New structural insights provide a different angle on steroid sulfatase action

A central part of human sulfation pathways is the spatially and temporally controlled desulfation of biologically highly potent steroid hormones. The responsible enzyme - steroid sulfatase (STS) - is highly expressed in placenta and peripheral tissues, such as fat, colon, and the brain. The shape of this enzyme and its mechanism are probably unique in biochemistry. STS was believed to be a transmembrane protein, spanning the Golgi double-membrane by stem region formed by two extended internal alpha-helices. New crystallographic data however challenge this view. STS now is portraited as a trimeric membrane-associated complex. We discuss the impact of these results on STS function and sulfation pathways in general and we hypothesis that this new STS structural understanding suggests product inhibition to be a regulator of STS enzymatic activity.

SUN-LB22 PLK1 as a New Treatment Target for Adrenocortical Carcinoma

Background: Adrenocortical carcinoma (ACC) is an aggressive malignancy with limited medical treatment options. We previously identified polo-like kinase 1 (PLK1) as one of most overexpressed genes in ACC; thus PLK1 represents a potential treatment target for this cancer type. Some PLK1 inhibitors are under evaluation in clinical trials for other solid organ malignancies, and seem to be more effective in TP53 mutated tumours. The aim of this study was to evaluate PLK1 protein levels in a large series of ACC and assess the in vitroefficacy of PLK1 inhibitors in two different ACC cell lines. Methods: 104 formalin-fixed paraffin-embedded ACC tissue samples with available genetic data were investigated. Nuclear PLK1 protein expression was evaluated by immunohistochemistry and a semi-quantitative H-score was calculated. PLK1 expression levels were correlated to clinical and histological parameters. Efficacy of PLK1-specific inhibitor Volasertib (0-200 nM) was tested in the standard NCI-H295R ACCcell line, which presents PLK-1 overexpression and a large TP53 deletion, and in the newly established MUC1 cell line, which bears a frameshift mutation in TP53. Cell proliferation was analysed using DNA fluorescence and cell apoptosis by Caspase Glo 3/7 assay. Results: Nuclear PLK1 expression was classified as high in 59% of ACC samples, with a significant difference noted between TP53-mutated (n=24) and wild-type (n=80) cases (87.5 vs 51%, p<0.01). PLK1 levels did not correlate with either progression-free or overall survival. H295R cells showed a significant time- and dose-dependent reduction of cell proliferation compared to vehicle control after 72h of Volasertib treatment (p<0.005 per trend, p=0.01 by 200nM by non-parametric two-way ANOVA). A less pronounced and non-significant trend towards inhibited proliferation was observed in MUC1 cells. Cell apoptosis was significantly higher in the H295R cells treated with 175nM and 200nM Volasertib when compared to control (p<0.05), while there was no significant difference in MUC1 cells. Conclusion:In this pilot study, we propose PLK1 inhibitors as promising candidates for treatment of a subset of ACC patients that may be pre-selected according to the tumour molecular pattern. We plan to extend functional experiments to further PLK1 inhibitors, including additional ACC cell lines with a different molecular profile.

NNT is a key regulator of adrenal redox homeostasis and steroidogenesis in male mice

Nicotinamide nucleotide transhydrogenase, NNT, is a ubiquitous protein of the inner mitochondrial membrane with a key role in mitochondrial redox balance. NNT produces high concentrations of NADPH for detoxification of reactive oxygen species by glutathione and thioredoxin pathways. In humans, NNT dysfunction leads to an adrenal-specific disorder, glucocorticoid deficiency. Certain substrains of C57BL/6 mice contain a spontaneously occurring inactivating Nnt mutation and display glucocorticoid deficiency along with glucose intolerance and reduced insulin secretion. To understand the underlying mechanism(s) behind the glucocorticoid deficiency, we performed comprehensive RNA-seq on adrenals from wild-type (C57BL/6N), mutant (C57BL/6J) and BAC transgenic mice overexpressing Nnt (C57BL/6J^BAC). The following results were obtained. Our data suggest that Nnt deletion (or overexpression) reduces adrenal steroidogenic output by decreasing the expression of crucial, mitochondrial antioxidant (Prdx3 and Txnrd2) and steroidogenic (Cyp11a1) enzymes. Pathway analysis also revealed upregulation of heat shock protein machinery and haemoglobins possibly in response to the oxidative stress initiated by NNT ablation. In conclusion, using transcriptomic profiling in adrenals from three mouse models, we showed that disturbances in adrenal redox homeostasis are mediated not only by under expression of NNT but also by its overexpression. Further, we demonstrated that both under expression or overexpression of NNT reduced corticosterone output implying a central role for it in the control of steroidogenesis. This is likely due to a reduction in the expression of a key steroidogenic enzyme, Cyp11a1, which mirrored the reduction in corticosterone output.

In vivo and in vitro properties of STX2484: a novel non-steroidal anti-cancer compound active in taxane-resistant breast cancer

BACKGROUND

STX2484 is a novel non-steroidal compound with potent anti-proliferative activity. These studies aimed to identify STX2484's mechanism of action, in vivo efficacy and activity in taxane-resistant breast cancer models.

METHODS

Effects of STX2484 and paclitaxel on proliferation, cell cycle and apoptosis were assessed in vitro in drug-resistant (MCF-7(DOX)) and non-resistant cells (MCF-7(WT)). STX2484 efficacy in βIII tubulin overexpression in MCF-7 cells was also determined. Anti-angiogenic activity was quantified in vitro by a co-culture model and in vivo using a Matrigel plug assay. An MDA-MB-231 xenograft model was used to determine STX2484 efficacy in vivo.

RESULTS

STX2484 is a tubulin disruptor, which induces p53 expression, Bcl2 phosphorylation, caspase-3 cleavage, cell cycle arrest and apoptosis. In addition, STX2484 is a potent anti-angiogenic agent in vitro and in vivo. In breast cancer xenografts, STX2484 (20 mg kg(-1) p.o.) suppressed tumour growth by 84% after 35 days of daily dosing, with limited toxicity. In contrast to paclitaxel, STX2484 efficacy was unchanged in two clinically relevant drug-resistant models.

