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Neurons have recently emerged as essential cellular constituents of the tumour microenvironment, and their activity has been shown to increase the growth of a diverse number of solid tumours1. Although the role of neurons in tumour progression has previously been demonstrated2, the importance of neuronal activity to tumour initiation is less clear—particularly in the setting of cancer predisposition syndromes. Fifteen per cent of individuals with the neurofibromatosis 1 (NF1) cancer predisposition syndrome (in which tumours arise in close association with nerves) develop low-grade neoplasms of the optic pathway (known as optic pathway gliomas (OPGs)) during early childhood3,4, raising the possibility that postnatal light-induced activity of the optic nerve drives tumour initiation. Here we use an authenticated mouse model of OPG driven by mutations in the neurofibromatosis 1 tumour suppressor gene (Nf1)5 to demonstrate that stimulation of optic nerve activity increases optic glioma growth, and that decreasing visual experience via light deprivation prevents tumour formation and maintenance. We show that the initiation of Nf1-driven OPGs (Nf1-OPGs) depends on visual experience during a developmental period in which Nf1-mutant mice are susceptible to tumorigenesis. Germline Nf1 mutation in retinal neurons results in aberrantly increased shedding of neuroligin 3 (NLGN3) within the optic nerve in response to retinal neuronal activity. Moreover, genetic Nlgn3 loss or pharmacological inhibition of NLGN3 shedding blocks the formation and progression of Nf1-OPGs. Collectively, our studies establish an obligate role for neuronal activity in the development of some types of brain tumours, elucidate a therapeutic strategy to reduce OPG incidence or mitigate tumour progression, and underscore the role of Nf1mutation-mediated dysregulation of neuronal signalling pathways in mouse models of the NF1 cancer predisposition syndrome. Mouse models of NF1-associated optic pathway glioma show that tumour initiation and growth are driven by aberrantly high levels of NLGN3 shedding in the optic nerve in response to retinal neuron activity.

Insulin-degrading enzyme (IDE, insulysin) is the best characterized catabolic enzyme implicated in proteolysis of insulin. Recently, a peptide inhibitor of IDE has been shown to affect levels of insulin, amylin, and glucagon in vivo. However, IDE(-/-) mice display variable phenotypes relating to fasting plasma insulin levels, glucose tolerance, and insulin sensitivity depending on the cohort and age of animals. Here, we interrogated the importance of IDE-mediated catabolism on insulin clearance in vivo. Using a structure-based design, we linked two newly identified ligands binding at unique IDE exosites together to construct a potent series of novel inhibitors. These compounds do not interact with the catalytic zinc of the protease. Because one of these inhibitors (NTE-1) was determined to have pharmacokinetic properties sufficient to sustain plasma levels >50 times its IDE IC50 value, studies in rodents were conducted. In oral glucose tolerance tests with diet-induced obese mice, NTE-1 treatment improved the glucose excursion. Yet in insulin tolerance tests and euglycemic clamp experiments, NTE-1 did not enhance insulin action or increase plasma insulin levels. Importantly, IDE inhibition with NTE-1 did result in elevated plasma amylin levels, suggesting the in vivo role of IDE action on amylin may be more significant than an effect on insulin. Furthermore, using the inhibitors described in this report, we demonstrate that in HEK cells IDE has little impact on insulin clearance. In total, evidence from our studies supports a minimal role for IDE in insulin metabolism in vivo and suggests IDE may be more important in helping regulate amylin clearance.

Paullinia cupana (guaraná) is an Amazonian plant that has been previously shown to be effective in treating chemotherapy-related fatigue (CRF) in patients with breast cancer. We aimed to evaluate the efficacy of a purified dry extract of P. cupana (PC-18) in patients with various solid tumors treated with chemotherapy.We included 40 patients with solid tumors who showed increases in their Brief Fatigue Inventory (BFI) questionnaire scores after 1 week of systemic chemotherapy. PC-18 was administered at 37.5 mg by mouth two times per day (PO bid), starting after 1 week of chemotherapy, for 3 weeks (induction phase). Patients who had an improvement in or stabilization of their BFI scores were randomized to receive either PC-18 at the same dose or placebo for the following 3 weeks (maintenance phase).After PC-18 treatment, the BFI fatigue scores improved or stabilized in 36 out of the 40 patients (mean BFI score difference = 2.503; 95% confidence interval: 1.716-3.375, p = .0002). Three weeks after randomization (16 patients on PC-18 and 17 on placebo), we observed no significant differences in the BFI, Functional Assessment of Chronic Illness Therapy, Hospital Anxiety and Depression Scale, and Pittsburgh Sleep Quality Index scores between patients randomized to PC-18 versus placebo.We conclude that the PC-18 extract may be effective for the treatment of CRF in patients with a variety of solid tumors. A conditioning effect, which was observed in patients who had a beneficial effect of PC-18 on CRF, may explain the better than expected fatigue scores of the placebo-treated patients.

