Individuals developing schizophrenia are hidden among adolescent substance misusers.

BACKGROUND: Strategies are needed to identify youth developing schizophrenia. The present study aimed to determine whether adolescents treated for substance misuse were at elevated risk to develop schizophrenia, whether this risk has changed since the late 1960s, and whether substance misuse in adolescence predicted poorer outcomes through adulthood. METHOD: In a Swedish city, since the mid-1960s there has been only one clinic for adolescent substance misuse. Three samples from this clinic were studied: 1992 individuals treated from 1968 to 1971 followed to age 50 years; 1576 treated from 1980 to 1984 followed to age 35 years; and 180 treated in 2004 followed to age 22 years. Each clinical sample was matched on age, sex and place of birth to an equal, or larger, number of randomly selected individuals from the general population. Schizophrenia, substance use disorders, physical disorders related to substance misuse, criminal convictions, poverty and death were identified using national registers. RESULTS: Individuals treated for substance misuse in adolescence were at increased risk to subsequently develop schizophrenia: in males the increase was approximately four-fold and in females between five- and seven-fold. There was no difference in risk for those treated in 1968-1971 and from 1980 to 1984 when cannabis use increased from 37.6% to 49.8% of the clinical samples. Among males who developed schizophrenia, treatment for substance misuse was associated with increased risk of substance use disorders and criminal convictions through adulthood. CONCLUSIONS: Treatment programmes for adolescents misusing substances include a disproportionate number developing schizophrenia. Early detection and treatment have the potential to improve long-term outcomes.

Human erythrocyte membranes are fluid down to -5 degrees C.

This first observation of the deuterium nuclear magnetic resonance (2H-NMR) spectrum of phospholipid molecules incorporated into intact human erythrocyte ghosts shows that the liquid crystalline phase is stable down to a temperature of -5 degrees C. The quality of the 3H-NMR spectra indicate that it is now possible to carry out clinical studies of erythrocyte membranes using the techniques employed in this study.

Transfer of cholesterol and oxysterol derivatives by the nonspecific lipid transfer protein (sterol carrier protein 2): a study on its mode of action.

The nonspecific lipid transfer protein (nsLTP) facilitates the transfer of both phospholipids and cholesterol between membrane interfaces. In this study, we have investigated the transport of 14C-labelled cholesterol, 7-ketocholesterol, 7 alpha-hydroxycholesterol and 25-hydroxycholesterol from a mixed lipid monolayer at the air/water interface to acceptor vesicles in the subphase. In the absence of nsLTP the transport of cholesterol was virtually nil, whereas the spontaneous transport of the oxysterol derivatives increased in the order 7-ketosterol less than 7 alpha-hydroxycholesterol less than 25-hydroxycholesterol. In the presence of nsLTP, the transport of both cholesterol and the oxysterol derivatives was greatly enhanced; the highest rate of transport was observed for 25-hydroxycholesterol. In the absence of vesicles, binding of cholesterol and of 25-hydroxycholesterol from the monolayer to nsLTP was negligible. Similarly, nsLTP did not bind cholesterol from radiolabeled bovine heart mitochondria under conditions where it stimulated the transfer of cholesterol to vesicles. In agreement with this failure to bind, nsLTP was unable to carry cholesterol between two separate monolayers. From the monolayer experiments it became apparent that nsLTP is highly surface-active. Measurement of the transport of cholesterol and of oxysterol derivatives by the monolayer-vesicles assay and of a series of pyrene-labeled phosphatidylcholine species by the fluorescent transfer assay showed a high correlation between the spontaneous and the nsLTP-mediated lipid transport. This supports the notion that nsLTP lowers the energy barrier for the lipid monomer-membrane interface equilibration process. In view of the above observations, we propose that nsLTP may facilitate the transfer of lipids by being part of a transient collisional complex between donor and acceptor membrane.

Activation of phosphatidylinositol transfer protein alpha and beta isoforms from inclusion bodies.

