Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Telmisartan for treatment of Covid-19 patients: an open randomized clinical trial

Background

The imbalance of the Renin Angiotensin System in favor of the angiotensin II has been described in Covid-19-patients. Angiotensin II regulates life processes, such as cell growth and division and can promote apoptosis initiating an inflammatory process with release of proinflammatory cytokines. Angiotensin receptor blockers (ARBs) block the AT1 receptor and could have a beneficial effect reducing Covid-19 inflammation.

Purpose

To assess whether Telmisartan is effective in reducing C-reactive protein (CRP) plasma levels in hospitalized patients with Covid-19, and improves clinical outcomes and length of stay and morbimortality.

Trial design

This is a parallel-group, randomized, two-arm, open-label, multicenter superiority trial with 1:1 allocation ratio.

Methods

Inclusion criteria: patients aged more than 18 years with less than 5 days of symptoms onset and after informed consent was obtained.

Exclusion criteria: Patients admitted to intensive care unit (ICU) or using mechanical ventilatory support or ongoing ARBs / angiotensin-converting enzyme inhibitors treatment at the time of randomization. Control arm received standard care alone and treatment arm Telmisartan 80 mg bid 14 days added to standard care. Primary outcome were CRP plasma levels at day 5 and 8 after randomization. Secondary outcomes included time to discharge at 15 days, admission to ICU and death at 15 and 30 days.

Results

158 patients were included in the analysis, 80 in the control and 78 in the telmisartan group. Day 5 control-group CRP levels were 6.06±6.95 mg/dL (n=66) while telmisartan group were 3.83±5.08 mg/dL (mean±SD; n=66, p<0.05). Day 8 CRP levels were 6.30±8.19 mg/dL (n=44) and 2.37±3.47 mg/dl (mean±SD; n=43, p<0.05) in the control and telmisartan groups, respectively. Kaplan-Meier analysis showed that Telmisartan-treated patients had lower median time to discharge (control=15 days; telmisartan=9 days). Death by day 30 was reduced by 81% in the telmisartan-treated group (control 22.54%, 16/71; telmisartan 4.29%, 3/70 participants; p=0.0023). Composite ICU, mechanical ventilation or death was reduced by telmisartan treatment at days 15 and 30. No telmisartan-related adverse events were reported.

Conclusions

Telmisartan, an inexpensive safe drug, in high doses, demonstrated anti-inflammatory effects and reduced morbimortality in Covid-19-hospitalized patients.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s):Hospital Escuela José de San Martín, ArgentinaHospital Español de Buenos Aires, Argentina Probability of discharge up to

Intrinsic Properties of Individual Inorganic Silicon-Electrolyte Interphase Constituents

Because of the complexity, high reactivity, and continuous evolution of the silicon-electrolyte interphase (SiEI), "individual" constituents of the SiEI were investigated to understand their physical, electrochemical, and mechanical properties. For the analysis of these intrinsic properties, known SiEI components (i.e., SiO₂, Li₂Si₂O₅, Li₂SiO₃, Li₃SiO_x, Li₂O, and LiF) were selected and prepared as amorphous thin films. The chemical composition, purity, morphology, roughness, and thickness of prepared samples were characterized using a variety of analytical techniques. On the basis of subsequent analysis, LiF shows the lowest ionic conductivity and relatively weak, brittle mechanical properties, while lithium silicates demonstrate higher ionic conductivities and greater mechanical hardness. This research establishes a framework for identifying components critical for stabilization of the SiEI, thus enabling rational design of new electrolyte additives and functional binders for the development of next-generation advanced Li-ion batteries utilizing Si anodes.

Oxidative stress-driven parvalbumin interneuron impairment as a common mechanism in models of schizophrenia

Parvalbumin inhibitory interneurons (PVIs) are crucial for maintaining proper excitatory/inhibitory balance and high-frequency neuronal synchronization. Their activity supports critical developmental trajectories, sensory and cognitive processing, and social behavior. Despite heterogeneity in the etiology across schizophrenia and autism spectrum disorder, PVI circuits are altered in these psychiatric disorders. Identifying mechanism(s) underlying PVI deficits is essential to establish treatments targeting in particular cognition. On the basis of published and new data, we propose oxidative stress as a common pathological mechanism leading to PVI impairment in schizophrenia and some forms of autism. A series of animal models carrying genetic and/or environmental risks relevant to diverse etiological aspects of these disorders show PVI deficits to be all accompanied by oxidative stress in the anterior cingulate cortex. Specifically, oxidative stress is negatively correlated with the integrity of PVIs and the extracellular perineuronal net enwrapping these interneurons. Oxidative stress may result from dysregulation of systems typically affected in schizophrenia, including glutamatergic, dopaminergic, immune and antioxidant signaling. As convergent end point, redox dysregulation has successfully been targeted to protect PVIs with antioxidants/redox regulators across several animal models. This opens up new perspectives for the use of antioxidant treatments to be applied to at-risk individuals, in close temporal proximity to environmental impacts known to induce oxidative stress.

A two phased study on health care professionals' perceptions of single or multi-use of intermittent catheters

AIMS

This two phase study aimed to explore health care professionals' teaching and prescribing practice related to intermittent catheterisation and to identify their perceptions about the possible implementation of a mixed (single and multi-use) package for intermittent catheterization.

INTRODUCTION

Single-use intermittent catheters are the norm in the UK although multi-use is common in some other countries. A recent Cochrane review found no difference in complications, including urinary tract infection rates, between those using single or multi-use catheters. A flexible option of both multi-use and single use intermittent catheters could provide users with more flexible choices in self-care. However, understanding health care professionals' perspectives is one of the keys to developing a multi-use intervention.

