Certification testing as an acute naturalistic stressor for disaster dog handlers

USA Federal Disaster Canine Teams, consisting of a handler and a dog, are essential for locating survivors following a disaster. Certification, required by the Federal Emergency Management Agency Urban Search and Rescue organization, requires two successful mock searches. Confirmation of the certification testing process as an acute stressor might offer further opportunities to consider stress effects on handlers and dogs in a controlled environment. This study used a pretest-posttest design to evaluate relationships between salivary hormone concentrations (cortisol and testosterone) and subjective stress ratings in handlers and controls, handler assessments of stress in their dogs, and posttest temperature and pulse rate in dogs. Posttest, both subjective stress ratings and salivary cortisol concentration were higher in handlers than controls with both correlated to handlers' assessment of stress in their dogs. Handlers' posttest salivary cortisol concentration was associated with posttest dog pulse and temperature. Posttest cortisol concentration was lower in handlers who were successfully certified compared with those who failed, and was also lower in handlers whose primary occupation was "firefighter". Salivary testosterone concentrations increased from pretest to posttest in handlers but decreased in controls, and higher posttest handler testosterone concentration was negatively associated with posttest dog pulse rate. These findings confirm certification testing as an acute stressor, suggest a relationship between stress and performance moderated by occupation, and demonstrate an interaction between handler stress and dog physiological responses. This certification testing offers a controlled environment for targeted evaluation of effects of an acute naturalistic stressor on disaster dog handlers and dogs.

12C+12C fusion reactions near the Gamow energy

The fusion reactions 12C(12C,alpha)20Ne and 12C(12C,p)23Na have been studied from E=2.10 to 4.75 MeV by gamma-ray spectroscopy using a C target with ultralow hydrogen contamination. The deduced astrophysical S(E)* factor exhibits new resonances at E< or =3.0 MeV, in particular, a strong resonance at E=2.14 MeV, which lies at the high-energy tail of the Gamow peak. The resonance increases the present nonresonant reaction rate of the alpha channel by a factor of 5 near T=8x10(8) K. Because of the resonance structure, extrapolation to the Gamow energy EG=1.5 MeV is quite uncertain. An experimental approach based on an underground accelerator placed in a salt mine in combination with a high efficiency detection setup could provide data over the full EG energy range.

[Primary headache in childhood and adolescence. The association between changes in family interaction patterns and therapy success--a pilot study]

INTRODUCTION

Family interaction patterns are often involved in diseases and disorders in childhood and adolescence in complex ways (e.g in their development, maintenance and cure). The present study deals with the role of family factors in success in a pediatric headache therapy consisting of group hypnotherapy and systemic family consultation.

METHODS

A sample of 12 outpatients, aged 9-15 years and balanced in sex, is investigated. Patients were diagnosed by IHS-criteria. Global symptom strain was measured by numeric rating scale (NRS) at pre-appointment and at 9-months follow-up appointment. Also family interaction patterns associated with the occurrence of headache symptoms were measured by content analysis.

RESULTS

We found an association between changes in two independently assessed variables: global symptom strain and family interaction patterns. (1) When patients assessed global symptom strain as unchanged, family interaction patterns associated with headache were also assessed as unchanged by observers; (2) when patients assessed their global symptom strain as positively changed, family interaction pattern associated with headache were also assessed as positively changed by observers.

CONCLUSION

These data provide empirical evidence about when to include family in treatment of pediatric headache: when rigid family interaction patterns associated with headache complicate a symptom change.

["If I were the department head in this case..."--interventional interview with patients and co-workers of a psychiatric department]

OBJECTIVE

How can patients and staff participate in redesigning psychiatric procedures through survey research?

METHODS

Using interviews with circular-hypothetical questioning, 58 patients and 30 staff members of a psychiatric department of a general hospital were interviewed about their preferences for change and continuity in clinical practices, and results were feedbacked.

RESULTS

Suggestions for change concerning doctors' rounds, the integration of music therapy, the number of individual sessions and the postdischarge care initiated real change.

CONCLUSIONS

Surveys planned cooperatively with staff and without competitive benchmarking can be effective tools in psychiatric organization development.

Validation of a new noncontact catheter system for electroanatomic mapping of left ventricular endocardium

BACKGROUND

Improvements in cardiac mapping are required to advance our understanding and treatment of arrhythmias. This study validated a new noncontact multielectrode array catheter and accompanying analysis system to provide electroanatomic mapping of the entire left ventricular (LV) endocardium during a single beat.

