Imaging Findings in Children Presenting with CNS Nelarabine Toxicity.

Nelarabine is a nucleoside analog critical for the treatment of patients with T-cell acute lymphoblastic leukemia/lymphoma. However, clinical peripheral and central neurologic adverse events associated with nelarabine administration have been reported. Neuroimaging of brain neurotoxicity has only been described in very few reports in pediatric patients so far. Six children with diagnosed T-cell acute lymphoblastic leukemia who clinically experienced possible, probable, or definite nelarabine-induced toxicity and underwent spine and/or brain MR imaging were reviewed. Neuroimaging findings showed a mixture of patterns including features of acute toxic leukoencephalopathy (seen in 6 cases), posterior reversible encephalopathy syndrome (2 cases), involvement of deep gray structures (1 case) and brainstem (2 cases), cranial and spinal neuropathy (2 cases each), and myelopathy (2 cases). Even though neuroimaging findings are nonspecific, the goal of this article was to alert the pediatric neuroradiologists, radiologists, and clinicians about the possibility of nelarabine-induced neurotoxicity and its broad neuroimaging spectrum.

Purification of human respiratory syncytial virus by ultracentrifugation in iodixanol density gradient.

Ultracentrifugation in sucrose density gradient remains the most commonly used technique for hRSV purification. However, the high viscosity and hyper-osmotic property of sucrose can cause damage to the extremely labile virus leading to loss of infectivity. To overcome these limitations, an alternative purification technique was developed using iodixanol as gradient medium, incorporating MgSO(4) as a stabilizing agent and EDTA to disaggregate the virus prior to infectivity assay. Virus particles were banded at the 20-36% interface after purification of polyethylene glycol-concentrated viruses by rate zonal ultracentrifugation on a 20-52% discontinuous iodixanol gradient. The presence of the virus was confirmed by viral fusion glycoprotein content using ELISA. After further purification by buoyant density ultracentrifugation on a 20-52% continuous gradient, the virus was recovered in the region of density 1.15-1.19 g/ml and this was confirmed by the coincidence of the infectivity titre, viral genome and fusion glycoprotein peaks. Analysis of recovery rates showed that the use of iodixanol increased the virus yield up to 69%. Iodixanol was also found to be non-toxic to HeLa cells used in infectivity assay, eliminating the need of its downstream removal by dialysis.

Inability of cytomegalovirus infection of cultured endothelial cells to induce HLA class II antigen expression.

Cytomegalovirus infection in the renal allograft recipient has been associated with the initiation of acute rejection. The mechanism of this induction is unknown. It may be related to renal tubular epithelial and endothelial expression of HLA class II antigens or a CMV immediate-early antigen that exhibits immunologic crossreactivity with HLA DR. In this study the ability of CMV to both infect and subsequently induce class II antigen expression on cultured human umbilical-vein endothelial cells (HUVEs), in the absence of cytokines, particularly gamma interferon, was tested. Individual HUVE cell lines were first proven to express HLA class II antigens in the presence of 10, 100, and 200 units of recombinant IFN-gamma as early as 24 hr postincubation by an immunohistochemical technique and by flow cytometry. These cell lines were successfully infected with CMV strains AD169 and CMV3 as determined by the presence of early and late viral antigens and CMV DNA. The degree of infection was dose and incubation-time dependent. Infection of HUVEs with these CMV strains and a nonattenuated clinical isolate failed to induce HLA DR, DP, or DQw1 expression in the absence of IFN-gamma. These findings support the hypothesis that endothelial cells in vivo may serve as reservoirs of CMV infection. They do not support the hypothesis that CMV produces an immediate-early antigen that has immunologic cross-reactivity with HLA DR. Furthermore, there is no support for the hypothesis that CMV independently induces HLA class II antigens in the absence of IFN-gamma.

Recent widows' kin support and orientations to self-sufficiency.

This paper examines two issues: the role of the adult child network in task support to widows, and whether widows' attitudes toward independence result in lower levels of task support. Data on recently widowed women suggest that many are quite self-sufficient; however, in those areas where support is needed, they largely rely on children. Widows' past experiences and attitudes toward independence influence the amount of overall help they receive, whereas income, number of children, and perceived willingness of children to help affect the proportion of help that comes from children.

Financial experience and well-being among mature widowed women.

Widowhood for women may be complicated by a lack of financial experience or knowledge, further diminishing well-being. Analyzed were data from 300 widowed women aged 60 and older regarding financial experience prior to widowhood, planning undertaken before death of spouse, and their effects on well-being in early widowhood. Shown by the findings was that preparation was associated with somewhat better well-being among widows, but financial experience prior to widowhood had no effect.