Fully active phosphatidylinositol transfer protein (PI-TP) isoforms alpha and beta have been obtained from Escherichia coli inclusion bodies. Folding and activation of PI-TPalpha was achieved in the presence of DiC7:0-phosphatidylcholine-Triton X-114 (PtdCho-TX114) mixed micelles. Replacement of DiC7:0-PtdCho with the natural ligands of PI-TPalpha, i.e. long-chain PtdCho and phosphatidylinositol, did not stimulate activation. Efficient activation of PI-TPalpha required a low temperature (4 degrees C), the presence of dithiothreitol, and was achieved at a relatively high protein concentration (i.e. up to 500 microg ml(-1)). The inclusion bodies yielded 10 mg homogeneous PI-TPalpha per liter of E. coli culture. Conditions for full activation of PI-TPbeta were similar to those for PI-TPalpha except that long-chain PtdCho-TX114 mixed micelles and a very low protein concentration (i.e. 10 microg ml(-1)) were required. In contrast to PI-TPalpha, PI-TPbeta lost its lipid transfer activity within a few days. This inactivation could be prevented by addition of beta-alanine. In summary, despite 94% sequence similarity, PI-TPalpha and PI-TPbeta display a striking difference both in their preference for the PtdCho acyl chain length required for activation, and in their conformational stability after folding.

The complete primary structure of phospholipase A2 from human pancreas.

The complete amino acid sequence of phospholipase A2 (phosphatide 2-acylhydrolase, EC 3.1.1.4) from human pancreas was determined. The protein consists of a single polypeptide chain of 125 amino acids and has a molecular weight of 14003. The chain is cross-linked by seven disulfide bridges. The main fragmentation of the polypeptide chain was accomplished by digestion of the reduced and thialaminated derivative of the protein with clostripain, yielding three fragments. The largest fragment (residues 7-100) was further degraded both with staphylococcal proteinase and chymotrypsin. The sequence was determined by automated Edman degradation of the intact protein and of several large peptide fragments. Phospholipase A2 from human pancreas contains the same number of amino acids (125) as the enzyme from horse, while the enzymes from pig and ox contain 124 and 123 residues, respectively. The enzymes show a high degree of homology; human phospholipase differs from the other enzymes by substitutions of 26 (porcine), 28 (bovine) and 32 (equine) residues, respectively.

Action of phospholipases on the phosphatidylcholine exchange protein from beef liver.

The phospholipases A2, C and D have been used to investigate the localization of phosphatidylcholine in the phosphatidylcholine exchange protein from beef liver. The rate of enzymatic hydrolysis of the protein-bound phosphatidylcholine was found to be very low. Addition of deoxycholate, isobutanol or dioxane to the native protein, under conditions where delipidation did not occur, greatly enhanced the hydrolytic action of the phospholipases. From these results it is concluded that phosphatidylcholine may be buried in the protein molecule.

Characterization of phosphatidylinositol-4-phosphate 5-kinase activities from bovine brain membranes.

Phosphatidylinositol-4-phosphate (PtdIns(4)P) kinase activity associated with bovine brain membranes, was released by NaCl treatment and partially purified by chromatography on phosphocellulose, phenylsepharose, Ultrogel AcA44, DEAE-cellulose and ATP-agarose. The final preparation contained a 6333-fold purified protein fraction with a specific activity of 171 nmol.min-1 x mg-1. Under conditions where this PtdIns(4)P kinase activity (PtdIns(4)P kinase activity b) did not bind to DEAE-cellulose, a PtdIns(4)P kinase activity purified earlier (Moritz, A., De Graan, P.N.E., Ekhart, P.F., Gispen, W.H. and Wirtz, K.W.A. (1990) J. Neurochem. 54, 351-354) does bind (PtdIns(4)P kinase activity a). Both enzyme activities specifically used PtdIns(4)P as substrate and phosphorylated the inositol moiety at the 5'-position. PtdIns(4) kinase activity a has an apparent Km of 18 microM for PtdIns(4)P whereas PtdIns(4)P kinase activity b has a Km of 4 microM. All other measured kinetic parameters (i.e., Km for ATP, Mg(2+)-dependence, pH optimum, activation by phosphatidylserine and inhibition by phosphatidylinositol 4,5-bisphosphate) were similar for both enzyme activities.

Characterization of mouse phosphatidylinositol transfer protein expressed in Escherichia coli.