METHODS AND RESULTS

A 9F 64-electrode balloon array catheter with an inflated size of 1.8x4.6 cm was used to simultaneously record electrical potentials generated by the heart and locate a standard electrophysiology (EP) catheter within the same chamber. By use of the recorded location of the EP-catheter tip, LV geometry was determined. Array potentials served as inputs to a high-order boundary-element method to produce 3360 potential points on the endocardial surface translatable into electrograms or color-coded activation maps. Three methods of validation were used: (1) driven electrodes in an in vitro tank were located; (2) waveforms generated from the array catheter were compared with catheter contact waveforms in canine LV; and (3) sites of local LV endocardial activation were located and marked with radiofrequency lesions. Tank testing located a driven electrode to within 2.33+/-0.44 mm. Correlation of timing and morphology of computed versus contact electrograms was 0.966. Radiofrequency lesions marked 17 endocardial pacing sites to within 4.0+/-3.2 mm.

CONCLUSIONS

This new system provides anatomically accurate endocardial isopotential mapping during a single cardiac cycle. The locator component enabled placement of a separate EP catheter to any site within the mapped chamber.

"Scientific basis of wound closure techniques." Evaluation of a new training program

A formal training program in wound repair entitled "Scientific Basis of Wound Closure Techniques" has been developed and is accredited by the Dannemiller Memorial Educational Foundation. This course is now available at no cost to medical schools, residencies, and continuing education programs for graduate physicians. A manual with its complementing videotape allow the course participant to gain the necessary psychomotor skills to repair wounds. Evaluation of the course taken by third-year medical students and first-year residents demonstrates a high level of satisfaction. After instituting the course, there was a noticeable change in the types of barriers, instruments, and wound closure techniques practiced in our emergency department.

Sheets, 3-D strands, trimensional (3-D) shapes, and sutures of either reinforced or nonreinforced expanded polytetrafluoroethylene for facial soft-tissue suspension, augmentation, and reconstruction

Expanded polytetrafluoroethylene (e-PTFE) is an expanded, fibrillated polymer recently used in facial reconstruction. This material is produced in two compositions: pure e-PTFE, for sheets, 3-D strands, and sutures; and e-PTFE reinforced with fluorinated ethylene propylene (FEP) for sheets and trimensional (3-D) shapes. This material has been used for facial soft-tissue suspension, augmentation, and reconstruction and has demonstrated advantages over autologous grafts due to its optimal tissue incorporation, low infection risk, and biological inertness.

Technical considerations in the use of polymethylmethacrylate in cranioplasty

Polymethylmethacrylate (PMMA) is a self-curing acrylic resin that can be used in the repair of cranial defects. It is available in three forms: PMMA without mesh, PMMA reinforced with mesh, and PMMA preformed to fit a defect. In cranioplasty, the size and location of the defects provide the selection criteria for the use of PMMA. PMMA without mesh is ideal for small defects (5 cm2-15 cm2). PMMA reinforced with mesh is used for moderate sized defects (16 cm2-49 cm2). For very large defects (> or = 50 cm2), a CT scan guided mold is recommended because it provides the ideal contour and shape that simulates the normal skull.

[Systemic counseling in dyssocial behavior, delinquency and violence]

The article summarizes characteristic interactive patterns in social systems concerned with acting-out, delinquent and violent behavior in adolescents. As a consequence, it develops a multi systems consultation approach. Core features of such an approach are the clarification of service demands and of available resources, the development of new and sometimes unusual cooperation, positive connotation of distrust and chaos, and an intelligent questioning of the usefulness of ones owen professional activities. At the end the question is raised, whether and in which ways educators, physicians and psychologists could involve themselves in political decision processes about media, work and welfare legislation, which influence their adolescent clients life situation.

Prognostic significance of multiple genetic lesions on chromosomes 19, 10, and 17 in oligodendrogliomas

Patients diagnosed with oligodendrogliomas/oligoastrocytomas and with somatic loss of genes on chromosome 19q13.2-q13.3 survived for >5-6 years, a survival period typical of the tumors of oligodendroglial origin. One patient with oligoastrocytoma, harboring allelic loss on chromosome 10p in the tumor DNA, had a recurrence five years later with progression to anaplastic astrocytoma. However, another patient with oligoastrocytoma, whose tumor suffered multiple genetic lesions on chromosomes 19q13.2-13.3, 10q22-24, and 17p13.1 (a point mutation in the p53 gene), had two subsequent recurrences as anaplastic astrocytomas and a survival period of 29 months. Our data suggest that in tumors of oligodendroglial origin the inactivation of a tumor suppressor gene on chromosome 10, especially in conjunction with other genetic aberrations, is indicative of aggressive clinical course.

