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E Kaplan

Publications and source records attributed to E Kaplan.

At least 19 recordsLinked to original sources
PubMed2005

Post-phototherapy neonatal bilirubin rebound: a potential cause of significant hyperbilirubinaemia.

AIM: To determine the incidence of post-phototherapy neonatal plasma total bilirubin (PTB) rebound. METHODS: A prospective clinical survey was performed on 226 term and near-term neonates treated with phototherapy in the well baby nursery of the Shaare Zedek Medical Center from January 2001 to September 2002. Neonates were tested for PTB 24 hours (between 12 and 36 hours) after discontinuation of phototherapy, with additional testing as clinically indicated. The main outcome measure, significant bilirubin rebound, was defined as a post-phototherapy PTB > or =256 micromol/l. Phototherapy was not reinstituted in all cases of rebound, but rather according to clinical indications. RESULTS: A total of 30 (13.3%) neonates developed significant rebound (mean (SD) PTB 287 (27) micromol/l, upper range 351 micromol/l). Twenty two of these (73%) were retreated with phototherapy at mean PTB 296 (29) micromol/l. Multiple logistic regression analysis showed significant risk for aetiological risk factors including positive direct Coombs test (odds ratio 2.44, 95% CI 1.25 to 4.74) and gestational age <37 weeks (odds ratio 3.21, 95% CI 1.29 to 7.96). A greater number of neonates rebounded among those in whom phototherapy was commenced < or =72 hours (26/152, 17%) compared with >72 hours (4/74, 5.4%) (odds ratio 3.61, 95% CI 1.21 to 10.77). CONCLUSION: Post-phototherapy neonatal bilirubin rebound to clinically significant levels may occur, especially in cases of prematurity, direct Coombs test positivity, and those treated < or =72 hours. These risk factors should be taken into account when planning post-phototherapy follow up.

Bilirubin↗
PubMed2005

The behavioural neurology assessment.

BACKGROUND: We present information regarding the standardization, reliability and clinical validity of two versions of the Behavioural Neurology Assessment (BNA). The BNA-Long Form consists of 24 subtests within separate domains: Attention, Memory, Language, Visuospatial Function, Executive Function, and Praxis. The BNA-Short Form consists of 13 subtests within the domains of Attention, Memory, Naming, Visuospatial Function and Executive Function. In addition to individual domain indices, a Grand Total score was calculated for both BNA versions. OBJECTIVE: To standardize the administration and scoring and validate the BNA for detection of dementia. METHODS: Standardized normative data were obtained on 115 healthy subjects ranging in age from 50 to 95. Test-retest stability was obtained on 19 subjects and clinical validity was investigated by administering the BNA and Mini-Mental Status Examination (MMSE) to 29 patients with dementia and 29 age-matched healthy subjects (controls). RESULTS: Age had a significant effect on all but the Visuospatial and Praxis indices of the BNA-Long Form and an effect on Naming and Grand Total score of the Short-Form. Internal consistency (Cronbach's coefficient alpha) was .87 and .67 for the Long and Short Forms (.95 and .96 for dementia and control groups combined). Test-retest stability was acceptable. Grand Total indices of both BNA versions showed significant, positive correlations with the MMSE. Both BNA versions had superior sensitivity to dementia relative to the MMSE (.93 versus .79). Specificity was equivalent to the MMSE (.93 versus .97). CONCLUSIONS: Positive predictive values of the BNA and MMSE are equivalent but the BNA provides superior negative predictive value.

Age Factors↗
PubMed2003

Spatiotemporal analysis of optical imaging data.

Previous methods for analyzing optical imaging data have relied heavily on temporal averaging. However, response dynamics are rich sources of information. Here, we develop and present a method that combines principal component analysis and multitaper harmonic analysis to extract the statistically significant spatial and temporal response from optical imaging data. We apply the method to both simulated data and experimental optical imaging data from the cat primary visual cortex.

Animals↗
PubMed2002

A population study of integrate-and-fire-or-burst neurons.