CONCLUSIONS

STX2484 is an orally bioavailable microtubule-disrupting agent with in vivo anti-angiogenic activity and excellent in vivo efficacy with no apparent toxicity. Crucially, STX2484 has superior efficacy to paclitaxel in models of clinical drug resistance.

BCRP expression does not result in resistance to STX140 in vivo, despite the increased expression of BCRP in A2780 cells in vitro after long-term STX140 exposure

The anti-proliferative and anti-angiogenic properties of the endogenous oestrogen metabolite, 2-methoxyoestradiol (2-MeOE2), are enhanced in a series of sulphamoylated derivatives of 2-MeOE2. To investigate possible mechanisms of resistance to these compounds, a cell line, A2780.140, eightfold less sensitive to the 3,17-O,O-bis-sulphamoylated derivative, STX140, was derived from the A2780 ovarian cancer cell line by dose escalation. Other cell lines tested did not develop STX140 resistance. RT-PCR and immunoblot analysis demonstrated that breast cancer resistance protein (BCRP) expression is dramatically increased in A2780.140 cells. The cells are cross-resistant to the most structurally similar bis-sulphamates, and to BCRP substrates, mitoxantrone and doxorubicin; but they remain sensitive to taxol, an MDR1 substrate, and to all other sulphamates tested. Sensitivity can be restored using a BCRP inhibitor, and this pattern of resistance is also seen in a BCRP-expressing MCF-7-derived cell line, MCF-7.MR. In mice bearing wild-type (wt) and BCRP-expressing tumours on either flank, both STX140 and mitoxantrone inhibited the growth of the MCF-7wt xenografts, but only STX140 inhibited growth of the MCF-7.MR tumours. In conclusion, STX140, a promising orally bioavailable anti-cancer agent in pre-clinical development, is highly efficacious in BCRP-expressing xenografts. This is despite an increase in BCRP expression in A2780 cells in vitro after chronic dosing with STX140.

The in vivo properties of STX243: a potent angiogenesis inhibitor in breast cancer

The steroidal-based drug 2-ethyloestradiol-3,17-O,O-bis-sulphamate (STX243) has been developed as a potent antiangiogenic and antitumour compound. The objective of this study was to ascertain whether STX243 is more active in vivo than the clinically relevant drug 2-methoxyoestradiol (2-MeOE2) and the structurally similar compound 2-MeOE2-3,17-O,O-bis-sulphamate (STX140). The tumour growth inhibition efficacy, antiangiogenic potential and pharmacokinetics of STX243 were examined using four in vivo models. Both STX243 and STX140 were capable of retarding the growth of MDA-MB-231 xenograft tumours (72 and 63%, respectively), whereas no inhibition was observed for animals treated with 2-MeOE2. Further tumour inhibition studies showed that STX243 was also active against MCF-7 paclitaxel-resistant tumours. Using a Matrigel plug-based model, in vivo angiogenesis was restricted with STX243 and STX140 (50 and 72%, respectively, using a 10 mg kg(-1) oral dose), thereby showing the antiangiogenic activity of both compounds. The pharmacokinetics of STX243 were examined at two different doses using adult female rats. The compound was orally bioavailable (31% after a single 10 mg kg(-1) dose) and resistant to metabolism. These results show that STX243 is a potent in vivo drug and could be clinically effective at treating a number of oncological conditions.

2-Methoxyoestradiol-3,17-O,O-bis-sulphamate and 2-deoxy-D-glucose in combination: a potential treatment for breast and prostate cancer

Drug combination therapy is a key strategy to improve treatment efficacy and survival of cancer patients. In this study the effects of combining 2-methoxyoestradiol-3,17-O,O-bis-sulphamate (STX140), a microtubule disruptor, with 2-deoxy-D-glucose (2DG) were assessed in MCF-7 (breast) and LNCaP (prostate) xenograft models in vivo. In mice bearing MCF-7 xenografts, daily p.o. administration of STX140 (5 mg kg⁻¹) resulted in a 46% (P<0.05) reduction of tumour volume. However, the combination of STX140 (5 mg kg⁻¹ p.o.) and 2DG (2 g kg⁻¹ i.p.) reduced tumour volume by 76% (P<0.001). 2-Methoxyoestradiol-3,17-O,O-bis-sulphamate also reduced tumour vessel density. 2-Deoxy-D-glucose alone had no significant effect on tumour volume or vessel density. A similar benefit of the combination treatment was observed in the LNCaP prostate xenograft model. In vitro the degree of inhibition of cell proliferation by STX140 was unaffected by oxygen concentrations. In contrast, the inhibition of proliferation by 2DG was enhanced under hypoxia by 20 and 25% in MCF-7 and LNCaP cells, respectively. The combination of STX140 and 2DG in LNCaP cells under normoxia or hypoxia inhibited proliferation to a greater extent than either compound alone. These results suggest that the antiangiogenic and microtubule disruption activities of STX140 may make tumours more susceptible to inhibition of glycolysis by 2DG. This is the first study to show the benefit of combining a microtubule disruptor with 2DG in the two most common solid tumours.

Steroid metabolism in breast cancer

The endocrine system and its steroids have long been thought to be instrumental in the etiology of breast cancer. A large proportion of cancerous breast tissues have been shown to express estrogen (ER), androgen (AR) and progesterone (PR) receptors. It is through these receptors that steroid hormones can exert their mitogenic effects. The local biosynthesis of estrogens is believed to play an integral part in the development of hormone-dependent breast cancer and recent studies on the use of inhibitors to block this steroid production has yielded an improvement of prognosis in breast cancer patients. Consequently, the understanding of the enzymes involved in the synthesis and metabolism of estrogens in breast cancer is paramount to treating this malignancy. This review examines the biological and clinical relevance of three key endocrine enzymes: steroid sulfatase (STS), aromatase (Arom), and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) type-1. The importance of the over expression and increased activity of these enzymes in breast tissue and on breast cancer is discussed. Importantly, the intratumoral biosynthesis of estrogens is examined in detail. The effects of new inhibitors of these enzymes on the growth of hormone-dependent breast cancer will also be investigated. First and second generation STS inhibitors and third generation aromatase inhibitors are showing significant promise, whereas inhibitors for 17beta-HSD type-1 are still at an early stage. However, such endocrine therapy that is currently being explored has shown promising results for patients with hormone-dependent breast cancer.

