N/A. PATIENTS OR PARTICIPANTS: FAAH (-/-) mice and their heterozygote (+/-) and control (+/+) littermates were used. INTERVENTIONS: Sleep deprivation. MEASUREMENTS AND RESULTS: FAAH (-/-) mice possess higher values of slow-wave sleep and more intense episodes of slow-wave sleep than do control littermates under baseline conditions that are not related to differences in Tb and LMA. A rebound of slow-wave sleep and rapid eye movement sleep as well an increase in the levels of slow-wave activity were observed after sleep deprivation in all genotypes. CONCLUSION: These findings support the role of fatty acid amides as possible modulators of sleep and indicate that the homeostatic mechanisms of sleep in FAAH (-/-) mice are not disrupted.     

Managing pain: The Challenge in Underserved Populations: Appropriate Use Versus Abuse and Diversion

ISSUE: Inadequate pain management is a serious public health problem that affects a wide cross-section of Americans. Patients are often denied sufficient medication, because physicians lack training and fear scrutiny from federal and state regulatory agencies. In addition, even the state-financed system of care, Medicaid, has been increasingly denying payment for the best treatment for pain management. These factors are complicated by physician bias about various subgroups and poor physician-patient communication. Comprehensive patient assessment plays a crucial role in determining appropriate treatment and identifying potential abuse problems. Physicians must routinely document medications analgesic effects and screen for potential ill effects and drug abuse. OBJECTIVE: To examine the prevalence of the undertreatment of pain, particularly among African Americans, and to recommend relevant proactive policy and practice changes to aid in eliminating this health problem. CONSENSUS PROCESS: In July 2002, the NMA convened the "Managing Pain: The Challenge in Underserved Populations: Appropriate Use versus Abuse and Diversion" Consensus Meeting in Washington, DC. The country's most renowned experts in the area of pain management and substance abuse reviewed substantial information regarding pain management and substance abuse including the following: --A draft summary paper on pain management and substance abuse that served as briefing material for consensus members; --Annotated bibliographies; --Articles on pain management and substance abuse; and --Key presentations on pain management and substance abuse.     

Expression microdissection: operator-independent retrieval of cells for molecular profiling.

Tissue microdissection is an important method for the study of disease states. However, it is difficult to perform high-throughput molecular analysis with current techniques. We describe here a prototype version of a novel technique (expression microdissection) that allows for the procurement of desired cells via molecular targeting. Expression microdissection (xMD) offers significant advantages over available methods, including an increase in dissection speed of several orders of magnitude. xMD may become a valuable tool for investigators studying cancer or other disease states in patient specimens and animal models.