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BACKGROUND: With the best prophylactics now available, venous thromboembolism after total knee replacement remains substantial (25% to 27%). Recombinant nematode anticoagulant protein c2 (rNAPc2) is a potent inhibitor of factor VIIa/tissue factor complex that has the potential to reduce this risk. The present study was performed to determine an efficacious and safe dose of rNAPc2 for prevention of venous thromboembolism after elective, unilateral total knee replacement. METHODS AND RESULTS: This open-label, sequential dose-ranging study was conducted in 11 centers in Canada, Europe, and the United States. Five regimens were tested. Injections were administered subcutaneously on the day of surgery (day 1) and days 3, 5, and optionally, day 7. Primary efficacy outcome was a composite of overall deep vein thrombosis based on mandatory unilateral venography (day 7+/-2) and confirmed symptomatic venous thromboembolism recorded </=48 hours after the last dose of rNAPc2. Primary safety outcome was major bleeding </=72 hours after the last dose. An independent, blinded Central Adjudication Committee assessed all outcome events. Of 293 patients studied, 251 (86%) could be evaluated for primary efficacy analysis. A dosage of 3.0 microgram/kg administered within 1 hour after surgery provided the best observed results, with an overall deep vein thrombosis rate of 12.2%, a proximal deep vein thrombosis rate of 1.3%, and a major bleeding rate of 2.3%. CONCLUSIONS: A randomized, double-blind trial that compared rNAPc2 with current best prophylactics is warranted based on encouraging, first-reported clinical results for a factor VIIa/tissue factor inhibitor evaluated for thrombosis prophylaxis.
STUDY DESIGN: We analyzed data from the Veterans Health Study, a longitudinal study of male patients receiving VA ambulatory care. OBJECTIVE: To determine whether clinical differences and/or race account for disparities between white and nonwhite patients in the use of lumbar spine radiographs. SUMMARY AND BACKGROUND DATA: Four hundred one patients with low back pain (LBP) receiving ambulatory care services in four VA outpatient clinics in the greater Boston area were followed for 12 months. METHODS: Participants were mailed the Medical Outcome Study Short Form Health Survey (SF-36) and had scheduled interviews that included the completion of a low back questionnaire, a comorbidity index, and a straight leg raising (SLR) test. Using self-reported racial data, patients were grouped as whites (315 patients) and nonwhites (among whom 22 were black, 4 nonwhite Hispanics, and 1 other race). RESULTS: Nonwhite patients had lumbar spine films more often (13 of 27, 48%) than white patients (87 of 315, 27%)(P = 0.02). Nonwhite patients had higher pain intensity scores than white patients (63 +/- 21 vs. 48 +/- 21, P < 0.01) and were more likely to have radiating leg pain (20 of 27, 76%; compared with 171 of 315, 55%; P = 0.01) than white patients. Nonwhite patients had worse physical functioning (P = 0.01), general health perception (P = 0.05), social functioning (P = 0.02), and role limitations because of emotional problems (P < 0.01). At higher LBP intensity level, nonwhite patients received more lumbar spine films (20 of 27, 74%) than did white patients (155 of 315, 50%)(P < 0.01). Among patients with positive SLR test, nonwhite patients also had lumbar spine films more often (5 of 22, 23%) than white patients (29 of 315, 11%) (P < 0.01). However, after adjusting for multiple clinical characteristics, race was no longer found to be an independent predictor of lumbar spine radiograph use. A positive SLR test remained to be associated with higher radiograph use, whereas better mental health status was associated with lower radiograph use. CONCLUSIONS: There was greater use of lumbar spine radiographs by nonwhite patients compared with white patients. This remained true when patients were subcategorized by severity of LBP or SLR test. However, race had no influence when multiple clinical characteristics of the patients were controlled for simultaneously. This study demonstrates the importance of careful and comprehensive case-mix adjustment when assessing apparent differences in the use of medical services.