The therapeutic potential of a series of orally bioavailable anti-angiogenic microtubule disruptors as therapy for hormone-independent prostate and breast cancers

Therapies for hormone-independent prostate and breast cancer are limited, with the effectiveness of the taxanes compromised by toxicity, lack of oral bioavailability and drug resistance. This study aims to identify and characterise new microtubule disruptors, which may have improved efficacy relative to the taxanes in hormone-independent cancer. 2-Methoxy-3-O-sulphamoyl-17β-cyanomethyl-oestra-1,3,5(10)-triene (STX641), 2-methoxy-3-hydroxy-17β-cyanomethyl-oestra-1,3,5(10)-triene (STX640) and 2-methoxyoestradiol-3,17-O,O-bis-sulphamate (STX140) were all potent inhibitors of cell proliferation in a panel of prostate and breast cancer cell lines. STX641 and STX640 significantly inhibited tumour growth in the MDA-MB-231 xenograft model. STX641 inhibited both in vitro and in vivo angiogenesis. Despite good in vivo activity, STX641 was not as potent in vivo as STX140. Therefore, STX140 was evaluated in the prostate hormone-independent PC-3 xenograft model. STX140 had superior efficacy to docetaxel, 2-MeOE2 and bevacizumab. In contrast to vinorelbine, no significant toxicity was observed. Furthermore, STX140 could be dosed daily over a 60-day period leading to tumour regression and complete responses, which were maintained after the cessation of dosing. This study demonstrates that STX641 and STX140 have considerable potential for the treatment of hormone-independent breast and prostate cancer. In contrast to the taxanes, STX140 can be dosed orally, with no toxicity being observed even after prolonged daily dosing.

In vivo inhibition of angiogenesis by sulphamoylated derivatives of 2-methoxyoestradiol

Drugs that inhibit growth of tumours and their blood supply could have considerable therapeutic potential. 2-Methoxyoestradiol-3,17-O,O-bis-sulphamate (2-MeOE2bisMATE) has been shown to inhibit the proliferation of MCF-7 (ER+) breast cancer cells and angiogenesis in vitro. 2-MeOE2bisMATE and its analogue, 17-Cym-2-MeOE2MATE, were investigated for their ability to inhibit in vivo angiogenesis and tumour growth. The mouse Matrigel plug assay for angiogenesis was used to investigate the effect of compounds on neovascularisation and was quantified using a FITC-dextran injection technique. Nude mice bearing tumours derived from MCF-7 cells were used to assess efficacy on tumour growth. Tumour sections were stained for VEGFR-2 and Ki67 to assess tumour angiogenesis and cell proliferation respectively. Matrigel plugs supplemented with basic fibroblast growth factor resulted in increased neovascularisation over 7 days. Oral administration of 2-MeOE2bisMATE for 7 days at 10 or 50 mg kg(-1) significantly reduced neovascularisation to or below control levels respectively. 17-Cym-2-MeOE2MATE at 20 mg kg(-1) was equally effective. 2-MeOE2bisMATE, dosed daily for 21 days, caused a 52% reduction in tumour growth at 5 mg kg(-1) and 38% regression at 20 mg kg(-1). 17-Cym-2-MeOE2MATE (20 mg kg(-1)) reduced tumour growth by 92%. Immunohistochemistry revealed a reduction in angiogenesis and proliferation. Matrigel plug and tumour imaging after FITC-dextran injection indicated that 2-MeOE2bisMATE caused a marked disruption of vasculature. These sulphamoylated oestrogen derivatives have been shown to be potent inhibitors of angiogenesis in vivo. This, together with their ability to inhibit tumour growth, indicates the potential of this new class of drugs for further development for cancer therapy.

hEGR1 is induced by EGF, inhibited by gefitinib in bladder cell lines and related to EGF receptor levels in bladder tumours

The effect of EGF and gefitinib on two EGFR-positive human bladder cancer cell lines has been investigated using array-based gene expression profiling. The most prominent transcript, increased up to 6.7-fold by EGF compared with controls in RT112 cells, was human early growth response protein 1 (hEGR1). This induction was prevented by gefitinib. The hEGR1 mRNA in EGF-treated samples was reduced in the presence of gefitinib, as was hEGR1 protein in cell lysates. In the RT4 cells, hEGR1 expression was halved in the presence of EGF and gefitinib in combination. In bladder tumour samples, there was a significant correlation between hEGR1 mRNA detected by RT-PCR and EGFR detected by ligand binding, (P=0.042). The induction by EGF of the hEGR1 gene, mRNA and protein in RT112 cells, and its inhibition by gefitinib, together with the detection of hEGR1 mRNA in bladder tumours, suggests that hEGR1 may be important in the EGFR growth-signalling pathway in bladder cancer and should be further investigated for its prognostic significance and as a potential therapeutic target.

Crisis resource management among strangers: principles of organizing a multidisciplinary group for crisis resource management

Patient safety depends on the skills, vigilance, and judgment of trained individuals working as members of a clinical team that includes anesthesiologists, surgeons, nurses, and technicians. Now, as never before, safe outcome depends both on better knowledge and better management. This requires organization of caregivers, who may be strangers from diverse disciplines, into teams. One can drill an individual to work safely alone. One can rehearse a series of scenarios with small groups (who regularly work together) to improve performance. But what does one do with an unrehearsed group, called together in an emergency from several different disciplines, usually including Anesthesia. These people may not know each other, their roles, their special skills, and may even be hazy about each other's goals. Rapid organization of such an ad hoc team becomes a critical priority where patient safety is at stake. The way by which such an ad hoc team from several disciplines can rapidly be helped to function effectively together is by teaching all the "strangers" the principles of Crisis Resource Management. These principles are not as well-presented in a written text or lecture format, as one cannot introduce the sense of urgency that emotionally charges and changes the impact. We believe the best teacher is experience gained in a realistic simulated environment using a model driven, full human simulator. This simulated environment is safe for both patient and trainee.

