The postsynaptic spectrin/4.1 membrane protein "accumulation machine"

An important aspect of the function of the membrane-associated cytoskeleton has been suggested to be to trap and retain selected transmembrane proteins at points on the cell surface specified by cell adhesion molecules. In the process, cell adhesion molecules are cross-linked to each other, and so junctional complexes are strengthened. In this short review, we will discuss recent advances in understanding the role of this "accumulation machine" in postsynaptic structures. Function in the brain depends on correct ordering of synaptic intercellular junctions, and in particular the recruitment of receptors and other apparatus of the signalling system to postsynaptic membranes. Spectrin has long been known to be a component of postsynaptic densities, and recent advances in molecular cloning indicate that beta spectrins at PSDs are all "long" C-terminal isoforms characterised by pleckstrin homology domains. Isoforms of protein 4.1 are also present at synapses. All four 4.1 proteins are represented in PSD preparations, but it is 4.1R that is most enriched in PSDs. 4.1R binds to several proteins enriched in PSDs, including the characteristic PSD intermediate filament, alpha-internexin. Both 4.1 and spectrin interact with ionotropic glutamate receptors (AMPA and NMDA receptors, respectively): 4.1 stabilises AMPA receptors on the cell surface. By linking these receptors to the cytoskeletal and cell adhesion molecules that specify glutamatergic synapses, the membrane protein accumulation machine is suggested to direct the formation of postsynaptic signalling complexes.

Genome sequence of the plant pathogen and biotechnology agent Agrobacterium tumefaciens C58

Agrobacterium tumefaciens is a plant pathogen capable of transferring a defined segment of DNA to a host plant, generating a gall tumor. Replacing the transferred tumor-inducing genes with exogenous DNA allows the introduction of any desired gene into the plant. Thus, A. tumefaciens has been critical for the development of modern plant genetics and agricultural biotechnology. Here we describe the genome of A. tumefaciens strain C58, which has an unusual structure consisting of one circular and one linear chromosome. We discuss genome architecture and evolution and additional genes potentially involved in virulence and metabolic parasitism of host plants.

Phenotypes Associated with SHOX Deficiency

Leri-Weill dyschondrosteosis (LWD) (MIM 127300) is a dominantly inherited skeletal dysplasia characterized phenotypically by Madelung wrist deformity, mesomelia, and short stature. LWD can now be defined genetically by haploinsufficiency of the SHOX (short stature homeobox-containing) gene. We have studied 21 LWD families (43 affected LWD subjects, including 32 females and 11 males, ages 3-56 yr) with confirmed SHOX abnormalities. We investigated the relationship between SHOX mutations, height deficit, and Madelung deformity to determine the contribution of SHOX haploinsufficiency to the LWD and Turner syndrome (TS) phenotypes. Also, we examined the effects of age, gender, and female puberty (estrogen) on the LWD phenotype. SHOX deletions were present in affected individuals from 17 families (81%), and point mutations were detected in 4 families (19%). In the LWD subjects, height deficits ranged from -4.6 to +0.6 SD (mean +/- SD = -2.2 +/- 1.0). There were no statistically significant effects of age, gender, pubertal status, or parental origin of SHOX mutations on height z-score. The height deficit in LWD is approximately two thirds that of TS. Madelung deformity was present in 74% of LWD children and adults and was more frequent and severe in females than males. The prevalence of the Madelung deformity was higher in the LWD vs. a TS population. The prevalence of increased carrying angle, high arched palate, and scoliosis was similar in the two populations. In conclusion, SHOX deletions or mutations accounted for all of our LWD cases. SHOX haploinsufficiency accounts for most, but not all, of the TS height deficit. The LWD phenotype shows some gender- and age-related differences.

Neurocognitive outcome in brain metastases patients treated with accelerated-fractionation vs. accelerated-hyperfractionated radiotherapy: an analysis from Radiation Therapy Oncology Group Study 91-04

PURPOSE

To evaluate neurocognitive outcome as measured by the Mini-Mental Status Examination (MMSE) among patients with unresectable brain metastases randomly assigned to accelerated fractionation (AF) vs. accelerated hyperfractionated (AH) whole-brain radiation therapy (WBRT).

METHODS AND MATERIALS

The Radiation Therapy Oncology Group (RTOG) accrued 445 patients with unresectable brain metastases to a Phase III comparison of AH (1.6 Gy b.i.d. to 54.4 Gy) vs. AF (3 Gy q.d. to 30 Gy). All had a KPS of >or= 70 and a neurologic function status of 0-2. Three hundred fifty-nine patients had MMSEs performed and were eligible for this analysis. Changes in the MMSE were analyzed according to criteria previously defined in the literature.

RESULTS

The median survival was 4.5 months for both arms. The average change in MMSE at 2 and 3 months was a drop of 1.4 and 1.1, respectively, in the AF arm as compared to a drop of 0.7 and 1.3, respectively, in the AH arm (p = NS). Overall, 91 patients at 2 months and 23 patients at 3 months had both follow-up MMSE and computed tomography/magnetic resonance imaging documentation of the status of their brain metastases. When an analysis was performed taking into account control of brain metastases, a significant effect on MMSE was observed with time and associated proportional increase in uncontrolled brain metastases. At 2 months, the average change in MMSE score was a drop of 0.6 for those whose brain metastases were radiologically controlled as compared to a drop of 1.9 for those with uncontrolled brain metastases (p = 0.47). At 3 months, the average change in MMSE score was a drop of 0.5 for those whose brain metastases were radiologically controlled as compared to a drop of 6.3 for those with uncontrolled brain metastases (p = 0.02).