DESIGN

A qualitative research framework using in-depth interviews to inform an on line survey.

METHOD

In-depth interviews were conducted with health care professionals based in the UK who prescribe catheters, teach intermittent catheterisation or manage an intermittent catheterisation service. The interviewees were selected to represent a range of clinical areas, experience and professions - continence advisors, urology, multiple sclerosis (MS) and spinal cord injury specialist nurses, and General Practitioners. Following framework analysis the themes and factors identified were used to develop an on-line survey which was disseminated through health care professional networks whose members saw patients who use intermittent catheters.

RESULTS

Nineteen health care professionals participated in the telephone interviews; 206 completed the survey. A wide range of professionals in terms of experience and specialty afforded rich information regarding the contextual issues around the teaching and prescribing of intermittent catheters. The primary finding was that health care professionals were concerned about 'minimising health risk' and maximising 'normalcy' for those using intermittent self-catheterisation. Health care professionals who worked in the acute setting or had no experience of re-use were most resistant to the re-use of catheters. Professionals requested evidence that a multi-use package would not increase the risk of developing a urinary tract infection or increase the burden of use to a patient before a mixed package would be considered.

CONCLUSIONS

For multi-use to be acceptable, evidence based guidelines must be available for healthcare professionals and cleaning methods must be acceptable and safe for intermittent catheter users. Further evidence may be required to establish that a mixed catheter package is equivalent to single use only, particularly for outcomes such as urinary tract infection, urethral injury and quality of life.

RELEVANCE TO CLINICAL PRACTICE

This paper highlights that if multi-use catheters are to be successfully introduced into clinical practice, the ease of use, safety and effectiveness of the cleaning technique will need to be convincingly demonstrated by a range of well-defined users.

UT-B Urea Transporter Localization in the Bovine Gastrointestinal Tract

Facilitative UT-B urea transporters play an important role in the urea nitrogen salvaging process that occurs in the gastrointestinal tract of mammals, particularly ruminants. Gastrointestinal UT-B transporters have previously been reported in various ruminant species-including cow, sheep and goat. In this present study, UT-B transporter localization was investigated in tissues throughout the bovine gastrointestinal tract. RT-PCR analysis showed that UT-B2 was the predominant UT-B mRNA transcript expressed in dorsal, ventral and cranial ruminal sacs, while alternative UT-B transcripts were present in other gastrointestinal tissues. Immunoblotting analysis detected a strong, glycosylated ~50 kDa UT-B2 protein in all three ruminal sacs. Immunolocalization studies showed that UT-B2 protein was predominantly localized to the plasma membrane of cells in the stratum basale layer of all ruminal sac papillae. In contrast, other UT-B protein staining was detected in the basolateral membranes of the surface epithelial cells lining the abomasum, colon and rectum. Overall, these findings confirm that UT-B2 cellular localization is similar in all ruminal sacs and that other UT-B proteins are located in epithelial cells lining various tissues in the bovine gastrointestinal tract.

Serine Racemase in Inhibitory Neurons at Striatum and it Might be Involved in Schizophrenia's Pathophysiology with d1 and d2 Receptors

Introduction

There is substantial evidence that hypofunction of the N-methyl-d-aspartate receptor (NMDAR) is a core pathophysiological mechanism underlying schizophrenia. d-serine and serine racemase (SR) (NMDAR co-agonist and it's producer) are thought to be involved in schizophrenia's pathophysiology as NMDAR function moderators. Our laboratory showed that excitatory neuron specific SR knock out (SRKO) mice still have just 50% reduction of SR whereas full SRKO mice had no SR. Furthermore d-serine and SR are found in inhibitory neurons not only in excitatory neurons with immunohistochemistry methods. Because NMDAR has excitatory functions, the existence of d-serine and SR in inhibitory neurons and their functions are of interest.

Aims

To elucidate the existence and roles of d-serine and SR in inhibitory neurons.

Methods

Inhibitory neuron marker, GAD65, specific conditional SRKO (GAD65 SRKO) mice were made by Cre-lox recombination method. The GAD65 SRKO mice were analyzed by HPLC for d-serine concentration, western blotting for SR expression, immunohistochemistry for SR positive cell's character identification and behavioral testing.

Results

GAD65 SRKO had about 50% reduction of SR in striatum but no reduction in hippocampus and frontal cortex. d-serine of GAD65 SRKO mice was not different from WT mice. Immunohistochemistry works revealed SR is in medium spiny neuron of striatum and has colocalization with DARRP-32, D1 receptor, and D2 receptor.

Conclusions

SR is expressed in inhibitory neurons at least in striatum. It might be involved in schizophrenia's pathophysiology because it colocalizes with D1 and D2 receptors.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Impact of reducing the threshold for acetylcysteine treatment in acute paracetamol poisoning: the recent United Kingdom experience

BACKGROUND

On 3 September 2012, the licensed indication for acetylcysteine was changed in the United Kingdom (UK) so that all patients with a plasma paracetamol concentration above a "100 mg/L" (4 h post ingestion) nomogram treatment line after an acute paracetamol (acetaminophen) overdose should be treated. This is a lower threshold than that used in the United States, Canada, Australia, and New Zealand. Here we report the impact of this change in the UK on the management of patients with acute overdose in different paracetamol concentration ranges.

METHODS

This is a cohort study, consisting of a retrospective analysis conducted on prospectively collected audit data in three UK hospitals. Following appropriate ethical and data protection authority approval, data for patients presenting within 24 h of an acute timed single paracetamol overdose were extracted. Numbers of admissions and use of antidote in relation to different paracetamol concentration bands (< 100 mg/L; 100-149 mg/L; 150-199 mg/L; and ≥ 200 mg/L at 4 h) were analyzed for one-year periods before and after the change.

