Characterizing and predicting the relationship between translaminar fracture toughness and pull-out length distributions under distinct temperatures.

The translaminar fracture toughness reflects the damage tolerance of a fibre-reinforced composite under longitudinal tension, which often governs the final failure of structures. One of the main energy-dissipation mechanisms that contributes to the translaminar toughness of composites is the fibre pull-out process. The present study aims to quantify and model the statistical distribution of fibre pull-out lengths formed on the translaminar fracture surface of composites, for the first time in the literature; this is done under different temperatures, so that the relationship between pull-out length distributions, micromechanical properties and the translaminar fracture toughness can be established. The fracture surfaces of cross-ply compact tension specimens tested under three different temperatures have been scanned through X-ray computed tomography to quantify the extent of fibre pull-out on the fracture surfaces; the distribution of pull-out lengths showed alarger average and larger variability with an increase in temperature, which also lead to an increase in translaminar fracture toughness. A similar trend has been captured by the proposed analytical model, which predicts the pull-out length distribution based on the analysis of quasi-fractal idealizations of the fracture surface, yielding an overall accuracy of more than 85%. This article is part of the theme issue 'Ageing and durability of composite materials'.

Parental home-based pulse oximetry monitoring for adults with intellectual disabilities at risk of serious respiratory problems including COVID-19: a brief report.

BACKGROUND: People with intellectual disabilities (ID) are at high risk of developing respiratory health issues. The COVID-19 pandemic has compounded this, with serious consequences, and for some, death. Despite home-based oxygen saturation monitoring being recommended for people with ID, there is a stark lack of evidence in the literature on its feasibility. METHOD: We conducted 3-day baseline home-based oxygen saturation monitoring, using pulse oximeters, with eight parents of nine adults with ID in Scotland. Two eligible parents also completed a further 2 weeks of monitoring, and returned an evaluation questionnaire on its feasibility. RESULTS: Baseline mean readings for eight adults with ID were within the normal range (%Sp02  ≥ 95), and for another one 94%. Fluctuations over the 3-day assessment period were experienced by six of these individuals. However, these variations were within limits which are not dangerous (lowest reading 92%), implying that parental home-based pulse oximetry monitoring is likely to be safe for adults with ID. The two parents who completed the evaluation found home-based pulse oximetry monitoring to be easy/very easy to do, and effective/very effective. CONCLUSIONS: This is the first research study, albeit with a very small sample, to report on the potential feasibility of parental home-based pulse oximetry monitoring for adults with ID. Home-based pulse oximetry monitoring appears to be safe in adults with ID at risk of developing serious respiratory problems, and not difficult for their parents to do. There is an urgent need to replicate this work, using a larger sample, to promote home-based respiratory health monitoring more widely for people with ID.

Prevalence of factors associated with edentulousness (no natural teeth) in adults with intellectual disabilities.

BACKGROUND: Poor oral health is largely preventable. Prevention includes toothbrushing and regular dental checks. Oral health has important consequences for general nutrition, chewing, communication, wider systemic disease, self-confidence and participation in society. This study investigated the prevalence of edentulousness (no natural teeth) in adults with intellectual disabilities (IDs) compared with the general population and associated factors. METHODS: An adult cohort with IDs residing in Greater Glasgow and Clyde, Scotland, underwent detailed health assessments between 2002 and 2004. Between 2004 and 2006, a subsample had an oral check. Data on edentulousness in the cohort were compared with adult participants from Greater Glasgow and Clyde in the 2008 Scottish Health Survey. Within the IDs cohort, binary logistic regression analyses investigated potential relationships between edentulousness and demographic and clinical factors. RESULTS: Five hundred sixty adults with IDs were examined [53.2% (298) male, mean age = 46.3 years, range 18-81 years] and compared with 2547 general population: edentulousness was 9% vs. 1% aged 25-34 years; 22% vs. 2% aged 35-44 years; 39% vs. 7% aged 45-54 years; 41% vs. 18% aged 55-64 years; and 76% vs. 34% aged 65-74 years. In both groups, edentulousness increased with age. After stratification for age, rates of edentulousness were consistently higher in the ID cohort. Odds ratios within age strata were not homogenous (Mantel-Haenszel test, P < 0.0001). Edentulousness was more likely in those with more severe IDs (adjusted odds ratio (AOR) = 2.36; 95% confidence interval (CI) [1.23 to 4.51]); those taking antipsychotics (AOR = 2.09; 95% CI [1.25 to 3.51]) and those living in the most deprived neighbourhoods (AOR = 2.69; 95% CI [1.11 to 6.50]). There was insufficient evidence for associations with sex, type of accommodation/support, antiepileptics, problem behaviours or autism. CONCLUSIONS: Adults with IDs have a high prevalence of edentulousness and need supported daily oral care to reduce the need for extractions. Despite previous reports on poor oral care and the move towards person-centred care, carers and care-giving organisations need greater support to implement daily oral care. Prescribers need awareness of the potentially contributory role of antipsychotics, which may relate to xerostomia.