CONCLUSION

Use of AH as compared to AF-WBRT was not associated with a significant difference in neurocognitive function as measured by MMSE in this patient population with unresectable brain metastases and limited survival. However, control of brain metastases had a significant impact on MMSE.

Functional versatility in the CRP-FNR superfamily of transcription factors: FNR and FLP

The cAMP receptor protein (CRP; sometimes known as CAP, the catabolite gene activator protein) and the fumarate and nitrate reduction regulator (FNR) of Escherichia coli are founder members of an expanding superfamily of structurally related transcription factors. The archetypal CRP structural fold provides a very versatile mechanism for transducing environmental and metabolic signals to the transcription machinery. It allows different functional specificities at the sensory, DNA-recognition and RNA-polymerase-interaction levels to be 'mixed and matched' in order to create a diverse range of transcription factors tailored to respond to particular physiological conditions. This versatility is clearly illustrated by comparing the properties of the CRP, FNR and FLP (FNR-like protein) regulators. At the sensory level, the basic structural fold has been adapted in FNR and FLP by the acquisition in the N-terminal region of different combinations of cysteine or other residues; which bestow oxygen/redox sensing mechanisms that are poised according to the oxidative stress thresholds affecting the metabolism of specific bacteria. At the DNA-recognition level, discrimination between distinct but related DNA targets is mediated by amino acid sequence modifications in the conserved core contact between the DNA-recognition helix and target DNA. And, at the level of RNA-polymerase-interaction, different combinations of three discrete regions contacting the polymerase (the activating regions) are used for polymerase recruitment and promoting transcription.

Patient evaluation of the hotel function of hospitals

BACKGROUND

A means of measuring patient satisfaction is essential in the effort to improve the quality of health care delivered in our nation's hospitals. Accurate feedback allows employers to better meet patients' needs and allows hospital administrators to improve service delivery. Patients are empowered by having a voice in the manner in which their health care is delivered. Moreover, improving the efficiency of the health care delivery system decreases health care costs. Hospital comparisons can be made readily available to a large audience through the Internet, resulting in empowerment of the patient and a universal improvement in hospital care. This is the first multi-institutional analysis of patient satisfaction among New York City and northern New Jersey area tertiary care hospitals. In this study, we evaluated the patient-assessed hotel function of hospitals in a single geographic region to determine whether clinically and statistically significant differences would be revealed that could provide beneficial information to stakeholders in the healthcare system.

METHODS

Patients (n = 261) who had spent a night during the past year in one of eleven hospitals within 60 miles of New York City were chosen at random from doctors' waiting rooms. On average, 24 patients from each hospital were surveyed. They were asked to complete a questionnaire that rated the various departments in the hospital on qualities such as courtesy, promptness, and cleanliness. The questionnaire also rated important characteristics of the patient experience, such as the ease of parking and the taste of the food. Each item on the survey was coded on a scale of 1 to 10 with 10 being the most positive response. The 26 specific questions were divided into 14 domains. Averages in each domain were compared by gender, age, and hospital identity, attractiveness, and setting. All statistical calculations were performed using SPSS/PC, and means were compared using t-tests.

RESULTS

Analysis designed to evaluate outcomes between each of the possible 54 pairs of hospitals comparisons revealed statistically significant differences as often as 44% of the time in some outcomes measures (logistics), but as rarely as 7% of the time in others (billing function). Clinically significant differences (>2 units per scale) were frequently evident, although the ranges differed dramatically depending on the domains surveyed. Although age, gender, and race/ethnicity were generally not predictive of satisfaction, non-urban setting was correlated with greater patient satisfaction.

CONCLUSION

By having access to patient satisfaction comparisons among hospitals, patients are empowered to make better choices, employers can identify and adapt to patient preferences, and administrators can improve the services delivered and decrease health care costs by improving efficiency. Although our study was somewhat limited by patient selection biases, the study's results suggest that Internet-based tools of comparison will enable patients to make free and informed decisions about their health care by comparing local hospitals and voting on their impressions of the facilities from which they receive care.

Radiosurgery for patients with brain metastases: a multi-institutional analysis, stratified by the RTOG recursive partitioning analysis method

PURPOSE

To estimate the potential improvement in survival for patients with brain metastases, stratified by the Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) class and treated with radiosurgery (RS) plus whole brain radiotherapy (WBRT).

METHODS AND MATERIALS

An analysis of the RS databases of 10 institutions identified patients with brain metastates treated with RS and WBRT. Patients were stratified into 1 of 3 RPA classes. Survival was evaluated using Kaplan-Meier estimates and proportional hazard regression analysis. A comparison of survival by class was carried out with the RTOG results in similar patients receiving WBRT alone.