Primary gastric mucosa-associated lymphoid tissue (MALT) lymphoma may develop from chronic infection with Helicobacter sp. in the mouse model. The mechanisms of pathogenesis remain unclear. Regulation of B-cell proliferation and death are important features to investigate. Proteins encoded by bcl-2 family genes, e.g., Bcl-X(L), regulate apoptosis; and alterations in the expression of these genes can contribute to the development of cancer. Our aim was to determine the role of Bcl-X(L) in B lymphocytes in the development of gastric MALT lymphoma associated with Helicobacter infection using the BALB/c mouse model. We analyzed 37 animals with Helicobacter-associated MALT (n = 25), low-grade MALT lymphoma (n = 10) and high-grade lymphoma (n = 2), investigating the in vivo distribution of Bcl-X(L) in B cells/B-lymphoma cells using immunohistochemical analysis. In vitro cultivation of B cells/B-lymphoma cells was employed to perform RT-PCR analysis of Bcl-X(L) mRNA expression after cell stimulation with Helicobacter antigen. We found significant Bcl-X(L) protein expression in B lymphocytes within MALT and low-grade MALT lymphoma, whereas there was no and minimal expression, respectively, of Bcl-X(L) in the 2 high-grade MALT lymphoma cases. Expression of bcl-X(L) mRNA in B lymphocytes was up-regulated in vitro upon Helicobacter-antigen stimulation and associated with prolonged cell survival. These findings support the hypothesis that Bcl-X(L) plays a role in the pathogenesis of B-cell MALT lymphoma by providing cell-survival signals and by triggering the acquisition of MALT.
Vascular endothelial growth factor (VEGF) is a potent angiogenic stimulator that acts by binding to high-affinity transmembrane receptors. Although both VEGF and its receptors are overexpressed in human pancreatic ductal adenocarcinoma (PDAC), this malignancy is not generally considered to be highly vascular. It is not known, therefore, whether the abundance of VEGF in PDAC is biologically relevant. To address this issue, we measured the angiogenic effects of pancreatic cancer cell-derived VEGF in an in vitro endothelial cell proliferation assay and characterized the consequences of suppressing VEGF expression on pancreatic tumor growth in an athymic nude mouse model. We found that human pancreatic cancer cell lines secrete large quantities of biologically active VEGF into conditioned medium (CM). Stable transfection of an anti-sense VEGF(189) (AS-VEGF(189)) expression construct into PANC-1 pancreatic cancer cells resulted in decreased VEGF expression and secretion, a decreased capacity of the resultant CM to enhance endothelial cell proliferation and a significant attenuation of tumor cell proliferation in vitro. Furthermore, when injected into athymic nude mice, AS-VEGF(189)-expressing cells exhibited an 80% decrease in tumor growth compared with control cells. These results support the hypothesis that VEGF promotes pancreatic cancer growth in vivo and suggest that anti-VEGF therapy may be useful in the treatment of this disease.
OBJECTIVES: To compare the efficacy of antidepressant drugs and generic counselling for treating mild to moderate depression in general practice. To determine whether the outcomes were similar for patients with randomly allocated treatment and those expressing a treatment preference. DESIGN: Randomised controlled trial, with patient preference arms. Follow up at 8 weeks and 12 months and abstraction of GP case notes. SETTING: 31 general practices in Trent region. PARTICIPANTS: Patients aged 18-70 who met research diagnostic criteria for major depression; 103 patients were randomised and 220 patients were recruited to the preference arms. MAIN OUTCOME MEASURES: Difference in mean Beck depression inventory score; time to remission; global outcome assessed by a psychiatrist using all data sources; and research diagnostic criteria. RESULTS: At 12 months there was no difference between the mean Beck scores in the randomised arms. Combining the randomised and patient preference groups, the difference in Beck scores was 0.4 (95% confidence interval -2.7 to 3.5). Patients choosing counselling did better than those randomised to it (mean difference in Beck score 4.6, 0.0 to 9.2). There was no difference in the psychiatrist's overall assessment of outcome between any of the groups. 221/265 (83%) of participants with a known outcome had a remission. Median time to remission was shorter in the group randomised to antidepressants than the other three groups (2 months v 3 months). 33/221 (15%) patients had a relapse. CONCLUSIONS: Generic counselling seems to be as effective as antidepressant treatment for mild to moderate depressive illness, although patients receiving antidepressants may recover more quickly. General practitioners should allow patients to have their preferred treatment.
