Undetected factor VIII in a patient with type 3 von Willebrands disease mistaken as severe haemophilia A

von Willebrand disease (VWD) type 3 is a rare disorder characterized by absent or <0.1 UmL(-1) of ristocetin cofactor (VWF:RCo), and a very low level of factor VIII (FVIII:C). A total absence of FVIII:C has never been reported in type 3 VWD. This case illustrates the effect of severe von Willebrand factor (VWF) deficiency on the factor VIII level.

Utilization of recombinant activated factor VII in southern Ontario in 85 patients with and without haemophilia

Recombinant activated factor VII (rFVIIa) is licensed for the treatment of bleeding in individuals with haemophilia and inhibitors. The use of rFVIIa appears to be increasing, and an increase in unlicensed use is suspected. There are currently few data about the specific indications for its use. The aim of this study was to describe the patterns of utilization of rFVIIa. We performed a retrospective cohort study using rFVIIa infusion data collected prospectively and clinical data collected retrospectively. Patients were identified using a tracking system designed to account for use of all coagulation factor concentrates issued in southern Ontario. Between 1 January 2001 and 31 December 2005, 85 patients received rFVIIa. 1164 infusions were given (8246.4 mg). Haemophilia patients with inhibitors accounted for 82.9% of rFVIIa infused and represented 8.2% of patients. The total amount of rFVIIa used increased each year from 2001 to 2004 and then decreased in 2005. The total number of infusions of rFVIIa administered annually increased. Both on-label and off-label use of rFVIIa increased. The number of patients with haemophilia receiving rFVIIa remained small and constant. The number of patients receiving rFVIIa for off-label indications increased markedly. Most rFVIIa infusions were given for licensed indications; however, these infusions represented <10% of patients treated. Overall, the utilization of rFVIIa is increasing, mostly for approved indications; however, the number of patients being prescribed rFVIIa for off-label indications has increased. The tracking system used in this study is a valuable tool to describe ongoing utilization patterns of rFVIIa.

Trends in the utilization and wastage of coagulation factor concentrates: the application of a regional tracking programme

The Commission of Inquiry on the Blood System in Canada ('Krever Commission', 1997) recommended an active programme of surveillance for all blood products. To describe trends in the utilization of coagulation factor concentrates using a comprehensive factor tracking programme. Between 2001 and 2004 in the region of Southern Ontario, we prospectively tracked all coagulation factor concentrates that were distributed from the national blood supplier, issued by hospitals for inpatient use or for home infusions, infused at hospital facilities or at home and wasted. Discrepancies were reconciled by independent audits. Trends in the utilization of FVIII, FIX and FVIIa concentrates are reported. A total of 466 patients with inherited or acquired bleeding disorders were registered. Utilization of FVIII, FIX and FVIIa increased by an average of 13.7%, 33.2% and 34.2% per year respectively. Most FVIII and FIX infusions were administered at home while most FVIIa infusions were in hospital. The increase in FVIII and FIX usage was attributable to an increase in per-patient use, predominantly for prophylaxis. In total, 1.7% of coagulation factor concentrates was wasted during the study period, at a cost of over 1 million Canadian dollars. Utilization of coagulation factor concentrates increased steadily during the study period. A regional programme to track utilization is feasible and may be used to describe trends, assist planning, and reduce costs by minimizing wastage.

Contribution of clinical breast examination to mammography screening in the early detection of breast cancer

OBJECTIVES

As the benefit of clinical breast examination (CBE) over that of screening mammography alone in reducing breast cancer mortality is uncertain, it is informative to monitor its contribution to interim measures of effectiveness of a screening programme. Here, the contribution of CBE to screening mammography in the early detection of breast cancer was evaluated.

SETTING

Four Canadian organised breast cancer screening programmes.

METHODS

Women aged 50-69 receiving dual screening (CBE and mammography) (n = 300,303) between 1996 and 1998 were followed up between screen and diagnosis. Outcomes assessed by mode of detection (CBE alone, mammography alone, or both CBE and mammography) included referral rate, positive predictive value, pathological features of tumours (size, nodal status, morphology), and cancer detection rates overall and for small cancers (< or = 10 mm or node-negative). Heterogeneity in findings across programmes was also assessed.

RESULTS

On first versus subsequent screen, CBE alone resulted in 28.5-36.7% of referrals, and 4.6-5.9% of cancers compared with 52.6-60.1% of referrals and 60.0-64.3% of cancers for mammography alone. Among cancers detected by CBE, 83.6-88.6% were also detected by mammography, whereas for mammographically detected cancers only 31.7-37.2% were also detected by CBE. On average, CBE increased the rate of detection of small invasive cancers by 2-6% over rates if mammography was the sole detection method. Without CBE, programmes would be missing three cancers for every 10,000 screens and 3-10 small invasive cancers in every 100,000 screens.

