Melatonin: effect on punished and nonpunished operant behavior of the pigeon.

Intramuscular injections of melatonin had a dose-dependent, rate-increasing effect on responding maintained by a fixed-interval schedule of positive reinforcement. When a punishment contingency was added to the fixed-interval schedule, the overall rates were not increased although responding was increased during the initial part of each interval.

Lysergic acid diethylamide- and mescaline-induced attenuation of the effect of punishment in the rat.

At a dose as low as 1 microgram per kilogram of body weight, lysergic acid diethylamide (LSD) significantly decreased the suppressive effect of electric shock on licking behavior of the rat. Attenuation of punishment was also obtained with mescaline, but neither dimethyltryptamine nor delta9-tetrahydrocannabinol was active in this test. Cyproheptadine and alpha-propyldopacetamide, drugs that interfere with the function of neurons that contain serotonin, have a behavioral effect similar to that of LSD and mescaline, which suggests that the attenuation of punishment produced by these hallucinogens may result from decreased activity of such neurons.

Steroid receptors in benign mastectomy tissue.

Estrogen and progesterone receptors (ERs and PRs, respectively) were measured in both cancerous and noncancerous components of 104 modified radical mastectomy specimens. In addition, ER and PR levels were determined for 14 benign breast specimens obtained by reduction mammoplasty. The receptor levels were measured by scatchard method. Each of these groups--cancerous, corresponding noncancerous, and mammoplasty specimens--were divided into subgroups according to their receptor levels. Fourteen of the 104 noncancerous specimens were found to be ER positive (ER+). Most cases of ER+ noncancerous tissue (13 of 14 cases) were associated with ER+ tumors. The reverse was not true because only 13 of 64 cases of the ER+ tumors were associated with positive ER in their noncancerous counterparts. Comparable results were obtained for PR. The average ER-PR level of the noncancerous mastectomy tissue was significantly higher than that of the mammoplasty specimens despite the similar histologic findings in both groups.

Speciation of cone snails and interspecific hyperdivergence of their venom peptides. Potential evolutionary significance of introns.

All 500 species of cone snails (Conus) are venomous predators. From a biochemical/genetic perspective, differences among Conus species may be based on the 50-200 different peptides in the venom of each species. Venom is used for prey capture as well as for interactions with predators and competitors. The venom of every species has its own distinct complement of peptides. Some of the interspecific divergence observed in venom peptides can be explained by differential expression of venom peptide superfamilies in different species and of peptide superfamily branching in various Conus lineages into pharmacologic groups with different targeting specificity. However, the striking interspecific divergence of peptide sequences is the dominant factor in the differences observed between venoms. The small venom peptides (typically 10-35 amino acids in length) are processed from larger prepropeptide precursors (ca. 100 amino acids). If interspecific comparisons are made between homologous prepropeptides, the three different regions of a Conus peptide precursor (signal sequence, pro-region, mature peptide) are found to have diverged at remarkably different rates. Analysis of synonymous and nonsynonymous substitution rates for the different segments of a prepropeptide suggests that mutation frequency varies by over an order of magnitude across the segments, with the mature toxin region undergoing the highest rate. The three sections of the prepropeptide which exhibit apparently different mutation rates are separated by introns. This striking segment-specific rate of divergence of Conus prepropeptides suggests a role for introns in evolution: exons separated by introns have the potential to evolve very different mutation rates. Plausible mechanisms that could underlie differing mutational frequency in the different exons of a gene are discussed.

Unilateral ureteral obstruction secondary to sarcoidosis.

An episode of unilateral ureteral obstruction secondary to sarcoidosis is described. Corticosteroid treatment resulted in prompt and complete resolution of the obstruction and associated lymphadenopathy. We believe this represents the first reported case of ureteral obstruction secondary to sarcoidosis.

Comparison of structural and stereoisomers of apomorphine on stereotyped behavior of the rat.

N-n-propylnorapomorphine (NPA) is 35 times more potent than apomorphine (APO) in producing stereotyped behavior in rats. The effect of NPA is blocked by perphenazine but unaltered by alpha-methyltyrosine pretreatment and is accompanied by a decrease in central dopamine turnover. The activity of APO and NPA appears to be primarily in the (-)-isomer, and is diminished but not lost by removal of either hydroxyl group from the catechol ring system.

Dopamine-mediated behavior produced by the enkephalin analogue FK 33-824.

