Suitability of passive integrated transponder tags and a new monitoring technique for at-risk madtoms (Noturus spp.)

Representative indices of population abundance for at-risk species are necessary to inform conservation decision-making. Many madtoms (Noturus spp.) are considered imperiled; however, the efficacy of frequent monitoring efforts has been questioned due to their cryptic and nocturnal behaviors. We systematically evaluated a madtom monitoring tool by (1) evaluating the use of small (8 × 2 mm), surgically implanted 125 kHz passive integrated transponder (PIT) tags for frecklebelly madtom N. munitus and (2) assessing the effectiveness of a radio-frequency identification (RFID)-enhanced artificial cover unit to index madtom abundance. Surgically implanted PIT tags had no apparent influence on madtom survival between 45 and 110 mm total length, and all tags were retained throughout a 21 d laboratory study. In experimental mesocosms, the enhanced cover units confirmed occupancy during nearly all replicates (77.6%), even at extremely low densities (n = 2 madtoms). The enhanced cover units provided representative estimates of madtom relative abundance (p < 0.01), whereas catch per unit effort was not significantly associated with previously validated visual observations (p = 0.12). Although madtom density and the number detected using the enhanced cover units were correlated, the gear was potentially saturated at relatively high densities (~20 fish per mesocosm) when deploying a single unit. In most cases, occupancy was confirmed within 12 h, and nearly half of the individuals were detected within ~72 h. Small PIT tags and RFID-enhanced artificial cover units offer novel opportunities to efficiently describe the ecology and population dynamics of madtoms.

0220 Sleep Deprivation Increases Self-Reported But Not Behavioral Avoidance

Introduction

A common form of emotion regulation is avoidance, in which attention toward negative stimuli results in avoiding (Elliot, 2006). Dysfunctional avoidance is linked to negative outcomes in various forms of psychopathology (Kashdan, Barrios, Forsyth, & Steger, 2006). Sleep challenges have been identified as a mechanism in numerous mental health disorders (Kryger, Roth, & Dement, 2017). These two mechanisms may be related. We hypothesized sleep deprived individuals would demonstrate more avoidance compared to baseline and a sleep as usual group as indexed by lower scores on a behavioral approach task (BAT) and more self-reported avoidance.

Methods

Fifty-two undergraduates (mean age: 18.87, white: 45, female: 35) without mental health disorders, sleep apnea symptoms, or use of medications that may impact sleep or wakefulness were recruited. Participants completed a Cognitive-Behavioral Avoidance Scale (CBAS modified) in which all questions were modified to elucidate present moment avoidance (ex. I would avoid attending social activities) and a BAT in which they were presented with a bedpan made to look and smell dirty. They were asked to complete seven hierarchical levels of engagement ex. (1) touching it with a tissue, (7) touching it with both hands then touching your face. The task ended when a participant declined to complete a step or they completed all seven. They were randomly assigned to 26 hours of sleep deprivation or sleep as usual. Students completed the CBAS modified and the BAT the next morning.

Results

After conducting a mixed ANOVA, there were no significant differences between or within groups in BAT steps completed. There were significant increases in self-reported behavioral social (p &lt; .001) and nonsocial (p &lt; .001), and cognitive nonsocial (p = .006), and social (p = .031) avoidance in the sleep deprivation group.

Conclusion

The study demonstrated a discrepancy between behavioral and self-report avoidance, suggesting a response bias after sleep loss. This investigation illuminates the effects of sleep loss on the transdiagnostic mechanism, avoidance. Note, there are no psychometric data for the modified CBAS. Future work should examine social forms of behavioral avoidance.

Support

This study was conducted using the University of Arkansas SONA system.

Presentation and patterns of late recurrence of olfactory groove meningiomas

The objective of this article is to present the recurrence pattern of olfactory groove meningiomas after surgical resection. Four patients, one female and three males, with surgically resected olfactory groove meningiomas presented with tumor recurrence. All patients underwent resection of an olfactory groove meningioma and later presented with recurrent tumors. The mean age at initial diagnosis was 47 years. All presented initially with vision changes, anosmia, memory dysfunction, and personality changes. Three patients had a preoperative MRI scan. All patients had a craniotomy, with gross total resection achieved in three, and 90% tumor removal achieved in the fourth. Involved dura was coagulated, but not resected, in all cases. Three patients were followed with routine head CT scans postoperatively, and none was followed with MRI scan. The mean time to recurrence was 6 years. Three patients presented with recurrent visual deterioration, and one presented with symptoms of nasal obstruction. Postoperative CT scans failed to document early tumor recurrence, whereas MRI documented tumor recurrence in all patients. Tumor resection and optic nerve decompression improved vision in two patients and stabilized vision in two. Complete resection was not possible because of extensive bony involvement around the anterior clinoid and inferior to the anterior cranial fossa in all cases. Evaluation of four patients with recurrent growth of olfactory groove meningiomas showed the epicenter of recurrence to be inferior to the anterior cranial fossa, with posterior extension involving the optic canals, leading to visual deterioration. This location led to a delay in diagnosis in patients who were followed only with routine CT scans. Initial surgical procedures should include removal of involved dura and bone, and follow-up evaluation should include formal ophthalmologic evaluations and routine head MRI scans.