Intracellular trafficking of factor VIII to von Willebrand factor storage granules

In plasma, von Willebrand factor (vWf) associates with Factor VIII (FVIII); however, the site at which these proteins first interact has not been defined. Administration of 1-desamino-8-D-arginine vasopressin (DDAVP) causes a rapid, concomitant elevation in plasma levels of both vWf and FVIII, suggesting the existence of a DDAVP-releasable storage pool for both proteins. To determine whether vWf and FVIII can associate intracellularly and colocalize to storage vesicles, we transfected AtT-20 cells with vWf and FVIII expression plasmids. FVIII alone was not detectable within storage granules; however, transfection of vWf cDNA into the same cell caused FVIII to alter its intracellular trafficking and to undergo granular storage, colocalizing to the vWf-containing granules. In contrast, colocalization of FVIII was not observed when these cells were transfected with plasmids encoding defective FVIII-binding vWf mutants. Transfection of bovine endothelial cells with FVIII further demonstrated vesicular storage of FVIII with vWf in Weibel-Palade bodies. Since gene therapy of hemophilia A may ultimately target endothelium or hematopoietic stem cells, the interaction between vWf and FVIII within a secretory cell is important. Thus, vWf can alter the intracellular trafficking of FVIII from a constitutive to a regulated secretory pathway, thereby producing an intracellular storage pool of both proteins.

Adrenocorticotropic hormone infusion as a novel treatment for postdural puncture headache

BACKGROUND AND OBJECTIVES

In two patients, one scheduled for epidural anesthesia and the other for placement of a spinal catheter for operative procedures, severe postdural puncture headache developed and was refractory to conservative therapy.

METHODS

The first patient had several unintentional dural punctures, and the second underwent a planned dural puncture with an 18-gauge needle for insertion of a 20-gauge catheter. When neither patient responded to conservative therapy following development of postdural puncture headache, an infusion of adrenocorticotropic hormone (ACTH) was given prior to consideration of epidural blood patching.

RESULTS

Both patients obtained complete and permanent relief from their headaches.

CONCLUSION

A single treatment with ACTH may offer an alternative therapy in the treatment of postdural puncture headache.

The peripheral pulse wave: information overlooked

although the waveform derived from a peripheral pulse monitor or pulse oximeter may resemble an arterial pressure waveform, it is in fact a visualization of blood volume change in transilluminated tissue caused by passage of blood: an indication of perfusion or blood flow. Most currently available pulse oximeters indicate this flow, but few display it in usable form. Since adequate tissue blood flow is a prerequisite for normal metabolic activity, it is a parameter that should merit a place in standard anesthesia or intensive care monitors. That the peripheral tissue blood flow is not routinely displayed may be in part due to the difficulty in quantifying data obtained: flow is not accurately measured as simply as pressure, even by invasive means. It is in the pattern of the waveform that beat-to-beat changes in stroke volume can be better seen than measured, or in the interaction of ventilation and circulation that tests general circulatory performance. The origin and interpretation of these changes are discussed and illustrated with examples. We indicate how new physiological tests of autonomic function and cardiac preload can be developed using pulse plethysmography. The importance and application of the Valsalva effect on the waveform is emphasized. This effect is particularly applicable for monitoring adequate fluid loading and the action of vasodilator drugs, which are both important in anesthesia. Differences between the arterial pulse pressure wave and tissue flow wave are discussed, as well as the cause of certain artifacts, including the wandering dicrotic notch.

The defective interaction between von Willebrand factor and factor VIII in a patient with type 1 von Willebrand disease is caused by substitution of Arg19 and His54 in mature von Willebrand factor

In this report we describe the further investigation of the von Willebrand factor (vWF)/FVIII interaction in a type 1 von Willebrand disease patient characterized by discrepant VIII:C levels as determined by one-stage and two-stage VIII:C assays. A solid-phase binding assay shows that this patient's plasma vWF is moderately defective in capturing recombinant FVIII. Sequence analysis of the FVIII-binding domain encoded by the vWF mRNA of the affected individual identified mutations in both vWF alleles. In allele A, the mutations C2344T and T2451A result in the substitution of Trp for Arg19 (R19W) and of G1n for His54 (H54Q) in mature vWF, respectively. This allele also contains a reported polymorphism (A2365G, Thr26Ala). Allele B, which is underexpressed at the RNA level, contains a one-nucleotide deletion in the FVIII-binding domain (delta G2515) that results in the premature termination of translation. Analysis of the binding of FVIII by full-length vWF transiently expressed in COS-7 cells confirms that the combined R19W and H54Q substitutions are the cause of the defective vWF/FVIII interaction in this patient. The FVIII-binding defect of vWF containing either mutation alone is approximately half that of the double mutant, which suggests that the effect of these mutations is additive. The mutant proteins are recognized equally well by vWF monoclonal antibodies MBC105.4, 32B12, and 31H3, which block the binding of FVIII by vWF, indicating that amino acids Arg19, Thr26, and His54 are not critical residues in the epitopes of these antibodies.

Phenotypic correction of activated protein C resistance following orthotopic liver transplantation

A 43-year-old white female underwent orthotopic liver transplantation in 1992 for cirrhosis related to primary sclerosing cholangitis. Pre-transplantation protein S (PS) studies revealed a discrepancy between PS activity and free PS antigen consistent with type II PS deficiency. Since the presence of activated protein C (APC) resistance has been reported to interfere with PS activity assays resulting in an apparent type II PS deficiency, we retrospectively tested a pre-transplantation frozen plasma sample for APC resistance. The sample was found to have an abnormal APC resistance ratio (APCR-R) of 1.71. Follow up testing 2 1/2 years post-transplantation revealed correction of the APC resistance phenotype (normalization of the APCR-R to 2.79). Analysis of DNA extracted from lymphocytes revealed the patient to be heterozygous for the FV mutation associated with APC resistance (FV Leiden). Hereditary APC resistance was confirmed by family studies which revealed the presence of APC resistance and heterozygous FV Leiden in her son. Although the patient's post-transplantation plasma FV is normal, her platelet FV remains heterozygous for FV Leiden. To what extent, if any, platelet FV Leiden in the absence of plasma FV Leiden may contribute to a predisposition to thrombosis is unknown.

