BACKGROUND: A thyroglossal duct cyst typically presents as a long-standing neck mass that becomes symptomatic when inflamed. Hoarseness is an uncommon complaint, and its association may suggest encroachment on and destruction of the larynx. Following removal of the cyst with the Sistrunk procedure, the larynx may need to be reconstructed. METHODS: A case is reported of a patient who was initially seen with hoarseness and a long-standing midline neck mass. Computed tomography (CT) demonstrated a large cystic neck mass that eroded the thyroid cartilage and encroached on the pre-epiglottic space and right paraglottic space. Although the clinical impression was that of laryngeal neoplasm, the CT diagnosis was that of a cyst. At surgery, a thyroglossal duct cyst was found and successfully removed with the Sistrunk procedure. Because the thyrohyoid membrane and thyroid perichondrium were preserved, the glottis did not require reconstruction. This case is presented and the literature of thyroglossal duct cysts that extend into the larynx is reviewed. CONCLUSIONS: The clinical and radiographic criteria that suggest encroachment of a thyroglossal duct cyst on the larynx are reviewed. The management and indications for laryngeal reconstruction are discussed.

Adult↗

PubMedDate not supplied

Discriminative stimulus properties of d-amphetamine and related compounds in rats.

Explore the source record for details and available documents.

Amphetamine↗

PubMedDate not supplied

Role of dopamine in d-amphetamine-induced discriminative responding.

In two-lever operant chambers, rats were trained in a food-reinforced discrimination task. Reward was contingent upon correct lever choices to the induced differential cue conditions of d-amphetamine (0.8 mg/kg) or saline throughout training on a differential reinforcement of low response rate (DRL-15 sec) schedule. Upon acquisition of discriminative response control the animals were pretreated with various neurochemical agents. Pretreatment with atropine, phentolamine, propranolol, methysergide or cinanserin did not block production of d-amphetamine lever responding. Nicotine and oxotremorine did not produce the amphetamine-like cueing effect. However, pimozide blocked the ability of animals to discriminate d-amphetamine and L-DOPA, in combination with Ro 4-4602 with or without amantadine, generated amphetamine-like responses. These results indicate a role of dopamine in the production of the amphetamine state and from the failure of apomorphine to exhibit the stimulus property of d-amphetamine and the antagonism by alpha-methyltyrosine of the d-amphetamine responding it is further suggested that this amphetamine state is produced via the releasing of newly synthesized dopamine.

Animals↗

PubMedDate not supplied

Role of serotonin in the discriminative stimulus properties of mescaline.

Rats were trained to discriminate intraperitoneally administered mescaline from saline in a two-lever operant chamber for food reinforcement. Reward was contingent upon responses made greater than 15 sec apart (DRL-15) on the appropriate lever paired with either drug or saline administration. Following the establishment of discriminative response control by mescaline, the animals were tested for stimulus generalization produced by mescaline after: (a) blockade of periphreral and central serotonin (5-HT) receptors with cinanserin, methysergide, or cyproheptadine; (b) blockade of peripheral 5-HT receptors with xylamidine tosylate; and (c) depletion of brain 5-HT with the tryptophan hydroxylase inhibitor p-chlorophenylalanine (PCPA). The results show that all three central 5-HT antagonists greatly reduced the discriminability of mescaline while the peripheral antagonist, xylamidine tosylate, was without effect. Furthermore, these agents at the doses employed did not effect the discriminability of saline. Depletion of 5-HT with PCPA potentiated the effects of a sub-threshold dose of mescaline and slightly reduced the discriminability of saline. The results indicate that mescaline produces its discriminative stimulus properties by directly stimulating central serotonergic receptors.

Animals↗

PubMedDate not supplied

Discriminative stimulus properties of mescaline: mescaline or metabolite?

The purpose of this study was to investigate possible similarities in the interoceptive stimuli produced by mescaline and its metabolites. Rats were trained in a 2 lever operant chamber to discriminate between the drugged state (mescaline 25 mg/kg) and the nondrugged state (saline). Following acquisition of discriminative response control the rats were pretreated with either saline, aldehyde dehydrogenase inhibitors or amine oxidase inhibitors and tested stimulus generalization produced by i.p. injections of 3, 4, 5-trimethoxyphenylethanol (TMPE), 3, 4, 5-trimethoxyphenylacetaldehyde (TMPA), N-acetylmescaline, mescaline or saline. The results indicated that both aldehyde dehydrogenase and amine oxidase inhibitors enhanced the effects of mescaline, while TMPE, TMPA and N-acetylmescaline failed to exhibit generalization to the mescaline state, regardless of pretreatment. These findings do not indicate the role of a metabolite in the interoceptive cue produced by mescaline.

Aldehyde Oxidoreductases↗

PubMedDate not supplied

Correlation between plasma cortisol and CSF catecholamines in endogenous depressed dexamethasone nonsuppressors.

Nineteen endogenous depressive in-patients (13 with major depression and 6 with bipolar disorder-depressed) and 10 other patients with dysthymic disorder serving as the control group were given the dexamethasone suppression test (DST, 1 mg/subject). The results showed that the DST sensitivity in endogenous depressives was 73.7% and the specificity was 90%. After the patients were treated daily for 6 weeks with 150-200 mg imipramine, 88.9% of those endogenous depressive patients who previously had a positive DST response exhibited a negative response. Moreover, a significantly negative correlation was found between the CSF norepinephrine level and the pre-dexamethasone 4 p.m. plasma cortisol level in those endogenous depressed patients who had a positive DST response. Pre-treatment data also showed that the 4 p.m. plasma cortisol had a significant negative correlation with CSF dopamine. These findings suggest that endogenous depression with positive DST could be related not only to a lower norepinephrine level, but also to a lower dopamine level.

Adult↗

PubMedDate not supplied

Trace element levels in human alcoholic brain.

Copper, magnesium, zinc and manganese levels in the temporal cortex of human alcoholic and control brains were measured by atomic absorption spectrophotometry using both the flame and graphite furnace. All of the 21 alcoholics were male with a mean age of 54.1 years; the 19 male controls had a mean age of 60.2 years. The only statistically significant change in ion levels was an increase in manganese concentration (expressed both as microgram/g wet weight and ng/mg protein) in the alcoholic group when compared to the control group. Five of the alcoholics had malignancies, while 16 of the controls had systemic malignancies. Covariance analysis showed there was no effect of age on the level of manganese in the temporal cortex.

Adult↗