Calpain Inhibition by α-Ketoamide and Cyclic Hemiacetal Inhibitors Revealed by X-ray Crystallography,

Calpains are intracellular calcium-activated cysteine proteases whose unregulated proteolysis following the loss of calcium homeostasis can lead to acute degeneration during ischemic episodes and trauma, as well as Alzheimer's disease and cataract formation. The determination of the crystal structure of the proteolytic core of mu-calpain (muI-II) in a calcium-bound active conformation has made structure-guided design of active site inhibitors feasible. We present here high-resolution crystal structures of rat muI-II complexed with two reversible calpain-specific inhibitors employing cyclic hemiacetal (SNJ-1715) and alpha-ketoamide (SNJ-1945) chemistries that reveal new details about the interactions of inhibitors with this enzyme. The SNJ-1715 complex confirms that the free aldehyde is the reactive species of the cornea-permeable cyclic hemiacetal. The alpha-ketoamide warhead of SNJ-1945 binds with the hydroxyl group of the tetrahedral adduct pointing toward the catalytic histidine rather than the oxyanion hole. The muI-II-SNJ-1945 complex shows residue Glu261 displaced from the S1' site by the inhibitor, resulting in an extended "open" conformation of the domain II gating loop and an unobstructed S1' site. This conformation offers an additional template for structure-based drug design extending to the primed subsites. An important role for the highly conserved Glu261 is proposed.

Crystal Structures of Calpain–E64 and –Leupeptin Inhibitor Complexes Reveal Mobile Loops Gating the Active Site

The endogenous calpain inhibitor, calpastatin, modulates some patho-physiological aspects of calpain signaling. Excess calpain can escape this inhibition and as well, many calpain isoforms and autolytically generated protease core fragments are not inhibited by calpastatin. There is a need, therefore, to develop specific, cell-permeable calpain inhibitors to block uncontrolled proteolysis and prevent tissue damage during brain and heart ischemia, spinal-cord injury and Alzheimer's diseases. Here, we report the first high-resolution crystal structures of rat mu-calpain protease core complexed with two traditional, low molecular mass inhibitors, leupeptin and E64. These structures show that access to a slightly deeper, but otherwise papain-like active site is gated by two flexible loops. These loops are divergent among the calpain isoforms giving a potential structural basis for substrate/inhibitor selectivity over other papain-like cysteine proteases and between members of the calpain family.

Mode-locked two-photon states

The concept of mode locking in laser is applied to a two-photon state with frequency entanglement. Cavity enhanced parametric down conversion is found to produce exactly such a state. The mode-locked two-photon state exhibits a comblike correlation function. An unbalanced Hong-Ou-Mandel type interferometer is used to measure the correlation function. A revival of the typical interference dip is observed. We will discuss a scheme for engineering of quantum states in time domain.

Allergic response to metabisulfite in lidocaine anesthetic solution

True allergies to local anesthetics are rare. It is common for practitioners to misdiagnose a serious adverse event to local anesthetics as an allergic reaction. The most likely causes for an allergic response are the preservative, antioxidant, or metabolites and not the anesthetic itself. This case report illustrates the need for practitioners to understand the many potential allergens in local anesthetics and to correctly diagnose patients that are truly allergic to the local anesthetic.

Pneumothorax with soft tissue emphysema following abrupt wake-up and self-extubation

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Thoracoscopic sympathectomy for hyperhidrosis palmaris: a periareolar approach

Severe hyperhidrosis palmaris represents a disabling problem for many patients. Thoracoscopic techniques that involve dissection and removal of the upper thoracic sympathetic chain are believed to result in the lowest incidence of recurrent symptoms. However, aside from an axillary incision, an additional upper anterior chest wall approach is usually required. Over the past 2 years, we have used a periareolar incision in eight patients to improve postoperative cosmesis for this benign condition.

Desmoplastic malignant melanoma of the palatal alveolar mucosa: sustained disease-free survival after surgery and postoperative radiotherapy

Aggressive surgical and radiotherapeutic management of a patient with desmoplastic malignant melanoma arising from the mucosa of the oral cavity has resulted in disease-free survival of more than 2(1/2) years after diagnosis. This case represents only the tenth reported instance of desmoplastic malignant melanoma arising from the oral cavity and only the third for which survival has exceeded 2 years. Details of the clinical, histopathologic, and therapeutic features of the case are provided to augment the paucity of literature available to clinicians managing this rare disease.