A perspective on the use of FVIII concentrates and cryoprecipitate prophylactically in surgery or therapeutically in severe bleeds in patients with von Willebrand disease unresponsive to DDAVP: results of an international survey. On behalf of the Subcommittee on von Willebrand Factor of the Scientific and Standardization Committee of the ISTH

An international registry was established by the Subcommittee on von Willebrand Factor of the SSC/ISTH on the treatment of patients with types of von Willebrand disease (vWD) unresponsive to DDAVP infusion. Data was collected on 76 surgical events in 64 patients from 19 treatment centers. Thirty-three non-mucosal, 12 mucosal, 10 orthopedic and 21 dental procedures were reported. In the 76 surgical events, 14 cases prophylactically received cryoprecipitate while 62 received factor VIII (FVIII) concentrate. Surgical hemostasis was reported as satisfactory, good, or excellent in 75 of the 76 cases. Post-infusion bleeding times were measured in only three of 14 surgical events treated with cryoprecipitate. All three cases had a reduction but not correction of the bleeding time. The post-infusion bleeding time was measured in 27 of 62 cases in which FVIII concentrates were used. The bleeding time time was normalized in 15, reduced but not normalized in eight, and not changed from baseline in four. Data was also collected from 16 treatment centers on 50 serious bleeding events in 35 patients. These included 19 gastrointestinal, 15 other mucosal, four central nervous system, seven orthopedic, and five other mucosal, four central nervous system, seven orthopedic, and five other bleeds. Eleven cases received cryoprecipitate and 39 received FVIII concentrate as primary therapy. The efficacy of treatment was considered good or excellent in 49 of 50 cases. Post-infusion bleeding times were measured in only 15 of the 50 reported bleeding events. The post-infusion bleeding time was normalized in six, decreased but not normalized in eight, and not changed from baseline in one. In this retrospective survey, FVIII concentrates were subjectively as efficacious as cryoprecipitate in both the surgical setting and for the treatment of severe bleeds in patients with types of vWd unresponsive to DDAVP. Since the bleeding time was monitored during therapy in only a minority of these cases, a definitive relationship between the efficacy of therapy and normalization or reduction of the bleeding time in these two clinical settings cannot be established from this study. A prospective study on the use of FVIII and/or vWf concentrates in these clinical settings is necessary to address this issue.

Activated protein C resistance in a neonate with venous thrombosis

A term infant had a life-threatening inferior venal caval thrombosis during the first 24 hours of life. The plasma from the infant and his mother was found to be resistant to activated protein C and to be heterozygous for the factor V mutation (FV Leiden) associated with this disorder. The presence of this hereditary disorder should be considered in infants with thrombosis and in infants with conditions predisposing them to thrombosis.

The polymerase chain reaction with sequence specific primers for the detection of the factor V mutation associated with activated protein C resistance

The prevalence of the Factor V (FV) mutation associated with activated protein C resistance (FV Leiden) and its significance as a genetic risk factor for venous thrombosis have necessitated the development of a simple, rapid, and accurate assay for its detection. The polymerase chain reaction with sequence specific primers (PCR-SSP) provides a powerful technique for the discrimination of alleles resulting from single base substitutions. PCR amplification was performed using a sense primer complementary to both FV alleles coupled with either of two antisense allele specific primers, one complementary to the normal FV allele and one complementary to the FV Leiden allele. PCR conditions were developed that favored amplification only in the case of perfect complementation between template DNA and allele specific primer. The FV genotype was assigned based on whether or not each allele specific primer set produced an amplified product. Assignment of genotypes correlated 100% with those determined by the method of PCR amplification followed by Mn1I digestion. PCR-SSP allows the rapid and accurate identification of carriers of the Factor V Leiden mutation by a simple PCR reaction without the need for the usual post-amplification specificity step.

The reproductive health of women with von Willebrand Disease unresponsive to DDAVP: results of an international survey. On behalf of the Subcommittee on von Willebrand Factor of the Scientific and Standardization Committee of the ISTH

An international registry was established on the reproductive health of women with types of von Willebrand disease (vWd) unresponsive to DDAVP. Data was collected on 44 women from 16 treatment centers in nine countries. Severe menorrhagia requiring blood product therapy occurred at least once in 80% of the women for whom data was reported. Most of the reported episodes occurred prior to the diagnosis of vWd and/or the use of oral contraceptive (OC) therapy. OC therapy was clinically effective in the treatment of chronic menorrhagia in 22 of 25 (88%) women treated. Two of the women, however, were unable to tolerate chronic OC use and a third became refractory to treatment. Hysterectomy was performed in 10 of the 44 women (23%). The reported indication for six of the procedures was menorrhagia. Seventy percent were performed at two treatment centers, suggesting different thresholds for the performance of the procedure. There were 69 pregnancies reported in 31 of the 44 women. Fifteen of the pregnancies resulted in spontaneous abortions. The incidence of miscarriage was 22% and appeared clustered, with 10 of 15 of the miscarriages occurring in just four of the women.

School-based clinics: overcoming the obstacles

Obstacles to the establishment of school-based clinics are investigated to determine possible strategies for the future. The current social environment necessitates a health care model that provides increased access and improved outcomes for children in particular. The advanced registered nurse practitioner is an integral part of the school-based clinic. Although opposition to school-based clinics has been well organized in the past, proponents are learning new ways to deal with this challenge.

Low dose epidural lidocaine/sufentanil is effective for outpatient lithotripsy

Lumbar epidural analgesia was administered to 60 ASA class 1 & 2 patients with 3 ml test dose of 1.5% lidocaine and bolus of 20 ml of 0.5% lidocaine containing 0.5 microgram/kg sufentanil. Bilateral decreased lumbar cold perception was accepted as evidence of analgesia despite persisting pinprick sensation in thoracic dermatomes. Oxygen saturation (SpO2), respiratory rate, cardiovascular parameters and leg muscle strength were monitored throughout and until 1 hour afterwards. Midazolam provided light sedation and atropine bradycardia control. Verbal communication was maintained. ESWL could start within 6-10 minutes of bolus, with analgesia adequate in 86% of patients, the rest being "rescued" with 5-10 ml 0.5% lidocaine or analgesic doses (20-30 mg IV) of ketamine. Leg weakness developed in 14%, with 1 patient fully paralyzed. All resolved within 1 hour. Topical urethral analgesia was used in males where cystoscopy preceded ESWL. Phenylephrine was required once for nild systolic hypotension, otherwise blood pressures were stable. Two of 4 patients experiencing pruritus needed naloxone relief. Itching appeared in skin recovering from sensory block while visceral analgesia persists. Excessive respiratory depression was not seen.