The feasibility of conducting strength and flexibility programs for elderly nursing home residents with dementia.

A strength and flexibility training program was designed to determine the feasibility of conducting such a program with elderly nursing home residents with dementia. Training sessions included a warm-up and cool-down to improve flexibility, and a variety of strength exercises using Therabands to improve strength. Ten subjects met three times per week for 20 minutes each session. Throughout the program, the number of repetitions and the resistance of the Therabands was increased. At the end of the 11-week training program, improvements occurred in strength and flexibility. We conclude that this strength training program is feasible to conduct for elderly persons with dementia.

Infiltrate of chronic lymphocytic leukemia appearing as a periapical radiolucent lesion.

This report presents a case of a mandibular premolar with a vital pulp and a periapical radiolucent lesion in a patient with a history of chronic lymphocytic leukemia. Biopsy of the lesion revealed an infiltrate of chronic lymphocytic leukemia in the mandible, which is quite rare. This lesion may have portended a worsening of the patient's condition and downgrading of her prognosis.

A scanning electron microscopic study of in vivo ultrasonic root-end preparations.

The purpose of this in vivo study was to evaluate root-ends for cracks after root resection and again after ultrasonic root-end preparation in patients undergoing endodontic surgery. Endodontic surgery was performed on 25 roots from 20 patients. In vivo vinyl polysiloxane impressions were made after root resection and again after ultrasonic root-end preparations. Epoxy resin casts were made from the impressions and scanning electron micrographic examination of the root-end replicas was performed. There was no evidence of cracks after root resection. One incomplete canal crack was evident after ultrasonic root-end preparation.

Solving endodontic isolation problems with interim buildups of reinforced glass ionomer cement.

A technique is presented for the expedient placement of interim buildups of type II glass ionomer cement as an aid for endodontic isolation of broken down teeth. The bond strength of glass ionomer cement to tooth structure is sufficient to withstand the forces of endodontic manipulation without the need for reinforcing pins. The material also shows promise as an intermediate endodontic seal. Variations of this technique are presented to address some other common isolation problems and the esthetic needs of the patient.

Comparison of dentinal crack incidence and of post removal time resulting from post removal by ultrasonic or mechanical force.

The purpose of this study was to compare the frequency of canal and intradentin cracks after intraradicular post removal using ultrasonic instrumentation or the Gonan post removal system. Sixty cadaver teeth were divided into 4 groups of 15 teeth each: group 1, ultrasonic removal; group 2, Gonan post removal system; group 3, cemented posts not removed; and group 4, no posts. Groups 1 and 2 were contralateral matched pairs. Para Posts were placed in groups 1, 2, and 3 to 7 mm apical to the cementoenamel junction and luted with ZnPO4 cement. The time required for post removal in groups 1 and 2 was recorded. The teeth were extracted, sectioned, and examined. Canal and intradentin cracks were mapped, and their frequency was recorded at each level. There were statistically more cracks present in the ultrasonic group than the no post group. There were no other differences that reached statistical significance. It took significantly longer for post removal using the ultrasonic tip versus the Gonan system.

A comparison of canal centering ability of four instrumentation techniques.

The purpose of this study was to compare three engine driven (nickel-titanium) NiTi instrument systems with hand files for their effect on canal transportation. Mesial roots of mature lower first molars with separate canals were paired on the basis of curvature and morphology. Canal lengths were standardized to 11 mm from orifice to apical foramen. Profile, Lightspeed, McXIM, and Flex-R hand filing techniques respectively were randomly assigned to one of the four canals of each tooth pair. The roots were mounted and sectioned at 1 mm, 3 mm, and 5 mm from working length using a modified Bramante technique. All sections were video imaged preoperatively after instrumentation to size #30 and after final instrumentation to size #40. The images were computer analyzed for changes in canal area and centering at each stage of instrumentation. Preparation time was also recorded. Data were analyzed using ANOVA. The NiTi systems remained better centered in the canal than stainless steel hand files. There were no significant differences among the NiTi systems at any level. The difference between hand filing and the NiTi techniques was more pronounced at size #40 than at size #30. The NiTi systems were all significantly faster than hand filing. No significant differences in preparation were found between the NiTi systems when canals were instrumented to the size nearest #40.

A comparative study of smear layer removal using different salts of EDTA.