Dehydroepiandrosterone and dihydrotestosterone recognition by human estrogenic 17beta-hydroxysteroid dehydrogenase. C-18/c-19 steroid discrimination and enzyme-induced strain

Steroid hormones share a very similar structure, but they behave distinctly. We present structures of human estrogenic 17beta-hydroxysteroid dehydrogenase (17beta-HSD1) complexes with dehydroepiandrosterone (DHEA) and dihydrotestosterone (DHT), providing the first pictures to date of DHEA and DHT bound to a protein. Comparisons of these structures with that of the enzyme complexed with the most potent estrogen, estradiol, revealed the structural basis and general model for sex hormone recognition and discrimination. Although the binding cavity is almost entirely composed of hydrophobic residues that can make only nonspecific interactions, the arrangement of residues is highly complementary to that of the estrogenic substrate. Relatively small changes in the shape of the steroid hormone can significantly affect the binding affinity and specificity. The K(m) of estrone is more than 1000-fold lower than that of DHEA and the K(m) of estradiol is about 10 times lower than that of DHT. The structures suggest that Leu-149 is the primary contributor to the discrimination of C-19 steroids and estrogens by 17beta-HSD1. The critical role of Leu-149 has been well confirmed by site-directed mutagenesis experiments, as the Leu-149 --> Val variant showed a significantly decreased K(m) for C-19 steroids while losing discrimination between estrogens and C-19 steroids. The electron density of DHEA also revealed a distortion of its 17-ketone toward a beta-oriented form, which approaches the transition-state conformation for DHEA reduction.

3D-structure of human estrogenic 17beta-HSD1: binding with various steroids

Human estrogenic dehydrogenase (17beta-HSD1) catalyses the last step in the biosynthesis of the active estrogens that stimulate the proliferation of breast cancer cells. While the primary substrate for the enzyme is estrone, the enzyme has some activity for the non-estrogenic substrates. To better understand the structure function relationships of 17beta-HSD1 and to provide a better ground for the design of inhibitors, we have determined the crystal structures of 17beta-HSD1 in complex with different steroids. The structure of the complex of estradiol with the enzyme determined previously (Azzi et al., Nature Structural Biology 3, 665-668) showed that the narrow active site was highly complementary to the substrate. The substrate specificity is due to a combination of hydrogen bonding and hydrophobic interactions between the steroid and the enzyme binding pocket. We have now determined structures of 17beta-HSD1 in complex with dihydrotestosterone and 20alpha-OH-progesterone. In the case of the C19 androgen, several residues within the enzyme active site make some small adjustments to accommodate the increased bulk of the substrate. In addition, the C19 steroids bind in a slightly different position from estradiol with shifts in positions of up to 1.4 A. The altered binding position avoids unfavorable steric interactions between Leu 149 and the C19 methyl group (Han et al., unpublished). The known kinetic parameters for these substrates can be rationalized in light of the structures presented. These results give evidence for the structural basis of steroid recognition by 17beta-HSD1 and throw light on the design of new inhibitors for this pivotal steroid enzyme.

Two non-reactive ternary complexes of estrogenic 17beta-hydroxysteroid dehydrogenase: crystallization and preliminary structural analysis

Human estrogenic 17beta-hydroxysteroid dehydrogenase (17beta-HSD1, EC1.1.1.62) is an important enzyme that catalyses the last step of active estrogen formation. 17Beta-HSD1 plays a key role in the proliferation of breast cancer cells. The three-dimensional structures of this enzyme and of the enzyme-estradiol complex have been solved (Zhu et al., 1993, J. Mol. Biol. 234:242; Ghosh et al., 1995, Structure 3:503; Azzi et al., 1996, Nature Struct. Biol. 3:665). The determination of the non-reactive ternary complex structure, which could mimic the transition state, constitutes a further critical step toward the rational design of inhibitors for this enzyme (Ghosh et al. 1995, Structure 3:503; Penning, 1996, Endocrine-Related Cancer, 3:41). To further study the transition state, two non-reactive ternary complexes, 17beta-HSD1-EM519-NADP+ and 17beta-HSD1-EM553-NADP+ were crystallized using combined methods of soaking and co-crystallization. Although they belong to the same C2 space group, they have different unit cells, with a = 155.59 A, b = 42.82 A, c = 121.15 A, beta = 128.5 degrees for 17beta-HSD1-EM519-NADP+, and a = 124.01 A, b = 45.16 A, c = 61.40 A, beta = 99.2 degrees for 17beta-HSD1-EM553-NADP+, respectively. Our preliminary results revealed that the inhibitors interact differently with the enzyme than do the natural substrates.

