Educators have hard choices; nationally, not just in Kansas.
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Biomedical subjects
Publications and source records attributed to S White.
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The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV/c2 WIMP mass and, at >75% C.L., the entire 3sigma allowed region for the WIMP signal reported by the DAMA experiment.
Synthetic polyamides composed of three types of aromatic amino acids, N-methylimidazole (Im), N-methylpyrrole (Py) and N-methyl-3-hydroxypyrrole (Hp) bind specific DNA sequences as antiparallel dimers in the minor groove. The side-by-side pairings of aromatic rings in the dimer afford a general recognition code that allows all four base-pairs to be distinguished. To examine the structural consequences of changing the DNA sequence context on T.A recognition by Hp/Py pairs in the minor groove, crystal structures of polyamide dimers (ImPyHpPy)(2) and the pyrrole counterpart (ImPyPyPy)(2) bound to the six base-pair target site 5'-AGATCT-3' in a ten base-pair oligonucleotide have been determined to a resolution of 2.27 and 2.15 A, respectively. The structures demonstrate that the principles of Hp/Py recognition of T.A are consistent between different sequence contexts. However, a general structural explanation for the non-additive reduction in binding affinity due to introduction of the hydroxyl group is less clear. Comparison with other polyamide-DNA cocrystal structures reveals structural themes and differences that may relate to sequence preference.
Current opinion of the genetic events driving colorectal tumourigenesis focuses on genomic instability. At least two apparently independent mechanisms are recognized, microsatellite instability and chromosomal instability. The genetic defects underlying each type of instability are only partially understood and controversy remains as to the role of p53 in the generation of chromosomal defects in colorectal cancer. This study sought to clarify the relationships between chromosomal abnormalities and defects of both p53 and mismatch repair. Extensive chromosomal analysis was undertaken, using flow cytometry and comparative genomic hybridization, of a series of sporadic colorectal cancers which had been grown to early passage as subcutaneous xenografts in SCID mice. Overall levels of chromosomal defects were observed to be low in RER+ cancers compared with RER- and distinctive patterns of chromosomal anomalies were found to be associated with both the RER+ and RER- phenotype. No particular level or pattern of chromosomal anomalies appeared to be associated with p53 status, supporting recent observations that abnormal p53 function is not sufficient to cause chromosomal anomalies in colorectal tumours.
BACKGROUND: Most people with epilepsy have a good prognosis and their seizures can be well controlled with the use of a single antiepileptic drug, but up to 30 % develop refractory epilepsy, especially those with partial seizures. In this review we summarise the current evidence regarding oxcarbazepine when used as an add-on treatment for drug-resistant partial epilepsy. OBJECTIVES: To evaluate the effects of oxcarbazepine when used as an add-on treatment for drug-resistant partial epilepsy. SEARCH STRATEGY: We searched the Cochrane Epilepsy Group's trials register, the Cochrane Controlled Trials Register (Cochrane Library Issue 1, 2000), MEDLINE (January 1966 to December 1999) and reference lists of articles. We also contacted Novartis (manufacturers of oxcarbazepine) and experts in the field. SELECTION CRITERIA: Randomized, placebo-controlled, double-blind, add-on trials of oxcarbazepine in patients with drug-resistant partial epilepsy. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trials for inclusion and extracted the relevant data. The following outcomes were assessed : (a) 50 % or greater reduction in seizure frequency; (b) treatment withdrawal (any reason); (c) side effects. Primary analyses were intention to treat. Summary odds ratios were estimated for each outcome. MAIN RESULTS: Overall Odds Ratio (OR) (95 % Confidence Interval (CIs)) for 50 % or greater reduction in seizure frequency compared to placebo 2.96 (2.20,4.00). Treatment withdrawal OR (95 % CIs) compared to placebo 2.17 (1.59,2.97). Side effects: OR (99 % CIs) compared to placebo, ataxia 2.93(1.72,4.99); dizziness 3.05 (1.99, 4. 67); fatigue 1.80 (1.02, 3.19); nausea 2.88 (1.77, 4.69); somnolence 2.55 (1.84, 3.55); diplopia 4.32 (2.65, 7.04), were significantly associated with oxcarbazepine. REVIEWERS' CONCLUSIONS: Oxcarbazepine has efficacy as an add-on treatment in patients with drug-resistant partial epilepsy, both in adults and children. However, trials reviewed were of relatively short duration, and provide no evidence about the long term effects of oxcarbazepine. Results cannot be extrapolated to monotherapy or to patients with other epilepsy types.
