Multiple forms of complement C3 in trout that differ in binding to complement activators

In all other species analyzed to date, the functionally active form of complement component C3 exists as the product of a single gene. We have now identified and characterized three functional C3 proteins (C3-1, C3-3, and C3-4) in trout that are the products of at least two distinct C3 genes. All three proteins are composed of an alpha-and a beta-chain and contain a thioester bond in the alpha-chain. However, they differ in their electrophoretic mobility, glycosylation, reactivity with monospecific C3 antibodies, and relative ability to bind to various surfaces (zymosan, Escherichia coli, erythrocytes). A comparison of the partial amino acid sequences of the three proteins showed that the amino acid sequence identity/similarity of C3-3 to C3-4 is 87/91%, while that of C3-3 and C3-4 to C3-1 is 51.5/65.5% and 60/73% respectively. Thus, trout possess multiple forms of functional C3 that represent the products of several distinct genes and differ in their ability to bind covalently to various complement activators.     

Distinct exocytotic responses of intact and permeabilised chromaffin cells after cleavage of the 25-kDa synaptosomal-associated protein (SNAP-25) or synaptobrevin by botulinum toxin A or B

Botulinum neurotoxin (BoNT) types A and B are Zn2+-requiring endoproteases which potently block neurotransmitter release by cleavage of a 25-kDa synaptosomal-associated protein (SNAP-25) and synaptobrevin, respectively. Synaptobrevin is important for the exocystosis of catecholamines from dense-core granules and evidence is presented here for the involvement of SNAP-25 in this process in neuroendocrine cells. The effects of BoNT/A and BoNT/B on regulated secretion were compared in intact bovine chromaffin cells to investigate the consequences of cleavage of the different targets. Catecholamine secretion elicited by Ba2+, by elevated K+ concentrations or by nicotine was prevented by each toxin. A very good correlation was observed between the extents of SNAP-25 cleavage or synaptobrevin cleavage and inhibition of secretion by BoNT/A or BoNT/B, respectively, which indicates the importance of SNAP-25 and synaptobrevin in regulated exocytosis. Despite truncation of almost the entire SNAP-25 pool by exposure of the cells to BoNT/A, a residual fraction of secretion persisted that was induced by 20microM Ca2+ (and to a lesser extent by 1 mM Ba2+) following permeabilisation. Addition of more BoNT/A failed to reduce this level of secretion. Inclusion of Mg.ATP, which greatly enhanced secretion from permeabilised cells, was required for Ca2+-stimulated or Ba2+-stimulated BoNT/A-resistant secretion. Furthermore, synaptobrevin is essential for this response because the response was not observed in BoNT/B treated cells. In view of the ability of BoNT/E to abolish secretion from permeabilised cells and to delete 26 amino acids from the C-terminus of SNAP-25, it can be deduced that cleavage of only nine residues by BoNT/A does not prevent the resultant truncated form exhibiting attenuated activity under the conditions created by permeabilisation. This identification of a novel component of secretion from permeabilised cells should facilitate investigation of the functional interaction of SNAP-25 with other proteins involved in regulated exocytosis.     

Neonate and infant heart transplantation

OBJECTIVE: To establish the prevalence of anticoagulant (AC) treatment, the indications, and the quality of care in primary health care. DESIGN: A cross-sectional study, in which patients on AC treatment were identified from laboratory records. The main and second indications for AC treatment and the last value of the AC-test were taken from medical records. SETTING: Eight Finnish health centres with a total population of 182091 inhabitants. RESULTS: A total of 1255 patients on AC treatment were identified, 48% of them men. The mean age was 68.9 years. The age-adjusted prevalence of AC treatment was 0.65%. The commonest main indication was atrial fibrillation (38%). It was the main or second indication in 591 patients (age-adjusted prevalence 0.30%). The next commonest main indication was deep vein thrombosis (15%), followed by pulmonary embolism (8%). A total of 274 (22%) patients were anticoagulated for cerebral circulatory disturbances. 86% of the latest prothrombin time values fell within recommended ranges. CONCLUSION: The prevalence of AC treatment in Finland seems to be high. The proportion of patients with atrial fibrillation is high, differing from the results in other countries. The monitoring of AC-treatment as the general practitioner's responsibility functions well. The quality of care is good, even in older age groups.     