A series of N-aryl pyridinone inhibitors of p38 mitogen activated protein (MAP) kinase were designed and prepared based on the screening hit SC-25028 (1) and structural comparisons to VX-745 (5). The focus of the investigation targeted the dependence of potency and metabolic stability on the benzyloxy connectivity, the role of the C-6 position and the substitution pattern on the N-phenyl ring. Further optimization produced the highly selective and potent pyridinones 2 and 3. These inhibitors exhibited activity in both acute and chronic models of inflammation.

Activation of the p38 kinase pathway in immune cells leads to the transcriptional and translational regulation of proinflammatory cytokines. Mitogen-activated protein kinase-activated protein kinase 2 (MK2), a direct downstream substrate of p38 kinase, regulates lipopolysaccharide (LPS)-stimulated tumor necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6) production through modulating the stability and translation of these mRNAs. Developing small-molecule inhibitors of MK2 may yield anti-inflammatory efficacy with a different safety profile relative to p38 kinase inhibitors. This article describes the pharmacologic properties of a benzothiophene MK2 inhibitor, PF-3644022 [(10R)-10-methyl-3-(6-methylpyridin-3-yl)-9,10,11,12-tetrahydro-8H-[1,4]diazepino[5',6':4,5]thieno[3,2-f]quinolin-8-one]. PF-3644022 is a potent freely reversible ATP-competitive compound that inhibits MK2 activity (K(i) = 3 nM) with good selectivity when profiled against 200 human kinases. In the human U937 monocytic cell line or peripheral blood mononuclear cells, PF-3644022 potently inhibits TNFalpha production with similar activity (IC(50) = 160 nM). PF-3644022 blocks TNFalpha and IL-6 production in LPS-stimulated human whole blood with IC(50) values of 1.6 and 10.3 microM, respectively. Inhibition of TNFalpha in U937 cells and blood correlates closely with inhibition of phospho-heat shock protein 27, a target biomarker of MK2 activity. PF-3644022 displays good pharmacokinetic parameters in rats and is orally efficacious in both the rat acute LPS-induced TNFalpha model and the chronic streptococcal cell wall-induced arthritis model. Dose-dependent inhibition of TNFalpha production in the acute model and inhibition of paw swelling in the chronic model is observed with ED(50) values of 6.9 and 20 mg/kg, respectively. PF-3644022 efficacy in the chronic inflammation model is strongly correlated with maintaining a C(min) higher than the EC(50) measured in the rat LPS-induced TNFalpha model.

Janus-associated kinases (JAKs) play critical roles in cytokine signaling, and have emerged as viable therapeutic targets in inflammation and oncology related diseases. To date, targeting JAK proteins with highly selective inhibitor compounds have remained elusive. We have expressed the active kinase domains for both JAK2 and JAK3 and devised purification protocols to resolve the non-, mono- (Y1007) and diphosphorylated (Y1007 and Y1008) states of JAK2 and non- and monophosphorylated states of JAK3 (Y980). An optimal purified protein yield of 20, 29 and 69mg per 20L cell culture was obtained for the three JAK2 forms, respectively, and 12.2 and 2.3mg per 10L fermentation for the two JAK3 forms allowing detailed biochemical and biophysical studies. To monitor the purification process we developed a novel HPLC activity assay where a sequential order of phosphorylation was observed whereby the first tyrosine residue was completely phosphorylated prior to phosphorylation of the tandem tyrosine residue. A Caliper-based microfluidics assay was used to determine the kinetic parameters (K(m) and k(cat)) for each phosphorylated state, showing that monophosphorylated (Y1007) JAK2 enzyme activity increased 9-fold over that of the nonphosphorylated species, and increased an additional 6-fold for the diphosphorylated (Y1007/Y1008) species, while phosphorylation of JAK3 resulted in a negligible increase in activity. Moreover, crystal structures have been generated for each isolated state of JAK2 and JAK3 with resolutions better than 2.4A. The generation of these reagents has enabled kinetic and structural characterization to inform the design of potent and selective inhibitors of the JAK family.

