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Biomedical subjects

E Kogan

Publications and source records attributed to E Kogan.

At least 19 recordsLinked to original sources
PubMed2003

Effects of rivastigmine on the quantitative EEG in demented Parkinsonian patients.

OBJECTIVES: Quantitative electroencephalogram (qEEG) can be used to measure the effects of drugs on the brain. We studied the effects of rivastigmine on the qEEG in Parkinson's disease (PD) patients with dementia. SUBJECTS AND METHODS: Demented PD patients (n=19) were treated with rivastigmine in an open label study. Recordings were obtained prior to and following 12 weeks of treatment. Results were analyzed using two-way ANOVA with repeated measures. RESULTS: A significant increase in the relative alpha (P < 0.05) activity was observed after treatment with rivastigmine. This was general rather than localized to specific brain surface areas. An increase in beta activity and decrease in the slower frequencies (delta and theta) were also observed; however, these were not statistically significant. CONCLUSION: qEEG may serve as an objective tool to monitor the effects of antidementia drug therapy. The changes characterized by increased faster frequencies and decreased slower frequencies that were observed may indicate increased arousal or improvement in the cognitive state of the patients as a consequence of the treatment with rivastigmine.

Aged↗
PubMed2001

Variant expression of CD44 in preneoplastic lesions of the lung.

BACKGROUND: Specific CD44 isoforms are cell surface adhesion molecules and have been shown to be associated with tumor progression and metastasis. In lung carcinoma, CD44 expression has been reported to be a feature of nonsmall cell lung carcinoma (NSCLC) but not small cell lung carcinoma. A specific variant, CD44v6, was shown to be expressed only in a subset of NSCLC, namely the squamous cell and bronchoalveolar carcinomas, suggesting that CD44 may play a role in lung carcinoma differentiation. METHODS: To determine whether differential CD44 expression is an early event in the pathogenesis of lung carcinoma, the authors investigated the pattern of expression of the standard (CD44s) and variant (CD44v6) isoforms by immunohistochemistry in normal lung, nonneoplastic specimens, and bronchial biopsies of preneoplastic lesions. RESULTS: In normal bronchial epithelium and all nonneoplastic cases, CD44s expression was limited to the basement membrane and adjacent lower strata of the epithelium, whereas CD44v6 was expressed within the basement membrane only. However, aberrant expression of both CD44s and CD44v6 was observed in all preneoplastic lesions examined. In cases of dysplasia, squamous metaplasia, goblet cell hyperplasia, and basal cell hyperplasia, all epithelial strata showed immunoreactivity for both isoforms, in contrast to normal epithelium, in which immunoreactivity was noted to be restricted to the basal layer cells. In contrast, CD44s and CD44v6 expression was completely absent in nearly all cases of adenomatosis. CONCLUSIONS: Altered CD44s and/or CD44v6 expression appears to be a feature of all preneoplastic lesions in the lung, the precise nature of which varies according to histologic tumor type. Therefore, the authors conclude that CD44s and CD44v6 may lend themselves to be markers of preneoplastic changes in the lung.

Glycoproteins↗
PubMed2000

Workshop III: late motor complications of Parkinson's disease.

The aim in the current treatment of Parkinson's disease is to delay L-Dopa administration and to keep the L-Dopa dosage as low as possible. Such a treatment strategy can delay the onset of late motor complications and reduce their severity. L-Dopa remains the most potent anti-parkinsonian medication, but its use for the initial therapy of Parkinson's disease is limited to elderly patients. In all other cases, dopamine agonists, budipine, amantadine and selegiline are primarily used. With the occurrence of late motor complications continuous dopamine receptor stimulation becomes essential. In this situation, combination therapy has to be individualized, with dopamine agonists playing a key role. In addition, COMT inhibitors, budipine, amantadine and selegiline may be used. Anticholinergic drugs are of very limited importance in the current treatment of Parkinson's disease.

Antiparkinson Agents↗
PubMed2000

Physically traumatic events in patients with epilepsy compared with non-epileptic subjects.

To determine the incidence of traumatic events among epileptic patients compared with non-epileptic individuals, we distributed a questionnaire on physically traumatic events occurring during the preceding three months to consecutive epileptic patients and to age- and sex-matched controls. There were 145 epileptic patients, 121 with seizures (age 36 +/- 15 y, 60 males) and 24 who were seizure free during this period (age 39 +/- 17 y, 13 males), and 145 controls (age 36 +/- 15 y, 73 males). There was no significant difference in the duration of epilepsy between the two groups of patients with epilepsy. Traumatic events (n= 27, three of them unrelated to seizure) were most common in patients with seizures, followed by controls (n= 20), and absent in seizure-free patients (P< 0.001). Patients with epilepsy most commonly injured the head while the extremities were more usually involved in controls. Patients with epilepsy had significantly more traumatic events at home, whereas controls underwent most traumatic events at work and in public areas. There was no significant difference in the type and severity of trauma between the two groups. We conclude that physically traumatic events not related to seizures are fewer among patients with epilepsy with and without seizures compared with controls, probably because of increased cautiousness.

