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Biomedical subjects

J B Snow

Publications and source records attributed to J B Snow.

At least 19 recordsLinked to original sources

WISC-III subtest patterns of ADHD and normal samples.

WISC-III subtest patterns of children with Attention Deficit Hyperactivity Disorder were compared with two other groups of children described in the WISC-III manual, a sample with Attention Deficit Hyperactivity Disorder and the WISC-III standardization sample. Subtest patterns of primary interest were the SCAD Index based on Symbol Search, Coding, Arithmetic, Digit Span, Bannatyne scores for Spatial, Verbal Conceptualization, Sequencing Ability, and the ACID Profile including Arithmetic, Coding, Information, and Digit Span. Comparisons of WISC-III scaled scores and subtest patterns for the samples with Attention Deficit Hyperactivity Disorder supported the congruence between them. Further, the cumulative percentages of children in the three samples who obtained differences between the SCAD Index and the Perceptual Organization Index were computed. Analysis indicated that 17 of the 35 subjects in the current sample obtained differences of 9 points or greater. The results were substantially different from the WISC-III standardization sample but congruent with the WISC-III sample of children with Attention Deficit Hyperactivity Disorder. These outcomes support the diagnostic utility of WISC-III subtest profile patterns for children with Attention Deficit Hyperactivity Disorder.

Adolescent↗

Convergence of olfactory and nasotrigeminal inputs and possible trigeminal contributions to olfactory responses in the rat thalamus.

To elucidate the role of trigeminal input on the olfactory system, field-evoked potentials were measured following electrical stimulation of the nasociliary branch of the trigeminal nerve in the olfactory-related structures in the rat brain. Significant potential changes were recorded in the mediodorsal nucleus of the thalamus and the lateral hypothalamic area. In the mediodorsal nucleus of the thalamus, the neurons responding to olfactory bulb electrical stimulation also responded to trigeminal nerve stimulation. Single neuronal responses of mediodorsal thalamic neurons following odorant stimulation were enhanced by blockade of the trigeminal nerve with procaine. These results suggest that olfactory and trigeminal pathways converge on the same neural elements within the mediodorsal nucleus of the thalamus and that the trigeminal input may modulate olfactory input in this nucleus.

Animals↗

Smell and taste disorders, a study of 750 patients from the University of Pennsylvania Smell and Taste Center.

Smell and taste disorders are common in the general population, yet little is known about their nature or cause. This article describes a study of 750 patients with complaints of abnormal smell or taste perception from the University of Pennsylvania Smell and Taste Center, Philadelphia. Major findings suggest that: chemosensory dysfunction influences quality of life; complaints of taste loss usually reflect loss of smell function; upper respiratory infection, head trauma, and chronic nasal and paranasal sinus disease are the most common causes of the diminution of the sense of smell, with head trauma having the greatest loss; depression frequently accompanies chemosensory distortion; low body weight accompanies burning mouth syndrome; estrogens protect against loss of the sense of smell in postmenopausal women; zinc therapy may provide no benefit to patients with chemosensory dysfunction; and thyroid hormone function is associated with oral sensory distortion. The findings are discussed in relation to management of patients with chemosensory disturbances.

Burning Mouth Syndrome↗

Randomized study of preoperative versus postoperative radiation therapy in advanced head and neck carcinoma: long-term follow-up of RTOG study 73-03.