Activation of adenosine A2A receptors (A2AR) has been shown to antagonize the function of D2 dopaminergic regulation of striatal gamma-aminobutyric acid (GABA)-ergic output and, thus, locomotor activity. Adenosine A2A receptor immunoreactivity (A2A-LI) has been localized to rat striatum by light microscopy by using a previously characterized human A2AR monoclonal antibody. In this study, we evaluated the localization of A2A-LI and its colocalization with GABA immunoreactivity (GABA-LI) in dorsolateral rat striatum by immunoelectron microscopy to further characterize the potential mechanism of purinergic control of striatal output. Ultrastructural analysis demonstrated A2A-LI associated with the plasma membrane and cytoplasmic membranous structures of striatal neurons. A2A-LI was prevalent in dendrites and dendritic spines ( approximately 70% of total A2A-profiles counted) and less prevalent in axons and axon terminals (23%), soma (3%), and glia (3%). Cellular elements exhibiting both A2A-LI and GABA-LI comprised 23% of the total profiles counted; colabeling was most common in dendrites. A2A-LI was observed primarily at asymmetric synapses (n = 70) (both pre- and postsynaptically but predominantly in the postsynaptic element) and less frequently at symmetric synapses (n = 17). Of the 714 A2A-immunoreactive profiles examined, 37% were apposed to GABA-labeled profiles. The most common appositions were A2A-labeled dendrites apposed to GABA-immunoreactive dendrites (n = 132), axon terminals (n = 28), and somata (n = 22) and A2A-labeled axons apposed to GABA-labeled dendrites (n = 58), axon terminals (n = 14), and somata (n = 9). Our findings suggest that adenosine may play an important role in modulating excitatory input to striatal neurons and that A2AR may modulate GABAergic signaling at several cellular sites within the rat striatum.
Terminal differentiation of lens fiber cells resembles the apoptotic process in that organelles are lost, DNA is fragmented, and changes in membrane morphology occur. However, unlike classically apoptotic cells, which are disintegrated by membrane blebbing and vesiculation, aging lens fiber cells are compressed into the center of the lens, where they undergo cell-cell fusion and the formation of specialized membrane interdigitations. In classically apoptotic cells, caspase cleavage of the cytoskeletal protein alpha-spectrin to approximately 150-kDa fragments is believed to be important for membrane blebbing. We report that caspase(s) cleave alpha-spectrin to approximately 150-kDa fragments and beta-spectrin to approximately 120- and approximately 80-kDa fragments during late embryonic chick lens development. These fragments continue to accumulate with age so that in the oldest fiber cells of the adult lens, most, if not all, of the spectrin is cleaved to discrete fragments. Thus, unlike classical apoptosis, where caspase-cleaved spectrin is short lived, lens fiber cells contain spectrin fragments that appear to be stable for the lifetime of the organism. Moreover, fragmentation of spectrin results in reduced membrane association and thus may lead to permanent remodeling of the membrane skeleton. Partial and specific proteolysis of membrane skeleton components by caspases may be important for age-related membrane changes in the lens.
Excitatory amino-acid carrier 1 (EAAC1) is a high-affinity Na+-dependent L-glutamate/D,L-aspartate cell-membrane transport protein. It is expressed in brain as well as several non-nervous tissues. In brain, EAAC1 is the primary neuronal glutamate transporter. It has a polarized distribution in cells and mainly functions perisynaptically to transport glutamate from the extracellular environment. In the kidney it is involved in renal acidic amino-acid re-absorption and amino-acid metabolism. Here we describe the identification and characterization of an EAAC1-associated protein, GTRAP3-18. Like EAAC1, GTRAP3-18 is expressed in numerous tissues. It localizes to the cell membrane and cytoplasm, and specifically interacts with carboxy-terminal intracellular domain of EAAC1. Increasing the expression of GTRAP3-18 in cells reduces EAAC1-mediated glutamate transport by lowering substrate affinity. The expression of GTRAP3-18 can be upregulated by retinoic acid, which results in a specific reduction of EAAC1-mediated glutamate transport. These studies show that glutamate transport proteins can be regulated potently and that GTRAP can modulate the transport functions ascribed to EAAC1. GTRAP3-18 may be important in regulating the metabolic function of EAAC1.
