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J O'Neal

Publications and source records attributed to J O'Neal.

15 recordsLinked to original sources
PubMed2001

OCP1, an F-box protein, co-localizes with OCP2/SKP1 in the cochlear epithelial gap junction region.

Immunohistochemical data indicate that OCP1 co-localizes exactly with OCP2 in the epithelial gap junction region of the guinea pig organ of Corti (OC). Despite the abundance of OCP1 in the OC, gaining access to its coding sequence -- and, in particular, the 5' end of the coding sequence -- proved unexpectedly challenging. The putative full-length OCP1 cDNA -- 1180 nucleotides in length -- includes a 67 nucleotide 5' leader sequence, 300 codons (including initiation and termination signals), and a 216 nucleotide 3' untranslated region. The cDNA encodes a protein having a predicted molecular weight of 33,700. The inferred amino acid sequence harbors an F-box motif spanning residues 52--91, consistent with a role for OCP1 and OCP2 in the proteasome-mediated degradation of select OC proteins. Although OCP1 displays extensive homology to an F-box protein recently cloned from rat brain (NFB42), clustered sequence non-identities indicate that the two proteins are transcribed from distinct genes. The presumptive human OCP1 gene was identified in the human genome databank. Located on chromosome 1p35, the inferred translation product exhibits 94% identity with the guinea pig OCP1 coding sequence.

Amino Acid Sequence↗
PubMed1999

Characterization of 6-epi-3-anhydroophiobolin B from Cochliobolus heterostrophus.

The new sesterterpenoid 6-epi-3-anhydroophiobolin B (1) and six known ophiobolins were isolated from the extracts of the fungus Cochliobolus heterostrophus race O. The structure of 6-epi-3-anhydroophiobolin B was deduced from analysis of spectral data and the structural characterization of dehydration and dimerization products. Ophiobolin A (2) showed potent activity in cytotoxicity assays and marginal activity in antimalarial assays.

Animals↗
PubMed1998

The newborn with hearing loss: detection in the nursery.

BACKGROUND: Early detection of hearing loss coupled with appropriate early intervention is critical to speech, language, and cognitive development. These competencies serve as the foundation for later academic skills. For these reasons, many states are undertaking aggressive efforts to screen all newborns before hospital discharge. Universal detection of hearing loss in newborns is a three-stage process composed of 1) the birth admission screen, 2) follow-up and diagnosis, and 3) intervention services. Breakdown at any stage jeopardizes the entire effort. The goals of this research are to examine the birth admission screen by reviewing outcome measurements for 54 228 Texas newborns and to evaluate factors that impact outcomes positively or negatively. METHODOLOGY: All newborns were screened for hearing loss using a physiologic test of auditory function; either screening auditory brainstem responses or transient evoked otoacoustic emissions. Screening occurred in the newborn and intensive care nurseries, before hospital discharge in 9 sites as part of the nursery protocol. Patients. A total of 54 228 newborns were available for screening. OUTCOME MEASURES: Four measures were evaluated and are reported: the number of births screened, the number of newborns who passed the screen before discharge, the number of infants who returned for follow-up, and the number of infants identified with hearing loss. A Birth Screening Performance Index is also calculated. RESULTS: Results are reported for calendar years 1994, 1995, 1996, and through June 1997. A total of 54 228 newborns were available for screening; 52 508 were screened before hospital discharge during their birth admission and 50 721 passed this screen. Infants returning for follow-up screen as outpatients numbered 1224. Over this 31/2-year span, 113 infants who failed the birth admission screening had hearing loss that was sensorineural in nature. From these data, the estimated incidence of hearing loss is 3.14/1000 infants. CONCLUSIONS: Screening in the nursery with low false-positive rates can be achieved when three elements are present: audiology involvement, hospital support, and automated data and information management. Follow-up measures need improvement. Better tracking methods may help assure that at-risk newborns are connected to services.

Evoked Potentials, Auditory, Brain Stem↗
PubMed1997

Ontogeny of dopamine agonist-induced sensitization: role of NMDA receptors.

In contrast to adults, preweanling rats exhibit behavioral sensitization for only a few days after cessation of dopamine (DA) agonist treatment. The reasons for this ontogenetic difference are uncertain, but maturational changes in the N-methyl-D-aspartate (NMDA) receptor may be responsible, since stimulation of these receptors is necessary for the development of DA agonist-induced sensitization in adult rats. The purpose of the present study was to examine the relationship between NMDA receptor functioning and DA agonist-induced sensitization during the preweanling period. To that end, 17-day-old rats were injected (i.p.) on 4 consecutive days with saline or 0.3 mg/kg dizocilpine (a non-competitive NMDA receptor antagonist) followed, 30 min later, by an injection of saline, 2.5 mg/kg amphetamine (an indirect DA agonist), or 1.0 mg/kg NPA (a direct DA agonist). Sensitization was tested 2 days later (i.e., at 22 days of age), with rats receiving a challenge injection of saline, amphetamine, NPA, or dizocilpine. Results showed that the NMDA antagonist had adult-like effects on the behavioral sensitization of preweanling rats, as amphetamine- and NPA-induced sensitization were eliminated by dizocilpine pretreatment. When given alone, dizocilpine substantially increased the locomotor activity (i.e., line-crosses) of preweanling rats, an effect that became sensitized with repeated drug treatment. Lastly, preweanling rats already sensitized to dizocilpine did not exhibit cross-sensitization to amphetamine or NPA. Thus, with few exceptions, NMDA receptor stimulation appears to modulate sensitization in a similar fashion across ontogeny. This finding suggests that maturational differences in the NMDA receptor system are not responsible for the lack of long-term sensitization in the younger animal.