Reduction in morbidity after iliac crest bone harvesting: the concept of preemptive analgesia

The technique of autologous iliac crest bone grafting is an important aspect in the treatment of patients with cleft lip, cleft palate, and other craniofacial disorders. In patients with cleft lip and palate, the alveolar bone graft creates a continuous maxillary arch, closes the oronasal fistula, provides bony support for facial soft tissue and teeth, and facilitates orthodontic movement of teeth. The anatomic and physiologic benefits of this and similar autologous bone graft procedures are apparent. However, pain at the donor site represents a significant source of postoperative morbidity. This study was conducted to evaluate postoperative pain and the ability to perform activities of daily living after bupivacaine infiltration to iliac crest donor sites. Thirty-four alveolar bone graft patients (18 females, 16 males) treated at two teaching hospitals were included in the study. Eleven of the patients received intraoperative bupivacaine at the iliac donor site and 23 did not. A questionnaire was returned by all participants, and telephone follow-up was obtained. Responses to postoperative pain, time period to ambulation, and ability to perform activities of daily living were evaluated. Patients who received postoperative bupivacaine experienced delayed onset of postoperative pain, earlier ambulation, and were able to return to normal daily activity in a shorter period of time than those patients who received no local anesthesia. The concept of preemptive analgesia and its application to craniofacial surgery is discussed.

Discharge planning and home follow-up of the elderly patient with heart failure

Older adults with heart failure have extensive and complex care needs. This article presents a framework for assessment and intervention with this fragile patient group. Comprehensive assessment of elders with heart failure includes gathering information about care, advocacy, and knowledge needs. Nursing interventions are focused on providing direct care, counseling, teaching, and advocacy. The unique role of the advanced practice nurse in discharge planning and home follow-up of elders with heart failure is emphasized.

Comparison of oral chloral hydrate with intramuscular ketamine, meperidine, and promethazine for pediatric sedation--preliminary report

Fifteen consecutive pediatric patients ranging from 3 to 5 years old were selected to receive one of three sedative/hypnotic techniques. Group 1 received oral chloral hydrate 50 mg/kg, and groups 2 and 3 received intramuscular ketamine 2 mg/kg and 3 mg/kg, respectively. In addition to ketamine, patients in groups 2 and 3 received transmucosal intramuscular injections of meperidine and promethazine into the masseter muscle. Sedation for the satisfactory completion of restorative dentistry was obtained for over 40 min on average in the chloral hydrate group, but completion of dental surgery longer than 40 min was achieved in groups 2 and 3 only by intravenous supplements of ketamine.

Crystallization and preliminary X-ray diffraction analysis of arginyl-tRNA synthetase from Escherichia coli

Arginyl-tRNA Synthetase, a class I aminoacyl tRNA synthetase playing a crucial role in protein biosynthesis, has been crystallized for the first time. Polyethylene glycol (PEG) was used as a precipitant, and the crystallization proceeded at pH 6.5. These single crystals diffracted to 2.8 A with a rotating anode X-ray source and R-axis IIc image plate detector. They have an orthorhombic space group P2(1)2(1)2 with unit cell parameters of a = 251.51 A, b = 53.12 A, and c = 52.35 A. A complete native data set has been collected at 3.1 A resolution for these crystals.

A comparison of cardiac rate-pressure product and pressure-rate quotient with Holter monitoring in patients with hypertension and cardiovascular disease: a follow-up report

OBJECTIVES

The purpose of this study was to evaluate patients with hypertension or cardiovascular disease, or both, for myocardial ischemia and cardiac arrhythmias while undergoing minor oral surgery.

STUDY DESIGN

Sixteen patients were studied with noninvasive monitoring including heart rate, systolic, diastolic, and mean arterial blood pressure to calculate rate-pressure product (systolic blood pressure multiplied by heart rate) and pressure-rate quotient (mean arterial pressure divided by heart rate). These calculated measures were compared with the incidence of cardiac arrhythmias and ST segment depression recorded on a continuous Holter monitoring system.

RESULTS

Nine of 16 (56%) developed supraventricular or ventricular ectopy during dental extractions or minor preprosthetic surgery performed with local anesthesia 2% xylocaine with 1/100,000 epinephrine dilution. Three of the nine patients who experienced these arrhythmias had coincident abnormal rate pressure product and pressure-rate quotient values. None of these patients exhibited ST-T wave changes suggestive of myocardial ischemia. Atrial or ventricular ectopy suggests that myocardial irritability was more likely to occur than ischemia as measured by Holter monitoring and compared with abnormal rate pressure product and pressure-rate quotient values recorded.

Spectrophotometric studies of complexation of C60 with aromatic hydrocarbons

The equilibrium constants for complexation of C60 with naphthalene, phenanthrene and pyrene in toluene have been determined by UV visible spectroscopy. The magnitude of the equilibrium constants was found to increase with decreasing ionization potential of the donor. Values for complexation enthalpy have been determined for the first time for C60/aromatic hydrocarbons. Well-defined charge transfer (C-T) bands have been observed for complexes of C60 with a variety of aromatic hydrocarbons, with C-T band maxima moving to higher frequency with increasing donor ionization potential.

Intravenous sedation in 200 geriatric patients undergoing office oral surgery

Two hundred geriatric patients ranging from age 65 to 92 yr (mean age 72 yr) were evaluated for office oral surgery and intravenous sedation. Surgical time ranged from 6 to 129 min. Monitored anesthesia care was utilized for the administration of fentanyl, midazolam or diazepam, and methohexital. No serious complications were seen and no patients were hospitalized.