Cancer management in the older patient is a growing concern, particularly with the increasing geriatric population and the high incidence of cancer among these individuals. Incidence of lung cancer in particular is known to rise with age. This article reviews prognosis, treatment options, and decision-making issues for both clinician and patient with respect to both non-small-cell and small-cell lung cancer in this population. Research findings dealing with response rates, survival rates, and symptom control in this age group are reviewed for radiotherapy, surgery, and for various chemotherapy agents, including gemcitabine, the taxanes, vinorelbine, and the topoisomerase 1 inhibitors. Quality- of-life issues are also addressed.
OBJECTIVES: Over the past decade, the glial protein S-100beta has been used to detect cerebral injury in a number of clinical settings including cardiac surgery. Previous investigations suggest that S-100beta is capable of identifying patients with cerebral dysfunction after cardiopulmonary bypass. Whether detection of elevated levels S-100beta reflects long-term cognitive impairment remains to be shown. The present study evaluated whether perioperative release of S-100beta after coronary artery operations with cardiopulmonary bypass could predict early or late neuropsychologic impairment. METHODS: A total of 100 patients undergoing elective coronary bypass without a previous history of neurologic events were prospectively studied. To exclude noncerebral sources of S-100beta, we did not use cardiotomy suction or retransfusion of shed mediastinal blood. Serial perioperative measurements of S-100beta were performed with the use of a new sensitive immunoluminometric assay up to 8 hours after the operation. Patients underwent cognitive testing on a battery of 11 tests before the operation, before discharge from the hospital, and 3 months later. RESULTS: No significant correlation was found between S-100beta release and neuropsychologic measures either 5 days or 3 months after the operation. CONCLUSION: Despite using a sensitive immunoluminometric assay of S-100beta, we found no evidence to support the suggestion that early release of S-100beta may reflect long-term neurologic injury capable of producing cognitive impairment.
Purpose: With the increasing use of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for scanning in oncology in our center, a radiation dose survey was performed to determine the impact on staff exposure. Conventional nuclear medicine procedures such as gallium scan, bone scans, and sestamibi cardiac scans are used for comparative purposes.Procedure: Patients were measured using a hand-held radiation monitor (Victoreen 450-P) at various distances and times that replicate typical patient contact scenarios in the Diagnostic Imaging Department.Results: We present our findings from the survey and the implications these have on staff radiation exposure. The data suggest that emerging oncologic techniques such as PET, high dose gallium-67, and high dose Tl-201 do not represent a significantly greater occupational radiation hazard than conventional nuclear medicine procedures.
PURPOSE: Retinopathy of prematurity (ROP) stage 3 eyes that require treatment have a greater tendency to myopia compared with eyes with mild ROP. As the mechanisms controlling this myopia are as yet ill understood, we undertook this study to investigate what effect the initial stage of ROP and modality of treatment had on ocular growth. METHODS: Eighty-five children were assessed. All children were refracted and underwent 'through-the-lid' biometry using the Zeiss Humphrey biometer 820. The printout obtained was then recorded on video so that the scan could be captured on computer for formal calibration and measurement by a masked observer. Differences in the distribution of variables between the stages of ROP were analysed by one-way analysis of variance, non-parametric Kruskal-Wallis one-way analysis of variance or Mann-Whitney U-test as appropriate. RESULTS: A difference between the stages of ROP was apparent only for posterior segment length (PSL) (R: p = 0.03; L: p = 0.05) and a borderline difference for anterior chamber depth (ACD) (R: p = 0.06; L: p = 0.06). However, if stage 3 was divided into categories of treated and untreated, axial length (AL) achieved borderline significance (R: p = 0.07; L: p = 0.05) but with no difference between laser-treated and the other stages for AL. Lens thickness (LT) also appears to be influenced by type of treatment (R: p = 0.06; L: p = 0.13). Myopia was associated with stage 3 (R + L: p = 0.0001) and if stage 3 was subdivided the significance was maintained only for the laser- and cryotherapy-treated eyes. CONCLUSIONS: Laser-treated eyes were less myopic than those treated with cryotherapy. AL does not explain all the myopia found in stage 3 treated eyes. The study confirms the tendency towards anterior segment arrest in stage 3 ROP.
