Constructing information booklets for day-case patients

As modern surgical and anaesthetic techniques develop even greater capabilities, the time in which to adequately undertake such nurse/patient discussions has past and will never return. Information provision is thus a challenge for day surgery. Many studies have suggested patients require differing levels of information i.e. full, partial and minimal disclosure. Future information booklets may need to be constructed in a more patient centred manner. This article attempts to provide a methodical approach to the required level of information, a guide to the construction of information booklets and suggestions for their application in day surgery.

Life and evolution in computers

This paper argues for the possibility of 'artificial life' and computational evolution, first by discussing (via a highly simplified version) John von Neumann's self-reproducing automation and then by presenting some recent work focusing on computational evolution, in which 'cellular automata', a form of parallel and decentralized computing system, are evolved via 'genetic algorithms'. It is argued that such in silico experiments can help to make sense of the question of whether we can eventually build computers that are intelligent and alive.

Is uterine papillary serous adenocarcinoma a manifestation of the hereditary breast-ovarian cancer syndrome?

BACKGROUND

Uterine papillary serous carcinoma (UPSC) shares common pathologic, genetic, and clinical features with other serous cancers of müllerian origin. The most common histologic type of ovarian tumor associated with BRCA mutations is papillary serous. Because of these histologic similarities, we postulated that, in some cases, UPSC may be a manifestation of a field defect in BRCA1 carriers, which also includes ovarian carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma.

METHODS

Fifty-six living patients with UPSC were contacted through their treating physicians and agreed to a family history interview and to provide a blood specimen for BRCA testing. The protein truncation test was used to detect mutations in exons 10 and 11 of BRCA1 and in exon 11 of BRCA2. The presence of four common mutations was assessed by PCR-based specific assays.

RESULTS

A high proportion of patients had a past history of breast cancer (11%) or a first-degree relative with breast cancer (29%). Four patients were from families with site-specific hereditary breast cancer. However, there was no clear example of the hereditary breast-ovarian cancer syndrome, and none of the 56 patients was found to carry a BRCA1 or BRCA2 mutation.

CONCLUSIONS

BRCA mutations do not appear to predispose to UPSC and this type of cancer does not appear to be a manifestation of the classical hereditary breast-ovarian cancer syndrome. The observed association between UPSC and breast cancer may be due to the presence of mutations in other cancer predisposing genes.

Long-term gene transfer to mouse fetuses with recombinant adenovirus and adeno-associated virus (AAV) vectors

We have developed a micro-injection technique to deliver recombinant adenovirus and AAV to mouse fetuses at day 15 after conception. Several routes of delivery, including injections to the amniotic fluid, the front limb, the placenta, the liver, and the retro-orbital venus plexus, were tested using an E1-deleted recombinant adenovirus (Ad.CBlacZ) or a recombinant adeno-associated virus (AAV.CMVlacZ) carrying a beta-galactosidase (lacZ) gene. Injection of Ad.CBlacZ into the amniotic cavity led to transgene expression in the skin and in the digestive tract of the fetuses. Injection of Ad.CBlacZ in the front limb resulted in LacZ expression in all major muscle groups around the injection site and at low levels in the liver. The other three routes of delivery, ie intra-placental, intra-hepatic and retro-orbital injections of Ad.CBlacZ, all led to lacZ expression predominantly in the liver. Further studies revealed a maximal tolerant dose (defined as the highest viral dose with < or =20% mortality in the injected fetuses) of 1 x 10(9) particles per fetus for intra- hepatic injections, 3 x 10(9) particles per fetus for intra-placental injection, 1 x 1010 particles per fetus for retro-orbital and intra-amniotic injections, and 2 x 10(10) particle per fetus for intra-muscular injection. The adenovirus-mediated lacZ expression in liver and muscle persisted for at least 6 weeks. Intra-muscular injection of AAV.CMVlacZ also resulted in lacZ expression in the muscle up to 3 months after birth with no indication of cellular immune response at the injection site. Taken together, our results demonstrated that prolonged transgene expression can be achieved by in utero gene transfer using either adenoviral or AAV vectors. The distribution of virus-mediated gene transfer appeared to determined mostly by the route of viral administration.

What genetic advances might mean for the consumer in mental illness

OBJECTIVE

Increased research efforts into screening young people at risk of schizophrenia is anticipated. The aim of the present paper is to consider the ethical concerns raised by this research from a consumer's perspective.