Studies on the three-dimensional structure of estrogenic 17 beta-hydroxysteroid dehydrogenase

The structure-function relationship of the estrogenic 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD1), a pivotal enzyme in the synthesis of active sex hormones, has been studied via protein chemistry and crystallography. A highly active and homogeneous 17 beta-HSD1 was prepared with a rapid purification from human placenta. We then characterized the native and expressed enzyme, and concluded, for the first time, that 17 beta-HSD1 is formed by two identical subunits. The enzyme was also overproduced in insect cells with a baculovirus expression system. The highly active 17 beta-HSD1 preparation was successfully crystallized in the presence of NADP-, polyethylene glycol, beta-octylglucoside and glycerol, resulting in the first diffraction quality crystals of any steroid-converting enzyme from a human source. The three-dimensional structure of 17 beta-HSD1 was determined at 2.2 A resolution, showing that the overall structure of the enzyme is similar to the other enzymes in the short-chain dehydrogenase family, with a conserved Tyr-X-X-X-Lys sequence and a serine residue in the active site. It is distinguished from the other known structures reported for short-chain dehydrogenases by the insertion of two helix-turn-helix motifs that appear to govern membrane association and substrate specificity [corrected]. More recently, the complex of 17 beta-HSD1 with estradiol has been successfully crystallized and its structure determined. The latter demonstrates detailed information of the interactions between the substrate and residues Ser142, Tyr155, His221 and Glu282 of the enzyme. These interactions and the complementarity of the substrate with the hydrophobic binding pocket make critical contributions to the enzyme specificity. The above results provide a strong basis for the design of potent inhibitors of this pivotal steroid dehydrogenase.

Interleukin-12 and B7.1 co-stimulation cooperate in the induction of effective antitumor immunity and therapy of established tumors

Interleukin-12 (IL-12) promotes specific and long-lasting anti-tumor immunity mediated by T cells in a variety of murine tumor models. IL-12 also synergizes with B7.1 (CD80) co-stimulation to induce proliferation and cytokine production by both human and murine T cells in vitro. We evaluated the combined anti-tumor efficacy of IL-12 and B7.1 gene delivery in two apparently poorly immunogenic tumor models (TS/A and MCA207). In both of these models, expression of B7.1 and production of IL-12 in the inoculum led to improved anti-tumor immunity, with up to 80% long-term tumor-free animals (vs 0-20% of mice remaining tumor free when inoculated with either B7.1- or IL-12-transfected tumors alone). Tumor-free mice were capable of rejecting a subsequent rechallenge with the wild-type tumor in 66% of the cases. Cooperativity was dependent upon the level of IL-12 secreted by engineered cells. IL-12 delivery required B7 expression of therapeutic effects to be observed in these models. Vaccines provided at a site distal to a control, non-transfected tumor slowed (TS/A) or abrogated (MCA207) the progression of wild-type tumors. The synergistic anti-tumor effects associated with combined application of B7.1- and IL-12-transfected tumors were partially negated by systemic administration of the CD28-B7.1/B7.2 antagonist CTLA4-Ig or by inoculation with neutralizing antibodies directed against murine interferon-gamma or tumor necrosis factor-alpha, two cytokines elicited in response to IL-12 stimulation. These data support the potential clinical utility of combined gene therapy using IL-12- and B7.1-engineered autologous cells (tumor or fibroblasts) as a vaccine to elicit specific anti-tumor immunity.

A resume or curriculum vitae for success

Nurses who are searching for new positions can enhance their job employment potential with well-written resumes. Scholarship and award recognition also can be improved by creating well-written resumes and/or curricula vitae. Appropriate cover letters effectively introduce nurses to employers or review committees. This article presents a few basic suggestions that can simplify the creation of any of these documents and help nurses produce a quality product.

Abnormally high pKa of an active-site glutamic acid residue in Bacillus circulans xylanase. The role of electrostatic interactions

The active site of Bacillus circulans xylanase (1,4-beta-D-xylanohydrolase, EC 3.2.1.8) contains two glutamic acid residues, Glu78 and Glu172, which are crucial for the catalytic activity of the enzyme. Fourier-transform infrared spectroscopy was used to determine the ionization state of these residues as a function of pH. For the wild-type enzyme, titration of one of the carboxylate groups occurs at pH 6.8. This titration is absent in the Glu78-->Gln and Glu172-->Gln variants of the enzyme. This, together with crystallographic data, indicates that Glu172 has an abnormally high pKa of 6.8, caused largely by electrostatic interactions of this residue with the proximal Glu78. Differential scanning calorimetry experiments with the wild-type xylanase and a number of its mutants have shown that the presence of two nearby carboxyl groups results in a pH-dependent destabilization of the protein structure.