Any realistic model of the neuronal pathway from the retina to the visual cortex (V1) must account for the bursting behavior of neurons in the lateral geniculate nucleus (LGN). A robust but minimal model, the integrate-and-fire-or-burst (IFB) model, has recently been proposed for individual LGN neurons. Based on this, we derive a dynamic population model and study a population of such LGN cells. This population model, the first simulation of its kind evolving in a two-dimensional phase space, is used to study the behavior of bursting populations in response to diverse stimulus conditions.

Action Potentials↗
PubMed2001

Quantitative short-term study of anal sphincter function after chemoradiation for rectal cancer.

HYPOTHESIS: Pelvic irradiation adversely affects anal sphincter function after proctectomy with coloanal anastomosis for low rectal and middle rectal (<10 cm from the anal verge) tumors. DESIGN: Case-control study. SETTING: Private, tertiary care referral center. PATIENTS: Patients treated for low rectal adenocarcinoma between January 1, 1994, and October 31, 1999. INTERVENTIONS: Anal manometric data were prospectively collected at the time of initial diagnosis and before ileostomy closure. MAIN OUTCOME MEASURES: Mean and maximum resting pressures (RPs) and squeeze pressures, threshold volume for sensation, and maximal tolerable volume. RESULTS: Twenty-three patients in the surgery group and 19 in the chemoradiotherapy group were considered for analysis; 15 patients had preoperative radiotherapy and 4 had postoperative radiotherapy. At the time of ileostomy closure, RPs were significantly lower in the chemoradiotherapy group than in the surgery group (32.7 +/- 17 vs 45.3 +/- 18 mm Hg; P =.03). Squeeze pressures were not significantly different between the surgery and chemoradiotherapy groups (108.7 +/- 56.7 vs 102.0 +/- 52.6 mm Hg; P =.69). The ratios of postresection to preresection RPs were also significantly lower in the chemoradiotherapy group (0.49 +/- 0.29) than in the surgery group (0.76 +/- 0.22) (P =.005). Eight to 12 weeks after proctectomy with coloanal anastomosis, a 24% decrease in RP was noted in the surgery group. The addition of adjuvant pelvic irradiation decreased RP by another 27%. CONCLUSION: Adequate shielding of the anal sphincter should be performed for low rectal cancers whenever a sphincter-preserving procedure is considered.

Adenocarcinoma↗
PubMed2001

Patterns of object relations and reality testing deficits in schizophrenia: clusters and their symptom and personality correlates.

Bell Object Relations Reality Testing Inventory (BORRTI) profile scores were used to cluster 222 outpatients with schizophrenia or schizoaffective disorder. An eight-cluster solution was subjected to replication analysis, and six clusters were found valid and replicable. These clusters were sorted into three pairs that were interpreted as follows: Residually Impaired consisted of Sealed-Over Recovery and Integrated Recovery; Socially Withdrawn consisted of Socially Withdrawn and Socially Withdrawn-Autistic; and Psychotically Egocentric consisted of Psychotically Egocentric and Psychotically Egocentric-Severe. Clusters were compared on Positive and Negative Syndrome Scale ratings and on subscales from the Eysenck Personality Questionnaire. MANOVAs indicated significant differences among clusters. These differences provided further interpretations of cluster membership. Implications for the use of BORRTI profiles for treatment and rehabilitation planning are discussed.

Adult↗
PubMed2001

Fractal features of dark, maintained, and driven neural discharges in the cat visual system.

We employ a number of statistical measures to characterize neural discharge activity in cat retinal ganglion cells (RGCs) and in their target lateral geniculate nucleus (LGN) neurons under various stimulus conditions, and we develop a new measure to examine correlations in fractal activity between spike-train pairs. In the absence of stimulation (i.e., in the dark), RGC and LGN discharges exhibit similar properties. The presentation of a constant, uniform luminance to the eye reduces the fractal fluctuations in the RGC maintained discharge but enhances them in the target LGN discharge, so that neural activities in the pair cease to be mirror images of each other. A drifting-grating stimulus yields RGC and LGN driven spike trains similar in character to those observed in the maintained discharge, with two notable distinctions: action potentials are reorganized along the time axis so that they occur only during certain phases of the stimulus waveform, and fractal activity is suppressed. Under both uniform-luminance and drifting-grating stimulus conditions (but not in the dark), the discharges of pairs of LGN cells are highly correlated over long time scales; in contrast discharges of RGCs are nearly uncorrelated with each other. This indicates that action-potential activity at the LGN is subject to a common fractal modulation to which the RGCs are not subjected.