METHOD

Insights into relevant ethical concerns obtained from personal experiences of psychotic illness are described.

RESULTS

A range of salient ethical issues were identified that need to be addressed in research proposals regarding the screening of people for schizophrenia risk factors.

CONCLUSIONS

The importance of research into the development of screening procedures for schizophrenia risk factors suggests that the ethical issues identified need urgent attention. Consumer input is essential in this endeavour.

Hair pulling in African Americans--only your hairdresser knows for sure: an exploratory study

The authors examined whether African American hair care professionals saw individuals who met general criteria for trichotillomania, chronic hair pulling that results in significant hair loss. Thirty-eight African American hair care professionals and 1 Caucasian hair care professional were interviewed about their customers' hair-pulling behavior and condition of their hair. Sixteen African American hair care professionals saw 21 individuals who met general criteria for trichotillomania and reportedly perceived the behavior to be problematic. Four African American hair care professionals saw 6 individuals who met general criteria for trichotillomania but did not reportedly perceive the behavior to be problematic. Hair care professionals attributed most customers' hair-pulling behavior to bad nerves, stress, habit, and worry. Hair care professionals appeared adept at treating the consequences of chronic hair pulling but offered little assistance for the actual pulling behavior. Hair care professionals' contact with individuals who engage in chronic hair pulling raises interesting implications for prevention.

Conservation of PCDHX in mammals; expression of human X/Y genes predominantly in brain

Protocadherins are members of the cadherin superfamily involved in cell-cell interactions critical in the development of the central nervous system. This paper describes the isolation, sequence, and expression analysis of two novel protocadherin genes from the hominid specific Yp11.2/Xq21.3 block of homology between the sex chromosomes. The X-(PCDHX) and Y-linked (PCDHY) genes share 98.1% nucleotide and 98.3% amino acid identity and have an identical gene structure of six exons. The open reading frames of PCDHX and PCDHY encode proteins of 1025 and 1037 amino acids respectively and specify seven extracellular cadherin domains. Small differences in amino acid sequence affect regions that potentially have a large impact on function: thus, the X and Y genes may be differentiated in this respect. Sequence analysis of cDNA clones shows that both the X and Y loci are transcribed. RT-PCR expression analysis of mRNA from a variety of tissues and cell lines has demonstrated that both transcripts are expressed predominantly in the brain, with differential regional expression. From studies in the NTERA pluripotential cell line (which differentiates along neuronal and spermatogenic pathways in response to retinoic acid), it emerges that the X and Y-linked genes are regulated differently. This indicates that PCDHX and PCDHY possess different promoter regions. These findings suggest a role for PCDHX and PCDHY in the brain, consistent with the involvement of protocadherins in segmental brain morphogenesis and function. The implications of Y-linked genes expressed predominantly in tissues and organs other than the testis are considered within the context of the concept of sexual selection.

Management of patients with suspected deep vein thrombosis in the emergency department: combining use of a clinical diagnosis model with D-dimer testing

The management of patients presenting to hospital Emergency Departments with suspected deep vein thrombosis is problematic since urgent diagnostic imaging is at times unavailable. We evaluated the accuracy of a rapidly available D-dimer test and the potential of combining D-dimer testing with an explicit clinical model to improve the management of patients with suspected deep vein thrombosis. Two hundred and fourteen patients with suspected deep vein thrombosis presenting to the Emergency Departments of two tertiary care institutions were enrolled in this prospective cohort study. Patients were evaluated by an Emergency Physician who determined the pre-test probability for deep vein thrombosis to be either low, moderate, or high using an explicit clinical model. Patients were managed according to their pre-test probability category by specific algorithms that in all cases included venous ultrasound imaging within 24 h and a 90-day follow-up for the development of thromboembolic complications. Patients also underwent fingerstick SimpliRED(R) whole blood agglutination D-dimer testing; however, D-dimer results did not influence subsequent patient management. D-dimer had a sensitivity of 82.5% and a specificity of 84.9% for the diagnosis of deep vein thrombosis. The observed negative predictive value of D-dimer was 96.9% (95% CI, 93.0% to 99.1%) overall, and 100% (95% CI, 96.3% to 100%) in low probability patients, 94.1% (95% CI, 83.8% to 98.8%) in moderate probability patients, and 86.7% (95% CI, 59.4% to 98.3%) in high probability patients. SimpliRED(R) D-dimer has a high negative predictive value and may be useful in excluding the diagnosis in patients at low pre-test probability for deep vein thrombosis.