A comparison of cardiac rate-pressure product and pressure-rate quotient in healthy and medically compromised patients

Healthy and medically compromised patients were studied to compare blood pressure and heart rate changes in response to stress of routine dental extractions performed while they were under local anesthesia. Thirty-nine patients divided into American Society of Anesthesiologists (ASA) I and II groups were noninvasively monitored every 5 minutes. Systolic, diastolic, and mean arterial pressures and heart rate were recorded. Rate pressure products (RPP) and pressure rate (PRQ) quotients were calculated and compared in each group. Significant results were measures of RPP greater than 12,000 and PRQ less than one. Of the 24 patients in the ASA I category, 50% demonstrated elevated RPP values, but only two of 24 had coincidental PRQ abnormalities. Of the 15 patients in the ASA II category, 80% demonstrated elevated RPP values, but two of 15 had coincidental PRQ abnormalities. Patients in the ASA II category had a higher incidence of RPP and PRQ abnormalities, as was expected. However, it is not known which of these two measures is a more sensitive indicator of increased risk associated with stimulation of the sympathetic-adrenergic axis during oral surgery performed with patients under local anesthesia. Correlation studies with continuous Holter monitoring for ST-T wave changes on electrocardiography are forthcoming.

Past and current drug use among Canadian correctional officers

Current and past drug use was assessed in a sample of 77 Canadian correctional officers working in two medium-security penitentiaries. 58% of correctional officers indicated past illicit drug use. This compares with 20% of Canadians who indicate illicit drug use. Correctional officers were more likely than the general population to have used marijuana and cocaine.

A survey of drinking behaviors of Canadian correctional officers

77 correctional officers from two Canadian medium security penitentiaries were surveyed concerning their use of alcohol. 94% reported drinking at least once during the preceding year. 45 men consumed alcohol more frequently than the 29 women, more often felt obligated to drink at social gatherings, and were more likely to believe that drinkers do not suffer health problems related to their drinking. Although other studies have indicated correctional officers have special problems with drinking, more similarities with the general population than differences were found in the present drinking patterns.

An unusual case of sympathetically maintained facial pain complicated by telangiectasia

A 32-year-old woman with a history of maxillary sinusitis, multiple surgical interventions in the maxillary sinus, and a hyperalgesic, erythematous skin lesion in her left infraorbital area, had severe burning pain in the left face. The dermal lesion was diagnosed as atypical telangiectasia and the sinus pathoses determined to be unrelated to her symptoms. Two diagnostic stellate ganglion blocks were performed with concurrent bilateral monitoring of blood flow in the infraorbital skin. Blood flow was significantly increased in the painful erythematous patch although no significant change in flow occurred in the unaffected contralateral skin. The changes correlated to patient's relief from pain. The patient's symptoms were subsequently controlled with an oral sympatholytic agent. This article demonstrates the usefulness of laser doppler flowmetry to establish the diagnosis of sympathetically maintained facial pain despite several confounding conditions and supports the theory that sympathetically maintained pain involves altered function of alpha-1 adrenoreceptors.

Thermostabilization of the Bacillus circulans xylanase by the introduction of disulfide bonds

The thermostability of the 20 396 Da Bacillus circulans xylanase was increased by the introduction of both intra- and intermolecular disulfide bridges by site-directed mutagenesis. Based on the 3-D structure of the enzyme, sites were chosen where favourable geometry for a bridge existed; in one case, to obtain favourable geometry additional mutations around the cysteine sites were designed by computer modelling. The disulfide bonds introduced into the xylanase were mostly buried and, in the absence of protein denaturants, relatively insensitive to reduction by dithiothreitol. The mutant proteins were examined for residual enzymatic activity after various thermal treatments, and were assayed for enzymatic activity at elevated temperatures to assess their productivity. We have examined one of these mutants by X-ray crystallography. All of the disulfide bond designs tested increased the thermostability of the B. circulans xylanase, but not all enhanced the activity of the enzyme at elevated temperatures.

Gender and age differences in the drinking behaviors of university students

A sample of 457 university students were queried concerning their use of alcohol. The majority (90%) of students reported drinking at least once over the past year, with men drinking more often. Age differences were noted, with older students (Mdn = 32.0 yr. vs 19.0 yr.) more likely to report drinking 4 to 6 times per week. Women generally had healthier attitudes concerning alcohol consumption, e.g., more likely to try to prevent a friend from driving after drinking, pay for use of a taxi, or have a designated driver. Men were more likely to indicate that it is socially acceptable to be intoxicated occasionally and also that most drinkers do not suffer health problems as a result of their drinking. The present study indicates a need to educate university students about the effects of alcohol with a particular emphasis needed for male students.