Dominant and sensitive control of oxidative flux by the ATP-ADP carrier in human skeletal muscle mitochondria: Effect of lysine acetylation.

The adenine nucleotide translocase (ANT) of the mitochondrial inner membrane exchanges ADP for ATP. Mitochondria were isolated from human vastus lateralis muscle (n = 9). Carboxyatractyloside titration of O2 consumption rate (Jo) at clamped [ADP] of 21 µM gave ANT abundance of 0.97 ±â€¯0.14 nmol ANT/mg and a flux control coefficient of 82% ±â€¯6%. Flux control fell to 1% ±â€¯1% at saturating (2 mM) [ADP]. The KmADP for Jo was 32.4 ±â€¯1.8 µM. In terms of the free (-3) ADP anion this KmADP was 12.0 ±â€¯0.7 µM. A novel luciferase-based assay for ATP production gave KmADP of 13.1 ±â€¯1.9 µM in the absence of ATP competition. The free anion KmADP in this case was 2.0 ±â€¯0.3 µM. Targeted proteomic analyses showed significant acetylation of ANT Lysine23 and that ANT1 was the most abundant isoform. Acetylation of Lysine23 correlated positively with KmADP, r = 0.74, P = 0.022. The findings underscore the central role played by ANT in the control of oxidative phosphorylation, particularly at the energy phosphate levels associated with low ATP demand. As predicted by molecular dynamic modeling, ANT Lysine23 acetylation decreased the apparent affinity of ADP for ANT binding.

Lycra splinting garments for adults with intellectual disabilities who fall due to gait or balance issues: a feasibility study.

BACKGROUND: Adults with intellectual disabilities (IDs) experience high rates of falls and have high rates of gait or balance issues which contribute to falls. Lycra splinting garments (LSGs) have potential to improve gait or balance, but they have never before been tested with adults with IDs who fall due to gait or balance issues. The aim of this study was to test in adults with IDs, the feasibility of using LSGs to improve movement and function and reduce falls, whilst also exploring usability and likely compliance. METHOD: A convenience sample of nine adults with IDs wore tailored LSGs over a 6-week assessment period. Laboratory-based foot clearance, balance, and gait measures were collected pre- and post-LSG-wear. Falls charts and questionnaires on usability and likely compliance were also completed. RESULTS: Seven participants experienced a reduction in falls during their six weeks of LSG wear; most notably in the group of five participants who wore lycra splinting socks, compared with only two in the group of four who wore lycra splinting shorts or leggings only. CONCLUSION: Lycra splinting socks are likely to bring about positive outcomes for adults with IDs who fall due to gait/balance issues on an individual case by case basis over time, but further research is required to test this hypothesis under randomised controlled trial conditions. Potential benefits of more intrusive LSGs are outweighed by reported problems with usability and compliance.

The provision of aids and adaptations, risk assessments, and incident reporting and recording procedures in relation to injury prevention for adults with intellectual disabilities: cohort study.

BACKGROUND: Adults with intellectual disabilities (IDs) experience a higher incidence of injury, compared with the general population. The aim of this study was to investigate the provision of aids and adaptations, residential service providers' individual risk assessments and training in these, and injury incident recording and reporting procedures, in relation to injury prevention. METHOD: Interviews were conducted with a community-based cohort of adults with IDs (n = 511) who live in Greater Glasgow, Scotland, UK and their key carer (n = 446). They were asked about their aids and adaptations at home, and paid carers (n = 228) were asked about individual risk assessments, their training, and incident recording and reporting procedures. RESULTS: Four hundred and twelve (80.6%) of the adults with IDs had at least one aid or adaptation at home to help prevent injury. However, a proportion who might benefit, were not in receipt of them, and surprisingly few had temperature controlled hot water or a bath thermometer in place to help prevent burns/scalds, or kitchen safety equipment to prevent burns/scalds from electric kettles or irons. Fifty-four (23.7%) of the paid carers were not aware of the adult they supported having had any risk assessments, and only 142 (57.9%) had received any training on risk assessments. Considerable variation in incident recording and reporting procedures was evident. CONCLUSION: More work is needed to better understand, and more fully incorporate, best practice injury prevention measures into routine support planning for adults with IDs within a positive risk-taking and risk reduction framework.