Responsibility for controlled drugs in operating departments

The difficulties experienced with the recruitment and retention of registered nurses has made it necessary for NHS trusts to review the traditional role of nurses and to transfer some of their duties to other groups of staff in order to maintain services. For example, in the operating department, operating department assistants and operating department practitioners (ODAs/ODPs) are undertaking some of the duties that were previously the responsibility of nurses. This article presents the findings of a survey to determine the extent to which ODAs/ODPs have access to controlled drugs in operating theatres. The survey was initially undertaken by the author in Welsh hospitals during 1998. The mixed responses generated discussion in the Duthie Review Committee (Committee Chairman, personal communication, Royal Pharmaceutical Society of Great Britain (RPSGB), 1999) and led to a collaborative exercise based on a random selection of NHS trust hospitals in England, Scotland and Northern Ireland to obtain a broader data across the UK. Despite a clear legal position concerning possession, the survey showed that practice varied widely and that some trusts may be contravening the Misuse of Drugs Regulations 1985 in order to keep the service running when registered nurses are not available.

Glucocorticoid-induced osteopenia in adolescent heart transplant recipients

BACKGROUND

Glucocorticoid-induced cushingoid symptoms, including osteopenia and osteoporosis are well-documented in adult heart transplant recipients (HTR). Bone mineral density (BMD) of the axial skeleton is diminished by 10% to 20% within 60 days after transplantation (Tx) and most adult HTR fulfill World Health Organization criteria for osteoporosis (BMD > 2.5 SD below norm). At present, we do not know whether glucocorticoids have similar deleterious effects in adolescent HTR.

METHODS

To determine the consequences of glucocorticoid immunosuppression on regional bone mineral density (BMD) and biochemical markers of bone metabolism in adolescent HTR, we studied 19 patients (aged 16 +/- 3) at 19 months (group mean) after Tx. We measured BMD (hydroxyapatite g/cm(2)) of the total body, lumbar spine, and pelvis using dual-energy X-ray absorptiometry (Lunar). Serum levels of bone-specific alkaline phosphatase and pyridinoline cross-links were determined by enzyme immunoassay in serum kits.

RESULTS

The BMD of the lumbar spine (-12%), femur neck (-13%), femur trochanter (-12%), and ward's triangle (-16%) were significantly (p < 0.05) lower in adolescent HTR than age- and gender-matched norms. Serum levels of alkaline phosphatase (29 +/- 6 vs 22 +/- 3 U/liter) and pyridinoline cross-links (5.3 +/- 1.1 vs 3.8 +/- 0.7 mmol/liter) were significantly (p < 0.05) elevated in adolescent HTR, compared with age- and gender-matched controls studied in our laboratory.

CONCLUSIONS

Our cross-sectional results demonstrate that BMD of the axial skeleton in adolescent HTR is significantly lower (-10% to 20%) than age-matched norms and that serum biochemical markers of bone metabolism are significantly elevated, suggesting accelerated bone turnover.

Review article: The molecular era of bladder research. Transgenic mice as experimental tools in the study of outlet obstruction

PURPOSE

To review the crucial role of transgenic mice as experimental tools in the study of outlet obstruction.

MATERIALS AND METHODS

We reviewed the literature for studies that have used mice as models for outlet obstruction.

RESULTS

The combination of genetic manipulations and cellular physiology defines state-of-the-art experiments that explore the reciprocal mesenchymal-epithelial interactions that regulate bladder cell mechanisms.

CONCLUSIONS

The use of transgenic mice in bladder research has provided important data with respect to the molecular signals that drive bladder development, homeostasis, and the response to injury.

Comparison of manual versus ambulatory blood pressure measurements with pharmacokinetic-pharmacodynamic modeling of antihypertensive compounds: application to moxonidine

OBJECTIVES

To compare the results of the pharmacokinetic-pharmacodynamic analyses of 24-hour ambulatory blood pressure measurements and manual blood pressure data in patients receiving moxonidine.