Human alcohol dehydrogenase (HsADH) comprises class I (alpha, beta, and gamma), class II (pi), and class IV (sigma) enzymes. Selective inhibitors of the enzymes could be used to prevent the metabolism of alcohols that form toxic products. Formamides are unreactive analogues of aldehydes and bind to the enzyme-NADH complex [Ramaswamy, S.; Scholze, M.; Plapp, B. V. Biochemistry 1997, 36, 3522-3527]. They are uncompetitive inhibitors against varied concentrations of alcohol, and this makes them effective even with saturating concentrations of alcohols. Molecular modeling led to the design and synthesis of a series of cyclic, linear, and disubstituted formamides. Evaluation of 23 compounds provided structure-function information and selective inhibitors for the enzymes, which have overlapping but differing substrate specificities. Monosubstituted formamides are good inhibitors of class I and II enzymes, and disubstituted formamides are selective for the alpha enzyme. Selective inhibitors, with Ki values at pH 7 and 25 degrees C of 0.33-0.74 microM, include N-cyclopentyl-N-cyclobutylformamide for HsADH alpha, N-benzylformamide for HsADH beta1, N-1-methylheptylformamide for HsADH gamma2, and N-heptylformamide for HsADH sigma and HsADH beta1.

The classical nuclear factor kappaB (NF-kappaB) signaling pathway is under the control of the IkappaB kinase (IKK) complex, which consists of IKK-1, IKK-2, and NF-kappaB essential modulator (NEMO). This complex is responsible for the regulation of cell proliferation, survival, and differentiation. Dysregulation of this pathway is associated with several human diseases, and as such, its inhibition offers an exciting opportunity for therapeutic intervention. NEMO binding domain (NBD) peptides inhibit the binding of recombinant NEMO to IKK-2 in vitro. However, direct evidence of disruption of this binding by NBD peptides in biological systems has not been provided. Using a cell system, we expanded on previous observations to show that NBD peptides inhibit inflammation-induced but not basal cytokine production. We report that these peptides cause the release of IKK-2 from an IKK complex and disrupt NEMO-IKK-2 interactions in cells. We demonstrate that by interfering with NEMO-IKK-2 interactions, NBD peptides inhibit IKK-2 phosphorylation, without affecting signaling intermediates upstream of the IKK complex of the NF-kappaB pathway. Furthermore, in a cell-free system of IKK complex activation by TRAF6 (TNF receptor-associated factor 6), we show that these peptides inhibit the ability of this complex to phosphorylate downstream substrates, such as p65 and inhibitor of kappaB alpha (IkappaB alpha). Thus, consistent with the notion that NEMO regulates IKK-2 catalytic activity by serving as a scaffold, appropriately positioning IKK-2 for activation by upstream kinase(s), our findings provide novel insights into the molecular mechanisms by which NBD peptides exert their anti-inflammatory effects in cells.

Signal transduction through the p38 mitogen-activated protein (MAP) kinase pathway is central to the transcriptional and translational control of cytokine and inflammatory mediator production. p38 MAP kinase inhibition hence constitutes a promising therapeutic strategy for treatment of chronic inflammatory diseases, based upon its potential to inhibit key pathways driving the inflammatory and destructive processes in these debilitating diseases. The present study describes the pharmacological properties of the N-phenyl pyridinone p38 MAP kinase inhibitor benzamide [3- [3-bromo-4-[(2,4-difluorophenyl)methoxy]-6-methyl-2- oxo-1(2H)-pyridinyl]-N,4-dimethyl-, (-)-(9CI); PH-797804]. PH-797804 is an ATP-competitive, readily reversible inhibitor of the alpha isoform of human p38 MAP kinase, exhibiting a K(i) = 5.8 nM. In human monocyte and synovial fibroblast cell systems, PH-797804 blocks inflammation-induced production of cytokines and proinflammatory mediators, such as prostaglandin E(2), at concentrations that parallel inhibition of cell-associated p38 MAP kinase. After oral dosing, PH-797804 effectively inhibits acute inflammatory responses induced by systemically administered endotoxin in both rat and cynomolgus monkeys. Furthermore, PH-797804 demonstrates robust anti-inflammatory activity in chronic disease models, significantly reducing both joint inflammation and associated bone loss in streptococcal cell wall-induced arthritis in rats and mouse collagen-induced arthritis. Finally, PH-797804 reduced tumor necrosis factor-alpha and interleukin-6 production in clinical studies after endotoxin administration in a dose-dependent manner, paralleling inhibition of the target enzyme. Low-nanomolar biochemical enzyme inhibition potency correlated with p38 MAP kinase inhibition in human cells and in vivo studies. In addition, a direct correspondence between p38 MAP kinase inhibition and anti-inflammatory activity was observed with PH-797804, thus providing confidence in dose projections for further human studies in chronic inflammatory disease.

