Measurement of Electron Neutrino Quasielastic and Quasielasticlike Scattering on Hydrocarbon at ⟨E_{ν}⟩=3.6 GeV.

The first direct measurement of electron neutrino quasielastic and quasielasticlike scattering on hydrocarbon in the few-GeV region of incident neutrino energy has been carried out using the MINERvA detector in the NuMI beam at Fermilab. The flux-integrated differential cross sections in the electron production angle, electron energy, and Q^{2} are presented. The ratio of the quasielastic, flux-integrated differential cross section in Q^{2} for ν_{e} with that of similarly selected ν_{µ}-induced events from the same exposure is used to probe assumptions that underpin conventional treatments of charged-current ν_{e} interactions used by long-baseline neutrino oscillation experiments. The data are found to be consistent with lepton universality and are well described by the predictions of the neutrino event generator GENIE.

Evidence for Neutral-Current Diffractive π

The MINERvA experiment observes an excess of events containing electromagnetic showers relative to the expectation from Monte Carlo simulations in neutral-current neutrino interactions with mean beam energy of 4.5 GeV on a hydrocarbon target. The excess is characterized and found to be consistent with neutral-current π^{0} production with a broad energy distribution peaking at 7 GeV and a total cross section of 0.26±0.02(stat.)±0.08(sys.)×10^{-39} cm^{2}. The angular distribution, electromagnetic shower energy, and spatial distribution of the energy depositions of the excess are consistent with expectations from neutrino neutral-current diffractive π^{0} production from hydrogen in the hydrocarbon target. These data comprise the first direct experimental observation and constraint for a reaction that poses an important background process in neutrino-oscillation experiments searching for ν_{µ} to ν_{e} oscillations.

p53 mediates apoptotic crisis in primary Abelson virus-transformed pre-B cells.

Transformation of pre-B cells by Abelson murine leukemia virus (Ab-MLV) involves a balance between positive, growth-stimulatory signals from the v-Abl oncoprotein and negative regulatory cues from cellular genes. This phenomenon is reflected by the clonal selection that occurs during Ab-MLV-mediated transformation in vivo and in vitro. About 50% of all Ab-MLV-transformed pre-B cells express mutant forms of p53 as they emerge from this process, suggesting that this protein may play an important role in the transformation process. Consistent with this idea, expression of p19(Arf), a protein whose function depends on the presence of a functional p53, is required for the apoptotic crisis that characterizes primary Ab-MLV transformants. To test the role of p53 in pre-B-cell transformation directly, we examined the response of Trp53(-/-) mice to Ab-MLV. The absence of p53 shortens the latency of Abelson disease induction but does not affect the frequency of cells susceptible to Ab-MLV-induced transformation. However, primary transformants derived from the null animals bypass the apoptotic crisis that characterizes the transition from primary transformant to fully malignant cell line. These effects do not require p21(Cip-1), a major downstream target of p53; however, consistent with a role of p19(Arf), transformants expressing mutant p53 and abundant p19 retain wild-type p19 sequences.

The absence of Msh2 alters abelson virus pre-B-cell transformation by influencing p53 mutation.

Defects in DNA mismatch repair predispose cells to the development of several types of malignant disease. The absence of Msh2 or Mlh1, two key molecules that mediate mismatch repair in eukaryotic cells, increases the frequency of mutation and also alters the response of some cells to apoptosis and cell cycle arrest. To understand the way these changes contribute to cancer predisposition, we examined the effects of defective mismatch repair on the multistep process of pre-B-cell transformation by Abelson murine leukemia virus. In this model, primary transformants undergo a prolonged apoptotic crisis followed by the emergence of fully transformed cell lines. The latter event is correlated to a loss of function of the p53 tumor suppressor protein and down-modulation of the p53 regulatory protein p19Arf. Analyses of primary transformants from Msh2 null mice and their wild-type littermates revealed that both types of cells undergo crisis. However, primary transformants from Msh2 null animals recover with accelerated kinetics, a phenomenon that is strongly correlated to the appearance of cells that have lost p53 function. Analysis of the kinetics with which p53 function is lost revealed that this change provides the dominant stimulus for emergence from crisis. Therefore, the absence of mismatch repair alters the molecular mechanisms involved in transformation by affecting a gene that controls apoptosis and cell cycle progression, rather than by affecting these processes directly.

