Biomedical subjects

S Estes

Publications and source records attributed to S Estes.

6 recordsLinked to original sources

PubMed1997

E2F activity is regulated by cell cycle-dependent changes in subcellular localization.

E2F directs the cell cycle-dependent expression of genes that induce or regulate the cell division process. In mammalian cells, this transcriptional activity arises from the combined properties of multiple E2F-DP heterodimers. In this study, we show that the transcriptional potential of individual E2F species is dependent upon their nuclear localization. This is a constitutive property of E2F-1, -2, and -3, whereas the nuclear localization of E2F-4 is dependent upon its association with other nuclear factors. We previously showed that E2F-4 accounts for the majority of endogenous E2F species. We now show that the subcellular localization of E2F-4 is regulated in a cell cycle-dependent manner that results in the differential compartmentalization of the various E2F complexes. Consequently, in cycling cells, the majority of the p107-E2F, p130-E2F, and free E2F complexes remain in the cytoplasm. In contrast, almost all of the nuclear E2F activity is generated by pRB-E2F. This complex is present at high levels during G1 but disappears once the cells have passed the restriction point. Surprisingly, dissociation of this complex causes little increase in the levels of nuclear free E2F activity. This observation suggests that the repressive properties of the pRB-E2F complex play a critical role in establishing the temporal regulation of E2F-responsive genes. How the differential subcellular localization of pRB, p107, and p130 contributes to their different biological properties is also discussed.

Animals↗

PubMed1997

Enhancement of attention processing by Kantroll in healthy humans: a pilot study.

This is the first report in humans of the effects of daily ingestion of a specific amino acid mixture, Kantroll, on cognitive event-related potentials (ERPs) associated with performance. Cognitive ERPs were generated by two computerized visual attention tasks, the Spatial Orientation Task (SOT) and Contingent Continuous Performance Task (CCPT), in normal young adult volunteers, where each subject acted as his own control for testing before and after 28-30 days of amino acid ingestion. A statistically significant amplitude enhancement of the P300 component of the ERPs was seen after Kantroll for both tasks, as well as improvement with respect to cognitive processing speeds. The enhancement of neurophysiologic function observed in this study on normal controls is consistent with the facilitation of recovery of individuals with RDS (i.e., substance use disorder, ADHD, carbohydrate bingeing) following the ingestion of the amino acid supplement, Kantroll, and warrants additional placebo-controlled, double-blind, studies to confirm and extend these results.

Adult↗

PubMed1993

Evidence of temporal lobe activation by discriminative spatial orientation.

The results from this spatial orientation, or cue priming, investigation found that targets presented to the contralateral visual fields differentially activated the temporal zones. For instance, stimulation within the right visual field lead to activation of the left temporal zones, as indexed by the relative prominence of the association negativity, N2. The converse was true for left visual field stimulation. For both visual field stimulation, the N2 component also showed an occipital and parietal distribution. The P300 component, which is presumed to be modulated by medial temporal lobe structures, showed the classic centroparietal distribution. Somewhat surprisingly, differences between the primed (e.g., 'facilitated') and 'normal' conditions for the N2 component appeared restricted to the occipital zones. Here, the significant variable was the N2 peak latency. Hence, the priming cue appears to quicken the maximal development of the N2 processing component, preferentially over the occipital cortex, and this may partially explain the faster reaction times in the 'facilitated' conditions for both visual fields.

Adult↗

PubMed1993

[Olmsted syndrome. Successful therapy by treatment with etretinate].

A 36-year-old North American patient has been suffering from Olmsted syndrome since early childhood. This rare inborn error of keratinization consists in pronounced, multilating keratoderma of palms and soles and associated periorificial keratoses. The patient has now been treated with etretinate for more than 6 years, resulting in a marked reduction of hyperkeratoses. Electron microscopic investigation of skin biopsies taken before and during therapy have confirmed the significant clinical improvement. Even though this retinoic acid derivative, a powerful regulating agent with a de-differentiating effect, cannot cure the basic defect, the marked hyperproliferation of the epidermis is reduced, so that terminal differentiation is delayed and thereby normalized. At the same time, the synthesis of keratinization proteins, such as keratins and keratohyalin, which is suppressed before therapy, increases. The familial connective tissue disorder existing independently of Olmsted syndrome in this patient (perhaps a mild form of Ehlers-Danlos syndrome) is not influenced by the retinoid therapy.

Adult↗

PubMed1992

Genital benign chronic pemphigus (Hailey-Hailey disease) presenting as condylomas.

BACKGROUND: Genital lesion sof benign chronic pemphigus (FBCP)(Hailey-Hailey disease) may present as verrucous papules. Genital warts and papular acantholytic dyskeratosis of the genitalia may be considered in the differential diagnosis. OBJECTIVE: Our purpose was to describe the clinical characteristics and histologic features of verrucous anogenital FBCP. METHODS: Six patients, five women and one man, with verrucous anogenital lesions of FBCP, initially diagnosed as warts, were examined and biopsy specimens were evaluated histologically. RESULTS: The lesions were located exclusively in the perineal and perianal regions with axillary involvement in one case. Family history was negative in three of the six cases. Histologic examination confirmed the diagnosis of FBCP but was significant for the absence of crusts and the presence of only minimal inflammation. CONCLUSION: Our cases and the literature are reviewed with the conclusion that all verrucoid genital lesions with the histologic characteristics of Hailey-Hailey disease may represent FBCP.

Adult↗

PubMed1988

Successful pregnancies from men with retrograde ejaculation with the use of washed sperm and gamete intrafallopian tube transfer (GIFT).

Viable sperm were collected from men suffering from retrograde ejaculation by the technique of rapid washing of semen/urine in a buffered collection solution. The utilization of washed semen/urine from two men with retrograde ejaculation in the GIFT procedure lead to successful conceptions and the birth of two healthy female babies. Thus, the technique of rapid washing of sperm from retrograde ejaculating men coupled with GIFT represents a viable alternative for the attainment of pregnancy.

Ejaculation↗