Status of Voicetype Dictation for Windows for the emergency physician

The purpose of this study is to assess the accuracy of the IBM VoiceType Dictation emergency medicine vocabulary domain under several conditions. The vocabulary domain, microphone position, and background noise markedly reduce dictation accuracy. Consequently, this voice recognition system is impractical in an emergency department setting.

Repeated inescapable stress produces a neuroleptic-like effect on the conditioned avoidance response

This study tests the hypothesis that the dopaminergic system mediates a restitutive response by decreasing its own activity in the face of events like persistent inescapable stress that threaten to interrupt organized mental activity. It is well established that neuroleptic drugs inhibit the conditioned avoidance response (CAR), but not the escape response, probably via a reduction in subcortical dopaminergic activity. We trained rats to perform the CAR and then subjected them to acute and chronic stress to determine whether this would result in inhibition of the CAR. Rats subjected to twice daily tailshock stress for 8 days showed inhibition of the CAR and a reduction in dopamine (DA) utilization in the nucleus accumbens. These findings are compatible with the hypothesis that an endogenous DA-dependent mechanism exists that mimics neuroleptic effects in the face of repeated stress. In humans this response may serve as a protection against psychotic decompensation from chronic endogenous or exogenous insult.

New instruments, bone liners, and tray for finger joint arthroplasty

Titanium circumferential grommets have been developed for finger joint arthroplasty that fit on the base of the silicone implant stems to protect the flexible hinge from tearing and fracture. To facilitate grommet insertion, new intramedullary bone rasps have been devised with a reverse cutting tooth pattern, an extended shaft for an improved view of the surgical field, and a redesigned cutting head to allow for grommet insertion. Surgical accessibility and ease of recognition have been facilitated by the development of color-coded sizers. All of the instruments necessary for finger joint surgery are available in a molded tray that has also been redesigned with a transparent lid and clearly labeled compartments for accurate determination of instruments and implant sizers.

First metatarsophalangeal joint arthroplasties in the Commonwealth of Virginia

This retrospective analysis of arthroplasty of the first metatarsophalangeal joint documents the incidence of surgery as well as the selection of the commercially available implants. During a 1-year period, 1994, arthroplasties were performed in 47 of the 1.7 million subscribers to Trigon Blue Cross Blue Shield of Virginia. Women received the majority of the arthroplasties (83%). Of the 47 cases, the silicone implant was predominantly used (83%). The most common indications for arthroplasty were hallux valgus (30%) and hallux rigidus (28%). Podiatrists performed 79% of the procedures, while orthopedic surgeons performed the remaining 21% of the cases. A prospective study is needed that will assess the long-term performance of the different implants.

An overview of first metatarsophalangeal joint implant arthroplasty

The metatarsophalangeal joint of the great toe often requires an arthroplasty to correct joint disease and pain. Today, joint replacement systems are combinations of components manufactured to optimize biological ingrowth, mechanical interlock, press fit, and cementing. Three different types of arthroplasties are available to foot surgeons: the double stem hinged silicone implant, the two-component joint mimicking implant, and a hemi-implant available for the phalanx. No comprehensive studies on very large populations have been conducted to accurately evaluate the beneficial long-term effects of these implants. This review article describes the development of the toe arthroplasty, details the commercially available implants, and addresses the advantages and adverse effects of each implant.

From the Canadian Dietetic Association. Concept of dietetic practice and framework for undergraduate education for the 21st century

Rapid change and marked diversity are expected to characterize the 21st century. If dietitians are to serve as change facilitators in this environment they will have to demonstrate greater flexibility and creativity, practise critical analysis and problem solving and employ creative thinking. Although provision of quality nutrition care will remain the unique contribution of dietitians, practitioners in the future will require a greater understanding of the impact of social, economic and political systems on food availability and food consumption and, in turn, health and well-being. Critical to the future practice of dietetics will be a greater understanding of research methodology, computer technology, quality improvement processes and risk management, principles governing learning and behaviour, personnel management and organizational behaviour, family and group dynamics, interpersonal communication and their application to dietetic practice. The Canadian Dietetic Association recently adopted a framework for the development of baccalaureate programs in dietetics designed to enable the dietetic practitioner to continue to make a unique contribution in the 21st century. The framework allows individual institutions the freedom and flexibility to plan programs that are compatible with their philosophy and organizational structure. In addition, it is predicted on the principle that a career in dietetics entails a lifetime commitment to education, of which the baccalaureate program is only the beginning.

