Standardizing postoperative handoffs using the evidence-based IPASS framework through a multidisciplinary initiative improves handoff communication for neurosurgical patients in the neuro-intensive care unit

Errors in communication are a major source of preventable medical errors. Neurosurgical patients frequently present to the neuro-intensive care unit (NICU) postoperatively, where handoffs occur to coordinate care within a large multidisciplinary team. A multidisciplinary working group at our institution started an initiative to improve postoperative neurosurgical handoffs using validated quality improvement methodology. Baseline handoff practices were evaluated through staff surveys and serial observations. A formalized handoff protocol was implemented using the evidence based IPASS format (Illness severity, Patient summary, Action list, Situational awareness and contingency planning, Synthesis by receiver). Cycles of objective observations and surveys were employed to track practice improvements and guide iterative process changes over one year. Surveys demonstrated improved perceptions of handoffs as organized (17.1% vs 69.7%, p < 0.001), efficient (27.0% vs. 72.7%, p < 0.001), comprehensive (17.1% vs. 66.7%, p < 0.001), and safe (18.0% vs. 66.7%, p < 0.001), noting improved teamwork (31.5% vs. 69.7%, p < 0.001). Direct observations demonstrated improved communication of airway concerns (47.1% observed vs. 92.3% observed, p < 0.001), hemodynamic concerns (70.6% vs. 97.1%, p = 0.001), intraoperative events (52.9% vs. 100%, p < 0.001), neurological examination (76.5% vs. 100%, p < 0.001), vital sign goals (70.6% vs. 100%, p < 0.001), and required postoperative studies (76.5% vs. 100%, p < 0.001). Receiving teams demonstrating improved rates of summarization (47.1% vs. 94.2%, p = 0.005) and asking questions (76.5% vs 98.1%, p = 0.004). The mean handoff time during long-term follow-up was 4.4 min (95% confidence interval = 3.9-5.0 min). Standardization of handoff practices yields improvements in communication practices for postoperative neurosurgical patients.

Effect of a Female External Urinary Catheter on Incidence of Catheter-Associated Urinary Tract Infection

Background Catheter-associated urinary tract infections (CAUTIs) can be fatal, and are a source of avoidable expense for patients and hospitals. Prolonged catheterization increases infection risk, and avoiding catheters is crucial for infection prevention. Male external urinary catheters are recommended as a tool to prevent the need for indwelling catheterization. Female external urinary catheters (FEUCs) have intermittently been marketed without wide adoption; one has recently become available but published data is limited. Objective This retrospective observational study was conducted to investigate the effect of FEUCs on indwelling catheter use and female CAUTIs. Methods FEUCs were introduced to intensive care units. CAUTI rates and indwelling catheter days were obtained before and after the introduction of the devices. Results  CAUTI rates decreased from 3.14 per 1000 catheter days to 1.42 per 1000 catheter days (p=0.013). Female indwelling catheter days decreased, while overall intensive care patient days increased. Conclusions Introduction of a FEUC was associated with a statistically significant decrease in CAUTI rate among female intensive care patients. The FEUC may prevent the need for indwelling catheters in some situations.

Development of an integrated electronic platform for patient self-report and management of adverse events during cancer treatment

Background

Significant adverse events (AE) during cancer therapy disrupt treatment and escalate to emergency admissions. Approaches to improve the timeliness and accuracy of AE reporting may improve safety and reduce health service costs. Reporting AE via patient reported outcomes (PROs), can improve clinician-patient communication and making data available to clinicians in 'real-time' using electronic PROs (ePROs) could potentially transform clinical practice by providing easily accessible records to guide treatment decisions. This manuscript describes the development of eRAPID (electronic patient self-Reporting of Adverse-events: Patient Information and aDvice) is a National Institute for Health Research-funded programme, a system for patients to self-report and manage AE online during and after cancer treatment.

Materials and methods

A multidisciplinary team of IT experts, staff and patients developed using agile principles a secure web application interface (QStore) between an existing online questionnaire builder (QTool) displaying real-time ePRO data to clinicians in the electronic patient record at Leeds Teaching Hospitals NHS Trust. Hierarchical algorithms were developed corresponding to Common Terminology Criteria for Adverse Events grading using the QTool question dependency function. Patient advocates (N = 9), patients (N = 13), and staff (N = 19) usability tested the system reporting combinations of AE.

Results

The eRAPID system allows patients to report AE from home on PC, tablet or any web enabled device securely during treatment. The system generates immediate self-management advice for low or moderate AE and for severe AE advice to contact the hospital immediately. Clinicians can view patient AE data in the electronic patient record and receive email notifications when patients report severe AE.