Hemorrhagic dilation of the fourth ventricle: an ominous predictor

Very little is known about the effect of computerized tomography (CT)-documented fourth intraventricular hemorrhage (IVH). An analysis of 50 patients with CT-documented fourth IVH treated between 1987 and 1992 is presented. The various etiologies included intraparenchymal hemorrhage with secondary fourth IVH (19 cases), spontaneous subarachnoid hemorrhage (18 cases), spontaneous IVH (seven cases), and trauma (six cases). Overall, 28 patients (56%) had hemorrhagic dilation of the fourth ventricle and all 28 suffered brain death, despite aggressive therapy in 79% of cases. Twenty-two patients (44%) had fourth IVH without dilation; of these, nine (41%) died and 13 (59%) experienced functional survival, despite aggressive care in 90% of cases. The survival rate was significantly worse for patients with dilation of the fourth ventricle (p < 0.01, chi-squared test). Of the 28 patients with fourth IVH associated with dilation, 25 (89%) had diffuse clot, involving the lateral and third ventricles as well, and three (11%) had isolated fourth IVH. Of the 22 patients with fourth IVH and no dilation, 13 (59%) had diffuse IVH (eight of these died and five had functional recovery) and nine (41%) had isolated fourth IVH (one died and eight had functional recovery). Diffuse ventricular clot was associated with an increased mortality rate for patients with fourth IVH and no dilation (p < 0.05). Of the 28 patients with fourth IVH associated with dilation, 24 (86%) presented with a Glasgow Coma Scale (GCS) score of 3 or 4, one with a GCS score of 6, and three with a GCS score of 13 to 15; all 28 died. For the 22 patients with fourth IVH and no dilation, nine presented with a GCS score of 3 to 5 (eight died and one had functional recovery), three had a GCS score of 6 to 8 (all three had functional survival), two had a GCS score of 9 to 12 (both had functional survival), and eight had a GCS score of 13 to 15 (one died and seven had functional survival). There was a greater chance of higher GCS scores in patients with fourth IVH and no hemorrhagic dilation (p < 0.01). Logistic regression multivariate analysis showed hemorrhagic fourth ventricular dilation to be the most significant outcome predictor (p = 0.0001), followed by GCS score (p = 0.007) and the presence of diffuse IVH (p = 0.0279).

Mutational and crystallographic analyses of the active site residues of the Bacillus circulans xylanase

Using site-directed mutagenesis we have investigated the catalytic residues in a xylanase from Bacillus circulans. Analysis of the mutants E78D and E172D indicated that mutations in these conserved residues do not grossly alter the structure of the enzyme and that these residues participate in the catalytic mechanism. We have now determined the crystal structure of an enzyme-substrate complex to 108 A resolution using a catalytically incompetent mutant (E172C). In addition to the catalytic residues, Glu 78 and Glu 172, we have identified 2 tyrosine residues, Tyr 69 and Tyr 80, which likely function in substrate binding, and an arginine residue, Arg 112, which plays an important role in the active site of this enzyme. On the basis of our work we would propose that Glu 78 is the nucleophile and that Glu 172 is the acid-base catalyst in the reaction.

Respiratory effects of a balanced anesthetic technique--revisited fifteen years later

Five hundred and fifty patients underwent general anesthesia with fentanyl, diazepam, and methohexital. Forty-seven (8.5%) developed signs of hypoventilation or airway obstruction. Arterial blood gas analysis revealed mild hypoxemia in three of the 47 cases and mild hypercarbia in six. Airway obstruction was more predictive of abnormal blood gas values than was hypoventilation.

26-10 Fab-digoxin complex: affinity and specificity due to surface complementarity

We have determined the three-dimensional structures of the antigen-binding fragment of the anti-digoxin monoclonal antibody 26-10 in the uncomplexed state at 2.7 A resolution and as a complex with digoxin at 2.5 A resolution. Neither the antibody nor digoxin undergoes any significant conformational changes upon forming the complex. Digoxin interacts primarily with the antibody heavy chain and is oriented such that the carbohydrate groups are exposed to solvent and the lactone ring is buried in a deep pocket at the bottom of the combining site. Despite extensive interactions between antibody and antigen, no hydrogen bonds or salt links are formed between 26-10 and digoxin. Thus the 26-10-digoxin complex is unique among the known three-dimensional structures of antibody-antigen complexes in that specificity and high affinity arise primarily from shape complementarity.

Site specificity of glycation of horse liver alcohol dehydrogenase in vitro

The site specificity of in vitro glycation of horse liver alcohol dehydrogenase (ADH) was examined and the results interpreted in terms of structural features of the enzyme molecule. In a phosphate buffer solution, glycation occurred at Lys231 (the main site of glycation in vivo), at Lys228 (which is not glycated in vivo), and at several unidentified positions. Buffer anions or NAD+ did not affect glycation of Lys231; this supported our hypothesis that the base catalyst which removes a proton from carbon 2 of a Lys231-attached aldimine is part of the ADH molecule [Shilton, B.H. & Walton, D.J. (1991) J. Biol. Chem. 266, 5587-5592]. Use of a molecular modelling programme indicated that this catalyst was likely to be the imidazole group of His348, exerting its effect through the hydroxyl of Thr347. Glycation of Lys228 occurred only in the presence of phosphate; in this case molecular modelling showed that the base catalyst could be a phosphate ion, bound to ADH at a positive region of the coenzyme binding site. NAD+ inhibited glycation of Lys228 by binding to the enzyme and restricting access to glucose.