Immunosuppression in experimental trypanosomiasis: effects of Trypanosoma equiperdum on the pathogenesis of influenza virus infection in deer mice (Peromyscus maniculatus).

The effects of Trypanosoma equiperdum infections on the immunological and pathological responses of deer mice (Peromyscus maniculatus) to influenza virus exposure were investigated. Mice carrying a 5 week trypanosome infection along with an age- and sex-matched trypanosome-free control group were simultaneously exposed to influenza Ao (WSN) virus. T. equiperdum infection significantly (P less than 0.01) converted a sub-lethal virus attack into a fatal pneumonic process in a small proportion of animals. In addition, the trypanosome caused a reduction (p less than 0.1) in virus replication on PID 1 and 2, accompanied later by a tendency towards virus persistence in the lungs of affected mice. This tendency was manifested by a log reduction in virus titres between PID 2 and 4 and PID 4 and 6 in the lungs of trypanosome-infected mice, compared to 2 log drops over the same periods in the lungs of control mice. T. equiperdum infection also significantly (p less than 0.001) depressed serum and pulmonary neutralizing antibody titres to influenza virus.

Torsional properties of nickel-titanium versus stainless steel endodontic files.

The purpose of this study was to evaluate and compare the torsional properties of stainless steel K-type .02 taper and nickel-titanium U-type .02 and .04 taper instruments. Torsion tests were performed on all three designs of instruments according to ANSI/ADA specification number 28. For each design, 20 instruments of each of three sizes (15, 25, and 35) were tested. The three parameters measured were maximum torque, torque at failure, and angular deflection. Stainless steel K-type .02 taper and nickel-titanium U-type .02 and .04 taper instruments met or exceeded specification standards for maximum torque. They also satisfied and far exceeded the standards for angular deflection at the failure point. The stainless steel instruments showed no significant difference between maximum torque and torque at failure, whereas both of the nickel-titanium instruments showed a significant differential between maximum torque and torque at failure.

Thermafil retreatment using a new "System B" technique or a solvent.

The solid plastic carrier in the Thermafil obturation system must be removed to facilitate retreatment. The purpose of this study was to compare the efficacy and time required to retreat canals obturated with Thermafil with plastic carriers using a new technique based on the System B HeatSource or a solvent. Fifty-two extracted human mandibular premolars with single canals were instrumented and then obturated with Thermafil with plastic carriers. After 2 wk storage at 22 degrees C and 100% humidity, they were randomly divided into 2 groups of 26 teeth each. Group 1 teeth were retreated using chloroform and hand files, whereas teeth in group 2 were retreated with a new technique using the System B HeatSource. The end point of retreatment was defined as complete removal of the plastic carrier. The time required for retreatment was recorded. Then, the apical 5 mm segment of each root was sectioned horizontally at 1 mm intervals and each section digitally imaged. The total area of the canal and the area of the canal occupied by gutta-percha and sealer were measured using NIH image software. Data were analyzed using an unpaired t test. The mean time for retrieval of the plastic carrier was significantly less for the System B technique (1.8 min) than for the solvent technique (3.6 min) (p < 0.001). The difference between the two groups in the amount of filling material (carrier, gutta-percha, and sealer) removed was not significant (p > 0.05).

Evaluation of pigmented intraorifice barriers in endodontically treated teeth.