The cDNA encoding mouse phosphatidylinositol transfer protein (PI-TP) was isolated by means of reverse transcriptase polymerase chain reaction. The nucleotide sequence of this cDNA has a high similarity (98%) with that of rat PI-TP; the predicted amino acid sequence is 99.6% identical to that of rat PI-TP. The cDNA encoding mouse PI-TP was cloned into the expression vector pET3d and the Escherichia coli strain BL21(DE3) was transformed with the resulting plasmid. After induction of the bacteria with isopropyl-beta-D-thiogalactopyranoside, PI-TP was efficiently expressed in the E. coli strain. It was estimated that 5% of the total soluble cell protein consisted of PI-TP. The recombinant mouse PI-TP was purified from the bacterial lysate in four steps: ammonium sulphate precipitation, anion-exchange chromatography, heparin-Sepharose affinity and gel filtration chromatography. Fractionation on the heparin-Sepharose affinity column yielded two forms: PI-TP Hepa1 and Hepa2. These two proteins have the same molecular mass of 35 kDa, both contain a phosphatidylglycerol molecule and both are recognized by anti-PI-TP antibody. Both recombinant proteins have an isoelectric point of 5.4 as compared to 5.5 for bovine brain PI-TP. Sequence analysis of the first 25 N-terminal amino acid residues showed that both forms are identical, except that PI-TP Hepa1 contains the initiator methionine which is lacking from PI-TP Hepa2. The two PI-TP forms have similar phospholipid-binding and transfer activity, comparable to that of bovine brain PI-TP. Both forms and bovine brain PI-TP are phosphorylated equally well in a Ca2+/phospholipid-dependent way by protein kinase C.

In vivo turnover of phospholipids in rabbit erythrocytes.

The rate of phospholipid turnover in erythrocyte membranes in vivo has been studied using a recently developed procedure (Kuypers, F.A., Easton, E.W., van den Hoven, R., Wensing, T., Roelofsen, B., Op den Kamp, J.A.F. and van Deenen, L.L.M. (1985) Biochim. Biophys. Acta 819, 170-178). The technique is based on the application of phospholipid transfer proteins in order to introduce trace amounts of radiolabelled phospholipids in the membrane of isolated erythrocytes, followed by re-injection of the erythrocytes into the bloodstream of the animal. The most abundant species of the phosphatidylcholine (PC) class, 1-palmitoyl,2-linoleoyl PC, has, on the basis of loss of the radioactivity in its fatty acyl part, a relatively high turnover with a half-time value of 1.5 days. Other PC species studied exhibit more moderate turnover rates of about 5 days for 1-palmitoyl,2-oleoyl PC and 1-stearoyl,2-arachidonoyl PC. Dipalmitoyl PC, labelled in the polar headgroup, turns over at a slow rate with a half-time value of 9 days. From these data and the relative abundance of the various species, it can be calculated that, on a daily basis in vivo, about one third of the total PC pool in rabbit erythrocyte membranes is replaced and/or modified by de-/reacylation. The only phosphatidylethanolamine (PE) species studied so far, 1-palmitoyl,2-arachidonoyl PE, appeared to be renewed at a relatively low rate with a half-time value of 12 days. The data demonstrate that the in vivo turnover values of phospholipids in the erythrocyte membrane may depend on their polar head group structure, their localization in the membrane and, to a large extent, on their fatty acid composition.

Phosphatidylcholine transfer protein from bovine liver contains highly unsaturated phosphatidylcholine species.

The phosphatidylcholine transfer protein (PC-TP) from bovine liver contains one molecule of non-covalently bound PC. In order to gain more insight into the physiological function of PC-TP, PC was extracted from bovine liver PC-TP and its molecular species composition identified by fast atom bombardment mass spectrometry. The prevailing molecular species were C18:0/C18:1-, C18:0/C18:2-, C18:0/C20:4-, C18:0/20:5- and C18:0/C22:5-PC accounting for 85% of the PC species present. This molecular species composition is not representative for what is present in bovine liver where these species account for 43% of the total PC content [Montfoort et al. (1971) Biochim. Biophys. Acta 231, 335-342]. Another striking observation is that PC species carrying a palmitoyl chain at the sn-1 position are nearly absent, despite these species being abundantly present in bovine liver. This study suggests that PC-TP could play a role in the metabolism of highly unsaturated, stearoyl-containing PC species.

