Novel spinal dysplasia in two generations

We report on a father and son with a previously undescribed skeletal abnormality and severe short stature. Antenatal sonographic evaluation of the propositus (son), obtained due to maternal pre-eclampsia, suggested an abnormal spine. At birth, no congenital anomalies were noted and transition to extra-uterine life was smooth. Radiographs performed five days after birth showed spina bifida, hemivertebrae in the mid-thoracic region, and widened lumbar in-terpedicular distances. MRI of the lower thoracic and lumbar vertebrae documented crescent-shaped appearance of the affected vertebrae and abnormally narrow A-P diameter of the vertebral bodies. Intervertebral discs were small, and the posterior elements, as well as the spinous processes of the affected vertebrae, were markedly hypoplas-tic. However, there was no narrowness of the spinal canal, and the limbs were unaffected. CT scan with three-dimensional reformatting of the thoracic and lumbar vertebrae documented unusual sagittal clefting of all of the vertebral bodies, which has previously been undescribed. The father had severe kyphoscoliosis and a height of 131.6 cm (?7.5 S.D.). Radiograph-ically, he was found to have multiple segmentation anomalies and diminished A-P diameter of his affected vertebral bodies. The multiple vertebral anomalies are the probable cause for the father's severe kyphoscoliosis. The pattern of inheritance suggests that an autosomal dominant gene is responsible for this condition and that father represennts a de novo mutationn. These radiographic abnormalities have not been described previously and represent a new form o vertebral spinal dysplasia. © 1995 Wiley-Liss, Inc.     

A case repot of Merkel cell carcinoma on chronic lymphocytic leukemia: differential diagnosis of coexisting lymphadenopathy and indications for early aggressive treatment

Background  

Chronic lymphocytic leukemia (CLL) is a monoclonal disorder, characterized by a progressive proliferation of functionally incompetent B lymphocytes. There is increased evidence of association between CLL and skin cancers, including the uncommon Merkel cell carcinoma (MCC).     

Comparative safety evaluation of the candidate vaginal microbicide C31G

C31G is currently the focus of clinical trials designed to evaluate this agent as a microbicidal and spermicidal agent. In the following studies, the in vivo safety of C31G was assessed with a Swiss Webster mouse model of cervicovaginal toxicity and correlated with results from in vitro cytotoxicity experiments and published clinical observations. A single exposure of unformulated 1% C31G resulted in mild-to-moderate epithelial disruption and inflammation at 2 and 4 h postapplication. The columnar epithelium of the cervix was the primary site of damage, while no perturbation of the vaginal mucosa was observed. In contrast, application of unformulated 1.7% C31G resulted in greater levels of inflammation in the cervical epithelium at 2 h postapplication and severe epithelial disruption that persisted to 8 h postapplication. Application of a nonionic aqueous gel formulation containing 1% C31G resulted in no apparent cervicovaginal toxicity at any time point evaluated. However, formulation of 1.7% C31G did not substantially reduce the toxicity associated with unformulated C31G at that concentration. These observations correlate with findings gathered during a recent clinical trial, in which once-daily applications resulted in no adverse events in women receiving the formulation containing 1% C31G, compared to moderate-to-severe adverse events in 30% of women receiving the 1.7% C31G formulation. The Swiss Webster mouse model was able to effectively discriminate between concentrations and formulations of C31G that produced distinct clinical effects in human trials. The Swiss Webster animal model may be a highly valuable tool for preclinical evaluation of candidate vaginal microbicides.     

Benefits of a school-based asthma treatment program in the absence of secondhand smoke exposure: results of a randomized clinical trial

BACKGROUND: Daily maintenance medications are recommended for all children with mild persistent to severe persistent asthma; however, poor adherence to these medications is common. OBJECTIVE: To evaluate the impact of school-based provision of inhaled corticosteroids on asthma severity among urban children with mild persistent to severe persistent asthma. DESIGN: Children aged 3 to 7 years with mild persistent to severe persistent asthma were identified at the start of the 2000-2001 and 2001-2002 school years in Rochester. Children were assigned randomly to a school-based care group (daily inhaled corticosteroids provided through the school) or a usual-care group (inhaled corticosteroids not given through school). MAIN OUTCOME MEASURE: Improvement in parent-reported symptom-free days. RESULTS: Of 242 eligible children, 184 were enrolled from 54 urban schools. Data for 180 children were available. Parents of children in the school-based care group had a greater improvement in quality of life compared with parents of children in the usual-care group (change score, 0.63 vs 0.24; P =.047); also, children in the school-based care group vs the usual-care group missed less school because of asthma (mean total days missed, 6.8 vs 8.8; P =.047) and experienced more symptom-free days during the early winter months (mean days per 2-week period, 9.2 vs 7.3; P =.02). A post hoc analysis revealed that all significant findings were produced by differences among children who were not exposed to secondhand smoke. Furthermore, among children not exposed to smoke, those in the school-based care group vs the usual-care group had more symptom-free days overall (11.5 vs 10.5; P =.046), had fewer days needing rescue medications (1.6 vs 2.3; P =.03), and were less likely to have had 3 or more acute visits for asthma (6 [13%] of 47 children vs 17 [31%] of 54 children; P =.03). CONCLUSIONS: School-based provision of inhaled corticosteroids significantly improved symptoms, quality of life, and absenteeism among urban children with mild persistent to severe persistent asthma. This effect was seen only among children not exposed to secondhand smoke.     