Iron studies and red cell transfusion in cardiothoracic and orthopaedic surgical patients: a retrospective audit at a tertiary hospital.

BACKGROUND AND OBJECTIVES: Preoperative diagnosis and treatment of anaemia are important to minimize adverse postoperative outcomes. This audit reviewed red cell transfusion practice, degree of anaemia, iron deficiency anaemia (IDA) and chronic disease or anaemia of inflammation (AI) in cardiothoracic and orthopaedic surgical patients who had available iron studies. MATERIALS AND METHODS: A total of 178 consecutive cardiothoracic and orthopaedic surgical patients with available iron studies were retrospectively reviewed. RESULTS: Of patients, 36·5% had preoperative iron studies. However, 63·2% males and 45·3% females with postoperative iron studies presented with anaemia; 38·5% patients with preoperative iron studies had AI; 21·5% IDA; 23·1% normal. For patients with iron studies requested within the first two postoperative intervals (≤ 5 days and 6 ≤ 10 days) 73·8% and 63·6%, respectively, had AI; few had classical IDA or were normal, and 51·5% patients transfused postsurgery had a discharge Hb ≥ 110 g/l. Restricting the discharge Hb to 90 or 100 g/l may have eliminated postsurgical transfusion in 14·8-42·6% patients. CONCLUSION: Iron studies were more commonly requested postoperatively despite many being anaemic at admission. A higher proportion of patients with postoperative iron studies had AI, and few had classical IDA or normal iron parameters, suggesting a transient inflammatory effect of surgery. This may mask underlying IDA or normal iron parameters and affect treatment. Preadmission assessment, including iron status, should be emphasized allowing diagnosis and correction of presurgical anaemia with treatment modalities other than red cell transfusion. In the postsurgical setting, consideration of a restrictive transfusion regimen sufficient to alleviate a patient's clinical symptoms would ensure that this valuable resource is appropriately used.

Global IRS-1 phosphorylation analysis in insulin resistance.

AIMS/HYPOTHESIS: IRS-1 serine phosphorylation is often elevated in insulin resistance models, but confirmation in vivo in humans is lacking. We therefore analysed IRS-1 phosphorylation in human muscle in vivo. METHODS: We used HPLC-electrospray ionisation (ESI)-MS/MS to quantify IRS-1 phosphorylation basally and after insulin infusion in vastus lateralis muscle from lean healthy, obese non-diabetic and type 2 diabetic volunteers. RESULTS: Basal Ser323 phosphorylation was increased in type 2 diabetic patients (2.1 ± 0.43, p ≤ 0.05, fold change vs lean controls). Thr495 phosphorylation was decreased in type 2 diabetic patients (p ≤ 0.05). Insulin increased IRS-1 phosphorylation at Ser527 (1.4 ± 0.17, p ≤ 0.01, fold change, 60 min after insulin infusion vs basal) and Ser531 (1.3 ± 0.16, p ≤ 0.01, fold change, 60 min after insulin infusion vs basal) in the lean controls and suppressed phosphorylation at Ser348 (0.56 ± 0.11, p ≤ 0.01, fold change, 240 min after insulin infusion vs basal), Thr446 (0.64 ± 0.16, p ≤ 0.05, fold change, 60 min after insulin infusion vs basal), Ser1100 (0.77 ± 0.22, p ≤ 0.05, fold change, 240 min after insulin infusion vs basal) and Ser1142 (1.3 ± 0.2, p ≤ 0.05, fold change, 60 min after insulin infusion vs basal). CONCLUSIONS/INTERPRETATION: We conclude that, unlike some aspects of insulin signalling, the ability of insulin to increase or suppress certain IRS-1 phosphorylation sites is intact in insulin resistance. However, some IRS-1 phosphorylation sites do not respond to insulin, whereas other Ser/Thr phosphorylation sites are either increased or decreased in insulin resistance.

Increased abundance of the adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif (APPL1) in patients with obesity and type 2 diabetes: evidence for altered adiponectin signalling.