RESULTS

Comparing the year before with the year after the change, there was no change in the numbers of patients presenting to hospital within 24 h of acute timed paracetamol overdose (1246 before and 1251 after), but more patients were admitted (759 before and 849 after) and treated with acetylcysteine (389 before and 539 after). Of the 150 additional patients treated with acetylcysteine in the year following the change, 114 (76%, 95% CI: 68.4-82.6) were in the 100-149 group and 9 (6.0%, 95% CI: 2.8-11.1) in the 150-199 group.

CONCLUSIONS

Changes to national guidelines for managing paracetamol poisoning in the UK have increased the numbers of patients with acute overdose treated with acetylcysteine, with most additional treatments occurring in patients in the 100-149 mg/L dose range, a group at low risk of hepatotoxicity and higher risk of adverse reactions.

MRI characteristics of nodular fasciitis of the musculoskeletal system

OBJECTIVE

To evaluate MRI imaging appearances of nodular fasciitis in a pathologic-proven series of 29 patients.

MATERIALS AND METHODS

Review of the orthopedic oncology and pathology databases yielded 51 cases of histologically proven nodular fasciitis. MR imaging was available in 29 patients. Three musculoskeletal radiologists retrospectively reviewed all cases in consensus. Imaging features evaluated included location in the body, size, compartmental localization, relationship to fascia, signal characteristics, enhancement pattern, transcompartmental extension, and osseous and intra-articular involvement.

RESULTS

There were 15 male and 14 female patients. Mean age was 33 years (range, 16-59 years). Lesions ranged in size from 1.6 to 9 cm with 84 % of lesions measuring less than 4 cm. Twenty-three lesions were located in the upper arm or shoulder girdle. Nine lesions were subcutaneous in location, nine were intra-muscular, and 11 were inter-muscular. Lesions were consistently ovoid in shape with broad fascial contact. They exhibited internal homogenous low T1 and heterogeneous intermediate T2 signal with surrounding edema and slightly inhomogeneous enhancement. Twelve lesions exhibited central non-enhancing areas. Trans-compartmental spread was demonstrated in nine lesions. Osseous changes were seen in five cases and included extrinsic cortical saucerization, medullary edema, and transcortical osseous invasion. Two lesions demonstrated intra-articular extension.

CONCLUSIONS

MR imaging features of nodular fasciitis are generally non-specific and can be mistaken for a soft tissue sarcoma. This series, the largest MRI series of musculoskeletal cases in the literature, confirms the predilection of nodular fasciitis for the upper extremity in young adults but also demonstrates that aggressive imaging features such as transcompartmental spread, and osseous and intra-articular involvement may be seen in association with this benign soft tissue lesion.

Abstract 5778: Fragment-based drug discovery of selective inhibitors of fibroblast growth factor receptor (FGFr)

Recent data in a number of tumour types has implicated Fibroblast Growth Factor (FGF) and Fibroblast Growth Factor receptor (FGFr) signalling as being key to the molecular pathology of cancer. This poster will describe fragment based drug discovery using biophysical screening to identify initial fragments. Subsequently, in the fragments-to-leads stage a detailed structural understanding of the binding interactions between the fragment and its target protein utilised X-ray crystallography and NMR. Starting with different fragments allows several lead series to be identified, often by synthesizing only small numbers of compounds.

A fragment screening campaign was conducted against the FGFr-1 to detect very low molecular weight compounds that bound to the hinge region of the kinase. The screening produced several fragment molecules (Molecular Weight &lt;250 Da) which were in the micromolar range and confirmed binding mode in X-ray crystallography. One X-ray hit series that was 120 uM verse FGFr-3 will be described. Several iterations of structure-guided medicinal chemistry led to the identification of a lead compound with 3 nM affinity for FGFr-3, good cell activity and 30-fold selectivity verse VEGFr-2 with good oral activity. The lead was optimised to afford a compound that showed good PK/PD and efficacy.

This poster represents first disclosure of the structure of the lead series and illustrates how a fragment-based drug discovery approach can be efficiently used to discover compounds advanced nanomolar compounds with oral bioavailability.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5778.

Tracheo-oesophageal fistula diagnosed with multidetector computed tomography

This case highlights important issues in investigation of patients with suspected tracheo-oesophageal fistula including the value of multidetector computed tomography, the importance of thorough imaging evaluation when high clinical suspicion of tracheo-oesophageal fistula exists and the value of close interaction between radiologists and intensive care physicians in the investigation of these patients.

Phase I study of topoisomerase I inhibitor exatecan mesylate (DX-8951f) given as weekly 24-hour infusions three of every four weeks

Exatecan mesylate (DX-8951f) is a topoisomerase I inhibitor that has increased solubility and antitumor activity compared with other topoisomerase I inhibitors. The purpose of this study was to establish a safe dose of DX-8951f given as a weekly 24-h infusion 3 of every 4 weeks. DX-8951f was administered as a 24-h continuous infusion in escalating doses. Twenty-seven patients were treated with 81 courses of the drug. Dose-limiting toxicities included neutropenia, thrombocytopenia, and inability to administer all three doses in the first cycle. In minimally pretreated patients, a dose of 0.8 mg/m(2) was tolerable. In patients who were heavily pretreated, a slightly lower dose, 0.53 mg/m(2), was tolerated without any severe toxicities. Nonhematological toxicities were mild and consisted of mild diarrhea, asthenia, mild nausea, and constipation. Pharmacokinetic parameters could be well described with a one-compartment model in most patients, although the application of the one-compartment model probably resulted in an underestimated elimination half-life. In conclusion, the recommended Phase II dose for DX-8951f administered as a weekly 24-h infusion on a 3-of-4 week schedule is 0.8 mg/m(2) in minimally pretreated patients and 0.53 mg/m(2) in patients who are heavily pretreated.