RESULTS

Five hundred two patients were eligible (261 men and 241 women, median age 59 years, range 26-83). The overall median survival was 10.7 months. A higher Karnofsky performance status (p = 0.0001), a controlled primary (median survival = 11.6 vs. 8.8 months, p = 0.0023), absence of extracranial metastases (median survival 13.4 vs. 9.1 months, p = 0.0001), and lower RPA class (median survival 16.1 months for class I vs. 10.3 months for class II vs. 8.7 months for class III, p = 0.000007) predicted for improved survival. Gender, age, primary site, radiosurgery technique, and institution were not prognostic. The addition of RS boosted results in median survival (16.1, 10.3, and 8.7 months for classes I, II, and III, respectively) compared with the median survival (7.1, 4.2, and 2.3 months, p <0.05) observed in the RTOG RPA analysis for patients treated with WBRT alone.

CONCLUSION

In the absence of randomized data, these results suggest that RS may improve survival in patients with BM. The improvement in survival does not appear to be restricted by class for well-selected patients.

Event-related fMRI with simultaneous and continuous EEG: description of the method and initial case report

We report on the initial imaging findings with a new technique for the simultaneous and continuous acquisition of functional MRI data and EEG recording. Thirty-seven stereotyped interictal epileptiform discharges (spikes) were identified on EEG recorded continuously during the fMRI acquisition on a patient with epilepsy. Localization of the BOLD activation associated with the EEG events was consistent with previous findings and EEG source modeling. The time course of activation was comparable with the physiological hemodynamic response function (HRF). The new methodology could lead to novel and important applications in many areas of neuroscience.

A man who inherited his SRY gene and Leri-Weill dyschondrosteosis from his mother and neurofibromatosis type 1 from his father

We report on a man with neurofibromatosis type 1 (NF1) and Leri-Weill dyschondrosteosis (LWD). His father had NF1. His mother had LWD plus additional findings of Turner syndrome (TS): high arched palate, bicuspid aortic valve, aortic stenosis, and premature ovarian failure. The proband's karyotype was 46,X,dic(X;Y)(p22.3;p11.32). Despite having almost the same genetic constitution as 47,XXY Klinefelter syndrome, he was normally virilized, although slight elevation of serum gonadotropins indicated gonadal dysfunction. His mother's karyotype was mosaic 45,X[17 cells]/46,X,dic(X;Y)(p22.3;p11.32)[3 cells].ish dic(X;Y)(DXZ1 +,DYZ1 + ). The dic(X;Y) chromosome was also positive for Y markers PABY, SRY, and DYZ5, but negative for SHOX. The dic(X;Y) chromosome was also positive for X markers DXZ1 and a sequence < 300 kb from PABX, suggesting that the deletion encompassed only pseudoautosomal sequences. Replication studies indicated that the normal X and the dic(X;Y) were randomly inactivated in the proband's lymphocytes. LWD in the proband and his mother was explained by SHOX haploinsufficiency. The mother's female phenotype was most likely due to 45,X mosaicism. This family segregating Mendelian and chromosomal disorders illustrates extreme sex chromosome variation compatible with normal male and female sexual differentiation. The case also highlights the importance of karyotyping for differentiating LWD and TS, especially in patients with findings such as premature ovarian failure or aortic abnormalities not associated with isolated SHOX haploinsufficiency.

Practice and policy of measuring quality of life and health economics in cancer clinical trials: a survey among co-operative trial groups

BACKGROUND

Co-operative groups have played an important role in the advance of health-related quality of life (HRQL) research. However, definitions of the concept, criteria for selection of existing instruments and methods for data collection and interpretation remain poorly defined in the literature. A survey was conducted amongst the major cancer co-operative groups in order to gain a better understanding of their current policy and processes to ensure optimal HRQL data collection within cancer clinical trials. The topic of health economics was similarly addressed.

METHODS

A written questionnaire was addressed to 16 major European and North American cancer co-operative groups. Eleven groups responded (response rate: 69%). however, one group could not provide information for the survey, thus ten questionnaires were available for analysis.

RESULTS

The results from this survey among co-operative groups show that HRQL (more than health economics) is recognized as an important, although usually secondary, outcome measure in oncology trials. On the whole, co-operative groups have a rather flexible policy towards the inclusion of HRQL (and HE) into their clinical trials, and practice is very much on a case-by-case basis, but use standard practice guidelines and internal procedures is to ensure well-defined study protocols and enhance good quality studies.