Animals↗
PubMed2001

Colonic J-pouch function in rectal cancer patients: impact of adjuvant chemoradiotherapy.

PURPOSE: The colonic J-pouch technique of reconstruction optimizes functional outcome after proctectomy with coloanal anastomosis. However, the impact of adjuvant chemoradiation therapy on pouch function in rectal cancer patients has not been investigated. METHODS: From January 1994 to December 1999, 74 patients with midrectal or low rectal tumors (less than 10 cm from the anal verge) underwent a proctectomy with coloanal anastomosis with colonic J-pouch reconstruction. Chemoradiation was offered in patients with Stage II and III disease. Radiation therapy was administered using a four-field technique including the anal canal, for a total dose of 50.4 Gy (1.8 Gy/fraction/day). Fifteen patients (20 percent) died with metastatic disease, five (6.8 percent) died of other causes without evidence of recurrence, and five (6.8 percent) were lost to follow-up. In addition, two patients had local recurrence (2.7 percent) at the time of follow-up. Forty-five of 47 eligible patients (96 percent) responded to a questionnaire designed to evaluate specifically the degree of continence and pouch evacuation. RESULTS: The mean age of patients was 68.9 (range, 42-88) years and the mean duration of follow-up was 28.8 (range, 1-69) months. There were 28 patients in the surgery alone group and 17 patients who received either preoperative (13) or postoperative (4) adjuvant chemoradiation therapy. Patients in the surgery alone group had a significantly better degree of continence (mean +/- standard deviation continence score: 18.1 +/- 2.9 vs. 13.3 +/- 4.1, P < 0.001) and were less likely to experience evacuatory problems (mean +/- standard deviation evacuation score: 21.3 +/- 3.7 vs. 16.4 +/- 3.5, P < 0.001). Use of a pad was more frequent in the chemoradiation therapy than in the surgery alone group (53 vs. 18 percent, P = 0.02). The incidence after functional disorders was also more frequent in the irradiated group of patients: incontinence to gas (76 vs. 43 percent, P = 0.03), to liquid stool (64 vs. 25 percent, P = 0.01), and to solid stool (47 vs. 11 percent, P = 0.01). Moreover, irradiated patients reported more frequent pouch-related specific problems, such as clustering (82 vs. 32 percent, P = 0.001), and sensation of incomplete evacuation (82 vs. 32 percent, P = 0.001). Finally, regression analysis demonstrated that radiation-induced sphincter dysfunction was progressive over time. CONCLUSIONS: Both preoperative and postoperative chemoradiation therapy adversely affects continence and evacuation in patients with colonic J-pouch. Because radiation-induced damage to the normal tissues is known to be cumulative over time, long-term progressive dysfunction of the anal sphincter and neorectum are causes of concern. Consideration should be given to excluding the anal canal from the field of irradiation in patients with Stage II and III rectal cancer, whenever a sphincter-preserving procedure is planned.

Adult↗
PubMed2001

MRI phenotype is associated with response to doxorubicin and cyclophosphamide neoadjuvant chemotherapy in stage III breast cancer.

BACKGROUND: The preferred management for women with stage II or locally advanced breast cancer (LABC) is neoadjuvant chemotherapy. Pathologic response to chemotherapy has been shown to be an excellent predictor of outcome. Surrogates that can predict pathologic response and outcome will fuel future changes in management. Magnetic resonance imaging (MRI) demonstrates that patients with LABC have distinct tumor patterns. We investigated whether or not these patterns predict response to therapy. METHODS: Thirty-three women who received neoadjuvant doxorubicin and cyclophosphamide chemotherapy for 4 cycles and serial breast MRI scans before and after therapy were evaluated for this study. Response to therapy was measured by change in the longest diameter on the MRI. RESULTS: Five distinct imaging patterns were identified: circumscribed mass, nodular tissue infiltration diffuse tissue infiltration, patchy enhancement, and septal spread. The likelihood of a partial or complete response as measured by change in longest diameter was 77%, 37.5%, 20%, and 25%, respectively. CONCLUSIONS: MRI affords three-dimensional characterization of tumors and has revealed distinct patterns of tumor presentation that predict response. A multisite trial is being planned to combine imaging and genetic information in an effort to better understand and predict response and, ultimately, to tailor therapy and direct the use of novel agents.