METHODS

32 patients with borderline to mild-to-moderate hypertension were enrolled in a double-blind, placebo-controlled phase II study. After receiving placebo for 1 week (run-in phase), the patients were randomly allocated to the placebo or the 0.6-, 0.9-, or 1.2-mg dose groups. Placebo and moxonidine were administered once daily for 1 week (drug-treatment phase). Four 24-hour ambulatory blood pressure measurement profiles were obtained for each individual. Plasma samples (n = 9) and four measurements of manual blood pressure were taken at the start and end of the drug-treatment phase. Two additional manual blood pressure measurements were taken during the run-in and drug-treatment phases.

RESULTS

Pharmacokinetics was described by a one-compartment model. For the 24-hour ambulatory blood pressure measurements, baseline circadian patterns were described with a two-cosine function model that included interindividual and interoccasion variability. Pharmacodynamics was described with use of an effect-compartment model [k(e0) = 0.37 (1/h)] and an Emax model. For diastolic blood pressure the maximum drug-induced decrease (Emax) was 30.9 mm Hg and the steady-state plasma drug concentration eliciting half of maximum effect (C50) was 1.33 microg/L. Interindividual variability was estimated for ke0 (24.8%) and Emax (33.3%). For the manual blood pressure measurements, data was described by a time-invariant baseline model combined with an effect-compartment model and an Emax model. Mean population estimates were in agreement with those obtained during the analysis of 24-hour ambulatory blood pressure measurements. However, interindividual variability could be estimated for the baseline parameter only.

CONCLUSIONS

Although similar typical population estimates for the drug action-related parameters were obtained with use of manual blood pressure data and 24-hour ambulatory blood pressure measurements, the latter allowed for a more detailed description of the individual pharmacodynamic profiles because interindividual variability in pharmacodynamic parameters could be estimated together with increased precision in parameter estimates.

Rapid genetic diagnosis in neonatal pulmonary artery thrombosis caused by homozygous antithrombin Budapest 3

We report a case of spontaneous left pulmonary artery thrombosis in a 3-day-old male neonate. The presentation of heparin resistance and thrombosis raised the possibility of a type II heparin binding site antithrombin deficiency. A continuous infusion of antithrombin concentrate was used successfully, following failure of plasma, to correct the heparin resistance. Rapid genetic analysis allowed sequencing of the antithrombin gene within 5 working days. This showed the infant to be homozygous for the substitution of C to T at nucleotide 2759. This base change causes mutation of the native leucine at codon 99 to a phenylalanine. This antithrombin variant has been previously reported (antithrombin Budapest 3) and results in reduced binding of heparin to antithrombin. Such a molecular diagnostic approach is feasible and warranted in such cases of neonatal thrombosis because of the diagnostic difficulties encountered.

Anxiety management: a distinct nursing role in day surgery

Improved anaesthetic techniques and the increase in minimal access surgery over the past 20 years has had a considerable impact upon the pattern of nursing care required by the surgical patient. In order to adapt to these changes some day surgery nurses have opted for an extension to their role while the majority have expanded their remit and perform nursing interventions within a multi-skilled role. Amid these changing patterns, the nursing profession has been active in conducting research into best practice concerning day surgery. Consequently, a great deal of information is available regarding areas for possible growth. One possible growth area which is also a vitally important issue for patients prior to day surgery is anxiety management. A future nursing role could involve formal anxiety management implicit within a multi-skilled role and as part of an expanded role. The role possibilities are discussed together with an information provision plan as both are central to the effective handling of pre-operative fears.

c-abl is involved in the association of p53 and trk A

The p53 tumour suppressor phosphoprotein associates with proteins involved in DNA replication, transcription, cell cycle machinery and regulation of its own expression. Recently it has been shown that p53 can also bind to trk A tyrosine kinase which is the receptor for nerve growth factor (NGF). This study demonstrates that p53 appears to associate with trk A via c-abl. Endogenous c-abl was detected when the trk A and p53 complex was immunoprecipitated from lysates of NGF stimulated NIH3T3 cells expressing trk A or NIH3T3 cells expressing trk A and a temperature sensitive p53 (val 135). Endogenous c-abl and trk A association was observed in NGF stimulated p53 negative fibroblasts transfected with trk A alone; suggesting that c-abl can independently bind to trk A in the absence of p53. Interestingly, association between endogenous p53 and trk A was not detected in NGF stimulated abl negative fibroblasts transfected with trk A or when these cells were exposed to gamma radiation. This result suggests that p53 preferentially binds to trk A in the presence of c-abl and that p53 and trk A do not appear to associate directly even if p53 is activated and its levels increased by gamma radiation. Overall, these data suggest that c-abl is possibly acting as an adaptor or bridge between p53 and trk A. Oncogene (2000).

