Transsphenoidal hypophysectomy: a laboratory approach and commentary

A laboratory technique for learning and practicing the transsphenoidal approach to hypophysectomy is described. The procedure utilizes a sphenoid block with the sella turcica at its center taken from a cadaver skull. The laboratory approach stimulates the operative technique, including the use of standard instruments designed for transsphenoidal hypophysectomy. Commentary on the historical background and applications of the transsphenoidal approach to the sella turcica is presented.     

Information, choice, and reactions to stress: A field experiment in a blood bank with laboratory analogue.

Two experiments examined the effects of various operations of personal control on reactions to stress. Exp I with 40 17–50 yr old blood donors incorporated 2 features into the blood-drawing procedure at a blood bank: providing donors with accurate information and allowing donors to choose the arm to be used. Measurement of nurses' actions to prevent donors from fainting and self-reports of discomfort indicated that the combination of choice and information was somewhat effective in reducing distress. However, providing either information or choice alone was more effective. In Exp II, using a cold pressor stimulus as stressor, 44 undergraduates given a choice (the option to terminate the aversive stimulus and choice of hand used) showed a reduction of aftereffects on a measure of attention to detail. Ss given information but not choice also showed this reduction. Combining information and choice was no different from either treatment alone. Results of both studies indicate that moderate levels of choice and information are optimal for coping with stress. An explanation is suggested, based on a contextually determined relationship among choice, information, and perceived control. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social competence and head injury: a practical approach

Social competence assessment and training has long focused on specific skills within the clinical setting. In addition, emphasis has been placed on identifying deficits relative to an arbitrary, often idiosyncratic metric. In this article, we discuss the importance of the principles that underlie communication and which are reflected in the range of behaviours described as 'social competence'. We review methods we have found productive in the training of these principles with persons who have suffered traumatic brain injuries.     

The multilevel latent covariate model: A new, more reliable approach to group-level effects in contextual studies.

In multilevel modeling (MLM), group-level (L2) characteristics are often measured by aggregating individual-level (L1) characteristics within each group so as to assess contextual effects (e.g., group-average effects of socioeconomic status, achievement, climate). Most previous applications have used a multilevel manifest covariate (MMC) approach, in which the observed (manifest) group mean is assumed to be perfectly reliable. This article demonstrates mathematically and with simulation results that this MMC approach can result in substantially biased estimates of contextual effects and can substantially underestimate the associated standard errors, depending on the number of L1 individuals per group, the number of groups, the intraclass correlation, the sampling ratio (the percentage of cases within each group sampled), and the nature of the data. To address this pervasive problem, the authors introduce a new multilevel latent covariate (MLC) approach that corrects for unreliability at L2 and results in unbiased estimates of L2 constructs under appropriate conditions. However, under some circumstances when the sampling ratio approaches 100%, the MMC approach provides more accurate estimates. Based on 3 simulations and 2 real-data applications, the authors evaluate the MMC and MLC approaches and suggest when researchers should most appropriately use one, the other, or a combination of both approaches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

RigFit: a new approach to superimposing ligand molecules

If structural knowledge of a receptor under consideration is lacking, drug design approaches focus on similarity or dissimilarity analysis of putative ligands. In this context the mutual ligand superposition is of utmost importance. Methods that are rapid enough to facilitate interactive usage, that allow to process sets of conformers and that enable database screening are of special interest here. The ability to superpose molecular fragments instead of entire molecules has proven to be helpful too. The RIGFIT approach meets these requirements and has several additional advantages. In three distinct test applications, we evaluated how closely we can approximate the observed relative orientation for a set of known crystal structures, we employed RIGFIT as a fragment placement procedure, and we performed a fragment-based database screening. The run time of RIGFIT can be traded off against its accuracy. To be competitive in accuracy with another state-of-the-art alignment tool, with which we compare our method explicitly, computing times of about 6 s per superposition on a common day workstation are required. If longer run times can be afforded the accuracy increases significantly. RIGFIT is part of the flexible superposition software FLEXS which can be accessed on the WWW [http:/(/)cartan.gmd.de/FlexS].     

MULTIFIT: a new approach to risk factor modification

The MULTIFIT system provides an infrastructure for the management of coronary risk factors and associated conditions. It is well integrated into standard medical practice, relying on existing personnel, facilities, and equipment. It integrates cognitive, executive, and organizational aspects of medical care delivery. It addresses an important national health goal: how to substitute relatively inexpensive preventive care for expensive palliative care for patients with established vascular disease.     

Nicotine replacement: a new approach to reducing tobacco-related harm

A case of transient abnormal myelopoiesis in a normal newborn without features of Down syndrome is described. The majority of bone marrow cells analysed belonged to a chromosomally abnormal clone with trisomy for chromosomes 18 and 21. Complex intrachromosomal rearrangements of one chromosome 21, demonstrated by fluorescence in situ hybridization using locus-specific probes, were found in a minor population of the clonal cells. These rearrangements involved loci previously shown to be rearranged in the leukaemic cells from patients with Down syndrome and leukaemia. However, the child's myeloproliferation resolved rapidly, with disappearance of the abnormal clone, and 3.5 years later she remains well.     