Conclusions

Evaluation of the system in a randomised controlled trial in breast, gynaecological and colorectal cancer patients undergoing systemic therapy is currently underway. To adapt eRAPID for different treatment groups, pilot studies are being undertaken with patients receiving pelvic radiotherapy and upper gastrointestinal surgery. ISRCTN88520246.

Abstract WP352: Self-Releasing Safety Belt Leads to Falls Reduction on Acute Stroke Unit

Intro: In 2015, a 21-bed acute stroke unit within a Comprehensive Stroke Center at an academic medical facility experienced a stark increase in their falls rate. A monthly average of 4.58 falls per 1,000 patient days was recorded for 2015, which was an increase over the two previous years.

Methods: Various options were discussed to address the high rate of falls based on the unit population and the types of falls. After discovering an increase in falls from the bedside chair it was decided to implement use of a self-releasing safety belt when the patients were out of bed to the chair. The belts incorporated an alarm tied into the call bell system that would be triggered when released. This allowed for an additional layer of alarm to elicit a staff response to the room prior to a patient falling. Nursing and therapy staffs were educated on the utilization of these self-releasing belts when assisting any patient from bed to chair. Every patient admitted with the diagnosis of stroke utilized these belts while out of bed to the chair, even those who were deemed fully independent.

Results: After implementation, the average fall per 1,000 patient days’ rate decreased from 4.58 falls to 3.89 falls per month. The total numbers of falls also decreased from 28 in 2015 to 20 in 2016. Falls from the chair, specifically, decreased from 11 in 2015 to 5 in 2016, representing a fifty percent decrease in falls from the chair with use of the self-releasing seatbelt.

Conclusions: Overall, the falls rate decreased, and the falls specifically from the chair decreased. Data collected reflects all falls on the unit during the period in question and was not limited to patients using the self-releasing safety belts or falls from the chair. The next steps will be to ensure this practice is utilized uniformly and to evaluate similar methods to reduce falls from the bed and drive our rates down to zero falls per month.

Cost of fractures commonly associated with osteoporosis in a managed-care population

OBJECTIVE

To examine direct costs of hip, vertebral, and non-hip non-vertebral (NHNV) fractures, and to estimate the rate of osteoporosis (OA) diagnosis and treatment in the fracture population.

METHODS

Subjects ≥ 45 years with a new hip, vertebral, or NHNV fragility (closed) fracture between June 30, 2002 and June 30, 2006 were studied retrospectively. All-cause and fracture-specific medical costs were calculated from medical claims in the 12-month baseline and follow-up periods. Total healthcare costs included pharmacy and medical costs. Diagnosis for OA and OA treatment were identified in both the baseline and follow-up period from diagnosis codes on medical claims for OA, and from pharmacy claims for treatment. Analyses were performed separately for commercial (COM) and Medicare Advantage (MA) populations and stratified by fracture type. Generalized linear models were estimated for total follow-up healthcare cost.

RESULTS

The study sample included 36,521 COM and 10,160 MA subjects. Hip fracture subjects had the highest follow-up medical costs in unadjusted and adjusted analyses (COM: mean $35,898; median $22,945; MA: mean $32,919; median $26,047). Follow-up costs were much higher than baseline costs. Fracture-related costs accounted for a large proportion of follow-up medical costs. Although rates of osteoporosis diagnosis and treatment increased from baseline to follow-up, the majority of both COM and MA subjects had no evidence of osteoporosis diagnosis or treatment in either period.

CONCLUSIONS

Despite limitations of this study, including conventional generalizability issues, and sensitivity and specificity of claims-based diagnoses, results are consistent with other research and provide compelling results of substantial cost burden of fractures related to osteoporosis. Low rates of osteoporosis diagnosis and treatment among patients with costly fragility fractures underscore the opportunity for managed care organizations to initiate comprehensive disease management programs in osteoporosis.