Proteolytic activation of a bovine brain protein with phosphatidylinositol transfer activity.

We have purified a 38 kDa protein from bovine brain which is cross-reactive with an affinity purified antibody against the 35 kDa phosphatidylinositol transfer protein from the same source. Controlled trypsinization of the 38 kDa protein yielded an immunoreactive protein of 35 kDa which displayed a 6-fold increase in phosphatidylinositol transfer activity and a 10-fold higher affinity for this phospholipid. The possibility that the 38 kDa protein is a precursor of the phosphatidylinositol transfer protein is discussed.

Improved results of lung transplantation for patients with cystic fibrosis.

Patients with cystic fibrosis pose particular challenges for lung transplant surgeons. Earlier reports from North American centers suggested that patients with cystic fibrosis were at greater risk for heart-lung or isolated lung transplantation than other patients with end-stage pulmonary disease. During a 3 1/2 year period, 44 patients with end-stage lung disease resulting from cystic fibrosis underwent double lung transplantation at this institution. During the same interval, 18 patients with cystic fibrosis died while waiting for lung transplantation. The ages of the recipients ranged from 8 to 45 years, and mean forced expiratory volume in 1 second was 21% predicted. Seven patients had Pseudomonas cepacia bacteria before transplantation. Bilateral sequential implantation with omentopexy was used in all patients. There were no operative deaths, although two patients required urgent retransplantation because of graft failure. Cardiopulmonary bypass was necessary in six procedures in five patients and was associated with an increased blood transfusion requirement, longer postoperative ventilation, and longer hospital stay. Actuarial survival was 85% at 1 year and 67% at 2 years. Infection was the most common cause of death within 6 months of transplantation (Pseudomonas cepacia pneumonia was the cause of death in two patients), and bronchiolitis obliterans was the most common cause of death after 6 months. Actuarial freedom from development of clinically significant bronchiolitis obliterans was 59% at 2 years. Results of pulmonary function tests improved substantially in survivors, with forced expiratory volume in 1 second averaging 78% predicted 2 years after transplantation. Double lung transplantation can be accomplished with acceptable morbidity and mortality in patients with cystic fibrosis.

Lung transplantation for mechanically ventilated patients.

As lung transplantation has become more successful, the selection criteria have broadened; however, some relative contraindications to lung transplantation are controversial. Some programs consider mechanical ventilation to be a major contraindication to lung transplantation because airway colonization with bacteria may lead to nosocomial infection and respiratory muscle deconditioning may necessitate prolonged postoperative ventilatory support. We report our experience of seven double lung transplant procedures on six patients requiring mechanical ventilation. Five patients with cystic fibrosis required preoperative mechanical ventilation for 7 to 19 days (mean, 10.7 days). One patient with acute lung injury required 115 days of preoperative mechanical ventilatory support. Only the latter patient required prolonged (27 days) postoperative mechanical ventilation because of respiratory muscle weakness; the others were extubated in 1 to 19 days (mean, 7.8 days). No early complications related to bacterial infection were seen. Two patients required temporary hemodialysis for transient kidney failure. Three patients had postoperative neurologic residua; one patient had a transient hemiparesis, and seizures developed in two patients. One patient died 3 months after transplantation from severe central nervous system complications with no evidence of pulmonary problems; and two patients died 17 months after transplantation, one of them receiving a second double lung transplant for obliterative bronchiolitis. Except for the patient who required prolonged preoperative ventilatory support, mechanical ventilation did not appear to play a role in the outcome of these patients. The posttransplantation hospital stay and hospital charges for patients requiring pretransplantation ventilatory support were not significantly different from those for other lung transplant recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolated lung transplantation for end-stage lung disease: a viable therapy.

