Granulocytic sarcoma of the brain: a case report and review of the literature

Granulocytic sarcoma (chloroma), a rare tumor usually associated with myelogenous leukemia, is capable of invading the meninges or brain parenchyma. Radiologic findings in a case of granulocytic sarcoma of the brain, as well as those in 11 previously reported cases of intracranial leukemic masses, are interpreted. On computed tomographic scans, the lesions can appear isodense or hyperdense, edema and necrosis are variable, and there is uniform enhancement following intravenous administration of contrast material. There may be some affinity for the posterior fossa.     

Comparison of monochromatic ocular aberrations measured with an objective cross-cylinder aberroscope and a Shack-Hartmann aberrometer.

Repeated measures of wavefront aberrations were taken along the line-of-sight of seven eyes using two instruments: an objective, cross-cylinder aberroscope (OA) and a Shack-Hartmann (SH) aberrometer. Both instruments were implemented on the same optical table to facilitate interleaved measurements on the same eyes under similar experimental conditions. Variability of repeated measures of individual coefficients tended to be much greater for OA data than for SH data. Although Zernike coefficients obtained from a single measurement were generally larger when measured with the OA than with the SH, the averages across five trials were often smaller for the OA. The Zernike coefficients obtained from the two instruments were not significantly correlated. Radial modulation-transfer functions and point-spread functions derived from the two sets of measurements were similar for some subjects, but not all. When average Zernike coefficients were used to determine optical quality, the OA indicated superior optics in some eyes, but the reverse trend was true if Zernike coefficients from individual trials were used. Possible reasons for discrepancies between the OA and SH measurements include difference in sampling density, quality of data images, alignment errors, and temporal fluctuations. Multivariate statistical analysis indicated that the SH aberrometer discriminated between subjects much better than did the objective aberroscope.     

Stepwise progression of kindling: Perspectives from the kindling antagonism model

What is the nature of the kindling process? We hypothesize that kindling is a discontinuous process involving discrete, stepwise transitions from one state of neural organization to another. Our data from the kindling antagonism paradigm argue that there are two critical transitions in the kindling process. These transitions constitute major steps in kindled seizure development. They act as "gates" controlling the ability of afterdischarge (AD) activity to effect the necessary reorganization of neural function which drives the kindling process. We identify two critical gates: 1) a forebrain gate which is dependent on norepinephrine (NE) and effects a discrete transition from nonconvulsive, stage 1 and 2 behaviors to stage 3 seizures, and 2) a brainstem gate which is also NE-dependent and effects a transition from stage 3 seizures to stage 4 and 5 seizures. These gates separate the kindling process into 3 "phases" which are different from, but overlap, the traditional behavioral stages of kindling defined by Racine. Current data suggest that these phases involve independent neural circuitry. They may also involve different physiological mechanisms, but this remains to be determined. This hypothesis is designed to provide a framework for the kindling process within which to search for kindling mechanisms.     

Laser-ultraviolet-A-induced ultraweak photon emission in mammalian cells

Photobiological research in the last 30 yr has shown the existence of ultraweak photon emission in biological tissue, which can be detected with sophisticated photomultiplier systems. Although the emission of this ultraweak radiation, often termed biophotons, is extremely low in mammalian cells, it can be efficiently increased by ultraviolet light. Most recently it was shown that UV-A (330 to 380 nm) releases such very weak cell radiation in differentiated human skin fibroblasts. Based on these findings, a new and powerful tool in the form of UV-A-laser-induced biophotonic emission of cultured cells was developed with the intention to detect biophysical changes between carcinogenic and normal cells. With suspension densities ranging from 1 to 8 x 10(6) cells/mL, it was evident that an increase of the UV-A-laser-light induced photon emission intensity could be observed in normal as well as melanoma cells. Using this new detection procedure of ultraweak light emission, photons in cell suspensions as low as 100 microL could be determined, which is a factor of 100 lower compared to previous procedures. Moreover, the detection procedure has been further refined by turning off the photomultiplier system electronically during irradiation leading to the first measurements of induced light emission in the cells after less than 10 micros instead of 150 ms, as reported in previous procedures. This improvement leads to measurements of light bursts up 10(7) photons/s instead of several hundred as found with classical designs. Overall, we find decreasing induction ratings between normal and melanoma cells as well as cancer-prone and melanoma cells. Therefore, it turns out that this highly sensitive and noninvasive device enables us to detect high levels of ultraweak photon emission following UV-A-laser-induced light stimulation within the cells, which enables future development of new biophysical strategies in cell research.     