SB-272183, a selective 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptor antagonist in native tissue

A novel compound, SB-272183 (5-Chloro-2, 3-dihydro-6-[4-methylpiperazin-1-yl]-1[4-pyridin-4-yl]napth-1-ylaminocarbonyl]-1H-indole), has been shown to have high affinity for human 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptors with pK(i) values of 8.0, 8.1 and 8.7 respectively and is at least 30 fold selective over a range of other receptors. [(35)S]-GTPgammaS binding studies showed that SB-272183 acts as a partial agonist at human recombinant 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptors with intrinsic activities of 0.4, 0.4 and 0.8 respectively, compared to 5-HT. SB-272183 inhibited 5-HT-induced stimulation of [(35)S]-GTPgammaS binding at human 5-HT(1A) and 5-HT(1B) receptors to give pA(2) values of 8.2 and 8.5 respectively. However, from [(35)S]-GTPgammaS autoradiographic studies in rat and human dorsal raphe nucleus, SB-272183 did not display intrinsic activity up to 10 microM but did block 5-HT-induced stimulation of [(35)S]-GTPgammaS binding. From electrophysiological studies in rat raphe slices in vitro, SB-272183 did not effect cell firing rate up to 1 microM but was able to attenuate (+)8-OH-DPAT-induced inhibition of cell firing to give an apparent pK(b) of 7.1. SB-272183 potentiated electrically-stimulated [(3)H]-5-HT release from rat and guinea-pig cortical slices at 100 and 1000 nM, similar to results previously obtained with the 5-HT(1B) and 5-HT(1D) receptor antagonist, GR127935. Fast cyclic voltammetry studies in rat dorsal raphe nucleus showed that SB-272183 could block sumatriptan-induced inhibition of 5-HT efflux, with an apparent pK(b) of 7.2, but did not effect basal efflux up to 1 microM. These studies show that, in vitro, SB-272183 acts as an antagonist at native tissue 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptors.

Properties of the C-terminal domain of 4.1 proteins

At the C-terminus of all known 4.1 proteins is a sequence domain unique to these proteins, known as the C-terminal domain (CTD). Mammalian CTDs are associated with a growing number of protein-protein interactions, although such activities have yet to be associated with invertebrate CTDs. Mammalian CTDs are generally defined by sequence alignment as encoded by exons 18-21. Comparison of known vertebrate 4.1 proteins with invertebrate (Caenorhabditis elegans and Drosophila melanogaster) 4.1 proteins indicates that mammalian 4.1 exon 19 represents a vertebrate adaptation that extends the sequence of the CTD with a Ser/Thr-rich sequence. The CTD was first described as a 22/24-kDa domain by chymotryptic digestion of erythrocyte 4.1 (4.1R) [Leto, T.L. & Marchesi, V.T. (1984) J. Biol. Chem. 259, 4603-4608]. Here we show that in 4.1R the 22/24-kDa fragment is not stable but rapidly processed to a 15-kDa fragment by chymotrypsin. The 15-kDa fragment is extremely stable, being resistant to overnight digestion in chymotrypsin on ice. Analysis of this fragment indicates that it is derived from residues 709-858 (SwissProt accession no. P48193), and represents the CTD of 4.1R. The fragment behaves as a globular monomer in solution. Secondary-structure predictions indicate that this domain is composed of five or six beta strands with an alpha helix before the most C-terminal of these. Together these data indicate that the CTD probably represents an independent folding structure which has gained function since the divergence of vertebrates from invertebrates.

A follow-up study of the characteristics of dean's letters

PURPOSE

To assess the content and quality of dean's letters since the publication of guidelines recommended by the Association of American Medical Colleges (AAMC) in 1989.

METHOD

In 1998, the dean's letter writers at all 124 U.S. medical schools were surveyed. The questionnaire incorporated items from two previous surveys (1981 and 1992). In addition, samples of dean's letters (n = 451) from all U.S. medical schools for the graduating class of 1998 were rated based on the AAMC's guidelines.

RESULTS

The response rate of the 1998 survey (66%) was lower than those of the two previous surveys (87% for 1992 and 85% for 1981). Schools that prepared letters that followed the AAMC's guidelines were somewhat more likely to have responded. According to the letter writers in 1998, close to 300,000 letters (approximately 1,050,000 pages total) were sent to residency directors, at an estimated cost of $26,000 per school. A total of 65% of schools produced adequate dean's letters based on the 1989 AAMC's guidelines, compared with 55% in 1992. Many schools were organizing the dean's letter in more readable formats, and more schools provided information that allowed for a comparison of students within the same school.

CONCLUSION

The improvements in dean's letters are encouraging, but ten years after the AAMC's guidelines, 35% of U.S. schools still produce unacceptable letters. With the addition of the electronic submission of information, it is time to review further improvements to the dean's letter.

Contrasting roles of p57(KIP2) and p21(WAF1/CIP1/SDI1) in transplanted human and bovine adrenocortical cells