The N-terminal domain (NTD) of the heme-regulated eukaryotic initiation factor (eIF)2alpha kinase (HRI) was aligned to sequences in the NCBI data base using ENTREZ and a PAM250 matrix. Significant similarity was found between amino acids 11-118 in the NTD of rabbit HRI and amino acids 16-120 in mammalian alpha-globins. Several conserved amino acid residues present in globins are conserved in the NTD of HRI. His83 of HRI was predicted to be equivalent to the proximal heme ligand (HisF8) that is conserved in all globins. Molecular modeling of the NTD indicated that its amino acid sequence was compatible with the globin fold. Recombinant NTD (residues 1-159) was expressed in Escherichia coli. Spectral analysis of affinity purified recombinant NTD indicated that the NTD contained stably bound hemin. Mutational analysis indicated that His83 played a critical structural role in the stable binding of heme to the NTD, and was required to stabilize full length HRI synthesized de novo in the rabbit reticulocyte lysate. These results indicate that the NTD of HRI is an autonomous heme-binding domain, with His83 possibly serving as the proximal heme binding ligand.
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The mechanism by which vagal nerve stimulation (VNS) exerts an anticonvulsant effect in humans is unknown. This study used (99m)Tc-HMPAO single photon emission tomography (SPECT) to examine the effects of VNS on regional cerebral activity in thalamic and insular regions. Seven subjects with epilepsy who had been receiving vagal nerve stimulation for at least 6 months underwent SPECT scanning with simultaneous scalp electroencephalographic (EEG) recording. Subjects were studied in two states; during VNS activity and during a comparison condition of VNS inactivity. A region of interest analysis demonstrated that rapid cycling stimulation (7 seconds on, 12 seconds off) was associated with relatively decreased activity in left and right medial thalamic regions. No systematic stimulation-related changes were observed on visual or spectral analysis of EEG data. The thalamus is involved in modulation of ongoing cortical EEG activity in animals. Our results support the hypothesis that VNS may exert an antiepileptic action by an effect on thalamic activity.
The aim of this study was to ascertain if the presence of patients' relatives during cardiopulmonary resuscitation altered perceived symptoms of stress in accident and emergency personnel participating in resuscitation attempts. An anonymous structured questionnaire survey of all accident and emergency staff participating in non-traumatic adult cardiopulmonary resuscitation was designed to elicit symptoms of an acute stress reaction within 24 hours based on ICD-10 diagnostic criteria. One hundred and fourteen staff replies were received, a reply rate of 89%. Twenty-five replies had two or more symptoms of an acute stress reaction. The grade or role of the staff member had no influence on the presence of stress symptoms. There was no difference in rates of reporting between staff resuscitating in the presence or absence of relatives. It is concluded that the presence of relatives witnessing resuscitation attempts does not affect self-reported stress symptoms in staff participating in resuscitation attempts.
BACKGROUND: The value of diving medicals in preventing incidents is uncertain and there has been only limited evaluation of the fitness to dive guidelines in a sport diving population. OBJECTIVE: To examine the need for routine diving medical examinations in the Scottish Sub-Aqua Club (SSAC) between 1991 and 1998. METHODS: A medical examination of all SSAC divers is performed at entry and then every one to five years based on their age and medical condition This information was analysed in terms of questionnaire findings and examination abnormalities. RESULTS: There were 2,962 medical forms available for analysis. Examination abnormalities were found in 174 subjects (5.9% of the population), with obesity affecting 75 subjects (2.5%). There was a linear increase in mean body mass index (r2 = 0.92), and a significant difference between 1991 and 1998 (mean (SD) of 24.1 (3.07) and 25.02 (3.4) respectively, p = 0.002) which was not related to age or sex distribution. There was also a significant increase in the prevalence of smokers (chi2 = 4.02, p = 0.045). The most common specialist referral was for evaluation of asthma, with hypertension and obesity as the next most common reasons. Most subjects were allowed to dive, with only 43 (25%) being failed outright. Overall, no examination abnormality alone caused a subject to be classified unfit to dive, and referrals were prompted by the answers in the questionnaire. CONCLUSIONS: No significant unexpected abnormalities were found on clinical examination in this population of sport divers. Conditions that prevented subjects from diving were detected by the questionnaire, and this prompted referral for further assessment by the medical advisors. Routine medical examinations were of little value.