AIMS/HYPOTHESIS: The adiponectin signalling pathway is largely unknown, but recently the adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif (APPL1), has been shown to interact directly with adiponectin receptor (ADIPOR)1. APPL1 is present in C2C12 myoblasts and mouse skeletal muscle, but its presence in human skeletal muscle has not been investigated. METHODS: Samples from type 2 diabetic, and lean and non-diabetic obese participants were analysed by: immunoprecipitation and western blot; HPLC-electrospray ionisation (ESI)-mass spectrometry (MS) analysis; peak area analysis by MS; HPLC-ESI-MS/MS/MS analysis; and RT-PCR analysis of APPL1 mRNA. RESULTS: Immunoprecipitation and western blot indicated a band specific to APPL1. Tryptic digestion and HPLC-ESI-MS analysis of whole-muscle homogenate APPL1 unambiguously identified APPL1 with 56% sequence coverage. Peak area analysis by MS validated western blot results, showing APPL1 levels to be significantly increased in type 2 diabetic and obese as compared with lean participants. Targeted phosphopeptide analysis by HPLC-ESI-MS/MS/MS showed that APPL1 was phosphorylated specifically on Ser(401). APPL1 mRNA expression was significantly increased in obese and type 2 diabetic participants as compared with lean participants. After bariatric surgery in morbidly obese participants with subsequent weight loss, skeletal muscle APPL1 abundance was significantly reduced (p < 0.05) in association with an increase in plasma adiponectin (p < 0.01), increased levels of ADIPOR1 (p < 0.05) and increased muscle AMP-activated protein kinase (AMPK) phosphorylation (p < 0.05). CONCLUSIONS/INTERPRETATION: APPL1 abundance is significantly higher in type 2 diabetic muscle; APPL1 is phosphorylated in vivo on Ser(401). Improvements in hyperglycaemia and hypoadiponectinaemia following weight loss are associated with reduced skeletal muscle APPL1, and increased plasma adiponectin levels and muscle AMPK phosphorylation.

Transfusion-related acute lung injury in a neutropenic patient.

Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion related morbidity and mortality. Current concepts regarding the pathogenesis of this disorder imply a "two-hit" model in which neutrophils are sequestered in the pulmonary capillary bed, and subsequently activated by substances in the transfused blood product. We report a case of TRALI in a patient with neutropenia and discuss the possible factors contributing to the respiratory symptoms in this patient. We also emphasise the importance of recognising mild cases of TRALI in order to investigate the implicated donor/s appropriately, and to minimise the risk for more severe episodes in other patients.

Neanderthal exploitation of marine mammals in Gibraltar.

Two coastal sites in Gibraltar, Vanguard and Gorham's Caves, located at Governor's Beach on the eastern side of the Rock, are especially relevant to the study of Neanderthals. Vanguard Cave provides evidence of marine food supply (mollusks, seal, dolphin, and fish). Further evidence of marine mammal remains was also found in the occupation levels at Gorham's Cave associated with Upper Paleolithic and Mousterian technologies [Finlayson C, et al. (2006) Nature 443:850-853]. The stratigraphic sequence of Gibraltar sites allows us to compare behaviors and subsistence strategies of Neanderthals during the Middle Paleolithic observed at Vanguard and Gorham's Cave sites. This evidence suggests that such use of marine resources was not a rare behavior and represents focused visits to the coast and estuaries.

Injuries, falls and accidents among adults with intellectual disabilities. Prospective cohort study.

BACKGROUND: Injuries are among the leading causes of death and disability in the world and a major public health concern. Falls are a common cause. Young persons with intellectual disabilities (ID) have a higher rate and different pattern of injuries than the general population, but little is known regarding adults. METHODS: The aim of this study was to determine the incidence and types of injuries experienced by a community-based cohort of adults with ID (n = 511) in a 12-month period. Face-to-face interviews were conducted with participants 2 years after they had first been recruited into a longitudinal study. RESULTS: Incidence of at least one injury in a 12-month period was 20.5% (105), of which 12.1% (62) was because of falls. Incident injury was predicted by having epilepsy and not having autism. Incident fall injury was predicted by urinary incontinence, while Down syndrome reduced risk. CONCLUSIONS: Adults with ID do experience a higher rate of injuries and falls when compared with the general population. The results of this study highlight this, and hence the need to work towards the development of interventions for injury and falls prevention in this population.

[Cross-link in fibrin polymerized by factor 13: epsilon-(gamma-glutamyl)lysine].