In embracing a multidisciplinary approach to the management of patients with sentinel node biopsy in breast cancer, the pathologist task is to screen sentinel nodes for possible metastasis. The consequences of missing sentinel node micrometastasis can directly influence treatment strategies, and this screening therefore has to be performed with more attention than usual. There is presently great diversity in the histopathological work-up of sentinel nodes, with many centres employing additional techniques such as immunohistochemistry, reverse transcription polymerase chain reaction or flow cytometry in addition to routine haematoxylin and eosin staining. In this review, we address the pathological validation and significance of micrometastasis in sentinel node biopsy in primary breast cancer.
Whereas large numbers of cells from a primary tumor may gain access to the circulation, few of them will give rise to metastases. The mechanism of elimination of these tumor cells, often termed "metastatic inefficiency," is poorly understood. In this study, we show that apoptosis in the lungs within 1-2 days of introduction of the cells is an important component of metastatic inefficiency. First, we show that death of transformed, metastatic rat embryo cells occurred via apoptosis in the lungs 24-48 h after injection into the circulation. Second, we show that Bcl-2 overexpression in these cells inhibited apoptosis in culture and also conferred resistance to apoptosis in vivo in the lungs 24-48 h after injection. This inhibition of apoptosis led to significantly more macroscopic metastases. Third, comparison between the extent of apoptosis by a poorly metastatic cell line to that by a highly metastatic cell line 24 h after injection in the lungs revealed more apoptosis by the poorly metastatic cell line. These results indicate that apoptosis, which occurs at 24-48 h after hematogenous dissemination in the lungs is an important determinant of metastatic inefficiency. Although prior work has shown an association between apoptosis in culture and metastasis in vivo, this work shows that apoptosis in vivo corresponds to decreased metastasis in vivo.
BACKGROUND: Acute urinary tract infection (UTI) is common in children. By the age of seven years, 8.4% of girls and 1.7% of boys will have suffered at least one episode. Symptoms are systemic rather than localised in early childhood and consist of fever, lethargy, anorexia, and vomiting. UTI is caused by E. coli in over 80% of cases and treatment consists of a course of antibiotics. Due to the unpleasant acute illness caused by UTI and the risk of pyelonephritis-induced permanent kidney damage, many children are given long-term antibiotics aimed at preventing recurrence. However these medications may cause side effects and promote the development of resistant bacteria. OBJECTIVES: To determine the efficacy and side effects of long-term antibiotics given to prevent recurrent UTI in children. SEARCH STRATEGY: A search of MEDLINE (1966 to Jan 2001), EMBASE (1988 to Jan 2001) and the Cochrane Controlled Trials Register for relevant randomised controlled trials without language restriction; reference lists of review articles; contact with content experts. SELECTION CRITERIA: Randomised comparisons of two or more antibiotics and placebo with one or more antibiotics to prevent recurrent UTI. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed and extracted information. For each trial, information was collected on the methods of the trial, participants, interventions and outcomes. A random-effects model was used to estimate a summary relative risk (RR) and a summary risk difference (RD) for recurrent UTI. Heterogeneity tests and subgroup analyses were carried out based on a priori hypothesis of plausible effect modification. MAIN RESULTS: There were three trials (n = 151) comparing antibiotics with placebo/no treatment. The duration of antibiotic prophylaxis treatment varied among the studies (10 weeks to 12 months). The method of allocation concealment in the three trials was inadequate, unclear and adequate. The overall rate of recurrent UTI in the placebo/no treatment group was 63% (48/76). Compared to placebo/no treatment, antibiotics reduced the risk of recurrent UTI (RR 0.36, 95% CI 0.16 to 0.77; RD -46%, 95% CI -59% to -33%). No side effects were described in any of these three trials. There was one double-blinded trial (n = 120) with unclear allocation concealment that compared two different types of antibiotics to prevent recurrent UTI. Nitrofurantoin was more effective than trimethoprim in preventing recurrent UTI over a six month period (RR 0.48, 95% CI 0.25 to 0.92; RD -18%, 95% CI -34% to -3%). However, patients receiving nitrofurantoin were more likely to discontinue the antibiotic due to side effects (mainly gastrointestinal) than patients receiving trimethoprim (RR 3.17, 95% CI 1.36 to 7.37; RD 22%, 95% CI 8% to 36%). REVIEWER'S CONCLUSIONS: Most published studies to date have been poorly designed with biases known to overestimate the true treatment effect. Large, properly randomised, double blinded trials are needed to determine the efficacy of long-term antibiotics for the prevention of UTI in susceptible children.