Accidents↗
PubMed2000

Wave scattering through classically chaotic cavities in the presence of absorption: An information-theoretic model

We propose an information-theoretic model for the transport of waves through a chaotic cavity in the presence of absorption. The entropy of the S-matrix statistical distribution is maximized, with the constraint =alphan: n is the dimensionality of S, and 0</=alpha</=1, alpha=0(1) meaning complete (no) absorption. For strong absorption our result agrees with a number of analytical calculations already given in the literature. In that limit, the distribution of the individual (angular) transmission and reflection coefficients becomes exponential (Rayleigh statistics), even for n=1. For n>>1 Rayleigh statistics is attained even with no absorption; here, we extend the study to alpha<1. The model is compared with random-matrix-theory numerical simulations: it describes the problem very well for strong absorption, but fails for moderate and weak absorptions. Thus, in the latter regime, some important physical constraint is missing in the construction of the model.

Journal Article↗
PubMed1997

Preferential histiotypic expression of CD44-isoforms in human lung cancer.

The CD44 transmembrane glycoprotein is expressed in most adult tissues and in the majority of neoplasias. Due to alternative splicing, this cell adhesion molecule exists in multiple isoforms some of which have been associated with specific types of tumours as well as with increased tumour metastasis. In this study, we have looked at the level and type of CD44 expression in lung cancer which represents a histologically heterogenous form of cancer composed of small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC), the latter subgroup comprising adenocarcinoma (ADC), bronchio-alveolar carcinoma (BAC), large cell carcinoma (LCC), and squamous cell carcinoma (SCC). We analysed 20 lung cancer cell lines and 64 primary tumours by RT-PCR and immunohistochemical detection of the CD44 standard and variant protein isoforms. Our results suggest that (i) CD44 is expressed in all histologically distinct subsets of lung cancer with a tendency SCC > BAC > ADC > LCC > SCLC, (ii) expression of the CD44 isoforms v5, v7, v8, and, most notably that of CD44 exon v6, strongly correlates with tumours of squamous cell and bronchio-alveolar carcinoma origin, tumours which commonly exhibit a comparatively low metastasizing potential, and (iii) the expression of CD44 isoforms is independent from the tumour size and lymph node status at surgery, the proliferative status of the tumour cell population (Ki67 antigen expression) and the histopathological grading (G1 to G3). Only non-differentiated tumours (G4), which were restricted to SCLC and LCC samples revealed markedly reduced CD44 standard and isoform antigen. In conclusion, our data point to a clear histiotype-related pattern of CD44 variant expression preferentially that of CD44v6 in SCC and BAC.

Adenocarcinoma↗
PubMed1997

Nuclear localization of insulin-like growth factor binding protein 3 in a lung cancer cell line.

Considerable evidence exists that lung cancer cell lines produce large amounts of insulin-like growth factor-binding proteins (IGFBPs). In addition, these cells are subject to an autocrine or paracrine growth control by insulin-like growth factors (IGFs). We now demonstrate by immunocytochemistry with IGFBP-3 antibodies that nuclei of a lung cancer cell line distinctly immunostain for IGFBP-3. This finding led us to investigate in more detail the localization of this protein that, to date, had only been known to occur extracellularly. Ligand blotting revealed that purified nuclear extracts contain a 43,000-Da IGFBP which can bind [I125]IGF-I. By Western blot this protein was identified as IGFBP-3. Thus, our data are consistent with the results of a previous structural study predicting a nuclear localization for IGFBP-3. Moreover, our findings raise the possibility that nuclear IGFBP-3 is functional and involved in the pathogenesis of lung cancer.

Blotting, Western↗
PubMed1996

Expression of bcl-2--protein in small cell lung cancer.

The expression of the proto-oncogene bcl-2, whose main function appears to be an inhibition of apoptosis, was investigated in 164 cases of primary small cell lung cancer by means of immunohistochemistry in a retrospective analysis. One-hundred twenty-five cases (76%) demonstrated expression of bcl-2. There was no difference in serum LDH levels and proliferative activity between the two groups. An analysis revealed a median survival time of 12 months for patients with bcl-2 positive tumors compared to 9.5 months for patients with bcl-2 negative tumors. Although statistical significance is not achieved, there is a trend towards longer survival in patients whose tumors express bcl-2. This tendency is also reflected by a higher rate of complete remission after chemotherapy: 40% in patients with bcl-2+ tumors versus 27% in patients with bcl-2- tumors. In multivariate analysis, tumor stage followed by Karnofsky index were the most valuable predictors for complete remission. LDH and tumor stage were most predictive for 1-year survival. Bcl-2 expression is frequent in SCLC and may reflect a less aggressive mechanism of transformation and a higher susceptibility to cytostatic treatment.

Adult↗
PubMedDate not supplied

Relationship of depression with measures of social functioning in adult drug abusers.

The present study describes the relationship between depression and several measures of social functioning--including employment, criminal activity, incarceration, marital functioning, and alcohol and drug use--in a population of adult drug abusers. Our investigation extends past work in this area by specifically investigating the effects of depression (as opposed to simple substance use) on social and interpersonal functioning. Predictably, elevated levels of depression were associated with increased use of hard drugs and alcohol, greater levels of institutionalization, reduced attendance at work or school, and lower overall rates of marital satisfaction. Consistent with previous reports, level of marijuana use was not related to severity of depression. It appears that depressed substance abusers experience significantly more social, vocational, and interpersonal dysfunction than their nondepressed counterparts. It is proposed that the efficacy of existing treatment programs for adult drug abusers will be enhanced through the addition of strategies to assess and ameliorate depression.

Adolescent↗