Cell division rates of primary human precursor B cells in culture reflect in vivo rates

Bone marrow stroma-based cultures provide a powerful model for studying cell division and apoptosis of primary human precursor B cells. Studies using this model are elucidating the mechanisms by which stromal cells inhibit apoptosis of cultured normal precursor B cells and have demonstrated that the apoptotic rate of cultured leukemic precursor B cells can predict clinical outcome in acute lymphoblastic leukemia. In contrast to apoptosis, cell division in this model has not been well characterized. In this study, we quantified the rates of cell division in cultured primary human normal and leukemic precursor B cells by labeling precursor B cells with the fluorescent dye carboxyfluorescein diacetate, succinimyl ester. Based on the rate of decreasing fluorescent signal over 3 weeks, normal CD19(+), CD10(+) precursor B cells divided once every 90.5 hours, a number that correlates well with the known in vivo rate of 65.5 hours. The division rates were similar among different cultures and constant throughout the 3 weeks of culture, suggesting that the variable expansions of precursor B cells seen among different samples and culture durations are not secondary to different cell division rates. Unlike normal cells, cultured leukemic B cells had a heterogeneous division rate that ranged from once every 26-240 hours. These rates correlated well with their respective in vivo proliferation index. These findings indicate that the stroma-based cultures faithfully replicate in vivo cell division rates and can be used to elucidate the pathways that regulate cell division of primary human precursor B cells.     

Determining the upper limits of stimulation for auditory steady-state response measurements

OBJECTIVE: To determine the maximum stimulus levels at which a measured auditory steady-state response (ASSR) can be assumed to be a reliable measure of auditory thresholds. DESIGN: ASSR thresholds were measured at octave frequencies from 500 to 4000 Hz in 10 subjects with profound hearing loss. These subjects provided no behavioral responses to sound at the limits of pure-tone audiometers and at the limits of the stimulus levels produced by the ASSR device. Subjects were divided into two groups of five, with repeated measures obtained within the same session in one group and repeated measures obtained in a separate session on a different day in the other group. RESULTS: ASSR thresholds were observed in all 10 subjects at each of four frequencies and in both trials. On average, these ASSR thresholds were observed at 100 dB HL (SD = 5 dB). Because these responses were at least 18 to 22 dB below the limits of the equipment where all subjects had no behavioral responses, it is reasonable to conclude that the ASSRs were not generated by the auditory system. CONCLUSIONS: An artifact or distortion may be present in the recording of ASSRs at high levels. These data bring into question the view that there is a wider dynamic range for ASSR measurements compared with auditory brain stem response measurements, at least with current implementation.     

Astigmatism after small-incision clear corneal cataract extraction and intraocular lens implantation in children

PURPOSE: To investigate the magnitude of postoperative astigmatism in children having cataract extraction with intraocular lens (IOL) implantation through a 3.0 mm superior clear corneal incision. SETTING: Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA. METHODS: This retrospective chart review comprised all pediatric patients having cataract surgery with IOL implantation through a 3.0 mm clear corneal incision from 1997 to 2002. One hundred two eyes of 75 patients were included. All refractions were performed manually by an experienced pediatric ophthalmologist. RESULTS: The mean postoperative retinoscopic cylinder in all patients was 0.63 diopter (D) (range 0.0 to 4.50 D) at 1 month, 0.40 D (range 0.0 to 1.75 D) at 6 months, and 0.51 D (range 0.0 to 2.50 D) at 1 year. Patients aged 0 to 36 months at the time of surgery had a mean postoperative cylinder of 0.22 D at 1 month, 0.03 D at 6 months, and 0.21 D at 1 year. Patients between 36 months and 6 years of age at surgery had a mean refractive cylinder of 0.50 D, 0.38 D, and 0.75 D, respectively. Patients older than 6 years at surgery had a mean refractive cylinder of 0.94 D, 0.75 D, and 0.76 D, respectively. CONCLUSIONS: Small-incision clear corneal cataract extraction with IOL implantation in children led to minimal postoperative astigmatism that remained stable over time. Less astigmatism was observed in children having surgery before they were 36 months old.     

Cognitive performance and subjective experience during combined exposures to whole-body vibration and noise

Objective The goal of this study was to examine the effects of noise and whole-body vibration, individually and combined, and at various stimulus intensity levels, on cognitive performance and subjective experience.Method Fifty-four participants (27 men and 27 women) with a mean age of 25 years, ranging from 19 to 30, were exposed for 20 min each to a 16-Hz sinusoidal whole-body vibration, a helicopter sound at 21 Hz, both stimuli combined, and a control condition. Participants were randomly assigned to one of three groups: low intensity [77 dB(A) noise and 1.0 m/s² vibration], medium intensity [81 dB(A)/1.6 m/s²] or high intensity [86 dB(A)/2.5 m/s². During each environmental exposure, short-term memory performance was tested with a visual Sternberg paradigm. Reaction time was measured as a dependent variable. Directly following each environmental exposure, participants rated the difficulty of the task and the annoyance level of the exposure stimulus.Results Results revealed no significant changes in reaction times due to environmental exposure or intensity level. However, participants significantly rated the combined exposure as both more annoying and more difficult than the other conditions. Further, the high-intensity group rated subjective annoyance significantly higher than the other groups for all conditions.Conclusions The results from this study indicate that performance alone is not a sufficient measure for the study of the effects of combined stimuli on a human operator.