Ogilvie''s syndrome: a new approach to an old problem

The effect of glucose infusion on renal handling of purine bases and oxypurinol was examined in 6 normal subjects. Five hundred milliliters of 1.1 M glucose solution were administered intravenously in 1 h. Fractional clearances of uric acid, xanthine and oxypurinol were significantly increased during glucose infusion, but that of hypoxanthine was not changed, while a 1-hour infusion of 500 ml of 1.1 M mannitol had no effect on the fractional clearances of purine bases and oxypurinol. These data indicate that the effect of glucose infusion on the renal clearances of uric acid, xanthine and oxypurinol was not related to osmotic diuresis but induced by glycosuria and/or hyperglycemia. Accordingly, the glycosuria- and/or hyperglycemia-induced decrease in the biological half-life of oxypurinol must be considered in the administration of allopurinol to gouty patients with uncontrolled diabetes mellitus.     

Deep cognitive activation: a new approach to the unconscious

Deep cognitive activation occurs when a thought is so accessible as to have measurable effects on behavior or judgement, but is yet not consciously reportable. This state of mind has unique properties mimicking some characteristics of the psychoanalytic unconscious, but following theoretically from a consideration of processes of cognitive activation. The sources and consequences of deep cognitive activation are examined, with a view toward understanding how this state is implicated in the assessment, etiology, and treatment of psychopathology.     

Low-tar medium-nicotine cigarettes: a new approach to safer smoking

The logic of expecting people who cannot stop smoking to switch to cigarettes that have hardly any nicotine is questionable. Tar and nicotine yields of cigarettes available in Britain today correlate 0-93, and further reduction of tar intake is limited by the reluctance of smokers to tolerate similar reductions in nicotine. A new approach would be to aim at lowering tar yields of cigarettes from the present average of 18 mg to around 6 mg but maintaining nicotine yields at around 1-0 to 1-2 mg, which would be acceptable to most smokers. This approach requires that emphasis be placed on tar: nicotine ratios as well as on the absolute yields. These ratios for brands on sale in Britain today average 14-2 and range from 9-6 to 20-8. They provide an additional guide for comparing the relative harmfulness of different brands. For example, 35% of cigarette smokers in Britain smoke either Embassy Filter or Players No 6 Filter; by changing to John Player Carlton King Size they could reduce their tar intake by more than 20% without having to suffer any nicotine deprivation.     

Mechanism of head and neck response to -Gx impact acceleration: a math modeling approach

Mathematical modeling has attained wider acceptance in recent years. In particular, the use of computer programs to simulate the dynamic response of a human in a crash situation has become an attractive alternative to full-scale experimental testing. This paper analyzes data on the dynamic response of the living human head and neck to -Gx impact acceleration, where the motion of the subject's head and neck in the midsagittal plane was monitored with inertial instrumentation and high-speed photography for confirmation. The Calspan "3D Computer Simulator of Motor Vehicle Crash Victims" was used to predict expected responses for the deceleration pulses employed. These estimates were compared to the fully instrumented human test runs. The standard 15-segment and 14-joint representation of the occupant was modified to include two sternoclavicular joints, increasing the articulation in the upper torso. Analysis of the data indicated that muscular activity in the head and neck seemed to be evident and does influence motion of the head, even at relatively high (10-G peak, 530 G/s onset) acceleration levels. Simulation of muscular contraction, using a spring-damper arrangement, improved the results significantly. Additionally, possible limitations to head-to-neck motion, such as ligament restrictions, were also modeled.     

Care tracker: a new approach to nursing care in ambulatory settings

It is becoming increasingly clear that mitochondrial Ca2+ uptake from and release into the cytosol has important consequences for neuronal and glial activity. Ca2+ regulates mitochondrial metabolism, and mitochondrial Ca2+ uptake and release modulate physiological and pathophysiological cytosolic responses. In glial cells, inositol 1,4,5-trisphosphate-dependent Ca2+ responses are faithfully translated into elevations in mitochondrial Ca2+ levels, which modifies cytosolic Ca2+ wave propagation and may activate mitochondrial enzymes. The location of mitochondria within neurones may partially determine their role in Ca2+ signalling. Neuronal death due to NMDA-evoked Ca2+ entry can be delayed by an inhibitor of the mitochondrial permeability transition pore, and mitochondrial dysfunction is being increasingly implicated in a number of neurodegenerative conditions. These findings are illustrative of an emerging realization by neuroscientists of the importance of mitochondrial Ca2+ regulation as a modulator of cellular energetics, endoplasmic reticulum Ca2+ release and neurotoxicity.     