We have determined feasibility and levels of agreement for visualizing the nuchal translucency within a time limit with three-dimensional (3D) and two-dimensional (2D) transvaginal ultrasound. A total of 213 women of median gestational age 13 weeks (range 11-14 weeks) undergoing first-trimester nuchal translucency (NT) thickness measurements with 2D transabdominal ultrasound were included in the study. Additionally all women underwent 2D and 3D transvaginal NT examination within a time limit of 90 s. These two methods were compared with each other and with our standard method (2D transabdominal ultrasound) with respect to visualization of fetal nuchal fold and to the levels of agreement. The nuchal fold was visualized by 3D and 2D transvaginal ultrasound in 85.9% (95% CI: 80.5%, 90.3%) and 25.8% (95% CI: 20.1%, 32.2%), respectively (p<0.001). There was a statistically significant underestimation of the NT by 2D transabdominal as compared with 3D transvaginal ultrasound of 0.1 mm (p<0.001), and by 3D transvaginal as compared with 2D transvaginal ultrasound of even 0.1 mm (p<0.001). 3D transvaginal ultrasound of the nuchal fold has increased feasibility to 2D transvaginal ultrasound within a short examination time and with minimal, but significant, measurement differences.
This study investigated human BOLD responses in primary and higher order olfactory cortices following presentation of short- and long-duration odorant stimuli using a 3-T MR scanner. The goal was to identify temporal differences in the course of the response that might underlie habituation. A short-duration stimulus (9 s) consistently activated the primary olfactory cortex (POC). After a long stimulus (60 s), the temporal form of the response differed in different parts of the olfactory network: (1) The POC (piriform, entorhinal cortex, amygdala) and, interestingly, the hippocampus and, to a certain degree, the anterior insula show a short, phasic increase in the signal, followed by a prolonged decrease below baseline. (2) In the orbitofrontal cortex a sustained increase in activation was seen. This increase lasted approximately as long as the duration of odorant presentation ( approximately 60 s). (3) The mediodorsal nucleus of the thalamus and the caudate nucleus responded with an increase in signal which returned to baseline after approximately 15 to 30 s. The correlated biphasic hemodynamic response in the POC, hippocampus, and anterior insula during prolonged olfactory stimulation suggests that these three areas may interact closely with each other in the control of habituation. These results extend recent data which showed habituation of the rat piriform cortex and dissociation between the POC and the orbitofrontal cortex.