Cell transplantation provides a way to compare the regulation of cell proliferation in the same cell type in cell culture and in a vascularized tissue structure in a host animal. The cyclin-dependent kinase inhibitors p57(KIP2), p21(WAF1/CIP1/SDI1) and p27(KIP1) have been extensively studied in cell culture but their role in growth control in tissues is less well understood. In the present experiments we compared the behavior of cell cycle inhibitors in human and bovine adrenocortical cells in culture and following cell transplantation in scid mice. p57 was expressed in the majority of cells in the intact human adrenal cortex. However, double immunofluorescence showed that cells that are in the cell cycle are p57(-) adrenocortical cells, p57 and p27 levels were not affected by inhibition of growth at high cell density, whereas p21 was higher in dividing than growth-inhibited cells. However, p21 was also high in senescent adrenocortical cells. After transplantation of human adrenocortical cells in scid mice, p57 and p27 were observed in most cells in the transplant tissue. Over time the number of p21(+) cells decreased greatly in human adrenocortical cells, but not in bovine adrenocortical cells. This difference correlated with lower levels of cell division (assessed by Ki-67 or incorporation of bromodeoxyuridine) in the human cells in transplant tissues in comparison to bovine cells. The differences between human and bovine cells were observed both when cells were transplanted beneath the kidney capsule and when cells were injected subcutaneously in collagen gel. We conclude that the behavior of p57, but not p21, is consistent with a role as a physiological mediator of proliferative quiescence in the adrenal cortex. The high level of p21 in dividing adrenocortical cells in culture, and in bovine adrenocortical cells in transplant tissues, may be a response to conflicting positive and negative growth influences. Cells may enter the cell cycle under the influence of a strong positive mitogenic signal, but coexisting negative growth stimuli trigger a p21-dependent block to further progression through the cell cycle. This model suggests that bovine adrenocortical cells respond to positive growth stimuli in transplant tissues but human cells lack this response.

Teleophthalmology: rationale, current issues, future directions

Relatively little information exists concerning the delivery of ophthalmic services via telemedicine, yet ophthalmology is particularly amenable to the utilization of such applications. This paper discusses the technological issues pertinent to the research, development, and assessment of teleophthalmology delivery systems and begins to define the parameters that will determine the sustainability of teleophthalmology. A prototype urban teleophthalmology delivery system is presented in the context of improving access to eye care for an underserved inner-city population. Potential enhancements to the prototype telephthalmology system are discussed.

Anaerobic acquisition of [4FE 4S] clusters by the inactive FNR(C20S) variant and restoration of activity by second-site amino acid substitutions

The FNR protein of Escherichia coli controls the transcription of target genes in response to anoxia. The anaerobic incorporation of oxygen-sensitive [4Fe 4S] clusters promotes dimerization, which in turn enhances DNA binding. Four potential iron ligands (C20, C23, C29 and C122) are essential for normal FNR activity in vivo. Three FNR variants (C20S, C23G and C29G) retained the ability to incorporate oxygen-sensitive [4Fe 4S] clusters and to bind target DNA with essentially unimpaired affinity, suggesting that their failure to function normally in vivo resides at a later stage in the signal transduction pathway. The C122 variant failed to assemble iron-sulphur clusters and to bind DNA. Second-site substitutions that partially restore activity to FNR(C20S) were generated by error-prone polymerase chain reaction and were located in the dimer interface, in the activating regions (AR1, 2 or 3) or close to C122. Substitutions at E47, R48, E123, I124, E127 or T128 allowed the extent of the FNR AR2 surface to be defined. Only one revertant, FNR(C20S Y69F G149S), specifically corrected the C20S defect. It was concluded that [4Fe 4S] cluster acquisition, dimerization and DNA binding are not sufficient to confer transcription regulatory activity on FNR: the iron-sulphur cluster must also be correctly liganded in order to establish effective activating contacts between FNR and RNA polymerase.

Phase I study of topotecan plus cranial radiation for glioblastoma multiforme: results of Radiation Therapy Oncology Group Trial 9507

PURPOSE

A phase I trial was conducted by the Radiation Therapy Oncology Group (RTOG) to determine the maximum-tolerated dose of topotecan that could be safely combined with standard cranial radiation for glioblastoma multiforme. A secondary objective was to document the acute and late toxicities of this combination of chemotherapy and radiation.

PATIENTS AND METHODS

Forty-seven patients with histologically confirmed glioblastoma multiforme were entered onto this phase I trial. Three cycles of topotecan were administered at 21-day intervals commencing at day 1 of cranial radiotherapy (60 Gy/30 fractions). Each cycle consisted of daily 30-minute intravenous (IV) infusions for 5 days. The dose of topotecan was escalated in three-dose increments from 0.5 mg/m(2)/d to 1.0 mg/m(2)/d to 1.5 mg/m(2)/d in different patient groups.

RESULTS

The majority of patients were over age 50. Three dose levels of topotecan were tested. Fifteen patients accrued to level 1 (topotecan dose 0.5 mg/m(2)/d). No grade 4 toxicities were seen. Sixteen patients accrued to level 2 (topotecan dose 1.0 mg/m(2)/d), five of whom had brief episodes of grade 4 neutropenia. Seventeen patients accrued to level 3 (1.5 mg/m(2)/d). Six of these patients had brief episodes of grade 4 neutropenia and four developed grade 3 thrombocytopenia. No serious nonhematologic or late toxicities were seen. Median survival for all patients was 9.7 months. There was no apparent difference in survival by topotecan dose schedule.

CONCLUSION

Toxicity was acceptable at an IV topotecan dose of 1.5 mg/m(2)/d administered daily for 5 days every 21 days for three cycles. A phase II trial has been performed using this dose of topotecan.

Nursing in the public sphere: health policy research in a changing world

AIMS OF THE PAPER

To identify recent trends in the academic field of health policy, setting them in the context of wider changes in the socio-political and research environments and considering their implications for nursing research.

BACKGROUND

Health policy is a well-established field of academic study and research in the United Kingdom (UK). The 1990s have seen some important intellectual developments in this field, as well as some major changes in the context of health-related research.