Safety and efficacy of ECT in patients with head injury: a case series

BACKGROUND: The role of postoperative radiotherapy and adjuvant chemotherapy in the treatment of synovial sarcoma remains to be determined. PROCEDURE: Twenty-five children were treated during a 23-year period with a multimodality approach. All of them had resection of the primary tumor (three amputations), followed by surgical retreatment in eight. Postoperative radiotherapy was delivered to 16 patients and adjuvant chemotherapy was given to 22. RESULTS: At the time of the report, 19 patients were alive and without evidence of disease. Six developed distant metastases (one associated with local recurrence); five of them died of their disease and one was alive in complete remission at 4 years from relapse. With a median follow-up of 9 years (range 2-23), the survival and the event-free survival at 5 years were 80% (SE 8.2) and 74% (SE 9.2), respectively. All relapsing patients had been classified as T2B. CONCLUSIONS: Multimodality treatment yielded satisfying survival results using limb-preserving surgery in most cases. Tumor size > 5 cm and invasiveness, which defined stage T2B, were the most important predictors of poor outcome. Evaluation of the role of adjuvant chemotherapy and radiotherapy awaits prospective studies, even if T2B patients, as well as children having nonradical surgery, seem worth managing by adjuvant treatments.     

Chemotherapy as a part of each treatment fraction in a twice-a-day hyperfractionated schedule: a new chemoradiotherapy approach for advanced head and neck cancer

In allergic asthma, there is convincing evidence that changes in eosinophil and lymphocyte state of activation in blood may reflect disease activity. We evaluated whether simple blood eosinophil or lymphocyte counts in atopic children with asthma could reflect the degree of allergic sensitization. Seventy-six asthmatic children, sensitized to house dust mites (HDM), in stable conditions at the time of the study, and 53 sex- and age-matched controls (CTR) were studied. As compared to CTR, allergic patients showed higher eosinophil numbers and percentages (p < 0.001) but similar lymphocyte numbers and proportions (p > 0.1). Both in CTR and in allergic patients, eosinophil counts did not correlate with lymphocyte counts (p > 0.05; each comparison) but positive correlations were observed between eosinophil numbers and percentages and paper radio immunosorbent test (PRIST) levels or radio-allergo sorbent test (RAST) classes (p < 0.001; each comparison). When allergic asthmatic individuals were subdivided according to their age into two subgroups (Gr), no differences were found in eosinophil and lymphocyte counts and in PRIST levels and RAST values between Gr1 (< or =5 years old [preschool children]) and Gr2 (>5 years old [school children]) (p > 0.05; each comparison). Interestingly, although positive correlations between eosinophil counts and PRIST levels were found in both subgroups (p < 0.05; each comparison), only in Gr2 did eosinophil counts correlate positively with RAST classes (p < 0.001). No correlations between lymphocyte counts and PRIST levels or RAST classes were demonstrated (p > 0.05; each comparison). These data suggest that although blood eosinophilia was similar in preschool and in allergic asthmatic school children sensitized to HDM, only in the oldest children did blood eosinophil counts appear to be related to the degree of HDM-specific sensitization.     

From laboratory studies to clinical trials: past benefits and future directions in hyperthermia

Three examples of clinical research trials that were direct outgrowths of hyperthermia laboratory investigations performed at Stanford University, as well as elsewhere, are reviewed and directions for future studies presented. The first series of laboratory-clinical studies investigated the influence of the number of hyperthermia treatments on tumour response in combined radiotherapy-hyperthermia regimens. A prospective randomized clinical trial was performed and showed no difference in response rate or duration of local control in combined radiation therapy-hyperthermia regimens comparing two versus six hyperthermia treatments. The results were in agreement with the laboratory studies in RIF murine tumours which suggested that persistent thermotolerance limited the effectiveness of multiple heat treatments in fractionated hyperthermia treatment regimens. The second prospective clinical trial was undertaken to investigate the influence of pretreatment tumour temperatures on subsequent response to radiotherapy and hyperthermia. In agreement with the laboratory studies, low (< 37 degrees C) pretreatment temperatures sensitized superficially located tumours to subsequent hyperthermia treatment. Lower pretreatment temperatures and larger differentials between minimum treatment temperatures and pretreatment maximum or mean temperatures were correlated with the duration of local control. The final studies investigated thermosensitizing agents, agents which were non-toxic at 37 degrees C but became cytotoxic at elevated temperatures. Thermosensitizers such as sulphydryl compounds have demonstrated up to 10,000-fold enhancement of cell killing at exposure to 43 degrees C for 1 h and may be considered for tumour sensitization. However, normal tissue may also be sensitized as was noted for topical anaesthetics such as lidocaine.(ABSTRACT TRUNCATED AT 250 WORDS)