Risk of fracture in women treated with monthly oral ibandronate or weekly bisphosphonates: the eValuation of IBandronate Efficacy (VIBE) database fracture study

The eValuation of IBandronate Efficacy (VIBE) head-to-head database fracture study compared fracture rates between patients treated with monthly ibandronate and weekly oral bisphosphonates (BPs). This large study included women >/=45 years old, newly prescribed monthly oral ibandronate or weekly oral alendronate or risedronate, and without malignancy or Paget's disease of bone. The primary analysis included patients who were adherent to treatment during the first 90 days after the index date. The risks of hip, nonvertebral, vertebral and any clinical fracture were compared using Cox proportional hazards models and adjusted for potential confounding factors. A secondary, "intent-to-treat" analysis included all patients who received at least one BP prescription. Sensitivity analyses based on the primary analysis compared patients receiving ibandronate with patients receiving weekly alendronate or risedronate separately, and explored the effect of excluding patients with potential confounding factors from the analysis. Further sensitivity analyses varied the requirement for adherence during the first 90 days after the index date. The primary analysis population included 7345 monthly ibandronate and 56,837 weekly BP patients. Fracture rates after the 12-month observational period were <2% and fracture risk was not significantly different between patients receiving monthly ibandronate or weekly BPs for hip, nonvertebral or any clinical fracture (adjusted relative risk: hip=1.06, p=0.84; nonvertebral=0.88, p=0.255; any clinical fracture=0.82, p=0.052). Ibandronate patients had a significantly lower risk of vertebral fracture than weekly BP patients (adjusted relative risk 0.36, 95% confidence interval 0.18-0.75, p=0.006). In the secondary, "intent-to-treat" analysis, relative risks of fracture were not significantly different between treatment groups for any fracture type. The results of the sensitivity analyses were generally consistent with the primary analysis. This retrospective cohort study found that patients treated with oral monthly ibandronate or weekly BPs (alendronate and risedronate) had similar, low risks of hip fracture, nonvertebral fracture and any clinical fracture. Ibandronate patients had a significantly lower relative risk of vertebral fracture than weekly BP patients; the clinical implications of these findings require further exploration and validation.

Disruption of sitting balance after stroke: influence of spoken output

OBJECTIVES

To identify the extent of dual task interference between cognitive and motor tasks, (cognitive motor interference (CMI)) in sitting balance during recovery from stroke; to compare CMI in sitting balance between stroke and non-stroke groups; and to record any changes to CMI during sitting that correlate with functional recovery.

METHOD

36 patients from stroke rehabilitation settings in three NHS trusts. Healthy control group: 21 older volunteers. Measures of seated postural sway were taken in unsupported sitting positions, alone, or concurrently with either a repetitive utterance task or an oral word category generation task. Outcome measures were variability of sway area, path length of sway, and the number of valid words generated.

RESULTS

Stroke patients were generally less stable than controls during unsupported sitting tasks. They showed greater sway during repetitive speech compared with quiet sitting, but did not show increased instability to posture between repetitive speech and word category generation. When compared with controls, stroke patients experienced greater dual task interferences during repetitive utterance but not during word generation. Sway during repetitive speech was negatively correlated with concurrent function on the Barthel ADL index.

CONCLUSIONS

The stroke patients showed postural instability and poor word generation skills. The results of this study show that the effort of verbal utterances alone was sufficient to disturb postural control early after stroke, and the extent of this instability correlated with concomitant Barthel ADL function.

Telomerase inhibitors--oligonucleotide phosphoramidates as potential therapeutic agents

We have designed, synthesized, and evaluated using physical, chemical and biochemical assays various oligonucleotide N3'-->P5' phosphoramidates, as potential telomerase inhibitors. Among the prepared compounds were 2'-deoxy, 2'-hydroxy, 2'-methoxy, 2'-ribo-fluoro, and 2'-arabino-fluoro oligonucleotide phosphoramidates, as well as novel N3'-->P5' thio-phosphoramidates. The compounds demonstrated sequence specific and dose dependent activity with IC50 values in the sub-nM to pM concentration range.

A screen for dominant negative mutants of SEC18 reveals a role for the AAA protein consensus sequence in ATP hydrolysis

An evolutionarily ancient mechanism is used for intracellular membrane fusion events ranging from endoplasmic reticulum-Golgi traffic in yeast to synaptic vesicle exocytosis in the human brain. At the heart of this mechanism is the core complex of N-ethylmaleimide-sensitive fusion protein (NSF), soluble NSF attachment proteins (SNAPs), and SNAP receptors (SNAREs). Although these proteins are accepted as key players in vesicular traffic, their molecular mechanisms of action remain unclear. To illuminate important structure-function relationships in NSF, a screen for dominant negative mutants of yeast NSF (Sec18p) was undertaken. This involved random mutagenesis of a GAL1-regulated SEC18 yeast expression plasmid. Several dominant negative alleles were identified on the basis of galactose-inducible growth arrest, of which one, sec18-109, was characterized in detail. The sec18-109 phenotype (abnormal membrane trafficking through the biosynthetic pathway, accumulation of a membranous tubular network, growth suppression, increased cell density) is due to a single A-G substitution in SEC18 resulting in a missense mutation in Sec18p (Thr(394)-->Pro). Thr(394) is conserved in most AAA proteins and indeed forms part of the minimal AAA consensus sequence that serves as a signature of this large protein family. Analysis of recombinant Sec18-109p indicates that the mutation does not prevent hexamerization or interaction with yeast alpha-SNAP (Sec17p), but instead results in undetectable ATPase activity that cannot be stimulated by Sec17p. This suggests a role for the AAA protein consensus sequence in regulating ATP hydrolysis. Furthermore, this approach of screening for dominant negative mutants in yeast can be applied to other conserved proteins so as to highlight important functional domains in their mammalian counterparts.