Three solutions of EDTA--a 15% concentration of the alkaline salt, a 15% concentration of the acid salt, and a 25% concentration of the alkaline salt--were evaluated for smear layer removal in root canal systems. All solutions were adjusted to pH 7.1 using either NaOH or HCl. When the EDTA solutions were alternately used for root canal irrigation with 5.25% NaOCl, they completely removed the smear layer in the middle and coronal thirds of canal preparations, but were less effective in the apical third. None of the EDTA solutions by themselves were effective at completely removing the smear layer at any level. The alkaline tetrasodium salt, pH adjusted with HCl, is more cost effective and performed equally as well as the more commonly used disodium salt.

Evaluation of diamond-coated ultrasonic instruments for root-end preparation.

Ultrasonic instrumentation has been associated with cracking of the dentin in the area of the root-end preparation. The purpose of this study was to evaluate root-end preparations for cracking and to describe cavosurface morphology after the use of diamond-coated instruments. Forty teeth were inspected for intradentin cracks, incomplete canal cracks, and complete canal cracks before and after preparation with a stainless steel CT-5 ultrasonic instrument and again after root-end preparation with an S12D/90 degrees diamond-coated instrument. Six teeth had polyvinylsiloxane impressions taken of the root ends after preparation with the CT-5 and again after preparation with the diamond-coated instrument. Replicas were made, split, sputter-coated, and inspected using the scanning electron microscope. This study indicates that use of the diamond-coated instrument for root-end preparation does not result in significant root-end cracking and that it can remove cracks created by a prior instrument's use. The use of the diamond-coated instrument resulted in a heavily abraded, debris-covered cavosurface that may affect the apical seal.

Evaluation of cracks associated with ultrasonic root-end preparation.

The purpose of this study was to evaluate the integrity of resected root-end surfaces of extracted human teeth after using ultrasonic tips at low or high frequencies for root-end preparation. Thirty bilaterally matched pairs of single-rooted human teeth had root-end resections using a low-speed diamond saw and were examined for root-end cracks. The matched pairs of teeth were then divided into two experimental groups, with one member of each pair being placed in each group. In group 1, root-end preparations were made with an ultrasonic tip on the lowest frequency setting. The preparations in group 2 were done on the highest power setting. Two investigators again examined the resected root-ends using a stereomicroscope at x20 to x63 and recorded the numbers, types, and location of the cracks. Three types of cracks were observed: canal cracks, intradentin cracks, and cemental cracks. There were significantly more root-ends with cracks after ultrasonic root-end preparation than after root-end resection only. In root-ends that had any cracks, significantly more canal cracks per root occurred when the ultrasonic tip was used on the high-frequency setting for root-end preparation than when the ultrasonic tip was used on the low power setting.

A comparison of four instrumentation techniques on apical canal transportation.

The ability of four instrumentation techniques to enlarge and maintain the central axis of 51 curved canals was evaluated radiographically. Curved canals in extracted human teeth were instrumented using a step-back preparation with K-files, crowndown preparation with K-files, sonic instrumentation with Shaper-Sonic files, and the NiTiMatic preparation system. Following coronal preflaring, each canal was instrumented to a #35 file 1 mm from the anatomic foramen. Radiographs were taken with mercury filling the canal system using a specially designed model that allowed for the pre- and postinstrumentation canal to be viewed on the same radiograph. Canal enlargement and apical transportation resulting from the various instrumentation techniques were evaluated using computer analysis. No statistically significant differences were found for canal transportation. Sonic instrumentation significantly increased coronal flaring. The crown-down and sonic techniques produced more ledges. Elbow formation was associated with all instrumentation techniques. The model system developed for this study provided an accurate method of assessing the preparation techniques and the instrument effects on the canal walls.

Evaluation for cracks associated with ultrasonic root-end preparation of gutta-percha filled canals.

Many clinicians use ultrasonics for root-end preparations. The purpose of this study was to evaluate resected root-end surfaces of bilaterally matched human teeth for cracks before and after ultrasonic root-end preparation. Twenty matched pairs of extracted single rooted teeth were divided into two experimental groups. In group 1, root-end resection was performed on uninstrumented teeth. In group 2, root-end resection was performed after the canals were instrumented and filled with gutta-percha. All teeth in both groups received root-end preparations using ultrasonic instrumentation at low power. Two examiners evaluated the root-ends after root-end resection and again after root-end preparation using zoom magnification of 20x to 63x. The number, types, and location of cracks were mapped. There were no significant differences when gutta-percha filled roots were compared to uninstrumented roots with regard to the number or type of cracks after root-end resection or root-end preparation. In addition, there were no significant differences in the number or type of cracks following root resection and ultrasonic root-end preparation when compared to teeth with root resection alone.

Effect of calcium hydroxide and four irrigation regimens on instrumented and uninstrumented canal wall topography.