(epsilon)-((gamma)-Glutamyl)lysine has been isolated from enzymatic hydrolyzates of cross-linked human fibrin. This compound was not detected in "non-cross-linked" fibrin prepared with ethylenediaminetetraacetic acid, which inhibits factor XIII; intermediate amounts were observed when the fibrin was prepared with glycine ethyl ester, which inhibits factor XIII competitively. These and ancillary experiments furnish conclusive evidence that epsilon-(gamma-glutamyl)lysine cross-links form in human fibrin during polymerization catalyzed by factor XIII.

Helium Flux from the Earth's Mantle as Estimated from Hawaiian Fumarolic Degassing.

Averaged helium to carbon dioxide ratios measured from systematic collections of gases from Sulphur Bank fumarole. Kilauea, Hawaii, when coupled with estimates of carbon in the earth's crust, give a helium flux of 1 x 105 atoms per square centimeter per second. This is within the lower range of other estimates, and may represent the flux from deep-seated sources in the upper mantle.

Adults with intellectual disabilities: prevalence, incidence and remission of aggressive behaviour and related factors.

INTRODUCTION: Aggressive behaviours can be disabling for adults with intellectual disabilities (ID), with negative consequences for the adult, their family and paid carers. It is surprising how little research has been conducted into the epidemiology of these needs, given the impact they can have. This study investigates point prevalence, 2-year incidence and 2-year remission rates for aggressive behaviour (physically aggressive, destructive and verbally aggressive), and it investigates which factors are independently associated with aggressive behaviour. METHODS: All adults with ID - within a geographically defined area of Scotland, UK - were recruited to a longitudinal cohort. At baseline, assessments were undertaken of demography, lifestyle, supports, development, problem behaviours, disabilities and physical and mental health. These were repeated for a 2-year period. RESULTS: At baseline, the participation rate was 1023 (65.5%). After 2 years, the cohort retention was 651 adults. The point prevalence of Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation (DC-LD) aggressive behaviour was 9.8% (95% confidence interval = 8.0-11.8%), 2-year incidence was 1.8%, and 2-year remission rate from all types of aggressive behaviour meeting DC-LD criteria was 27.7%. The factors independently associated with aggressive behaviours were lower ability, female gender, not living with a family carer, not having Down syndrome, having attention-deficit hyperactivity disorder and having urinary incontinence. Incidence of aggressive behaviour meeting DC-LD criteria in adult life is similar to that for each of psychotic, anxiety and organic disorders. CONCLUSIONS: Aggressive behaviour is common among adults with ID, but contrary to previous suggestions, more than a quarter remit within the short to medium term. This is important knowledge for professionals as well as the person and her/his family and paid carers. There is much yet to learn about the mechanisms underpinning aetiology and maintenance of aggressive behaviour in this population, and exploratory epidemiological investigations such as this have a role to play in progressing research towards further hypothesis testing and trials to influence clinical practice, service development and policy.

Cost estimation of a health-check intervention for adults with intellectual disabilities in the UK.

BACKGROUND: High rates of health needs among adults with intellectual disabilities flag the need for information about the economic consequences of strategies to identify and address unmet needs. Health-check interventions are one such strategy, and have been demonstrated to effect health gains over the following 12-month period. However, little is known about their effects on service use and costs, and hence how affordable such interventions are. METHODS: We examined service use patterns and costs over a 12-month period for 50 adult participants with intellectual disabilities who received a health-check intervention and 50 individually matched control participants who received standard care only. RESULTS: The health-check intervention was cheap, and it did not have associated higher costs in terms of service usage. Indeed, mean cost of care for the adults who received standard care only was greater than for the adults who received the health-check intervention. The higher costs were due to differences in unpaid carer support costs. CONCLUSION: This is the first study to report the associated service use, and costs of a health-check intervention to improve the health of adults with intellectual disabilities and reduce health inequalities. Results suggest this intervention is cheap and affordable compared with standard care, supporting clinical outcome evidence for its introduction into health care policy and implementation. However, further research is needed to confirm this finding with a larger sample.

Adults with intellectual disabilities: prevalence, incidence and remission of self-injurious behaviour, and related factors.