Monophosphoryl lipid A protects against endotoxic shock via inhibiting neutrophil infiltration and preventing disseminated intravascular coagulation

The major objective of the present study was to determine the effects of a partial structure of the lipid A moiety of gram-negative lipopolysaccharide, monophosphoryl lipid A (MLA), on endotoxin-induced mortality and disseminated intravascular coagulation (DIC) in rats. A second objective was to examine the role of polymorphonuclear neutrophil invasion to visceral organs, including lung, liver, heart, and kidney in the pathogenesis of the compromised multiorgan function which occurs in endotoxic shock. Finally, a third aim was to determine if the potential protective effects of MLA might be mediated via inhibiting neutrophil invasion to various visceral organs. Male Sprague-Dawley rats (220-260 g) were fasted over night and used the following day. In control rats, endotoxin (S. abortus equi LPS, 15 mg/kg, i.v.) produced a 89% mortality at 48 hr following its administration, and gross pathological and laboratory signs of DIC at 3 hr after injection. The latter included increased serum fibrin(ogen) degradation products (FDP, 24.00 +/- 7.81 vs. 0 micrograms/ml, P < .05), prothrombin time (PT, 16.20 +/- 1.12 vs. 13.03 +/- 0.20 sec, P < .05), and activated partial thromboplastin time (APTT, 32.70 +/- 3.83 vs. 20.11 +/- 0.60 sec, P < .05), and decreased plasma fibrinogen (233.2 +/- 41.6 vs. 406.3 +/- 23.2 mg/dl, P < .05) as well as evidence of gross visceral hemorrhage. Pretreatment with MLA (5 mg/kg) for 24 hr produced a marked reduction in endotoxin-induced mortality at 48 hr (0% versus 89% in controls) and inhibited all of the manifestations of DIC produced by endotoxin.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of combined estrogen/progestogen treatment in women with hyperprolactinemic amenorrhea

Eleven women with hyperprolactinemic amenorrhea were treated with a combined estrogen/progestogen preparation (Loestrin 30) for 3 months as hormone replacement therapy because of estrogen deficiency, with a view to protection against osteoporosis. Serum prolactin levels rose during the 1st month of treatment (p < 0.05) but did not rise significantly further during the 2nd and 3rd months. The levels rose in proportion to pretreatment levels by 28% (median), and fell significantly but not completely during the 1-week treatment-free intervals. After the study period, prolactin values appeared to remain stable in those women who continued longer on treatment, and returned to around pretreatment values in those who stopped. In one woman there was radiological evidence of pituitary tumor growth during treatment. This study shows that estrogen/progestogen treatment in standard contraceptive dosage usually leads to only moderate and non-progressive stimulation of pituitary activity in women with hyperprolactinemic amenorrhea, but occasional excessive growth of a prolactinoma can occur and treatment needs to be monitored. Women with relatively high prolactin levels seem to be at particular risk. Safer variations of estrogen therapy such as lower dosage or combination with a protective low dose of a dopamine agonist should also be considered.

Fine mapping of monoclonal antibody epitopes on human von Willebrand factor using a recombinant peptide library

A recombinant human von Willebrand factor (vWF) cDNA fragment library was constructed in lambda gt11 for the localization of anti-vWF monoclonal antibody epitopes. Twelve of 21 monoclonal antibodies screened identified epitopes expressed in lambda gt11 as beta-galactosidase fusion proteins. By sequence analysis, these antigenic determinants were localized to segments ranging from 17 to 105 amino acids in length. Four epitopes apparently shared by more than one antibody were identified, suggesting the presence of immuno-dominant epitopes within vWF. Monoclonal antibody C3, which blocks factor VIII (FVIII) binding to vWF, bound to the same epitope previously identified by a second monoclonal antibody which also blocks this function, suggesting that this region may be at or near the vWF/FVIII binding domain. Three antibodies recognize the same region within the vWF A2 repeat. Mutations near this region appear to be responsible for Type IIA von Willebrand's disease. The co-localization of these antibodies suggests that this domain might be exposed on the surface of vWF, consistent with its apparent increased sensitivity to plasma proteases.

A synthetic factor VIII peptide of eight amino acid residues (1677-1684) contains the binding region of an anti-factor VIII antibody which inhibits the binding of factor VIII to von Willebrand factor

The monoclonal anti-factor VIII (FVIII) antibody C4 has previously been reported to inhibit the binding of purified FVIII to immobilized von Willebrand factor (vWF). The binding area of C4 was identified to be within fifteen amino acid residues (1670-1684) based on the ability of a synthetic FVIII peptide consisting of amino acid residues 1670-1684 to completely inhibit the binding of C4 to FVIII. We now report the further localization of the binding region of C4 to within eight amino acid residues (1677-1684) of FVIII light chain. Nine new overlapping FVIII peptides were synthesized based on the amino acid sequence of the acidic region of FVIII light chain and tested, along with seven previously tested peptides, for the ability to inhibit C4 binding to FVIII in an ELISA assay. Three synthetic FVIII peptides 1670-1684, 1675-1690, and 1677-1684 demonstrated dose dependent inhibition of C4 binding to FVIII. The three reactive peptides contain residues 1677-1684 in common. Since C4 can completely inhibit the binding of FVIII to vWF, this report further localizes an eight amino acid residue region of FVIII which may be important in the mediation of vWF binding.