DESIGN

A selective review of the relevant literature.

CONCLUSIONS

The Department of Health's new Research & Development strategy can be understood as part of a wider trend, moving away from the traditional, university-based model of knowledge production towards a new one which involves other groups, such as employers, practitioners and patients. This may increase the opportunities for health care professionals in general - and nurses in particular - to influence the research agenda and to participate as researchers in the critical evaluation of health policy.

Protein 4.1 in forebrain postsynaptic density preparations: enrichment of 4.1 gene products and detection of 4.1R binding proteins

4.1 Proteins are a family of multifunctional cytoskeletal components (4.1R, 4.1G, 4.1N and 4.1B) derived from four related genes, each of which is expressed in the nervous system. Using subcellular fractionation, we have investigated the possibility that 4.1 proteins are components of forebrain postsynaptic densities, cellular compartments enriched in spectrin and actin, whose interaction is regulated by 4.1R. Antibodies to each of 4.1R, 4.1G, 4.1N and 4.1B recognize polypeptides in postsynaptic density preparations. Of these, an 80-kDa 4.1R polypeptide is enriched 11-fold in postsynaptic density preparations relative to brain homogenate. Polypeptides of 150 and 125 kDa represent 4.1B; of these, only the 125 kDa species is enriched (threefold). Antibodies to 4.1N recognize polypeptides of approximately 115, 100, 90 and 65 kDa, each enriched in postsynaptic density preparations relative to brain homogenate. Minor 225 and 200 kDa polypeptides are recognized selectively by specific anti-4.1G antibodies; the 200 kDa species is enriched 2.5-fold. These data indicate that specific isoforms of all four 4.1 proteins are components of postsynaptic densities. Blot overlay analyses indicate that, in addition to spectrin and actin, postsynaptic density polypeptides of 140, 115, 72 and 66 kDa are likely to be 4.1R-interactive. Of these, 72 kDa and 66 kDa polypeptides were identified as neurofilament L and alpha-internexin, respectively. A complex containing 80 kDa 4.1R, alpha-internexin and neurofilament L was immunoprecipitated with anti-4.1R antibodies from brain extract. We conclude that 4.1R interacts with the characteristic intermediate filament proteins of postsynaptic densities, and that the 4.1 proteins have the potential to mediate the interactions of diverse components of postsynaptic densities.

Recursive partitioning analysis of 1999 Radiation Therapy Oncology Group (RTOG) patients with locally-advanced non-small-cell lung cancer (LA-NSCLC): identification of five groups with different survival

PURPOSE

Survival of patients with locally-advanced non-small-cell lung cancer (LA-NSCLC) is predicted by the stage of the disease and other characteristics. This analysis was undertaken to identify these characteristics in a large cooperative group patient population, as well as to define subgroups of the population with differing outcomes.

PATIENTS AND METHODS

Analysis included 1,999 patients treated in 9 RTOG trials between 1983 and 1994 with thoracic irradiation (RT) with (n = 355) or without chemotherapy (CT).

RESULTS

In univariate analysis, the following characteristics were significantly associated with an improved survival: use of CT, CT delivered without major deviation, abnormal pulmonary function tests, normal hemoglobin, protein, LDH and BUN, presence of dyspnea, hemoptysis, cough or hoarseness, uninvolved lymph nodes, T1 or T2 stage, no malignant pleural effusion (PE), weight loss of < 8%, Karnofsky performance status (KPS) of at least 90, adenocarcinoma histology, female gender, and age less than 70 years. Recursive partitioning analysis (RPA) was subsequently applied to identify 5 patient subgroups with significantly different median survival times (MST): Group I, KPS of > or = 90, who received chemotherapy (MST 16.2 months); Group II, KPS of > or = 90, who received no CT, but had no PE (MST 11.9 months); Group III, KPS < 90, younger than 70 years, with non-large cell histology (MST 9.6 months); Group IV, KPS > or = 90, but with PE, or KPS < 90, younger than 70 years, and with large cell histology, or older than 70 years, but without PE (MST 5.6-6.4 months); Group V, older than 70, with PE (MST 2.9 months).

CONCLUSION

Cisplatinum-based CT improves survival, for excellent prognosis of LA-NSCLC patients, over RT alone. The presence of a malignant pleural effusion is a major negative prognostic factor for survival. The identification of RPA prognostic groups among patients with LA-NSCLC provides prognostic information and may serve as a basis of stratification in future trials.

Phase II, two-arm RTOG trial (94-11) of bischloroethyl-nitrosourea plus accelerated hyperfractionated radiotherapy (64.0 or 70.4 Gy) based on tumor volume (> 20 or < or = 20 cm(2), respectively) in the treatment of newly-diagnosed radiosurgery-ineligible glioblastoma multiforme patients

PURPOSE

To compare survivorship, and acute and delayed toxicities following radiation therapy (RT) of radiosurgery-ineligible glioblastoma multiforme (GBM) patients treated with tumor volume-influenced, high-dose accelerated, hyperfractionated RT plus bischloroethyl-nitrosourea (BCNU), using prior RTOG malignant glioblastoma patients as historical controls.