Adult↗
PubMed2001

The dynamics of primate retinal ganglion cells.

A knowledge of the dynamics (temporal properties) of neuronal populations is essential for an understanding of their function, and is also crucial when one attempts to develop computational or mathematical models of the neurons. Here we review the temporal properties of the receptive fields (RFs) of the two best-studied types of ganglion cells in the primate retina, those that project to the parvocellular (P) and magnocellular (M) layers of the dorsal lateral geniculate nucleus. The center and surround mechanisms of the P RFs are approximately linear, and their impulse responses are very similar, although the surround lags the center by a few milliseconds. The center and surround are chromatically opponent. With the appropriate stimulus, one can find significant nonlinearities in their responses, and also in the interaction between the center and surround. The phase lag between the responses of the center and surround depends on the temporal frequency, so that at high temporal frequency the antagonism between them is reduced or abolished. The temporal responses of M cells are nonlinear, and with increasing contrast they show the effects of a contrast gain control. The different dynamical properties of the two populations suggest that M cells participate in motion analysis, while P cells are used for the analysis of form, texture, and perhaps color.

Animals↗
PubMed2001

Verbal and design fluency in patients with frontal lobe lesions.

The ability to generate items belonging to categories in verbal fluency tasks has been attributed to frontal cortex. Nonverbal fluency (e.g., design fluency) has been assessed separately and found to rely on the right hemisphere or right frontal cortex. The current study assessed both verbal and nonverbal fluency in a single group of patients with focal, frontal lobe lesions and age- and education-matched control participants. In the verbal fluency task, participants generated items belonging to both letter cues (F, A, and S) and category cues (animals and boys' names). In the design fluency task, participants generated novel designs by connecting dot arrays with 4 straight lines. A switching condition was included in both verbal and design fluency tasks and required participants to switch back and forth between different sets (e.g., between naming fruits and furniture). As a group, patients with frontal lobe lesions were impaired, compared to control participants, on both verbal and design fluency tasks. Patients with left frontal lesions performed worse than patients with right frontal lesions on the verbal fluency task, but the 2 groups performed comparably on the design fluency task. Both patients and control participants were impacted similarly by the switching conditions. These results suggest that verbal fluency is more dependent on left frontal cortex, while nonverbal fluency tasks, such as design fluency, recruit both right and left frontal processes.

Aged↗
PubMed2001

Prevalence and mechanisms of macrolide resistance in Streptococcus pyogenes in Santiago, Chile.

Thirty-two macrolide-resistant Streptococcus pyogenes isolates were found among 594 clinical isolates collected from 1990 to 1998 in Santiago, Chile, for an overall prevalence of 7.2%. Among the 32 resistant isolates, 28 (87.5%) presented the M phenotype and 4 (12. 5%) presented the MLS(B) phenotype. Serotyping and pulsed-field gel electrophoresis analysis showed genetic diversity among the resistant isolates.

Anti-Bacterial Agents↗
PubMed2001

Different underlying mechanisms for deficits in concept formation in dementia.

We investigated the different mechanisms that may underlie deficits in verbal concept formation among patients with Alzheimer's disease (AD) and ischaemic vascular dementia (IVD) associated with periventricular and deep white matter alterations. Concept formation was assessed with the WAIS-R Similarities subtest (SIM). Two types of errors were re-coded from the 0-point responses as scored by the WAIS-R manual. In set errors (e.g., dog-lion "they're alive") were coded when patients reported a very vague superordinate concept for the word pair. Out of set responses (e.g., dog-lion "the lion roars and the dog barks") were coded when a response was clearly out of mental set, i.e., when participants were unable to provide a superordinate concept for the word pair. Between-group comparisons demonstrated no difference in SIM test performance according to the scoring system described in the WAIS-R manual. Nonetheless, AD patients produced a greater proportion of in set errors, while IVD patients produced a greater proportion of out of set errors. Out of set errors were highly associated with measures of executive function, while in set errors were associated with measures related to delayed recognition memory and semantic intrusion errors. We conclude that the underlying deficits that contribute to poor concept formation differ between AD and IVD patients. In IVD impaired concept formation is related to deficits in the executive systems necessary to monitor responses and sustain mental set. In AD, by contrast, the deficit appears to be secondary to impaired verbal response selection.