Age, gender, and location as factors in permission to smoke among university students

A sample of 457 (177 men, 280 women) university undergraduates were surveyed on their use of tobacco and locations where smokers have been told not to smoke. 21% of the students (20% of men, 22% of women) surveyed indicated that they smoked. Age differences were noted, with the older men and women more likely to use tobacco than their younger peers. In general, men were more likely than women to be asked not to smoke. The large number of smokers who have been asked not to smoke may indicate an increase in social pressure to reduce the use of tobacco in public.

Perceived level of stress among university undergraduate students in Edmonton, Canada

A sample of 457 (177 men, 280 women) undergraduate students were surveyed regarding perceived level of stress. Women were more likely than men to report an unacceptable stress level. To reduce stress, women were more likely to indicate a need to limit commitments, exercise, and worry less. Reasons for not reducing stress were lack of time and lack of self-discipline, both of which were reported significantly more often by women. The present data suggest health education interventions are needed to assist students in coping with the stress they experience.

Drug use among university undergraduate students

A sample of 457 undergraduate university students were surveyed to assess their current use of illicit drugs. Such information is to be used as a baseline to examine the effectiveness of drug prevention programs designed for this population. Marijuana was the most common illicit drug used among these students, and men were significantly more likely to report use. Age differences were noted; older students (age greater than or equal to 22 yr.) were more likely to report drug use than those students under 22 years of age. The age differences suggest that there may be a shift away from drug use among the younger students. The low over-all rate of drug use may make difficult the evaluation of prevention programs.

Temporomandibular joint after meniscoplasty: appearance at MR imaging

Twenty-five temporomandibular joints (TMJs) were studied in 20 patients who had undergone meniscoplasty. In all patients, preoperative magnetic resonance (MR) images showed anteriorly dislocated disks; all patients underwent a similar postoperative MR examination an average of 6 months after surgery. The results of these studies were correlated with clinical results of surgery, which were classified as poor, fair, good, or excellent at follow-up MR imaging. In 10 TMJs (eight patients [40%]) the clinical results were excellent or good; in 15 TMJs (12 patients [60%]), fair or poor. The position of the disk relative to its preoperative position was a good discriminator in determination of the clinical success of meniscoplasty. After surgery, in all patients with good or excellent results, the disks appeared to be in a normal or an improved position compared with that prior to surgery; in those with poor or fair results, the TMJs had anteriorly dislocated disks that showed no improvement.

Auriculotemporal syndrome following the preauricular approach to temporomandibular joint surgery

Forty-seven joints in 28 patients were examined 4 months to 10 years after temporomandibular joint (TMJ) surgery via a modified preauricular approach. Many patients had undergone multiple procedures. None of the patients had any subjective or objective evidence of auriculotemporal syndrome (ATS), although patients in previous studies with more extensive incisions have demonstrated ATS. It was concluded that ATS is an unlikely complication following TMJ surgery. A small incision without an oblique superior extension may further reduce the risk.

Clinical, radiographic, and pathological features of symptomatic Rathke's cleft cysts

The clinical, radiographic, and pathological findings in 155 patients with symptomatic Rathke's cleft cysts are discussed. Eight patients were treated by the authors and 147 were collected in a review of the literature. This lesion occurred more often in female than male patients by a 2:1 margin, and the mean age at presentation was 38 years. The average patient had been symptomatic for nearly 3 years at the time of treatment, with the most common symptoms and signs being pituitary dysfunction, visual disturbances, and headaches. Affected children generally were pituitary dwarfs. The sella was enlarged in 80% of cases, and the cyst was situated in both an intrasellar and a suprasellar location in 71%. Computerized tomography revealed a low-density cystic mass with capsular enhancement in one-half of the cases. A variable appearance was seen with magnetic resonance imaging. Partial excision and drainage of the cyst by the transsphenoidal approach is the recommended treatment, as the recurrence rate is low. Most symptoms and signs improved or resolved following surgery with the exception of hypopituitarism and diabetes insipidus. The cyst lining was usually composed of ciliated cuboidal or columnar epithelium. Theories as to the origin of Rathke's cleft cysts are also discussed.

Contemporary management of neurofibromatosis

The neurofibromatoses are two distinct entities with different genetic origins. The phenotypic expressions and required treatments are different. The devastating nature of neurofibromatosis-2 may be more effectively controlled through the application of advanced imaging techniques and contemporary neurotologic procedures. The most common manifestation of neurofibromatosis-2 is that of bilateral acoustic neuromas. The eventual total bilateral sensorineural deafness associated with this condition can be obviated in selected cases if the diagnosis is established early. Follow-up data are reported for three patients in whom hearing was preserved in at least one ear. When removal with hearing preservation is not possible, subtotal tumor removal with decompression of the internal auditory canals may delay progression of hearing loss. A new approach to tumors of the pterygomaxillary fossa that have extended to the middle cranial fossa has been successfully applied and is described.