An analysis of cerebral blood flow in acute closed-head injury using technetium-99m-HMPAO SPECT and computed tomography

Technetium-99m-hexamethylpropyleneamine (HMPAO) SPECT and x-ray CT were compared in 15 patients with acute closed-head injury. There were 44 focal lesions in all. Fifteen (34%) lesions were seen on both x-ray and SPECT. Seventeen (39%) lesions were seen only on SPECT. Twelve (27%) of the lesions were seen on x-ray tomography only. Of the lesions seen on x-ray tomography but not on SPECT, two were subarachnoid hemorrhage, two were thin subdural hematomas, and eight were contusions. This study shows that SPECT can detect focal disturbances of cerebral blood flow that are not seen on x-ray tomography. It also suggests that there are two types of contusions: those with a decreased cerebral blood flow (i.e., detectable on SPECT) and those with a cerebral blood flow equal to that of the surrounding brain.

[Systemic concepts in residential placement: considerations for pedagogics, counseling and organization]

The paper starts from an analysis of typical problems in residential child care, which can be identified on different system levels (family, family and residential child care unit, family and larger systems, child care as a profession). More recent systems concepts (such as autopoiesis, role of the observer, "fitting", limits of planning in human systems) are used to develop suggestions for everyday practice of residential child care--from intake to dismissal, from crisis intervention to family education, from job satisfaction to management issues.

Geochemical Logging With Spectrometry Tools

Summary

A geochemical logging tool (GLT SM) string, measuring natural, activation, and prompt neutron-capture gamma rays, produces logs of the most abundant and a few trace inorganic element concentrations. Direct measurements of Al concentrations are provided. A geochemically based closure model is used to derive Si, Ca, Fe, S, Gd, and Ti concentrations. The only significant spectroscopically undetermined element, Mg, is inferred by comparing measured with derived photoelectric factor. Analysis algorithms, demonstrations of accuracy and precision, and applications of geochemically derived formation properties are discussed.

Introduction

Elemental Analysis by Spectroscopy.

This paper describes a nuclear geochemical tool string designed to determine a sufficient number of elemental concentrations through logging measurements to permit a satisfactory geochemical description of the formation. The tool string combines measurements of natural radioactivity with the natural gamma ray tool (NGT SM), delayed activation (for aluminum) with a new tool called the aluminum activation clay tool (AACT TM) and tau-gated thermal neutron-capture spectroscopy with the gamma ray spectrometer tool (GST TM). The components of the tool string are described in the next section.

Three new features of nuclear spectroscopic logging measurements are introduced in this paper. First, an algorithm is presented to determine Al concentrations, in weight percent, from delayed-activation count-rate measurements. The count rates are corrected for the complex effects of the subsurface environment on the neutron and gamma ray physics. Natural activity measurements of Th, U, and K are directly calibrated in weight percent. Second, a new method is presented to calculate elemental concentrations from pulsed-neutron-capture measurements. Thus, all elemental concentrations are provided in weight percent. In most gamma ray spectroscopy measurements, the fraction of the detected spectrum that can be attributed to a particular element is linearly proportional to the concentration of that element in the volume of the measurement. However, determining the proportionality constant can be essentially impossible under neutron-capture logging conditions when pulsed neutron generators with variable and uncalibrated neutron yields are used.

Thus, we have taken a new approach that renormalizes the relative yields from each clement measured through thermal neutron-capture reactions in a self-consistent manner to obtain the elemental concentrations. The key to this approach is focusing only on elements that are contained in the rock and not present in the fluids.

The renormalization procedure is based on the geochemical fact that in all core analyses, the rock elemental oxides, measured in weight percent, sum to 100 %. The elements measured by capture, activation, and natural spectroscopy compose, with few exceptions, most of the significant elements seen as oxides, or carbonates, in the formations. Therefore, one can use the absolute elemental concentrations measured by natural K activity and delayed All activity, induced with a calibrated neutron source, to renormalize the prompt capture elemental contributions from the formation rock in a closure relationship.