Novelty-elicited, noradrenaline-dependent enhancement of excitability in the dentate gyrus

In order to relate noradrenaline-dependent potentiation in the dentate gyrus to behavioural events, rats were made to explore an environment in which their encounters with novel stimuli could be strictly controlled and monitored. Previous experiments have shown that an encounter with novel objects in a holeboard elicits a burst response in a large population of noradrenergic neurons of the locus coeruleus. Such a burst response has been demonstrated to produce a large and transient potentiation of the population spike in the dentate gyrus. In the present series of experiments, rats were chronically implanted with stimulating electrodes in the perforant pathway and recording electrodes in the dentate gyrus. Evoked potentials were monitored in the awake rat, first while it was resting quietly in a familiar environment and then while it was exploring the holeboard containing a novel object in a specific hole. There was a tonic increase in population spike amplitude when the rat was placed in the novel holeboard environment, but this effect gradually dissipated. This increase was partly blocked by the beta-noradrenergic antagonist propranolol. In addition there was a robust phasic increase in spike amplitude when the rat encountered a novel stimulus. This phasic response lasted approximately 50-75 s and was absent in animals treated with propranolol. These results show that a behavioural encounter with a novel stimulus can transiently enhance information transmission through the hippocampus, and suggest that activation of the noradrenergic system by the novel stimulus mediates this behavior-dependent gating.

In situ analysis of changes in telomere size during replicative aging and cell transformation

Telomeres have been shown to gradually shorten during replicative aging in human somatic cells by Southern analysis. This study examines telomere shortening at the single cell level by fluorescence in situ hybridization (FISH). FISH and confocal microscopy of interphase human diploid fibroblasts (HDFs) demonstrate that telomeres are distributed throughout the nucleus with an interchromosomal heterogeneity in size. Analysis of HDFs at increasing population doubling levels shows a gradual decrease in spot size, intensity, and detectability of telomeric signal. FISH of metaphase chromosomes prepared from young and old HDFs shows a heterogeneity in detection frequency for telomeres on chromosomes 1, 9, 15, and Y. The interchromosomal distribution of detection frequencies was similar for cells at early and late passage. The telomeric detection frequency for metaphase chromosomes also decreased with age. These observations suggest that telomeres shorten at similar rates in normal human somatic cels. T-antigen transformed HDFs near crisis contained telomere signals that were low compared to nontransformed HDFs. A large intracellular heterogeneity in telomere lengths was detected in two telomerase-negative cell lines compared to normal somatic cells and the telomerase-positive 293 cell line. Many telomerase-negative immortal cells had telomeric signals stronger than those in young HDFs, suggesting a different mechanism for telomere length regulation in telomerase-negative immortal cells. These studies provide an in situ demonstration of interchromosomal heterogeneity in telomere lengths. Furthermore, FISH is a reliable and sensitive method for detecting changes in telomere size at the single cell level.

A subset of patients with recurrent spontaneous abortion is deficient in transforming growth factor beta-2-producing "suppressor cells" in uterine tissue near the placental attachment site

PROBLEM

To determine if patients with unexplained recurrent miscarriage have a deficiency of decidual immunosuppressor cells that produce transforming growth factor beta type 2, as has been found in mice with abortion due to rejection and/or trophoblast failure.

METHODS

Decidual biopsy specimens were taken as near to the placental attachment site as possible under ultrasound guidance from first trimester legal termination (control) patients with recurrent miscarriage and non-viable pregnancy, and from patients with sporadic missed abortion. The tissue was tested for TGF beta-2+ suppressor cells by in situ hybridization, immunohistochemistry, and analysis of supernatants.