CONCLUSIONS

Inclusion of CBE in an organised programme contributes minimally to early detection.

Nitric oxide inhibition of IGF-1 stimulated proteoglycan synthesis: role of cGMP

Insulin-like growth factor (IGF-1) is critical for normal development and maintenance of cartilage, however arthritic cartilage responds poorly to IGF-1; part of this insensitivity is mediated by nitric oxide (NO). These studies test if cGMP is responsible for NO dependent insensitivity to IGF-1 in chondrocytes in situ in organ culture and in monolayer culture. Lapine cartilage and chondrocytes in monolayer culture and cartilage from osteoarthritic human knees were used. Tissues were exposed to NO from iNOS induced by IL-1, and proteoglycan synthesis in response to IGF-1 was evaluated in the presence and absence of cGMP dependent protein kinase (PKG) inhibitors. PKG activators inhibited IGF-1 responses in cartilage but not chondrocytes in monolayer. IL-1 stimulated cGMP synthesis in both monolayer and organ cultures. However, PKG inhibitors in cartilage slices but not in monolayer cultures restored response to IGF-1. PKG activity was detected in both fresh and monolayer chondrocytes, confirming this part of the cGMP signal cascade is intact in both of the preparations evaluated. Arthritic cartilage response to IGF-1 was restored by both N(G)-monomethyl-L-arginine inhibition of NO synthesis and PKG inhibitors. The data suggests that cGMP mediated effects are critical to NO actions on chondrocytes in situ in the cartilage matrix and supports a role for cGMP in the pathophysiologic effects of NO in osteoarthritis.

Insomnia related to dysthymia: polysomnographic and psychometric comparison with normal controls and acute therapeutic trials with trazodone

Utilizing polysomnography (PSG) and psychometry, objective and subjective sleep and awakening quality was investigated in 11 patients (mean age 50 +/- 14) with nonorganic insomnia (F 51.0) related to dysthymia (F 34.1) as compared with 11 age- and sex-matched normal controls. Patients demonstrated decreased sleep efficiency and sleep stage S2 as well as increased sleep latency to S1, S2 and S3, wakefulness within the total sleep period, number of awakenings, S1 and REM sleep. There was no intergroup difference in REM latency. Subjective sleep quality and the total score of the Self-Assessment Scale for Sleep and Awakening Quality (SSA) were deteriorated as were evening and morning well-being, mood, affectivity and drowsiness. Noopsychic measures showed deteriorated numerical memory, fine motor activity and reaction time variability. In a placebo-controlled crossover design study, the acute effects of 100 mg trazodone, a serotonin reuptake inhibitor with a sedative action due to 5HT(2) and alpha(1) receptor blockade, were investigated in the patients. As compared with placebo, trazodone induced an increase in slow-wave sleep (S3 + 4), a lengthening of REM latency, a decrease in REM sleep and a normalization of the periodic leg movement (PLM) index. In the morning, there was a minimal increase in somatic complaints and a decrease in critical flicker frequency and systolic blood pressure. In conclusion, our study demonstrated that dysthymia induced significant changes in objective and subjective sleep and awakening quality, which were counteracted by 100 mg trazodone, thus suggesting a key-lock principle in the treatment of nonorganic insomnia related to dysthymia with this drug.

Separation of a breast cancer cell line from human blood using a quadrupole magnetic flow sorter

We have developed a quadrupole magnetic flow sorter (QMS) to facilitate high-throughput binary cell separation. Optimized QMS operation requires the adjustment of three flow parameters based on the immunomagnetic characteristics of the target cell sample. To overcome the inefficiency of semiempirical operation/optimization of QMS flow parameters, a theoretical model of the QMS sorting process was developed. Application of this model requires measurement of the magnetophoretic mobility distribution of the cell sample by the cell tracking velocimetry (CTV) technique developed in our laboratory. In this work, the theoretical model was experimentally tested using breast carcinoma cells (HCC1954) overexpressing the HER-2/neu gene, and peripheral blood leukocytes (PBLs). The magnetophoretic mobility distribution of immunomagnetically labeled HCC1954 cells was measured using the CTV technique, and then theoretical predictions of sorting recoveries were calculated. Mean magnetophoretic mobilities of (1-3) x 10(-4) mm(3)/(T A s) were obtained depending on the labeling conditions. Labeled HCC1954 cells were mixed with unlabeled PBLs to form a "spiked" sample to be separated by the QMS. Fractional recoveries of cells for different flow parameters were examined and compared with theoretical predictions. Experimental results showed that the theoretical model accurately predicted fractional recoveries of HCC1954 cells. High-throughput (3.29 x 10(5) cells/s) separations with high recovery (0.89) of HCC1954 cells were achieved.