Third, the most significant element not measured spectroscopically, magnesium, can be determined when it is present in a significant concentration by comparing the measured photoelectric cross section for the formation with the theoretical cross section calculated with the assumption that no Mg is present.

After the means for determining the elemental concentrations are described, examples are provided to demonstrate the viability of the elemental concentrations determined by neutron-induced gamma ray spectroscopy through comparisons of logging results with laboratory analysis of cores from the logged wells. Examples of elemental concentration repeatability are provided. Finally, the last part of this paper discusses several applications in which elemental concentrations can be used to enhance the formation description.

Spectroscopic measurements of gamma rays were originally introduced to separate the contribution of particular elements to the total activity seen in a detector. Natural activity can be separated into the Th, U, and K components. Other logging measurements use a neutron source to initiate reactions that produced gamma rays. However, there are many difficulties associated with relating the fraction of a gamma ray spectrum to the absolute concentration of an element in the formation, and most of the original work concentrated on the use of relative spectral contributions, such as carbon/oxygen, to indicate gross formation properties like oil saturation. Recent geochemical research has shown that when a sufficient number of elemental concentrations is determined, a detailed mineralogy of the formation can be estimated. From this mineralogical description, many formation properties can be better characterized and other properties can be derived that could not otherwise be obtained except, perhaps, by detailed analyses of core samples. These properties include better porosity determination from logs, sandstone classification, cation exchange capacity, grain-size distribution, and permeability.

Tool String Description

Nuclear geochemical logging involves three separate modes of gamma ray spectroscopy to make a comprehensive elemental analysis of the formation. Fig. 1 shows the recommended configuration of this new openhole tool string. The first measurement is performed by the NGS tool, which passes by the formation before any neutron source can induce radioactivity. The concentrations of K, Th, and U in the formation are derived from the gamma ray spectrum recorded from these naturally radioactive elements and their daughter products. The second and newest measurement in the nuclear geochemical logging toot is performed by the AACT. The AACT is a modified NGS tool. The modification consists of three more windows added to the spectrometer to remove potentially interfering Mn activation. The AACT, the NGS tool above it, and the 252Cf neutron source [carried in the compensated neutron tool with epithermal measurements (CNT-G)] between them allow a measurement of activation gamma rays to derive formation aluminum concentration. The GST at the bottom of the tool string, in Fig. 1, measures the spectrum of capture gamma rays from elements in the formation. The GST uses a pulsed 14-MeV neutron generator to induce the capture reactions. The spectrum from the GST, in conjunction with elemental concentrations from the NGS tool and AACT, allows derivation of the concentration of elements in the formation rock, such as Si, Ca, Fe, S, Ti, K, and Gd. The GST is also sensitive to H and Cl, but these elements are not used in determining the rock geochemistry.

Secondary measurements are made by the auxiliary measurement sonde (AMS TM) for determining borehole salinity and mud temperature, the CNT-G for apparent neutron slowing length of the formation, Ls, and as a carrier for the 252Cf source, and the formation neutron capture cross section, sigma form, obtained from the GST. These measurements are used in the environmental correction of the derived Al concentration. Data from the tools in the string are sent by telemetry to the surface by the telemetry communication cartridge or cable communication cartridge (cable communication electronics), also shown in Fig. 1.

Measures of central tendency, variability, and relative standing in nonnormal distributions: alternatives to the mean and standard score

There are two major disadvantages to reporting test results in standardized scores such as z-scores or t-scores when describing individuals with disabilities. (1) Raw scores on many tasks from disabled individuals are notoriously nonnormal. They are asymmetric, in that they are skewed toward poor scores. (2) Low z-scores give a false impression of dysfunction because able-bodied subjects are often grossly overqualified for the application in question; they may have levels of strength or quickness several orders of magnitude greater than what is needed to do the assessment task. A recommended alternative is to describe the performance of disabled individuals using nonparametric statistics, and to report scores in boxplots, showing the extremes, the median, and the quartiles. Such points are easy to calculate and to interpret, and they are robust against outliers.