METHODS AND MATERIALS

One hundred four of 108 patients accrued from June 1994 through May 1995 from 26 institutions were analyzable. Patients were histologically confirmed with GBM, and previously untreated. Treatment assignment (52 patients/arm) was based on tumor mass (TM), defined as the product of the maximum diameter and greatest perpendicular dimension of the titanium-gadolinium-enhanced postoperative MRI: Arm A, 64 Gy, TM > 20 cm(2); or Arm B, 70.4 Gy, TM < or = 20 cm(2). Both Arms A and B received BCNU (80 mg/m(2), under hyperhydration) days 1-3, 56-58, then 4 cycles, each 8 weeks, for a total of 6 treatment series.

RESULTS

During the 24 months immediately post-treatment, the overall median survival was 9.1 months in Arm A (64 Gy) and 11.0 months in Arm B (70.4 Gy). Median survival in recursive partitioning analysis (RPA) Class III/IV was 10.4 months in Arm A and 12.2 months in Arm B, while RPA Class V/VI was 7.6 months in Arm A and 6.1 months in Arm B. There were no grade 4 neurological toxicities in Arm A; 2 grade 4 neurological toxicities were observed in Arm B (1 motor deficit, 1 necrosis at 157 days post-treatment).

CONCLUSION

This strategy of high-dose, accelerated hyperfractionated radiotherapy shortens overall RT treatment times while allowing dose escalation, and it provides the potential for combination with currently available, as well as newer, chemotherapy agents. Survival is comparable with previously published RTOG data, and toxicities are within acceptable limits.

Randomized phase III study comparing Best Supportive Care to Biafine as a prophylactic agent for radiation-induced skin toxicity for women undergoing breast irradiation: Radiation Therapy Oncology Group (RTOG) 97-13

PURPOSE

To determine if Biafine compared to Best Supportive Care (BSC) is effective in minimizing or preventing radiation-induced dermatitis in women undergoing breast irradiation.

METHODS AND MATERIALS

Patients were randomized between Biafine (n = 83) vs. BSC (n = 89). The institutions identified preference for BSC at the time of randomization. A no-treatment arm was allowed (16% received no treatment). Patients were instructed to apply randomized product three times a day, but not within 4 h of their daily RT session. Application began following their first radiation treatment and continued 2 weeks postradiation. Skin dermatitis was scored weekly utilizing the RTOG and ONS (Oncology Nursing Society) skin toxicity scales, a weekly patient satisfaction and quality-of-life questionnaire.

RESULTS

Using the RTOG toxicity scale there was no overall difference for maximum dermatitis during RT between Biafine and BSC (p = 0.77). There was no difference in maximum toxicity by arm or breast size. There was an interaction between breast size and toxicity, with large-breasted women exhibiting more toxicity. Large-breasted women receiving Biafine were more likely to have no toxicity 6 weeks post RT.

CONCLUSION

There was no overall difference between BSC and Biafine in the prevention, time to, or duration of radiation-induced dermatitis.

Ultrasonography of the femoral vessels in the groin: implications for vascular access

The femoral artery and vein are commonly used for access to the circulation. Accidental puncture of one vessel whilst attempting to cannulate the other is a common complication. Identification of relevant surface anatomical landmarks and ultrasonography of both groins was performed on 50 consecutive adult patients admitted to the intensive care unit. In most patients there was overlap of the artery over the vein far closer to the inguinal ligament than conventional anatomical texts would indicate. The frequency and degree of overlap increased as the vessels descended distally towards the knee. Surface anatomical landmarks were not useful in predicting the underlying anatomy. The side-by-side relationship of artery and vein is commonest close to the inguinal ligament. Therefore, to avoid damage to the neighbouring vessel, percutaneous access should be undertaken just below the inguinal ligament.

Zinc uptake, oxidative stress and the FNR-like proteins of Lactococcus lactis

Lactococcus lactis ssp. cremoris MG1363 contains two FNR homologues, FlpA and FlpB, encoded by the distal genes of two paralogous operons (orfX(A/B)-orfY(A/B)-flpA/B). An flpA flpB double mutant strain is hypersensitive to hydrogen peroxide and has a depleted intracellular Zn(II) pool. The phenotypes of the flp mutant strains suggest that FlpA and FlpB control the expression of high and low affinity ATP-dependent Zn(II) uptake systems, respectively. Plate tests revealed that expression from a orfX(B)::lac reporter was activated by Cd(II), consistent with other Zn(II)-regulated systems. The link between a failure to acquire Zn(II) and hypersensitivity to oxidative stress suggests that Zn(II) may be required to protect vulnerable protein thiols from oxidation.