PH-797804 is a diarylpyridinone inhibitor of p38alpha mitogen-activated protein (MAP) kinase derived from a racemic mixture as the more potent atropisomer (aS), first proposed by molecular modeling and subsequently confirmed by experiments. On the basis of structural comparison with a different biaryl pyrazole template and supported by dozens of high-resolution crystal structures of p38alpha inhibitor complexes, PH-797804 is predicted to possess a high level of specificity across the broad human kinase genome. We used a structural bioinformatics approach to identify two selectivity elements encoded by the TXXXG sequence motif on the p38alpha kinase hinge: (i) Thr106 that serves as the gatekeeper to the buried hydrophobic pocket occupied by 2,4-difluorophenyl of PH-797804 and (ii) the bidentate hydrogen bonds formed by the pyridinone moiety with the kinase hinge requiring an induced 180 degrees rotation of the Met109-Gly110 peptide bond. The peptide flip occurs in p38alpha kinase due to the critical glycine residue marked by its conformational flexibility. Kinome-wide sequence mining revealed rare presentation of the selectivity motif. Corroboratively, PH-797804 exhibited exceptionally high specificity against MAP kinases and the related kinases. No cross-reactivity was observed in large panels of kinase screens (selectivity ratio of >500-fold). In cellular assays, PH-797804 demonstrated superior potency and selectivity consistent with the biochemical measurements. PH-797804 has met safety criteria in human phase I studies and is under clinical development for several inflammatory conditions. Understanding the rationale for selectivity at the molecular level helps elucidate the biological function and design of specific p38alpha kinase inhibitors.

Nuclear factor-kappaB (NF-kappaB) is one of the major families of transcription factors activated during the inflammatory response in asthma and chronic obstructive pulmonary disease. Inhibitory factor-kappaB kinase 2 (IKK-2) has been shown to play a pivotal role in cytokine-induced NF-kappaB activation in airway epithelium and in disease-relevant cells. Nevertheless, the potential toxicity of specific IKK-2 inhibitors may be unacceptable for oral delivery in chronic obstructive pulmonary disease. Therefore, local delivery to the lungs is an attractive alternative that warrants further exploration. Here, we describe potent and selective small-molecule IKK-2 inhibitors [8-(5-chloro-2-(4-methylpiperazin-1-yl)isonicotinamido)-1-(4-fluorophenyl)-4,5-dihydro-1H-benzo[g]indazole-3-carboxamide (PHA-408) and 8-(2-(3,4-bis(hydroxymethyl)-3,4-dimethylpyrrolidin-1-yl)-5-chloroisonicotinamido)-1-(4-fluorophenyl)-4,5-dihydro-1H-benzo-[g]indazole-3-carboxamide (PF-184)] that are competitive for ATP have slow off-rates from IKK-2 and display broad in vitro anti-inflammatory activities resulting from NF-kappaB pathway inhibition. Notably, PF-184 has been designed to have high systemic clearance, which limits systemic exposure and maximizes the effects locally in the airways. We used an inhaled lipopolysaccharide-induced rat model of neutrophilia to address whether inhibiting NF-kappaB activation locally within the airways would show anti-inflammatory effects in the absence of systemic exposure. PHA-408, a low-clearance compound previously shown to be efficacious orally in a rodent model of arthritis, dose-dependently attenuated inhaled lipopolysaccharide-induced cell infiltration and cytokine production. Interestingly, PF-184 produced comparable dose-dependent anti-inflammatory activity by intratracheal administration and was as efficacious as intratracheally administered fluticasone propionate (fluticasone). Together, these results support the potential therapeutic utility of IKK-2 inhibition in inflammatory pulmonary diseases and demonstrate anti-inflammatory efficacy of an inhaled IKK-2 inhibitor in a rat airway model of neutrophilia.