Clinical and treatment effects on 3H-clonidine and 3H-imipramine binding in elderly depressed patients

3H-clonidine and 3H-imipramine binding were measured in depressed patients, 55 years and older. There was no significant difference in either 3H-clonidine or 3H-imipramine binding between depressed patients and age- and sex-matched controls. There was no significant correlation between 3H-clonidine or 3H-imipramine binding and severity of depression before treatment. There was a significant negative correlation between the KD of 3H-imipramine binding sites and Hamilton score over seven weeks of antidepressant treatment. There was no significant difference between receptor data of responders and nonresponders to antidepressant treatment.

Functional organization of the electroreceptive midbrain in an elasmobranch (Platyrhinoidis triseriata). A single-unit study

The response properties of 322 single units in the electroreceptive midbrain (lateral mesencephalic nucleus, LMN) of the thornback ray, Platyrhinoidis triseriata, were studied using uniform and local electric fields. Tactile, visual, or auditory stimuli were also presented to test for multimodality. Most LMN electrosensory units (81%) are silent in the absence of stimulation. Those with spontaneous activity fired irregularly at 0.5 to 5 impulses/s, the lower values being more common. Two units had firing rates greater than 10/s. Midbrain electrosensory units are largely phasic, responding with one or a few spikes per stimulus onset or offset or both, but the adaptation characteristics of some neurons are complex. The same neuron can exhibit phasic or phasic-tonic responses, depending upon orientation of the electric field. Tonic units without any initial phasic over-shoot were not recorded. Even the phasic-tonic units adapt to a step stimulus within several seconds. Unit thresholds are generally lower than 0.3 microV/cm, the weakest stimulus delivered, although thresholds as high as 5 microV/cm were recorded, Neuronal responses reach a maximum, with few exceptions, at 100 microV/cm and decrease rapidly at higher intensities. LMN neurons are highly sensitive to stimulus repetition rates: most responded to frequencies of 5 pulses/s or less; none responded to rates greater than 10/s. Three distinct response patterns are recognized. Best frequencies in response to sinusoidal stimuli range from 0.2 Hz (the lowest frequency delivered) to 4 Hz. Responses decrease rapidly at 8 Hz or greater, and no units responded to frequencies greater than 32 Hz. Most LMN neurons have small, well defined excitatory electroreceptive fields (RFs) exhibiting no surround inhibition, at least as detectable by methods employed here. Seventy-eight percent of units recorded had RFs restricted to the ventral surface: of these, 98% were contralateral. The remaining 22% of units had disjunct dorsal and ventral receptive fields. Electrosensory RFs on the ventral surface are somatotopically organized. Anterior, middle, and posterior body surfaces are mapped at the rostral, middle, and caudal levels, respectively, of the contralateral LMN. The lateral, middle, and medial body are mapped at medial, middle, and lateral levels of the nucleus. Moreover, the RFs of all units isolated in a given dorsoventral electrode track are nearly superimposable. About 40% of LMN, measured from the dorsal surface, is devoted to input from ventral electroreceptors located in a small region rostral and lateral to the mouth.(ABSTRACT TRUNCATED AT 400 WORDS)

Expression of the Thy-1 antigen in long-term cultures of embryonic mouse spinal cord

Immunofluorescent studies of the Thy-1 antigen in cultures of mouse spinal cord demonstrated positivity on the surfaces of a fraction of neurons and glia. Positivity was evident by one week and increased slowly over the lifespan of the cultures, often several months. Thy-1 positivity was most apparent in regions of clustering of neurons and glia. Neuroglial clusters were identified by morphologic appearance; the identity of astrocytes was confirmed by immunofluorescent staining of glial fibrillary acidic protein.

Mesencephalic and diencephalic cobalt-lysine injections in an elasmobranch: evidence for two parallel electrosensory pathways

Iontophoretic injections of cobaltous lysine have revealed a direct projection from the electroreceptive lateral mesencephalic nucleus to the ipsilateral diencephalic posterior lateral nucleus in the thornback ray, Platyrhinoidis triseriata. Since it is known that the latter nucleus projects to the contralateral pallium, this completes the anatomical description of an electrosensory pathway from receptors to telencephalon in an elasmobranch. In addition, diencephalic injections into the electroreceptive anterior nucleus indicate there is a second, parallel electrosensory system which projects to the hypothalamus.