Synthetic factor VIII peptides with amino acid sequences contained within the C2 domain of factor VIII inhibit factor VIII binding to phosphatidylserine

The effective activation of factor X by factor IXa requires the co-factor activity of activated factor VIII (FVIII). Factor Xa formation is also dependent on the presence of negatively charged phospholipid. A phospholipid binding domain of FVIII has been reported to be present on the FVIII light chain. Recent observations on a subset of human FVIII inhibitors have implicated the carboxyl-terminal C2 domain of FVIII as containing a possible phospholipid binding site. The purpose of this study was to investigate directly the role of the C2 domain in phospholipid binding. Twenty-six overlapping peptides, which span the entire C2 domain of FVIII, were synthesized. The ability of these peptides to inhibit the binding of purified human FVIII to immobilized phosphatidylserine was evaluated in an enzyme-linked immunosorbent assay. Three overlapping synthetic FVIII peptides, 2303-2317, 2305-2332, and 2308-2322, inhibited FVIII binding to phosphatidylserine by greater than 90% when tested at a concentration of 100 mumols/L. A fourth partially overlapping peptide, 2318-2332, inhibited FVIII binding by 65%. These results suggest that the area described by these peptides, residues 2303 to 2332, may play an important role in the mediation of FVIII binding to phospholipid.

A murine monoclonal anti-factor VIII inhibitory antibody and two human factor VIII inhibitors bind to different areas within a twenty amino acid segment of the acidic region of factor VIII heavy chain

The factor VIII (FVIII) binding regions of the monoclonal anti-FVIII inhibitory antibody C5 and a human FVIII inhibitor antibody have previously been reported to be contained within amino acid residues 351-365 of FVIII. Localization of the binding regions of these two antibodies was based on their reactivity with four synthetic FVIII peptides. Nineteen synthetic FVIII peptides spanning the entire acidic region of the FVIII heavy chain have now been evaluated for the ability to inhibit the binding of C5 to FVIII in an ELISA assay. The smallest peptide tested that inhibited C5 binding to FVIII consisted of residues 351-361. Those peptides that were able to inhibit C5 binding in the ELISA assay were also able to neutralize the FVIII inhibitory activity of C5 in plasma. The FVIII inhibitory activity of two human FVIII inhibitor antibodies was also partially neutralized by peptides from this region. Evaluation of the pattern of peptides reactive with the three antibodies indicates that the binding regions of these antibodies are in very close proximity to each other, but are not identical. Their respective binding regions are contained within residues 351-361 (C5), 354-362 (inhibitor 1), and 342-354 (inhibitor 2). These results suggest that this 20 amino acid segment of the acidic region of the heavy chain of FVIII may be functionally important in the expression of FVIII procoagulant activity.

Factor VIII structure and function

The relatively recent ability to obtain highly purified factor VIII (FVIII) preparations from plasma products, the cloning of the FVIII gene, and the expression of recombinant FVIII have provided the basis for significant advancements in the understanding of the structure-function relationships of FVIII. Evaluation of the molecular structure of FVIII has revealed the presence of domains of significant internal amino acid sequence homology as well as homology with similar structural domains of factor V. Specific proteolytic cleavage sites have been identified in the molecule and the use of site directed mutagenesis has identified those proteolytic cleavage sites required for the activation of FVIII. Deletion and substitution variants of FVIII as well as the precise epitope mapping of FVIII antibodies which inhibit the procoagulant function of the protein or its binding to von Willebrand factor have provided insight into the identification of regions of FVIII which are required for normal function.

Effect of bladder filling on embryo transfer

We have investigated a claim that bladder filling, by straightening an anteverted uterus into line with the vagina, might facilitate embryo transfer through the cervix after in vitro fertilization. In a randomized controlled trail in 66 women with and 76 without a filled bladder, we found no significant differences in difficulties encountered at embryo transfer or in the chance of pregnancy.

Localization of the binding regions of a murine monoclonal anti-factor VIII antibody and a human anti-factor VIII alloantibody, both of which inhibit factor VIII procoagulant activity, to amino acid residues threonine351-serine365 of the factor VIII heavy chain

We have localized the binding region of a previously described monoclonal anti-factor VIII (FVIII) inhibitory antibody (C5) to amino acid residues Thr351-Ser365 of the thrombin-generated 54-kD fragment of the heavy chain of FVIII. Synthetic FVIII peptides were examined for the ability to competitively inhibit the binding of C5 to FVIII in an ELISA system. The synthetic FVIII peptide Thr351-Ser365 blocked C5 binding to FVIII in a dose-dependent manner in this system. Two other synthetic FVIII peptides, Asn340-Glu354 and Glu342-Asp356, which partially overlapped Thr351-Ser365, also blocked C5 binding to FVIII. Blocking of C5 binding with these peptides, however, required much greater concentrations (greater than 100 times stronger) than that required for Thr351-Ser365. The Thr351-Ser365 peptide also neutralized the FVIII inhibitory activity of C5 in plasma. A human FVIII inhibitor (anti-FVIII heavy chain alloantibody) was also partially neutralized by Thr351-Ser365. Thr351-Ser365 lies between a thrombin cleavage site (Arg372) and an activated protein C cleavage site (Arg336) and may be at or near a region of functional importance in the expression of FVIII procoagulant activity.

An immunogenic region within residues Val1670-Glu1684 of the factor VIII light chain induces antibodies which inhibit binding of factor VIII to von Willebrand factor

We have identified a monoclonal anti-factor VIII (FVIII) antibody, C4, which inhibits the binding of purified human FVIII to purified human von Willebrand factor (vWF). Both whole immunoglobulin C4 and its Fab fragment demonstrated dose-dependent inhibition of FVIII binding to vWF immobilized on the surface of polystyrene beads. Synthetic peptides based on the amino acid sequence of FVIII were tested for the ability to block the binding of C4 to FVIII in an enzyme-linked immunosorbent assay system. A single synthetic FVIII pentadecapeptide, consisting of residues Val1670-Glu1684, was able to inhibit C4 binding to FVIII. Under the conditions used, the Val1670-Glu1684 peptide demonstrated total inhibition of C4 binding at a concentration of 1 microM. Synthetic FVIII peptides flanking and overlapping the Val1670-Glu1684 peptide had no significant inhibitory activity on C4 binding in concentrations up to 100 microM. A polyclonal antibody made to the Val1670-Glu1684 peptide also demonstrated inhibition of FVIII binding to vWF. Polyclonal antibodies made to synthetic FVIII peptides flanking and partially overlapping the Val1670-Glu1684 sequence did not demonstrate such inhibition. Localization of the binding region of the monoclonal anti-FVIII antibody C4 to residues Val1670-Glu1684 suggests that this site is at, or near, a major vWF binding domain of FVIII.