BACKGROUND: Self-injurious behaviour (SIB) is a serious condition, with implications for the person, their family and financial costs to the state providing care. The previously reported prevalence of SIB has ranged from 1.7% to 41%, or 1.7%-23.7% in community studies. There has been little study of remission rate, and incidence has not previously been reported. SIB has been reported to be individually associated with lower ability, autism and communication impairments, but given the inter-relationships between these three factors, it is not known whether they are independently associated with SIB. This study investigates the point prevalence, incidence and remission rates of SIB among the adult population with intellectual disabilities (ID), and explores which factors are independently associated with SIB. METHOD: A prospective cohort study design was used in a general community setting. The participants were all adults (16 years and over) with ID in a defined geographical area. Individual assessments were conducted with all participants. RESULTS: The point prevalence of SIB (as defined by DC-LD) was 4.9%, the two-year incidence was 0.6%, and two-year remission rate was 38.2%. Independently related to SIB were: lower ability level, not living with a family carer, having attention deficit hyperactivity disorder, visual impairment, and not having Down syndrome. Other factors, including communication impairment, autism, and level of deprivation of the area resided within, were not related. CONCLUSIONS: SIB is not as enduring and persistent as previously thought; a significant proportion gains remission in this time period. This should provide hope for families, paid carers and professionals, and reduce therapeutic nihilism. Our study is a first tentative step towards identifying risk-markers for SIB, and developing aetiological hypotheses for subsequent testing. The extent to which SIB may be a relapsing-remitting (episodic) condition requires further investigation, so does further hypothesis-based investigation of factors that might be predictive of incidence of, and remission from, SIB.

Brucella ceti associated pathology in the testicle of a harbour porpoise (Phocoena phocoena).

Brucellosis is reported increasingly in marine mammals and the marine species of Brucella are capable of causing community acquired zoonotic infections in humans as well as abortion in cattle as a result of experimental infection. This case report describes pathology associated with an isolate of Brucella ceti that was successfully cultured from, and immunolabelled in, the testis and epididymis of an adult sexually mature free-living harbour porpoise (Phocoena phocoena). This is the first report of such pathology in any species of cetacean, and suggests the potential for sexual transmission and/or sterility as sequelae to infection similar to those reported in terrestrial animals.

Diagnosis of preclinical scrapie in live sheep by the immunohistochemical examination of rectal biopsies.

In most sheep infected with a transmissible spongiform encephalopathy (tse) the disease-associated prion protein (PrP(d)) accumulates in tissues of the lymphoreticular system, suggesting that it might be detected in biopsy specimens. A procedure has been developed to obtain biopsy specimens of rectal mucosa in which PrP(d) has been detected by immunohistochemistry in preclinically infected sheep of all susceptible PrP genotypes. It is probable that PrP(d) increases with the age of sheep or period of incubation. PrP(d) was detectable approximately halfway through the incubation period, with sheep of some PrP genotypes showing positive results earlier than others. For a preclinical diagnosis, the risk of a false negative result was approximately 9 per cent for samples containing 10 follicles, a figure that was reached in 87 per cent of the biopsies. The rectal biopsies had the same sensitivity and time of onset of PrP(d) accumulation as biopsies of the palatine tonsil, but provided larger numbers of follicles. The procedure is simple and quick, does not require dedicated specific instruments, sedation or general anaesthesia, and can be performed repeatedly on the same sheep without detrimental effects to either the animal or the number of follicles obtained.

Fibrinogen Bethesda: a congenital dysfibrinogenemia with delayed fibrinopeptide release.

A dysfibrinogenemia (fibrinogen Bethesda) was detected in a 9 yr old male of Mexican-English extraction who had a lifelong history of mild bleeding diathesis. The prothrombin and partial thromboplastin times were moderately prolonged; the thrombin and Reptilase times were markedly prolonged. The plasma fibrinogen level was normal by conventional methods but was markedly reduced by the Clauss method. Results of all other tests for clotting factors, fibrinolysis, antithrombin levels, clot stabilization, and fibrin(ogen) degradation products were normal. The patient's plasma and fibrinogen inhibited the clotting of normal plasma or fibrinogen by thrombin. Family studies revealed that the propositus' mother and two siblings exhibited these abnormalities to a lesser degree and indicated an autosomal dominant inheritance. Fibrinogen Bethesda was similar to normal fibrinogen in the following respects: metabolic turnover time (measured in the propositus' mother); immunodiffusion, ultracentrifugal, electrophoretic (on cellulose acetate or polyacrylamide gel), and chromatographic (on DEAE-cellulose) characteristics; sialic acid content; and aggregation of fibrin monomers. By contrast, fibrinogen Bethesda gave an abnormal immunoelectrophoretic pattern especially when whole plasma (as opposed to purified fibrinogen) was examined, and it showed a pronounced decrease in the rate of fibrinopeptide release by thrombin. This decrease, which was shown to involve both fibrinopeptides A and B, distinguishes fibrinogen Bethesda from previously reported dysfibrinogenemias.