A case-control study of the association of sickle cell trait and chronic open-angle glaucoma

Chronic open-angle glaucoma is reported to be more common in blacks than in whites. The reasons for a higher prevalence of this disease in blacks are unclear. Two recent small case series from clinical practice have been published in which secondary open-angle glaucoma was diagnosed in blacks with sickle cell trait who had experienced either traumatic or nontraumatic hyphema. The association of sickle cell trait and chronic open-angle glaucoma has been tested only in a small case-control study of uncontrolled chronic open-angle glaucoma patients undergoing surgery. No significant association was found. However, the higher prevalence of sickle cell trait in blacks compared with whites raises the question of whether the presence of sickle hemoglobin is a risk factor for chronic open-angle glaucoma in the black population. To test for a possible association between this disease and sickle cell trait, we conducted a case-control study in black ophthalmic patients at the University of Pennsylvania and affiliated hospitals between December 1981 and July 1982. Sickle cell trait, as measured by the sickle cell preparation test, was no more prevalent in patients with chronic open-angle glaucoma than in age- and sex-matched ophthalmic clinic controls. It is unlikely that hemoglobin SA is a risk factor for chronic open-angle glaucoma.

Introduction of superhelical turns into DNA by adenoviral core proteins and chromatin assembly factors

The interaction in vitro between adenoviral histone-like proteins and DNA in the presence of chromatin assembly factors was investigated. Viral core protein VII or its precursor pVII was incubated with DNA in the presence of an extract of HeLa cell chromatin, which mediates nucleosome assembly from histones and DNA. We have demonstrated that either protein can introduce superhelical turns into relaxed closed-circular DNA and that the presence of chromatin extract is necessary for the supertwisting effect. A greater density of superhelical turns was produced by pVII than by VII, but neither protein-DNA interaction resulted in the "physiological" amount of supertwisting produced by histones. The inhibition of histone-induced supercoiling by both proteins and the protection of turns in supertwisted starting material are also described. The nucleosome assembly factor, nucleoplasmin, fails to mediate the introduction of superhelical turns by VII or pVII.

The auditory brain stem response in five vertebrate classes

In representative elasmobranchs, osteichthyans, amphibians, reptiles and birds, average evoked potentials in response to acoustic clicks and tone bursts were recorded intracranially, but outside the brain, or extracranially. Controls against artifacts and tests after transections show that these potentials conform to criteria for auditory brain stem responses (ABRs). Brief waves in a 10-15 msec sequence originate successively in the eighth nerve, medulla and midbrain; there is little contribution to the latter waves from the lower levels. This response pattern appears to be consistent within each species and is similar to that extensively studied in mammals. Some of its features are remarkably alike in all the vertebrate classes tested, implying a generality in the existence of a subset of auditory neurons at several brain levels that are highly synchronous in activity, even after several synapses, and geometrically oriented to add their macroscopic, open, dipole fields. The intensity, repetition rate and the power spectrum of the click stimuli have little effect on the ABR pattern, except when the peak energy is in the low frequency range. In the range below ca. 700 Hz frequency content has a considerable effect; lower frequencies broaden certain waves. Cooling has marked and differential effects on component processes. Reversing click phase, e.g. from initial compression to initial rarefaction, can show no effect or any of several effects, depending on the species. Tone bursts evoke onset ABRs and in some cases after a transitional period a sustained frequency following response. The ABR resembles a click evoked potential even when stimulus rise time is slow. Background tones of particular frequency are most efficient in masking click evoked ABRs; white noise is less efficient. The ABR should be useful in neuroethology since it can be studied without invading the brain. It can tell that the brain is sensitive to a sound. In an immobilized animal it can be recorded in a single sweep, or it can be averaged from an awake tethered animal. It shows good sensitivity and at least some correspondence with behavioral measures of hearing.

Effect of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate and its nonpromoting analogue 4-O-methyl-TPA on dorsal dermal melanocytes of the Syrian golden hamster (Mesocricetus auratus)

The effect of the tumor promoter TPA and its inactive structural analogue 4-O-methyl-TPA on the induction of dorsal skin melanosis in the normal Syrian golden hamster and on the promotion of melanomas in DMBA-initiated animals was investigated. Both phenomena were observed in TPA-treated hamsters but could not be detected after exposure of animals to 4-O-methyl-TPA. In contrast to results obtained with a variety of other laboratory animals, neither TPA nor 4-O-methyl-TPA were able to induce epidermal hyperplasia of hamster dorsal skin.