[Fatigue and stress sensitivity of physicians after 16 hours on duty at the emergency department]

In addition to their 40-hour working week (Mon-Fri, 8 a.m.-4 p.m.) residents at the emergency department of the General Hospital of Vienna have to do approximately six 24-hour duties. The reasons for conducting the present field study were physicians' complaints about tiring night duties. 11 residents (4 women, 7 men; aged between 28 and 43 years, x = 33.5 +/- 4.9 years; working at the emergency department for 4-50 months, x = 31 +/- 20 months) were tested on an ordinary working day at 9 a.m. and midnight. Self-rating concerning sleep duration, perception of stress and workload on the days of the investigations were found to be representative of other prolonged duties. Subjects reported a usual nocturnal sleep duration of only 6-7 hours. Stress was regarded as moderate by most of the volunteers. Blood pressure and pulse rates did not show diurnal changes. Generally, residents felt significantly (p < 0.01) less awake at night than in the morning, but reported only slight vegetative and somatic stress reactions or annoyances as assessed by the Fahrenberg self-rating scale. Interindividual differences were found; residents who had been working at the emergency department for a longer period experienced a more pronounced impairment. Further studies are required in order to objectify a nocturnal decrease in vigilance (by means of computer-assisted EEG) and to evaluate potential performance deficits (by means of psychometric tests).

Bacillus intermedius ribonuclease as inhibitor of cell proliferation and membrane current

The antiproliferative action of the guanine-specific ribonuclease secreted by Bacillus intermedius (binase) was studied in different chicken and mouse cell lines. The proliferation rate of chicken embryo fibroblasts, either normal or Rous sarcoma virus-transformed, was significantly reduced by binase treatment. Among mouse fibroblasts, v-ras-transformed NIH3T3 cells were sensitive to binase, whereas the growth of non-transformed, v-src-transformed or v-fms-transformed NIH3T3 cells was not affected. A 48 h treatment with binase inhibited the Ca2+-dependent K+ current of v-ras-transformed NIH3T3 cells but had no effect on this membrane current in non-transformed and in v-src- or v-fms-transformed NIH3T3 cells. Our results suggest that mammalian cells expressing the ras-oncogene are a potential target for the antiproliferative action of binase.

Performance of screening mammography in organized programs in Canada in 1996. The Database Management Subcommittee to the National Committee for the Canadian Breast Cancer Screening Initiative

BACKGROUND

The results of randomized trials show that breast cancer screening by mammography reduces breast cancer mortality by up to 40% in women aged 50-69 years. Because of these results, by 1998, 22 countries, including Canada, had established population-based organized screening programs. This paper presents the results of screening mammography in 1996 for 7 provincially organized breast cancer screening programs in Canada.

METHODS

Analyses of interim performance indicators for screening mammography have been calculated from data submitted to the Canadian Breast Cancer Screening database. The data set consisted of data from 7 provincial programs and was limited to mammographic screens for women aged 50-69 years (n = 203,303). Screening outcomes and performance indicators were calculated for abnormalities detected by screening mammography only.

RESULTS

The abnormal recall rate was 9.5% for first screens and 4.6% for subsequent screens, and the cancer detection rate per 1000 women screened was 6.9 for first screens and 3.8 for subsequent screens. The positive predictive value (i.e., the proportion of women who tested positive by mammography who were found to have breast cancer on screen-initiated diagnostic work-up) increased from 7.2% at the first screen to 8.2% at subsequent screens. Estimated participation rates within organized programs varied from 10.6% to 54.2%, depending on the province.

INTERPRETATION

For 1996, organized breast cancer screening programs met or exceeded many of the interim measures used in international programs. It is possible to translate the benefits of breast cancer screening by mammography, as demonstrated in randomized trials, into population-based community programs. Screening mammography through organized programs should increase to allow more comprehensive monitoring in Canada.