RESULTS

TGF beta-2-related suppressor molecules similar but not identical to those identified in pregnant mice were released by decidual lymphoid cells. Fifty percent of 14 recurrent miscarriage patients showed a lack of suppressor cells and 59% were subnormal in comparison to 20 controls and 5 sporadic miscarriage patients, where 80-85% of the patients had detectable suppressor cells.

CONCLUSIONS

Suppressor cell deficiency is compatible with a role for rejection and/or trophoblast failure in some patients with recurrent miscarriage. Presence of suppressor cells in most patients with missed abortion (4/5) is compatible with an alternative cause of fetal death, similar to findings reported in genetic fetal death mice.

Acquisition of conditional discriminations in hippocampal lesioned and decorticated rats: evidence for learning that is separate from both simple classical conditioning and configural learning

This study examined whether hippocampal or neocortical lesions would impair acquisition of a discrimination task using taste aversions. Rats were injected with a drug 15 min before a flavored solution-lithium chloride pairing. On alternate days, vehicle injections preceded and followed access to the same flavored solution. Rats learned to consume significantly more of the flavored solution after vehicle injections than after drug injections. Rats with hippocampal lesions or neonatal decortication performed as well as controls. Rats with hippocampal lesions also learned a similar task in which visual and textural cues predicted whether access to a flavored solution would be followed by an injection of lithium chloride or vehicle. However, these hippocampal lesions did impair performance in the Morris water task. Occasion setting may involve a type of learning dissociated from both simple classical conditioning and configural learning.

Vaccine potential of a herpes simplex virus type 1 mutant with an essential glycoprotein deleted

Several approaches to the production of vaccines to human herpesviruses have been proposed. Subunit vaccines, subunits delivered by live vectors, and rationally attenuated vaccines have all been shown to be efficacious in animal models but suffer from uncertainties as to the roles of individual genes involved in pathogenesis and the most relevant components of the immune response required for protection in humans and the target antigens involved. With these problems in mind, we examined the vaccine potential of a fully disabled herpes simplex virus type 1 mutant that is capable of only a single round of replication, since a virus of this type should induce the full spectrum of immune responses but has no pathogenic potential. A virus has been described which lacks essential glycoprotein H (gH) and can be propagated in a cell line which supplies gH in trans (A. Forrester, H. Farrell, G. Wilkinson, J. Kaye, N. Davis-Poynter, and T. Minson, J. Virol. 66:341-348, 1992). Infection of normal cells with this mutant is indistinguishable from a wild-type infection, except that the resulting progeny are gH negative and noninfectious: the virus is self-limiting. Infection of mice by the ear pinna route was similarly self-limiting in that input infectivity decreased rapidly at the inoculation site and no infectivity was detected in sensory ganglia. Animals given a wide range of doses of the gH-negative mutant produced both humoral and T-cell responses to herpes simplex virus type 1 and proved solidly resistant to challenge with a high dose of wild-type virus. The gH-negative mutant is presumably capable of establishing a latent infection, but since no infectious virus was detected in numerous attempts to reactivate the mutant, the risk of a pathogenic outcome is minimal.

Ibotenate lesions of the hippocampus enhance latent inhibition in conditioned taste aversion and increase resistance to extinction in conditioned taste preference

In 2 experiments, the effects of axon-sparing lesions of the hippocampus on performance in aversive and appetitive taste conditioning tasks were investigated. In Experiment 1, hippocampally lesioned rats showed no impairment of conditioned taste aversion learning relative to control subjects, but they did display an increased sensitivity to latent inhibition (LI). In Experiment 2, the same hippocampectomized rats acquired a conditioned taste preference but failed to show any evidence of extinction. The influence of the neurotoxic lesion on LI is in the opposite direction to the effect typically found following hippocampal damage induced by traditional methods. Accordingly, the data present challenges for most current theories of hippocampal function.

Daily variation in active glycogen phosphorylase patches in the molecular layer of rat dentate gyrus

A larger number of discrete patches of active glycogen phosphorylase (alpha GP) were found in the molecular layer of the hippocampal dentate gyrus in rats sacrificed during the daily dark phase (mean = 28.7/section) than during the light phase (mean = 7.8/section). Light-dark differences in the patterns of alpha GP may reflect circadian differences in metabolic demand in the hippocampus. Patch sizes were consistent with increased activation of single astrocytes or perisynaptic astrocyte clusters by focal input at night.