Effects of amphetamine,methylphenidate, and apomorphine on regional brain serotonin and 5-hydroxyindole acetic acid

Electrophysiological and cytofluorometric data suggest that doses of amphetamine which enhance locomotor activity and promote focused stereotypies produce pronounced effects on serotonin pathways in the CNS. However, the biochemical evidence regarding changes in serotonergic function produced by moderate doses of this drug is inconsistent. Therefore, the present study was designed to further examine the effects of amphetamine (1–5 mg/kg) on regional brain serotonin and its metabolite and to compare these effects to behaviorally comparable doses of methylphenidate and apomorphine. At doses which produce a multiphasic behavioral response pattern, including a stereotypy phase consisting primarily of repetitive head movements and occasional oral stereotypies, amphetamine (3 mg/kg) and methylphenidate (30 mg/kg) increased levels of 5HIAA in striatum and frontal cortex, two brain regions which receive serotonergic projections from the dorsal raphe nucleus. In contrast, these drugs decreased or had no effect on 5HIAA levels in hippocampus, a brain region which receives its serotonergic innervation from the median raphe nucleus. A moderate dose of apomorphine (0.5 mg/kg) produced a comparable pattern of neurochemical effects. These data are consistent with electrophysiological and cytofluorometric data suggesting enhanced dorsal raphe serotonergic function following amphetamine-like stimulants. Pretreatment of animals with -methyltyrosine at a dose sufficient to prevent the locomotor stimulation and stereotypy promoted by amphetamine, or by haloperidol, failed to prevent the amphetamine-induced increase in 5HIAA, indicating that these serotonergic effects are not secondary to the amphetamine facilitation of dopaminergic transmission. The results of this study suggest that serotonin may play a modulatory role in the behavioral effects of amphetamine-like stimulants which is dependent for its expression on an intact dopamine system.Abbreviations DA dopamine - AMPH S(+)amphetamine - 5HT serotonin - MP methylphenidate - APO apomorphine - 5HIAA 5-hydroxyindoleacetic acid - MT -methyltyrosine - DOPAC 3,4-dihydroxyphenylacetic acid - HVA homovanillic acid - HAL haloperidol     

Triathlete characterization and response to prolonged strenuous competition

The purpose of this study was to characterize triathletes and to assess their responses to prolonged, strenuous competition. Nine triathletes (6 males, 3 females) participated. Mean V0(2)max and percentage of body fat were 72.0 ml X kg-1 X min-1 and 7.1%, respectively, in the four males who finished in the top 15. This compared to values of 58.4 ml X kg-1 X min-1/10.2% and 58.7 ml X kg-1 X min-1/12.6% in the other males and females, respectively. In the 5 wk preceding competition (Hawaii "Ironman Triathlon World Championship") the average daily training of the four top 15 male competitors consisted of swimming 2720 m, running 13.6 km, and biking 84.0 km. This was approximately 1.5 times greater than that of the other athletes. The average training diet was 59% carbohydrate, 21% fat, and 20% protein. Immediately following competition, SGOT, SGPT, and serum LDH were increased 700, 262, and 222% (P less than 0.004), respectively, and still remained marginally elevated 5-6 d later (P less than 0.02). Immediately following competition, serum triglycerides remained unchanged, while serum glucose, glycerol, and nonesterified fatty acids increased 52, 248, and 191% (P less than 0.005), respectively. By 5-6 d post-competition glucose had returned to normal, while triglycerides were elevated 94% (P less than 0.005) and nonsterified fatty acids were decreased 58% (P less than 0.01).     

Frailty,Race/Ethnicity,Functional Status,and Adverse Outcomes After Total Hip/Knee Arthroplasty: A Moderation Analysis

BackgroundAlthough frailty has been shown to be associated with adverse outcomes in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), prior studies have not examined how race/ethnicity might moderate these associations. We aimed to assess race/ethnicity as a potential moderator of the associations of frailty and functional status with arthroplasty outcomes.MethodsThe National Surgical Quality Improvement Program was queried for patients who underwent THA or TKA from 2011 to 2017. Frailty was assessed using the modified frailty index. Regression analyses were conducted to examine associations connecting frailty/functional status with 30-day readmission, adverse discharge, and length of stay (LOS). Further analyses were conducted to investigate race/ethnicity as a potential moderator of these relationships.ResultsWe identified 219,143 TKA and 130,022 THA patients. Frailty and nonindependent functional status were positively associated with all outcomes (P < .001). Compared to White non-Hispanic patients, Black non-Hispanic patients had higher odds for all outcomes after TKA (P < .001) and for adverse discharge/longer LOS after THA (P < .001). Similar associations were observed for Hispanics for the adverse discharge/LOS outcomes. Race/ethnicity moderated the effects of frailty in TKA for all outcomes and in THA for adverse discharge/LOS. Race/ethnicity moderated the effects of nonindependent function in TKA for adverse discharge/LOS and on LOS alone for THA.ConclusionDisparities for Black non-Hispanic and Hispanic patients persist for readmission, adverse discharge, and LOS. However, the effects of increasing frailty and nonindependent functional status on these outcomes were the most pronounced among White non-Hispanic patients.     

Child Abuse: Imaging Findings Pertaining to the Musculoskeletal System

Both underrecognized and underreported, child abuse has a spectrum of findings on imaging of the musculoskeletal structures that may permit the radiologist to first suggest the occurrence of child abuse or to help support clinical concern for a diagnosis of child abuse. This article will discuss the approach to imaging of the musculoskeletal system in suspected child abuse, illustrate many of the more common imaging findings, and present imaging pitfalls and alternative diagnostic considerations. Injuries to the brain, spinal cord, gastrointestinal and genitourinary systems, and cardiopulmonary structures are outside the scope of this article.