The role of the trehalose system in regulating the maltose regulon of Escherichia coli

The maltose regulon consists of 10 genes encoding an ABC transporter for maltose and maltodextrins as well as enzymes necessary for their degradation. MalK, the energy-transducing subunit of the transport system, acts phenotypically as a repressor of MalT, the transcriptional activator of the mal genes. Using MacConkey maltose indicator plates we isolated an insertion mutation that strongly reduced the repressing effect of overproduced MalK. The insertion had occurred in treR encoding the repressor of the trehalose system. The loss of TreR function led to derepression of treB encoding an enzymeIITre of the PTS for trehalose and of treC encoding TreC, the cytoplasmic trehalose-6-phosphate hydrolase. Further analysis revealed that maltose can enter the cell by facilitated diffusion through enzymeIITre, thus causing induction of the maltose system. In addition, derepression of TreC by itself caused induction of the maltose system, and a mutant lacking TreC was reduced in the uninduced level of mal gene expression indicating synthesis of endogenous inducer by TreC. Extracts containing TreC transformed [14C]-maltose into another 14C-labelled compound (preliminarily identified as maltose 1-phosphate) that is likely to be an alternative inducer of the maltose system.

Horizontal gene transfer involved in the convergent evolution of the plasmid-encoded enantioselective 6-hydroxynicotine oxidases

The D- and L-specific nicotine oxidases are flavoproteins involved in the oxidative degradation of nicotine by the Gram-positive soil bacterium Arthrobacter nicotinovorans. Their structural genes are located on a 160-kbp plasmid together with those of other nicotine-degrading enzymes. They are structurally unrelated at the DNA as well as at the protein level. Each of these oxidases possesses a high degree of substrate specificity; their catalytic stereoselectivity is absolute, although they are able to bind both enantiomeric substrates with a similar affinity. It appears that the existence of these enzymes is the result of convergent evolution. The amino acid sequence of 6-hydroxy-l-nicotine oxidase (EC 1.5.3.6) as derived from the respective structural gene shows considerable structural similarity with eukaryotic monoamine oxidases (EC 1.4.3.4) but not with monoamine oxidases from prokaryotic bacteria including those of the genus Arthrobacter. These similarities are not confined to the nucleotide-binding sites. A 100-amino acid stretch at the N-terminal regions of 6-hydroxy-l-nicotine oxidase and human monoamine oxidases A possess a 35% homology. Overall, 27.0, 26.9, and 25.8% of the amino acid positions of the monoamine oxidases of Aspergillus niger (N), humans (A), and rainbow trout (Salmo gairdneri) are identical to those of 6-hydroxy-l-nicotine oxidase (Smith-Waterman algorithm). In addition, the G+C content of the latter enzyme is in the range of that of eukaryotic monoamine oxidases and definitely lower than that of the A. nicotinovorans DNA and even that of the pAO1 DNA. The primary structure of 6-hydroxy-d-nicotine oxidase (EC 1.5.3.5) does not reveal its evolutionary history as easily. Significant similarities are found with a mitomycin radical oxidase from Streptomyces lavendulae (23.3%) and a "hypothetical protein" from Mycobacterium tuberculosis (26.0%). It is proposed that the plasmid-encoded gene of 6-hydroxy-l-nicotine oxidase evolved after horizontal transfer from an eukaryotic source.

Gene structures and properties of enzymes of the plasmid-encoded nicotine catabolism of Arthrobacter nicotinovorans

Arthrobacter nicotinovorans is a Gram-positive aerobic soil bacterium able to grow on nicotine as its sole source of carbon and nitrogen. The initial steps of nicotine catabolism are catalyzed by nicotine dehydrogenase, the l- and d-specific 6-hydroxynicotine oxidases, and ketone dehydrogenase. The genes encoding these enzymes reside on a 160 kb plasmid, pAO1. The cccDNA of this plasmid was isolated in high purity and reasonable yield. It served as template material for the construction of a lambda-phage DNA library of the plasmid. The genes coding for 6-hydroxy-l-nicotine oxidase and for the subunits of the heterotrimeric ketone dehydrogenase were identified, subcloned and sequenced. The 6-hlno gene was identified as a 1278 bp open reading frame; its regulatory elements were also recognized. The derived primary structure of the monomer of apo-6-hydroxy-l-nicotine oxidase (46,264.5 Da) agrees with the data obtained by partial amino acid sequencing. 6-Hydroxy-l-nicotine oxidase and 6-hydroxy-d-nicotine oxidase were expressed in Escherichia coli and obtained in a state of high purity and crystallized. Ketone dehydrogenase (KDH) was found to be a heterotrimer with subunits of molecular mass 89,021.71, 26,778.65 and 17,638.88. The genes of KDH-A and KDH-B are juxtaposed; the A of the stop codon of KDH-A is used in the start codon of KDH-B, eliciting a frame shift. KDH-C is separated from KDH-A by 281 bp.