Wild-type coat protein gene of tobacco mosaic virus mutant Ni 2519

Tobacco mosaic virus mutant Ni 2519 has a selected temperature-sensitive defect in the spreading of local lesions, and additional reported defects in virus assembly and in host range. Here we show that the temperature-sensitive local lesion-spreading defect (which maps in the assembly origin within the gene encoding protein p30) is probably independent of mutations in the pseudoassembly origin or of host range defects resulting from other mutations in the coat protein. One new host range mutant has been isolated.

Noradrenergic and locus coeruleus modulation of the perforant path-evoked potential in rat dentate gyrus supports a role for the locus coeruleus in attentional and memorial processes

The perforant path-dentate gyrus synapse has provided a model system for functional neural plasticity in adult mammalian brain. NMDA-dependent long-term changes in neural connectivity occur at this synapse in response to high-frequency input. Norepinephrine (NE) applied exogenously or released endogenously can initiate both a short- and a long-term potentiation (LTP) of the dentate gyrus response to perforant path input. Triggering of the potentiated response depends on beta-receptor activation and does not require a high-frequency stimulus. An increase in locus coeruleus (LC) activity can initiate both short and LTP of the perforant path response, although a reduction in LC activity does not alter baseline perforant path responses. This chapter considers differences between NE modulation in vitro and in vivo, differences and similarities between NE-LTP and frequency-induced LTP, and the surprising specificity of NE effects at the perforant path synapse. Studies of NE in the dentate gyrus support a role for the LC in promoting both short- and long-term enhancement of responses to complex sensory inputs and are consistent with a role for the LC in memorial as well as attentional processes.

Cytostasis of different tumours by a murine PPD-reactive CD4+ T lymphocyte clone is mediated by interferon-gamma and tumour necrosis factor alone or synergistically

We have shown that a murine CD4+ PPD-reactive T lymphocyte clone was weakly cytotoxic towards the syngeneic tumour B16 melanoma and MC6A fibrosarcoma which had been coated with PPD using a monoclonal antibody-PPD heteroconjugate. Cell-free supernatants produced by PPD-stimulated T lymphocyte clones were however highly cytostatic for the two tumour targets when assayed over 48-72 h. In this study we have demonstrated good titres of tumour necrosis factor (TNF) and interferon-gamma (IFN-gamma) in the supernatants, which accounted for their observed cytostatic activity on the tumour targets. The high level of cytostasis seen with the B16 melanoma using the supernatants could be attributed to their sensitivity to the cytostatic activity of IFN-gamma; the lower levels of cytostasis seen with the IFN-gamma-resistant MC6A target was the result of IFN-gamma increasing the sensitivity of this target to TNF. Antibodies to IFN-gamma were able to neutralize the majority of the cytostatic activity of the supernatants on both targets, consistent with the role demonstrated for this lymphokine.

MK-801 and AP5 impair acquisition, but not retention, of the Morris milk maze

The effects of the NMDA blockers, AP5 and MK-801, were assessed in two spatial tests. AP5 (10 micrograms in 2 microliters ICV, N = 6), or MK-801 (0.07 mg/kg IP, N = 6), significantly increased open-field activity in male Long-Evans rats in two 3-min tests (Days 1 and 2) compared to control groups receiving equal volume saline injections (N = 12). In the Morris milk maze, NMDA blockade significantly impaired acquisition performance on two blocks of six trials, which followed each open-field test. Only control animals showed evidence of acquisition on a drug-free retention test assessing latency to reach the expected platform area and number of crossings in the area on Day 4. Retention was tested in control animals under NMDA blockade on Day 6. There was no effect of NMDA blockade on retention in the Morris milk maze. These results support the hypothesis that NMDA receptors are critical for the initiation of synaptic modification underlying place learning, but are not necessary in synaptic transmission during retrieval of place information.

Locus coeruleus potentiation of dentate gyrus responses: evidence for two systems

Glutamate activation of the locus coeruleus (LC) and norepinephrine (NE) have both been shown to potentiate the perforant path (PP)-evoked population spike. This potentiation may be short-lasting, the population spike returning to baseline levels within minutes after NE-application or LC activation, or can be long-lasting, persisting 20 minutes or more after termination of the NE or glutamate manipulation. In the present study LC electrical stimulation (333 Hz, 15 msec) initiated 40 msec prior to a PP stimulus reliably caused short-lasting potentiation of the dentate gyrus population spike amplitude (mean maximal = 161%, N = 22). With 50 LC-PP pairings a long-lasting potentiation (greater than 30 min after offset of LC stimulation) was seen in 10/22 experiments. Propranolol (20-30 mg/kg IP) did not block the potentiating effect of LC electrical simulation but completely suppressed the potentiating effect of glutamate activation of the LC in the same animals (N = 5). The beta receptor dependence of short-and long-lasting hippocampal NE potentiation has been previously demonstrated. The inability of a beta receptor antagonist to attenuate the potentiation induced by LC electrical stimulation suggests there are two distinct systems. Both the beta-NE-dependent and the beta-NE-independent system are capable of inducing long-lasting potentiation of the PP-evoked potential.