The use of propofol in a group of older patients undergoing oesophagoscopy

Propofol (Diprivan; Stuart) a new, very short-acting intravenous anaesthetic agent, was tested in its aqueous emulsion formulation. Used as an induction and maintenance agent, its anaesthetic properties, dosage requirements and side-effects were compared with those of thiopentone in 40 American Society of Anesthesiologists class I and II patients scheduled for routine oesophagoscopy. Both heart rate and diastolic blood pressure were more stable in the propofol group, and recovery times were significantly shorter. Patients were remarkably clear-headed after propofol. When the quality of anaesthesia was independently assessed by an anaesthetist and a surgeon, propofol was rated good or satisfactory in all subjects, and thiopentone in 80%. Anaphylactoid reactions associated with the previous Cremophor EL formulation were not encountered, and pain on injection was experienced in 10% of propofol subjects as against 5% who received thiopentone. This new intravenous agent produces safe and predictable anaesthesia followed by rapid recovery, making it especially suitable for outpatient anaesthesia.

Propofol in total intravenous anaesthesia without nitrous oxide

Propofol and methohexitone were evaluated as hypnotics in a total intravenous anaesthesia technique without nitrous oxide in 50 patients of ASA grade 1 or 2. Analgesia was provided by a constant alfentanil infusion and the depth of anaesthesia was controlled by varying the infusion rate of propofol or methohexitone. Induction and intubation responses were smooth and moderate in the propofol group and side effects were few. Control of depth of anaesthesia, blood pressure and pulse rate was relatively easy in this group but more difficult and sometimes inadequate in the methohexitone group, in which side effects were more frequent. The mean infusion rate for propofol was 0.12 mg/kg/minute, similar to those found in studies using nitrous oxide without an opioid. Recovery times were short in both groups but those in the propofol group tended to be shorter. Postoperatively 96% of the propofol patients were clear-headed within 20 minutes, in contrast to only 48% in the methohexitone group. We conclude that propofol together with alfentanil, both given by a bolus plus infusion technique, provide controllable and satisfactory total intravenous anaesthesia without recourse to nitrous oxide or other inhalational agents. Methohexitone was not as satisfactory as propofol.

A major factor VIII binding domain resides within the amino-terminal 272 amino acid residues of von Willebrand factor

We have identified a Factor VIII (FVIII) binding domain residing within the amino-terminal 272 amino acid residues of the mature von Willebrand Factor (vWF) subunit. Two-dimensional crossed immunoelectrophoresis showed direct binding of purified human FVIII to purified human vWF. After proteolytic digestion of vWF with Staphylococcus aureus V8 protease (SP), FVIII binding was seen only with the amino-terminal SP fragment III and not with the carboxyl-terminal SP fragment II. A monoclonal anti-vWF antibody (C3) partially blocked FVIII binding to vWF and SP fragment III. FVIII also bound to vWF which had been adsorbed to polystyrene beads. This binding was inhibited in a dose-dependent manner by whole vWF, SP fragment III, and by monoclonal antibody C3. Binding could not be inhibited by SP fragment I, which contains the middle portion of the vWF molecule, or by reduced and alkylated whole vWF. SP fragment II caused only minimal inhibition. Trypsin cleavage of SP fragment III produced a monomeric 35-kDa fragment containing the amino-terminal 272 amino acid residues of vWF. This fragment reacted with monoclonal antibody C3 and inhibited the binding of FVIII to vWF in a dose-dependent manner. These studies demonstrate that a major FVIII binding site resides within the amino-terminal 272 amino acid residues of vWF.

Norethisterone treatment to control timing of the IVF cycle

The use of norethisterone to control the timing of the preceding menstrual cycle and in consequence the timing of the in-vitro fertilization (IVF) cycle has been evaluated in a therapeutic IVF programme in which oocyte recovery was limited to 2 days each week. A consecutive series of 181 cycles after norethisterone and 29 untreated controls were compared. Menstruation occurred 2-3 days after norethisterone as planned in 82% of patients overall and in 87% of patients whose menstrual cycle length varied by no more than 2 days about the median. Norethisterone treatment did not significantly affect the outcome of IVF treatment compared with the controls in respect to cycles abandoned (12 versus 0%, respectively), peak follicular diameter (mean 18.1 mm versus 18.3 mm 48 h before laparoscopy), oocyte recovery rate (4.6 versus 4.5 per patient), oocyte morphology (63% versus 52% mature), or fertilization rate (72 versus 65% of mature oocytes). Clinical pregnancies were too few for comparison (rates 27 versus 9% per laparoscopy) but the overall rate (23%) indicated effectiveness of the methods. Prior norethisterone treatment appears to be an effective and useful means of controlling the timing of the oocyte recovery in IVF treatment.

Population study of causes, treatment, and outcome of infertility

Specialist infertility practice was studied in a group of 708 couples within a population of residents of a single health district in England. They represented an annual incidence of 1.2 couples for every 1000 of the population. At least one in six couples needed specialist help at some time in their lives because of an average of infertility of 21/2 years, 71% of whom were trying for their first baby. Those attending gynaecology clinics made up 10% of new and 22% of all attendances. Failure of ovulation (amenorrhoea or oligomenorrhoea) occurred in 21% of cases and was successfully treated (two year conception rates of 96% and 78%). Tubal damage (14%) had a poor outlook (19%) despite surgery. Endometriosis accounted for infertility in 6%, although seldom because of tubal damage, cervical mucus defects or dysfunction in 3%, and coital failure in up to 6%. Sperm defects or dysfunction were the commonest defined cause of infertility (24%) and led to a poor chance of pregnancy (0-27%) without donor insemination. Obstructive azoospermia or primary spermatogenic failure was uncommon (2%) and hormonal causes of male infertility rare. Infertility was unexplained in 28% and the chance of pregnancy (overall 72%) was mainly determined by duration of infertility. In vitro fertilisation could benefit 80% of cases of tubal damage and 25% of unexplained infertility--that is, 18% of all cases, representing up to 216 new cases each year per million of the total population.