Since March 1999 there have been three inquiries concerned either in whole or in part with the removal of human tissue from bodies during post-mortem examinations and its retention thereafter. Two of these at least have had to consider the law relating to the matter, and a commissioned paper and a submission about it to one, the Bristol Royal Infirmary Inquiry, have been mounted on the Inquiry's Web site. The main part of this article consists of the slightly revised text of a submission to the Inquiry by way of comment on these. Among the major points made in this submission are that (a) insufficient consideration has been given to the present status of the common law right of a person arranging a funeral to have the body of the deceased given Christian burial in the burial ground of the parish in which he or she died or of which he or she was a parishoner; (b) insufficient account has been taken of the scope of permissible modes of dealing with a dead body; and that (c) the implications this has for the common law offence of preventing Christian (or decent) burial have not been fully explored.
OBJECTIVE: To assess dose-response relationships to a single dose of botulinum toxin 'A' in upper limb spasticity associated with stroke or head injury. DESIGN: A double-blind placebo-controlled randomized dose ranging study. SETTING: A regional centre for neuroscience and a neurorehabilitation outpatient clinic. SUBJECTS: Twenty-one hemiplegic patients with troublesome upper limb spasticity. Nineteen with stroke and two with head injury. MAIN OUTCOME MEASURES: Spasticity (modified Ashworth), range of movement, posture (postural alignment and finger curl), disability (upper body dressing time and Frenchay Arm Test), patient-reported global assessment scale. RESULTS: Combining data from all doses of botulinum toxin there was a significant reduction in spasticity at the wrist and fingers associated with a greater range of passive movement at the wrist and less finger curl at rest. There was a tendency for a further reduction in spasticity at elbow and wrist to occur with increasing dose but not for finger spasticity or curl. Effects present at six weeks were lost by 12 weeks except for a small improvement in elbow range of movement at the 1,500 Mu dose. There was no change in upper limb disability but a significant increase in patients' global assessment of benefit. CONCLUSION: Botulinum toxin produced beneficial effects in spasticity and passive range of movement in the hemiplegic upper limb. Increasing the dose increased the magnitude of response for impairments in some muscle groups but had little effect on duration of response.
Interdisciplinary teams play a critical role in the delivery of geriatric health care. Health care professionals are commonly left to develop teamwork skills by chance. Medical team function differs from traditional group theory in that all members are caregivers. A non-competitive supportive atmosphere is appropriate for patient care. We propose a participatory (autonomy supportive) model fostering self-realization and positive reinforcement as an organizing philosophy. The primary group task is to maximize patient functional independence and personal goals. Leadership is task-dependent.
Idiopathic thrombocytopenic purpura is a condition that is characterized by persistently low platelet counts. Idiopathic thrombocytopenic purpura results from splenic sequestration and accelerated platelet destruction mediated by antiplatelet antibody. Most cases arise in previously healthy patients, mostly women ages 20 to 40. Clinical symptoms consist of bruising, petechiae, mucosal bleeding, menorrhagia, and intracranial bleeding. Platelet-associated immunoglobulin G can be detected in 90 per cent of patients. Therapy for adults and children is somewhat different. Splenectomy in adults should be considered in patients who fail to respond to steroids, develop thrombocytopenia after taper, or develop steroid toxicity. Ninety per cent of children will maintain normal platelet counts in 9 to 12 months. Some will recover spontaneously without medical therapy. Splenectomy in children is recommended if idiopathic thrombocytopenic purpura persists for more than one year or fails to respond to steroids. Our purpose was to determine whether management of idiopathic thrombocytopenic purpura in patients who undergo splenectomy at our institutions is appropriate and effective. We undertook a 5-year retrospective review of 27 patients with idiopathic thrombocytopenic purpura which have undergone splenectomy. All of the 27 patients were referred to surgeons after initial medical management. The patients were divided into two groups on the basis of length of therapy: longer than 6 months and less than 6 months. The longer than 6 months group contained 15 patients. This group had a postoperative complication rate of 40 per cent. Those in the group with <6 months therapy had a complication rate of 7 per cent. Average follow-up for all patients was 20 months. Eighty-eight per cent of the patients had complete response. Three per cent had a partial response with platelet counts >50,000. The partial response group did not respond well to preoperative steroid boluses with a great rise in platelet counts. Eighteen per cent of patients received platelet transfusions. Sixty per cent of the transfusions were given for inappropriate reasons. A large percentage of our patients had prolonged medical therapy before splenectomy. The inappropriate use of platelets was a common error in management. Patients treated for more than 6 months had more postoperative complications. An initial increase in platelets after steroid bolus is a good indicator for favorable response to splenectomy. We conclude that splenectomy is a safe and effective method of treatment for idiopathic thrombocytopenic purpura with no deaths or postsplenectomy sepsis to date.