Intraperitoneal injection of FK 33-824 produced apomorphine-like stereotyped behavior in rats. Antagonism of this stereotypy by naloxone and neuroleptics suggests that FK 33-824 can activate opiate and dopamine receptors in the brain. Because increased dopaminergic neuronal activity is thought to be involved in schizophrenia and dopamine-mediated stereotypy has been used as an animal model for this illness, these results are consistent with an involvement of endogenous opiate-like peptides in schizophrenia. This involvement provides a possible mechanism for the reported improvement in schizophrenic psychosis produced by naloxone.

Post-scabetic nodules: a lymphohistiocytic reaction rich in indeterminate cells.

We studied six infants and two adult cases of nodular scabies with immunostains and electron microscopy. All eight cases have had either direct (KOH) or family histories of scabies and were treated with lindane 1% cream or permethrin 5% cream. Family members responded very well, but our patients developed multiple papulo-nodular lesions which were initially very pruritic and, in some cases, persisted from several months to over one year. H & E stain of biopsied tissue sections revealed a heavy perivascular and periappendageal lymphohistiocytic cell infiltration. Immunophenotype of these cells was compatible with Langerhans cells, i.e. CD1A (+), S-100 (+) and HLA-DR (+). Electron microscopy showed that these histiocytic cells satisfied all the ultrastructural criteria of Langerhans cells except for the absence of Birbeck's granules. Lag, a monoclonal antibody for Birbeck's granules, was negative. "Persistent nodules in scabies" or "nodular scabies" seems to represent a prolonged response of indeterminate cells-lymphocytes to mite antigens.

Ultrasound Guided Balloon Angioplasty: What is its Role?

A modified angioplasty catheter has been developed which can be guided-into position with duplex ultrasound. This reduces the risks of ionizing radiation and contrast agents and uses a modality familiar to the vascular surgeon. This catheter was tested successfully in a canine model for safety, accuracy and therapeutic efficacy. Following FDA approval, clinical trials in humans were initiated. This paper describes the preliminary results with use of this device in humans.

Construct validity of the Sivik Psychosomaticism Test and test of operational style: correlations with Karolinska Scheme of Personality.

To evaluate the construct validity (convergent and divergent) of Sivik Psycho Somaticism test (SPS) and test of Operationality (OPER), Pearson correlation coefficients between SPS scales and subscales and Karolinska Scheme of Personality (KSP) were calculated. Seventy-eight healthy individuals and 196 psychosomatic patients completed the SPS and OPER tests and KSP. The results show that the SPS and OPER subscales are significantly correlated to most KSP subscales. The correlations were higher for the psychosomatic group than for the normal population. The results confirm the validity of the SPS and OPER constructs.

Construct validity of the Sivik Psychosomaticism Test and test of operational style: correlations with four Minnesota Multiphasic Personality Inventory (MMPI) subscales.

To evaluate the construct validity (convergent and divergent) of the Sivik Psycho Somaticism test (SPS) and test of Operationality (OPER), Pearson correlation coefficients between SPS scales and subscales, OPER and Minnesota Multiphasic Personality Inventory (MMPI) subscales Hypochondria (Hs), Depression (D), Hysteria (Hy) and Alexithymia (Al) were calculated. Eighty-eight healthy individuals and 285 psychosomatic patients completed the SPS and OPER tests and MMPI; Hs, D, Hy and Al. The results show that most of the SPS subscales and OPER are significantly correlated to several MMPI subscales in both a normal and a psychosomatic population. The results are in concordance with the theoretical hypotheses and confirm the validity of the SPS and OPER constructs.

Ageing and spatial reversal learning in humans: findings from a virtual water maze.

Deterioration in spatial memory with normal ageing is well accepted. Animal research has shown spatial reversal learning to be most vulnerable to pathological changes in the brain, but this has never been tested in humans. We studied ninety participants (52% females, 20-80 yrs) in a virtual water maze with a reversal learning procedure. Neuropsychological functioning, mood and personality were assessed to control moderator effects. For data analysis, participants were subdivided post hoc into groups aged 20-24, 25-34, 35-44, 45-64 and 65-80 yrs. Initial spatial learning occurred in all age groups but 65-80-yrs-olds never reached the level of younger participants. When tested for delayed recall of spatial memory, younger people frequented the target area but those over 65 yrs did not. In spatial reversal learning, age groups over 45 yrs were deficient and the 65-80-yrs-olds showed no evidence of reversal. Spatial measures were associated with neuropsychological functioning. Extraversion and measures of depression moderated the age effect on the learning index with older introverted and non-depressed individuals showing better results. Measures of anxiety moderated the age effect on reversal learning with older people having higher anxiety scores showing a preserved reversal learning capability. Results confirmed age to be a major factor in spatial tasks but further showed neuropsychological functioning, psycho-affective determinants and personality traits to be significant predictors of individual differences.