The purpose of this study was to evaluate the effectiveness of three pigmented glass ionomer cements used as intraorifice barriers to prevent coronal microleakage. One hundred ten extracted mandibular human premolars were divided into four experimental groups of 25 teeth each and two control groups of 5 teeth each. The experimental teeth were instrumented and obturated using thermoplasticized gutta-percha and AH26 sealer. Group 1 teeth received no further treatment. Teeth in groups 2 through 4 had 1 of 3 pigmented glass ionomers (Vitrebond, GC America, and Ketac-Bond) placed as an intraorifice barrier. Positive control teeth were instrumented but not obturated. The negative control teeth were instrumented, obturated, and externally sealed with epoxy resin. The coronal 3 mm of each root was sealed into the lumen of an 18-mm segment of latex surgical tubing. After the apparatus was sterilized, 2.0 ml of a 24 h growth of Proteus vulgaris in trypticase soy broth (TSB) was placed in the coronal reservoir of the tooth. The inoculated apparatus was placed into a presterilized test tube containing 1.5 ml of TSB and incubated for 90 days at 37 degrees C. The TSB in the lower reservoir was observed daily for turbidity, which would indicate leakage along the full length of the obturated root canal. To determine if differences in microbial leakage occurred among the four experimental groups, Pearson's chi 2 and Fisher's exact tests were performed. The confidence level was set at 95%. The positive and negative controls validated the microbial testing method. The teeth without an intraorifice barrier leaked significantly more than teeth with Vitrebond intraorifice barriers (p < 0.05). The difference in leakage among the experimental glass ionomer barriers was not significant (p > 0.05).

Effect of two obturation techniques on the filling of lateral canals and the main canal.

The three-dimensional obturation of the root canal system is widely accepted as a key factor for successful endodontic therapy. The purpose of this study was to evaluate the obturation of lateral canals and the main canal using cold lateral condensation versus the gutta-percha coated rigid carrier. Thirty epoxy blocks with five lateral canals placed at varying angles from the main canal were used. Each experimental group was obturated by a board certified endodontist with clinical experience in the respective obturation technique. The length of gutta-percha and sealer in the lateral canals was measured under a microscope (x30, Unitron) to the nearest 0.5 mm. The blocks were sectioned with an Isomet Plus precision saw (Buehler, Lake Bluff, IL) and copious water irrigation perpendicular to the main canal at the apex, the height of contour, and at 0.8, 1.6 and 2.4 mm from the canal apex. A microscope (x100, Leitz, Switzerland) was used to determine voids. There was significantly (p < .001) more gutta-percha in the lateral canals with the gutta-percha coated rigid carrier technique. In contrast, the cold lateral condensation technique had significantly (p < .001) more sealer in the lateral canals. However, there was no significant (p < .05) difference, in gutta-percha-plus-sealer filling of the lateral canals, between the two techniques. In the apical 1 mm of the main canal there were significantly (p < .011) fewer voids with the gutta-percha coated rigid carrier technique compared to the cold lateral condensation. In the model chosen, the gutta-percha coated rigid carrier technique and the cold lateral condensation technique were equally effective in filling lateral canals. In filling the main canal, however, the coated rigid carrier technique was more effective.

Periapical central giant cell granuloma: a potential endodontic misdiagnosis.

This retrospective study ascertained the incidence and clinicopathologic features of central giant cell granulomas (CGCGs) associated with teeth with necrotic pulps or teeth that had received previous endodontic treatment and determined whether periapical CGCGs can result in endodontic misdiagnosis. Clinical and histopathologic data of biopsy specimens diagnosed as CGCG were collected from the archives of the Oral Pathology Laboratory, Temple University, and were reviewed. Over the 9-year period, 16 of 79 cases (20%) of CGCG were associated with a tooth that had a history of pulp necrosis. Of those, 14 (88%) were associated with previous root canal treatment. The data from this series of 79 cases of CGCG also showed that CGCGs were less common in women, less common before age 30, and did not cross the midline of the jaw as often as previously reported. Clinical and histopathologic data were compared from (1) CGCGs associated with teeth with vital pulps or that occurred in edentulous areas; (2) CGCGs associated with teeth with necrotic pulps; and (3) 194 cases of periapical granulomas and radicular cysts. These data strongly suggest that CGCGs associated with teeth with necrotic pulps are not directly related to periapical inflammation and may be misdiagnosed as endodontic lesions. Posttreatment follow-up and routine submission of periapical surgical specimens are emphasized.

Summary of the means used to positively identify the American victims in the Canary Islands crash.