This is a report of a 10-year median follow-up of a randomized, prospective study investigating the optimal sequencing of radiation therapy (RT) in relation to surgery for operable advanced head and neck cancer. In May 1973, the Radiation Therapy Oncology Group (RTOG) began a Phase III study of preoperative radiation therapy (50.0 Gy) versus postoperative radiation therapy (60.0 Gy) for supraglottic larynx and hypopharynx primaries. Of 277 evaluable patients, duration of follow-up is 9-15 years, with 7.6% patients lost to follow-up before 7 years. Loco-regional control was significantly better for 141 postoperative radiation therapy patients than for 136 preoperative radiation therapy patients (p = 0.04), but absolute survival was not affected (p = 0.15). When the analysis was restricted to supraglottic larynx primaries (60 postoperative radiation therapy patients versus 58 preoperative radiation therapy patients), the difference for loco-regional control was highly significant (p = .007), but not for survival (p = 0.18). In considering only supraglottic larynx, 78% of loco-regional failures occurred in the first 2 years. Thirty-one percent (18/58) of preoperative patients failed locally within 2 years versus 18% (11/60) of postoperative patients. After 2 years, distant metastases and second primaries became the predominant failure pattern, especially in postoperative radiation therapy patients. This shift in the late failure pattern along with the increased number of unrelated deaths negated any advantage in absolute survival for postoperative radiation therapy patients. The rates of severe surgical and radiation therapy complications were similar between the two arms. Because of an increased incidence of late distant metastases and secondary primaries, additional therapeutic intervention is required beyond surgery and postoperative irradiation to impact significantly upon survival.

Adult↗

Photochemical effects of laser irradiation on neuritic outgrowth of olfactory neuroepithelial explants.

The photochemical effect of low-intensity laser irradiation (LILI) on the maturation and regeneration of olfactory-immature estrus day 15 (E15) and olfactory-mature estrus day 22 (E22) rat fetuses was studied. Neuritic outgrowths of olfactory bipolar receptor cells were quantified in olfactory neuroepithelial explants. Explants in the experimental groups were irradiated with a helium-neon laser using different incident energy densities (IEDs). Explants in another group were exposed to fluorescent light. Control explants did not receive laser or fluorescent light irradiation. Neuritic outgrowths were analyzed on a regular basis for 12 days. Analysis of variance was used to evaluate the data. The parameters of neuritic outgrowth in E15 fetuses showed a significant increase of 30% to 50% vs. the control with a single laser irradiation of 0.5 J/cm2 IED. The rate of neuritic outgrowth observed in the E22 fetuses was less than in the E15 fetuses. The parameters of neuritic outgrowth in E22 fetuses showed a significant and substantially greater percentage increase than in the E15 fetuses with daily laser irradiations of 0.05 and 0.5 J/cm2 IED when compared to the control. The magnitude of these increases appears to be of biological significance as well as statistical significance.

Analysis of Variance↗

Surgical quality control in head and neck cancer. Study 73-03 of the Radiation Therapy Oncology Group.

The measurement of quality of medical care has always been a topic of concern to physicians and other health care professionals. During an age of increasing competitiveness in the health care environment, the ability to assess accurately the quality of the care delivered has become increasingly important. The head and neck surgeons within the Radiation Therapy Oncology Group have examined this problem and have developed an evaluation tool that was then applied retrospectively in an attempt to evaluate the quality of surgery performed in a randomized study. The analysis of the results suggested that the retrospective approach to surgical quality control is fraught with hazards and is unlikely to fulfill the goals set for it.

Clinical Trials as Topic↗

Effects of locus ceruleus and olfactory bulb stimulation on rat olfactory tubercle neuron activity.

The effects of electrical stimulation of the olfactory bulb and the locus ceruleus on olfactory tubercle neurons were examined in rat models. Ipsilateral stimulation of the olfactory bulb produced excitation in 31% of olfactory tubercle neurons tested and inhibition in 17%. Twenty-two percent of the olfactory tubercle neurons were excited, whereas 9% were inhibited by ipsilateral stimulation of the locus ceruleus. Contralateral stimulation of the locus ceruleus produced similar responses in the same neuron entities. A negative-positive evoked potential was recorded in the olfactory tubercle after ipsilateral and contralateral stimulation of the locus ceruleus. Thirty-three percent of the olfactory tubercle neurons that responded orthodromically or antidromically to stimulation of the olfactory bulb were excited by ipsilateral stimulation of the locus ceruleus. In contrast, only 10% responded with excitation to ipsilateral stimulation of the locus ceruleus among the olfactory tubercle neurons that were unresponsive to stimulation of the olfactory bulb. These findings suggest that olfactory tubercle neurons that receive input from or sending output to the olfactory bulb are influenced by the noradrenergic system of the locus ceruleus. A possible role of the olfactory tubercle in olfactory transduction will also be discussed.

Animals↗