Activation of a Ca2+-dependent K+ current in mouse fibroblasts by lysophosphatidic acid requires a pertussis toxin-sensitive G protein and Ras

Lysophosphatidic acid (LPA) is a bioactive lipid that acts through G protein-coupled plasma membrane receptors and mediates a wide range of cellular responses. Here we report that LPA activates a K+ current in NIH3T3 mouse fibroblasts that leads to membrane hyperpolarization. The activation occurs with an EC50 value of 1.7 nM LPA. The K+ current is Ca2+-dependent, voltage-independent, and completely blocked by the K+ channel blockers charybdotoxin, margatoxin, and iberiotoxin with IC50 values of 1.7, 16, and 62 nM, respectively. The underlying K+ channels possess a single channel conductance of 33 pS in symmetrical K+ solution. Pretreatment of cells with pertussis toxin (PTX), Clostridium sordellii lethal toxin, or a farnesyl protein transferase inhibitor reduced the K+ current amplitude in response to LPA to about 25% of the control value. Incubation of cells with the protein tyrosine kinase inhibitor genistein or microinjection of the neutralizing anti-Ras monoclonal antibody Y13-259 reduced it by more than 50%. In contrast, the phospholipase C inhibitor U-73122 and the protein kinase A activator 8-bromo-cAMP had no effect. These results indicate that the K+ channel activation by LPA is mediated by a signal transduction pathway involving a PTX-sensitive G protein, a protein tyrosine kinase, and Ras. LPA is already known to activate Cl- channels in various cell types, thereby leading to membrane depolarization. In conjunction with our results that demonstrate LPA-induced membrane hyperpolarization by activation of K+ channels, LPA appears to be significantly involved in the regulation of the cellular membrane potential.

The MOS 36-Item Short Form Health Survey: reliability, validity, and preliminary findings in schizophrenic outpatients

OBJECTIVES

The authors test the reliability and validity of the Medical Outcomes Study Short Form 36-Item Health Survey (SF-36) as a written, self-administered survey in outpatients with chronic schizophrenia.

METHODS

Thirty-six schizophrenic outpatients completed a written and oral form of the SF-36. A psychiatrist rated the patients using the Brief Psychiatric Rating Scale to determine severity of psychopathology. Cognitive functioning and academic achievement were also assessed. Internal consistency, test-retest reliability, concurrent and discriminative validity of the oral and written versions were determined.

RESULTS

The SF-36 in both forms was shown to have good internal consistency, stability, and concurrent validity. The mental health SF-36 subscales had poor discriminant validity, compared with the physical functioning scale that demonstrated good discriminant validity.

CONCLUSIONS

The validity of using the written form of the SF-36 on a sample of patients with chronic mental illness was demonstrated. The SF-36 appears to be an appropriate outcome measure for changes in physical and role functioning in consumers of outpatient mental health programs.

Activation of a Ca2+-dependent K+ current by the oncogenic receptor protein tyrosine kinase v-Fms in mouse fibroblasts

We investigated the effects of the receptor-coupled protein tyrosine kinase (RTK) v-Fms on the membrane current properties of NIH3T3 mouse fibroblasts. We found that v-Fms, the oncogenic variant of the macrophage colony-stimulating factor receptor c-Fms, activates a K+ current that is absent in control cells. The activation of the K+ current was Ca2+-dependent, voltage-independent, and was completely blocked by the K+ channel blockers charybdotoxin, margatoxin and iberiotoxin with IC50 values of 3 nM, 18 nM and 76 nM, respectively. To identify signalling components that mediate the activation of this K+ current, NIH3T3 cells that express different mutants of the wild-type v-Fms receptor were examined. Mutation of the binding site for the Ras-GTPase-activating protein led to a complete abolishment of the K+ current. A reduction of 76% and 63%, respectively, was observed upon mutation of either of the two binding sites for the growth factor receptor binding protein 2. Mutation of the ATP binding lobe, which disrupts the protein tyrosine kinase activity of v-Fms, led to a 55% reduction of the K+ current. Treatment of wild-type v-Fms cells with Clostiridium sordellii lethal toxin or a farnesyl protein transferase inhibitor, both known to inhibit the biological function of Ras, reduced the K+ current amplitude to 17% and 6% of the control value, respectively. This is the first report showing that an oncogenic RTK can modulate K+ channel activity. Our results indicate that this effect is dependent on the binding of certain Ras-regulating proteins to the v-Fms receptor and is not abolished by disruption of its intrinsic protein tyrosine kinase activity. Furthermore, our data suggest that Ras plays a key role for K+ channel activation by the oncogenic RTK v-Fms.