Amphetamine↗
PubMed1993

Absolute sensitivity measured psychophysically and using auditory steady-state potentials.

Absolute thresholds were measured psychophysically (behaviorally) and physiologically in the same subjects. Psychophysical thresholds were obtained using a modified method of limits. Physiological thresholds were based on auditory steady-state potentials recorded from the scalp. The stimuli for both types of test were click trains, periodic tone bursts and amplitude-modulated tones. The center frequency of the bursts and amplitude-modulated tones was 480 or 2000 Hz. It was found that psychophysical thresholds improved, and physiological thresholds worsened as the stimulus became more frequency-specific. Because of this interaction, the differences between psychophysical and physiological thresholds increased monotonically as a function of frequency specificity. Physiological thresholds obtained with the low-frequency stimuli were lower than those acquired with the high-frequency stimuli, while psychophysical thresholds obtained with the two frequencies were essentially the same.

Acoustic Stimulation↗
PubMed1993

Stress and coping behavior of nurses in Desert Storm.

1. Though 100% of the nurses viewed the experience as positive, findings from other studies reinforce the importance of combat stress related factors on noncombatant personnel in the combat zone. 2. The single most agreed-upon stressor was reported as "lack of leadership response," which included lack of information, direction, and recognition. There was a positive correlation between perceived lack of leadership and the seeking of increased authority behavior in command officers. 3. Factors contributing most to maintaining positive working conditions were described as "developing psychologic coping skills" or "support from friends and socialization." 4. Those nurses who were older and had more education used the most effective coping behaviors.

Adaptation, Psychological↗
PubMed1990

Bovine IgG1, but not IgG2, binds to human B cells and inhibits antibody secretion.

We previously observed that milk-derived bovine IgG, but not serum-derived bovine IgG, strongly inhibits antibody secretion by pokeweed mitogen (PWM)-stimulated human peripheral blood mononuclear cells (PBMC). Bovine milk contains a greater percentage of IgG1 (90%) than does bovine serum (53%). To determine whether bovine IgG subclasses have different functional capabilities, we have examined the effects of bovine IgG1 and IgG2 subclasses upon not only antibody secretion but also mitogenesis by human PBMC. Both bovine IgG subclasses markedly inhibited PWM-stimulated mitogenesis. However, only bovine IgG1, and not IgG2, inhibited antibody secretion during a 14-day in vitro culture period. Also, antibody secretion was inhibited following a 24-hr preincubation of human PBMC with bovine IgG1, but not with IgG2. To determine whether these differences corresponded to specificities of human Fc gamma receptors on subsets of mononuclear cells, fluorescence-activated cell sorter (FACS) analyses were performed. Both bovine IgG subclasses bound to human monocytes. However, only bovine IgG1 bound to human B cells, and bovine IgG1 bound more avidly to human B cells than did human IgG. One model to explain these findings is that inhibition of mitogenesis may be due to the binding of both bovine IgG1 and IgG2 subclasses to monocytes; whereas subclass-specific inhibition of antibody secretion may result from the selective binding of bovine IgG1, but not bovine IgG2, to B cells. The observation that bovine IgG1 has a greater avidity for human B lymphocyte Fc receptors than human IgG may have important implications for future studies of Fc gamma receptors on human leucocytes.

Animals↗
PubMed1975

Intracranial esthesioneuroblastoma. A light and electron microscopic study.

A 31 year-old black woman with unilateral facial dysesthesia was found to have an intracranial parasellar mass that extended into the sphenoid sinus. By light microscopy, the neoplasm appeared as nests of poorly differentiated neuroblasts in a finely fibrillary stroma and was diagnosed as an esthesineuroblastoma. Electron microscopy confirmed the neuroblastic nature of the tumor with demonstration of neurites containing neurofilaments and neurotubules, synapses and dense cored biogenic amine granules in perikarya and processes. This neoplasm was further characterized by the presence of numerous dystrophic axons that were evident only by electron microscopy.

Adult↗
PubMedDate not supplied

Postoperative transient bradycardia and asystole after bilateral bunionectomies performed using spinal anesthesia.

Medical complications after elective bunionectomy procedures are rarely encountered. This paper presents a case report of a healthy 51-year-old male patient who experienced transient bradycardia and asystole postoperatively after bilateral bunionectomies. The foot surgeon must be prepared for, be able to recognize, and then treat these untoward medical events.

Anesthesia, Spinal↗