Partial characterization of an immortalized human trophoblast cell-line, TCL-1, which possesses a CSF-1 autocrine loop

High doses of morphine produce a state of behavioural inactivity and muscular rigidity. This type of 'catalepsy' is clearly different from the state which is produced by the administration of neuroleptics, e.g. haloperidol. While haloperidol-induced catalepsy can easily be antagonised by NMDA receptor antagonists, there has been a report that the non-competitive NMDA receptor antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5,10-imine (MK-801) potentiates morphine-induced catalepsy. The aim of this study was to further examine the role of glutamate receptors in the mediation of morphine-induced catalepsy. To this end we coadministered morphine (20, 40, 60 mg/kg i.p.) with MK-801 (0.1 and 0.3 mg/kg i.p.), the competitive NMDA receptor antagonist DL-(E)-2-amino-4-methyl-5-phosphono-3-pentoic acid (CGP 37849) (2 and 6 mg/kg i.p.), or 1-(4-aminophenyl)-4-methyl-7,8-methylen-dioxy-5H-2,3- benzodiazepine (GYKI 52466) (2 and 4 mg/kg), an antagonist of the AMPA type of glutamate receptors, respectively. The degree of catalepsy was assessed using two different methods, the 'bar/podium/grid' test which is commonly used to measure neuroleptic-induced catalepsy, and a test for the presence or absence of righting reflexes after turning the animals into a supine position. It was found that in the 'bar/podium/grid' test coadministration of both NMDA receptor antagonists significantly and dose-dependently augmented morphine-induced catalepsy. The results using the AMPA receptor antagonist were less clear since the lower dose of GYKI 52466 tended to attenuate the morphine effect whereas the higher dose augmented morphine-induced catalepsy in some cases. While placing the animals on the bar and on the podium produced essentially the same results, the grid was found to be inapplicable for the measurement of morphine-induced catalepsy since the animals did not cling to the grid and fell off almost immediately after being released from the experimenter's hand. With respect to the righting reflexes it was found that the number of animals not showing these responses increased when MK-801 or CGP 37849 was coadministered with morphine. In contrast, most of the animals treated with GYKI 52466 and morphine displayed intact righting reflexes. It is concluded that glutamatergic transmission plays an important role in the mediation of morphine-induced catalepsy, though different to that of haloperidol-induced catalepsy, and that NMDA and AMPA receptors are differentially involved in different aspects of the associated behavioural state.     

Comparative toxicity of azinphos-methyl to house mice, laboratory mice, deer mice, and gray-tailed voles

A laboratory toxicity study on house mice and laboratory mice (Mus musculus), gray-tailed voles (Microtus canicaudus), and deer mice (Peromyscus maniculatus) was conducted as part of a comprehensive laboratory and field study to field validate laboratory-based risk assessment of pesticides. The single dose oral LD50 for the organophosphorus insecticide azinphos-methyl (Guthion) was 10, 11, 32, and 48 mg/kg body weight in wild house mice, laboratory mice, gray-tailed voles, and deer mice, respectively. Ten-day dietary LC50s were 277 ppm for laboratory mice, 297 ppm for gray-tailed voles, and 1,180 ppm for deer mice. All treated animals lost more weight, consumed less food, and had depressed brain cholinesterase (ChE) activity compared to controls. Five-day LC50s were significantly higher than 10-day LC50s for laboratory mice and deer mice. For all three species, animals that died during dietary LC50 tests had mean ChE activity of 50-55% while survivors had 56-70% of controls. The conclusions were that: (1) Laboratory mice were not representative of deer mice or gray-tailed voles with respect to sensitivity to azinphos-methyl, but provided a conservative estimate for risk assessment; (2) 10-day dietary LC50 tests indicate substantially greater estimates of toxicity of azinphos-methyl to rodents than do 5-day tests; and (3) brain ChE depression of 45-50% was lethal in these species.     