The topography of instrumented and uninstrumented canal walls exposed to calcium hydroxide and four different irrigation regimens was observed by scanning electron microscopy. After chemomechanical debridement, one tooth in each matched pair was medicated with calcium hydroxide. One week later, the teeth were irrigated and split longitudinally for evaluation. When no calcium hydroxide was used, predentin and pulpal debris covered the dentinal tubules of the uninstrumented surfaces in specimens irrigated with water or EDTA, but was absent on uninstrumented surfaces in specimens irrigated with NaOCl or NaOCl and EDTA. A typical smear layer was absent in instrumented specimens irrigated with NaOCl and EDTA, but covered the dentinal tubules of the instrumented surfaces of the EDTA irrigated specimens (partially) and the water or NaOCl irrigated specimens (completely). Calcospherites or their remnants were seen on the uninstrumented canal walls of specimens irrigated with NaOCl or NaOCl and EDTA, respectively. Calcium hydroxide use did not alter the surface topography in specimens irrigated with water, EDTA, or NaOCl, but seemed to erode the intertubular dentin in specimens irrigated with NaOCl and EDTA. All irrigants seemed to effectively remove most of the calcium hydroxide.

The topography of root ends resected with fissure burs and refined with two types of finishing burs.

OBJECTIVES: This study compared the surface topography of roots resected with #57, Lindeman, and Multi-purpose burs. Further comparisons were made after refinements with either a multifluted carbide or an ultrafine diamond finishing bur. STUDY DESIGN: Three groups of single-rooted human teeth were resected with each resection bur, and resin replicas of the root ends were made. Root ends from each resection bur group were finished with either a multifluted carbide or an ultrafine diamond finishing bur, and the root ends were replicated. All replicas were evaluated at a magnification of x20 for smoothness and surface irregularities. Data analysis was done with the Wilcoxon signed rank test and the chi-square test at a significance level of p < 0.05. RESULTS: The Multi-purpose bur produced a smoother and more uniplanar surface than the #57 bur and caused less damage to the root than either the #57 or the Lindeman bur. The multifluted carbide finishing bur tended to improve the smoothness of the root end, while the ultrafine diamond tended to roughen the surface. CONCLUSIONS: The Multi-purpose bur produced the smoothest and most uniplanar resected root-end surface with the least root shattering. The multifluted carbide finishing bur produced a smoother surface than the ultrafine diamond bur.

Demineralization of resected root-ends with methylene blue dye.

OBJECTIVES: This study evaluated the ability of methylene blue solutions of different concentration, pH, and time exposure to remove the smear layer from resected root-ends. STUDY DESIGN: Resected root-ends were treated with either 2% methylene blue dye for intervals of 5 to 11 minutes or 1% methylene blue for 7 to 9 minutes and examined with a scanning electron microscope for smear layer removal. Two minute applications of saline solution and 50% citric acid served as controls. RESULTS: All methylene blue solutions were found to be ineffective in removing the smear layer at all time intervals tested. An experimental solution of 1% methylene blue in 50% citric acid was found to predictably remove the smear layer during a 2 minute application and retained all the favorable staining characteristics of the dye. Fifty percent citric acid solutions applied for 3 minutes appeared to overdemineralize the root-end and gave poorer results than 2 minute applications. CONCLUSIONS: Smear layer removal was pH dependent. Methylene blue solutions are clinically unsuitable for smear layer removal.

Chronic boron or copper deficiency induces limb teratogenesis in Xenopus.

Sets of adult male and female Xenopus laevis were administered a boron-deficient (-B) diet under low-boron culture conditions, a boron-supplemented (+B) diet under ambient boron culture conditions, a copper-deficient (-Cu) diet under low-copper culture conditions, or a copper-supplemented (+Cu) diet under ambient copper culture conditions, for 120 d. Adults from each group were' subsequently bred, and the progeny were cultured and bred. Results from these studies indicated that although pronounced effects on adult reproduction and early embryo-larval development were noted in the -B F1 generation, no effects on limb development were observed. No significant effects on reproduction, early embryogenesis, or limb development were noted in the +B group, irrespective of generation. Highly specific forelimb and hindlimb defects, including axial flexures resulting in crossed limbs and reduction deficits, were observed in -B F2 larvae, but not in the +B F2 larvae. As was noted in the boron-deficiency studies, significant effects on reproduction and early embryo development were observed in the -Cu F1 generation, but not in the +Cu F, generation. Unlike the effects associated with boron deficiency, maldevelopment of the hindlimbs (32 responders, n = 40) was found in the F1 generation.