OBJECTIVES: To evaluate factors associated with decisions to refuse ICU admission and to assess the outcome of refused patients. DESIGN AND SETTING: Prospective, descriptive evaluation in a multi-disciplinary intensive care unit, university referral hospital. PATIENTS AND PARTICIPANTS: All adult emergency referrals over a 7-month period. INTERVENTIONS: The number of beds available at the time of referral, the patient's age, gender, diagnosis, mortality probability model score and hospital survival were documented. The outcome of the referral and the reason for refusal were recorded. MEASUREMENTS AND RESULTS: Of 624 patients 388 were admitted and 236 (38%) refused. Reasons for refusal were triage (n=104), futility (n=82) and inappropriate referral (too well; n=50). The standardised mortality ratio (SMR) for refused and admitted groups was 1.24 (95% CI 1.05-1.46) and 0.93 (0.78-1.09) respectively. The SMR ratio (refused SMR/admitted SMR) was highest in the middle range of illness (1.95, 1.19-3.20). Inappropriate referrals had a better than expected outcome despite refusal, with a SMR ratio of 0.39 (0.11-0.99). Excluding inappropriate referrals, multivariate analysis demonstrated that refusal was associated with older age, diagnostic group and severity of illness. Triage decisions were associated with a diagnosis of sepsis, and futility decisions with greater severity of illness and recent cardiac arrest. CONCLUSIONS: Refusal of admission to our ICU is common. Excess mortality of patients refused is most marked in the middle range of severity of illness. Age, diagnostic group, and severity of illness are important in decision making. Strategies should be developed to create admission criteria that would identify patients in the middle range of severity of illness who should benefit most from ICU care.
OBJECTIVE: This study was done to investigate the frequency of HLA-DRB1 antigens in juvenile-onset systemic lupus erythematosus (SLE) in the Taiwanese population. PATIENTS AND METHODS: Thirty-four Taiwanese patients with juvenile onset SLE and 200 unrelated healthy controls were studied. HLA-DRB1 typing was performed with polymerase chain reaction (PCR) and the sequence-specific oligonucleotide probe (SSO) typing method. RESULT: Among the 14 investigated DRB1 alleles, the frequency of HLA-DRB1*1602 was higher in juvenile onset SLE patients than the controls (15.15% vs 4.50%, odds ratio 3.66, 95% confidence interval 1.15-11.68, Pc = 0.04). Although there were differences in the frequencies of DRB1*0301, DRB1*0803, and DRB1*1501 between patients and controls, the associations were statistically insignificant. CONCLUSION: The frequency of HLA-DRB1*1602 was significantly higher in patients with juvenile onset SLE than in healthy controls. This finding differs from those in the previous studies in Caucasian and Japanese adult onset SLE patients.
In many plant species, selenium (Se) volatilization is limited by the reduction of selenate and its chemical conversion to organic Se compounds, a process that may be facilitated by rhizosphere microbes. This study was conducted to determine if pickleweed (Salicornia bigelovii Torr.), which is characterized by having high rates of Se volatilization from selenate, is able to reduce selenate into organic forms of Se axenically, or whether it requires the presence of microbes. X-ray absorption spectroscopy analysis showed that shoots and roots of pickleweed plants supplied with 50 microM selenate accumulated Se predominantly in organic Se forms (about 65-75% of the total accumulated Se), regardless of whether the plants were grown axenically or in the presence of microbes. The results suggest that, unlike other species for which selenate reduction appears to be rate limiting. e.g. Indian mustard (Brassica juncea L.) and broccoli (Brassica oleracea L.), pickleweed is unusual in that it has an enhanced capacity to reduce selenate to organic forms that is independent of the presence of rhizosphere microbes.
OBJECTIVE: To determine whether prehospital critical care teams (CCT) would result in improved functional outcomes for road trauma related severe head injury in the Australian setting, when compared with standard advanced life support measures provided by paramedics. METHODS: Retrospective review of 250 patients treated by paramedics and 46 patients treated by CCT transported directly from the accident scene, with a prehospital Glasgow coma scale (GCS)< or =8. RESULTS: CCT-treated patients had longer median prehospital times (113 versus 45 min, P<0.001), and a higher prehospital intubation rate (100% versus 36%, P<0.001) than paramedic-treated patients. On multivariate analysis, revised trauma score > or =4.45 (odds ratio [OR] 2.31, 95% CI: 1.15-4.65), lower injury severity score (OR 1.04, 95% CI: 1.02-1.06), age< or =25 years (OR 1.76, 95% CI: 1.13-2.75), absence of an acute subdural haematoma (OR 3.36, 95% CI: 1.89-5.95) and prehospital treatment by a CCT (OR 2.70, 95% CI: 1.48-4.95) independently predicted better outcome. CONCLUSION: The range of advanced interventions provided by the CCT were associated with improved functional outcome. Further studies are required to determine the individual factors responsible.