RNA export mediated by tap involves NXT1-dependent interactions with the nuclear pore complex

Nuclear export of ribonucleoprotein complexes requires cis-acting signals and recognition by receptors that mediate translocation through the nuclear pore complex. Translocation is likely to involve a series of physical interactions between the ribonucleoprotein complex and nucleoporins within the nuclear pore complex. Here, we have characterized the function of NXT1 in the context of the Tap-dependent RNA export pathway. Tap has been implicated in the nuclear export of RNA transcripts derived from Mason-Pfizer monkey virus that contain the constitutive transport element. We demonstrate that NXT1 stimulates binding of a Tap-RNA complex to nucleoporins in vitro, and we provide mutational analysis that shows these interactions are necessary for nuclear export of an intron-containing viral mRNA in vivo. Tap contains separate domains for binding to nucleoporins and NXT1, both of which are critical for its export function. RNA export is mediated by a heterodimer of Tap and NXT1, and the function of NXT1 on this pathway is to regulate the affinity of the Tap-RNA complex for nucleoporins within the nuclear pore complex. We propose that NXT1-dependent binding of the Tap-RNA complex to the nucleoporin p62, which we have reconstituted in vitro using recombinant proteins, represents a single step of the translocation reaction.

Valuing people as individuals: development of an instrument through a survey of person-centredness in secondary care

BACKGROUND

Person-centred care is regarded as the optimum way of delivering health care and is defined as valuing people as individuals (Winefield et al. 1996). So how can practitioners find out if their service 'values people as individuals'? Serious doubts have been expressed about the validity of the concept of patient satisfaction and the ability of instruments to measure patients' views of care. However, qualitative research among people who had experienced problems with their health care has identified an alternative concept better able to articulate patient's complex experiences (Coyle 1997). The study found that that patients' identity was threatened by experiences perceived as dehumanizing, objectifying, disempowering and devaluing. Thus the concept of 'personal identity threat' showed the extent to which people felt valued (or not) as individuals.

AIM OF THE STUDY

The aim of the research reported in this paper is to build upon the earlier qualitative work and to identify the frequency and distribution of inpatients' experiences of 'personal identity threat'.

DESIGN/METHODS

The study adopted a cross-sectional survey design. Ninety-seven patients from general medical, surgical and otolaryngology wards completed a questionnaire developed from the qualitative study containing items on dehumanization, objectification, disempowerment and devaluation.

FINDINGS

Although many patients expressed positive sentiments about their care, problems were highlighted around power/control, involvement in care, and the approachability and availability of staff. The findings also revealed that women were more at risk than men of 'threats to identity' in health care settings.

CONCLUSIONS

Improvements are suggested to help promote a service that truly values people as individuals. These include improving health practitioners' understanding of the impact of illness on everyday life, promoting practitioners' listening and enquiring skills, and increasing the 'visibility' and availability of staff. Further research should also explore gender and age differences in perceptions of the lay-practitioner relationship.

Phase I and pharmacokinetic study of exatecan mesylate (DX-8951f): a novel camptothecin analog

PURPOSE

To determine the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetic (PK) profile, and recommended phase II dose of Exatecan mesylate (DX-8951f) when administered as a 24-hour continuous infusion every 3 weeks to patients with solid tumors.

PATIENTS AND METHODS

Twenty-two patients with advanced solid tumors, all previously treated, and with performance status < or = 2, were entered. The starting dose of DX-8951f was 0.15 mg/m(2); the dose was escalated according to the modified continual reassessment method. The drug was administered until disease progression or until unacceptable toxic effects occurred.

RESULTS

Seven dose escalations were completed, and a total of 53 courses were delivered (median, two courses; range, one to eight courses) during the study. At doses 1.2 mg/m(2) and lower, toxicities were mostly grade 1, primarily hematologic. In the initial cohort of three patients treated at 2.4 mg/m(2), grade 2 hematologic toxicity was observed. Of the six additional patients entered at 2.4 mg/m(2), three had grade 3 or 4 granulocytopenia. At doses higher than 2.4 mg/m(2), DLT granulocytopenia was observed. Nonhematologic toxicities, including nausea, vomiting, diarrhea, fatigue, and alopecia, were mild to moderate. Neither complete nor partial responses were observed, but four patients had stable disease. The PK profile of DX-8951f seemed linear at the doses administered. The plasma clearance, total volume of distribution, and terminal elimination half-life were approximately 3 L/h, 40 L, and 14 hours, respectively.

CONCLUSION

The DLT of this DX-8951f schedule was granulocytopenia for minimally pretreated patients, and both granulocytopenia and thrombocytopenia for heavily pretreated patients. The MTD for both minimally and heavily pretreated patients was 2.4 mg/m(2). DX-8951f seems to have a linear PK profile on the basis of single-dose administration. The recommended phase II dose with this schedule is 2.4 mg/m(2) for minimally pretreated patients. A lower dose should be used for heavily pretreated patients.