On board the Pan American aircraft, 326 were killed as a result of the collision with the KLM aircraft at Santa Cruz de Tenerife airport in the Canary Islands on 27 March, 1977. Of the remains returned to the United States, 212 were identified as Americans from the Pan Am, four from the KLm aircraft. Dental comparison provided the principal means of identification, especially ante- and post-mortem radiographs. Medical X-rays were extremely useful and provided the next most frequently used means of identification. Fingerprints, medical finding, and personal effects were also used, but less extensively than might be expected. The severe charring and the inability to prove conclusively to whom many of the personal effects belonged accounted for these differences. The use of medical X-rays for identification was possible in large part because many of the passengers were older and had numerous antemortem X-rays available for comparison.

Analysis of gases and pH of blood at altitude.

The accuracy of a system for measuring pH and gas in blood in a changing-altitude environment was studied. No problems were encountered when arterial blood was measured, provided the instrument was properly calibrated. Failure to calibrate to the correct altitude settings caused major variations in measuring oxygen levels in blood. Standard gases used for calibrating were measured at altitude without recalibrating the system; approximately 80% of the oxygen and 90% of the carbon dioxide partial-pressure values were within 3 mm Hg of their expected value. More deviation occurred for Po2 values as the altitude increased. Frequently, the Po2 electrode malfunctioned, particularly above 8000 ft (2438 m). The Corning Blood Gas System, which was used in this study, was capable of making accurate determinations of gas in blood if properly operated and calibrated to specific altitude levels.

Treatment of Mycobacterium ulcerans infection by hyperbaric oxygenation.

Mycobacterium ulcerans causes chronic nectotizing ulcers of the skin and subcutaneous tissue and is a serious health problem in some tropical countries. Chemotherapy has not been effective, and the treatment of choice is extensive debridement followed by skin grafting. In spite of this, many infections are complicated by disfiguring scars, contraction deformities, and--rarely--amputation. There are other procedures that may promote healing (e.g., heat treatment, rifampicin), but none has been completely evaluated. In our study, hyperbaric oxygenation (HBO), an effective treatment for many bacterial diseases, including some mycobacterial infections, was used to treat mice with M. ulcerans-infected footpads. Three groups (40 mice/group) were treated daily with 100% oxygen by three different protocols: 2.5 ATA for 2 h; 2.5 ATA for 1.25 h, twice a day; and 2 ATA for 3.5 h. The degree of infection in the treated mice was compared weekly with 40 positive controls (infected, not treated). The HBO therapy was more effective in the group treated at 2.5 ATA for 1.25 h, twice a day. After 25 weeks, there had been two feet autoamputated and only 12 deaths among the mice, as compared to 18 feet amputated and 24 deaths in the control group. Thus, hyperbaric oxygenation has a beneficial effect in mice and, if used in conjunction with other therapeutic procedures in man, may be an effective therapeutic adjunct in treating M. ulcerans infections.

Use of personal effects in the Canary Island accident investigation.

Personal effects were used extensively to provide supportive evidence for identification and in seven cases it provided the main means of identification. Personal effects were received from the Canary Islands in numbered plastic bags, having been removed from each remains. In a few cases, personal effects must have been taken from locations near a remains because four bags were found to contain identifiable personal effects that did not match the remains with the same number. therefore, personal effects were utilized less frequently than might normally occur in the course of such investigations. Thorough searches of each remains, especially X-ray, yielded additional effects during the investigation at Dover. A small dedicated team was formed which was responsible for cleaning, cataloging, and requesting antemortem information necessary for the identification process. They made extensive use of color Polaroid photography.

Mycobacterium ulcerans infection: treatment with rifampin, hyperbaric oxygenation, and heat.

The effectiveness of hyperbaric oxygenation (HBO), heat, and rifampin for treating mice infected with Mycobacterium ulcerans was analyzed. Four hundred mice were innouclated in the hind footpads with 10(8) organisms. The seven treatment groups (50 mice each) were HBO (2.5 ATA for 1.5 h, twice a day), rifampin (RIF) (20 mg/kg body weight/d), heat (mice maintained at 37 degrees C), and all combinations of the three treatments. The severity of infection in the treated mice was compared weekly for 20 weeks with that of infected controls. The most effective treatments were RIF/HEAT and RIF/HBO/HEAT, RIF/HBO/HEAT treatment was further evaluated to determine the effectiveness of treating mice at various stages of infection. Three hundred mice were inoculated in the hind footpads, and, as the infection progressed, they were separated into groups (50 mice/group) according to the severity of infection. The treatment groups were compared to positive controls. The effectiveness of therapy was indirectly proportional to the severity of infection.