Intensive postremission chemotherapy in adults with acute myeloid leukemia. Cancer and Leukemia Group B

BACKGROUND: About 65 percent of previously untreated adults with primary acute myeloid leukemia (AML) enter complete remission when treated with cytarabine and an anthracycline. However, such responses are rarely durable when conventional postremission therapy is administered. Uncontrolled trials have suggested that intensive postremission therapy may prolong these complete remissions. METHODS: We treated 1088 adults with newly diagnosed AML with three days of daunorubicin and seven days of cytarabine and randomly assigned patients who had a complete remission to receive four courses of cytarabine at one of three doses: 100 mg per square meter of body-surface area per day for five days by continuous infusion, 400 mg per square meter per day for five days by continuous infusion, or 3 g per square meter in a 3-hour infusion every 12 hours (twice daily) on days 1, 3, and 5. All patients then received four courses of monthly maintenance treatment. RESULTS: Of the 693 patients who had a complete remission, 596 were randomly assigned to receive postremission cytarabine. After a median follow-up of 52 months, the disease-free survival rates in the three treatment groups were significantly different (P = 0.003). Relative to the 100-mg group, the hazard ratios were 0.67 for the 3-g group (95 percent confidence interval, 0.53 to 0.86) and 0.75 for the 400-mg group (95 percent confidence interval, 0.60 to 0.94). The probability of remaining in continuous complete remission after four years for patients 60 years of age or younger was 24 percent in the 100-mg group, 29 percent in the 400-mg group, and 44 percent in the 3-g group (P = 0.002). In contrast, for patients older than 60, the probability of remaining disease-free after four years was 16 percent or less in each of the three postremission cytarabine groups. CONCLUSIONS: These data support the concept of a dose-response effect for cytarabine in patients with AML who are 60 years of age or younger. The results with the high-dose schedule in this age group are comparable to those reported in similar patients who have undergone allogeneic bone marrow transplantation during a first remission.     

Modeling considerations in seismic assessment of RC bridges using state-of-practice structural analysis software tools

The increasing awareness of the general society toward the seismic safety of structures has led to more restrictive performance requirements hence, many times, to the need of using new and more accurate methods of analysis of structures. Among these, nonlinear static procedures are becoming, evermore, the preferred choice of the majority of design codes, as an alternative to complete nonlinear time-history analysis for seismic design and assessment of structures. The many available software tools should therefore be evaluated and well understood, in order to be easily and soundly employed by the practitioners. The study presented herein intends to contribute to this need by providing further insight with respect to the use of commonly employed structural analysis software tools in nonlinear analysis of bridge structures. A comparison between different nonlinear modeling assumptions is presented, together with the comparison with real experimental results. Furthermore, alternative adaptive pushover procedures are proposed and applied to a case study bridge, based on a generic plastic hinge model. The adopted structural analysis program proved to be accurate, yielding reliable estimates, both in terms of local plastic hinge behavior and global structural behavior.     

Fatigue crack in large-scale tubular joints for offshore structures

Tubular members have been used for constructing offshore structures. Large-scale fatigue tests of welded tubular K-joints under the balanced in-plane bending brace were carried out to investigate the fatigue behavior of API 2W Gr.50 steel produced by POSCO. The experimental results were verified by numerical approaches and compared with the IIW, DnV RP-C203 and API RP 2A-WSD design curves. The test results based on the hot spot stress were in agreement with the design curves. The SCF factor for tubular K-jo...     

Changes in blood flow velocity and diameter of the middle cerebral artery during hyperventilation: assessment with MR and transcranial Doppler sonography

PURPOSE: To compare blood flow velocity changes within the middle cerebral artery (MCA) during hyperventilation, as measured with by both transcranial Doppler sonography and MR imaging, with the diameter of the MCA as measured with MR imaging alone. METHODS: The studies were performed in six healthy volunteers ranging in age from 22 to 31 years (mean, 27 years). Transcranial Doppler sonography was carried out with a range-gated 2-MHz transducer. MR examinations were done on a 1.5-T imaging unit. MR angiography was performed using the time-of-flight technique. MR flow measurements were carried out by using the phase-mapping technique with an ECG-triggered phase-contrast sequence. RESULTS: During hyperventilation, the mean blood flow velocity of the proximal MCA declined by 49.6% +/- 5.7 (mean +/- standard deviation) as measured with Doppler sonography, and by 47% +/- 4.6 as measured with MR flow calculation. The diameter of the MCA (3.4 +/- 0.3 mm) remained unchanged on MR imaging studies (3.3 +/- 0.3 mm). CONCLUSION: We found a good correlation between relative flow velocity changes measured by transcranial Doppler sonography and MR techniques. MR imaging revealed no significant changes in the diameter of the proximal MCA during normal versus hyperventilation. Relative changes in flow velocity in the MCA would thereby reflect relative changes in cerebral blood flow, at least during hyperventilation.