DX-8951f: summary of phase I clinical trials

Exatecan mesylate (DX-8951f) is a new hexacyclic camptothecin analogue with favorable attributes compared to topotecan and CPT-11, including watersolubility, greater potency against topoisomerase I, lack of esterase-dependent activation, broad antitumor activity, and low cross-resistance against MDR-1 overexpressing tumors. In preclinical studies, the compound demonstrated a favorable toxicology profile with hematologic dose-limiting toxicity and moderate gastrointestinal toxicity, linear pharmacokinetics, P450 hepatic metabolism (CYP3A4 and CYP1A2), and predominately fecal excretion. The results of six U.S. and European phase I clinical trials as well as two Japanese studies are presented including total DX-8951 and lactone DX-8951 pharmacokinetics. The toxicity profile was similar for all schedules of administration. Hematologic toxicity was dose-dependent and reversible. Neutropenia was dose-limiting in minimally pretreated patients, whereas neutropenia and thrombocytopenia were dose-limiting in heavily pretreated patients. Non-hematologic toxicity included moderate gastrointestinal toxicity (nausea, vomiting > diarrhea), transient elevation of hepatic transaminases, asthenia, and alopecia. Two cases of acute pancreatitis not predicted by preclinical toxicology were also observed. Antineoplastic activity was detected in several solid tumor types: non-small cell lung cancer, extrapulmonary small cell cancer, colorectal cancer, hepatocellular cancer, and sarcoma. Antitumor activity was seen in CPT-11 and topotecan-resistant tumors. Pharmacokinetics were linear within the dose range tested. A pharmacokinetic/pharmacodynamic model predictive of DX-8951f-induced neutropenia in individual patients was developed. The daily x5, every 3-week schedule with the drug administered as a 30-minute intravenous infusion was selected for future phase II clinical trials based on its superior antitumor activity.

Galantamine, a cholinesterase inhibitor that allosterically modulates nicotinic receptors: effects on the course of Alzheimer's disease

Despite the proven efficacy of acetylcholinesterase inhibitors in Alzheimer's disease, there is a need for new and more effective treatments. Galantamine is a novel treatment for Alzheimer's disease that inhibits acetylcholinesterase and modulates nicotinic receptors. In randomized, double-blind, placebo-controlled studies of up to 6 months duration, galantamine significantly improved cognitive function. Galantamine also had beneficial effects on instrumental and basic activities of daily living, and postponed the progression of behavioral symptoms. Patients who completed one of the 6-month, placebo-controlled studies were eligible to enter a 6-month, open-extension study of the 24-mg/day dose of galantamine. At the end of 12 months, cognitive function and activities of daily living were preserved in those patients who had been treated throughout the study with galantamine 24 mg/day. At 12 months, this group of patients had significantly better cognitive functions than patients who had been treated with a placebo for 6 months before receiving galantamine. These studies indicate that galantamine postpones the progression of symptoms in Alzheimer's disease. Since galantamine shows the greatest benefits when treatment is started early, its long-term benefits may result from an effect on the underlying disease process; such an effect might be mediated by galantamine's concomitant action on nicotinic receptors.

DX-8951f, a hexacyclic camptothecin analog, on a daily-times-five schedule: a phase I and pharmacokinetic study in patients with advanced solid malignancies

PURPOSE

To assess the feasibility of administering DX-8951f (exatecan mesylate), a water-soluble, camptothecin analog, as a 30-minute intravenous infusion daily for 5 days every 3 weeks, determine the maximum-tolerated dose (MTD) and pharmacokinetic (PK) behavior of DX-8951f, and seek preliminary evidence of anticancer activity.

PATIENTS AND METHODS

Patients with advanced solid malignancies were treated with escalating doses of DX-8951f. After three patients were treated at the first dose level, doses were to be escalated in increments of 100%, using a single patient at each dose level unless moderate toxicity was observed. The MTD, defined as the highest dose level at which the incidence of dose-limiting toxicity did not exceed 20%, was calculated separately for minimally pretreated (MP) and heavily pretreated (HP) patients. The PK and excretory profiles of DX-8951, the anhydrous form of DX-8951f, were also characterized.

RESULTS

Thirty-six patients were treated with 130 courses of DX-8951f at six dose levels ranging from 0.1 to 0.6 mg/m(2)/d. Brief, noncumulative neutropenia was the most common toxicity observed. Severe myelosuppression (neutropenia that was protracted and/or associated with fever and/or severe thrombocytopenia) was consistently experienced by HP and MP patients at doses exceeding 0.3 and 0.5 mg/m(2)/d, respectively. Nonhematologic toxicities (nausea, vomiting, and diarrhea) were also observed, but these effects were rarely severe. Objective antitumor activity included partial responses in one patient each with platinum-resistant extrapulmonary small-cell and fluoropyrimidine- and irinotecan-resistant colorectal carcinoma, and minor responses in patients with prostate, hepatocellular, thymic, primary peritoneal, and irinotecan-resistant colorectal carcinomas. The PKs of total DX-8951 were linear and well fit by a three-compartment model.

CONCLUSION

The recommended doses for phase II studies of DX-8951f as a 30-minute infusion daily for 5 days every 3 weeks are 0.5 and 0.3 mg/m(2)/d for MP and HP patients, respectively. The characteristics of the myelosuppressive effects of DX-8951f, paucity of severe nonhematologic toxicities, and antitumor activity against a wide range of malignancies warrant broad disease-directed evaluations of DX-8951f on this schedule.

An exploration of the epistemological intricacies of using qualitative data to develop a quantitative measure of user views of health care

Nurse researchers are increasingly combining qualitative and quantitative methods in order to understand more fully the world of research subjects. Qualitative data are often used to explore the subjective meanings behind survey responses and to develop quantitative measures and scales. Insights from qualitative data help researchers to design instruments which are more sensitive to respondents' meanings and interpretations. The aim of this paper is to highlight the epistemological and methodological complexities involved in this enterprise through drawing on our own experience of developing an instrument to examine person-centredness in health care from a qualitative study of dissatisfaction. The intricacies of this project relate to: epistemological continuity and inconsistency; research roles; reflexivity; confirmation; and completeness. Through discussing the literature around integrating methods, we suggest that researchers could be assisted in their attempts to develop conceptually sound quantitative measures by extending the concept of reflexivity (used in qualitative research) to the quantitative components of mixed method studies. This would aid conceptual clarity by making explicit the social, cultural, and political construction of knowledge, and would also encourage researchers to reflect upon the ethical and political consequences of their research.