Size at birth and cord blood levels of insulin, insulin-like growth factor I (IGF-I), IGF-II, IGF-binding protein-1 (IGFBP-1), IGFBP-3, and the soluble IGF-II/mannose-6-phosphate receptor in term human infants. The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood

Experimental rodent studies demonstrate that insulin-like growth factor II (IGF-II) promotes fetal growth, whereas the nonsignaling IGF-II receptor (IGF2R) is inhibitory; in humans their influence is as yet unclear. A soluble, circulating form of IGF2R inhibits IGF-II mediated DNA synthesis and may therefore restrain fetal growth. We measured cord blood levels of IGF-II, soluble IGF2R, insulin, IGF-I, IGF-binding protein-1 (IGFBP-1), and IGFBP-3 and examined their relationships to weight, length, head circumference, ponderal index, and placental weight at birth in 199 normal term singletons. IGF-II levels correlated with levels of IGF-I (r = 0.29; P < 0.0005), IGFBP-3 (r = 0.45; P < 0.0005), and soluble IGF2R (r = 0.20; P < 0.005). Insulin and IGF-I were positively related to all parameters of size at birth. IGF-II was weakly related to ponderal index (r = 0.18; P < 0.05) and placental weight (r = 0.18; P < 0.05), and the molar ratio of IGF-II to IGF2R was also related to birth weight (r = 0.15; P < 0.05). Correlations between the IGFs and size at birth were stronger in nonprimiparous pregnancies; in these, IGF-I (r = 0.52; P < 0.0005), IGFBP-3 (r = 0.41; P < 0.0005), and the IGF-II to IGF2R ratio (r = 0.40; P < 0.0005) were most closely related to placental weight, together accounting for 39% of its variance. We demonstrate for the first time relationships between circulating IGF-II and soluble IGF2R levels and size at birth, supporting their putative opposing roles in human fetal growth.

The pathological substrate of limbic epilepsy: neuronal loss in the medial dorsal thalamic nucleus as the consistent change

PURPOSE

The focus of research in limbic epilepsy has been the hippocampus because of its well-known pathology of hippocampal atrophy and sclerosis as well as the strong propensity for this structure to seize under a variety of circumstances. There is ample evidence, however, for pathological alterations in other regions of the limbic system in limbic/mesial temporal lobe epilepsy, including the amygdala, the entorhinal cortex, and, in some cases, the thalamus. In this preliminary evaluation of the pathological substrate for limbic epilepsy, we wished to determine if there was consistent anatomic change at extrahippocampal sites.

METHODS

We compared paraffin sections of brains from rats with chronic spontaneous limbic epilepsy and age-matched controls to determine the consistency of the pathology at five sites: the hippocampus, amygdala, entorhinal cortex, piriform cortex, and medial dorsal thalamus.

RESULTS

In a qualitative evaluation of these sections taken from standardized positions, we found that the medial dorsal thalamic nucleus in the epileptic animals was the site that was consistently involved with neuronal loss. With all other sites, at least several animals had qualitatively normal tissue.

CONCLUSIONS

This finding suggests that neuronal loss in the medial dorsal thalamus may be the consistent pathology in limbic epilepsy, at least in an animal model of the disorder. The presence of a structurally abnormal subcortical region with broad connections to the limbic sites involved with chronic epilepsy may have implications for our understanding of the pathophysiology of this disorder.

Nursing in the public sphere: breaching the boundary between research and policy

Nurses and nursing are associated traditionally with activities in a private sphere. This paper argues that, if clinical care is to be improved, nurses need to take a more active public role in making and implementing health policy at both local and national levels. In the current climate, empirical evidence is one of the most important tools for influencing health policy. This paper discusses contemporary models of the policy-making process before outlining a number of strategies that could be used to increase the policy impact of nursing research. Finally, while the current climate in the United Kingdom health-care arena presents opportunities for researchers to have an impact on policy, the growth of health policy research as a distinct field of scholarship also poses a number of challenges and dangers.

Carriage of HFE mutations and outcome of surgical resection for hepatocellular carcinoma in cirrhotic patients

BACKGROUND

Aggressive hepatocellular carcinoma (HCC) complicates frequently hereditary hemochromatosis, a disease for which a strong candidate gene, named HFE, has recently been identified. Patients with HCC who are heterozygotes for mutations in the HFE gene might have distinct features and a distinct disease course.

METHODS

The presence of the 2 mutations associated with hereditary hemochromatosis (C282Y and H63D) was sought by restriction fragment length polymorphism in 61 cirrhotic patients (46 males and 15 females) who underwent resection for HCC at a single institution.

RESULTS

There were 4 heterozygotes for the C282Y mutation and 6 homozygotes + 20 heterozygotes for the H63D mutation, with no compound heterozygotes. Carriage of >/= 1 HFE mutated allele was significantly more frequent in HCC patients than in 149 control subjects (44% vs. 29%, P = 0.005). Among C282Y heterozygotes, 3 of 4 were female, compared with 12 of 57 wild-type carriers (P = 0.015); no gender distribution existed among patients carrying H63D alleles (6 of 26 vs. 9 of 35, P = 0.813). Survival was longer for patients with wild-type HFE than for those with mutated HFE (67% vs. 22% at 3 years; hazard ratio = 0.42, 95% confidence interval = 0.21-0.80) (P < 0.01). The negative effect on survival that resulted from possessing >/= 1 HFE mutated allele was maintained even after adjustment for gender, age, presence of tumor capsule, presence of comorbid factors, Okuda stage, Edmonson grading, and number of lesions (P = 0.01).

CONCLUSIONS

Testing for HFE mutations may help identify HCC patients with dismal prognoses for whom surgical resection may not represent the best treatment option.