Correlation of choice reaction time performance with biorhythmic criticality and cycle phase.

The biorhythm theory correlates behavior to physical, emotional, and intellectual cycles. It states that an individual's behavior is influenced by these three cycles which begin at the moment of birth and operate thereafter simultaneously. The theory is commonly tested when the occurrence of accidents is compared to the phase of the biorhythm cycles. If the theory is true, more accidents would occur on a critical day than would be expected by a random distribution. A second method to test the theory is used in this paper, where actual performance of a laboratory task is correlated with the phases of the cycle. Performance was measured in a choice reaction time (CRT) task with each task composed of 400 light flashes. The methods and results are presented and discussed. The conclusion reached from analyses of the data was that performance in the CRT task was no influenced by biorhythms.

Role of radiology in aviation accident investigation.

Radiographic screening of fatality victims for skeletal detail, dental and surgical artifacts, personal effects, and foreign bodies is of established value. Radiography as the primary means of positive victim identification, through comparison with antemortem films and records, is an important new role. Data on sources of injury and relationships between victims and the crash environment may be derived from radiographic injury patterns and may be correlated with mechanisms of injury production. The result of such analysis is improved safety design. Such radiography poses unique technical and logistical problems, often involving temporary or remote facilities, which must be solved with consideration for privacy and safety. Advance planning is essential for maximum benefit from radiographic investigation.

Administrative organization and function during the identification process for mass disasters--Canary Islands crash.

The administrative functions associated with large-scale medical and identification efforts in accident investigations are substantial and contribute directly to the overall conduct of the operation. We envisioned the administrative role as one primarily responsible for integration of all antemortem and postmortem information. This required each individual involved to be thoroughly familiar with the data. This required constructions of numerous lists, charts, and records. Secondly, its role involved data storage to document the identifications made. Finally, its role required summary status reporting both during and after the main investigation. Fortunately, we haven't had many accidents the size of the one occuring in the Canary Islands. However, this leaves us with little corporate knowledge on handling administrative matters. This article is designed to explain the who, what, why, and how administration was handled in this accident, and the lessons we learned.

Joint Committee on Aviation Pathology: XVIII. Correlation of occurrence of aircraft accidents with biorhythmic criticality and cycle phase in U.S. Air Force, U.S. Army, and civil aviation pilots.

The correlation of occurrence of aircraft accidents to critical and negative phases of the biorhythm cycles was investigated. Data from 880 U.S. Air Force pilot-involved accident cases were studied and added to 4,279 previously reported cases. The data were tested by chi-square analysis under the null hypothesis that there is no effect of biorhythm on aviation accidents. Under this hypothesis, the expected number of accidents occurring on critical days should be 179.13 for the U.S. Air Force; there were 179. In analyzing the effect of biorhythmic criticality for pilot-involved cases from all sources, there were were 300 individual chi-square values computed. The frequency of these values by their percentile distribution so closely matched the theoretical distribution that there was no evidence whatsoever to indicate an effect of biorhythmic criticality. There no correlation between multiply negative or individually negative phases of the biorhythm cycles and aircraft accidents in the U.S. Air Force or in the combined pilot-involved accident group.

Radiologic evaluation of the jaundiced patient. Diagnostic and therapeutic role of current procedures.

Radiologic evaluation of the jaundiced patient generally begins with ultrasound. Computed tomography may provide better information regarding the exact level of obstruction, but it is more expensive and time-consuming than ultrasound and carries the risk associated with intravenous contrast. It thus should be used only when ultrasound findings are likely to be inadequate. Percutaneous transhepatic cholangiography and endoscopic retrograde cholangiopancreatography are both relatively safe, reliable procedures for direct opacification of the biliary tree. The choice depends on clinical and ultrasound findings. Percutaneous transhepatic cholangiography provides a foundation for percutaneous drainage if necessary. Cholescintigraphy in the jaundiced patient provides physiologic information but poor anatomic detail. It is useful in establishing common duct functional patency.