Seeing the wood for the trees: defining the forgotten concept of patient dissatisfaction in the light of patient satisfaction research

Studies of patient satisfaction are regarded by many as the most important way to obtain patients' views. To date, relatively few studies have focussed specifically on dissatisfaction. Concerns have been expressed about the validity of the concept of satisfaction. Dissatisfaction, however, has received little attention since it has been assumed to be the opposite of satisfaction and thus already defined. Therefore a series of assumptions have also been made about dissatisfaction, which may or may not compromise its validity or usefulness. The aim of this review is to clarify the concept of dissatisfaction by examining what studies of patient satisfaction can and cannot tell us about dissatisfaction; identifying assumptions; and finally by suggesting how research might best be oriented to accommodate the complexity of patient experiences.

Understanding dissatisfied users: developing a framework for comprehending criticisms of health care work

Recent government proposals have underlined the importance of ascertaining users' views of health care. Traditionally these have been obtained through satisfaction surveys. However, researchers argue that the focus of attention should now shift to exploring dissatisfaction because it highlights more clearly any problems in lay-practitioner relationships. Research has shown that dissatisfaction is a complex social construct which is underpinned by a range of values, beliefs, attitudes and experiences. The aim of this paper is to provide insights into the meaning of dissatisfaction by exploring how dissatisfied users attribute cause, responsibility and blame for their untoward experiences. Forty-one people were identified from a household survey of user views as experiencing problems with their health care. They were interviewed in depth, and a grounded theory approach was used to construct a framework inductively from their accounts. This identified a number of normative expectations through which health work was routinely criticized; these included respondents casting aspersions on the professional integrity of health care practitioners and preserving their own moral identity through demonstrating competence, knowledge, rationality, reasonableness and concern for others. Moreover, it is argued that these patterns help practitioners to understand how dissatisfied users' perceive subsequent health care encounters.

Differentiation of normal and abnormal airway protection during swallowing using the penetration-aspiration scale

Accidental loss of food or liquids into the airway while eating or drinking is perhaps the most clinically significant consequence of dysphagia. Although videofluoroscopic recording of swallowing is the current gold standard for identifying and determining remediation for aspiration, results are generally described in descriptive terms, thus limiting information and lending to errors of interpretation. We previously published an 8-point scale to quantitate selected aspects of penetration and aspiration conveying depth of airway invasion and whether or not material entering the airway is expelled (Rosenbek et al., 1996, Dysphagia 11:93-98). The present study defines the distribution of the Penetration-Aspiration Scale scores in healthy normal subjects of different genders and ages. The scale was also used with two groups of patients known to have significant dysphagia relative to stroke or head and neck cancer. Significant differences found among groups are discussed.

Acute management of spinal cord injury

Demographic trends in the occurrence of injury and improvements in the early management of spinal trauma are changing the long-term profile of patients with spinal cord injuries. More patients are surviving the initial injury, and proportionately fewer patients are sustaining complete injuries. While preventive efforts to reduce the overall incidence of spinal cord injury are important, a number of steps can be taken to minimize secondary injury once the initial trauma has occurred. Recent efforts have focused on understanding the biochemical basis of secondary injury and developing pharmacologic agents to intervene in the progression of neurologic deterioration. The Third National Acute Spinal Cord Injury Study investigators concluded that methylprednisolone improves neurologic recovery after acute spinal cord injury and recommended that patients who receive methylprednisolone within 3 hours of injury should be maintained on the treatment regimen for 24 hours. When methylprednisolone therapy is initiated 3 to 8 hours after injury, it should continue for 48 hours. In addition to the adoption of the guidelines of that study, rapid reduction and stabilization of injuries causing spinal cord compression are critical steps in optimizing patients' long-term neurologic and functional outcomes.

The meaning of patient satisfaction: an explanation of high reported levels

The social policy background to the proliferation of patient satisfaction surveys is a desire for increased patient representation and participation. Within this context, it is assumed that satisfaction surveys embody patients' evaluations of services. However, as most surveys report high satisfaction levels, the interpretation of satisfaction as the outcome of an active evaluation has been called into question. The aim of this study is to identify whether and how service users evaluate services. This was made possible through unstructured in-depth interviews with users of mental health services and through more structured discussion around their responses on a patient satisfaction questionnaire (CSQ 18B) whose psychometric properties has been well documented. Twenty-nine people with current or recent contact with mental health services within the British National Health Service were interviewed. The data revealed that service users frequently described their experiences in positive or negative terms. However, the process by which these experiences were transformed into "evaluations" of the service was complex. Consequently, many expressions of "satisfaction" on the CSQ 18B hid a variety of reported negative experiences. An explanation for this lack of correspondence is outlined.

Frequency-range discriminations: special and general abilities in zebra finches (Taeniopygia guttata) and humans (Homo sapiens)

The acoustic frequency ranges in birdsongs and human speech can provide important pitch cues for recognition. Zebra finches and humans were trained to sort contiguous frequencies into 3 or 8 ranges, based on associations between the ranges and reward. The 3-range task was conducted separately in 3 spectral regions. Zebra finches discriminated 3 ranges in the medium and high spectral regions faster than in the low region and discriminated 8 ranges with precision. Humans discriminated 3 ranges in all 3 spectral regions to the same modest standard and acquired only a crude discrimination of the lowest and highest of 8 ranges. The results indicate that songbirds have a special sensitivity to the pitches in conspecific songs and, relative to humans, have a remarkable general ability to sort pitches into ranges.