Nursing intervention for pre-operative anxiety

Surgical nursing is changing as the type of surgical procedures being performed are becoming more complex and the time for delivering nursing care is reducing. This has resulted in condensing the acute physical care required into a few hours, often to the detriment of other aspects of nursing intervention such as pre- and post-operative anxiety management. A pre-operative psychological care plan for use in a modern, dynamic, surgical arena is briefly outlined as no such strategy currently exists.

Adduct formation between alkali metal ions and divalent metal salicylaldimine complexes having methoxy substituents. A structural investigation

Sodium, potassium, and cesium salts (iodides, nitrates, acetates, and tetraphenylborates) form 1/1, 1/2 and 2/3 adducts with MLn [M = Co, Ni, Cu, and Zn; n = 1-4; H2L1 = N,N'-(3-methoxysalicyliden)ethane-1,2-diamine; H2L2, H2L3, and H2L4 are the -propane-1,2-diamine, -o-phenylenediamine, and -propane-1,3-diamine analogues of H2L1). Metal salicyladimine, alkali metal, and anion all exert influence on stoichiometry and reactivity. Sodium ions tend to reside within the planes of the salicylaldimine oxygens, as in Na(NO3)(MeOH).NiL4 (1), Na(NO3)(MeOH).CuL1 (2; both with unusual seven-coordinated sodium), and Na.(NiL4)2I.EtOH.H2O (3; with dodecahedral sodium coordination geometry). Potassium and cesium tend to locate between salicylaldimine ligands as in KI.NiL4 (4) and [Cs(NO3).NiL4]3.MeOH (5; structures with infinite sandwich assemblies), CsI.(NiL2)2.H2O (6), CsI3.(NiL4)2 (7; simple sandwich structures), and [K(MeCN)]2.(NiL4)3 (8; a triple-decker sandwich structure). Crystal data for 1 are the following: triclinic, P1, a = 7.3554(6) A, b = 11.2778(10) A, c = 13.562(2) A, alpha = 96.364(10) degrees, beta = 101.924(9) degrees, gamma = 96.809(10) degrees, Z = 2. For 2, triclinic, P1, a = 7.2247(7) A, b = 11.0427(6) A, c = 13.5610(12) A, alpha = 94.804(5) degrees, beta = 98.669(7) degrees, gamma = 99.26(6) Z = 2. For 3, orthorhombic, Pbca, a = 14.4648(19) A, b = 20.968(3) A, c = 28.404(3) A, Z = 8. For 4, triclinic, P1, a = 12.4904(17) A, b = 13.9363(13) A, c = 14.1060(12) A, alpha = 61.033(7) degrees, beta = 89.567(9) degrees, gamma = 71.579(10) degrees, Z = 2. For 5, monoclinic. P2(1)/n, a = 12.5910(2) A, b = 23.4880(2) A, c = 22.6660(2) A, beta = 99.3500(1) degree, Z = 4. For 6, orthorhombic, Pbca, a = 15.752(3) A, b = 23.276(8) A, c = 25.206(6) A, Z = 8. For 7, triclinic, P1, a = 9.6809(11) A, b = 10.0015(13) A, c = 11.2686(13) A, alpha = 101.03 degrees, beta = 90.97 degrees, gamma = 100.55 degrees, Z = 2. For 8, monoclinic, C2/c, a = 29.573(5) A, b = 18.047(3) A, c = 23.184(3) A, beta = 122.860(10) degrees, Z = 8.

Insider/outsider partnerships in an ethnographic study of shared governance

The benefits of research being undertaken by more than one researcher cannot be underestimated. Having one researcher with intimate knowledge of the organisation and another who could provide a dispassionate view, paid dividends in this study into shared governance from an ethnographic perspective.

Efficacy of sacroiliac corticosteroid injections in patients with inflammatory spondyloarthropathy: results of a 6 month controlled study

OBJECTIVE

To evaluate changes in articular symptoms, spinal mobility, and global function over 6 months after intraarticular injections of long acting corticosteroid into the sacroiliac (SI) joints of patients with inflammatory low back pain (ILBP).