Phase I study of a 5-day schedule of mitoxantrone (dihydroxyanthracenedione)

Mitoxantrone (1,4-dihydroxy-5,8-bis[[2-[(2-hydroxyethyl)amino]ethyl]amino]-9,10-anthracenedione dihydrochloride) in animal studies appears to have a mechanism of action and broad antitumor spectrum similar to the anthracyclines and in preliminary animal studies is without cardiotoxicity. To determine the maximally tolerated dose, mitoxantrone was given to 25 patients with various advanced solid tumors. Sixteen patients had received prior doxorubicin and/or lomustine (CCNU). Myelosuppression was the major toxic effect. All 13 patients who received mitoxantrone doses greater than or equal to 2.73 mg/m2 x 5 days experienced moderate (2000--3000 cells/mm3) or severe (less than 2000 cells/mm3) leukopenia. Thrombocytopenia was also encountered in three of these 13 patients (severe in one, less than 50,000 cells/mm3). At dose levels less than 2.73 mg/m2 x 5 days, myelosuppression was seen in four of 12 patients (three with mild leukopenia and one with mild thrombocytopenia). The blood cell count nadir occurred at 10 days and full recovery occurred by Day 21. Minor clinically insignificant ECG changes occurred in five patients. Minor and transient antitumor effects were seen in five patients. The maximum tolerated dose of mitoxantrone over a 5-day course is 2.73 mg/m2, with leukopenia being the limiting toxic effect.

Effect of administering a high dosage glucocorticoid bolus on the survival and subcapsular hydrostatic pressure of rat kidney allografts

In order to measure the subcapsular pressure in normal and allotransplanted rat kidneys, a microcatheter was inserted into the subcapsular space and the hydrostatic pressure (SHP) continuously recorded with a transducer. The SHP was found to increase significantly up to the 5th day after transplantation. A single bolus injection of prednisolone on the day of transplantation or on the 4th post-operative day resulted in considerably lower SHPs being recorded. In contrast, graft survival was prolonged only when prednisolone was given on day 0 but not on day 4. Thus, it was concluded that the mode of action of prednisolone differs according to its time of administration.

Surface markers and size of lymphocytes in human umbilical cord blood stimulated into deoxyribonucleic acid synthesis by Epstein-Barr Virus

We characterized subpopulations of lymphocytes in human umbilical cord blood which are stimulated into deoxyribonucleic acid synthesis by Epstein-Barr virus. Lymphocytes were examined simultaneously for deoxyribonucleic acid synthesis by autoradiography and for surface markers by rosette formation with sheep erythrocytes or erythrocytes coated with antibody and mouse complement (EAC). The subpopulation which incorporated [3H]thymidine after exposure to virus consisted mainly of cells which formed rosettes with EAC. Lymphocytes were enriched or depleted of thymus-derived lymphocytes (T cells), null cells, or cells forming rosettes with EAC. The extent of sensitivity of the cells to stimulation by Epstein-Barr virus correlated with the proportion of the population which formed rosettes with EAC. When mononuclear cell populations were depleted of T lymphocytes and then fractionated by size, small lymphocytes showed higher rates of deoxyribonucleic acid synthesis after virus exposure and higher transformation frequency than did larger cells or unfractionated cells. Thus, the cells which are stimulated into deoxyribonucleic acid synthesis by Epstein-Barr virus appear to be the same as cells which are ultimately transformed.

Narcotics and the hypothalamic-pituitary-gonadal axix: acute effects on luteinizing hormone, testosterone and androgen-dependent systems

The effects of narcotics on several aspects of the hypothalamic-pituitary-gonadal axis were examined in the male rat. Our results indicate that a large number of narcotics acutely depress serum luteinizing hormone levels and that these reduced gonadotropin levels lead to a subsequent fall (1-2 hours later) in serum testosterone levels. The luteinizing hormone-depleting effect of the narcotics appears to represent a specific narcotic action since the (-)-isomers of the narcotics were much more effective than the ()-isomers, naloxone antagonized their effects and tolerance rapidly developed. Further, our studies indicate that the impairment of the functional and structural integrity of the secondary sex organs produced by chronic narcotic administration is not due to a direct effect of these drugs since they have no effect on the uptake of subcellular distribution of testosterone in the secondary sex organs or on the androgen-dependent accumulation of myo-inositol. Consequently, it appears that the testosterone depletion produced by the narcotics is solely responsible for their adverse effect on the secondary sex organs. The results of these studies suggest that the effects of the narcotics on the hypothalamic-pituitary-gonadal axis are confined to either the hypthalamus or the pituitary gland.