Pfcrk-1, a developmentally regulated cdc2-related protein kinase of Plasmodium falciparum

A gene encoding a novel cdc2-related protein kinase has been identified in Plasmodium falciparum, using degenerate oligonucleotides designed to hybridise to regions that are conserved in members of the cdc2 gene family. This gene, called Pfcrk-1, is located on chromosome 4. It is most closely related to the p58GTA gene family, members of which are negative regulators of cell growth in vertebrates. Pfcrk-1 is developmentally regulated, as indicated by stage-specific accumulation of mRNA in gametocytes.

Detection and measurement of simulated early rheumatoid lesions of the hand using digital subtraction radiography

The ability of digital subtraction radiography, a new technique to detect and quantify small bone lesions, is demonstrated. Discrete lesions in the metacarpals of cadaver hands simulated erosive bone loss. Radiographs made before and after removal of bone were digitized and subtracted. Density changes on subtraction images were determined, and bone loss was estimated by an automatic procedure that compared changes in radiographic density with a calibration wedge included in the radiographs. Comparison of estimated bone loss with the weight of bone removed showed reproducible detection and measurement of bone lesions as small as 4.6 mg, a size undetectable using current radiographic methods. Subtraction radiographs of bone chips overlaid on the hand of a volunteer indicated detection limits were similar in vivo. This technique enhanced the radiographic visibility of erosive lesions and thus has the potential to improve the detection of subtle bone changes in clinical settings.

Effect of local or systemic treatment prior to primary tumor removal on the production and response to a serum growth-stimulating factor in mice

This report indicates that not only does the preoperative administration of cyclophosphamide or radiation prevent the kinetic changes observed in a distant tumor focus following tumor removal but that the preoperative administration of the antiestrogen tamoxifen and the luteinizing hormone-releasing hormone analogue Zoladex are equally effective in that regard. It also provides evidence indicating that serum obtained from mice treated with those therapies when transferred to a recipient bearing a tumor of a similar type to that in the donor fails to stimulate DNA synthesis in the tumor of the recipient. In contrast, an increase in labeling index occurs following transfer of serum obtained following tumor removal from untreated mice. Moreover, when tumor-bearing mice were treated by each of the four modalities prior to receiving serum obtained from untreated donors following removal of a tumor, no kinetic changes were observed in the tumor of the serum recipient.

Presence of a growth-stimulating factor in serum following primary tumor removal in mice

The effect of removal of a primary tumor on the kinetics of cells in a metastasis was evaluated using six different tumors (C3H, MXTa, MXTb, MC54, CD8, and 3LL) which varied relative to their origin, histology, and the strain of mice in which they were carried. There was an increase in the labeling index (LI) of distant tumor focus ("metastasis") associated with the removal of each of the tumor types and unrelated to operative and anesthetic trauma. Information presented supports the presence of a serum growth factor as being responsible for the phenomenon. Serum obtained from mice following removal of a tumor, when transferred to a recipient with the same type of tumor as in the donor, resulted in an increase in the LI of the tumor. Multiple injections of serum failed to add to the increase but did prolong its presence, suggesting that there is a finite population of cells, most likely in the G1-G0 phase, which are capable of responding to the stimulating factor. The transfer of serum obtained following removal of a tumor type different from that in recipients resulted in findings which indicate that tumors producing a stimulating growth factor are those capable of responding to it. Serum obtained from animals with unremoved tumors or less than 18 h after removal failed to substantially augment the LI of tumors in recipients. It is postulated that the growth factor released by a tumor is in an inactive form which becomes activated over time. Observations indicate that medium conditioned by the growth of C3H tumor contains a growth-stimulating factor which is capable of increasing the LI of a C3H tumor in a recipient in a fashion similar to that obtained following tumor removal. That finding indicates the capability of the tumor to elaborate growth-stimulating material which may be similar to that found in serum. The findings presented refute the premise that removal of a primary tumor is a local phenomenon with no other biological consequences. They indicate that, following primary tumor removal, metastatic behavior may be affected by an interplay of growth factor(s) which can influence the outcome of a host to its tumor.

Cerebrospinal fluid correlates of depression in Huntington's disease

Patients with Huntington's disease (HD) commonly have concomitant depressive disorders. Prompted by reports of elevated corticotropin releasing factor (CRF) and reduced 5-hydroxyindoleacetic acid (5-HIAA) concentrations in lumbar cerebrospinal fluid (CSF) of patients with major depression, these CSF constituents were examined in 56 nonmedicated patients who were in the early stages of HD. Elevated CRF concentrations were found in patients with HD in comparison with a control group of 21 subjects without neurologic illness. The CSF 5-HIAA concentrations in patients with HD did not differ from that in four normal volunteers. Patients with HD who had depressive disorders (major depression or dysthymia) did not differ from those without depression with respect to CSF 5-HIAA or CRF concentration. However, a positive correlation was observed between severity of major depression and CRF concentration. These findings suggest that the depression associated with HD may differ neurochemically from that seen in other major depressive disorders, and support the notion that clinically significant depressive symptoms reflect heterogeneous pathophysiologic conditions with different neurochemical correlates.