Alkaline phosphatase (AP) has several isoforms including bone alkaline phosphatase (BAP). We evaluated BAP and AP for screening for bone metastasis (BM) in patients with solid tumours. This is a prospective non-blinded study conducted at ABC Foundation School of Medicine Oncology clinics. A total of 40 subjects without a history of cancer and 62 patients with various solid tumours referred for a bone scan had serum drawn for BAP and AP determination. Bone alkaline phosphatase and AP levels in patients with cancer and BM, without BM and with no cancer, were 70.32 +/- 3.65 and 310.21 +/- 16.87 U/L; 41.40 +/- 2.80 and 113.23 +/- 12.95 U/L; 21.19 +/- 2.76 and 148.05 +/- 12.79 U/L respectively (P < 0.0001 for both AP and BAP). For BAP and AP sensitivity, specificity, positive and negative predictive values were 0.86 and 0.52; 0.69 and 1; 0.45 and 1; 0.94 and 0.87 respectively. ROC AUC value for BAP was 0.89 and for AP was 0.93. We conclude that BAP is more sensitive than AP, whereas AP had a remarkable specificity of 100%. In screening for BM in patients with solid tumours, obtaining initially BAP and then selecting for further investigation only patients with an abnormal AP may be a cost and resource saving strategy.

International audience; Study design:Retrospective study.Objectives:To determine the potential impact of rehabilitation care on associated symptoms and functional improvements of paraplegic patients with metastatic spinal cord compression.Setting:CMN Propara, Montpellier (France).Measures:Demographics, Functional Independence Measure (FIM), Frankel Modified Score and Visual Analog Scale (VAS) for pain, intercurrent adverse medical events and neurological outcome, duration of stay, survival time, rehospitalization in a non-Spinal Cord Injury unit, number of contracts defining the patients rehabilitation goals, number of contracts defining the patients duration of stay within the rehabilitation center.Results:We reviewed the charts of 26 patients. The initial neurological profile was paraplegia or paraparesis for 24 patients and quadriparesis for 2 patients. Regarding functional improvements: four patients demonstrated a poor functional evolution, five patients showed no functional improvements or very slight improvements and all the other patients showed an increase in their overall functional aptitudes. At the end of the stay, 14 patients were urinary independent. Our study reports 52 rehospitalizations in an another unit and 101 outpatient visits during their rehabilitation stay in a physical medicine and rehabilitation (PM&R) center. For the 14 patients who were deceased at the time of data collection, the median survival rate post-paraplegia was 12.7 months. A total of 12 of the 14 patients spent more than a third of their remaining survival time in a rehabilitation center.Discussion:Compared to the patients' life expectancy, their stay in a rehabilitation center is too long and prevents them from spending time with family and loved ones. The occurrence rate of the associated symptoms is high because of both cancer-related disorders and neurological disorders caused by the spinal cord lesion. PM&R professionals are faced with patients affected by chronic pain and fatigue as well as frequent rehospitalizations, short stays and outpatient stays, in the primary oncology unit. This study focuses on the need to privilege the patients' comfort over their functional rehabilitation.Spinal Cord advance online publication, 10 June 2008; doi:10.1038/sc.2008.75.

A new class of potent kinase inhibitors selective for mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2 or MK-2) for the treatment of rheumatoid arthritis has been prepared and evaluated. These inhibitors have IC50 values as low as 10 nM against the target and have good selectivity profiles against a number of kinases including CDK2, ERK, JNK, and p38. These MK-2 inhibitors have been shown to suppress TNFalpha production in U397 cells and to be efficacious in an acute inflammation model. The structure-activity relationships of this series, the selectivity for MK-2 and their activity in both in vitro and in vivo models are discussed. The observed selectivity is discussed with the aid of an MK-2/inhibitor crystal structure.