METHODS

Nineteen patients with symptoms of ILBP were studied. Thirteen (68%) had radiographic evidence of sacroiliitis. The remaining 6 patients (32%) had normal imaging studies and thus were considered to have mechanical low back pain. All patients received bilateral SI joint injections of triamcinolone hexacetonide (40 mg/joint) under computer tomographic guidance. Outcome variables included the duration of low back morning stiffness, back pain (by visual analog scale, McGill Pain Questionnaire), spinal mobility (chest expansion, Schober test, 10 cm segments test, finger-fibula distance), and self-report health status (SF-36).

RESULTS

Both groups of patients showed a transient improvement in stiffness and pain, spinal mobility, and general health status that was most pronounced at 1-3 months after intraarticular therapy. This did not reach statistical significance (p > 0.05) and by 6 months, followup all outcome variables had reverted to pretherapy levels in both groups.

CONCLUSION

These preliminary observations suggest that SI corticosteroid injections are ineffective in the management of patients with inflammatory spondyloarthropathy.

Contracted plasma and blood volume in chronic heart failure

OBJECTIVES

The purpose of this study was to determine if long-term pharmacotherapy mediated changes in intravascular plasma and blood volumes in patients with chronic heart failure (CHF).

BACKGROUND

Intravascular fluid volume expansion is an acute compensatory adaptation to ventricular dysfunction in patients with CHF. To our knowledge there are no reports on plasma and blood volume measures in clinically stable patients with CHF receiving standard pharmacotherapy. Such information may provide a better understanding of the clinical hallmarks of heart failure.

METHODS

Plasma volume (PV) and blood volume (BV) were measured in 12 patients (62.8 +/- 8.2 years old, 175.2 +/- 6.8 cm, 96.2 +/- 18.2 kg, peak oxygen consumption (VO2max) 15.2 +/- 3.3 ml/kg per min) with CHF secondary to coronary artery disease (left ventricular ejection fraction 31.2 +/- 9.7, New York Heart Association functional class 2.5 +/- 0.5) and seven healthy subjects (71.7 +/- 5.3 years old, 177.1 +/- 10.8 cm, 84.4 +/- 11.7 kg, VO2max 26.0 +/- 6.5 ml/kg per min) 3 to 4 h after eating and after supine rest using the Evan's blue dye dilution technique. Venous blood samples were collected before blue dye infusion and analyzed for hematocrit (corrected 4% for trapped plasma and venous to whole body hematocrit ratio) and hemoglobin.

RESULTS

Hematocrit was 36.6 +/- 3.5% and 37.4 +/- 1.1%, and hemoglobin was 15.4 +/- 1.9 and 16.2 +/- 1.4 g/dl for patients with CHF and control subjects, respectively. Absolute PV was 3489.3 +/- 655.0 and 3728.7 +/- 813.2 ml, and absolute BV was 5,496.8 +/- 1,025.4 and 5,942.4 +/- 1,182.2 ml in patients with CHF and control subjects, respectively. Relative PV was 34.1 +/- 12.9 versus 44.5 +/- 9.0 ml/kg (p < or = 0.05), and relative BV was 58.5 +/- 12.3 versus 70.8 +/- 12.6 ml/kg (p < or = 0.05) in patients with CHF and control subjects, respectively.

CONCLUSIONS

Our data indicate significantly lower intravascular volumes in patients with CHF than in control subjects, indicating a deconditioned state or excessive diuresis, or both. The contracted PV and BV may contribute to exercise intolerance, shortness of breath and chronic fatigue, secondary to reduced cardiac output or regional blood flow, or both.

Schools as catalysts for healthy communities

Four school superintendents with a shared commitment to students' needs were able to forge a coalition that brought positive change to an entire region. Helping students and their families was a rallying issue for all community agencies. Initially, the four districts joined to apply for grant funding to link schools and social services providers. This served as a model and catalyst for many other cooperative community efforts.

Heterozygous factor XI deficiency associated with three novel mutations

To determine the utility of single-stranded conformation polymorphism (SSCP) analysis for screening mutations in the factor XI (fXI) gene, we investigated three patients with heterozygous factor XI deficiency. DNA sequence analysis confirmed three novel mutations; a CGC --> TGC (Arg308Cys) mutation in exon 9, a GCT-->GTT (Ala412Val) mutation in exon 11 and an AGC --> AGA (Ser576Arg) mutation in exon 15. We postulated on the structural implications of these missense mutations. Our results demonstrated that genotypic analysis is a useful tool for conclusive differentiation between heterozygous factor XI deficiency and normal subjects.