Cerebrospinal fluid homovanillic acid and parkinsonism in Huntington's disease

In Huntington's disease (HD), normal or decreased levels of homovanillic acid (HVA) in cerebrospinal fluid (CSF) have been reported but have not been analyzed with respect to severity of parkinsonism, which in certain cases may be a predominant feature of the illness. We obtained CSF by lumbar puncture from four groups of nonmedicated subjects: (1) those with HD in the earliest stages of illness (n = 51), (2) those with parkinsonism, including idiopathic (n = 10) and atypical forms (n = 4), (3) those with nonparkinsonian movement disorders (n = 19), and (4) normal volunteers (n = 4). HVA was determined by high-pressure liquid chromatography with electrochemical detection, and motor signs were assessed in standardized fashion. The parkinsonian group had reduced levels of CSF HVA, but the other groups showed no significant differences. For those with HD, no correlation was found between HVA level and severity of parkinsonism, and there were no differences in HVA level between those subjects with (n = 14) or without (n = 37) prominent parkinsonism or between subjects whose age at illness onset was 30 years or less (n = 16) and those whose age at onset was over 30 (n = 35). Our findings indicate that in early, untreated HD, CSF HVA is in the normal range and does not correlate with the severity of parkinsonism. This observation supports neuropathological findings suggesting that parkinsonian features in HD are largely related to the loss of postsynaptic striatal dopamine receptors rather than to presynaptic nigral degeneration.

The effect of propranolol on catecholamine clearance

Normal subjects given propranolol increased their plasma t1/2 for infused isoproterenol from 2.68 to 6.25 minutes. Propranolol increased plasma norepinephrine (NE) levels only slightly. Propranolol increased the t1/2 of isoproterenol but not that of NE in men with autonomic nervous system degeneration. This suggests that propranolol acts on nonneuronal uptake-2 processes, rather than on uptake-1 mechanisms. alpha-Blockers slow uptake-1 and beta-blockers slow uptake-2 processes. When 27 subjects exercised, those who attained the highest plasma levels of the alpha- and beta-receptor agonist NE also had the briefest apparent t1/2 for NE. Adrenergic receptor blocking drugs slow catecholamine clearance. NE may stimulate its own clearance.

Interpretation of pulmonary artery wedge pressure and pullback blood gas determinations during positive end-expiratory pressure ventilation and after exclusion of the bronchial circulation in the dog

Left atrial pressure (LAP) and pulmonary artery wedge pressure (PWP) were measured at different heights during graded increases in positive end-expiratory pressure (PEEP). Six healthy anesthetized dogs were placed in lateral decubitus positions with a balloon-tipped pulmonary artery catheter inserted in each lung. PWP in the gravitationally superior lung overestimated LAP at 15 and at 20 cm H2O PEEP (p less than 0.05). PWP in the dependent lung was virtually identical to LAP at all degrees of PEEP. Wedge blood could be aspirated through the distal lumen of the pulmonary artery catheters during balloon inflation at all degrees of PEEP except for 3 attempts. PCO2 in wedge blood in both the nondependent and dependent lungs at all degrees of PEEP was consistently lower than PCO2 in arterial blood (p less than 0.05). Wedge blood was arterialized, i.e., oxygen saturation greater than 95%, in all but 4 specimens. Surgical elimination of the bronchial artery supply to the lung in 3 dogs did not affect PWP or blood gas measurements. We conclude that in this animal model: (1) the tip of a pulmonary artery catheter must be below the level of the left atrium, Zone III location, to accurately reflect LAP at high degrees of PEEP; (2) arterialization of wedge blood samples does not guarantee that PWP reflects LAP; (3) bronchial artery blood supply does not affect PWP or wedge blood gas measurements, even at high degrees of PEEP.

Relapse in chronic schizophrenics treated with fluphenazine decanoate is associated with low serum neuroleptic levels

Seventy-three chronic schizophrenic outpatients were studied for 1 year to determine if neuroleptic drug levels could be useful in preventing relapse. All patients received fluphenazine decanoate i.m., and serum level of neuroleptic was determined by radioreceptorassay. Clinical improvement was measured using the Global Assessment Scale. Results indicate that serum neuroleptic drug levels may be useful in the outpatient management of chronic schizophrenics.

Dipeptides of glutamate and aspartate may be endogenous neuroexcitants in the rat hippocampal slice

The dipeptide N-acetylaspartylglutamate (NAAG), and possibly the related dipeptide aspartylglutamate (AG), have been found in high concentrations in rat brain, and have been shown to bind avidly and selectively to a subset of glutamate (GLUT) receptors. Certain observations regarding GLUT and aspartate might be explained if the endogenous transmitter were a compound composed of both amino acids. We therefore examined the electrophysiological actions of NAAG and AG in the rat in vitro rat hippocampal slice model. NAAG or AG and GLUT were applied locally to cells by a dual-barrel pressure technique. Intracellular recordings from 34 CA1 pyramidal neurons showed depolarizations and conductance increases resembling evoked excitatory postsynaptic potential in 15 of 20 cells exposed to NAAG, and 14 of 14 exposed to AG. Many GLUT-responsive sites did not respond to AG, and most did not respond to NAAG. Responses to NAAG were usually too small to induce cell firing; they were best detected, therefore, by intracellular recording. With extracellular unit recordings, GLUT was equally excitatory in stratum radiatum and pyramidale of CA1 (N = 19; p greater than 0.10, one-way analysis of variance). In contrast, AG was considerably more potent (N = 21; p less than 0.01) in stratum radiatum. NAAG was not noted to excite cells when applied to stratum pyramidale. The region of maximal responsiveness to AG in CA1 coincided with the area of the dendritic tree receiving Schaffer collateral-commissural afferents. This spatial profile, together with other neuropharmacological evidence, support the candidacy of glutamate-containing peptides as endogenous excitatory compounds in certain pathways of hippocampus.