A Tribute to John G. Watkins,PhD: “Leave a trail of wisdom …”

The results of administering the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) of Shor and E. Orne (1962) to a Spanish sample are on the whole consistent with those results obtained in other normative studies, especially Bongartz's work with a German sample, and they confirm HGSHS:A's usefulness in non-Anglophone countries. The Spanish HGSHS:A's reliability and validity remain within the limits reported for other locales, but there are certain discrepancies with respect to the difficulty of two HGSHS:A items.     

Hypnotizability as affected by attitudinal and motivational variables

The purpose of the study was two-fold: to discover whether task-motivated Ss would be more hypnotizable than those not given task-motivation instructions, and to discover whether the attitude of the E would affect Ss hypnotizability. The Barber Suggestibility Scale was employed for measuring susceptibility to hypnosis. Ss were divided randomly into 6 groups of 10: Group 1 (task-motivated-E neutral); Group 2 (non task-motivated-E neutral); Group 3 (task-motivated-E friendly); Group 4 (task-motivated-E harsh); Group 5 (non task-motivated-E friendly); and Group 6 (non task-motivated-E harsh). Analyses of variance, both for objective and subjective scores, did not yield significant results for the task-motivation variable but did yield significant results (p = .01) for the variable dealing with E attitude.     

Cognitive components of social anxiety

Designed a self-report questionnaire to measure the frequency of occurrence of self-relevant cognitions that accompany the experience of social distress. Male and female college students were asked to recall an experience of social anxiety and to report associated cognitions. One hundred and seventeen representative cognitions were selected and administered to a second sample, along with the Fear of Negative Evaluation Scale and the Social Avoidance and Distress Scale. Twenty-one items were selected on the basis of their ability to predict social anxiety. Factor-analysis indicated a four-factor solution. This new measure may provide a means of identifying cognitive targets for treatment planning as well as an instrument for assessing change in cognitions associated with psychotherapeutic intervention.     

Characterization of the methemoglobin forming metabolites of benzocaine and lidocaine

1.?Topical anesthesia with benzocaine or lidocaine occasionally causes methemoglobinemia, an uncommon but potentially fatal disorder where the blood has a reduced ability to transport oxygen. Previous in vitro studies using human whole blood have shown that benzocaine causes more methemoglobin (MetHb) formation than lidocaine, and that both compounds require metabolic transformation to form the MetHb producing species. In the current investigation, the active species of benzocaine forming the MetHb was investigated.

2.?HPLC analysis of benzocaine samples incubated with human hepatic S9 showed the formation of a peak with the same UV spectrum and retention time as benzocaine hydroxylamine (BenzNOH). To confirm the activity of BenzNOH, MetHb production following exposure to the compound was determined in whole human blood using an Avoximeter 4000 CO-oximeter.

3.?BenzNOH produced MetHb in a concentration dependent manner without the need for metabolic activation. Benzocaine in the presence of metabolic activation required a concentration of 500?μM to produce a similar degree of MetHb formation as 20?μM BenzNOH without activation. Previous work suggested that two metabolites of lidocaine may also form MetHb; N-hydroxyxylidine and 4-hydroxyxylidine. Of these two metabolites 4-hydroxyxylidine produced the most MetHb in whole blood in vitro in the absence of metabolic activation, however BenzNOH produced up to 14.2 times more MetHb than 4-hydroxyxylidine at a similar concentration.

4.?These results suggest that the ability of benzocaine to form MetHb is likely to be mediated through its hydroxylamine metabolite and that this metabolite is inherently more active than the potentially MetHb-forming metabolites of lidocaine.     

It’s what’s inside that counts: egg contaminant concentrations are influenced by estimates of egg density,egg volume,and fresh egg mass

In egg contaminant studies, it is necessary to calculate egg contaminant concentrations on a fresh wet weight basis and this requires accurate estimates of egg density and egg volume. We show that the inclusion or exclusion of the eggshell can influence egg contaminant concentrations, and we provide estimates of egg density (both with and without the eggshell) and egg-shape coefficients (used to estimate egg volume from egg morphometrics) for American avocet (Recurvirostra americana), black-necked stilt (Himantopus mexicanus), and Forster’s tern (Sterna forsteri). Egg densities (g/cm³) estimated for whole eggs (1.056 ± 0.003) were higher than egg densities estimated for egg contents (1.024 ± 0.001), and were 1.059 ± 0.001 and 1.025 ± 0.001 for avocets, 1.056 ± 0.001 and 1.023 ± 0.001 for stilts, and 1.053 ± 0.002 and 1.025 ± 0.002 for terns. The egg-shape coefficients for egg volume (K _v ) and egg mass (K _w ) also differed depending on whether the eggshell was included (K _v  = 0.491 ± 0.001; K _w  = 0.518 ± 0.001) or excluded (K _v  = 0.493 ± 0.001; K _w  = 0.505 ± 0.001), and varied among species. Although egg contaminant concentrations are rarely meant to include the eggshell, we show that the typical inclusion of the eggshell in egg density and egg volume estimates results in egg contaminant concentrations being underestimated by 6–13 %. Our results demonstrate that the inclusion of the eggshell significantly influences estimates of egg density, egg volume, and fresh egg mass, which leads to egg contaminant concentrations that are biased low. We suggest that egg contaminant concentrations be calculated on a fresh wet weight basis using only internal egg-content densities, volumes, and masses appropriate for the species. For the three waterbirds in our study, these corrected coefficients are 1.024 ± 0.001 for egg density, 0.493 ± 0.001 for K _v , and 0.505 ± 0.001 for K _w .     

CYP2E1 hydroxylation of aniline involves negative cooperativity

CYP2E1 plays a role in the metabolic activation and elimination of aniline, yet there are conflicting reports on its mechanism of action, and hence relevance, in aniline metabolism. Based on our work with similar compounds, we hypothesized that aniline binds two CYP2E1 sites during metabolism resulting in cooperative reaction kinetics and tested this hypothesis through rigorous in vitro studies. The kinetic profile for recombinant CYP2E1 demonstrated significant negative cooperativity based on a fit of data to the Hill equation (n = 0.56). Mechanistically, the data were best explained through a two-binding site cooperative model in which aniline binds with high affinity (K_s = 30 μM) followed by a second weaker binding event (K_ss = 1100 uM) resulting in a threefold increase in the oxidation rate. Binding sites for aniline were confirmed by inhibition studies with 4-methylpyrazole. Inhibitor phenotyping experiments with human liver microsomes validated the central role for CYP2E1 in aniline hydroxylation and indicated minor roles for CYP2A6 and CYP2C9. Importantly, inhibition of minor metabolic pathways resulted in a kinetic profile for microsomal CYP2E1 that replicated the preferred mechanism and parameters observed with the recombinant enzyme. Scaled modeling of in vitro CYP2E1 metabolism of aniline to in vivo clearance, especially at low aniline levels, led to significant deviations from the traditional model based on non-cooperative, Michaelis–Menten kinetics. These findings provide a critical mechanistic perspective on the potential importance of CYP2E1 in the metabolic activation and elimination of aniline as well as the first experimental evidence of a negatively cooperative metabolic reaction catalyzed by CYP2E1.