Affective mixed states in bipolar disorders are a current matter of scientific debate and represent a complex clinical picture with coexisting manic and depressive symptoms. Treatment of mixed states is regarded as an important challenge. As diagnostic uncertainties complicate systematic clinical evaluations of this patient group, generally accepted clinical treatment guidelines are lacking yet. In this review the significance as well as the problems and risks of new treatment options are discussed.

Confirmed cases of poisoning resulting from the ingestion of Colchicum autumnale in mistake for Allium ursinum were analysed retrospectively. The study included 32 patients between 27 and 90 years. The severity of the intoxication was graded on the basis of the poisoning severity score (PSS). All the patients developed diarrhea and/or vomiting after a latency period of between 2 and 24 h. All those patients with a latency of9 h suffered only mild poisoning. If the leaves were boiled before being eaten, 64% of the patients suffered moderate, severe or fatal poisoning; when the leaves were eaten raw, only 33%. It is presumed that heating may promote the liberation of colchicines from the plant. Eight of the nine patients with severe or fatal poisoning were older than 65 years. A possible cause of the more serious course in the elderly may be a decrease in renal clearance. In addition, a diminished sense of smell may allow the absence of the typical garlic smell and taste of Allium ursinum to go unrecognised.

Using PET with the opioidergic ligand [11C]diprenorphine, the authors demonstrate decreased tracer binding in the pineal gland of cluster headache patients vs healthy volunteers. Opioid receptor availability in the hypothalamus and cingulate cortex depended on the duration of the headache disorder. Therefore, the pathophysiology of cluster headache may relate to opioidergic dysfunction in circuitries generating the biologic clock.

The kinetic mechanism of mitogen-activated protein kinase activated protein kinase-2 (MAPKAPK2) was investigated using a peptide (LKRSLSEM) based on the phosphorylation site found in serum response factor (SRF). Initial velocity studies yielded a family of double-reciprocal lines that appear parallel and indicative of a ping-pong mechanism. The use of dead-end inhibition studies did not provide a definitive assignment of a reaction mechanism. However, product inhibition studies suggested that MAPKAPK2 follows an ordered bi-bi kinetic mechanism, where ATP must bind to the enzyme prior to the SRF-peptide and the phosphorylated product is released first, followed by ADP. In agreement with these latter results, surface plasmon resonance measurements demonstrate that the binding of the inhibitor peptide to MAPKAPK2 requires the presence of ATP. Furthermore, competitive inhibitors of ATP, adenosine 5'-(beta,gamma-imino)triphosphate (AMPPNP) and a staurosporine analog (K252a), can inhibit this ATP-dependent binding providing further evidence that the peptide substrate binds preferably to the E:ATP complex.

The controlled study presented here was designed to examine the influence of the degree of structure of a coping-orientated therapy, the changes between the beginning and the end of therapy concerning satisfaction with therapy, psychopathology, attitude towards medication, coping behaviour and social variables, the effects on the days of hospitalisation within one year after the end of treatment and the relevant variables to predict the outcome twelve months later. It could be shown that patients in a relatively unstructured supportive group therapy wished to discuss topics that are very similar to those of coping-orientated therapy, that coping-orientated therapy results especially in an increase in knowledge about illness and treatment and that the therapeutic outcome after a one-year period can best be predicted by the degree of active coping strategies, social adaptation, trust in medication and cognitive variables.

The isolated vascular effects of intravenous administration of the angiotensin converting enzyme (ACE) inhibitor enalaprilat were investigated. Thirty male patients undergoing cardiopulmonary bypass (CPB) were studied. According to a randomized sequence, 0.04 mg kg-1 enalaprilat (low-dose, n = 10), 0.08 mg kg-1 (high-dose, n = 10) enalaprilat or saline solution as placebo (control group, n = 10) was given as an i.v. bolus during CPB. Changes in mean arterial pressure (MAP) and venous reservoir (RV) of the extracorporeal circulation were studied as indices of arterial resistance and venous capacitance. Mean arterial blood pressure (MAP) and peripheral vascular resistance (SVR) were significantly more reduced in the high-dose enalaprilat group (MAP: -36 mm Hg after 9 min; SVR: -836 dyn s cm-5) than in the low-dose group (MAP: -13 mm Hg after 10 min). Volume of the reservoir (RV) decreased in both enalaprilat treated groups indicating additional (dose-dependent) venous pooling effects of the substance (low-dose: -300 ml; high-dose: -520 ml; control group: -100 ml). Skin capillary blood flow measured by laser Doppler flowmetry (LDF) increased after injection of 0.04 mg kg-1 enalaprilat, whereas it decreased significantly when MAP fell markedly in patients treated with high-dose enalaprilat. I.v. enalaprilat had dose-dependent vasodilating properties in the arterial and venous vessel system indicating reduction in pre- and afterload. Microcirculation in both enalaprilat treated groups improved as long as reduction in blood pressure was not limited.