DSP-4 treatment accelerates kindling

Norepinephrine depletion of the central nervous system by peripheral N-(2-chloroethyl)-N-ethyl bromobenzylamine administration accelerates the development of seizures kindled by repeated stimulation of the amygdala. These data, in conjunction with previous 6-hydroxydopamine data, demonstrate the robustness of this phenomenon and emphasize the importance of noradrenergic innervation originating from the locus ceruleus in the suppression of seizure development.

Physical health correlates of attitudes toward aging in the elderly

Attitudes toward aging were assessed in three groups of elderly men (age 65-85), including: hospitalized veterans, veteran outpatients, and a group of non-hospitalized "healthy" veteran volunteers, using the Rosencranz and McNevin Semantic Differential Scale. Social objects rated included an "old man", a "young man", and the participant, himself, ("self"). Attitudes toward "old men" were significantly more negative than attitudes toward "young men" in all three groups. In addition, significant group by "object-rated" interactions were obtained on the autonomous/dependent and instrumental/ineffective dimensions of this scale. These interactions were attributable to a more negative "self" rating by the hospitalized group. These results suggest that within the population studied, older persons in poor health tend to view themselves more like the stereotyped "old person" than do healthy old people, who tend to perceive themselves as being more like a "young person".

A comparison of physical health and psychosocial variables as predictors of reaction time and serial learning performance in elderly men

Choice reaction time and serial learning tasks were studied in three groups of elderly men (aged 65 to 85), including (a) hospitalized veterans, (b) veteran outpatients, and (c) nonhospitalized veteran volunteers. Demographic variables, life satisfaction, and attitudes toward aging, as well as objective and subjective measures of physical impairment, were assessed in each group. The three groups differed on both reaction time and serial learning measures. Multivariate analysis revealed that objective physical health assessments were the best predictors of reaction time performance, whereas subjective assessments best predicted serial learning performance. More negative attitudes and life satisfaction were associated with impaired physical health, but these psychosocial measures were poor predictors of behavioral performance.

Acetylcholinesterase in pontomedullary catecholamine neurons of the adult albino rat

This study investigated the cholinesterasic reactivity of catecholamine neurons in the rat hindbrain with the aid of a two-step histochemical procedure. First, catecholamine cells were visualized by their formaldehyde/glutaraldehyde induced specific histofluorescence and then poststained in the same tissue with a thiocholine technique for acetylcholinesterase (AChE). Processing the vibratome-sectioned tissue in phosphate buffer subsequent to initial aldehyde fixation permitted satisfactory preservation of both amine fluorophores and esterasic reactivity. Our results, in both randomly sampled and serially sectioned material, unequivocally establish the presence of AChE in all pontomedullary cell groups emitting catecholamine fluorescence, the majority of which are known to consist of noradrenaline perikarya. Hence in contrast to previous reports the occurrence of AChE in central noradrenaline neurons appears to be generalized. The intensity of histofluorescence and esterasic staining were uncorrelated in most regions. It remains for future study to determine whether AChE in brain catecholamine neurons indicates their cholinoceptivity or subserves the catabolism of other neuromediators such as substance P.

Mechanism of resistance of variants of the Lewis lung carcinoma to N-(phosphonacetyl)-L-aspartic acid