Journal Article↗
PubMed2001

Quantifying qualitative features of Block Design performance among healthy older adults.

Block Design tasks are neuropsychologically valuable, but standard scoring sacrifices potentially useful information that could elucidate the cognitive processes underlying performance failures. Qualitative indices that were proposed in the WAIS-R-NI [Kaplan, E., Fein, D., Morris, R., & Delis, D. (1991). The WAIS-R as a neuropsychological instrument [Manual]. San Antonio, TX: Psychological Corporation] should help to remedy this situation but have received little research attention. We present WAIS-R Block Design data for 177 healthy older adults (aged 50-90) incorporating several qualitative measures, outlining normative ranges and examining age differences. Proportional scoring, counts of single-block placement and rotation errors, counts of parameter-violating errors such as breaking configuration, and availability of implicit grid information all offer potentially valuable supplementary data that can enrich clinical interpretation of Block Design protocols.

Journal Article↗
PubMed2000

Object relations and reality testing in early- and late-onset schizophrenia.

One hundred fifty-seven U.S. military veterans with schizophrenia were divided into early-onset (i.e., onset at age 20 or before, n = 36) and late-onset (i.e., onset after age 30, n = 28) groups and completed the Bell Object Relations and Reality Testing Inventory (BORRTI), the Positive and Negative Syndrome Scale, and several representative neuropsychological instruments. Participants were compared on background characteristics and test measures. The early-onset group demonstrated significantly more object-relations and reality-testing deficits than the late-onset group. In contrast, no significant group differences were found on symptom or neuropsychological variables. An a posteriori three-group analysis that included the middle age of onset group (i.e., ages 21 to 30) found that the middle group had mean values that fell between early- and late-onset groups on most variables. No distinct patterns of BORRTI subscale scores distinguished the middle group. The finding that object-relations and reality-testing deficits are more pronounced in early-onset schizophrenia has implications for the treatment and rehabilitation of schizophrenia.

Adult↗
PubMed2000

A principal components-based method for the detection of neuronal activity maps: application to optical imaging.

We present a novel analysis technique for the extraction of neuronal activity patterns from functional imaging data. We illustrate this technique on data from optical imaging. Optical imaging of the mammalian visual cortex probe the patterns in which the neuronal responses to various aspects of the visual world, such as orientation and color, are spatially organized within the cortex. Recovering these patterns from the image data is a challenging problem as the neuronal response signal is extremely weak in comparison to the background vegetative processes (e.g., circulation and respiration). The proposed technique obtains the neuronal activity pattern using a combination of principal component analysis and statistical significance testing. The performance of this method is compared with the results of existing analysis techniques. The comparison shows the new method to be more sensitive than previous methods.

Animals↗
PubMed2000

Speed and memory in WAIS-R-NI Digit Symbol performance among healthy older adults.

Although roles have been proposed for both graphomotor speed and learning in the execution of Digit Symbol, few data have been available concerning performance across the adult lifespan on the Symbol Copy, paired associates, or free recall measures derived from Digit Symbol and recommended in the WAIS-R-NI. We report findings on 177 healthy older adults (ages 50-90), providing normative data by age group, education level, and gender. As previously reported, Digit Symbol scores decline steeply with age (r = -.64). Symbol Copy speed declines almost as steeply (r = -.58). Incidental learning, however, declines only modestly (r = -.26 on both measures). Symbol Copy is a far stronger correlate of Digit Symbol (r = .72) than are paired associates or free recall (r = .26 and r = .28, respectively). The 2 incidental learning measures do, however, offer valuable supplementary information as part of a comprehensive individual assessment. When low Digit Symbol scores are produced by slowing on Symbol Copy, further evaluation of perceptual and motor speed and dexterity are indicated. When low incidental learning scores are obtained, further evaluation of memory is warranted. Qualitative analysis of errors (e.g., rotations) made on the incidental learning procedures may also be valuable.

Adult↗