Since January 1990, we have performed 29 isolated lung transplantations in 28 patients with end-stage lung disease (12 single, 16 bilateral). Recipient diagnoses were: cystic fibrosis (11), chronic obstructive pulmonary disease (6), pulmonary fibrosis (6), eosinophilic granulomatosis (1), postinfectious lung disease (1), adult respiratory distress syndrome (1), and primary pulmonary hypertension (2). There have been four deaths, two in patients with pulmonary fibrosis and two in patients with primary pulmonary hypertension. Four patients have undergone transplantation while on ventilatory support for respiratory failure (2 with cystic fibrosis, 1 having redo lung transplantation with cystic fibrosis, and 1 with adult respiratory distress syndrome); all of these have survived. Six patients required cardiopulmonary bypass, which was associated with increased transfusion requirement. All patients 2 months after discharge have returned to an active life-style, except for 2 patients who currently await retransplantation. Preoperative pulmonary rehabilitation has resulted in significant improvement in exercise performance in all patients. Immunosuppression consists of cyclosporine, azathioprine, and antilymphoblast globulin (University of Minnesota), withholding systemic steroids in the early postoperative period. We have employed bronchial omentopexy in all but four transplants; there has been one partial bronchial dehiscence, two instances of bronchomalacia requiring internal stenting, and one airway stenosis. Cytomegalovirus disease has been seen frequently (15 cases), but has responded well to treatment with ganciclovir. Other complication shave included one drug-related prolonged postoperative ventilation, thrombosis of a left lung after bilateral lung transplantation requiring retransplantation, five episodes of unilateral phrenic nerve palsy after bilateral lung transplantation (4 resolved), and the requirement of massive transfusion (greater than 10 units) in 5 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The binding of phosphatidylcholine to the phosphatidylcholine transfer protein: affinity and role in folding.

Bovine liver phosphatidylcholine transfer protein (PC-TP) has been expressed in Escherichia coli and purified to homogeneity from the cytosol fraction at a yield of 0.45 mg PC-TP per 10 mg total cytosolic protein. In addition, active PC-TP was obtained from inclusion bodies. An essential factor in the activation of PC-TP was phosphatidylcholine (PC) present in the folding buffer. PC-TP from the cytosol contains phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) with a preference for the di-monounsaturated species over the saturated species as determined by fast atom bombardment mass spectrometry (FAB-MS). By incubation with microsomal membranes the endogenous PE and PG were replaced by PC. Relative to the microsomal PC species composition, PC-TP bound preferentially C16:0/C20:4-PC and C16:0/C18:2-PC (twofold enriched) whereas the major microsomal species C18:0/C18:1-PC and C18:0/C18:2-PC were distinctly less bound. PC-TP is structurally homologous to the lipid-binding domain of the steroidogenic acute regulatory protein (Nat. Struct. Biol. 7 (2000) 408). Replacement of Lys(55) present in one of the beta-strands forming the lipid-binding site, with an isoleucine residue yielded an inactive protein. This suggests that Lys(55) be involved in the binding of the PC molecule.

Moving beyond lean and mean.

Traditional downsizing strategies often ignore the fact that corporate resources are inefficiently deployed. Here is a six-step approach to realigning, eliminating, and reallocating resources to improve overall operations.

[Palliative sedation in a man with oral cancer; the Royal Dutch Medical Association guidelines not always sufficient]. / Palliatieve sedatie bij een man met mondkanker: KNMG-richtlijn is niet altijd toereikend.

BACKGROUND: Palliative sedation is an effective treatment option in patients with refractory symptoms in the last phase of life. In 2009 the Royal Dutch Medical Association (KNMG) published revised guidelines. The dosage of propofol recommended in these guidelines is, however, based on one single study. CASE DESCRIPTION: A 60-year-old patient with a history of psychiatric disease and alcohol abuse was admitted to the palliative care unit suffering from unbearable pain from a squamous carcinoma of the floor of the oral cavity. Adequate treatment of his symptoms was initially possible, but when his symptoms became refractory we initiated continual sedation. Adequate symptom control was only achieved when propofol was administered in a high dosage of 150 mg/h and levomepromazine administration was reinitiated. CONCLUSION: In our opinion the advised starting dose of propofol is too low, especially in comparison with sedation in regional anaesthesia described in the literature. Furthermore, we advocate that administration of drugs from step 2, midazolam and levomepromazine, is not discontinued when propofol sedation is commenced in step 3.