Variants of the Lewis lung carcinoma were selected for resistance to N-(phosphonacetyl)-L-aspartic acid (PALA) by treatment of tumor-bearing mice with repetitive subcurative doses of PALA. The specific activity of the target enzyme, L-aspartic acid transcarbamylase (ATCase), was measured in the four variants developed. Three had markedly elevated ATCase activities; however, the fourth line, LL/PALA-C, had an ATCase activity identical to that of the parent, PALA-sensitive line (LL/O). One high-ATCase variant, LL/PALA-J, and LL/PALA-C were compared with LL/O in subsequent biochemical studies on the mechanism of resistance to PALA. Enzyme activities in the salvage pathways which phosphorylate pyrimidine nucleosides and deoxynucleosides were found to be similar in all three lines. ATCase in these lines exhibits closely comparable kinetics with its natural substrates as well as with PALA. The time courses of restitution of ATCase after a single therapeutic dose of PALA show that both resistant variants recover full activity more rapidly than the parent. Additionally, inhibition of ATCase 24 hr following graded doses of PALA is lower in the resistant lines. The uptake of [14C]PALA in vitro into cell lines derived from the three Lewis lung carcinomas apparently occurs by passive diffusion and at comparable rates in both sensitive and resistant cells. Analysis of the nucleotide content of tumors reveals comparable spectrums of purine and pyrimidine nucleotide levels in the LL/O and LL/PALA-C lines, whereas the LL/PALA-J line has augmented nucleotide pools. In all three lines, 24 hr after treatment with PALA (400 mg/kg), uridine and cytidine nucleotide levels were substantially diminished (70 to 80%) while adenosine 5'-triphosphate and guanosine 5'-triphosphate levels were elevated (50 to 100%). Estimations of precursor flux through the de novo pyrimidine pathway by measuring orotate and orotidine levels in tumors of mice treated with pyrazofurin (an inhibitor of orotidine-5'-monophosphate decarboxylase) and either 0.9% NaCl solution or PALA shows that PALA treatment eliminates orotate and orotidine accumulation in LL/O but reduces it by only 75 and 50% in LL/PALA-C and LL/PALA-J, respectively. Similarly, PALA treatment (20 microM) of tumor lines in culture provokes a dramatic decrease in the incorporation of NaH14CO3 into pyrimidine intermediates and nucleotides in the LL/O cell line only. Determinations of specific activities of the other enzymes in this pathway reveal that the activity of carbamyl phosphate synthetase II, the rate-limiting step, is elevated 2- to 3-fold in both resistant lines. Since carbamyl phosphate synthetase II exists as a complex with ATCase, the suggestion is made that levels of carbamyl phosphate synthetase II are collaterally important determinants of PALA activity. An augmented pool of carbamyl phosphate in the resistant variants may serve to competitively displace PALA from ATCase, diminish enzyme inhibition, and allow pyrimidine biosynthesis to proceed despite therapy.

Partial purification, characterization, and assay of a slightly acidic insulin-like peptide (ILAs) from human plasma

An insulin radioreceptor assay (RRA) using human placental microsomal membranes was used to measure insulin-like activity (ILA) extracted from human plasma concentrates (Cohn fraction IV-4) by acid ethanol. The soluble activity (ILAs), chromatographed on Sephadex G-75 in 1 M acetic acid, migrated as a small molecule (fractional elution volume, 0.56) ahead of insulin (fractional elution volume, 0.70), whereas at neutral pH, ILAs migrated as a large molecular weight species. The ILAs peak from acid gel filtration on Sephadex was further purified by chromatography on carboxymethyl cellulose (CMC). The ILAs peak from both Sephadex and CMC diluted parallel to the porcine insulin standard in the insulin RRA and was totally unreactive in an insulin RIA. The CMC-purified material was iodinated and purified by binding to and elution from human placental membranes. The binding of [125I]ILAs to human placental membranes was inhibited only minimally by insulin and proinsulin and not at all by epidermal growth factor, nerve growth factor, glucagon, or lactogenic hormones, including human growth hormone. Multiplication-stimulating activity (MSA) inhibited in a manner parallel to ILAs. A Scatchard plot of the binding data was nonlinear. Sephadex ILAs was subjected to isoelectric focusing. The fractions assayed in both insulin and ILAs RRAs yielded comparable results. Peaks of ILA were observed at pHs 5.3, 6.6, and 8.4. When CMC-ILA was subjected to isoelectric focusing in polyacrylamide, a single peak of activity migrating between pH 6.2-6.8 was seen. [125I]ILAs focused at exactly the same pH. Electrophoresis of CMC-ILAs in acid-urea revealed a sharp peak of activity migrating with one of the five protein bands seen after staining. Again, [125I]ILAs comigrated with unlabeled ILAs. The molecular weight of ILAs, as determined on a calibrated Sephadex G-150 column at neutral pH, was 9,000-10,000 daltons. CMC-ILAs stimulated [14C]glucose incorporation into triglycerides of rat adipose tissue and augmented [3H]thymidine incorporation into human fibroblasts, chicken embryo fibroblasts, and BALB 3T3 cells as well as [35S]sulfate incorporation into macromolecules of rabbit chondrocyte culture medium. In summary, ILAs isolated on the basis of a RRA for insulin is a slightly acidic peptide with some of the biological activities expected of a somatomedin.