The potential importance of several functional amino acids in the activity of L-aspartase from Escherichia coli has been examined by site-directed mutagenesis. Amino acids whose importance in enzyme activity was suggested by chemical modification and pH dependence studies were chosen as candidates for investigation. The selection of the particular amino acid targets was guided by homology comparisons among the other sequenced bacterial L-aspartases and by the broader comparison among the fumarase-aspartase enzyme family. Substitution of the most highly conserved cysteine with either serine or alanine, or the most highly conserved histidine with leucine, had no significant effect on the activity of L-aspartase or on the sensitivity of these mutated L-aspartases to cysteine and histidine specific modifying reagents. However, alteration of each of the two conserved lysines to arginine did cause dramatic changes in the catalytic properties of the enzyme. Modification of lysine 54 results in the complete loss of enzyme activity. However, this activity loss appears to be related to changes in the subunit association properties of the arginine 54 mutant. Lysine 326 appears to be involved in substrate binding. Modification of this residue causes a 5-fold increase in the Km for aspartic acid, a drastic decrease in kcat/Km, and a change in the divalent metal ion requirements of the enzyme.

Investigation of GFAP (Glial Fibrillary Acidic Protein) in 175 brain tumours showed varying amounts of fibrillary acidic protein in every glioma. In ependymal and oligodendroglial tumours a high number of positive neoplastic elements were detected, GFAP positive were also the peri-vascular cells of a so-called astroblastoma. In pilocytic astrocytomas, Rosenthal fibers were in part GFAP positive, in part negative. In giant cells gliomas, giant cells were GFAP negative or weakly positive. Intraleptomeningeal growing tumour cells presented usually a very strong positivity. In 8 recurring oligodendrogliomas, the number of GFAP positive tumour cells was the same in the primary tumour and in its recurrence. These results demonstrate that GFAP is not a specific astrocytic, but a glial-specific protein. Although GFAP is usually present in greater concentration in differentiated, slow growing gliomas, absolute reliable predictions on biological behaviour of the individual tumour are not possible, because a high GFAP content can be detected also in malignant tumours. GFAP investigation does not seem reliable for solving the pathogenetic problems of undifferentiated tumours: the results obtained in 50 medulloblastomas showed that the investigation of small tumour samples or the positivity of a single cell are inadequate data for a correct evaluation of the findings, especially bearing in mind that GFAP of degenerated astrocytes can be phagocytised by other cells, these findings giving rise to misinterpretations.

Carp erythrocytes were fractionated by angle-head centrifugation which yielded fractions with a linear increase in density. Haematological examinations revealed that the heavier red blood cells of carp had greater volumes (MCV), more haemoglobin (MCH) and higher haemoglobin concentrations (MCHC) than light ones. The same experiments with human red cell fractions yielded a decrease in MCV, constant MCH and an increase in MCHC. Haemoglobin content in individual erythrocytes was also determined by scanning stage absorbance cytophotometry to establish the frequency distribution of the cellular haemoglobin contents. In carp, the distribution was symmetrical with the means increasing with density. No such change with cell density was found in human erythrocytes. Both carp and human erythrocytes incorporated [2-14C]glycine in vitro. After gel filtration, radioactivity was detected in carp, but not in human, haemoglobin fractions. 14C was found in all three haemoglobin fractions, obtained by isoelectric focusing, and was present in the haem and in the globin. [2-14C]glycine-labelled erythrocytes were reinjected into chronically cannulated carp and followed in vivo for several months. With time, the main peak of scintillation counts shifted from red cell fractions of low to high density. This is considered as evidence that density and age of red cells in carp are positively correlated and that erythrocytes can synthesize haemoglobin while circulating in the peripheral blood.

An acceptable policy on the drug problem specifies who will be its focus, when employees should be questioned about or tested for drugs, why the problem should be addressed at all, and what the institution should be concerned about. The more explicit policymakers are about the values that determine the answers to these questions, the better able they will be to devise a fair and equitable program. U.S. culture favors the contractual model of justice. It dictates that the power anyone can have over another must be strictly limited to the terms of the agreement they have entered into and that obligations should be similarly limited. A stress on the value of individual freedom is therefore implicit in the contractual justice perspective, and institutions and individuals who subscribe to it would be expected to resist drug testing programs as long as possible. On the other hand, a "distributive/contributive" model of justice, as advocated by the U.S. bishops in their 1986 pastoral letter on economic justice, emphasizes the mutual responsibility of institutions (or societies) and individuals for the total well-being of one another. Committed to the communal values of inclusion and participation, the distributive/contributive ideal of justice would give institutions an alternative, and perhaps more constructive, perspective on the issues involved in the problem of drug use.

Seven cases of hemangioma of the optic disc are presented. A survey of the literature is summarized and the differential diagnosis and appropriate management discussed.

In an attempt to determine the role of vitamin E in retrolental fibroplasia (RLF) we report our experience with 191 infants of less than 1500 g birth weight. Of these infants, 16.75% had evidence of acute RLF in hospital, 8.4% had cicatricial RLF at follow-up, and four infants (2.1%) were blind, none of whom had received supplementary vitamin E. The incidence of cicatricial RLF at follow-up was significantly lower in infants who received vitamin E early after birth (12 h) than in those who did not (3 of 105 versus 13 of 86, X2 = 9.26, P = 0.002), as was the incidence of Grade III or greater cicatrix (0 of 105 versus 7 of 86, X2 with Yates = 6.72, P = 0.01). Stepwise multiple linear regression analysis revealed three factors distinguishing infants who developed cicatricial RLF from those who did not: the lack of early vitamin E supplements (P = 0.0023), the significantly larger number of arterial PO2 values over 100 mmHg (P = 0.0056), and the presence of an intraventricular haemorrhage (P = 0.0032). The incidence and severity of necrotizing enterocolitis was similar in infants who received vitamin E and in those who did not. It is recommended that vitamin E be given within the first 12 hours of birth to all infants of less than 1500 g who require supplementary oxygen.

126 appropriate-for-gestational age neonates born in hospital with birth-weights of 750 g-1500 g were prospectively studied in a randomised trial to determine the effect of intramuscular vitamin E on the frequency and severity of retrolental fibroplasia (RLF). In the 99 who lived for more than one month the frequency of active RLF in the vitamin E and control groups in the nursery (18.8% vs 23.5%) and at discharge (8.3% vs 19.6% was not significantly different. Vitamin E had significantly reduced the severity of RLF at follow-up eye examination 6-33 months after discharge (p less than 0.01). 3 control infants (760 g, 780 g, 1020 g) were blind in both eyes (grade V cicatricial RLF), whereas the most severe grade of disease in the vitamin E infants was grade II cicatrix. Infants in whom RLF developed were gestationally younger (p = 0.005), required a longer period of mechanical ventilation (p = 0.035), had a greater exposure to oxygen (p = 0.03), and had a greater number of arterial PO2 values between 75 and 99 mm Hg (p = 0.004). Early administration of vitamin E, while not affecting the frequency of RLF, will significantly reduce its severity and subsequent eye damage, and such treatment is recommended for all low-birth-weight infants of less than 1250 g who require supplementary oxygen.

In cardiopulmonary resuscitation (CPR) of dogs after anoxic cardiac arrest the effect was compared of epinephrine (E) alone (50 micrograms/kg, n = 11) to that of epinephrine plus calcium chloride (20 mg/kg) and of diltiazem (150 micrograms/kg 30 sec after E and 25-50 micrograms/kg/min after restoration of spontaneous circulation). The success of resuscitation was 100% in the epinephrine group and the diltiazem group but only 70% in the calcium group (p less than 0.05). In the phase of restoration of spontaneous circulation, calcium increased the critical hemodynamic parameters leading to O2 consumption whereas diltiazem decreased them (heart rate, LVdp/dt max, afterload). Diltiazem improved the oxygen demand/supply ratio by increasing coronary blood flow significantly and decreasing oxygen demand. The significant increase in CPK activity reflected unfavorable oxygen balance in the calcium group. It is concluded that calcium should not be given in CPR, although calcium antagonism represents a promising new pharmacological principle in this field.